Subterranean Termite Resistance of Polystyrene-Treated Wood from Three Tropical Wood Species

PubMed Central

Hadi, Yusuf Sudo; Massijaya, Muh Yusram; Arinana, A.

2016-01-01

The objective of this work was to investigate the resistance of three Indonesian wood species to termite attack. Samples from sengon (Falcataria moluccana), mangium (Acacia mangium), and pine (Pinus merkusii) were treated with polystyrene at loading levels of 26.0%, 8.6%, and 7.7%, respectively. Treated and untreated samples were exposed to environmental conditions in the field for 3 months. Untreated specimens of sengon, mangium, and pine had resistance ratings of 3.0, 4.6, and 2.4, respectively, based on a 10-point scale from 0 (no resistance) to 10 (complete or near-complete resistance). Corresponding resistance values of 7.8, 7.2, and 8.2 were determined for specimens treated with polystyrene. Overall weight loss values of 50.3%, 23.3%, and 66.4% were found for untreated sengon, mangium, and pine samples, respectively; for treated samples, the values were 7.6%, 14.4%, and 5.1%, respectively. Based on the findings in this study, overall resistance to termite attack was higher for treated samples compared to untreated samples. PMID:27455331

Segment-specific resistivity improves body fluid volume estimates from bioimpedance spectroscopy in hemodialysis patients.

PubMed

Zhu, F; Kuhlmann, M K; Kaysen, G A; Sarkar, S; Kaitwatcharachai, C; Khilnani, R; Stevens, L; Leonard, E F; Wang, J; Heymsfield, S; Levin, N W

2006-02-01

Discrepancies in body fluid estimates between segmental bioimpedance spectroscopy (SBIS) and gold-standard methods may be due to the use of a uniform value of tissue resistivity to compute extracellular fluid volume (ECV) and intracellular fluid volume (ICV). Discrepancies may also arise from the exclusion of fluid volumes of hands, feet, neck, and head from measurements due to electrode positions. The aim of this study was to define the specific resistivity of various body segments and to use those values for computation of ECV and ICV along with a correction for unmeasured fluid volumes. Twenty-nine maintenance hemodialysis patients (16 men) underwent body composition analysis including whole body MRI, whole body potassium (40K) content, deuterium, and sodium bromide dilution, and segmental and wrist-to-ankle bioimpedance spectroscopy, all performed on the same day before a hemodialysis. Segment-specific resistivity was determined from segmental fat-free mass (FFM; by MRI), hydration status of FFM (by deuterium and sodium bromide), tissue resistance (by SBIS), and segment length. Segmental FFM was higher and extracellular hydration of FFM was lower in men compared with women. Segment-specific resistivity values for arm, trunk, and leg all differed from the uniform resistivity used in traditional SBIS algorithms. Estimates for whole body ECV, ICV, and total body water from SBIS using segmental instead of uniform resistivity values and after adjustment for unmeasured fluid volumes of the body did not differ significantly from gold-standard measures. The uniform tissue resistivity values used in traditional SBIS algorithms result in underestimation of ECV, ICV, and total body water. Use of segmental resistivity values combined with adjustment for body volumes that are neglected by traditional SBIS technique significantly improves estimations of body fluid volume in hemodialysis patients.

Relation between the Change in Mean Platelet Volume and Clopidogrel Resistance in Patients Undergoing Percutaneous Coronary Intervention.

PubMed

Koh, Young-Youp; Kim, Hyung Ho; Choi, Dong-Hyun; Lee, Young-Min; Ki, Young-Jae; Kang, Seong-Ho; Park, Geon; Chung, Joong-Wha; Chang, Kyong-Sig; Hong, Soon-Pyo

2015-01-01

We aimed to determine the association between the change in mean platelet volume (MPV) over time and aspirin/ clopidogrel resistance in patients undergoing percutaneous coronary intervention (PCI). The MPV and platelet function were analysed in 302 patients who underwent PCI. MPV changes were associated with increased aspirin reaction units (ARU, r = 0.114; P = 0.047), increased P2Y12 reaction units (PRU, r = 0.193; P = 0.001), and decreased P2Y12% inhibition (PI%, r = - 0.273; P < 0.001). The group with increasing MPV values showed significantly higher PRU values and lower PI% compared with the group with decreasing MPV values (222.5 ± 73.9 vs. 195.6 ± 63.7 PRU, P = 0.001; 24.1 ± 21.0 vs. 32.8 ± 18.5 PI%, P < 0.001, respectively). The clopidogrel resistant group (≥235 PRU or ≤15% of PI%) showed a significantly higher positive change in MPV (ΔMPV) values than the clopidogrel responder group (0.53 ± 0.78 vs. 0.13 ± 0.69 fL, P < 0.001). When the ΔMPV cut-off level was set at 0.20 fL using the receiver operating characteristic curve, the sensitivity and specificity for differentiating between the clopidogrel resistant and responder groups were 72.6% and 59.3%, respectively. After adjusting for traditional risk factors, the odds ratio in the clopidogrel resistant group with ΔMPV ≥0.2 fL was 4.10 (95% confidence interval; 1.84-9.17). In conclusion, ΔMPV was associated with PRU and PI%; a positive ΔMPV was an independent predictive marker for clopidogrel resistance after PCI.

Heat resistance of Escherichia coli O157:H7 in apple juice.

PubMed

Splittstoesser, D F; McLellan, M R; Churey, J J

1996-03-01

The objective was to determine the effect of cider composition on the heat resistance of Escherichia coli O157:H7. The average D52 value in a model Empire apple juice was 18 min with a z value of 4.8 degrees C. Increasing the Brix from 11.8 to 16.5 degrees had no effect on thermal resistance, while increasing L-malic acid from 0.2 to 0.8%, or reducing the pH from 4.4 to 3.6 sensitized the cells to heat. The greatest effect on heat resistance was afforded by the preservatives benzoic and sorbic acids: D50 values in ciders containing 1,000 mg/l were 5.2 min in the presence of sorbic acid and only 0.64 min in the presence of benzoic acid. Commercial apple juice concentrates yielded lower numbers of survivors than single-strength juices even though their higher sugar concentrations of about 46 degrees Brix increased heat resistance.

The in vitro effects of retrograded starch (resistant starch type 3) from lotus seed starch on the proliferation of Bifidobacterium adolescentis.

PubMed

Zhang, Yi; Wang, Ying; Zheng, Baodong; Lu, Xu; Zhuang, Weijing

2013-11-01

Prebiotics such as oligosaccharides, fructans, and resistant starch (RS) stimulate the growth of beneficial bacteria in large bowel and modify the human gastrointestinal environment. In this study, compared with glucose (GLU) and high amylose maize starch (HAMS), the in vitro effects of LRS3 and P-LRS3 (RS3 and purified RS3 prepared from lotus seed starch) on the proliferation of bifidobacteria were assessed by assessing the changes in optical density (OD), pH values, short chain fatty acid (SCFA) production, and tolerance ability to gastrointestinal conditions. Significantly higher OD values were obtained from media containing LRS3 and P-LRS3, and especially in the medium containing P-LRS3, the OD value of which reached 1.36 when the concentration of the carbon source was 20 g L(-1). Additionally, the lag phase of bifidobacteria was 8 h in the medium with LRS3 or P-LRS3, whereas it was 16 h in the medium with GLU or HAMS. What is more, a higher content of butyric acid was obtained in the P-LRS3 medium. Compared with GLU and HAMS media, bifidobacteria had a higher tolerance to gastrointestinal conditions in LRS3 and P-LRS3 media. It shows that lotus seed resistant starch, especially P-LRS3, could stimulate the growth of bifidobacteria. The rough surface of resistant starch and the SCFAs produced during fermentation might influence the proliferation of bifidobacteria.

Chemical Changes during Maize Tissue Aging and Its Relationship with Mediterranean Corn Borer Resistance.

PubMed

López-Malvar, Ana; Ordás, Bernardo; Souto, Carlos; Encina, Antonio; Malvar, Rosa A; Santiago, Rogelio

2017-10-25

The Mediterranean corn borer (MCB), Sesamia nonagrioides Lef, is an important pest of maize in temperate areas, causing significant stalk lodging and yield losses. The main goals of this study were to determine possible changes in chemical traits (phenols, flavonoids, anthocyanins, sugars, fibers, and lignin) during plant development after the flowering stage and to assess how those traits may differ in diverse genotypes of maize, such as MCB resistant and susceptible. Higher values for some particular traits in more mature tissues seemed to increase their effectiveness against the MCB attack. A decreased amount of borer damage in the field was recorded in the resistant inbred line and in older tissues (7.90 cm vs 31.70 cm as the mean for the stalk tunnel length). In accordance with these results, the resistant inbred line showed a higher degree of hemicellulose cross-linkage (due to ferulic and diferulic acids), higher soluble sugar content, and higher stalk strength. The use of resistant varieties and early sowings is highly recommended as an integrated approach to reduce the yield losses produced by this pest.

c-axis preferential orientation of hydroxyapatite accounts for the high wear resistance of the teeth of black carp (Mylopharyngodon piceus)

PubMed Central

Fu, Jimin; He, Chong; Xia, Biao; Li, Yan; Feng, Qiong; Yin, Qifang; Shi, Xinghua; Feng, Xue; Wang, Hongtao; Yao, Haimin

2016-01-01

Biological armors such as mollusk shells have long been recognized and studied for their values in inspiring novel designs of engineering materials with higher toughness and strength. However, no material is invincible and biological armors also have their rivals. In this paper, our attention is focused on the teeth of black carp (Mylopharyngodon piceus) which is a predator of shelled mollusks like snails and mussels. Nanoscratching test on the enameloid, the outermost layer of the teeth, indicates that the natural occlusal surface (OS) has much higher wear resistance compared to the other sections. Subsequent X-ray diffraction analysis reveals that the hydroxyapatite (HAp) crystallites in the vicinity of OS possess c-axis preferential orientation. The superior wear resistance of black carp teeth is attributed to the c-axis preferential orientation of HAp near the OS since the (001) surface of HAp crystal, which is perpendicular to the c-axis, exhibits much better wear resistance compared to the other surfaces as demonstrated by the molecular dynamics simulation. Our results not only shed light on the origin of the good wear resistance exhibited by the black carp teeth but are of great value to the design of engineering materials with better abrasion resistance. PMID:27001150

[Molecular epidemiologic study on Mycobacterium tuberculosis from drug resistance monitoring sites of Guangdong Province, 2015].

PubMed

Huang, X C; Guo, H X; Wu, Z H; Guo, C X; Wei, W J; Li, H C; Sun, Q; Zhang, C C; Li, Z Y; Chen, T; Zhong, Q; Zhou, L

2017-05-12

Objective: To understand the characteristics of Mycobacterium tuberculosis (MTB) in epidemiology and distribution from Guangdong Province, and to explore the risk factors associated with drug resistance. Methods: A total of 225 clinical strains of MTB collected from 5 drug resistance monitoring sites of Guangdong Province in 2015 were tested by Regions of Difference 105 (RD105) deletion test and 15 loci mycobacterial interspersed repetitive units (MIRU) were used for genotyping. Gene clustering was analyzed using BioNumerics7.6. Drug susceptibility test was tested by proportion method. The statistical analysis used chi-square test and multivariate logistic regression. Results: There were 158 (70.2%) Beijing family strains from the 225 cases. Hunter-gaston index of MIRU loci varied from each other. The MTBs from Guangdong Province were categorized into 2 gene clusters by clustering analysis in which the rate of cluster of complexⅠwas significantly higher than complexⅡ(χ(2) values were 9.331, P values were 0.020). It was found by multivariate logistic regression that Qub11b was associated with resistance to rifampicin and isoniazid ( P values were 0.013, 0.012 respectively.), ETR F with resistance to isoniazid, streptomycin, ethambutol and ofloxacin ( P values were 0.039, 0.040, 0.023 and 0.003 respectively), Mtub21 with resistance to capreomycin ( P values were 0.040), and QUB26 with resistance to ethionamide ( P values were 0.047). Conclusions: The genes of MTB from Guangdong Province were of polymorphisms and the distribution of strains were stable. QUB11b, ETR F, Mtub21 and QUB26 could be related to biomarkers for predicting drug resistance.

Antimicrobial susceptibilities and molecular typing of neisseria gonorrhoeae isolates at a medical centre in Taiwan, 2001-2013 with an emphasis on high rate of azithromycin resistance among the isolates.

PubMed

Liu, Yen-Hung; Huang, Yu-Tsung; Liao, Chun-Hsing; Hsueh, Po-Ren

2018-05-01

A high prevalence of gonococcal resistance to various antimicrobials and Neisseria gonorrhoeae isolates exhibiting resistance to extended-spectrum cephalosporins have been reported in the past few decades. A total of 226 N. gonorrhoeae isolates obtained from the National Taiwan University Hospital from 2001 to 2013 were evaluated. The minimum inhibitory concentrations (MICs) of the isolates to antimicrobials were determined by the agar dilution method and interpreted using the 2017 clinical breakpoints or epidemiological cut-off values recommended by the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST). The genetic relatedness of these isolates was determined by multilocus sequence typing. None of the isolates was resistant to ceftriaxone and cefotaxime, and the resistance rates to cefixime, spectinomycin, cefpodoxime, ciprofloxacin, and penicillin were 0.4%, 0.4%, 13.3%, 91.6%, and 87.6%, respectively. The rate of isolates resistant to azithromycin was 14.6% (EUCAST criteria), which is higher than in previous surveillance studies. A total of 57 sequence types (ST) were identified, and ST1901, ST7365, and ST1927 prevailed. Isolates of ST8143 emerged after 2011. ST1901 isolates had relatively higher MIC values for ceftriaxone and azithromycin than those of the other STs. In conclusion, ceftriaxone remains an effective drug of choice for gonorrhoeal management in Taiwan. High rates of azithromycin resistance among N. gonorrhoeae isolates were found. The circulating ST1901 strains with high MIC values for ceftriaxone and azithromycin and the emerging ST8143 strains were alarming. Copyright © 2018 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Use of resistant ACCase mutants to screen for novel inhibitors against resistant and susceptible forms of ACCase from grass weeds.

PubMed

Shukla, Amit; Nycholat, Corwin; Subramanian, Mani V; Anderson, Richard J; Devine, Malcolm D

2004-08-11

The aryloxyphenoxypropionic acid (AOPP) and cyclohexanedione (CHD) herbicides inhibit the first committed enzyme in fatty acid biosynthesis, acetyl CoA carboxylase (ACCase). The frequent use of AOPP and CHD herbicides has resulted in the development of resistance to these herbicides in many grass weed species. New herbicides that inhibit both the susceptible and resistant forms of ACCase in grass weeds would have obvious commercial appeal. In the present study, an attempt was made to identify molecules that target both the herbicide-sensitive and -resistant forms of ACCase. Seven experimental compounds, either CHD-like or AOPP-CHD hybrids, were synthesized and assayed against previously characterized susceptible and resistant forms of ACCase. All seven compounds inhibited ACCase from sensitive biotypes of Setaria viridis and Eleusine indica (I50 values from 6.4 to >100 microM) but were not particularly potent compared to some commercialized herbicides (I50 values of 0.08-5.6 microM). In almost all cases, the I50 values for each compound assayed against the resistant ACCases were higher than those against the corresponding sensitive ACCase, indicating reduced binding to the resistant ACCases. One compound, a CHD analogue, was almost equally effective against the resistant and susceptible ACCases, although it was not a very potent ACCase inhibitor per se (I50 of 51 and 76 microM against susceptible ACCase from S. viridis and E. indica, respectively). The AOPP-CHD hybrid molecules also inhibited some of the resistant ACCases, with I50 values ranging from 6.4 to 50 microM. These compounds may be good leads for developing ACCase inhibitors that target a wider range of ACCase isoforms, including those found in AOPP- and CHD-resistant weed biotypes.

Obesity-related insulin resistance in adolescents: a systematic review and meta-analysis of observational studies.

PubMed

Thota, P; Perez-Lopez, F R; Benites-Zapata, V A; Pasupuleti, V; Hernandez, A V

2017-03-01

Insulin resistance is common among obese adolescents; however, the extent of this problem is not clear. We conducted a systematic review of PubMed-Medline, CINAHL, The Web of Science, EMBASE and Scopus for observational studies evaluating components defining insulin resistance (insulin, C-peptide and homeostatic model assessment-insulin resistance [HOMA-IR]) in obese adolescents (12-18 years) versus non-obese adolescents. Our systematic review and meta-analysis followed the PRISMA guidelines. Data were combined using a random-effects model and summary statistics were calculated using the mean differences (MDs). 31 studies were included (n = 8655). In 26 studies, fasting insulin levels were higher in obese adolescents when compared to non-obese adolescents (MD = 64.11 pmol/L, 95%CI 49.48-78.75, p < 0.00001). In three studies, fasting C-peptide levels were higher in obese adolescents when compared to non-obese adolescents (MD = 0.29 nmol/L, 95%CI 0.22-0.36, p < 0.00001). In 24 studies, HOMA-IR values were higher in obese adolescents when compared to non-obese adolescents (MD = 2.22, 95%CI 1.78-2.67, p < 0.00001). Heterogeneity of effects among studies was moderate to high. Subgroup analyses showed similar results to the main analyses. Circulating insulin and C-peptide levels and HOMA-IR values were significantly higher in obese adolescents compared to those non-obese.

Evaluation of fracture torque resistance of orthodontic mini-implants.

PubMed

Dalla Rosa, Fernando; Burmann, Paola Fp; Ruschel, Henrique C; Vargas, Ivana A; Kramer, Paulo F

2016-12-01

This study sought to assess the fracture torque resistance of mini-implants used for orthodontic anchorage. Five commercially available brands of mini-implants were used (SIN®, CONEXÃO®, NEODENT®, MORELLI®, andFORESTADENT®). Ten mini-implants of each diameter of each brand were tested, for a total 100 specimens. The mini-implants were subject to a static torsion test as described in ASTMstandard F543. Analysis of variance (ANOVA) with the Tukey multiple comparisons procedure was used to assess results. Overall, mean fracture strength ranged from 15.7 to 70.4 N·cm. Mini-implants with larger diameter exhibited higher peak torque values at fracture and higher yield strength, regardless of brand. In addition, significant differences across brands were observed when implants were stratified by diameter. In conclusion, larger mini-implant diameter is associated with increased fracture torque resistance. Additional information on peak torque values at fracture of different commercial brands of mini-implants may increase the success rate of this orthodontic anchorage modality. Sociedad Argentina de Investigación Odontológica.

Thermal resistance of Listeria monocytogenes in sausage meat.

PubMed

Farber, J M; Hughes, A; Holley, R; Brown, B

1989-01-01

The heat resistance of a mixture of 10 different strains of Listeria monocytogenes inoculated into ground meat and ground meat plus cure was examined. D-values for ground meat ranged from 1.01 min at 62 degrees C to 13.18 min at 56 degrees C. The D-values obtained for ground meat plus cure were approximately 5-8 fold times higher than those for ground meat alone. These results imply that rare meats and possibly some cooked fermented meats may not be heated adequately to inactivate Listeria.

Mechanical properties and microstructures of glass-ionomer cements.

PubMed

Xie, D; Brantley, W A; Culbertson, B M; Wang, G

2000-03-01

The objective of this study was to determine the flexural strength (FS), compressive strength (CS), diametral tensile strength (DTS), Knoop hardness (KHN) and wear resistance of ten commercial glass-ionomer cements (GICs). The fracture surfaces of these cements were examined using scanning electron microscopic (SEM) techniques to ascertain relationships between the mechanical properties and microstructures of these cements. Specimens were fabricated according to the instructions from each manufacturer. The FS, CS, DTS, KHN and wear rate were measured after conditioning the specimens for 7 d in distilled water at 37 degrees C. One-way analysis of variance with the post hoc Tukey-Kramer multiple range test was used to determine which specimen groups were significantly different for each test. The fracture surface of one representative specimen of each GIC from the FS tests was examined using a scanning electron microscope. The resin-modified GICs (RM GICs) exhibited much higher FS and DTS, not generally higher CS, often lower Knoop hardness and generally lower wear resistance, compared to the conventional GICs (C GICs). Vitremer (3M) had the highest values of FS and DTS; Fuji II LC (GC International) and Ketac-Molar (ESPE) had the highest CS; Ketac-Fil (ESPE) had the highest KHN. Ketac-Bond (ESPE) had the lowest FS; alpha-Silver (DMG-Hamburg) had the lowest CS. Four GICs (alpha-Fil (DMG-Hamburg), alpha-Silver, Ketac-Bond and Fuji II) had the lowest values of DTS, which were not significantly different from each other; alpha-Silver and Ketac-Silver had the lowest values of KHN. The highest wear resistance was exhibited by alpha-Silver and Ketac-Fil; F2LC had the lowest wear resistance. The C GICs exhibited brittle behavior, whereas the RM GICs underwent substantial plastic deformation in compression. The more integrated the microstructure, the higher were the FS and DTS. Higher CS was correlated with smaller glass particles, and higher KHN was found where there was a combination of smaller glass particles and lower porosity. Larger glass particle sizes and a more integrated microstructure contributed to a higher wear resistance. The mechanical properties of GICs were closely related to their microstructures. Factors such as the integrity of the interface between the glass particles and the polymer matrix, the particle size, and the number and size of voids have important roles in determining the mechanical properties.

Mapping a Pristine Glaciofluvial Aquifer on the Canadian Shield Using Ground-Penetrating Radar and Electrical Resistivity Tomography

NASA Astrophysics Data System (ADS)

Graves, L. W.; Shirokova, V.; Bank, C.

2013-12-01

Our study aims to construct a 3D structural model of an unconfined pristine aquifer in Laurentian Hills, Ontario, Canada. The stratigraphy of the study site, which covers about 5400 square meters, features reworked glaciofluvial sands and glacial till on top of Canadian Shield bedrock. A network of 25 existing piezometers provides ground-truth. We used two types of geophysical surveys to map the water table and the aquifer basin. Ground-penetrating radar (GPR) collected 40 profiles over distances up to 140 meters using 200MHz and 400MHz antennas with a survey wheel. The collected radargrams show a distinct reflective layer, which can be mapped to outcrops of glacial till within the area. This impermeable interface forms the aquitard. Depths of the subsurface features were calculated using hyperbolic fits on the radargrams in Matlab by determining wave velocity then converting measured two-way-time to depth. Electrical resistivity was used to determine the water table elevations because the unconfined water table did not reflect the radar waves. 20 resistivity profiles were collected in the same area using Wenner-Alpha and dipole-dipole arrays with both 24 and 48 electrodes and for 0.5, 0.75, 1.0 and 2.0 meter spacing. The inverted resistivity models show low resistivity values (<1000 Ohm.m) below 2 to 5 meter depths and higher resistivity values (2000-6000 Ohm.m) above 1 to 2 meter depths. These contrasting resistivity values correspond to saturated and wet sand (lower resistivity) to dry sand (higher resistivity); a correlation we could verify with several bore-hole logs. The water table is marked on the resistivity profiles as a steep resistivity gradient, and the depth can be added to the comprehensive 3D model. This model also incorporates hydrogeological characteristics and geochemical anomalies found within the aquifer. Ongoing seasonal and annual monitoring of the aquifer using geophysical methods will bring a fourth dimension to our understanding of this dynamic system. GPR Profile with Glacial Till Interface.

Defining landscape resistance values in least-cost connectivity models for the invasive grey squirrel: a comparison of approaches using expert-opinion and habitat suitability modelling.

PubMed

Stevenson-Holt, Claire D; Watts, Kevin; Bellamy, Chloe C; Nevin, Owen T; Ramsey, Andrew D

2014-01-01

Least-cost models are widely used to study the functional connectivity of habitat within a varied landscape matrix. A critical step in the process is identifying resistance values for each land cover based upon the facilitating or impeding impact on species movement. Ideally resistance values would be parameterised with empirical data, but due to a shortage of such information, expert-opinion is often used. However, the use of expert-opinion is seen as subjective, human-centric and unreliable. This study derived resistance values from grey squirrel habitat suitability models (HSM) in order to compare the utility and validity of this approach with more traditional, expert-led methods. Models were built and tested with MaxEnt, using squirrel presence records and a categorical land cover map for Cumbria, UK. Predictions on the likelihood of squirrel occurrence within each land cover type were inverted, providing resistance values which were used to parameterise a least-cost model. The resulting habitat networks were measured and compared to those derived from a least-cost model built with previously collated information from experts. The expert-derived and HSM-inferred least-cost networks differ in precision. The HSM-informed networks were smaller and more fragmented because of the higher resistance values attributed to most habitats. These results are discussed in relation to the applicability of both approaches for conservation and management objectives, providing guidance to researchers and practitioners attempting to apply and interpret a least-cost approach to mapping ecological networks.

Collateral Ventilation to Congenital Hyperlucent Lung Lesions Assessed on Xenon-Enhanced Dynamic Dual-Energy CT: an Initial Experience

PubMed Central

Yang, Dong Hyun; Kim, Namkug; Park, Seung Il; Kim, Dong Kwan; Kim, Ellen Ai-Rhan

2011-01-01

Objective We wanted to evaluate the resistance to collateral ventilation in congenital hyperlucent lung lesions and to correlate that with the anatomic findings on xenon-enhanced dynamic dual-energy CT. Materials and Methods Xenon-enhanced dynamic dual-energy CT was successfully and safely performed in eight children (median age: 5.5 years, 4 boys and 4 girls) with congenital hyperlucent lung lesions. Functional assessment of the lung lesions on the xenon map was done, including performing a time-xenon value curve analysis and assessing the amplitude of xenon enhancement (A) value, the rate of xenon enhancement (K) value and the time of arrival value. Based on the A value, the lung lesions were categorized into high or low (A value > 10 Hounsfield unit [HU]) resistance to collateral ventilation. In addition, the morphologic CT findings of the lung lesions, including cyst, mucocele and an accessory or incomplete fissure, were assessed on the weighted-average CT images. The xenon-enhanced CT radiation dose was estimated. Results Five of the eight lung lesions were categorized into the high resistance group and three lesions were categorized into the low resistance group. The A and K values in the normal lung were higher than those in the low resistance group. The time of arrival values were delayed in the low resistance group. Cysts were identified in five lesions, mucocele in four, accessory fissure in three and incomplete fissure in two. Either cyst or an accessory fissure was seen in four of the five lesions showing high resistance to collateral ventilation. The xenon-enhanced CT radiation dose was 2.3 ± 0.6 mSv. Conclusion Xenon-enhanced dynamic dual-energy CT can help visualize and quantitate various degrees of collateral ventilation to congenital hyperlucent lung lesions in addition to assessing the anatomic details of the lung. PMID:21228937

Collateral ventilation to congenital hyperlucent lung lesions assessed on xenon-enhanced dynamic dual-energy CT: an initial experience.

PubMed

Goo, Hyun Woo; Yang, Dong Hyun; Kim, Namkug; Park, Seung Il; Kim, Dong Kwan; Kim, Ellen Ai-Rhan

2011-01-01

We wanted to evaluate the resistance to collateral ventilation in congenital hyperlucent lung lesions and to correlate that with the anatomic findings on xenon-enhanced dynamic dual-energy CT. Xenon-enhanced dynamic dual-energy CT was successfully and safely performed in eight children (median age: 5.5 years, 4 boys and 4 girls) with congenital hyperlucent lung lesions. Functional assessment of the lung lesions on the xenon map was done, including performing a time-xenon value curve analysis and assessing the amplitude of xenon enhancement (A) value, the rate of xenon enhancement (K) value and the time of arrival value. Based on the A value, the lung lesions were categorized into high or low (A value > 10 Hounsfield unit [HU]) resistance to collateral ventilation. In addition, the morphologic CT findings of the lung lesions, including cyst, mucocele and an accessory or incomplete fissure, were assessed on the weighted-average CT images. The xenon-enhanced CT radiation dose was estimated. Five of the eight lung lesions were categorized into the high resistance group and three lesions were categorized into the low resistance group. The A and K values in the normal lung were higher than those in the low resistance group. The time of arrival values were delayed in the low resistance group. Cysts were identified in five lesions, mucocele in four, accessory fissure in three and incomplete fissure in two. Either cyst or an accessory fissure was seen in four of the five lesions showing high resistance to collateral ventilation. The xenon-enhanced CT radiation dose was 2.3 ± 0.6 mSv. Xenon-enhanced dynamic dual-energy CT can help visualize and quantitate various degrees of collateral ventilation to congenital hyperlucent lung lesions in addition to assessing the anatomic details of the lung.

Insulin resistance (HOMA-IR) cut-off values and the metabolic syndrome in a general adult population: effect of gender and age: EPIRCE cross-sectional study

PubMed Central

2013-01-01

Background Insulin resistance has been associated with metabolic and hemodynamic alterations and higher cardio metabolic risk. There is great variability in the threshold homeostasis model assessment of insulin resistance (HOMA-IR) levels to define insulin resistance. The purpose of this study was to describe the influence of age and gender in the estimation of HOMA-IR optimal cut-off values to identify subjects with higher cardio metabolic risk in a general adult population. Methods It included 2459 adults (range 20–92 years, 58.4% women) in a random Spanish population sample. As an accurate indicator of cardio metabolic risk, Metabolic Syndrome (MetS), both by International Diabetes Federation criteria and by Adult Treatment Panel III criteria, were used. The effect of age was analyzed in individuals with and without diabetes mellitus separately. ROC regression methodology was used to evaluate the effect of age on HOMA-IR performance in classifying cardio metabolic risk. Results In Spanish population the threshold value of HOMA-IR drops from 3.46 using 90th percentile criteria to 2.05 taking into account of MetS components. In non-diabetic women, but no in men, we found a significant non-linear effect of age on the accuracy of HOMA-IR. In non-diabetic men, the cut-off values were 1.85. All values are between 70th-75th percentiles of HOMA-IR levels in adult Spanish population. Conclusions The consideration of the cardio metabolic risk to establish the cut-off points of HOMA-IR, to define insulin resistance instead of using a percentile of the population distribution, would increase its clinical utility in identifying those patients in whom the presence of multiple metabolic risk factors imparts an increased metabolic and cardiovascular risk. The threshold levels must be modified by age in non-diabetic women. PMID:24131857

Insulin resistance (HOMA-IR) cut-off values and the metabolic syndrome in a general adult population: effect of gender and age: EPIRCE cross-sectional study.

PubMed

Gayoso-Diz, Pilar; Otero-González, Alfonso; Rodriguez-Alvarez, María Xosé; Gude, Francisco; García, Fernando; De Francisco, Angel; Quintela, Arturo González

2013-10-16

Insulin resistance has been associated with metabolic and hemodynamic alterations and higher cardio metabolic risk. There is great variability in the threshold homeostasis model assessment of insulin resistance (HOMA-IR) levels to define insulin resistance. The purpose of this study was to describe the influence of age and gender in the estimation of HOMA-IR optimal cut-off values to identify subjects with higher cardio metabolic risk in a general adult population. It included 2459 adults (range 20-92 years, 58.4% women) in a random Spanish population sample. As an accurate indicator of cardio metabolic risk, Metabolic Syndrome (MetS), both by International Diabetes Federation criteria and by Adult Treatment Panel III criteria, were used. The effect of age was analyzed in individuals with and without diabetes mellitus separately. ROC regression methodology was used to evaluate the effect of age on HOMA-IR performance in classifying cardio metabolic risk. In Spanish population the threshold value of HOMA-IR drops from 3.46 using 90th percentile criteria to 2.05 taking into account of MetS components. In non-diabetic women, but no in men, we found a significant non-linear effect of age on the accuracy of HOMA-IR. In non-diabetic men, the cut-off values were 1.85. All values are between 70th-75th percentiles of HOMA-IR levels in adult Spanish population. The consideration of the cardio metabolic risk to establish the cut-off points of HOMA-IR, to define insulin resistance instead of using a percentile of the population distribution, would increase its clinical utility in identifying those patients in whom the presence of multiple metabolic risk factors imparts an increased metabolic and cardiovascular risk. The threshold levels must be modified by age in non-diabetic women.

Increased fitness and realized heritability in emamectin benzoate-resistant Chrysoperla carnea (Neuroptera: Chrysopidae).

PubMed

Mansoor, Muhammad Mudassir; Abbas, Naeem; Shad, Sarfraz Ali; Pathan, Attaullah Khan; Razaq, Muhammad

2013-10-01

The common green lacewing Chrysoperla carnea is a key biological control agent employed in integrated pest management (IPM) programs for managing various insect pests. A field collected population of C. carnea was selected for emamectin benzoate resistance in the laboratory and fitness costs and realized heritability were investigated. After five generations of selection with emamectin benzoate, C. carnea developed a 318-fold resistance to the insecticide. The resistant population had a relative fitness of 1.49, with substantially higher emergence rate of healthy adults, fecundity and hatchability and shorter larval duration, pupal duration, and development time compared to the susceptible population. Mean population growth rates; such as the intrinsic rate of natural population increase and biotic potential were higher for the emamectin benzoate selected population compared to the susceptible population. The realized heritability (h(2)) value of emamectin benzoate resistance was 0.34 in emamectin benzoate selected population of C. carnea. Chrysoperla species which show resistance to insecticides makes them compatible with those IPM systems where emamectin benzoate is employed.

Heat resistance of Bacillus cereus spores: effects of milk constituents and stabilizing additives.

PubMed

Mazas, M; López, M; Martínez, S; Bernardo, A; Martin, R

1999-04-01

Heat resistance of Bacillus cereus spores (ATCC 7004, 4342, and 9818) heated in different types of milk (skim, whole, and concentrated skim milk), skim milk containing stabilizing additives (sodium citrate, monopotassium phosphate, or disodium phosphate, 0.1%), and cream was investigated. Thermal resistance experiments were performed at temperatures within the range of 92 to 115 degrees C under continuous monitoring of pH. For strain 4342 no significant differences (P < 0.05) in D values were detected in any case. For strains 7004 and 9818 higher D values of about 20% were obtained in whole and concentrated skim milk than those calculated in skim milk. From all stabilizing additives tested, only sodium citrate and sodium phosphate increased the heat resistance for strain 9818. However, when the menstruum pH was measured at the treatment temperature, different pH values were found between the heating media. The differences in heat resistance observed could be due to a pH effect rather than to the difference in the substrates in which spores were heated. In contrast, when cream (fat content 20%) was used, lower D values were obtained, especially for strains 7004 and 9818. z values were not significantly modified by the milk composition, with an average z value of 7.95+/-0.20 degrees C for strain 7004, 7.88+/-0.10 degrees C for strain 4342, and 9.13+/-0.16 degrees C for strain 9818.

Linezolid susceptibility in Helicobacter pylori, including strains with multidrug resistance.

PubMed

Boyanova, Lyudmila; Evstatiev, Ivailo; Gergova, Galina; Yaneva, Penka; Mitov, Ivan

2015-12-01

Only a few studies have evaluated Helicobacter pylori susceptibility to linezolid. The aim of the present study was to assess linezolid susceptibility in H. pylori, including strains with double/multidrug resistance. The susceptibility of 53 H. pylori strains was evaluated by Etest and a breakpoint susceptibility testing method. Helicobacter pylori resistance rates were as follows: amoxicillin, 1.9%; metronidazole, 37.7%; clarithromycin, 17.0%; tetracycline, 1.9%; levofloxacin, 24.5%; and linezolid (>4 mg/L), 39.6%. The linezolid MIC50 value was 31.2-fold higher than that of clarithromycin and 10.5-fold higher than that of levofloxacin; however, 4 of 11 strains with double/multidrug resistance were linezolid-susceptible. The MIC range of the oxazolidinone agent was larger (0.125-64 mg/L) compared with those in the previous two reports. The linezolid resistance rate was 2.2-fold higher in metronidazole-resistant strains and in strains resistant to at least one antibiotic compared with the remaining strains. Briefly, linezolid was less active against H. pylori compared with clarithromycin and levofloxacin, and linezolid resistance was linked to resistance to metronidazole as well as to resistance to at least one antibiotic. However, linezolid activity against some strains with double/multidrug resistance may render the agent appropriate to treat some associated H. pylori infections following in vitro susceptibility testing of the strains. Clinical trials are required to confirm this suggestion. Copyright © 2015 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Effect of r-value and texture on plastic deformation and necking behavior in interstitial-free steel sheets

NASA Astrophysics Data System (ADS)

Oh, Gyu-Jin; Lee, Kye-Man; Huh, Moo-Young; Park, Jin Eon; Park, Soo Ho; Engler, Olaf

2017-01-01

Three initial tensile specimens having different textures and, in consequence, different r-values were cut from a sheet of an interstitial-free steel. Using these specimens, the effect of r-value and texture on plastic deformation and the necking behavior were studied by tackling the strain state and texture during tensile tests. A reduced decrease in work hardening rate of tensile specimens with higher r-values led to a slower onset of diffuse necking which offers an increased uniform elongation. A slower reduction in thickness of specimens with a higher r-value provided a favorable resistance against onset of failure by localized necking.

Temperature dependence of the electrical resistivity of LaxLu1-xAs

NASA Astrophysics Data System (ADS)

Rahimi, S.; Krivoy, E. M.; Lee, J.; Michael, M. E.; Bank, S. R.; Akinwande, D.

2013-08-01

We investigate the temperature-dependent resistivity of single-crystalline films of LaxLu1-xAs over the 5-300 K range. The resistivity was separated into lattice, carrier and impurity scattering regions. The effect of impurity scattering is significant below 20 K, while carrier scattering dominates at 20-80 K and lattice scattering dominates above 80 K. All scattering regions show strong dependence on the La content of the films. While the resistivity of 600 nm LuAs films agree well with the reported bulk resistivity values, 3 nm films possessed significantly higher resistivity, suggesting that interfacial roughness significantly impacts the scattering of carriers at the nanoscale limit.

Gait of dairy cows on floors with different slipperiness.

PubMed

Telezhenko, E; Magnusson, M; Bergsten, C

2017-08-01

This study assessed the slip resistance of different types of solid flooring in cattle housing using a range of technical tests and gait analysis. Dynamic and static coefficient of friction, skid resistance, and abrasiveness were tested on concrete flooring with a smooth finish, a grooved pattern, or a tamped pattern, acid-resistant mastic asphalt, soft rubber mats, and a worn slatted concrete floor. Coefficients of friction and skid resistance were tested under clean and slurry-soiled conditions. Linear kinematic variables were assessed in 40 cows with trackway measurements after the cows passed over the floors in a straight walk. All gait variables were assessed as deviations from those obtained on the slatted concrete floor, which was used as a baseline. The coefficient of friction tests divided the floors into 3 categories: concrete flooring, which had a low coefficient of friction (0.29-0.41); mastic asphalt flooring, which had medium values (0.38-0.45); and rubber mats, which had high values (0.49-0.57). The highest abrasion (g/10 m) was on the asphalt flooring (4.48), and the concrete flooring with a tamped pattern had significantly higher abrasiveness (2.77) than the other concrete floors (1.26-1.60). Lowest values on the skid-resistance tests (dry/wet) were for smooth concrete (79/35) and mastic asphalt (65/47), especially with a slurry layer on the surface. Gait analysis mainly differentiated floors with higher friction and abrasion by longer strides and better tracking. Step asymmetry was lower on floors with high skid-resistance values. The most secure cow gait, in almost every aspect, was observed on soft rubber mats. Relationships between gait variables and physical floor characteristics ranged from average to weak (partial correlations 0.54-0.16). Thus, none of the physical characteristics alone was informative enough to characterize slip resistance. With reference to gait analysis, the abrasiveness of the hard surfaces was more informative than the coefficient of friction, but the effect of pattern was better detected by skid-resistance measurements. Consequently, several physical characteristics are needed to objectively describe the slip resistance of cattle floors. Soft rubber mats gave better tracking than hard, solid floors, even with a grooved surface or a tamped pattern. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Biophysical response of young pomegranate trees to surface and sub-surface drip irrigation and deficit irrigation

USDA-ARS?s Scientific Manuscript database

Due to recurring agricultural water shortages, many farmers are looking for crops that have both some degree of drought resistance and a higher economic value. Pomegranate has been identified as a crop with potential drought tolerance, and high economic values. To manage limited water effectively, i...

The Associations Between Increasing Degrees of HOMA-IR and Measurements of Adiposity Among Euglycemic U.S. Adults.

PubMed

Boyer, William R; Johnson, Tammie M; Fitzhugh, Eugene C; Richardson, Michael R; Churilla, James R

2016-03-01

The purpose of this study was to examine the associations between increasing degrees of insulin resistance (using the homeostatic model assessment of insulin resistance [HOMA-IR]) and two measures of adiposity in a nationally representative sample of euglycemic U.S. adults. Sample included adult participants (≥ 20 years of age) [N = 1586 (body mass index, BMI model), N = 1577 (waist circumference, WC model)] from the 1999-2004 National Health and Nutrition Examination Survey (NHANES). HOMA-IR was categorized into quartiles. BMI and WC were examined continuously as the dependent variables. Following adjustment for covariates, those with HOMA-IR values in the second, third, and fourth quartiles had significantly higher BMIs (P < 0.001) compared with subjects in the first quartile. In the model using WC, significantly higher WCs were found in subjects in the second, third, and fourth quartiles of HOMA-IR (P < 0.001) compared with those in the first quartile. A significant moderate correlation was found between HOMA-IR and BMI (R(2) = 0.4171, P < 0.001), as well as HOMA-IR and WC (R(2) = 0.4826, P < 0.001). Having a higher HOMA-IR value is associated with higher BMI and WC values in euglycemic subjects.

Defense Responses to Mycotoxin-Producing Fungi Fusarium proliferatum, F. subglutinans, and Aspergillus flavus in Kernels of Susceptible and Resistant Maize Genotypes.

PubMed

Lanubile, Alessandra; Maschietto, Valentina; De Leonardis, Silvana; Battilani, Paola; Paciolla, Costantino; Marocco, Adriano

2015-05-01

Developing kernels of resistant and susceptible maize genotypes were inoculated with Fusarium proliferatum, F. subglutinans, and Aspergillus flavus. Selected defense systems were investigated using real-time reverse transcription-polymerase chain reaction to monitor the expression of pathogenesis-related (PR) genes (PR1, PR5, PRm3, PRm6) and genes protective from oxidative stress (peroxidase, catalase, superoxide dismutase and ascorbate peroxidase) at 72 h postinoculation. The study was also extended to the analysis of the ascorbate-glutathione cycle and catalase, superoxide dismutase, and cytosolic and wall peroxidases enzymes. Furthermore, the hydrogen peroxide and malondialdehyde contents were studied to evaluate the oxidation level. Higher gene expression and enzymatic activities were observed in uninoculated kernels of resistant line, conferring a major readiness to the pathogen attack. Moreover expression values of PR genes remained higher in the resistant line after inoculation, demonstrating a potentiated response to the pathogen invasions. In contrast, reactive oxygen species-scavenging genes were strongly induced in the susceptible line only after pathogen inoculation, although their enzymatic activity was higher in the resistant line. Our data provide an important basis for further investigation of defense gene functions in developing kernels in order to improve resistance to fungal pathogens. Maize genotypes with overexpressed resistance traits could be profitably utilized in breeding programs focused on resistance to pathogens and grain safety.

Hyperinsulinemia in polycystic ovary disease.

PubMed

Arthur, L S; Selvakumar, R; Seshadri, M S; Seshadri, L

1999-09-01

To evaluate the prevalence of hyperinsulinemia and insulin resistance in women with polycystic ovary disease (PCOD). Forty women with clinical and biochemical evidence of PCOD and 20 with regular menstrual cycles were studied prospectively. All women underwent a three-hour oral glucose tolerance test following a 100-g glucose load. Plasma sugar and insulin levels were measured. The one-, two- and three-hour insulin values were significantly higher in women with PCOD. The sum insulin, cumulative insulin, peak insulin and area under the insulin response curve were similarly higher in women with PCOD than in the controls. The presence of hirsutism was more often associated with hyperinsulinemia and insulin resistance, but body mass index and menstrual irregularity were not. Hyperinsulinemia and insulin resistance seem to be commonly associated with PCOD.

Error-prone PCR mutation of Ls-EPSPS gene from Liriope spicata conferring to its enhanced glyphosate-resistance.

PubMed

Mao, Chanjuan; Xie, Hongjie; Chen, Shiguo; Valverde, Bernal E; Qiang, Sheng

2017-09-01

Liriope spicata (Thunb.) Lour has a unique LsEPSPS structure contributing to the highest-ever-recognized natural glyphosate tolerance. The transformed LsEPSPS confers increased glyphosate resistance to E. coli and A. thaliana. However, the increased glyphosate-resistance level is not high enough to be of commercial value. Therefore, LsEPSPS was subjected to error-prone PCR to screen mutant EPSPS genes capable of endowing higher resistance levels. A mutant designated as ELs-EPSPS having five mutated amino acids (37Val, 67Asn, 277Ser, 351Gly and 422Gly) was selected for its ability to confer improved resistance to glyphosate. Expression of ELs-EPSPS in recombinant E. coli BL21 (DE3) strains enhanced resistance to glyphosate in comparison to both the LsEPSPS-transformed and -untransformed controls. Furthermore, transgenic ELs-EPSPS A. thaliana was about 5.4 fold and 2-fold resistance to glyphosate compared with the wild-type and the Ls-EPSPS-transgenic plants, respectively. Therefore, the mutated ELs-EPSPS gene has potential value for has potential for the development of glyphosate-resistant crops. Copyright © 2016 Elsevier Inc. All rights reserved.

New target for rice lodging resistance and its effect in a typhoon.

PubMed

Ishimaru, Ken; Togawa, Eiji; Ookawa, Taiichro; Kashiwagi, Takayuki; Madoka, Yuka; Hirotsu, Naoki

2008-02-01

We demonstrated the new target for lodging resistance in rice (Oryza sativa L.) by the analysis of physiological function of a locus for lodging resistance in a typhoon (lrt5) with the near isogenic line under rice "Koshihikari" genetic background (tentatively named S1). The higher lodging resistance of S1 was observed during a typhoon in September 2004 (28 days after heading), when most other plants in "Koshihikari" became lodged. Visual observations showed that bending of the upper stems triggered lodging during the typhoon; the upper stem of "Koshihikari" buckled completely, whereas that of S1 remained straight. In addition to the strong rain and winds during the typhoon, the weight of the buckled upper plant parts increased the pressure on adjacent plants and caused a domino effect in "Koshihikari". Young's modulus, an indicator of the rigidity of the culm, was significantly higher in S1 than in "Koshihikari". In the upper culm, the starch content in S1 was 4.8 times the value in "Koshihikari", and senescence was delayed in the upper leaves of S1. These results suggest that the rigidity of the upper culm by the higher starch content (as a result of delayed senescence in the upper leaves) may be responsible for the higher lodging resistance during a typhoon in rice.

Laboratory comparison of the mechanical properties of TRUShape with several nickel-titanium rotary instruments.

PubMed

Elnaghy, A M; Elsaka, S E

2017-08-01

To assess and compare the mechanical properties of TRUShape (TRS) with several nickel-titanium rotary instruments. Cyclic fatigue, torsional resistance, flexibility and surface microhardness of TRS (size 25, 0.06v taper), ProTaper Next X2 (PTN X2, size 25, 0.06 taper), ProTaper Gold (PTG F2; size 25, 0.08 taper) and ProTaper Universal (PTU F2; size 25, 0.08 taper) instruments were evaluated. The topographical structures of the fracture surfaces of instruments were assessed using a scanning electron microscope. The cyclic fatigue resistance, torsional resistance and microhardness data were analysed using one-way analysis of variance (anova) and Tukey's post hoc tests. The fragment length and bending resistance data were analysed statistically with the Kruskal-Wallis H-test and Mann-Whitney U-tests. The statistical significance level was set at P < 0.05. PTN and PTG instruments revealed significantly higher resistance to cyclic fatigue than TRS and PTU instruments (P < 0.001). PTN instruments revealed significantly higher torsional resistance compared with the other instruments (P < 0.001). PTG instrument had significantly higher flexibility than the other tested brands (P < 0.05). However, for microhardness, the PTU had significantly higher surface microhardness values compared with other tested brands (P < 0.05). TRS instruments had lower resistance to cyclic fatigue and lower flexibility compared with PTG and PTN instruments. TRS, PTG and PTU instruments had lower resistance to torsional stress than PTN instruments. TRS and PTG instruments had comparable surface microhardness. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Effects of coupling between sample and electrode on the electrical resistivity measurements of conductive samples

NASA Astrophysics Data System (ADS)

Lee, T. J.; Lee, S. K.

2015-12-01

A resistivity measurement system for conductive core samples has been setup using a high resolution nano-voltmeter. Using the system, in this study, various coupling effects between electrodes and the samples are discussed including contact resistance, lead resistance, temperature dependence, and heat produced within the samples by applied current. The lead resistance was over 10 times higher than the resistance of the conductive samples such as graphite or nichrome, even though the electrodes and lead lines were made of silver. Furthermore, lead resistance itself showed very strong temperature dependence, so that it is essential to subtract the lead resistance from the measured values at corresponding temperature. Minimization of contact resistance is very important, so that the axial loads are needed as big as possible unless the deformation of sample occurs.

Numerical Calculation of Internal Human Body Resistances at Power Frequency, and Comparison of them with Experimental Ones

NASA Astrophysics Data System (ADS)

Tarao, Hiroo; Hayashi, Noriyuki; Hamamoto, Isao; Isaka, Katsuo

A numerical method, which is newly developed here, is used in order to calculate internal body resistances in a voxelized biological model. By using this method, the internal resistances of an anatomical human model were calculated for the two current paths: 1400 Ω for a hand to foot, and 1500 Ω for a hand to hand. They are compared with experimental ones (500 ∼ 600 Ω for the hand to foot and 500 ∼ 700 Ω for the hand to hand), resulting in the conclusion that the numerical values of the internal resistance are twice or three times higher than the experimental ones. While there is the discrepancy between the calculated and measured results in the absolute values, the profiles of their relative values along the current paths showed good agreement. This implies that the factors such as the anisotropy of muscle conductivity and the difference between in vivo and in vitro conductivities need to be considered. In fact, in consideration of those factors, the calculated results approached the experimental ones.

A Study on Sealing Process of Anodized Al Alloy Film

NASA Astrophysics Data System (ADS)

Tsujita, Takeshi; Sato, Hiroshi; Tsukahara, Sonoko; Ishikawa, Yuuichi

Since sealing is an important process to improve the corrosion resistance in practical application of anodized aluminum, we prepared anodic oxide films on A5052 alloy in an oxalic acid bath and a sulfuric acid bath, sealed them at various conditions, and analyzed them by scanning electron microscopy, acid-dissolution examination, admittance measurements and infrared spectroscopy. The pore radius of the oxalic acid anodized film was about 5 times larger than that of sulfuric acid anodized film, while the corrosion resistance of the former showed about 2 times higher value than the latter with the same sealed state and amount of hydroxide formed by sealing process of the former was 6 times larger than the latter, respectively. Steam sealing formed dense hydroxide and boiling water sealing formed big coral-like hydroxide, whereas the corrosion resistance of the film sealed by the former showed about 1.5 times higher value than that sealed by the latter, respectively. Thus microstructure of anodic oxide films and their surface morphology after sealing process clearly depended on their anodizing solution and the sealing condition and showed obvious relation to electric and corrosive properties.

Serum vascular endothelial growth factor B is elevated in women with polycystic ovary syndrome and can be decreased with metformin treatment.

PubMed

Cheng, Feifei; Zhao, Lu; Wu, Yuanyuan; Huang, Tiantian; Yang, Gangyi; Zhang, Zhanyu; Wu, Yijia; Jia, Fang; Wu, Jinlin; Chen, Chen; Liu, Dongfang

2016-03-01

To determine serum vascular endothelial growth factor B (VEGF-B) levels in polycystic ovary syndrome, their association with insulin resistance and β-cell dysfunction, and the effect of metformin on serum VEGF-B levels. A cross-sectional, interventional study. We recruited 103 women with polycystic ovary syndrome and 96 age-matched healthy controls. Serum VEGF-B levels were determined in all participants, and 44 polycystic ovary syndrome patients randomly received metformin. We measured VEGF-B levels in healthy controls and women with polycystic ovary syndrome before and after metformin treatment. Women with polycystic ovary syndrome had higher serum VEGF-B levels, which decreased with metformin treatment. In the lean and overweight/obese groups, patients with polycystic ovary syndrome had higher plasma VEGF-B levels than did healthy controls (P < 0·05). VEGF-B levels were correlated with body mass index, body fat percentage, M values, homeostasis model assessment of insulin resistance and β-cell function indices. A multiple linear regression analysis showed that VEGF-B level was associated with M values after adjusting for age, body mass index, serum sex hormones and serum lipids in women with polycystic ovary syndrome. Serum VEGF-B is significantly higher in women with polycystic ovary syndrome and is closely and positively related to insulin resistance. Metformin treatment reduces VEGF-B levels and ameliorates insulin resistance. © 2015 John Wiley & Sons Ltd.

Decrease of fear avoidance beliefs following person-centered progressive resistance exercise contributes to reduced pain disability in women with fibromyalgia: secondary exploratory analyses from a randomized controlled trial.

PubMed

Palstam, Annie; Larsson, Anette; Löfgren, Monika; Ernberg, Malin; Bjersing, Jan; Bileviciute-Ljungar, Indre; Gerdle, Björn; Kosek, Eva; Mannerkorpi, Kaisa

2016-05-21

Fibromyalgia (FM) is characterized by persistent widespread pain, increased pain sensitivity and tenderness. Women with FM also report disability, in terms of negative consequences on activities of daily living. Our recent randomized controlled trial (RCT) is the first study of resistance exercise to show positive effects on pain disability. The resistance exercise program of our RCT emphasized active involvement of participants in planning and progression of the exercise, using the principles of person-centeredness, to support each participant's ability to manage the exercise and the progress of it. The aim of this sub-study was to investigate explanatory factors for reduced pain disability in women with FM participating in a 15-week person-centered progressive resistance exercise program. A total of 67 women with FM were included in this sub-study of an RCT examining the effects of person-centered progressive resistance exercise performed twice a week for 15 weeks. Tests of physical capacity and health-related questionnaires were assessed at baseline and after the intervention period. Multivariable stepwise regression was used to analyze explanatory factors for improvements in pain disability. Reduced pain disability was explained by higher pain disability at baseline together with decreased fear avoidance beliefs about physical activity (R (2) = 28, p = 0.005). The improvements in the disability domains of recreation and social activity were explained by decreased fear avoidance beliefs about physical activity together with higher baseline values of each disability domain respectively (R (2) = 32, p = 0.025 and R (2) = 30, p = 0.017). The improvement in occupational disability was explained by higher baseline values of occupational disability (R (2) = 19, p = 0.001). The person-centered resistance exercise intervention, based on principles of self-efficacy, had a positive effect on recreational, social and occupational disability. The reduced pain disability seemed to be mediated by decreased fear avoidance beliefs. Age, symptom duration, pain intensity, and muscle strength at baseline had no explanatory value for reduced pain disability, indicating that the person-centered resistance exercise program has the potential to work for anyone with FM who has interest in physical exercise. The trial was registered on October 21, 2010 with ClinicalTrials.gov identification number: NCT01226784 .

Temporal Relationship Between Hyperuricemia and Insulin Resistance and Its Impact on Future Risk of Hypertension.

PubMed

Han, Tianshu; Lan, Li; Qu, Rongge; Xu, Qian; Jiang, Ruyue; Na, Lixin; Sun, Changhao

2017-10-01

Although hyperuricemia and insulin resistance significantly correlated, their temporal sequence and how the sequence influence on future risk of hypertension are largely unknown. This study assessed temporal relationship between uric acid and insulin resistance and its impact on future risk of hypertension by examining a longitudinal cohort including 8543 subjects aged 20 to 74 years from China, with an average follow-up of 5.3 years. Measurements of fasting uric acid, as well as fasting and 2-hour serum glucose and insulin, were obtained at baseline and follow-up. Indicators of hepatic and peripheral insulin resistance were calculated. Cross-lagged panel and mediation analysis were used to examine the temporal relationship between uric acid and insulin resistance and its impact on follow-up hypertension. After adjusting for covariates, the cross-lagged path coefficients ( β 1 values) from baseline uric acid to follow-up insulin resistance indices were significantly greater than path coefficients ( β 2 values) from baseline insulin resistance indices to follow-up uric acid ( β 1 =0.110 versus β 2 =0.017; P <0.001, for hepatic insulin resistance; β 1 =-0.208 versus β 2 =-0.021; P <0.001, for peripheral insulin resistance). The path coefficients from baseline uric acid to follow-up insulin resistance indices in the hypertensive group were significantly greater than that in the normotensive group ( P <0.001 for the difference of β 1 values in the 2 groups). Insulin resistance partially mediated the effect of uric acid on subsequent hypertension, and the mediation effect of peripheral insulin resistance was significantly greater than that of hepatic insulin resistance (31.3% versus 13.2%; P <0.001, for the difference of mediation effects). These findings provide evidence that higher uric acid levels probably precede insulin resistance, and peripheral insulin resistance likely plays a more important role in the development of hypertension than hepatic insulin resistance does. © 2017 American Heart Association, Inc.

Cyclic fatigue resistance of R-Pilot, WaveOne Gold Glider, and ProGlider glide path instruments.

PubMed

Keskin, Cangül; İnan, Uğur; Demiral, Murat; Keleş, Ali

2018-02-17

The aim of the present study was to compare the cyclic fatigue resistance of R-Pilot (VDW; Munich, Germany) with ProGlider (Denstply Sirona; Ballaigues, Switzerland) and WaveOne Gold Glider (Denstply Sirona; Ballaigues, Switzerland) glide path instruments. R-Pilot, ProGlider, and WaveOne Gold Glider instruments were collected (n = 15) and tested in a dynamic cyclic fatigue test device, which has an artificial canal with 60° angle of curvature and a 5-mm radius of curvature. All instruments were operated until fracture occurred, and both time to fracture (TF) and the lengths of the fractured fragments were recorded. Mean and standard deviations of TF and fragment length were calculated for each reciprocating system. TF data and fractured fragment length data were subjected to one-way ANOVA and post-hoc Tukey tests (P < 0.05). Also a Weibull analysis was performed on TF data. The cyclic fatigue resistance values of the WaveOne Gold Glider and R-Pilot were significantly higher than those of the ProGlider (P < 0.05), with no significant difference between them (P > 0.05). Weibull analysis revealed that WaveOne Gold Glider showed the highest predicted TF value for 99% survival rate, which was followed by R-Pilot and ProGlider. Regarding the length of the fractured tips, there were no significant differences among the instruments (P > 0.05). The reciprocating WaveOne Gold Glider and R-Pilot instruments had significantly higher cyclic fatigue resistance than rotary ProGlider instruments. This study reported that novel reciprocating glide path instruments exhibited higher cyclic fatigue resistance than rotating glide path instrument.

Insulin Resistance and Body Fat Distribution in South Asian Men Compared to Caucasian Men

PubMed Central

Lin, Ping; Seenivasan, Thanalakshmi; Livingston, Edward H.; Snell, Peter G.; Grundy, Scott M.

2007-01-01

Objective South Asians are susceptible to insulin resistance even without obesity. We examined the characteristics of body fat content, distribution and function in South Asian men and their relationships to insulin resistance compared to Caucasians. Research Design and Methods Twenty-nine South Asian and 18 Caucasian non-diabetic men (age 27±3 and 27±3 years, respectively) underwent euglycemic-hyperinsulinemic clamp for insulin sensitivity, underwater weighing for total body fat, MRI of entire abdomen for intraperitoneal (IP) and subcutaneous abdominal (SA) fat and biopsy of SA fat for adipocyte size. Results Compared to Caucasians, in spite of similar BMI, South Asians had higher total body fat (22±6 and 15±4% of body weight; p-value<0.0001), higher SA fat (3.5±1.9 and 2.2±1.3 kg, respectively; p-value = 0.004), but no differences in IP fat (1.0±0.5 and 1.0±0.7 kg, respectively; p-value = 0.4). SA adipocyte cell size was significantly higher in South Asians (3491±1393 and 1648±864 µm2; p-value = 0.0001) and was inversely correlated with both glucose disposal rate (r-value = −0.57; p-value = 0.0008) and plasma adiponectin concentrations (r-value = −0.71; p-value<0.0001). Adipocyte size differences persisted even when SA was matched between South Asians and Caucasians. Conclusions Insulin resistance in young South Asian men can be observed even without increase in IP fat mass and is related to large SA adipocytes size. Hence ethnic excess in insulin resistance in South Asians appears to be related more to excess truncal fat and dysfunctional adipose tissue than to excess visceral fat. PMID:17726542

Reduced susceptibility to chlorhexidine disinfectant among New Delhi metallo-beta-lactamase-1 positive Enterobacteriaceae and other multidrug-resistant organisms: Report from a tertiary care hospital in Karachi, Pakistan.

PubMed

Mal, P B; Farooqi, J; Irfan, S; Hughes, M A; Khan, E

2016-01-01

We analysed susceptibility of multidrug-resistant organisms (MDROs) including New Delhi metallo-beta-lactamase-1 positive Enterobacteriaceae to chlorhexidine and compared results to their susceptible counterparts. Susceptibilities of chlorhexidine digluconate in a standard (CHX-S) preparation and two commercial disinfectants containing different CHX concentrations (2% w/v and 4% w/w) were performed. MDROs had narrower range of higher CHX-S minimum inhibitory concentrations (MICs) as compared to pan-sensitive organisms. The MIC values for commercial disinfectants products for MDROs were many folds higher (20-600 times), than CHX-S for in vitro use. Increasing antibiotic resistance among bacterial isolates can be an indirect marker of reduced susceptibility to chlorhexidine in hospital setting.

Multi-frequency bioelectrical impedance: a comparison between the Cole-Cole modelling and Hanai equations with the classical impedance index approach.

PubMed

Deurenberg, P; Andreoli, A; de Lorenzo, A

1996-01-01

Total body water and extracellular water were measured by deuterium oxide and bromide dilution respectively in 23 healthy males and 25 healthy females. In addition, total body impedance was measured at 17 frequencies, ranging from 1 kHz to 1350 kHz. Modelling programs were used to extrapolate impedance values to frequency zero (extracellular resistance) and frequency infinity (total body water resistance). Impedance indexes (height2/Zf) were computed at all 17 frequencies. The estimation errors of extracellular resistance and total body water resistance were 1% and 3%, respectively. Impedance and impedance index at low frequency were correlated with extracellular water, independent of the amount of total body water. Total body water showed the greatest correlation with impedance and impedance index at high frequencies. Extrapolated impedance values did not show a higher correlation compared to measured values. Prediction formulas from the literature applied to fixed frequencies showed the best mean and individual predictions for both extracellular water and total body water. It is concluded that, at least in healthy individuals with normal body water distribution, modelling impedance data has no advantage over impedance values measured at fixed frequencies, probably due to estimation errors in the modelled data.

Antimicrobial Susceptibility of Bordetella bronchiseptica Isolates from Swine and Companion Animals and Detection of Resistance Genes.

PubMed

Prüller, Sandra; Rensch, Ulrike; Meemken, Diana; Kaspar, Heike; Kopp, Peter A; Klein, Günter; Kehrenberg, Corinna

2015-01-01

Bordetella bronchiseptica causes infections of the respiratory tract in swine and other mammals and is a precursor for secondary infections with Pasteurella multocida. Treatment of B. bronchiseptica infections is conducted primarily with antimicrobial agents. Therefore it is essential to get an overview of the susceptibility status of these bacteria. The aim of this study was to comparatively analyse broth microdilution susceptibility testing according to CLSI recommendations with an incubation time of 16 to 20 hours and a longer incubation time of 24 hours, as recently proposed to obtain more homogenous MICs. Susceptibility testing against a panel of 22 antimicrobial agents and two fixed combinations was performed with 107 porcine isolates from different farms and regions in Germany and 43 isolates obtained from companion animals in Germany and other European countries. Isolates with increased MICs were investigated by PCR assays for the presence of resistance genes. For ampicillin, all 107 porcine isolates were classified as resistant, whereas only a single isolate was resistant to florfenicol. All isolates obtained from companion animals showed elevated MICs for β-lactam antibiotics and demonstrated an overall low susceptibility to cephalosporines. Extension of the incubation time resulted in 1-2 dilution steps higher MIC50 values of porcine isolates for seven antimicrobial agents tested, while isolates from companion animals exhibited twofold higher MIC50/90 values only for tetracycline and cefotaxime. For three antimicrobial agents, lower MIC50 and MIC90 values were detected for both, porcine and companion animal isolates. Among the 150 isolates tested, the resistance genes blaBOR-1 (n = 147), blaOXA-2, (n = 4), strA and strB (n = 17), sul1 (n = 10), sul2 (n = 73), dfrA7 (n = 3) and tet(A) (n = 8) were detected and a plasmid localisation was identified for several of the resistance genes.

Antimicrobial Susceptibility of Bordetella bronchiseptica Isolates from Swine and Companion Animals and Detection of Resistance Genes

PubMed Central

Prüller, Sandra; Rensch, Ulrike; Meemken, Diana; Kaspar, Heike; Kopp, Peter A.; Klein, Günter; Kehrenberg, Corinna

2015-01-01

Bordetella bronchiseptica causes infections of the respiratory tract in swine and other mammals and is a precursor for secondary infections with Pasteurella multocida. Treatment of B. bronchiseptica infections is conducted primarily with antimicrobial agents. Therefore it is essential to get an overview of the susceptibility status of these bacteria. The aim of this study was to comparatively analyse broth microdilution susceptibility testing according to CLSI recommendations with an incubation time of 16 to 20 hours and a longer incubation time of 24 hours, as recently proposed to obtain more homogenous MICs. Susceptibility testing against a panel of 22 antimicrobial agents and two fixed combinations was performed with 107 porcine isolates from different farms and regions in Germany and 43 isolates obtained from companion animals in Germany and other European countries. Isolates with increased MICs were investigated by PCR assays for the presence of resistance genes. For ampicillin, all 107 porcine isolates were classified as resistant, whereas only a single isolate was resistant to florfenicol. All isolates obtained from companion animals showed elevated MICs for β-lactam antibiotics and demonstrated an overall low susceptibility to cephalosporines. Extension of the incubation time resulted in 1–2 dilution steps higher MIC50 values of porcine isolates for seven antimicrobial agents tested, while isolates from companion animals exhibited twofold higher MIC50/90 values only for tetracycline and cefotaxime. For three antimicrobial agents, lower MIC50 and MIC90 values were detected for both, porcine and companion animal isolates. Among the 150 isolates tested, the resistance genes bla BOR-1 (n = 147), bla OXA-2, (n = 4), strA and strB (n = 17), sul1 (n = 10), sul2 (n = 73), dfrA7 (n = 3) and tet(A) (n = 8) were detected and a plasmid localisation was identified for several of the resistance genes. PMID:26275219

Fe, Co, Ni: Electrical Resistivity Along their Melting Boundaries

NASA Astrophysics Data System (ADS)

Silber, R. E.; Ezenwa, I.; Secco, R.; Yong, W.

2017-12-01

Electrical resistivity of Fe, Co, and Ni was measured at pressures up to 11 GPa and temperatures into their liquid states in multi-anvil and cubic-anvil presses. Two thermocouples placed at opposite ends of the wire sample served as T probes as well as 4-wire resistance electrodes in a switched circuit. A polarity switch was also used to remove any bias associated with current flow and voltage measurement using thermocouple legs. Post experimental examination of recovered and sectioned samples was done using electron microprobe analyses to check for diffusion in our samples. The observed large jumps in resistivity at the high P melting T of each metal is consistent with its known P,T phase diagram and with post-run compositional analyses. The electrical resistivity behavior in these late transition metals as a function of increasing P and T shows expected trends consistent with 1atm data. Within the error of measurement, the resistivity values at the melting T at high P of Co and Ni appear to mimic their 1 atm value suggesting constant resistivity along the melting boundary. For liquid Fe, resistivity decreases along the melting boundary up to the triple point at 5.2 GPa, and then is nearly constant at higher pressures. The results are compared to prediction by Stacey and Loper (PEPI, 2007).

[Features of metabolic syndrome in patients with depressive disorder].

PubMed

Zeman, M; Jirák, R; Zák, A; Jáchymová, M; Vecka, M; Tvrzická, E; Vávrová, L; Kodydková, J; Stanková, B

2009-01-01

Depressive disorder is a serious illness with a high incidence, proxime accessit after anxiety disorders among the psychiatric diseases. It is accompanied by an increased risk of development of type 2 diabetes mellitus, cardiovascular disease, and by increased all-cause mortality. Recently published data have suggested that factors connected with the insulin resistance are at the background of this association. In this pilot study we have investigated parameters of lipid metabolism and glucose homeostasis in consecutively admitted patients suffering from depressive disorder (DD) (group of 42 people), in 57 patients with the metabolic syndrome (MetS) and in a control group of 49 apparently healthy persons (CON). Depressive patients did not differ from the control group by age or body mass index (BMI) value, but they had statistically significantly higher concentrations of serum insulin, C-peptide, glucose, triglycerides (TG), conjugated dienes in LDL particles (CD-LDL), higher value of microalbuminuria and of insulin resistance (HOMA-IR) index. They simultaneously had significantly lower value of the insulin sensitivity (QUICKI) index. In comparison with the MetS group the depressive patients were characterized by significantly lower both systolic and diastolic blood pressure, BMI , serum TG, apolipoprotein B, uric acid, C-peptide and by higher concentrations of apolipoprotein A-I and HDL-cholesterol. On the contrary, we have not found statistically significant differences between the DD and MetS groups in the concentrations of serum insulin, glucose, HOMA and QUICKI indices, in CD-LDL and MAU. In this pilot study, we have found in patients with depressive disorder certain features of metabolic syndrome, especially insulin resistance and oxidative stress.

Some Properties of Composite Panels Made from Wood Flour and Recycled Polyethylene

PubMed Central

Ozdemir, Turgay; Mengeloglu, Fatih

2008-01-01

This study investigated the effect of board type (unmodified vs. MAPE modified) on the surface quality and thickness swelling-water absorption properties of recycled high density polyethylene (HDPE) based wood plastic composites. Additionally, two commercially available coatings (cellulosic coating and polyurethane lacquer coating) were also applied to composite surfaces and their adhesion strength, abrasion and scratch resistance, and gloss values were determined. This study showed that modification of the composites with MAPE coupling agent increased the surface smoothness and reduced the water absorption and thickness swelling of the panels. Abrasion resistance of the composites was also improved through MAPE modification. Regardless of board type, higher scratch resistance and gloss values were observed for polyurethane lacquer coated samples compared to those of cellulosic varnish coated ones. Improvement of adhesion strength was also seen on SEM micrographs. PMID:19330092

Racial/ethnic differences in the influence of cultural values, alcohol resistance self-efficacy, and alcohol expectancies on risk for alcohol initiation.

PubMed

Shih, Regina A; Miles, Jeremy N V; Tucker, Joan S; Zhou, Annie J; D'Amico, Elizabeth J

2012-09-01

Prior research has reported racial/ethnic differences in the early initiation of alcohol use, suggesting that cultural values that are central to specific racial/ethnic groups may be influencing these differences. This 1-year longitudinal study examines associations between two types of cultural values, parental respect (honor for one's parents) and familism (connectedness with family), both measured at baseline, and subsequent alcohol initiation in a sample of 6,054 (approximately 49% male, 57% Hispanic, 22% Asian, 18% non-Hispanic White, and 4% non-Hispanic Black) middle school students in Southern California. We tested whether the associations of cultural values with alcohol initiation could be explained by baseline measures of alcohol resistance self-efficacy (RSE) and alcohol expectancies. We also explored whether these pathways differed by race/ethnicity. In the full sample, adolescents with higher parental respect were less likely to initiate alcohol use, an association that was partially explained by higher RSE and fewer positive alcohol expectancies. Familism was not significantly related to alcohol initiation. Comparing racial/ethnic groups, higher parental respect was protective against alcohol initiation for Whites and Asians, but not Blacks or Hispanics. There were no racial/ethnic differences in the association between familism and alcohol initiation. Results suggest that cultural values are important factors in the decision to use alcohol and these values appear to operate in part, by influencing alcohol positive expectancies and RSE. Interventions that focus on maintaining strong cultural values and building strong bonds between adolescents and their families may help reduce the risk of alcohol initiation. PsycINFO Database Record (c) 2012 APA, all rights reserved.

Electromigration in epitaxial Cu(001) lines

NASA Astrophysics Data System (ADS)

Ramanath, G.; Kim, H.; Goindi, H. S.; Frederick, M. J.; Shin, C.-S.; Goswami, R.; Petrov, I.; Greene, J. E.

2002-04-01

We report the electromigration (EM) response of single-domain epitaxial Cu(001) lines on layers of Ta, TaN, and TiN. Epitaxial Cu(001) lines on nitride layers exhibit nearly two orders of magnitude higher mean-time-to-failure (MTTF) values than those on Ta, indicating the strong influence of the underlayer. The activation energy of EM for Cu on the nitrides is ˜0.8-1.2 eV, and that of Cu on Ta is ˜0.2 eV, for 200-300 °C. Our results also indicate that the MTTF values correlate inversely to the crystal quality of the Cu layers measured by X-ray diffraction. The EM resistance of epitaxial Cu lines with different crystal quality on TaN were measured to separate the effects of interface chemistry and crystal quality. While higher quality epitaxial films reveal a higher EM resistance, the magnitude of the change is smaller than that obtained by changing the interface chemistry. Epitaxial lines exhibit more than 3-4 orders of magnitude higher MTTF than polycrystalline lines on the same underlayer. Based upon our results, we propose that the Cu/underlayer interface chemistry and presence of grain boundary diffusion play important roles in unpassivated Cu films.

Corrosion resistance of a laser spot-welded joint of NiTi wire in simulated human body fluids.

PubMed

Yan, Xiao-Jun; Yang, Da-Zhi

2006-04-01

The purpose of this study was to investigate corrosion resistance of a laser spot-welded joint of NiTi alloy wires using potentiodynamic tests in Hank's solution at different PH values and the PH 7.4 NaCl solution for different Cl- concentrations. Scanning electron microscope observations were carried out before and after potentiodynamic tests. The composition of a laser spot-welded joint and base metal were characterized by using an electron probe microanalyzer. The results of potentiodynamic tests showed that corrosion resistance of a laser spot-welded joint of NiTi alloy wire was better than that of base metal, which exhibited a little higher breakdown potential and passive range, and a little lower passive current density. Corrosion resistances of a laser spot-welded joint and base metal decreased with increasing of the Cl- concentration and PH value. The improvement of corrosion resistance of the laser spot-welded joint was due to the decrease of the surface defects and the increase of the Ti/Ni ratio. (c) 2005 Wiley Periodicals, Inc.

Association between Triglyceride to HDL-C Ratio (TG/HDL-C) and Insulin Resistance in Chinese Patients with Newly Diagnosed Type 2 Diabetes Mellitus.

PubMed

Ren, Xingxing; Chen, Zeng Ai; Zheng, Shuang; Han, Tingting; Li, Yangxue; Liu, Wei; Hu, Yaomin

2016-01-01

To explore the association between the triglyceride to HDL-C ratio (TG/HDL-C) and insulin resistance in Chinese patients with newly diagnosed type 2 diabetes mellitus. Patients with newly diagnosed type 2 diabetes mellitus (272 men and 288 women) were enrolled and divided into three groups according to TG/HDL-C tertiles. Insulin resistance was defined by homeostatic model assessment of insulin resistance (HOMA-IR). Demographic information and clinical characteristics were obtained. Spearman's correlation was used to estimate the association between TG/HDL-C and other variables. Multiple logistic regression analyses were adopted to obtain probabilities of insulin resistance. A receiver operating characteristic analysis was conducted to evaluate the ability of TG/HDL-C to discriminate insulin resistance. TG/HDL-C was associated with insulin resistance in Chinese patients with newly diagnosed T2DM (Spearman's correlation coefficient = 0.21, P < 0.01). Patients in the higher tertiles of TG/HDL-C had significantly higher HOMA-IR values than patients in the lower tertiles [T1: 2.68(1.74-3.70); T2: 2.96(2.29-4.56); T3: 3.09(2.30-4.99)]. Multiple logistic regression analysis showed that TG/HDL-C was significantly associated with HOMA-IR, and patients in the higher TG/HDL-C tertile had a higher OR than those in the lower TG/HDL-C tertile, after adjusting for multiple covariates including indices for central obesity [T1: 1; T2: 4.02(1.86-8.71); T3: 4.30(1.99-9.29)]. Following stratification of waist circumference into quartiles, the effect of TG/HDL-C on insulin resistance remained significant irrespective of waist circumference. TG/HDL-C was associated with insulin resistance independent of waist circumference. Whether it could be a surrogate marker for insulin resistance in Chinese patients with newly diagnosed type 2 diabetes mellitus still needs to be confirmed by more researches.

[Relationship between the triglyceride/high-density lipoprotein-cholesterol ratio, insulin resistance index and cardiometabolic risk factors in women with polycystic ovary syndrome].

PubMed

Roa Barrios, Marlene; Arata-Bellabarba, Gabriela; Valeri, Lenin; Velázquez-Maldonado, Elsy

2009-02-01

To evaluate the relationship between the triglyceride/high density lipoprotein cholesterol (TG/HDL-c) ratio, insulin resistance index and cardiometabolic risk factors in women with polycystic ovary syndrome (PCOS). The present crosssectional study analyzed 62 women with PCOS and 48 healthy women (control group) aged 17- 35 years old. Body mass index (BMI), waist circumference (WC) and blood pressure were registered. Plasma concentrations of glucose, insulin, triglycerides, total cholesterol and HDL-c were measured. TheTG/HDL-c ratio, homeostasis model assessment for insulin resistance (HOMA(IR)) and quantitative insulin sensitivity check index (QUICKI) were calculated. Women with PCOS showed significantly higher values of the TG/HDL-c ratio and HOMA(IR), and a significantly lower QUICKI value. These differences were related to BMI and WC, with the highest values being observed in obese patients. The 50th percentile for the TG/HDL-c ratio was 3.64; the TG/cHDL ratio was positively correlated with BMI, WC and HOMA(IR) (r=0.48, p<0.001; r=0.58, p<0.001; r=0.43, p<0.001 respectively) and was negatively correlated with the QUICKI (r=-0.51; p<0.001). Women with PCOS showed a higher frequency of fasting glucose > 100 mg/dl (10% vs 3%; p<0.05), triglycerides>150 mg/dl (55% vs 20%; p<0.05) and WC>80 cm (82.3% vs 43.8%; p<0.001). Metabolic syndrome was also more frequent in women with PCOS than in controls (31% vs 10%). The independent variable with the strongest influence on TG/HDL-c was WC (p<0.001). This cross-sectional study demonstrates that women with PCOS show significantly higher values of the TG/HDL-c ratio, which is closely related to WC and insulin resistance and sensitivity indexes (HOMA(IR), QUICKI). The TG/HDL-c ratio could be considered as a useful and practical method to identify an increased risk of cardiovascular disease in patients with PCOS.

Hanle measurements of electrodeposited Fe/GaAs spin tunnel contacts

NASA Astrophysics Data System (ADS)

Majumder, Sarmita; Hohertz, Donna; McNeil, James; SpringThorpe, Anthony; Kavanagh, Karen L.

2014-03-01

We report spin transport in electrodeposited Fe/n-GaAs tunnel diodes via three-terminal Hanle measurements. For temperatures between 20 K and 150 K, the spin resistance was up to 20 times higher than expected from theoretical calculations and 1000 times larger compared to a vacuum-deposited counterpart. This higher spin resistance was correlated with a higher contact resistance, and a higher concentration of oxygen impurities in the electrodeposited Fe film and interface, as detected via x-ray photoelectron and Auger spectroscopies, and inferred from Fe film nucleation rates. These results can be explained via a small effective tunnel-contact area of 5%, but extra spin filtering via interfacial states or magnetic oxide layers cannot be ruled out. The spin diffusion times (8.5 ± 0.4 ns to 1.8 ± 0.4 ns, for 20 K to 150 K) extracted from Lorentzian fits were in good agreement with values obtained from earlier 4-terminal Hanle measurements (7.8 ± 0.4 ns to 3.2 ± 0.4 ns, for 25 K to 77 K), both 10 times slower than reported vacuum-deposited contacts.

Estimation method of finger tapping dynamics using simple magnetic detection system

NASA Astrophysics Data System (ADS)

Kandori, Akihiko; Sano, Yuko; Miyashita, Tsuyoshi; Okada, Yoshihisa; Irokawa, Masataka; Shima, Keisuke; Tsuji, Toshio; Yokoe, Masaru; Sakoda, Saburo

2010-05-01

We have developed the simple estimation method of a finger tapping dynamics model for investigating muscle resistance and stiffness during tapping movement in normal subjects. We measured finger tapping movements of 207 normal subjects using a magnetic finger tapping detection system. Each subject tapped two fingers in time with a metronome at 1, 2, 3, 4, and 5 Hz. The velocity and acceleration values for both the closing and opening tapping data were used to estimate a finger tapping dynamics model. Using the frequency response of the ratio of acceleration to velocity of the mechanical impedance parameters, we estimated the resistance (friction coefficient) and compliance (stiffness). We found two dynamics models for the maximum open position and tap position. In the maximum open position, the extensor muscle resistance was twice as high as the flexor muscle resistance and males had a higher spring constant. In the tap position, the flexor muscle resistance was much higher than the extensor muscle resistance. This indicates that the tapping dynamics in the maximum open position are controlled by the balance of extensor and flexor muscle friction resistances and the flexor stiffness, and the flexor friction resistance is the main component in the tap position. It can be concluded that our estimation method makes it possible to understand the tapping dynamics.

Estimation method of finger tapping dynamics using simple magnetic detection system.

PubMed

Kandori, Akihiko; Sano, Yuko; Miyashita, Tsuyoshi; Okada, Yoshihisa; Irokawa, Masataka; Shima, Keisuke; Tsuji, Toshio; Yokoe, Masaru; Sakoda, Saburo

2010-05-01

We have developed the simple estimation method of a finger tapping dynamics model for investigating muscle resistance and stiffness during tapping movement in normal subjects. We measured finger tapping movements of 207 normal subjects using a magnetic finger tapping detection system. Each subject tapped two fingers in time with a metronome at 1, 2, 3, 4, and 5 Hz. The velocity and acceleration values for both the closing and opening tapping data were used to estimate a finger tapping dynamics model. Using the frequency response of the ratio of acceleration to velocity of the mechanical impedance parameters, we estimated the resistance (friction coefficient) and compliance (stiffness). We found two dynamics models for the maximum open position and tap position. In the maximum open position, the extensor muscle resistance was twice as high as the flexor muscle resistance and males had a higher spring constant. In the tap position, the flexor muscle resistance was much higher than the extensor muscle resistance. This indicates that the tapping dynamics in the maximum open position are controlled by the balance of extensor and flexor muscle friction resistances and the flexor stiffness, and the flexor friction resistance is the main component in the tap position. It can be concluded that our estimation method makes it possible to understand the tapping dynamics.

The use of genomic information increases the accuracy of breeding value predictions for sea louse (Caligus rogercresseyi) resistance in Atlantic salmon (Salmo salar).

PubMed

Correa, Katharina; Bangera, Rama; Figueroa, René; Lhorente, Jean P; Yáñez, José M

2017-01-31

Sea lice infestations caused by Caligus rogercresseyi are a main concern to the salmon farming industry due to associated economic losses. Resistance to this parasite was shown to have low to moderate genetic variation and its genetic architecture was suggested to be polygenic. The aim of this study was to compare accuracies of breeding value predictions obtained with pedigree-based best linear unbiased prediction (P-BLUP) methodology against different genomic prediction approaches: genomic BLUP (G-BLUP), Bayesian Lasso, and Bayes C. To achieve this, 2404 individuals from 118 families were measured for C. rogercresseyi count after a challenge and genotyped using 37 K single nucleotide polymorphisms. Accuracies were assessed using fivefold cross-validation and SNP densities of 0.5, 1, 5, 10, 25 and 37 K. Accuracy of genomic predictions increased with increasing SNP density and was higher than pedigree-based BLUP predictions by up to 22%. Both Bayesian and G-BLUP methods can predict breeding values with higher accuracies than pedigree-based BLUP, however, G-BLUP may be the preferred method because of reduced computation time and ease of implementation. A relatively low marker density (i.e. 10 K) is sufficient for maximal increase in accuracy when using G-BLUP or Bayesian methods for genomic prediction of C. rogercresseyi resistance in Atlantic salmon.

Variability in HOMA-IR, lipoprotein profile and selected hormones in young active men.

PubMed

Keska, Anna; Lutoslawska, Grazyna; Czajkowska, Anna; Tkaczyk, Joanna; Mazurek, Krzysztof

2013-01-01

Resistance to insulin actions is contributing to many metabolic disturbances. Such factors as age, sex, nutrition, body fat, and physical activity determine body insulin resistance. Present study attempted to asses insulin resistance and its metabolic effects with respect to energy intake in young, lean, and active men. A total of 87 men aged 18-23 participated in the study. Plasma levels of glucose, insulin, lipoproteins, cortisol, and TSH were determined. Insulin resistance was expressed as Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) and calculated using homeostatic model. The median value of HOMA-IR (1.344) was used to divide subjects into two groups. Men did not differ in anthropometric parameters, daily physical activity, and plasma TSH and cortisol levels. However, in men with higher HOMA-IR significantly lower daily energy intake was observed concomitantly with higher TG, TC, and HDL-C concentrations in plasma versus their counterparts with lower HOMA-IR. Exclusively in subjects with higher HOMA-IR significant and positive correlation was noted between HOMA-IR and TC and LDL-C. We concluded that despite a normal body weight and physical activity, a subset of young men displayed unfavorable changes in insulin sensitivity and lipid profile, probably due to insufficient energy intake.

Teaching as a Healing Craft: Decolonizing the Classroom and Creating Spaces of Hopeful Resistance through Chicano-Indigenous Pedagogical Praxis

ERIC Educational Resources Information Center

Villanueva, Silvia Toscano

2013-01-01

This paper builds upon the edict for self-determination in El Plan de Santa Barbara: a Chicano plan for higher education (1969), which calls for "strategic use of education," by placing value on needs of the community (La Causa, p. 9). For me, this passage translates into valuing needs of community-college students entering my classes…

Comparative analysis on antibiotic resistance characteristics of Listeria spp. and Enterococcus spp. isolated from laying hens and eggs in conventional and organic keeping systems in Bavaria, Germany.

PubMed

Schwaiger, K; Schmied, E-M V; Bauer, J

2010-05-01

By investigating the prevalence and antimicrobial resistance characteristics of Gram-positive bacteria from organic and conventional keeping systems of laying hens, it was to be determined to what extent these properties are influenced by the different systems. For this purpose, a total of 799 cloacal swabs and 800 egg samples were examined. Prevalences for all selected bacteria from cloacal swabs were much the same for both organic and caged birds: Listeria spp.1.3%[org] versus 1.6%[con]; Enterococcus spp. 95.5%[org] versus 97.5%[con]. Egg contents and eggshells were generally contaminated to a lesser extent, primarily with Enterococcus spp. Listeria isolates were susceptible to almost all tested antibiotics, only three Listeria innocua from conventional keepings were resistant to clindamycin; one isolate additionally to imipenem. High percentages of Enterococcus faecalis were resistant to doxycycline and macrolides. Enterococcus faecium proved to have high resistance rates to clindamycin, fosfomycin and erythromycin; 9.1% were even resistant to the reserve antibiotic synercid. Further, Enterococcus spp. showed higher resistance rates to doxycycline, erythromycin, fosfomycin and rifampicin. No glycopeptide resistant enterococci were detected. A correlation between keeping system and resistance/susceptibility rates could be demonstrated. In detail, E. faecalis from organic laying hen husbandries showed significant lower resistance prevalences to tylosin, streptomycin and doxycycline; susceptibility rates were higher for enrofloxacin and ciprofloxacin. Rifampicin and imipenem were more effective in isolates from conventional keepings (P < 0.05). The amounts of resistant isolates of the Enterococcus raffinosus from organic farms were significantly lower, the amounts of sensitive isolates were significantly higher than from conventional farms concerning eight antibiotics (P < 0.05). When comparing the susceptibility/resistance rates, as well as the mean minimum inhibitory concentrations values, the consistent tendency is that bacteria from organic layer flocks are more susceptible to antimicrobials. These results show that organic livestock farming plays a part in contributing to reduced antibiotic resistance.

RESISTANCE TO INNOVATION IN HIGHER EDUCATION, A SOCIAL PSYCHOLOGICAL EXPLORATION FOCUSED ON TELEVISION AND THE ESTABLISHMENT. THE JOSSEY-BASS SERIES IN HIGHER EDUCATION.

ERIC Educational Resources Information Center

EVANS, RICHARD I.; LEPPMANN, PETER K.

FOR THIS CASE STUDY, 80 PERCENT (319) OF THE FACULTY AT THE URBAN UNIVERSITY RETURNED A QUESTIONNAIRE DESIGNED TO IDENTIFY VALUES, PERSONALITY TRAITS, AND ATTITUDES TOWARD INSTRUCTIONAL TELEVISION (ITV) AND 14 TEACHING METHODS. AN HYPOTHESIS DERIVED FOR FUTURE RESEARCH WAS--ACCEPTANCE OF INNOVATION VARIES DIRECTLY WITH THE PERSONALITY ATTRIBUTE…

No evidence of insulin resistance in normal weight vegetarians. A case control study.

PubMed

Valachovicová, Martina; Krajcovicová-Kudlácková, Marica; Blazícek, Pavel; Babinská, Katarína

2006-02-01

Diets rich in carbohydrates with a low glycemic index and with high fiber content are associated with flat post-prandial rises of blood glucose, minimal post-prandial insulin secretion and maintenance of insulin sensitivity. Protective food commodities in the prevention of cardiovascular disease, insulin resistance syndrome or diabetes are crucial components of the vegetarian diet. Insulin resistance values were assessed in relation to different nutrition. Metabolic abnormality is a predictor of age-related diseases and can be more pronounced in obese subjects. Insulin resistance values in normal weight subjects of two different nutritional habits were correlated with age. Fasting concentrations of glucose and insulin as well as calculated values of insulin resistance IR (HOMA) were assessed in two nutritional groups of apparently healthy adult subjects (age range 19 - 64 years) with normal weight (body mass index 18.6 - 25.0 kg/m(2)): a vegetarian group (95 long-term lacto-ovo-vegetarians; duration of vegetarianism 10.2 +/- 0.5 years) and a non-vegetarian control group (107 subjects of general population on traditional western diet). Intake of energy and main nutrients (fats, saccharides, proteins) was similar in both groups. Glucose and insulin concentrations and IR (HOMA) values were significantly lower in vegetarians (glucose 4.47 +/- 0.05 vs. 4.71 +/- 0.07 mmol/l; insulin 4.96 +/- 0.23 vs. 7.32 +/- 0.41 mU/l; IR (HOMA) 0.99 +/- 0.05 vs. 1.59 +/- 0.10). IR (HOMA) dependence on age was only significant in subjects on a western diet. A significant increase of IR was found already in the age range 31-40 years, compared to vegetarians and it continued in later age decades. Age independent and low insulin resistance values in vegetarians are a consequence of an effective diet prevention by long-term frequent consumption of protective food. Vegetarians had a significantly higher consumption of whole grain products, pulses, products from oat and barley. The results of age independent and low values of insulin resistance document a beneficial effect of long-term vegetarian nutrition in prevention of metabolic syndrome, diabetes and cardiovascular disease.

Verification of B-lymphocyte activating factor's involvement in the exacerbation of insulin resistance as well as an autoimmune response in patients with nonalcoholic steatohepatitis and patients with HCV-related chronic liver disease.

PubMed

Himoto, Takashi; Fujita, Koji; Nomura, Takako; Tani, Joji; Morishita, Asahiro; Yoneyama, Hirohito; Haba, Reiji; Masaki, Tsutomu

2017-01-01

Ten to forty percent of nonalcoholic steatohepatitis (NASH) and HCV-related chronic liver disease (CLD-C) patients have antinuclear antibodies (ANAs). However, the relationship between autoimmune response and insulin resistance remains uncertain among those patients. The primary purpose of this study was to investigate whether or not ANA status was associated with the development of insulin resistance and obesity in NASH and CLD-C patients. Degrees of hepatic fibrosis and steatosis were evaluated by the classification proposed by Brunt et al. Obesity and insulin resistance were estimated by calculating body mass index and the value of homeostasis model of for assessment of insulin resistance (HOMA-IR), respectively. A revised scoring system was applied to the diagnosis of autoimmune hepatitis (AIH). Serum B-lymphocyte activating factor (BAFF) levels were determined, using an ELISA technique. Ten of 25 (40%) NASH patients and 9 of 22 (41%) CLD-C patients had ANAs, though the titers were weak in most patients. Only one NASH patient met the category of "definite" AIH among the enrolled patients. Serum IgG levels were significantly higher in NASH and CLD-C patients with ANAs than in those without ANAs, and NASH and CLD-C patients with ANAs had significantly higher HOMA-IR values than those without ANAs (6.81 ± 3.36 vs. 4.00 ± 2.57, p = 0.0305, 3.01 ± 1.31 vs. 1.28 ± 0.50, p = 0.0011). CLD-C patients with ANAs had more advanced hepatic fibrosis and steatosis than those without ANAs, while ANA status was not associated with hepatic fibrosis or steatosis in NASH patients. Obesity was independent of ANA status in both subjects. Serum BAFF levels were significantly higher in CLD-C patients with ANAs than those in CLD-C patients without ANAs (1303 ± 268 vs. 714 ± 143 pg/ml, p = 0.0036). A close correlation between serum BAFF level and the HOMA-IR value was observed in CLD-C patients (r = 0.467, p = 0.0485). Our data suggest that NASH and CLD-C patients with ANAs have more severe insulin resistance than those without ANAs. More advanced insulin resistance deriving from excessive BAFF production may result in severe hepatic fibrosis and steatosis in CLD-C patients with ANAs.

Radiation resistance of lactobacilli isolated from radurized meat relative to growth and environment.

PubMed

Hastings, J W; Holzapfel, W H; Niemand, J G

1986-10-01

Of 113 lactobacilli isolated from radurized (5 kGy) minced meat, 7 Lactobacillus sake strains, 1 L. curvatus strain, and 1 L. farciminis strain were used for radiation resistance studies in a semisynthetic substrate (i.e., modified MRS broth). Five reference Lactobacillus spp., one Staphylococcus aureus strain, and one Salmonella typhimurium strain were used for comparative purposes. All L. sake isolates exhibited the phenomenon of being more resistant to gamma-irradiation in the exponential (log) phase than in the stationary phase of their growth cycles by a factor of 28%. Four references strains also exhibited this phenomenon, with L. sake (DSM 20017) showing a 68% increase in resistance in the log phase over the stationary phase. This phenomenon was not common to all bacteria tested and is not common to all strains with high radiation resistance. Four L. sake isolates and three reference strains were used in radiation sensitivity testing in a natural food system (i.e., meat). The bacteria were irradiated in minced meat and packaged under four different conditions (air, vacuum, CO2, and N2). Organisms exhibited the highest death rate (lowest D10 values [doses required to reduce the logarithm of the bacterial population by 1] ) under CO2 packaging conditions, but resistance to irradiation was increased under N2. The D10 values of the isolates were generally greater than those of the reference strains. The D10 values were also higher (approximately two times) in meat than in semisynthetic growth medium.

Radiation resistance of lactobacilli isolated from radurized meat relative to growth and environment.

PubMed Central

Hastings, J W; Holzapfel, W H; Niemand, J G

1986-01-01

Of 113 lactobacilli isolated from radurized (5 kGy) minced meat, 7 Lactobacillus sake strains, 1 L. curvatus strain, and 1 L. farciminis strain were used for radiation resistance studies in a semisynthetic substrate (i.e., modified MRS broth). Five reference Lactobacillus spp., one Staphylococcus aureus strain, and one Salmonella typhimurium strain were used for comparative purposes. All L. sake isolates exhibited the phenomenon of being more resistant to gamma-irradiation in the exponential (log) phase than in the stationary phase of their growth cycles by a factor of 28%. Four references strains also exhibited this phenomenon, with L. sake (DSM 20017) showing a 68% increase in resistance in the log phase over the stationary phase. This phenomenon was not common to all bacteria tested and is not common to all strains with high radiation resistance. Four L. sake isolates and three reference strains were used in radiation sensitivity testing in a natural food system (i.e., meat). The bacteria were irradiated in minced meat and packaged under four different conditions (air, vacuum, CO2, and N2). Organisms exhibited the highest death rate (lowest D10 values [doses required to reduce the logarithm of the bacterial population by 1] ) under CO2 packaging conditions, but resistance to irradiation was increased under N2. The D10 values of the isolates were generally greater than those of the reference strains. The D10 values were also higher (approximately two times) in meat than in semisynthetic growth medium. PMID:3096207

Acute physiological responses to different circuit training protocols.

PubMed

Monteiro, A G; Alveno, D A; Prado, M; Monteiro, G A; Ugrinowitsch, C; Aoki, M S; Piçarro, I C

2008-12-01

The purpose of present study was to compare the acute physiological responses to a circuit weight training with the responses to a combined circuit training (weight training and treadmill run). The sample consisted of 25 individuals at an average state of training, 10 men and 15 female, between 18 and 35 year old. There were selected 60 second sets of resistance exercises to the circuit weight training (CWT). Whereas in the combined circuit training (CCT), the subjects spent 30 seconds on the same resistance exercises and 30 seconds running on the treadmill. The rest intervals between the sets lasted 15 seconds. The analysis of variance (ANOVA) with 5% significance level was utilized to the statistical analysis of the results. Comparing circuit training protocols, it was noted that CCT elicits a higher relative and absolute VO2 and energy expenditure values than CWT for both genders (P<0.05). Regarding inter-gender comparison, males showed higher absolute and relative VO2 and absolute energy expenditure values for both CWT and CCT than females (P<0.05). Females showed a significant greater %VO2max value for both CWT and CCT. Due to the experimental conditions used to state both circuit training bouts (CWT and CCT), the VO2 rate found was higher than the values reported by previous studies which used heavier weight lift. CCT seems adequate to produce cardiovascular improvements and greater energy expenditure for both men and women, while CWT group classes are sufficient only for unfit women.

Evaluation of retention and fracture resistance of different fiber reinforced posts: An in vitro study.

PubMed

Pruthi, Varun; Talwar, Sangeeta; Nawal, Ruchika Roongta; Pruthi, Preeti Jain; Choudhary, Sarika; Yadav, Seema

2018-01-01

The aim of this study was to evaluate retention & fracture resistance of different fibre posts. 90 extracted human permanent maxillary central incisors were used in this study. For retention evaluation, after obturation, post space preparation was done in all root canals and posts were cemented under three groups. Later, the posts were grasped & pulled out from the roots with the help of a three-jaw chuck at a cross-head speed of 5mm/min. Force required to dislodge each post was recorded in Newtons. To evaluate the fracture behavior of posts, artificial root canals were drilled into aluminium blocks and posts were cemented. Load required to fracture each post was recorded in Newtons. The results of the present study show the mean retention values for Fibrekleer Parallel post were significantly greater than those for Synca Double tapered post & Bioloren Tapered post. The mean retention values of the Double tapered post & the tapered post were not statistically different. The Synca Double tapered post had the highest mean load to fracture, and this value was significantly higher than those of FibreKleer Parallel & Bioloren Tapered post. The mean fracture resistance values of Parallel & tapered post were not statistically different. This study showed parallel posts to have better retention than tapered and double tapered posts. Regarding the fracture resistance, double tapered posts were found to be better than parallel and tapered posts.

The Influence of the Brain‐Derived Neurotropic Factor Val66Met ‐Genotype and HMG‐CoA Reductase Inhibitors on Insulin Resistance in the Schizophrenia and Bipolar Populations

PubMed Central

Burghardt, K.J.; Pop‐Busui, R.; Bly, M.J.; Grove, T.B.; Taylor, S.F.; Ellingrod, V.L.

2012-01-01

Abstract Introduction: The brain‐derived neurotrophic factor (BDNF) Val66Met variant and HMG‐COA reductase inhibitors (statins) have been implicated in insulin resistance with a possible increased risk of diabetes. We sought to determine the effect of the BDNF Met variant and statin medication use on insulin resistance in schizophrenia and bipolar disorder using the homeostasis model assessment of insulin resistance (HOMA‐IR). Methods: A cross‐sectional design was used and patients with diabetes or on any medications affecting glucose regulation were ‐excluded. Associations between insulin resistance and genotype were then analyzed by ANOVA and regression analysis. Subjects were grouped by BDNF genotype as well as presence of statin. Results: Two hundred fifty‐two subjects with a mean age of 44 years were included. The group was 53% male and 41% had a diagnosis of bipolar disorder; 78% and 19% were receiving atypical antipsychotics (AAPs) and statin medications, respectively. Analysis showed schizophrenia subjects with the BDNF met allele as well as schizophrenia subjects with both the BDNF met allele and were receiving a statin had significantly higher HOMA‐IR values compared to the other groups (p= 0.046 and p= 0.016, respectively). Conclusions: Our results suggest that in the metabolically high‐risk population of schizophrenia the BDNF met allele alone and in combination with statin medications is associated with higher insulin resistance values. This was not seen in the bipolar population. Further validation of these associations remains necessary. Clin Trans Sci 2012; Volume 5: 486–490 PMID:23253673

[Field resistance of Phytophthora melonis to metalaxyl in South China].

PubMed

Wu, Yongguan; Lu, Shaofeng; Huang, Siliang; Fu, Gang; Chen, Liang; Xie, Dasen; Li, Qiqin; Cen, Zhenlu

2011-08-01

Phytophthora melonis is the casual agent of wax gourd and cucumber Phytophthora blight which becomes a constraint for sustainable production of the related crops. Metalaxyl is one of the principal fungicides for controlling the disease now. The objectives of the present study were: (1) to investigate the baseline sensitivity and field resistance of P. melonis to metalaxyl in South China; (2) to test the occurrence of metalaxyl-resistant mutants from metalaxyl-sensitive wild type strains exposed to the fungicide; and (3) to monitor the development of metalaxyl resistance in P. melonis population. Over 400 samples of wax gourd and cucumber Phytophthora blight were collected from Guangxi Zhuang Autonomous Region and Guangdong province during 2007-2010, and 193 strains of P. melonis were isolated and purified. The sensitivity of the isolated strains to metalaxyl was tested using mycelial growth rate method in vitro and floating-leaf-disk method in vivo, respectively. The metalaxyl-sensitive strains were induced on PDA plates containing 10 microg/mL metalaxyl. The sensitive, moderately resistant and resistant strains were recorded as 29.0% , 18.1% and 52.8%, respectively, among 193 tested strains. The frequency and level of resistance of P. melonis from Guangdong were higher than that from Guangxi. The strains from cucumber was generally more resistant to metalaxyl than those from wax gourd. The metalaxyl-resistant strains were frequently detected as predominant populations in most of the sampling sites and the highest resistance index (4226.9) was confirmed. Metalaxyl-resistant (M1r) mutants could be isolated from approximately 60% of the sensitive wild-type strains. The resistance level of the M mutants was 189-407 times higher than that of their sensitive parental strains. The EC50 values of 9 sensitive strains from a sampling site without a record of phenylamide fungicide application ranged from 0.0429 to 0.5461 microg/mL. Their mean EC50 value (0.3200 +/- 0.1617 microg/mL) was considered as the baseline sensitivity of P. melonis to metalaxyl in South China. Metalaxyl-resistant strains universally occur in South China, especially in the vegetable-growing areas with a longer history of metalaxyl application. The establishment of the baseline sensitivity of P. melonis to metalaxyl will provide a science-based guide for evaluating and further monitoring resistance of the pathogen to the fungicide.

The association between cardiovascular risk factors and anthropometric obesity indicators in university students in São Luís in the State of Maranhão, Brazil.

PubMed

de Carvalho, Carolina Abreu; Fonseca, Poliana Cristina de Almeida; Barbosa, José Bonifácio; Machado, Soraia Pinheiro; dos Santos, Alcione Miranda; da Silva, Antonio Augusto Moura

2015-02-01

The article aims to evaluate the relation between cardiovascular risk factors (CVRF) and anthropometric indicators in a sample of university students from São Luís-MA, Brazil. It is a cross-sectional study conducted with 968 university students, with median age of 22. Glycemia, triglycerides, HDL-c, smoking, alcohol consumption, physical inactivity, metabolic syndrome (Joint Interim Statement criteria) and insulin resistance (IR), were associated and correlated with anthropometric indicators such as BMI, WC, WHR and WHtR. Associations were found between TGL, SH, SM and higher values of all anthropometric variables. The RI was associated with higher BMI values and WHtR in men and women. The low HDL-c was associated with higher values of all anthropometric variables in women. Consumption of alcohol was associated with higher values of BMI and WC in women and WHR in men and WHtR. Smoking was associated with higher values of WHtR in both sexes. Physical inactivity was associated with higher values of WHR in men only. The highest correlations were established for women between TGL and BMI CC, WHR and WHtR. The indicators most associated with CVRF were BMI, WC and WHtR in females and WHR and WHtR in men.

[Research on Resistant Starch Content of Rice Grain Based on NIR Spectroscopy Model].

PubMed

Luo, Xi; Wu, Fang-xi; Xie, Hong-guang; Zhu, Yong-sheng; Zhang, Jian-fu; Xie, Hua-an

2016-03-01

A new method based on near-infrared reflectance spectroscopy (NIRS) analysis was explored to determine the content of rice-resistant starch instead of common chemical method which took long time was high-cost. First of all, we collected 62 spectral data which have big differences in terms of resistant starch content of rice, and then the spectral data and detected chemical values are imported chemometrics software. After that a near-infrared spectroscopy calibration model for rice-resistant starch content was constructed with partial least squares (PLS) method. Results are as follows: In respect of internal cross validation, the coefficient of determination (R2) of untreated, pretreatment with MSC+1thD, pretreatment with 1thD+SNV were 0.920 2, 0.967 0 and 0.976 7 respectively. Root mean square error of prediction (RMSEP) were 1.533 7, 1.011 2 and 0.837 1 respectively. In respect of external validation, the coefficient of determination (R2) of untreated, pretreatment with MSC+ 1thD, pretreatment with 1thD+SNV were 0.805, 0.976 and 0.992 respectively. The average absolute error was 1.456, 0.818, 0.515 respectively. There was no significant difference between chemical and predicted values (Turkey multiple comparison), so we think near infrared spectrum analysis is more feasible than chemical measurement. Among the different pretreatment, the first derivation and standard normal variate (1thD+SNV) have higher coefficient of determination (R2) and lower error value whether in internal validation and external validation. In other words, the calibration model has higher precision and less error by pretreatment with 1thD+SNV.

Normal adiponectin levels despite abnormal glucose tolerance (or diabetes) and inflammation in adult patients with cystic fibrosis.

PubMed

Hammana, I; Malet, A; Costa, M; Brochiero, E; Berthiaume, Y; Potvin, S; Chiasson, J-L; Coderre, L; Rabasa-Lhoret, R

2007-06-01

Circulating adiponectin levels are negatively associated with glucose intolerance, inflammation and central adiposity. Since these conditions are common in cystic fibrosis (CF), we examined whether adiponectin values are altered in these patients. To determine if CF patients have altered adiponectin levels and if these levels correlate with glucose tolerance categories (normal, impaired glucose tolerance (IGT) and cystic fibrosis-related diabetes (CFRD)), insulin resistance or inflammatory markers such as fibrinogen and C-reactive protein (CRP). Oral glucose tolerance tests (OGTTs) were performed and adiponectin levels were measured in 90 CF patients not known to be diabetic and 15 healthy controls matched for age, sex and body mass index (BMI). Inflammatory markers, serum albumin concentrations and the clinical status of CF patients (i.e. pulmonary function) were also examined. CF pathology was characterized by a high prevalence (43.5%) of glucose tolerance abnormalities: 26.5% of IGT and 17.0% of newly diagnosed CFRD. CF patients also presented systemic inflammation as revealed by a significant increase of fibrinogen (P=0.029) in all patients and higher CRP levels in CFRD patients compared to the controls (P<0.05). On the other hand, CF and control subjects had similar albumin serum concentration. While CF patients and controls had similar serum adiponectin values, women had significantly higher hormone levels than men (P<0.001). Adiponectin levels did not correlate with glucose tolerance, inflammatory markers or insulin resistance. On the other hand, they correlated positively with both total and HDL-cholesterol (P<0.001). CF patients did not show any alterations in adiponectin levels despite insulin resistance, glucose intolerance and sub clinical chronic inflammation. Thus, CF appears to be one of the rare conditions in which discordance between adiponectin values and insulin resistance or inflammation is evident.

The structure and physical-mechanical properties of the heat-resistant Ni-Co-Cr-Al-Y intermetallic coating obtained using rebuilt plasma equipment

NASA Astrophysics Data System (ADS)

Tarasenko, Yu. P.; Tsareva, I. N.; Berdnik, O. B.; Fel, Ya. A.; Kuzmin, V. I.; Mikhalchenko, A. A.; Kartaev, E. V.

2014-12-01

Results of a study of the structure, physico-mechanical properties, and the resistance to heat of Ni-Co-Cr-Al-Y intermetallic coatings obtained by powder spraying on the standard UPU-3D plasma spray facility (plasmatron with self-establishing arc length) and on the rebuilt facility equipped with the enhanced-power PNK-50 plasmatron with sectionalized inter-electrode insert, are reported. Coatings of higher density ( ρ = 7.9 g/cm3) and higher microhardness (H μ = 770 kg-force/mm2) with lower porosity values ( P = 5.7 %, P c = 5.1 %, and P 0 = 0.6 %) and high resistance to heat ((M - M0)/M0 = 1.2) were obtained. The developed coating is intended for protection of the working surfaces of turbine engine blades in gas-turbine power plants.

Synthesis and electrical behavior of Ni-Ti substituted Y-type hexaferrites for high frequency application

NASA Astrophysics Data System (ADS)

Ahmad, Bashir; Ashiq, Muhammad Naeem; Mumtaz, Saleem; Ali, Irshad; Najam-Ul-Haq, Muhmmad; Sadiq, Imran

2018-04-01

This article reports the fabrication of Ni-Ti doped derivatives of Sr2Co2Fe12-2xO22 by economical Sol-gel method. At room temperature X-ray diffraction (XRD) pattern of powder was obtained after sintering at 1050 °C. The XRD analysis revealed the formation of pure Sr-Y hexaferrite phase. It was found that the observed values of dielectric parameters decreased with increasing Ni-Ti substitution. The higher values of dielectric constants and dielectric loss factor at lower frequency were owing to surface charge polarization. In all the samples the resonance peaks were also observed. The observed room temperature DC electrical resistivity found to increase from 1.8x106 to 4.9x109 ohm cm. The observed activation energies values of the fabricated materials are found in 0.52-0.82 eV range. The decrease in dielectric parameters and increase in resistivity of the fabricated samples with substituents suggest these materials have worth application in micro-wave devices as such devices required highly resistive materials.

[Application value of Xpert MTB/RIF in diagnosis of spinal tuberculosis and detection of rifampin resistance].

PubMed

Jin, Yang-Hui; Shi, Shi-Yuan; Zheng, Qi; Shen, Jian; Ying, Xiao-Zhang; Wang, Yi-Fan

2017-09-25

To investigate the application value of Xpert MTB/RIF in diagnosis of spinal tuberculosis and detection of rifampin resistance. The 109 pus specimens were obtained from patients who were primaryly diagnosed as spinal tuberculosis. All of the pus specimens were detected by acid-fast stain, liquid fast culturing by BACTEC MGIT 960 and Xpert MTB/RIF assay to definite the differences in sensitivity and specificity of mycobacterium tuberculosis among detecting methods. Pus specimens obtained by different methods were deteceded by MTB/RIF test to analyze the self-influence on Xpert MTB/RIF test. The result of liquid fast culturing by BACTEC MGIT 960 was used as the gold standard; and the value of Xpert MTB/RIF assay in detecting rifampin resistance was analyzed. The sensitivity of acid-fast stain, liquid fast culturing by BACTEC MGIT 960 and Xpert MTB/RIF assay were 25.92%, 48.15%, 77.78%, respectively. The sensitivity of pus specimens obtained from open surgery, ultrasound positioning puncture and biopsy the sensitivity were 83.78%, 76.47%, 44.68% respectively deteceded by MTB/RIF test. According to the gold standard of the results of liquid fast culturing by BACTEC MGIT 960 assay, the sensitivity and specificity of Xpert MTB/RIF assay in detecting rifampin resistance were 80%(4/5) and 90.70%(39/43), respectively. Xpert MTB/RIF assay has higher value in diagnosis of spinal tuberculosi, and also can detect rifampin resistance. The number of mycobacterium tuberculosis in pus specimens has a great influence in the sensitivity of Xpert MTB/RIF assay.

Measurement of volume resistivity/conductivity of metallic alloy in inhibited seawater by optical interferometry techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Habib, K.

2011-03-15

Optical interferometry techniques were used for the first time to measure the volume resistivity/conductivity of carbon steel samples in seawater with different concentrations of a corrosion inhibitor. In this investigation, the real-time holographic interferometry was carried out to measure the thickness of anodic dissolved layer or the total thickness, U{sub total}, of formed oxide layer of carbon steel samples during the alternating current (ac) impedance of the samples in blank seawater and in 5-20 ppm TROS C-70 inhibited seawater, respectively. In addition, a mathematical model was derived in order to correlate between the ac impedance (resistance) and the surface (orthogonal)more » displacement of the surface of the samples in solutions. In other words, a proportionality constant [resistivity ({rho}) or conductivity ({sigma})= 1/{rho}] between the determined ac impedance [by electrochemical impedance spectroscopy (EIS) technique] and the orthogonal displacement (by the optical interferometry techniques) was obtained. The value of the resistivity of the carbon steel sample in the blank seawater was found similar to the value of the resistivity of the carbon steel sample air, around 1 x 10{sup -5}{Omega} cm. On the contrary, the measured values of the resistivity of the carbon steel samples were 1.85 x 10{sup 7}, 3.35 x 10{sup 7}, and 1.7 x 10{sup 7}{Omega} cm in 5, 10, and 20 ppm TROS C-70 inhibited seawater solutions, respectively. Furthermore, the determined value range of {rho} of the formed oxide layers, from 1.7 x 10{sup 7} to 3.35 x 10{sup 7}{Omega} cm, is found in a reasonable agreement with the one found in literature for the Fe oxide-hydroxides, i.e., goethite ({alpha}-FeOOH) and for the lepidocrocite ({gamma}-FeOOH), 1 x 10{sup 9}{Omega} cm. The {rho} value of the Fe oxide-hydroxides, 1 x 10{sup 9}{Omega} cm, was found slightly higher than the {rho} value range of the formed oxide layer of the present study. This is because the former value was determined by a dc method rather than by an electromagnetic method, i.e., holographic interferometry with applications of EIS, i.e., ac method. As a result, erroneous measurements were recorded due to the introduction of heat to Fe oxide-hydroxides.« less

Waist circumference and insulin resistance: a cross-sectional study of Japanese men

PubMed Central

Tabata, Shinji; Yoshimitsu, Shinichiro; Hamachi, Tadamichi; Abe, Hiroshi; Ohnaka, Keizo; Kono, Suminori

2009-01-01

Background Visceral obesity is positively related to insulin resistance. The nature of the relationship between waist circumference and insulin resistance has not been known in Japanese populations. This study examined the relationship between waist circumference and insulin resistance and evaluated the optimal cutoff point for waist circumference in relation to insulin resistance in middle-aged Japanese men. Methods Study subjects included 4800 Japanese men aged 39 to 60 years. Insulin resistance was evaluated by the homeostasis model assessment of insulin resistance (HOMA-IR). The relationship of waist circumference with HOMA-IR was assessed by use of adjusted means of HOMA-IR and odds ratios of elevated HOMA-IR defined as the highest quintile (≥2.00). Receiver operating characteristics (ROC) curve analysis using Youden index and the area under curve (AUC) was employed to determine optimal cutoffs of waist circumference in relation to HOMA-IR. Results Adjusted geometric means of HOMA-IR and prevalence odds of elevated HOMA-IR were progressively higher with increasing levels of waist circumference. In the ROC curve analysis, the highest value of Youden index was obtained for a cutoff point of 85 cm in waist circumference across different values of HOMA-IR. Multiple logistic regression analysis also indicated that the AUC was consistently the largest for a waist circumference of 85 cm. Conclusion Waist circumference is linearly related to insulin resistance, and 85 cm in waist circumference is an optimal cutoff in predicting insulin resistance in middle-aged Japanese men. PMID:19138424

Solid-State Thermionic Power Generators: An Analytical Analysis in the Nonlinear Regime

NASA Astrophysics Data System (ADS)

Zebarjadi, M.

2017-07-01

Solid-state thermionic power generators are an alternative to thermoelectric modules. In this paper, we develop an analytical model to investigate the performance of these generators in the nonlinear regime. We identify dimensionless parameters determining their performance and provide measures to estimate an acceptable range of thermal and electrical resistances of thermionic generators. We find the relation between the optimum load resistance and the internal resistance and suggest guidelines for the design of thermionic power generators. Finally, we show that in the nonlinear regime, thermionic power generators can have efficiency values higher than the state-of-the-art thermoelectric modules.

[Investigation of in vitro metronidazole resistance in the clinical isolates of Trichomonas vaginalis].

PubMed

Ertabaklar, Hatice; Yaman Karadam, Senem; Malatyalı, Erdoğan; Ertuğ, Sema

2016-10-01

Trichomonas vaginalis, a flagellated, urogenital anaerobic protozoon is reported as an important cause of vaginitis with a global distribution. Although metronidazole is the primary choice of drug for the treatment of trichomoniasis, the presence of resistant isolates from many different countries highlights the need of novel drugs for the treatment. Many studies from Turkey mostly dealing with the in vitro effects of compounds and natural products against T.vaginalis have been reported, however, only one study has been encountered searching the metronidazole resistance in a single T.vaginalis isolate. The aim of this study was to determine the in vitro metronidazole resistance and minimum lethal concentrations (MLCs) of the isolates from symptomatic cases. T.vaginalis strains isolated from vaginal discharge samples of symptomatic women that were sent to Adnan Menderes University Faculty of Medicine, Research and Training Hospital Parasitology Laboratory, between 2009-2014 period, were included in the study. The strains were isolated by the inoculation of samples into trypticase-yeast-maltose medium supplemented with 10% fetal calf serum. A total of 40 T.vaginalis isolates stored by cryopreservation were revived before the experiments. T.vaginalis trophozoites were incubated with different concentrations of metronidazole (200, 100, 50, 25, 12.5, 6.25, 3.12, 1.56 μg/ml) and the viability of cells were examined in both aerobic and anaerobic conditions under phase contrast microscope. Additionally, non-motile isolates were further inoculated into fresh media and viability was checked. The wells containing motile trophozoites after 48 hours of incubation with 15 µg/ml and/or higher metronidazole concentration in anaerobic condition and 75 µg/ml and/or higher metronidazole concentration in aerobic conditions were determined as resistant isolates. Of the 40 T.vaginalis isolates three (7.5%) were resistant to metronidazole. MLC mean values of metronidazole-sensitive isolates were 27.17 µg/ml in aerobic and 7.75 µg/ml in anaerobic conditions. The rate of metronidazole resistance detected in this study was higher than most of reports from different countries. Despite being limited to the isolates from Aydin province (located at Agean region of Turkey), the present study has a value as it presented the existence of metronidazole-resistant isolates in Turkey for the first time. More research from other parts of Turkey is needed to better understand the metronidazole resistance at a national scale and to investigate novel strategies for the treatment. Moreover, further studies need to be carried out in order to clarify the relationship between clinical treatment response and in vitro metronidazole resistance in trichomoniasis.

Responses of striped stem borer, Chilo suppressalis (Lepidoptera: Pyralidae), from Taiwan to a range of insecticides.

PubMed

Cheng, Xuan; Chang, Cheng; Dai, Shu-Mei

2010-07-01

Information on the insecticide susceptibility of striped stem borer, Chilo suppressalis (Walker), is essential for an effective pest management programme. An early detection of resistance development can prompt the modification of current control methods and increase the lifespan of insecticides through the rotation of chemicals with different modes of action. In this study, the susceptibility of this pest in Taiwan to four classes of insecticides has been examined. Over 1000-fold resistance to carbofuran was detected in C. suppressalis collected from Chiayi and Changhua prefectures, with estimated LC(50) values of > 3 mg cm(-2). In addition, 61-fold resistance to cartap was found in the Chiayi population. On the other hand, all tested populations of rice stem borer were still relatively susceptible to chlorpyrifos, fipronil and permethrin, with LC(50) values ranging from 30 to 553 ng cm(-2). Chilo suppressalis populations collected from the central parts of Taiwan have a higher degree of resistance to the tested insecticides than those from northern areas. The occurrence of high resistance to carbofuran in the Chiayi and Changhua areas suggests that this compound should be replaced with chemicals having a different mode of action, such as chlorpyrifos, fipronil and permethrin, to which low cross-resistance has been detected. Copyright (c) 2010 Society of Chemical Industry.

Influence of electrical coupling on early afterdepolarizations in ventricular myocytes.

PubMed

Saiz, J; Ferrero, J M; Monserrat, M; Ferrero, J M; Thakor, N V

1999-02-01

Computer modeling is used to study the effect of electrical coupling between a myocardial zone where early afterdepolarizations (EAD's) can develop and the normal neighboring tissue. The effects of such coupling on EAD development and on the likelihood of EAD propagation as an ectopic beat are studied. The influence on EAD formation is investigated by approximating two partially coupled myocardial zones modeled as two active elements coupled by a junctional resistance R. For R values lower than 800 omega cm2, the action potentials are transmitted to the coupled element, and for R values higher than 850 omega cm2 they are blocked. In both ranges of R, when the electrical coupling increases, the EAD's appear at more negative takeoff potentials with higher amplitudes and upstrokes. The EAD's are not elicited if the electrical coupling is too high. In a separate model of two one-dimensional cardiac fiber segments partially coupled by a resistance R, critical R values exist, between 42 and 54 omega cm2, that facilitate EAD propagation. These results demonstrate that in myocardial zones favorable to the formation of EAD, the electrical coupling dramatically affects initiation of EAD and its spread to the neighboring tissue.

Essential oil optimizes the susceptibility of Callosobruchus maculatus and enhances the nutritional qualities of stored cowpea Vigna unguiculata.

PubMed

Akami, Mazarin; Chakira, Hamada; Andongma, Awawing A; Khaeso, Kanjana; Gbaye, Olajire A; Nicolas, Njintang Y; Nukenine, E-N; Niu, Chang-Ying

2017-08-01

The intensive use of synthetic pesticides in cowpea storage has led to the development of resistance by Callosobruchus maculatus and subsequent degradation of grain quality. In an attempt to circumvent these constraints, the susceptibility of C. maculatus to 2,2-dichlorovinyldimethyl phosphate (DDVP) and Lippia adoensis essential oil (EO) was investigated and variations in the proportions of nutritional values of treated grains 150 days after storage were assessed. The survival rate was recorded after five generations. The resistance index and biochemical parameters of grains were determined. The results from this study revealed that the survival rate and resistance index significantly increased proportionally with damage in DDVP treatments ( r  = 0.889; p  = 0.018) while in EO treatments, those values remained low without significant variations ( p  = 0.0764) throughout the generations. DDVP stored grains yielded higher crude protein values, but lower carbohydrates, tannins, phenolics and minerals compared to EO. Eighteen amino acids were detected in EO treated grains and 14 in DDVP which was devoid of albumin and prolamin. Lippia adoensis EO could therefore represent a safe alternative bio-pesticide to cope with insect resistance and enhance the nutritional qualities of stored cowpea seeds.

Essential oil optimizes the susceptibility of Callosobruchus maculatus and enhances the nutritional qualities of stored cowpea Vigna unguiculata

PubMed Central

Chakira, Hamada; Andongma, Awawing A.; Khaeso, Kanjana; Gbaye, Olajire A.; Nicolas, Njintang Y.; Nukenine, E.-N.; Niu, Chang-Ying

2017-01-01

The intensive use of synthetic pesticides in cowpea storage has led to the development of resistance by Callosobruchus maculatus and subsequent degradation of grain quality. In an attempt to circumvent these constraints, the susceptibility of C. maculatus to 2,2-dichlorovinyldimethyl phosphate (DDVP) and Lippia adoensis essential oil (EO) was investigated and variations in the proportions of nutritional values of treated grains 150 days after storage were assessed. The survival rate was recorded after five generations. The resistance index and biochemical parameters of grains were determined. The results from this study revealed that the survival rate and resistance index significantly increased proportionally with damage in DDVP treatments (r = 0.889; p = 0.018) while in EO treatments, those values remained low without significant variations (p = 0.0764) throughout the generations. DDVP stored grains yielded higher crude protein values, but lower carbohydrates, tannins, phenolics and minerals compared to EO. Eighteen amino acids were detected in EO treated grains and 14 in DDVP which was devoid of albumin and prolamin. Lippia adoensis EO could therefore represent a safe alternative bio-pesticide to cope with insect resistance and enhance the nutritional qualities of stored cowpea seeds. PMID:28879012

Geothermal Exploration By Using Time Domain IP Method:Balikesir (Gure) And Canakkale (Geyikli) Cases From Turkey

NASA Astrophysics Data System (ADS)

Tezel, O.; Ozcep, F.

2017-12-01

Geothermal energy is heat derived from the earth. It is the thermal energy contained in the rock and fluid (that fills the fractures and pores within the rock) in the earth's crust. These resources are always at a temperature higher than 20°C. Geothermal energy requires no fuel, and is therefore virtually emission free and independent of fluctuations in fuel cost. Since a geothermal power plant doesn't rely on transient sources of energy, unlike, for example, wind turbines or solar panels, its capacity factor can be quite large. Induced polarization (IP) results at geothermal regions show prominent, extended low resistivity zones. Environmental-IP methods can assist in the assessment of the acid generating potential of waste rock and tailings from mine operations. Resistivity can be used to map contamination plumes. Resistivity and chargeability values were determined using the IP method on geothermal resources in Balikesir Güre (Turkey). In this study we found low resistance values and high chargeability values at the geothermal resource. Finally drilling and IP results were correlated to verify our findings. After the positive results of obtained data, a similar study was carried out in Geyikli Area (Canakkale) and a geothermal resource with 450C temperature of 5 lt/sec was explored at a depth of 970 m.

The impact of insulin resistance on clinical, hormonal and metabolic parameters in lean women with polycystic ovary syndrome.

PubMed

Yildizhan, Begum; Anik Ilhan, Gokce; Pekin, Tanju

2016-10-01

This study was performed to assess insulin resistance (IR) in lean women with polycystic ovary syndrome (PCOS). Retrospective analysis of 100 consecutive lean (body mass index <25 kg/m 2 ) PCOS subjects was performed. Subjects were divided into two groups according to homeostasis model assessment IR index (HOMA-IR), as IR + and IR-. A HOMA-IR value >2.5 was used to indicate IR. A total of 100 lean PCOS subjects were enrolled in the study, of which 47% were insulin resistant. Comparison of group means showed significantly higher values for waist-to-hip ratio (WHR), diastolic blood pressure and Ferriman-Gallwey score (FGS) in IR + group. HOMA-IR values were found to be positively correlated with WHR (r = 0.500, p < 0.01), systolic blood pressure (r = 0.265, p < 0.01), diastolic blood pressure (r = 0.273, p < 0.01), estradiol levels (r = 0.218, p < 0.05), FGS (r = 0.456, p < 0.01) and total testosterone levels (r = 0.291, p < 0.01). When evaluating PCOS subjects, the insulin resistant group should be separated as unique and IR should also be evaluated in lean women with PCOS.

Slower phloem transport in gymnosperm trees can be attributed to higher sieve element resistance.

PubMed

Liesche, Johannes; Windt, Carel; Bohr, Tomas; Schulz, Alexander; Jensen, Kaare H

2015-04-01

In trees, carbohydrates produced in photosynthesizing leaves are transported to roots and other sink organs over distances of up to 100 m inside a specialized transport tissue, the phloem. Angiosperm and gymnosperm trees have a fundamentally different phloem anatomy with respect to cell size, shape and connectivity. Whether these differences have an effect on the physiology of carbohydrate transport, however, is not clear. A meta-analysis of the experimental data on phloem transport speed in trees yielded average speeds of 56 cm h(-1) for angiosperm trees and 22 cm h(-1) for gymnosperm trees. Similar values resulted from theoretical modeling using a simple transport resistance model. Analysis of the model parameters clearly identified sieve element (SE) anatomy as the main factor for the significantly slower carbohydrate transport speed inside the phloem in gymnosperm compared with angiosperm trees. In order to investigate the influence of SE anatomy on the hydraulic resistance, anatomical data on SEs and sieve pores were collected by transmission electron microscopy analysis and from the literature for 18 tree species. Calculations showed that the hydraulic resistance is significantly higher in the gymnosperm than in angiosperm trees. The higher resistance is only partially offset by the considerably longer SEs of gymnosperms. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Association between insulin resistance and risk of complications in children and adolescents with type 1 diabetes.

PubMed

Krochik, Andrea G; Botto, Marianela; Bravo, Mónica; Hepner, Mirta; Frontroth, Juan P; Miranda, Miguel; Mazza, Carmen

2015-01-01

It has been hypothesized that insulin resistance may be involved in the development of type 1 diabetes complications and early diagnosis would be important for their prevention. Our aim was to study insulin resistance in our population of children with type 1 diabetes and to identify associated early risk factors for micro- and macrovascular complications. A descriptive, cross-sectional study was conducted including 150 children with type 1 diabetes. Anthropometric, bioelectric impedance, carotid Doppler ultrasonography, electromyography, and conduction velocity studies were performed. Baseline plasma glucose, lipid profile, uric acid, plasma thyrotropin, glycosylated hemoglobin A1C, and microalbuminuria were assessed. More insulin-resistant patients were defined as those having an estimated glucose disposal rate (eGDR) value below the first quartile. Clinically manifest microvascular complications were not found in any of the patients. More insulin-resistant patients had a greater sub scapular fold thickness, a higher incidence of obesity (12% vs. 1.7% p 0.007), higher fructosamine levels (496 vs. 403 p<0.00019, and a higher incidence of altered lipid metabolism (70% vs. 39% p 0.0007). In the subgroup of patients with lower eGDR there were more children with lipid disorders, obesity, and worse diabetic control, which, if not corrected, may lead to development of micro- and macrovascular complications. Copyright © 2014 Diabetes India. Published by Elsevier Ltd. All rights reserved.

Different fatigue-resistant leg muscles and EMG response during whole-body vibration.

PubMed

Simsek, Deniz

2017-12-01

The purpose of this study was to determine the effects of static whole-body vibration (WBV) on the Electromyograhic (EMG) responses of leg muscles, which are fatigue-resistant in different manner. The study population was divided into two groups according to the values obtained by the Fatigue Index [Group I: Less Fatigue Resistant (LFR), n=11; Group II: More Fatigue Resistant (MFR), n=11]. The repeated electromyographic (EMG) activities of four leg muscles were analyzed the following determinants: (1) frequency (30 Hz, 35 Hz and 40 Hz); (2) stance position (static squat position); (3) amplitude (2 mm and 4 mm) and (4) knee flexion angle (120°), (5) vertical vibration platform. Vibration data were analyzed using Minitab 16 (Minitab Ltd, State College, PA, USA). The significance level was set at p<.05. The study results showed that static WBV stimuli given at different frequencies and amplitudes resulted in a significant increase (p<.05) in compared, the LFR group showed significantly (1) higher rates of quadriceps femoris and hamstring muscle fatigue (p<.05), (2) higher levels of knee extensor and flexor torque (p<.05) and (3) higher percentage increases in EMG activation at higher frequencies (max at 40 Hz) and amplitudes (4 mm) (p<.05). The present study can be used for the optimal prescription of vibration exercise and can serve to guide the development of training programs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of cooking methods on selected physicochemical and nutritional properties of barlotto bean, chickpea, faba bean, and white kidney bean.

PubMed

Güzel, Demet; Sayar, Sedat

2012-02-01

The effects of atmospheric pressure cooking (APC) and high-pressure cooking (HPC) on the physicochemical and nutritional properties of barlotto bean, chickpea, faba bean, and white kidney bean were investigated. The hardness of the legumes cooked by APC or HPC were not statistically different (P > 0.05). APC resulted in higher percentage of seed coat splits than HPC. Both cooking methods decreased Hunter "L" value significantly (P < 0.05). The "a" and "b" values of dark-colored seeds decreased after cooking, while these values tended to increase for the light-colored seeds. The total amounts of solid lost from legume seeds were higher after HPC compared with APC. Rapidly digestible starch (RDS) percentages increased considerably after both cooking methods. High pressure cooked legumes resulted in higher levels of resistant starch (RS) but lower levels of slowly digestible starch (SDS) than the atmospheric pressure cooked legumes.

In vitro assessment of competency for different lingual brackets in sliding mechanics.

PubMed

Lalithapriya, S; Kumaran, N Kurunji; Rajasigamani, K

2015-01-01

To determine the static frictional resistance of different lingual brackets at different second order angulations when coupled with stainless steel (SS) archwire in dry and wet conditions. Using a modified jig, frictional resistance was evaluated under different conditions for a total of 270 upper premolar lingual brackets (0.018″ × 0.025″ - conventional - 7(th) generation and STb, self-ligating - evolution) with no in-built tip or torque together with 0.016″ × 0.022″ straight length SS archwires. For conventional brackets, the archwire was secured with 0.008″ preformed SS short ligature ties. One way analysis of variance with Tukey HSD as post-hoc test was applied for degree wise and bracket wise comparison within dry condition and wet condition. For pair wise comparison Student's t-test was used. Under both conditions the static frictional resistance is significantly higher for self-ligating brackets at 0°, while at 5° and 10° it is higher for 7(th) generation brackets. Statistically, significant difference does not exist at 0° between conventional brackets and the same was found at 5° and 10° between STb and self-ligating brackets. With an increase in second order angulations, all the evaluated samples exhibited an increased frictional value. Wet condition samples obtained a higher value than their corresponding dry condition. The self-ligating bracket evaluated in this in vitro study is not beneficial in reducing friction during en-mass retraction due to its interactive clip type.

Association between Triglyceride to HDL-C Ratio (TG/HDL-C) and Insulin Resistance in Chinese Patients with Newly Diagnosed Type 2 Diabetes Mellitus

PubMed Central

Ren, Xingxing; Chen, Zeng.ai; Zheng, Shuang; Han, Tingting; Li, Yangxue; Liu, Wei; Hu, Yaomin

2016-01-01

Objectives To explore the association between the triglyceride to HDL-C ratio (TG/HDL-C) and insulin resistance in Chinese patients with newly diagnosed type 2 diabetes mellitus. Methods Patients with newly diagnosed type 2 diabetes mellitus (272 men and 288 women) were enrolled and divided into three groups according to TG/HDL-C tertiles. Insulin resistance was defined by homeostatic model assessment of insulin resistance (HOMA-IR). Demographic information and clinical characteristics were obtained. Spearman’s correlation was used to estimate the association between TG/HDL-C and other variables. Multiple logistic regression analyses were adopted to obtain probabilities of insulin resistance. A receiver operating characteristic analysis was conducted to evaluate the ability of TG/HDL-C to discriminate insulin resistance. Results TG/HDL-C was associated with insulin resistance in Chinese patients with newly diagnosed T2DM (Spearman’s correlation coefficient = 0.21, P < 0.01). Patients in the higher tertiles of TG/HDL-C had significantly higher HOMA-IR values than patients in the lower tertiles [T1: 2.68(1.74–3.70); T2: 2.96(2.29–4.56); T3: 3.09(2.30–4.99)]. Multiple logistic regression analysis showed that TG/HDL-C was significantly associated with HOMA-IR, and patients in the higher TG/HDL-C tertile had a higher OR than those in the lower TG/HDL-C tertile, after adjusting for multiple covariates including indices for central obesity [T1: 1; T2: 4.02(1.86–8.71); T3: 4.30(1.99–9.29)]. Following stratification of waist circumference into quartiles, the effect of TG/HDL-C on insulin resistance remained significant irrespective of waist circumference. Conclusions TG/HDL-C was associated with insulin resistance independent of waist circumference. Whether it could be a surrogate marker for insulin resistance in Chinese patients with newly diagnosed type 2 diabetes mellitus still needs to be confirmed by more researches. PMID:27115999

Acute resistance exercise with blood flow restriction in elderly hypertensive women: haemodynamic, rating of perceived exertion and blood lactate.

PubMed

Pinto, Roberta R; Karabulut, Murat; Poton, Roberto; Polito, Marcos D

2018-01-01

This study aimed to compare haemodynamic, rating of perceived exertion and blood lactate responses during resistance exercise with blood flow restriction (BFR) compared with traditional high-intensity resistance exercise in hypertensive older women. Eighteen hypertensive women (age = 67·0 ± 1·7 years.) undertook three random sessions: (i) three sets; 10 repetitions; 20% of one repetition maximum (1RM) with BFR; (ii) three sets; 10 repetitions; 65% of 1RM; without BFR; and (iii) no-exercise with BFR. The exercise sessions were performed on knee extension equipment. Systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR), stroke volume (SV) and cardiac output (CO) were significantly higher (P<0·05) in all sets of exercise sessions than the control. No statistically significant differences were detected between exercise sessions. However, SBP, DBP and systemic vascular resistance were higher (P<0·05) and SV and CO were lower (P<0·05) during the rest intervals in the session with BFR. The perceived exertion was significantly higher (P<0·01) in the 1st (4·8 ± 0·4 versus 3·1 ± 0·3), 2nd (7·3 ± 0·4 versus 5·7 ± 0·4) and 3rd sets (8·6 ± 0·5 versus 7·5 ± 0·4) of the traditional high-intensity resistance exercise compared with the exercise with BFR. Blood lactate was higher (P<0·05) in the traditional high-intensity resistance exercise (6·2 ± 0·7 mmol) than in the exercise with BFR (4·5 ± 0·4 mmol). In comparison with high-intensity resistance exercise, low-intensity resistance exercise with BFR can elicit: (i) same haemodynamic values during exercise; (ii) lower rating of perceived exertion; (iii) lower blood lactate; (iv) higher haemodynamic demand during the rest intervals. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Investigation of Sintering Temperature on Attrition Resistance of Highly Porous Diatomite Based Material

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garderen, Noemie van; Clemens, Frank J.; Scharf, Dagobert

2010-05-30

Highly porous diatomite based granulates with a diameter of 500 mum have been produced by an extrusion method. In order to investigate the relation between microstructure, phase composition and attrition resistance of the final product, the granulates were sintered between 800 and 1300 deg. C. Mean pore size of the granulates was evaluated by Hg-porosimetry. An increase of the pore size is observed in the range of 3.6 nm to 40 mum with increasing sintering temperature. Higher mean pore radii of 1.6 mum and 5.7 mum obtained by sintering at 800 and 1300 deg. C respectively. X-ray diffraction shows thatmore » mullite phase appears at 1100 deg. C due to the presence of clay. At 1100 deg. C diatomite (amorphous silicate) started to transform into alpha-cristobalite. Attrition resistance was determined by evaluating the amount of ground material passed through a sieve with a predefined mesh size. It was observed that a material sintered at high temperature leads to an increase of attrition resistance due to the decrease of total porosities and phase transformation. Due to the reason that attrition resistance significantly increased by sintering the granulates at higher temperature, a so called attrition resistance index was determined in order to compare all the different attrition resistance values. This attrition resistance index was determined by using the exponential component of the equation obtained from attrition resistance curves. It permits comparison of the attrition behaviour without a time influence.« less

[Inactivation of the chlorine-resistant bacteria isolated from the drinking water distribution system].

PubMed

Chen, Yu-Qiao; Duan, Xiao-Di; Lu, Pin-Pin; Wang, Qian; Zhang, Xiao-Jian; Chen, Chao

2012-01-01

Inactivation experiments of seven strains of chlorine-resistant bacteria, isolated from a drinking water distribution system, were conducted with four kinds of disinfectants. All the bacteria showed high resistance to chlorine, especially for Mycobacterium mucogenicum. The CT value of 99.9% inactivation for M. mucogenicum, Sphingomonas sanguinis and Methylobacterium were 120 mg x (L x min)(-1), 7 mg x (L x min)(-1) and 4 mg x (L x min)(-1), respectively. The results of inactivation experiments showed that chlorine dioxide and potassium monopersulfate could inactive 5 lg of M. mucogenicum within 30 min, which showed significantly higher efficiency than free chlorine and monochloramine. Free chlorine was less effective because the disinfectant decayed very quickly. Chloramination needed higher concentration to meet the disinfection requirements. The verified dosage of disinfectants, which could effectively inactivate 99.9% of the highly chlorine-resistant M. mucogenicum within 1 h, were 3.0 mg/L monochloramine, 1.0 mg/L chlorine dioxide (as Cl2), and 1.0 mg/L potassium monopersulfate (as Cl2). It was suggested that the water treatment plants increase the concentration of monochloramine or apply chlorine dioxide intermittently to control the disinfectant-resistant bacteria.

The relationship between insulin resistance and periodontitis is not affected by Mediterranean diet in a Spanish population.

PubMed

Pulido-Moran, M; Bullon, P; Morillo, J M; Battino, M; Quiles, J L; Ramirez-Tortosa, MCarmen

2017-05-01

To examine the insulin resistance measured by surrogate indices in subjects with and without periodontitis and to find out any correlation among dietary intake with insulin resistance. Fifty-five patients were recruited to participate in this cross-sectional study. Insulin resistance measured by the homoeostasis model assessment (HOMA-IR) and the quantitative insulin sensitivity check index moreover glycaemia, creatinine, uric acid, high density lipoproteins, low density lipoproteins, very low density lipoproteins and triglycerides among others. True periodontal disease was elucidated through the examination of probing pocket depth, clinical attachment level, recession of the gingival margin and gingival bleeding. The statistical analyses used were the student's T-test for independent variables, Kolmogorov-Smirnov if variations were homogeneous; if not, the Mann-Whitney U Test was applied instead. Correlations between variables were assessed using Pearson's correlation coefficients. True periodontal disease was confirmed through the greater values of probing pocket depth, clinical attachment level, gingival margin and gingival bleeding in the periodontitis group in comparison with non-periodontitis group. Insulin resistance was evidenced by the greater values of HOMA-IR as well as by the lower quantitative insulin sensitivity check index values in the periodontitis group. Fasting insulin, glucose, uric acid, creatinine, low density lipoproteins, triglycerides and very low density lipoprotein levels were significant higher in periodontitis group. Pearson's correlations did not show any association among diet data and insulin resistance parameters in periodontitis patients. A putative systemic relationship between insulin resistance and periodontitis exists but it does not seem conceivable any effect of diet over such relationship. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of heat input on pitting corrosion in super duplex stainless steel weld metals

NASA Astrophysics Data System (ADS)

Shin, Yong taek; Shin, Hak soo; Lee, Hae woo

2012-12-01

Due to the difference in reheating effects depending on the heat input of subsequent weld passes, the microstructure of the weld metal varies between acicular type austenite and a mixture of polygonal type and grain boundary mixed austenite. These microstructural changes may affect the corrosion properties of duplex stainless steel welds. This result indicates that the pitting resistance of the weld can be strongly influenced by the morphology of the secondary austenite phase. In particular, the ferrite phase adjacent to the acicular type austenite phase shows a lower Pitting Resistance Equivalent (PRE) value of 25.3, due to its lower chromium and molybdenum contents, whereas the secondary austenite phase maintains a higher PRE value of more than 38. Therefore, it can be inferred that the pitting corrosion is mainly due to the formation of ferrite phase with a much lower PRE value.

Wear resistance of Polymethyl Methacrylate (PMMA) with the Addition of Bone Ash, Hydroxylapatite and Keratin

NASA Astrophysics Data System (ADS)

Emre, G.; Akkus, A.; Karamış, M. B.

2018-01-01

In this study mechanichal and tribological properties of keratin, bone ash and hydroxylapatite by adding to PMMA ( known as the main prosthesis material) were investigated. Hydroxylapatite, bone ash, and keratin materials were added as PMMA in to the content of PMMA, in the proportions of %1, %3 and %5, respectively. The resulting mixtures were put into the molds and solidified in order to obtain samples to be used in the wear experiments. Each experiment was conducted by preparing three experimental samples. The wear data were compared according to the average values of the experimental samples. In the wear test, the results were also evaluated according to the average values obtained from each group and the results of the control group. It was observed that, the wear resistance of the PMMA including 3%, 5% bone ash and PMMA including 5% keratin flour were higher than the values of the control group.

Dihydroartemisinin–piperaquine resistance in Plasmodium falciparum malaria in Cambodia: a multisite prospective cohort study

PubMed Central

Amaratunga, Chanaki; Lim, Pharath; Suon, Seila; Sreng, Sokunthea; Mao, Sivanna; Sopha, Chantha; Sam, Baramey; Dek, Dalin; Try, Vorleak; Amato, Roberto; Blessborn, Daniel; Song, Lijiang; Tullo, Gregory S; Fay, Michael P; Anderson, Jennifer M; Tarning, Joel; Fairhurst, Rick M

2016-01-01

Background Artemisinin resistance in Plasmodium falciparum threatens to reduce the efficacy of artemisinin combination therapies (ACTs), thus compromising global efforts to eliminate malaria. Recent treatment failures with dihydroartemisinin-piperaquine, the current first-line ACT in Cambodia, suggest that piperaquine resistance may be emerging in this country. We explored the relation between artemisinin resistance and dihydroartemisinin–piperaquine failures, and sought to confirm the presence of piperaquine-resistant P falciparum infections in Cambodia. Methods In this prospective cohort study, we enrolled patients aged 2–65 years with uncomplicated P falciparum malaria in three Cambodian provinces: Pursat, Preah Vihear, and Ratanakiri. Participants were given standard 3-day courses of dihydroartemisinin–piperaquine. Peripheral blood parasite densities were measured until parasites cleared and then weekly to 63 days. The primary outcome was recrudescent P falciparum parasitaemia within 63 days. We measured piperaquine plasma concentrations at baseline, 7 days, and day of recrudescence. We assessed phenotypic and genotypic markers of drug resistance in parasite isolates. The study is registered with ClinicalTrials.gov, number NCT01736319. Findings Between Sept 4, 2012, and Dec 31, 2013, we enrolled 241 participants. In Pursat, where artemisinin resistance is entrenched, 37 (46%) of 81 patients had parasite recrudescence. In Preah Vihear, where artemisinin resistance is emerging, ten (16%) of 63 patients had recrudescence and in Ratanakiri, where artemisinin resistance is rare, one (2%) of 60 patients did. Patients with recrudescent P falciparum infections were more likely to have detectable piperaquine plasma concentrations at baseline compared with non-recrudescent patients, but did not differ significantly in age, initial parasite density, or piperaquine plasma concentrations at 7 days. Recrudescent parasites had a higher prevalence of kelch13 mutations, higher piperaquine 50% inhibitory concentration (IC50) values, and lower mefloquine IC50 values; none had multiple pfmdr1 copies, a genetic marker of mefloquine resistance. Interpretation Dihydroartemisinin–piperaquine failures are caused by both artemisinin and piperaquine resistance, and commonly occur in places where dihydroartemisinin–piperaquine has been used in the private sector. In Cambodia, artesunate plus mefloquine may be a viable option to treat dihydroartemisinin–piperaquine failures, and a more effective first-line ACT in areas where dihydroartemisinin–piperaquine failures are common. The use of single low-dose primaquine to eliminate circulating gametocytes is needed in areas where artemisinin and ACT resistance is prevalent. Funding National Institute of Allergy and Infectious Diseases. PMID:26774243

Overexpression of ShCYP51B and ShatrD in Sclerotinia homoeocarpa Isolates Exhibiting Practical Field Resistance to a Demethylation Inhibitor Fungicide

PubMed Central

Hulvey, Jon; Popko, James T.; Sang, Hyunkyu; Berg, Andrew

2012-01-01

We investigated genetic factors that govern the reduced propiconazole sensitivity of Sclerotinia homoeocarpa field isolates collected during a 2-year field efficacy study on dollar spot disease of turf in five New England sites. These isolates displayed a >50-fold range of in vitro sensitivity to a sterol demethylation inhibitor (DMI) fungicide, propiconazole, making them ideal for investigations of genetic mechanisms of reduced DMI sensitivity. The CYP51 gene homolog in S. homoeocarpa (ShCYP51B), encoding the enzyme target of DMIs, is likely a minor genetic factor for reduced propiconazole sensitivity, since there were no differences in constitutive relative expression (RE) values and only 2-fold-higher induced RE values for insensitive than for sensitive isolate groups. Next, we mined RNA-Seq transcriptome data for additional genetic factors and found evidence for the overexpression of a homolog of Botrytis cinerea atrD (BcatrD), ShatrD, a known efflux transporter of DMI fungicides. The ShatrD gene showed much higher constitutive and induced RE values for insensitive isolates. Several polymorphisms were found upstream of ShatrD but were not definitively linked to overexpression. The screening of constitutive RE values of ShCYP51B and ShatrD in isolates from two golf courses that exhibited practical field resistance to propiconazole uncovered evidence for significant population-specific overexpression of both genes. However, linear regression demonstrated that the RE of ShatrD displays a more significant relationship with propiconazole sensitivity than that of ShCYP51B. In summary, our results suggest that efflux is a major determinant of the reduced DMI sensitivity of S. homoeocarpa genotypes in New England, which may have implications for the emergence of practical field resistance in this important turfgrass pathogen. PMID:22798361

The effect of various backfilling techniques on the fracture resistance of simulated immature teeth performed apical plug with Biodentine.

PubMed

Topçuoğlu, Hüseyin Sinan; Kesim, Bertan; Düzgün, Salih; Tuncay, Öznur; Demirbuga, Sezer; Topçuoğlu, Gamze

2015-07-01

To evaluate the fracture resistance of simulated immature teeth that had been backfilled using different materials after using Biodentine as the apical plug material. Seventy-five single-rooted teeth were divided into five groups (n = 15). The 15 teeth in group 1 served as a negative control group and received no treatment. The remaining 60 teeth were instrumented to a #6 Peeso reamer to obtain a standard internal diameter of 1.5 mm. The apical 4 mm of 60 teeth was filled with Biodentine. The backfilling was then performed on each group as follows: group 2--no backfilling (positive control), group 3--gutta-percha, group 4--fiber post, and group 5--Biodentine. Specimens were then subjected to fracture testing. The force required to fracture each specimen was recorded, and the data were statistically analyzed. The mean fracture values of groups 1 and 4 were significantly higher than groups 2, 3, and 5 (P < 0.05). The values of groups 3 and 5 were significantly higher than group 2 (P < 0.05). The backfilling with fiber post after an apical Biodentine plug provided the highest fracture resistance among all experimental groups. © 2014 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Experimental Investigations on the Pull-Out Behavior of Tire Strips Reinforced Sands.

PubMed

Li, Li-Hua; Chen, Yan-Jun; Ferreira, Pedro Miguel Vaz; Liu, Yong; Xiao, Heng-Lin

2017-06-27

Waste tires have excellent mechanical performance and have been used as reinforcing material in geotechnical engineering; however, their interface properties are poorly understood. To further our knowledge, this paper examines the pull-out characteristics of waste tire strips in a compacted sand, together with uniaxial and biaxial geogrids also tested under the same conditions. The analysis of the results shows that the interlocking effect and pull-out resistance between the tire strip and the sand is very strong and significantly higher than that of the geogrids. In the early stages of the pull-out test, the resistance is mainly provided by the front portion of the embedded tire strips, as the pull-out test continues, more and more of the areas towards the end of the tire strips are mobilized, showing a progressive failure mechanism. The deformations are proportional to the frictional resistance between the tire-sand interface, and increase as the normal stresses increase. Tire strips of different wear intensities were tested and presented different pull-out resistances; however, the pull-out resistance mobilization patterns were generally similar. The pull-out resistance values obtained show that rubber reinforcement can provide much higher pull-out forces than the geogrid reinforcements tested here, showing that waste tires are an excellent alternative as a reinforcing system, regardless of the environmental advantages.

Thin film materials and devices for resistive temperature sensing applications

NASA Astrophysics Data System (ADS)

Basantani, Hitesh A.

Thin films of vanadium oxide (VOx) and hydrogenated amorphous silicon (a-Si:H) are the two dominant material systems used in resistive infrared radiation detectors (microbolometers) for sensing long wave infrared (LWIR) wavelengths in the 8--14 microm range. Typical thin films of VO x (x < 2) currently used in the bolometer industry have a magnitude of temperature coefficient of resistance (TCR) between 2%/K -- 3%/K. In contrast, thin films of hydrogenated germanium (SiGe:H) have |TCR| between 3%/K to 4%/K. Devices made from either of these materials have resulted in similar device performance with NETD ≈ 25 mK. The performance of the microbolometers is limited by the electronic noise, especially 1/f noise. Therefore, regardless of the choice of bolometer sensing material and read out circuitry, manufacturers are constantly striving to reduce 1/f noise while simultaneously increasing TCR to give better signal to noise ratios in their bolometers and ultimately, better image quality with more thermal information to the end user. In this work, thin films of VOx and hydrogenated germanium (Ge:H), having TCR values > 4 %/K are investigated as potential candidates for higher sensitivity next generation of microbolometers. Thin films of VO x were deposited by Biased Target Ion Beam Deposition (BTIBD) (˜85 nm thick). Electrical characterization of lateral resistor structures showed resistivity ranging from 104 O--cm to 2.1 x 104 O--cm, TCR varying from --4%/K to --5%/K, normalized Hooge parameter (alphaH/n) of 5 x 10 -21 to 5 x 10-18 cm3. Thin films of Ge:H were deposited by plasma enhanced chemical vapor deposition (PECVD) by incorporating an increasing amount of crystal fraction in the growing thin films. Thin films of Ge:H having a mixed phase, amorphous + nanocrystalline, having a |TCR| > 6 %/K were deposited with resistivity < 2,300 O--cm and a normalized Hooge's parameter 'alphaH/n' < 2 x 10-20 cm3. Higher TCR materials are desired, however, such materials have higher resistivity and therefore unacceptable large electrical resistance in a lateral resistor configuration. This work looks at an alternate bolometer device design which incorporates higher TCR materials in a vertically integrated configuration. Thin films of high TCR hydrogenated germanium (Ge:H, |TCR| > 6%/K) and vanadium oxide (VOx, TCR > 5%/K) were integrated in lateral and through film configuration. The electrical performance of the vertically integrated devices is compared with lateral resistance structures. It was confirmed experimentally that the device impedance was significantly lowered while maintaining the signal to noise ratio of the lateral resistor configuration. The vertically integrated devices allow higher device currents without any increase in self heating. These structures may help reduce integration time and may result in higher frame rate. Finally, one dimensional arrays were fabricated using both lateral and vertically integrated configurations and their performance was evaluated. It was found that the performance of the lateral devices was limited by noise floor of the measurement setup used. However, due to the lower impedance of the vertically integrated resistors, a higher signal and therefore higher signal to noise ratio could be obtained. These vertically integrated devices exhibited low RMS noise values of 12 mK.

Particle acceleration with anomalous pitch angle scattering in 2D magnetohydrodynamic reconnection simulations

NASA Astrophysics Data System (ADS)

Borissov, A.; Kontar, E. P.; Threlfall, J.; Neukirch, T.

2017-09-01

The conversion of magnetic energy into other forms (such as plasma heating, bulk plasma flows, and non-thermal particles) during solar flares is one of the outstanding open problems in solar physics. It is generally accepted that magnetic reconnection plays a crucial role in these conversion processes. In order to achieve the rapid energy release required in solar flares, an anomalous resistivity, which is orders of magnitude higher than the Spitzer resistivity, is often used in magnetohydrodynamic (MHD) simulations of reconnection in the corona. The origin of Spitzer resistivity is based on Coulomb scattering, which becomes negligible at the high energies achieved by accelerated particles. As a result, simulations of particle acceleration in reconnection events are often performed in the absence of any interaction between accelerated particles and any background plasma. This need not be the case for scattering associated with anomalous resistivity caused by turbulence within solar flares, as the higher resistivity implies an elevated scattering rate. We present results of test particle calculations, with and without pitch angle scattering, subject to fields derived from MHD simulations of two-dimensional (2D) X-point reconnection. Scattering rates proportional to the ratio of the anomalous resistivity to the local Spitzer resistivity, as well as at fixed values, are considered. Pitch angle scattering, which is independent of the anomalous resistivity, causes higher maximum energies in comparison to those obtained without scattering. Scattering rates which are dependent on the local anomalous resistivity tend to produce fewer highly energised particles due to weaker scattering in the separatrices, even though scattering in the current sheet may be stronger when compared to resistivity-independent scattering. Strong scattering also causes an increase in the number of particles exiting the computational box in the reconnection outflow region, as opposed to along the separatrices as is the case in the absence of scattering.

Biophysical responses of young pomegranate tree to different irrigation and nitrogen treatments

USDA-ARS?s Scientific Manuscript database

Due to recurrent water shortages in California, many farmers are looking for crops that have some degree of drought resistance and higher economic value. Pomegranate has been identified as a crop with drought and salinity tolerance, and nutritional benefits. There are currently approximately 6,000 h...

Detecting Defects Within Soil-Bentonite Slurry Cutoff Walls Using Electrical Resistivity Methods

NASA Astrophysics Data System (ADS)

Aborn, L.; Jacob, R. W.; Mucelli, A.

2016-12-01

Installed in the subsurface, vertical cutoff walls may limit groundwater movement. The effectiveness of these walls can be undermined by defects, for example high permeability material, within the wall. An efficient way of detecting these defects in a soil-bentonite slurry cutoff wall has yet to be established. We installed an approximately 200-meter long and 7-meter deep soil-bentonite slurry cutoff wall for the purposes of research. The wall was constructed adjacent to a natural wetland, the Montandon Marsh near Lewisburg, PA. The wall is composed of soil-bentonite backfill and was designed to be a typical low permeability material. We evaluate the capability of non-invasive geophysical techniques, specifically electrical resistivity, to detect high permeability defects that are expected to have higher electrical resistivity values than the backfill material. The laboratory measured electrical resistivity of the backfill used for construction was 12.27-ohm meters. During construction, designed defects of saturated fine-grained sand bags were deployed at different positions and depths within the wall. To create larger defects multiple bags were tied together. Laboratory resistivity testing of the sand and the filled sand bags indicates values between 125-ohm meters at full saturation and 285-ohm meters at partial saturation. Post construction, we collected electrical resistivity data using a 28-channel system along the centerline of the cutoff wall, which indicated the backfill material to have a resistivity value of 15-ohm meters. The electrical resistivity profile was affected by the sidewalls of the trench, as expected, which may explain the difference between laboratory results and field measurements. To minimize the sidewalls obscuring the defects, we developed electrodes that are pushed into the backfill at different depths to collect subsurface resistivity. Different arrays and electrode spacings are being tested. Our presentation will report the most effective method for detecting defects within a soil-bentonite cutoff wall.

Clinical resistance and decreased susceptibility in Streptococcus suis isolates from clinically healthy fattening pigs.

PubMed

Callens, Bénédicte F; Haesebrouck, Freddy; Maes, Dominiek; Butaye, Patrick; Dewulf, Jeroen; Boyen, Filip

2013-04-01

Streptococcus suis (S. suis) has often been reported as an important swine pathogen and is considered as a new emerging zoonotic agent. Consequently, it is important to be informed on its susceptibility to antimicrobial agents. In the current study, the Minimum Inhibitory Concentration (MIC) population distribution of nine antimicrobial agents has been determined for nasal S. suis strains, isolated from healthy pigs at the end of the fattening period from 50 closed or semiclosed pig herds. The aim of the study was to report resistance based on both clinical breakpoints (clinical resistance percentage) and epidemiological cutoff values (non-wild-type percentage). Non-wild-type percentages were high for tetracycline (98%), lincomycin (92%), tilmicosin (72%), erythromycin (70%), tylosin (66%), and low for florfenicol (0%) and enrofloxacin (0.3%). Clinical resistance percentages were high for tetracycline (95%), erythromycin (66%), tylosin (66%), and low for florfenicol (0.3%) and enrofloxacin (0.3%). For tiamulin, for which no clinical breakpoint is available, 57% of the isolates did not belong to the wild-type population. Clinical resistance and non-wild-type percentages differed substantially for penicillin. Only 1% of the tested S. suis strains was considered as clinically resistant, whereas 47% of the strains showed acquired resistance when epidemiological cutoff values were used. In conclusion, MIC values for penicillin are gradually increasing, compared to previous reports, although pigs infected with strains showing higher MICs may still respond to treatment with penicillin. The high rate of acquired resistance against tiamulin has not been reported before. Results from this study clearly demonstrate that the use of different interpretive criteria contributes to the extent of differences in reported antimicrobial resistance results. The early detection of small changes in the MIC population distribution of isolates, while clinical failure may not yet be observed, provides the opportunity to implement appropriate risk management steps.

A comparison of the motivational factors between CrossFit participants and other resistance exercise modalities: a pilot study.

PubMed

Fisher, James; Sales, Adele; Carlson, Luke; Steele, James

2017-09-01

Understanding resistance exercise motives and participation is essential in increasing exercise adherence and reducing comorbidities. CrossFit is a fitness movement that has seen an explosive growth in popularity worldwide; however, little research has investigated the motivational factors within this "niche" resistance exercise environment. The aim of this study was to explore the motivational factors of CrossFit participants in comparison to other resistance exercise participants. Using an independent-group design, quantitative data was collected using exercise motivations inventory-2 (EMI-2) questionnaire, for a total of 314 male and female participants (CrossFit: N.=68, group resistance exercise: N.=55, alone: N.=125, personal trainer: N.=66). The present study suggest that CrossFit participants were more likely to report higher levels of intrinsic motives, such as enjoyment, challenge and affiliation, whereas personal training clients reported higher values for health related motives such as positive health, ill-health avoidance and weight management. The findings suggest that the motivations for engaging in CrossFit may be similar to those seen in sport participation, and therefore may have an influence on facilitating long-term adherence in comparison with other resistance exercise modalities. This article also discusses health related motives as being extrinsic in nature but reflecting intrinsic characteristics, potentially also facilitating long term adherence. The present research helps develop further understanding of motivational variables within differing resistance exercise modalities.

Association between Myeloperoxidase Levels and Risk of Insulin Resistance in Egyptian Obese Women

PubMed Central

Zaki, Moushira; Basha, Walaa; Reyad, Hanaa; Mohamed, Ramy; Hassan, Naglaa; Kholousi, Shams

2018-01-01

BACKGROUND: Myeloperoxidase (MPO) is an enzyme involved in the pathogenesis of several diseases. AIM: The current study aimed to investigate serum MPO levels in obese Egyptian women and assess its relation with insulin resistance (IR) and other biochemical risk parameters. METHODS: The study included 80 obese women and 50 age-and-sex-matched healthy controls. Insulin resistance (IR) was evaluated by the Homeostasis Model Assessment-Insulin Resistance (HOMA-IR). Serum MPO, fasting glucose, insulin and blood lipids and anthropometry were measured. Obese cases were divided into three groups based on MPO tertiles. ROC analysis was performed to obtain the optimal cut-off values of MPO to predicate IR in obese women. RESULTS: The mean serum MPO was significantly higher in obese cases than controls. Cases in the highest MPO tertile had higher HOMA-IR, blood lipids and pressure levels compared with those in the lower tertile. The cutoff point of MPO was > 87.8 (ng/mL) and area under curves was 0.82 (p < 0.01) for diagnosis of IR. MPO levels were higher in obese Egyptian women than healthy controls. CONCLUSION: Elevation of MPO was associated with abnormal metabolic parameters. MPO might be used as an earlier biomarker for IR and metabolic disturbance in obese women. PMID:29731928

Self-duality and a Hall-insulator phase near the superconductor-to-insulator transition in indium-oxide films.

PubMed

Breznay, Nicholas P; Steiner, Myles A; Kivelson, Steven Allan; Kapitulnik, Aharon

2016-01-12

We combine measurements of the longitudinal (ρxx) and Hall (ρxy) resistivities of disordered 2D amorphous indium-oxide films to study the magnetic-field tuned superconductor-to-insulator transition (H-SIT) in the T --> 0 limit. At the critical field, Hc, the full resistivity tensor is T independent with ρxx(Hc) = h/4e(2) and ρxy(Hc) = 0 within experimental uncertainty in all films (i.e., these appear to be "universal" values); this is strongly suggestive that there is a particle-vortex self-duality at H = Hc. The transition separates the (presumably) superconducting state at H < Hc from a "Hall-insulator" phase in which ρxx --> ∞ as T --> 0 whereas ρxy approaches a nonzero value smaller than its "classical value" H/nec; i.e., 0 < ρxy < H/nec. A still higher characteristic magnetic field, Hc* > Hc, at which the Hall resistance is T independent and roughly equal to its classical value, ρxy ≈ H/nec, marks an additional crossover to a high-field regime (probably to a Fermi insulator) in which ρxy > H/nec and possibly diverges as T --> 0. We also highlight a profound analogy between the H-SIT and quantum-Hall liquid-to-insulator transitions (QHIT).

Improvement of corrosion resistance of low-alloy steels by resurfacing using multifunction cavitation in water

NASA Astrophysics Data System (ADS)

Ijiri, Masataka; Yoshimura, Toshihiko

2018-02-01

Low-alloy steels are based on carbon steel in combination with several percent or less (in many cases, 1 mass%) alloying elements, and they offer improved resistance to corrosion at a cost slightly higher than that of carbon steel. However, these materials do not exhibit the same corrosion resistance as stainless steel. The authors have previously developed a novel multifunction cavitation (MFC) technique, which combines ultrasonic cavitation with water jet cavitation. In this study, MFC was used to modify the surface of Cr-Mo steel (SCM435) and Ni-Cr-Mo steel (SNCM630). MFC was found to improve the residual stress value of the material as the result of surface modification while also imparting high strength and superior corrosion resistance.

The effects of stage-specific selection on the development of benzimidazole resistance in Haemonchus contortus in sheep.

PubMed

Taylor, M A; Hunt, K R; Goodyear, K L

2002-10-16

Resistance to the benzimidazole (BDZ) class of anthelmintics in nematodes of sheep has become a common and global phenomenon. The rate at which the selection process and development of resistance occurs is influenced by a number of factors. Of these, the effects of stage-specific exposures to anthelmintic were investigated with a BDZ-resistant strain of Haemonchus contortus (HCR) over five parasite generations. Sheep were infected at each generation with the HCR strain and were treated with thiabendazole (TBZ), either 5 days post-infection (p.i.) (larval line), 21 days p.i. (adult line), or left untreated (no selection line). Additionally eggs from each generation were exposed to TBZ (egg line). Geometric worm burdens were calculated from post-mortem worm counts, both at the start of the study, and after the final selection studies for each of the selection lines. Egg hatch assays (EHAs) were also conducted throughout the study. All data relating to worm burdens and EHAs for each generation were analysed by linear regression to produce dose titration curves and lethal dose(50) (LD(50)) values for each of the selection lines. Over the five generations, LD(50) values on dose-response were increased and worm survival occurred at higher dose rates of TBZ irrespective of the parasite stage exposed to treatment. A similar picture was seen with ED(50) values, which showed a fluctuating but generally upward trend for each of the three selection lines. In contrast, LD(50) and ED(50) values were decreased in the no selection line, indicating some degree of reversion albeit to levels still considered to be BDZ-resistant.

Relationship between high white blood cell count and insulin resistance (HOMA-IR) in Korean children and adolescents: Korean National Health and Nutrition Examination Survey 2008-2010.

PubMed

Park, J-M; Lee, D-C; Lee, Y-J

2017-05-01

Increasing evidence has indicated that insulin resistance is associated with inflammation. However, few studies have investigated the association between white blood cell (WBC) count and insulin resistance, as measured by a homeostasis model assessment of insulin resistance (HOMA-IR) in a general pediatric population. This study aimed to examine the association between WBC count and insulin resistance as measured by HOMA-IR in a nationally representative sample of children and adolescents. In total, 2761 participants (1479 boys and 1282 girls) aged 10-18 years were selected from the 2008-2010 Korean National Health and Nutrition Examination Survey. Insulin resistance was defined as a HOMA-IR value greater than the 90th percentile. The odds ratios and 95% confidence intervals for insulin resistance were determined using multiple logistic regression analysis. The mean values of most cardiometabolic variables tended to increase proportionally with WBC count quartiles. The prevalence of insulin resistance significantly increased in accordance with WBC count quartiles in both boys and girls. Compared to individuals in the lowest WBC count quartile, the odds ratio for insulin resistance for individuals in the highest quartile was 2.84 in boys and 3.20 in girls, after adjusting for age, systolic blood pressure, body mass index, and waist circumference. A higher WBC count was positively associated with an increased risk of insulin resistance in Korean children and adolescents. This study suggests that WBC count could facilitate the identification of children and adolescents with insulin resistance. Copyright © 2017 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

The slip resistance of common footwear materials measured with two slipmeters.

PubMed

Chang, W R; Matz, S

2001-12-01

The slip resistance of 16 commonly used footwear materials was measured with the Brungraber Mark II and the English XL on 3 floor surfaces under surface conditions of dry, wet, oily and oily wet. Three samples were used for each material combination and surface condition. The results of a one way ANOVA analysis indicated that the differences among different samples were statistically significant for a large number of material combinations and surface conditions. The results indicated that the ranking of materials based on their slip resistance values depends highly on the slipmeters, floor surfaces and surface conditions. For contaminated surfaces including wet, oily and oily wet surfaces, the slip resistance obtained with the English XL was usually higher than that measured with the Brungraber Mark II. The correlation coefficients between the slip resistance obtained with these two slipmeters calculated for different surface conditions indicated a strong correlation with statistical significance.

Low temperature resistivity plateau and non-saturating magnetoresistance in Type-II Weyl semimetal WP2

NASA Astrophysics Data System (ADS)

Nagpal, V.; Kumar, P.; Sudesh, Patnaik, S.

2018-04-01

We have studied the resistivity and magnetoresistance (MR) properties of the recently predicted type-II Weyl semimetal WP2. Polycrystalline WP2 is synthesized using solid state reaction and crystallizes in an orthorhombic structure with the Cmc21 spacegroup. The temperature dependent resistivity is enhanced with the application of magnetic field and a resistivity plateau is observed at low temperatures. We find a small dip in resistivity around 30K at 5T field suggesting that there might be a metal-insulator-like transition at higher magnetic fields. A non-saturating magnetoresistance is observed at low temperatures with maximum MR ˜ 94% at 2K and 6T. The value of MR decreases with the increase in temperature. We see a deviation from Kohler's power law which implies that the system comprises of two types of charge carriers.

Estimating SPT-N Value Based on Soil Resistivity using Hybrid ANN-PSO Algorithm

NASA Astrophysics Data System (ADS)

Nur Asmawisham Alel, Mohd; Ruben Anak Upom, Mark; Asnida Abdullah, Rini; Hazreek Zainal Abidin, Mohd

2018-04-01

Standard Penetration Resistance (N value) is used in many empirical geotechnical engineering formulas. Meanwhile, soil resistivity is a measure of soil’s resistance to electrical flow. For a particular site, usually, only a limited N value data are available. In contrast, resistivity data can be obtained extensively. Moreover, previous studies showed evidence of a correlation between N value and resistivity value. Yet, no existing method is able to interpret resistivity data for estimation of N value. Thus, the aim is to develop a method for estimating N-value using resistivity data. This study proposes a hybrid Artificial Neural Network-Particle Swarm Optimization (ANN-PSO) method to estimate N value using resistivity data. Five different ANN-PSO models based on five boreholes were developed and analyzed. The performance metrics used were the coefficient of determination, R2 and mean absolute error, MAE. Analysis of result found that this method can estimate N value (R2 best=0.85 and MAEbest=0.54) given that the constraint, Δ {\\bar{l}}ref, is satisfied. The results suggest that ANN-PSO method can be used to estimate N value with good accuracy.

Resistance Management for San Jose Scale (Hemiptera: Diaspididae).

PubMed

Buzzetti, K; Chorbadjian, R A; Nauen, R

2015-12-01

The San Jose scale Diaspidiotus perniciosus Comstock is one of the most important pests of deciduous fruit trees. The major cause of recent outbreaks in apple orchards is thought to be the development of insecticide resistance, specifically organophosphates. The first report was given in North America, and now, in Chile. In the present study, San Jose scale populations collected from two central regions of Chile were checked for their susceptibility to different mode of action insecticides in order to establish alternatives to manage this pest. No evidence of cross resistance between organophosphates insecticides and acetamiprid, buprofezin, pyriproxyfen, spirotetramat, sulfoxaflor, or thiacloprid was found. Baselines of LC50-LC95 for different life stages of San Jose scale are given, as reference to future studies of resistance monitoring. The systemic activity of acetamiprid, spirotetramat, and thiacloprid was higher than the contact residue effect of these compounds. For sulfoxaflor, both values were similar. Program treatments including one or more of these compounds are compared in efficacy and impact on resistance ratio values. In order to preserve new insecticides as an important tool to control San Jose scale, resistance management programs should be implemented, considering insecticide mode of action classes alternated or mixed. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Clinical Implications of Changing Parameters on an Elliptical Trainer.

PubMed

Kaplan, Yonatan; Nyska, Meir; Palmanovich, Ezequiel; Shanker, Rebecca

2014-06-01

Specific weightbearing instructions continue to be a part of routine orthopaedic clinical practice on an injured or postoperative extremity. Researchers and clinicians have struggled to define the best weightbearing strategies to maximize clinical outcomes. To investigate the average percentage body weight (APBW) values, weightbearing distribution percentages (WBDP), and cadence values on the entire foot, hindfoot, and forefoot during changing resistance and incline on an elliptical trainer, as well as to suggest clinical implications. Descriptive laboratory study. An original research study was performed consisting of 30 asymptomatic subjects (mean age, 29.54 ± 12.64 years; range, 21-69 years). The protocol included 3 consecutive tests of changing resistance and incline within a speed range of 70 to 95 steps/min. The SmartStep weightbearing gait analysis system was utilized to measure the values. The APBW values for the entire foot ranged between 70% and 81%, the hindfoot values were between 27% and 57%, and the forefoot values between 42% and 70%. With regard to WBDP, the forefoot remained planted on the pedal (stance phase) 2 to 3 times more as compared with the hindfoot raise in the swing phase. The study findings highlight the fact that elliptical training significantly reduces weightbearing in the hindfoot, forefoot, and entire foot even at higher levels of resistance and incline. Weightbearing on the hindfoot consistently displayed the lowest weightbearing values. Orthopaedic surgeons, now equipped with accurate weightbearing data, may recommend using the elliptical trainer as a weightbearing exercise early on following certain bony or soft tissue pathologies and lower limb surgical procedures.

Heat Tolerances of Salmonella, Cronobacter sakazakii, and Pediococcus acidilactici Inoculated into Galactooligosaccharide.

PubMed

Bang, Jihyun; Choi, Moonkak; Jeong, Haeseok; Lee, Sangseob; Kim, Yoonbin; Ryu, Jee-Hoon; Kim, Hoikyung

2017-07-01

Food-grade galactooligosaccharide (GOS) with low water activity (a w of ca. 0.7) is used as an ingredient in various foods. We evaluated heat tolerances of Salmonella, Cronobacter sakazakii, and Pediococcus acidilactici at temperatures (70 to 85°C) used during the saturation process of GOS by comparing decimal reduction time (D-values) and thermal resistance constants (z-values). To determine the D- and z-values, GOS containing Salmonella (5.1 to 5.8 log CFU/g) or C. sakazakii (5.3 to 5.9 log CFU/g) was heat treated at 70, 77.5, or 85°C for up to 40, 25, or 15 s, respectively, and GOS containing P. acidilactici (6.1 to 6.5 log CFU/g) was heat treated at 70, 77.5, or 85°C for up to 150, 75, or 40 s, respectively. The D-values were calculated using a linear model for heating time versus microbial population for each bacterium. When the D-values for Salmonella, C. sakazakii, and P. acidilactici in GOS were compared, the thermal resistance of all bacteria decreased as the temperature increased. Among the three bacteria, P. acidilactici had higher D-values than did Salmonella and C. sakazakii. The z-values of Salmonella, C. sakazakii, and P. acidilactici were 30.10, 33.18, and 13.04°C, respectively. Overall order of thermal resistance was P. acidilactici > Salmonella ≈ C. sakazakii. These results will be useful for selecting appropriate heat treatment conditions for the decontamination of pathogenic microorganisms during GOS manufacturing.

The erythrocyte osmotic resistance test as screening tool for cholesterol-related lysosomal storage diseases.

PubMed

López de Frutos, Laura; Cebolla, Jorge J; Irún, Pilar; Köhler, Ralf; Giraldo, Pilar

2018-05-01

Erythrocyte volume regulation and membrane elasticity are essential for adaptation to osmotic and mechanical stress, and life span. Here, we evaluated whether defective cholesterol trafficking caused by the rare lysosomal storages diseases (LSDs), Niemann-Pick type C (NPC) and Lysosomal acid lipase (LAL) deficiency (LALD) impairs these properties. Moreover, we tested whether measurements of cholesterol membrane content and osmotic resistance serve as a screening test for these LSDs. Patients were genotyped for mutations in NPC1, NPC2, or LIPA genes. We measured LSD plasma biomarkers and LAL activity. Red blood cells (RBC) membrane cholesterol content was evaluated in 73 subjects. Osmotic resistance tests (ORT) were conducted in 121 blood samples from LSD suspected patients and controls. We did not find statistically significant differences between RBC cholesterol content between subjects and controls. However, the ORT, particularly at 0.49% (w/v) hypotonic sodium chloride solution, revealed a significant higher osmotic resistance in LSDs patients than in controls. We established a cut-off value of ≤51% of haemolysis with sensibility and specificity values of 80% and 70%, respectively. NPC and LALD do not alter cholesterol content in the RBC membrane but increase osmotic resistance. Therefore, ORT serves as screening test for the studied LSDs. Copyright © 2018 Elsevier B.V. All rights reserved.

Electrical resistivity of ultrafine-grained copper with nanoscale growth twins

NASA Astrophysics Data System (ADS)

Chen, X. H.; Lu, L.; Lu, K.

2007-10-01

We have investigated electrical resistivities of high-purity ultrafine-grained Cu containing different concentrations of nanoscale growth twins, but having identical grain size. The samples were synthesized by pulsed electrodeposition, wherein the density of twins was varied systematically by adjusting the processing parameters. The electrical resistivity of the Cu specimen with a twin spacing of 15nm at room temperature (RT) is 1.75μΩcm (the conductivity is about 97% IACS), which is comparable to that of coarse-grained (CG) pure Cu specimen. A reduction in twin density for the same grain size (with twin lamellar spacings of 35 and 90nm, respectively) results in an increment in electrical resistivity from 1.75to2.12μΩcm. However, the temperature coefficient of resistivity at RT for these Cu specimens is insensitive to the twin spacing and shows a consistent value of ˜3.78×10-3/K, which is slightly smaller than that of CG Cu (3.98×10-3/K). The increased electrical resistivities of the Cu samples were ascribed dominantly to the intrinsic grain boundary (GB) scattering, while the GB defects and GB energy would decrease with increasing twin density. Transmission electron microscope observations revealed the GB configuration difference from the Cu samples with various twin densities. Plastic deformation would induce an apparent increase in the resistivity. The higher of the twin density, the higher increment of RT resistivity was detected in the Cu specimens subjected to 40% rolling strain. Both the deviated twin boundaries and strained GBs may give rise to an increase in the resistivity.

Comparative cold resistance of three Columbia River organisms. [Thermal stresses, fishes, Crustaceans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Becker, C.H.; Genoway, R.G.; Schneider, M.J.

1977-01-01

Resistance to abrupt and gradual cold shock was determined in bioassays with pumpkinseed (Lepomis gibbosus), rainbow trout (Salmo gairdneri) and a northwestern crayfish (Pacifastacus leniusculus) acclimated to higher temperatures at 5 C increments. Test criteria were median tolerance limits (TLm) for 96-h exposures after abrupt cold shock, and 50% loss of equilibrium (LE50) for decline rates of 18, 15, 10, 5 and 1 C/h during gradual cold shock. Cold resistance depended on original acclimation temperature (AT) and varied among species under both test conditions in the order: pumpkinseed < rainbow trout < crayfish. The lower TLm limit for pumpkinseed wasmore » 12.3 C at 30 C AT, 9.6 C at 25 C AT, 4.5 C at 20 C AT, and 2.7 C at 15 C AT. Rainbow trout at 20, 15 and 10 C AT survived abrupt exposures to cold down to 3.3, 1.4 and 0.5 C, respectively. Crayfish at 25, 20 and 15 C AT survived exposures down to 2.5, 0.4 and 0.0 C, respectively. TLm values were slightly above LE50 values for both fish species but well below for crayfish. Partial adaptation significantly lowered LE values at decline rates below 18 C/h for pumpkinseed, and to a lesser extent for the other two species, thus extending the lower margin of cold resistance.« less

Prediction of clinical response to drugs in ovarian cancer using the chemotherapy resistance test (CTR-test).

PubMed

Kischkel, Frank Christian; Meyer, Carina; Eich, Julia; Nassir, Mani; Mentze, Monika; Braicu, Ioana; Kopp-Schneider, Annette; Sehouli, Jalid

2017-10-27

In order to validate if the test result of the Chemotherapy Resistance Test (CTR-Test) is able to predict the resistances or sensitivities of tumors in ovarian cancer patients to drugs, the CTR-Test result and the corresponding clinical response of individual patients were correlated retrospectively. Results were compared to previous recorded correlations. The CTR-Test was performed on tumor samples from 52 ovarian cancer patients for specific chemotherapeutic drugs. Patients were treated with monotherapies or drug combinations. Resistances were classified as extreme (ER), medium (MR) or slight (SR) resistance in the CTR-Test. Combination treatment resistances were transformed by a scoring system into these classifications. Accurate sensitivity prediction was accomplished in 79% of the cases and accurate prediction of resistance in 100% of the cases in the total data set. The data set of single agent treatment and drug combination treatment were analyzed individually. Single agent treatment lead to an accurate sensitivity in 44% of the cases and the drug combination to 95% accuracy. The detection of resistances was in both cases to 100% correct. ROC curve analysis indicates that the CTR-Test result correlates with the clinical response, at least for the combination chemotherapy. Those values are similar or better than the values from a publication from 1990. Chemotherapy resistance testing in vitro via the CTR-Test is able to accurately detect resistances in ovarian cancer patients. These numbers confirm and even exceed results published in 1990. Better sensitivity detection might be caused by a higher percentage of drug combinations tested in 2012 compared to 1990. Our study confirms the functionality of the CTR-Test to plan an efficient chemotherapeutic treatment for ovarian cancer patients.

Study of iron deposit using seismic refraction and resistivity in Carajás Mineral Province, Brazil

NASA Astrophysics Data System (ADS)

Nogueira, Pedro Vencovsky; Rocha, Marcelo Peres; Borges, Welitom Rodrigues; Silva, Adalene Moreira; Assis, Luciano Mozer de

2016-10-01

This work comprises the acquisition, processing and interpretation of 2D seismic shallow refraction (P-wave) and resistivity profiles located in the iron ore deposit of N4WS, Carajás Mineral Province (CMP), northern Brazil. The geophysical methods were used to identify the boundaries of the iron ore deposit. Another objective was to evaluate the potentiality of these geophysical methods in that geological context. In order to validate the results, the geophysical lines were located to match a geological borehole line. For the seismic refraction, we used 120 channels, spaced by 10 m, in a line of 1190 m, with seven shot points. The resistivity method used in the acquisition was the electrical resistivity imaging, with pole-pole array, in order to reach greater depths. The resistivity line had a length of 1430 m, with 10 m spacing between electrodes. The seismic results produced a model with two distinct layers. Based on the velocities values, the first layer was interpreted as altered rocks, and the second layer as more preserved rocks. It was not possible to discriminate different lithologies with the seismic method inside each layer. From the resistivity results, a zone of higher resistivity (> 3937 Ω·m) was interpreted as iron ore, and a region of intermediate resistivity (from 816 to 2330 Ω·m) as altered rocks. These two regions represent the first seismic layer. On the second seismic layer, an area with intermediated resistivity values (from 483 to 2330 Ω·m) was interpreted as mafic rocks, and the area with lower resistivity (< 483 Ω·m) as jaspilite. Our results were compared with geological boreholes and show reasonable correlation, suggesting that the geophysical anomalies correspond to the main variations in composition and physical properties of rocks.

Faculty Attitudes toward General Education Assessment: A Qualitative Study about Their Motivation

ERIC Educational Resources Information Center

MacDonald, Sarah K.; Williams, Laura M.; Lazowski, Rory A.; Horst, S. Jeanne; Barron, Kenneth E.

2014-01-01

As assessment becomes an ever more critical facet of higher education, it is apparent that some faculty do not always value assessment (Crossley & Wang, 2010; Ebersole, 2009). Further, faculty may react with resistance, particularly when they perceive that assessment is being imposed upon them from external sources (Crossley & Wang, 2010;…

Radiation resistance of lactobacilli isolated from radurized meat relative to growth and environment. [Lactobacillus sake; Lactobacillus curvatus; Lactobacillus farciminis; Staphylococcus aureus; Salmonella typimurium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hastings, J.W.; Holzapfel, W.H.; Niemand, J.G.

1986-10-01

Of 113 lactobacilli isolated from radurized (5 kGy) minced meat, 7 Lactobacillus sake strains, 1 L. curvatus strain, and 1 L. farciminis strain were used for radiation resistance studies in a semisynthetic substrate (i.e., modified MRS broth). Five reference Lactobacillus spp. one Staphylococcus aureus strain, and one Salmonella typhimurium strain were used for comparative purposes. All L. sake isolates exhibited the phenomenon of being more resistant to gamma-irradiation in the exponential (log) phase than in the stationary phase of their growth cycles by a factor of 28%. Four reference strains also exhibited this phenomenon, with L. sake (DSM 20017) showingmore » a 68% increase in resistance in the log phase over the stationary phase. This phenomenon was not common to all bacteria tested and is not common to all strains with high radiation resistance. Four L. sake isolates and three reference strains were used in radiation sensitivity testing in a natural food system (i.e., meat). The bacteria were irradiated in minced meat and packaged under four different conditions (air, vacuum, CO/sub 2/, and N/sub 2/). Organisms exhibited the highest death rate (lowest D/sub 10/ values (doses required to reduce the logarithm of the bacterial population by 1) under CO/sub 2/ packaging conditions, but resistance to irradiation was increased under N/sub 2/. The D/sup 10/ values of the isolates were generally greater than those of the reference strains. The D/sup 10/ values were also higher (approximately two times) in meat than in a semisynthetic growth medium.« less

Evaluating conducting network based transparent electrodes from geometrical considerations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Ankush; Kulkarni, G. U., E-mail: guk@cens.res.in

2016-01-07

Conducting nanowire networks have been developed as viable alternative to existing indium tin oxide based transparent electrode (TE). The nature of electrical conduction and process optimization for electrodes have gained much from the theoretical models based on percolation transport using Monte Carlo approach and applying Kirchhoff's law on individual junctions and loops. While most of the literature work pertaining to theoretical analysis is focussed on networks obtained from conducting rods (mostly considering only junction resistance), hardly any attention has been paid to those made using template based methods, wherein the structure of network is neither similar to network obtained frommore » conducting rods nor similar to well periodic geometry. Here, we have attempted an analytical treatment based on geometrical arguments and applied image analysis on practical networks to gain deeper insight into conducting networked structure particularly in relation to sheet resistance and transmittance. Many literature examples reporting networks with straight or curvilinear wires with distributions in wire width and length have been analysed by treating the networks as two dimensional graphs and evaluating the sheet resistance based on wire density and wire width. The sheet resistance values from our analysis compare well with the experimental values. Our analysis on various examples has revealed that low sheet resistance is achieved with high wire density and compactness with straight rather than curvilinear wires and with narrower wire width distribution. Similarly, higher transmittance for given sheet resistance is possible with narrower wire width but of higher thickness, minimal curvilinearity, and maximum connectivity. For the purpose of evaluating active fraction of the network, the algorithm was made to distinguish and quantify current carrying backbone regions as against regions containing only dangling or isolated wires. The treatment can be helpful in predicting the properties of a network simply from image analysis and will be helpful in improvisation and comparison of various TEs and better understanding of electrical percolation.« less

Evaluating conducting network based transparent electrodes from geometrical considerations

NASA Astrophysics Data System (ADS)

Kumar, Ankush; Kulkarni, G. U.

2016-01-01

Conducting nanowire networks have been developed as viable alternative to existing indium tin oxide based transparent electrode (TE). The nature of electrical conduction and process optimization for electrodes have gained much from the theoretical models based on percolation transport using Monte Carlo approach and applying Kirchhoff's law on individual junctions and loops. While most of the literature work pertaining to theoretical analysis is focussed on networks obtained from conducting rods (mostly considering only junction resistance), hardly any attention has been paid to those made using template based methods, wherein the structure of network is neither similar to network obtained from conducting rods nor similar to well periodic geometry. Here, we have attempted an analytical treatment based on geometrical arguments and applied image analysis on practical networks to gain deeper insight into conducting networked structure particularly in relation to sheet resistance and transmittance. Many literature examples reporting networks with straight or curvilinear wires with distributions in wire width and length have been analysed by treating the networks as two dimensional graphs and evaluating the sheet resistance based on wire density and wire width. The sheet resistance values from our analysis compare well with the experimental values. Our analysis on various examples has revealed that low sheet resistance is achieved with high wire density and compactness with straight rather than curvilinear wires and with narrower wire width distribution. Similarly, higher transmittance for given sheet resistance is possible with narrower wire width but of higher thickness, minimal curvilinearity, and maximum connectivity. For the purpose of evaluating active fraction of the network, the algorithm was made to distinguish and quantify current carrying backbone regions as against regions containing only dangling or isolated wires. The treatment can be helpful in predicting the properties of a network simply from image analysis and will be helpful in improvisation and comparison of various TEs and better understanding of electrical percolation.

Resistivity control of unintentionally doped GaN films

NASA Astrophysics Data System (ADS)

Grzegorczyk, A. P.; Macht, L.; Hageman, P. R.; Rudzinski, M.; Larsen, P. K.

2005-05-01

GaN epilayers were grown on sapphire substrates via low temperature GaN and AlN nucleation layers (NL) by metalorganic chemical vapor phase epitaxy (MOCVD). The morphology of the individual NLs strongly depends on the carrier gas used during the growth and recrystallization and this is the key factor for control of the resistivity of the GaN layer grown on it. The GaN nucleation layer grown in presence of N2 has a higher density of islands with a statistically smaller diameter than the samples grown in H2 atmosphere. The NL grown in N2 enables the growth GaN with a sheet resistivity higher than 3×104 cm as opposed to a 0.5 cm value obtained for the NL grown in H2. Introduction of an additional intermediate (IL) low temperature (GaN or AlN) nucleation layer changes the GaN epilayer resistivity to about 50 cm, regardless of the carrier gas used during the growth of the IL. Defect selective etching demonstrated that control of the type and density of the dislocations in GaN enables the growth of highly resistive layers without any intentional acceptor doping (Mg, Zn). It will be demonstrated that by changing the ratio of edge type to screw dislocations the resistivity of the layer can be changed by a few orders of magnitude.

Experimental Investigations on the Pull-Out Behavior of Tire Strips Reinforced Sands

PubMed Central

Li, Li-Hua; Chen, Yan-Jun; Ferreira, Pedro Miguel Vaz; Liu, Yong; Xiao, Heng-Lin

2017-01-01

Waste tires have excellent mechanical performance and have been used as reinforcing material in geotechnical engineering; however, their interface properties are poorly understood. To further our knowledge, this paper examines the pull-out characteristics of waste tire strips in a compacted sand, together with uniaxial and biaxial geogrids also tested under the same conditions. The analysis of the results shows that the interlocking effect and pull-out resistance between the tire strip and the sand is very strong and significantly higher than that of the geogrids. In the early stages of the pull-out test, the resistance is mainly provided by the front portion of the embedded tire strips, as the pull-out test continues, more and more of the areas towards the end of the tire strips are mobilized, showing a progressive failure mechanism. The deformations are proportional to the frictional resistance between the tire-sand interface, and increase as the normal stresses increase. Tire strips of different wear intensities were tested and presented different pull-out resistances; however, the pull-out resistance mobilization patterns were generally similar. The pull-out resistance values obtained show that rubber reinforcement can provide much higher pull-out forces than the geogrid reinforcements tested here, showing that waste tires are an excellent alternative as a reinforcing system, regardless of the environmental advantages. PMID:28773069

Higher hdl levels are a preventive factor for metabolic syndrome in obese Turkish children.

PubMed

Özer, Samet; Yılmaz, Resul; Özlem Kazanci, Nafia; Sönmezgöz, Ergün; Karaaslan, Erhan; Altuntaş, Buket; Emre Kuyucu, Yunus

2014-10-03

The definition of childhood metabolic syndrome has not been described clearly. Childhood obesity is increasing gradually, and the incidence of childhood metabolic syndrome is also rising. We aimed to show metabolic syndrome components and preventive factors for metabolic syndrome in obese children Methods: In the present study, 187 obese children and adolescents 5-18 years old were investigated retrospectively. Demographic data, anthropometric measurements, body mass index, blood pressure values, insulin levels, oral glucose tolerance test results, total cholesterol, high density lipoprotein, and triglyceride levels were obtained from hospital records. A body mass index > 95th percentile was considered obese. Insulin resistance was calculated according to the oral glucose tolerance test with 1.75 g/kg glucose maximum 75 g glucose. The insulin sensitivity index and homeostatic model assessment-insulin resistance (HOMA IR) were calculated and compared. Metabolic syndrome was diagnosed according to the modified WHO criteria adapted for metabolic syndrome in children. Abnormal glucose homeostasis was detected in 53% of subjects. Dyslipidaemia was present in 45.7% and hypertension in 16.6% of the patients. Metabolic syndrome was identified in 24.6% of obese children and adolescents. High HOMA-IR values and fasting glucose levels, elevated triglycerides and lower HDL levels were an indication of metabolic syndrome. Obesity and insulin resistance are significant factors for the development of metabolic syndrome in children and adolescents. In obese children higher HDL levels are preventive factor for metabolic syndrome. Preventing obesity and insulin resistance may decrease the prevalence of metabolic syndrome. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Correlation of Resistivity Value with Geotechnical N-Value of Sedimentary Area in Nusajaya, Johor, Malaysia

NASA Astrophysics Data System (ADS)

Akip Tan, S. N. Mohd; Edy Tonnizam, M.; Saad, R.; Dan, M. F. Md; Nordiana, M. M.; Hazreek, Z. A. M.; Madun, A.

2018-04-01

Electrical resistivity survey and the geotechnical SPT blow counts (N-value) were carried out simultaneously on the tropically weathered sedimentary rock mass for an excavation project at Nusajaya, Johor, Malaysia. This study aims to determine subsurface profile by using 2D-resistivity methods and correlate with N-value derived from boring works. Four boreholes were investigated in five survey lines that revealed the site is underlain by moderately to completely weathered sandstone, clay, silt and shale. Data analysis from 2D-resistivity image shows that zones with high resistivity value generally have high N-value, and vice versa. Five zones have inversed the proportional relation between N-value and resistivity Ωm value due to different types of soil lithology. It indicates that 2D-resistivity is significance to detect bodies of anomalous materials or estimating the depth of bedrock. As a conclusion, the integration of geophysical and geotechnical analysis provides a promise approach to understand some relationship concerning the subsurface subsurface ground through the combination of 2D-resistivity and N-value.

Effect of android to gynoid fat ratio on insulin resistance in obese youth.

PubMed

Aucouturier, Julien; Meyer, Martine; Thivel, David; Taillardat, Michel; Duché, Pascale

2009-09-01

Upper body fat distribution is associated with the early development of insulin resistance in obese children and adolescents. To determine if an android to gynoid fat ratio is associated with the severity of insulin resistance in obese children and adolescents, whereas peripheral subcutaneous fat may have a protective effect against insulin resistance. The pediatric department of University Hospital, Clermont-Ferrand, France. A retrospective analysis using data from medical consultations between January 2005 and January 2007. Data from 66 obese children and adolescents coming to the hospital for medical consultation were used in this study. Subjects were stratified into tertiles of android to gynoid fat ratio determined by dual-energy x-ray absorptiometry. Insulin resistance was assessed by the homeostasis model of insulin resistance (HOMA-IR) index. There were no differences in weight, body mass index, and body fat percentage between tertiles. Values of HOMA-IR were significantly increased in the 2 higher tertiles (mean [SD], tertile 2, 2.73 [1.41]; tertile 3, 2.89 [1.28]) compared with the lower tertile (tertile 1, 1.67 [1.24]) of android to gynoid fat ratio (P < .001). The HOMA-IR value was significantly associated with android to gynoid fat ratio (r = 0.35; P < .01). Android fat distribution is associated with an increased insulin resistance in obese children and adolescents. An android to gynoid fat ratio based on dual-energy x-ray absorptiometry measurements is a useful and simple technique to assess distribution of body fat associated with an increased risk of insulin resistance.

The Relationship between Type 2 Diabetes Mellitus and Non-Alcoholic Fatty Liver Disease Measured by Controlled Attenuation Parameter.

PubMed

Chon, Young Eun; Kim, Kwang Joon; Jung, Kyu Sik; Kim, Seung Up; Park, Jun Yong; Kim, Do Young; Ahn, Sang Hoon; Chon, Chae Yoon; Chung, Jae Bock; Park, Kyeong Hye; Bae, Ji Cheol; Han, Kwang Hyub

2016-07-01

The severity of non-alcoholic fatty liver disease (NAFLD) in type 2 diabetes mellitus (T2DM) population compared with that in normal glucose tolerance (NGT) individuals has not yet been quantitatively assessed. We investigated the prevalence and the severity of NAFLD in a T2DM population using controlled attenuation parameter (CAP). Subjects who underwent testing for biomarkers related to T2DM and CAP using Fibroscan® during a regular health check-up were enrolled. CAP values of 250 dB/m and 300 dB/m were selected as the cutoffs for the presence of NAFLD and for moderate to severe NAFLD, respectively. Biomarkers related to T2DM included fasting glucose/insulin, fasting C-peptide, hemoglobin A1c (HbA1c), glycoalbumin, and homeostasis model assessment of insulin resistance of insulin resistance (HOMA-IR). Among 340 study participants (T2DM, n=66; pre-diabetes, n=202; NGT, n=72), the proportion of subjects with NAFLD increased according to the glucose tolerance status (31.9% in NGT; 47.0% in pre-diabetes; 57.6% in T2DM). The median CAP value was significantly higher in subjects with T2DM (265 dB/m) than in those with pre-diabetes (245 dB/m) or NGT (231 dB/m) (all p<0.05). Logistic regression analysis showed that subjects with moderate to severe NAFLD had a 2.8-fold (odds ratio) higher risk of having T2DM than those without NAFLD (p=0.02; 95% confidence interval, 1.21-6.64), and positive correlations between the CAP value and HOMA-IR (ρ0.407) or fasting C-peptide (ρ0.402) were demonstrated. Subjects with T2DM had a higher prevalence of severe NAFLD than those with NGT. Increased hepatic steatosis was significantly associated with the presence of T2DM, and insulin resistance induced by hepatic fat may be an important mechanistic connection.

Association between Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and Components of Metabolic Syndrome in Young Chinese Men.

PubMed

Ying, X; Song, Zh; Zhao, Ch; Jiang, Y

2011-01-01

To investigate the prevalence of metabolic syndrome (MetS) in young Chinese population and assess the association between HOMA-IR and different components of MetS in young Chinese men. Overall 5576 young Chinese subjects (age range [19-44 yr], 3636 men) were enrolled in, who visited our Health Care Center for a related health checkup from March to December 2008. The international diabetes federation (IDF) definition for MetS was used. The SPSS statistical package, version 11.5 was used for the statistical analysis. The prevalence of MetS was 21.81% in young men and 5.62% in young women. According to suffering from different numbers of MetS components, the male subjects were divided into four groups. Numbers of MetS components were more and HOMA-IR values were significantly higher. In this male population, the quartile of HOMA-IR was higher, values of triglyceride (TG), fasting plasma glucose (FBG), systolic blood pressure(SBP), diastolic blood pressure(DBP) and waist circumference (WC) were all significantly higher, as well as high density lipoprotein cholesterol (HDL-C) value was significantly lower (P= 0.000). In Spearman's correlation analysis, HOMA-IR was positively correlated with TG, FBG, SBP, DBP and WC, and negatively correlated with HDL-C (r= 0.460, 0.464, 0.362, 0.346, 0.586, -0.357, respectively, all P value= 0.000). The prevalence of MetS in these young Chinese men was obviously high. Insulin resistance played an important role in occurrence and development of MetS. Waist circumference was the best correlation with HOMA-IR among all components of MetS.

Evaluation of anodic behavior of commercially pure titanium in tungsten inert gas and laser welds.

PubMed

Orsi, Iara Augusta; Raimundo, Larica B; Bezzon, Osvaldo Luiz; Nóbilo, Mauro Antonio de Arruda; Kuri, Sebastião E; Rovere, Carlos Alberto D; Pagnano, Valeria Oliveira

2011-12-01

This study evaluated the resistance to corrosion in welds made with Tungsten Inert Gas (TIG) in specimens made of commercially pure titanium (cp Ti) in comparison with laser welds. A total of 15 circular specimens (10-mm diameter, 2-mm thick) were fabricated and divided into two groups: control group-cp Ti specimens (n = 5); experimental group-cp Ti specimens welded with TIG (n = 5) and with laser (n = 5). They were polished mechanically, washed with isopropyl alcohol, and dried with a drier. In the anodic potentiodynamic polarization assay, measurements were taken using a potentiostat/galvanostat in addition to CorrWare software for data acquisition and CorrView for data visualization and treatment. Three curves were made for each working electrode. Corrosion potential values were statistically analyzed by the Student's t-test. Statistical analysis showed that corrosion potentials and passive current densities of specimens welded with TIG are similar to those of the control group, and had lower values than laser welding. TIG welding provided higher resistance to corrosion than laser welding. Control specimens welded with TIG were more resistant to local corrosion initiation and propagation than those with laser welding, indicating a higher rate of formation and growth of passive film thickness on the surfaces of these alloys than on specimens welded with laser, making it more difficult for corrosion to occur. © 2011 by the American College of Prosthodontists.

Shallow lithological structure across the Dead Sea Transform derived from geophysical experiments

USGS Publications Warehouse

Stankiewicz, J.; Munoz, G.; Ritter, O.; Bedrosian, P.A.; Ryberg, T.; Weckmann, U.; Weber, M.

2011-01-01

In the framework of the DEad SEa Rift Transect (DESERT) project a 150 km magnetotelluric profile consisting of 154 sites was carried out across the Dead Sea Transform. The resistivity model presented shows conductive structures in the western section of the study area terminating abruptly at the Arava Fault. For a more detailed analysis we performed a joint interpretation of the resistivity model with a P wave velocity model from a partially coincident seismic experiment. The technique used is a statistical correlation of resistivity and velocity values in parameter space. Regions of high probability of a coexisting pair of values for the two parameters are mapped back into the spatial domain, illustrating the geographical location of lithological classes. In this study, four regions of enhanced probability have been identified, and are remapped as four lithological classes. This technique confirms the Arava Fault marks the boundary of a highly conductive lithological class down to a depth of ???3 km. That the fault acts as an impermeable barrier to fluid flow is unusual for large fault zone, which often exhibit a fault zone characterized by high conductivity and low seismic velocity. At greater depths it is possible to resolve the Precambrian basement into two classes characterized by vastly different resistivity values but similar seismic velocities. The boundary between these classes is approximately coincident with the Al Quweira Fault, with higher resistivities observed east of the fault. This is interpreted as evidence for the original deformation along the DST originally taking place at the Al Quweira Fault, before being shifted to the Arava Fault. 

The value of Doppler ultrasound in predicting delayed graft function occurrence after kidney transplantation.

PubMed

Mocny, Grzegorz; Bachul, Piotr; Chang, Ea-Sle; Kulig, Piotr

The aim of this study was to assess the predictive value of blood flow velocity and vascular resistance measured by Doppler ultrasound in terms of pulsatility index (PI) and resistive index (RI) respectively, in the occurrence of delayed graft function (DGF) after kidney transplantation. This prospective study enrolled kidney transplant recipients operated from January 2005 to April 2009 in the 1st Department of General, Oncological and Gastroenterological Surgery, Jagiellonian University Medical College, Kraków, Poland. The medical records of 53 kidney transplant recipients from deceased donors were reviewed. PI and RI values of the graft arcuate artery were calculated immediately after blood flow restoration and on the 1st, 2nd, 4th and 8th post-operative day. DGF was observed in 20 patients (37.7%), while 33 patients (62.3%) had immediate restoration of the kidney function. The mean intraoperative values of RI and PI from patients with DGF were significantly higher in comparison to patients without DGF (0.9 vs. 0.74, p <0.001; 1.76 vs. 1.54, p = 0.019, respectively). Post-operatively, the RI and PI values remained stable and significantly higher in DGF group. The highest sensitivity of RI to predict DGF occurrence was observed intraoperatively and on the first postoperative day, with values of 77.8% and 72.2%, respectively. The risk of DGF occurrence with intraoperative RI value ≥0.9 increased by 13-fold, and with intraoperative PI value ≥1.9 by 12-fold. This increase was even more prominent during the first post-operative day with RI value ≥0.9 or PI value ≥1.9 with 19-fold increase in the risk of DGF occurrence. According to our study, the utilization of Doppler ultrasound with measurement of hemodynamic parameters (PI, RI), play a crucial role in predicting the outcomes of kidney transplantation.

Evidence for insulin resistance in nonobese patients with polycystic ovarian disease.

PubMed

Jialal, I; Naiker, P; Reddi, K; Moodley, J; Joubert, S M

1987-05-01

In this study seven normal weight Indian patients with polycystic ovarian disease (PCOD) with no evidence of acanthosis nigricans and 7 age- and weight-matched normal Indian women were studied to determine whether PCOD patients were insulin-resistant. While all 14 women had normal glucose tolerance, the PCOD women had significantly higher mean plasma glucose levels at 30 and 60 min and higher mean incremental glucose areas [incremental areas: PCOD, 9.0 +/- 2.2 (+/- SEM); normal women, 4.0 +/- 0.8 mmol/L; P less than 0.05]. Insulin responses were significantly higher in the PCOD compared to normal women (incremental areas: PCOD, 623.8 +/- 78.3; normal women, 226.2 +/- 30.3 microU/mL; P less than 0.001). Both serum testosterone and androstenedione levels correlated with the insulin areas (r = 0.82; P less than 0.001 and r = 0.86; P less than 0.001, respectively). [125I] Insulin binding to erythrocytes revealed decreased maximum specific binding in the PCOD women (6.9 +/- 0.6%) compared to that in normal women (9.2 +/- 0.7%; P less than 0.02). While Scatchard analysis revealed similar receptor numbers, ID50 values demonstrated decreased receptor affinity in the women with PCOD. In conclusion, in the absence of acanthosis nigricans, nonobese patients with PCOD are insulin resistant, and this insulin resistance correlates with the hyperandrogenism.

Plant responses to extreme climatic events: a field test of resilience capacity at the southern range edge.

PubMed

Herrero, Asier; Zamora, Regino

2014-01-01

The expected and already observed increment in frequency of extreme climatic events may result in severe vegetation shifts. However, stabilizing mechanisms promoting community resilience can buffer the lasting impact of extreme events. The present work analyzes the resilience of a Mediterranean mountain ecosystem after an extreme drought in 2005, examining shoot-growth and needle-length resistance and resilience of dominant tree and shrub species (Pinus sylvestris vs Juniperus communis, and P. nigra vs J. oxycedrus) in two contrasting altitudinal ranges. Recorded high vegetative-resilience values indicate great tolerance to extreme droughts for the dominant species of pine-juniper woodlands. Observed tolerance could act as a stabilizing mechanism in rear range edges, such as the Mediterranean basin, where extreme events are predicted to be more detrimental and recurrent. However, resistance and resilience components vary across species, sites, and ontogenetic states: adult Pinus showed higher growth resistance than did adult Juniperus; saplings displayed higher recovery rates than did conspecific adults; and P. nigra saplings displayed higher resilience than did P. sylvestris saplings where the two species coexist. P. nigra and J. oxycedrus saplings at high and low elevations, respectively, were the most resilient at all the locations studied. Under recurrent extreme droughts, these species-specific differences in resistance and resilience could promote changes in vegetation structure and composition, even in areas with high tolerance to dry conditions.

Plant Responses to Extreme Climatic Events: A Field Test of Resilience Capacity at the Southern Range Edge

PubMed Central

Herrero, Asier; Zamora, Regino

2014-01-01

The expected and already observed increment in frequency of extreme climatic events may result in severe vegetation shifts. However, stabilizing mechanisms promoting community resilience can buffer the lasting impact of extreme events. The present work analyzes the resilience of a Mediterranean mountain ecosystem after an extreme drought in 2005, examining shoot-growth and needle-length resistance and resilience of dominant tree and shrub species (Pinus sylvestris vs Juniperus communis, and P. nigra vs J. oxycedrus) in two contrasting altitudinal ranges. Recorded high vegetative-resilience values indicate great tolerance to extreme droughts for the dominant species of pine-juniper woodlands. Observed tolerance could act as a stabilizing mechanism in rear range edges, such as the Mediterranean basin, where extreme events are predicted to be more detrimental and recurrent. However, resistance and resilience components vary across species, sites, and ontogenetic states: adult Pinus showed higher growth resistance than did adult Juniperus; saplings displayed higher recovery rates than did conspecific adults; and P. nigra saplings displayed higher resilience than did P. sylvestris saplings where the two species coexist. P. nigra and J. oxycedrus saplings at high and low elevations, respectively, were the most resilient at all the locations studied. Under recurrent extreme droughts, these species-specific differences in resistance and resilience could promote changes in vegetation structure and composition, even in areas with high tolerance to dry conditions. PMID:24489971

Expression of multidrug resistance-associated protein (MRP) and multidrug resistance (MDR1) genes in acute myeloid leukemia.

PubMed

Zhou, D C; Zittoun, R; Marie, J P

1995-10-01

The frequency, prognostic value and interrelation of MRP and MDR1 gene expressions were investigated by quantitative reverse transcription polymerase chain reaction (RT-PCR) in 91 cases of de novo acute myeloid leukemia (AML), of which 51 were newly diagnosed, 21 were relapsed, and 19 were refractory patients. As compared with normal bone marrow cells and peripheral granulocytes, an overexpression of MRP gene was found in 24% (22 of 91) cases of de novo AML. The incidence of MRP gene overexpression tended to be higher in relapsed patients than in newly diagnosed patients (38 vs 18%, P = 0.063). In 52 evaluable newly diagnosed and relapsed patients treated with MDR-related drugs, both MRP and MDR1 gene overexpressions correlated to a higher rate of emergence of clinical drug resistance (83 vs 22%, P = 0.005; and 67 vs 24%, P = 0.045, respectively). A positive correlation was found between MRP and MDR1 gene overexpressions (R = 0.53, P < 0.001). Analysis of 46 evaluable MDR1-negative cases revealed a trend for higher resistant disease rate in MRP-positive patients as compared with MRP-negative patients (100 vs 20%, P = 0.053). These data suggest that MRP, like MDR1, may have an important negative impact on the outcome of chemotherapy, and that there may be a common mechanism of induction for the overexpression of these two genes.

Non-destructive, ultra-low resistance, thermally stable contacts for use on shallow junction InP solar cells

NASA Technical Reports Server (NTRS)

Weizer, V. G.; Fatemi, N. S.; Korenyi-Both, A. L.

1993-01-01

Contact formation to InP is plagued by violent metal-semiconductor intermixing that takes place during the contact sintering process. Because of this the InP solar cell cannot be sintered after contact deposition. This results in cell contact resistances that are orders of magnitude higher than those that could be achieved if sintering could be performed in a non-destructive manner. We report here on a truly unique contact system involving Au and Ge, which is easily fabricated, which exhibits extremely low values of contact resistivity, and in which there is virtually no metal-semiconductor interdiffusion, even after extended sintering. We present a description of this contact system and suggest possible mechanisms to explain the observed behavior.

Effect of incorporating finger millet in wheat flour on mixolab behavior, chapatti quality and starch digestibility.

PubMed

Sharma, Bharati; Gujral, Hardeep Singh; Solah, Vicky

2017-09-15

Wheat and finger millet flour (two cultivars) were blended in the ratio (3:1) to form a composite flour and its dough properties were studied on the mixolab. The chapatti making and digestibility behavior of the composite flour was also investigated. The wheat finger millet (WFM) flour blend displayed up to 30.7% higher total phenolic content (TPC), 38.2% higher total flavonoid content (TFC) and 75.4% higher antioxidant activity (AOA) than the wheat flour. Chapattis prepared from the composite blends exhibited lower retrogradation as evident by the mixolab retrogradation index, higher values of soluble starch and soluble amylose in stored chapatti. The slowly digestible starch (SDS) correlated positively (R=0.816, p<0.05) with TPC and water absorption correlated positively (R=0.995, p<0.05) with damage starch content. The chapattis made from the composite flour had higher SDS and resistant starch (RS) values demonstrating potential as a food with functional characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Antibiotics and Antibiotic Resistance Genes in Sediment of Honghu Lake and East Dongting Lake, China.

PubMed

Yang, Yuyi; Cao, Xinhua; Lin, Hui; Wang, Jun

2016-11-01

Sediment is an ideal medium for the aggregation and dissemination of antibiotics and antibiotic resistance genes (ARGs). The levels of antibiotics and ARGs in Honghu Lake and East Dongting Lake of central China were investigated in this study. The concentrations of eight antibiotics (four sulfonamides and four tetracyclines) in Honghu Lake were in the range 90.00-437.43 μg kg -1 (dry weight (dw)) with mean value of 278.21 μg kg -1 dw, which was significantly higher than those in East Dongting Lake (60.02-321.04 μg kg -1 dw, mean value of 195.70 μg kg -1 dw). Among the tested three sulfonamide resistance genes (sul) and eight tetracycline resistance genes (tet), sul1, sul2, tetA, tetC, and tetM had 100 % detection frequency in sediment samples of East Dongting Lake, while only sul1, sul2, and tetC were observed in all samples of Honghu Lake. The relative abundance of sul2 was higher than that of sul1 at p < 0.05 level in both lakes. The relative abundance of tet genes in East Dongting Lake was in the following order: tetM > tetB > tetC > tetA. The relative abundance of sul1, sul2, and tetC in East Dongting Lake was significantly higher than those in Honghu Lake. The abundance of background bacteria may play an important role in the horizontal spread of sul2 and tetC genes in Honghu Lake and sul1 in East Dongting Lake, respectively. Redundancy analysis indicated that tetracyclines may play a more important role than sulfonamides in the abundance of sul1, sul2, and tetC gens in Honghu Lake and East Dongting Lake.

Evaluation of Xpert MTB/RIF Versus AFB Smear and Culture to Identify Pulmonary Tuberculosis in Patients With Suspected Tuberculosis From Low and Higher Prevalence Settings

PubMed Central

Luetkemeyer, Anne F.; Firnhaber, Cynthia; Kendall, Michelle A.; Wu, Xingye; Mazurek, Gerald H.; Benator, Debra A.; Arduino, Roberto; Fernandez, Michel; Guy, Elizabeth; Johnson, Pamela; Metchock, Beverly; Sattler, Fred; Telzak, Edward; Wang, Yun F.; Weiner, Marc; Swindells, Susan; Sanne, Ian M.; Havlir, Diane V.; Grinsztejn, Beatriz; Alland, David

2016-01-01

Background. The Xpert MTB/RIF (Xpert) assay is a rapid nucleic acid amplification test widely used in settings of high tuberculosis prevalence to detect tuberculosis as well as rpoB mutations associated with rifampin resistance. Data are needed on the diagnostic performance of Xpert in lower-prevalence settings to inform appropriate use for both tuberculosis detection and the need for respiratory isolation. Methods. Xpert was compared to 2 sputum samples, each evaluated with acid-fast bacilli (AFB) smear and mycobacterial culture using liquid and solid culture media, from participants with suspected pulmonary tuberculosis from the United States, Brazil, and South Africa. Results. Of 992 participants enrolled with evaluable results, 22% had culture-confirmed tuberculosis. In 638 (64%) US participants, 1 Xpert result demonstrated sensitivity of 85.2% (96.7% in participants with AFB smear-positive [AFB+] sputum, 59.3% with AFB smear-negative [AFB–] sputum), specificity of 99.2%, negative predictive value (NPV) of 97.6%, and positive predictive value of 94.9%. Results did not differ between higher- and low-prevalence settings. A second Xpert assay increased overall sensitivity to 91.1% (100% if AFB+, 71.4% if AFB–), with specificity of 98.9%. In US participants, a single negative Xpert result predicted the absence of AFB+/culture-positive tuberculosis with an NPV of 99.7%; NPV of 2 Xpert assays was 100%, suggesting a role in removing patients from airborne infection isolation. Xpert detected tuberculosis DNA and mutations associated with rifampin resistance in 5 of 7 participants with rifampin-resistant, culture-positive tuberculosis. Specificity for rifampin resistance was 99.5% and NPV was 98.9%. Conclusions. In the United States, Xpert testing performed comparably to 2 higher-tuberculosis-prevalence settings. These data support the use of Xpert in the initial evaluation of tuberculosis suspects and in algorithms assessing need for respiratory isolation. PMID:26839383

Electrical resistivity characterization of anisotropy in the Biscayne Aquifer.

PubMed

Yeboah-Forson, Albert; Whitman, Dean

2014-01-01

Electrical anisotropy occurs when electric current flow varies with azimuth. In porous media, this may correspond to anisotropy in the hydraulic conductivity resulting from sedimentary fabric, fractures, or dissolution. In this study, a 28-electrode resistivity imaging system was used to investigate electrical anisotropy at 13 sites in the Biscayne Aquifer of SE Florida using the rotated square array method. The measured coefficient of electrical anisotropy generally ranged from 1.01 to 1.12 with values as high as 1.36 found at one site. The observed electrical anisotropy was used to estimate hydraulic anisotropy (ratio of maximum to minimum hydraulic conductivity) which ranged from 1.18 to 2.83. The largest values generally were located on the Atlantic Coastal Ridge while the lowest values were in low elevation areas on the margin of the Everglades to the west. The higher values of anisotropy found on the ridge may be due to increased dissolution rates of the oolitic facies of the Miami formation limestone compared with the bryozoan facies to the west. The predominate trend of minimum resistivity and maximum hydraulic conductivity was E-W/SE-NW beneath the ridge and E-W/SW-NE farther west. The anisotropy directions are similar to the predevelopment groundwater flow direction as indicated in published studies. This suggests that the observed anisotropy is related to the paleo-groundwater flow in the Biscayne Aquifer. © 2013, National Ground Water Association.

Influence of Blended Cements with Calcareous Fly Ash on Chloride Ion Migration and Carbonation Resistance of Concrete for Durable Structures.

PubMed

Glinicki, Michał A; Jóźwiak-Niedźwiedzka, Daria; Gibas, Karolina; Dąbrowski, Mariusz

2016-01-02

The objective of this paper is to examine the possible use of new blended cements containing calcareous fly ash in structural concrete, potentially adequate for structural elements of nuclear power plants. The investigation included five new cements made with different contents of non-clinker constituents: calcareous fly ash, siliceous fly ash, ground granulated blastfurnace slag, and a reference cement-ordinary Portland cement. The influence of innovative cements on the resistance of concrete to chloride and carbonation exposure was studied. Additionally, an evaluation of the microstructure was performed using optical microscopy on concrete thin sections. Test results revealed a substantial improvement of the resistance to chloride ion penetration into concrete containing blended cements. The resistance was higher for increased clinker replacement levels and increased with curing time. However, concrete made with blended cements exhibited higher depth of carbonation than the Portland cement concrete, except the Portland-fly ash cement with 14.3% of calcareous fly ash. The thin sections analysis confirmed the values of the carbonation depth obtained from the phenolphthalein test. Test results indicate the possible range of application for new cements containing calcareous fly ash.

Influence of Blended Cements with Calcareous Fly Ash on Chloride Ion Migration and Carbonation Resistance of Concrete for Durable Structures

PubMed Central

Glinicki, Michał A.; Jóźwiak-Niedźwiedzka, Daria; Gibas, Karolina; Dąbrowski, Mariusz

2016-01-01

The objective of this paper is to examine the possible use of new blended cements containing calcareous fly ash in structural concrete, potentially adequate for structural elements of nuclear power plants. The investigation included five new cements made with different contents of non-clinker constituents: calcareous fly ash, siliceous fly ash, ground granulated blastfurnace slag, and a reference cement—ordinary Portland cement. The influence of innovative cements on the resistance of concrete to chloride and carbonation exposure was studied. Additionally, an evaluation of the microstructure was performed using optical microscopy on concrete thin sections. Test results revealed a substantial improvement of the resistance to chloride ion penetration into concrete containing blended cements. The resistance was higher for increased clinker replacement levels and increased with curing time. However, concrete made with blended cements exhibited higher depth of carbonation than the Portland cement concrete, except the Portland-fly ash cement with 14.3% of calcareous fly ash. The thin sections analysis confirmed the values of the carbonation depth obtained from the phenolphthalein test. Test results indicate the possible range of application for new cements containing calcareous fly ash. PMID:28787821

Vitamin D insufficiency is associated with insulin resistance independently of obesity in primary schoolchildren. The healthy growth study.

PubMed

Moschonis, George; Androutsos, Odysseas; Hulshof, Toine; Dracopoulou, Maria; Chrousos, George P; Manios, Yannis

2018-04-02

To explore the associations of vitamin D status and obesity with insulin resistance (IR) in children. A sample of 2282 schoolchildren (9-13 years old) in Greece was examined. Sociodemographic, anthropometric (weight, height), biochemical (fasting plasma glucose, serum insulin and 25(OH)D), pubertal status and physical activity data were collected, using standard methods. The "Vitamin D Standardization Program" protocol was applied to standardize serum 25(OH)D values. The prevalence of vitamin D insufficiency (serum 25(OH)D < 50 nmol/L) was higher in obese children compared to their over- and normal-weight counterparts (60.5% vs 51.6% and 51%, P = .017). Furthermore, children with IR (both obese and non-obese) had higher prevalence of vitamin D insufficiency compared to non-obese, non-insulin resistant children (66% and 59.2% vs 49.8%, P < .05), possibly indicating that IR is associated with vitamin D insufficiency, independently of obesity. In line with the above, the results from logistic regression analyses controlled for several potential confounders, showed a 1.48 (95% C.I: 1.2-1.84) higher likelihood for vitamin D insufficiency for insulin resistant children compared to the non-insulin resistant ones, while no significant association was observed with obesity. The present study revealed a high prevalence of vitamin D insufficiency among schoolchildren in Greece, particularly among obese and insulin resistant ones. In addition, it highlighted that the significant association of vitamin D insufficiency with IR is possibly independent of obesity. Further clinical trials are needed to confirm this possible independent association but also explore the potential beneficial effect of vitamin D supplementation on IR and possibly on weight management too. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Solid oxide fuel cells with bi-layered electrolyte structure

NASA Astrophysics Data System (ADS)

Zhang, Xinge; Robertson, Mark; Decès-Petit, Cyrille; Xie, Yongsong; Hui, Rob; Qu, Wei; Kesler, Olivera; Maric, Radenka; Ghosh, Dave

In this work, we have developed solid oxide fuel cells with a bi-layered electrolyte of 2 μm SSZ and 4 μm SDC using tape casting, screen printing, and co-firing processes. The cell reached power densities of 0.54 W cm -2 at 650 °C and 0.85 W cm -2 at 700 °C, with open circuit voltage (OCV) values larger than 1.02 V. The electrical leaking between anode and cathode through an SDC electrolyte has been blocked in the bi-layered electrolyte structure. However, both the electrolyte resistance (R el) and electrode polarization resistance (R p,a+c) increased in comparison to cells with single-layered SDC electrolytes. The formation of a solid solution of (Ce, Zr)O 2- x during sintering process and the flaws in the bi-layered electrolyte structure seem to be the main causes for the increase in the R el value (0.32 Ω cm 2) at 650 °C, which is almost one order of magnitude higher than the calculated value.

Antibacterial activity of Zuccagnia punctata Cav. ethanolic extracts.

PubMed

Zampini, Iris C; Vattuone, Marta A; Isla, Maria I

2005-12-01

The present study was conducted to investigate antibacterial activity of Zuccagnia punctata ethanolic extract against 47 strains of antibiotic-resistant Gram-negative bacteria and to identify bioactive compounds. Inhibition of bacterial growth was investigated using agar diffusion, agar macrodilution, broth microdilution and bioautographic methods. Zuccagnia punctata extract was active against all assayed bacteria (Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Enterobacter cloacae, Serratia marcescens, Morganella morganii, Acinetobacter baumannii, Pseudomonas aeruginosa, Stenotrophomonas maltophilia) with minimal inhibitory concentration (MIC) values ranging from 25 to 200 microg/mL. Minimal bactericidal concentration (MBC) values were identical or two-fold higher than the corresponding MIC values. Contact bioautography, indicated that Zuccagnia punctata extracts possess one major antibacterial component against Pseudomonas aeruginosa and at least three components against. Klebsiella pneumoniae and Escherichia coli. Activity-guided fractionation of 1he ethanol extract on a silica gel column yielded a compound (2',4'-dihydroxychalcone), which exhibited strong antibacterial activity with MIC values between 0.10 and 1.00 microg/mL for Proteus mirabilis, Enterobacter cloacae, Serratia marcescens, Morganella morganii, Acinetobacter baumannii, Pseudomonas aeruginosa, Stenotrophomonas maltophilia. These values are lower than imipenem (0.25-16 microg/mL). Zuccagnia punctata might provide promising therapeutic agents against infections with multi-resistant Gram-negative bacteria.

Investigation for surface resistance of yttrium-barium-copper-oxide thin films on various substrates for microwave applications

NASA Astrophysics Data System (ADS)

Yao, Hongjun

High temperature superconducting (HTS) materials such as YBCO (Yttrium-Barium-Copper-Oxide) are very attractive in microwave applications because of their extremely low surface resistance. In the proposed all-HTS tunable filter, a layer of HTS thin film on a very thin substrate (100 mum) is needed to act as the toractor that can be rotated to tune the frequency. In order to provide more substrate candidates that meet both electrical and mechanical requirements for this special application, surface resistance of YBCO thin films on various substrates was measured using microstrip ring resonator method. For alumina polycrystalline substrate, a layer of YSZ (Yttrium stabilized Zirconia) was deposited using IBAD (ion beam assisted deposition) method prior to YBCO deposition. The surface resistance of the YBCO thin film on alumina was found to be 22 mO due to high-angle grain boundary problem caused by the mixed in-plane orientations and large FWHM (full width at half maximum) of the thin film. For YBCO thin films on a YSZ single crystal substrate, the surface resistance showed even higher value of 30 mO because of the mixed in-plane orientation problem. However, by annealing the substrate in 200 Torr oxygen at 730°C prior to deposition, the in-plane orientation of YBCO thin films can be greatly improved. Therefore, the surface resistance decreased to 1.4 mO, which is still more than an order higher than the reported best value. The YBCO thin films grown on LaAlO3 single crystal substrate showed perfect in-plane orientation with FWHM less 1°. The surface resistance was as low as 0.032 mO. A tunable spiral resonator made of YBCO thin film on LaAlO3 single crystal substrate demonstrated that the resonant frequency can be tuned in a rang as large as 500 MHz by changing the gap between toractor and substrate. The Q-factor was more than 12,000, which ensured the extraordinarily high sensitivity for the proposed all-HTS tunable filter.

Inheritance mode and mechanisms of resistance to imidacloprid in the house fly Musca domestica (Diptera:Muscidae) from China.

PubMed

Ma, Zhuo; Li, Jing; Zhang, Yi; Shan, Chao; Gao, Xiwu

2017-01-01

Imidacloprid is a neonicotinoid insecticide that is effective against house fly, Musca domestica L., which is a major pest with the ability to develop resistance to insecticides. In the present study, we investigated the inheritance mode, the cross-resistance pattern and the mechanisms of resistance to imidacloprid. A near-isogenic house fly line (N-IRS) with 78-fold resistance to imidacloprid was used to demonstrate the mode of inheritance. The overlapping confidence limits of LC50 values and the slopes of the log concentration-probit lines between the reciprocal F1 and F1' progenies suggest that imidacloprid resistance is inherited autosomally in the house fly. There was incomplete dominant inheritance in the F1 and F1' progenies, based on dominance values of 0.77 and 0.75, respectively. A monogenic inheritance model revealed that imidacloprid resistance is governed by more than one factor. Compared to the field strain (CFD), the N-IRS strain developed more cross-resistance to chlorfenapyr and no cross-resistance to chlorpyrifos and acetamiprid, but showed negative cross-resistance to beta-cypermethrin and azamethiphos. Three synergists, diethyl malate (DEM), s,s,s-tributylphosphorotrithioate (DEF), and piperonyl butoxide (PBO), showed significant synergism against to imidacloprid (4.55-, 4.46- and 3.34-fold respectively) in the N-IRS strain. However, both DEM and PBO had no synergism and DEF only exhibited slight synergism in the CSS strain. The activities of carboxylesterase (CarE), glutathione S-transferases (GSTs) and cytochrome P450 in the N-IRS strain were significantly higher than in the CSS strain. But similar synergistic potential of DEF to imidacloprid between the CSS and N-IRS strain suggested that GSTs and cytochrome P450 played much more important role than esterase for the N-IRS strain resistance to imidacloprid. These results should be helpful for developing an improved management strategy to delay the development of imidacloprid resistance in house fly.

Inheritance mode and mechanisms of resistance to imidacloprid in the house fly Musca domestica (Diptera:Muscidae) from China

PubMed Central

Zhang, Yi; Shan, Chao

2017-01-01

Imidacloprid is a neonicotinoid insecticide that is effective against house fly, Musca domestica L., which is a major pest with the ability to develop resistance to insecticides. In the present study, we investigated the inheritance mode, the cross-resistance pattern and the mechanisms of resistance to imidacloprid. A near-isogenic house fly line (N-IRS) with 78-fold resistance to imidacloprid was used to demonstrate the mode of inheritance. The overlapping confidence limits of LC50 values and the slopes of the log concentration-probit lines between the reciprocal F1 and F1’ progenies suggest that imidacloprid resistance is inherited autosomally in the house fly. There was incomplete dominant inheritance in the F1 and F1’ progenies, based on dominance values of 0.77 and 0.75, respectively. A monogenic inheritance model revealed that imidacloprid resistance is governed by more than one factor. Compared to the field strain (CFD), the N-IRS strain developed more cross-resistance to chlorfenapyr and no cross-resistance to chlorpyrifos and acetamiprid, but showed negative cross-resistance to beta-cypermethrin and azamethiphos. Three synergists, diethyl malate (DEM), s,s,s-tributylphosphorotrithioate (DEF), and piperonyl butoxide (PBO), showed significant synergism against to imidacloprid (4.55-, 4.46- and 3.34-fold respectively) in the N-IRS strain. However, both DEM and PBO had no synergism and DEF only exhibited slight synergism in the CSS strain. The activities of carboxylesterase (CarE), glutathione S-transferases (GSTs) and cytochrome P450 in the N-IRS strain were significantly higher than in the CSS strain. But similar synergistic potential of DEF to imidacloprid between the CSS and N-IRS strain suggested that GSTs and cytochrome P450 played much more important role than esterase for the N-IRS strain resistance to imidacloprid. These results should be helpful for developing an improved management strategy to delay the development of imidacloprid resistance in house fly. PMID:29228021

Flowable composites for bonding orthodontic retainers.

PubMed

Tabrizi, Sama; Salemis, Elio; Usumez, Serdar

2010-01-01

To test the null hypothesis that there are no statistically significant differences between flowables and an orthodontic adhesive tested in terms of shear bond strength (SBS) and pullout resistance. To test the SBS of Light Bond, FlowTain, Filtek Supreme, and Tetric Flow were applied to the enamel surfaces of 15 teeth. Using matrices for application, each composite material was cured for 40 seconds and subjected to SBS testing. To test pullout resistance, 15 samples were prepared for each composite in which a wire was embedded; then the composite was cured for 40 seconds. Later, the ends of the wire were drawn up and tensile stress was applied until the resin failed. Findings were analyzed using an ANOVA and a Tukey HSD test. The SBS values for Light Bond, FlowTain, Filtek Supreme, and Tetric Flow were 19.0 +/- 10.9, 14.7 +/- 9.3, 22.4 +/- 16.3, and 16.8 +/- 11.8 MPa, respectively, and mean pullout values were 42.2 +/- 13.0, 24.0 +/- 6.9, 26.3 +/- 9.4, and 33.8 +/- 18.0 N, respectively. No statistically significant differences were found among the groups in terms of SBS (P > .05). On the other hand, Light Bond yielded significantly higher pullout values compared with the flowables Filtek Supreme and Flow-Tain (P < .01). However, there were no significant differences among the pullout values of flowables, nor between Light Bond and Tetric Flow (P > .05). The hypothesis is rejected. Light Bond yielded significantly higher pullout values compared with the flowables Filtek Supreme and FlowTain. However, flowable composites provided satisfactory SBS and wire pullout values, comparable to a standard orthodontic resin, and therefore can be used as an alternative for direct bonding of lingual retainers.

Predicting genotypes environmental range from genome-environment associations.

PubMed

Manel, Stéphanie; Andrello, Marco; Henry, Karine; Verdelet, Daphné; Darracq, Aude; Guerin, Pierre-Edouard; Desprez, Bruno; Devaux, Pierre

2018-05-17

Genome-environment association methods aim to detect genetic markers associated with environmental variables. The detected associations are usually analysed separately to identify the genomic regions involved in local adaptation. However, a recent study suggests that single-locus associations can be combined and used in a predictive way to estimate environmental variables for new individuals on the basis of their genotypes. Here, we introduce an original approach to predict the environmental range (values and upper and lower limits) of species genotypes from the genetic markers significantly associated with those environmental variables in an independent set of individuals. We illustrate this approach to predict aridity in a database constituted of 950 individuals of wild beets and 299 individuals of cultivated beets genotyped at 14,409 random Single Nucleotide Polymorphisms (SNPs). We detected 66 alleles associated with aridity and used them to calculate the fraction (I) of aridity-associated alleles in each individual. The fraction I correctly predicted the values of aridity in an independent validation set of wild individuals and was then used to predict aridity in the 299 cultivated individuals. Wild individuals had higher median values and a wider range of values of aridity than the cultivated individuals, suggesting that wild individuals have higher ability to resist to stress-aridity conditions and could be used to improve the resistance of cultivated varieties to aridity. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Development of a hybrid paclitaxel-loaded arsenite nanoparticle (HPAN) delivery system for synergistic combined therapy of paclitaxel-resistant cancer

NASA Astrophysics Data System (ADS)

Chen, Fei-yan; Zhang, Yu; Chen, Xiang-yu; Li, Jia-qian; Xiao, Xiao-ping; Yu, Lu-lu; Tang, Qun

2017-04-01

Multidrug resistance (MDR) is a major reason for failure of chemotherapy in a variety of human tumors. For instance, paclitaxel (PTX) has been widely used as a first-line anticancer drug, but resistance to PTX is becoming increasingly serious. Herein, we propose a strategy of combined therapy to overcome MDR of PTX by introducing a hybrid paclitaxel-loaded gadolinium arsenite nanoparticle (HPAN), where PTX was conjugated with rod-shaped gadolinium arsenite (GdAsOx) nanoparticle (NP). Triggered by endogenous inorganic phosphate (Pi), the hybrid nanoparticles readily collapse, thereby releasing PTX and arsenic trioxide (ATO). An MTT assay indicated IC50 values for HPAN one order of magnitude lower than for a simple equivalent mixture of PTX and ATO against PTX-resistant human colon cancer cells (HCT 166), indicating remarkable synergistic effect. Species type-dependent cellular uptake, induced apoptosis, and cell cycle modulation were also evaluated. Cellular uptake tests indicate that the HPAN presents higher PTX intracellular loading for the PTX-resistant cells and longer intracellular retention time, displaying resistance to drug efflux from the cancer cell than pristine PTX or the equivalent mixture of PTX and ATO. Cell cycle and apoptosis tests consistently proved that addition of HPAN resulted in higher G2/M and apoptosis in PTX-resistant cells. In vivo anticancer experiments evidenced that HPAN had better therapeutic effect on the resistant tumor in the murine xenograft model than pristine PTX or a mixture of PTX and ATO. Our results suggest that HPAN might enhance the therapeutic index and overcome PTX resistance and also demonstrate that the combined therapy is not only related to the species of combined agents but also their physiochemical states.

Effect of electron beam and gamma radiation on drug-susceptible and drug-resitant listeria monocytogenes strains in salmon under different temperature.

PubMed

Skowron, Krzysztof; Grudlewska, Katarzyna; Gryń, Grzegorz; Skowron, Karolina Jadwiga; Świeca, Agnieszka; Paluszak, Zbigniew; Zimek, Zbigniew; Rafalski, Andrzej; Gospodarek-Komkowska, Eugenia

2018-05-04

To investigate the effect of gamma radiation and high energy electron beam doses on the inactivation of antibiotic-susceptible and antibiotic-resistant Listeria monocytogenes strains inoculated on the surface of raw salmon fillets stored at different temperature (-20°C, 4°C and 25°C). The population of bacteria strains resistance to penicillin, ampicillin, meropenem, erythromycin and trimethoprim-sulfamethoxazole was generated. When using gamma irradiation, the theoretical lethal dose ranged from 1.44 to 5.68 kGy and for electron beam the values ranged from 2.99 to 6.83 kGy. The theoretical lethal dose for both radiation methods was higher for antibiotic-resistant strains. Gamma radiation proved to be a more effective method for extending salmon fillet shelf-life. The evaluation of PFGE electrophoregram revealed that the repair of radiation-caused DNA damage occurred faster in antibiotic-resistant L. monocytogenes strains. The number of live L. monocytogenes cells, 40 hours after irradiation, also was higher in antibiotic-resistant strain suspension. The present study showed that gamma radiation was more effective in the elimination of the tested microorganisms and food preservation, than a high energy electron beam. The antibiotic-resistant L. monocytogenes strains were more resistant to both radiation methods. There are a lot of research on the effect of radiation on the number of bacteria in food products. However, there is almost no information about the effect of strain properties, such as drug susceptibility, virulence, etc., on their resistance to ionizing radiation. An increasing number of drug resistant bacterial strains isolated from food, encourages to take up this research subject. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Uncertainty analysis of least-cost modeling for designing wildlife linkages.

PubMed

Beier, Paul; Majka, Daniel R; Newell, Shawn L

2009-12-01

Least-cost models for focal species are widely used to design wildlife corridors. To evaluate the least-cost modeling approach used to develop 15 linkage designs in southern California, USA, we assessed robustness of the largest and least constrained linkage. Species experts parameterized models for eight species with weights for four habitat factors (land cover, topographic position, elevation, road density) and resistance values for each class within a factor (e.g., each class of land cover). Each model produced a proposed corridor for that species. We examined the extent to which uncertainty in factor weights and class resistance values affected two key conservation-relevant outputs, namely, the location and modeled resistance to movement of each proposed corridor. To do so, we compared the proposed corridor to 13 alternative corridors created with parameter sets that spanned the plausible ranges of biological uncertainty in these parameters. Models for five species were highly robust (mean overlap 88%, little or no increase in resistance). Although the proposed corridors for the other three focal species overlapped as little as 0% (mean 58%) of the alternative corridors, resistance in the proposed corridors for these three species was rarely higher than resistance in the alternative corridors (mean difference was 0.025 on a scale of 1 10; worst difference was 0.39). As long as the model had the correct rank order of resistance values and factor weights, our results suggest that the predicted corridor is robust to uncertainty. The three carnivore focal species, alone or in combination, were not effective umbrellas for the other focal species. The carnivore corridors failed to overlap the predicted corridors of most other focal species and provided relatively high resistance for the other focal species (mean increase of 2.7 resistance units). Least-cost modelers should conduct uncertainty analysis so that decision-makers can appreciate the potential impact of model uncertainty on conservation decisions. Our approach to uncertainty analysis (which can be called a worst-case scenario approach) is appropriate for complex models in which distribution of the input parameters cannot be specified.

Apparent Resistivity and Estimated Interaction Potential of Surface Water and Groundwater along Selected Canals and Streams in the Elkhorn-Loup Model Study Area, North-Central Nebraska, 2006-07

USGS Publications Warehouse

Teeple, Andrew; Vrabel, Joseph; Kress, Wade H.; Cannia, James C.

2009-01-01

In 2005, the State of Nebraska adopted new legislation that in part requires local Natural Resources Districts to include the effect of groundwater use on surface-water systems in their groundwater management plan. In response the U.S. Geological Survey, in cooperation with the Upper Elkhorn, Lower Elkhorn, Upper Loup, Lower Loup, Middle Niobrara, Lower Niobrara, Lewis and Clark, and Lower Platte North Natural Resources Districts, did a study during 2006-07 to investigate the surface-water and groundwater interaction within a 79,800-square-kilometer area in north-central Nebraska. To determine how streambed materials affect surface-water and groundwater interaction, surface geophysical and lithologic data were integrated at four sites to characterize the hydrogeologic conditions within the study area. Frequency-domain electromagnetic and waterborne direct- current resistivity profiles were collected to map the near-surface hydrogeologic conditions along sections of Ainsworth Canal near Ainsworth, Nebraska; Mirdan and Geranium Canals near Ord, Nebraska; North Loup River near Ord, Nebraska; and Middle Loup River near Thedford, Nebraska. Lithologic data were collected from test holes at each site to aid interpretation of the geophysical data. Geostatistical analysis incorporating the spatial variability of resistivity was used to account for the effect of lithologic heterogeneity on effective hydraulic permeability. The geostatistical analysis and lithologic data descriptions were used to make an interpretation of the hydrogeologic system and derive estimates of surface-water/groundwater interaction potential within the canals and streambeds. The estimated interaction potential at the Ainsworth Canal site and the Mirdan and Geranium Canal site is generally low to moderately low. The sediment textures at nearby test holes typically were silt and clay and fine-to-medium sand. The apparent resistivity values for these sites ranged from 2 to 120 ohm-meters. The vertical and horizontal variability of the apparent resistivity data were consistently low. Low resistive variability indicates little lithologic heterogeneity for either canal site. The surface-water/groundwater interaction-potential estimates are in agreement with the narrow frequency distribution of resistivity, low apparent resistivities, low spatial heterogeneity, and test-hole grain-size ranges. The estimated surface-water/groundwater interaction potential at the North Loup and Middle Loup River sites is moderate to moderately high. The sediment textures at nearby test holes were predominantly fine, medium, and coarse sand with some silt and silty to sandy clay. The apparent resistivity values for these sites ranged from 34 to 1,338 ohm-meters. The vertical variability of the resistivity data was moderately high. The horizontal variability at these sites is low to moderately low. The higher resistive variability at these sites indicates generally greater lithologic heterogeneity than at either the Ainsworth Canal site or the Mirdan and Geranium Canal site. The surface-water/groundwater interaction-potential estimates are in agreement with the generally moderate to high apparent resistivity, the greater spatial heterogeneity, and the variable lithologic texture. A higher interaction potential as compared to the canal sites is expected because of the higher subsurface resistivity and greater lithologic heterogeneity.

MMP-7, sFas and FasL serum levels for predicting docetaxel resistance and survival in castration-resistant prostate cancer.

PubMed

Szarvas, Tibor; Sevcenco, Sabina; Módos, Orsolya; Keresztes, Dávid; Nyirády, Péter; Csizmarik, Anita; Ristl, Robin; Puhr, Martin; Hoffmann, Michèle J; Niedworok, Christian; Hadaschik, Boris; Maj-Hes, Agnieszka; Shariat, Shahrokh F; Kramer, Gero

2018-05-26

To assess the predictive value of pre-chemotherapy MMP-7, sFas, FasL serum levels as well as their changes during therapy. Serum levels of MMP-7, Fas and FasL were determined by ELISA in 96 CRPC patients; 21 docetaxel-resistant who received one single series and 75 docetaxel-sensitive who received repeated series of docetaxel. In addition to the 96 pretreatment serum samples, 987 sera collected during chemotherapy were also analysed. Higher pretreatment serum MMP-7, sFas and PSA levels were significantly associated with both docetaxel-resistance (p=0.007, p=0.001, p<0.001, respectively) and shorter cancer-specific survival (p<0.001, p=0.041, p<0.001, respectively). High MMP-7 remained an independent predictor of both docetaxel resistance (HR: 2.298, 95% CI: 1.354-3.899, p=0.002) and poor cancer-specific survival (HR=2.11, 95%Cl 1.36-3.30, p=0.001) in multivariable analyses. Higher increase of MMP-7 levels in the 2 nd treatment holiday and higher increase of PSA levels in the 1 st and 2 nd holidays were predictive of survival. Pretreatment serum MMP-7 levels may help to select CRPC patients who are likely to benefit from docetaxel chemotherapy. Furthermore, MMP-7 alone or in combination with PSA could be used for therapy monitoring. Correlative studies embedded in clinical trials are necessary to validate these biomarkers for clinical decision-making. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Impact of heat treatments on the fatigue resistance of different rotary nickel-titanium instruments.

PubMed

Braga, Lígia Carolina Moreira; Faria Silva, Ana Cristina; Buono, Vicente Tadeu Lopes; de Azevedo Bahia, Maria Guiomar

2014-09-01

The aim of this study was to assess the influence of M-Wire (Dentsply Tulsa Dental Specialties, Tulsa, OK) and controlled memory technologies on the fatigue resistance of rotary nickel-titanium (NiTi) files by comparing files made using these 2 technologies with conventional NiTi files. Files with a similar cross-sectional design and diameter were chosen for the study: new 30/.06 files of the EndoWave (EW; J. Morita Corp, Osaka, Japan), HyFlex (HF; Coltene/Whaledent, Inc, Cuyahoga Falls, OH), ProFile Vortex (PV; Dentsply Tulsa Dental Specialties, Tulsa, OK), and Typhoon (TYP; Clinician's Choice Dental Products, New Milford, CT) systems together with ProTaper Universal F2 instruments (PTU F2; Dentsply Maillefer, Ballaigues, Switzerland). The compositions and transformation temperatures of the instruments were analyzed using x-ray energy-dispersive spectroscopy and differential scanning calorimetry, whereas the mean file diameter values at 3 mm from the tip (D3) were measured using image analysis software. The average number of cycles to failure was determined using a fatigue test device. X-ray energy-dispersive spectroscopy analysis showed that, on average, all the instruments exhibited the same chemical composition, namely, 51% Ni-49% Ti. The PV, TYP, and HF files exhibited increased transformation temperatures. The PTU F2, PV, and TYP files had similar D3 values, which were less than those of the EW and HF files. The average number of cycles to failure values were 150% higher for the TYP files compared with the PV files and 390% higher for the HF files compared with the EW files. M-Wire and controlled memory technologies increase the fatigue resistance of rotary NiTi files. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Energy cost of isolated resistance exercises across low- to high-intensities

PubMed Central

Garrido, Nuno Domingos; Vianna, Jeferson; Sousa, Ana Catarina; Alves, José Vilaça; Marques, Mário Cardoso

2017-01-01

This study aimed to estimate the energy cost across various intensities at eight popular resistance exercises: half squat, 45° inclined leg press, leg extension, horizontal bench press, 45° inclined bench press, lat pull down, triceps extension and biceps curl. 58 males (27.5 ± 4.9 years, 1.78 ± 0.06 m height, 78.67 ± 10.7 kg body mass and 11.4 ± 4.1% estimated body fat) were randomly divided into four groups of 14 subjects each. For each group, two exercises were randomly assigned and on different days, they performed four bouts of 5-min constant-intensity for each of the two assigned exercises: 12%, 16%, 20% and 24% 1-RM. Later, the subjects performed exhaustive bouts at 80% 1-RM in the same two exercises. The mean values of VO2 at the last 30s of exercise at 12, 16, 20 and 24% 1-RM bouts were plotted against relative intensity (% 1-RM) in a simple linear regression mode. The regressions were then used to predict O2 demand for the higher intensity (80% 1-RM). Energy cost rose linearly with exercise intensity in every exercise with the lowest mean values were found in biceps curl and the highest in half squat exercise (p<0.001). Half squat exercise presented significant (p<0.001) higher values of energy cost in all intensities, when compared with the remaining exercises. This study revealed that low-intensity resistance exercise provides energy cost comprised between 3 and 10 kcal∙min-1. Energy cost rose past 20 kcal∙min-1 at 80% 1-RM in leg exercise. In addition, at 80% 1-RM, it was found that upper body exercises are less anaerobic than lower-body exercises. PMID:28742112

Static resistivity image of a cubic saline phantom in magnetic resonance electrical impedance tomography (MREIT).

PubMed

Lee, Byung Il; Oh, Suk Hoon; Woo, Eung Je; Lee, Soo Yeol; Cho, Min Hyeong; Kwon, Ohin; Seo, Jin Keun; Baek, Woon Sik

2003-05-01

In magnetic resonance electrical impedance tomography (MREIT) we inject currents through electrodes placed on the surface of a subject and try to reconstruct cross-sectional resistivity (or conductivity) images using internal magnetic flux density as well as boundary voltage measurements. In this paper we present a static resistivity image of a cubic saline phantom (50 x 50 x 50 mm3) containing a cylindrical sausage object with an average resistivity value of 123.7 ohms cm. Our current MREIT system is based on an experimental 0.3 T MRI scanner and a current injection apparatus. We captured MR phase images of the phantom while injecting currents of 28 mA through two pairs of surface electrodes. We computed current density images from magnetic flux density images that are proportional to the MR phase images. From the current density images and boundary voltage data we reconstructed a cross-sectional resistivity image within a central region of 38.5 x 38.5 mm2 at the middle of the phantom using the J-substitution algorithm. The spatial resolution of the reconstructed image was 64 x 64 and the reconstructed average resistivity of the sausage was 117.7 ohms cm. Even though the error in the reconstructed average resistivity value was small, the relative L2-error of the reconstructed image was 25.5% due to the noise in measured MR phase images. We expect improvements in the accuracy by utilizing an MRI scanner with higher SNR and increasing the size of voxels scarifying the spatial resolution.

The associations between increasing degrees of homeostatic model assessment for insulin resistance and muscular strengthening activities among euglycaemic US adults.

PubMed

Boyer, William R; Johnson, Tammie M; Fitzhugh, Eugene C; Richardson, Michael R; Churilla, James R

2015-11-01

To examine the associations between the homeostatic model assessment for insulin resistance and self-reported muscular strengthening activity in a nationally representative sample of euglycaemic US adults. Sample included euglycaemic adults (⩾20 years of age (n = 2009)) from the 1999 to 2004 National Health and Nutrition Examination Survey. Homeostatic model assessment for insulin resistance was categorized into quartiles and was the primary independent variable of interest. No reported muscular strengthening activity was the dependent variable. Following adjustment for covariates, those with homeostatic model assessment for insulin resistance values in fourth (odds ratio: 2.04, 95% confidence interval: 1.35-3.06, p < 0.001) quartile were found to have significantly greater odds of reporting no muscular strengthening activity. Following further adjustment for non-muscular strengthening activity specific aerobic leisure-time physical activity, results remained significant for the fourth (odds ratio: 2.30, 95% confidence interval: 1.50-3.52, p < 0.001) quartile. A significant trend was seen across quartiles of homeostatic model assessment for insulin resistance for increasing prevalence of no muscular strengthening activity (p < 0.001). Having a higher homeostatic model assessment for insulin resistance value is associated with greater odds of reporting no muscular strengthening activity among euglycaemic US adults. This implies that subjects with an increasing degree of insulin resistance are more likely to not engage in muscular strengthening activity, an exercise modality that has been shown to reduce the risk of several cardiometabolic diseases and improve glycaemic status. © The Author(s) 2015.

South Asian women: identities and conflicts.

PubMed

Inman, Arpana G

2006-04-01

This study investigated the effects of education, level of religiosity, ethnic identity (internal and external), and racial identity statuses (conformity, dissonance, resistance, and awareness) on cultural value conflict for first and second generation South Asian women (N = 193). Cultural value conflict was examined in two areas, intimate relations and sex-role expectations. Results revealed that level of religiosity was more predictive of intimate relations conflict for second generation than first generation women. Furthermore, higher ratings in internal ethnic identity predicted greater intimate relations conflict in first generation women, while both internal and external ethnic identity predicted intimate relations conflict in second generation women. Finally, higher dissonance scores in racial identity predicted greater conflicts in sex-role expectations for second generation women alone.

Effect of unsaponifiable matter extracted from Pistacia khinjuk fruit oil on the oxidative stability of olive oil.

PubMed

Tavakoli, Javad; Estakhr, Parviz; Jelyani, Aniseh Zarei

2017-08-01

The present study was carried out to investigate the improvement of oxidative stability of refined olive oil using various concentrations of unsaponifiable matters extracted from Pistacia khinjuk fruit oil (UFO). For further elucidation of UFO antioxidative power, tertbutylhydroquinone (TBHQ) was used in an olive oil sample, too. Oxidative stability of olive oil samples without and with different levels of UFO (50, 100, 250, 500, 750 and 1000 ppm) and TBHQ (100 ppm) were studied via evaluation of conjugated diene value, carbonyl value, oil/oxidative stability index, acid value and total tocopherol (TT) contents through 8 h thermal process at 170 °C. Results obtained by oxidative stability assays revealed that the highest antioxidative activity of olive oil was obtained by 100 ppm of UFO, followed using 100, 250, 500, 750, and 1000 ppm of UFO and 100 ppm TBHQ, respectively. Evaluation of the relationship between oxidative stability indexes and TT changes indicated a strong correlation (R 2  = 0.9718) between mean relative resistance to oxidation and relative resistance to TT reduction during thermal process. By promotion of relative resistance to TT reduction, olive oil samples' relative resistance to oxidation was enhanced exponentially; implying importance of TT in promotion of oxidative stability of edible oils. The results obtained in this study showed that UFO has higher antioxidative activity compared to TBHQ; thus UFO can be considered as a natural antioxidant with ideal antioxidative activity.

Pitting corrosion resistance of nickel-titanium rotary instruments with different surface treatments in seventeen percent ethylenediaminetetraacetic Acid and sodium chloride solutions.

PubMed

Bonaccorso, Antonio; Tripi, Teresa Roberta; Rondelli, Gianni; Condorelli, Guglielmo Guido; Cantatore, Giuseppe; Schäfer, Edgar

2008-02-01

This study evaluated the pitting corrosion resistance of nickel-titanium (NiTi) rotary instruments with different surface treatments in 17% ethylenediaminetetraacetic acid (EDTA) and NaCl solutions. Electropolished RaCe instruments were allocated to group A, non-electropolished RaCe instruments to group B, and physical vapor deposition (PVD)-coated Alpha files to group C (10 instruments per group). Electrochemical measurements were carried out by using a potentiostat for galvanic current measurements. On the basis of electrochemical tests, no localized corrosion problems are to be expected in EDTA. In NaCl, pitting potential occurred at higher values for the electropolished and PVD instruments, indicating an increased corrosion resistance. There appears to be a risk of corrosion for NiTi instruments without surface treatments in contact with NaCl. NiTi files with PVD and electropolishing surface treatments showed an increase corrosion resistance.

[Inactivation of Mycobacteria mucogenicum in drinking water: chlorine resistance and mechanism analysis].

PubMed

Zheng, Qi; Chen, Chao; Zhang, Xiao-Jian; Lu, Pin-Pin; Liu, Yuan-Yuan; Chen, Yu-Qiao

2013-02-01

In recent years, chlorine-resistant bacteria were detected in drinking water distribution systems which threatened the drinking water safety. Our group detected one strain named Mycobacteria mucogenicum from the drinking water distribution system of a city in south China. This paper studied chlorine resistance and mechanism of Mycobacteria mucogenicum. Inactivation experiments of one strain Mycobacteria mucogenicum were conducted with free chlorine, monochloramind and chlorine dioxide. The CT values of 99.9% inactivation by free chlorine, monochloramine and chlorine dioxide were detected as (76.25 +/- 47.55)mg.min.L-1, (1396 +/-382)mg.min.L-1, (13.5 +/- 4.9) mg.min L-1. Using transmission electronmicroscopy (TEM) observed the inactivation process of Mycobacteria mucogenicum. The bacteria surface hydrophobic of Mycobacteria mucogenicum was 37.2%. Mycobacteria mucogenicum has a higher hydrophobicity than other bacteria which prevented the diffusion of chlorine into cells. Mycobacteria mucogenicum is more resistant to chorine than other bacteria.

Antimicrobial susceptibility pattern of Brachyspira intermedia isolates from European layers.

PubMed

Verlinden, Marc; Boyen, Filip; Pasmans, Frank; Garmyn, An; Haesebrouck, Freddy; Martel, An

2011-09-01

A broth microdilution method was used to determine the antimicrobial susceptibility of 20 Brachyspira intermedia isolates obtained from different layer flocks in Belgium and The Netherlands between 2008 and 2010. The antimicrobial agents used were tylosin, tilmicosin, tiamulin, valnemulin, doxycycline, and lincomycin. The minimal inhibitory concentration (MIC) distribution patterns of tylosin, tilmicosin, lincomycin, and doxycycline were bimodal, demonstrating acquired resistance against doxycycline in three strains, against the macrolides in two strains, and against lincomycin in one strain. The MICs of tiamulin and valnemulin showed a monomodal distribution, but with tailing toward the higher MIC values, possibly suggesting low-level acquired resistance in six isolates. Sequencing revealed a G1058C mutation in the 16S rRNA gene in all doxycycline-resistant strains. The strain resistant to tylosin, tilmicosin, and lincomycin had an A2058T mutation in the 23S rRNA gene.

Self-duality and a Hall-insulator phase near the superconductor-to-insulator transition in indium-oxide films

PubMed Central

Breznay, Nicholas P.; Steiner, Myles A.; Kivelson, Steven Allan; Kapitulnik, Aharon

2016-01-01

We combine measurements of the longitudinal (ρxx) and Hall (ρxy) resistivities of disordered 2D amorphous indium-oxide films to study the magnetic-field tuned superconductor-to-insulator transition (H-SIT) in the T→0 limit. At the critical field, Hc, the full resistivity tensor is T independent with ρxx(Hc)=h/4e2 and ρxy(Hc)=0 within experimental uncertainty in all films (i.e., these appear to be “universal” values); this is strongly suggestive that there is a particle–vortex self-duality at H=Hc. The transition separates the (presumably) superconducting state at HHc, at which the Hall resistance is T independent and roughly equal to its classical value, ρxy≈H/nec, marks an additional crossover to a high-field regime (probably to a Fermi insulator) in which ρxy>H/nec and possibly diverges as T→0. We also highlight a profound analogy between the H-SIT and quantum-Hall liquid-to-insulator transitions (QHIT). PMID:26712029

One-Hour Postload Hyperglycemia Confers Higher Risk of Hepatic Steatosis to HbA1c-Defined Prediabetic Subjects.

PubMed

Fiorentino, Teresa Vanessa; Andreozzi, Francesco; Mannino, Gaia Chiara; Pedace, Elisabetta; Perticone, Maria; Sciacqua, Angela; Perticone, Francesco; Sesti, Giorgio

2016-11-01

Individuals with glycated hemoglobin (HbA1c)-defined prediabetes (HbA1c value of 5.7-6.4%) and 1-hour plasma glucose ≥155 mg/dL during an oral glucose tolerance test have an increased risk of developing type 2 diabetes. To evaluate the degree to which HbA1c-defined prediabetes and 1-hour postload glucose ≥155 mg/dL individually and jointly associate with hepatic steatosis and related biomarkers. A cross-sectional analysis was performed on 1108 White individuals. Ambulatory care. Anthropometric and metabolic characteristics including hepatic steatosis assessed by ultrasonography. Compared with the normal group (HbA1c <5.7%), HbA1c-defined prediabetic and diabetic individuals exhibit higher values of fasting, 1-hour, and 2-hour postload glucose; fasting and 2-hour postload insulin; triglycerides; uric acid; homeostasis model of assessment for insulin resistance; liver insulin resistance index; liver enzymes; and inflammatory biomarkers; and lower levels of high-density lipoprotein cholesterol and IGF-1. Prediabetic and diabetic subjects have increased risk of hepatic steatosis (1.5- and 2.46-fold, respectively). Stratifying participants according to HbA1c and 1-hour postload glucose, we found that individuals with HbA1c-defined prediabetes and 1-hour postload glucose ≥155 mg/dL have significantly higher risk of hepatic steatosis as compared with individuals with HbA1c-defined prediabetes but 1-hour postload glucose <155 mg/dL. Individuals with HbA1c-defined prediabetes and 1-hour postload glucose ≥155 mg/dL exhibit higher values of liver enzymes; fasting, 1-hour, and 2-hour postload glucose; insulin; triglycerides; uric acid; and inflammatory biomarkers; and lower levels of high-density lipoprotein and IGF-1. These data suggest that a value of 1-hour postload glucose ≥155 mg/dL may be helpful to identify a subset of individuals within HbA1c-defined glycemic categories at higher risk of hepatic steatosis.

Frequency dependence of trapped flux sensitivity in SRF cavities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Checchin, M.; Martinello, M.; Grassellino, A.

In this paper, we present the frequency dependence of the vortex surface resistance of bulk niobium accelerating cavities as a function of different state-of-the-art surface treatments. Higher flux surface resistance per amount of trapped magnetic field - sensitivity - is observed for higher frequencies, in agreement with our theoretical model. Higher sensitivity is observed for N-doped cavities, which possess an intermediate value of electron mean-free-path, compared to 120° C and EP/BCP cavities. Experimental results from our study showed that the sensitivity has a non-monotonic trend as a function of the mean-free-path, including at frequencies other than 1.3 GHz, and thatmore » the vortex response to the rf field can be tuned from the pinning regime to flux-flow regime by manipulating the frequency and/or the mean-free-path of the resonator, as reported in our previous studies. The frequency dependence of the trapped flux sensitivity to the amplitude of the accelerating gradient is also highlighted.« less

Frequency dependence of trapped flux sensitivity in SRF cavities

DOE PAGES

Checchin, M.; Martinello, M.; Grassellino, A.; ...

2018-02-13

In this paper, we present the frequency dependence of the vortex surface resistance of bulk niobium accelerating cavities as a function of different state-of-the-art surface treatments. Higher flux surface resistance per amount of trapped magnetic field - sensitivity - is observed for higher frequencies, in agreement with our theoretical model. Higher sensitivity is observed for N-doped cavities, which possess an intermediate value of electron mean-free-path, compared to 120° C and EP/BCP cavities. Experimental results from our study showed that the sensitivity has a non-monotonic trend as a function of the mean-free-path, including at frequencies other than 1.3 GHz, and thatmore » the vortex response to the rf field can be tuned from the pinning regime to flux-flow regime by manipulating the frequency and/or the mean-free-path of the resonator, as reported in our previous studies. The frequency dependence of the trapped flux sensitivity to the amplitude of the accelerating gradient is also highlighted.« less

[The effect of altered oxygen partial pressure on the resisitance to hypoxia and expression of oxygen-sensitive genes in Drosophila melanogaster].

PubMed

Berezovs'kyĭ, V Ia; Chaka, O H; Litovka, I H; Levashov, M I; Ianko, R V

2014-01-01

As a result of resistance test to hypoxia of Drosophilas melanogaster of Oregon strain, we identified a high resistance (Group II) and low resistance (Group III) subpopulations of flies. Flies from groups II and III were incubated in a constant normobaric hypoxia (Po2=62-64 mm Hg) for 10 generations. A highly resistant group (Group IV) were exposed to a shortterm anoxia (Po,=1,5 mm Hg, 5 min) every generation. Larvae from Groups II, III, and IV demonstrated significantly elevated levels of Sir and CG 14740 expression. Larvae from Group II had a significantly higher expression of CG 14740 compared to group III. The restitution time after exposure to anoxia was significantly reduced in Group II (on 31% of the control values) Our results suggest that long-term adaptation to low oxygen partial pressure of highly resistant Drosophila significantly reduces the time of restitution and increases the expression of Sir2 and CG14740 genes.

Deciphering the factors influencing the discrepant fate of antibiotic resistance genes in sludge and water phases during municipal wastewater treatment.

PubMed

Zhang, Junya; Yang, Min; Zhong, Hui; Liu, Mengmeng; Sui, Qianwen; Zheng, Libing; Tong, Juan; Wei, Yuansong

2018-06-09

The discrepant fate of antibiotic resistance genes (ARGs) in sludge and water phases was investigated in a municipal wastewater treatment plant, and a lab-scale A 2 O-MBR was operated to provide background value of ARGs. The influencing factors of ARGs including microbial community, co-selection from heavy metals, biomass and horizontal gene transfer were concerned. Results showed that iA 2 O (inversed A 2 O) showed better ARGs reduction, and longer SRT (sludge retention time) increased ARGs relative abundance while reduced the gene copies of ARGs in the effluent, but significantly increased the ARGs in sludge phase. Compared to background value, the most enriched ARG was tetX in water phase, while it was intI1 in sludge phase. There existed higher abundance of multi-resistant bacteria in sludge phase, and microbial community determined the fate of ARGs in both water and sludge phase, while the direct effects from horizontal gene transfer should not be overlooked especially in water phase. Copyright © 2018 Elsevier Ltd. All rights reserved.

A Black Phosphate Conversion Coating on Steel Surface Using Antimony(III)-Tartrate as an Additive

NASA Astrophysics Data System (ADS)

Li, Feng; Wang, Guiping

2016-05-01

A novel black phosphate conversion coating was formed on steel surface through a Zn-Mn phosphating bath containing mainly ZnO, H3PO4, Mn(H2PO4)2, and Ca(NO3)2, where antimony(III)-tartrate was used as the blackening agent of phosphatization. The surface morphology and composition of the coating were characterized by scanning electron microscopy, energy dispersion spectroscopy, and x-ray photoelectron spectroscopy. Corrosion resistance of the coating was studied by potentiodynamic polarization curves and electrochemical impedance spectroscopy. The pH value of the solution had significant influence on the formation and corrosion resistance of the coating. The experimental results indicated that the Sb plays a vital role in the blackening of phosphate conversion coating. The optimal concentration of antimony(III)-tartrate in the phosphating bath used in this experiment was 1.0 g L-1, as higher values reduced the corrosion resistance of the coating. In addition, by saponification and oil seals, the corrosion duration of the black phosphate coating in a copper sulfate spot test can be as long as 20 min.

Influence of ceramic thickness and ceramic materials on fracture resistance of posterior partial coverage restorations.

PubMed

Bakeman, E M; Rego, N; Chaiyabutr, Y; Kois, J C

2015-01-01

This study evaluated the influence of ceramic thickness and ceramic materials on fracture resistance of posterior partial coverage ceramic restorations. Forty extracted molars were allocated into four groups (n=10) to test for two variables: 1) the thickness of ceramic (1 mm or 2 mm) and 2) the ceramic materials (a lithium disilicate glass-ceramic [IPS e.max] or leucite-reinforced glass ceramic [IPS Empress]). All ceramic restorations were luted with resin cement (Variolink II) on the prepared teeth. These luted specimens were loaded to failure in a universal testing machine, in the compression mode, with a crosshead speed of 1.0 mm/min. The data were analyzed using two-way analysis of variance and the Tukey Honestly Significantly Different multiple comparison test (α =0.05). The fracture resistance revealed a significant effect for materials (p<0.001); however, the thickness of ceramic was not significant (p=0.074), and the interaction between the thickness of ceramic and the materials was not significant (p=0.406). Mean (standard deviation) fracture resistance values were as follows: a 2-mm thickness of a lithium disilicate bonded to tooth structure (2505 [401] N) revealed a significantly higher fracture resistance than did a 1-mm thickness of leucite-reinforced (1569 [452] N) and a 2-mm thickness of leucite-reinforced ceramic bonded to tooth structure (1716 [436] N) (p<0.05). There was no significant difference in fracture resistance values between a lithium disilicate ceramic at 1-mm thickness (2105 [567] N) and at 2-mm thickness. Using a lithium disilicate glass ceramic for partial coverage restoration significantly improved fracture resistance compared to using a leucite-reinforced glass ceramic. The thickness of ceramic had no significant effect on fracture resistance when the ceramics were bonded to the underlying tooth structure.

Molecular Diversity Analysis and Genetic Mapping of Pod Shatter Resistance Loci in Brassica carinata L.

PubMed Central

Raman, Rosy; Qiu, Yu; Coombes, Neil; Song, Jie; Kilian, Andrzej; Raman, Harsh

2017-01-01

Seed lost due to easy pod dehiscence at maturity (pod shatter) is a major problem in several members of Brassicaceae family. We investigated the level of pod shatter resistance in Ethiopian mustard (Brassica carinata) and identified quantitative trait loci (QTL) for targeted introgression of this trait in Ethiopian mustard and its close relatives of the genus Brassica. A set of 83 accessions of B. carinata, collected from the Australian Grains Genebank, was evaluated for pod shatter resistance based on pod rupture energy (RE). In comparison to B. napus (RE = 2.16 mJ), B. carinata accessions had higher RE values (2.53 to 20.82 mJ). A genetic linkage map of an F2 population from two contrasting B. carinata selections, BC73526 (shatter resistant with high RE) and BC73524 (shatter prone with low RE) comprising 300 individuals, was constructed using a set of 6,464 high quality DArTseq markers and subsequently used for QTL analysis. Genetic analysis of the F2 and F2:3 derived lines revealed five statistically significant QTL (LOD ≥ 3) that are linked with pod shatter resistance on chromosomes B1, B3, B8, and C5. Herein, we report for the first time, identification of genetic loci associated with pod shatter resistance in B. carinata. These characterized accessions would be useful in Brassica breeding programs for introgression of pod shatter resistance alleles in to elite breeding lines. Molecular markers would assist marker-assisted selection for tracing the introgression of resistant alleles. Our results suggest that the value of the germplasm collections can be harnessed through genetic and genomics tools. PMID:29250080

Antimicrobial resistance of Listeria monocytogenes and Listeria innocua from meat products and meat-processing environment.

PubMed

Gómez, Diego; Azón, Ester; Marco, Noelia; Carramiñana, Juan J; Rota, Carmina; Ariño, Agustín; Yangüela, Javier

2014-09-01

A total of 336 Listeria isolates from ready-to-eat (RTE) meat products and meat-processing environments, consisting of 206 Listeria monocytogenes, and 130 Listeria innocua isolates, were characterized by disc diffusion assay and minimum inhibitory concentration (MIC) values for antimicrobial susceptibility against twenty antimicrobials. Resistance to one or two antimicrobials was observed in 71 L. monocytogenes isolates (34.5%), and 56 L. innocua isolates (43.1%). Multidrug resistance was identified in 24 Listeria isolates, 18 belonging to L. innocua (13.9%) and 6 to L. monocytogenes (2.9%). Oxacillin resistance was the most common resistance phenotype and was identified in 100% Listeria isolates. A medium prevalence of resistance to clindamycin (39.3% isolates) and low incidence of resistance to tetracycline (3.9% isolates) were also detected. Listeria isolates from RTE meat products displayed higher overall antimicrobial resistance (31.3%) than those from the environment (13.4%). All the strains assayed were sensitive to the preferred antibiotics used to treat listeriosis. Results showed that although antimicrobial resistance in L. monocytogenes still occurs at a low prevalence, L. innocua can form a reservoir of resistance genes which may transfer between bacterial species, including transference to organisms capable of causing disease in humans. Copyright © 2014 Elsevier Ltd. All rights reserved.

Functioning efficiency of intermediate coolers of multistage steam-jet ejectors of steam turbines

NASA Astrophysics Data System (ADS)

Aronson, K. E.; Ryabchikov, A. Yu.; Brodov, Yu. M.; Zhelonkin, N. V.; Murmanskii, I. B.

2017-03-01

Designs of various types of intermediate coolers of multistage ejectors are analyzed and thermal effectiveness and gas-dynamic resistance of coolers are estimated. Data on quantity of steam condensed from steam-air mixture in stage I of an ejector cooler was obtained on the basis of experimental results. It is established that the amount of steam condensed in the cooler constitutes 0.6-0.7 and is almost independent of operating steam pressure (and, consequently, of steam flow) and air amount in steam-air mixture. It is suggested to estimate the amount of condensed steam in a cooler of stage I based on comparison of computed and experimental characteristics of stage II. Computation taking this hypothesis for main types of mass produced multistage ejectors into account shows that 0.60-0.85 of steam amount should be condensed in stage I of the cooler. For ejectors with "pipe-in-pipe" type coolers (EPO-3-200) and helical coolers (EO-30), amount of condensed steam may reach 0.93-0.98. Estimation of gas-dynamic resistance of coolers shows that resistance from steam side in coolers with built-in and remote pipe bundle constitutes 100-300 Pa. Gas-dynamic resistance of "pipein- pipe" and helical type coolers is significantly higher (3-6 times) compared with pipe bundle. However, performance by "dry" (atmospheric) air is higher for ejectors with relatively high gas-dynamic resistance of coolers than those with low resistance at approximately equal operating flow values of ejectors.

Mathematical quantification of the induced stress resistance of microbial populations during non-isothermal stresses.

PubMed

Garre, Alberto; Huertas, Juan Pablo; González-Tejedor, Gerardo A; Fernández, Pablo S; Egea, Jose A; Palop, Alfredo; Esnoz, Arturo

2018-02-02

This contribution presents a mathematical model to describe non-isothermal microbial inactivation processes taking into account the acclimation of the microbial cell to thermal stress. The model extends the log-linear inactivation model including a variable and model parameters quantifying the induced thermal resistance. The model has been tested on cells of Escherichia coli against two families of non-isothermal profiles with different constant heating rates. One of the families was composed of monophasic profiles, consisting of a non-isothermal heating stage from 35 to 70°C; the other family was composed of biphasic profiles, consisting of a non-isothermal heating stage followed by a holding period at constant temperature of 57.5°C. Lower heating rates resulted in a higher thermal resistance of the bacterial population. This was reflected in a higher D-value. The parameter estimation was performed in two steps. Firstly, the D and z-values were estimated from the isothermal experiments. Next, the parameters describing the acclimation were estimated using one of the biphasic profiles. This set of parameters was able to describe the remaining experimental data. Finally, a methodology for the construction of diagrams illustrating the magnitude of the induced thermal resistance is presented. The methodology has been illustrated by building it for a biphasic temperature profile with a linear heating phase and a holding phase. This diagram provides a visualization of how the shape of the temperature profile (heating rate and holding temperature) affects the acclimation of the cell to the thermal stress. This diagram can be used for the design of inactivation treatments by industry taking into account the acclimation of the cell to the thermal stress. Copyright © 2017 Elsevier B.V. All rights reserved.

Identification of anaerobic threshold by analysis of heart rate variability during discontinuous dynamic and resistance exercise protocols in healthy older men.

PubMed

Simões, Rodrigo Polaquini; Castello-Simões, Viviane; Mendes, Renata Gonçalves; Archiza, Bruno; Dos Santos, Daniel Augusto; Bonjorno, José Carlos; de Oliveira, Claudio Ricardo; Catai, Aparecida Maria; Arena, Ross; Borghi-Silva, Audrey

2014-03-01

The purposes of this study were to determine anaerobic threshold (AT) during discontinuous dynamic and resistive exercise protocols by analysing of heart rate variability (HRV) and blood lactate (BL) in healthy elderly subjects and compare the cardiovascular, metabolic and autonomic variables obtained from these two forms of exercise. Fourteen elderly (70 ± 4 years) apparently healthy males underwent the following tests: (i) incremental ramp test on cycle ergometer, (ii) one repetition maximum (1RM) leg press at 45°, (iii) a discontinuous exercise test on a cycle ergometer (DET-C) protocol and (iv) a resistance exercise leg press (DET-L) protocol. Heart rate, blood pressure and BL were obtained during each increment of exercise intensity. No significant differences (P>0·05) were found between methods of AT determination (BL and HRV) nor the relative intensity corresponding to AT (30% of maximum intensity) between the types of exercise (DET-C and DET-L). Furthermore, no significant differences (P>0·05) were found between the DET-C and DET-L in relation to HRV, however, the DET-L provided higher values of systolic blood pressure and BL (P<0·05) from the intensity corresponding to AT. We conclude that HRV was effective in determination of AT, and the parasympathetic modulation responses obtained during dynamic and resistive exercise protocols were similar when compared at the same relative intensity. However, DET-L resulted in higher values of blood pressure and BL at workloads beyond AT. © 2013 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Tumor necrosis factor- α, adiponectin and their ratio in gestational diabetes mellitus

PubMed Central

Khosrowbeygi, Ali; Rezvanfar, Mohammad Reza; Ahmadvand, Hassan

2018-01-01

Background: It has been suggested that inflammation might be implicated in the gestational diabetes mellitus (GDM) complications, including insulin resistance. The aims of the current study were to explore maternal circulating values of TNF-α, adiponectin and the adiponectin/TNF-α ratio in women with GDM compared with normal pregnancy and their relationships with metabolic syndrome biomarkers. Methods: Forty women with GDM and 40 normal pregnant women were included in the study. Commercially available enzyme-linked immunosorbent assay methods were used to measure serum levels of TNF-α and total adiponectin. Results: Women with GDM had higher values of TNF-α (225.08±27.35 vs 115.68±12.64 pg/ml, p<0.001) and lower values of adiponectin (4.50±0.38 vs 6.37±0.59 µg/ml, p=0.003) and the adiponectin/TNF-α ratio (4.31±0.05 vs 4.80±0.07, P<0.001) than normal pregnant women. The adiponectin/TNF-α ratio showed negative correlations with insulin resistance (r=-0.68, p<0.001) and triglyceride (r=-0.39, p=0.014) and a positive correlation with insulin sensitivity (r=0.69, p<0.001). Multiple linear regression analysis showed that values of the adiponectin /TNF-α ratio were independently associated with insulin resistance. Binary logistic regression analysis showed that GDM was negatively associated with adiponectin /TNF-α ratio. Conclusions: In summary, the adiponectin/TNF-α ratio decreased significantly in GDM compared with normal pregnancy. The ratio might be an informative biomarker for assessment of pregnant women at high risk of insulin resistance and dyslipidemia and for diagnosis and therapeutic monitoring aims in GDM. PMID:29387323

Serotypes and Antimicrobial Resistance in Salmonella enterica Recovered from Clinical Samples from Cattle and Swine in Minnesota, 2006 to 2015.

PubMed

Hong, Samuel; Rovira, Albert; Davies, Peter; Ahlstrom, Christina; Muellner, Petra; Rendahl, Aaron; Olsen, Karen; Bender, Jeff B; Wells, Scott; Perez, Andres; Alvarez, Julio

2016-01-01

Salmonellosis remains one of the leading causes of foodborne disease worldwide despite preventive efforts at various stages of the food production chain. The emergence of multi-drug resistant (MDR) non-typhoidal Salmonella enterica represents an additional challenge for public health authorities. Food animals are considered a major reservoir and potential source of foodborne salmonellosis; thus, monitoring of Salmonella strains in livestock may help to detect emergence of new serotypes/MDR phenotypes and to gain a better understanding of Salmonella epidemiology. For this reason, we analyzed trends over a nine-year period in serotypes, and antimicrobial resistance, of Salmonella isolates recovered at the Minnesota Veterinary Diagnostic Laboratory (MVDL) from swine (n = 2,537) and cattle (n = 1,028) samples. Prevalence of predominant serotypes changed over time; in swine, S. Typhimurium and S. Derby decreased and S. Agona and S. 4,5,12:i:- increased throughout the study period. In cattle, S. Dublin, S. Montevideo and S. Cerro increased and S. Muenster became less frequent. Median minimum inhibitory concentration (MIC) values and proportion of antibiotic resistant isolates were higher for those recovered from swine compared with cattle, and were particularly high for certain antibiotic-serotype combinations. The proportion of resistant swine isolates was also higher than observed in the NARMS data, probably due to the different cohort of animals represented in each dataset. Results provide insight into the dynamics of antimicrobial resistant Salmonella in livestock in Minnesota, and can help to monitor emerging trends in antimicrobial resistance.

Association Between Insulin Resistance and Bone Structure in Nondiabetic Postmenopausal Women.

PubMed

Shanbhogue, Vikram V; Finkelstein, Joel S; Bouxsein, Mary L; Yu, Elaine W

2016-08-01

The clinical consequences of insulin resistance and hyperinsulinemia on bone remain largely unknown. The objective of the study was to evaluate the effect of insulin resistance on peripheral bone geometry, volumetric bone mineral density (vBMD), bone microarchitecture, and estimated bone strength. This cross-sectional study included 146 postmenopausal, nondiabetic Caucasian women (mean age 60.3 ± 2.7 y) who were participating in the Study of Women's Health Across the Nation. There were no interventions. High-resolution peripheral quantitative computed tomography was used to assess bone density and microstructure at the distal radius and tibia. Fasting insulin and glucose were measured and insulin resistance was estimated using homeostasis model assessment of insulin resistance (HOMA-IR), with higher values indicating greater insulin resistance. There was a negative association between HOMA-IR and bone size and a positive association between HOMA-IR and total vBMD, trabecular vBMD, trabecular thickness, and cortical thickness at the radius and tibia. These relationships remained, even after adjusting for body weight and other potential covariates (eg, time since menopause, cigarette smoking, physical activity, prior use of osteoporosis medications or glucocorticoids). In nondiabetic, postmenopausal women, insulin resistance was associated with smaller bone size, greater volumetric bone mineral density, and generally favorable bone microarchitecture at weight-bearing and nonweight-bearing skeletal sites. These associations were independent of body weight and other potential covariates, suggesting that hyperinsulinemia directly affects bone structure independent of obesity and may explain, in part, the higher trabecular bone density and favorable trabecular microarchitecture seen in individuals with type 2 diabetes mellitus.

Determination of anisotropic karst features in the Biscayne Aquifer using multi electrical resistivity imaging techniques

NASA Astrophysics Data System (ADS)

Yeboah-Forson, A.; Whitman, D.

2012-12-01

The Biscayne Aquifer of Southeast Florida is characterized by limestone cavities and solution hole features that are often beneath the surface and are difficult to detect and quantify accurately. Electrical resistivity imaging (ERI) is often used to image the subsurface for detection of cavities and other karst features. A recent regional study of electrical anisotropy derived from rotated square array measurements measured coefficients of anisotropy of 1.12 or less. At one particular site however, the coefficient of anisotropy was found to be as high as 1.36 with the average minimum resistivity direction trending 105°. The highest values of anisotropy are found at squares array sizes equivalent to effective depths of 4-9m. The cause of this higher anisotropy and its associated orientation was investigated using a combination of azimuthal 2-D profiles and a 3-D tomography survey using a mixed dipole gradient array. Results indicate a low resistivity zone at a depth of 5-10 m in the saturated zone (10-40Ωm) trending 109° in the 2-D profiles and the presence of low resistivity zone (14-43Ωm) trending 90-105° in the 3-D model. This observed lower resistivity zone is at least 50% lower than the surrounding resistivity. Although further geophysical studies are planned at the site, the primary analysis from these three contrasting ERI techniques indicates that the cause of higher anisotropy might be due to the presence of a solution cavity oriented in the E-SE direction.

Serum AMH levels and insulin resistance in women with PCOS.

PubMed

Sahmay, Sezai; Aydogan Mathyk, Begum; Sofiyeva, Nigar; Atakul, Nil; Azemi, Aslı; Erel, Tamer

2018-05-01

To compare the serum AMH levels between women with and without insulin resistance (IR) in polycystic ovary syndrome (PCOS). 293 women with PCOS according to the Rotterdam criteria were enrolled into our study. Insulin resistance was diagnosed according to the Homeostatic model assessment insulin resistant (HOMA-IR) formula and the cut-off point was set to more than 2.5. Women were grouped according to the presence of insulin resistance (IR) (HOMA-IR ≥ 2.5). Serum AMH and other hormones were compared between the IR (+) and IR (-) groups. Additionally, AMH percentiles were (<25, 25-75, >75) constructed; HOMA-IR and BMI values in women with/without IR were compared in different percentiles. Further, HOMA-IR, BMI and AMH values were measured across different PCOS phenotypes. The prevalence of IR was 45%. The prevalence of IR was 57% in women with BMI ≥ 25. Serum AMH levels were not significantly different among women with and without IR. Also, HOMA-IR values were not significant among different AMH percentiles. However, in each AMH percentile BMI were found to be higher in women with IR than in women without IR. The median HOMA-IR values were the highest in women with BMI ≥ 25 in both IR (+) and IR (-) groups. No significant difference was found among PCOS phenotypes in terms of HOMA-IR and BMI. Positive correlations were found between BMI, free testosterone and HOMA-IR. However, no correlation was found between AMH and HOMA-IR. The serum AMH levels between women with IR and without IR in PCOS were not significantly different. Also, we did not reveal a correlation between serum AMH levels and IR in women with PCOS. IR was not correlated with different PCOS phenotypes either. We found a positive correlation between BMI and IR. IR should be investigated in women with PCOS having a BMI ≥ 25, independent of their phenotype or AMH levels. Copyright © 2018 Elsevier B.V. All rights reserved.

Tank tests to determine the effect of varying design parameters of planing-tail hulls II : effect of varying depth of step, angle of after- body keel, length of afterbody chine, and gross load

NASA Technical Reports Server (NTRS)

Dawson, John R; Mckann, Robert; Hay, Elizabeth S

1946-01-01

The second part of a series of tests made in Langley tank no. 2 to determine the effect of varying design parameters of planing-tail hulls is presented. Results are given to show the effects on resistance characteristics of varying angle of afterbody keel, depth of step, and length of afterbody chine. The effect of varying the gross load is shown for one configuration. The resistance characteristics of planing-tail hulls are compared with those of a conventional flying-boat hull. The forces on the forebody and afterbody of one configuration are compared with the forces on a conventional hull. Increasing the angle of afterbody keel had small effect on hump resistance and no effect on high-speed resistance but increased free-to-trim resistance at intermediate speeds. Increasing the depth of step increased hump resistance, had little effect on high-speed resistance, and increased free-to-trim resistance at intermediate speeds. Omitting the chines on the forward 25 percent of the afterbody had no appreciable effect on resistance. Omitting 70 percent of the chine length had almost no effect on maximum resistance but broadened the hump and increased spray around the afterbody. Load-resistance ratio at the hump decreased more rapidly with increasing load coefficient for the planing-tail hull than for the representative conventional hull, although the load-resistance ratio at the hump was greater for the planing-tail hull than for the conventional hull throughout the range of loads tested. At speeds higher than hump speed, load-resistance ratio for the planing-tail hull was a maximum at a particular gross load and was slightly less at heavier and lighter gross loads. The planing-tail hull was found to have lower resistance than the conventional hull at both the hump and at high speeds, but at intermediate speeds there was little difference. The lower hump resistance of the planing-tail hull was attributed to the ability of the afterbody to carry a greater percentage of the total load while maintaining a higher value of load-resistance ratio.

Optimization of resistant starch formation from high amylose corn starch by microwave irradiation treatments and characterization of starch preparations.

PubMed

Mutlu, Selime; Kahraman, Kevser; Öztürk, Serpil

2017-02-01

The effects of microwave irradiation on resistant starch (RS) formation and functional properties in high-amylose corn starch, Hylon VII, by applying microwave-storing cycles and drying processes were investigated. The Response Surface Methodology (RSM) was used to optimize the reaction conditions, microwave time (2-4min) and power (20-100%), for RS formation. The starch:water (1:10) mixtures were cooked and autoclaved and then different microwave-storing cycles and drying (oven or freeze drying) processes were applied. The RS contents of the samples increased with increasing microwave-storing cycle. The highest RS (43.4%) was obtained by oven drying after 3 cycles of microwave treatment at 20% power for 2min. The F, p (<0.05) and R 2 values indicated that the selected models were consistent. Linear equations were obtained for oven-dried samples applied by 1 and 3 cycles of microwave with regression coefficients of 0.65 and 0.62, respectively. Quadratic equation was obtained for freeze-dried samples applied by 3 cycles of microwave with a regression coefficient of 0.83. The solubility, water binding capacity (WBC) and RVA viscosity values of the microwave applied samples were higher than those of native Hylon VII. The WBC and viscosity values of the freeze-dried samples were higher than those of the oven-dried ones. Copyright © 2016 Elsevier B.V. All rights reserved.

Electrical and morphological properties of magnetocaloric nano ZnNi ferrite

NASA Astrophysics Data System (ADS)

Hemeda, O. M.; Mostafa, Nasser Y.; Abd Elkader, Omar H.; Hemeda, D. M.; Tawfik, A.; Mostafa, M.

2015-11-01

A series of Zn1-xNixFe2O4 nano ferrite (with x=0, 0.2, 0.4, 0.6, 0.8, and 1) compositions were synthesized using the combustion technique. The powder samples were characterized by XRD. The X-ray analysis showed that the samples were single phase spinel cubic structure. The AC resistivity decreases by increasing the frequency from 1 kHz to 10 kHz. As the frequency of the applied field increases the hopping of charge carrier also increase, thereby decreasing the resistivity. A shift in dielectric maximum is observed toward higher temperature with increasing the Ni content from 536 K to 560 K at 1 kHz. The HRTEM (high resolution TEM) images of four compositions have lattice spacing which confirms the crystalline nature of the samples. The surface morphology SEM of the sample consists of some grains with relatively homogenies distribution with an average size varying from 0.85 to 0.92 μm. The values for entropy change in this work are still small but are significally higher than the values that have been reported for iron oxide nanoparticle. The magnetic entropy change was calculated from measurements of M (H, T) where H is the magnetic field and T is the temperature. The maximum value of entropy change (ΔS) obtained near Curie temperature which makes these material candidates for magnetocaloric applications.

Strong antimicrobial activity of xanthohumol and other derivatives from hops (Humulus lupulus L.) on gut anaerobic bacteria.

PubMed

Cermak, Pavel; Olsovska, Jana; Mikyska, Alexandr; Dusek, Martin; Kadleckova, Zuzana; Vanicek, Jiri; Nyc, Otakar; Sigler, Karel; Bostikova, Vanda; Bostik, Pavel

2017-11-01

Anaerobic bacteria, such as Bacteroides fragilis or Clostridium perfringens, are part of indigenous human flora. However, Clostridium difficile represents also an important causative agent of nosocomial infectious antibiotic-associated diarrhoea. Treatment of C. difficile infection is problematic, making it imperative to search for new compounds with antimicrobial properties. Hops (Humulus lupulus L.) contain substances with antibacterial properties. We tested antimicrobial activity of purified hop constituents humulone, lupulone and xanthohumol against anaerobic bacteria. The antimicrobial activity was established against B. fragilis, C. perfringens and C. difficile strains according to standard testing protocols (CLSI, EUCAST), and the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBC) were calculated. All C. difficile strains were toxigenic and clinically relevant, as they were isolated from patients with diarrhoea. Strongest antimicrobial effects were observed with xanthohumol showing MIC and MBC values of 15-107 μg/mL, which are close to those of conventional antibiotics in the strains of bacteria with increased resistance. Slightly higher MIC and MBC values were obtained with lupulone followed by higher values of humulone. Our study, thus, shows a potential of purified hop compounds, especially xanthohumol, as alternatives for treatment of infections caused by select anaerobic bacteria, namely nosocomial diarrhoea caused by resistant strains. © 2017 APMIS. Published by John Wiley & Sons Ltd.

Effect of different cements on the biomechanical behavior of teeth restored with cast dowel-and-cores-in vitro and FEA analysis.

PubMed

Soares, Carlos José; Raposo, Luís Henrique Araújo; Soares, Paulo Vinícius; Santos-Filho, Paulo César Freitas; Menezes, Murilo Sousa; Soares, Priscilla Barbosa Ferreira; Magalhães, Denildo

2010-02-01

To test the hypothesis that the type of cement used for fixation of cast dowel-and-cores might influence fracture resistance, fracture mode, and stress distribution of single-rooted teeth restored with this class of metallic dowels. The coronal portion was removed from 40 bovine incisors, leaving a 15 mm root. After endodontic treatment and standardized root canal relief at 10 mm, specimens were embedded in polystyrene resin, and the periodontal ligament was simulated with polyether impression material. The specimens were randomly divided into four groups (n = 10), and restored with Cu-Al cast dowel-and-cores cemented with one of four options: conventional glass ionomer cement (GI); resin-modified glass ionomer cement (GR); dual-cure resin cement (RC); or zinc-phosphate cement (ZP). Sequentially, fracture resistance of the specimens was tested with a tangential load at a 135 degrees angle with a 0.5 mm/min crosshead speed. Data were analyzed using one-way analysis of variance (ANOVA) and the Fisher test. Two-dimensional finite element analysis (2D-FEA) was then performed with representative models of each group simulating a 100 microm cement layer. Results were analyzed based on von Mises stress distribution criteria. The mean fracture resistance values were (in N): RC, 838.2 +/- 135.9; GI, 772.4 +/- 169.8; GR, 613.4 +/- 157.5; ZP, 643.6 +/- 106.7. FEA revealed that RC and GR presented lower stress values than ZP and GI. The higher stress concentration was coincident with more catastrophic failures, and consequently, with lower fracture resistance values. The type of cement influenced fracture resistance, failure mode, and stress distribution on teeth restored with cast dowel-and-cores.

Experimental Investigation of the Resistance Performance and Heave and Pitch Motions of Ice-Going Container Ship Under Pack Ice Conditions

NASA Astrophysics Data System (ADS)

Guo, Chun-yu; Xie, Chang; Zhang, Jin-zhao; Wang, Shuai; Zhao, Da-gang

2018-04-01

In order to analyze the ice-going ship's performance under the pack ice conditions, synthetic ice was introduced into a towing tank. A barrier using floating cylinder in the towing tank was designed to carry out the resistance experiment. The test results indicated that the encountering frequency between the ship model and the pack ice shifts towards a high-velocity point as the concentration of the pack ice increases, and this encountering frequency creates an unstable region of the resistance, and the unstable region shifts to the higher speed with the increasing concentration. The results also showed that for the same speed points, the ratio of the pack ice resistance to the open water resistance increases with the increasing concentration, and for the same concentrations, this ratio decreases as the speed increases. Motion characteristics showed that the mean value of the heave motion increases as the speed increases, and the pitch motion tends to increase with the increasing speed. In addition, the total resistance of the fullscale was predicted.

Experimental study on the flow/ heat transfer performance of micro-scale pin fin coating with super-hydrophobic surface adding Nano particle

NASA Astrophysics Data System (ADS)

Hua, Junye; Duan, Yuanyuan; Li, Gui; Xu, Qiong; Li, Dong; Wu, Wei; Zhao, Xiaobao; Qiu, Delai

2018-02-01

The experimental studies on heat transfer and flow resistance characteristics of ellipse-shape micro pin fin have been conducted which is drafted with hydrophobic material, holding the various contact angles fulfilled by adjusting the amount of Nano particle. The results show that with the increases of contact angle(83°,99.5°, 119.5°and 151.5°), the bottom wall temperature rises under the same flow rate. Under a certain heating condition with heating power as 100 W, the average convective heat transfer coefficient decreases with the increase of contact angle with the same Re. The value of Nu for ellipse-shape micro pin fin increases with a higher Re, with the maximum value under experimental condition of Nu as 25. Besides, the friction coefficient of micro pin fin experimental section drafted hydrophobicity treatment significantly decreases, compared with the smooth micro pin fin experimental section (θ = 83°). While the higher contact angle has obvious positive influences on friction coefficient under the same Re. Generally, the flow resistance performance of ellipse-shape micro pin fin drafted with hydrophobic material is better than that without any treatment.

Characterisation of capacitively coupled HV/HR-CMOS sensor chips for the CLIC vertex detector

NASA Astrophysics Data System (ADS)

Kremastiotis, I.

2017-12-01

The capacitive coupling between an active sensor and a readout ASIC has been considered in the framework of the CLIC vertex detector study. The CLICpix Capacitively Coupled Pixel Detector (C3PD) is a High-Voltage CMOS sensor chip produced in a commercial 180 nm HV-CMOS process for this purpose. The sensor was designed to be connected to the CLICpix2 readout chip. It therefore matches the dimensions of the readout chip, featuring a matrix of 128×128 square pixels with 25μm pitch. The sensor chip has been produced with the standard value for the substrate resistivity (~20 Ωcm) and it has been characterised in standalone testing mode, before receiving and testing capacitively coupled assemblies. The standalone measurement results show a rise time of ~20 ns for a power consumption of 5μW/pixel. Production of the C3PD HV-CMOS sensor chip with higher substrate resistivity wafers (~20, 80, 200 and 1000 Ωcm) is foreseen. The expected benefits of the higher substrate resistivity will be studied using future assemblies with the readout chip.

First confirmation and characterization of target and non-target site resistance to glyphosate in Palmer amaranth (Amaranthus palmeri) from Mexico.

PubMed

Dominguez-Valenzuela, Jose Alfredo; Gherekhloo, Javid; Fernández-Moreno, Pablo Tomás; Cruz-Hipolito, Hugo Enrique; Alcántara-de la Cruz, Ricardo; Sánchez-González, Eduardo; De Prado, Rafael

2017-06-01

Following the introduction of glyphosate-resistant (GR)-cotton crops in Mexico, farmers have relied upon glyphosate as being the only herbicide for in-season weed control. Continuous use of glyphosate within the same year and over multiple successive years has resulted in the selection of glyphosate resistance in Palmer amaranth (Amarantus palmeri). Dose-response assays confirmed resistance in seven different accessions. The resistance ratio based on GR 50 values (50% growth reduction) varied between 12 and 83. At 1000 μM glyphosate, shikimic acid accumulation in the S-accession was 30- to 2-fold higher at compared to R-accessions. At 96 h after treatment, 35-44% and 61% of applied 14 C-glyphosate was taken up by leaves of plants from R- and S-accessions, respectively. At this time, a significantly higher proportion of the glyphosate absorbed remained in the treated leaf of R-plants (55-69%) compared to S-plants (36%). Glyphosate metabolism was low and did not differ between resistant and susceptible plants. Glyphosate was differentially metabolized to AMPA and glyoxylate in plants of R- and S-accessions, although it was low in both accessions (<10%). There were differences in 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) enzyme activity by 50% (I 50 ) between R- and S-accessions. However, no significant differences were found in the basal EPSPS activity (μmol inorganic phosphate μg -1 total soluble protein min -1 ) between R- and S-accessions. A point mutation Pro-106-Ser was evidenced in three accessions. The results confirmed the resistance of Palmer amaranth accessions to glyphosate collected from GR-cotton crops from Mexico. This is the first study demonstrating glyphosate-resistance in Palmer amaranth from Mexico. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Investigation of Coastal Hydrogeology Utilizing Geophysical and Geochemical Tools along the Broward County Coast, Florida

USGS Publications Warehouse

Reich, Christopher D.; Swarzenski, Peter W.; Greenwood, W. Jason; Wiese, Dana S.

2008-01-01

Geophysical (CHIRP, boomer, and continuous direct-current resistivity) and geochemical tracer studies (continuous and time-series 222Radon) were conducted along the Broward County coast from Port Everglades to Hillsboro Inlet, Florida. Simultaneous seismic, direct-current resistivity, and radon surveys in the coastal waters provided information to characterize the geologic framework and identify potential groundwater-discharge sites. Time-series radon at the Nova Southeastern University National Coral Reef Institute (NSU/NCRI) seawall indicated a very strong tidally modulated discharge of ground water with 222Rn activities ranging from 4 to 10 disintegrations per minute per liter depending on tidal stage. CHIRP seismic data provided very detailed bottom profiles (i.e., bathymetry); however, acoustic penetration was poor and resulted in no observed subsurface geologic structure. Boomer data, on the other hand, showed features that are indicative of karst, antecedent topography (buried reefs), and sand-filled troughs. Continuous resistivity profiling (CRP) data showed slight variability in the subsurface along the coast. Subtle changes in subsurface resistivity between nearshore (higher values) and offshore (lower values) profiles may indicate either a freshening of subsurface water nearshore or a change in sediment porosity or lithology. Further lithologic and hydrologic controls from sediment or rock cores or well data are needed to constrain the variability in CRP data.

Preparation and characterization of novel PVDF nanofiltration membranes with hydrophilic property for filtration of dye aqueous solution

NASA Astrophysics Data System (ADS)

Nikooe, Naeme; Saljoughi, Ehsan

2017-08-01

In the present research, for the first time PVDF/Brij-58 blend nanofiltration membranes with remarkable performance in filtration of dye aqueous solution were prepared via immersion precipitation. A noticeable improvement in water permeation and fouling resistance of the PVDF membranes was achieved by using Brij-58 surfactant as a hydrophilic additive. Scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR) and water contact angle were applied for the investigation of membrane morphology, detection of the surface chemical composition and relative hydrophilicity/hydrophobicity, respectively. The membrane performance was studied and compared by determination of pure water flux (PWF) and filtration of synthetic reactive dye aqueous solutions as well as bovine serum albumin (BSA) as foulant model. It was found out that addition of 4 wt.% Brij-58 to the casting solution results in formation of membrane with remarkable hydrophilicity and fouling resistance (contact angle of 46° and flux recovery ratio (FRR) = 90%), higher porosity and consequently noticeable PWF (31.2 L/m2 h) and recognized dye rejection value (90%) in comparison with the pristine PVDF nanofiltration membrane. Addition of Brij-58 surfactant to the casting solution resulted in formation of NF membrane with higher hydrophilicity and permeability as well as higher dye rejection value in comparison with the addition of PEG 400 additive.

Climatic cycles recorded in the Middle Eocene hemipelagites from a Dinaric foreland basin of Istria (Croatia)

NASA Astrophysics Data System (ADS)

Lužar-Oberiter, Borna; Hochuli, Peter A.; Babić, Ljubomir; Glumac, Bosiljka; Tibljaš, Darko

2010-06-01

Middle Eocene hemipelagic marls from the Pazin-Trieste Basin, a foreland basin of the Croatian Dinarides, display repetitive alternations of two types of marls with different resistance to weathering. This study focuses on the chemical composition, stable isotopes, and palynomorph content of these marls in order to better understand the nature of their cyclic deposition and to identify possible paleoenvironmental drivers responsible for their formation. The less resistant marls (LRM) have consistently lower carbonate content, lower δ18O and δ13C values, and more abundant dinoflagellate cysts than the more resistant marls (MRM). We interpret these differences between the two marl types to be a result of climatic variations, likely related to Milankovitch oscillations. Periods with wetter climate, associated with increased continental runoff, detrital and nutrient influx produced the LRM. Higher nutrient supply sparked higher dinoflagellate productivity during these times, while reduced salinity and stratification of the water column may have hampered the productivity of calcareous nannoplankton and/or planktonic foraminifera. In contrast, the MRM formed during dryer periods which favoured higher carbonate accumulation rates. This study provides new information about the sedimentary record of short-scale climate variations reflected in wet-dry cycles during an overall warm, greenhouse Earth.

Resistance to lambda-cyhalothrin in Spanish field populations of Ceratitis capitata and metabolic resistance mediated by P450 in a resistant strain.

PubMed

Arouri, Rabeh; Le Goff, Gaelle; Hemden, Hiethem; Navarro-Llopis, Vicente; M'saad, Mariem; Castañera, Pedro; Feyereisen, René; Hernández-Crespo, Pedro; Ortego, Félix

2015-09-01

The withdrawal of malathion in the European Union in 2009 resulted in a large increase in lambda-cyhalothrin applications for the control of the Mediterranean fruit fly, Ceratitis capitata, in Spanish citrus crops. Spanish field populations of C. capitata have developed resistance to lambda-cyhalothrin (6-14-fold), achieving LC50 values (129-287 ppm) higher than the recommended concentration for field treatments (125 ppm). These results contrast with the high susceptibility to lambda-cyhalothrin found in three Tunisian field populations. We have studied the mechanism of resistance in the laboratory-selected resistant strain W-1Kλ (205-fold resistance). Bioassays with synergists showed that resistance was almost completely suppressed by the P450 inhibitor PBO. The study of the expression of 53 P450 genes belonging to the CYP4, CYP6, CYP9 and CYP12 families in C. capitata revealed that CYP6A51 was overexpressed (13-18-fold) in the resistant strain. The W-1Kλ strain also showed high levels of cross-resistance to etofenprox (240-fold) and deltamethrin (150-fold). Field-evolved resistance to lambda-cyhalothrin has been found in C. capitata. Metabolic resistance mediated by P450 appears to be the main resistance mechanism in the resistant strain W-1Kλ. The levels of cross-resistance found may compromise the effectiveness of other pyrethroids for the control of this species. © 2014 Society of Chemical Industry. © 2014 Society of Chemical Industry.

Identification of the critical sites of NNRTI-resistance in reverse transcriptase of HIV-1 CRF_BC strains.

PubMed

Huang, Yang; Li, Zhenpeng; Xing, Hui; Jiao, Yang; Ouyang, Yabo; Liao, Lingjie; Jiang, Shibo; Armstrong, Rebecca; Shao, Yiming; Ma, Liying

2014-01-01

The polymorphisms involved in drug resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs) in HIV-1 CRF_BC, the most prevalent HIV-1 strain in China, have been poorly characterized. To reveal the drug resistance mutations, we compared the gene sequences of pol region of HIV-1 CRF_BC from 631 treatment-naïve and 363 treatment-experienced patients using the selection pressure-based method. We calculated an individual Ka/Ks value for each specific amino acid mutation. Result showed that eight polymorphic mutations (W88C, K101Q, I132L, R135L, T139K/R, H221Y and L228R) in RT for treatment-experienced patients were identified, while they, except for R135L, were completely absent in those from treatment-naïve patients. The I132L and T139K/R mutants exhibited high-level resistance to DLV and NVP and moderate resistance to TMC-125 and EFV, while the K101Q and H221Y mutants exhibited an increased resistance to all four NNRTIs tested. The W88C, R135L, and L228R may be RTI-induced adaptive mutations. Y181C+K101Q mutant showed a 2.5-, 4.4-, and 4.7-fold higher resistance to TMC-125, NVP and EFV, respectively, than Y181C alone mutant, while Y181C+H221Y or K103N+H221Y mutants had significantly higher resistance to all four NNRTIs than Y181C or K103N mutants. K103N+T139K and G190A+T139K mutant induce higher resistance (2.0∼14.2-fold and 1.5∼7.2-fold, respectively) to all four NNRTIs than K103N or G190A alone mutation. I132L and T139K/R are rare but critical mutations associated with NNRTI-resistance for some NNRTIs. K101Q, H221Y and T139K can enhance K103N/Y181C/G190A-assocated NNRTI-resistance. Monitoring these mutations will provide useful information for rational design of the NNRTI-based antiretroviral regimen for HIV-1 CRF_BC-infected patients.

Inactivation of Salmonella during cocoa roasting and chocolate conching.

PubMed

Nascimento, Maristela da Silva do; Brum, Daniela Merlo; Pena, Pamela Oliveira; Berto, Maria Isabel; Efraim, Priscilla

2012-10-15

The high heat resistance of Salmonella in foods with low water activity raises particular issues for food safety, especially chocolate, where outbreak investigations indicate that few colony-forming units are necessary to cause salmonellosis. This study evaluated the efficiency of cocoa roasting and milk chocolate conching in the inactivation of Salmonella 5-strain suspension. Thermal resistance of Salmonella was greater in nibs compared to cocoa beans upon exposure at 110 to 130°C. The D-values in nibs were 1.8, 2.2 and 1.5-fold higher than those calculated for cocoa beans at 110, 120 and 130°C. There was no significant difference (p>0.05) between the matrices only at 140°C. Since in the conching of milk chocolate the inactivation curves showed rapid death in the first 180 min followed by a lower inactivation rate, and two D-values were calculated. For the first time interval (0-180 min) the D-values were 216.87, 102.27 and 50.99 min at 50, 60 and 70°C, respectively. The other D-values were determined from the second time interval (180-1440 min), 1076.76 min at 50°C, 481.94 min at 60°C and 702.23 min at 70°C. The results demonstrated that the type of matrix, the process temperature and the initial count influenced the Salmonella resistance. Copyright © 2012 Elsevier B.V. All rights reserved.

Mechanism of Sulfonylurea Herbicide Resistance in the Broadleaf Weed, Kochia scoparia

PubMed Central

Saari, Leonard L.; Cotterman, Josephine C.; Primiani, Michael M.

1990-01-01

Selection of kochia (Kochia scoparia) biotypes resistant to the sulfonylurea herbicide chlorsulfuron has occurred through the continued use of this herbicide in monoculture cereal-growing areas in the United States. The apparent sulfonylurea resistance observed in kochia was confirmed in greenhouse tests. Fresh and dry weight accumulation in the resistant kochia was 2- to >350-fold higher in the presence of four sulfonylurea herbicides as compared to the susceptible biotype. Acetolactate synthase (ALS) activity isolated from sulfonylurea-resistant kochia was less sensitive to inhibition by three classes of ALS-inhibiting herbicides, sulfonylureas, imidazolinones, and sulfonanilides. The decrease in ALS sensitivity to inhibition (as measured by the ratio of resistant I50 to susceptible I50) was 5- to 28-fold, 2- to 6-fold, and 20-fold for sulfonylurea herbicides, imidazolinone herbicides, and a sulfonanilide herbicide, respectively. No differences were observed in the ALS-specific activities or the rates of [14C]chlorsulfuron uptake, translocation, and metabolism between susceptible and resistant kochia biotypes. The Km values for pyruvate using ALS from susceptible and resistant kochia were 2.13 and 1.74 mm, respectively. Based on these results, the mechanism of sulfonylurea resistance in this kochia biotype is due solely to a less sulfonylurea-sensitive ALS enzyme. PMID:16667465

Mechanism of sulfonylurea herbicide resistance in the broadleaf weed, Kochia scoparia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saari, L.L.; Cotterman, J.C.; Primiani, M.M.

Selection of kochia (Kochia scoparia) biotypes resistant to the sulfonylurea herbicide chlorsulfuron has occurred through the continued use of this herbicide in monoculture cereal-growing areas in the United States. The apparent sulfonylurea resistance observed in kochia was confirmed in greenhouse tests. Fresh and dry weight accumulation in the resistance kochia was 2- to >350-fold higher in the presence of four sulfonylurea herbicides as compared to the susceptible biotype. Acetolactate synthase (ALS) activity isolated from sulfonylurea-resistant kochia was less sensitive to inhibition by three classes of ALS-inhibiting herbicides, sulfonylureas, imidazolinones, and sulfonanilides. The decrease in ALS sensitivity to inhibition (as measuredmore » by the ratio of resistant I{sub 50} to susceptible I{sub 50}) was 5- to 28-fold, 2- to 6-fold, and 20-fold for sulfonylurea herbicides, imidazolinone herbicides, and a sulfonanilide herbicide, respectively. No differences were observed in the ALS-specific activities or the rates of ({sup 14}C)chlorsulfuron uptake, translocation, and metabolism between susceptible and resistant kochia biotypes. The K{sub m} values for pyruvate using ALS from susceptible and resistant kochia were 2.13 and 1.74 mM, respectively. Based on these results, the mechanism of sulfonylurea resistance in this kochia biotype is due solely to a less sulfonylurea-sensitive ALS enzyme.« less

Spatio-temporal evolution of apparent resistivity during coal-seam hydraulic flushing

NASA Astrophysics Data System (ADS)

Li, Dexing; Wang, Enyuan; Song, Dazhao; Qiu, Liming; Kong, Xiangguo

2018-06-01

Hydraulic flushing in gas predrainage is widely used, but the hydraulic-flushing effect is evaluated in a traditional way, by determining the desorption volume, moisture content, gas drainage rate and other conventional indices. To verify the rationality and feasibility of the multielectrode resistivity method in the evaluation of coal-seam hydraulic flushing and to research the spatio-temporal evolution of apparent resistivity during hydraulic flushing, a field test was conducted in 17# coal seam at Nuodong Mine, Guizhou. During hydraulic flushing, four stages were defined according to the variation in coal rock resistivity with time, namely, the preparation stage, the sharply decreasing stage, the rapidly increasing stage and the steady stage. The apparent resistivity of the coal rock mass is affected mainly by its own degree of fragmentation and flushing volume. A more serious rupture and a greater flushing volume yield a smaller apparent resistivity during the sharply decreasing stage and a higher resistivity during the stable stage. After three months of gas predrainage, the residual gas content and the gas pressure at different points in the expected affected area decrease below the critical value. Changes in the residual gas content and gas pressure at these points are consistent with the apparent resistivity, which validates the rationality and feasibility of the multielectrode resistivity method in evaluating coal-seam hydraulic flushing.

Serum LBP Is Associated with Insulin Resistance in Women with PCOS.

PubMed

Zhu, Qibo; Zhou, Huang; Zhang, Aipin; Gao, Rufei; Yang, Shumin; Zhao, Changhong; Wang, Yue; Hu, Jinbo; Goswami, Richa; Gong, Lilin; Li, Qifu

2016-01-01

Lipopolysaccharide-binding protein (LBP) is closely associated with many metabolic disorders. However, no study has been done to explore the relationship between LBP and polycystic ovary syndrome (PCOS). The objective of this study was to investigate whether the serum LBP level is elevated and associated with insulin resistance (IR) in PCOS. In this cross-sectional study, 117 PCOS patients and 121 age-matched controls were recruited. Hyperinsulinemic-euglycemic clamp was performed with an expression of M value for insulin sensitivity. Fasting serum samples were collected to detect LBP, lipids, insulin, sex hormones and high sensitive C reactive protein (hs-CRP). Pearson's correlation and multiple linear regression was used to analyze the associations between M value and LBP level. The study was performed in a clinical research center. Compared with controls, PCOS subjects had a significantly higher LBP concentration (33.03±14.59 vs. 24.35±10.31 μg/ml, p<0.001), and lower M value (8.21±3.06 vs. 12.31±1.72 mg/min/kg, p<0.001). Both in lean and overweight/obese individuals, serum LBP level was higher in PCOS subjects than that in controls. M value was negatively correlated with body mass index (BMI), fasting serum insulin, triglycerides, low-density lipoprotein cholesterol (LDL-c), free testosterone, high sensitive C reactive protein (hs-CRP) and LBP, whereas positively correlated with high-density lipoprotein cholesterol (HDL-c) and sex hormone binding globulin (SHBG). Serum LBP level was associated with M value after adjusting for BMI, fasting serum insulin, SHBG, as well as hs-CRP. Serum LBP level significantly is elevated in PCOS, and is independently associated with IR in PCOS.

Evaluation of manometric temperature measurement, a process analytical technology tool for freeze-drying: part II measurement of dry-layer resistance.

PubMed

Tang, Xiaolin Charlie; Nail, Steven L; Pikal, Michael J

2006-01-01

The purpose of this work was to study the factors that may cause systematic errors in the manometric temperature measurement (MTM) procedure used to determine product dry-layer resistance to vapor flow. Product temperature and dry-layer resistance were obtained using MTM software installed on a laboratory freeze-dryer. The MTM resistance values were compared with the resistance values obtained using the "vial method." The product dry-layer resistances obtained by MTM, assuming fixed temperature difference (DeltaT; 2 degrees C), were lower than the actual values, especially when the product temperatures and sublimation rates were low, but with DeltaT determined from the pressure rise data, more accurate results were obtained. MTM resistance values were generally lower than the values obtained with the vial method, particularly whenever freeze-drying was conducted under conditions that produced large variations in product temperature (ie, low shelf temperature, low chamber pressure, and without thermal shields). In an experiment designed to magnify temperature heterogeneity, MTM resistance values were much lower than the simple average of the product resistances. However, in experiments where product temperatures were homogenous, good agreement between MTM and "vial-method" resistances was obtained. The reason for the low MTM resistance problem is the fast vapor pressure rise from a few "warm" edge vials or vials with low resistance. With proper use of thermal shields, and the evaluation of DeltaT from the data, MTM resistance data are accurate. Thus, the MTM method for determining dry-layer resistance is a useful tool for freeze-drying process analytical technology.

A comparison of efficacy of six prediction models for intravenous immunoglobulin resistance in Kawasaki disease.

PubMed

Qian, Weiguo; Tang, Yunjia; Yan, Wenhua; Sun, Ling; Lv, Haitao

2018-03-09

Kawasaki disease (KD) is the most common pediatric vasculitis. Several models have been established to predict intravenous immunoglobulin (IVIG) resistance. The present study was aimed to evaluate the efficacy of prediction models using the medical data of KD patients. We collected the medical records of patients hospitalized in the Department of Cardiology in Children's Hospital of Soochow University with a diagnosis of KD from Jan 2015 to Dec 2016. IVIG resistance was defined as recrudescent or persistent fever ≥36 h after the end of their IVIG infusion. Patients with IVIG resistance tended to be younger, have higher occurrence of rash and changes of extremities. They had higher levels of c-reactive protein, aspartate aminotransferase, neutrophils proportion (N%), total bilirubin and lower level of albumin. Our prediction model had a sensitivity of 0.72 and a specificity of 0.75. Sensitivity of Kobayashi, Egami, Kawamura, Sano and Formosa were 0.72, 0.44, 0.48, 0.20, and 0.68, respectively. Specificity of these models were 0.62, 0.82, 0.66, 0.91, and 0.48, respectively. Our prediction model had a powerful predictive value in this area, followed by Kobayashi model while all the other prediction models had less excellent performances than ours.

Relationship Between Crystalline Structure and Hardness of Ti-Si-N-O Coatings Fabricated by dc Sputtering

NASA Astrophysics Data System (ADS)

García-González, Leandro; Hernández-Torres, Julián; Mendoza-Barrera, Claudia; Meléndez-Lira, Miguel; García-Ramírez, Pedro J.; Martínez-Castillo, Jaime; Sauceda, Ángel; Herrera-May, Agustin L.; Muñoz Saldaña, Juan; Espinoza-Beltrán, Francisco J.

2008-08-01

Ti-Si-N-O coatings were deposited on AISI D2 tool steel and silicon substrates by dc reactive magnetron co-sputtering using a target of Ti-Si with a constant area ratio of 0.2. The substrate temperature was 400 °C and reactive atmosphere of nitrogen and argon. For all samples, argon flow was maintained constant at 25 sccm, while the flow of the nitrogen was varied to analyze the structural changes related to chemical composition and resistivity. According to results obtained by x-ray diffraction and stoichiometry calculations by x-ray energy dispersive spectroscopy the Ti-Si-N-O coatings contain two solid solutions. The higher crystalline part corresponds to titanium oxynitrure. Hardness tests on the coatings were carried out using the indentation work model and the hardness value was determined. Finally, the values of hardness were corroborated by nanoindentation test, and values of Young’s modulus and elastic recovery were discussed. We concluded that F2TSN sample ( F Ar = 25 sccm, F N = 5 sccm, P = 200 W, and P W = 8.9 × 10-3 mbar) presented the greatest hardness and the lowest resistivity values, due to its preferential crystalline orientation.

Immortality of Cu damascene interconnects

NASA Astrophysics Data System (ADS)

Hau-Riege, Stefan P.

2002-04-01

We have studied short-line effects in fully-integrated Cu damascene interconnects through electromigration experiments on lines of various lengths and embedded in different dielectric materials. We compare these results with results from analogous experiments on subtractively-etched Al-based interconnects. It is known that Al-based interconnects exhibit three different behaviors, depending on the magnitude of the product of current density, j, and line length, L: For small values of (jL), no void nucleation occurs, and the line is immortal. For intermediate values, voids nucleate, but the line does not fail because the current can flow through the higher-resistivity refractory-metal-based shunt layers. Here, the resistance of the line increases but eventually saturates, and the relative resistance increase is proportional to (jL/B), where B is the effective elastic modulus of the metallization system. For large values of (jL/B), voiding leads to an unacceptably high resistance increase, and the line is considered failed. By contrast, we observed only two regimes for Cu-based interconnects: Either the resistance of the line stays constant during the duration of the experiment, and the line is considered immortal, or the line fails due to an abrupt open-circuit failure. The absence of an intermediate regime in which the resistance saturates is due to the absence of a shunt layer that is able to support a large amount of current once voiding occurs. Since voids nucleate much more easily in Cu- than in Al-based interconnects, a small fraction of short Cu lines fails even at low current densities. It is therefore more appropriate to consider the probability of immortality in the case of Cu rather than assuming a sharp boundary between mortality and immortality. The probability of immortality decreases with increasing amount of material depleted from the cathode, which is proportional to (jL2/B) at steady state. By contrast, the immortality of Al-based interconnects is described by (jL) if no voids nucleate, and (jL/B) if voids nucleate.

Resistivity imaging of Aluto-Langano geothermal field using 3-D magnetotelluric inversion

NASA Astrophysics Data System (ADS)

Cherkose, Biruk Abera; Mizunaga, Hideki

2018-03-01

Magnetotelluric (MT) method is a widely used geophysical method in geothermal exploration. It is used to image subsurface resistivity structures from shallow depths up to several kilometers of depth. Resistivity imaging using MT method in high-enthalpy geothermal systems is an effective tool to identify conductive clay layers that cover the geothermal systems and to detect a potential reservoir. A resistivity model is vital for deciding the location of pilot and production sites at the early stages of a geothermal project. In this study, a 3-D resistivity model of Aluto-Langano geothermal field was constructed to map structures related to a geothermal resource. The inversion program, ModEM was used to recover the 3-D resistivity model of the study area. The 3-D inversion result revealed the three main resistivity structures: a high-resistivity surface layer related to unaltered volcanic rocks at shallow depth, underlain by a conductive zone associated with the presence of conductive clay minerals, predominantly smectite. Beneath the conductive layer, the resistivity increases gradually to higher values related to the formation of high-temperature alteration minerals such as chlorite and epidote. The resistivity model recovered from 3-D inversion in Aluto-Langano corresponds very well to the conceptual model for high-enthalpy volcanic geothermal systems. The conductive clay cap is overlying the resistive propylitic upflow zone as confirmed by the geothermal wells in the area.

Impact of substrate and thermal boundary resistance on the performance of AlGaN/GaN HEMTs analyzed by means of electro-thermal Monte Carlo simulations

NASA Astrophysics Data System (ADS)

García, S.; Íñiguez-de-la-Torre, I.; Mateos, J.; González, T.; Pérez, S.

2016-06-01

In this paper, we present results from the simulations of a submicrometer AlGaN/GaN high-electron-mobility transistor (HEMT) by using an in-house electro-thermal Monte Carlo simulator. We study the temperature distribution and the influence of heating on the transfer characteristics and the transconductance when the device is grown on different substrates (sapphire, silicon, silicon carbide and diamond). The effect of the inclusion of a thermal boundary resistance (TBR) is also investigated. It is found that, as expected, HEMTs fabricated on substrates with high thermal conductivities (diamond) exhibit lower temperatures, but the difference between hot-spot and average temperatures is higher. In addition, devices fabricated on substrates with higher thermal conductivities are more sensitive to the value of the TBR because the temperature discontinuity is greater in the TBR layer.

Effect of prophylactic bronchodilator treatment with intravenous colforsin daropate, a water-soluble forskolin derivative, on airway resistance after tracheal intubation.

PubMed

Wajima, Zen'ichiro; Shiga, Toshiya; Yoshikawa, Tatsusuke; Ogura, Akira; Imanaga, Kazuyuki; Inoue, Tetsuo; Ogawa, Ryo

2003-07-01

After induction of anesthesia, lung resistance increases. The authors hypothesized that prophylactic bronchodilator treatment with intravenous colforsin daropate, a water-soluble forskolin derivative, before tracheal intubation would result in decreased lung resistance and increased lung compliance after tracheal intubation when compared with placebo medication. Forty-six adult patients were randomized to placebo or colforsin daropate treatment. Patients in the control group received normal saline; patients in the colforsin group received 0.75 microg. kg-1 x min-1 colforsin daropate intravenously until the study ended. Thirty minutes after the study began, the authors administered 5 mg/kg thiamylal and 5 microg/kg fentanyl for induction of general anesthesia and 0.3 mg/kg vecuronium for muscle relaxation. A 15-mg. kg-1. h-1 continuous infusion of thiamylal followed anesthetic induction. Four, 8, 12, and 16 min after tracheal intubation, mean airway resistance (R(awm)), expiratory airway resistance (R(awe)), and dynamic lung compliance (C(dyn)) were measured. Patients in the colforsin group had significantly lower R(awm) and R(awe) and higher C(dyn) after intubation than those in the control group. Differences in R(awm), R(awe), and C(dyn) between the two groups persisted through the final measurement at 16 min. At 4 min after intubation, smokers had a higher R(awm) and a lower C(dyn) than nonsmokers in the control group. After treatment by intravenous colforsin daropate, R(awm), R(awe), and C(dyn) values were similar for smokers and nonsmokers after tracheal intubation. Prophylactic treatment with colforsin daropate produced lower R(awm) and R(awe) and higher C(dyn) after tracheal intubation when compared with placebo medication. Pretreatment before intubation may be beneficial and advantageous for middle-aged smokers.

Effect of vibration during fatiguing resistance exercise on subsequent muscle activity during maximal voluntary isometric contractions.

PubMed

McBride, Jeffrey M; Porcari, John P; Scheunke, Mark D

2004-11-01

This investigation was designed to determine if vibration during fatiguing resistance exercise would alter associated patterns of muscle activity. A cross-over design was employed with 8 subjects completing a resistance exercise bout once with a vibrating dumbbell (V) (44 Hz, 3 mm displacement) and once without vibration (NV). For both exercise bouts, 10 sets were performed with a load that induced concentric muscle failure during the 10th repetition. The appropriate load for each set was determined during a pretest. Each testing session was separated by 1 week. Electromyography (EMG) was obtained from the biceps brachii muscle at 12 different time points during a maximum voluntary contraction (MVC) at a 170 degrees elbow angle after each set of the dumbbell exercise. The time points were as follows: pre (5 minutes before the resistance exercise bout), T1-T10 (immediately following each set of resistance exercise), and post (15 minutes after the resistance exercise bout). EMG was analyzed for median power frequency (MPF) and maximum (mEMG). NV resulted in a significant decrease in MPF at T1-T4 (p < or 0.05) and a significant increase in mEMG at T2 during the MVC. V had an overall trend of lower mEMG in comparison to NV. The mEMG and MPF values associated with NV were similar to previously reported investigations. The lower mEMG values and the higher MPF of V in comparison to NV are undocumented. The EMG patterns observed with vibration may indicate a more efficient and effective recruitment of high threshold motor units during fatiguing contractions. This may indicate the usage of vibration with resistance exercise as an effective tool for strength training athletes.

Landscape genetic analyses reveal fine-scale effects of forest fragmentation in an insular tropical bird.

PubMed

Khimoun, Aurélie; Peterman, William; Eraud, Cyril; Faivre, Bruno; Navarro, Nicolas; Garnier, Stéphane

2017-10-01

Within the framework of landscape genetics, resistance surface modelling is particularly relevant to explicitly test competing hypotheses about landscape effects on gene flow. To investigate how fragmentation of tropical forest affects population connectivity in a forest specialist bird species, we optimized resistance surfaces without a priori specification, using least-cost (LCP) or resistance (IBR) distances. We implemented a two-step procedure in order (i) to objectively define the landscape thematic resolution (level of detail in classification scheme to describe landscape variables) and spatial extent (area within the landscape boundaries) and then (ii) to test the relative role of several landscape features (elevation, roads, land cover) in genetic differentiation in the Plumbeous Warbler (Setophaga plumbea). We detected a small-scale reduction of gene flow mainly driven by land cover, with a negative impact of the nonforest matrix on landscape functional connectivity. However, matrix components did not equally constrain gene flow, as their conductivity increased with increasing structural similarity with forest habitat: urban areas and meadows had the highest resistance values whereas agricultural areas had intermediate resistance values. Our results revealed a higher performance of IBR compared to LCP in explaining gene flow, reflecting suboptimal movements across this human-modified landscape, challenging the common use of LCP to design habitat corridors and advocating for a broader use of circuit theory modelling. Finally, our results emphasize the need for an objective definition of landscape scales (landscape extent and thematic resolution) and highlight potential pitfalls associated with parameterization of resistance surfaces. © 2017 John Wiley & Sons Ltd.

Cross-Linkable, Solvent-Resistant Fullerene Contacts for Robust and Efficient Perovskite Solar Cells with Increased JSC and VOC.

PubMed

Watson, Brian L; Rolston, Nicholas; Bush, Kevin A; Leijtens, Tomas; McGehee, Michael D; Dauskardt, Reinhold H

2016-10-05

The active layers of perovskite solar cells are also structural layers and are central to ensuring that the structural integrity of the device is maintained over its operational lifetime. Our work evaluating the fracture energies of conventional and inverted solution-processed MAPbI 3 perovskite solar cells has revealed that the MAPbI 3 perovskite exhibits a fracture resistance of only ∼0.5 J/m 2 , while solar cells containing fullerene electron transport layers fracture at even lower values, below ∼0.25 J/m 2 . To address this weakness, a novel styrene-functionalized fullerene derivative, MPMIC 60 , has been developed as a replacement for the fragile PC 61 BM and C 60 transport layers. MPMIC 60 can be transformed into a solvent-resistant material through curing at 250 °C. As-deposited films of MPMIC 60 exhibit a marked 10-fold enhancement in fracture resistance over PC 61 BM and a 14-fold enhancement over C 60 . Conventional-geometry perovskite solar cells utilizing cured films of MPMIC 60 showed a significant, 205% improvement in fracture resistance while exhibiting only a 7% drop in PCE (13.8% vs 14.8% PCE) in comparison to the C 60 control, enabling larger V OC and J SC values. Inverted cells fabricated with MPMIC 60 exhibited a 438% improvement in fracture resistance with only a 6% reduction in PCE (12.3% vs 13.1%) in comparison to those utilizing PC 61 BM, again producing a higher J SC .

The impact of temperature loading on massive concrete block resistance

NASA Astrophysics Data System (ADS)

Beran, Pavel; Kočí, Jan

2017-07-01

Very large and massive concrete blocks with thickness in interval 3.5 - 6 meters are often designed in cement industry. These massive blocks have high heat inertial and thus the thermal stress due to nonlinear temperature gradient in concrete block may occur. The coupled thermo-mechanical analysis of concrete block in Prague Czech Republic and Sterlitamak Russia was made. By the numerical model of concrete block was analyzed the typical year (called reference year) in particular localities. The results show that in concrete block the thermal stresses which are higher than the tensile strength of concrete originate. Therefore, the concrete block should be reinforced by steel rods. The values of stresses are markedly affected by climate. The significantly higher values of thermal stresses were detected in Sterlitamak than in Prague.

Evaluation of Genome-Enabled Selection for Bacterial Cold Water Disease Resistance Using Progeny Performance Data in Rainbow Trout: Insights on Genotyping Methods and Genomic Prediction Models.

PubMed

Vallejo, Roger L; Leeds, Timothy D; Fragomeni, Breno O; Gao, Guangtu; Hernandez, Alvaro G; Misztal, Ignacy; Welch, Timothy J; Wiens, Gregory D; Palti, Yniv

2016-01-01

Bacterial cold water disease (BCWD) causes significant economic losses in salmonid aquaculture, and traditional family-based breeding programs aimed at improving BCWD resistance have been limited to exploiting only between-family variation. We used genomic selection (GS) models to predict genomic breeding values (GEBVs) for BCWD resistance in 10 families from the first generation of the NCCCWA BCWD resistance breeding line, compared the predictive ability (PA) of GEBVs to pedigree-based estimated breeding values (EBVs), and compared the impact of two SNP genotyping methods on the accuracy of GEBV predictions. The BCWD phenotypes survival days (DAYS) and survival status (STATUS) had been recorded in training fish (n = 583) subjected to experimental BCWD challenge. Training fish, and their full sibs without phenotypic data that were used as parents of the subsequent generation, were genotyped using two methods: restriction-site associated DNA (RAD) sequencing and the Rainbow Trout Axiom® 57 K SNP array (Chip). Animal-specific GEBVs were estimated using four GS models: BayesB, BayesC, single-step GBLUP (ssGBLUP), and weighted ssGBLUP (wssGBLUP). Family-specific EBVs were estimated using pedigree and phenotype data in the training fish only. The PA of EBVs and GEBVs was assessed by correlating mean progeny phenotype (MPP) with mid-parent EBV (family-specific) or GEBV (animal-specific). The best GEBV predictions were similar to EBV with PA values of 0.49 and 0.46 vs. 0.50 and 0.41 for DAYS and STATUS, respectively. Among the GEBV prediction methods, ssGBLUP consistently had the highest PA. The RAD genotyping platform had GEBVs with similar PA to those of GEBVs from the Chip platform. The PA of ssGBLUP and wssGBLUP methods was higher with the Chip, but for BayesB and BayesC methods it was higher with the RAD platform. The overall GEBV accuracy in this study was low to moderate, likely due to the small training sample used. This study explored the potential of GS for improving resistance to BCWD in rainbow trout using, for the first time, progeny testing data to assess the accuracy of GEBVs, and it provides the basis for further investigation on the implementation of GS in commercial rainbow trout populations.

Evaluation of Genome-Enabled Selection for Bacterial Cold Water Disease Resistance Using Progeny Performance Data in Rainbow Trout: Insights on Genotyping Methods and Genomic Prediction Models

PubMed Central

Vallejo, Roger L.; Leeds, Timothy D.; Fragomeni, Breno O.; Gao, Guangtu; Hernandez, Alvaro G.; Misztal, Ignacy; Welch, Timothy J.; Wiens, Gregory D.; Palti, Yniv

2016-01-01

Bacterial cold water disease (BCWD) causes significant economic losses in salmonid aquaculture, and traditional family-based breeding programs aimed at improving BCWD resistance have been limited to exploiting only between-family variation. We used genomic selection (GS) models to predict genomic breeding values (GEBVs) for BCWD resistance in 10 families from the first generation of the NCCCWA BCWD resistance breeding line, compared the predictive ability (PA) of GEBVs to pedigree-based estimated breeding values (EBVs), and compared the impact of two SNP genotyping methods on the accuracy of GEBV predictions. The BCWD phenotypes survival days (DAYS) and survival status (STATUS) had been recorded in training fish (n = 583) subjected to experimental BCWD challenge. Training fish, and their full sibs without phenotypic data that were used as parents of the subsequent generation, were genotyped using two methods: restriction-site associated DNA (RAD) sequencing and the Rainbow Trout Axiom® 57 K SNP array (Chip). Animal-specific GEBVs were estimated using four GS models: BayesB, BayesC, single-step GBLUP (ssGBLUP), and weighted ssGBLUP (wssGBLUP). Family-specific EBVs were estimated using pedigree and phenotype data in the training fish only. The PA of EBVs and GEBVs was assessed by correlating mean progeny phenotype (MPP) with mid-parent EBV (family-specific) or GEBV (animal-specific). The best GEBV predictions were similar to EBV with PA values of 0.49 and 0.46 vs. 0.50 and 0.41 for DAYS and STATUS, respectively. Among the GEBV prediction methods, ssGBLUP consistently had the highest PA. The RAD genotyping platform had GEBVs with similar PA to those of GEBVs from the Chip platform. The PA of ssGBLUP and wssGBLUP methods was higher with the Chip, but for BayesB and BayesC methods it was higher with the RAD platform. The overall GEBV accuracy in this study was low to moderate, likely due to the small training sample used. This study explored the potential of GS for improving resistance to BCWD in rainbow trout using, for the first time, progeny testing data to assess the accuracy of GEBVs, and it provides the basis for further investigation on the implementation of GS in commercial rainbow trout populations. PMID:27303436

Anti-Mullerian hormone and insulin resistance in classic phenotype lean PCOS.

PubMed

Caglar, Gamze Sinem; Kahyaoglu, Inci; Pabuccu, Recai; Demirtas, Selda; Seker, Rabia

2013-10-01

This study is designed to explore the correlation between AMH levels and IR in normal weight PCOS women. This prospective study was conducted on 55 patients, who were admitted to obstetrics and gynecology department of a university clinic. Study group was consisted of 34 patients diagnosed as polycystic ovary syndrome (PCOS) according to the Rotterdam Criteria, whereas control group was consisted of 21 healthy volunteers without any features of clinical or biochemical hyperandrogenism, who had regular menstrual cycles. BMI ≥ 25 kg/m(2) were considered overweight and obese and excluded. Blood samples were obtained during days 2-3 after spontaneous menses or progesterone-induced withdrawal bleeding after overnight fasting for at least 12 h. The weight, height, hip and waist circumferences of the patients were measured. Fasting insulin and glucose (FPG) levels were used for calculating different insulin resistance indexes (Homeostatic Model Assessment (HOMA-IR), Quantitative Insulin Sensitivity Check Index (QUICKI)). No significant difference was found between PCOS and control groups regarding the mean age, BMI, waist to hip ratio (WHR), mean values of FPG, FPG/insulin ratio and HOMA B (p > 0.05). AMH values were significantly higher in PCOS cases when compared with controls (4.7 vs. 3.4 ng/mL) (p < 0.05).The mean values of HOMA-IR and QUICKI indexes were significantly higher among PCOS cases when compared with controls. E2 levels were significantly lower and Total-T were significantly higher in PCOS patients. When PCOS cases are categorized according to the existence of IR, no difference in Total-T and AMH levels between both groups. Although not statistically significant, a negative correlation of AMH with HOMA-IR and a positive correlation with QUICKI index were found. Among the hormone parameters, AMH was found to be positively correlated with Total-T (r = 0.332, p = 0.013). Although the relation between AMH and androgen production is supported by current evidence, the mechanism underlying the relation between AMH and insulin resistance is not clear yet.

[Estimated glucose disposal rate in patients under 18 years of age with type 1 diabetes mellitus and overweight or obesity].

PubMed

Palomo Atance, Enrique; Ballester Herrera, M José; Giralt Muiña, Patricio; Ruiz Cano, Rafael; León Martín, Alberto; Giralt Muiña, Juan

2013-01-01

To assess the estimated glucose disposal rate (eGDR), insulin dose, and lipoprotein profile in children with type 1 diabetes mellitus (T1DM) and overweight or obesity as compared to children with T1DM and normal weight. A total of 115 patients (aged 5-16 years) with T1DM on intensive insulin therapy were recruited. The following parameters were measured: weight, height, body mass index, waist and hip circumference, insulin dose, eGDR, glycosylated hemoglobin, blood pressure, and lipoprotein profile. Results were stratified by sex and age. No significant differences were found in eGDR between children with normal weight, overweight, and obesity. However, obese children older than 11 years had lower eGDR values (9.3±1.3 vs 10.1±0.8 mg kg(-1)min(-1); p<0.01). Insulin dose was higher in overweight and obese children, especially in IU/m2/day (37.7 vs 36.1 vs. 29.4 respectively; p<0.01). Obese children had higher low-density lipoprotein cholesterol levels than children with overweight and normal weight (106.5 vs 91.7 vs 91.5mg/dL respectively; p<0.01). No correlation was found between waist circumference and the different markers of insulin resistance. Values of eGDR values were lower in obese children with T1DM older than 11 years, and this may therefore be considered a marker of insulin resistance. Insulin dose was higher in diabetic patients with overweight or obesity, specially in IU/m2/day. Obese children with T1DM had a lipoprotein profile of cardiovascular risk. Copyright © 2012 SEEN. Published by Elsevier Espana. All rights reserved.

Change of point mutations in Helicobacter pylori rRNA associated with clarithromycin resistance in Italy.

PubMed

De Francesco, Vincenzo; Zullo, Angelo; Giorgio, Floriana; Saracino, Ilaria; Zaccaro, Cristina; Hassan, Cesare; Ierardi, Enzo; Di Leo, Alfredo; Fiorini, Giulia; Castelli, Valentina; Lo Re, Giovanna; Vaira, Dino

2014-03-01

Primary clarithromycin resistance is the main factor affecting the efficacy of Helicobacter pylori therapy. This study aimed: (i) to assess the concordance between phenotypic (culture) and genotypic (real-time PCR) tests in resistant strains; (ii) to search, in the case of disagreement between the methods, for point mutations other than those reported as the most frequent in Europe; and (iii) to compare the MICs associated with the single point mutations. In order to perform real-time PCR, we retrieved biopsies from patients in whom H. pylori infection was successful diagnosed by bacterial culture and clarithromycin resistance was assessed using the Etest. Only patients who had never been previously treated, and with H. pylori strains that were either resistant exclusively to clarithromycin or without any resistance, were included. Biopsies from 82 infected patients were analysed, including 42 strains that were clarithromycin resistant and 40 that were clarithromycin susceptible on culture. On genotypic analysis, at least one of the three most frequently reported point mutations (A2142C, A2142G and A2143G) was detected in only 23 cases (54.8%), with a concordance between the two methods of 0.67. Novel point mutations (A2115G, G2141A and A2144T) were detected in a further 14 out of 19 discordant cases, increasing the resistance detection rate of PCR to 88% (P<0.001; odds ratio 6.1, 95% confidence interval 2-18.6) and the concordance to 0.81. No significant differences in MIC values among different point mutations were observed. This study suggests that: (i) the prevalence of the usually reported point mutations may be decreasing, with a concomitant emergence of new mutations; (ii) PCR-based methods should search for at least six point mutations to achieve good accuracy in detecting clarithromycin resistance; and (iii) none of the tested point mutations is associated with significantly higher MIC values than the others.

The influence of electrode and separator thickness on the cell resistance of symmetric cellulose-polypyrrole-based electric energy storage devices

NASA Astrophysics Data System (ADS)

Tammela, Petter; Olsson, Henrik; Strømme, Maria; Nyholm, Leif

2014-12-01

The influence of the cell design of symmetric polypyrrole and cellulose-based electric energy storage devices on the cell resistance was investigated using chronopotentiometric and ac impedance measurements with different separator and electrode thicknesses. The cell resistance was found to be dominated by the electrolyte and current collector resistances while the contribution from the composite electrode material was negligible. Due to the electrolyte within the porous electrodes thin separators could be used in combination with thick composite electrodes without loss of performance. The paper separator contributed with a resistance of ∼1.5 Ω mm-1 in a 1.0 M NaNO3 electrolyte and the tortuosity value for the separator was about 2.5. The contribution from the graphite foil current collectors was about ∼0.4-1.1 Ω and this contribution could not be reduced by using platinum foil current collectors due to larger contact resistances. The introduction of chopped carbon fibres into the electrode material or the application of pressure across the cells, however, decreased the charge transfer resistance significantly. As the present results demonstrate that cells with higher charge storage capacities but with the same cell resistance can be obtained by increasing the electrode thickness, the development of paper based energy storage devices is facilitated.

Expanded Normal Weight Obesity and Insulin Resistance in US Adults of the National Health and Nutrition Examination Survey

PubMed Central

Martinez, Keilah E.; Bailey, Bruce W.

2017-01-01

This study aims to expand the evaluation of normal weight obesity (NWO) and its association with insulin resistance using an NHANES (1999–2006) sample of US adults. A cross-sectional study including 5983 men and women (50.8%) was conducted. Body fat percentage (BF%) was assessed using dual-energy X-ray absorptiometry. Expanded normal weight obesity (eNWO) categories, pairings of BMI and body fat percentage classifications, were created using standard cut-points for BMI and sex-specific median for BF%. Homeostatic model assessment-insulin resistance (HOMA-IR) levels were used to index insulin resistance. Mean ± SE values were BMI: 27.9 ± 0.2 (women) and 27.8 ± 0.1 (men); body fat percentage: 40.5 ± 0.2 (women) and 27.8 ± 0.2 (men); and HOMA-IR: 2.04 ± 0.05 (women) and 2.47 ± 0.09 (men). HOMA-IR differed systematically and in a dose-response fashion across all levels of the eNWO categories (F = 291.3, P < 0.0001). As BMI levels increased, HOMA-IR increased significantly, and within each BMI category, higher levels of body fat were associated with higher levels of HOMA-IR. Both high BMI and high BF% were strongly related to insulin resistance. Insulin resistance appears to increase incrementally according to BMI levels primarily and body fat levels secondarily. Including a precise measure of body fat with BMI adds little to the utility of BMI in the prediction of insulin resistance. PMID:28812029

Association Between Insulin Resistance and Bone Structure in Nondiabetic Postmenopausal Women

PubMed Central

Finkelstein, Joel S.; Bouxsein, Mary L.; Yu, Elaine W.

2016-01-01

Context: The clinical consequences of insulin resistance and hyperinsulinemia on bone remain largely unknown. Objective: The objective of the study was to evaluate the effect of insulin resistance on peripheral bone geometry, volumetric bone mineral density (vBMD), bone microarchitecture, and estimated bone strength. Design, Setting, and Participants: This cross-sectional study included 146 postmenopausal, nondiabetic Caucasian women (mean age 60.3 ± 2.7 y) who were participating in the Study of Women's Health Across the Nation. Interventions: There were no interventions. Main Outcome Measures: High-resolution peripheral quantitative computed tomography was used to assess bone density and microstructure at the distal radius and tibia. Fasting insulin and glucose were measured and insulin resistance was estimated using homeostasis model assessment of insulin resistance (HOMA-IR), with higher values indicating greater insulin resistance. Results: There was a negative association between HOMA-IR and bone size and a positive association between HOMA-IR and total vBMD, trabecular vBMD, trabecular thickness, and cortical thickness at the radius and tibia. These relationships remained, even after adjusting for body weight and other potential covariates (eg, time since menopause, cigarette smoking, physical activity, prior use of osteoporosis medications or glucocorticoids). Conclusions: In nondiabetic, postmenopausal women, insulin resistance was associated with smaller bone size, greater volumetric bone mineral density, and generally favorable bone microarchitecture at weight-bearing and nonweight-bearing skeletal sites. These associations were independent of body weight and other potential covariates, suggesting that hyperinsulinemia directly affects bone structure independent of obesity and may explain, in part, the higher trabecular bone density and favorable trabecular microarchitecture seen in individuals with type 2 diabetes mellitus. PMID:27243136

Electrical resistivity of fluid methane multiply shock compressed to 147 GPa

NASA Astrophysics Data System (ADS)

Wang, Yi-Gao; Liu, Fu-Sheng; Liu, Qi-Jun; Wang, Wen-Peng

2018-01-01

Shock wave experiments were carried out to measure the electrical resistivity of fluid methane. The pressure range of 89-147 GPa and the temperature range from 1800 to 2600 K were achieved with a two-stage light-gas gun. We obtained a minimum electrical resistivity value of 4.5 × 10-2 Ω cm at pressure and temperature of 147 GPa and 2600 K, which is two orders of magnitude higher than that of hydrogen under similar conditions. The data are interpreted in terms of a continuous transition from insulator to semiconductor state. One possibility reason is chemical decomposition of methane in the shock compression process. Along density and temperature increase with Hugoniot pressure, dissociation of fluid methane increases continuously to form a H2-rich fluid.

Comparison of corrosion behavior between coarse grained and nano/ultrafine grained alloy 690

NASA Astrophysics Data System (ADS)

Jinlong, Lv; Tongxiang, Liang; Chen, Wang; Ting, Guo

2016-01-01

The effect of grain refinement on corrosion resistance of alloy 690 was investigated. The electron work function value of coarse grained alloy 690 was higher than that of nano/ultrafine grained one. The grain refinement reduced the electron work function of alloy 690. The passive films formed on coarse grained and nano/ultrafine grained alloy 690 in borate buffer solution were studied by potentiodynamic curves and electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy. The results showed that the grain refinement improved corrosion resistance of alloy 690. This was attributed to the fact that grain refinement promoted the enrichment of Cr2O3 and inhibited Cr(OH)3 in the passive film. More Cr2O3 in passive film could significantly improve the corrosion resistance of the nano/ultrafine grained alloy 690.

Zn-site Substitution Effect in YbCo2Zn20

NASA Astrophysics Data System (ADS)

Kobayashi, Riki; Takamura, Haruki; Higa, Yasuyuki; Ikeda, Yoichi; Matsubayashi, Kazuyuki; Uwatoko, Yoshiya; Yoshizawa, Hideki; Aso, Naofumi

2017-04-01

We have investigated the substitution effect of YbCo2(Zn1-xTx)20 (T = Cu, Ga, and Cd) systems by using the experiments of X-ray powder diffraction (XRPD), specific heat, magnetic susceptibility, magnetization, and electrical resistivity in order to find out a material that approaches a quantum critical point by chemical pressure. The XRPD and electrical resistivity measurements clarify that the Cu-substitution makes the lattice constants shrink and keeps the magnetic electrical resistivity high, while the Ga- and the Cd-substitution show opposite relation of the Cu-substitution. However, we could not detect clear substitution effect in the specific heat, magnetic susceptibility, and magnetization measurements of Cu-substitution system within our experiments. It is necessary that to study the Cu-substitution samples that have higher x value at lower temperature.

Optimization study on inductive-resistive circuit for broadband piezoelectric energy harvesters

NASA Astrophysics Data System (ADS)

Tan, Ting; Yan, Zhimiao

2017-03-01

The performance of cantilever-beam piezoelectric energy harvester is usually analyzed with pure resistive circuit. The optimal performance of such a vibration-based energy harvesting system is limited by narrow bandwidth around its modified natural frequency. For broadband piezoelectric energy harvesting, series and parallel inductive-resistive circuits are introduced. The electromechanical coupled distributed parameter models for such systems under harmonic base excitations are decoupled with modified natural frequency and electrical damping to consider the coupling effect. Analytical solutions of the harvested power and tip displacement for the electromechanical decoupled model are confirmed with numerical solutions for the coupled model. The optimal performance of piezoelectric energy harvesting with inductive-resistive circuits is revealed theoretically as constant maximal power at any excitation frequency. This is achieved by the scenarios of matching the modified natural frequency with the excitation frequency and equating the electrical damping to the mechanical damping. The inductance and load resistance should be simultaneously tuned to their optimal values, which may not be applicable for very high electromechanical coupling systems when the excitation frequency is higher than their natural frequencies. With identical optimal performance, the series inductive-resistive circuit is recommended for relatively small load resistance, while the parallel inductive-resistive circuit is suggested for relatively large load resistance. This study provides a simplified optimization method for broadband piezoelectric energy harvesters with inductive-resistive circuits.

Biocide and antibiotic resistance of Enterococcus faecalis and Enterococcus faecium isolated from the swine meat chain.

PubMed

Rizzotti, Lucia; Rossi, Franca; Torriani, Sandra

2016-12-01

In this study nine strains of Enterococcus faecalis and 12 strains of Enterococcus faecium, isolated from different sample types in the swine meat chain and previously characterized for the presence of antibiotic resistance genes, were examined for phenotypic tolerance to seven biocides (chlorexidine, benzalkonium chloride, triclosan, sodium hypochlorite, 2-propanol, formaldehyde and hydrogen peroxide) and resistance to nine antibiotics (ampicillin, vancomycin, gentamicin, kanamycin, streptomycin, erythromycin, clindamycin, tetracycline and chloramphenicol). Moreover, the presence of efflux system encoding genes qacA/B, qacC, qacE, qacEΔ1, emeA, and stress response genes, sigV and gsp65, involved in the tolerance to biocides, was analysed. Most strains were not tolerant to the biocides, but showed minimum inhibitory concentrations (MICs) higher than the recommended cut-off values for all the antibiotics tested, except for vancomycin and chloramphenicol. Only weak correlations, if any, were found between biocide and antibiotic resistance data. One E. faecalis strain was tolerant to triclosan and one E. faecium strain, with higher tolerance to chlorexidine than the other strains tested, was found to carry a qacA/B gene. Our results indicated that phenotypic resistance to antibiotics is very frequent in enterococcal isolates from the swine meat chain, but phenotypic tolerance to biocides is not common. On the other hand, the gene qacA/B was found for the first time in the species E. faecium, an indication of the necessity to adopt measures suitable to control the spread of biocide resistance determinants among enterococci. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Reconstruction of urban land space based on minimum cumulative resistance model: a case study of Xintang Town, Guangzhou City].

PubMed

Zhong, Shi-Yu; Wu, Qing; Li, Yu; Cheng, Jin-Ping

2012-11-01

Based on the source-sink landscape theory and the principles of ecosystem services, the minimum cumulative resistance (MCR) model was modified, where the urban center construction land was taken as the expansion source, and the contribution rate of ecological land ecosystem services value was considered as the resistance coefficient. With the modified MCR, the urban spatial expansion process of Xintang Town, Guangzhou City was successfully simulated, and, based on the protection of ecological security pattern, the optimum path for reconstructing urban land space was put forward. The simulated urban spatial expansion short path in 1988-2008 was in accordance with the real situation. By the modified MCR, the urban space was divided into four zones of high, higher, medium, and low resistance, with the area of 80.84, 78.90, 24.26, and 61.88 km2, respectively. The expansion path of the urban space was along the route from low to medium and then to high resistance zones successively. The land suitable for eco-protection and construction had an area of 159.74 km2 and 86.14 km2, while the ecological conflict area (17.37 km2) was mainly located in higher and high resistance zones, being 10.38 and 6.99 km2, respectively. The modified MCR could not only effectively reflect the distribution area of urban land use and the conflict relationship between urban construction and ecological protection, but also reasonably judge the best developmental short path for urban spatial expansion.

Temperature, soluble solids and pH effect on Alicyclobacillus acidoterrestris viability in lemon juice concentrate.

PubMed

Maldonado, María C; Belfiore, Carolina; Navarro, Antonio R

2008-02-01

Alicyclobacillus acidoterrestris is a thermoacidophilic, non-pathogenic, spore-forming bacterium detected in spoiled commercial pasteurized fruit juice. Apple, white grape and tomato are particularly susceptible. A. acidoterrestris spores are resistant to lemon juice pasteurization (2 min at 82 degrees C), and they can germinate and grow causing spoilage. This contamination is characterized by a medicinal or disinfectant smell attributed to guaiacol (o-dihydroxybenzene) production and other taint chemicals. The aim of this work was to study the influence of temperature (82, 86, 92 and 95 degrees C), total soluble solids (SS) (6.20, 9.8, 50 and 68 degrees Brix) and pH (2.28, 2.45, 2.80, 3.25, 3.5) on decimal reduction time (D) of the A. acidoterrestris in clarified and non-clarified concentrated lemon juice. Once D-value was determined, the resistance of A. acidoterrestris at the assayed temperatures was confirmed. SS and pH influence spore viability, because spore resistance increases with higher SS (50 degrees Brix 22 min 82 degrees C-68 degrees Brix 28 min 82 degrees C) and pH values (pH 2.28, 17 min-pH 4.00, 22 min). Bacterial growth was lower in clarified lemon juice, 26 min at 82 degrees C, than in non-clarified lemon juice, 51 min at 82 degrees C. Temperature was the parameter that had the greatest influence on the D value.

Influence of different final irrigation regimens and various endodontic filling materials on vertical root fracture resistance.

PubMed

Sungur, D D; Altundasar, E; Uzunoglu, E; Yilmaz, Z

2016-01-01

The aim of this study was to evaluate the influence of different endodontic materials and final irrigation regimens on vertical root fracture (VRF) resistance. Eighty human teeth were prepared then assigned into two groups (n = 40) according to the final irrigations. G1: 5 mL, 5.25% sodium hypochlorite (NaOCl), G2: 5 mL, 2% chlorhexidine gluconate (CHX). Each group was assigned into four subgroups according to the obturation system used (n = 10): A: iRoot SP/single gutta-percha cone (SGP), B: Only iRoot SP, C: Mineral trioxide aggregate (MTA)-Fillapex/SGP, D: AH26/SGP. The specimens were embedded in acrylic molds and subjected to compressive loading at a rate of 1 mm min until VRF occurred. Data were analyzed via three-way ANOVA tests. The statistically significant difference was found among groups (P < 0.05). The G1A and G1B and G1D revealed significantly higher-VRF values than G1C (P = 0.023). The roots filled with MTA-Fillapex revealed lower-VRF values than the other subgroups (P < 0.05). Groups irrigated with NaOCl had significantly lower-VRF values than the groups irrigated with CHX (P < 0.05). Final irrigation regimens could alter VRF resistance of root canals filled with different obturation technique and root canal sealers.

Development of microheaters for gas sensor with an AT-Mega 8535 temperature controller using a PWM (pulse width modulation) method

NASA Astrophysics Data System (ADS)

Megayanti, Meti; Panatarani, Camellia; Joni, I. Made

2016-03-01

Microheater is the main component in gas sensor characterized by their sensitivity, selectivity, and time response of gas sensor which is depend on the microheater temperature stability. A Cu microheater was developed and utilized AT-Mega 8535 controller using a PWM (pulse width modulation) method. This control system is interfaced to the PC to observe the real time temperature response of the microheater. Three initial resistance (R0) variations of microheater were developed in an open loop control system. The power characteristic of designed microheater depends on the specified microheater initial resistance. The smaller R0, the less power required to reach a temperature setting value. The developed microheater was designed to reach a temperature setting value of 250°C having resistance 0.531 Ω for 1.979 Watt and 0.265 Ω for 1.072 Watt respectively. The results of the investigation on the control performances shows microheater-control system achieved operating temperature up to 250°C. The response of the temperature control shows smallest R0 resulted in a high stability with short settling time, short delay time and small ripple for temperature setting values higher than 150°C. The obtained error of microheater temperature with R0 = 0.265 is 8.596 %. It is concluded that the developed microheater can be utilized as a component of a gas sensor.

Thermodynamics properties and combustion performance investigation of higher chain alcohol-RON 92 gasoline system

NASA Astrophysics Data System (ADS)

Oktavian, Rama; Darmawan, Rhezaldian Eka; Diarahmawati, Ayu; Kartiko, Intan Dyah; Rachmawati, Rizqi Tri

2017-03-01

The increasing consumption of fossil fuel in Indonesia is not followed by the rising on domestic oil production. This will lead to the depletion of fossil fuel reserves that will affect the availability of energy resources. Biofuel is considered as the critical solution to solve this problem in Indonesia. In recent years, alcohol produced from biomass has been used as an oxygenated compound in gasoline to increase the octane number and reduce pollutants resulting from motor vehicle exhaust emissions. However, the use of alcohol as an additive compounds is still limited to ethanol. In fact, the use of higher-chain alcohol such as 1-butanol offers more benefits over ethanol due to its higher calorific value. 1-butanol also has good characteristics for gasoline mixture such as less corrosive than ethanol, more resistant to water contamination, its low vapor pressure which leads to more safety application. This work investigated the effect of 1-butanol addition on the thermodynamic properties of gasoline-ethanol blend, in the form of density values, isobaric expansion coefficient, and the calorific value. The addition of 1-butanol up to 15% weight (80% RON 92-5% ethanol-15% 1-butanol) gives higher density to alcohol-gasoline blend up to 2% compared with pure RON 92 gasoline. Moreover, this addition produces the calorific value of gasoline blend of 11,313 cal/gr compared to pure RON 92 gasoline with the calorific value of 12,117 cal/gram. This blend can reduce the RON 92 gasoline consumption up to 15% from calorific value perspective.

Phosphorene/rhenium disulfide heterojunction-based negative differential resistance device for multi-valued logic

NASA Astrophysics Data System (ADS)

Shim, Jaewoo; Oh, Seyong; Kang, Dong-Ho; Jo, Seo-Hyeon; Ali, Muhammad Hasnain; Choi, Woo-Young; Heo, Keun; Jeon, Jaeho; Lee, Sungjoo; Kim, Minwoo; Song, Young Jae; Park, Jin-Hong

2016-11-01

Recently, negative differential resistance devices have attracted considerable attention due to their folded current-voltage characteristic, which presents multiple threshold voltage values. Because of this remarkable property, studies associated with the negative differential resistance devices have been explored for realizing multi-valued logic applications. Here we demonstrate a negative differential resistance device based on a phosphorene/rhenium disulfide (BP/ReS2) heterojunction that is formed by type-III broken-gap band alignment, showing high peak-to-valley current ratio values of 4.2 and 6.9 at room temperature and 180 K, respectively. Also, the carrier transport mechanism of the BP/ReS2 negative differential resistance device is investigated in detail by analysing the tunnelling and diffusion currents at various temperatures with the proposed analytic negative differential resistance device model. Finally, we demonstrate a ternary inverter as a multi-valued logic application. This study of a two-dimensional material heterojunction is a step forward toward future multi-valued logic device research.

Phosphorene/rhenium disulfide heterojunction-based negative differential resistance device for multi-valued logic

PubMed Central

Shim, Jaewoo; Oh, Seyong; Kang, Dong-Ho; Jo, Seo-Hyeon; Ali, Muhammad Hasnain; Choi, Woo-Young; Heo, Keun; Jeon, Jaeho; Lee, Sungjoo; Kim, Minwoo; Song, Young Jae; Park, Jin-Hong

2016-01-01

Recently, negative differential resistance devices have attracted considerable attention due to their folded current–voltage characteristic, which presents multiple threshold voltage values. Because of this remarkable property, studies associated with the negative differential resistance devices have been explored for realizing multi-valued logic applications. Here we demonstrate a negative differential resistance device based on a phosphorene/rhenium disulfide (BP/ReS2) heterojunction that is formed by type-III broken-gap band alignment, showing high peak-to-valley current ratio values of 4.2 and 6.9 at room temperature and 180 K, respectively. Also, the carrier transport mechanism of the BP/ReS2 negative differential resistance device is investigated in detail by analysing the tunnelling and diffusion currents at various temperatures with the proposed analytic negative differential resistance device model. Finally, we demonstrate a ternary inverter as a multi-valued logic application. This study of a two-dimensional material heterojunction is a step forward toward future multi-valued logic device research. PMID:27819264

Pyrethroid resistance alters the blood-feeding behavior in Puerto Rican Aedes aegypti mosquitoes exposed to treated fabric

PubMed Central

Bloomquist, Jeffrey R.; Bernier, Ulrich R.

2017-01-01

Emerging insecticide resistance is a major issue for vector control. It decreases the effectiveness of insecticides, thereby requiring greater quantities for comparable control with a net increase in risk of disease resurgence, product cost, and damage risk to the ecosystem. Pyrethroid resistance has been documented in Puerto Rican populations of Aedes aegypti (L.) mosquitoes. In this study, topical toxicity of five insecticides (permethrin, etofenprox, deltamethrin, DDT, transfluthrin) was determined for susceptible (Orlando—ORL) and resistant (Puerto Rico—PR) strains of Ae. aegypti. Resistance ratios were calculated using LD50 values, and high resistance ratios for permethrin (112) and etofenprox (228) were observed for the Puerto Rico strain. Behavioral differences in blood-feeding activity for pyrethroid-resistant and pyrethroid-susceptible strains of Ae. aegypti when exposed to pyrethroid-treated cloth were also explored. Strains were exposed for 15 min to a range of concentrations of pyrethroid-treated uniform fabric in a cage that contained 60 female Ae. aegypti mosquitoes. Interestingly, the resistance ratios for blood-feeding were similar for permethrin (61) and etofenprox (70), but were lower than their respective resistance ratios for topical toxicity, suggesting that knockdown resistance was the primary mechanism of resistance in the blood feeding assays. Results showed a rightward shift in the dose-response curves for blood-feeding that indicated higher concentrations of pyrethroids were necessary to deter blood-feeding behavior in the pyrethroid-resistant Puerto Rican strain of Ae. aegypti. PMID:28931018

Relevant role of efflux pumps in high levels of rifaximin resistance in Escherichia coli clinical isolates.

PubMed

Gomes, C; Ruiz, L; Pons, M J; Ochoa, T J; Ruiz, J

2013-09-01

Enteropathogens have shown a high level of resistance against commonly used antibacterial drugs in Peru and it is necessary to explore alternative treatments. The aim of this study was to analyse the in vitro activity of rifaximin against diarrhoeagenic and commensal Escherichia coli in children less than 2 years of age. The minimal inhibitory concentration (MIC) to rifampicin and rifaximin was determined for 210 strains in the presence and absence of phenyl-arginine-β-naphthylamide (PAβN) and the mechanisms of resistance were investigated. The MIC levels ranged between 8 and >256 mg/litre and the predominant mechanism of resistance to rifaximin was the efflux pumps inhibited by PAβN in 95.2% of the isolates. The present MIC values are higher than those observed in other studies. Efflux pumps inhibited by PAβN were the cause of the rifaximin resistance in the majority of cases and suggest the presence of an environmental selective pressure. Consequently, rifaximin should be used with caution in the treatment of diarrhoea in Peru.

Detection of Shallow Buried Archaeological Remains Structure using 2-D Resistivity Method at Sungai Batu, Lembah Bujang, Kedah

NASA Astrophysics Data System (ADS)

Ismail, Nurina; Nordiana, M. M.; Saidin, M.; Masnan, S. S. K.; Abir, I. A.

2018-04-01

In an archaeological study, 2-D resistivity becomes important tools for the scientific investigation and also can be applied to map shallow subsurface structures at the archaeological site. The main purpose of the research is to locate the shallow buried archaeological remains structure in the area of Sungai Batu, Lembah Bujang, Kedah (Malaysia). Resistivity surveys have been applied using a Pole-dipole array with both 5 survey lines for SB1 and SB2 sites using 0.75 m electrode spacing. Both results revealed high resistivity zone with ≥ 3000 Ωm at a depth ranging from 0-1.5 m at the study area. SB1 site conducting an excavation to validate the result obtain while SB2 is not conducting any excavation. Besides that, the other characteristics of the buried archaeological remains are indicated as mound area and there is exposed remain found on top of the surface. Based on the archaeological evidence, the higher resistivity value indicates the interesting anomaly which is clay bricks for archaeological excavation.

Modeling and Simulation of the Gonghe geothermal field (Qinghai, China) Constrained by Geophysical

NASA Astrophysics Data System (ADS)

Zeng, Z.; Wang, K.; Zhao, X.; Huai, N.; He, R.

2017-12-01

The Gonghe geothermal field in Qinghai is important because of its variety of geothermal resource types. Now, the Gonghe geothermal field has been a demonstration area of geothermal development and utilization in China. It has been the topic of numerous geophysical investigations conducted to determine the depth to and the nature of the heat source, and to image the channel of heat flow. This work focuses on the causes of geothermal fields used numerical simulation method constrained by geophysical data. At first, by analyzing and inverting an magnetotelluric (MT) measurements profile across this area we obtain the deep resistivity distribution. Using the gravity anomaly inversion constrained by the resistivity profile, the density of the basins and the underlying rocks can be calculated. Combined with the measured parameters of rock thermal conductivity, the 2D geothermal conceptual model of Gonghe area is constructed. Then, the unstructured finite element method is used to simulate the heat conduction equation and the geothermal field. Results of this model were calibrated with temperature data for the observation well. A good match was achieved between the measured values and the model's predicted values. At last, geothermal gradient and heat flow distribution of this model are calculated(fig.1.). According to the results of geophysical exploration, there is a low resistance and low density region (d5) below the geothermal field. We recognize that this anomaly is generated by tectonic motion, and this tectonic movement creates a mantle-derived heat upstream channel. So that the anomalous basement heat flow values are higher than in other regions. The model's predicted values simulated using that boundary condition has a good match with the measured values. The simulated heat flow values show that the mantle-derived heat flow migrates through the boundary of the low-resistance low-density anomaly area to the Gonghe geothermal field, with only a small fraction moving to other regions. Therefore, the mantle-derived heat flow across the tectonic channel to the cohesive continuous supply heat for Gonghe geothermal field, is the main the main causes of abundant geothermal resources.

Electrical resistivity and geotechnical assessment of subgrade soils in southwestern part of Nigeria

NASA Astrophysics Data System (ADS)

Adebisi, N. O.; Ariyo, S. O.; Sotikare, P. B.

2016-07-01

The subgrade soils in areas underlain by the slightly Migmatized to Non-migmatized Metasedimentary and Metaigneous rocks of Southwestern Nigeria have been considerably investigated. However, a serious research which employs electrical resistivity method for insight into the profile development, as well as estimation of resistance to deformation for predicting the stability of flexible highway pavements is yet to be carried out. In this study, Vertical Electrical Sounding (VES) were carried out after a reconnaissance survey based on stable and unstable locations on the road. Index and strength tests related to road construction were also carried out on bulk samples obtained from stable and failed (unstable) locations of the Ago-Iwoye/Ishara highway. Results show mostly three (3) layers in the profiles with H, HK, and HKH curve types. The subgrade soils below the stable locations have better vertical and interval variations in the resistivities (89-1095 Ωm) to a depth of 3.4 m as against those from the failed portions. Those from the stable locations also have higher specific gravity (2.72), low-medium plasticity and A-2-6 kaolinitic clayey soils with higher compacted density (2090 kg/m3) compared to subgrade soils from the failed locations. On the basis of Califonia Bearing Ratio (CBR), subgrade soils at stable locations have greater strength than those obtained from failed locations. Estimated resistance to deformation (R-value) and resilient modulus (MR) proved to be the overriding parameters for predicting the stability of the flexible highway pavements.

Free chlorine inactivation of fungi in drinking water sources.

PubMed

Pereira, V J; Marques, R; Marques, M; Benoliel, M J; Barreto Crespo, M T

2013-02-01

The effectiveness of free chlorine for the inactivation of fungi present in settled surface water was tested. In addition, free chlorine inactivation rate constants of Cladosporium tenuissimum, Cladosporium cladosporioides, Phoma glomerata, Aspergillus terreus, Aspergillus fumigatus, Penicillium griseofulvum, and Penicillium citrinum that were found to occur in different source waters were determined in different water matrices (laboratory grade water and settled water). The effect of using different disinfectant concentrations (1 and 3 mg/l), temperatures (21 and 4 °C), and pH levels (6 and 7) was addressed. The sensitivity degree of different fungi isolates to chlorine disinfection varied among different genera with some species showing a higher resistance to disinfection and others expected to be more prone to protection from inactivation by the water matrix components. When the disinfection efficiency measured in terms of the chlorine concentration and contact time (Ct) values needed to achieve 99% inactivation were compared with the Ct values reported as being able to achieve the same degree of inactivation of other microorganisms, fungi were found to be more resistant to chlorine inactivation than bacteria and viruses and less resistant than Cryptosporidium oocysts. Copyright © 2012 Elsevier Ltd. All rights reserved.

Evaluation of insulin resistance in two kinds of South American camelids: llamas and alpacas.

PubMed

Araya, A V; Atwater, I; Navia, M A; Jeffs, S

2000-10-01

Insulin resistance was evaluated in South American camelids, llamas and alpacas, by use of the minimal model test and the insulin tolerance test. Animals were catheterized for long-term studies and tamed to minimize stress during evaluation. Results indicated a low insulin sensitivity index (SI) = 0 to 0.97, median = 0.39 x 10(-4) min/uIU x ml, about a fifth the value in other mammals and humans. The KITT was between 1.43 and 3.19 %/min, also significantly lower than that reported for humans. Glycosylated hemoglobin concentration was 6%, and HbAlc concentration was 5.5%; red blood cell lifetime, as measured by use of the 51Cr method, was 120 days, similar to the value in humans. We concluded that llamas and alpacas have naturally higher blood glucose concentration than do humans and other mammals during the glucose tolerance test. Using the same mathematical tools to evaluate glucose metabolism as those used in people, South American camelids appear to be resistant to insulin. Thus, the South American camelid may be a useful new animal model for the study of sugar metabolism and various facets of diabetes mellitus, especially protection from the deleterious effects of glycosylation.

Insulin resistance and metabolic syndrome in children of parents with diabetes mellitus.

PubMed

Altinli, Sebnem; Elevli, Murat; Ozkul, Ayse Ayaz; Kara, Pinar Gizem; Karsidag, Kubilay; Dogru, Macit

2007-03-01

The aim of this prospective study was to research features of insulin resistance and metabolic syndrome in offspring of diabetic parents and to find out whether there is a risk of developing type 2 diabetes mellitus (DM) in these children. Study participants were 30 children of parents with type 1 DM (DM1) (Group I) and 11 children of parents with type 2 DM (DM2) (Group II) who were being followed up in the Diabetes Department of Haseki Research and Training Hospital. The results were compared with a control group of 17 children in the same age group (Group III). There were no statistically significant differences between the Group I and the control group in fasting blood glucose, oral glucose tolerance test values, 1st 2nd and hour insulin, homeostasis model assessment (HOMA) values, body mass index (BMI), systolic and diastolic blood pressure, and lipid parameters, i.e. HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol, total cholesterol, and triglycerides. Fasting, 1st and 2nd hour blood insulin levels, HOMA values, BMI, and systolic blood pressure values were significantly higher in Group II compared to the control group (p < 0.05). There were no statistically significant differences between Group II and the control group in lipid parameters, fasting blood glucose, OGTT values, or diastolic blood pressure. We conclude that in our population there is a tendency of insulin resistance and metabolic syndrome in the offspring of parents with DM2, and a risk for developing DM2. Thus, children of patients with DM2 should be followed up so as to recognize early metabolic defects of glucose metabolism and to plan effective preventive efforts to reduce cardiovascular and atherosclerotic risk factors.

Isolation and identification of lipopeptide antibiotics from Paenibacillus elgii B69 with inhibitory activity against methicillin-resistant Staphylococcus aureus.

PubMed

Ding, Rui; Wu, Xue-Chang; Qian, Chao-Dong; Teng, Yi; Li, Ou; Zhan, Zha-Jun; Zhao, Yu-Hua

2011-12-01

Two lipopeptide antibiotics, pelgipeptins C and D, were isolated from Paenibacillus elgii B69 strain. The molecular masses of the two compounds were both determined to be 1,086 Da. Mass-spectrometry, amino acid analysis and NMR spectroscopy indicated that pelgipeptin C was the same compound as BMY-28160, while pelgipeptin D was identified as a new antibiotic of the polypeptin family. These two peptides were active against all the tested microorganisms, including antibiotic-resistant pathogenic bacterial strains such as methicillin-resistant Staphylococcus aureus (MRSA). Time-kill assays demonstrated that pelgipeptin D exhibited rapid and effective bactericidal action against MRSA at 4×MIC. Based on acute toxicity test, the intraperitoneal LD50 value of pelgipeptin D was slightly higher than that of the structurally related antimicrobial agent polymyxin B. Pelgipeptins are highly potent antibacterial and antifungal agents, particularly against MRSA, and warrant further investigation as possible therapeutic agents for bacteria infections resistant to currently available antibiotics.

Study on the corrosion properties of nanocrystalline nickel electrodepositied by reverse pulse current

NASA Astrophysics Data System (ADS)

Cheng, Wen; Ge, Wen; Yang, Qian; Qu, Xinxin

2013-07-01

Nanocrystalline nickel coatings were produced by the method of reverse pulse electrodepositing on the surface of steel sheets. The crystallite size of nanocrystalline nickel coatings was determined by X-ray diffraction (XRD). The effect of saccharin concentration on the crystallite size of the coatings was studied. The average crystallite sizes were diminished as a result of increasing saccharin concentration. CHI660C electrochemical workstation was used to determine the Tafel polarization curves and electrochemical impedance spectroscopy (EIS) of the coatings. The value of corrosion potential, natural corrosion current density, polarizaiton resistance and impedance was calculated, the results suggested that smaller grain size led to higher polarization resistance. EIS gave the charge transfer resistance Rct and pore resistance Rpo variation trend from beginning to 30 min. Scanning electron microscopy (SEM) examination showed the surface morphology of the nickel coatings after the neutral salt spray (NSS) test or bathing in 10% HCl. The images indicated that the corrosion behavior of nanocrystalline nickel coatings was pitting corrosion, the mechanism was also discussed.

Study of high resistance inorganic coatings on graphite fibers. [for graphite-epoxy composite materials

NASA Technical Reports Server (NTRS)

Galasso, F. S.; Veltri, R. D.; Scola, D. A.

1979-01-01

Coatings made of boron, silicon carbide, silica, and silica-like materials were studied to determine their ability to increase resistance of graphite fibers. The most promising results were attained by chemical vapor depositing silicon carbide on graphite fiber followed by oxidation, and drawing graphite fiber through ethyl silicate followed by appropriate heat treatments. In the silicon carbide coating studies, no degradation of the graphite fibers was observed and resistance values as high as three orders of magnitude higher than that of the uncoated fiber was attained. The strength of a composite fabricated from the coated fiber had a strength which compared favorably with those of composites prepared from uncoated fiber. For the silica-like coated fiber prepared by drawing the graphite fiber through an ethyl silicate solution followed by heating, coated fiber resistances about an order of magnitude greater than that of the uncoated fiber were attained. Composites prepared using these fibers had flexural strengths comparable with those prepared using uncoated fibers, but the shear strengths were lower.

Dysanapsis and the resistive work of breathing during exercise in healthy men and women.

PubMed

Dominelli, Paolo B; Molgat-Seon, Yannick; Bingham, Derek; Swartz, Philippa M; Road, Jeremy D; Foster, Glen E; Sheel, A William

2015-11-15

We asked if the higher work of breathing (Wb) during exercise in women compared with men is explained by biological sex. We created a statistical model that accounts for both the viscoelastic and the resistive components of the total Wb and independently compares the effects of biological sex. We applied the model to esophageal pressure-derived Wb values obtained during an incremental cycle test to exhaustion. Subjects were healthy men (n = 17) and women (n = 18) with a range of maximal aerobic capacities (V̇o2 max range: men = 40-68 and women = 39-60 ml·kg(-1)·min(-1)). We also calculated the dysanapsis ratio using measures of lung recoil and forced expiratory flow as index of airway caliber. By applying the model we found that the differences in the total Wb during exercise in women are due to a higher resistive Wb rather than viscoelastic Wb. We also found that the higher resistive Wb is independently explained by biological sex. To account for the known effect of lung volumes on the dysanapsis ratio we compared the sexes with an analysis of covariance procedures and found that when vital capacity was accounted for the adjusted mean dysanapsis ratio is statistically lower in women (0.17 vs. 0.25 arbitrary units; P < 0.05). Our collective findings suggest that innate sex-based differences may exist in human airways, which result in significant male-female differences in the Wb during exercise in healthy subjects. Copyright © 2015 the American Physiological Society.

Percentiles of fasting serum insulin, glucose, HbA1c and HOMA-IR in pre-pubertal normal weight European children from the IDEFICS cohort.

PubMed

Peplies, J; Jiménez-Pavón, D; Savva, S C; Buck, C; Günther, K; Fraterman, A; Russo, P; Iacoviello, L; Veidebaum, T; Tornaritis, M; De Henauw, S; Mårild, S; Molnár, D; Moreno, L A; Ahrens, W

2014-09-01

The aim of this study is to present age- and sex-specific reference values of insulin, glucose, glycosylated haemoglobin (HbA1c) and the homeostasis model assessment to quantify insulin resistance (HOMA-IR) for pre-pubertal children. The reference population consists of 7074 normal weight 3- to 10.9-year-old pre-pubertal children from eight European countries who participated in at least one wave of the IDEFICS ('identification and prevention of dietary- and lifestyle-induced health effects in children and infants') surveys (2007-2010) and for whom standardised laboratory measurements were obtained. Percentile curves of insulin (measured by an electrochemiluminescence immunoassay), glucose, HbA1c and HOMA-IR were calculated as a function of age stratified by sex using the general additive model for location scale and shape (GAMLSS) method. Levels of insulin, fasting glucose and HOMA-IR continuously show an increasing trend with age, whereas HbA1c shows an upward trend only beyond the age of 8 years. Insulin and HOMA-IR values are higher in girls of all age groups, whereas glucose values are slightly higher in boys. Median serum levels of insulin range from 17.4 and 13.2 pmol l(-1) in 3-<3.5-year-old girls and boys, respectively, to 53.5 and 43.0 pmol l(-1) in 10.5-<11-year-old girls and boys. Median values of glucose are 4.3 and 4.5 mmol l(-1) in the youngest age group and 49.3 and 50.6 mmol l(-1) in the oldest girls and boys. For HOMA-IR, median values range from 0.5 and 0.4 in 3-<3.5-year-old girls and boys to 1.7 and 1.4 in 10.5-<11-year-old girls and boys, respectively. Our study provides the first standardised reference values for an international European children's population and provides the, up to now, largest data set of healthy pre-pubertal children to model reference percentiles for markers of insulin resistance. Our cohort shows higher values of Hb1Ac as compared with a single Swedish study while our percentiles for the other glucose metabolic markers are in good accordance with previous studies.

Multidrug-resistant bacteria infection and nursing quality management application in the department of physical examination.

PubMed

Xu, Li; Luo, Qiang; Chen, Liangzhen; Jiao, Lingmei

2017-09-01

The main problem of clinical prevention and control of multi drug resistant bacteria infection is to strengthen the monitoring of pathogenic bacteria spectrum, this study research on the multi drug-resistant bacteria infection and nursing quality management application in the department of physical examination. The results of this study showed that the number of patients with multiple drug resistant infections showed an increasing trend. Therefore, once the patients with multiple drug-resistant bacteria infection are found, the prevention and control of the patients with multiple drug-resistant bacteria should be strictly followed, and the patient's medication care should be highly valued. Also, the nurses need to be classified based on the knowledge and skill characteristics of the nurses in the department of physical examination, and compare the nursing effect before and after classification and grouping. The physicians and individuals receiving physical examinations in the department of physical examination had a higher degree of satisfaction for nursing effect after classification compared with those before classification. Classification and grouping management helps improve the nursing quality and overall quality of the nurses in the department of physical examination.

Development of the radiation-resistant strain of Moraxella osloensis and effect of penicillin G on its growth

NASA Astrophysics Data System (ADS)

Lim, Sangyong; Yun, Hyejeong; Joe, Minho; Kim, Dongho

2009-07-01

A series of repeated exposures to γ-radiation with intervening outgrowth of survivors was used to develop radioresistant cultures of Moraxella osloensis that have been recognized as potential pathogenic microorganism. The D10 value of the radiation-resistant strain, 5.903±0.006 kGy, was increased by four-fold compared to the parent wild-type strain, 1.637±0.004 kGy. Since most strains of M. osloensis are sensitive to penicillin, we have surveyed the sensitivity of radiation-resistant strain to this antibiotic. When the optical density was monitored after the addition of penicillin G, the radioresistant strain appeared to be more resistant to only a low concentration of penicillin G (0.5 U/ml) than the parent strain. Interestingly, however, there was no apparent difference in the number of viable cells between both strains. Scanning electron microscope data showed that the resistance cells were generally larger than the parent cells, suggesting that this increase in size may cause a higher optical density of radioresistant cells. In conclusion, radiation mutation does not affect the penicillin resistance of M. osloensis.

Insulin secretion and insulin resistance in Korean women with gestational diabetes mellitus and impaired glucose tolerance.

PubMed

Yang, Sae Jeong; Kim, Tae Nyun; Baik, Sei Hyun; Kim, Tae Sun; Lee, Kwan Woo; Nam, Moonsuk; Park, Yong Soo; Woo, Jeong-Teak; Kim, Young Seol; Kim, Sung-Hoon

2013-05-01

The aim was to compare the insulin sensitivity and secretion index of pregnant Korean women with normal glucose tolerance (NGT), gestational impaired glucose tolerance (GIGT; only one abnormal value according to the Carpenter and Coustan criteria), and gestational diabetes mellitus (GDM). A cross-sectional study was performed with 1,163 pregnant women with positive (1-hour plasma glucose ≥ 7.2 mmol/L) in a 50-g oral glucose challenge test (OGCT). The 100-g oral glucose tolerance test (OGTT) was used to stratify the participants into three groups: NGT (n = 588), GIGT (n = 294), and GDM (n = 281). The GDM group had higher homeostasis model assessment of insulin resistance and lower insulin sensitivity index (ISOGTT), quantitative insulin sensitivity check index, homeostasis model assessment for estimation of index β-cell secretion (HOMA-B), first and second phase insulin secretion, and insulin secretion-sensitivity index (ISSI) than the NGT group (p ≤ 0.001 for all). Moreover, the GIGT group had lower ISOGTT, HOMA-B, first and second phase insulin secretion, and ISSI than the NGT group (p < 0.001 for all). Among the GIGT subjects, the 1-hour plasma glucose abnormal levels group showed significantly greater weight gain during pregnancy and higher values in the 50-g OGCT than the other two groups. Moreover, the 1-hour and 2-hour abnormal levels groups had poorer insulin secretion status than the 3-hour abnormal levels group. Korean women with GDM show impairments of both insulin secretion and insulin sensitivity. In addition, GIGT is associated with both β-cell dysfunction and insulin resistance.

A low insertion loss GaAs pHEMT switch utilizing dual n +-doping AlAs etching stop layers design

NASA Astrophysics Data System (ADS)

Chien, Feng-Tso; Lin, Da-Wei; Yang, Chih-Wei; Fu, Jeffrey S.; Chiu, Hsien-Chin

2010-03-01

A low insertion loss single-pole-single-throw (SPST) pseudomorphic high electron mobility transistor (pHEMT) switch utilizing the n +-type doping in AlAs etching stop layer was fabricated and investigated. This novel design reduces device sheet resistance resulting in an improvement of dc and rf power performance. In addition, the gate recess selectivity for GaAs/AlAs interface was not sacrificed after highly n +-type doping in AlAs etching stop layer. The pHEMT with n +-AlAs etching stop layer, also named Modified pHEMT (M-pHEMT), demonstrated a lower sheet resistance ( Rsh) of 65.9 Ω/γ, a higher maximum drain-to-source current ( Idmax) of 317.8 mA/mm and a higher peak transconductance ( gm) of 259.3 mS/mm which are superior to standard pHEMT performance with values of 71.9 Ω/γ, 290.3 mA/mm and 252.1 mS/mm, respectively. Due to a significant sheet resistance improvement from this novel epitaxial design, an SPST pHEMT switch was realized to manifest its industrial application potential. The results achieved an on-state insertion loss of 1.42 dB, an off-state isolation of 13.02 dB at 0.9 GHz, which were superior to traditional pHEMT switch under same condition of operation with values of 1.68 dB and 11.42 dB, respectively. It is proved that dual n +-doping AlAs etching stop layers scheme is beneficial for low loss microwave switches applications.

Metabolic syndrome and renal sodium handling in three ethnic groups living in England.

PubMed

Barbato, A; Cappuccio, F P; Folkerd, E J; Strazzullo, P; Sampson, B; Cook, D G; Alberti, K G M M

2004-01-01

Increased proximal renal sodium re-absorption is associated with central adiposity and insulin resistance in white men. Our study examined whether this association also exists in other ethnic groups with different prevalences of insulin resistance and associated metabolic abnormalities. We studied the association between fractional renal excretion of endogenous lithium (FELi) and metabolic syndrome in a population study of 1190 randomly selected men and women who where 40 to 59 years of age (426 white, 397 of African and 367 of South Asian origin). Anthropometric values, blood pressure, biochemical values, questionnaire data and timed urine collections were obtained with standardised techniques. Endogenous lithium in serum and urine was measured by absorption spectrophotometry. Metabolic markers were the homeostasis model assessment (HOMA) index, waist circumference, serum triglycerides, serum HDL cholesterol and metabolic syndrome as defined by Adult Treatment Panel III criteria. In white men and women a higher rate of proximal sodium re-absorption was inversely associated with higher waist circumference, serum triglycerides and HOMA index, and with lower serum HDL cholesterol (all p< or =0.001). No associations were found in people of African or South Asian origin. The former had lower FELi than the other groups. White people with the metabolic syndrome had a lower FELi than those without (15.9% vs 19.0%; p=0.003). No difference was found in people of African or South Asian origin. Increased proximal sodium re-absorption is associated with the metabolic syndrome in white men and women. This relationship is not seen in people of African or South Asian origin, despite a greater degree of insulin resistance.

Development of Ultra-high Purity (UHP) Fe-Based Alloys with High Creep and Oxidation Resistance for A-USC Technology

NASA Astrophysics Data System (ADS)

Hamdani, Fethi; Das, Nishith K.; Shoji, Tetsuo

2018-06-01

The design of ultra-high purity (UHP) Fe-based model alloys for advanced ultra-supercritical (A-USC) technology is attempted in this work. Creep testing has been performed in air at 700 °C and a stress level of 150 MPa. Analysis of the fracture surface and cross section of the crept specimen was performed. To evaluate the oxidation resistance in A-USC conditions, oxidation testing was performed in supercritical water (SCW) at 700 °C and 25 MPa. Weight gain (WG) measurements and meticulous characterization of the oxide scale were carried out. Based on thermodynamics and density functional theory calculations, some reactive elements in the Fe-Cr-Ni system were designated to promote precipitation strengthening and to improve the hydrogen-accelerated oxidation resistance. The addition of a 2 wt pct Mo into Fe-22Cr-22Ni-0.6Nb wt pct-based matrix did not significantly improve the creep resistance. The addition of 0.26 wt pct Zr coupled with cold working was effective for improving creep properties. The Mo-modified model alloy showed almost the same WG value as SUS310, while the Zr-modified alloy showed a higher WG value. Meanwhile, a Cr-enriched continuous oxide layer was formed at the oxidation front of the Zr-modified alloy and SUS310S after exposure to SCW conditions.

The realization of temperature controller for small resistance measurement system

NASA Astrophysics Data System (ADS)

Sobecki, Jakub; Walendziuk, Wojciech; Idzkowski, Adam

2017-08-01

This paper concerns the issues of construction and experimental tests of a temperature stabilization system for small resistance increments measurement circuits. After switching the system on, a PCB board heats up and the long-term temperature drift altered the measurement result. The aim of this work is reducing the time of achieving constant nominal temperature by the measurement system, which would enable decreasing the time of measurements in the steady state. Moreover, the influence of temperatures higher than the nominal on the measurement results and the obtained heating curve were tested. During the working process, the circuit heats up to about 32 °C spontaneously, and it has the time to reach steady state of about 1200 s. Implementing a USART terminal on the PC and an NI USB-6341 data acquisition card makes recording the data (concerning temperature and resistance) in the digital form and its further processing easier. It also enables changing the quantity of the regulator settings. This paper presents sample results of measurements for several temperature values and the characteristics of the temperature and resistance changes in time as well as their comparison with the output values. The object identification is accomplished due to the Ziegler-Nichols method. The algorithm of determining the step characteristics parameters and examples of computations of the regulator settings are included together with example characteristics of the object regulation.

Development of Ultra-high Purity (UHP) Fe-Based Alloys with High Creep and Oxidation Resistance for A-USC Technology

NASA Astrophysics Data System (ADS)

Hamdani, Fethi; Das, Nishith K.; Shoji, Tetsuo

2018-03-01

The design of ultra-high purity (UHP) Fe-based model alloys for advanced ultra-supercritical (A-USC) technology is attempted in this work. Creep testing has been performed in air at 700 °C and a stress level of 150 MPa. Analysis of the fracture surface and cross section of the crept specimen was performed. To evaluate the oxidation resistance in A-USC conditions, oxidation testing was performed in supercritical water (SCW) at 700 °C and 25 MPa. Weight gain (WG) measurements and meticulous characterization of the oxide scale were carried out. Based on thermodynamics and density functional theory calculations, some reactive elements in the Fe-Cr-Ni system were designated to promote precipitation strengthening and to improve the hydrogen-accelerated oxidation resistance. The addition of a 2 wt pct Mo into Fe-22Cr-22Ni-0.6Nb wt pct-based matrix did not significantly improve the creep resistance. The addition of 0.26 wt pct Zr coupled with cold working was effective for improving creep properties. The Mo-modified model alloy showed almost the same WG value as SUS310, while the Zr-modified alloy showed a higher WG value. Meanwhile, a Cr-enriched continuous oxide layer was formed at the oxidation front of the Zr-modified alloy and SUS310S after exposure to SCW conditions.

Evolution of insecticide resistance in non-target black flies (Diptera: Simuliidae) from Argentina.

PubMed

Montagna, Cristina Mónica; Gauna, Lidia Ester; D'Angelo, Ana Pechen de; Anguiano, Olga Liliana

2012-06-01

Black flies, a non-target species of the insecticides used in fruit production, represent a severe medical and veterinary problem. Large increases in the level of resistance to the pyrethroids fenvalerate (more than 355-fold) and deltamethrin (162-fold) and a small increase in resistance to the organophosphate azinphos methyl (2-fold) were observed between 1996-2008 in black fly larvae under insecticide pressure. Eventually, no change or a slight variation in insecticide resistance was followed by a subsequent increase in resistance. The evolution of pesticide resistance in a field population is a complex and stepwise process that is influenced by several factors, the most significant of which is the insecticide selection pressure, such as the dose and frequency of application. The variation in insecticide susceptibility within a black fly population in the productive area may be related to changes in fruit-pest control. The frequency of individuals with esterase activities higher than the maximum value determined in the susceptible population increased consistently over the sampling period. However, the insecticide resistance was not attributed to glutathione S-transferase activity. In conclusion, esterase activity in black flies from the productive area is one mechanism underlying the high levels of resistance to pyrethroids, which have been recently used infrequently. These enzymes may be reselected by currently used pesticides and enhance the resistance to these insecticides.

Pharmacodynamic effects of amoxicillin versus cefotaxime against penicillin-susceptible and penicillin-resistant pneumococcal strains: a phase I study.

PubMed Central

Aguilar, L; Rosendo, J; Balcabao, I P; Martín, M; Giménez, M J; Frías, J; Prieto, J

1997-01-01

Serum bactericidal activity against a penicillin-susceptible strain and a penicillin-resistant strain of Streptococcus pneumoniae (amoxicillin and cefotaxime MICs, 0.001 and 1 microg/ml, respectively, and MBCs, 0.01 and 2 microg/ml, respectively) was measured in 12 healthy volunteers who each received an oral 875-mg dose of amoxicillin and an intramuscular 1-g dose of cefotaxime in a crossover fashion. The areas under the bactericidal activity-time curves for the two strains were found to be similar for both antibiotics despite the significantly higher (P < 0.002) AUC/MIC and peak level/MIC values for cefotaxime. PMID:9174206

Anaerobic Treatment of Wastewaters Containing Perchlorate from Munitions Handling and Production

DTIC Science & Technology

2008-01-01

of contact is Frank Novak. The technical reviewer was Dr. Paul Hatzinger of Shaw Environmental, Lawrenceville, NJ. The work was managed and executed... Neubert and Caswell 1997). Higher numerical value indicates lower resistance and resilience (Hashsham et al. 2000). ERDC/CERL TR-08-3 39 As...Gradient Gel Electrophoresis (DGGE) in Microbial Ecology. Microbial Ecology Manual, 2nd ed. Kluwer Academic/Plenum Publisher, The Netherlands. Neubert , M

Light Management in Transparent Conducting Oxides by Direct Fabrication of Periodic Surface Arrays

NASA Astrophysics Data System (ADS)

Eckhardt, S.; Sachse, C.; Lasagni, A. F.

Line- and hexagonal-like periodic textures were fabricated on aluminium zinc oxide (AZO) using direct laser interference patterning method. It was found that hexagonally patterned surfaces show a higher performance in both transparency and diffraction properties compared to line-like textured and non-patterned substrates. Furthermore, the electrical resistance of the processed AZO coated substrates remained below the tolerance values for transparent conducting electrodes.

[Clinical value of insulin resistance in fasting normoglycemia].

PubMed

Perova, N V; Ozerova, I N; Aleksandrovich, O V; Metel'skaia, V A; Shal'nova, S A

2011-01-01

Aim of the study was to clarify the question of the presence of manifestations of insulin resistance (IR) in fasting normoglycemia and to assess their association with risk of development and presence of clinically overt cardiovascular diseases (CVD) caused by atherosclerosis. We included into this study 1127 men and women older than 55 years with normal blood serum level of glucose in fasting state (<6.1 mmol/l) without diabetes mellitus selected from a random sample of Moscow inhabitants (n=1186). In participants selected for this study we determined risk factors, calculated indexes of IR (HOMA-IR) and functional capacity of pancreatic -cells (HOMA-%B) using fasting levels of glucose and insulin. The examined subsample was divided into quartiles according to values of HOMA-IR. It was shown that in the 4-th quartile HOMA-%B was substantially higher than in other quartiles. With this values of body mass index and waist circumference were also highest in the 4-th quartile. Fasting insulin level compared with glucose level contributed more to determination of values of indexes of both IR and functional capacity of pancreatic -cells. In the upper 4-th quartile signs of atherogenic dyslipidemia appearing as higher concentration of triglycerides and lowered concentration of high density lipoprotein cholesterol manifested to the greatest degree. At statistical analysis of probability of CVD with clinical manifestations it was shown that in the 4-th quartile of distribution of HOMA-IR (>2.7) values of odds ratio (OR) of development of arterial hypertension (AH), total CVD, angina pectoris, history of brain stroke were elevated. With that in the 3-rd quartile of distribution i.e. at HOMA-IR >1.9 there were higher ORs of development of AH, CVD, angina pectoris. Thus even in the range of normal fasting glucose concentrations in subjects older than 55 years we detected IR associated with elevated risk of development of atherosclerosis related CVD. For detection of IR it is appropriate to measure in blood serum not only concentration of glucose but also fasting insulin level with subsequent calculation of HOMA-IR and HOMA-%B indexes.

Flexibility and torsional behaviour of rotary nickel-titanium PathFile, RaCe ISO 10, Scout RaCe and stainless steel K-File hand instruments.

PubMed

Nakagawa, R K L; Alves, J L; Buono, V T L; Bahia, M G A

2014-03-01

To assess and compare the flexibility and torsional resistance of PathFile, RaCe ISO 10 and Scout RaCe instruments in relation to stainless steel K-File hand instruments. Rotary PathFile (sizes 13, 16 and 19; .02 taper), Race ISO 10 (size 10; 0.02, 0.04 and 0.06 tapers), Scout RaCe (sizes 10, 15 and 20; 0.02 taper) and hand K-File (sizes 10, 15 and 20; 0.02 taper) instruments were evaluated. Alloy chemical composition, phases present and transformation temperatures were determined for the NiTi instruments. For all instruments, diameters at each millimetre from the tip as well as cross-sectional areas at 3 mm from the tip were measured based on ANSI/ADA Specification No. 101 using image analysis software. Resistance to bending and torsional resistance were determined according to specification ISO 3630-1. Vickers microhardness measurements were also taken in all instruments to assess their strength. Data were analysed using analysis of variance (α = 0.05). The alloys used in the manufacture of the three types of NiTi instruments had approximately the same chemical composition, but the PathFile instruments had a higher Af transformation temperature and contained a small amount of B19' martensite. All instruments had diameter values within the standard tolerance. The bending and torsional resistance values were significantly increased relative to the instrument diameter and cross-sectional area. PathFile instruments were the most flexible and the least torque resistant, whilst the stainless steel instruments were the least flexible although they were more torque resistant than the NiTi instruments. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Regulation of oxidative stress in response to acute aerobic and resistance exercise in HIV-infected subjects: a case-control study.

PubMed

Deresz, L F; Sprinz, E; Kramer, A S; Cunha, G; de Oliveira, A R; Sporleder, H; de Freitas, D R J; Lazzarotto, A R; Dall'Ago, P

2010-11-01

Human immunodeficiency virus (HIV)-infected subjects have increased levels of oxidative stress which could impair immunological function and therefore contribute to the progression of AIDS. These characteristics are usually evaluated at rest and responses to exercise have yet to be evaluated. The aim of the present study was to assess the effect of a bout of aerobic exercise followed by resistance exercises on antioxidant system in HIV-infected and non-HIV subjects. There were included 14 cases (HIV-positive) and 14 controls (HIV-negative). The exercise protocol consisted of a single session of 20 minutes on a cycloergometer followed by a set of six resistance exercises. The activity of glutathione S-transferase (GST) and catalase were measured in plasma samples, total glutathione (TGSH) and thiobarbituric acid reactive substances (TBARS) were measured in erythrocytes. T CD4+ cells, T CD8+, viral load, complete blood count, and white blood count were also assessed. All measurements were performed at three times: baseline, after aerobic exercise, and after resistance exercises. At baseline, the HIV group had lower GST activity than controls, but after the exercise session GST values were similar in both groups. Compared to the control group TGSH was significantly lower in the HIV group at baseline, after aerobic and resistance exercises. The control group presented higher TBARS values after aerobic exercise compared to the HIV group. The neutrophil count was lower in the HIV group after aerobic and resistance exercises. These data indicate that HIV-infected subjects had lower antioxidant activity at rest. Physical exercise stimulated the enzymatic activity similarly in both groups.

Trimethoprim Resistance of Dihydrofolate Reductase Variants from Clinical Isolates of Pneumocystis jirovecii

PubMed Central

Cody, V.; Pace, J.; Torkelson, P.; Gangjee, A.

2013-01-01

Pneumocystis jirovecii is an opportunistic pathogen that causes serious pneumonia in immunosuppressed patients. Standard therapy and prophylaxis include trimethoprim (TMP)-sulfamethoxazole; trimethoprim in this combination targets dihydrofolate reductase (DHFR). Fourteen clinically observed variants of P. jirovecii DHFR were produced recombinantly to allow exploration of the causes of clinically observed failure of therapy and prophylaxis that includes trimethoprim. Six DHFR variants (S31F, F36C, L65P, A67V, V79I, and I158V) showed resistance to inhibition by trimethoprim, with Ki values for trimethoprim 4-fold to 100-fold higher than those for the wild-type P. jirovecii DHFR. An experimental antifolate with more conformational flexibility than trimethoprim showed strong activity against one trimethoprim-resistant variant. The two variants that were most resistant to trimethoprim (F36C and L65P) also had increased Km values for dihydrofolic acid (DHFA). The catalytic rate constant (kcat) was unchanged for most variant forms of P. jirovecii DHFR but was significantly lowered in F36C protein; one naturally occurring variant with two amino acid substitutions (S106P and E127G) showed a doubling of kcat, as well as a Km for NADPH half that of the wild type. The strongest resistance to trimethoprim occurred with amino acid changes in the binding pocket for DHFA or trimethoprim, and the strongest effect on binding of NADPH was linked to a mutation involved in binding the phosphate group of the cofactor. This study marks the first confirmation that naturally occurring mutations in the gene for DHFR from P. jirovecii produce variant forms of DHFR that are resistant to trimethoprim and may contribute to clinically observed failures of standard therapy or prophylaxis. PMID:23896474

Joint innversion of seismic and magnetotelluric data in the Parkfield Region of California using the normalized cross-gradient constraint

USGS Publications Warehouse

Bennington, Ninfa L.; Zhang, Haijiang; Thurber, Cliff; Bedrosian, Paul A.

2015-01-01

We present jointly inverted models of P-wave velocity (Vp) and electrical resistivity for a two-dimensional profile centered on the San Andreas Fault Observatory at Depth (SAFOD). Significant structural similarity between main features of the separately inverted Vp and resistivity models is exploited by carrying out a joint inversion of the two datasets using the normalized cross-gradient constraint. This constraint favors structurally similar Vp and resistivity images that adequately fit the seismic and magnetotelluric (MT) datasets. The new inversion code, tomoDDMT, merges the seismic inversion code tomoDD and the forward modeling and sensitivity kernel subroutines of the MT inversion code OCCAM2DMT. TomoDDMT is tested on a synthetic dataset and demonstrates the code’s ability to more accurately resolve features of the input synthetic structure relative to the separately inverted resistivity and velocity models. Using tomoDDMT, we are able to resolve a number of key issues raised during drilling at SAFOD. We are able to infer the distribution of several geologic units including the Salinian granitoids, the Great Valley sequence, and the Franciscan Formation. The distribution and transport of fluids at both shallow and great depths is also examined. Low values of velocity/resistivity attributed to a feature known as the Eastern Conductor (EC) can be explained in two ways: the EC is a brine-filled, high porosity region, or this region is composed largely of clay-rich shales of the Franciscan. The Eastern Wall, which lies immediately adjacent to the EC, is unlikely to be a fluid pathway into the San Andreas Fault’s seismogenic zone due to its observed higher resistivity and velocity values.

Quantitative Genetic Analysis Reveals Potential to Genetically Improve Fruit Yield and Drought Resistance Simultaneously in Coriander

PubMed Central

Khodadadi, Mostafa; Dehghani, Hamid; Jalali Javaran, Mokhtar

2017-01-01

Enhancing water use efficiency of coriander (Coriandrum sativum L.) is a major focus for coriander breeding to cope with drought stress. The purpose of this study was; (a) to identify the predominant mechanism(s) of drought resistance in coriander and (b) to evaluate the genetic control mechanism(s) of traits associated with drought resistance and higher fruit yield. To reach this purpose, 15 half-diallel hybrids of coriander and their six parents were evaluated under well-watered and water deficit stressed (WDS) in both glasshouse lysimetric and field conditions. The parents were selected for their different response to water deficit stress following preliminary experiments. Results revealed that the genetic control mechanism of fruit yield is complex, variable and highly affected by environment. The mode of inheritance and nature of gene action for percent assimilate partitioned to fruits were similar to those for flowering time in both well-watered and WDS conditions. A significant negative genetic linkage was found between fruit yield and percent assimilate partitioned to root, percent assimilate partitioned to shoot, root number, root diameter, root dry mass, root volume, and early flowering. Thus, to improve fruit yield under water deficit stress, selection of low values of these traits could be used. In contrast, a significant positive genetic linkage between fruit yield and percent assimilate partitioned to fruits, leaf relative water content and chlorophyll content indicate selection for high values of these traits. These secondary or surrogate traits could be selected during early segregating generations. The early ripening parent (P1; TN-59-230) contained effective genes involved in preferred percent assimilate partitioning to fruit and drought stress resistance. In conclusion, genetic improvement of fruit yield and drought resistance could be simultaneously gained in coriander when breeding for drought resistance. PMID:28473836

Effect of Pulse and dc Formation on the Performance of One-Transistor and One-Resistor Resistance Random Access Memory Devices

NASA Astrophysics Data System (ADS)

Liu, Hong-Tao; Yang, Bao-He; Lv, Hang-Bing; Xu, Xiao-Xin; Luo, Qing; Wang, Guo-Ming; Zhang, Mei-Yun; Long, Shi-Bing; Liu, Qi; Liu, Ming

2015-02-01

We investigate the effect of the formation process under pulse and dc modes on the performance of one transistor and one resistor (1T1R) resistance random access memory (RRAM) device. All the devices are operated under the same test conditions, except for the initial formation process with different modes. Based on the statistical results, the high resistance state (HRS) under the dc forming mode shows a lower value with better distribution compared with that under the pulse mode. One of the possible reasons for such a phenomenon originates from different properties of conductive filament (CF) formed in the resistive switching layer under two different modes. For the dc forming mode, the formed filament is thought to be continuous, which is hard to be ruptured, resulting in a lower HRS. However, in the case of pulse forming, the filament is discontinuous where the transport mechanism is governed by hopping. The low resistance state (LRS) can be easily changed by removing a few trapping states from the conducting path. Hence, a higher HRS is thus observed. However, the HRS resistance is highly dependent on the length of the gap opened. A slight variation of the gap length will cause wide dispersion of resistance.

Expression analysis of several antiviral related genes to BmNPV in different resistant strains of silkworm, Bombyx mori

PubMed Central

Cheng, Yang; Wang, Xue-yang; Du, Chang; Gao, Juan; Xu, Jia-ping

2014-01-01

Abstract Bombyx mori L. (Lepidoptera: Bombycidae) nucleopolyhedrovirus (BmNPV) is a highly pathogenic virus in the sericultural industry, often causing severe damage leading to large economic losses. The immune mechanisms of B. mori against this virus remain obscure. Previous studies had demonstrated Bmlipase-1, BmNox and Bmserine protease-2 showing antiviral activity in vitro , but data on the transcription levels of these proteins in different resistant strains were not reported. In order to determine the resistance level of the four different strains (P50, A35, A40, A53) and gain a better understanding of the mechanism of resistance to BmNPV in B. mori , the relative expression level of the genes coding the three antiviral proteins in larval haemolymph and midgut of different B. mori strains resistant to BmNPV was determined. The results showed that these genes expressed significantly higher in the resistant strains compared to the susceptible strain, and the differential expression levels were consistent with the LC50 values in different strains. The transcription level of the target genes almost all up-regulated in the larvae midgut and down-regulated in the haemolymph. The results indicate the correlation of these genes to BmNPV resistance in B. mori. PMID:25373223

Identification of Sungai Batu Sediment using 2-D Resistivity Imaging and Seismic Refraction Methods for Ancient River Mapping at Kedah, Malaysia

NASA Astrophysics Data System (ADS)

Andika, F.; Saad, R.; Saidin, M. M.; Muztaza, N. M.; Amsir

2018-04-01

Sungai Batu is an earliest civilization in Southeast Asia with evidenced by the discovery of riverside jetty, iron smelting, and ritual monuments. The evidences can lead to prediction of buried river caused by geological and sedimentation process. This study was conducted to study sediment deposit characteristic and to map thickness of the sediments using 2-D resistivity imaging and seismic refraction for ancient river mapping. A total of thirty, 2-D resistivity and nine seismic survey lines were conducted at the study area. Four of the lines R1-R4 and S1-S4 were correlated and validated with existing on site boreholes BH1-BH4 to identify sediment type and thickness. The validated values applied to the remaining survey lines which no borehole record to map the subsurface of the study area. Based on the results, Sungai Batu area consist of clay with resistivity value of 6.6-25.9 Ω.m and velocity value of 716.9-1606.9 m/s; sandy clay with resistivity value of 6-265.1 Ω.m and velocity value of 1003.6-1901.4 m/s; while shale was identified with resistivity value of >668.6 Ω.m and velocity value of >2051.7 m/s. Boundary between clay/sandy clay with shale was identified with resistivity value of 314 Ω.m and velocity value of 1822 m/s. The integration of the 2-D resistivity and seismic refraction identified that the thickness of Sungai Batu sediment is 0-150 m and Sungai Batu ancient river was successfully map based on thickness of sediment which is >45 m.

Understanding the effects of cationic dopants on α-MnO 2 oxygen reduction reaction electrocatalysis

DOE PAGES

Lambert, Timothy N.; Vigil, Julian A.; White, Suzanne E.; ...

2017-01-09

Nickel-doped α-MnO 2 nanowires (Ni–α-MnO 2) were prepared with 3.4% or 4.9% Ni using a hydrothermal method. A comparison of the electrocatalytic data for the oxygen reduction reaction (ORR) in alkaline electrolyte versus that obtained with α-MnO 2 or Cu–α-MnO 2 is provided. In general, Ni-α-MnO 2 (e.g., Ni-4.9%) had higher n values (n = 3.6), faster kinetics (k = 0.015 cm s –1), and lower charge transfer resistance (R CT = 2264 Ω at half-wave) values than MnO 2 (n = 3.0, k = 0.006 cm s –1, R CT = 6104 Ω at half-wave) or Cu–α-MnO 2 (Cu-2.9%,more » n = 3.5, k = 0.015 cm s –1, R CT = 3412 Ω at half-wave), and the overall activity for Ni–α-MnO 2 trended with increasing Ni content, i.e., Ni-4.9% > Ni-3.4%. As observed for Cu–α-MnO 2, the increase in ORR activity correlates with the amount of Mn 3+ at the surface of the Ni–α-MnO 2 nanowire. Examining the activity for both Ni–α-MnO 2 and Cu–α-MnO 2 materials indicates that the Mn 3+ at the surface of the electrocatalysts dictates the activity trends within the overall series. Single nanowire resistance measurements conducted on 47 nanowire devices (15 of α-MnO 2, 16 of Cu–α-MnO 2-2.9%, and 16 of Ni–α-MnO 2-4.9%) demonstrated that Cu-doping leads to a slightly lower resistance value than Ni-doping, although both were considerably improved relative to the undoped α-MnO 2. As a result, the data also suggest that the ORR charge transfer resistance value, as determined by electrochemical impedance spectroscopy, is a better indicator of the cation-doping effect on ORR catalysis than the electrical resistance of the nanowire.« less

Total nasal resistance among Sasang constitutional types: a population-based study in Korea

PubMed Central

2013-01-01

Background There have been many attempts to find an objective phenotype by Sasang constitutional types (SCTs) on an anatomical, physiological, and psychological basis, but there has been no research on total nasal resistance (TNR) among SCTs. Methods We assessed the value of the TNR in the SCTs classified by an integrated diagnostic model. Included in the study were 1,346 individuals (701 males, 645 females) who participated in the Korean Genome and Epidemiology Study (KoGES). The TNR was measured by active anterior rhinomanometry (AAR) at transnasal pressures of 100 and 150 Pascal (Pa). Results The average TNR was 0.186 ± 0.004 Pa/cm3/second at 100 Pa in the Tae-eum (TE), 0.193 ± 0.007 in the So-eum (SE), and 0.208 ± 0.005 in the So-yang (SY) types. Under condition of 150 Pa the TE type had a TNR value of 0.217 ± 0.004, the SE type was 0.230 ± 0.008, and the SY type was 0.243 ± 0.005. Higher values of TNR were more likely to be reported in the SY type at 100 Pa and 150 Pa. In the stratified analysis by sex, the SY type in males and females tended to have higher TNR value than the TE and SE types at transnasal pressure of both 100 Pa and 150 Pa. Conclusions These results provide new approaches to understand the functional characteristics among the SCTs in terms of nasal physiology. Further studies are required to clarify contributing factors for such a difference. PMID:24180585

ERT and Well Data Tie for Nickel Laterite Characterization

NASA Astrophysics Data System (ADS)

Aswad, Sabrianto; Mamela Mais, Difar; Syamsuddin; Wanni

2018-03-01

The need of ERT method in nickel latentes exploration can’t be deny. This method have capability to make exploration more effective and efficient. In reality this method still remain ambiguity in its application, especially for geologist and mining expert. These ambiguity related with layer zone determination (limonite, saprolite and bedrock), the same resistivity values in the different zones and determination of bedrock. This paper try to expose interesting fact to overcome this ambiguity by using ERT data and drill data tie. This tie will show characteristic of nickel lateric based on resisitivity value and the contribution of chemistry element for resistivity value. Data ERT was collected by using gradient configuration and well data consist of mayor element and minor element. Tie result showed difference resistivity value in limonite layer influence by Fe, H2O and Ni, where resistivity value from saprolite layer influenced by Fe, H2O, Si02, MgO, Al, Cr, and Ni in certain accumulation. In bedrock layer, almost all drill data did not reach bedrock but only reached the boulder alone, it is supported by the value of the resistivity of rock unserpentinized peridotite which should show a relatively large resistivity value

[Atopic eczema: psychophysiological reactivity with standardized stressors].

PubMed

Münzel, K; Schandry, R

1990-11-01

In 18 atopic eczema patients with active symptomatology and 15 control subjects a comparison of reactivity to psychological stressors was made. The physiological measures were heart rate, peripheral vasomotor response, skin resistance level, spontaneous fluctuations of the skin resistance, and forearm skin temperature. In addition, self-ratings of subjective state, situational anxiety, and social anxiety were assessed. Mental arithmetic performed undisturbed and in distracting conditions, and anticipation of the latter and of having to speak in public served as stressors. The results show higher reaction values of the eczema patients for heart rate, peripheral vasomotor response, fluctuations of skin resistance and subjective tension. A subgroup of patients with extreme skin irritation (itching) reacted with an elevation of skin temperature, in contrast to control subjects and patients with less marked itching, in whom skin temperature dropped slightly. The results suggest that atopic eczema may have a psychophysiological component.

Activity of xanthine oxidase in plasma correlates with indices of insulin resistance and liver dysfunction in Japanese patients with type 2 diabetes mellitus and metabolic syndrome: A pilot exploratory study.

PubMed

Sunagawa, Sumito; Shirakura, Takashi; Hokama, Noboru; Kozuka, Chisayo; Yonamine, Masato; Namba, Toyotaka; Morishima, Satoko; Nakachi, Sawako; Nishi, Yukiko; Ikema, Tomomi; Okamoto, Shiki; Matsui, Chieko; Hase, Naoki; Tamura, Mizuho; Shimabukuro, Michio; Masuzaki, Hiroaki

2018-06-03

There is a controversy whether hyperuricemia is an independent risk for cardiometabolic diseases. Serum level of uric acid is affected by a wide variety of factors involved in its production and excretion. On the other hand, evidence has accumulated that locally and systemically activated xanthine oxidase (XO), a rate limiting enzyme for production of uric acid, is linked to metabolic derangement in humans and rodents. We therefore explored the clinical implication of plasma XO activity in patients with type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS). We enrolled 60 patients with T2DM and MetS. MetS was defined according to the 2005 International Diabetes Federation guidelines. Plasma XO activity was measured by highly sensitive fluorometric assay measuring the conversion of pterin to isoxanthopterin, and explored associations between the value of plasma XO activity and metabolic parameters. Value of plasma XO activity was correlated with indices of insulin resistance and level of circulating liver transaminases. On the other hand, level of serum uric acid was not correlated with indices of insulin resistance. The value of plasma XO activity was not correlated with serum uric acid level. Plasma XO activity correlates with indices of insulin resistance and liver dysfunction in Japanese patients with T2DM and MetS. Through assessing the plasma XO activity, patients demonstrating normal level of serum uric acid with higher activity of XO can be screened, thereby possibly providing a clue to uncover metabolic risks in T2DM and MetS. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Cold water immersion enhances recovery of submaximal muscle function after resistance exercise.

PubMed

Roberts, Llion A; Nosaka, Kazunori; Coombes, Jeff S; Peake, Jonathan M

2014-10-15

We investigated the effect of cold water immersion (CWI) on the recovery of muscle function and physiological responses after high-intensity resistance exercise. Using a randomized, cross-over design, 10 physically active men performed high-intensity resistance exercise followed by one of two recovery interventions: 1) 10 min of CWI at 10°C or 2) 10 min of active recovery (low-intensity cycling). After the recovery interventions, maximal muscle function was assessed after 2 and 4 h by measuring jump height and isometric squat strength. Submaximal muscle function was assessed after 6 h by measuring the average load lifted during 6 sets of 10 squats at 80% of 1 repetition maximum. Intramuscular temperature (1 cm) was also recorded, and venous blood samples were analyzed for markers of metabolism, vasoconstriction, and muscle damage. CWI did not enhance recovery of maximal muscle function. However, during the final three sets of the submaximal muscle function test, participants lifted a greater load (P < 0.05, Cohen's effect size: 1.3, 38%) after CWI compared with active recovery. During CWI, muscle temperature decreased ∼7°C below postexercise values and remained below preexercise values for another 35 min. Venous blood O2 saturation decreased below preexercise values for 1.5 h after CWI. Serum endothelin-1 concentration did not change after CWI, whereas it decreased after active recovery. Plasma myoglobin concentration was lower, whereas plasma IL-6 concentration was higher after CWI compared with active recovery. These results suggest that CWI after resistance exercise allows athletes to complete more work during subsequent training sessions, which could enhance long-term training adaptations. Copyright © 2014 the American Physiological Society.

Triglycerides and glucose index: a useful indicator of insulin resistance.

PubMed

Unger, Gisela; Benozzi, Silvia Fabiana; Perruzza, Fernando; Pennacchiotti, Graciela Laura

2014-12-01

Insulin resistance assessment requires sophisticated methodology of difficult application. Therefore, different estimators for this condition have been suggested. The aim of this study was to evaluate the triglycerides and glucose (TyG) index as a marker of insulin resistance and to compare it to the triglycerides/HDL cholesterol ratio (TG/HDL-C), in subjects with and without metabolic syndrome (MS). An observational, cross-sectional study was conducted on 525 adults of a population from Bahia Blanca, Argentina, who were divided into two groups: with MS (n=89) and without MS (n=436). The discriminating capacities for MS of the TyG index, calculated as Ln (TG [mg/dL] x glucose [mg/dL]/2), and the TG/HDL-C ratio were evaluated. Pre-test probability for MS was 30%. The mean value of the TyG index was higher in the group with MS as compared to the group without MS and its correlation with the TG/HDL-C ratio was good. The cut-off values for MS in the overall population were 8.8 for the TyG index (sensitivity=79%, specificity=86%), and 2.4 for the TG/HDL-C ratio (sensitivity=88%, specificity=72%). The positive likelihood ratios and post-test probabilities for these parameters were 5.8 vs 3.1 and 72% vs 58% respectively. The cut-off point for the TyG index was 8.8 in men and 8.7 in women; the respective values for TG/C-HDL were 3.1 in men and 2.2 in women. The TyG index was a good discriminant of MS. Its simple calculation warrants its further study as an alternative marker of insulin resistance. Copyright © 2014 SEEN. Published by Elsevier Espana. All rights reserved.

Insulin resistance, adipokine profile and hepatic expression of SOCS-3 gene in chronic hepatitis C.

PubMed

Wójcik, Kamila; Jabłonowska, Elżbieta; Omulecka, Aleksandra; Piekarska, Anna

2014-08-14

To analyze adipokine concentrations, insulin resistance and hepatic expression of suppressor of cytokine signaling 3 (SOCS-3) in patients with chronic hepatitis C genotype 1 with normal body weight, glucose and lipid profile. The study group consisted of 31 patients with chronic hepatitis C and 9 healthy subjects. Total levels of adiponectin, leptin, resistin, visfatin, omentin, osteopontin and insulin were measured using an ELISA kit. The hepatic expression of SOCS-3 was determined by the use of the reverse transcription polymerase chain reaction method. Homeostasis model assessment for insulin resistance (HOMA-IR) values were significantly higher in hepatitis C virus (HCV) infected patients without metabolic disorders compared to healthy controls (2.24 vs 0.59, P = 0.0003). Hepatic steatosis was observed in 32.2% of patients with HCV infection and was found in patients with increased HOMA-IR index (2.81 vs 1.99, P = 0.05) and reduced adiponectin level (5.96 vs 8.37, P = 0.04). Inflammatory activity (G ≥ 2) was related to increased osteopontin concentration (34.04 vs 23.35, P = 0.03). Advanced liver fibrosis (S ≥ 2) was associated with increased levels of omentin and osteopontin (436.94 vs 360.09, P = 0.03 and 32.84 vs 20.29, P = 0.03) and reduced resistin concentration (1.40 vs 1.74, P = 0.047). No correlations were reported between adipokine profile, HOMA-IR values and hepatic expression of the SOCS-3 gene. We speculated that no relationship between adipokines and HOMA-IR values may indicate that HCV can induce insulin resistance itself. Some adipokines appear to be biochemical markers of steatosis, inflammation and fibrosis in patients with chronic HCV infection. © 2014 Baishideng Publishing Group Inc. All rights reserved.

Characterization of riverbed sediments hydraulic conductivity using slug tests and electrical resistivity tomography and induced polarization tomogrpahy.

NASA Astrophysics Data System (ADS)

Nguyen, F.; Benoit, S.; Gommers, K.; Ghysels, G.; Hermans, T.; Huysmans, M.

2017-12-01

Hydraulic conductivity of river sediments ranges from values smaller than 10-9 m/s to values higher than 10-2 m/s, with a dominance in values between 10-7 m/s and 10-3 m/s. Both horizontal hydraulic conductivity and vertical hydraulic conductivity show spatial variation in a riverbed. The spatial variation in hydraulic conductivity is due to the influence of the sedimentary and geomorphological environment as well as the method of determination, including scale, size and imprecision of the applied method. The characterization of the spatial variability of hydraulic conductivity in riverbeds is important because of its effect on the interaction between river and groundwater. These river - groundwater interactions influence water resource management, water quality and functioning of the riparian ecosystem. It is necessary in the simulation of 3D flow between river and aquifer near the interface and thus, it also determines contaminant transport and biogeochemical modelling in this riparian or hyporheic zone. Different processes occur in this specific zone such as transport, degradation, transformation, precipitation and sorption of substances, all dependent on hydraulic conductivity. Several methods exist to determine the hydraulic conductivity in river beds, both direct and indirect methods, from field to laboratory experiments or numerical modelling, but the uncertainty on obtained K values is often large because of the large variability of K. In the recent years, research has been performed on the usefulness of geophysical methods on rivers, in particular Electrical Resistivity Tomography (ERT) and Induced Polarization (IP). The implementation of ERT and IP in rivers provides a continuous image of the resistivity and chargeability of the subsurface, respectively, and can be used in several applications as proxies for hydraulic conductivity. This work reports and investigate a correlation between hydraulic conductivity measured by slug tests at an experimental site, and electrical resistivity, chargeability and normalized chargeability for riverbeds sediments.

Surface properties of thermally treated composite wood panels

NASA Astrophysics Data System (ADS)

Croitoru, Catalin; Spirchez, Cosmin; Lunguleasa, Aurel; Cristea, Daniel; Roata, Ionut Claudiu; Pop, Mihai Alin; Bedo, Tibor; Stanciu, Elena Manuela; Pascu, Alexandru

2018-04-01

Composite finger-jointed spruce and oak wood panels have been thermally treated under standard pressure and oxygen content conditions at two different temperatures, 180 °C and respectively 200 °C for short time periods (3 and 5 h). Due to the thermally-aided chemical restructuration of the wood components, a decrease in water uptake and volumetric swelling values with up to 45% for spruce and 35% for oak have been registered, comparing to the reference samples. In relation to water resistance, a 15% increase of the dispersive component of the surface energy has been registered for the thermal-treated spruce panels, which impedes water spreading on the surface. The thermal-treated wood presents superior resistance to accelerated UV exposure and subsequently, with up to 10% higher Brinell hardness values than reference wood. The proposed thermal treatment improves the durability of the finger-jointed wood through a more economically and environmental friendly method than traditional impregnation, with minimal degradative impact on the structural components of wood.

Study of the Effects of High Temperatures on the Engineering Properties of Steel 42CrMo4

NASA Astrophysics Data System (ADS)

Brnic, Josip; Turkalj, Goran; Canadija, Marko; Lanc, Domagoj; Brcic, Marino

2015-02-01

The paper presents and analyzes the experimental results of the effect of elevated temperatures on the engineering properties of steel 42CrMo4. Experimental data relating to the mechanical properties of the material, the creep resistance as well as Charpy impact energy. Temperature dependence of the mentioned properties is also shown. Some of creep curves were simulated using rheological models and an analytical equation. Finally, an assessment of fracture toughness was made that was based on experimentally determined Charpy impact energy. Based on the obtained results it is visible that the tensile strength (617 MPa) and yield strength (415 MPa) have the highest value at the room temperature while at the temperature of 700 °C (973 K) these values significantly decrease. This steel can be considered resistant to creep at 400 °C (673 K), but at higher temperatures this steel can be subjected to low levels of stress in a shorter time.

The Discontinuity in the First Derivative of the ITS-90 at the Triple Point of Water

NASA Astrophysics Data System (ADS)

Rusby, R. L.

2010-09-01

This paper investigates the discontinuity in the derivative [d W/d T 90]TPW of the ITS-90 at the triple point of water, using data for over 40 calibrated standard platinum resistance thermometers (SPRTs). It finds that the discontinuity is in most cases somewhere between 0 and -6 parts in 105, in relative terms, but that the higher numerical values are obtained for `less ideal' SPRTs (those with lower temperature coefficients of resistance), and also for sub-ranges not extending beyond the indium point. These results are investigated vis-à-vis the long-standing observation that the ITS-90 reference values W r(Ga) and W r(Hg) are not completely consistent with data for W(Ga) and W(Hg) for real SPRTs. It discusses what may be done in a future scale to ensure continuity in the first derivative, and it concludes with a comment about the acceptance criteria for SPRTs in the scale.

C-Peptide, Baseline and Postprandial Insulin Resistance after a Carbohydrate-Rich Test Meal - Evidence for an Increased Insulin Clearance in PCOS Patients?

PubMed

Stassek, J; Erdmann, J; Ohnolz, F; Berg, F D; Kiechle, M; Seifert-Klauss, V

2017-01-01

Introduction Known characteristics of patients with PCOS include infertility, menstrual disorders, hirsutism and also often insulin resistance. These symptoms increase with increasing body weight. In the LIPCOS study ( L ifestyle I ntervention for Patients with Polycystic Ovary Syndrome [ PCOS ]) long-term changes of the PCOS in dependence on pregnancy and parenthood were systematically assessed. In the framework of the LIPCOS study, PCOS patients were given a standardised carbohydrate-rich test meal in order to examine glucose homeostasis and insulin secretion. The results were compared with those of a eumenorrhoeic control group who all had corresponding BMI values and corresponding ages. Methods and Patients 41 PCOS patients (without diabetes) and 68 controls received a standardised carbohydrate-rich test meal (260 kcal, 62 % carbohydrates, 32 % fat, 6 % proteins) in order to generate a submaximal insulin and glucose stimulation. The values were determined at baseline and postprandial after 60, 120 and 180 minutes. In addition, the corresponding C-peptide levels were recorded. Results In the PCOS patients (n = 41), the insulin secretion test after a standardised test meal showed almost identical baseline and postprandial insulin levels when compared with those of the age- and BMI-matched eumenorrhoeic controls (n = 68). In the PCOS patients, the baseline and postprandial glucose levels were significantly elevated (92.88 ± 10.28 [PCOS] vs. 85.07 ± 9.42 mg/dL [controls]; p < 0.001) so was C-peptide (p < 0.025). Conclusions In the present study we have shown for the first time that, after consumption of a standardised test meal, PCOS patients formally exhibit a higher fasting insulin resistance than controls. In spite of the higher stimulated C-peptide levels, the insulin levels did not increase more strongly with increasing glucose levels than in controls which may be indicative of a higher insulin clearance in PCOS patients.

Atomic Force Microscopy Measurements of the Mechanical Properties of Cell Walls on Living Bacterial Cells

NASA Astrophysics Data System (ADS)

Bailey, Richard; Mullin, Nic; Turner, Robert; Foster, Simon; Hobbs, Jamie

2014-03-01

Staphylococcus aureus is a major cause of infection in humans, including the Methicillin resistant strain, MRSA. However, very little is known about the mechanical properties of these cells. Our investigations use AFM to examine live S. aureus cells to quantify mechanical properties. These were explored using force spectroscopy with different trigger forces, allowing the properties to be extracted at different indentation depths. A value for the cell wall stiffness has been extracted, along with a second, higher value which is found upon indenting at higher forces. This higher value drops as the cells are exposed to high salt, sugar and detergent concentrations, implying that this measurement contains a contribution from the internal turgor pressure. We have monitored these properties as the cells progress through the cell cycle. Force maps were taken over the cells at different stages of the growth process to identify changes in the mechanics throughout the progression of growth and division. The effect of Oxacillin has also been studied, to better understand its mechanism of action. Finally mutant strains of S. aureus and a second species Bacillus subtilis have been used to link the mechanical properties of the cell walls with the chain lengths and substructures involved.

IRIS II Study: Sensitivity and specificity of intact proinsulin, adiponectin, and the proinsulin/adiponectin ratio as markers for insulin resistance.

PubMed

Langenfeld, Matthias R; Forst, Thomas; Standl, Eberhard; Strotmann, Hermann-Josef; Lübben, Georg; Pahler, Sabine; Kann, Peter; Pfützner, Andreas

2004-12-01

This study was performed to compare the specificity and sensitivity of intact proinsulin, adiponectin, and their ratio (proinsulin/adiponectin) in the prediction of insulin resistance as assessed by the homeostasis model assessment (HOMA) score (> or =2 = resistant). Using a cross-sectional approach, 500 orally treated patients with type 2 diabetes (272 women, 238 men; mean +/- SD age, 64.8 +/- 11.6 years; hemoglobin A1c, 7.0 +/- 1.5%; disease duration, 5.8 +/- 6.1 years) were investigated. Various cutoffs for body mass index-adjusted adiponectin and proinsulin/adiponectin were compared with the established cutoff value of 10 pmol/L for fasting proinsulin. Fasting proinsulin correlated more closely with the HOMA score (r = 0.560, P < 0.001) than fasting adiponectin (r = -0.204, P < 0.001) or proinsulin/adiponectin (r = 0.355, P < 0.001). For proinsulin, specificity and sensitivity for insulin resistance in correlation to the HOMA score results were 96% and 70%, respectively. At a comparable specificity level to proinsulin, adiponectin did not reach a comparable sensitivity (14%), while the proinsulin/adiponectin ratio almost reached the same sensitivity (65%). Overall, patients with elevated proinsulin had a higher prevalence of micro- and macrovascular disease [odds ratio 1.47 (adiponectin, 1.08; proinsulin/ adiponectin, 1.48) and 1.34 (adiponectin, 1.32; proinsulin/adiponectin, 1.27), respectively]. Elevation of fasting intact proinsulin seems to be the more specific marker for insulin resistance and increased cardiovascular risk than suppression of fasting adiponectin. Formation of the ratio does not lead to a further increase in the predictive value.

Cyclic fatigue resistance of ProTaper Next nickel-titanium rotary files.

PubMed

Elnaghy, A M

2014-11-01

To compare the cyclic fatigue resistance of ProTaper Next files (PTN; Dentsply Maillefer, Ballaigues, Switzerland) with Twisted Files (TF; SybronEndo, Orange, CA, USA), HyFlex CM (HF; ColténeEndo/Whaledent, Inc, Cuyahoga Falls, OH, USA) and ProTaper Universal (PT; Dentsply Maillefer). Size 25, .06 taper for PTN X2, TF, HF and PT F1 size 20, .07 taper were rotated in simulated canals until failure, and the number of cycles to failure (NCF) was recorded to evaluate their cyclic fatigue resistance. A scanning electron microscope was used to characterize the topographic features of the fracture surfaces of broken files. The data of the NCF and fragment length values were analysed statistically using one-way analysis of variance and Tukey post hoc tests. Statistical significance level was set at P < 0.05. Twisted Files had a significantly higher resistance to cyclic fatigue than the other instruments (P < 0.05). No significant difference was found in NCF between PTN and HF (P > 0.05); however, there was a significant difference (P < 0.05) of both these systems with PT, which exhibited the lowest mean NCF. The ranking in the NCF values was: TF > PTN > HF > PT. The fracture cross-sections of all brands revealed similar fractographic features, including crack origins, fatigue zone and an overload fast fracture zone. The new ProTaper Next had greater resistance to cyclic fatigue compared with ProTaper and HyFlex CM but not the Twisted Files. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Latent heat exchange in the boreal and arctic biomes.

PubMed

Kasurinen, Ville; Alfredsen, Knut; Kolari, Pasi; Mammarella, Ivan; Alekseychik, Pavel; Rinne, Janne; Vesala, Timo; Bernier, Pierre; Boike, Julia; Langer, Moritz; Belelli Marchesini, Luca; van Huissteden, Ko; Dolman, Han; Sachs, Torsten; Ohta, Takeshi; Varlagin, Andrej; Rocha, Adrian; Arain, Altaf; Oechel, Walter; Lund, Magnus; Grelle, Achim; Lindroth, Anders; Black, Andy; Aurela, Mika; Laurila, Tuomas; Lohila, Annalea; Berninger, Frank

2014-11-01

In this study latent heat flux (λE) measurements made at 65 boreal and arctic eddy-covariance (EC) sites were analyses by using the Penman-Monteith equation. Sites were stratified into nine different ecosystem types: harvested and burnt forest areas, pine forests, spruce or fir forests, Douglas-fir forests, broadleaf deciduous forests, larch forests, wetlands, tundra and natural grasslands. The Penman-Monteith equation was calibrated with variable surface resistances against half-hourly eddy-covariance data and clear differences between ecosystem types were observed. Based on the modeled behavior of surface and aerodynamic resistances, surface resistance tightly control λE in most mature forests, while it had less importance in ecosystems having shorter vegetation like young or recently harvested forests, grasslands, wetlands and tundra. The parameters of the Penman-Monteith equation were clearly different for winter and summer conditions, indicating that phenological effects on surface resistance are important. We also compared the simulated λE of different ecosystem types under meteorological conditions at one site. Values of λE varied between 15% and 38% of the net radiation in the simulations with mean ecosystem parameters. In general, the simulations suggest that λE is higher from forested ecosystems than from grasslands, wetlands or tundra-type ecosystems. Forests showed usually a tighter stomatal control of λE as indicated by a pronounced sensitivity of surface resistance to atmospheric vapor pressure deficit. Nevertheless, the surface resistance of forests was lower than for open vegetation types including wetlands. Tundra and wetlands had higher surface resistances, which were less sensitive to vapor pressure deficits. The results indicate that the variation in surface resistance within and between different vegetation types might play a significant role in energy exchange between terrestrial ecosystems and atmosphere. These results suggest the need to take into account vegetation type and phenology in energy exchange modeling. © 2014 John Wiley & Sons Ltd.

Comparison of spa Types, SCCmec Types and Antimicrobial Resistance Profiles of MRSA Isolated from Turkeys at Farm, Slaughter and from Retail Meat Indicates Transmission along the Production Chain

PubMed Central

Vossenkuhl, Birgit; Brandt, Jörgen; Fetsch, Alexandra; Käsbohrer, Annemarie; Kraushaar, Britta; Alt, Katja; Tenhagen, Bernd-Alois

2014-01-01

The prevalence of MRSA in the turkey meat production chain in Germany was estimated within the national monitoring for zoonotic agents in 2010. In total 22/112 (19.6%) dust samples from turkey farms, 235/359 (65.5%) swabs from turkey carcasses after slaughter and 147/460 (32.0%) turkey meat samples at retail were tested positive for MRSA. The specific distributions of spa types, SCCmec types and antimicrobial resistance profiles of MRSA isolated from these three different origins were compared using chi square statistics and the proportional similarity index (Czekanowski index). No significant differences between spa types, SCCmec types and antimicrobial resistance profiles of MRSA from different steps of the German turkey meat production chain were observed using Chi-Square test statistics. The Czekanowski index which can obtain values between 0 (no similarity) and 1 (perfect agreement) was consistently high (0.79–0.86) for the distribution of spa types and SCCmec types between the different processing stages indicating high degrees of similarity. The comparison of antimicrobial resistance profiles between the different process steps revealed the lowest Czekanowski index values (0.42–0.56). However, the Czekanowski index values were substantially higher than the index when isolates from the turkey meat production chain were compared to isolates from wild boar meat (0.13–0.19), an example of a separated population of MRSA used as control group. This result indicates that the proposed statistical method is valid to detect existing differences in the distribution of the tested characteristics of MRSA. The degree of similarity in the distribution of spa types, SCCmec types and antimicrobial resistance profiles between MRSA isolates from different process stages of turkey meat production may reflect MRSA transmission along the chain. PMID:24788143

Flow resistance dynamics in step‐pool channels: 2. Partitioning between grain, spill, and woody debris resistance

USGS Publications Warehouse

Wilcox, Andrew C.; Nelson, Jonathan M.; Wohl, Ellen E.

2006-01-01

In step‐pool stream channels, flow resistance is created primarily by bed sediments, spill over step‐pool bed forms, and large woody debris (LWD). In order to measure resistance partitioning between grains, steps, and LWD in step‐pool channels we completed laboratory flume runs in which total resistance was measured with and without grains and steps, with various LWD configurations, and at multiple slopes and discharges. Tests of additive approaches to resistance partitioning found that partitioning estimates are highly sensitive to the order in which components are calculated and that such approaches inflate the values of difficult‐to‐measure components that are calculated by subtraction from measured components. This effect is especially significant where interactions between roughness features create synergistic increases in resistance such that total resistance measured for combinations of resistance components greatly exceeds the sum of those components measured separately. LWD contributes large proportions of total resistance by creating form drag on individual pieces and by increasing the spill resistance effect of steps. The combined effect of LWD and spill over steps was found to dominate total resistance, whereas grain roughness on step treads was a small component of total resistance. The relative contributions of grain, spill, and woody debris resistance were strongly influenced by discharge and to a lesser extent by LWD density. Grain resistance values based on published formulas and debris resistance values calculated using a cylinder drag approach typically underestimated analogous flume‐derived values, further illustrating sources of error in partitioning methods and the importance of accounting for interaction effects between resistance components.

Flow resistance dynamics in step-pool channels: 2. Partitioning between grain, spill, and woody debris resistance

NASA Astrophysics Data System (ADS)

Wilcox, Andrew C.; Nelson, Jonathan M.; Wohl, Ellen E.

2006-05-01

In step-pool stream channels, flow resistance is created primarily by bed sediments, spill over step-pool bed forms, and large woody debris (LWD). In order to measure resistance partitioning between grains, steps, and LWD in step-pool channels we completed laboratory flume runs in which total resistance was measured with and without grains and steps, with various LWD configurations, and at multiple slopes and discharges. Tests of additive approaches to resistance partitioning found that partitioning estimates are highly sensitive to the order in which components are calculated and that such approaches inflate the values of difficult-to-measure components that are calculated by subtraction from measured components. This effect is especially significant where interactions between roughness features create synergistic increases in resistance such that total resistance measured for combinations of resistance components greatly exceeds the sum of those components measured separately. LWD contributes large proportions of total resistance by creating form drag on individual pieces and by increasing the spill resistance effect of steps. The combined effect of LWD and spill over steps was found to dominate total resistance, whereas grain roughness on step treads was a small component of total resistance. The relative contributions of grain, spill, and woody debris resistance were strongly influenced by discharge and to a lesser extent by LWD density. Grain resistance values based on published formulas and debris resistance values calculated using a cylinder drag approach typically underestimated analogous flume-derived values, further illustrating sources of error in partitioning methods and the importance of accounting for interaction effects between resistance components.

Correlations between Colonization of Onion Thrips and Leaf Reflectance Measures across Six Cabbage Varieties

PubMed Central

Bálint, János; Nagy, Balázs Vince; Fail, József

2013-01-01

The main purpose of this study was to reveal if the UV-A, and visible light reflection of leaves of white cabbage varieties is correlated to resistance against onion thrips. The antixenotic resistance (AR) against onion thrips and thrips damage differed between varieties Balashi, Bloktor, Riana – considered resistant – and Green Gem, Hurricane, Quisor – considered susceptible. The solar UV-A (340–400 nm) and visible (401–650 nm) light reflection of white cabbage leaves were recorded. Correlation between AR against onion thrips and reflection of leaves in UV-A and visible range of the studied white cabbage varieties were computed. According to the AR evaluation onion thrips density was always higher on susceptible than on resistant varieties. The UV-A light reflection of head forming leaves and the contrast between head and exterior leaves (H/E) was negatively correlated with onion thrips host preference at an early stage of cabbage head formation. The visible light reflection of both head forming and exterior leaves was also negatively correlated with onion thrips host preference. Susceptible varieties had greater damage ratings at harvest than resistant ones and positive correlations were observed between AR and damage. AR against onion thrips may be affected by differences in reflection of cabbage leaves at an early growth stage. It is suggested that more intensive reflection of leaves and/or higher contrast values between the reflectance intensity of head versus outer leaves made the resistant varieties less attractive to onion thrips. Our results reported here provide the first evidence of negative correlation between UV-A and visible reflection of leaves and AR of white cabbage against a dangerous insect pest, opening new perspectives for understanding the role of reflection by plant leaves in pest management. PMID:24040093

Accessory renal arteries: Prevalence in resistant hypertension and an important role in nonresponse to radiofrequency renal denervation.

PubMed

VonAchen, Paige; Hamann, Jason; Houghland, Thomas; Lesser, John R; Wang, Yale; Caye, David; Rosenthal, Kristi; Garberich, Ross F; Daniels, Mary; Schwartz, Robert S

The aim of this study was to understand the role of accessory renal arteries in resistant hypertension, and to establish their role in nonresponse to radiofrequency renal denervation (RDN) procedures. Prior studies suggest a role for accessory renal arteries in hypertensive syndromes, and recent clinical trials of renal denervation report that these anomalies are highly prevalent in resistant hypertension. This study evaluated the relationships among resistant hypertension, accessory renal arteries, and the response to radiofrequency (RF) renal denervation. Computed Tomography Angiography (CTA) and magnetic resonance imaging (MRI) scans from 58 patients with resistant hypertension undergoing RF renal denervation (RDN) were evaluated. Results were compared with CT scans in 57 healthy, normotensive subjects undergoing screening as possible renal transplant donors. All scans were carefully studied for accessory renal arteries, and were correlated with long term blood pressure reduction. Accessory renal arteries were markedly more prevalent in the hypertensive patients than normotensive renal donors (59% vs 32% respectively, p=0.004). RDN had an overall nonresponse rate of 29% (response rate 71%). Patients without accessory vessels had a borderline higher response rate to RDN than those with at least one accessory vessel (83% vs 62% respectively, p=0.076) and a higher RDN response than patients with untreated accessory arteries (83% vs 55%; p=0.040). For accessory renal arteries and nonresponse, the sensitivity was 76%, specificity 49%, with positive and negative predictive values 38% and 83% respectively. Accessory renal arteries were markedly over-represented in resistant hypertensives compared with healthy controls. While not all patients with accessory arteries were nonresponders, nonresponse was related to both the presence and non-treatment of accessory arteries. Addressing accessory renal arteries in future clinical trials may improve RDN therapeutic efficacy. Copyright © 2016 Elsevier Inc. All rights reserved.

[Effect of metabolic uncontrolled diabetes mellitus (DM) on the resistance index of renal (IR) Interlobar arteries assessed with pulsed Doppler].

PubMed

Muraira-Cárdenas, Luis Cesar; Barrios-Pérez, Martín

2016-01-01

Diabetes mellitus is a chronic degenerative disease characterized by elevated hyperglycemia, triggering a series of processes and culminating in chronic, uncontrolled, cellular and vascular damage in different organs. To assess whether the elevated glycosylated hemoglobin, microalbuminuria, and the time evolution of more than 10 years of diabetes mellitus are associated with elevated resistance index of the interlobar renal arteries assessed with pulsed Doppler in patients with metabolic uncontrolled diabetes mellitus. Transversal-analytical, observational, prospective study that included diabetic patients attending UMAE abdominal ultrasound in 25 of IMSS, from October 15, 2014 to November 15, 2014, which was performed for pulsed Doppler index resistance of vascular interlobar renal arteries and was collected from electronic medical records: age, sex, glycated hemoglobin, and microalbuminuria. The association between metabolic uncontrolled diabetes mellitus was analyzed with the elevation of resistance index by χ(2) test or Fisher, being significant with a value of p < 0.05, and to assess the magnitude of the association that was measured with a response magnitude of 95%. 63 patients with type 2 diabetes were examined, with an average age of 52.3 ± 14.2 years, 41 were older than 50 years (65.0%), 26 with hypertension (41.2%), 32 with higher levels of glycated hemoglobin 7 (50.8%), 35 with normoalbuminuria (55.6%), 28 with microalbuminuria (44.4%), and 39 with a time evolution of diabetes of more than 10 years (61.9%). We observed a statistically significant difference between microalbuminuria and increased duration of diabetes mellitus with high resistance index. The alterations in renal microvasculature conditioned by the occurrence of microalbuminuria in diabetic nephropathy and the duration of diabetes are strongly associated with higher resistance index.

ABT492 and levofloxacin: comparison of their pharmacodynamics and their abilities to prevent the selection of resistant Staphylococcus aureus in an in vitro dynamic model.

PubMed

Firsov, Alexander A; Vostrov, Sergey N; Lubenko, Irene Yu; Arzamastsev, Alexander P; Portnoy, Yury A; Zinner, Stephen H

2004-07-01

To compare the kinetics of killing/regrowth of differentially susceptible clinical isolates of Staphylococcus aureus exposed to ABT492 and levofloxacin and to explore their relative abilities to prevent the selection of resistant mutants. Three clinical isolates of S. aureus--including two ciprofloxacin-susceptible S. aureus, 201 and 480--and a ciprofloxacin-resistant S. aureus 866, were exposed to clinically achievable ratios of area under the curve (AUC) to MIC in a dynamic model that simulated human pharmacokinetics of ABT492 (400 mg) and levofloxacin (500 mg) as a single dose. In addition, S. aureus 201 was exposed to single and multiple doses of ABT492 and levofloxacin (both once daily for 3 days) over wide ranges of 24 h AUC/MIC (AUC24/MIC) including clinically achievable AUC24/MIC ratios. With each isolate, ABT492 at clinically achievable AUC/MICs produced greater anti-staphylococcal effects than levofloxacin. Areas between the control growth and the time--kill curves (ABBC in single dose simulations and the sum of ABBCs determined after the first, second and third dosing in multiple dose simulations--ABBC(1+2+3)) were higher with ABT492 than levofloxacin. Moreover, at comparable AUC/MICs and AUC24/MICs, the maximal reductions in the starting inoculum of ABT492-exposed S. aureus were more pronounced than with levofloxacin. Loss in susceptibility of S. aureus 201 exposed to ABT492 or levofloxacin depended on the simulated AUC24/MIC. Although the maximal increase in MIC (MICfinal) related to its initial value (MICinitial) was seen at a higher AUC24/MIC ratio of ABT492 (120 h) than levofloxacin (50 h), similar AUC24/MICs (240 and 200 h, respectively) were protective against the selection of resistant S. aureus. These threshold values are readily achievable with 400 mg ABT492 (AUC24/MIC 870 h) but not with 500 mg levofloxacin (AUC24/MIC 70 h). Overall, these findings predict greater efficacy of clinically achievable AUC/MIC (or AUC24/MIC) of ABT492 both in terms of the anti-staphylococcal effect and prevention of the selection of resistant mutants.

Homeostatic model assessment indices in evaluation of insulin resistance and secretion in hemodialysis patients

PubMed Central

Niemczyk, Stanisław; Szamotulska, Katarzyna; Giers, Kinga; Jasik, Mariusz; Bartoszewicz, Zbigniew; Romejko-Ciepielewska, Katarzyna; Paklerska, Ewa; Gomółka, Małgorzata; Matuszkiewicz-Rowińska, Joanna

2013-01-01

Background Some previous observations suggest that insulin resistance and glucose metabolism disturbances are frequent complications of chronic kidney disease. However, there are no conclusive studies on other indices of the effectiveness of insulin action in end-stage renal disease (ESRD) patients, including chronically hemodialysed (HD) ones. Material/Methods The groups comprised 33 non-diabetic ESRD hemodialysed patients and 33 healthy controls matched for age, sex, and body mass index (BMI). In both groups, HOMA-%B, HOMA-%S, HOMA-IR indices, and DI were calculated using HOMA1 and HOMA2 as measures of insulin resistance. The indices were also assessed in subgroups divided according to BMI. Results Mean fasting plasma glucose concentrations were lower in ESRD patients than in healthy persons (82.4±10.4 vs. 93.9±11.6, p=0.001). Fasting serum insulin concentrations were similar in both groups (median 6.8 vs. 6.0 mU/l, p=0.698). HOMA1-%B values were higher in ESRD patients than controls (median 137.1 vs. 81.6, p=0.002). HOMA1-%S (median 75.6 vs. 71.5) and HOMA1-IR (median 1.3 vs. 1.4) values were not significantly different (p=0.264 and p=0.189, respectively). DI1 levels were higher for HD patients than for healthy subjects (median 1.16 vs. 0.53, p<0.001). In subgroup analysis, all statistically significant differences were restricted mainly to persons with BMI <25 kg/m2. Similar results as for the HOMA1 model were obtained for HOMA2. Conclusions 1. HOMA beta-cell function is strongly correlated with HOMA insulin resistance in HD patients. 2. In non-diabetic ESRD hemodialysed patients, the HOMA indices and DI may be useful and important models in interpretation of glucose metabolism disturbances. PMID:23867834

Assessment of groundwater contamination by gypsum dissolution in San Luis Potosí (México) using geoelectrical characterization

NASA Astrophysics Data System (ADS)

Arango-Galvan, C.; Ramos-Leal, J. A.; Yáñez-Rodríguez, M. A.; Corbo-Camargo, F.

2017-12-01

The Cerritos and Río Verde aquifers in San Luis Potosí (central México) make up a very complex aquifer system that is seriously affected by the overexploitation and the high concentration of sulphates. Currently, it is partially closed for extraction causing a substantial decrease in per capita drinking water availability affecting to more than 50,000 inhabitants in the region. Therefore, a very comprehensive study has been proposed in order to evaluate not only the groundwater contamination distribution but also to better know the aquifer configuration and its main hydrogeological characteristics as well. These studies include a detailed geological reconnaissance, hydrogeochemical analyses and a geoelectrical characterization. The main goal is to assess the aquifer geometry and to identify the gypsum horizons causing the presence of higher concentrations of sulphates in drinking water. A total of 26 audiomagnetotelluric soundings were measured and modelled along profiles following a perpendicular direction to the NW regional trending. Two-dimensional resistivity models suggest the presence of a shallow conductive layer (C1) with resistivity values ranging from 10 to 20 Ohm.m. It is related to the upper aquifer with a very low exploitation potential. A less conductive horizon (C2; 50 Ohm.m) underlying the shallow aquifer could be related to a very fractured limestone horizon forming a confined aquifer in the middle of the valley. A very resistive layer (R1) is observed underlying C1 and C2 units. This strata shows higher resistivity values (>100 Ohm.m) and could be associated with a reefal limestone identified as El Abra Formation. Finally, a conductive layer (<100 Ohm.m) observed beneath this horizon could be related to the oldest stratigraphic unit outcropping on the region, the Guaxcamá Formation, a gypsum-enriched unit, that contributes to the presence of sulphates in the upper aquifers by dissolution processes.

Insulin resistance and associated factors among HIV-infected patients in sub-Saharan Africa: a cross sectional study from Cameroon.

PubMed

Noumegni, Steve Raoul Ngongang; Nansseu, Jobert Richie; Ama, Vicky Jocelyne Moor; Bigna, Jean Joel; Assah, Felix Kembe; Guewo-Fokeng, Magellan; Leumi, Steve; Katte, Jean-Claude; Dehayem, Mesmin; Kengne, Andre Pascal; Sobngwi, Eugene

2017-08-10

Little is known on the magnitude and correlates of insulin resistance in HIV-infected people in Africa. We determined the prevalence of insulin resistance and investigated associated factors in HIV-infected adult Cameroonians. We conducted a cross-sectional study at the Yaoundé Central Hospital, Cameroon; during which we enrolled HIV-infected people aged 30 to 74 years with no previous history of cardiovascular disease. An homeostatic model assessment of insulin resistance (HOMA-IR) like index served to assess insulin sensitivity with insulin resistance defined by values of 2.1 or higher. We included 452 patients (20% men). Their mean age was 44.4 ± 9.8 years and 88.5% of them were on antiretroviral therapy (93.3% on first line regimen including Zidovudine, lamivudine and Efavirenz/Nevirapine). Of all participants, 28.5% were overweight, 19.5% had obesity and 2.0% had diabetes. The prevalence of insulin resistance was 47.3% without any difference between patients on ART and those ART-naïve (48.5% vs. 38.5%; p = 0.480). Obesity was the only factor independently associated with insulin resistance (adjusted odds ratio: 2.28; 95% confidence interval: 1.10-4.72). Insulin resistance is present in nearly half of HIV-infected patients in Cameroon despite a low prevalence rate of diabetes, and is associated with obesity.

Glottal volume velocity waveform characteristics in subjects with and without vocal training, related to gender, sound intensity, fundamental frequency, and age.

PubMed

Sulter, A M; Wit, H P

1996-11-01

Glottal volume velocity waveform characteristics of 224 subjects, categorized in four groups according to gender and vocal training, were determined, and their relations to sound-pressure level, fundamental frequency, intra-oral pressure, and age were analyzed. Subjects phonated at three intensity conditions. The glottal volume velocity waveforms were obtained by inverse filtering the oral flow. Glottal volume velocity waveforms were parameterized with flow-based (minimum flow, ac flow, average flow, maximum flow declination rate) and time-based parameters (closed quotient, closing quotient, speed quotient), as well as with derived parameters (vocal efficiency and glottal resistance). Higher sound-pressure levels, intra-oral pressures, and flow-parameter values (ac flow, maximum flow declination rate) were observed, when compared with previous investigations. These higher values might be the result of the specific phonation tasks (stressed /ae/ vowel in a word and a sentence) or filtering processes. Few statistically significant (p < 0.01) differences in parameters were found between untrained and trained subjects [the maximum flow declination rate and the closing quotient were higher in trained women (p < 0.001), and the speed quotient was higher in trained men (p < 0.005)]. Several statistically significant parameter differences were found between men and women [minimum flow, ac flow, average flow, maximum flow declination rate, closing quotient, glottal resistance (p < 0.001), and closed quotient (p < 0.005)]. Significant effects of intensity condition were observed on ac flow, maximum flow declination rate, closing quotient, and vocal efficiency in women (p < 0.005), and on minimum flow, ac flow, average flow, maximum flow declination rate, closed quotient, and vocal efficiency in men (p < 0.01).

Psychopathology in adolescents with TLE and FLE.

PubMed

Huemer, Julia; Plattner, Belinda; Planer, Nadja; Steiner, Hans; Feucht, Martha

2016-11-01

To describe the rates and types of psychiatric disorders among adolescents with chronic symptomatic epilepsies and to evaluate syndrome-specific differences between temporal lobe (TLE) and frontal lobe (FLE) epilepsies. A cross-sectional single-center study design applying the Youth Self Report (YSR) to investigate psychopathological symptoms and the Weinberger Adjustment Inventory (WAI) to investigate personality dimensions was used. Consecutive adolescents between 14 and 18 years of age with drug-resistant symptomatic TLE and FLE were investigated during pre-surgical evaluation prior to epilepsy surgery. Data from twenty-eight patients (19 with TLE and 9 with FLE) were analyzed for this report. Compared with the test norm, higher prevalence rates and a wider range of psychopathological symptoms were seen in patients with TLE. This result was not seen in patients with FLE. Concerning personality dimensions, significantly higher values of repressive defensiveness and significantly lower values of positive emotion and confidence were found in patients with TLE. In contrast, significantly lower levels of distress and significantly higher levels of repressive defensiveness and denial of distress were seen in patients with FLE. Comparing TLE with FLE, a significantly higher mean score for distress, and a significantly lower mean score for positive emotion and denial of distress were found in patients with TLE. In summary, psychiatric comorbidity was frequently found in this sample of youths with chronic drug-resistant localization-related epilepsies. Although results have to be interpreted with caution because of the small sample size, psychiatric symptomatology was significantly different between TLE and FLE. Our results show that continuous and syndrome-specific psychiatric monitoring is essential in young patients with epilepsy. Copyright © 2016 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

Time course of haemodynamic, respiratory and inflammatory disturbances induced by experimental acute pulmonary polystyrene microembolism.

PubMed

Dolci, Daniel T; Fuentes, Carolina B; Rolim, Denise; Park, Marcelo; Schettino, Guilherme P P; Azevedo, Luciano C P

2010-01-01

The time course of cardiopulmonary alterations after pulmonary embolism has not been clearly demonstrated and nor has the role of systemic inflammation on the pathogenesis of the disease. This study aimed to evaluate over 12 h the effects of pulmonary embolism caused by polystyrene microspheres on the haemodynamics, lung mechanics and gas exchange and on interleukin-6 production. Ten large white pigs (weight 35-42 kg) had arterial and pulmonary catheters inserted and pulmonary embolism was induced in five pigs by injection of polystyrene microspheres (diameter approximately 300 micromol l(-1)) until a value of pulmonary mean arterial pressure of twice the baseline was obtained. Five other animals received only saline. Haemodynamic and respiratory data and pressure-volume curves of the respiratory system were collected. A bronchoscopy was performed before and 12 h after embolism, when the animals were euthanized. The embolism group developed hypoxaemia that was not corrected with high oxygen fractions, as well as higher values of dead space, airway resistance and lower respiratory compliance levels. Acute haemodynamic alterations included pulmonary arterial hypertension with preserved systemic arterial pressure and cardiac index. These derangements persisted until the end of the experiments. The plasma interleukin-6 concentrations were similar in both groups; however, an increase in core temperature and a nonsignificant higher concentration of bronchoalveolar lavage proteins were found in the embolism group. Acute pulmonary embolism induced by polystyrene microspheres in pigs produces a 12-h lasting hypoxaemia and a high dead space associated with high airway resistance and low compliance. There were no plasma systemic markers of inflammation, but a higher central temperature and a trend towards higher bronchoalveolar lavage proteins were found.

Dietary fibre: challenges in production and use of food composition data.

PubMed

Westenbrink, Susanne; Brunt, Kommer; van der Kamp, Jan-Willem

2013-10-01

Dietary fibre is a heterogeneous group of components for which several definitions and analytical methods were developed over the past decades, causing confusion among users and producers of dietary fibre data in food composition databases. An overview is given of current definitions and analytical methods. Some of the issues related to maintaining dietary fibre values in food composition databases are discussed. Newly developed AOAC methods (2009.01 or modifications) yield higher dietary fibre values, due to the inclusion of low molecular weight dietary fibre and resistant starch. For food composition databases procedures need to be developed to combine 'classic' and 'new' dietary fibre values since re-analysing all foods on short notice is impossible due to financial restrictions. Standardised value documentation procedures are important to evaluate dietary fibre values from several sources before exchanging and using the data, e.g. for dietary intake research. Copyright © 2012 Elsevier Ltd. All rights reserved.

Electro-mechanical characterization of structural supercapacitors

NASA Astrophysics Data System (ADS)

Gallagher, T.; LaMaster, D.; Ciocanel, C.; Browder, C.

2012-04-01

The paper presents electrical and mechanical properties of structural supercapacitors and discusses limitations associated with the approach taken for the electrical properties evaluation. The structural supercapacitors characterized in this work had the electrodes made of carbon fiber weave, separator made of several cellulose based products, and the solid electrolyte made as PEGDGE based polymer blend. The reported electrical properties include capacitance and leakage resistance; the former was measured using cyclic voltammetry. Mechanical properties have been evaluated thorough tensile and three point bending tests performed on structural supercapacitor coupons. The results indicate that the separator material plays an important role on the electrical as well as mechanical properties of the structural capacitor, and that Celgard 3501 used as separator leads to most benefits for both mechanical and electrical properties. Specific capacitance and leakage resistance as high as 1.4kF/m3 and 380kΩ, respectively, were achieved. Two types of solid polymer electrolytes were used in fabrication, with one leading to higher and more consistent leakage resistance values at the expense of a slight decrease in specific capacitance when compared to the other SPE formulation. The ultimate tensile strength and modulus of elasticity of the developed power storage composite were evaluated at 466MPa and 18.9MPa, respectively. These values are 58% and 69% of the tensile strength and modulus of elasticity values measured for a single layer composite material made with the same type of carbon fiber and with a West System 105 epoxy instead of solid polymer electrolyte.

Technical note: Antimicrobial susceptibility of Portuguese isolates of Staphylococcus aureus and Staphylococcus epidermidis in subclinical bovine mastitis.

PubMed

Nunes, S F; Bexiga, R; Cavaco, L M; Vilela, C L

2007-07-01

To evaluate the antimicrobial resistance traits of staphylococci responsible for subclinical bovine mastitis in Portugal, the minimum inhibitory concentrations (MIC) of 7 antimicrobial agents, frequently administered for mastitis treatment, were determined for 30 Staphylococcus aureus and 31 Staphylococcus epidermidis field isolates. Beta-lactamase production was detected through the use of nitrocefin-impregnated discs. The MIC that inhibited 90% of the isolates tested (MIC90) of penicillin, oxacillin, cefazolin, gentamicin, sulfamethoxazole/trimethoprim, oxytetracycline, and enrofloxacin were, respectively, 4, 0.5, 1, 1, 0.25, 0.25, and 0.06 microg/mL for Staph. aureus and > or = 64, 8, 1, 32, > or = 64, > or = 64, and 0.06 microg/mL for Staph. epidermidis. All Staph. aureus isolates showed susceptibility to oxacillin, cefazolin, gentamicin, sulphamethoxazole/trimethoprim, and enrofloxacin. Beta-lactamase production was detected in 20 of these isolates (66.7%), all of which were resistant to penicillin. Of the 31 Staph. epidermidis tested, 24 (77.4%) were beta-lactamase positive. All isolates were susceptible to both cefazolin and enrofloxacin. Nine Staph. epidermidis isolates were resistant to oxacillin, with MIC values ranging from 4 to 8 microg/mL. The MIC values of 5 antimicrobial agents tested were higher than those reported in other countries. Enrofloxacin was the only exception, showing lower MIC values compared with other reports. Overall, the antimicrobial agents tested in our study, with the exception of penicillin, were active against the 61 isolates studied.

Development of microheaters for gas sensor with an AT-Mega 8535 temperature controller using a PWM (pulse width modulation) method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Megayanti, Meti; Panatarani, Camellia; Joni, I. Made, E-mail: imadejoni@phys.unpad.ac.id

Microheater is the main component in gas sensor characterized by their sensitivity, selectivity, and time response of gas sensor which is depend on the microheater temperature stability. A Cu microheater was developed and utilized AT-Mega 8535 controller using a PWM (pulse width modulation) method. This control system is interfaced to the PC to observe the real time temperature response of the microheater. Three initial resistance (R0) variations of microheater were developed in an open loop control system. The power characteristic of designed microheater depends on the specified microheater initial resistance. The smaller R0, the less power required to reach amore » temperature setting value. The developed microheater was designed to reach a temperature setting value of 250°C having resistance 0.531 Ω for 1.979 Watt and 0.265 Ω for 1.072 Watt respectively. The results of the investigation on the control performances shows microheater-control system achieved operating temperature up to 250°C. The response of the temperature control shows smallest R0 resulted in a high stability with short settling time, short delay time and small ripple for temperature setting values higher than 150°C. The obtained error of microheater temperature with R0 = 0.265 is 8.596 %. It is concluded that the developed microheater can be utilized as a component of a gas sensor.« less

Correlation between magnetocaloric and electrical properties based on phenomenological models in La0.47Pr0.2Pb0.33MnO3 perovskite

NASA Astrophysics Data System (ADS)

Mechi, Nesrine; Alzahrani, Bandar; Hcini, Sobhi; Bouazizi, Mohamed Lamjed; Dhahri, Abdessalem

2018-06-01

We have investigated the correlation between magnetocaloric and electrical properties of La0.47Pr0.2Pb0.33MnO3 perovskite prepared using the sol-gel method. Rietveld analysis of X-ray diffraction (XRD) pattern shows pure crystalline phase with rhombohedral ? structure. Magnetic entropy change, relative cooling power (RCP) and specific heat were predicted from M(T, μ0H) data at different magnetic fields with the help of the phenomenological model. The magnetic entropy change reaches a maximum value ? of about 3.96 J kg-1 K-1 for μ0H = 5 T corresponding to RCP of 183 J kg-1. These values are relatively higher, making our sample a promising candidate for the magnetic refrigeration. Electrical-resistivity measurements were well fitted with the phenomenological percolation model, which is based on the phase segregation of ferromagnetic-metallic clusters and paramagnetic-semiconductor regions. The temperature and magnetic field dependences of resistivity data, ρ(T, μ0H), allowed us to determine the magnetic entropy change ?. Results show that the as-obtained magnetic entropy change values are similar to those determined from the phenomenological model.

An Integrated 3D Hydrogeological, Geophysical, and Microbiological Investigation of Geochemical Gradients in a Pristine Aquifer Located in Laurentian Hills, ON, Canada

NASA Astrophysics Data System (ADS)

Shirokova, V.; Graves, L.; Stojanovic, S.; Enright, A. M.; Bank, C.; Ferris, F. G.

2013-12-01

A pristine glaciofluvial aquifer displaying naturally occurring geochemical gradients was investigated using hydrogeological, geophysical, and microbiological methods. A network of 25 piezometers was used to collect samples for groundwater chemical analysis, including parameters such as total iron (Fe), ferrous iron (Fe2+), sulphate (SO42-), sulfur (S2-), ammonium (NH4+), nitrate (NO3-), nitrite (NO2-), silica (SiO2), phosphate (PO43-), pH, and oxidation reduction potential (ORP). Ion concentration values between piezometers were interpolated using kriging and inverse distance weighting. Yearly analysis of the network shows spatially and temporally persistent plumes of iron and sulfur. A 3D model of the aquifer was compiled to aid in the understanding of the nature and origin of the geochemical gradients. The resulting maps showed zones with high concentrations of dissolved total iron (predominantly soluble ferric iron and complexed iron compounds), followed immediately downgradient by a high concentration of ferrous iron. Similarly, zones of high sulfide concentration were followed by areas of high sulfate concentration. There was some overlap between the iron and sulfur plumes, and ion concentrations were higher in years with a lower water table elevation. Metagenomic analysis revealed a diverse microbial community in the sediment, capable of the biogeochemical cycling of iron, sulfur, and nitrogen. The aquifer basin, as bounded by a till aquitard, was delineated using ground penetrating radar tomography from 45 lines. The plumes corresponded to an area where there is large, channel-like depression in the till boundary. Flow vectors from hydrogeological modelling indicated increased velocity followed by a slowing and convergence of groundwater in this location. Resistivity values from 20 lines varied in general from high values (2000-6000 Ohm.m) above 1-2 m to lower values (less than 1000 Ohm.m) below 2 to a 5m depth. The resistivity surveys consistently showed low resistivity values in areas of ionic enrichment, the location of the geochemical plumes, and high resistivity values at the top of the vadose zone including below dry sand outcrops. Fluorescent microscopy suggests the plumes are associated with attached subsurface bacteria dominated by species such as Gallionella and Leptothrix. These bacteria are likely responsible for conductive anomalies (<200 Ohm.m), observed in the resistivity models, that were at the centre of areas with high ionic concentrations. The above aquifer chemical network is currently being computationally simulated, and attempts are being made to determine the extents to which biotic and abiotic processes contribute to the formation of the geochemical gradients.

Phenotypic subgroups of polycystic ovary syndrome have different intra-renal resistance symptoms.

PubMed

Ciftci, Ceylan F; Uckuyu, Ayla; Karadeli, Elif; Turhan, Erdem; Toprak, Erzat; Ozcimen, Emel E

2012-12-01

The polycystic ovary syndrome (PCOS) is known to be related with increased metabolic and cardiovascular risks. Various phenotypic subgroups of PCOS have been proven to have metabolic and endocrine disorders with varying degrees of severity However, intra-renal vascular resistance, which is an indirect indication of atherosclerosis, remains unknown in PCOS subgroups. In this study we examined whether PCOS subgroups have different intra-renal resistance symptoms. 98 PCOS patients (diagnosed according to the Rotterdam criteria) 30 controls were included in the study The diagnosis of PCOS was established in the presence of at least two of the following criteria: 1-oligo and/or amenorrhea (OM); 2-clinic and/or biochemical signs of hyperandrogenism (HA); 3-polycystic ovarian morphology (PCO) detected by transvaginal ultrasonography 37 patients (Group 1) met all three criteria (HA+OM+PCO), 29 patients (Group 2) met two of the criteria including hyperandrogenism (HA+OM or HA+PCO) and the remaining 32 patients (Group 3) had no hyperandrogenism but fulfilled the other two criteria; PCO+OM. Renal Doppler ultrasonography and hormonal/biochemical analyses were carried out. The first outcome measure was designated as the differences in the renal resistive index (RRI) values of the groups, and the second outcome measure was designated as the relation of RRI with the insulin resistance and lipid profile. In Group 1, the RRI and the homeostasis model assessment of insulin resistance (HOMA-IR) values were significantly higher than in Group 3 and controls (P < 0.031, P < 0.001, respectively after adjusting for age and BMI). The RRI and HOMA-IR values in Group 3 were similar to those of the control group. It was determined that RRI has a positive correlation with HOMA-IR (r = 0.784, P < .0001) and BMI (r = 0.645, P < .0001). In this study we demonstrated that PCOS subgroups have metabolic and endocrine disorders and cardiovascular risks of varying degrees of severity Moreover, we showed that there was no increase of metabolic and cardiovascular risks in PCOS patients without hyperandrogenism.

Wear resistance of a modified polymethyl methacrylate artificial tooth compared to five commercially available artificial tooth materials.

PubMed

Kamonwanon, Pranithida; Yodmongkol, Sirasa; Chantarachindawong, Rojcharin; Thaweeboon, Sroisiri; Thaweeboon, Boonyanit; Srikhirin, Toemsak

2015-08-01

Wear resistance is a limitation of artificial denture teeth. Improving the wear resistance of conventional artificial denture teeth is of value to prosthodontic patients. The purpose of this in vitro study was to evaluate the wear resistance and hardness of modified polymethyl methacrylate artificial denture teeth compared to 5 commercially available artificial tooth materials. This study evaluated 180 artificial denture teeth (6 groups) that included 3 groups of conventional artificial teeth (MajorDent, Cosmo HXL, and Gnathostar), 2 groups of composite resin artificial teeth (Endura and SR Orthosit PE), and 1 group of modified surface artificial teeth. The flattened buccal surface of each tooth (n=15) was prepared for investigation with the Vickers hardness test and the elucidate wear test (n=15) by using a brushing machine. Each group was loaded for 18,000 cycles, at 2 N, and 150 rpm. The wear value was identified with a profilometer. The data were statistically analyzed by using 1-way ANOVA and post hoc Turkey honestly significant difference tests (α=.001). The tribologies were observed under a scanning electron microscope, and the cytotoxicities were evaluated by MTT assay. The Vickers hardnesses ranged from 28.48 to 39.36. The wear depths and worn surface area values ranged from 1.12 to 10.79 μm and from 6.74 to 161.95 μm(2). The data revealed that the modified artificial denture teeth were significantly harder and exhibited significantly higher wear resistance than did the conventional artificial teeth (P<.001). The scanning electron microscopic images revealed cross sections of the conventional artificial denture teeth with intensively worn surface areas after brushing. The cytotoxicity test revealed 97.85% cell viability, which indicates the nontoxicity of the modified surface of this material. Within the limitations of this study, the polymethyl methacrylate modified surface artificial denture teeth was not significantly different from that of the composite resin artificial denture teeth, with the exceptions that the surface was harder and more wear resistant. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

[Gly482Ser polymorphism of the coactivator-1alpha of the activated receptor of peroxisome gamma proliferation in individuals from Maracaibo, Venezuela].

PubMed

Zambrano, Mariana; Fernández, Erika; López, Maciel; Rangel, Annell; de Romero, Pilar; Fernández, Virginia; Marina Morales, Luz; Molero-Conejo, Emperatriz; Connell, Lissett; Raleigh, Xiomara; Aranguren-Mendez, José

2009-09-01

The aim of this study was to determine the association of the Gly482Ser polymorphism of the PGC-1 gene with insulin resistance and type 2 diabetes mellitus in subjects from the city of Maracaibo. The study was performed on 64 no-diabetic subjects (36 without insulin resistance and 28 with insulin resistance) and 13 with type 2 diabetes. A clinical and nutritional history was carried out and the evaluation of anthropometric parameters was included. Fasting serum glucose, fasting serum insulin, total cholesterol, HDL-C and LDL-C, were measured. The Gly482Ser polymorphism was detected by PCR-RFLP. It was found that the allelic frequencies for A and G were 0.36 and 0.64, respectively. The population was found in genetic equilibrium of Hardy Weinberg. The genotypes of the polymorphism Gly482Ser were not associated with insulin resistance and type 2 diabetes mellitus (OR = 1.320, p = 0.74; OR = 2, p = 0.47 respectively). Nevertheless, the diabetic subjects with the genotype AA presented values of LDL-C higher (p < 0.05) than the individuals with the genotypes GG and GA. The diabetics with the genotype GA showed significantly higher concentrations of triglycerides (>150 mg/dL) compared with the genotype GG. According to the results, the polymorphism Gly482Ser of the PGC-1 gene would be able to contribute to the cardiovascular risk in type 2 diabetics, while in the insulin resistant individuals, this polymorphism was not associated with cardiovascular risk factors.

Effect of resistance exercise intensity on the expression of PGC-1α isoforms and the anabolic and catabolic signaling mediators, IGF-1 and myostatin, in human skeletal muscle.

PubMed

Schwarz, Neil A; McKinley-Barnard, Sarah K; Spillane, Mike B; Andre, Thomas L; Gann, Joshua J; Willoughby, Darryn S

2016-08-01

The purpose of this study was to investigate the acute messenger (mRNA) expression of the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) isoforms, insulin-like growth factor-1Ea (IGF-1Ea), and myostatin in response to 2 resistance exercise intensities. In a uniform-balanced, crossover design, 10 participants performed 2 separate testing sessions involving a lower body resistance exercise component consisting of a lower intensity (50% of 1-repetition maximum; 1RM) protocol and a higher intensity (80% of 1RM) protocol of equal volumes. Muscle samples were obtained at before exercise, 45 min, 3 h, 24 h, and 48 h postexercise. Resistance exercise did not alter total PGC-1α mRNA expression; however, distinct responses of each PGC-1α isoform were observed. The response of each isoform was consistent between sessions, suggesting no effect of resistance exercise intensity on the complex transcriptional expression of the PGC-1α gene. IGF-1Ea mRNA expression significantly increased following the higher intensity session compared with pre-exercise and the lower intensity session. Myostatin mRNA expression was significantly reduced compared with pre-exercise values at all time points with no difference between exercise intensity. Further research is needed to determine the effects of the various isoforms of PGC-1α in human skeletal muscle on the translational level as well as their relation to the expression of IGF-1 and myostatin.

Degradation of (La(0.8)Sr(0.2))(0.98)MnO(3-δ)-Zr(0.84)Y(0.16)O(2-γ) composite electrodes during reversing current operation.

PubMed

Hughes, Gareth A; Railsback, Justin G; Yakal-Kremski, Kyle J; Butts, Danielle M; Barnett, Scott A

2015-01-01

Reversing-current operation of solid oxide cell (La(0.8)Sr(0.2))(0.98)MnO(3-δ)-Zr(0.84)Y(0.16)O(2-γ) (LSM-YSZ) oxygen electrodes is described. Degradation was characterized by impedance spectroscopy in symmetric cells tested at 800 °C in air with a symmetric current cycle with a period of 12 hours. No change in cell resistance could be detected, in 1000 h tests with a sensitivity of ∼1% per kh, at a current density of 0.5 A cm(-2) corresponding to an overpotential of 0.18 V. At a current density to 0.6 A cm(-2) (0.33 V overpotential) measurable resistance degradation at a rate of 3% per kh was observed, while higher current/overpotential values led to faster degradation. Degradation was observed mainly in the ohmic resistance for current densities of 0.6, 0.8 and 0.9 A cm(-2), with little change in the polarization resistance. Polarization degradation, mainly observed at higher current density, was present as an increase in an impedance response at ∼30 kHz, apparently associated with the resistance of YSZ grain boundaries within the electrode. Microstructural and chemical analysis showed significant changes in electrode structure after the current cycling, including an increase in LSM particle size and a reduction in the amount of YSZ and LSM at the electrode/electrolyte interface - the latter presumably a precursor to delamination.

Prevalence and genetic mechanisms of antimicrobial resistance in Staphylococcus species: A multicentre report of the indian council of medical research antimicrobial resistance surveillance network.

PubMed

Rajkumar, Sunanda; Sistla, Sujatha; Manoharan, Meerabai; Sugumar, Madhan; Nagasundaram, Niveditha; Parija, Subhash Chandra; Ray, Pallab; Bakthavatchalam, Yamuna Devi; Veeraraghavan, Balaji; Kapil, Arti; Walia, Kamini; Ohri, V C

2017-01-01

Routine surveillance of antimicrobial resistance (AMR) is an essential component of measures aimed to tackle the growing threat of resistant microbes in public health. This study presents a 1-year multicentre report on AMR in Staphylococcus species as part of Indian Council of Medical Research-AMR surveillance network. Staphylococcus species was routinely collected in the nodal and regional centres of the network and antimicrobial susceptibility testing was performed against a panel of antimicrobials. Minimum inhibitory concentration (MIC) values of vancomycin (VAN), daptomycin, tigecycline and linezolid (LNZ) against selected methicillin-resistant Staphylococcus aureus(MRSA) isolates were determined by E-test and MIC creep, if any, was determined. Resistant genotypes were determined by polymerase chain reaction for those isolates showing phenotypic resistance. The prevalence of MRSA was found to be range from moderate (21%) to high (45%) among the centres with an overall prevalence of 37.3%. High prevalence of resistance was observed with commonly used antimicrobials such as ciprofloxacin and erythromycin in all the centres. Resistance to LNZ was not encountered except for a single case. Full-blown resistance to VAN in S. aureus was not observed; however, a few VAN-intermediate S. aureus isolates were documented. The most common species of coagulase negative staphylococci (CoNS) identified was Staphylococcus haemolyticus and Staphylococcus epidermidis. Resistance among CoNS was relatively higher than S. aureus. Most phenotypically resistant organisms possessed the corresponding resistance genes. There were localised differences in the prevalence of resistance between the centres. The efficacy of the anti-MRSA antimicrobials was very high; however, almost all these antimicrobials showed evidence of creeping MIC.

[Changes in hemodynamics and oxygen metabolism of different Child-grade patients during orthotopic liver transplantation without veno-venous bypass].

PubMed

Zhao, Dong; Wang, Tian-long; Pan, Fang; Zhao, Lei; Zhang, Lian-feng; Yang, Ba-xian

2006-08-18

To investigate the changes in hemodynamics and oxygen metabolism of different Child-grade patients during orthotopic liver transplantation (OLT) without veno-venous bypass. Forty patients with end-stage liver disease undergoing non veno-venous OLT under general anesthesia were enrolled in this research. Swan-Ganz catheter was placed in the pulmonary artery via right internal jugular vein and right radial artery was cannulated to monitor mean pulmonary artery pressure (mPAP) and artery blood pressure (ABP) continuously. Pulmonary capillary wedge pressure (PCWP) and central venous pressure (CVP) were also recorded. Cardiac output (CO) was recorded at several time points, such as, 30 min after induction (T1), when inferior vena cava and portal vein were clamped (T2), 30 min after portal vein was clamped (T3), 10 min after unclamping of portal vein (T4), 60 min after graft reperfusion (T5) and at the end of the operation (T6). Blood samples were taken from radial and pulmonary artery for blood gas analysis and hemodynamic parameters, such as, cardiac index (CI), stroke volume index (SVI), pulmonary vascular resistance index (PVRI), and system vascular resistance index (SVRI); oxygen delivery (DO2) and oxygen consumption (VO2) were also calculated at these time points. (1) The mPAP values were much higher in group C than in group A or B at all time points. CVP was significantly increased at T1 or T2 in group C as compared with those points of Child's B or C. PCWP was increased significantly after unclamping of portal vein in all three groups and was much higher at several points in Child's C than in Child's A or B. The SVRI value of T1 and the PVRI value of T3 were much lower in group C than those points in group A and the value of SVRI/PVRI was less than normal except at T3 point. And blood gas analysis elucidated that PaO2 was higher than 400 mm Hg at any points. (2) Oxygen consumption was significantly decreased during the operation due to less blood supply and was reverted to normal at the end point of the operation in all patients. Oxygen delivery was all at least 1,000 mL/min during OLT and there was no significant difference between different groups or different points. The hemodynamic state of high cardiac output with low peripheral resistance deteriorated when patients' Child-grade shifted from A to C. VO2 was less than normal value during OLT until the end point.

Effects of saturation deficit on desiccation resistance and water balance in seasonal populations of the tropical drosophilid Zaprionus indianus.

PubMed

Kalra, Bhawna; Parkash, Ravi

2016-10-15

Seasonally varying populations of ectothermic insect taxa from a given locality are expected to cope with simultaneous changes in temperature and humidity through phenotypic plasticity. Accordingly, we investigated the effect of saturation deficit on resistance to desiccation in wild-caught flies from four seasons (spring, summer, rainy and autumn) and corresponding flies reared in the laboratory under season-specific simulated temperature and humidity growth conditions. Flies raised under summer conditions showed approximately three times higher desiccation resistance and increased levels of cuticular lipids compared with flies raised in rainy season conditions. In contrast, intermediate trends were observed for water balance-related traits in flies reared under spring or autumn conditions but trait values overlapped across these two seasons. Furthermore, a threefold difference in saturation deficit (an index of evaporative water loss due to a combined thermal and humidity effect) between summer (27.5 mB) and rainy (8.5 mB) seasons was associated with twofold differences in the rate of water loss. Higher dehydration stress due to a high saturation deficit in summer is compensated by storage of higher levels of energy metabolite (trehalose) and cuticular lipids, and these traits correlated positively with desiccation resistance. In Z. indianus, the observed changes in desiccation-related traits due to plastic effects of simulated growth conditions correspond to similar changes exhibited by seasonal wild-caught flies. Our results show that developmental plastic effects under ecologically relevant thermal and humidity conditions can explain seasonal adaptations for water balance-related traits in Z. indianus and are likely to be associated with its invasive potential. © 2016. Published by The Company of Biologists Ltd.

Population-based cross-sectional study on insulin resistance and insulin-secretory capacity in Japanese school children.

PubMed

Nishimura, Rimei; Sano, Hironari; Onda, Yoshiko; Tsujino, Daisuke; Ando, Kiyotaka; Ebara, Futoshi; Matsudaira, Toru; Ishikawa, Shinichiro; Sakamoto, Takuya; Tajima, Naoko; Utsunomiya, Kazunori

2017-09-01

Little information is available regarding the status of insulin resistance (IR) and insulin deficiency (ID), as well as their relationship with obesity in children using the homeostasis model assessment (HOMA) in a population-based setting. The study included a total of 445 ninth-grade children participating in health check-up programs implemented in Tsunan Town, Niigata, Japan (boys/girls, 252/193 [participation rates: 98.1/95.5%]). HOMA of insulin resistance ≥2.5 was defined as IR, and HOMA of β-cell function <40 defined as ID. The medians (25-75th percentiles) of HOMA of insulin resistance, HOMA of β-cell function, Disposition Index and body mass index in boys were 1.2 (0.8-1.7), 64 (44-93), 52 (43-64) and 19.2 (18.0-20.7) kg/m 2 , respectively, vs 1.5 (1.0-2.0), 86 (63-120), 60 (50-74) and 20.4 (18.9-22.0) kg/m 2 , respectively, in girls. The HOMA of insulin resistance, HOMA of β-cell function and Disposition Index values were significantly higher in the girls (P = 0.002, P < 0.001 and P < 0.001, respectively). Those with IR accounted for a significantly higher proportion of girls than boys (15.5/8.7%; P = 0.027); those with obesity accounted for 9.9/10.7% (boys/girls); and those with IR and obesity accounted for 2.4/4.7%. Those with ID accounted for a significantly higher proportion of boys than girls (20.6/8.8%; P = 0.001), whereas those with ID and obesity accounted for a very small proportion of either group (0.4/0.5%). The presence of IR was higher among the girls. In contrast, ID was more frequent among the boys. The infrequent presence of ID among children might support the presence of non-obese type 2 diabetes adults in Japan. © 2017 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

Two complementary approaches to quantify variability in heat resistance of spores of Bacillus subtilis.

PubMed

den Besten, Heidy M W; Berendsen, Erwin M; Wells-Bennik, Marjon H J; Straatsma, Han; Zwietering, Marcel H

2017-07-17

Realistic prediction of microbial inactivation in food requires quantitative information on variability introduced by the microorganisms. Bacillus subtilis forms heat resistant spores and in this study the impact of strain variability on spore heat resistance was quantified using 20 strains. In addition, experimental variability was quantified by using technical replicates per heat treatment experiment, and reproduction variability was quantified by using two biologically independent spore crops for each strain that were heat treated on different days. The fourth-decimal reduction times and z-values were estimated by a one-step and two-step model fitting procedure. Grouping of the 20 B. subtilis strains into two statistically distinguishable groups could be confirmed based on their spore heat resistance. The reproduction variability was higher than experimental variability, but both variabilities were much lower than strain variability. The model fitting approach did not significantly affect the quantification of variability. Remarkably, when strain variability in spore heat resistance was quantified using only the strains producing low-level heat resistant spores, then this strain variability was comparable with the previously reported strain variability in heat resistance of vegetative cells of Listeria monocytogenes, although in a totally other temperature range. Strains that produced spores with high-level heat resistance showed similar temperature range for growth as strains that produced low-level heat resistance. Strain variability affected heat resistance of spores most, and therefore integration of this variability factor in modelling of spore heat resistance will make predictions more realistic. Copyright © 2017. Published by Elsevier B.V.

[Triptolide reverses apatinib resistance in gastric cancer cell line MKN45 via inhibition of heat shock protein 70].

PubMed

Teng, F; Xu, Z Y; Lyu, H; Wang, Y P; Wang, L J; Huang, T; Sun, J C; Zhu, H T; Ni, Y X; Cheng, X D

2018-02-23

Objective: To investigate the effect of triptolide, a specific inhibitor of heat shock protein 70 (HSP70), on apatinib resistance in gastric cancer cells line MKN45. Methods: The apatinib-resistant cells (MKN45/AR) and MKN45 parental cells were treated with apatinib, triptolide and apatinib combined with triptolide, respectively. CCK-8 assay was performed to determine the half maximal inhibitory concentration (IC(50)) of MKN45/AR and MKN45 cells in the presence of different treatment. The mRNA expression of heat shock protein gene (HSPA1A and HSPA1B) was detected by RT-PCR, while the protein expression of heat shock protein 70 was analyzed using Western blot in MKN45/AR and MKN45 cells. Results: The IC(50) values of apatinib-sensitive and apatinib-resistant MKN45 cells were 10.411 μmol/L and 70.527 μmol/L, respectively, showing a significant difference ( P <0.05). The mRNA expression of HSPA1A and HSPA1B in MKN45/AR cells was significantly higher than that in MKN45 cells ( P <0.001). The protein expression of heat shock protein 70 was significantly decreased after 0.25 μmol/L triptolide treatment in MKN45/AR cells ( P <0.01). When heat shock protein 70 was inhibited by triptolide, the IC(50) value of apatinib in MKN45/AR cells was reduced to 11.679 μmol/L, which was significantly lower than cells treated with apatinib alone ( P <0.05). Conclusions: The apatinib-resistant MKN45 cells have high levels of heat shock protein 70. Low doses of triptolide can significantly inhibit heat shock protein 70, leading to reverse the resistance phenotype of MKN45/AR cells. Therefore, inhibition of heat shock protein 70 provides a new therapy strategy for patients with apatinib resistance.

Prevalence and Antimicrobial Resistance of Enterobacteriaceae in Shell Eggs from Small-Scale Poultry Farms and Farmers' Markets.

PubMed

Kilonzo-Nthenge, A; Nahashon, S N; Godwin, S; Liu, S; Long, D

2016-12-01

Public health concerns over the emergence of antimicrobial resistant bacteria have increased recently. The purpose of this study was to investigate the prevalence of antimicrobial resistant Enterobacteriaceae in shell eggs purchased from small poultry farms and farmers' markets. A total of 504 eggs were pooled to make 252 composite samples, consisting of 2 eggs per composite. The microbial quality of shell eggs was determined by standard quantitative, biochemical, and PCR techniques. Susceptibility to 13 antimicrobial agents was determined by the Kirby-Bauer disk diffusion technique, and results were interpreted based on Clinical and Laboratory Standards Institute values. Shell eggs and egg contents were positive for Escherichia coli (11.9 and 5.2%, respectively), Enterobacter (9.1 and 7.9%), and Serratia (11.5 and 4.8%). Salmonella was isolated from 3.6% of egg shells but not from egg contents. Mean (±SD) Enterobacteriaceae levels (4.4 ± 2.0 log CFU per eggshell) on shell eggs from poultry farms was significantly higher (P ≤ 0.05) than that on shell eggs from farmers' markets (2.1 ± 1.3 log CFU per eggshell). Of the 134 isolates recovered, resistance among isolates from farm and market shell eggs to erythromycin was most common (48.5 and 32.8%, respectively) followed by ampicillin (44.8 and 17.2%), and tetracycline (29.9 and 17.2%). The multiple antibiotic resistance index value for E. coli and Pantoea was 0.62, and that for Salmonella and Klebsiella terrigena was 0.08, indicating that Enterobacteriaceae in shell eggs can be resistant to multiple antimicrobial agents. These data reveal that shell eggs from small poultry farms and farmers' markets can harbor antimicrobial resistant pathogenic and commensal bacteria. Thus, failure to properly handle shell eggs poses a potential health hazard to consumers.

Irrigation model of bleached Kraft mill wastewater through volcanic soil as a pollutants attenuation process.

PubMed

Navia, R; Inostroza, X; Diez, M C; Lorber, K E

2006-05-01

An irrigation process through volcanic soil columns was evaluated for bleached Kraft mill effluent pollutants retention. The system was designed to remove color and phenolic compounds and a simple kinetic model for determining the global mass transfer coefficient and the adsorption rate constant was used. The results clearly indicate that the global mass transfer coefficient values (K(c)a) and the adsorption rate constants are higher for the irrigation processes onto acidified soil. This means that the pretreatment of washing the volcanic soil with an acid solution has a positive effect on the adsorption rate for both pollutant groups. The enhanced adsorption capacity is partially explained by the activation of the metal oxides present in the soil matrix during the acid washing process. Increasing the flow rate from 1.5 to 2.5 ml/min yielded higher (K(c)a) values and adsorption rate constants for both pollutant groups. For instance, regarding color adsorption onto acidified soil, there is an increment of 43% in the (K(c)a) value for the experiment with a flow rate of 2.5 ml/min. Increasing the porosity of the column from 0.55 to 0.59, yielded a decrease in the (K(c)a) values for color and phenolic compounds adsorption processes. Onto natural soil for example, these decreases reached 21% and 24%, respectively. Therefore, the (K(c)a) value is dependent on both the liquid-phase velocity (external resistance) and the soil fraction in the column (internal resistance); making forced convection and diffusion to be the main transport mechanisms involved in the adsorption process. Analyzing the adsorption rate constants (K(c)a)/m, phenolic compounds and color adsorption rates onto acidified soil of 2.25 x 10(-6) and 2.62 x 10(-6) l/mg min were achieved for experiment 1. These adsorption rates are comparable with other adsorption systems and adsorbent materials.

Can Fetuin-A Be a Marker for Insulin Resistance and Poor Glycemic Control in Children with Type 1 Diabetes Mellitus?

PubMed

Şiraz, Ülkü Gül; Doğan, Murat; Hatipoğlu, Nihal; Muhtaroğlu, Sabahattin; Kurtoğlu, Selim

2017-12-15

Metabolic impairment in type 1 diabetes mellitus (T1DM) with poor glycemic control causes insulin resistance, non-alcoholic fatty liver disease (NAFLD), atherosclerosis, and increased carotid intima-media thickness (CIMT). Fetuin-A has a protective effect in cardiovascular disorders and is increased in hepatosteatosis. We aimed to investigate the reliability of fetuin-A levels in early detection of diabetic complications in children with T1DM and to identify a cut-off value that may show poor metabolic control. The study included 80 patients who had T1DM for at least 5 years and who had no chronic complications or an auto-immune disorder. Blood samples were drawn to measure hemoglobin A1c (HbA1c), biochemical parameters, and fetuin-A levels. Anthropometric parameters were also measured. Percent body fat was calculated. Hepatosteatosis and CIMT were assessed by sonography. Mean age of the patients was 13.5 years. Grade 1 hepatosteatosis was detected in 10%. Patients were stratified into 2 groups based on presence of NAFLD. Fetuin-A level was increased in patients with NAFLD. We identified a fetuin-A cut-off value (514.28 ng/mL; sensitivity: 47.34; specificity: 96.72) that may predict NAFLD. HbA1c and total cholesterol levels were found to be higher in patients with fetuin-A levels above higher the cut-off value. Fetuin-A is a reliable parameter in the prediction of complications and poor glycemic control in patients with T1DM.

High Heating Rates Affect Greatly the Inactivation Rate of Escherichia coli.

PubMed

Huertas, Juan-Pablo; Aznar, Arantxa; Esnoz, Arturo; Fernández, Pablo S; Iguaz, Asunción; Periago, Paula M; Palop, Alfredo

2016-01-01

Heat resistance of microorganisms can be affected by different influencing factors. Although, the effect of heating rates has been scarcely explored by the scientific community, recent researches have unraveled its important effect on the thermal resistance of different species of vegetative bacteria. Typically heating rates described in the literature ranged from 1 to 20°C/min but the impact of much higher heating rates is unclear. The aim of this research was to explore the effect of different heating rates, such as those currently achieved in the heat exchangers used in the food industry, on the heat resistance of Escherichia coli. A pilot plant tubular heat exchanger and a thermoresistometer Mastia were used for this purpose. Results showed that fast heating rates had a deep impact on the thermal resistance of E. coli. Heating rates between 20 and 50°C/min were achieved in the heat exchanger, which were much slower than those around 20°C/s achieved in the thermoresistometer. In all cases, these high heating rates led to higher inactivation than expected: in the heat exchanger, for all the experiments performed, when the observed inactivation had reached about seven log cycles, the predictions estimated about 1 log cycle of inactivation; in the thermoresistometer these differences between observed and predicted values were even more than 10 times higher, from 4.07 log cycles observed to 0.34 predicted at a flow rate of 70 mL/min and a maximum heating rate of 14.7°C/s. A quantification of the impact of the heating rates on the level of inactivation achieved was established. These results point out the important effect that the heating rate has on the thermal resistance of E. coli, with high heating rates resulting in an additional sensitization to heat and therefore an effective food safety strategy in terms of food processing.

High Heating Rates Affect Greatly the Inactivation Rate of Escherichia coli

PubMed Central

Huertas, Juan-Pablo; Aznar, Arantxa; Esnoz, Arturo; Fernández, Pablo S.; Iguaz, Asunción; Periago, Paula M.; Palop, Alfredo

2016-01-01

Heat resistance of microorganisms can be affected by different influencing factors. Although, the effect of heating rates has been scarcely explored by the scientific community, recent researches have unraveled its important effect on the thermal resistance of different species of vegetative bacteria. Typically heating rates described in the literature ranged from 1 to 20°C/min but the impact of much higher heating rates is unclear. The aim of this research was to explore the effect of different heating rates, such as those currently achieved in the heat exchangers used in the food industry, on the heat resistance of Escherichia coli. A pilot plant tubular heat exchanger and a thermoresistometer Mastia were used for this purpose. Results showed that fast heating rates had a deep impact on the thermal resistance of E. coli. Heating rates between 20 and 50°C/min were achieved in the heat exchanger, which were much slower than those around 20°C/s achieved in the thermoresistometer. In all cases, these high heating rates led to higher inactivation than expected: in the heat exchanger, for all the experiments performed, when the observed inactivation had reached about seven log cycles, the predictions estimated about 1 log cycle of inactivation; in the thermoresistometer these differences between observed and predicted values were even more than 10 times higher, from 4.07 log cycles observed to 0.34 predicted at a flow rate of 70 mL/min and a maximum heating rate of 14.7°C/s. A quantification of the impact of the heating rates on the level of inactivation achieved was established. These results point out the important effect that the heating rate has on the thermal resistance of E. coli, with high heating rates resulting in an additional sensitization to heat and therefore an effective food safety strategy in terms of food processing. PMID:27563300

Copolymer natural latex in concrete: Dynamic evaluation through energy dissipation of polymer modified concrete

NASA Astrophysics Data System (ADS)

Andayani, Sih Wuri; Suratman, Rochim; Imran, Iswandi; Mardiyati

2018-05-01

Portland cement concrete have been used in construction due to its strength and ecomical value. But it has some limitations, such low flexural strength, low tensile strength, low chemical resistant and etc. Due to its limitations in flexural and tensile strength, Portland cement concrete more susceptible by seismic force. There are some methods for improving its limitations. Polymer addition into concrete mixture could be one of solution for improving the flexural and tensile strength, in aiming to get erthquake resistant properties. Also, the eartquake resistant could be achieved by improving energy dissipation capacity. In this research, the earthquake resistant evalution was approached from dynamic evaluation through energy dissipation capacity, after polymer addition as concrete additives. The polymers were natural latex (Indonesian naural resource) grafted with styrene and methacrylate, forming copolymer - natural latex methacrylate (KOLAM) and copolymer - natural latex styrene (KOLAS). They were added into concrete mixture resulting polymer modified concrete. The composition of polymer are 1%, 5% and 10% weight/weight of cement. The higher capacity of energy dissipation will give more capability in either absorbing or dissipating energy, and it was predicted would give better earthquake resistant.. The use of KOLAM gave better performance than KOLAS in energy dissipation capacity. It gave about 46% for addition of 1% w/w compared to Portland cement concrete. But for addition 5% w/w and 10% w/w, they gave about 7% and 5% higher energy dissipation capacity. The KOLAM addition into concrete mixture would reduce the maximum impact load with maximumabout 35% impact load reducing after 1% w/w addition. The higher concentration of KOLAM in concrete mixture, lower reducing of impact load, they were about 4% and 3% for KOLAM 5% and 10%. For KOLAS addition in any compositions, there were no positive trend either in energy dissipation capacity or impact load properties, compared to Portland cement concrete.

Adipocytokines, neuropeptide Y and insulin resistance in overweight women with gynoid and android type of adipose tissue distribution.

PubMed

Orbetzova, Maria M; Koleva, Daniela I; Mitkov, Mitko D; Atanassova, Iliana B; Nikolova, Julia G; Atanassova, Pepa K; Genchev, Gencho D

2012-01-01

The AIM of the study was to compare the levels of certain adipose tissue hormones in women with the two main morphological types of obesity - android and gynoid obesity. The study included 2 groups of age- and weight-matched women with android (n = 32) and gynoid (n = 27) type of obesity, and a group of age-matched healthy women (n = 24) with normal weight and body constitution. Leptin, resistin, tumour necrosis factor alpha (TNFalpha), neuropeptide Y (NPY), glucose and insulin were measured. HOMA index was calculated. Leptin levels in the women with gynoid obesity did not differ significantly from those in the controls and the women with android obesity. The controls had significantly lower leptin levels compared with the android obesity women. NPY was significantly higher in the control women compared to the women with android obesity and did not differ significantly between the two groups of obese women. TNFalpha levels in all groups were very similar. Resistin did not show significant differences between all groups but tended to have the lowest levels in the controls. In the women with android obesity, insulin was significantly higher than that in the women with gynoid obesity and the controls. Insulin resistance was found in the women with android obesity only. Basal insulin and HOMA index in the women with gynoid obesity did not differ significantly from the values in the control group. The results from this study contribute to understanding the association of adipose tissue hormones and insulin resistance in obesity. When adipose tissue is predominantly distributed in the abdominal area at similar amount and percentage of body fats, leptin production is higher and insulin resistance develops. In the gynoid type of adipose tissue predisposition, overt insulin resistance is not found, leptin levels does not differ significantly from those in the control group.

[Antiradical activity and resistance of flaxseed oil enriched with the antioxidants to oxidative changes].

PubMed

Guseva, D A; Prozorovskaia, N N; Rusina, I F; Ipatova, O M

2008-01-01

Using the chemiluminescence technique, the effective concentration of antioxidants (AO) and its reactivity towards peroxyl radicals (constant k7) have been measured for the oil "Ubicato-flax" (biological active supplement) and flaxseed oil, enriched with Aronia melanocarpa extract. Ubicato-flax exhibited the highest antiradical activity but it was less resistant to oxidative changes as compared with flaxseed oil + extract. Ubicato oil produced on basis of natural AO exhibited higher antiradical activity in comparison with Ubicato oil produced on basis of the chemical synthetic AO. Aronia extract added to flaxseed oil caused marked inhibition of the increase in the peroxide value. Ubicato-flax may serve as a source of AO for not more than 6 months.

Analysis of Laser Injection Condition and Electrical Properties in Local BSF for Laser Fired Contact c-Si Solar Cell Applications.

PubMed

Park, Cheolmin; Choi, Gyuho; Balaji, Nagarajan; Ju, Minkyu; Lee, Youn-Jung; Lee, Haeseok; Yi, Junsin

2018-07-01

A crystalline silicon (c-Si) local-back-contact (LBC) solar cell for which a laser-condition-optimized surface-recombination velocity (SRV), a contact resistance (Rc), and local back surface fields (LBSFs) were utilized is reported. The effect of the laser condition on the rear-side electrical properties of the laser-fired LBC solar cell was studied. The Nd:YAG-laser (1064-nm wavelength) power and frequency were varied to obtain LBSF values with a lower contact resistance. A 10-kHz laser power of 44 mW resulted in an Rc of 0.125 ohms with an LBSF thickness of 2.09 μm and a higher open-circuit voltage (VOC) of 642 mV.

Reference values for airway resistance in newborns, infants and preschoolers from a Latin American population.

PubMed

Gochicoa, Laura G; Thomé-Ortiz, Laura P; Furuya, María E Y; Canto, Raquel; Ruiz-García, Martha E; Zúñiga-Vázquez, Guillermo; Martínez-Ramírez, Filiberto; Vargas, Mario H

2012-05-01

Several studies have determined reference values for airway resistance measured by the interrupter technique (Rint) in paediatric populations, but only one has been done on Latin American children, and no studies have been performed on Mexican children. Moreover, these previous studies mostly included children aged 3 years and older; therefore, information regarding Rint reference values for newborns and infants is scarce. Rint measurements were performed on preschool children attending eight kindergartens (Group 1) and also on sedated newborns, infants and preschool children admitted to a tertiary-level paediatric hospital due to non-cardiopulmonary disorders (Group 2). In both groups, Rint values were inversely associated with age, weight and height, but the strongest association was with height. The linear regression equation for Group 1 (n = 209, height 86-129 cm) was Rint = 2.153 - 0.012 × height (cm) (standard deviation of residuals 0.181 kPa/L/s). The linear regression equation for Group 2 (n = 55, height 52-113 cm) was Rint = 4.575 - 0.035 × height (cm) (standard deviation of residuals 0.567 kPa/L/s). Girls tended to have slightly higher Rint values than boys, a difference that diminished with increasing height. In this study, Rint reference values applicable to Mexican children were determined, and these values are probably also applicable to other paediatric populations with similar Spanish-Amerindian ancestries. There was an inverse relationship between Rint and height, with relatively large between-subject variability. © 2012 The Authors. Respirology © 2012 Asian Pacific Society of Respirology.

Unraveling resistive versus collisional contributions to relativistic electron beam stopping power in cold-solid and in warm-dense plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vauzour, B.; Laboratoire d'Optique Appliquée, ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau; Debayle, A.

2014-03-15

We present results on laser-driven relativistic electron beam propagation through aluminum samples, which are either solid and cold or compressed and heated by laser-induced shock. A full numerical description of fast electron generation and transport is found to reproduce the experimental absolute K{sub α} yield and spot size measurements for varying target thicknesses, and to sequentially quantify the collisional and resistive electron stopping powers. The results demonstrate that both stopping mechanisms are enhanced in compressed Al samples and are attributed to the increase in the medium density and resistivity, respectively. For the achieved time- and space-averaged electronic current density, 〈j{submore » h}〉∼8×10{sup 10} A/cm{sup 2} in the samples, the collisional and resistive stopping powers in warm and compressed Al are estimated to be 1.5 keV/μm and 0.8 keV/μm, respectively. By contrast, for cold and solid Al, the corresponding estimated values are 1.1 keV/μm and 0.6 keV/μm. Prospective numerical simulations involving higher j{sub h} show that the resistive stopping power can reach the same level as the collisional one. In addition to the effects of compression, the effect of the transient behavior of the resistivity of Al during relativistic electron beam transport becomes progressively more dominant, and for a significantly high current density, j{sub h}∼10{sup 12} A/cm{sup 2}, cancels the difference in the electron resistive stopping power (or the total stopping power in units of areal density) between solid and compressed samples. Analytical calculations extend the analysis up to j{sub h}=10{sup 14} A/cm{sup 2} (representative of the full-scale fast ignition scenario of inertial confinement fusion), where a very rapid transition to the Spitzer resistivity regime saturates the resistive stopping power, averaged over the electron beam duration, to values of ∼1 keV/μm.« less

Evaluation of Aspirin and Clopidogrel resistance in patients with Acute Coronary Syndrome by using Adenosine Diposphate Test and Aspirin Test

PubMed Central

O, Ibrahim; M, Oteh; A, A Syukur; HH, Che Hassan; W, S Fadilah; Rahman, MM

2013-01-01

Objectives: To evaluate Aspirin and Clopidogrel resistance/non-responders in patients with acute coronary syndrome (ACS) by using adenosine diposphate and aspirin tests. Methodology: In the study patients with ACS loaded with 300 mg of clopidogrel and 300 mg aspirin and patients on stable daily dose of 75 mg of clopidogrel (more than 3 days) underwent PCI. Response to clopidogrel and Aspirin was assessed by Adenosine Diphosphate (ADP) Test (20 µmol/L) and Aspirin Test (Acetyl Acid) (ASP) 20 µmol/L, respectively, using the Multiplate Platelet Function Analyzer (Dynabyte Medical, Munich, Germany). Results: Sixty four patients were included in this study out of which 57 were with ACS and 7 scheduled for percutaneous coronary intervention (PCI) electively. The proportion of Aspirin good responders and adequate responders were 76.56% and 18.75%, respectively while adequate response and good response to Clopidogrel accounted for 29.7 and 48.4%, respectively Hyperlipidaemia was only co-morbidity associated with higher AUC ADP value (p: 0.046). Hypertriglyceridaemia and serum calcium were weakly correlated with higher AUC ADP serum calcium r=0.08, triglyceride r=0.12. Patients admitted for scheduled PCI and on stable dose of 75mg clopidogrel exhibited lower AUC ADP value as compared to those admitted with acute coronary syndrome given loading dose of 300mg of Clopidogrel. Post loading dose measurement of anti-platelet therapy among ACS patients using the Multiplate Platelet Function Analyzer showed comparable results with other methods. Conclusions : As determined by Multiplate Platelet Function Analyzer, Aspirin resistance/non-responders in this study in acute coronary syndrome patients accounted for 4.69% while Non-responders in Clopidogrel was 21.9%. PMID:24353516

Fire resistant behaviour of cellulosic textile functionalized with wastage plant bio-molecules: A comparative scientific report.

PubMed

Basak, Santanu; Wazed Ali, S

2018-07-15

Three different wastage plant based bio-molecules named banana peel powder (Musa acuminata) (BPP), coconut shell (Cocos nucifera) extract (CSE) and pomegranate rind (Punica granatum) extract (PRE) have been explored as fire resistant material on the cellulosic polymer (cotton fabric). To this end, extracts have been applied to the cotton fabric in different concentration at elevated temperature for specific time period. Treated cotton fabric showed 6 (BPP), 8.5 (CSE) and 12 (PRE) times lower vertical burning rate compared to the control cotton fabric. Thermo-gravimetry (TG) curves and the limiting oxygen index (LOI) value revealed that the PRE extract (LOI: 32) treated fabric encompassed more thermal stability compared to the BPP (LOI:26) and the CSE (LOI: 27) treated fabric as it showed higher oxygen index and more weight retention (40%) at higher temperature 450°C. Moreover, the carbonaceous samples remained after the burning of the extracts and the treated fabrics showed structural integration and more carbon content [65.6 (PRE extract) and 76.3% (PRE treated cotton)] compared to the fragile, net like char of the control cotton fabric, having less carbon content (49.8%). Gas Chromatography Mass spectroscopy (GC-MS) of the different extracts (CSE, PRE, BPP) used for the study showed the presence of high molecular weight aromatic phenolic compounds, tannin based compound and the nitrogen containing alkaloids, responsible for fire resistant effect of the different extract treated fabric. Besides fire retardancy, all the treated fabric showed attractive natural colour (measured by colour strength values) and there has been no adverse effect on the tensile strength property of the fabric after the treatment. Copyright © 2018 Elsevier B.V. All rights reserved.

Insulin secretion and insulin resistance in Korean women with gestational diabetes mellitus and impaired glucose tolerance

PubMed Central

Yang, Sae Jeong; Kim, Tae Nyun; Baik, Sei Hyun; Kim, Tae Sun; Lee, Kwan Woo; Nam, Moonsuk; Park, Yong Soo; Woo, Jeong-Teak; Kim, Young Seol

2013-01-01

Background/Aims The aim was to compare the insulin sensitivity and secretion index of pregnant Korean women with normal glucose tolerance (NGT), gestational impaired glucose tolerance (GIGT; only one abnormal value according to the Carpenter and Coustan criteria), and gestational diabetes mellitus (GDM). Methods A cross-sectional study was performed with 1,163 pregnant women with positive (1-hour plasma glucose ≥ 7.2 mmol/L) in a 50-g oral glucose challenge test (OGCT). The 100-g oral glucose tolerance test (OGTT) was used to stratify the participants into three groups: NGT (n = 588), GIGT (n = 294), and GDM (n = 281). Results The GDM group had higher homeostasis model assessment of insulin resistance and lower insulin sensitivity index (ISOGTT), quantitative insulin sensitivity check index, homeostasis model assessment for estimation of index β-cell secretion (HOMA-B), first and second phase insulin secretion, and insulin secretion-sensitivity index (ISSI) than the NGT group (p ≤ 0.001 for all). Moreover, the GIGT group had lower ISOGTT, HOMA-B, first and second phase insulin secretion, and ISSI than the NGT group (p < 0.001 for all). Among the GIGT subjects, the 1-hour plasma glucose abnormal levels group showed significantly greater weight gain during pregnancy and higher values in the 50-g OGCT than the other two groups. Moreover, the 1-hour and 2-hour abnormal levels groups had poorer insulin secretion status than the 3-hour abnormal levels group. Conclusions Korean women with GDM show impairments of both insulin secretion and insulin sensitivity. In addition, GIGT is associated with both β-cell dysfunction and insulin resistance. PMID:23682224

Influence of critical closing pressure on systemic vascular resistance and total arterial compliance: A clinical invasive study.

PubMed

Chemla, Denis; Lau, Edmund M T; Hervé, Philippe; Millasseau, Sandrine; Brahimi, Mabrouk; Zhu, Kaixian; Sattler, Caroline; Garcia, Gilles; Attal, Pierre; Nitenberg, Alain

2017-12-01

Systemic vascular resistance (SVR) and total arterial compliance (TAC) modulate systemic arterial load, and their product is the time constant (Tau) of the Windkessel. Previous studies have assumed that aortic pressure decays towards a pressure asymptote (P∞) close to 0mmHg, as right atrial pressure is considered the outflow pressure. Using these assumptions, aortic Tau values of ∼1.5seconds have been documented. However, a zero P∞ may not be physiological because of the high critical closing pressure previously documented in vivo. To calculate precisely the Tau and P∞ of the Windkessel, and to determine the implications for the indices of systemic arterial load. Aortic pressure decay was analysed using high-fidelity recordings in 16 subjects. Tau was calculated assuming P∞=0mmHg, and by two methods that make no assumptions regarding P∞ (the derivative and best-fit methods). Assuming P∞=0mmHg, we documented a Tau value of 1372±308ms, with only 29% of Windkessel function manifested by end-diastole. In contrast, Tau values of 306±109 and 353±106ms were found from the derivative and best-fit methods, with P∞ values of 75±12 and 71±12mmHg, and with ∼80% completion of Windkessel function. The "effective" resistance and compliance were ∼70% and ∼40% less than SVR and TAC (area method), respectively. We did not challenge the Windkessel model, but rather the estimation technique of model variables (Tau, SVR, TAC) that assumes P∞=0. The study favoured a shorter Tau of the Windkessel and a higher P∞ compared with previous studies. This calls for a reappraisal of the quantification of systemic arterial load. Crown Copyright © 2017. Published by Elsevier Masson SAS. All rights reserved.

Development of three-dimensional lung multicellular spheroids in air- and liquid-interface culture for the evaluation of anticancer therapeutics.

PubMed

Meenach, Samantha A; Tsoras, Alexandra N; McGarry, Ronald C; Mansour, Heidi M; Hilt, J Zach; Anderson, Kimberly W

2016-04-01

Three-dimensional (3D) lung multicellular spheroids (MCS) in liquid-covered culture (LCC) and air-interface culture (AIC) conditions have both been developed for the evaluation of aerosol anticancer therapeutics in solution and aerosols, respectively. The MCS were formed by seeding lung cancer cells on top of collagen where they formed spheroids due to the prevalence of cell-to-cell interactions. LCC MCS were exposed to paclitaxel (PTX) in media whereas AIC MCS were exposed to dry powder PEGylated phospholipid aerosol microparticles containing paclitaxel. The difference in viability for 2D versus 3D culture for both LCC and AIC was evaluated along with the effects of the particles on lung epithelium via transepithelial electrical resistance (TEER) measurements. For LCC and AIC conditions, the 3D spheroids were more resistant to treatment with higher IC50 values for A549 and H358 cell lines. TEER results initially indicated a decrease in resistance upon drug or particle exposure, however, these values increased over the course of several days indicating the ability of the cells to recover. Overall, these studies offer a comprehensive in vitro evaluation of aerosol particles used in the treatment of lung cancer while introducing a new method for culturing lung cancer MCS in both LCC and AIC conditions.

Fabrication of Nd3+ and Mn2+ ions Co-doped Spinal Strontium Nanoferrites for High Frequency Device Applications

NASA Astrophysics Data System (ADS)

Ahmad, Iqbal; Shah, Syed Mujtaba; Ashiq, Muhammad Naeem; Nawaz, Faisal; Shah, Afzal; Siddiq, Muhammad; Fahim, Iqra; Khan, Samiullah

2016-10-01

Microemulsion method has been used for the synthesis of high resistive spinal nanoferrites with nominal composition Sr1- x Nd x Fe2- y Mn y O4 (0.0 ≤ x ≤ 0.1, 0.0 ≤ y ≤ 1.0) for high frequency device applications. It has been confirmed by x-ray diffraction (XRD) results that these ferrites have a cubic spinal structure with a mean crystallite size ranging from 34 mm to 47 nm. The co-substitution of Nd3+ and Mn2+ ions was performed, and its effect on electrical, dielectric and impedance properties was analyzed employing direct current (DC) resistivity measurements, dielectric measurements and electrochemical impedance spectroscopy (EIS). The DC resistivity ( ρ) value was the highest for the composition Sr0.90Nd0.1FeMnO4, but for the same composition, dielectric parameters and alternating current (AC) conductivity showed their minimum values. In the lower frequency range, the magnitudes of dielectric parameters decrease with increasing frequency and show an almost independent frequency response at higher frequencies. Dielectric polarization has been employed to explain these results. It was inferred from the results of EIS that the conduction process in the studied ferrite materials is predominantly governed by grain boundary volume.

Frost hardening and dehardening potential in temperate trees from winter to budburst.

PubMed

Vitra, Amarante; Lenz, Armando; Vitasse, Yann

2017-10-01

We investigated how deciduous trees can adjust their freezing resistance in response to temperature during the progress of the ecodormancy phase, from midwinter to budburst. We regularly sampled twigs of four different temperate deciduous tree species from January to the leaf-out date. Using computer-controlled freezers and climate chambers, the freezing resistance of buds was measured directly after sampling and also after the application of artificial hardening and dehardening treatments, simulating cold and warm spells. The thermal time to budburst in forcing conditions (c. 20°C) was also quantified at each sampling as a proxy for dormancy depth. Earlier flushing species showed higher freezing resistance than late flushing species at either similar bud development stage or similar dormancy depth. Overall, freezing resistance and its hardening and dehardening potential dramatically decreased during the progress of ecodormancy and became almost nil during budburst. Our results suggest that extreme cold events in winter are not critical for trees, as freezing resistance can be largely enhanced during this period. By contrast, the timing of budburst is a critical component of tree fitness. Our results provide quantitative values of the freezing resistance dynamics during ecodormancy, particularly valuable in process-based species distribution models. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Slip resistance of casual footwear: implications for falls in older adults.

PubMed

Menz, H B; Lord, S T; McIntosh, A S

2001-01-01

A large proportion of falls in older people are caused by slipping. Previous occupational safety research suggests that inadequate footwear may contribute to slipping accidents; however, no studies have assessed the slip resistance of casual footwear. To evaluate the slip resistance of different types of casual footwear over a range of common household surfaces. The slip resistance of men's Oxford shoes and women's fashion shoes with different heel configurations was determined by measuring the dynamic coefficient of friction (DCoF) at heel contact (in both dry and wet conditions) on a bathroom tile, concrete, vinyl flooring and a terra cotta tile using a specially-designed piezoelectric force plate apparatus. Analysis of variance revealed significant shoe, surface, and shoe-surface interaction effects. Men's Oxford shoes exhibited higher average DCoF values than the women's fashion shoes, however, none of the shoes could be considered safe on wet surfaces. Application of a textured sole material did not improve slip resistance of any of the shoes on wet surfaces. Heel geometry influences the slip resistance of casual footwear on common household surfaces. The suboptimal performance of all of the test shoes on wet surfaces suggests that a safety standard for casual footwear is required to assist in the development of safe footwear for older people. Copyright 2001 S. Karger AG, Basel

The effect of thermal treatment on the resistance of nickel-titanium rotary files in cyclic fatigue.

PubMed

Zinelis, Spiros; Darabara, Myrsini; Takase, Toshiyuki; Ogane, Kaoru; Papadimitriou, George D

2007-06-01

The purpose of this study was to determine the effect of various thermal treatments on the fatigue resistance of a nickel-titanium (NiTi) engine-driven endodontic file. Fifteen groups of 5 files each of ISO 30 and taper .04 were tested in this study. The cutting tip (5 mm from the end) of files from 14 groups were heat treated for 30 minutes in temperatures 250 degrees C, 300 degrees C, 350 degrees C, 375 degrees C, 400 degrees C, 410 degrees C, 420 degrees C, 425 degrees C, 430 degrees C, 440 degrees C, 450 degrees C, 475 degrees C, 500 degrees C, and 550 degrees C, respectively, while 1 group was used as reference. The files were placed in a device that allowed the instruments to be tested for rotating bending fatigue inside an artificial root canal. The number of rotations to breakage was recorded for each file. The mean values of all groups were statistically analyzed using 1-way analysis of variance and Student Newman Keuls multiple comparison test at alpha = .05. The 430 degrees C and 440 degrees C groups showed the highest values, with fatigue resistance decreasing for thermal treatment at lower and higher temperatures. This may be the result of metallurgical changes during annealing. Within the limitations of the low sample size and the specific instrument size tested, it appears that the appropriate thermal treatment may significantly increase the fatigue resistance of the NiTi file tested.

Identification of novel tyrosine kinase inhibitors for drug resistant T315I mutant BCR-ABL: a virtual screening and molecular dynamics simulations study

NASA Astrophysics Data System (ADS)

Banavath, Hemanth Naick; Sharma, Om Prakash; Kumar, Muthuvel Suresh; Baskaran, R.

2014-11-01

BCR-ABL tyrosine kinase plays a major role in the pathogenesis of chronic myeloid leukemia (CML) and is a proven target for drug development. Currently available drugs in the market are effective against CML; however, side-effects and drug-resistant mutations in BCR-ABL limit their full potential. Using high throughput virtual screening approach, we have screened several small molecule databases and docked against wild-type and drug resistant T315I mutant BCR-ABL. Drugs that are currently available, such as imatinib and ponatinib, were also docked against BCR-ABL protein to set a cutoff value for our screening. Selected lead compounds were further evaluated for chemical reactivity employing density functional theory approach, all selected ligands shows HLG value > 0.09900 and the binding free energy between protein-ligand complex interactions obtained was rescored using MM-GBSA. The selected compounds showed least ΔG score -71.53 KJ/mol to maximum -126.71 KJ/mol in both wild type and drug resistant T315I mutant BCR-ABL. Following which, the stability of the docking complexes were evaluated by molecular dynamics simulation (MD) using GROMACS4.5.5. Results uncovered seven lead molecules, designated with Drug-Bank and PubChem ids as DB07107, DB06977, ST013616, DB04200, ST007180 ST019342, and DB01172, which shows docking scores higher than imatinib and ponatinib.

Inappropriate Use of Homeostasis Model Assessment Cutoff Values for Diagnosing Insulin Resistance in Pediatric Studies.

PubMed

Fox, Carrie; Bernardino, Lourdes; Cochran, Jill; Essig, Mary; Bridges, Kristie Grove

2017-11-01

Assessing pediatric patients for insulin resistance is one way to identify those who are at a high risk of developing type 2 diabetes mellitus. The homoeostasis model assessment (HOMA) is a measure of insulin resistance based on fasting blood glucose and insulin levels. Although this measure is widely used in research, cutoff values for pediatric populations have not been established. To assess the validity of HOMA cutoff values used in pediatric studies published in peer-reviewed journals. Studies published from January 2010 to December 2015 were identified through MEDLINE. Initial screening of abstracts was done to select studies that were conducted in pediatric populations and used HOMA to assess insulin resistance. Subsequent full-text review narrowed the list to only those studies that used a specific HOMA score to diagnose insulin resistance. Each study was classified as using a predetermined fixed HOMA cutoff value or a cutoff that was a percentile specific to that population. For studies that used a predetermined cutoff value, the references cited to provide evidence in support of that cutoff were evaluated. In the 298 articles analyzed, 51 different HOMA cutoff values were used to classify patients as having insulin resistance. Two hundred fifty-five studies (85.6%) used a predetermined fixed cutoff value, but only 72 (28.2%) of those studies provided a reference that supported its use. One hundred ten studies (43%) that used a fixed cutoff either cited a study that did not mention HOMA or provided no reference at all. Tracing of citation history indicated that the most commonly used cutoff values were ultimately based on studies that did not validate their use for defining insulin resistance. Little evidence exists to support HOMA cutoff values commonly used to define insulin resistance in pediatric studies. These findings highlight the importance of validating study design elements when training medical students and novice investigators. Using available data to generate population ranges for HOMA would improve its clinical utility.

Acquired resistance to chlorhexidine - is it time to establish an 'antiseptic stewardship' initiative?

PubMed

Kampf, G

2016-11-01

Chlorhexidine digluconate (CHG) is an antimicrobial agent used for different types of applications in hand hygiene, skin antisepsis, oral care, and patient washing. Increasing use raises concern regarding development of acquired bacterial resistance. Published data from clinical isolates with CHG minimum inhibitory concentrations (MICs) were reviewed and compared to epidemiological cut-off values to determine resistance. CHG resistance is rarely found in Escherichia coli, Salmonella spp., Staphylococcus aureus or coagulase-negative staphylococci. In Enterobacter spp., Pseudomonas spp., Proteus spp., Providencia spp. and Enterococcus spp., however, isolates are more often CHG resistant. CHG resistance may be detected in multi-resistant isolates such as extremely drug-resistant Klebsiella pneumoniae. Isolates with a higher MIC are often less susceptible to CHG for disinfection. Although cross-resistance to antibiotics remains controversial, some studies indicate that the overall exposure to CHG increases the risk for resistance to some antibiotic agents. Resistance to CHG has resulted in numerous outbreaks and healthcare-associated infections. On an average intensive care unit, most of the CHG exposure would be explained by hand hygiene agents when liquid soaps or alcohol-based hand rubs contain CHG. Exposure to sub-lethal CHG concentration may enhance resistance in Acinetobacter spp., K. pneumoniae, and Pseudomonas spp., all species well known for emerging antibiotic resistance. In order to reduce additional selection pressure in nosocomial pathogens it seems to make sense to restrict the valuable agent CHG to those indications with a clear patient benefit and to eliminate it from applications without any benefit or with a doubtful benefit. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Evaluation of the users value of salts against apple scab and powdery mildew for the integrated fruit production.

PubMed

Creemers, P; Van Laer, S; Van Mechelen, A; Vorstermans, B; Hauke, K

2007-01-01

As new fungicides are mainly unisite action fungicides, the problem of fungicide resistance development is becoming more important every year. Combining chemical fungicides, which is the best anti-resistance strategy, is not always possible or recommended in the case when the number of available chemical fungicides are limited or a reduction in fungicide use is asked for. Therefore the use of salts as an anti-resistance strategy was looked upon. The salts evaluated were K(HCO3), KH2PO3, KHPO4 and K2SiO3. When using these salts as an anti-resistance strategy the efficacy obtained when spraying the compounds alone was often to low to be used in rotation with chemical fungicides. Only with K(HCO3)2 a good efficacy can be observed in some years. The variation in efficacy with K(HCO3)2 observed is higher for powdery mildew. Chitosan was also included in the trials against powdery mildew, however chitosan had no effect on the infestation.

Effects of three related amides on microecosystem stability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flum, T.F.; Shannon, L.J.

1987-04-01

Three related amides (diuron, 2-(octyloxy) acetanilide, and salicylanilide) were evaluated for toxicity to aquatic microcosm communities. Effects were measured at the ecosystem level using changes in pH, Eh (redox potential), and dissolved oxygen as indicators of toxicity. These values were used to calculate the resistance, resilience, and relative instability of the microecosystems to each compound at comparable dose levels of approximately 2500 micrograms/liter. Such measures have often been used in a theoretical context, but have not received wide practical application. The systems showed low resistance and no resilience to diuron, high resistance and low resilience to 2-(octyloxy) acetanilide, and nomore » response to salicylanilide. At a higher exposure level (9800 micrograms/liter salicylanilide), the systems showed low resistance and high resilience. Both this approach and more traditional dose-response measures of toxicity indicated that diuron was clearly the most toxic compound, followed by 2-(octyloxy) acetanilide and salicylanilide. While microcosm toxicity tests were slightly less sensitive than some single species tests, they provided important additional information on the extent of perturbations and the rate of ecosystem recovery.« less

Development of MATLAB Scripts for the Calculation of Thermal Manikin Regional Resistance Values

DTIC Science & Technology

2016-01-01

CALCULATION OF THERMAL MANIKIN REGIONAL RESISTANCE VALUES DISCLAIMER The opinions or assertions contained herein are the private views of the...USARIEM TECHNICAL NOTE TN16-1 DEVELOPMENT OF MATLAB® SCRIPTS FOR THE CALCULATION OF THERMAL MANIKIN REGIONAL RESISTANCE VALUES...performed by thermal manikin and modeling personnel. Steps to operate the scripts as well as the underlying calculations are outlined in detail

Electrically Variable Resistive Memory Devices

NASA Technical Reports Server (NTRS)

Liu, Shangqing; Wu, Nai-Juan; Ignatiev, Alex; Charlson, E. J.

2010-01-01

Nonvolatile electronic memory devices that store data in the form of electrical- resistance values, and memory circuits based on such devices, have been invented. These devices and circuits exploit an electrically-variable-resistance phenomenon that occurs in thin films of certain oxides that exhibit the colossal magnetoresistive (CMR) effect. It is worth emphasizing that, as stated in the immediately preceding article, these devices function at room temperature and do not depend on externally applied magnetic fields. A device of this type is basically a thin film resistor: it consists of a thin film of a CMR material located between, and in contact with, two electrical conductors. The application of a short-duration, low-voltage current pulse via the terminals changes the electrical resistance of the film. The amount of the change in resistance depends on the size of the pulse. The direction of change (increase or decrease of resistance) depends on the polarity of the pulse. Hence, a datum can be written (or a prior datum overwritten) in the memory device by applying a pulse of size and polarity tailored to set the resistance at a value that represents a specific numerical value. To read the datum, one applies a smaller pulse - one that is large enough to enable accurate measurement of resistance, but small enough so as not to change the resistance. In writing, the resistance can be set to any value within the dynamic range of the CMR film. Typically, the value would be one of several discrete resistance values that represent logic levels or digits. Because the number of levels can exceed 2, a memory device of this type is not limited to binary data. Like other memory devices, devices of this type can be incorporated into a memory integrated circuit by laying them out on a substrate in rows and columns, along with row and column conductors for electrically addressing them individually or collectively.

Influence of ferrule preparation with or without glass fiber post on fracture resistance of endodontically treated teeth

PubMed Central

de LIMA, Alexandra Furtado; SPAZZIN, Aloísio Oro; GALAFASSI, Daniel; CORRER-SOBRINHO, Lourenço; CARLINI-JÚNIOR, Bruno

2010-01-01

Objective This study evaluated the effect of ferrule preparation (Fp) on the fracture resistance of endodontically treated teeth, restored with composite resin cores with or without glass fiber posts. Material and Methods Forty-four bovine teeth were sectioned 19 or 17 mm (2 mm ferrule) from the apex, endodontically treated and assigned to four groups (n = 11): Group 1: Fp and post; Group 2: Fp and without post; Group 3: without Fp and with post; Group 4: without Fp and without post. All specimens were restored with composite resin core and metal crown. Specimens were subjected to fracture resistance testing in a universal testing machine at a crosshead speed of 0.5 mm/min. The data were analyzed by two-way ANOVA and Tukey’s tests (α=0.05). Results The mean fracture resistance values were as follows: Group 1: 573.3 N; Group 2: 552.5 N; Group 3: 275.3 N; Group 4: 258.6 N. Significantly higher fracture resistance was found for the groups with Fp (p<0.001). Conclusion There was no statistically significant interaction between the "Fp" and "post" factors (p = 0.954). The ferrule preparation increased the fracture resistance of endodontically treated teeth. However, the use of glass fiber post showed no significant influence on the fracture resistance. PMID:20835570

Flow resistance and hydraulic geometry in contrasting reaches of a bedrock channel

NASA Astrophysics Data System (ADS)

Ferguson, R. I.; Sharma, B. P.; Hardy, R. J.; Hodge, R. A.; Warburton, J.

2017-03-01

Assumptions about flow resistance in bedrock channels have to be made for mechanistic modeling of river incision, paleoflood estimation, flood routing, and river engineering. Field data on bedrock flow resistance are very limited and calculations generally use standard alluvial-river assumptions such as a fixed value of Manning's n. To help inform future work, we measured how depth, velocity, and flow resistance vary with discharge in four short reaches of a small bedrock channel, one with an entirely rock bed and the others with 20-70% sediment cover, and in the alluvial channel immediately upstream. As discharge and submergence increase in each of the partly or fully alluvial reaches there is a rapid increase in velocity and a strong decline in both n and the Darcy-Weisbach friction factor f. The bare-rock reach follows a similar trend from low to medium discharge but has increasing resistance at higher discharges because of the macroroughness of its rock walls. Flow resistance at a given discharge differs considerably between reaches and is highest where the partial sediment cover is coarsest and most extensive. Apart from the effect of rough rock walls, the flow resistance trends are qualitatively consistent with logarithmic and variable-power equations and with nondimensional hydraulic geometry, but quantitative agreement using sediment D84 as the roughness height is imperfect.

Mitochondrial “power” drives tamoxifen resistance: NQO1 and GCLC are new therapeutic targets in breast cancer

PubMed Central

Fiorillo, Marco; Sotgia, Federica; Sisci, Diego; Cappello, Anna Rita; Lisanti, Michael P.

2017-01-01

Here, we identified two new molecular targets, which are functionally sufficient to metabolically confer the tamoxifen-resistance phenotype in human breast cancer cells. Briefly, ~20 proteins were first selected as potential candidates, based on unbiased proteomics analysis, using tamoxifen-resistant cell lines. Then, the cDNAs of the most promising candidates were systematically transduced into MCF-7 cells. Remarkably, NQO1 and GCLC were both functionally sufficient to autonomously confer a tamoxifen-resistant metabolic phenotype, characterized by i) increased mitochondrial biogenesis, ii) increased ATP production and iii) reduced glutathione levels. Thus, we speculate that pharmacological inhibition of NQO1 and GCLC may be new therapeutic strategies for overcoming tamoxifen-resistance in breast cancer patients. In direct support of this notion, we demonstrate that treatment with a known NQO1 inhibitor (dicoumarol) is indeed sufficient to revert the tamoxifen-resistance phenotype. As such, these findings could have important translational significance for the prevention of tumor recurrence in ER(+) breast cancers, which is due to an endocrine resistance phenotype. Importantly, we also show here that NQO1 has significant prognostic value as a biomarker for the prediction of tumor recurrence. More specifically, higher levels of NQO1 mRNA strongly predict patient relapse in high-risk ER(+) breast cancer patients receiving endocrine therapy (mostly tamoxifen; H.R. > 2.15; p = 0.007). PMID:28411284

Increased Glycolytic ATP Synthesis Is Associated with Tafenoquine Resistance in Leishmania major▿

PubMed Central

Manzano, José Ignacio; Carvalho, Luis; Pérez-Victoria, José M.; Castanys, Santiago; Gamarro, Francisco

2011-01-01

Tafenoquine (TFQ), an 8-aminoquinoline used to treat and prevent Plasmodium infections, could represent an alternative therapy for leishmaniasis. Indeed, TFQ has shown significant leishmanicidal activity both in vitro and in vivo, where it targets Leishmania mitochondria and activates a final apoptosis-like process. In order not to jeopardize the life span of this potential antileishmania drug, it is important to determine the likelihood that Leishmania will develop resistance to TFQ and the mechanisms of resistance induced. To address this issue, a TFQ-resistant Leishmania major promastigote line (R4) was selected. This resistance, which is unstable in a drug-free medium (revertant line), was maintained in intramacrophage amastigote forms, and R4 promastigotes were found to be cross-resistant to other 8-aminoquinolines. A decreased TFQ uptake, which is probably associated with an alkalinization of the intracellular pH rather than drug efflux, was observed for both the R4 and revertant lines. TFQ induces a decrease in ATP synthesis in all Leishmania lines, although total ATP levels were maintained at higher values in R4 parasites. In contrast, ATP synthesis by glycolysis was significantly increased in R4 parasites, whereas mitochondrial ATP synthesis was similar to that in wild-type parasites. We therefore conclude that increased glycolytic ATP synthesis is the main mechanism underlying TFQ resistance in Leishmania. PMID:21199921

Increased glycolytic ATP synthesis is associated with tafenoquine resistance in Leishmania major.

PubMed

Manzano, José Ignacio; Carvalho, Luis; Pérez-Victoria, José M; Castanys, Santiago; Gamarro, Francisco

2011-03-01

Tafenoquine (TFQ), an 8-aminoquinoline used to treat and prevent Plasmodium infections, could represent an alternative therapy for leishmaniasis. Indeed, TFQ has shown significant leishmanicidal activity both in vitro and in vivo, where it targets Leishmania mitochondria and activates a final apoptosis-like process. In order not to jeopardize the life span of this potential antileishmania drug, it is important to determine the likelihood that Leishmania will develop resistance to TFQ and the mechanisms of resistance induced. To address this issue, a TFQ-resistant Leishmania major promastigote line (R4) was selected. This resistance, which is unstable in a drug-free medium (revertant line), was maintained in intramacrophage amastigote forms, and R4 promastigotes were found to be cross-resistant to other 8-aminoquinolines. A decreased TFQ uptake, which is probably associated with an alkalinization of the intracellular pH rather than drug efflux, was observed for both the R4 and revertant lines. TFQ induces a decrease in ATP synthesis in all Leishmania lines, although total ATP levels were maintained at higher values in R4 parasites. In contrast, ATP synthesis by glycolysis was significantly increased in R4 parasites, whereas mitochondrial ATP synthesis was similar to that in wild-type parasites. We therefore conclude that increased glycolytic ATP synthesis is the main mechanism underlying TFQ resistance in Leishmania.

Effect of Atomic Oxygen Exposure on Surface Resistivity Change of Spacecraft Insulator Material

NASA Astrophysics Data System (ADS)

Mundari, Noor Danish Ahrar; Khan, Arifur Rahman; Chiga, Masaru; Okumura, Teppei; Masui, Hirokazu; Iwata, Minoru; Toyoda, Kazuhiro; Cho, Mengu

Spacecraft surface charging can lead to arcing and a loss of electricity generation capability in solar panels or even loss of a satellite. The charging problem may be further aggravated by atomic oxygen (AO) exposure in Low Earth orbits, which modifies the surface of materials like polyimide, Teflon, anti-reflective coatings, cover glass etc, used on satellite surfaces, affecting materials properties, such as resistivity, secondary electron emissivity and photo emission, which govern the charging behavior. These properties are crucial input parameters for spacecraft charging analysis. To study the AO exposure effect on charging governing properties, an atomic oxygen exposure facility based on laser detonation of oxygen was built. The facility produces AO with a peak velocity value around 10-12km/s and a higher flux than that existing in orbit. After exposing the polyimide test material to the equivalent of 10 years of AO fluence at an altitude of 700-800 km, surface charging properties like surface resistivity and volume resistivity were measured. The measurement was performed in a vacuum using the charge storage decay method at room temperature, which is considered the most appropriate for measuring resistivity for space applications. The results show that the surface resistivity increases and the volume resistivity remains almost the same for the AO exposure fluence of 5.4×1018 atoms cm-2.

Splice form variant and amino acid changes in MDR49 confers DDT resistance in transgenic Drosophila

PubMed Central

Seong, Keon Mook; Sun, Weilin; Clark, John M.; Pittendrigh, Barry R.

2016-01-01

The ATP-binding cassette (ABC) transporters represent a superfamily of proteins that have important physiological roles in both prokaryotes and eukaryotes. In insects, ABC transporters have previously been implicated in insecticide resistance. The 91-R strain of Drosophila melanogaster has been intensely selected with DDT over six decades. A recent selective sweeps analysis of 91-R implicated the potential role of MDR49, an ABC transporter, in DDT resistance, however, to date the details of how MDR49 may play a role in resistance have not been elucidated. In this study, we investigated the impact of structural changes and an alternative splicing event in MDR49 on DDT-resistance in 91-R, as compared to the DDT susceptible strain 91-C. We observed three amino acid differences in MDR49 when 91-R was compared with 91-C, and only one isoform (MDR49B) was implicated in DDT resistance. A transgenic Drosophila strain containing the 91-R-MDR49B isoform had a significantly higher LD50 value as compared to the 91-C-MDR49B isoform at the early time points (6 h to 12 h) during DDT exposure. Our data support the hypothesis that the MDR49B isoform, with three amino acid mutations, plays a role in the early aspects of DDT resistance in 91-R. PMID:27003579

Splice form variant and amino acid changes in MDR49 confers DDT resistance in transgenic Drosophila.

PubMed

Seong, Keon Mook; Sun, Weilin; Clark, John M; Pittendrigh, Barry R

2016-03-22

The ATP-binding cassette (ABC) transporters represent a superfamily of proteins that have important physiological roles in both prokaryotes and eukaryotes. In insects, ABC transporters have previously been implicated in insecticide resistance. The 91-R strain of Drosophila melanogaster has been intensely selected with DDT over six decades. A recent selective sweeps analysis of 91-R implicated the potential role of MDR49, an ABC transporter, in DDT resistance, however, to date the details of how MDR49 may play a role in resistance have not been elucidated. In this study, we investigated the impact of structural changes and an alternative splicing event in MDR49 on DDT-resistance in 91-R, as compared to the DDT susceptible strain 91-C. We observed three amino acid differences in MDR49 when 91-R was compared with 91-C, and only one isoform (MDR49B) was implicated in DDT resistance. A transgenic Drosophila strain containing the 91-R-MDR49B isoform had a significantly higher LD50 value as compared to the 91-C-MDR49B isoform at the early time points (6 h to 12 h) during DDT exposure. Our data support the hypothesis that the MDR49B isoform, with three amino acid mutations, plays a role in the early aspects of DDT resistance in 91-R.

Expression analysis of several antiviral related genes to BmNPV in different resistant strains of silkworm, Bombyx mori.

PubMed

Cheng, Yang; Wang, Xue-yang; Du, Chang; Gao, Juan; Xu, Jia-ping

2014-05-30

Bombyx mori L. (Lepidoptera: Bombycidae) nucleopolyhedrovirus (BmNPV) is a highly pathogenic virus in the sericultural industry, often causing severe damage leading to large economic losses. The immune mechanisms of B. mori against this virus remain obscure. Previous studies had demonstrated Bmlipase-1, BmNox and Bmserine protease-2 showing antiviral activity in vitro, but data on the transcription levels of these proteins in different resistant strains were not reported. In order to determine the resistance level of the four different strains (P50, A35, A40, A53) and gain a better understanding of the mechanism of resistance to BmNPV in B. mori, the relative expression level of the genes coding the three antiviral proteins in larval haemolymph and midgut of different B. mori strains resistant to BmNPV was determined. The results showed that these genes expressed significantly higher in the resistant strains compared to the susceptible strain, and the differential expression levels were consistent with the LC50 values in different strains. The transcription level of the target genes almost all up-regulated in the larvae midgut and down-regulated in the haemolymph. The results indicate the correlation of these genes to BmNPV resistance in B. mori. This is an open access paper. We use the Creative Commons Attribution 3.0 license that permits unrestricted use, provided that the paper is properly attributed.

High-intensity and resistance training and elite young athletes.

PubMed

Ratel, Sébastien

2011-01-01

Although in the past resistance and high-intensity exercise training among young children was the subject of numerous controversies, it is now well-documented that this training mode is a safe and effective means of developing maximal strength, maximal power output and athletic performance in youth, provided that exercises are performed with appropriate supervision and precautions. Muscular strength and power output values measured from vertical jump and Wingate anaerobic tests are higher in elite than in non-elite young athletes and normal children, and the specific training effects on maximal power output normalised for body size are clearly more distinct before puberty. At present, there is no scientific evidence to support the view that high-intensity and/or resistance training might hinder growth and maturation in young children. Pre-pubertal growth is not adversely affected by sport at a competitive level and anthropometric factors are of importance for choice of sport in children. However, coaches, teachers and parents should be aware that unsupervised high-intensity and resistance training programmes involving maximal loads or too frequently repeated resistance exercises increase the risk of injury. Resistance training alone is an effective additional means of developing athletic performance throughout planned youth sports training programmes. Strategies for enhancing the effectiveness and safety of youth resistance and high-intensity exercise training are discussed in this chapter. Copyright © 2011 S. Karger AG, Basel.

RNA expression of genes involved in cytarabine metabolism and transport predicts cytarabine response in acute myeloid leukemia.

PubMed

Abraham, Ajay; Varatharajan, Savitha; Karathedath, Sreeja; Philip, Chepsy; Lakshmi, Kavitha M; Jayavelu, Ashok Kumar; Mohanan, Ezhilpavai; Janet, Nancy Beryl; Srivastava, Vivi M; Shaji, Ramachandran V; Zhang, Wei; Abraham, Aby; Viswabandya, Auro; George, Biju; Chandy, Mammen; Srivastava, Alok; Mathews, Vikram; Balasubramanian, Poonkuzhali

2015-07-01

Variation in terms of outcome and toxic side effects of treatment exists among acute myeloid leukemia (AML) patients on chemotherapy with cytarabine (Ara-C) and daunorubicin (Dnr). Candidate Ara-C metabolizing gene expression in primary AML cells is proposed to account for this variation. Ex vivo Ara-C sensitivity was determined in primary AML samples using MTT assay. mRNA expression of candidate Ara-C metabolizing genes were evaluated by RQPCR analysis. Global gene expression profiling was carried out for identifying differentially expressed genes between exvivo Ara-C sensitive and resistant samples. Wide interindividual variations in ex vivo Ara-C cytotoxicity were observed among samples from patients with AML and were stratified into sensitive, intermediately sensitive and resistant, based on IC50 values obtained by MTT assay. RNA expression of deoxycytidine kinase (DCK), human equilibrative nucleoside transporter-1 (ENT1) and ribonucleotide reductase M1 (RRM1) were significantly higher and cytidine deaminase (CDA) was significantly lower in ex vivo Ara-C sensitive samples. Higher DCK and RRM1 expression in AML patient's blast correlated with better DFS. Ara-C resistance index (RI), a mathematically derived quotient was proposed based on candidate gene expression pattern. Ara-C ex vivo sensitive samples were found to have significantly lower RI compared with resistant as well as samples from patients presenting with relapse. Patients with low RI supposedly highly sensitive to Ara-C were found to have higher incidence of induction death (p = 0.002; RR: 4.35 [95% CI: 1.69-11.22]). Global gene expression profiling undertaken to find out additional contributors of Ara-C resistance identified many apoptosis as well as metabolic pathway genes to be differentially expressed between Ara-C resistant and sensitive samples. This study highlights the importance of evaluating expression of candidate Ara-C metabolizing genes in predicting ex vivo drug response as well as treatment outcome. RI could be a predictor of ex vivo Ara-C response irrespective of cytogenetic and molecular risk groups and a potential biomarker for AML treatment outcome and toxicity. Original submitted 22 December 2014; Revision submitted 9 April 2015.

Measurement of oxytetracycline and emamectin benzoate in freshwater sediments downstream of land based aquaculture facilities in the Atlantic Region of Canada.

PubMed

Lalonde, Benoit A; Ernst, William; Greenwood, Lyndsay

2012-09-01

This study investigated the occurrence of oxytetracycline (OTC) and emamectin benzoate (EB) in sediments located near the effluent outfall from four freshwater aquaculture facilities in Atlantic Canada. While two facilities had no detectable concentrations of EB or OTC, two facilities had detectable concentrations of one or both of these chemicals. Concentrations ranged from <0.05-18 mg/kg to <0.01-2.5 mg/kg for OTC and EB respectively. Although these values could not be compared with freshwater toxicant values, some of the concentrations of EB and OTC detected were higher than LC(50) values calculated for marine invertebrates. OTC concentrations measured in this study are also of a magnitude which has been known to produce resistant bacteria.

Significant differences in parameters of glucose metabolism in children of hypertensive and normotensive parents.

PubMed

Gryko, Anna; Głowińska-Olszewska, Barbara; Płudowska, Katarzyna; Smithson, W Henry; Owłasiuk, Anna; Żelazowska-Rutkowska, Beata; Wojtkielewicz, Katarzyna; Milewski, Robert; Chlabicz, Sławomir

2017-01-01

In the recent years, alterations in the carbohydrate metabolism, including insulin resistance, are considered as risk factors in the development of hypertension and its complications in young age. Hypertension is associated with significant cardiovascular morbidity and mortality. The onset of pathology responsible for the development of hypertension, as well as levels of biomarkers specific for early stages of atherosclerosis are poorly understood. To compare a group of children whose parents have a history of hypertension (study group) with a group of children with normotensive parents (reference group), with consideration of typical risk factors for atherosclerosis, parameters of lipid and carbohydrate metabolism, anthropometric data and new biomarkers of early cardiovascular disease (hsCRP, adiponectin, sICAM-1). The study population consists of 84 children. Of these, 40 children (mean age 13.6±2.7 years) had a parental history of hypertension, and 44 aged 13.1±3.7 yrs were children of normotensive parents. Anthropometric measurements were taken, and measurements of blood pressure, lipid profile, glucose and insulin levels were carried out. The insulin resistance index (HOMA IR) was calculated. Levels of hsCRP, soluble cell adhesion molecules (sICAM) and adiponectin were measured. There were no statistically significant differences in anthropometric parameters (body mass, SDS BMI, skin folds) between groups. Values of systolic blood pressure were statistically significantly higher in the study group (Me 108 vs. 100 mmHg, p= 0.031), as were glycaemia (Me 80 vs. 67 mg/dl p<0.001) and insulinaemia levels (Me 8.89 vs. 5.34 µIU/ml, p=0.024). Higher, statistically significant values of HOMA IR were found in the study group (children of hypertensive parents) (Me 1.68 vs. 0.80 mmol/l × mU/l, p=0.007). Lower adiponectin levels (Me 13959.45 vs. 16822 ng/ml, p=0.020) were found in children with a family history of hypertension. No significant differences were found in the levels of sICAM, hsCRP, and parameters of lipid metabolism. Family history of hypertension is correlated with higher values of systolic blood pressure and higher values of parameters for carbohydrate metabolism in children. Hypertension in parents is a risk factor for cardiovascular disease in their children. © Polish Society for Pediatric Endocrinology and Diabetology.

Gender differences in the association between food insecurity and insulin resistance among U.S. adults: National Health and Nutrition Examination Survey, 2005-2010.

PubMed

Liu, Junxiu; Park, Yong-Moon Mark; Berkowitz, Seth A; Hu, Qingwei; Han, Kyungdo; Ortaglia, Andrew; McKeown, Robert E; Liese, Angela D

2015-09-01

To examine gender-specific associations between food insecurity and insulin resistance in a representative U.S. Data on 5533 adults of 20 years of age or more (2742 men and 2791 women) without diabetes from the 2005-2010 National Health and Nutrition Examination Survey were analyzed. Respondents were categorized as having full, marginal, low, or very low food security using a validated scale. Insulin-resistant individuals were defined as those with a homeostasis model assessment of insulin resistance value 2.5 or more. Insulin resistance was higher in both normal-weight (P = .001) and overweight or obese (P < .001) women with lower food security, but no linear trend was found in men. In multiple logistic regression analyses, however, very low food security-compared with full food security-was associated with insulin resistance in normal-weight men (odds ratio, 3.99; 95% confidence interval, 1.71-9.33), and marginal food insecurity was associated with insulin resistance in overweight or obese men (odds ratio, 2.07; 95% confidence interval, 1.18-3.64) after adjusting for potential confounders. In women, the association between food insecurity and insulin resistance was no longer significant after adjustment. Food insecurity is associated with insulin resistance in adults without diabetes, and this effect varies by gender in normal-weight and overweight or obese populations. Improving food security status may help reduce insulin resistance, an underlying risk factor for diabetes and cardiovascular disease. Copyright © 2015 Elsevier Inc. All rights reserved.

Pathological changes in Alzheimer"s brain evaluated with fluorescence emission analysis (FEA)

NASA Astrophysics Data System (ADS)

Christov, Alexander; Ottman, Todd; Grammas, Paula

2004-07-01

Development of AD is associated with cerebrovascular deposition of amyloid beta (Aβ) as well as a progressive increase in vasular collagen content. Both AΒ and collagen are naturally fluorescent compounds when exposed to UV light. We analyzed autofluorescence emitted from brain tissue samples and isolated brain resistance vessels harvested postmortem from patients with Alzheimer's disease (AD) and age-matched controls. Fluorescence emission, excited at 355 nm with an Nd:YAG laser, was measured using a fiber-optic based fluorescence spectroscopic system for tissue analysis. Significantly higher values of fluorescence emission intensity (P<0.001) in the spectral region from 465 to 490 nm were detected in brain resistance vessel samples from AD patients compared to the normal individuals. Results from western blot analysis showed elevated levels of type I and type III collagen, and reduced levels of type IV collagen in resistance vessels from AD patients, compared to control samples. In addition, using direct scanning of the cortical suface for fluoresxcence emission by the laser-induced fluorescence spectroscopy system we detected a significantly (P<0.05) higher level of apoptosis in AD brain tissue compared to age-matched controls. Fluorescence emission analysis (FEA) appears to be a sensitive technique for detecting structural changes in AD brain tissue.

Array of Josephson junctions with a nonsinusoidal current-phase relation as a model of the resistive transition of unconventional superconductors

NASA Astrophysics Data System (ADS)

Carbone, Anna; Gilli, Marco; Mazzetti, Piero; Ponta, Linda

2010-12-01

An array of resistively and capacitively shunted Josephson junctions with nonsinusoidal current-phase relation is considered for modeling the transition in high-Tc superconductors. The emergence of higher harmonics, besides the simple sinusoid Ic sin ϕ, is expected for dominant d-wave symmetry of the Cooper pairs, random distribution of potential drops, dirty grains, or nonstationary conditions. We show that additional cosine and sine terms act, respectively, by modulating the global resistance and by changing the Josephson coupling of the mixed superconductive-normal states. First, the approach is applied to simulate the transition in disordered granular superconductors with the weak-links characterized by nonsinusoidal current-phase relation. In granular superconductors, the emergence of higher-order harmonics affects the slope of the transition. Then, arrays of intrinsic Josephson junctions, naturally formed by the CuO2 planes in cuprates, are considered. The critical temperature suppression, observed at values of hole doping close to p =1/8, is investigated. Such suppression, related to the sign change and modulation of the Josephson coupling across the array, is quantified in terms of the intensities of the first and second sinusoids of the current-phase relation. Applications are envisaged for the design and control of quantum devices based on stacks of intrinsic Josephson junctions.

Evaluation of microhardness, surface roughness, and wear behavior of different types of resin composites polymerized with two different light sources.

PubMed

Topcu, Fulya Toksoy; Erdemir, Ugur; Sahinkesen, Gunes; Yildiz, Esra; Uslan, Ibrahim; Acikel, Cengizhan

2010-02-01

The microhardness, surface roughness and wear resistance of different types of resin composites, polymerized by a Quartz Tungsten Halogen (QTH) or Light Emitting Diode (LED) light curing units (LCU) were evaluated in this in vitro study. Cylindrical blocks were prepared from composites (8 mm in diameter, and 2 mm in thickness) and polymerized by a LED or a QTH LCU. Vickers hardness was measured on the top and bottom surfaces of the specimens. Surface roughness was measured with a surface profilometer on the top of the specimens. For the wear test, specimens were tested in a conventional pin-on-disc tribology machine under 15 N loads. The statistical analyses were performed by one-way analysis of variance (ANOVA) and t-tests, including the Bonferroni correction. Nanocomposite material Clearfil Majesty Posterior showed the highest hardness values in all polymerization types at the top and bottom surfaces (p < 0.05). Microhybrid Clearfil APX and hybrid Quixfil composites demonstrated the greatest surface roughness. Wear resistance of Clearfil Majesty Posterior was found to be the highest among the other tested resin composites. The results indicated that Clearfil Majesty Posterior demonstrated higher microhardness, less surface roughness, and higher wear resistance when compared with the other tested materials for both polymerization types.

Reproducibility and effect of posture on impulse oscillation parameters in persons with spinal cord injury

PubMed Central

Cirnigliaro, Christopher M.; Lesser, Marvin; Moyer, Jeremy; Kirshblum, Steven C.; Bauman, William A.; Spungen, Ann M.

2012-01-01

Background The impulse oscillation system (IOS) offers significant value in the assessment of airway dynamics in persons with spinal cord injury (SCI) because of minimal patient effort but measurement reproducibility in SCI is unknown. Objective To evaluate between-day reproducibility and the effect of posture on airway resistance [respiratory resistances at 5 Hz (R5) and 20 Hz (R20)] in subjects with tetraplegia, paraplegia and able-bodied controls. Methods Ten subjects with tetraplegia, 10 subjects with paraplegia and 11 able-bodied individuals were evaluated using IOS. Three 30 second trials were obtained in each while in the seated and supine position on Day 1, and repeated on Day 2. Results The within-day coefficient of variation (CV%) for R5 and R20 were comparable in the 3 study groups in the seated and supine positions. Compared to controls, the between-day CV% for the combined data was higher in subjects with tetraplegia and paraplegia for R5 seated, and was higher in subjects with tetraplegia for R5 supine. Conclusions IOS has applicability to the study of within-day respiratory resistance in SCI. However, performing longer-term studies in subjects with tetraplegia and paraplegia may be problematic because of the greater variability for R5 when compared to able-bodied individuals. PMID:22330188

Linkages between the life-history evolution of tropical and temperate birds and the resistance of cultured skin fibroblasts to oxidative and non-oxidative chemical injury

PubMed Central

Jimenez, Ana Gabriela; Harper, James M.; Queenborough, Simon A.; Williams, Joseph B.

2013-01-01

SUMMARY A fundamental challenge facing physiological ecologists is to understand how variation in life history at the whole-organism level might be linked to cellular function. Thus, because tropical birds have higher annual survival and lower rates of metabolism, we hypothesized that cells from tropical species would have greater cellular resistance to chemical injury than cells from temperate species. We cultured dermal fibroblasts from 26 tropical and 26 temperate species of birds and examined cellular resistance to cadmium, H2O2, paraquat, thapsigargin, tunicamycium, methane methylsulfonate (MMS) and UV light. Using ANCOVA, we found that the values for the dose that killed 50% of cells (LD50) from tropical birds were significantly higher for H2O2 and MMS. When we tested for significance using a generalized least squares approach accounting for phylogenetic relationships among species to model LD50, we found that cells from tropical birds had greater tolerance for Cd, H2O2, paraquat, tunicamycin and MMS than cells from temperate birds. In contrast, tropical birds showed either lower or no difference in tolerance to thapsigargin and UV light in comparison with temperate birds. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to be more resistant to forms of oxidative and non-oxidative stress than cells from shorter-lived temperate species. PMID:23264487

Linkages between the life-history evolution of tropical and temperate birds and the resistance of cultured skin fibroblasts to oxidative and non-oxidative chemical injury.

PubMed

Jimenez, Ana Gabriela; Harper, James M; Queenborough, Simon A; Williams, Joseph B

2013-04-15

A fundamental challenge facing physiological ecologists is to understand how variation in life history at the whole-organism level might be linked to cellular function. Thus, because tropical birds have higher annual survival and lower rates of metabolism, we hypothesized that cells from tropical species would have greater cellular resistance to chemical injury than cells from temperate species. We cultured dermal fibroblasts from 26 tropical and 26 temperate species of birds and examined cellular resistance to cadmium, H(2)O(2), paraquat, thapsigargin, tunicamycium, methane methylsulfonate (MMS) and UV light. Using ANCOVA, we found that the values for the dose that killed 50% of cells (LD(50)) from tropical birds were significantly higher for H(2)O(2) and MMS. When we tested for significance using a generalized least squares approach accounting for phylogenetic relationships among species to model LD(50), we found that cells from tropical birds had greater tolerance for Cd, H(2)O(2), paraquat, tunicamycin and MMS than cells from temperate birds. In contrast, tropical birds showed either lower or no difference in tolerance to thapsigargin and UV light in comparison with temperate birds. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to be more resistant to forms of oxidative and non-oxidative stress than cells from shorter-lived temperate species.

Cross-resistance and synergism bioassays suggest multiple mechanisms of pyrethroid resistance in western corn rootworm populations

PubMed Central

Souza, Dariane; Zukoff, Sarah N.; Meinke, Lance J.; Siegfried, Blair D.

2017-01-01

Recently, resistance to the pyrethroid bifenthrin was detected and confirmed in field populations of western corn rootworm, Diabrotica virgifera virgifera LeConte from southwestern areas of Nebraska and Kansas. As a first step to understand potential mechanisms of resistance, the objectives of this study were i) to assess adult mortality at diagnostic concentration-LC99 to the pyrethroids bifenthrin and tefluthrin as well as DDT, ii) estimate adult and larval susceptibility to the same compounds as well as the organophosphate methyl-parathion, and iii) perform synergism experiments with piperonyl butoxide (PBO) (P450 inhibitor) and S,S,S-tributyl-phosphorotrithioate (DEF) (esterase inhibitor) in field populations. Most of the adult field populations exhibiting some level of bifenthrin resistance exhibited significantly lower mortality to both pyrethroids and DDT than susceptible control populations at the estimated LC99 of susceptible populations. Results of adult dose-mortality bioassays also revealed elevated LC50 values for bifenthrin resistant populations compared to the susceptible control population with resistance ratios ranging from 2.5 to 5.5-fold for bifenthrin, 28 to 54.8-fold for tefluthrin, and 16.3 to 33.0 for DDT. These bioassay results collectively suggest some level of cross-resistance between the pyrethroids and DDT. In addition, both PBO and DEF reduced the resistance ratios for resistant populations although there was a higher reduction in susceptibility of adults exposed to PBO versus DEF. Susceptibility in larvae varied among insecticides and did not correlate with adult susceptibility to tefluthrin and DDT, as most resistance ratios were < 5-fold when compared to the susceptible population. These results suggest that both detoxifying enzymes and target site insensitivity might be involved as resistance mechanisms. PMID:28628635

Surveillance of Helicobacter pylori Antibiotic Susceptibility in Indonesia: Different Resistance Types among Regions and with Novel Genetic Mutations

PubMed Central

Miftahussurur, Muhammad; Syam, Ari Fahrial; Nusi, Iswan Abbas; Makmun, Dadang; Waskito, Langgeng Agung; Zein, Lukman Hakim; Akil, Fardah; Uwan, Willy Brodus; Simanjuntak, David; Wibawa, I Dewa Nyoman; Waleleng, Jimmy Bradley; Saudale, Alexander Michael Joseph; Yusuf, Fauzi; Mustika, Syifa; Adi, Pangestu; Maimunah, Ummi; Maulahela, Hasan; Rezkitha, Yudith Annisa Ayu; Subsomwong, Phawinee; Nasronudin; Rahardjo, Dadik; Suzuki, Rumiko; Akada, Junko; Yamaoka, Yoshio

2016-01-01

Information regarding Helicobacter pylori antibiotic resistance in Indonesia was previously inadequate. We assessed antibiotic susceptibility for H. pylori in Indonesia, and determined the association between virulence genes or genetic mutations and antibiotic resistance. We recruited 849 dyspeptic patients who underwent endoscopy in 11 cities in Indonesia. E-test was used to determine the minimum inhibitory concentration of five antibiotics. PCR-based sequencing assessed mutations in 23S rRNA, rdxA, gyrA, gyrB, and virulence genes. Next generation sequencing was used to obtain full-length sequences of 23S rRNA, infB, and rpl22. We cultured 77 strains and identified 9.1% with clarithromycin resistance. Low prevalence was also found for amoxicillin and tetracycline resistance (5.2% and 2.6%, respectively). In contrast, high resistance rates to metronidazole (46.7%) and levofloxacin (31.2%) were demonstrated. Strains isolated from Sumatera Island had significantly higher metronidazole resistance than those from other locations. Metronidazole resistant strains had highly distributed rdxA amino acid substitutions and the 23S rRNA A2143G mutation was associated with clarithromycin resistance (42.9%). However, one strain with the highest MIC value had a novel mutation in rpl22 without an A2143G mutation. Mutation at Asn-87 and/or Asp-91 of gyrA was associated with levofloxacin-resistance and was related to gyrB mutations. In conclusions, although this is a pilot study for a larger survey, our current data show that Indonesian strains had the high prevalence of metronidazole and levofloxacin resistance with low prevalence of clarithromycin, amoxicillin, and tetracycline resistance. Nevertheless, clarithromycin- or metronidazole-based triple therapy should be administered with caution in some regions of Indonesia. PMID:27906990

Surveillance of Helicobacter pylori Antibiotic Susceptibility in Indonesia: Different Resistance Types among Regions and with Novel Genetic Mutations.

PubMed

Miftahussurur, Muhammad; Syam, Ari Fahrial; Nusi, Iswan Abbas; Makmun, Dadang; Waskito, Langgeng Agung; Zein, Lukman Hakim; Akil, Fardah; Uwan, Willy Brodus; Simanjuntak, David; Wibawa, I Dewa Nyoman; Waleleng, Jimmy Bradley; Saudale, Alexander Michael Joseph; Yusuf, Fauzi; Mustika, Syifa; Adi, Pangestu; Maimunah, Ummi; Maulahela, Hasan; Rezkitha, Yudith Annisa Ayu; Subsomwong, Phawinee; Nasronudin; Rahardjo, Dadik; Suzuki, Rumiko; Akada, Junko; Yamaoka, Yoshio

2016-01-01

Information regarding Helicobacter pylori antibiotic resistance in Indonesia was previously inadequate. We assessed antibiotic susceptibility for H. pylori in Indonesia, and determined the association between virulence genes or genetic mutations and antibiotic resistance. We recruited 849 dyspeptic patients who underwent endoscopy in 11 cities in Indonesia. E-test was used to determine the minimum inhibitory concentration of five antibiotics. PCR-based sequencing assessed mutations in 23S rRNA, rdxA, gyrA, gyrB, and virulence genes. Next generation sequencing was used to obtain full-length sequences of 23S rRNA, infB, and rpl22. We cultured 77 strains and identified 9.1% with clarithromycin resistance. Low prevalence was also found for amoxicillin and tetracycline resistance (5.2% and 2.6%, respectively). In contrast, high resistance rates to metronidazole (46.7%) and levofloxacin (31.2%) were demonstrated. Strains isolated from Sumatera Island had significantly higher metronidazole resistance than those from other locations. Metronidazole resistant strains had highly distributed rdxA amino acid substitutions and the 23S rRNA A2143G mutation was associated with clarithromycin resistance (42.9%). However, one strain with the highest MIC value had a novel mutation in rpl22 without an A2143G mutation. Mutation at Asn-87 and/or Asp-91 of gyrA was associated with levofloxacin-resistance and was related to gyrB mutations. In conclusions, although this is a pilot study for a larger survey, our current data show that Indonesian strains had the high prevalence of metronidazole and levofloxacin resistance with low prevalence of clarithromycin, amoxicillin, and tetracycline resistance. Nevertheless, clarithromycin- or metronidazole-based triple therapy should be administered with caution in some regions of Indonesia.

Effective flow resistivity of highway pavements.

PubMed

Rochat, Judith L; Read, David R

2013-12-01

In the case of highway traffic noise, propagating sound is influenced by the ground over which it travels, whether it is the pavement itself or the ground between the highway and nearby communities. Properly accounting for ground type in modeling can increase accuracy in noise impact determinations and noise abatement design. Pavement-specific effective flow resistivity values are being investigated for inclusion in the Federal Highway Administration Traffic Noise Model, which uses these values in the sound propagation algorithms and currently applies a single effective flow resistivity value to all pavement. Pavement-specific effective flow resistivity values were obtained by applying a modified version of the American National Standards Institute S1.18 standard. The data analysis process was tailored to allow for increased sensitivity and extraction of effective flow resistivity values for a broad range of pavements (sound absorptive to reflective). For porous pavements (sound absorptive), it was determined that examination of the measured data can reveal influence from an underlying structure. Use of such techniques can aid in the design of quieter pavements.

[Expression and significance of c-fos in resistant cell line TU177/VCR of larynx squamous cell carcinoma].

PubMed

Li, G D; Hu, X L; Xing, J F; Shi, R Y; Li, X; Li, J F; Li, T L

2018-04-07

Objective: To explore the effect of c-fos on multidrug resistance of laryngeal cancer TU177 cells. Method: Increasing drug concentration gradient is adopted to establish the stability of the laryngeal cancer drug resistance in cell line; RT-PCR and Western blot were used to detect difference of the c-fos between TU177 and TU177/VCR cells; plasmids with human c-fos knockdown or over expression were transfected into TU177/VCR and TU177 cells respectively, and the effects of different treatment on cell proliferation were investigated with MTT. Results: The drug resistance of TU177/VCR cells was 26.25-fold in vincristine (VCR), 7.33-fold in Paclitaxel (TAX), 2.41 in cisplatin (DDP), and 5.50 in 5-fluorouracil (5-FU), comparing with TU177( P <0.05). The TU177/VCR cells had significantly higher c-fos expression compared to TU177 cells( P <0.05). The results showed that the IC(50) values of 5-FU for the NC group and c-fos shRNA group were (306.2±6.3)μmol/L and (81.3±3.9)μmol/L, respectively, which was decreased by 73% in the c-fos shRNA group compared to that in the NC group ( P <0.05). Similarly, the results showed that the IC(50) values for 5-FU were (55.3±9.4) μmol/L in NC group and (288.1±7.3)μmol/L in c-fos WT group, which was increased 5.21-fold in c-fos WT cells. Conclusion: C-fos plays important role in multidrug resistance of larynx cancer cell TU177/VCR, and might become a new molecular target for laryngeal cancer treatment.

Assessment of peak power and short-term work capacity.

PubMed

MacIntosh, Brian R; Rishaug, Peter; Svedahl, Krista

2003-02-01

The purpose of this study was to evaluate conditions for conducting a 30 s Wingate test such as load selection, and the method of starting the test (stationary or flying start). Nine male and four female athletes volunteered to be tested on four laboratory visits. Tests were performed on a modified Monark cycle ergometer (Varberg, Sweden) equipped with force transducers on the friction belt and an optical encoder for velocity measurement. Power was calculated with the moment of inertia (I) of the flywheel taken into consideration. One laboratory visit was used to determine individualized optimal resistance conditions. The other three visits were for performance of one of three Wingate tests: a flying start with 0.834 N x kg(-1) [85 g x kg(-1) body weight (BW)] resistance (FLY-0.8); a stationary start with 0.834 N x kg(-1) BW resistance (ST-0.8), or a stationary start with optimal resistance (ST-OPT). FLY-0.8 gave a lower (P<0.05) value for short-term work capacity [19,986 (827) J] than either ST-OPT [23,014 (1,167) J] or ST-0.8 [22,321 (1075) J]. Peak power output per pedal revolution was lower ( P<0.005) for FLY-0.8 [833 (40) W] than for either ST-0.8 [974 (57) W] or ST-OPT [989 (61) W]. The results of this study demonstrate that higher values for peak power and short-term work capacity are obtained with a test from a stationary start. It is apparently not necessary to use an individualized optimal resistance when I is considered in a Wingate test initiated from a standstill.

Using a multi-method approach based on soil radon deficit, resistivity, and induced polarization measurements to monitor non-aqueous phase liquid contamination in two study areas in Italy and India.

PubMed

Castelluccio, Mauro; Agrahari, Sudha; De Simone, Gabriele; Pompilj, Francesca; Lucchetti, Carlo; Sengupta, Debashish; Galli, Gianfranco; Friello, Pierluigi; Curatolo, Pierpaolo; Giorgi, Riccardo; Tuccimei, Paola

2018-05-01

Geochemical and geophysical surveys employing radon deficit, resistivity, and induced polarization (IP) measurements were undertaken on soil contaminated with non-aqueous phase liquids (NAPLs) in two different sites in India and in Italy. Radon deficit, validated through the comparison with average soil radon in reference unpolluted areas, shows the extension of contamination in the upper part of the unsaturated aquifers. In site 1 (Italy), the spill is not recent. A residual film of kerosene covers soil grains, inhibiting their chargeability and reducing electrical resistivity difference with background unpolluted areas. No correlation between the two parameters is observed. Soil volatile organic compounds (VOCs) concentration is not linked with radon deficit, supporting the old age of the spillage. NAPL pollution in sites 2a and 2b (India) is more recent and probably still active, as demonstrated by higher values of electrical resistivity. A good correlation with IP values suggests that NAPL is still distributed as droplets or as a continuous phase in the pores, strengthening the scenario of a fresh spill or leakage. Residual fraction of gasoline in the pore space of sites 2a and 2b is respectively 1.5 and 11.8 kg per cubic meter of terrain. This estimation is referred to the shallower portion of the unsaturated aquifer. Electrical resistivity is still very high indicating that the gasoline has not been strongly degraded yet. Temperature and soil water content influence differently radon deficit in the three areas, reducing soil radon concentration and partly masking the deficit in sites 2a and 2b.

DPC 681 and DPC 684: Potent, Selective Inhibitors of Human Immunodeficiency Virus Protease Active against Clinically Relevant Mutant Variants

PubMed Central

Kaltenbach, Robert F.; Trainor, George; Getman, Daniel; Harris, Greg; Garber, Sena; Cordova, Beverly; Bacheler, Lee; Jeffrey, Susan; Logue, Kelly; Cawood, Pamela; Klabe, Ronald; Diamond, Sharon; Davies, Marc; Saye, Joanne; Jona, Janan; Erickson-Viitanen, Susan

2001-01-01

Human immunodeficiency virus (HIV) protease inhibitors (PIs) are important components of many highly active antiretroviral therapy regimens. However, development of phenotypic and/or genotypic resistance can occur, including cross-resistance to other PIs. Development of resistance takes place because trough levels of free drug are inadequate to suppress preexisting resistant mutant variants and/or to inhibit de novo-generated resistant mutant variants. There is thus a need for new PIs, which are more potent against mutant variants of HIV and show higher levels of free drug at the trough. We have optimized a series of substituted sulfonamides and evaluated the inhibitors against laboratory strains and clinical isolates of HIV type 1 (HIV-1), including viruses with mutations in the protease gene. In addition, serum protein binding was determined to estimate total drug requirements for 90% suppression of virus replication (plasma IC90). Two compounds resulting from our studies, designated DPC 681 and DPC 684, are potent and selective inhibitors of HIV protease with IC90s for wild-type HIV-1 of 4 to 40 nM. DPC 681 and DPC 684 showed no loss in potency toward recombinant mutant HIVs with the D30N mutation and a fivefold or smaller loss in potency toward mutant variants with three to five amino acid substitutions. A panel of chimeric viruses constructed from clinical samples from patients who failed PI-containing regimens and containing 5 to 11 mutations, including positions 10, 32, 46, 47, 50, 54, 63, 71, 82, 84, and 90 had mean IC50 values of <20 nM for DPC 681 and DPC 681, respectively. In contrast, marketed PIs had mean IC50 values ranging from 200 nM (amprenavir) to >900 nM (nelfinavir). PMID:11600351

Rapid antifungal susceptibility testing by matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis.

PubMed

Vella, Antonietta; De Carolis, Elena; Vaccaro, Luisa; Posteraro, Patrizia; Perlin, David S; Kostrzewa, Markus; Posteraro, Brunella; Sanguinetti, Maurizio

2013-09-01

The widespread use of antifungal agents, which is likely to expand with their enhanced availability, has promoted the emergence of drug-resistant strains. Antifungal susceptibility testing (AFST) is now an essential procedure for guiding appropriate antifungal therapy. Recently, we developed a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based method that enables the detection of fungal isolates with reduced echinocandin susceptibility, relying on the proteome changes that are detectable after a 15-h exposure of fungal cells to serial drug concentrations. Here, we describe a simplified version of this approach that facilitates discrimination of the susceptible and resistant isolates of Candida albicans after a 3-h incubation in the presence of "breakpoint" level drug concentrations of the echinocandin caspofungin (CSF). Spectra at concentrations of 0 (null), 0.03 (intermediate), and 32 (maximal) μg/ml of CSF were used to create individual composite correlation index (CCI) matrices for 65 C. albicans isolates, including 13 fks1 mutants. Isolates are then classified as susceptible or resistant to CSF if the CCI values of spectra at 0.03 and 32 μg/ml are higher or lower, respectively, than the CCI values of spectra at 0.03 and 0 μg/ml. In this way, the drug resistance of C. albicans isolates to echinocandin antifungals can be quickly assessed. Furthermore, the isolate categorizations determined using MALDI-TOF MS-based AFST (ms-AFST) were consistent with the wild-type and mutant FKS1 genotypes and the AFST reference methodology. The ms-AFST approach may provide a rapid and reliable means of detecting emerging antifungal resistance and accelerating the initiation of appropriate antifungal treatment.

Processing, microstructure and mechanics of functionally graded Al A359/SiC(p) composite

NASA Astrophysics Data System (ADS)

Rodriguez-Castro, Ramon

2000-11-01

Metal matrix composites (MMCs) have great promise for high temperature, high strength, wear resistant applications. However, their brittleness has limited their use in load bearing applications. Functionally graded MMCs with a reinforcement concentration higher on the surface than in the interior offer new opportunities, as these materials will have high surface hardness as well as high resistance to crack growth towards the interior. In this dissertation the processing and mechanical properties of a functionally graded MMC are investigated. Rectangular blocks (100 mmx60 mmx50 mm) of functionally graded SiC particulate reinforced aluminum A359 matrix composite were prepared by centrifugal casting techniques. The reinforcement volume fraction profiles varied as the centrifugal force was applied, owing to the different densities of Al and SiC. The casting at 1300 rpm (angular velocity) had a well-mixed, refined microstructure with the maximum SiC volume fraction of 44% near the outer surface of the blocks. This surface exhibited an elevated hardness. The effect of SiC particulate reinforcement on strengthening of A359 Al alloy was experimentally studied by tensile testing specimens prepared from the cast blocks. There was a continuous increase in tensile and yield strength with increasing SiC volume fractions in the range of 0.20 to 0.30. On the contrary, there was a reduction in tensile and yield strength for SiC concentrations in the range of 0.30 to 0.40. The elasticity modulus increased with increasing SiC volume fractions in the whole reinforcement range (0.20--0.40). Fractographic analysis by SEM revealed a ductile failure process of void growth in the matrix, but the amount of the void growth was less when the SiC concentration was higher. SEM also revealed SiC reinforcement fracture and decohesion, with the particle fracture increasing with the particle concentration. Appropriate flat specimens with a continuously graded microstructure for fracture mechanics testing were machined from the cast blocks. No published work has reported specimens of similar characteristics (size of the specimens and continuous reinforcement gradation). Fracture mechanics of the composite specimens with the crack parallel to the gradation in elastic properties was studied to investigate the effect of the nonhomogeneous microstructure on fracture toughness. Fatigue pre-cracking was used and a limited amount of fatigue crack propagation data was gathered. Low values of DeltaKth and increased crack growth resistance in the Paris region were observed for the functionally graded composite compared to a homogeneous 20 vol% composite. R-curve (KR) behavior of fracture was investigated in the functionally graded composite. At elevated SiC concentrations (low values of crack length), limited dissipation of energy by restrained plastic deformation of the matrix at the crack tip produced low fracture toughness values. On the contrary, at longer crack lengths SiC content decreased and there was more absorption of energy, resulting in higher fracture toughness values. In addition, the crack growth resistance behavior of the FGM composite was compared to the corresponding behavior of an Al A359/SiCp 20 vol% homogeneous composite. The latter exhibited a declining KR-curve behavior whereas the FGM composite displayed an increasing KR-curve behavior. Consequently, this increasing crack growth resistance behavior displayed by the functionally graded Al A359/SiCp composite shows that tailored changes in the microstructure could circumvent the low toughness inherent in MMCs.

Determination of Flow Resistance Coefficient for Vegetation in Open Channel: Laboratory study

NASA Astrophysics Data System (ADS)

Aliza Ahmad, Noor; Ali, ZarinaMd; Arish, Nur Aini Mohd; Munirah Mat Daud, Azra; Fatin Amirah Alias, Nur

2018-04-01

This study focused on determination of flow resistances coefficient for grass in an open channel. Laboratory works were conducted to examine the effects of varying of roughness elements on the flume to determine flow resistance coefficient and also to determine the optimum flow resistance with five different flow rate, Q. Laboratory study with two type of vegetation which are Cow Grass and Pearl Grass were implementing to the bed of a flume. The roughness coefficient, n value is determine using Manning’s equation while Soil Conservation Services (SCS) method was used to determine the surface resistance. From the experiment, the flow resistance coefficient for Cow Grass in range 0.0008 - 0.0039 while Pearl Grass value for the flow resistance coefficient are in between 0.0013 - 0.0054. As a conclusion the vegetation roughness value in open channel are depends on density, distribution type of vegetation used and physical characteristic of the vegetation itself

Anticancer potential and mechanism of action of mango ginger (Curcuma amada Roxb.) supercritical CO₂ extract in human glioblastoma cells.

PubMed

Ramachandran, Cheppail; Lollett, Ivonne V; Escalon, Enrique; Quirin, Karl-Werner; Melnick, Steven J

2015-04-01

Mango ginger (Curcuma amada Roxb.) is among the less-investigated species of Curcuma for anticancer properties. We have investigated the anticancer potential and the mechanism of action of a supercritical CO2 extract of mango ginger (CA) in the U-87MG human glioblastoma cell line. CA demonstrated higher cytotoxicity than temozolomide, etoposide, curcumin, and turmeric force with IC50, IC75, and IC90 values of 4.92 μg/mL, 12.87 μg/mL, and 21.30 μg/mL, respectively. Inhibitory concentration values of CA for normal embryonic mouse hypothalamus cell line (mHypoE-N1) is significantly higher than glioblastoma cell line, indicating the specificity of CA against brain tumor cells. CompuSyn analysis indicates that CA acts synergistically with temozolomide and etoposide for the cytotoxicity with combination index values of <1. CA treatment also induces apoptosis in glioblastoma cells in a dose-dependent manner and downregulates genes associated with apoptosis, cell proliferation, telomerase activity, oncogenesis, and drug resistance in glioblastoma cells. © The Author(s) 2014.

Assessment of insulin resistance in Chinese PCOS patients with normal glucose tolerance.

PubMed

Gao, Jing; Zhou, Li; Hong, Jie; Chen, Chen

2017-11-01

The study aimed to investigate insulin resistance (IR) status in polycystic ovary syndrome (PCOS) women with normal glucose tolerance (NGT), and further to evaluate feasible diagnostic method for those patients. Three hundred and twenty-five PCOS women with NGT and ninety-five healthy age-matched controls were recruited with Rotterdam criterion and 75 g oral glucose tolerance test (OGTT). IR status was estimated following a glycemic and insulinemic OGTT (0, 30, 60, 120, and 180 min). A modified HOMA-IR formula was applied to each time-course value of glycemia and insulinemia. The predictive performance of each IR index was analyzed with the use of ROC curves. Compared with healthy controls, both non-obese and obese PCOS patients with NGT had a higher BMI, serum glucose, insulin value (p < .05). The best predictive index of IR in non-obese PCOS-NGT was a HOMA-M30 value of 20.36 or more (AUC: 0.753). In obese PCOS-NGT population, the best predictive performance was obtained by a HOMA-M60 value of 32.17 or more (AUC: 0.868). IR was common in Chinese PCOS women with NGT, and the early assessment of IR should be heeded. We recommended HOMA-M30 (Cutoff: 20.36) and HOMA-M60 (Cutoff: 32.17) as the best predictive parameters for non-obese and obese PCOS-NGT patients, respectively.

RX-P873, a Novel Protein Synthesis Inhibitor, Accumulates in Human THP-1 Monocytes and Is Active against Intracellular Infections by Gram-Positive (Staphylococcus aureus) and Gram-Negative (Pseudomonas aeruginosa) Bacteria

PubMed Central

Buyck, Julien M.; Peyrusson, Frédéric

2015-01-01

The pyrrolocytosine RX-P873, a new broad-spectrum antibiotic in preclinical development, inhibits protein synthesis at the translation step. The aims of this work were to study RX-P873's ability to accumulate in eukaryotic cells, together with its activity against extracellular and intracellular forms of infection by Staphylococcus aureus and Pseudomonas aeruginosa, using a pharmacodynamic approach allowing the determination of maximal relative efficacies (Emax values) and bacteriostatic concentrations (Cs values) on the basis of Hill equations of the concentration-response curves. RX-P873's apparent concentration in human THP-1 monocytes was about 6-fold higher than the extracellular one. In broth, MICs ranged from 0.125 to 0.5 mg/liter (S. aureus) and 2 to 8 mg/liter (P. aeruginosa), with no significant shift in these values against strains resistant to currently used antibiotics being noted. In concentration-dependent experiments, the pharmacodynamic profile of RX-P873 was not influenced by the resistance phenotype of the strains. Emax values (expressed as the decrease in the number of CFU from that in the initial inoculum) against S. aureus and P. aeruginosa reached more than 4 log units and 5 log units in broth, respectively, and 0.7 log unit and 2.7 log units in infected THP-1 cells, respectively, after 24 h. Cs values remained close to the MIC in all cases, making RX-P873 more potent than antibiotics to which the strains were resistant (moxifloxacin, vancomycin, and daptomycin for S. aureus; ciprofloxacin and ceftazidime for P. aeruginosa). Kill curves in broth showed that RX-P873 was more rapidly bactericidal against P. aeruginosa than against S. aureus. Taken together, these data suggest that RX-P873 may constitute a useful alternative for infections involving intracellular bacteria, especially Gram-negative species. PMID:26014952

Characterization of ultrafiltration of undiluted and diluted stored urine.

PubMed

Ouma, J; Septien, S; Velkushanova, K; Pocock, J; Buckley, C

2016-11-01

Urine ultrafiltration (UF) was studied in terms of flux, permeability, resistance and fouling. Two types of samples were used: stored urine representing the feedstock obtained from urine diversion dry toilets; and diluted stored urine representing the feedstock obtained from urinals. Three different filtration experiment sets were adopted in this study. For the first case, pressure was set in an ascending order, i.e. from 10 to 60 kPa during filtration of stored urine. For the second case, pressure was set in a descending order, i.e. from 60 to 10 kPa for the same feed stream. The third case involved filtration of diluted urine with pressure in ascending order, i.e. from 10 to 60 kPa. The results indicated that diluted urine had higher flux than undiluted urine with maximum values of 43 and 26 L·m -2 ·h -1 respectively. Cake formation was the dominating fouling mechanism during urine filtration with a contribution of about 90% to the total hydraulic resistance. The contribution of chemically irreversible fouling was low (-2%), unless operating from high to low pressures. Indeed, irreversible fouling appeared to be greater during the experiments starting at higher pressure. Although undiluted urine had a higher fouling potential compared to diluted urine, the specific cake resistance was higher for diluted urine, probably due to a denser cake caused by lower particle sizes in that sample. The permeate obtained after urine filtration had much lower suspended solids content compared to the feedstock, with rejections up to 99%. The concentration of the ionic species remained unchanged, and 75% of the organic compounds and dissolved solids remained in the permeate. Urine UF could then be used as pre-treatment to remove suspended solids.

Evaluating the association of APOA2 polymorphism with insulin resistance in adolescents.

PubMed

Zaki, Moushira Erfan; Amr, Khalda Sayed; Abdel-Hamid, Mohamed

2014-12-01

265T>C SNP in the APOA-II gene promoter may be associated with obesity risk and insulin resistance (IR). This study aims to analyze the association between the APOA2 - 265T>C SNP and risk for obesity and IR in adolescents. The study was conducted on 500 adolescents. They were 240 obese and 260 non-obese individuals, aged 16-21 years old. Their mean age was 18.25 ± 2.54 years. Variables examined body weight, height, waist circumference (WC), systolic and diastolic blood pressure (BP), body fat percentage (BF%), and abdominal visceral fat layer. Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) was used as a biomarker for IR. BF% was assessed by body composition analyzer and abdominal visceral fat thickness was determined by ultrasonography. The APOA2 - 265T>C polymorphism genotype was analyzed by PCR amplification of a 273-bp fragment. Genotype frequencies were in Hardy-Weinberg equilibrium. The frequency of the mutant C allele was significantly higher in obese cases than non-obese cases. After multivariate adjustment, waist, BF%, visceral adipose layer and HOMA-IR were significantly higher in homozygous allele CC carriers than TT + TC carriers. Homozygous individuals for the CC allele had statistically higher values of energy intake, total fat (g/day) and saturated fat (SATFAT) than carriers of the T allele. Homozygous individuals for the C allele had higher obesity risk than carriers of the T allele and had elevated levels of visceral adipose tissue. Moreover, the present study shows that the CC polymorphism is associated with the development of IR [OR 1.89 (1.35-2.91), P = .012] and remains significant after adjusting for gender, age and body mass index.

Genetic association analysis of ATP binding cassette protein family reveals a novel association of ABCB1 genetic variants with epilepsy risk, but not with drug-resistance.

PubMed

Balan, Shabeesh; Bharathan, Sumitha Prameela; Vellichiramal, Neetha Nanoth; Sathyan, Sanish; Joseph, Vijai; Radhakrishnan, Kurupath; Banerjee, Moinak

2014-01-01

Epilepsy constitutes a heterogeneous group of disorders that is characterized by recurrent unprovoked seizures due to widely different etiologies. Multidrug resistance remains a major issue in clinical epileptology, where one third of patients with epilepsy continue to have seizures. Role of efflux transporters in multidrug resistant epilepsy has been attributed to drug-resistant epilepsy although, with discrepant observation in genetic studies. These discrepancies could be attributed to variety of factors such as variable definition of the anti-epileptic drug (AED)-resistance, variable epilepsy phenotypes and ethnicities among the studies. In the present study we inquired the role of multidrug transporters ABCB1 and ABCG2 variants in determining AED-resistance and susceptibility to epilepsy in three well-characterized cohorts comprising of mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) (prototype for AED-resistant epilepsy); juvenile myoclonic epilepsy (JME) (prototype for AED-responsive epilepsy); and healthy non-epileptic controls, in 738 subjects of Malayalam speaking south Indian ancestry. ABCB1 and ABCG2 variants were not found to be associated with drug resistance when AED-resistant and AED-responsive cohorts were compared. However, a significant association was observed between ABCB1 (C3435T) rs1045642 and risk of having epilepsy (MTLE-HS and JME pooled cohort; genotypic p-value = 0.0002; allelic p-value = 0.004). This association was seen persistent with MTLE-HS (genotypic p-value = 0.0008; allelic p-value = 0.004) and also with JME (genotypic p-value = 0.01; allelic p-value = 0.05) cohort individually. In-silico functional prediction indicated that ABCB1 rs1045642 has a deleterious impact on protein coding function and in splicing regulation. We conclude that the ABCB1 and ABCG2 variants do not confer to AED-resistance in the study population. However, ABCB1 rs1045642 increases vulnerability to epilepsy with greater tendency for MTLE-HS in south Indian ancestry from Kerala.

Mutual information and redundancy in spontaneous communication between cortical neurons.

PubMed

Szczepanski, J; Arnold, M; Wajnryb, E; Amigó, J M; Sanchez-Vives, M V

2011-03-01

An important question in neural information processing is how neurons cooperate to transmit information. To study this question, we resort to the concept of redundancy in the information transmitted by a group of neurons and, at the same time, we introduce a novel concept for measuring cooperation between pairs of neurons called relative mutual information (RMI). Specifically, we studied these two parameters for spike trains generated by neighboring neurons from the primary visual cortex in the awake, freely moving rat. The spike trains studied here were spontaneously generated in the cortical network, in the absence of visual stimulation. Under these conditions, our analysis revealed that while the value of RMI oscillated slightly around an average value, the redundancy exhibited a behavior characterized by a higher variability. We conjecture that this combination of approximately constant RMI and greater variable redundancy makes information transmission more resistant to noise disturbances. Furthermore, the redundancy values suggest that neurons can cooperate in a flexible way during information transmission. This mostly occurs via a leading neuron with higher transmission rate or, less frequently, through the information rate of the whole group being higher than the sum of the individual information rates-in other words in a synergetic manner. The proposed method applies not only to the stationary, but also to locally stationary neural signals.

Slope monitoring by using 2-D resistivity method at Sungai Batu, Pulau Pinang, Malaysia

NASA Astrophysics Data System (ADS)

Azman, Muhamad Iqbal Mubarak Faharul; Yusof, Azim Hilmy Mohd; Ismail, Nur Azwin; Ismail, Noer El Hidayah

2017-07-01

Slope is a dynamic system of geo-environmental phenomena that related to the movement of the soil and rock masses. In Pulau Pinang, the occurrence of slope related phenomena such as landslide and rock fall has become a huge issue especially during rainy season as the government would have to invest more for the people safety. 2-D resistivity method is one of the geophysical methods that can be applied to overcome this issue thus prepare countermeasure actions. Monitoring is one of the common acquisition technique that has been used in solving such issue. This technique was applied to identify and monitor changes at the suspected area and thus, countermeasure steps can be taken accordingly and not blindfolded. Starting from August until November 2016, a 200 m survey line of 2-D resistivity survey had been conducted monthly at Sungai Batu, Pulau Pinang slope for monitoring purpose. Three resistivity ranges were able to detect within the subsurface. Resistivity value of 250 - 400 Ωm indicated the low resistivity value and interpreted as the weak zone located at distance of 90 - 120 m with depth of 10 m. Intermediate resistivity value was interpreted as weathered granite zone with resistivity value of 400 - 1500 Ωm was found at almost along survey line. High resistivity value was > 5000 Ωm and interpreted as granitic bedrock located at depth of > 20 m. Aside from weathered granite zone and weak zone, a fracture was found develop over time at distance of 130 - 140 m. The features found have the potential to be the cause for slope failure phenomena to occur. As a conclusion, monitoring slope using 2-D resistivity method is a success and indeed helpful in overcome landslide and rock fall issue as a pre-countermeasure action.

Health care reform: can a communitarian perspective be salvaged?

PubMed

Callahan, Daniel

2011-10-01

The United States is culturally oriented more toward individual rights and values than to communitarian values. That proclivity has made it hard to develop a common good, or solidarity-based, perspective on health care. Too many people believe they have no obligation to support the health care of others and resist a strong role for government, higher taxation, or reduced health benefits. I argue that we need to build a communitarian perspective on the concept of solidarity, which has been the concept underlying European health care systems, by focusing not on individual needs, but rather, on those of different age groups--that is, what people need at different stages of life.

Association between insulin resistance and oxidative stress parameters in obese adolescents with non-alcoholic fatty liver disease.

PubMed

Pirgon, Özgür; Bilgin, Hüseyin; Çekmez, Ferhat; Kurku, Hüseyin; Dündar, Bumin Nuri

2013-01-01

Non-alcoholic fatty liver disease (NAFLD) has become one of the most common chronic liver diseases in children. The aim of this study was to investigate the associations of oxidative stress with insulin resistance and metabolic risk factors in obese adolescents with NAFLD. Forty-six obese adolescents (23 girls and 23 boys, mean age: 12.8 ± 2.2 years) and 29 control subjects (15 girls and 14 boys, mean age: 12.7 ± 2.7 years) were enrolled in the study. The obese subjects were divided into two groups (NAFLD group and non-NAFLD group) based on the elevated alanine aminotransferase levels (>30 IU/L) and the presence or absence of liver steatosis detected by ultrasonography. Insulin resistance was evaluated by homeostasis model assessment (HOMA-IR) from fasting samples. Plasma total antioxidant status (TAS) and total oxidant status (TOS) level measurements (REL Assay Diagnostics) were done in all participants. The ratio of TOS to TAS was regarded as an oxidative stress index (OSI), an indicator of the degree of OS. Fasting insulin levels and HOMA-IR values in the NAFLD group were significantly higher than in the non-NAFLD and control groups. TAS measurements were decreased in both obese groups (NAFLD and non-NAFLD) in comparison with the control group. TOS and OSI measurements were higher in the NAFLD group than in the non-NAFLD and control groups. OSI was positively correlated with fasting insulin (r=0.67, p=0.01) and HOMA-IR (r=0.71, p=0.02) in the NAFLD obese group. In this cross-sectional study, elevated OS markers in obese adolescents with NAFLD were associated with insulin resistance. This data suggest that an antioxidant therapy might have a potential for treating NAFLD associated with insulin resistance.

Biocide and antibiotic susceptibility of Salmonella isolates obtained before and after cleaning at six Danish pig slaughterhouses.

PubMed

Gantzhorn, Mette Rørbæk; Pedersen, Karl; Olsen, John Elmerdahl; Thomsen, Line Elnif

2014-07-02

Salmonella sp. continues to be one of the most important foodborne pathogens. Control measures in terms of cleaning and disinfection on food production plants are very important for limiting the risk of contaminated food products to reach the consumer. In the last decade concern has arisen that bacteria exposed to disinfectants can develop resistance toward disinfectants and can have a higher risk of developing antibiotic resistance. The objectives of this study were to examine the prevalence of biocide resistant Salmonella sp. in Danish pig slaughterhouses, to evaluate if there was a correlation between susceptibilities to biocides and antibiotics, and to examine if cleaning and disinfection select isolates with changed susceptibility toward biocides or antibiotics. Salmonella sp. was isolated from the environment in Danish pig slaughterhouses before and after cleaning and disinfection. The susceptibility toward three different biocides, triclosan and two commercial disinfection products: Desinfect Maxi, a quaternary ammonium compound, and Incimaxx DES, an acetic compound, was determined. We found no resistance toward the biocides tested, but we did find that isolates obtained after cleaning had higher minimum inhibitory concentration (MIC) values toward one of the disinfectants (Incimaxx DES) compared to isolates obtained before cleaning and disinfection. This could indicate selection of strains that are more tolerant, due to the cleaning and disinfection. Furthermore, we found that there was a weak statistical correlation between MICs toward the biocides and some antibiotics, but no difference in log(MIC)s toward antibiotics between isolates obtained before and after cleaning, nor did we find any difference in the number of resistances of isolates obtained before and after cleaning and disinfection. Copyright © 2014 Elsevier B.V. All rights reserved.

The relationship of thioredoxin-1 and cisplatin resistance: its impact on ROS and oxidative metabolism in lung cancer cells.

PubMed

Wangpaichitr, Medhi; Sullivan, Elizabeth J; Theodoropoulos, George; Wu, Chunjing; You, Min; Feun, Lynn G; Lampidis, Theodore J; Kuo, Macus T; Savaraj, Niramol

2012-03-01

Elimination of cisplatin-resistant lung cancer cells remains a major obstacle. We have shown that cisplatin-resistant tumors have higher reactive oxygen species (ROS) levels and can be exploited for targeted therapy. Here, we show that increased secretion of the antioxidant thioredoxin-1 (TRX1) resulted in lowered intracellular TRX1 and contributed to higher ROS in cisplatin-resistant tumors in vivo and in vitro. By reconstituting TRX1 protein in cisplatin-resistant cells, we increased sensitivity to cisplatin but decreased sensitivity to elesclomol (ROS inducer). Conversely, decreased TRX1 protein in parental cells reduced the sensitivity to cisplatin but increased sensitivity to elesclomol. Cisplatin-resistant cells had increased endogenous oxygen consumption and mitochondrial activity but decreased lactic acid production. They also exhibited higher levels of argininosuccinate synthetase (ASS) and fumarase mRNA, which contributed to oxidative metabolism (OXMET) when compared with parental cells. Restoring intracellular TRX1 protein in cisplatin-resistant cells resulted in lowering ASS and fumarase mRNAs, which in turn sensitized them to arginine deprivation. Interestingly, cisplatin-resistant cells also had significantly higher basal levels of acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS). Overexpressing TRX1 lowered ACC and FAS proteins expressions in cisplatin-resistant cells. Chemical inhibition and short interfering RNA of ACC resulted in significant cell death in cisplatin-resistant compared with parental cells. Conversely, TRX1 overexpressed cisplatin-resistant cells resisted 5-(tetradecyloxy)-2-furoic acid (TOFA)-induced death. Collectively, lowering TRX1 expression through increased secretion leads cisplatin-resistant cells to higher ROS production and increased dependency on OXMET. These changes raise an intriguing therapeutic potential for future therapy in cisplatin-resistant lung cancer.

Low resistivity and permeability in actively deforming shear zones on the San Andreas Fault at SAFOD

USGS Publications Warehouse

Morrow, Carolyn A.; Lockner, David A.; Hickman, Stephen H.

2015-01-01

The San Andreas Fault Observatory at Depth (SAFOD) scientific drillhole near Parkfield, California crosses the San Andreas Fault at a depth of 2.7 km. Downhole measurements and analysis of core retrieved from Phase 3 drilling reveal two narrow, actively deforming zones of smectite-clay gouge within a roughly 200 m-wide fault damage zone of sandstones, siltstones and mudstones. Here we report electrical resistivity and permeability measurements on core samples from all of these structural units at effective confining pressures up to 120 MPa. Electrical resistivity (~10 ohm-m) and permeability (10-21 to 10-22 m2) in the actively deforming zones were one to two orders of magnitude lower than the surrounding damage zone material, consistent with broader-scale observations from the downhole resistivity and seismic velocity logs. The higher porosity of the clay gouge, 2 to 8 times greater than that in the damage zone rocks, along with surface conduction were the principal factors contributing to the observed low resistivities. The high percentage of fine-grained clay in the deforming zones also greatly reduced permeability to values low enough to create a barrier to fluid flow across the fault. Together, resistivity and permeability data can be used to assess the hydrogeologic characteristics of the fault, key to understanding fault structure and strength. The low resistivities and strength measurements of the SAFOD core are consistent with observations of low resistivity clays that are often found in the principal slip zones of other active faults making resistivity logs a valuable tool for identifying these zones.

Heat capacity, resistivity, and angular dependent magnetization studies of single crystal Nd 1 + ϵ Fe 4 B 4 for ϵ ≈ 1 7

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conner, Benjamin S.; Susner, Michael A.; UES Inc., Beavercreek, OH

Advances in crystal growth have allowed for synthesis of large single crystals of Nd 1+ϵFe 4B 4, a well-known phase with a modulated structure. As a result we are able to report heat capacity and resistivity measurements on a single crystal Nd 1+ϵFe 4B 4 sample with a distribution of ϵ that skews towards the solubility limit of Nd near ϵ ≈ 17. Heat capacity measurements show evidence of crystal field splitting at temperatures higher than the long-range ferromagnetic Curie temperature. Heat capacity, resistivity, and magnetization measurements all confirm a Curie temperature of 7 K which is lower than previouslymore » reported values in the Nd 1+ϵFe 4B 4 system. Here, we also perform measurements of the angular dependence of the magnetization and discover behavior associated with the magnetic anisotropy that is inconsistent with the simple description previously proposed.« less

Superconducting characteristics in purified tantalum-foils

NASA Astrophysics Data System (ADS)

Hu, Qinghua; Wang, Zhihe

2018-07-01

We have conducted extensive investigations on the electrical transport and magnetization on a purified tantalum foil with extremely sharp resistive transition (transition width ΔTc < 0.02 K) at 0 T and residual resistivity ratio ρ290K/ρ5K= 16.75. Many effects, such as anisotropic field-induced resistive broadening and second peak of the magnetization-hysteresis loop, are observed in the sample. The maximum upper critical field determined by criteria of R/Rn = 0.9 is about 1.08 T rather weak compared to that in cuprate and/or iron-based superconductors. Although the value of upper critical field Hc2(0) and the field dependence of effective pinning energy U show that the flux pinning potential is weaker, the critical current density Jc(2 K, 0 T) = 1.145 × 105 A/cm2 and the effect of second peak indicate that there should be higher collective vortex pinning potential in the tantalum foil. The carriers are dominated by holes with the density n = 6.6 × 1022/cm3.

Heat capacity, resistivity, and angular dependent magnetization studies of single crystal Nd 1 + ϵ Fe 4 B 4 for ϵ ≈ 1 7

DOE PAGES

Conner, Benjamin S.; Susner, Michael A.; UES Inc., Beavercreek, OH; ...

2017-04-04

Advances in crystal growth have allowed for synthesis of large single crystals of Nd 1+ϵFe 4B 4, a well-known phase with a modulated structure. As a result we are able to report heat capacity and resistivity measurements on a single crystal Nd 1+ϵFe 4B 4 sample with a distribution of ϵ that skews towards the solubility limit of Nd near ϵ ≈ 17. Heat capacity measurements show evidence of crystal field splitting at temperatures higher than the long-range ferromagnetic Curie temperature. Heat capacity, resistivity, and magnetization measurements all confirm a Curie temperature of 7 K which is lower than previouslymore » reported values in the Nd 1+ϵFe 4B 4 system. Here, we also perform measurements of the angular dependence of the magnetization and discover behavior associated with the magnetic anisotropy that is inconsistent with the simple description previously proposed.« less

Microbial desalination cells packed with ion-exchange resin to enhance water desalination rate.

PubMed

Morel, Alexandre; Zuo, Kuichang; Xia, Xue; Wei, Jincheng; Luo, Xi; Liang, Peng; Huang, Xia

2012-08-01

A novel configuration of microbial desalination cell (MDC) packed with ion-exchange resin (R-MDC) was proposed to enhance water desalination rate. Compared with classic MDC (C-MDC), an obvious increase in desalination rate (DR) was obtained by R-MDC. With relatively low concentration (10-2 g/L NaCl) influents, the DR values of R-MDC were about 1.5-8 times those of C-MDC. Ion-exchange resins packed in the desalination chamber worked as conductor and thus counteracted the increase in ohmic resistance during treatment of low concentration salt water. Ohmic resistances of R-MDC stabilized at 3.0-4.7 Ω. By contrast, the ohmic resistances of C-MDC ranged from 5.5 to 12.7 Ω, which were 55-272% higher than those of R-MDC. Remarkable improvement in desalination rate helped improve charge efficiency for desalination in R-MDC. The results first showed the potential of R-MDC in the desalination of water with low salinity. Copyright © 2012 Elsevier Ltd. All rights reserved.

Extrinsic origins of the apparent relaxorlike behavior in CaCu3Ti4O12 ceramics at high temperatures: A cautionary tale

NASA Astrophysics Data System (ADS)

Li, Ming; Sinclair, Derek C.; West, Anthony R.

2011-04-01

Although the origins of the high effective permittivity observed in CaCu3Ti4O12 (CCTO) ceramics and single crystals at ˜100-400 K have been resolved, the relaxorlike temperature- and frequency-dependence of permittivity obtained from fixed frequency capacitance measurements at higher temperatures reported in the literature remains unexplained, especially as CCTO adopts a centrosymmetric cubic crystal structure in the range of ˜35-1273 K. Impedance spectroscopy studies reveal that this type of relaxorlike behavior is an artifact induced mainly by a nonohmic sample-electrode contact impedance. In addition, an instrument-related parasitic series inductance and resistance effect modifies the measured capacitance values as the sample resistance decreases with increasing temperature. This can lead to an underestimation of the sample capacitance and, in extreme cases, to so-called `negative capacitance.' Such a relaxorlike artifact and negative capacitance behavior are not unique to CCTO and may be expected in other leaky dielectrics whose resistance is low.

Long-Wavelength Infrared Sensing by Cytochrome C Protein Thin Film Deposited by the Spin Coating Method

PubMed Central

Lai, Bo-Yu; Chu, Chung-Hao; Su, Guo-Dung John

2013-01-01

High infrared absorption, large temperature coefficient of resistance (TCR) and small 1/f noise are preferred characteristics for sensing materials used in bolometers. In this paper, we discuss a cytochrome c protein as a potential sensing material for long-wavelength bolometers. We simulated and experimentally proved high infrared absorption of cytochrome c in the wavelength between 8 μm and 14 μm. Cytochrome c thin films were deposited on a hydrophilic surface using the spin coating method. The resistance variation with temperature is measured and we show that the TCR of cytochrome c thin films is consistently higher than 20%. The measured values of 1/f noise were as low as 2.33 × 10−13 V2/Hz at 60 Hz. Finally, we test the reliability of cytochrome c by measuring the resistance changes over time under varying conditions. We found that cytochrome c thin films deteriorated significantly without appropriate packaging. PMID:24264331

Quantum Hall resistance standards from graphene grown by chemical vapour deposition on silicon carbide

NASA Astrophysics Data System (ADS)

Lafont, F.; Ribeiro-Palau, R.; Kazazis, D.; Michon, A.; Couturaud, O.; Consejo, C.; Chassagne, T.; Zielinski, M.; Portail, M.; Jouault, B.; Schopfer, F.; Poirier, W.

2015-04-01

Replacing GaAs by graphene to realize more practical quantum Hall resistance standards (QHRS), accurate to within 10-9 in relative value, but operating at lower magnetic fields than 10 T, is an ongoing goal in metrology. To date, the required accuracy has been reported, only few times, in graphene grown on SiC by Si sublimation, under higher magnetic fields. Here, we report on a graphene device grown by chemical vapour deposition on SiC, which demonstrates such accuracies of the Hall resistance from 10 T up to 19 T at 1.4 K. This is explained by a quantum Hall effect with low dissipation, resulting from strongly localized bulk states at the magnetic length scale, over a wide magnetic field range. Our results show that graphene-based QHRS can replace their GaAs counterparts by operating in as-convenient cryomagnetic conditions, but over an extended magnetic field range. They rely on a promising hybrid and scalable growth method and a fabrication process achieving low-electron-density devices.

Influence of hydroxyapatite on the corrosion resistance of the Ti-13Nb-13Zr alloy.

PubMed

Duarte, Laís T; Biaggio, Sonia R; Rocha-Filho, Romeu C; Bocchi, Nerilso

2009-05-01

Electrochemical analyses on the biocompatible alloy Ti-13Nb-13Zr wt% in an electrolyte simulating physiological medium (PBS solution) are reported. Hydroxyapatite (HA) films were obtained on the alloy by electrodeposition at constant cathodic current. Samples of the alloy covered with an anodic-oxide film or an anodic-oxide/HA film were analyzed by open circuit potential and electrochemical impedance spectroscopy measurements during 180 days in the PBS electrolyte. Analyses of the open-circuit potential (E (oc)) values indicated that the oxide/HA film presents better protection characteristics than the oxide only. This behavior was corroborated by the higher film resistances obtained from impedance data, indicating that, besides improving the alloy osteointegration, the hydroxyapatite film may also increase the corrosion protection of the biomaterial.

Development of a New Generation of 4-Aminoquinoline Antimalarial Compounds Using Predictive Pharmacokinetic and Toxicology Models

PubMed Central

Ray, Sunetra; Madrid, Peter B.; Catz, Paul; LeValley, Susanna E.; Furniss, Michael J.; Rausch, Linda L.; Guy, R. Kiplin; DeRisi, Joseph L.; Iyer, Lalitha V.; Green, Carol E.; Mirsalis, Jon C.

2010-01-01

Among the known antimalarial drugs, chloroquine (CQ) and other 4-aminoquinolines have shown high potency and good bioavailability, yet complications associated with drug resistance necessitate the discovery of effective new antimalarial agents. ADMETa prediction studies were employed to evaluate a library of new molecules based on the 4-aminoquinolone-related structure of CQ. Extensive in vitro screening and in vivo pharmacokinetic studies in mice helped to identify two lead molecules, 18 and 4, with promising in vitro therapeutic efficacy, improved ADMET properties, low risk for drug-drug interactions, and desirable pharmacokinetic profiles. Both 18 and 4 are highly potent antimalarial compounds, with IC50 values = 5.6 nM and 17.3 nM, respectively, against the W2 (CQ-resistant) strain of Plasmodium falciparum (IC50 for CQ = 382 nM). When tested in mice, these compounds were found to have biological half-lives and plasma exposure values similar to or higher than those of CQ; they are therefore desirable candidates to pursue in future clinical trials. PMID:20361799

Progress Report on Long Hold Time Creep Fatigue of Alloy 617 at 850°C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carroll, Laura Jill

Alloy 617 is the leading candidate material for an intermediate heat exchanger for the very high temperature reactor. To evaluate the behavior of this material in the expected service conditions, strain-controlled cyclic tests that include long hold times up to 240 minutes at maximum tensile strain were conducted at 850°C. In terms of the total number of cycles to failure, the fatigue resistance decreased when a hold time was added at peak tensile strain. Increases in the tensile hold duration degraded the creep-fatigue resistance, at least to the investigated strain controlled hold time of up to 60 minutes at themore » 0.3% strain range and 240 minutes at the 1.0% strain range. The creep-fatigue deformation mode is considered relative to the lack of saturation, or continually decreasing number of cycles to failure with increasing hold times. Additionally, preliminary values from the 850°C creep-fatigue data are calculated for the creep-fatigue damage diagram and have higher values of creep damage than those from tests at 950°C.« less

Combined application of vertical electrical sounding and 2D electrical resistivity imaging for geothermal groundwater characterization: Hammam Sayala hot spring case study (NW Tunisia)

NASA Astrophysics Data System (ADS)

Chabaane, Achref; Redhaounia, Belgacem; Gabtni, Hakim

2017-10-01

The following work is an attempt to enhance and optimize the potential exploitation of the Hammam Sayala thermal spring (NW Tunisia). This hot spring is located at 10 km of South-western Béja city, with higher temperature values around 42 °C and a low discharge value of about 1 l s-1. The geological and structural settings of the study area are complex and associated with faults and Triassic intruded salt and evaporate. An integrated geophysical approach using Electrical Resistivity Tomography (ERT), Induced Polarization (IP) and Vertical Electrical Sounding (VES) techniques can provide a high-resolution subsurface image of the principal geothermal plume and associated pathways. These data were used to determine and understand the mechanisms responsible of the rise of hot water flowing out onto the surface. Our results add new information of the hydrothermal system's context in Hammam Sayala area, which can help to create a therapeutic center opening new perspectives in the Béja region and to encourage regional thermal tourism development.

Slope failures evaluation and landslides investigation using 2-D resistivity method

NASA Astrophysics Data System (ADS)

Nordiana, M. M.; Azwin, I. N.; Nawawi, M. N. M.; Khalil, A. E.

2018-06-01

Slope failure is a complex phenomenon that may caused to landslides. Buildings and infrastructure such as transportation facilities and pipelines located within the boundaries of a landslide can be damaged or destroyed. Slope failure classification and various factors contributing to the instability using 2-D resistivity survey conducted in Selangor, Malaysia are described. Six 2-D resistivity survey lines with 5 m minimum electrode spacing using Pole-dipole array were performed. The data were processed using Res2Dinv and surfer10 software to evaluate the subsurface characteristics. The 2-D resistivity results show that the subsurface consist of two main zones. The first zone was alluvium or highly weathered with resistivity value of 100-1000 Ω m and depth of >30 m. This zone consists of saturated area with resistivity value of 1-100 Ω m and boulders with resistivity value of 1200-7000 Ω m. The second zone with resistivity value of >7000 Ω m was interpreted as granitic bedrock. The study area was characterized by saturated zones, highly weathered zone, highly contain of sand and boulders that will trigger slope failure in the survey area. This will cause to low strength of soil, debris flow and movement of earth. On the basis of the case examples described, 2-D resistivity method is categorized into desirable and useful method in determination of slope failure and future assessments.

Changes in Hormonal Concentrations after Different Heavy-Resistance Exercise Protocols in Women

DTIC Science & Technology

1993-01-01

men, we values were 62.1 ± 5.6% (SD) carbohydrate , 13.5 ± 2.3% have previously demonstrated that these two acute pro- protein, and 24.4 ± 6.3% fat...growth hormone. These find- hormone has a complex influence on carbohydrate me- ings may be due to the much higher resting baseline of tabolism, with its...A. WESEMAN. B. P. CONROY, S. E. acteristics of national -caliber United States women weightlifters . GORDON. J. R. HOFFMAN, AND C. M. MARESH. The

Insulin resistance index (HOMA-IR) in the differentiation of patients with non-alcoholic fatty liver disease and healthy individuals.

PubMed

Salgado, Ana Lúcia Farias de Azevedo; Carvalho, Luciana de; Oliveira, Ana Claudia; Santos, Virgínia Nascimento dos; Vieira, Jose Gilberto; Parise, Edison Roberto

2010-01-01

Due to its good correlation to glycemic clamp, HOMA-IR has been widely utilized as insulin resistance index in clinical and epidemiological studies involving non-alcoholic fatty liver disease carriers. However, values used for this parameter have shown large variability. To identify the HOMA-IR cut value that best distinguishes non-diabetic non-alcoholic fatty liver disease patients from a control group. One hundred sixteen non-alcoholic fatty liver disease patients were studied, diagnosed by clinical, biochemical, and liver image or biopsy criteria, and 88 healthy individuals, without any liver disease and testing for oral glucose tolerance within normality. These groups did not differ in age and gender. All were submitted to oral glucose tolerance test and blood samples were collected for glucose and insulin measurements by immunofluorometric method. HOMA-IR was calculated according to the formula: fasting insulin (microU/L) x fasting glucose (nmol/L)/22.5. NAFLD patients showed higher insulin, glycemia, and HOMA-IR values than control group, even when excluding glucose intolerant and diabetes mellitus patients by their glycemic curves. HOMA-IR 75th percentile for control group was 1.78 and the best area under the curve index was obtained for HOMA-IR values of 2.0 [AUC= 0.840 (0.781-0.899 CI 95%), sensitivity (Se): 85%, specificity (Sp): 83%] while value 2.5 showed best specificity without important loss in sensitivity [AUC=0,831 (0.773-0.888) Se = 72%, Sp = 94%]. HOMA-IR values above or equal to 2.0 or 2.5 show enhanced diagnostic value in distinguishing non-alcoholic fatty liver disease carriers from control group individuals.

Prevalence and clinical characteristics of patients with true resistant hypertension in central and Eastern Europe: data from the BP-CARE study.

PubMed

Brambilla, Gianmaria; Bombelli, Michele; Seravalle, Gino; Cifkova, Renata; Laurent, Stephane; Narkiewicz, Krzysztof; Facchetti, Rita; Redon, Josep; Mancia, Giuseppe; Grassi, Guido

2013-10-01

Scanty information is available on the clinical characteristics of resistant hypertension in Central and East European countries. The Blood Pressure (BP) control rate and CArdiovascular Risk profilE (BP-CARE) study allowed us to assess the prevalence and the main clinical features of resistant hypertension in this population. The study was carried out in 1312 treated hypertensive patients living in nine Central and East European countries. Four hundred and twenty-three patients had apparent resistant hypertension, of whom 168 had pseudo-resistant hypertension (noncompliant/white-coat) and 255 were true treatment-resistant hypertension patients (TRH). Clinical BP values in TRH amounted to 157.4±16.9/91.8±10.0 mmHg despite the daily use of 3.6±0.7 drugs. Their 24-h BP values were 149.5±16.5/97.5±9.8 mmHg. Compared to controlled hypertensive patients (n=368) and uncontrolled nonresistant hypertensive patients (n=521), TRH were older with a greater prevalence of women. They showed a higher rate of previous cardiovascular events and a very high cardiovascular risk profile. Estimated glomerular filtration rate was significantly lower in TRH as compared to controlled hypertensive patients and uncontrolled nonresistant hypertensive patients. Overall, target organ damage was more frequently detected in TRH than in controlled hypertensive patients and uncontrolled nonresistant hypertensive patients. The factor most frequently associated with TRH was severity of hypertension followed by age, total cholesterol, BMI and history of heart failure. The present study provides evidence that the prevalence of TRH in Central and East European countries is similar to that found in Western Europe and USA. It also shows the very high cardiovascular risk of TRH and the elevated association of this condition with obesity, renal failure, organ damage and history of cardiovascular events.

Evaluation of the larval migration inhibition assay for detecting macrocyclic lactone resistance in Dirofilaria immitis.

PubMed

Evans, Christopher C; Moorhead, Andrew R; Storey, Bobby E; Blagburn, Byron L; Wolstenholme, Adrian J; Kaplan, Ray M

2017-11-15

Anthelmintics of the macrocyclic lactone (ML) drug class are widely used as preventives against the canine heartworm (Dirofilaria immitis). Over the past several years, however, reports of ML lack of efficacy (LOE) have emerged, in which dogs develop mature heartworm infection despite the administration of monthly prophylactics. More recently, isolates from LOE cases have been used to infect laboratory dogs and the resistant phenotype has been confirmed by the establishment of adult worms in the face of ML treatment at normally preventive dosages. Testing for and monitoring resistance in D. immitis requires a validated biological or molecular diagnostic assay. In this study, we assessed a larval migration inhibition assay (LMIA) that we previously optimized for use with D. immitis third-stage larvae (L 3 ). We used this assay to measure the in vitro ML susceptibilities of a known-susceptible laboratory strain of D. immitis and three highly suspected ML-resistant isolates originating from three separate LOE cases; progeny from two of these isolates have been confirmed ML-resistant by treatment of an infected dog in a controlled setting. A nonlinear regression model was fit to the dose-response data, from which IC 50 values were calculated. The D. immitis LMIA yielded consistent and reproducible dose-response data; however, no statistically significant differences in drug susceptibility were observed between control and LOE parasites. Additionally, the drug concentrations needed to paralyze the L 3 were much higher than those third- and fourth-stage larvae would experience in vivo. IC 50 values ranged from 1.57 to 5.56μM (p≥0.19). These data could suggest that ML resistance in this parasite is not mediated through a reduced susceptibility of L 3 to the paralytic effects of ML drugs, and therefore motility-based assays are likely not appropriate for measuring the effects of MLs against D. immitis in this target stage. Published by Elsevier B.V.

Are preference and resistance to change convergent expressions of stimulus value?

PubMed

Podlesnik, Christopher A; Jimenez-Gomez, Corina; Shahan, Timothy A

2013-07-01

Behavioral momentum theory asserts that preference and relative resistance to disruption depend on reinforcement rates and provide converging expressions of the conditioned value of discriminative stimuli. However, preference and resistance to disruption diverge when assessing preference during brief extinction probes. We expanded upon this opposing relation by arranging target stimuli signaling equal variable-interval schedules across components of a multiple schedule. We paired one target stimulus with a richer reinforced alternative and the other with a leaner alternative. Furthermore, we varied reinforcement rates for the paired alternatives to assess the effects of manipulating relative conditioned value on preference and resistance to disruption by presession feeding, intercomponent food, and extinction. We replicated the opposing relation between preference and resistance to disruption but varying reinforcement rates for the paired alternatives did not systematically affect preference or resistance to disruption beyond levels observed in our initial condition. Importantly, we found that only preference between the target stimuli was related to relative baseline response rates in the presence of those stimuli. These findings suggest that preference during extinction probes might reveal more about baseline response rates between concurrently available alternatives than relative conditioned value. Resistance to disruption, conversely, appears to better reflect conditioned value because it is less confounded with baseline response rates and is a function of all sources of reinforcement obtained in the presence of a stimulus context. © Society for the Experimental Analysis of Behavior.

Development of a High Slip-resistant Footwear Outsole Using a Hybrid Rubber Surface Pattern

PubMed Central

YAMAGUCHI, Takeshi; HOKKIRIGAWA, Kazuo

2014-01-01

Abstract: The present study examined whether a new footwear outsole with tread blocks and a hybrid rubber surface pattern, composed of rough and smooth surfaces, could increase slip resistance and reduce the risk of fall while walking on a wet floor surface. A drag test was performed to measure static and dynamic coefficient of friction (SCOF and DCOF, respectively) values for the footwear with the hybrid rubber surface pattern outsole and two types of commercially available boots that are conventionally used in food factories and restaurant kitchens with respect to a stainless steel floor covered with glycerol solution. Gait trials were conducted with 14 participants who wore the footwear on the wet stainless steel floor. The drag test results indicated that the hybrid rubber surface pattern sole exhibited higher SCOF (≥0.44) and DCOF (≥0.39) values than the soles of the comparative footwear (p<0.001). Because of such high SCOF and DCOF values, the slip frequency (p<0.01), slip distance (p<0.001), and slip velocity (p<0.001) for the footwear with the hybrid rubber surface pattern outsole were significantly lower than those for the comparative footwear, which resulted in no falls during trials. PMID:25055846

Characterization of a Laser Surface-Treated Martensitic Stainless Steel.

PubMed

Al-Sayed, S R; Hussein, A A; Nofal, A A; Hassab Elnaby, S I; Elgazzar, H

2017-05-29

Laser surface treatment was carried out on AISI 416 machinable martensitic stainless steel containing 0.225 wt.% sulfur. Nd:YAG laser with a 2.2-KW continuous wave was used. The aim was to compare the physical and chemical properties achieved by this type of selective surface treatment with those achieved by the conventional treatment. Laser power of different values (700 and 1000 W) with four corresponding different laser scanning speeds (0.5, 1, 2, and 3 m•min-1) was adopted to reach the optimum conditions for impact toughness, wear, and corrosion resistance for laser heat treated (LHT) samples. The 0 °C impact energy of LHT samples indicated higher values compared to the conventionally heat treated (CHT) samples. This was accompanied by the formation of a hard surface layer and a soft interior base metal. Microhardness was studied to determine the variation of hardness values with respect to the depth under the treated surface. The wear resistance at the surface was enhanced considerably. Microstructure examination was characterized using optical and scanning electron microscopes. The corrosion behavior of the LHT samples was also studied and its correlation with the microstructures was determined. The corrosion data was obtained in 3.5% NaCl solution at room temperature by means of a potentiodynamic polarization technique.

Characterization of a Laser Surface-Treated Martensitic Stainless Steel

PubMed Central

Al-Sayed, S. R.; Hussein, A. A.; Nofal, A. A.; Hassab Elnaby, S. I.; Elgazzar, H.

2017-01-01

Laser surface treatment was carried out on AISI 416 machinable martensitic stainless steel containing 0.225 wt.% sulfur. Nd:YAG laser with a 2.2-KW continuous wave was used. The aim was to compare the physical and chemical properties achieved by this type of selective surface treatment with those achieved by the conventional treatment. Laser power of different values (700 and 1000 W) with four corresponding different laser scanning speeds (0.5, 1, 2, and 3 m·min−1) was adopted to reach the optimum conditions for impact toughness, wear, and corrosion resistance for laser heat treated (LHT) samples. The 0 °C impact energy of LHT samples indicated higher values compared to the conventionally heat treated (CHT) samples. This was accompanied by the formation of a hard surface layer and a soft interior base metal. Microhardness was studied to determine the variation of hardness values with respect to the depth under the treated surface. The wear resistance at the surface was enhanced considerably. Microstructure examination was characterized using optical and scanning electron microscopes. The corrosion behavior of the LHT samples was also studied and its correlation with the microstructures was determined. The corrosion data was obtained in 3.5% NaCl solution at room temperature by means of a potentiodynamic polarization technique. PMID:28772955

A pull out test to compare two riparian species, Phyllanthus sellowianus and Sebastiania schottiana in terms of root anchorage ability

NASA Astrophysics Data System (ADS)

Hörbinger, Stephan; Sutili, Fabricio J.; Rauch, Hans Peter

2013-04-01

Soil bioengineering has become manifold applied in large parts of Brazil in recent years. The first projects were realized in the region of Rio Grande do Sul within river stabilization works to protect agricultural land of small regional farmers. As result of research work the species Sebastiania schottiana and Phyllanthus sellowianus showed very adequate morpho-physiological properties and seem to be appropriate for the use in soil bioengineering. The aim of the present study was to examine a still unknown but crucial factor, the resistance of the above mentioned species against being pulled out. The pull out resistance is an indicator for the stability of the soil-root matrix and expresses the stabilizing effects of plants on soil. Furthermore it is an applicable index to compare the qualification of the species to be used in soil bioengineering works. Another objective was to investigate plant characteristics, which correlate to the pull out resistance of the investigated species, to be able to draft up efficient plant strategies for future restoration works on eroded river embankments. For the experiment a special apparatus was designed, which enables to implement a pull out process with a constant rate and generate a graph of the plants resistance force versus its displacement. P. sellowianus showed a significant higher resistance against being pulled out than S. schottiana. The analyses of root and shoot properties of P. sellowianus showed more favorable morpho-physiological properties in terms of pull out resistance, a bigger amount of biomass, both above and below ground and also a higher amount of anchorage. The Cross-Sectional-Areas (CSA) of the shoots showed in both species the strongest correlation of the investigated shoot and root properties with the maximum resistance against being pulled out. Thus it can be concluded that the CSA can be used as a value to assess the stabilization effects of the plants. The experiments showed that some root and shoot properties do have a great impact on the pullout strength and that P. sellowianus can be preferred for slope stabilization works as it exhibits outstanding resistance against being pulled out.

Leaf Morphological Characters Can Be a Factor for Intra-Varietal Preference of Whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) among Eggplant Varieties.

PubMed

Hasanuzzaman, Abu Tayeb Mohammad; Islam, Md Nazrul; Zhang, Yi; Zhang, Chen-Yang; Liu, Tong-Xian

2016-01-01

The sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae) MEAM1, is considered a serious pest of horticultural and many other crops. While eggplant (Solanum melongena) is one of the most favored host plants, the whiteflies exhibit preferences among different varieties. We hypothesized that certain morphological leaf characteristics of different varieties, like leaf trichome density, trichome length, leaf lamina thickness and leaf color, may affect whitefly landing, feeding and oviposition. In this study, we investigated the variation in leaf morphological characters among selected eggplant varieties and evaluated the effect of these leaf characteristics in rendering eggplant varieties either susceptible or resistant to B. tabaci. We evaluated eight eggplant varieties in choice feeding tests, and we found that the varieties JinSheng Zilongchangqie (JSZ) and H149 were the highly preferred varieties with the highest numbers of whitefly adults and eggs. Significantly lower numbers of whitefly adult eggs were found on the resistant variety Tuo Lu Bamu (TLB). The varieties JinGuangbo Luqie (JGL), JinGuangbo Ziquanqie (JGZ), DaYang Ziguanqie (DYZ), QinXing Ziguanqie (QXZ), and QinXing Niuxinqie (QXN) were moderately favored by B. tabaci. Leaf trichome density, trichome length and leaf lamina thickness were positively correlated with numbers of whitefly adults and eggs. B. tabaci was less attracted to the leaves that reflect long and middle wavelength light (higher R and G values) than to the bright green leaves (medium G value), but the short wavelength light (higher B value) had no significant effect on whitefly preference. The degree of hue had a positive effect, and saturation and brightness had a negative effect on whitefly attraction.

Resistance Potential of Bread Wheat Genotypes Against Yellow Rust Disease Under Egyptian Climate.

PubMed

Mahmoud, Amer F; Hassan, Mohamed I; Amein, Karam A

2015-12-01

Yellow rust (stripe rust), caused by Puccinia striiformis f. sp. tritici, is one of the most destructive foliar diseases of wheat in Egypt and worldwide. In order to identify wheat genotypes resistant to yellow rust and develop molecular markers associated with the resistance, fifty F8 recombinant inbred lines (RILs) derived from a cross between resistant and susceptible bread wheat landraces were obtained. Artificial infection of Puccinia striiformis was performed under greenhouse conditions during two growing seasons and relative resistance index (RRI) was calculated. Two Egyptian bread wheat cultivars i.e. Giza-168 (resistant) and Sakha-69 (susceptible) were also evaluated. RRI values of two-year trial showed that 10 RILs responded with RRI value >6 <9 with an average of 7.29, which exceeded the Egyptian bread wheat cultivar Giza-168 (5.58). Thirty three RILs were included among the acceptable range having RRI value >2 <6. However, only 7 RILs showed RRI value <2. Five RILs expressed hypersensitive type of resistance (R) against the pathogen and showed the lowest Average Coefficient of Infection (ACI). Bulked segregant analysis (BSA) with eight simple sequence repeat (SSR), eight sequence-related amplified polymorphism (SRAP) and sixteen random amplified polymorphic DNA (RAPD) markers revealed that three SSR, three SRAP and six RAPD markers were found to be associated with the resistance to yellow rust. However, further molecular analyses would be performed to confirm markers associated with the resistance and suitable for marker-assisted selection. Resistant RILs identified in the study could be efficiently used to improve the resistance to yellow rust in wheat.

Toward ethnocultural diversification of higher education.

PubMed

Hall, Gordon C Nagayama; Martinez, Charles R; Tuan, Mia; McMahon, Timothy R; Chain, Jennifer

2011-07-01

Attitudes toward ethnocultural diversification in higher education mirror attitudes toward paying taxes. Dissenters are opposed to paying taxes or to ethnocultural diversification. Passive Supporters value the benefits of taxes or ethnocultural diversification, but pay taxes or engage in diversity efforts only when required to do so. Active Supporters pay taxes or support diversity efforts even if they are not required to do so. Mandatory approaches to decrease the resistance of Dissenters to ethnocultural diversification may be necessary, whereas compelling voluntary approaches may be useful to mobilize Passive Supporters. Solutions need to be tailored to the needs of European Americans and persons of color. This article offers a conceptual framework for future research and interventions.

Toward Ethnocultural Diversification of Higher Education

PubMed Central

Nagayama Hall, Gordon C.; Martinez, Charles R.; Tuan, Mia; McMahon, Timothy R.; Chain, Jennifer

2011-01-01

Attitudes toward ethnocultural diversification in higher education mirror attitudes toward paying taxes. Dissenters are opposed to paying taxes or to ethnocultural diversification. Passive Supporters value the benefits of taxes or ethnocultural diversification, but pay taxes or engage in diversity efforts only when required to do so. Active Supporters pay taxes or support diversity efforts even if they are not required to do so. Mandatory approaches to decrease the resistance of Dissenters to ethnocultural diversification may be necessary, whereas compelling voluntary approaches may be useful to mobilize Passive Supporters. Solutions need to be tailored to the needs of European Americans and persons of color. This article offers a conceptual framework for future research and interventions. PMID:21787056

Reference Values of Impulse Oscillometric Lung Function Indices in Adults of Advanced Age

PubMed Central

Schulz, Holger; Flexeder, Claudia; Behr, Jürgen; Heier, Margit; Holle, Rolf; Huber, Rudolf M.; Jörres, Rudolf A.; Nowak, Dennis; Peters, Annette; Wichmann, H.-Erich; Heinrich, Joachim; Karrasch, Stefan

2013-01-01

Background Impulse oscillometry (IOS) is a non-demanding lung function test. Its diagnostic use may be particularly useful in patients of advanced age with physical or mental limitations unable to perform spirometry. Only few reference equations are available for Caucasians, none of them covering the old age. Here, we provide reference equations up to advanced age and compare them with currently available equations. Methods IOS was performed in a population-based sample of 1990 subjects, aged 45–91 years, from KORA cohorts (Augsburg, Germany). From those, 397 never-smoking, lung healthy subjects with normal spirometry were identified and sex-specific quantile regression models with age, height and body weight as predictors for respiratory system impedance, resistance, reactance, and other parameters of IOS applied. Results Women (n = 243) showed higher resistance values than men (n = 154), while reactance at low frequencies (up to 20 Hz) was lower (p<0.05). A significant age dependency was observed for the difference between resistance values at 5 Hz and 20 Hz (R5–R20), the integrated area of low-frequency reactance (AX), and resonant frequency (Fres) in both sexes whereas reactance at 5 Hz (X5) was age dependent only in females. In the healthy subjects (n = 397), mean differences between observed values and predictions for resistance (5 Hz and 20 Hz) and reactance (5 Hz) ranged between −1% and 5% when using the present model. In contrast, differences based on the currently applied equations (Vogel & Smidt 1994) ranged between −34% and 76%. Regarding our equations the indices were beyond the limits of normal in 8.1% to 18.6% of the entire KORA cohort (n = 1990), and in 0.7% to 9.4% with the currently applied equations. Conclusions Our study provides up-to-date reference equations for IOS in Caucasians aged 45 to 85 years. We suggest the use of the present equations particularly in advanced age in order to detect airway dysfunction. PMID:23691036

Complex structure of Piton de la Fournaise and its underlying lithosphere revealed by magnetotelluric 3D inversion

NASA Astrophysics Data System (ADS)

Gailler, Lydie-Sarah; Martí, Anna; Lénat, Jean-François

2018-05-01

La Réunion is a large volcanic construction resting on Paleocene oceanic crust. Through the 3D inversion of a large set of magnetotelluric (MT) soundings, our results reveal the general resistivity structure of the western part of Piton de la Fournaise volcano down to its base and the first 10 km or so of the underlying lithosphere. The resistivity pattern shows a general stratification of the resistivity values. An upper resistive layer corresponds to unsaturated and water-saturated lava flows. This layer is thinner (a few hundred meters) in the Enclos and Plaine des Sables/Fond de la Rivière de l'Est areas than on the NW flank where it reaches 2000 m. Below, the rest of the edifice is distinctly more conductive and shows highly conductive patches. The origin of the globally weak resistivity of the lower part of the construction is not established but can be tentatively attributed to a higher degree of alteration. The case of the highly conductive patches is different. Resistivity values of a few Ω·m imply the presence of highly conductive fluids and/or minerals that, in this context, are generally associated with hydrothermal phenomena. In the Enclos, highly conductive patches are unambiguously attributed to the presently active hydrothermal system. Beneath the Plaine des Sables/Fond de la Rivière de l'Est, they may be associated with hydrothermal alteration developed by the ancient volcanic center. The larger highly conductive patches are found below sea level and above the crust beneath the NW flank, at depths significantly larger than the others. This area coincides with the path of the N120 rift zone, with a deep ( 10-20 km) seismicity and with diffuse CO2 degassing. A relationship may therefore be inferred between deep magmatic activity, eruptive activity and postulated highly conductive hydrothermal zone. In the globally weak resistivity of the lower part of the edifice, a dome of moderate resistivity (>1 kΩ·m) is centered beneath the Plaine des Sables. It is wider than a dense intrusive complex inferred from gravity models in the same area. The present resolution of both MT and gravity models cannot exclude a same nature for both structures. Beneath 4 km b.s.l., an increase of the resistivity values underlines an interface in good agreement with the inferred location of the transition between the edifice and the oceanic crust at this depth. The upper lithosphere shows resistivity values above 250 Ω·m. This study therefore demonstrates the capability of the method to image major shallow structures such as the hydrothermally altered zones, and deeper ones such as the heterogeneity of the crust. Fig. A.1. a) Location of the resistivity soundings used in this study at the scale of Piton de la Fournaise. b) Zoom on each set of soundings from various organizations. The study area is framed in red. Fig. B.1. Comparison between the raw data and model responses (xx, xy, yx, yy) at all sites and periods. Circles: measured data; dots: model responses. Black and blue: xx, xy; red and pink: yx and yy.

Influence of Cyclic Flexural Deformation on the Torsional Resistance of Controlled Memory and Conventional Nickel-titanium Instruments.

PubMed

Acosta, Eufemia Carolina Peláez; Resende, Pedro Damas; Peixoto, Isabella Faria da Cunha; Pereira, Érika Sales Joviano; Buono, Vicente Tadeu Lopes; Bahia, Maria Guiomar de Azevedo

2017-04-01

The aim of this study was to evaluate the influence of cyclic deformation on the torsional resistance of controlled memory (CM) nickel-titanium files in comparison with superelastic (SE) instruments with similar geometric and dimensional characteristics. New 30/.06 HyFlex (HF; Coltene/Whaledent, Inc, Cuyahoga Falls, OH), Typhoon (Clinician's Choice Dental Products, New Milford, CT), RaCe (FKG, La-Chaux De Fonds, Switzerland), and ProTaper Universal F2 instruments (F2; Dentsply Maillefer, Ballaigues, Switzerland) were assessed. The diameter and pitch length were measured along the active part of the instruments. The number of cycles to failure (Nf) in flexural fatigue and the torsional resistance were evaluated for new files (n = 10). Ten new instruments of each type were fatigued to 3/4 of their fatigue life and then submitted to torsion until rupture. Data were analyzed using 1-way analysis of variance (α = .05). New CM files had a significantly higher Nf when compared with SE instruments; HF exhibited the highest value (P = .001). The mean torque value for F2 was the highest (P = .001). CM files precycled to 3/4 Nf had a significantly lower torque than the new files (HF: P = .003, Typhoon: P = .001), whereas the SE instruments displayed no significant differences (F2: P = .059, RaCe: P = .079). Cyclic flexural loading significantly reduced the torsional resistance of CM instruments. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Insulin-sensitive obese children display a favorable metabolic profile.

PubMed

Vukovic, Rade; Mitrovic, Katarina; Milenkovic, Tatjana; Todorovic, Sladjana; Soldatovic, Ivan; Sipetic-Grujicic, Sandra; Zdravkovic, Dragan

2013-02-01

Most of what is known about the metabolically healthy obese phenomenon is derived from studies in the adult population and no standardized criteria to identify these individuals exist to date. The aim of this study was to determine if the preserved insulin sensitivity evaluated by homeostatic model assessment of insulin resistance (HOMA-IR) index is associated with favorable metabolic profile in the obese children. We studied a group of 248 children and adolescents (150 female, 98 male), aged 5.9-18.9 years with diet-induced obesity (BMI >95th percentile). The entire cohort was divided into quartiles based on levels of insulin resistance determined by HOMA-IR index. Subjects in the lower quartile of HOMA-IR were classified as insulin-sensitive group (ISG), whereas children in the upper quartile were categorized as insulin-resistant group (IRG). The ISG subjects had values of HOMA-IR ≤2.75 while the children from the IRG group had HOMA-IR ≥6.16. Subjects from ISG group had lower basal β-cell activity and were less likely to have impaired fasting glucose or impaired glucose tolerance. Concentrations of LDL and total cholesterol, triglycerides, and transaminases were lower and HDL cholesterol levels were higher in ISG subjects. Findings obtained by the use of Matsuda index correlated well with the findings obtained by the use of HOMA-IR. Lower HOMA-IR values were significantly associated with favorable metabolic profile in studied children, which correlates with findings in the adult population and emphasizes the need for further, longitudinal studies of insulin resistance development in childhood obesity.

Crossflow microfiltration of yeast suspensions in tubular filters.

PubMed

Redkar, S G; Davis, R H

1993-01-01

Crossflow microfiltration experiments were performed on yeast suspensions through 0.2-microns pore size ceramic and polypropylene tubes at various operating conditions. The initial transient flux decline follows dead-end filtration theory, with the membrane resistance determined from the initial flux and the specific cake resistance determined from the rate of flux decline due to cake buildup. For long times, the observed fluxes reach steady or nearly steady values, presumably as a result of the cake growth being arrested by the shear exerted at its surface. The steady-state fluxes increase with increasing shear rate and decreasing feed concentration, and they are nearly independent of transmembrane pressure. The steady-state fluxes for unwashed yeast in deionized water or fermentation media are typically 2-4 times lower than those predicted by a model based on the properties of nonadhesive, rigid spheres undergoing shear-induced back-diffusion. In contrast, the steady-state fluxes observed for washed yeast cells in deionized water are only 10-30% below the predicted values. The washed yeast cells also exhibited specific cake resistances that are an order of magnitude lower than those for the unwashed yeast. The differences are due to the presence of extracellular proteins and other macromolecules in the unwashed yeast suspensions. These biopolymers cause higher cell adhesion and resistance in the cake layer, so that the cells at the top edge are not free to diffuse away. This is manifested as a concentration jump from the edge of the cake layer to the sheared suspension adjacent to it.(ABSTRACT TRUNCATED AT 250 WORDS)

Groundwater Exploration in Baja California, Mexico, Using Audiomagnetotellurics

NASA Astrophysics Data System (ADS)

Antonio, R.; Arroyo, A.; Romo, J.; Vazquez, R.

2007-12-01

Guadalupe Valley, in Ensenada B. C. Mexico, basis of the winery industry of the region, is known by their climatic attributes for vineyard cultivation. In this place, the crop growing depends totally on underground water extracted of an aquifer contained in two separate small basins. In order to estimate the depth to water level, as well as the thickness of one of these basins, we carry out a geophysical survey using audio-magnetotellurics (AMT). We carried out five profiles in a frequency range between 1 Hz and 750 kHz to estimate the electrical conductivity of the ground. We know that this physical property is enhanced by the permeability as well as by the salinity of fluids in the aquifer. In contrast, the crystalline rocks forming the basement of the basin are very bad conductors of electricity. Based on the AMT observations we construct 2-D models of the ground resistivity distribution. Our results show a clear resistivity contrast between sediments and bedrock. The sediments have resistivity values that oscillate from 40 to 100 Ohm-m, associated with lithology and/or permeability changes. Some conductive bodies (5 to 15 Ohms-m) are observed at depths shallower that 150 m, which might be caused by the presence of water with higher salinity, or alternatively, by clay lens. The bottom of the basin has resistivity values larger than 300 Ohm-m typical of the granitic rocks composing the bedrock. The spatial variation of the basement depth suggests the presence a normal fault, in agreement with a graben structure proposed in former studies.

Power- and Low-Resistance-State-Dependent, Bipolar Reset-Switching Transitions in SiN-Based Resistive Random-Access Memory

NASA Astrophysics Data System (ADS)

Kim, Sungjun; Park, Byung-Gook

2016-08-01

A study on the bipolar-resistive switching of an Ni/SiN/Si-based resistive random-access memory (RRAM) device shows that the influences of the reset power and the resistance value of the low-resistance state (LRS) on the reset-switching transitions are strong. For a low LRS with a large conducting path, the sharp reset switching, which requires a high reset power (>7 mW), was observed, whereas for a high LRS with small multiple-conducting paths, the step-by-step reset switching with a low reset power (<7 mW) was observed. The attainment of higher nonlinear current-voltage ( I-V) characteristics in terms of the step-by-step reset switching is due to the steep current-increased region of the trap-controlled space charge-limited current (SCLC) model. A multilevel cell (MLC) operation, for which the reset stop voltage ( V STOP) is used in the DC sweep mode and an incremental amplitude is used in the pulse mode for the step-by-step reset switching, is demonstrated here. The results of the present study suggest that well-controlled conducting paths in a SiN-based RRAM device, which are not too strong and not too weak, offer considerable potential for the realization of low-power and high-density crossbar-array applications.

Critical soil bulk density for soybean growth in Oxisols

NASA Astrophysics Data System (ADS)

Keisuke Sato, Michel; Veras de Lima, Herdjania; Oliveira, Pedro Daniel de; Rodrigues, Sueli

2015-10-01

The aim of this study was to evaluate the critical soil bulk density from the soil penetration resistance measurements for soybean root growth in Brazilian Amazon Oxisols. The experiment was carried out in a greenhouse using disturbed soil samples collected from the northwest of Para characterized by different texture. The treatments consisted of a range of soil bulk densities for each soil textural class. Three pots were used for soybean growth of and two for the soil penetration resistance curve. From the fitted model, the critical soil bulk density was determined considering the penetration resistance values of 2 and 3 MPa. After sixty days, plants were cut and root length, dry mass of root, and dry mass of shoots were determined. At higher bulk densities, the increase in soil water content decreased the penetration resistance, allowing unrestricted growth of soybean roots. Regardless of soil texture, the penetration resistance of 2 and 3 MPa had a slight effect on root growth in soil moisture at field capacity and a reduction of 50% in the soybean root growth was achieved at critical soil bulk density of 1.82, 1.75, 1.51, and 1.45 Mg m-3 for the sandy loam, sandy clay loam, clayey, and very clayey soil.

All-nanotube stretchable supercapacitor with low equivalent series resistance.

PubMed

Gilshteyn, Evgenia P; Amanbayev, Daler; Anisimov, Anton S; Kallio, Tanja; Nasibulin, Albert G

2017-12-12

We report high-performance, stable, low equivalent series resistance all-nanotube stretchable supercapacitor based on single-walled carbon nanotube film electrodes and a boron nitride nanotube separator. A layer of boron nitride nanotubes, fabricated by airbrushing from isopropanol dispersion, allows avoiding problem of high internal resistance and short-circuiting of supercapacitors. The device, fabricated in a two-electrode test cell configuration, demonstrates electrochemical double layer capacitance mechanism and retains 96% of its initial capacitance after 20 000 electrochemical charging/discharging cycles with the specific capacitance value of 82 F g -1 and low equivalent series resistance of 4.6 Ω. The stretchable supercapacitor prototype withstands at least 1000 cycles of 50% strain with a slight increase in the volumetric capacitance from 0.4 to 0.5 mF cm -3 and volumetric power density from 32 mW cm -3 to 40 mW cm -3 after stretching, which is higher than reported before. Moreover, a low resistance of 250 Ω for the as-fabricated stretchable prototype was obtained, which slightly decreased with the strain applied up to 200 Ω. Simple fabrication process of such devices can be easily extended making the all-nanotube stretchable supercapacitors, presented here, promising elements in future wearable devices.

Differential Effects of High-Carbohydrate and High-Fat Diet Composition on Metabolic Control and Insulin Resistance in Normal Rats

PubMed Central

Ble-Castillo, Jorge L.; Aparicio-Trapala, María A.; Juárez-Rojop, Isela E.; Torres-Lopez, Jorge E.; Mendez, Jose D.; Aguilar-Mariscal, Hidemi; Olvera-Hernández, Viridiana; Palma-Cordova, Leydi C.; Diaz-Zagoya, Juan C.

2012-01-01

The macronutrient component of diets is critical for metabolic control and insulin action. The aim of this study was to compare the effects of high fat diets (HFDs) vs. high carbohydrate diets (HCDs) on metabolic control and insulin resistance in Wistar rats. Thirty animals divided into five groups (n = 6) were fed: (1) Control diet (CD); (2) High-saturated fat diet (HSFD); (3) High-unsaturated fat diet (HUFD); (4) High-digestible starch diet, (HDSD); and (5) High-resistant starch diet (HRSD) during eight weeks. HFDs and HCDs reduced weight gain in comparison with CD, however no statistical significance was reached. Calorie intake was similar in both HFDs and CD, but rats receiving HCDs showed higher calorie consumption than other groups, (p < 0.01). HRSD showed the lowest levels of serum and hepatic lipids. The HUFD induced the lowest fasting glycemia levels and HOMA-IR values. The HDSD group exhibited the highest insulin resistance and hepatic cholesterol content. In conclusion, HUFD exhibited the most beneficial effects on glycemic control meanwhile HRSD induced the highest reduction on lipid content and did not modify insulin sensitivity. In both groups, HFDs and HCDs, the diet constituents were more important factors than caloric intake for metabolic disturbance and insulin resistance. PMID:22754464

Somatostatin analogs and disease control in castration-resistant prostate cancer: different biological behavior? Case series and review of the literature.

PubMed

D'Angelillo, Rolando Maria; Greco, Carlo; Fiore, Michele; Ippolito, Edy; Eolo Trodella, Luca; Iurato, Aurelia; Molfese, Elisabetta; Ramella, Sara; Trodella, Lucio

2014-01-01

Castration-resistant prostate cancer is a recent biological behavior where disease can elude androgen deprivation therapy (ADT). Several pathways have been described, including neuroendocrine dedifferentiation. Patients with neuroendocrine dedifferentiation show an increase in chromogranin A (CgA) along with a PSA increase. Our aim was to evaluate the response of patients with castration-resistant prostate cancer and high CgA serum levels after treatment with inhibitors of neuroendocrine cells (somatostatin analogs) in combination with ADT. From January 2009 to April 2011, 10 patients with castration-resistant prostate cancer and rising PSA levels along with a CgA increase were evaluated. The therapy was based on somatostatin analogs and LHRH anologs. Total PSA and CgA were measured every 2 months. In 9 of the 10 patients, a reduction of the values of pre-treatment CgA was detected, while a reduction of PSA was found in 8 patients. No grade 2 or higher toxicity was recorded. Only 3 patients had grade 1 gastrointestinal toxicity. Time to progression was 13 months. Therapy with somatostatin analogs could increase the therapeutic window of ADT with a low toxicity profile in a subpopulation of patients with castration-resistant prostate cancer who experience a rise in CgA due to neuroendocrine regulation.

Aquaculture changes the profile of antibiotic resistance and mobile genetic element associated genes in Baltic Sea sediments.

PubMed

Muziasari, Windi I; Pärnänen, Katariina; Johnson, Timothy A; Lyra, Christina; Karkman, Antti; Stedtfeld, Robert D; Tamminen, Manu; Tiedje, James M; Virta, Marko

2016-04-01

Antibiotics are commonly used in aquaculture and they can change the environmental resistome by increasing antibiotic resistance genes (ARGs). Sediment samples were collected from two fish farms located in the Northern Baltic Sea, Finland, and from a site outside the farms (control). The sediment resistome was assessed by using a highly parallel qPCR array containing 295 primer sets to detect ARGs, mobile genetic elements and the 16S rRNA gene. The fish farm resistomes were enriched in transposon and integron associated genes and in ARGs encoding resistance to antibiotics which had been used to treat fish at the farms. Aminoglycoside resistance genes were also enriched in the farm sediments despite the farms not having used aminoglycosides. In contrast, the total relative abundance values of ARGs were higher in the control sediment resistome and they were mainly genes encoding efflux pumps followed by beta-lactam resistance genes, which are found intrinsically in many bacteria. This suggests that there is a natural Baltic sediment resistome. The resistome associated with fish farms can be from native ARGs enriched by antibiotic use at the farms and/or from ARGs and mobile elements that have been introduced by fish farming. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Radial distribution of the contributions to band broadening of a silica-based semi-preparative monolithic column.

PubMed

Abia, Jude A; Mriziq, Khaled S; Guiochon, Georges A

2009-04-01

Using an on-column local electrochemical microdetector operated in the amperometric mode, band elution profiles were recorded at different radial locations at the exit of a 10 mm id, 100 mm long silica-based monolithic column. HETP plots were then acquired at each of these locations, and all these results were fitted to the Knox equation. This provided a spatial distribution of the values of the eddy diffusion (A), the molecular diffusion (B), and the resistance to the kinetics of mass transfer (C) terms. Results obtained indicate that the wall region yields higher A values and smaller C values than the central core region. Significant radial fluctuations of these contributions to band broadening occur throughout the exit column cross-section. This phenomenon is due to the structural radial heterogeneity of the column.

Alpha-actinin-3 (ACTN3) R577X polymorphism influences knee extensor peak power response to strength training in older men and women.

PubMed

Delmonico, Matthew J; Kostek, Matthew C; Doldo, Neil A; Hand, Brian D; Walsh, Sean; Conway, Joan M; Carignan, Craig R; Roth, Stephen M; Hurley, Ben F

2007-02-01

The alpha-actinin-3 (ACTN3) R577X polymorphism has been associated with muscle power performance in cross-sectional studies. We examined baseline knee extensor concentric peak power (PP) and PP change with approximately 10 weeks of unilateral knee extensor strength training (ST) using air-powered resistance machines in 71 older men (65 [standard deviation = 8] years) and 86 older women (64 [standard deviation = 9] years). At baseline in women, the XX genotype group had an absolute (same resistance) PP that was higher than the RR (p =.005) and RX genotype groups (p =.02). The women XX group also had a relative (70% of one-repetition maximum [1-RM]) PP that was higher than that in the RR (p =.002) and RX groups (p =.008). No differences in baseline absolute or relative PP were observed between ACTN3 genotype groups in men. In men, absolute PP change with ST in the RR (n = 16) group approached a significantly higher value than in the XX group (n = 9; p =.07). In women, relative PP change with ST in the RR group (n = 16) was higher than in the XX group (n = 17; p =.02). The results indicate that the ACTN3 R577X polymorphism influences the response of quadriceps muscle power to ST in older adults.

The effect of resistance level and stability demands on recruitment patterns and internal loading of spine in dynamic flexion and extension using a simple trunk model.

PubMed

Zeinali-Davarani, Shahrokh; Shirazi-Adl, Aboulfazl; Dariush, Behzad; Hemami, Hooshang; Parnianpour, Mohamad

2011-07-01

The effects of external resistance on the recruitment of trunk muscles in sagittal movements and the coactivation mechanism to maintain spinal stability were investigated using a simple computational model of iso-resistive spine sagittal movements. Neural excitation of muscles was attained based on inverse dynamics approach along with a stability-based optimisation. The trunk flexion and extension movements between 60° flexion and the upright posture against various resistance levels were simulated. Incorporation of the stability constraint in the optimisation algorithm required higher antagonistic activities for all resistance levels mostly close to the upright position. Extension movements showed higher coactivation with higher resistance, whereas flexion movements demonstrated lower coactivation indicating a greater stability demand in backward extension movements against higher resistance at the neighbourhood of the upright posture. Optimal extension profiles based on minimum jerk, work and power had distinct kinematics profiles which led to recruitment patterns with different timing and amplitude of activation.

Patterns in Soil Electrical Resistivity Across Land Uses in the Calhoun Critical Zone Observatory Landscape

NASA Astrophysics Data System (ADS)

Markewitz, D.; Sutter, L.; Richter, D. D., Jr.

2017-12-01

Soil Electrical Resistivity Tomography (ERT) was measured across the Calhoun Critical Zone Observatory in relation to land use cover. ERT can help identify patterns in soil and saprolite physical attributes and moisture content through multiple meters. ERT data were generated with an AGI Supersting R8 with a 28 probe dipole-dipole array on a 1.5 meter spacing providing information through the upper 9 m. In Nov/Dec 2016 ten soil pits were dug to 3m depth in agricultural fields, pine forests, and hardwood forests across the CCZO and ERT measures were taken centered on these pits. ERT values ranged from 200 to 2500 Ohm-m. ERT patterns in the agricultural field demonstrated a limited resistivity gradient (200-700 Ohm-m) appearing moist throughout. In contrast, research areas under pine and hardwood forest had stronger resistivity gradients reflecting both moisture and physical attributes (i.e., texture or rock content). For example, research area 2 under pine had an area of higher resistivity that correlated with a band of saprolite that was readily visible in the exposed profile. In research area 7 and 8 that included both pine and hardwood forest resistivity gradients had contradictory patterns of high to low resistivity from top to bottom. In research area 7 resistivity was highest at the surface and decreased with depth, a common pattern when water table is at depth. In research area 8 the inverse was observed with low resistivity above and resistivity increasing with depth, a pattern observed in upper landscape positions on ridges with moist clay above dry saprolite. ERT patterns did reflect a large difference in the measured agricultural fields compared to forest while other difference appeared to reflect landscape position.

Abnormally banded chromosomal regions in doxorubicin-resistant B16-BL6 murine melanoma cells.

PubMed

Slovak, M L; Hoeltge, G A; Ganapathi, R

1986-08-01

B16-BL6 murine melanoma cells were selected for cytogenetic evaluation during the stepwise development of increasing resistance in vitro to the antitumor antibiotic, doxorubicin (DOX). Karyotypic studies demonstrated extensive heteroploidy with both numerical and structural abnormalities which were not present in the parental DOX-sensitive B16-BL6 cells. Trypsin-Giemsa banding revealed the presence of several marker chromosomes containing abnormally banding regions (ABRs) in the 44-fold B16-BL6 DOX-resistant subline. These ABRs appeared to be more homogeneously staining at the higher DOX concentrations. Length measurements (ABR index) in seven banded metaphases indicated a direct correlation with increasing DOX concentration. When the DOX-resistant cells were grown in drug-free medium for 1 yr, the drug-resistant phenotype gradually declined in parallel with the level of resistance and the ABR index. DOX-induced cytogenetic damage examined by sister chromatid exchange methodology in parental B16-BL6 cells indicated a linear sister chromatid exchange:DOX dose-response relationship. However, after continuous treatment of parental B16-BL6 cells with DOX (0.01 microgram/ml) for 30 days, sister chromatid exchange scores were found to return to base-line values. The B16-BL6 resistant cells demonstrated a cross-resistant phenotype with N-trifluoroacetyladriamycin-14-valerate, actinomycin D, and the Vinca alkaloids but not with 1-beta-D-arabinofuranosylcytosine. The results suggest that ABR-containing chromosomes in DOX-resistant sublines may represent cytogenetic alterations of specific amplified genes involved in the expression of DOX resistance. Further studies are required to identify and define the possible gene products and to correlate their relationship to the cytotoxic action of doxorubicin.

Breeding aflatoxin-resistant maize lines using recent advances in technologies - a review.

PubMed

Brown, Robert L; Menkir, Abebe; Chen, Zhi-Yuan; Bhatnagar, Deepak; Yu, Jiujiang; Yao, Haibo; Cleveland, Thomas E

2013-01-01

Aflatoxin contamination caused by Aspergillus flavus infection of corn is a significant and chronic threat to corn being used as food or feed. Contamination of crops at levels of 20 ng g(-1) or higher (as regulated by the USFDA) by this toxin and potent carcinogen makes the crop unsalable, resulting in a significant economic burden on the producer. This review focuses on elimination of this contamination in corn which is a major US crop and the basis of many products. Corn is also "nature's example" of a crop containing heritable resistance to aflatoxin contamination, thereby serving as a model for achieving resistance to aflatoxin contamination in other crops as well. This crop is the largest production grain crop worldwide, providing food for billions of people and livestock and critical feedstock for production of biofuels. In 2011, the economic value of the US corn crop was US$76 billion, with US growers producing an estimated 12 billion bushels, more than one-third of the world's supply. Thus, the economics and significance of corn as a food crop and the threat to food safety due to aflatoxin contamination of this major food crop have prompted the many research efforts in many parts of the world to identify resistance in corn to aflatoxin contamination. Plant breeding and varietal selection has been used as a tool to develop varieties resistance to disease. This methodology has been employed in defining a few corn lines that show resistance to A. flavus invasion; however, no commercial lines have been marketed. With the new tools of proteomics and genomics, identification of resistance mechanisms, and rapid resistance marker selection methodologies, there is an increasing possibility of finding significant resistance in corn, and in understanding the mechanism of this resistance.

Structural characteristics of slowly digestible starch and resistant starch isolated from heat-moisture treated waxy potato starch.

PubMed

Lee, Chang Joo; Moon, Tae Wha

2015-07-10

The objective of this study was to investigate the structural characteristics of slowly digestible starch (SDS) and resistant starch (RS) fractions isolated from heat-moisture treated waxy potato starch. The waxy potato starch with 25.7% moisture content was heated at 120°C for 5.3h. Scanning electron micrographs of the cross sections of RS and SDS+RS fractions revealed a growth ring structure. The branch chain-length distribution of debranched amylopectin from the RS fraction had a higher proportion of long chains (DP ≥ 37) than the SDS+RS fraction. The X-ray diffraction intensities of RS and SDS+RS fractions were increased compared to the control. The SDS+RS fraction showed a lower gelatinization enthalpy than the control while the RS fraction had a higher value than the SDS+RS fraction. In this study we showed the RS fraction is composed mainly of crystalline structure and the SDS fraction consists of weak crystallites and amorphous regions. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Effect of addition of instant corn flour on rheological characteristics of wheat flour and breadmaking III].

PubMed

Martínez, F; el-Dahs, A A

1993-12-01

The instant corn flour prepared by the hydrothermal process using corn grits soaked in water at room temperature (28-30 degrees C) for 5 hours and steaming for 1 minute at 118 degrees C presented characteristics similar to that of flours prepared with grits soaked in water at temperature higher than room temperature and different steaming time (5 and 15 minutes). The addition of instant corn flour up of a 25% mixture with wheat flour reduced the peak of maximum viscosity during the heating cycle; however, the final viscosity during the cooling cycle was increased. The water absorption was increased with the increase of substitution in the level of wheat flour. Extensibility, maximum resistance and values of area were reduced with an increase in the level of instant corn flour in the mixture. However, extension resistance and proportional number were increased. Bread prepared from a mixture of instant corn flour and wheat flour showed higher weight with low loaf volume, color and texture of the crumb related to bread wheat.

The effect of an atomically deposited layer of alumina on NiO in P-type dye-sensitized solar cells.

PubMed

Natu, Gayatri; Huang, Zhongjie; Ji, Zhiqiang; Wu, Yiying

2012-01-10

We present a systematic investigation of the fundamental effects of an atomically deposited alumina (AlO(x)H(y)) onto the NiO films in p-type dye-sensitized solar cells (p-DSCs). With P1 as the sensitizing dye and 0.1 M I(2) and 1.0 M LiI in 3-methoxypropionitrile as the electrolyte, one atomic layer deposition (ALD) cycle of alumina was used to achieve a 74% increase in the overall conversion efficiency of a NiO-based DSC. The open circuit voltage of the cells increased from 0.11 to 0.15 V, and the short circuit current density increased from 0.83 to 0.95 mA/cm(2). Adsorption isotherm studies were performed to show that the amount of dye adsorbed on the NiO-alumina film is slightly lower than the amount adsorbed on the nontreated NiO film. The increased J(sc) was therefore assigned to the increased efficiency of carrier collection at the semiconductor-FTO interface. Our study of the photocurrent onset potentials of NiO and NiO-alumina films with the chopped light measurement technique showed no definitive difference in the onset potential values. However, the DSCs based on NiO-alumina showed a higher recombination resistance value from the electrochemical impedance studies and a higher diode ideality factor from the V(oc) versus ln(light intensity) plots as compared to the DSCs based on untreated NiO. It has thus been established that the increase in V(oc) upon alumina treatment arises due to a higher resistance for electron-hole recombination across NiO surface locally.

Subsurface material identification and sensor selection

NASA Astrophysics Data System (ADS)

T, H.; Reghunadh, R.; Ramesh, M. V.

2017-12-01

In India, most of the landslides occur during monsoon season and causes huge loss of life and property. Design of an early warning system for highly landslide prone area will reduce losses to a great extent. The in-situ monitoring systems needs deployment of several sensors inside a borehole for monitoring a particular slope. Amrita Center for Wireless Networks and Applications (AmritaWNA), Amrita University has designed, developed and deployed a Wireless Sensor Network (WSN) for real time landslide monitoring using geotechnical instruments and sensors like rain gauge, moisture sensor, piezometer, strain gauge, tilt meter and geophone inside a Deep Earth Probe (DEP) at different locations. These sensors provide point measurements of the subsurface at a higher accuracy. Every landslide prone terrain is unique with respect to its geology, hydrological conditions, meteorological conditions, velocity of movement etc. The decision of installing different geotechnical instruments in a landslide prone terrain is a crucial step to be considered. Rain gauge, moisture sensor, and piezometer are usually used in clay rich areas to sense the moisture and pore pressure values. Geophone and Crack meter are instruments used in rocky areas to monitor cracks and vibrations associated with a movement. Inclinometer and Strain gauge are usually placed inside a casing and can be used in both rocky and soil areas. In order to place geotechnical instruments and sensors at appropriate places Electrical Resistivity Tomography (ERT) method can be used. Variation in electrical resistivity values indicate the changes in composition, layer thickness, or contaminant levels. The derived true resistivity image can be used for identifying the type of materials present in the subsurface at different depths. We have used this method for identifying the type of materials present in our site at Chandmari (Sikkim). Fig 1 shows the typical resistivity values of a particular area in Chandmari site. The results shows that the area has more clay so the placement of moisture sensor and piezometer are required instead of placing geophone, crack meter etc.

Accurate measurement of junctional conductance between electrically coupled cells with dual whole-cell voltage-clamp under conditions of high series resistance.

PubMed

Hartveit, Espen; Veruki, Margaret Lin

2010-03-15

Accurate measurement of the junctional conductance (G(j)) between electrically coupled cells can provide important information about the functional properties of coupling. With the development of tight-seal, whole-cell recording, it became possible to use dual, single-electrode voltage-clamp recording from pairs of small cells to measure G(j). Experiments that require reduced perturbation of the intracellular environment can be performed with high-resistance pipettes or the perforated-patch technique, but an accompanying increase in series resistance (R(s)) compromises voltage-clamp control and reduces the accuracy of G(j) measurements. Here, we present a detailed analysis of methodologies available for accurate determination of steady-state G(j) and related parameters under conditions of high R(s), using continuous or discontinuous single-electrode voltage-clamp (CSEVC or DSEVC) amplifiers to quantify the parameters of different equivalent electrical circuit model cells. Both types of amplifiers can provide accurate measurements of G(j), with errors less than 5% for a wide range of R(s) and G(j) values. However, CSEVC amplifiers need to be combined with R(s)-compensation or mathematical correction for the effects of nonzero R(s) and finite membrane resistance (R(m)). R(s)-compensation is difficult for higher values of R(s) and leads to instability that can damage the recorded cells. Mathematical correction for R(s) and R(m) yields highly accurate results, but depends on accurate estimates of R(s) throughout an experiment. DSEVC amplifiers display very accurate measurements over a larger range of R(s) values than CSEVC amplifiers and have the advantage that knowledge of R(s) is unnecessary, suggesting that they are preferable for long-duration experiments and/or recordings with high R(s). Copyright (c) 2009 Elsevier B.V. All rights reserved.

Interferon-γ-inducible protein-10 in chronic hepatitis C: Correlations with insulin resistance, histological features & sustained virological response.

PubMed

Crisan, Dana; Grigorescu, Mircea Dan; Radu, Corina; Suciu, Alina; Grigorescu, Mircea

2017-04-01

One of the multiple factors contributing to virological response in chronic hepatitis C (CHC) is interferon-gamma-inducible protein-10 (IP-10). Its level reflects the status of interferon-stimulated genes, which in turn is associated with virological response to antiviral therapy. The aim of this study was to evaluate the role of serum IP-10 levels on sustained virological response (SVR) and the association of this parameter with insulin resistance (IR) and liver histology. Two hundred and three consecutive biopsy proven CHC patients were included in the study. Serum levels of IP-10 were determined using ELISA method. IR was evaluated by homeostasis model assessment-IR (HOMA-IR). Histological features were assessed invasively by liver biopsy and noninvasively using FibroTest, ActiTest and SteatoTest. Predictive factors for SVR and their interrelations were assessed. A cut-off value for IP-10 of 392 pg/ml was obtained to discriminate between responders and non-responders. SVR was obtained in 107 patients (52.70%). Area under the receiver operating characteristic curve for SVR was 0.875 with a sensitivity of 91.6 per cent, specificity 74.7 per cent, positive predictive value 80.3 per cent and negative predictive value 88.7 per cent. Higher values of IP-10 were associated with increasing stages of fibrosis (P<0.01) and higher grades of inflammation (P=0.02, P=0.07) assessed morphologically and noninvasively through FibroTest and ActiTest. Significant steatosis and IR were also associated with increased levels of IP-10 (P=0.01 and P=0.02). In multivariate analysis, IP-10 levels and fibrosis stages were independently associated with SVR. Our findings showed that the assessment of serum IP-10 level could be a predictive factor for SVR and it was associated with fibrosis, necroinflammatory activity, significant steatosis and IR in patients with chronic HCV infection.

Increased antibiotic resistance exhibited by the biofilm of Vibrio cholerae O139.

PubMed

Gupta, Preeti; Mankere, Bharti; Chekkoora Keloth, Shami; Tuteja, Urmil; Pandey, Pratibha; Chelvam, Kulanthaivel Thava

2018-04-24

Vibrio cholerae, the aetiological agent of the deadly diarrhoeal disease cholera, is known to form biofilm. The antibiotic susceptibility status of biofilm of V. cholerae O139, an important epidemic strain in India and other countries, has not previously been studied in detail. Antibiotic susceptibility status of planktonic and biofilm cultures of V. cholerae O139 was evaluated by determining MIC, MBC and minimum biofilm eradication concentration (MBEC) values of five different classes of antibiotics using established methods. Effects of antibiotic treatment on planktonic and biofilm cultures were analysed by scanning electron microscopy. The virulence of the antibiotic-surviving population (ASP) was evaluated using an infant mouse model. The frequency of spontaneous mutants and inheritability of antibiotic resistance were determined with standard methods. The antibiotic resistance exhibited by biofilm of V. cholerae O139 was found to be significantly higher (P < 0.05) than its planktonic counterpart. The biofilm-associated antibiotic resistance was found to be transient and exclusive to the biofilm culture. The frequency of ASP clones among antibiotic-treated biofilm cultures occurred at a rate of 0.012%-0.95% and these clones were found to retain the virulence and antibiotic resistance of their parent strains. The biofilm of V. cholerae O139 was found to be resistant to different types of antibiotics tested. This unconventional biofilm resistance highlights the hidden danger of antimicrobial escape by V. cholerae, increased risk of cholera transmission and its continued persistence in the environment.

Insulin resistance and its association with the components of the metabolic syndrome among obese children and adolescents.

PubMed

Juárez-López, Carlos; Klünder-Klünder, Miguel; Medina-Bravo, Patricia; Madrigal-Azcárate, Adrián; Mass-Díaz, Eliezer; Flores-Huerta, Samuel

2010-06-07

Insulin resistance is the primary metabolic disorder associated with obesity; yet little is known about its role as a determinant of the metabolic syndrome in obese children. The aim of this study is to assess the association between the degree of insulin resistance and the different components of the metabolic syndrome among obese children and adolescents. An analytical, cross-sectional and population-based study was performed in forty-four public primary schools in Campeche City, Mexico. A total of 466 obese children and adolescents between 11-13 years of age were recruited. Fasting glucose and insulin concentrations, high density lipoprotein cholesterol, triglycerides, waist circumference, systolic and diastolic blood pressures were measured; insulin resistance and metabolic syndrome were also evaluated. Out of the total population studied, 69% presented low values of high density lipoprotein cholesterol, 49% suffered from abdominal obesity, 29% had hypertriglyceridemia, 8% presented high systolic and 13% high diastolic blood pressure, 4% showed impaired fasting glucose, 51% presented insulin resistance and 20% metabolic syndrome. In spite of being obese, 13% of the investigated population did not present any metabolic disorder. For each one of the components of the metabolic syndrome, when insulin resistance increased so did odds ratios as cardiometabolic risk factors. Regardless of age and gender an increased degree of insulin resistance is associated with a higher prevalence of disorders in each of the components of the metabolic syndrome and with a heightened risk of suffering metabolic syndrome among obese children and adolescents.

Effects of stroke resistance on rowing economy in club rowers post-season.

PubMed

Kane, D A; Mackenzie, S J; Jensen, R L; Watts, P B

2013-02-01

In the sport of rowing, increasing the impulse applied to the oar handle during the stroke can result in greater boat velocities; this may be facilitated by increasing the surface area of the oar blade and/or increasing the length of the oars. The purpose of this study was to compare the effects of different rowing resistances on the physiological response to rowing. 5 male and 7 female club rowers completed progressive, incremental exercise tests on an air-braked rowing ergometer, using either low (LO; 100) or high (HI; 150) resistance (values are according to the adjustable "drag factor" setting on the ergometer). Expired air, blood lactate concentration, heart rate, rowing cadence, and ergometer power output were monitored during the tests. LO rowing elicited significantly greater cadences (P<0.01) and heart rates (P<0.05), whereas rowing economy (J · L O(2) equivalents(-1)) was significantly greater during HI rowing (P<0.05). These results suggest that economically, rowing with a greater resistance may be advantageous for performance. Moreover, biomechanical analysis of ergometer rowing support the notion that the impulse generated during the stroke increases positively as a function of rowing resistance. We conclude that an aerobic advantage associated with greater resistance parallels the empirical trend toward larger oar blades in competitive rowing. This may be explained by a greater stroke impulse at the higher resistance. © Georg Thieme Verlag KG Stuttgart · New York.

Influence of the preparation design and artificial aging on the fracture resistance of monolithic zirconia crowns.

PubMed

Mitov, Gergo; Anastassova-Yoshida, Yana; Nothdurft, Frank Phillip; von See, Constantin; Pospiech, Peter

2016-02-01

The aim of this study was to evaluate the fracture resistance and fracture behavior of monolithic zirconia crowns in accordance with the preparation design and aging simulation method. An upper first molar was prepared sequentially with three different preparation designs: shoulderless preparation, 0.4 mm chamfer and 0.8 mm chamfer preparation. For each preparation design, 30 monolithic zirconia crowns were fabricated. After cementation on Cr-Co alloy dies, the following artificial aging procedures were performed: (1) thermal cycling and mechanical loading (TCML): 5000 cycles of thermal cycling 5℃-55℃ and chewing simulation (1,200,000 cycles, 50 N); (2) Low Temperature Degradation simulation (LTD): autoclave treatment at 137℃, 2 bar for 3 hours and chewing simulation; and (3) no pre-treatment (control group). After artificial aging, the crowns were loaded until fracture. The mean values of fracture resistance varied between 3414 N (LTD; 0.8 mm chamfer preparation) and 5712 N (control group; shoulderless preparation). Two-way ANOVA analysis showed a significantly higher fracture loads for the shoulderless preparation, whereas no difference was found between the chamfer preparations. In contrast to TCML, after LTD simulation the fracture strength of monolithic zirconia crowns decreased significantly. The monolithic crowns tested in this study showed generally high fracture load values. Preparation design and LTD simulation had a significant influence on the fracture strength of monolithic zirconia crowns.

Electrical, structural and morphological properties of chemically sprayed F-doped ZnO films: effect of the ageing-time of the starting solution, solvent and substrate temperature

NASA Astrophysics Data System (ADS)

Guillén-Santiago, A.; Olvera, M. De La L.; Maldonado, A.; Asomoza, R.; Acosta, D. R.

2004-04-01

Conductive and highly transparent fluorine-doped zinc oxide (ZnO:F) thin films were deposited onto glass substrates by the chemical spray technique, using zinc acetate and hydrofluoric acid as precursors. Electrical, structural, morphological and optical characteristics were analyzed as a function of the ageing-time of the starting solution, alcoholic solvent type (methanol or ethanol) and the substrate temperature. The results show that these variables play a crucial role on the physical properties measured. The growth rates obtained were of 3 nm/s, showing that the chemical species involved are adequate for the film growth. The effect of the solution ageing-time on the electrical properties was monitored along three weeks. A gradual resistivity decrease with the ageing-time was observed, until a minimum value is reached, at 7 or 9 days depending on the alcohol employed. Films deposited after this time have resistivity values slightly higher. All the films were polycrystalline, with a hexagonal wurtzite structure whose preferential growth is strongly dependent on the deposition variables. Under optimal deposition conditions, ZnO:F films with a high transmittance in the visible spectrum (>85%), resistivity as low as 7 × 10-3 cm and maximum electronic mobility around of 4 cm2/(V-s) were obtained.

A Comparative Study of Thermal Conductivity and Tribological Behavior of Squeeze Cast A359/AlN and A359/SiC Composites

NASA Astrophysics Data System (ADS)

Shalaby, Essam. A. M.; Churyumov, Alexander. Yu.; Besisa, Dina. H. A.; Daoud, A.; Abou El-khair, M. T.

2017-07-01

A comparative study of thermal and wear behavior of squeeze cast A359 alloy and composites containing 5, 10 and 15 wt.% AlN and SiC particulates was investigated. It was pointed out that A359/AlN composites have a superior thermal conductivity as compared to A359 alloy or even to A359/SiC composites. Composites wear characteristics were achieved by pins-on-disk instrument over a load range of 20-60 N and a sliding speed of 2.75 m/s. Results showed that A359/AlN and A359/SiC composites exhibited higher wear resistance values compared to A359 alloy. Moreover, A359/AlN composites showed superior values of wear resistance than A359/SiC composites at relatively high loads. Friction coefficients and contact surface temperature for A359/AlN specimens decreased as AlN content increased, while they increased for A359/SiC. Investigations of worn surfaces revealed that A359/AlN composites were covered up by aluminum nitrides and iron oxides, which acted as smooth layers. However, A359/SiC composites were mainly covered only by iron oxides. The superior thermal conductivity and the significant wear resistance of the developed A359/AlN composites provided a high durable material suitable for industrial applications.

Carrier Selective, Passivated Contacts for High Efficiency Silicon Solar Cells based on Transparent Conducting Oxides

DOE PAGES

Young, David L.; Nemeth, William; Grover, Sachit; ...

2014-01-01

We describe the design, fabrication and results of passivated contacts to n-type silicon utilizing thin SiO 2 and transparent conducting oxide layers. High temperature silicon dioxide is grown on both surfaces of an n-type wafer to a thickness <50 Å, followed by deposition of tin-doped indium oxide (ITO) and a patterned metal contacting layer. As deposited, the thin-film stack has a very high J0, contact, and a non-ohmic, high contact resistance. However, after a forming gas anneal, the passivation quality and the contact resistivity improve significantly. The contacts are characterized by measuring the recombination parameter of the contact (J0, contact)more » and the specific contact resistivity (ρ contact) using a TLM pattern. The best ITO/SiO 2 passivated contact in this study has J 0,contact = 92.5 fA/cm 2 and ρ contact = 11.5 mOhm-cm 2. These values are placed in context with other passivating contacts using an analysis that determines the ultimate efficiency and the optimal area fraction for contacts for a given set of (J0, contact, ρ contact) values. The ITO/SiO 2 contacts are found to have a higher J0, contact, but a similar ρ contact compared to the best reported passivated contacts.« less

Microstructure, Wear Resistance and Oxidation Behavior of Ni-Ti-Si Coatings Fabricated on Ti6Al4V by Laser Cladding.

PubMed

Zhuang, Qiaoqiao; Zhang, Peilei; Li, Mingchuan; Yan, Hua; Yu, Zhishui; Lu, Qinghua

2017-10-30

The Ni-Ti-Si composite coatings were successfully fabricated on Ti6Al4V by laser cladding. The microstructure were studied by SEM (scanning electron microscopy) and EDS (energy dispersive spectrometer). It has been found that Ti₂Ni and Ti₅Si₃ phases exist in all coatings, and some samples have TiSi₂ phases. Moreover, due to the existence of these phases, coatings presented relatively higher microhardness than that of the substrate (826 HV (Vickers hardness)) and the microhardness value of coating 3 is about twice larger than that of the substrate. During the dry sliding friction and wear test, due to the distribution of the relatively ductile phase of Ti₂Ni and reinforcement phases of Ti₅Si₃ and TiSi₂, the coatings performed good wear resistance. The oxidation process contains two stages: the rapid oxidation and slow oxidation by high temperature oxidation test at 800 °C for 50 h. Meanwhile, the value of the oxidation weight gain of the substrate is approximately three times larger than that of the coating 4. During the oxidation process, the oxidation film formed on the coating is mainly consisted of TiO₂, Al₂O₃ and SiO₂. Phases Ti₂Ni, Ti₅Si₃, TiSi₂ and TiSi were still found and it could be responsible for the improvement in oxidation resistance of the coatings by laser cladding.

Adolescent and Adult African Americans Have Similar Metabolic Dyslipidemia

PubMed Central

Gidding, Samuel S.; Keith, Scott W.; Falkner, Bonita

2015-01-01

Background African Americans (AA) have lower triglycerides (TG) and higher high density lipoprotein-cholesterol (HDL-C) than other ethnic groups yet they also have higher risk for developing diabetes mellitus despite the strong relationship of dyslipidemia with insulin resistance. No studies directly compare adolescents and adults with regard to relationships amongst dyslipidemia, C-reactive protein (hsCRP), and insulin resistance. Here we compare AA adolescents to adults with regard to the relationships of adiposity-related lipid risk markers (TG/HDL ratio and non HDL-C) with body mass index (BMI), waist circumference (WC), homeostasis model of insulin resistance (HOMA), and hsCRP. Methods Two cohorts of healthy AA were recruited from the same urban community. Participants in each cohort were stratified by TG/HDL ratio (based on adult tertiles) and non-HDL-C levels. BMI, WC, HOMA and hsCRP were compared in adolescents and adults in the low, middle and high lipid strata. Results Prevalence of TG/HDL ratio greater than 2.028 (high group) was 16% (44/283) in adolescents and 33% (161/484) in adults; prevalence of non HDL-C above 145 and 160 respectively was 8% (22/283) in adolescents and 12% (60/484) in adults. HsCRP values were lower and HOMA values were higher in adolescents (both p < 0.01). As both TG/HDL ratio and non HDL-C strata increased, BMI, WC, HOMA, and hsCRP increased in both adolescents and adults. In the high TG/HDL and non HDL-C groups, BMI and WC were similar in adolescents vs. adults (BMI 34 kg/m2 vs 32 kg/m2; WC 101 cm vs 101 cm). After adjusting for non-HDL-C and other covariates, a 2-fold increase in TG/HDL was associated with increases of 10.4% in hsCRP (95% CI: 1.1% – 20.5%) and 24.2% in HOMA (95% CI: 16.4% – 32.6%). Non-HDL-C was not significant in models having TG/HDL. Conclusions Elevated TG/HDL ratio is associated with similar inflammation and metabolic risk relationships in adolescent and adult African-Americans. PMID:26073396

OCT and shear-force evaluations of zirconia Fixed Partial Prosthesis processed with a conventional CAD/CAM technology

NASA Astrophysics Data System (ADS)

Zaharia, C.; Gabor, A.; Sinescu, C.; Topala, F. I.; Negrutiu, M. L.; Levai, C. M.; Duma, V. F.; Bradu, A.; Podoleanu, A. Gh.

2016-03-01

Introduction. Dental ceramics show better biocompatibility and aesthetic properties in dental constructs with regard to metals. However, they also have an insufficient mechanical stability, as well as low resistance limits due to their fragility. Taking into account these aspects, glass infiltrated with ceramic materials such as alumina (i.e., zirconiareinforced ceramics) is being nowadays considered a better material for full fixed partial prostheses (FPPs) than ceramics: the former has a higher mechanical resistance, which makes it more appropriate for restoration areas, where there is an increased mechanical stress. The interest for zirconia is growing due both to its resistance and to the possibility to develop such prostheses using the CAD/CAM technology. Materials and methods. 24 all ceramic FPPs created with CAD/CAM technology were used. The models were scanned with Zeno Wieland Scanner, a one touch scanning machine which requires between 45-60 s for a full model scan. The scanner provides 3 axis-architecture and automatic data processing. The zirconia infrastructures resulted from milling zirconia green disks in Wieland units, followed by the deposition of ceramic masses and then by burning procedures. All the samples were assessed with a Time Domain Optical Coherence Tomography (TD-OCT) system working at a wavelenght of 1300 nm. Using OCT investigations, material defects were detected in the areas of maximal tension, i.e. the connectors, the oclusal, and the cervical areas. These samples with defects in the above areas have not been considered for the study further on. Finally, the samples were loaded in a MultiTest 5 i Mecmesin system and tested until fracture occurred. The MultiTest 5-i creates tensile and compression forces of up to 5 kN. Results and discussions. All the test samples survived a dynamic load of 1.2 x 107 cycles and a thermal cycle mixer simulator version; signs of failure in terms of fracture lines were observed in all samples. The average value of the force necessary to break the FPPs obtained from the tests is 1750 N. Conclusions. Conventional metal-ceramic fixed partial dentures are still considered the standard for edentulous spaces in the posterior region. Therefore, the resistance of metal-ceramic fixed partial dentures has served in this study as a guide for new ceramics tests. All the values from this study conducted in FPP with zirconia frames were much lower than the values reported for metal ceramic fixed partial dentures (i.e., 2500-3000 N), but higher that 1000 N, which is considered the lowest resistance point to be utilized in the rear region of the oral cavity.

Short communication: In vitro antimicrobial susceptibility of Mycoplasma bovis isolates identified in milk from dairy cattle in Belgium, Germany, and Italy.

PubMed

Barberio, A; Flaminio, B; De Vliegher, S; Supré, K; Kromker, V; Garbarino, C; Arrigoni, N; Zanardi, G; Bertocchi, L; Gobbo, F; Catania, S; Moroni, P

2016-08-01

The objective of this study was to assess the in vitro antimicrobial susceptibility of 73 isolates of Mycoplasma bovis isolated from milk of dairy cattle herds of Belgium, Germany, and Italy. Minimal inhibitory concentration (MIC) values were determined by the microbroth dilution method for the following antimicrobials: erythromycin, spiramycin, tilmicosin, tylosin, lincomycin, enrofloxacin, doxycycline, oxytetracycline, florfenicol, and tiamulin. Macrolides, florfenicol, oxytetracycline, and enrofloxacin, were chosen because they represent antimicrobials families commonly used in several countries for treatment of M. bovis, and their MIC values in cattle population are reported in several studies, allowing a comparison with previous data. Doxycycline and tiamulin were selected to assess the susceptibility of M. bovis to new antimicrobials, because they are not registered in the European Union for the treatment of dairy cattle. Among the agents of the different antimicrobial classes, the macrolides showed the highest concentration to inhibit 90% of isolates (MIC90), all above the highest concentration tested: >8μg/mL for erythromycin, >16μg/mL for spiramycin, and >32μg/mL for tilmicosin and tylosin. Also the MIC90 of lincomycin was above the highest concentration tested (>32μg/mL), but the distribution of the MIC values was almost perfectly bimodal: 41 isolates had a MIC ≤0.5μg/mL and 30 isolates >32μg/mL. Oxytetracycline had a 2-fold higher concentration to inhibit 50% of isolates (2 vs. 0.5μg/mL) and 1-fold higher MIC90 (4 vs. 2μg/mL) than doxycycline. Enrofloxacin and florfenicol had both a MIC90 of 2μg/mL, whereas tiamulin had a MIC90 of 0.5μg/mL. Significant differences on the MIC values were found among the 3 countries for several antimicrobials: compared with Germany, Belgium and Italy showed significantly higher MIC for lincomycin, spiramycin, and tylosin, and lower for oxytetracycline and florfenicol. The Belgian isolates showed the lowest MIC for enrofloxacin compared with Germany and Italy. The MIC results obtained in our study suggest the presence of a high level of resistance of M. bovis isolates originating from milk to macrolides in all countries involved in this study. On the contrary, a low level of resistance was found against the antimicrobials that are not used in cattle, such as tiamulin and doxycycline, highlighting a possible link between antimicrobial treatments and development of resistance in the studied M. bovis population. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Interplay among Resistance Profiles, High-Risk Clones, and Virulence in the Caenorhabditis elegans Pseudomonas aeruginosa Infection Model.

PubMed

Sánchez-Diener, Irina; Zamorano, Laura; López-Causapé, Carla; Cabot, Gabriel; Mulet, Xavier; Peña, Carmen; Del Campo, Rosa; Cantón, Rafael; Doménech-Sánchez, Antonio; Martínez-Martínez, Luis; Arcos, Susana C; Navas, Alfonso; Oliver, Antonio

2017-12-01

The increasing prevalence of nosocomial infections produced by multidrug-resistant (MDR) or extensively drug-resistant (XDR) Pseudomonas aeruginosa is frequently linked to widespread international strains designated high-risk clones. In this work, we attempted to decipher the interplay between resistance profiles, high-risk clones, and virulence, testing a large ( n = 140) collection of well-characterized P. aeruginosa isolates from different sources (bloodstream infections, nosocomial outbreaks, cystic fibrosis, and the environment) in a Caenorhabditis elegans infection model. Consistent with previous data, we documented a clear inverse correlation between antimicrobial resistance and virulence in the C. elegans model. Indeed, the lowest virulence was linked to XDR profiles, which were typically linked to defined high-risk clones. However, virulence varied broadly depending on the involved high-risk clone; it was high for sequence type 111 (ST111) and ST235 but very low for ST175. The highest virulence of ST235 could be attributed to its exoU + type III secretion system (TTSS) genotype, which was found to be linked with higher virulence in our C. elegans model. Other markers, such as motility or pigment production, were not essential for virulence in the C. elegans model but seemed to be related with the higher values of the statistical normalized data. In contrast to ST235, the ST175 high-risk clone, which is widespread in Spain and France, seems to be associated with a particularly low virulence in the C. elegans model. Moreover, the previously described G154R AmpR mutation, prevalent in ST175, was found to contribute to the reduced virulence, although it was not the only factor involved. Altogether, our results provide a major step forward for understanding the interplay between P. aeruginosa resistance profiles, high-risk clones, and virulence. Copyright © 2017 American Society for Microbiology.

Evaluation of different models to segregate Pelibuey and Katahdin ewes into resistant or susceptible to gastrointestinal nematodes.

PubMed

Palomo-Couoh, Jovanny Gaspar; Aguilar-Caballero, Armando Jacinto; Torres-Acosta, Juan Felipe de Jesús; Magaña-Monforte, Juan Gabriel

2016-12-01

This study evaluated four models based on the number of eggs per gram of faeces (EPG) to segregate Pelibuey or Katahdin ewes during the lactation period into resistant or susceptible to gastrointestinal nematodes (GIN) in tropical Mexico. Nine hundred and thirty EPG counts of Pelibuey ewes and 710 of Katahdin ewes were obtained during 10 weeks of lactation. Ewes were segregated into resistant, intermediate and susceptible, using their individual EPG every week. Then, data of every ewe was used to provide a reference classification, which included all the EPG values of each animal. Then, four models were evaluated against such reference. Model 1 was based on the 10-week mean EPG count ± 2 SE. Models 2, 3 and 4 were based on the mean EPG count of 10, 5 and 2 weeks of lactation. The cutoff points for the segregation of ewe in those three models were the quartiles ≤Q1 (low elimination) and ≥Q3 (high elimination). In all the models evaluated, the ewes classified as resistant had lower EPG than intermediates and susceptible (P < 0.001) while ewes classified as susceptible had higher EPG than intermediate and resistant (P < 0.001). According to J Youden test, models presented concordance with the reference group (>70 %). Model 3 tended to show higher sensitivity and specificity with the reference data, but no difference was found with other models. The present study showed that the phenotypic marker EPG might serve to identify and segregate populations of adult ewes during the lactation period. All models used served to segregate Pelibuey and Katahdin ewes into resistant, intermediate and susceptible. The model 3 (mean of 5 weeks) could be used because it required less sampling effort without losing sensitivity or specificity in the segregation of animals. However, model 2 (mean of 2 weeks) was less labour-intensive.

Interplay among Resistance Profiles, High-Risk Clones, and Virulence in the Caenorhabditis elegans Pseudomonas aeruginosa Infection Model

PubMed Central

Sánchez-Diener, Irina; López-Causapé, Carla; Mulet, Xavier; Cantón, Rafael; Doménech-Sánchez, Antonio; Martínez-Martínez, Luis; Arcos, Susana C.; Navas, Alfonso

2017-01-01

ABSTRACT The increasing prevalence of nosocomial infections produced by multidrug-resistant (MDR) or extensively drug-resistant (XDR) Pseudomonas aeruginosa is frequently linked to widespread international strains designated high-risk clones. In this work, we attempted to decipher the interplay between resistance profiles, high-risk clones, and virulence, testing a large (n = 140) collection of well-characterized P. aeruginosa isolates from different sources (bloodstream infections, nosocomial outbreaks, cystic fibrosis, and the environment) in a Caenorhabditis elegans infection model. Consistent with previous data, we documented a clear inverse correlation between antimicrobial resistance and virulence in the C. elegans model. Indeed, the lowest virulence was linked to XDR profiles, which were typically linked to defined high-risk clones. However, virulence varied broadly depending on the involved high-risk clone; it was high for sequence type 111 (ST111) and ST235 but very low for ST175. The highest virulence of ST235 could be attributed to its exoU+ type III secretion system (TTSS) genotype, which was found to be linked with higher virulence in our C. elegans model. Other markers, such as motility or pigment production, were not essential for virulence in the C. elegans model but seemed to be related with the higher values of the statistical normalized data. In contrast to ST235, the ST175 high-risk clone, which is widespread in Spain and France, seems to be associated with a particularly low virulence in the C. elegans model. Moreover, the previously described G154R AmpR mutation, prevalent in ST175, was found to contribute to the reduced virulence, although it was not the only factor involved. Altogether, our results provide a major step forward for understanding the interplay between P. aeruginosa resistance profiles, high-risk clones, and virulence. PMID:28923877

Differences in Cardiometabolic Risk between Insulin-Sensitive and Insulin-Resistant Overweight and Obese Children.

PubMed

Khan, Unab I; McGinn, Aileen P; Isasi, Carmen R; Groisman-Perelstein, Adriana; Diamantis, Pamela M; Ginsberg, Mindy; Wylie-Rosett, Judith

2015-06-01

It is known that 15-30% overweight/obese adults do not suffer cardiometabolic consequences. There is limited literature examining factors that can be used to assess cardiometabolic health in overweight/obese children. If such factors can be identified, they would aid in differentiating those most in need for aggressive management. Baseline data from 7- to 12-year-old, overweight, and obese children enrolled in a weight management program at an urban hospital were analyzed. Homeostatic model assessment for insulin resistance (HOMA-IR) <2.6 was used to define insulin-sensitive and HOMA-IR ≥2.6 was used to defined insulin-resistant participants. Demographics, physical activity measures, and cardiometabolic risk factors were compared between the two phenotypes. Odds ratios (ORs) examining the association between intermediate endpoints (metabolic syndrome [MetS], nonalcoholic fatty liver disease [NAFLD], systemic inflammation, and microalbuminuria) and the two metabolic phenotypes were evaluated. Of the 362 overweight/obese participants, 157 (43.5%) were insulin sensitive and 204 (56.5%) were insulin resistant. Compared to the insulin-sensitive group, the insulin-resistant group was older (8.6±1.6 vs. 9.9±1.7; p<0.001) and had a higher BMI z-score (1.89±0.42 vs. 2.04±0.42; p=0.001). After multivariable adjustment, compared to the insulin-sensitive group, the insulin-resistant group had higher odds of having MetS (OR, 5.47; 95% confidence interval [CI]: 1.72, 17.35; p=0.004) and NAFLD (OR, 8.66; 95% CI, 2.48, 30.31; p=0.001), but not systemic inflammation (OR, 1.06; 95% CI: 0.56, 2.03; p=0.86) or microalbuminuria (OR, 1.71; 95% CI, 0.49, 6.04; p=0.403). Using a HOMA-IR value of ≥2.6, clinical providers can identify prepubertal and early pubertal children most at risk. Focusing limited resources on aggressive weight interventions may lead to improvement in cardiometabolic health.

Dual design resistor for high voltage conditioning and transmission lines

DOEpatents

Siggins, Timothy Lynn [Newport News, VA; Murray, Charles W [Hayes, VA; Walker, Richard L [Norfolk, VA

2007-01-23

A dual resistor for eliminating the requirement for two different value resistors. The dual resistor includes a conditioning resistor at a high resistance value and a run resistor at a low resistance value. The run resistor can travel inside the conditioning resistor. The run resistor is capable of being advanced by a drive assembly until an electrical path is completed through the run resistor thereby shorting out the conditioning resistor and allowing the lower resistance run resistor to take over as the current carrier.

The reinforcing value and liking of resistance training and aerobic exercise as predictors of adult's physical activity.

PubMed

Flack, Kyle D; Johnson, LuAnn; Roemmich, James N

2017-10-01

Reinforcing value (motivating value) is a stronger predictor than hedonic value (liking) for engaging in drug use, gambling, and eating. The associations of reinforcing value and liking with physical activity of adults have not yet been studied and may depend on the modes of exercise (e.g., aerobic/cardiovascular exercise, resistance training) under consideration. The purpose of this study was to test associations of the reinforcing value and liking of aerobic exercise training (AT) and resistance exercise training (RT) modes of exercise with usual participation in aerobic and resistance exercise in adults. Men (n=38) and women (n=50) were measured for their liking and relative reinforcing value (RRV) of AT and RT, for their usual vigorous physical activity (VPA) participation, and for usual resistance exercise behavior (Yale physical activity questionnaire). The RRV of AT (RRVAT) and liking of AT were correlated, (r=0.22, p<0.04), as were the RRV of RT (RRVRT) and liking of RT (r=0.42, p˂0.01). The reinforcing value for, but not the liking of, a mode of exercise predicted how much an individual engaged in that mode of exercise. RRVAT (p˂0.01) was positively associated with usual VPA. RRVRT (p˂0.01) was positively associated with RT behavior. The hedonic value of AT and of RT were not associated (p>0.30) with VPA or RT behavior. Reinforcing value of a mode of exercise is a stronger predictor than the liking of that mode of exercise for usual amount of participation in the exercise. Published by Elsevier Inc.

Definition of new cut‐offs of BMI and waist circumference based on body composition and insulin resistance: differences between children, adolescents and adults

PubMed Central

Hübers, M.; Pourhassan, M.; Braun, W.; Geisler, C.

2017-01-01

Summary Objective This study aims to determine associations between anthropometric traits, regional fat depots and insulin resistance in children, adolescents and adults to define new cut‐offs of body mass index (BMI) or waist circumference (WC). Design Cross‐sectional data were assessed in 433 children, adolescents and adults (aged: 6–60 years, BMI: 23.6 [21.0–27.7] kg m−2). Total adipose tissue (TAT), regional subcutaneous adipose tissue (SATtotal, SATtrunk) and visceral adipose tissue (VAT) were determined by whole‐body magnetic resonance imaging, fat mass by air‐displacement plethysmography. Insulin resistance was evaluated by homeostasis model assessment of insulin resistance (HOMA‐IR). Bivariate as well as partial correlations and regression analyses were used. Cut‐off values of BMI and WC related to regional fat depots and HOMA‐IR were analysed by receiver operating characteristics curve. Results In adults, TAT, SATtotal and SATtrunk increased linearly with increasing BMI and WC, whereas they followed a cubic function in children and adolescents with a steep increase at BMI and WC ≥1 standard deviation score and VAT at WC ≥2 standard deviation score. Sex differences were apparent in adults with women having higher masses of TAT and SAT and men having higher VAT. Using established BMI or WC cut‐offs, correspondent masses of TAT, SATtotal, SATtrunk and VAT increased from childhood to adulthood. In all age groups, there were positive associations between BMI, WC, SATtrunk, VAT and HOMA‐IR. When compared with normative cut‐offs of BMI or WC, HOMA‐IR‐derived cut‐offs of regional fat depots were lower in all age groups. Conclusions Associations between BMI, WC and regional fat depots varied between children, adolescents, young and older adults. When compared with BMI‐derived and WC‐derived values, an insulin resistance‐derived cut‐off corresponded to lower masses of regional fat depots. Thus, established BMI and WC cut‐offs are not appropriate to assess metabolic disturbances associated with obesity; therefore, new cut‐offs of BMI and WC are needed for clinical practice. PMID:29071103

Spatiotemporal analysis of the agricultural drought risk in Heilongjiang Province, China

NASA Astrophysics Data System (ADS)

Pei, Wei; Fu, Qiang; Liu, Dong; Li, Tian-xiao; Cheng, Kun; Cui, Song

2017-06-01

Droughts are natural disasters that pose significant threats to agricultural production as well as living conditions, and a spatial-temporal difference analysis of agricultural drought risk can help determine the spatial distribution and temporal variation of the drought risk within a region. Moreover, this type of analysis can provide a theoretical basis for the identification, prevention, and mitigation of drought disasters. In this study, the overall dispersion and local aggregation of projection points were based on research by Friedman and Tukey (IEEE Trans on Computer 23:881-890, 1974). In this work, high-dimensional samples were clustered by cluster analysis. The clustering results were represented by the clustering matrix, which determined the local density in the projection index. This method avoids the problem of determining a cutoff radius. An improved projection pursuit model is proposed that combines cluster analysis and the projection pursuit model, which offer advantages for classification and assessment, respectively. The improved model was applied to analyze the agricultural drought risk of 13 cities in Heilongjiang Province over 6 years (2004, 2006, 2008, 2010, 2012, and 2014). The risk of an agricultural drought disaster was characterized by 14 indicators and the following four aspects: hazard, exposure, sensitivity, and resistance capacity. The spatial distribution and temporal variation characteristics of the agricultural drought risk in Heilongjiang Province were analyzed. The spatial distribution results indicated that Suihua, Qigihar, Daqing, Harbin, and Jiamusi are located in high-risk areas, Daxing'anling and Yichun are located in low-risk areas, and the differences among the regions were primarily caused by the aspects exposure and resistance capacity. The temporal variation results indicated that the risk of agricultural drought in most areas presented an initially increasing and then decreasing trend. A higher value for the exposure aspect increased the risk of drought, whereas a higher value for the resistance capacity aspect reduced the risk of drought. Over the long term, the exposure level of the region presented limited increases, whereas the resistance capacity presented considerable increases. Therefore, the risk of agricultural drought in Heilongjiang Province will continue to exhibit a decreasing trend.

Adhesive Cementation Promotes Higher Fatigue Resistance to Zirconia Crowns.

PubMed

Campos, F; Valandro, L F; Feitosa, S A; Kleverlaan, C J; Feilzer, A J; de Jager, N; Bottino, M A

The aim of this study was to investigate the influence of the cementation strategy on the fatigue resistance of zirconia crowns. The null hypothesis was that the cementation strategy would not affect the fatigue resistance of the crowns. Seventy-five simplified molar tooth crown preparations were machined in glass fiber-filled epoxy resin. Zirconia crowns were designed (thickness=0.7 mm), milled by computer-aided design/computer-aided manufacturing, and sintered, as recommended. Crowns were cemented onto the resin preparations using five cementation strategies (n=15): ZP, luting with zinc phosphate cement; PN, luting with Panavia F resin cement; AL, air particle abrasion with alumina particles (125 μm) as the crown inner surface pretreatment + Panavia F; CJ, tribochemical silica coating as crown inner surface pretreatment + Panavia F; and GL, application of a thin layer of porcelain glaze followed by etching with hydrofluoric acid and silanization as crown inner surface pretreatment + Panavia F. Resin cement was activated for 30 seconds for each surface. Specimens were tested until fracture in a stepwise stress fatigue test (10,000 cycles in each step, 600 to 1400 N, frequency of 1.4 Hz). The mode of failure was analyzed by stereomicroscopy and scanning electron microscopy. Data were analyzed by Kaplan-Meier and Mantel-Cox (log rank) tests and a pairwise comparison (p<0.05) and by Weibull analysis. The CJ group had the highest load mean value for failure (1200 N), followed by the PN (1026 N), AL (1026 N), and GL (1013 N) groups, while the ZP group had the lowest mean value (706 N). Adhesively cemented groups (CJ, AL, PN, and GL) needed a higher number of cycles for failure than the group ZP did. The groups' Weibull moduli (CJ=5.9; AL=4.4; GL=3.9; PN=3.7; ZP=2.1) were different, considering the number of cycles for failure data. The predominant mode of failure was a fracture that initiated in the cement/zirconia layer. Finite element analysis showed the different stress distribution for the two models. Adhesive cementation of zirconia crowns improves fatigue resistance.

A Risk Assessment Model for Bacterial Leaf Spot of Pepper (Capsicum annuum), Caused by Xanthomonas euvesicatoria, Based on Concentrations of Macronutrients, Micronutrients, and Micronutrient Ratios.

PubMed

Dutta, B; Langston, D B; Luo, X; Carlson, S; Kichler, J; Gitaitis, R

2017-11-01

The phytopathogenic bacterium Xanthomonas euvesicatoria causes bacterial leaf spot (BLS) of pepper and has a worldwide distribution. BLS is difficult to control and an integrated management strategy that incorporates crop rotation, use of clean seed and clean plants, weed control, resistant varieties, applications of bactericides, biocontrol agents, and systemic acquired resistance (SAR) inducers is generally recommended. However, even with that arsenal of weapons, BLS can still be responsible for severe losses under favorable environmental conditions. Thus, additional tools need to be added to an overall integrated management strategy to combat BLS. In this article, we developed several models from 2012 to 2014 that were based on how macronutrients, micronutrients, and micronutrient ratios affect BLS severity. Factors used to select a model for validation included highly significant P values, high adjusted R 2 values, low variance inflation factor values (<5), root mean square error, Mallow's Cp, and high Akaike's information criterion correction values. In addition, salicylic acid (SA) concentrations and relative expression of nonexpresser pathogenesis-related gene1 (NPR1) and pathogenesis-related protein 1 (PR1) in pepper tissues were also considered in model selection. A model (ECGA1) consisting of concentrations of copper, manganese, potassium, and the iron/zinc ratio as independent variables was used for validation in three different commercial pepper fields in Georgia: Colquitt County and Worth County in 2015 and Tift County in 2016. When area under the disease progress curve (AUDPC) values for two field sites (Colquitt and Worth Counties) in 2015 were pulled together and plotted against ECGA1-predicted values for both sites, the resulting relationship was highly significant (P = 0.0001) with an R 2 value of 0.92. A significant relationship between observed AUDPC versus predicted values was also observed in Tift County in 2016 (P < 0.001; adjusted R 2 = 0.98). Relative gene expression of both NPR1 and PR1 genes was significantly (P < 0.01) higher in pepper grown in predicted low-risk sites compared with pepper from high-risk sites in Colquitt, Worth, and Tift Counties. Although BLS severity will fluctuate depending on environmental conditions, the data indicate that the level of risk at a particular location may be influenced by how macronutrient and micronutrient concentrations affect plant disease resistance genes in the SAR pathway.

Genome-wide association and genomic prediction of resistance to viral nervous necrosis in European sea bass (Dicentrarchus labrax) using RAD sequencing.

PubMed

Palaiokostas, Christos; Cariou, Sophie; Bestin, Anastasia; Bruant, Jean-Sebastien; Haffray, Pierrick; Morin, Thierry; Cabon, Joëlle; Allal, François; Vandeputte, Marc; Houston, Ross D

2018-06-08

European sea bass (Dicentrarchus labrax) is one of the most important species for European aquaculture. Viral nervous necrosis (VNN), commonly caused by the redspotted grouper nervous necrosis virus (RGNNV), can result in high levels of morbidity and mortality, mainly during the larval and juvenile stages of cultured sea bass. In the absence of efficient therapeutic treatments, selective breeding for host resistance offers a promising strategy to control this disease. Our study aimed at investigating genetic resistance to VNN and genomic-based approaches to improve disease resistance by selective breeding. A population of 1538 sea bass juveniles from a factorial cross between 48 sires and 17 dams was challenged with RGNNV with mortalities and survivors being recorded and sampled for genotyping by the RAD sequencing approach. We used genome-wide genotype data from 9195 single nucleotide polymorphisms (SNPs) for downstream analysis. Estimates of heritability of survival on the underlying scale for the pedigree and genomic relationship matrices were 0.27 (HPD interval 95%: 0.14-0.40) and 0.43 (0.29-0.57), respectively. Classical genome-wide association analysis detected genome-wide significant quantitative trait loci (QTL) for resistance to VNN on chromosomes (unassigned scaffolds in the case of 'chromosome' 25) 3, 20 and 25 (P < 1e06). Weighted genomic best linear unbiased predictor provided additional support for the QTL on chromosome 3 and suggested that it explained 4% of the additive genetic variation. Genomic prediction approaches were tested to investigate the potential of using genome-wide SNP data to estimate breeding values for resistance to VNN and showed that genomic prediction resulted in a 13% increase in successful classification of resistant and susceptible animals compared to pedigree-based methods, with Bayes A and Bayes B giving the highest predictive ability. Genome-wide significant QTL were identified but each with relatively small effects on the trait. Tests of genomic prediction suggested that incorporating genome-wide SNP data is likely to result in higher accuracy of estimated breeding values for resistance to VNN. RAD sequencing is an effective method for generating such genome-wide SNPs, and our findings highlight the potential of genomic selection to breed farmed European sea bass with improved resistance to VNN.

Effect of rapid set binder on early strength and permeability of HES latex modified road repair pre-packed concrete

NASA Astrophysics Data System (ADS)

Han, J. W.; Lee, S. K.; Yu, C.; Park, C. G.

2015-12-01

The early strength development characteristics and permeability resistance of high early strength (HES) pre-packed road repair concrete incorporating a rapid-set binder material were evaluated for emergency repairs to road pavement. The rapid-set binder is a mixture of rapid-set cement and silica sands whose fluidity improves with the addition of styrene butadiene latex (latex). The resulting mixture has a compressive strength of 21 MPa or higher and a flexural strength of greater than 3.5 MPa after 4 hours, the maximum curing age allowed for emergency repair materials. This study examines the strength development properties and permeability resistance of HES latex-modified pre-packed road repair concrete using a rapid- set binder as a function of the latex-to-binder mixing ratio at values of 0.40, 0.33, 0.29 and 0.25. Both early strength development properties and permeability resistance increased as the ratio of latex to rapid-set binder decreased. The mixture showed a compressive strength of 21 MPa or higher after 4 hours, which is the design standard of emergency repair concrete, only when this ratio was 0.29 or lower. A flexural strength of 3.5 MPa or greater was observed after hours only when this ratio was 0.33 or lower. The standard for permeability resistance, less than 2,000 C of chloride after 7 days of curing, was satisfied by all ratios. The ratio of latex to rapid-set binder satisfying all of the conditions for an emergency road repair material was 0.29 or less.

Epicardial adipose tissue is associated with visceral fat, metabolic syndrome, and insulin resistance in menopausal women.

PubMed

Fernández Muñoz, María J; Basurto Acevedo, Lourdes; Córdova Pérez, Nydia; Vázquez Martínez, Ana Laura; Tepach Gutiérrez, Nayive; Vega García, Sara; Rocha Cruz, Alberto; Díaz Martínez, Alma; Saucedo García, Renata; Zárate Treviño, Arturo; González Escudero, Eduardo Alberto; Degollado Córdova, José Antonio

2014-06-01

Epicardial adipose tissue has been associated with several obesity-related parameters and with insulin resistance. Echocardiographic assessment of this tissue is an easy and reliable marker of cardiometabolic risk. However, there are insufficient studies on the relationship between epicardial fat and insulin resistance during the postmenopausal period, when cardiovascular risk increases in women. The objective of this study was to examine the association between epicardial adipose tissue and visceral adipose tissue, waist circumference, body mass index, and insulin resistance in postmenopausal women. A cross sectional study was conducted in 34 postmenopausal women with and without metabolic syndrome. All participants underwent a transthoracic echocardiogram and body composition analysis. A positive correlation was observed between epicardial fat and visceral adipose tissue, body mass index, and waist circumference. The values of these correlations of epicardial fat thickness overlying the aorta-right ventricle were r = 0.505 (P < .003), r = 0.545 (P < .001), and r = 0.515 (P < .003), respectively. Epicardial adipose tissue was higher in postmenopausal women with metabolic syndrome than in those without this syndrome (mean [standard deviation], 544.2 [122.9] vs 363.6 [162.3] mm(2); P = .03). Epicardial fat thickness measured by echocardiography was associated with visceral adipose tissue and other obesity parameters. Epicardial adipose tissue was higher in postmenopausal women with metabolic syndrome. Therefore, echocardiographic assessment of epicardial fat may be a simple and reliable marker of cardiovascular risk in postmenopausal women. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

Effect of resistance training and hypocaloric diets with different protein content on body composition and lipid profile in hypercholesterolemic obese women.

PubMed

García-Unciti, M; Martinez, J A; Izquierdo, M; Gorostiaga, E M; Grijalba, A; Ibañez, J

2012-01-01

Lifestyle changes such as following a hypocaloric diet and regular physical exercise are recognized as effective non-pharmacological interventions to reduce body fat mass and prevent cardiovascular disease risk factors. To evaluate the interactions of a higher protein (HP) vs. a lower protein (LP) diet with or without a concomitant progressive resistance training program (RT) on body composition and lipoprotein profile in hypercholesterolemic obese women. Retrospective study derived from a 16-week randomized controlled-intervention clinical trial. Twenty five sedentary, obese (BMI: 30-40 kg/m²) women, aged 40-60 with hypercholesterolemia were assigned to a 4-arm trial using a 2 x 2 factorial design (Diet x Exercise). Prescribed diets had the same calorie restriction (-500 kcal/day), and were categorized according to protein content as: lower protein (< 22% daily energy intake, LP) vs. higher protein (> 22% daily energy intake, HP). Exercise comparisons involved habitual activity (control) vs. a 16-week supervised whole-body resistance training program (RT), two sessions/wk. A significant decrease in weight and waist circumference was observed in all groups. A significant decrease in LDL-C and Total-Cholesterol levels was observed only when a LP diet was combined with a RT program, the RT being the most determining factor. Interestingly, an interaction between diet and exercise was found concerning LDL-C values. In this study, resistance training plays a key role in improving LDL-C and Total-Cholesterol; however, a lower protein intake (< 22% of daily energy intake as proteins) was found to achieve a significantly greater reduction in LDL-C.

HIV drug resistance surveillance for prioritizing treatment in resource-limited settings

PubMed Central

Walensky, Rochelle P.; Weinstein, Milton C.; Yazdanpanah, Yazdan; Losina, Elena; Mercincavage, Lauren M.; Touré, Siaka; Divi, Nomita; Anglaret, Xavier; Goldie, Sue J.; Freedberg, Kenneth A.

2008-01-01

Background Sentinel testing programs for HIV drug resistance in resource-limited settings can inform policy on antiretroviral therapy (ART) and drug sequencing. Objective To examine the value of resistance surveillance in influencing recommendations toward effective and cost-effective sequencing of ART regimens. Methods A state-transition model of HIV infection was adapted to simulate clinical care in Côte d’Ivoire and evaluate the incremental cost-effectiveness of (1) no ART; (2) ART beginning with a non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimen followed by a boosted protease inhibitor (PI)-based regimen; and (3) ART beginning with a boosted PI-based regimen followed by an NNRTI-based regimen. Results At a 5% prevalence of NNRTI resistance, a strategy that started with a PI-based regimen had a smaller health benefit and higher cost-effectiveness ratio than a strategy that started with an NNRTI-based regimen (cost-effectiveness ratio $910/year of life saved). Results consistently favored initiation with an NNRTI-based regimen, regardless of the population prevalence of NNRTI resistance (up to 76%) and the efficacy of an NNRTI-based regimen in the setting of resistance. The most influential parameters on the cost-effectiveness of sequencing strategies were boosted PI-based regimen costs and the efficacy of this regimen when used as second-line therapy. Conclusions Drug costs and treatment efficacies, but not NNRTI resistance levels, were most influential in determining optimal HIV drug sequencing in Côte d’Ivoire. Results of surveillance for NNRTI resistance should not be used as a major guide to treatment policy in resource-limited settings. PMID:17457091

Antibiotic Resistance in Salmonella Enteritidis Isolates Recovered from Chicken, Chicken Breast, and Humans Through National Antimicrobial Resistance Monitoring System Between 1996 and 2014.

PubMed

Paudyal, Narayan; Pan, Hang; Li, Xiaoliang; Fang, Weihuan; Yue, Min

2018-06-21

Salmonella enterica subspecies enterica serotype Enteritidis (S. Enteritidis) is one of the leading causes for human salmonellosis all over the world. We analyzed the surveillance data of 18 years on antimicrobial resistance profiling of S. Enteritidis collected and isolated by the National Antimicrobial Resistance Monitoring System (NARMS) from humans, chicken, and chicken breasts. Statistical tool based on the unique individual antibiotic minimum inhibitory concentration (MIC) profiling was used to compare antimicrobial resistance in the isolates. A machine-learning algorithm, Random Forest matrix, segregated a collection of 6819 S. Enteritidis into multiple populations. The MIC value of 13 common antibiotics to individual isolate when taken as the best classifier, resulted in two distinct groups represented herein as Population-I and Population-II. Population-I, which spread within a small tight cluster, comprised all the chicken and chicken breasts' isolates as well as about 13.4% of the human isolates, whereas the Population-II consisted of the human isolates only, with a larger spread over wider area away from the Population-I (p < 0.001). Few overlapping, yet diverse clusters between humans and chicken as well as higher level of resistance of chicken breast isolate toward third-generation cephalosporins and tetracyclines compared to those from human isolates, highlight differences in their population structure. These findings indicate a complex driver for enriching antibiotic-resistant Salmonella in the food-chain other than those of chicken origin. This warrants for other strategies in addition to the judicious/restricted use of antibiotics to mitigate the threat of antimicrobial resistance.

Despite higher body fat content, Ecuadorian subjects with Laron syndrome have less insulin resistance and lower incidence of diabetes than their relatives.

PubMed

Guevara-Aguirre, Jaime; Procel, Patricio; Guevara, Carolina; Guevara-Aguirre, Marco; Rosado, Verónica; Teran, Enrique

2016-06-01

In the present pandemics of obesity and insulin resistant diabetes mellitus (DM), the specific contribution of etiological factors such as shifts in nutritional and exercise patterns, genetic and hormonal, is subject of ongoing research. Among the hormonal factors implicated, we selected obesity-driven insulin resistance for further evaluation. It is known that growth hormone (GH) has profound effects on carbohydrate metabolism. In consequence, we compared the effects of the lack of the counter-regulatory effects of GH, in a group of subjects with GH receptor deficiency (GHRD) due to a mutated GH receptor vs. that of their normal relatives. It was found that, despite their obesity, subjects with GHRD, have diminished incidence of diabetes, lower glucose and insulin concentrations, and lower values of indexes indicative of insulin resistance such as HOMA-IR. The GHRD subjects were also capable of appropriately handling glucose or mixed meal loads despite diminished insulin secretion. These observations allow us to suggest that the association of obesity with increased risk for diabetes appears to be dependent on intact growth hormone signaling. Copyright © 2015 Elsevier Ltd. All rights reserved.

Rolling resistance and propulsion efficiency of manual and power-assisted wheelchairs.

PubMed

Pavlidou, Efthymia; Kloosterman, Marieke G M; Buurke, Jaap H; Rietman, Johan S; Janssen, Thomas W J

2015-11-01

Rolling resistance is one of the main forces resisting wheelchair propulsion and thus affecting stress exerted on the upper limbs. The present study investigates the differences in rolling resistance, propulsion efficiency and energy expenditure required by the user during power-assisted and manual propulsion. Different tire pressures (50%, 75%, 100%) and two different levels of motor assistance were tested. Drag force, energy expenditure and propulsion efficiency were measured in 10 able-bodied individuals under different experimental settings on a treadmill. Results showed that drag force levels were significantly higher in the 50%, compared to the 75% and 100% inflation conditions. In terms of wheelchair type, the manual wheelchair displayed significantly lower drag force values than the power-assisted one. The use of extra-power-assisted wheelchair appeared to be significantly superior to conventional power-assisted and manual wheelchairs concerning both propulsion efficiency and energy expenditure required by the user. Overall, the results of the study suggest that the use of power-assisted wheelchair was more efficient and required less energy input by the user, depending on the motor assistance provided. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Ballistic Resistance of Honeycomb Sandwich Panels under In-Plane High-Velocity Impact

PubMed Central

Yang, Shu; Wang, Dong; Yang, Li-Jun

2013-01-01

The dynamic responses of honeycomb sandwich panels (HSPs) subjected to in-plane projectile impact were studied by means of explicit nonlinear finite element simulations using LS-DYNA. The HSPs consisted of two identical aluminum alloy face-sheets and an aluminum honeycomb core featuring three types of unit cell configurations (regular, rectangular-shaped, and reentrant hexagons). The ballistic resistances of HSPs with the three core configurations were first analyzed. It was found that the HSP with the reentrant auxetic honeycomb core has the best ballistic resistance, due to the negative Poisson's ratio effect of the core. Parametric studies were then carried out to clarify the influences of both macroscopic (face-sheet and core thicknesses, core relative density) and mesoscopic (unit cell angle and size) parameters on the ballistic responses of the auxetic HSPs. Numerical results show that the perforation resistant capabilities of the auxetic HSPs increase as the values of the macroscopic parameters increase. However, the mesoscopic parameters show nonmonotonic effects on the panels' ballistic capacities. The empirical equations for projectile residual velocities were formulated in terms of impact velocity and the structural parameters. It was also found that the blunter projectiles result in higher ballistic limits of the auxetic HSPs. PMID:24187526

Experimental Study on Rebar Corrosion Using the Galvanic Sensor Combined with the Electronic Resistance Technique

PubMed Central

Xu, Yunze; Li, Kaiqiang; Liu, Liang; Yang, Lujia; Wang, Xiaona; Huang, Yi

2016-01-01

In this paper, a new kind of carbon steel (CS) and stainless steel (SS) galvanic sensor system was developed for the study of rebar corrosion in different pore solution conditions. Through the special design of the CS and SS electronic coupons, the electronic resistance (ER) method and zero resistance ammeter (ZRA) technique were used simultaneously for the measurement of both the galvanic current and the corrosion depth. The corrosion processes in different solution conditions were also studied by linear polarization resistance (LPR) and the measurements of polarization curves. The test result shows that the galvanic current noise can provide detailed information of the corrosion processes. When localized corrosion occurs, the corrosion rate measured by the ER method is lower than the real corrosion rate. However, the value measured by the LPR method is higher than the real corrosion rate. The galvanic current and the corrosion current measured by the LPR method shows linear correlation in chloride-containing saturated Ca(OH)2 solution. The relationship between the corrosion current differences measured by the CS electronic coupons and the galvanic current between the CS and SS electronic coupons can also be used to evaluate the localized corrosion in reinforced concrete. PMID:27618054

Experimental Study on Rebar Corrosion Using the Galvanic Sensor Combined with the Electronic Resistance Technique.

PubMed

Xu, Yunze; Li, Kaiqiang; Liu, Liang; Yang, Lujia; Wang, Xiaona; Huang, Yi

2016-09-08

In this paper, a new kind of carbon steel (CS) and stainless steel (SS) galvanic sensor system was developed for the study of rebar corrosion in different pore solution conditions. Through the special design of the CS and SS electronic coupons, the electronic resistance (ER) method and zero resistance ammeter (ZRA) technique were used simultaneously for the measurement of both the galvanic current and the corrosion depth. The corrosion processes in different solution conditions were also studied by linear polarization resistance (LPR) and the measurements of polarization curves. The test result shows that the galvanic current noise can provide detailed information of the corrosion processes. When localized corrosion occurs, the corrosion rate measured by the ER method is lower than the real corrosion rate. However, the value measured by the LPR method is higher than the real corrosion rate. The galvanic current and the corrosion current measured by the LPR method shows linear correlation in chloride-containing saturated Ca(OH)₂ solution. The relationship between the corrosion current differences measured by the CS electronic coupons and the galvanic current between the CS and SS electronic coupons can also be used to evaluate the localized corrosion in reinforced concrete.

Ballistic resistance of honeycomb sandwich panels under in-plane high-velocity impact.

PubMed

Qi, Chang; Yang, Shu; Wang, Dong; Yang, Li-Jun

2013-01-01

The dynamic responses of honeycomb sandwich panels (HSPs) subjected to in-plane projectile impact were studied by means of explicit nonlinear finite element simulations using LS-DYNA. The HSPs consisted of two identical aluminum alloy face-sheets and an aluminum honeycomb core featuring three types of unit cell configurations (regular, rectangular-shaped, and reentrant hexagons). The ballistic resistances of HSPs with the three core configurations were first analyzed. It was found that the HSP with the reentrant auxetic honeycomb core has the best ballistic resistance, due to the negative Poisson's ratio effect of the core. Parametric studies were then carried out to clarify the influences of both macroscopic (face-sheet and core thicknesses, core relative density) and mesoscopic (unit cell angle and size) parameters on the ballistic responses of the auxetic HSPs. Numerical results show that the perforation resistant capabilities of the auxetic HSPs increase as the values of the macroscopic parameters increase. However, the mesoscopic parameters show nonmonotonic effects on the panels' ballistic capacities. The empirical equations for projectile residual velocities were formulated in terms of impact velocity and the structural parameters. It was also found that the blunter projectiles result in higher ballistic limits of the auxetic HSPs.

Structure dependent resistivity and dielectric characteristics of tantalum oxynitride thin films produced by magnetron sputtering

NASA Astrophysics Data System (ADS)

Cristea, D.; Crisan, A.; Cretu, N.; Borges, J.; Lopes, C.; Cunha, L.; Ion, V.; Dinescu, M.; Barradas, N. P.; Alves, E.; Apreutesei, M.; Munteanu, D.

2015-11-01

The main purpose of this work is to present and to interpret the change of electrical properties of TaxNyOz thin films, produced by DC reactive magnetron sputtering. Some parameters were varied during deposition: the flow of the reactive gases mixture (N2 and O2, with a constant concentration ratio of 17:3); the substrate voltage bias (grounded, -50 V or -100 V) and the substrate (glass, (1 0 0) Si or high speed steel). The obtained films exhibit significant differences. The variation of the deposition parameters induces variations of the composition, microstructure and morphology. These differences cause variation of the electrical resistivity essentially correlated with the composition and structural changes. The gradual decrease of the Ta concentration in the films induces amorphization and causes a raise of the resistivity. The dielectric characteristics of some of the high resistance TaxNyOz films were obtained in the samples with a capacitor-like design (deposited onto high speed steel, with gold pads deposited on the dielectric TaxNyOz films). Some of these films exhibited dielectric constant values higher than those reported for other tantalum based dielectric films.

Exploration of the Chaotic Behaviour in a Buck-Boost Converter Depending on the Converter and Load Elements

NASA Astrophysics Data System (ADS)

Demirbaş, Şevki; Fidanboy, Hikmet; Kurt, Erol

2016-08-01

In this paper, detailed analyses of the chaotic behavior observed in a buck-boost converter are presented. Although this basic converter system is already known world-wide for the purpose of dc-dc conversion of the output of renewable energy systems, it indicates certain chaotic regimes where both the output amplitude and frequency change randomly. This chaotic regime can yield an unstable output over the resistive or resistive/inductive electrical loads. This study presents a detailed map for the regular and chaotic regions in terms of material parameters, such as converter capacitance C, resistive load R, and inductive load L. Thus, the stable area of operation for efficient and renewable electricity production will be ascertained for the studied converter system. We emphasize that the material parameters C, R, and L play important roles in generating energy from the solar cell; indeed, the stability increases with higher values of the converter capacitor and load inductance, whereas it decreases according to the resistive load. A number of periodic windows have been observed and the output frequency gives a broad-band spectrum of up to 50 kHz.

Effect of cements on fracture resistance of monolithic zirconia crowns

PubMed Central

Nakamura, Keisuke; Mouhat, Mathieu; Nergård, John Magnus; Lægreid, Solveig Jenssen; Kanno, Taro; Milleding, Percy; Örtengren, Ulf

2016-01-01

Abstract Objectives The present study investigated the effect of cements on fracture resistance of monolithic zirconia crowns in relation to their compressive strength. Materials and methods Four different cements were tested: zinc phosphate cement (ZPC), glass-ionomer cement (GIC), self-adhesive resin-based cement (SRC) and resin-based cement (RC). RC was used in both dual cure mode (RC-D) and chemical cure mode (RC-C). First, the compressive strength of each cement was tested according to a standard (ISO 9917-1:2004). Second, load-to-failure test was performed to analyze the crown fracture resistance. CAD/CAM-produced monolithic zirconia crowns with a minimal thickness of 0.5 mm were prepared and cemented to dies with each cement. The crown–die samples were loaded until fracture. Results The compressive strength of SRC, RC-D and RC-C was significantly higher than those of ZPC and GIC (p < 0.05). However, there was no significant difference in the fracture load of the crown between the groups. Conclusion The values achieved in the load-to-failure test suggest that monolithic zirconia crowns with a minimal thickness of 0.5 mm may have good resistance against fracture regardless of types of cements. PMID:27335900

Resistance to cycloxaprid in Laodelphax striatellus is associated with altered expression of nicotinic acetylcholine receptor subunits.

PubMed

Zhang, Yueliang; Han, Yangchun; Yang, Qiong; Wang, Lihua; He, Peng; Liu, Zewen; Li, Zhong; Guo, Huifang; Fang, Jichao

2018-04-01

Cycloxaprid is a new oxabridged cis-configuration neonicotinoid insecticide, the resistance development potential and underlying resistance mechanism of which were investigated in the small brown planthopper, Laodelphax striatellus (Fallén), an important agricultural pest of rice. A cycloxaprid-resistant strain (YN-CPD) only achieved 10-fold higher resistance, in contrast to 106-fold higher resistance to buprofezin and 332-fold higher resistance to chlorpyrifos achieved after exposure to similar selection pressure, and the cycloxaprid selected line showed no cross-resistance to the buprofezin and chlorpyrifos-selected resistance strains. Moreover, we identified 10 nicotinic acetylcholine receptor (nAChR) subunits from the transcriptome of L. striatellus, and six segments had open reading frames (ORFs). While we did not find mutations in the nAChR genes of L. striatellus, subunits Lsα1 and Lsβ1 exhibited, respectively, 9.60-fold and 3.36-fold higher expression in the resistant strain, while Lsα8 exhibited 0.44-fold lower expression. Suppression of Lsα1 through ingestion of dsLsα1 led to an increase in susceptibility to cycloxaprid. The findings indicate that resistance to cycloxaprid develops slowly compared with resistance to other chemicals and without cross-resistance to chlorpyrifos or buprofezin; over-expressed Lsα1 is associated with low cycloxaprid resistance levels, but the importance of over-expressed Lsβ1 and reduced expression of Lsα8 could not be excluded. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Flavonoid Accumulation Plays an Important Role in the Rust Resistance of Malus Plant Leaves.

PubMed

Lu, Yanfen; Chen, Qi; Bu, Yufen; Luo, Rui; Hao, Suxiao; Zhang, Jie; Tian, Ji; Yao, Yuncong

2017-01-01

Cedar-apple rust ( Gymnosporangium yamadai Miyabe) is a fungal disease that causes substantial injury to apple trees and results in fruit with reduced size and quality and a lower commercial value. The molecular mechanisms underlying the primary and secondary metabolic effects of rust spots on the leaves of Malus apple cultivars are poorly understood. Using HPLC, we found that the contents of flavonoid compounds, especially anthocyanin and catechin, were significantly increased in rust-infected symptomatic tissue (RIT). The expression levels of structural genes and MYB transcription factors related to flavonoid biosynthesis were one- to seven-fold higher in the RIT. Among these genes, CHS, DFR, ANS, FLS and MYB10 showed more than a 10-fold increase, suggesting that these genes were expressed at significantly higher levels in the RIT. Hormone concentration assays showed that the levels of abscisic acid (ABA), ethylene (ETH), jasmonate (JA) and salicylic acid (SA) were higher in the RIT and were consistent with the expression levels of McNCED, McACS, McLOX and McNPR1 , respectively. Our study explored the complicated crosstalk of the signal transduction pathways of ABA, ETH, JA and SA; the primary metabolism of glucose, sucrose, fructose and sorbitol; and the secondary metabolism of flavonoids involved in the rust resistance of Malus crabapple leaves.

Testing limits to airflow perturbation device (APD) measurements.

PubMed

Lopresti, Erika R; Johnson, Arthur T; Koh, Frank C; Scott, William H; Jamshidi, Shaya; Silverman, Nischom K

2008-10-31

The Airflow Perturbation Device (APD) is a lightweight, portable device that can be used to measure total respiratory resistance as well as inhalation and exhalation resistances. There is a need to determine limits to the accuracy of APD measurements for different conditions likely to occur: leaks around the mouthpiece, use of an oronasal mask, and the addition of resistance in the respiratory system. Also, there is a need for resistance measurements in patients who are ventilated. Ten subjects between the ages of 18 and 35 were tested for each station in the experiment. The first station involved testing the effects of leaks of known sizes on APD measurements. The second station tested the use of an oronasal mask used in conjunction with the APD during nose and mouth breathing. The third station tested the effects of two different resistances added in series with the APD mouthpiece. The fourth station tested the usage of a flexible ventilator tube in conjunction with the APD. All leaks reduced APD resistance measurement values. Leaks represented by two 3.2 mm diameter tubes reduced measured resistance by about 10% (4.2 cmH2O.sec/L for control and 3.9 cm H2O.sec/L for the leak). This was not statistically significant. Larger leaks given by 4.8 and 6.4 mm tubes reduced measurements significantly (3.4 and 3.0 cm cmH2O.sec/L, respectively). Mouth resistance measured with a cardboard mouthpiece gave an APD measurement of 4.2 cm H2O.sec/L and mouth resistance measured with an oronasal mask was 4.5 cm H2O.sec/L; the two were not significantly different. Nose resistance measured with the oronasal mask was 7.6 cm H2O.sec/L. Adding airflow resistances of 1.12 and 2.10 cm H2O.sec/L to the breathing circuit between the mouth and APD yielded respiratory resistance values higher than the control by 0.7 and 2.0 cm H2O.sec/L. Although breathing through a 52 cm length of flexible ventilator tubing reduced the APD measurement from 4.0 cm H2O.sec/L for the control to 3.6 cm H2O.sec/L for the tube, the difference was not statistically significant. The APD can be adapted for use in ventilated, unconscious, and uncooperative patients with use of a ventilator tube and an oronasal mask without significantly affecting measurements. Adding a resistance in series with the APD mouthpiece has an additive effect on resistance measurements, and can be used for qualitative calibration. A leak size of at least the equivalent of two 3.2 mm diameter tubes can be tolerated without significantly affecting APD measurements.

Insulin resistance and associated factors: a cross-sectional study of bank employees.

PubMed

Salaroli, Luciane Bresciani; Cattafesta, Monica; Molina, Maria Del Carmen Bisi; Zandonade, Eliana; Bissoli, Nazaré Souza

2017-04-01

Insulin resistance is characterized by the failure of target cells to respond to normal levels of circulating insulin, and this condition is related to cardiovascular disease. This study sought to evaluate the prevalence of insulin resistance and its association with markers of metabolic abnormalities and metabolic syndrome in bank employees. A cross-sectional study was performed on 498 working men and women aged ≥20 years old. The Homeostasis Model Assessment (HOMA-IR) was used to determine the presence of insulin resistance based on cut-off values of ≤2.71 for normal insulin levels and >2.71 for insulin resistance, as established for the adult Brazilian population. It was observed that the 52 (10.4%) overweight individuals with insulin resistance were 4.97 times (95%CI 1.31-18.83) more likely to have high HOMA-IR values than the normal-weight participants; among those who were obese, the likelihood increased to 17.87 (95%CI 4.36-73.21). Individuals with large waist circumferences were 3.27 times (95%CI 1.03-10.38) more likely to develop insulin resistance than those who were within normal parameters. The HOMA-IR values differed between subjects with and without metabolic syndrome, with values of 2.83±2.5 and 1.10±0.81 (p=0.001), respectively. The levels of insulin, ultrasensitive C-reactive protein and uric acid were also associated with insulin resistance. The prevalence of insulin resistance among bank employees is high, and insulin resistance is associated with and serves as a marker of metabolic syndrome. Cardiovascular disease and metabolic syndrome-associated metabolic abnormalities were observed, and insulin resistance may be a risk factor in this group of professionals.

Insulin resistance and associated factors: a cross-sectional study of bank employees

PubMed Central

Salaroli, Luciane Bresciani; Cattafesta, Monica; Molina, Maria del Carmen Bisi; Zandonade, Eliana; Bissoli, Nazaré Souza

2017-01-01

OBJECTIVE: Insulin resistance is characterized by the failure of target cells to respond to normal levels of circulating insulin, and this condition is related to cardiovascular disease. This study sought to evaluate the prevalence of insulin resistance and its association with markers of metabolic abnormalities and metabolic syndrome in bank employees. METHODS: A cross-sectional study was performed on 498 working men and women aged ≥20 years old. The Homeostasis Model Assessment (HOMA-IR) was used to determine the presence of insulin resistance based on cut-off values of ≤2.71 for normal insulin levels and >2.71 for insulin resistance, as established for the adult Brazilian population. RESULTS: It was observed that the 52 (10.4%) overweight individuals with insulin resistance were 4.97 times (95%CI 1.31-18.83) more likely to have high HOMA-IR values than the normal-weight participants; among those who were obese, the likelihood increased to 17.87 (95%CI 4.36-73.21). Individuals with large waist circumferences were 3.27 times (95%CI 1.03-10.38) more likely to develop insulin resistance than those who were within normal parameters. The HOMA-IR values differed between subjects with and without metabolic syndrome, with values of 2.83±2.5 and 1.10±0.81 (p=0.001), respectively. The levels of insulin, ultrasensitive C-reactive protein and uric acid were also associated with insulin resistance. CONCLUSION: The prevalence of insulin resistance among bank employees is high, and insulin resistance is associated with and serves as a marker of metabolic syndrome. Cardiovascular disease and metabolic syndrome-associated metabolic abnormalities were observed, and insulin resistance may be a risk factor in this group of professionals. PMID:28492722