PHAGE FORMATION IN STAPHYLOCOCCUS MUSCAE CULTURES

PubMed Central

Price, Winston H.

1952-01-01

1. The synthesis of ribonucleic acid, desoxyribomicleic acid, and protein in S. muscae has been studied: (a) during the lag phase, (b) during the early log phase, and (c) while the cells are forming an adaptive enzyme for lactose utilization. 2. During the lag phase there may be a 60 per cent increase in ribonucleic acid and protein and a 50 per cent increase in dry weight without a change in cell count, as determined microscopically, or an increase in turbidity. 3. During this period, the increase in protein closely parallels the increase in ribonucleic acid, in contrast to desoxyribonucleic acid, which begins to be synthesized about 45 minutes after the protein and ribonucleic acid have begun to increase. 4. The RNA N/protein N ratio is proportional to the growth rate of all S. muscae strains studied. 5. While the RNA content per cell during the early log phase depends upon the growth rate, the DNA content per cell is fairly constant irrespective of the growth rate of the cell. 6. Resting cells of S. muscae have approximately the same RNA content per cell irrespective of their prospective growth rate. 7. While the cells are adapting to lactose, during which time there is little or no cellular division, there is never an increase of protein without a simultaneous increase in ribonucleic acid, the RNA N/protein N ratio during these intervals being approximately 0.15. 8. Lactose-adapting cells show a loss of ribonucleic acid. The purines-pyrimidines of the ribonucleic acid can be recovered in the cold 5 per cent trichloroacetic acid fraction, but the ribose component is completely lost from the system. 9. The significance of these results is discussed in relation to the importance of ribonucleic acid for protein synthesis. PMID:14955617

Recovery of cat retinal ganglion cell sensitivity following pigment bleaching.

PubMed Central

Bonds, A B; Enroth-Cugell, C

1979-01-01

1. The threshold illuminance for small spot stimulation of on-centre cat retinal ganglion cells was plotted vs. time after exposure to adapting light sufficiently strong to bleach significant amounts of rhodopsin. 2. When the entire receptive field of an X- or Y-type ganglion cell is bleached by at most 40%, recovery of the cell's rod-system proceeds in two phases: an early relatively fast one during which the response appears transient, and a late, slower one during which responses become more sustained. Log threshold during the later phase is well fit by an exponential in time (tau = 11.5-38 min). 3. After bleaches of 90% of the underlying pigment, threshold is cone-determined for as long as 40 min. Rod threshold continues to decrease for at least 85 min after the bleach. 4. The rate of recovery is slower after strong than after weak bleaches; 10 and 90% bleaches yield time constants for the later phase of 11.5 and 38 min, respectively. This contrasts with an approximate time constant of 11 min for rhodopsin regeneration following any bleach. 5. The relationship between the initial elevation of log rod threshold extrapolated from the fitted exponential curves and the initial amount of pigment bleached is monotonic, but nonlinear. 6. After a bleaching exposure, the maintained discharge is initially very regular. The firing rate first rises, then falls to the pre-bleach level, with more extended time courses of change in firing rate after stronger exposures. The discharge rate is restored before threshold has recovered fully. 7. The change in the response vs. log stimulus relationship after bleaching is described as a shift of the curve to the right, paired with a decrease in slope of the linear segment of the curve. PMID:521963

Rich Medium Composition Affects Escherichia coli Survival, Glycation, and Mutation Frequency during Long-Term Batch Culture.

PubMed

Kram, Karin E; Finkel, Steven E

2015-07-01

Bacteria such as Escherichia coli are frequently grown to high density to produce biomolecules for study in the laboratory. To achieve this, cells can be incubated in extremely rich media that increase overall cell yield. In these various media, bacteria may have different metabolic profiles, leading to changes in the amounts of toxic metabolites produced. We have previously shown that stresses experienced during short-term growth can affect the survival of cells during the long-term stationary phase (LTSP). Here, we incubated cells in LB, 2× yeast extract-tryptone (YT), Terrific Broth, or Super Broth medium and monitored survival during the LTSP, as well as other reporters of genetic and physiological change. We observe differential cell yield and survival in all media studied. We propose that differences in long-term survival are the result of changes in the metabolism of components of the media that may lead to increased levels of protein and/or DNA damage. We also show that culture pH and levels of protein glycation, a covalent modification that causes protein damage, affect long-term survival. Further, we measured mutation frequency after overnight incubation and observed a correlation between high mutation frequencies at the end of the log phase and loss of viability after 4 days of LTSP incubation, indicating that mutation frequency is potentially predictive of long-term survival. Since glycation and mutation can be caused by oxidative stress, we measured expression of the oxyR oxidative stress regulator during log-phase growth and found that higher levels of oxyR expression during the log phase are consistent with high mutation frequency and lower cell density during the LTSP. Since these complex rich media are often used when producing large quantities of biomolecules in the laboratory, the observed increase in damage resulting in glycation or mutation may lead to production of a heterogeneous population of plasmids or proteins, which could affect the quality of the end products yielded in some laboratory experiments. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Production of extracellular chitinase Beauveria bassiana under submerged fermentation conditions

NASA Astrophysics Data System (ADS)

Elawati, N. E.; Pujiyanto, S.; Kusdiyantini, E.

2018-05-01

Chitinase-producing microbes have attracted attention as one of the potential agents for control of phytopathogenic fungi and insect pests. The fungus that potentially produces chitinase is Beauveria bassiana. This study aims to determine the growth curve and chitinase activities of B. bassiana isolated from Helopeltis antonii insects after application. Method of measuring growth curve was done by dry cell period method, while for measurement of enzyme activity done by measuring absorbance at spectrophotometer. The results showed optimum growth time of B. bassiana with the highest cell count of 0.031 g on day 4 which was log phase, while the highest enzyme activity was 0,585 U / mL on the 4th day for 7 days incubation. Based on these results when correlated growth with enzyme production, chitinase enzyme products are produced in log phase and categorized as primary metabolism.

Long-Term Survival Phase Cells of Salmonella Typhimurium ATCC 14028 Have Significantly Greater Resistance to Ultraviolet Radiation in 0.85% Saline and Apple Juice.

PubMed

Wang, Fei; Mendonça, Aubrey; Brehm-Stecher, Byron F; Dickson, James; DiSpirito, Alan; Shaw, Angela; Thomas-Popo, Emalie

2018-05-31

Nonendospore-forming pathogenic bacteria in the long-term survival (LTS) phase can remain viable for months or years and may show reduced susceptibility to various antimicrobial interventions. In the present study, we investigated the response of LTS phase Salmonella enterica serovar Typhimurium (ATCC 14028) to ultraviolet (UV) radiation in 0.85% (w/v) saline and apple juice and the extent of sublethal injury in LTS phase survivors. The LTS-phase Salmonella Typhimurium cells were cultured at 35°C for 14 days in tryptic soy broth with 0.6% (w/v) yeast extract (TSBYE). Exponential- and stationary-phase cells, cultured in TSBYE (35°C) for 2.5 and 18 h, respectively, served as control samples. Cells (10 7 CFU [colony-forming unit]/mL) from each physiological state were exposed to UV light in saline (80 μW/cm 2 ) and apple juice (1500 μW/cm 2 ). The Salmonella Typhimurium survivors were plated for enumeration on either tryptic soy agar with 0.6% yeast extract or xylose-lysine-tergitol 4 (XLT4) agar and colonies counted after incubation (35°C, 24 h). Of all the growth phases tested, LTS phase cells were consistently impacted the least by UV treatment (p < 0.05). In saline, D-values of exponential, stationary, and LTS Salmonella Typhimurium were 0.35, 0.38, and 0.49 min, respectively. D-values in apple juice at pH 3.63 and pH 5.65 were 2.52, 3.19, and 3.57 min and 3.24, 3.50, and 4.18 min, respectively. UV radiation (80 μW/cm 2 ) of Salmonella Typhimurium in saline for 2.5 min reduced the number of exponential- and stationary-phase cells by ∼7.19 and 6.30 log 10 CFU/mL, respectively. In contrast, LTS cells were only reduced by 5.08 log 10 CFU/mL. Among the three physiological states, LTS phase cells had the least sublethal injury in the surviving population (p < 0.05). These results indicate that the LTS state cross-protects Salmonella Typhimurium against UV radiation and should be considered in determination of the UV radiation D-value for this pathogen.

The retrotransposon Tf1 assembles virus-like particles that contain excess Gag relative to integrase because of a regulated degradation process.

PubMed

Atwood, A; Lin, J H; Levin, H L

1996-01-01

The retrotransposon Tf1, isolated from Schizosaccharomyces pombe, contains a single open reading frame with sequences encoding Gag, protease, reverse transcriptase, and integrase (IN). Tf1 has previously been shown to possess significant transposition activity. Although Tf1 proteins do assemble into virus-like particles, the assembly does not require readthrough of a translational reading frame shift or stop codon, common mechanisms used by retroelements to express Gag in molar excess of the polymerase proteins. This study was designed to determine if Tf1 particles contain equal amounts of Gag and polymerase proteins or whether they contain the typical molar excess of Gag. After using two separate methods to calibrate the strength of our antibodies, we found that both S. pombe extracts and partially purified Tf1 particles contained a 26-fold molar excess of Gag relative to IN. Knowing that Gag and IN are derived from the same Tf1 primary translation product, we concluded that the excess Gag most likely resulted from specific degradation of IN. We obtained evidence of regulated IN degradation in comparisons of Tf1 protein extracted from log-phase cells and that extracted from stationary-phase cells. The log-phase cells contained equal molar amounts of Gag and IN, whereas cells approaching stationary phase rapidly degraded IN, leaving an excess of Gag. Analysis of the reverse transcripts indicated that the bulk of reverse transcription occurred within the particles that possess a molar excess of Gag.

The relative proportions of different lipid classes and their fatty acid compositions change with culture age in the cariogenic dental pathogen Streptococcus mutans UA159.

PubMed

Custer, Jenny E; Goddard, Bryan D; Matter, Stephen F; Kaneshiro, Edna S

2014-06-01

The oral cariogenic bacterial pathogen Streptococcus mutans strain UA159 has become an important research organism strain since its genome was sequenced. However, there is a paucity of information on its lipidome using direct analytical biochemical approaches. We here report on comprehensive analyses of the major lipid classes and their fatty acids in cells grown in batch standing cultures. Using 2-D high-performance thin-layer chromatography lipid class composition changes were detected with culture age. More lipid components were detected in the stationary-phase compared to log-phase cells. The major lipids identified included 1,3-bis(sn-3'-phosphatidyl)-sn-glycerol (phosphatidylglycerol), 1,3-diphosphatidylglycerol (cardiolipin), aminoacyl-phosphatidylglycerol, monoglucosyldiacylglycerol, diglucosyldiacylglycerol, diglucosylmonoacylglycerol and, glycerophosphoryldiglucosyldiacylglycerol. Culture age also affected the fatty acid composition of the total polar lipid fraction. Thus, the major lipid classes detected in log-phase and stationary-phase cells were isolated and their fatty acids were analyzed by gas-liquid chromatography to determine the basis for the fatty acid compositional changes in the total polar lipid fraction. The analyses showed that the relative proportions of these acids changed with culture age within individual lipid classes. Hence fatty acid changes in the total polar lipid fraction reflected changes in both lipid class composition and fatty acid compositions within individual lipid classes.

Assessment of Enterotoxin Production and Cross-Contamination of Staphylococcus aureus between Food Processing Materials and Ready-To-Eat Cooked Fish Paste.

PubMed

Tango, Charles Nkufi; Hong, Sung-Sam; Wang, Jun; Oh, Deog-Hwan

2015-12-01

This study evaluated Staphylococcus aureus growth and subsequent staphylococcal enterotoxin A production in tryptone soy broth and on ready-to-eat cooked fish paste at 12 to 37 °C, as well as cross-contamination between stainless steel, polyethylene, and latex glove at room temperature. A model was developed using Barany and Roberts's growth model, which satisfactorily described the suitable growth of S. aureus with R(2)-adj from 0.94 to 0.99. Except at 12 °C, S. aureus cells in TSB presented a lag time lower (14.64 to 1.65 h), grew faster (0.08 to 0.31 log CFU/h) and produced SEA at lower cell density levels (5.65 to 6.44 log CFU/mL) compare to those inoculated on cooked fish paste with data of 16.920 to 1.985 h, 0.02 to 0.23 log CFU/h, and 6.19 to 7.11 log CFU/g, respectively. Staphylococcal enterotoxin type A (SEA) visual immunoassay test showed that primary SEA detection varied considerably among different storage temperature degrees and media. For example, it occurred only during exponential phase at 30 and 37 °C in TSB, but in cooked fish paste it took place at late exponential phase of S. aureus growth at 20 and 25 °C. The SEA detection test was negative on presence of S. aureus on cooked fish paste stored at 12 and 15 °C, although cell density reached level of 6.12 log CFU/g at 15 °C. Cross-contamination expressed as transfer rate of S. aureus from polyethylene surface to cooked fish paste surface was slower than that observed with steel surface to cooked fish paste under same conditions. These results provide helpful information for controlling S. aureus growth, SEA production and cross-contamination during processing of cooked fish paste. © 2015 Institute of Food Technologists®

Listeria monocytogenes grown at 7° C shows reduced acid survival and an altered transcriptional response to acid shock compared to L. monocytogenes grown at 37° C.

PubMed

Ivy, R A; Wiedmann, M; Boor, K J

2012-06-01

Survival of the food-borne pathogen Listeria monocytogenes in acidic environments (e.g., in the human stomach) is vital to its transmission. Refrigerated, ready-to-eat foods have been sources of listeriosis outbreaks. The purpose of this study was to determine whether growth at a low temperature (i.e., 7°C) affects L. monocytogenes survival or gene transcription after exposure to a simulated gastric environment (i.e., acid shock at 37°C). L. monocytogenes cells grown at 7°C were less resistant to artificial gastric fluid (AGF) or acidified brain heart infusion broth (ABHI) than bacteria grown at higher temperatures (i.e., 30°C or 37°C). For L. monocytogenes grown at 7°C, stationary-phase cells were more resistant to ABHI than log-phase cells, indicating that both temperature and growth phase affect acid survival. Microarray transcriptomic analysis revealed that the number and functional categories of genes differentially expressed after acid shock differed according to both growth temperature and growth phase. The acid response of L. monocytogenes grown to log phase at 37°C involved stress-related transcriptional regulators (i.e., σ(B), σ(H), CtsR, and HrcA), some of which have been implicated in adaptation to the intracellular environment. In contrast, for bacteria grown at 7°C to stationary phase, acid exposure did not result in differential expression of the stress regulons examined. However, two large operons encoding bacteriophage-like proteins were induced, suggesting lysogenic prophage induction. The adaptive transcriptional response observed in 37°C-grown cells was largely absent in 7°C-grown cells, suggesting that temperatures commonly encountered during food storage and distribution affect the ability of L. monocytogenes to survive gastric passage and ultimately cause disease.

Optimisation of α-terpineol production by limonene biotransformation using Penicillium digitatum DSM 62840.

PubMed

Tai, Ya-Nan; Xu, Min; Ren, Jing-Nan; Dong, Man; Yang, Zi-Yu; Pan, Si-Yi; Fan, Gang

2016-02-01

In this study, (R)-(+)-limonene biotransformation using three fungal strains was compared. Penicillium digitatum DSM 62840 was distinguished for its capacity to transform limonene into α-terpineol with high regioselectivity. Growth kinetics in submerged liquid culture and the effects of growth phase and contact time on biotransformation were studied using this strain. Substrate concentration, co-solvent selection, and cultivation conditions were subsequently optimised. The maximum concentration of α-terpineol (833.93 mg L(-1)) was obtained when the pre-culture medium was in medium log-phase by adding 840 mg L(-1) substrate dissolved in ethanol and cultivation was performed at 24 °C, 150 rpm, and pH 6.0 for 12 h. Addition of small amounts of (R)-(+)-limonene (84 mg L(-1)) at the start of fungal log-phase growth yielded a 1.5-fold yield of α-terpineol, indicating that the enzyme was inducible. Among these three strains tested, P. digitatum DSM 62840 was proved to be an efficient biocatalyst to transform (R)-(+)-limonene to α-terpineol. Further studies revealed that the optimal growth phase for biotransformation was in the medium log phase of this strain. The biotransformation represented a wide tolerance of temperature; α-terpineol concentration underwent no significant change at 8-32 °C. The biotransformation could also be performed using resting cells. © 2015 Society of Chemical Industry.

Assessment of rate of drug release from oil vehicle using a rotating dialysis cell.

PubMed

Larsen, D H; Fredholt, K; Larsen, C

2000-09-01

The rate constants for transfer of model compounds (naproxen and lidocaine) from oily vehicle (Viscoleo) to aqueous buffer phases were determined by use of the rotating dialysis cell. Release studies were done for the partly ionized compounds at several pH values. A correlation between the overall first-order rate constant related to attainment of equilibrium, k(obs), and the pH-dependent distribution coefficient, D, determined between oil vehicle and aqueous buffer was established according to the equation: logk(obs)=-0.71 logD-0.22 (k(obs) in h(-1)). Based on this correlation it was suggested that the rate constant of a weak electrolyte at a specified D value could be considered equal to the k(obs) value for a non-electrolyte possessing a partition coefficient, P(app), the magnitude of which was equal to D. Specific rate constants k(ow) and k(wo) were calculated from the overall rate constant and the pH-dependent distribution coefficient. The rate constant representing the transport from oily vehicle to aqueous phase, k(ow), was found to be significantly influenced by the magnitude of the partition coefficient P(app) according to: logk(ow)=-0.71 logP(app)-log(P(app)+1)-0.22 (k(ow) in h(-1)).

Immunovirological response to triple nucleotide reverse-transcriptase inhibitors and ritonavir-boosted protease inhibitors in treatment-naive HIV-2-infected patients: The ACHIEV2E Collaboration Study Group.

PubMed

Benard, Antoine; van Sighem, Ard; Taieb, Audrey; Valadas, Emilia; Ruelle, Jean; Soriano, Vicente; Calmy, Alexandra; Balotta, Claudia; Damond, Florence; Brun-Vezinet, Françoise; Chene, Geneviève; Matheron, Sophie

2011-05-01

Triple nucleoside reverse-transcriptase inhibitors (NRTIs) are recommended by the World Health Organization as first-line regimen in treatment-naïve HIV-2-infected patients. However, ritonavir-boosted protease inhibitor (PI/r)-containing regimens are frequently prescribed. In the absence of previous randomized trials, we retrospectively compared these regimens in observational cohorts. HIV-2-infected patients from 7 European cohorts who started triple NRTI or PI/r since January 1998 were included. Piecewise linear models were used to estimate CD4 cell count and plasma HIV-2 RNA level slopes, differentiating an early phase (until end of month 3) and a second phase (months 4-12). On-treatment analyses censored data at major treatment modification and systematically at month 12. Forty-four patients started triple NRTI therapy and 126 started PI/r therapy. Overall, the median CD4 cell count was 191 cells/mm(3) and the median plasma HIV-2 RNA level was ≥2.7 log(10) copies/ml in 61% of the patients at combination antiretroviral therapy (cART) initiation; the median duration of the first cART was 20 months, not differing between groups. PI/r regimens were associated with better CD4 cell count and HIV-2 RNA level outcomes, compared with NRTI regimens. Estimated CD4 cell count slopes were +6 and +12 cells/mm(3)/month during the early phase (P = .22), and -60 cells/mm(3)/year versus +76 cells/mm(3)/year during the second phase (P = .002), for triple NRTI and PI/r, respectively. Estimated mean HIV-2 RNA levels at month 12 in patients with detectable viremia at cART initiation were 4.0 and 2.2 log(10) copies/ml, respectively (P = .005). In this observational study, PI/r-containing regimens showed superior efficacy over triple NRTI regimens as first-line therapy in HIV-2-infected patients.

Dynamic light scattering: A fast and reliable method to analyze bacterial growth during the lag phase.

PubMed

Vargas, Susana; Millán-Chiu, Blanca E; Arvizu-Medrano, Sofía M; Loske, Achim M; Rodríguez, Rogelio

2017-06-01

A comparison between plate counting (PC) and dynamic light scattering (DLS) is reported. PC is the standard technique to determine bacterial population as a function of time; however, this method has drawbacks, such as the cumbersome preparation and handling of samples, as well as the long time required to obtain results. Alternative methods based on optical density are faster, but do not distinguish viable from non-viable cells. These inconveniences are overcome by using DLS. Two different bacteria strains were considered: Escherichia coli and Staphylococcus aureus. DLS was performed at two different illuminating conditions: continuous and intermittent. By the increment of particle size as a function of time, it was possible to observe cell division and the formation of aggregates containing very few bacteria. The scattered intensity profiles showed the lag phase and the transition to the exponential phase of growth, providing a quantity proportional to viable bacteria concentration. The results revealed a clear and linear correlation in both lag and exponential phase, between the Log 10 (colony-forming units/mL) from PC and the Log 10 of the scattered intensity I s from DLS. These correlations provide a good support to use DLS as an alternative technique to determine bacterial population. Copyright © 2017 Elsevier B.V. All rights reserved.

A functional glycogen biosynthesis pathway in Lactobacillus acidophilus: expression and analysis of the glg operon

PubMed Central

Goh, Yong Jun; Klaenhammer, Todd R

2013-01-01

Glycogen metabolism contributes to energy storage and various physiological functions in some prokaryotes, including colonization persistence. A role for glycogen metabolism is proposed on the survival and fitness of Lactobacillus acidophilus, a probiotic microbe, in the human gastrointestinal environment. L. acidophilus NCFM possesses a glycogen metabolism (glg) operon consisting of glgBCDAP-amy-pgm genes. Expression of the glg operon and glycogen accumulation were carbon source- and growth phase-dependent, and were repressed by glucose. The highest intracellular glycogen content was observed in early log-phase cells grown on trehalose, which was followed by a drastic decrease of glycogen content prior to entering stationary phase. In raffinose-grown cells, however, glycogen accumulation gradually declined following early log phase and was maintained at stable levels throughout stationary phase. Raffinose also induced an overall higher temporal glg expression throughout growth compared with trehalose. Isogenic ΔglgA (glycogen synthase) and ΔglgB (glycogen-branching enzyme) mutants are glycogen-deficient and exhibited growth defects on raffinose. The latter observation suggests a reciprocal relationship between glycogen synthesis and raffinose metabolism. Deletion of glgB or glgP (glycogen phosphorylase) resulted in defective growth and increased bile sensitivity. The data indicate that glycogen metabolism is involved in growth maintenance, bile tolerance and complex carbohydrate utilization in L. acidophilus. PMID:23879596

Antisense RNA that Affects Rhodopseudomonas palustris Quorum-Sensing Signal Receptor Expression

DTIC Science & Technology

2012-01-01

antisense molecules were produced, we performed a Northern blot analysis with RNA harvested from wild-type and rpaR-mutant R. palustris cells by using...aeruginosa, cells were grown to late-log phase, harvested by cen- trifugation, suspended in SDS/PAGE buffer, and lysed by boiling and sonication. Cell...a selectable DNA fragment. Gene 29:303–313. 17. Egland KA, Greenberg EP (1999) Quorum sensing in Vibrio fischeri: Elements of the luxl promoter. Mol

Amplitude Analysis and Modeling of Regional Phases in PNE Profiles in Northern Eurasia and Seismic Regionalization

DTIC Science & Technology

2006-06-30

ratios (Lg/Pn, Lg/Pg, Lg/Sn, and Lg/ Pcod ,), a constant window length was used to measure the phase amplitudes. The phases were identified by correlating...log(ýo-) = (Yp + yp,,o-dLg)(log( 2) -log ))+Q( + p.o-71Lg)(x 2 - (2.9) ’ 4 pcod ,2 APCoda Therefore, the difference of log(ALg/Apcoda) between

Interaction of Escherichia coli with polymorphonuclear leukocytes in pathogenesis of urinary tract infection in mice.

PubMed Central

Iwahi, T; Imada, A

1988-01-01

Two type 1 fimbria-producing strains of Escherichia coli, 31-B and K12W1-3, and two type 1 fimbriae-defective mutants derived from 31-B, BH5 and BH9, were compared for their capacity to induce vesical infection in mice undergoing water diuresis and to interact in vitro with murine peritoneal exudate polymorphonuclear leukocytes (PMN). Strains 31-B and BH5 caused rapid bacterial multiplication in the bladder wall after being inoculated intrabladderly; their log-phase cells grown at 37 degrees C, in striking contrast to their stationary-phase or 17 degrees C-grown cells, resisted phagocytic killing by PMN in the presence of normal murine serum. Strains K12W1-3 and BH9 failed to cause vesical infection, and their cells were always susceptible to the opsonophagocytic killing by PMN irrespective of the growth conditions. Nevertheless, the log-phase cells of the three isogenic strains, 31-B, BH5, and BH9, grown at 37 degrees C gave almost the same chemiluminescent response patterns during incubation with PMN in normal serum. The phagocytic resistance in strains 31-B and BH5 was eliminated by briefly treating bacterial cells with EDTA. These results suggest that the two virulent strains may express an antiphagocytic activity during their growth in the bladder and continue to stimulate the oxidative metabolic burst of PMN without being ingested and killed, and that the antiphagocytic activity may be related to a bacterial surface component(s) that is removed by EDTA. PMID:2894364

Comparison of adsorption coefficient (K[sub oc]) for soils and HPLC retention factors of aromatic hydrocarbons using a chemically immobilized humic acid column in RP-HPLC

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

Szabo, G.; Bulman, R.A.

The determination of soil adsorption coefficients (K[sub oc]) via HPLC capacity factors (k[prime]) has been studied, including the effect of column type and mobile phase composition on the correlation between log K[sub oc] and log k[prime]. K[sub oc] values obtained by procedures other than HPLC correlate well with HPLC capacity factors determined on a chemically immobilized humic acid stationary phase, and it is suggested that this phase is a better model for the sorption onto soil or sediment than the octadecyl-, phenyl- and ethylsilica phases. By using log k[prime][sub w] a theoretical capacity factor has been obtained by extrapolation ofmore » the retention data in a binary solvent system to pure aqueous eluent. There is a better correlation between log K[sub oc] and log k[prime][sub w] than the correlation between log K[sub oc] and log k[prime].« less

Fate of Shiga toxin-producing O157:H7 and non-O157:H7 Escherichia coli cells within blade-tenderized beef steaks after cooking on a commercial open-flame gas grill.

PubMed

Luchansky, John B; Porto-Fett, Anna C S; Shoyer, Bradley A; Call, Jeffrey E; Schlosser, Wayne; Shaw, William; Bauer, Nathan; Latimer, Heejeong

2012-01-01

We compared the fate of cells of both Shiga toxin-producing Escherichia coli O157:H7 (ECOH) and Shiga toxin-producing non-O157:H7 E. coli (STEC) in blade-tenderized steaks after tenderization and cooking on a gas grill. In phase I, beef subprimal cuts were inoculated on the lean side with about 5.5 log CFU/g of a five-strain mixture of ECOH or STEC and then passed once through a mechanical blade tenderizer with the lean side facing up. In each of two trials, 10 core samples were removed from each of two tenderized subprimals and cut into six consecutive segments starting from the inoculated side. Ten total cores also were obtained from two nontenderized (control) subprimals, but only segment 1 (the topmost segment) was sampled. The levels of ECOH and STEC recovered from segment 1 were about 6.0 and 5.3 log CFU/g, respectively, for the control subprimals and about 5.7 and 5.0 log CFU/g, respectively, for the tenderized subprimals. However, both ECOH and STEC behaved similarly in terms of translocation, and cells of both pathogen cocktails were recovered from all six segments of the cores obtained from tenderized subprimals, albeit at lower levels in segments 2 to 6 than those found in segment 1. In phase II, steaks (2.54 and 3.81 cm thick) cut from tenderized subprimals were subsequently cooked (three steaks per treatment) on a commercial open-flame gas grill to internal temperatures of 48.9, 54.4, 60.0, 65.6, and 71.1°C. Regardless of temperature or thickness, we observed 2.0- to 4.1-log and 1.5- to 4.5-log reductions in ECOH and STEC levels, respectively. Both ECOH and STEC behaved similarly in response to heat, in that cooking eliminated significant numbers of both pathogen types; however, some survivors were recovered due, presumably, to uneven heating of the blade-tenderized steaks.

Carbon storage regulator A contributes to the virulence of Haemophilus ducreyi in humans by multiple mechanisms.

PubMed

Gangaiah, Dharanesh; Li, Wei; Fortney, Kate R; Janowicz, Diane M; Ellinger, Sheila; Zwickl, Beth; Katz, Barry P; Spinola, Stanley M

2013-02-01

The carbon storage regulator A (CsrA) controls a wide variety of bacterial processes, including metabolism, adherence, stress responses, and virulence. Haemophilus ducreyi, the causative agent of chancroid, harbors a homolog of csrA. Here, we generated an unmarked, in-frame deletion mutant of csrA to assess its contribution to H. ducreyi pathogenesis. In human inoculation experiments, the csrA mutant was partially attenuated for pustule formation compared to its parent. Deletion of csrA resulted in decreased adherence of H. ducreyi to human foreskin fibroblasts (HFF); Flp1 and Flp2, the determinants of H. ducreyi adherence to HFF cells, were downregulated in the csrA mutant. Compared to its parent, the csrA mutant had a significantly reduced ability to tolerate oxidative stress and heat shock. The enhanced sensitivity of the mutant to oxidative stress was more pronounced in bacteria grown to stationary phase compared to that in bacteria grown to mid-log phase. The csrA mutant also had a significant survival defect within human macrophages when the bacteria were grown to stationary phase but not to mid-log phase. Complementation in trans partially or fully restored the mutant phenotypes. These data suggest that CsrA contributes to virulence by multiple mechanisms and that these contributions may be more profound in bacterial cell populations that are not rapidly dividing in the human host.

Proliferation and apoptosis in malignant and normal cells in B-cell non-Hodgkin's lymphomas.

PubMed Central

Stokke, T.; Holte, H.; Smedshammer, L.; Smeland, E. B.; Kaalhus, O.; Steen, H. B.

1998-01-01

We have examined apoptosis and proliferation in lymph node cell suspensions from patients with B-cell non-Hodgkin's lymphoma using flow cytometry. A method was developed which allowed estimation of the fractions of apoptotic cells and cells in the S-phase of the cell cycle simultaneously with tumour-characteristic light chain expression. Analysis of the tumour S-phase fraction and the tumour apoptotic fraction in lymph node cell suspensions from 95 B-cell non-Hodgkin's lymphoma (NHL) patients revealed a non-normal distribution for both parameters. The median fraction of apoptotic tumour cells was 1.1% (25 percentiles 0.5%, 2.7%). In the same samples, the median fraction of apoptotic normal cells was higher than for the tumour cells (1.9%; 25 percentiles 0.7%, 4.0%; P = 0.03). The median fraction of tumour cells in S-phase was 1.4% (25 percentiles 0.8%, 4.8%), the median fraction of normal cells in S-phase was significantly lower than for the tumour cells (1.0%; 25 percentiles 0.6%, 1.9%; P = 0.004). When the number of cases was plotted against the logarithm of the S-phase fraction of the tumour cells, a distribution with two Gaussian peaks was needed to fit the data. One peak was centred around an S-phase fraction of 0.9%; the other was centred around 7%. These peaks were separated by a valley at approximately 3%, indicating that the S-phase fraction in NHL can be classified as 'low' (< 3%) or 'high' (> 3%), independent of the median S-phase fraction. The apoptotic fractions were log-normally distributed. The median apoptotic fraction was higher (1.5%) in the 'high' S-phase group than in the 'low' S-phase group (0.8%; P = 0.02). However, there was no significant correlation between the two parameters (P > 0.05). PMID:9667654

Carbon-Starvation Induces Cross-Resistance to Thermal, Acid, and Oxidative Stress in Serratia marcescens

PubMed Central

Pittman, Joseph R.; Kline, La’Kesha C.; Kenyon, William J.

2015-01-01

The broad host-range pathogen Serratia marcescens survives in diverse host and non-host environments, often enduring conditions in which the concentration of essential nutrients is growth-limiting. In such environments, carbon and energy source starvation (carbon-starvation) is one of the most common forms of stress encountered by S. marcescens. Related members of the family Enterobacteriaceae are known to undergo substantial changes in gene expression and physiology in response to the specific stress of carbon-starvation, enabling non-spore-forming cells to survive periods of prolonged starvation and exposure to other forms of stress (i.e., starvation-induced cross-resistance). To determine if carbon-starvation also results in elevated levels of cross-resistance in S. marcescens, both log-phase and carbon-starved cultures, depleted of glucose before the onset of high cell-density stationary-phase, were grown in minimal media at either 30 °C or 37 °C and were then challenged for resistance to high temperature (50 °C), low pH (pH 2.8), and oxidative stress (15 mM H2O2). In general, carbon-starved cells exhibited a higher level of resistance to thermal stress, acid stress, and oxidative stress compared to log-phase cells. The extent of carbon-starvation-induced cross-resistance was dependent on incubation temperature and on the particular strain of S. marcescens. In addition, strain- and temperature-dependent variations in long-term starvation survival were also observed. The enhanced stress-resistance of starved S. marcescens cells could be an important factor in their survival and persistence in many non-host environments and within certain host microenvironments where the availability of carbon sources is suboptimal for growth. PMID:27682115

Fungicidal activity of tioconazole in relation to growth phase of Candida albicans and Candida parapsilosis.

PubMed Central

Beggs, W H

1984-01-01

It was shown that tioconazole possesses an important property not shared by ketoconazole and miconazole, its well-known relatives in the imidazole group of antifungal drugs. At a concentration of 3.8 X 10(-5) M, tioconazole, like miconazole, caused rapid 2- to 3-log reductions in CFU per milliliter when added to late-logarithmic-phase Candida albicans or Candida parapsilosis cells. Only tioconazole, however, exerted similar reductions when added to diluted stationary-phase cultures. This growth-phase-independent lethal action has important clinical implications and may explain the superior performance of tioconazole, which was observed in earlier comparative drug studies. PMID:6097174

An Analogue VLSI Implementation of the Meddis Inner Hair Cell Model

NASA Astrophysics Data System (ADS)

McEwan, Alistair; van Schaik, André

2003-12-01

The Meddis inner hair cell model is a widely accepted, but computationally intensive computer model of mammalian inner hair cell function. We have produced an analogue VLSI implementation of this model that operates in real time in the current domain by using translinear and log-domain circuits. The circuit has been fabricated on a chip and tested against the Meddis model for (a) rate level functions for onset and steady-state response, (b) recovery after masking, (c) additivity, (d) two-component adaptation, (e) phase locking, (f) recovery of spontaneous activity, and (g) computational efficiency. The advantage of this circuit, over other electronic inner hair cell models, is its nearly exact implementation of the Meddis model which can be tuned to behave similarly to the biological inner hair cell. This has important implications on our ability to simulate the auditory system in real time. Furthermore, the technique of mapping a mathematical model of first-order differential equations to a circuit of log-domain filters allows us to implement real-time neuromorphic signal processors for a host of models using the same approach.

Serum-free microcarrier based production of replication deficient Influenza vaccine candidate virus lacking NS1 using Vero cells

PubMed Central

2011-01-01

Background Influenza virus is a major health concern that has huge impacts on the human society, and vaccination remains as one of the most effective ways to mitigate this disease. Comparing the two types of commercially available Influenza vaccine, the live attenuated virus vaccine is more cross-reactive and easier to administer than the traditional inactivated vaccines. One promising live attenuated Influenza vaccine that has completed Phase I clinical trial is deltaFLU, a deletion mutant lacking the viral Nonstructural Protein 1 (NS1) gene. As a consequence of this gene deletion, this mutant virus can only propagate effectively in cells with a deficient interferon-mediated antiviral response. To demonstrate the manufacturability of this vaccine candidate, a batch bioreactor production process using adherent Vero cells on microcarriers in commercially available animal-component free, serum-free media is described. Results Five commercially available animal-component free, serum-free media (SFM) were evaluated for growth of Vero cells in agitated Cytodex 1 spinner flask microcarrier cultures. EX-CELL Vero SFM achieved the highest cell concentration of 2.6 × 10^6 cells/ml, whereas other SFM achieved about 1.2 × 10^6 cells/ml. Time points for infection between the late exponential and stationary phases of cell growth had no significant effect in the final virus titres. A virus yield of 7.6 Log10 TCID50/ml was achieved using trypsin concentration of 10 μg/ml and MOI of 0.001. The Influenza vaccine production process was scaled up to a 3 liter controlled stirred tank bioreactor to achieve a cell density of 2.7 × 10^6 cells/ml and virus titre of 8.3 Log10 TCID50/ml. Finally, the bioreactor system was tested for the production of the corresponding wild type H1N1 Influenza virus, which is conventionally used in the production of inactivated vaccine. High virus titres of up to 10 Log10 TCID50/ml were achieved. Conclusions We describe for the first time the production of Influenza viruses using Vero cells in commercially available animal-component free, serum-free medium. This work can be used as a basis for efficient production of attenuated as well as wild type Influenza virus for research and vaccine production. PMID:21835017

Regulation of phosphoenolpyruvate carboxykinase and pyruvate kinase in Saccharomyces cerevisiae grown in the presence of glycolytic and gluconeogenic carbon sources and the role of mitochondrial function on gluconeogenesis.

PubMed

Wilson, A J; Bhattacharjee, J K

1986-12-01

Phosphoenolpyruvate carboxykinase (PEPCKase) and pyruvate kinase (PKase) were measured in Saccharomyces cerevisiae grown in the presence of glycolytic and gluconeogenic carbon sources. The PEPCKase activity was highest in ethanol-grown cells. However, high PEPCKase activity was also observed in cells grown in 1% glucose, especially as compared with the activity of sucrose-, maltose-, or galactose-grown cells. Activity was first detected after 12 h when glucose was exhausted from the growth medium. The PKase activity was very high in glucose-grown cells; considerable activity was also present in ethanol- and pyruvate-grown cells. The absolute requirement of respiration for gluconeogenesis was demonstrated by the absence or significantly low levels of PEPCKase and fructose-1,6-bisphosphatase activities observed in respiratory deficient mutants, as well as in wild-type S. cerevisiae cells grown in the presence of glucose and antimycin A or chloramphenicol. Obligate glycolytic and gluconeogenic enzymes were present simultaneously only in stationary phase cells, but not in exponential phase cells; hence futile cycling could not occur in log phase cells regardless of the presence of carbon source in the growth medium.

Photodynamic Therapy for Acinetobacter baumannii Burn Infections in Mice

DTIC Science & Technology

2009-06-29

37°C, 100 rpm) to an optical density at 600 nm of 0.6 to 0.8, which corresponds to 108 cells/ml (mid-log phase). This suspension was then...camera to quantify any dark toxicity of the conjugate to the bacteria. The mice were then illuminated with 660 15 nm light delivered by a noncoherent

Determination of reversed-phase high performance liquid chromatography based octanol-water partition coefficients for neutral and ionizable compounds: Methodology evaluation.

PubMed

Liang, Chao; Qiao, Jun-Qin; Lian, Hong-Zhen

2017-12-15

Reversed-phase liquid chromatography (RPLC) based octanol-water partition coefficient (logP) or distribution coefficient (logD) determination methods were revisited and assessed comprehensively. Classic isocratic and some gradient RPLC methods were conducted and evaluated for neutral, weak acid and basic compounds. Different lipophilicity indexes in logP or logD determination were discussed in detail, including the retention factor logk w corresponding to neat water as mobile phase extrapolated via linear solvent strength (LSS) model from isocratic runs and calculated with software from gradient runs, the chromatographic hydrophobicity index (CHI), apparent gradient capacity factor (k g ') and gradient retention time (t g ). Among the lipophilicity indexes discussed, logk w from whether isocratic or gradient elution methods best correlated with logP or logD. Therefore logk w is recommended as the preferred lipophilicity index for logP or logD determination. logk w easily calculated from methanol gradient runs might be the main candidate to replace logk w calculated from classic isocratic run as the ideal lipophilicity index. These revisited RPLC methods were not applicable for strongly ionized compounds that are hardly ion-suppressed. A previously reported imperfect ion-pair RPLC method was attempted and further explored for studying distribution coefficients (logD) of sulfonic acids that totally ionized in the mobile phase. Notably, experimental logD values of sulfonic acids were given for the first time. The IP-RPLC method provided a distinct way to explore logD values of ionized compounds. Copyright © 2017 Elsevier B.V. All rights reserved.

High-throughput determination of octanol/water partition coefficients using a shake-flask method and novel two-phase solvent system.

PubMed

Morikawa, Go; Suzuka, Chihiro; Shoji, Atsushi; Shibusawa, Yoichi; Yanagida, Akio

2016-01-05

A high-throughput method for determining the octanol/water partition coefficient (P(o/w)) of a large variety of compounds exhibiting a wide range in hydrophobicity was established. The method combines a simple shake-flask method with a novel two-phase solvent system comprising an acetonitrile-phosphate buffer (0.1 M, pH 7.4)-1-octanol (25:25:4, v/v/v; AN system). The AN system partition coefficients (K(AN)) of 51 standard compounds for which log P(o/w) (at pH 7.4; log D) values had been reported were determined by single two-phase partitioning in test tubes, followed by measurement of the solute concentration in both phases using an automatic flow injection-ultraviolet detection system. The log K(AN) values were closely related to reported log D values, and the relationship could be expressed by the following linear regression equation: log D=2.8630 log K(AN) -0.1497(n=51). The relationship reveals that log D values (+8 to -8) for a large variety of highly hydrophobic and/or hydrophilic compounds can be estimated indirectly from the narrow range of log K(AN) values (+3 to -3) determined using the present method. Furthermore, log K(AN) values for highly polar compounds for which no log D values have been reported, such as amino acids, peptides, proteins, nucleosides, and nucleotides, can be estimated using the present method. The wide-ranging log D values (+5.9 to -7.5) of these molecules were estimated for the first time from their log K(AN) values and the above regression equation. Copyright © 2015 Elsevier B.V. All rights reserved.

Cell-free DNA: A Neglected Source for Antibiotic Resistance Genes Spreading from WWTPs.

PubMed

Zhang, Yan; Li, Aolin; Dai, Tianjiao; Li, Feifei; Xie, Hui; Chen, Lujun; Wen, Donghui

2018-01-02

Cell-associated ARGs in wastewater treatment plants (WWTPs) has been concerned, however, cell-free ARGs in WWTPs was rarely studied. In this study, the abundances of four representative ARGs, sulII, tetC, bla PSE-1 , and ermB, in a large municipal WWTP were investigated in both cell-associated and cell-free fractions. Cell-associated ARGs was the dominant ARGs fraction in the raw wastewater. After biological treatment, sludge settling, membrane filtration, and disinfection, cell-associated ARGs were substantially reduced, though the ratios of ARG/16S rRNA gene were increased with disinfection. Cell-free ARGs persisted in the WWTP with a removal of 0.36 log to 2.68 logs, which was much lower than the removal of cell-associated ARGs (3.21 logs to 4.14 logs). Therefore, the abundance ratio of cell-free ARGs to cell-associated ARGs increased from 0.04-1.59% to 2.00-1895.08% along the treatment processes. After 25-day-storage, cell-free ARGs in both biological effluent and disinfection effluent increased by 0.14 log to 1.99 logs and 0.12 log to 1.77 logs respectively, reflecting the persistence and low decay rate of cell-free ARGs in the discharge water. Therefore, cell-free ARGs might be a kind of important but previously neglected pollutant from WWTPs, which added potential risks to the effluent receiving environments.

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

Li, Tingting; Kirchhoff, Helmut; Gargouri, Mahmoud

Mixotrophic growth of microalgae offers great potential as an efficient strategy for biofuel production. In this study, photosynthetic regulation of mixotrophically cultured Chlorella sorokiniana cells was systematically evaluated. Mixotrophic cells in the exponential growth phase showed the highest photosynthetic activity, where maximum photosynthetic O 2 evolution was approximately 3- and 4-fold higher than cells in the same phase grown photoautotrophically in 1% CO 2 (in air) and air, respectively. Additionally, characteristic chlorophyll fluorescence parameters demonstrated that no limitation in electron transport downstream of PSII was detected in mixotrophic cells. Up-regulation of photosynthetic activity was associated with high total ribulose-1, 5-bisphosphatemore » carboxylase/oxygenase (Rubisco) carboxylase activity and expression level of phosphoribulokinase (PRK). After 3 days, photosynthetic O 2 evolution of mixotrophic cells that went to the stationary phase, was strongly reduced, with reduced photochemical efficiency and reorganization of the PSII complex. Simultaneously, enzymatic activity for Rubisco carboxylase and mRNA levels of Rubisco and PRK diminished. Importantly, there was almost no non-photochemical quenching for mixotrophic cells, whether grown in log or stationary phase. A decline in the quantum efficiency of PSII and an oxidized plastoquinone pool (PQ pool) was observed under N-depleted conditions during mixotrophic growth. Finally, these results demonstrate that photosynthesis is regulated differently in mixotrophically cultured C. sorokiniana cells than in cells grown under photoautotrophic conditions, with a particularly strong impact by nitrogen levels in the cells.« less

Micellar versus hydro-organic mobile phases for retention-hydrophobicity relationship studies with ionizable diuretics and an anionic surfactant.

PubMed

Ruiz-Angel, M J; Carda-Broch, S; García-Alvarez-Coque, M C; Berthod, A

2004-03-19

Logarithm of retention factors (log k) of a group of 14 ionizable diuretics were correlated with the molecular (log P o/w) and apparent (log P(app)) octanol-water partition coefficients. The compounds were chromatographed using aqueous-organic (reversed-phase liquid chromatography, RPLC) and micellar-organic mobile phases (micellar liquid chromatography, MLC) with the anionic surfactant sodium dodecyl sulfate (SDS), in the pH range 3-7, and a conventional octadecylsilane column. Acetonitrile was used as the organic modifier in both modes. The quality of the correlations obtained for log P(app) at varying ionization degree confirms that this correction is required in the aqueous-organic mixtures. The correlation is less improved with SDS micellar media because the acid-base equilibriums are shifted towards higher pH values for acidic compounds. In micellar chromatography, an electrostatic interaction with charged solutes is added to hydrophobic forces; consequently, different correlations should be established for neutral and acidic compounds, and for basic compounds. Correlations between log k and the isocratic descriptors log k(w), log k(wm) (extrapolated retention to pure water in the aqueous-organic and micellar-organic systems, respectively), and psi0 (extrapolated mobile phase composition giving a k = 1 retention factor or twice the dead time), and between these descriptors and log P(app) were also satisfactory, although poorer than those between log k and log P(app) due to the extrapolation. The study shows that, in the particular case of the ionizable diuretics studied, classical RPLC gives better results than MLC with SDS in the retention hydrophobicity correlations.

Zone fluidics for measurement of octanol-water partition coefficient of drugs.

PubMed

Wattanasin, Panwadee; Saetear, Phoonthawee; Wilairat, Prapin; Nacapricha, Duangjai; Teerasong, Saowapak

2015-02-20

A novel zone fluidics (ZF) system for the determination of the octanol-water partition coefficient (Pow) of drugs was developed. The ZF system consisted of a syringe pump with a selection valve, a holding column, a silica capillary flow-cell and an in-line spectrophotometer. Exact microliter volumes of solvents (octanol and phosphate buffer saline) and a solution of the drug, sandwiched between air segments, were sequentially loaded into the vertically aligned holding column. Distribution of the drug between the aqueous and octanol phases occurred by the oscillation movement of the syringe pump piston. Phase separation occurred due to the difference in densities. The liquid zones were then pushed into the detection flow cell. In this method, absorbance measurements in only one of the phase (octanol or aqueous) were employed, which together with the volumes of the solvents and pure drug sample, allowed the calculation of the Pow. The developed system was applied to the determination of the Pow of some common drugs. The log (Pow) values agreed well with a batch method (R(2)=0.999) and literature (R(2)=0.997). Standard deviations for intra- and inter-day analyses were both less than 0.1log unit. This ZF system provides a robust and automated method for screening of Pow values in the drug discovery process. Copyright © 2014 Elsevier B.V. All rights reserved.

Extractive biodegradation and bioavailability assessment of phenanthrene in the cloud point system by Sphingomonas polyaromaticivorans.

PubMed

Pan, Tao; Deng, Tao; Zeng, Xinying; Dong, Wei; Yu, Shuijing

2016-01-01

The biological treatment of polycyclic aromatic hydrocarbons is an important issue. Most microbes have limited practical applications because of the poor bioavailability of polycyclic aromatic hydrocarbons. In this study, the extractive biodegradation of phenanthrene by Sphingomonas polyaromaticivorans was conducted by introducing the cloud point system. The cloud point system is composed of a mixture of (40 g/L) Brij 30 and Tergitol TMN-3, which are nonionic surfactants, in equal proportions. After phenanthrene degradation, a higher wet cell weight and lower phenanthrene residue were obtained in the cloud point system than that in the control system. According to the results of high-performance liquid chromatography, the residual phenanthrene preferred to partition from the dilute phase into the coacervate phase. The concentration of residual phenanthrene in the dilute phase (below 0.001 mg/L) is lower than its solubility in water (1.18 mg/L) after extractive biodegradation. Therefore, dilute phase detoxification was achieved, thus indicating that the dilute phase could be discharged without causing phenanthrene pollution. Bioavailability was assessed by introducing the apparent logP in the cloud point system. Apparent logP decreased significantly, thus indicating that the bioavailability of phenanthrene increased remarkably in the system. This study provides a potential application of biological treatment in water and soil contaminated by phenanthrene.

Designing primers and evaluation of the efficiency of propidium monoazide - Quantitative polymerase chain reaction for counting the viable cells of Lactobacillus gasseri and Lactobacillus salivarius.

PubMed

Lai, Chieh-Hsien; Wu, Sih-Rong; Pang, Jen-Chieh; Ramireddy, Latha; Chiang, Yu-Cheng; Lin, Chien-Ku; Tsen, Hau-Yang

2017-07-01

The purpose of this study is to evaluate the efficiency of using propidium monoazide (PMA) real-time quantitative polymerase chain reaction (qPCR) to count the viable cells of Lactobacillus gasseri and Lactobacillus salivarius in probiotic products. Based on the internal transcription spacer and 23S rRNA genes, two primer sets specific for these two Lactobacillus species were designed. For a probiotic product, the total deMan Rogosa Sharpe plate count was 8.65±0.69 log CFU/g, while for qPCR, the cell counts of L. gasseri and L. salivarius were 8.39±0.14 log CFU/g and 8.57±0.24 log CFU/g, respectively. Under the same conditions, for its heat-killed product, qPCR counts for L. gasseri and L. salivarius were 6.70±0.16 log cells/g and 7.67±0.20 log cells/g, while PMA-qPCR counts were 5.33±0.18 log cells/g and 5.05±0.23 log cells/g, respectively. For cell dilutions with a viable cell count of 8.5 log CFU/mL for L. gasseri and L. salivarius, after heat killing, the PMA-qPCR count for both Lactobacillus species was near 5.5 log cells/mL. When the PMA-qPCR counts of these cell dilutions were compared before and after heat killing, although some DNA might be lost during the heat killing, significant qPCR signals from dead cells, i.e., about 4-5 log cells/mL, could not be reduced by PMA treatment. Increasing PMA concentrations from 100 μM to 200 μM or light exposure time from 5 minutes to 15 minutes had no or, if any, only minor effect on the reduction of qPCR signals from their dead cells. Thus, to differentiate viable lactic acid bacterial cells from dead cells using the PMA-qPCR method, the efficiency of PMA to reduce the qPCR signals from dead cells should be notable. Copyright © 2016. Published by Elsevier B.V.

Autologous CD34+ cell therapy improves exercise capacity, angina frequency and reduces mortality in no-option refractory angina: a patient-level pooled analysis of randomized double-blinded trials.

PubMed

Henry, Timothy D; Losordo, Douglas W; Traverse, Jay H; Schatz, Richard A; Jolicoeur, E Marc; Schaer, Gary L; Clare, Robert; Chiswell, Karen; White, Christopher J; Fortuin, F David; Kereiakes, Dean J; Zeiher, Andreas M; Sherman, Warren; Hunt, Andrea S; Povsic, Thomas J

2018-01-05

Autologous CD34+ (auto-CD34+) cells represent an attractive option for the treatment of refractory angina. Three double-blinded randomized trials (n = 304) compared intramyocardial (IM) auto-CD34+ cells with IM placebo injections to affect total exercise time (TET), angina frequency (AF), and major adverse cardiac events (MACE). Patient-level data were pooled from the Phase I, Phase II ACT-34, ACT-34 extension, and Phase III RENEW trials to determine the efficacy and safety of auto-CD34+ cells. Treatment effects for TET were analysed using an analysis of covariance mixed-effects model and for AF using Poisson regression in a log linear model with repeated measures. The Kaplan-Meier rate estimates for MACE were compared using the log-rank test. Autologous CD34+ cell therapy improved TET by 46.6 s [3 months, 95% confidence interval (CI) 13.0 s-80.3 s; P = 0.007], 49.5 s (6 months, 95% CI 9.3-89.7; P = 0.016), and 44.7 s (12 months, 95% CI - 2.7 s-92.1 s; P = 0.065). The relative frequency of angina was 0.78 (95% CI 0.63-0.98; P = 0.032), 0.66 (0.48-0.91; P = 0.012), and 0.58 (0.38-0.88; P = 0.011) at 3-, 6- and 12-months in auto-CD34+ compared with placebo patients. Results remained concordant when analysed by treatment received and when confined to the Phase III dose of 1 × 105 cells/kg. Autologous CD34 + cell therapy significantly decreased mortality (12.1% vs. 2.5%; P = 0.0025) and numerically reduced MACE (38.9% vs. 30.0; P = 0.14) at 24 months. Treatment with auto-CD34+ cells resulted in clinically meaningful durable improvements in TET and AF at 3-, 6- and 12-months, as well as a reduction in 24-month mortality in this patient-level meta-analysis. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.

Log-Gabor Weber descriptor for face recognition

NASA Astrophysics Data System (ADS)

Li, Jing; Sang, Nong; Gao, Changxin

2015-09-01

The Log-Gabor transform, which is suitable for analyzing gradually changing data such as in iris and face images, has been widely used in image processing, pattern recognition, and computer vision. In most cases, only the magnitude or phase information of the Log-Gabor transform is considered. However, the complementary effect taken by combining magnitude and phase information simultaneously for an image-feature extraction problem has not been systematically explored in the existing works. We propose a local image descriptor for face recognition, called Log-Gabor Weber descriptor (LGWD). The novelty of our LGWD is twofold: (1) to fully utilize the information from the magnitude or phase feature of multiscale and orientation Log-Gabor transform, we apply the Weber local binary pattern operator to each transform response. (2) The encoded Log-Gabor magnitude and phase information are fused at the feature level by utilizing kernel canonical correlation analysis strategy, considering that feature level information fusion is effective when the modalities are correlated. Experimental results on the AR, Extended Yale B, and UMIST face databases, compared with those available from recent experiments reported in the literature, show that our descriptor yields a better performance than state-of-the art methods.

Effect of cell-surface hydrophobicity on bacterial conversion of water-immiscible chemicals in two-liquid-phase culture systems.

PubMed

Hamada, Takahiro; Maeda, Yusuke; Matsuda, Hiroyuki; Sameshima, Yuka; Honda, Kohsuke; Omasa, Takeshi; Kato, Junichi; Ohtake, Hisao

2009-08-01

The effect of bacterial cell-surface hydrophobicity on the bioconversion of water-immiscible chemicals in an aqueous-organic (A/O) two-liquid-phase culture system was investigated. Escherichia coli JM109 and Rhodococcus opacus B-4 were used as hydrophilic and hydrophobic whole-cell catalysts, respectively. Hydroxylation reactions of monoaromatics, including toluene (log P(ow)=2.9), ethylbenzene (3.1), n-propylbenzene (3.4), and sec-butylbenzene (3.7), were employed as model conversions. When the todC1C2BA genes encoding Pseudomonas putida toluene dioxygenase were expressed in E. coli JM109, the yield of hydroxylated monoaromatics decreased with increasing substrate hydrophobicity. By contrast, R. opacus transformants, which expressed the todC1C2BA genes, showed high performance in the hydroxylation of monoaromatics, irrespective of substrate hydrophobicity. When the R. opacus transformants were examined for their ability to hydroxylate monoaromatics in an aqueous single-liquid-phase culture, the reaction velocity was markedly lower than that observed in the A/O two-liquid-phase culture. These results suggested that R. opacus B-4 accessed the hydrophobic substrates in the oil phase, thus making it more effective for the bioconversion reactions.

Protein farnesyltransferase in plants: molecular characterization and involvement in cell cycle control.

PubMed Central

Qian, D; Zhou, D; Ju, R; Cramer, C L; Yang, Z

1996-01-01

Farnesylation is required for membrane targeting, protein-protein interactions, and the biological activity of key regulatory proteins, such as Ras small GTPases and protein kinases in a wide range of eukaryotes. In this report, we describe the molecular identification of a plant protein farnesyltransferase (FTase) and evidence for its role in the control of the cell cycle in plants. A pea gene encoding a homolog of the FTase beta subunit was previously cloned using a polymerase chain reaction-based strategy. A similar approach was used to clone a pea gene encoding a homolog of the FTase alpha subunit. The biochemical function of the pea FTase homologs was demonstrated by the reconstitution of FTase enzyme activity using FTase fusion proteins coexpressed in Escherichia coll. RNA gel blot analyses showed that levels of FTase mRNAs are generally higher in tissues, such as those of nodules, that are active in cell division. The relationship of FTase to cell division was further analyzed during the growth of suspension-cultured tobacco BY-2 cells. A biphasic fluctuation of FTase enzyme activity preceded corresponding changes in mitotic activity at the early log phase of cell growth. Moreover, manumycin, a specific inhibitor of FTase, was effective in inhibiting mitosis and growth in these cells. Using synchronized BY-2 cells, manumycin completely blocked mitosis when added at the early S phase but not when added at the G2 phase. These data suggest that FTase is required for the plant cell cycle, perhaps by modulating the progression through the S phase and the transition from G1 to the S phase. PMID:8989889

Assessment of photosynthesis regulation in mixotrophically cultured microalga Chlorella sorokiniana

DOE PAGES

Li, Tingting; Kirchhoff, Helmut; Gargouri, Mahmoud; ...

2016-07-19

Mixotrophic growth of microalgae offers great potential as an efficient strategy for biofuel production. In this study, photosynthetic regulation of mixotrophically cultured Chlorella sorokiniana cells was systematically evaluated. Mixotrophic cells in the exponential growth phase showed the highest photosynthetic activity, where maximum photosynthetic O 2 evolution was approximately 3- and 4-fold higher than cells in the same phase grown photoautotrophically in 1% CO 2 (in air) and air, respectively. Additionally, characteristic chlorophyll fluorescence parameters demonstrated that no limitation in electron transport downstream of PSII was detected in mixotrophic cells. Up-regulation of photosynthetic activity was associated with high total ribulose-1, 5-bisphosphatemore » carboxylase/oxygenase (Rubisco) carboxylase activity and expression level of phosphoribulokinase (PRK). After 3 days, photosynthetic O 2 evolution of mixotrophic cells that went to the stationary phase, was strongly reduced, with reduced photochemical efficiency and reorganization of the PSII complex. Simultaneously, enzymatic activity for Rubisco carboxylase and mRNA levels of Rubisco and PRK diminished. Importantly, there was almost no non-photochemical quenching for mixotrophic cells, whether grown in log or stationary phase. A decline in the quantum efficiency of PSII and an oxidized plastoquinone pool (PQ pool) was observed under N-depleted conditions during mixotrophic growth. Finally, these results demonstrate that photosynthesis is regulated differently in mixotrophically cultured C. sorokiniana cells than in cells grown under photoautotrophic conditions, with a particularly strong impact by nitrogen levels in the cells.« less

Competitive fitness during feast and famine: how SOS DNA polymerases influence physiology and evolution in Escherichia coli.

PubMed

Corzett, Christopher H; Goodman, Myron F; Finkel, Steven E

2013-06-01

Escherichia coli DNA polymerases (Pol) II, IV, and V serve dual roles by facilitating efficient translesion DNA synthesis while simultaneously introducing genetic variation that can promote adaptive evolution. Here we show that these alternative polymerases are induced as cells transition from exponential to long-term stationary-phase growth in the absence of induction of the SOS regulon by external agents that damage DNA. By monitoring the relative fitness of isogenic mutant strains expressing only one alternative polymerase over time, spanning hours to weeks, we establish distinct growth phase-dependent hierarchies of polymerase mutant strain competitiveness. Pol II confers a significant physiological advantage by facilitating efficient replication and creating genetic diversity during periods of rapid growth. Pol IV and Pol V make the largest contributions to evolutionary fitness during long-term stationary phase. Consistent with their roles providing both a physiological and an adaptive advantage during stationary phase, the expression patterns of all three SOS polymerases change during the transition from log phase to long-term stationary phase. Compared to the alternative polymerases, Pol III transcription dominates during mid-exponential phase; however, its abundance decreases to <20% during long-term stationary phase. Pol IV transcription dominates as cells transition out of exponential phase into stationary phase and a burst of Pol V transcription is observed as cells transition from death phase to long-term stationary phase. These changes in alternative DNA polymerase transcription occur in the absence of SOS induction by exogenous agents and indicate that cell populations require appropriate expression of all three alternative DNA polymerases during exponential, stationary, and long-term stationary phases to attain optimal fitness and undergo adaptive evolution.

In vitro and in silico modeling of chromosomal instability

NASA Astrophysics Data System (ADS)

Andreev, Sergey; Eidelman, Yuri; Krasavin, Eugene; Govorun, Raisa; Koshlan, Igor; Pyatenko, Valentina; Korovchuk, Olga; Khvostunov, Igor; Sevankaev, Alexander

Exposure to ionizing radiation increases cancer risk in human population. Cancer is thought to originate from an altered expression of certain number of specific genes. It is widely recognized that chromosome aberrations (CA) are involved in stable change in expression of genes by gain or loss of their functions. Thus CA can contribute to initiation or progression of cancer. Radiation induces CA immediately after exposure (in first cell cycle) and results in formation of delayed CA in descendants of irradiated cells, or chromosomal instability phenotype (CI). Therefore quantification of CI is a prerequisite of any mechanistic model of radiation induced cancer risks. To quantify CI we designed a set of in vitr o and in silico experiments. Two experimental models for study of CI in vitro, CHO-K1 wild-type and V79 HPRT-mutant cells, were exploited. Chromosome and chromatid type aberrations (Giemsa staining) were scored following exposure to gamma-radiation and accelerated ions (protons, LET=0.22 keV/µm, 7 Li3+ , LET=20 keV/µm, 14 7+ N , LET=77 keV/µm). The obtained results suggested that slowly growing colonies of HPRT mutant cells originating from lowand high-LET irradiated wt V79 cells were formed. After 14 N7+ ions irradiation about 50-100% of colonies had the decreased growth rate and CI phenotype was observed mainly in slowly growing colonies. High, compared to control, level of unstable CA (dicentrics) was observed in the progeny of gamma-irradiated CHO-K1 cells at different time points up to 30 cell generations. CA frequency, the number of cells with aberrations and the shape of a CA-vs-time curve were found to be dependent on the cell culture state (stationary or logarithmic phase) in which they were irradiated. Inhibition of replication and repair DNA synthesis by ara-C and hydroxyurea resulted in small modification of CA dynamics for stat-phase cells. For log-phase cell culture, in contrast, DNA synthesis inhibitors drastically impacted CA dynamics. In order to investigate the relationship between radiation-induced DNA double-strand breaks, CA and their transmission through cell division cycles we proposed a mechanism of CI incorporating the idea of breakage-fusion-bridge cycle. It explains in biophysical terms the generation of CA, in particular, of unstable type, in cells survived radiation exposure. The in silico experiments were carried out to elucidate different scenarios of CI. The computational data showed that the increased frequency of delayed dicentrics at different times after exposure could be well described for both stat and log-phase exposed cultures by the proposed mechanism if the fraction of cells in different cell cycle phases at the time of iradiation is taken into account. The perspectives for further experimental and theoretical mechanistic study of CI and possible implications for cancer risk modeling are discussed.

Electrical properties, phase transitions and conduction mechanisms of the [(C2H5)NH3]2CdCl4 compound

NASA Astrophysics Data System (ADS)

Mohamed, C. Ben; Karoui, K.; Saidi, S.; Guidara, K.; Rhaiem, A. Ben

2014-10-01

The [(C2H5)NH3]2CdCl4 hybrid material was prepared and its calorimetric study and electric properties were investigated at low temperature. The X-ray powder diffractogram has shown that the compound is crystallized in the orthorhombic system with Abma space group, and the refined unit cell parameters are a=7.546 Å, b=7.443 Å, and c=21.831 Å. The calorimetric study has revealed two endothermic peaks at 216 K and 357 K, which are confirmed by the variation of fp and σdc as a function of temperature. The equivalent circuit based on the Z-View-software was proposed and the conduction mechanisms were determined. The obtained results have been discussed in terms of the correlated barrier hopping model (CBH) in phase I (low temperature (OLT)), non-overlapping small polaron tunneling model (NSPT) in phase II (room temperature (ORT)) and the overlapping large polaron tunneling model in phase III (high temperature (OHT)). The density of localized states NF(E) at the Fermi level and the binding energy Wm were calculated. The variation of the dielectric loss log(εʺ) with log(ω) was found to follow the empirical law, ε″=B ωm(T).

Effectiveness of Vaporous Hydrogen Peroxide for the Decontamination of Representative Military Materials

DTIC Science & Technology

2004-11-16

Agent Resistant Coating (CARC) Geobacillus stearothermophilus ATCC 7953 Flott Glass Galvanized aluminum Polyimid (Kapton) Nylon Webbing Runway...spores were harvested from 7-10 day –old cultures plated upon Lemko Agar. The spores were washed thrice in sterile distilled water (dH2O), and...NEGATIVE SURROGATE Inocula of log-phase Y. ruckeri were prepared immediately before application to sterile coupons. Cells were grown in nutrient

Sage Gene Expression Profiles Characterizing Cure

DTIC Science & Technology

2005-10-01

achieved in haematological malignancies. In addition, tumour cell lines showed a log-linear dose re- sponse when exposed to alkylating agents [26,27...direct carcinogen, N-methyl nitrosourea (NMU) and an indirect carcinogen, 7,12- dimethylbenzanthracene each depend upon the estrous cycle phase at the...a single dose of N-methyl-N- nitrosourea . Cancer Res 45: 3042–3047, 1995 8. Nagasawa H, Yanai R, Taniguchi H: Importance of mammary gland DNA synthesis

Hepatitis B surface antigen levels during natural history of chronic hepatitis B: a Chinese perspective study.

PubMed

Zeng, Lin-Yan; Lian, Jiang-Shan; Chen, Jian-Yang; Jia, Hong-Yu; Zhang, Yi-Min; Xiang, Dai-Rong; Yu, Liang; Hu, Jian-Hua; Lu, Ying-Feng; Zheng, Lin; Li, Lan-Juan; Yang, Yi-Da

2014-07-21

To determine the baseline hepatitis B surface antigen (HBsAg) levels during the different phases of chronic hepatitis B (CHB) patients in China. Six hundred and twenty-three hepatitis B virus or un-infected patients not receiving antiviral therapy were analyzed in a cross-sectional study. The CHB patients were classified into five phases: immune-tolerant (IT, n = 108), immune-clearance (IC, n = 161), hepatitis B e antigen negative hepatitis (ENH, n = 149), low-replicative (LR, n = 135), and liver cirrhosis (LC, n = 70). HBsAg was quantified (Abbott ARCHITECT assay) and correlated with hepatitis B virus (HBV) DNA, and serum alanine aminotransferase/aspartate aminotransferase (ALT/AST) in each phase of CHB was also determined. Median HBsAg titers were different in each phase of CHB (P < 0.001): IT (4.85 log10 IU/mL), IC (4.36 log10 IU/mL), ENH (2.95 log10 IU/mL), LR (3.18 log10 IU/mL) and LC (2.69 log10 IU/mL). HBsAg titers were highest in the IT phase and lowest in the LC phase. Serum HBsAg titers showed a strong correlation with HBV viral load in the IC phase (r = 0.683, P < 0.001). No correlation between serum HBsAg level and ALT/AST was observed. The mean baseline HBsAg levels differ significantly during the five phases of CHB, providing evidence on the natural history of HBV infection. HBsAg quantification may predict the effects of immune-modulator or oral nucleos(t)ide analogue therapy.

Logarithmic compression methods for spectral data

DOEpatents

Dunham, Mark E.

2003-01-01

A method is provided for logarithmic compression, transmission, and expansion of spectral data. A log Gabor transformation is made of incoming time series data to output spectral phase and logarithmic magnitude values. The output phase and logarithmic magnitude values are compressed by selecting only magnitude values above a selected threshold and corresponding phase values to transmit compressed phase and logarithmic magnitude values. A reverse log Gabor transformation is then performed on the transmitted phase and logarithmic magnitude values to output transmitted time series data to a user.

Kinetic Behavior of Escherichia coli on Various Cheeses under Constant and Dynamic Temperature.

PubMed

Kim, K; Lee, H; Gwak, E; Yoon, Y

2014-07-01

In this study, we developed kinetic models to predict the growth of pathogenic Escherichia coli on cheeses during storage at constant and changing temperatures. A five-strain mixture of pathogenic E. coli was inoculated onto natural cheeses (Brie and Camembert) and processed cheeses (sliced Mozzarella and sliced Cheddar) at 3 to 4 log CFU/g. The inoculated cheeses were stored at 4, 10, 15, 25, and 30°C for 1 to 320 h, with a different storage time being used for each temperature. Total bacteria and E. coli cells were enumerated on tryptic soy agar and MacConkey sorbitol agar, respectively. E. coli growth data were fitted to the Baranyi model to calculate the maximum specific growth rate (μ max; log CFU/g/h), lag phase duration (LPD; h), lower asymptote (log CFU/g), and upper asymptote (log CFU/g). The kinetic parameters were then analyzed as a function of storage temperature, using the square root model, polynomial equation, and linear equation. A dynamic model was also developed for varying temperature. The model performance was evaluated against observed data, and the root mean square error (RMSE) was calculated. At 4°C, E. coli cell growth was not observed on any cheese. However, E. coli growth was observed at 10°C to 30°C with a μ max of 0.01 to 1.03 log CFU/g/h, depending on the cheese. The μ max values increased as temperature increased, while LPD values decreased, and μ max and LPD values were different among the four types of cheese. The developed models showed adequate performance (RMSE = 0.176-0.337), indicating that these models should be useful for describing the growth kinetics of E. coli on various cheeses.

Acridine orange staining reaction as an index of physiological activity in Escherichia coli

NASA Technical Reports Server (NTRS)

McFeters, G. A.; Singh, A.; Byun, S.; Callis, P. R.; Williams, S.

1991-01-01

The assumption that the acridine orange (AO) color reaction may be used as an index of physiological activity was investigated in laboratory grown Escherichia coli. Spectrofluorometric observations of purified nucleic acids, ribosomes and the microscopic color of bacteriophage-infected cells stained with AO confirmed the theory that single-stranded nucleic acids emit orange to red fluorescence while those that are double-stranded fluoresce green in vivo. Bacteria growing actively in a rich medium could be distinguished from cells in stationary phase by the AO reaction. Cells from log phase appeared red, whereas those in stationary phase were green. However, this differentiation was not seen when the bacteria were grown in a minimal medium or when a variation of the staining method was used. Also, shifting bacteria in stationary phase to starvation conditions rapidly changed their AO staining reaction. Boiling and exposure to lethal concentrations of azide and formalin resulted in stationary-phase cells that appeared red after staining but bacteria killed with chlorine remained green. These findings indicate that the AO staining reaction may be suggestive of physiological activity under defined conditions. However, variables in staining and fixation procedures as well as uncertainties associated with mixed bacterial populations in environmental samples may produce results that are not consistent with the classical interpretation of this reaction. The importance of validating the putative physiological implications of this staining reaction is stressed.

Oxygen Consumption Rates of Bacteria under Nutrient-Limited Conditions

PubMed Central

Riedel, Timothy E.; Nealson, Kenneth H.; Finkel, Steven E.

2013-01-01

Many environments on Earth experience nutrient limitation and as a result have nongrowing or very slowly growing bacterial populations. To better understand bacterial respiration under environmentally relevant conditions, the effect of nutrient limitation on respiration rates of heterotrophic bacteria was measured. The oxygen consumption and population density of batch cultures of Escherichia coli K-12, Shewanella oneidensis MR-1, and Marinobacter aquaeolei VT8 were tracked for up to 200 days. The oxygen consumption per CFU (QO2) declined by more than 2 orders of magnitude for all three strains as they transitioned from nutrient-abundant log-phase growth to the nutrient-limited early stationary phase. The large reduction in QO2 from growth to stationary phase suggests that nutrient availability is an important factor in considering environmental respiration rates. Following the death phase, during the long-term stationary phase (LTSP), QO2 values of the surviving population increased with time and more cells were respiring than formed colonies. Within the respiring population, a subpopulation of highly respiring cells increased in abundance with time. Apparently, as cells enter LTSP, there is a viable but not culturable population whose bulk community and per cell respiration rates are dynamic. This result has a bearing on how minimal energy requirements are met, especially in nutrient-limited environments. The minimal QO2 rates support the extension of Kleiber's law to the mass of a bacterium (100-fg range). PMID:23770901

Parvovirus B19 Replication and Expression in Differentiating Erythroid Progenitor Cells

PubMed Central

Bua, Gloria; Manaresi, Elisabetta; Bonvicini, Francesca; Gallinella, Giorgio

2016-01-01

The pathogenic Parvovirus B19 (B19V) is characterized by a strict adaptation to erythroid progenitor cells (EPCs), a heterogeneous population of differentiating cells with diverse phenotypic and functional properties. In our work, we studied the dynamics of B19V infection in EPCs in dependence on the cell differentiation stage, in terms of distribution of infected cells, synthesis of viral nucleic acids and production of infectious virus. EPCs at early differentiation stage led to an abortive infection, without viral genome replication and a very low transcriptional activity. EPCs at later stages were permissive, with highest levels of viral replicative activity at day 9 (+3.0 Log from 2 to 48 hpi) and lower levels at day 18 (+1.5 Log from 2 to 48 hpi). B19V DNA increment was in accordance with the percentage of cells positive to flow-FISH assay (41.4% at day 9, 1.1% at day 18). Quantitation of total RNA indicated a close association of genome replication and transcription with viral RNA accumulation within infected cells related to viral DNA increase during the course of infection. Analysis of the different classes of mRNAs revealed two distinct pattern of genome expression profile with a fine regulation in the frequency utilization of RNA processing signals: an early phase, when cleavage at the proximal site leading to a higher relative production of mRNA for NS protein, and a late phase, when cleavage at the distal site was more frequent leading to higher relative abundance of mRNA for VP and 11 kDA proteins. Infectious virus was released from cells at day 6–15, but not at day 18. Our results, providing a detailed description of B19V replication and expression profile in differentiating EPCs, highlight the very tight adaptation of B19V to a specific cellular target defined both by its erythroid lineage and its differentiation stage. PMID:26845771

Preliminary Study of Hyptis pectinata (L.) Poit Extract Biotransformation by Aspergillus niger

NASA Astrophysics Data System (ADS)

Rejeki, D. S.; Aminin, A. L. N.; Suzery, M.

2018-04-01

One alternative approach to increase the content of bioactive compounds is fermentation. Hyptis pectinata (L.) Poit is a plant that can be found in tropical area and potentially as anticancer, anti-inflammatory, insect repellant, antiviral and antioxidant. In this research, efforts have been made to increase bioactive plant capacity of Hyptis pectinata (L.) Poit through submerged fermentation using Aspergillus niger. The study was performed by adding methanol extract of Hyptis pectinata (L.) Poit on two conditions, that was added at the beginning of fermentation and while entering a phase of death. Aspergillus niger growth rate in both conditions was observed by determining the dry weight of cells every 24 hours. The transformation profil of extract was observed after 24 hours of extract addition in early death phase by the TLC method. The results show that the addition of Hyptis pectinata (L.) Poit extract at log phase triggers the cells to growth faster, whereas the addition at the early death phase precisely accelerates cell death. TLC profile shows the emergence of new compounds suspected as the products of transformation of Hyptis pectinata (L.) Poit extract on day 8 after addition of extract.

Microbiological Evaluation of Containment Isolators for the Care of Patients with Exotic Diseases.

DTIC Science & Technology

1980-02-01

The microbiological integrity of containment isolators obtained from Vickers Limited Medical Engineering was evaluated using aerosols of Tl coliphage ...diluted in sterile distilled water (SDW). Aliquots for plate counts were mixed with log phase host cells and the mixture spread evenly on pre-dried...of water was diffi- cult to maintain and measure accurately even with sensitive meters, and finally visual observation of the curvature of the side

Synchronization of Mammalian Cells and Nuclei by Centrifugal Elutriation.

PubMed

Banfalvi, Gaspar

2017-01-01

Synchronized populations of large numbers of cells can be obtained by centrifugal elutriation on the basis of sedimentation properties of small round particles, with minimal perturbation of cellular functions. The physical characteristics of cell size and sedimentation velocity are operative in the technique of centrifugal elutriation also known as counterstreaming centrifugation. The elutriator is an advanced device for increasing the sedimentation rate to yield enhanced resolution of cell separation. A random population of cells is introduced into the elutriation chamber of an elutriator rotor running in a specially designed centrifuge. By increasing step-by-step the flow rate of the elutriation fluid, successive populations of relatively homogeneous cell size can be removed from the elutriation chamber and used as synchronized subpopulations. For cell synchronization by centrifugal elutriation, early log S phase cell populations are most suitable where most of the cells are in G1 and S phase (>80 %). Apoptotic cells can be found in the early elutriation fractions belonging to the sub-Go window. Protocols for the synchronization of nuclei of murine pre-B cells and high-resolution centrifugal elutriation of CHO cells are given. The verification of purity and cell cycle positions of cells in elutriated fractions includes the measurement of DNA synthesis by [ 3 H]-thymidine incorporation and DNA content by propidium iodide flow cytometry.

SigCH, an extracytoplasmic function sigma factor of Porphyromonas gingivalis regulates the expression of cdhR and hmuYR.

PubMed

Ota, Koki; Kikuchi, Yuichiro; Imamura, Kentaro; Kita, Daichi; Yoshikawa, Kouki; Saito, Atsushi; Ishihara, Kazuyuki

2017-02-01

Extracytoplasmic function (ECF) sigma factors play an important role in the bacterial response to various environmental stresses. Porphyromonas gingivalis, a prominent etiological agent in human periodontitis, possesses six putative ECF sigma factors. So far, information is limited on the ECF sigma factor, PGN_0319. The aim of this study was to investigate the role of PGN_0319 (SigCH) of P. gingivalis, focusing on the regulation of hmuY and hmuR, which encode outer-membrane proteins involved in hemin utilization, and cdhR, a transcriptional regulator of hmuYR. First, we evaluated the gene expression profile of the sigCH mutant by DNA microarray. Among the genes with altered expression levels, those involved in hemin utilization were downregulated in the sigCH mutant. To verify the microarray data, quantitative reverse transcription PCR analysis was performed. The RNA samples used were obtained from bacterial cells grown to early-log phase, in which sigCH expression in the wild type was significantly higher than that in mid-log and late-log phases. The expression levels of hmuY, hmuR, and cdhR were significantly decreased in the sigCH mutant compared to wild type. Transcription of these genes was restored in a sigCH complemented strain. Compared to the wild type, the sigCH mutant showed reduced growth in log phase under hemin-limiting conditions. Electrophoretic mobility shift assays showed that recombinant SigCH protein bound to the promoter region of hmuY and cdhR. These results suggest that SigCH plays an important role in the early growth of P. gingivalis, and directly regulates cdhR and hmuYR, thereby playing a potential role in the mechanisms of hemin utilization by P. gingivalis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Determination of the n-octanol/water partition coefficients of weakly ionizable basic compounds by reversed-phase high-performance liquid chromatography with neutral model compounds.

PubMed

Liang, Chao; Han, Shu-ying; Qiao, Jun-qin; Lian, Hong-zhen; Ge, Xin

2014-11-01

A strategy to utilize neutral model compounds for lipophilicity measurement of ionizable basic compounds by reversed-phase high-performance liquid chromatography is proposed in this paper. The applicability of the novel protocol was justified by theoretical derivation. Meanwhile, the linear relationships between logarithm of apparent n-octanol/water partition coefficients (logKow '') and logarithm of retention factors corresponding to the 100% aqueous fraction of mobile phase (logkw ) were established for a basic training set, a neutral training set and a mixed training set of these two. As proved in theory, the good linearity and external validation results indicated that the logKow ''-logkw relationships obtained from a neutral model training set were always reliable regardless of mobile phase pH. Afterwards, the above relationships were adopted to determine the logKow of harmaline, a weakly dissociable alkaloid. As far as we know, this is the first report on experimental logKow data for harmaline (logKow = 2.28 ± 0.08). Introducing neutral compounds into a basic model training set or using neutral model compounds alone is recommended to measure the lipophilicity of weakly ionizable basic compounds especially those with high hydrophobicity for the advantages of more suitable model compound choices and convenient mobile phase pH control. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mechanisms of action of (meth)acrylates in hemolytic activity, in vivo toxicity and dipalmitoylphosphatidylcholine (DPPC) liposomes determined using NMR spectroscopy.

PubMed

Fujisawa, Seiichiro; Kadoma, Yoshinori

2012-01-01

We investigated the quantitative structure-activity relationships between hemolytic activity (log 1/H(50)) or in vivo mouse intraperitoneal (ip) LD(50) using reported data for α,β-unsaturated carbonyl compounds such as (meth)acrylate monomers and their (13)C-NMR β-carbon chemical shift (δ). The log 1/H(50) value for methacrylates was linearly correlated with the δC(β) value. That for (meth)acrylates was linearly correlated with log P, an index of lipophilicity. The ipLD(50) for (meth)acrylates was linearly correlated with δC(β) but not with log P. For (meth)acrylates, the δC(β) value, which is dependent on the π-electron density on the β-carbon, was linearly correlated with PM3-based theoretical parameters (chemical hardness, η; electronegativity, χ; electrophilicity, ω), whereas log P was linearly correlated with heat of formation (HF). Also, the interaction between (meth)acrylates and DPPC liposomes in cell membrane molecular models was investigated using (1)H-NMR spectroscopy and differential scanning calorimetry (DSC). The log 1/H(50) value was related to the difference in chemical shift (ΔδHa) (Ha: H (trans) attached to the β-carbon) between the free monomer and the DPPC liposome-bound monomer. Monomer-induced DSC phase transition properties were related to HF for monomers. NMR chemical shifts may represent a valuable parameter for investigating the biological mechanisms of action of (meth)acrylates.

Mechanisms of Action of (Meth)acrylates in Hemolytic Activity, in Vivo Toxicity and Dipalmitoylphosphatidylcholine (DPPC) Liposomes Determined Using NMR Spectroscopy

PubMed Central

Fujisawa, Seiichiro; Kadoma, Yoshinori

2012-01-01

We investigated the quantitative structure-activity relationships between hemolytic activity (log 1/H50) or in vivo mouse intraperitoneal (ip) LD50 using reported data for α,β-unsaturated carbonyl compounds such as (meth)acrylate monomers and their 13C-NMR β-carbon chemical shift (δ). The log 1/H50 value for methacrylates was linearly correlated with the δCβ value. That for (meth)acrylates was linearly correlated with log P, an index of lipophilicity. The ipLD50 for (meth)acrylates was linearly correlated with δCβ but not with log P. For (meth)acrylates, the δCβ value, which is dependent on the π-electron density on the β-carbon, was linearly correlated with PM3-based theoretical parameters (chemical hardness, η; electronegativity, χ; electrophilicity, ω), whereas log P was linearly correlated with heat of formation (HF). Also, the interaction between (meth)acrylates and DPPC liposomes in cell membrane molecular models was investigated using 1H-NMR spectroscopy and differential scanning calorimetry (DSC). The log 1/H50 value was related to the difference in chemical shift (ΔδHa) (Ha: H (trans) attached to the β-carbon) between the free monomer and the DPPC liposome-bound monomer. Monomer-induced DSC phase transition properties were related to HF for monomers. NMR chemical shifts may represent a valuable parameter for investigating the biological mechanisms of action of (meth)acrylates. PMID:22312284

Decontamination of materials contaminated with Francisella philomiragia or MS2 bacteriophage using PES-Solid, a solid source of peracetic acid.

PubMed

Buhr, T L; Young, A A; Johnson, C A; Minter, Z A; Wells, C M

2014-08-01

The aim of the study was to develop test methods and evaluate survival of Francisella philomiragia cells and MS2 bacteriophage after exposure to PES-Solid (a solid source of peracetic acid) formulations with or without surfactants. Francisella philomiragia cells (≥7·6 log10 CFU) or MS2 bacteriophage (≥6·8 log10 PFU) were deposited on seven different test materials and treated with three different PES-Solid formulations, three different preneutralized samples and filter controls at room temperature for 15 min. There were 0-1·3 log10 CFU (<20 cells) of cell survival, or 0-1·7 log10 (<51 PFU) of bacteriophage survival in all 21 test combinations (organism, formulation and substrate) containing reactive PES-Solid. In addition, the microemulsion (Dahlgren Surfactant System) showed ≤2 log10 (100 cells) of viable F. philomiragia cells, indicating the microemulsion achieved <2 log10 CFU on its own. Three PES-Solid formulations and one microemulsion system (DSS) inactivated F. philomiragia cells and/or MS2 bacteriophage that were deposited on seven different materials. A test method was developed to show that reactive PES-Solid formulations and a microemulsion system (DSS) inactivated >6 log10 CFU/PFU F. philomiragia cells and/or MS2 bacteriophage on different materials. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Post-processing application of chemical solutions for control of Listeria monocytogenes, cultured under different conditions, on commercial smoked sausage formulated with and without potassium lactate-sodium diacetate.

PubMed

Geornaras, Ifigenia; Skandamis, Panagiotis N; Belk, Keith E; Scanga, John A; Kendall, Patricia A; Smith, Gary C; Sofos, John N

2006-12-01

This study evaluated post-processing chemical solutions for their antilisterial effects on commercial smoked sausage formulated with or without 1.5% potassium lactate plus 0.05% sodium diacetate, and contaminated (approximately 3-4 log cfu/cm(2)) with 10-strain composite Listeria monocytogenes inocula prepared under various conditions. Inoculated samples were left untreated, or were immersed (2 min, 25 +/- 2 degrees C) in solutions of acetic acid (2.5%), lactic acid (2.5%), potassium benzoate (5%) or Nisaplin (0.5%, equivalent to 5000 IU/ml of nisin) alone, and in sequence (Nisaplin followed by acetic acid, lactic acid or potassium benzoate), before vacuum packaging and storage at 10 degrees C (48 days). Acetic acid, lactic acid or potassium benzoate applied alone reduced initial L. monocytogenes populations by 0.4-1.5 log cfu/cm(2), while treatments including Nisaplin caused reductions of 2.1-3.3 log cfu/cm(2). L. monocytogenes on untreated sausage formulated with antimicrobials had a lag phase duration of 10.2 days and maximum specific growth rate (mu(max)) of 0.089 per day, compared to no lag phase and mu(max) of 0.300 per day for L. monocytogenes on untreated product that did not contain antimicrobials in the formulation. The immersion treatments inhibited growth of the pathogen for 4.9-14.8 days on sausage formulated without potassium lactate-sodium diacetate; however, in all cases significant (P < 0.05) growth occurred by the end of storage. The antilisterial activity of chemical solutions was greatly enhanced when applied to product formulated with antimicrobials; growth was completely inhibited on sausage treated with acetic or lactic acid alone, and in sequence with Nisaplin. In general, habituation (15 degrees C, 7 days) of L. monocytogenes cells, planktonically or as attached cells to stainless-steel coupons in sausage homogenate prior to contamination of product, resulted in shorter lag phase durations compared with cells cultivated planktonically in a broth medium. Furthermore, when present, high levels of spoilage flora were found to suppress growth of the pathogen. Findings of this study could be useful to US meat processors in their efforts to select required regulatory alternatives for control of post-processing contamination in meat products.

Paralogous Ribosomal Protein L32-1 and L32-2 in Fission Yeast May Function Distinctively in Cellular Proliferation and Quiescence by Changing the Ratio of Rpl32 Paralogs

PubMed Central

Sun, Lei; Yang, Xiaowei; Chen, Feifei; Li, Rongpeng; Li, Xuesong; Liu, Zhenxing; Gu, Yuyu; Gong, Xiaoyan; Liu, Zhonghua; Wei, Hua; Huang, Ying; Yuan, Sheng

2013-01-01

Fission yeast cells express Rpl32-2 highly while Rpl32-1 lowly in log phase; in contrast, expression of Rpl32-1 raises and reaches a peak level while Rpl32-2 is downregulated to a low basic level when cells enter into stationary phase. Overexpression of Rpl32-1 inhibits cell growth while overexpression of Rpl32-2 does not. Deleting rpl32-2 impairs cell growth more severely than deleting rpl32-1 does. Cell growth impaired by deleting either paralog can be rescued completely by reintroducing rpl32-2, but only partly by rpl32-1. Overexpression of Rpl32-1 inhibits cell division, yielding 4c DNA and multiple septa, while overexpressed Rpl32-2 promotes it. Transcriptomics analysis proved that Rpl32 paralogs regulate expression of a subset of genes related with cell division and stress response in a distinctive way. This functional difference of the two paralogs is due to their difference of 95th amino acid residue. The significance of a competitive inhibition between Rpl32 paralogs on their expression is discussed. PMID:23577148

Analysis of soybean tissue culture protein dynamics using difference gel electrophoresis.

PubMed

Miernyk, Ján A; Jett, Alissa A; Johnston, Mark L

2016-01-01

Excised hypocotyls from developing soybean (Glycine max (L.) merr. cv. Jack) were cultivated on agar-solidified medium until callus formed. The calli were then propagated in liquid medium until stable, relatively uniform, finely-divided suspension cultures were obtained. Cells were typically transferred to fresh medium at 7-day intervals. Cultures were harvested by filtration five days (early log phase) or eight days (late log phase) after transfer. In order to evaluate dynamic changes, both intracellular and extracellular proteins were analyzed by 2-dimensional difference gel electrophoresis. Selected spots were subjected to in-gel tryptic-digestion and the resultant peptides were analyzed by nLC-MS/MS. In follow-up studies gel-free shot-gun analyses led to identification of 367 intracellular proteins and 188 extracellular proteins. The significance of the described research is two-fold. First a gel-based proteomics method was applied to the study of the dynamics of the secretome (extracellular proteins). Second, results of a shot-gun non-gel based proteomic survey of both cellular and extracellular proteins are presented. Published by Elsevier B.V.

Differential requirements of two recA mutants for constitutive SOS expression in Escherichia coli K-12.

PubMed

Long, Jarukit Edward; Renzette, Nicholas; Centore, Richard C; Sandler, Steven J

2008-01-01

Repairing DNA damage begins with its detection and is often followed by elicitation of a cellular response. In E. coli, RecA polymerizes on ssDNA produced after DNA damage and induces the SOS Response. The RecA-DNA filament is an allosteric effector of LexA auto-proteolysis. LexA is the repressor of the SOS Response. Not all RecA-DNA filaments, however, lead to an SOS Response. Certain recA mutants express the SOS Response (recA(C)) in the absence of external DNA damage in log phase cells. Genetic analysis of two recA(C) mutants was used to determine the mechanism of constitutive SOS (SOS(C)) expression in a population of log phase cells using fluorescence of single cells carrying an SOS reporter system (sulAp-gfp). SOS(C) expression in recA4142 mutants was dependent on its initial level of transcription, recBCD, recFOR, recX, dinI, xthA and the type of medium in which the cells were grown. SOS(C) expression in recA730 mutants was affected by none of the mutations or conditions tested above. It is concluded that not all recA(C) alleles cause SOS(C) expression by the same mechanism. It is hypothesized that RecA4142 is loaded on to a double-strand end of DNA and that the RecA filament is stabilized by the presence of DinI and destabilized by RecX. RecFOR regulate the activity of RecX to destabilize the RecA filament. RecA730 causes SOS(C) expression by binding to ssDNA in a mechanism yet to be determined.

Cellular Metabolic Activity and the Oxygen and Hydrogen Stable Isotope Composition of Intracellular Water and Metabolites

NASA Astrophysics Data System (ADS)

Kreuzer-Martin, H. W.; Hegg, E. L.

2008-12-01

Intracellular water is an important pool of oxygen and hydrogen atoms for biosynthesis. Intracellular water is usually assumed to be isotopically identical to extracellular water, but an unexpected experimental result caused us to question this assumption. Heme O isolated from Escherichia coli cells grown in 95% H218O contained only a fraction of the theoretical value of labeled oxygen at a position where the O atom was known to be derived from water. In fact, fewer than half of the oxygen atoms were labeled. In an effort to explain this surprising result, we developed a method to determine the isotope ratios of intracellular water in cultured cells. The results of our experiments showed that during active growth, up to 70% of the oxygen atoms and 50% of the hydrogen atoms in the intracellular water of E. coli are generated during metabolism and can be isotopically distinct from extracellular water. The fraction of isotopically distinct atoms was substantially less in stationary phase and chilled cells, consistent with our hypothesis that less metabolically-generated water would be present in cells with lower metabolic activity. Our results were consistent with and explained the result of the heme O labeling experiment. Only about 40% of the O atoms on the heme O molecule were labeled because, presumably, only about 40% of the water inside the cells was 18O water that had diffused in from the culture medium. The rest of the intracellular water contained 16O atoms derived from either nutrients or atmospheric oxygen. To test whether we could also detect metabolically-derived hydrogen atoms in cellular constituents, we isolated fatty acids from log-phase and stationary phase E. coli and determined the H isotope ratios of individual fatty acids. The results of these experiments showed that environmental water contributed more H atoms to fatty acids isolated in stationary phase than to the same fatty acids isolated from log-phase cells. Stable isotope analyses of biomass of Bacillus subtilis, a Gram-positive bacterium, showed the same pattern. Rapidly-dividing cells derived fewer of their O and H atoms from environmental water than did more slowly-growing cells and spores. To test whether a eukaryotic cell, surrounded by only a membrane, would also maintain an isotopic gradient and a detectable percentage of metabolic water, we applied our approach to cultured rat fibroblasts. Preliminary results showed that approximately 50% of the O and H atoms in exponentially growing cells were derived from metabolic activity. In quiescent cells, metabolic activity generated approximately 25% of the O and H atoms in intracellular water. Thus far, the data we have obtained is consistent with the following model: (1) Intracellular water is composed of water that diffuses in from the extracellular environment and water that is created as a result of metabolic activity. (2) The relative amounts of environmental and metabolic water inside a cell are a function of the cell's metabolic activity. (3) The oxygen and hydrogen isotope ratios of cellular metabolites are a function of those of intracellular water, and therefore reflect the metabolic activity of the cell at the time of biosynthesis.

Regulated Exopolysaccharide Production in Myxococcus xanthus

PubMed Central

Kim, Sang-Hoon; Ramaswamy, Srinivas; Downard, John

1999-01-01

Myxococcus xanthus fibrils are cell surface-associated structures composed of roughly equal amounts of polysaccharide and protein. The level of M. xanthus polysaccharide production under different conditions in the wild type and in several mutants known to have alterations in fibril production was investigated. Wild-type exopolysaccharide increased significantly as cells entered the stationary phase of growth or upon addition of Ca2+ to growing cells, and the polysaccharide-induced cells exhibited an enhanced capacity for cell-cell agglutination. The activity of the key gluconeogenic pathway enzyme phosphoenolpyruvate carboxykinase (Pck) also increased under these conditions. Most fibril-deficient mutants failed to produce polysaccharide in a stationary-phase- or Ca2+-dependent fashion. However, regulation of Pck activity was generally unimpaired in these mutant strains. In an stk mutant, which overproduces fibrils, polysaccharide production and Pck activity were constitutively high under the conditions tested. Polysaccharide production increased in most fibril-deficient strains when an stk mutant allele was present, indicating that these fibril-deficient mutants retained the basic cellular components required for fibril polysaccharide production. In contrast to other divalent cations tested, Sr2+ effectively replaced Ca2+ in stimulating polysaccharide production, and either Ca2+ or Sr2+ was required for fruiting-body formation by wild-type cells. By using transmission electron microscopy of freeze-substituted log-phase wild-type cells, fibril material was observed as a cell surface-associated layer of uniform thickness composed of filaments with an ordered structure. PMID:10049381

Physiological consequences of starvation in Pseudomonas putida: degradation of intracellular protein and loss of activity of the inducible enzymes of L-arginine catabolism.

PubMed

Fan, C L; Rodwell, V W

1975-12-01

We investigated the degradation of radioisotopically labeled intracellular protein in starved, intact cells of Pseudomonas putida P2 (ATCC 25571) and the regulation of this process. Intracellular protein isotopically labeled with L-[4,5-3H]leucine during log-phase growth at 30 C is degraded at rates of 1 to 2%/h in log-phase cells and 7 to 9%/h in starved cells. Rifampin, chloramphenicol, and tosyllysine chloromethylketone lower the rate of protein degradation by starved cells. Addition to starved cells of a nutrient upon which the culture is induced for growth rapidly lowers the rate of protein degradation from 7 to 9%/h to less than 1.5%/h. A nutrient that is oxidized but that cannot immediately support growth also lowers the rate of starvation-induced protein degradation. Proteolytic activity of cell extracts requires a divalent metal ion and may be inhibited up to 60% by tosyllysine chloromethylketone or p-toluenesulfonyl fluoride. Rifampin and chloramphenicol have no effect. In contrast to intact cells, extracts of growing or starving cells degrade protein at equivalent rates. We also investigated the stabilities of the inducible transport system and of four inducible intracellular enzymes of L-arginine catabolism. These include: the membrane-associated, L-arginine-specific transport system; L-arginine oxidase (oxidase); alpha-ketoarginine decarboxylase (decarboxylase); gamma-guanidinobutyraldehyde dehydrogenase ( dehydrogenase); and gamma-guanidinobutyrate amidinohydrolase (hydrolase). In starved cells, the rates of loss of activities were: transport and dehydrogenase activities, stable; oxidase and decarboxylase activities, 20 to 30%/h; hydrolase activity, 5 to 8%/h. Chloramphenicol decreases the rate of loss of oxidase, decarboxylase, and hydrolase activity, whereas p-toluenesulfonyl fluoride lowers the rate of loss of decarboxylase but not of oxidase or hydrolase activity. Addition to starved cells of a nutrient for which they are already induced for growth (e.g., malate, a noninducer of arginine catabolic enzymes) decreases the rate of loss of oxidase and decarboxylase activity but not that of the hydrolase.

The development of a high-throughput measurement method of octanol/water distribution coefficient based on hollow fiber membrane solvent microextraction technique.

PubMed

Bao, James J; Liu, Xiaojing; Zhang, Yong; Li, Youxin

2014-09-15

This paper describes the development of a novel high-throughput hollow fiber membrane solvent microextraction technique for the simultaneous measurement of the octanol/water distribution coefficient (logD) for organic compounds such as drugs. The method is based on a designed system, which consists of a 96-well plate modified with 96 hollow fiber membrane tubes and a matching lid with 96 center holes and 96 side holes distributing in 96 grids. Each center hole was glued with a sealed on one end hollow fiber membrane tube, which is used to separate the aqueous phase from the octanol phase. A needle, such as microsyringe or automatic sampler, can be directly inserted into the membrane tube to deposit octanol as the accepted phase or take out the mixture of the octanol and the drug. Each side hole is filled with aqueous phase and could freely take in/out solvent as the donor phase from the outside of the hollow fiber membranes. The logD can be calculated by measuring the drug concentration in each phase after extraction equilibrium. After a comprehensive comparison, the polytetrafluoroethylene hollow fiber with the thickness of 210 μm, an extraction time of 300 min, a temperature of 25 °C and atmospheric pressure without stirring are selected for the high throughput measurement. The correlation coefficient of the linear fit of the logD values of five drugs determined by our system to reference values is 0.9954, showed a nice accurate. The -8.9% intra-day and -4.4% inter-day precision of logD for metronidazole indicates a good precision. In addition, the logD values of eight drugs were simultaneously and successfully measured, which indicated that the 96 throughput measure method of logD value was accurate, precise, reliable and useful for high throughput screening. Copyright © 2014 Elsevier B.V. All rights reserved.

Inactivation and sublethal injury of Escherichia coli and Listeria innocua by high hydrostatic pressure in model suspensions and beetroot juice

NASA Astrophysics Data System (ADS)

Sokołowska, Barbara; Skąpska, Sylwia; Niezgoda, Jolanta; Rutkowska, Małgorzata; Dekowska, Agnieszka; Rzoska, Sylwester J.

2014-01-01

Cells exposed to different physical and chemical treatments, including high hydrostatic pressure (HHP), suffer from injuries that could be reversible in food materials when stored. Escherichia coli and Listeria innocua cells suspended in phosphate-buffered saline (PBS) (model suspensions), and acidified beetroot juice were subjected to a pressure of 400 MPa at a temperature of 20°C for up to 10 min. The difference between the viable and non-injured cells was used to estimate the number of injured survivors. The reduction in E. coli cell number was 3.4-4.1 log after 10 min pressurization in model suspensions and 6.2 log in beetroot juice. Sublethally injured cells in PBS accounted for up to 2.7 log after 10 min HHP treatment and 0.8 log in beetroot juice. The reduction in L. innocua cell number after 10 min pressure treatment reached from 3.8 to 4.8 log, depending on the initial concentration in model suspensions. Among the surviving L. innocua cells, even up to 100% were injured. L. innocua cells were completely inactivated after 1 min HHP treatment in beetroot juice.

Survival of Listeria monocytogenes in a simulated recirculating brine chiller system.

PubMed

Gailey, J K; Dickson, J S; Dorsa, W

2003-10-01

Contamination by Listeria monocytogenes of processed meats after cooking presents a significant food safety risk. The purpose of this study was to determine the survival of L. monocytogenes in a simulated recirculating brine chiller system using pH values of 5, 6, and 7 with free chlorine concentrations of 0, 3, 5, and 10 ppm in 20% salt brine at -12 degrees C. At pH values of 5, 6, and 7 with chlorine concentrations of 2 and 3 ppm, using 10(8) CFU in a test tube system, an immediate drop of 0.28 log CFU/ml with no significance between treatments (P > 0.05), followed by a steady survival phase with a slope close to 0, was observed. In brine at a pH of 5 with 5 and 10 ppm of chlorine, an initial drop of 0.8 log CFU/ml was observed, which was followed by a steady survival phase with a destruction slope close to zero. At an inoculation concentration of 10(2) CFU in a test tube system (pH values of 5 and 7 with 0 and 10 ppm of chlorine), the average initial drop for all treatments was 0.1 log CFU/ml, which was followed by a steady survival phase. In a recirculating system, very few cells were destroyed during the brine chilling process, but only low numbers of L. monocytogenes were recovered from the brine and uninoculated hot dogs. Although little destruction of L. monocytogenes was noted, the dilution effect observed during the study indicates that environmental contamination of a brine chiller system poses little danger of postcooking contamination for processed meats if the system is regularly cleaned and sanitized.

Changes in the proteome of Escherichia coli during growth at 15 degrees C after incubation at 2, 6 or 8 degrees C for 4 days.

PubMed

Jones, T H; Johns, M W; Gill, C O

2008-06-10

For better understanding of the complex behaviour of Escherichia coli at chiller temperatures, log phase E. coli grown at 15 degrees C were incubated at 8, 6, or 2 degrees C for 4 days, and were then incubated at 15 degrees C for 12 h. Cultures were sampled after incubation at the lower temperatures, and during subsequent incubation at 15 degrees C. Proteins extracted from the samples were separated by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). Spots of 45 previously identified proteins that were differentially expressed at 15 or < or =8 degrees C were quantified by image analysis. After incubation at 8 or 6 degrees C for 4 days cells were growing with or without formation of elongated cells (filaments), respectively, but growth did not occur at 2 degrees C. In cells incubated at 8 or 6 degrees C proteins associated with the stress response and energy generation were upregulated and proteins associated with protein synthesis were downregulated, while protein levels in cells incubated at 2 degrees C were little changed. When cells were then incubated at 15 degrees C, the levels of differentially expressed proteins in cells that had been incubated at 8 or 6 degrees C decreased or increased towards the levels found in cells growing at 15 degrees C, but some proteins were still under or over expressed after 12 h. In cells incubated at 15 degrees C after incubation at 2 degrees C, the levels of many of the proteins declined but the levels of proteins associated with protein synthesis increased. The findings indicate that the physiological states of log phase E. coli incubated at < or =2 degrees C or at higher chiller temperature are different, but that for both states incubation at an above chiller temperature for >3 generations is required before protein levels adjusted to those usual for the higher temperature. Cells in these different physiological states may respond differently to other stresses encountered during warming of chilled foods.

sugE: A gene involved in tributyltin (TBT) resistance of Aeromonas molluscorum Av27.

PubMed

Cruz, Andreia; Micaelo, Nuno; Félix, Vitor; Song, Jun-Young; Kitamura, Shin-Ichi; Suzuki, Satoru; Mendo, Sónia

2013-01-01

The mechanism of bacterial resistance to tributyltin (TBT) is still unclear. The results herein presented contribute to clarify that mechanism in the TBT-resistant bacterium Aeromonas molluscorum Av27. We have identified and cloned a new gene that is involved in TBT resistance in this strain. The gene is highly homologous (84%) to the Aeromonas hydrophila-sugE gene belonging to the small multidrug resistance gene family (SMR), which includes genes involved in the transport of lipophilic drugs. In Av27, expression of the Av27-sugE was observed at the early logarithmic growth phase in the presence of a high TBT concentration (500 μM), thus suggesting the contribution of this gene for TBT resistance. E. coli cells transformed with Av27-sugE become resistant to ethidium bromide (EtBr), chloramphenicol (CP) and tetracycline (TE), besides TBT. According to the Moriguchi logP (miLogP) values, EtBr, CP and TE have similar properties and are substrates for the sugE-efflux system. Despite the different miLogP of TBT, E. coli cells transformed with Av27-sugE become resistant to this compound. So it seems that TBT is also a substrate for the SugE protein. The modelling studies performed also support this hypothesis. The data herein presented clearly indicate that sugE is involved in TBT resistance of this bacterium.

Live encapsulated Lactobacillus acidophilus cells in yogurt for therapeutic oral delivery: preparation and in vitro analysis of alginate-chitosan microcapsules.

PubMed

Urbanska, Aleksandra Malgorzata; Bhathena, Jasmine; Prakash, Satya

2007-09-01

Targeted delivery of live microencapsulated bacterial cells has strong potential for application in treating various diseases, including diarrhea, kidney failure, liver failure, and high cholesterol, among others. This study investigates the potential of microcapsules composed of two natural polymers, alginate and chitosan (AC), and the use of these artificial cells in yogurt for delivery of probiotic Lactobacillus acidophilus bacterial live cells. Results show that the integrity of AC microcapsules was preserved after 76 h of mechanical shaking in MRS broth and after 12 h and 24 h in simulated gastric and intestinal fluids. Using an in vitro computer-controlled simulated human gastrointestinal (GI) model, we found 8.37 log CFU/mL of viable bacterial cells were present after 120 min of gastric exposure and 7.96 log CFU/mL after 360 min of intestinal exposure. In addition, AC microcapsules composed of chitosan 10 and 100 at various concentrations were subjected to 4-week storage in 2% milk fat yogurt or 0.85% physiological solution. It was found that 9.37 log CFU/mL of cells encapsulated with chitosan 10 and 8.24 log CFU/mL of cells encapsulated with chitosan 100 were alive after 4 weeks. The AC capsule composed of 0.5% chitosan 10 provided the highest bacterial survival of 9.11 log CFU/mL after 4 weeks. Finally, an investigation of bacterial viability over 72 h in different pH buffers yielded highest survival of 6.34 log CFU/mL and 10.34 log CFU/mL at pH 8 for free and AC-encapsulated cells, respectively. We conclude from these findings that encapsulation allows delivery of a higher number of bacteria to desired targets in the GI tract and that microcapsules containing bacterial cells are good candidates for oral artificial cells for bacterial cell therapy.

Ultrastructural analysis of Phytomonas species from Euphorbia pinea reveals trans-cytoplasmic filaments 10 nm in diameter.

PubMed

Page, A M; Lagnado, J R

2000-10-01

Phytomonas sp. derived from Euphorbia pinea are digenetic plant trypanosomes that are transmitted by the squashbug Stenocephalus agilis and exist exclusively as promastigotes. The stable sub-pellicular microtubular array, the flagellar axoneme and the paraflagellar rod represent the major cytoskeletal components common to all trypanosomes. The work described in this paper examines in detail the ultrastructural morphology of the organism and highlights a number of novel structural features, and in particular, the presence of some detergent-resistant proteins which take the form of bundles of trans-cytoplasmic filaments of ca. 10 nm in diameter, seen in cells from both log- and stationary-phase cultures. The ultrastructural morphology and immunological cross-reactivity of these filaments are described, and their relationship to filamentous bundles previously reported in stationary-phase cultures of Crithidia fasciculata and to intermediate filaments of animal cells is discussed.

Acetic acid fermentation of acetobacter pasteurianus: relationship between acetic acid resistance and pellicle polysaccharide formation.

PubMed

Kanchanarach, Watchara; Theeragool, Gunjana; Inoue, Taketo; Yakushi, Toshiharu; Adachi, Osao; Matsushita, Kazunobu

2010-01-01

Acetobacter pasteurianus strains IFO3283, SKU1108, and MSU10 were grown under acetic acid fermentation conditions, and their growth behavior was examined together with their capacity for acetic acid resistance and pellicle formation. In the fermentation process, the cells became aggregated and covered by amorphous materials in the late-log and stationary phases, but dispersed again in the second growth phase (due to overoxidation). The morphological change in the cells was accompanied by changes in sugar contents, which might be related to pellicle polysaccharide formation. To determine the relationship between pellicle formation and acetic acid resistance, a pellicle-forming R strain and a non-forming S strain were isolated, and their fermentation ability and acetic acid diffusion activity were compared. The results suggest that pellicle formation is directly related to acetic acid resistance ability, and thus is important to acetic acid fermentation in these A. pasteurianus strains.

Characterization of Ascentis RP-Amide column: Lipophilicity measurement and linear solvation energy relationships.

PubMed

Benhaim, Deborah; Grushka, Eli

2010-01-01

This study investigates lipophilicity determination by chromatographic measurements using the polar embedded Ascentis RP-Amide stationary phase. As a new generation of amide-functionalized silica stationary phase, the Ascentis RP-Amide column is evaluated as a possible substitution to the n-octanol/water partitioning system for lipophilicity measurements. For this evaluation, extrapolated retention factors, log k'w, of a set of diverse compounds were determined using different methanol contents in the mobile phase. The use of n-octanol enriched mobile phase enhances the relationship between the slope (S) of the extrapolation lines and the extrapolated log k'w (the intercept of the extrapolation),as well as the correlation between log P values and the extrapolated log k'w (1:1 correlation, r2 = 0.966).In addition, the use of isocratic retention factors, at 40% methanol in the mobile phase, provides a rapid tool for lipophilicity determination. The intermolecular interactions that contribute to the retention process in the Ascentis RP-Amide phase are characterized using the solvation parameter model of Abraham.The LSER system constants for the column are very similar to the LSER constants of the n-octanol/water extraction system. Tanaka radar plots are used for quick visual comparison of the system constants of the Ascentis RP-Amide column and the n-octanol/water extraction system. The results all indicate that the Ascentis RP-Amide stationary phase can provide reliable lipophilic data. Copyright 2009 Elsevier B.V. All rights reserved.

Long-term bioconcentration kinetics of hydrophobic chemicals in Selenastrum capricornutum and Microcystis aeruginosa

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

Koelmans, A.A.; Woude, H. van der; Hattink, J.

1999-06-01

The bioconcentration of two chlorobenzenes (CBs) and of seven polychlorobiphenyls (PCBs) to Selenastrum capricornutum and Microcystis aeruginosa was studied with accumulation experiments followed by gas purge elimination experiments. Henry's law constants at 10 C were needed to interpret the gas purge results and were measured in control experiments. For the M. aerogunisa culture, steady-state uptake was reached within days, whereas uptake by S. capricornutum took several weeks. The relationships between the log bioconcentration factors (BCF) and log octanol-water partition coefficients (K[sub OW]) were nonlinear, with relatively low values for the more hydrophobic PCBs. Rate constants for the elimination of CBsmore » and PCBs from the algal cells were shown to be larger than 1 per day when calculated with a one-compartment model. With such large rate constants, it is unlikely that the curvature observed for these species is caused by slow kinetics or that algal growth affects BCF by dilution of CB or PCB concentrations. The log BCF-log K[sub OW] relationships could be described by a simple three-phase model that accounted for the binding of CBs and PCBs to dissolved organic carbon (DOC). Modeling bioconcentration of hydrophobic chemicals in phytoplankton should account for the binding to DOC.« less

CROSS-RESISTANCE OF ESCHERICHIA COLI B TO PENICILLIN AND IONIZING RADIATION

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

Kutas-Mannhardt, V.

The radiosensitivity of cultures resistant to 1500 IU/ml, 2000 IU/ml, 2500 IU/ml of penicillin, produced from strain E. coli B was examined. Cultures in the log-phase were streaked in monocellular layers on the agar surface and exposed to x irradiation. As a result of penicillin treatment cell-filaments consisting of several segments were formed. Measurement of viability of x- irradiated cultures proved that penicillin resistant cultures are considerably more radioresistant than the parent strain B, non-treated with penicillin. (auth)

Haemophilus ducreyi Hfq contributes to virulence gene regulation as cells enter stationary phase.

PubMed

Gangaiah, Dharanesh; Labandeira-Rey, Maria; Zhang, Xinjun; Fortney, Kate R; Ellinger, Sheila; Zwickl, Beth; Baker, Beth; Liu, Yunlong; Janowicz, Diane M; Katz, Barry P; Brautigam, Chad A; Munson, Robert S; Hansen, Eric J; Spinola, Stanley M

2014-02-11

To adapt to stresses encountered in stationary phase, Gram-negative bacteria utilize the alternative sigma factor RpoS. However, some species lack RpoS; thus, it is unclear how stationary-phase adaptation is regulated in these organisms. Here we defined the growth-phase-dependent transcriptomes of Haemophilus ducreyi, which lacks an RpoS homolog. Compared to mid-log-phase organisms, cells harvested from the stationary phase upregulated genes encoding several virulence determinants and a homolog of hfq. Insertional inactivation of hfq altered the expression of ~16% of the H. ducreyi genes. Importantly, there were a significant overlap and an inverse correlation in the transcript levels of genes differentially expressed in the hfq inactivation mutant relative to its parent and the genes differentially expressed in stationary phase relative to mid-log phase in the parent. Inactivation of hfq downregulated genes in the flp-tad and lspB-lspA2 operons, which encode several virulence determinants. To comply with FDA guidelines for human inoculation experiments, an unmarked hfq deletion mutant was constructed and was fully attenuated for virulence in humans. Inactivation or deletion of hfq downregulated Flp1 and impaired the ability of H. ducreyi to form microcolonies, downregulated DsrA and rendered H. ducreyi serum susceptible, and downregulated LspB and LspA2, which allow H. ducreyi to resist phagocytosis. We propose that, in the absence of an RpoS homolog, Hfq serves as a major contributor of H. ducreyi stationary-phase and virulence gene regulation. The contribution of Hfq to stationary-phase gene regulation may have broad implications for other organisms that lack an RpoS homolog. Pathogenic bacteria encounter a wide range of stresses in their hosts, including nutrient limitation; the ability to sense and respond to such stresses is crucial for bacterial pathogens to successfully establish an infection. Gram-negative bacteria frequently utilize the alternative sigma factor RpoS to adapt to stresses and stationary phase. However, homologs of RpoS are absent in some bacterial pathogens, including Haemophilus ducreyi, which causes chancroid and facilitates the acquisition and transmission of HIV-1. Here, we provide evidence that, in the absence of an RpoS homolog, Hfq serves as a major contributor of stationary-phase gene regulation and that Hfq is required for H. ducreyi to infect humans. To our knowledge, this is the first study describing Hfq as a major contributor of stationary-phase gene regulation in bacteria and the requirement of Hfq for the virulence of a bacterial pathogen in humans.

Lipophilicity Assessment of Ruthenium(II)-Arene Complexes by the Means of Reversed-Phase Thin-Layer Chromatography and DFT Calculations

PubMed Central

Shweshein, Khalil Salem A. M.; Andrić, Filip; Radoičić, Aleksandra; Gruden-Pavlović, Maja; Tešić, Živoslav; Milojković-Opsenica, Dušanka

2014-01-01

The lipophilicity of ten ruthenium(II)-arene complexes was assessed by reversed-phase thin-layer chromatography (RP-TLC) on octadecyl silica stationary phase. The binary solvent systems composed of water and acetonitrile were used as mobile phase in order to determine chromatographic descriptors for lipophilicity estimation. Octanol-water partition coefficient, logK OW, of tested complexes was experimentally determined using twenty-eight standard solutes which were analyzed under the same chromatographic conditions as target substances. In addition, ab initio density functional theory (DFT) computational approach was employed to calculate logK OW values from the differences in Gibbs' free solvation energies of the solute transfer from n-octanol to water. A good overall agreement between DFT calculated and experimentally determined logK OW values was established (R 2 = 0.8024–0.9658). PMID:24587761

Application of a polarity parameter model to the separation of fat-soluble vitamins by reversed-phase HPLC.

PubMed

Herrero-Martínez, José Manuel; Izquierdo, Pere; Sales, Joaquim; Rosés, Martí; Bosch, Elisabeth

2008-10-01

The retention behavior of a series of fat-soluble vitamins has been established on the basis of a polarity retention model: log k = (log k)(0) + p (P(m) (N) - P(s) (N)), with p being the polarity of the solute, P(m) (N) the mobile phase polarity, and (log k)(0) and P(m) (N) two parameters for the characterization of the stationary phase. To estimate the p-values of solutes, two approaches have been considered. The first one is based on the application of a QSPR model, derived from the molecular structure of solutes and their log P(o/w), while in the second one, the p-values are obtained from several experimental measurements. The quality of prediction of both approaches has also been evaluated, with the second one giving more accurate results for the most lipophilic vitamins. This model allows establishing the best conditions to separate and determine simultaneously some fat-soluble vitamins in dairy foods.

Assessment of the chromatographic lipophilicity of eight cephalosporins on different stationary phases.

PubMed

Dąbrowska, Monika; Starek, Małgorzata; Komsta, Łukasz; Szafrański, Przemysław; Stasiewicz-Urban, Anna; Opoka, Włodzimierz

2017-04-01

The retention behaviors were investigated for a series of eight cephalosporins in thin-layer chromatography (TLC) using stationary phases of RP-2, RP-8, RP-18, NH 2 , DIOL, and CN chemically bonded silica gel. Additionally, various binary mobile phases (water/methanol and water/acetone) were used in different volume proportions. The retention behavior of the analyzed molecules was defined by R M0 constant. In addition, reversed phase high performance liquid chromatography (RP-HPLC) was performed in lipophilicity studies by using immobilized artificial membrane (IAM) stationary phase. Obtained chromatographic data (R M0 and logk' IAM ) were correlated with the lipophilicity, expressed as values of the log calculated (logP calc ) and experimental (logP exp(shake-flask) ) partition coefficient. Principal component analysis (PCA) was applied in order to obtain an overview of similarity or dissimilarity among the analyzed compounds. Hierarchical cluster analysis (HCA) was performed to compare the separation characteristics of the applied stationary phases. This study was undertaken to identify the best chromatographic system and chromatographic data processing method to enable the prediction of logP values. A comprehensive chromatographic investigation into the retention of the analyzed cephalosporins revealed a similar behavior on RP-18, RP-8 and CN stationary phases. The weak correlations obtained between experimental and certain computed lipophilicity indices revealed that R M0 and PC1/RM are relevant lipophilicity parameters and the RP-8, CN and RP-18 plates are appropriate stationary phases for lipophilicity investigation, whereas computational approaches still cannot fully replace experimentation. Copyright © 2017 Elsevier B.V. All rights reserved.

Antibody to hepatitis B core antigen levels in the natural history of chronic hepatitis B: a prospective observational study.

PubMed

Jia, Wei; Song, Liu-Wei; Fang, Yu-Qing; Wu, Xiao-Feng; Liu, Dan-Yang; Xu, Chun; Wang, Xiao-Mei; Wang, Wen; Lv, Dong-Xia; Li, Jun; Deng, Yong-Qiong; Wang, Yan; Huo, Na; Yu, Min; Xi, Hong-Li; Liu, Dan; Zhou, Yi-Xing; Wang, Gui-Qiang; Xia, Ning-Shao; Zhang, Ming-Xiang

2014-12-01

Previous studies have revealed antibody to hepatitis B core antigen (anti-HBc) levels as a predictor of treatment response in hepatitis B early antigen (HBeAg)-positive chronic hepatitis B (CHB) patients in both interferon and nucleos(t)ide analog therapy cohorts. However, there is no information about anti-HBc levels in the natural history of CHB. This study aimed to define anti-HBc levels of different phases in the natural history of CHB. Two hundred eleven treatment-naive CHB patients were included in the study. They were classified into 4 phases: immune tolerance (IT) phase (n = 39), immune clearance (IC) phase (n = 48), low or no-replicative (LR) phase (n = 55), and HBeAg-negative hepatitis (ENH, n = 69). Fifty patients who were HBsAg negative and anti-HBc positive were also recruited as past HBV infection (PBI) control group. Anti-HBc levels were measured by a newly developed double-sandwich immunoassay. Correlation of anti-HBc levels with alanine aminotransferase (ALT) and other HBV-related markers within each phase was performed. Serum anti-HBc levels were statistically significant between patients in different phases of CHB (P < 0.001). The median anti-HBc levels were: IT (3.17 log 10 IU/mL), IC (4.39 log 10 IU/mL), LR (3.29 log 10 IU/mL), ENH (4.12 log 10 IU/mL), and PBI (0.61 log 10 IU/mL). There existed a strong correlation in IC (r = 0.489, P < 0.001), a poor correlation in ENH (r = 0.275, P = 0.042), and no correlation in patients with ALT reached 5 times upper limit of normal (r = 0.120, P = 0.616). Anti-HBc levels show significant differences during the natural course of CHB. These results may provide some potentially useful insights into hepatitis B pathogenesis and immune activation against hepatitis B virus.

REAL-TIME TRACER MONITORING OF RESERVOIR STIMULATION PROCEDURES VIA ELECTRONIC WIRELINE AND TELEMETRY DATA TRANSMISSION

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

George L. Scott III

2005-01-01

Finalized Phase 2-3 project work has field-proven two separate real-time reservoir processes that were co-developed via funding by the National Energy Technology Laboratory (NETL). Both technologies are presently patented in the United States and select foreign markets; a downhole-commingled reservoir stimulation procedure and a real-time tracer-logged fracturing diagnostic system. Phase 2 and early Phase 3 project work included the research, development and well testing of a U.S. patented gamma tracer fracturing diagnostic system. This stimulation logging process was successfully field-demonstrated; real-time tracer measurement of fracture height while fracturing was accomplished and proven technically possible. However, after the initial well tests,more » there were several licensing issues that developed between service providers that restricted and minimized Realtimezone's (RTZ) ability to field-test the real-time gamma diagnostic system as was originally outlined for this project. Said restrictions were encountered after when one major provider agreed to license their gamma logging tools to another. Both of these companies previously promised contributory support toward Realtimezone's DE-FC26-99FT40129 project work, however, actual support was less than desired when newly-licensed wireline gamma logging tools from one company were converted by the other from electric wireline into slickline, batter-powered ''memory'' tools for post-stimulation logging purposes. Unfortunately, the converted post-fracture measurement memory tools have no applications in experimentally monitoring real-time movement of tracers in the reservoir concurrent with the fracturing treatment. RTZ subsequently worked with other tracer gamma-logging tool companies for basic gamma logging services, but with lessened results due to lack of multiple-isotope detection capability. In addition to real-time logging system development and well testing, final Phase 2 and Phase 3 project work included the development of a real-time reservoir stimulation procedure, which was successfully field-demonstrated and is presently patented in the U.S. and select foreign countries, including Venezuela, Brazil and Canada. Said patents are co-owned by RTZ and the National Energy Technology Lab (NETL). In 2002, Realtimezone and the NETL licensed said patents to Halliburton Energy Services (HES). Additional licensing agreements (LA) are anticipated with other service industry companies in 2005. Final Phase 3 work has led to commercial applications of the real-time reservoir stimulation procedure. Four successfully downhole-mixed well tests were conducted with commercially expected production results. The most recent, fourth field test was a downhole-mixed stimulated well completed in June, 2004, which currently produces 11 BOPD with 90 barrels of water per day. Conducted Phase 2 and Phase 3 field-test work to date has resulted in the fine-tuning of a real-time enhanced stimulation system that will significantly increase future petroleum well recoveries in the United States and foreign petroleum fields, both onshore and offshore, and in vertical and horizontal wells.« less

Predicting outgrowth and inactivation of Clostridium perfringens in meat products during low temperature long time heat treatment.

PubMed

Duan, Zhi; Hansen, Terese Holst; Hansen, Tina Beck; Dalgaard, Paw; Knøchel, Susanne

2016-08-02

With low temperature long time (LTLT) cooking it can take hours for meat to reach a final core temperature above 53°C and germination followed by growth of Clostridium perfringens is a concern. Available and new growth data in meats including 154 lag times (tlag), 224 maximum specific growth rates (μmax) and 25 maximum population densities (Nmax) were used to developed a model to predict growth of C. perfringens during the coming-up time of LTLT cooking. New data were generate in 26 challenge tests with chicken (pH6.8) and pork (pH5.6) at two different slowly increasing temperature (SIT) profiles (10°C to 53°C) followed by 53°C in up to 30h in total. Three inoculum types were studied including vegetative cells, non-heated spores and heat activated (75°C, 20min) spores of C. perfringens strain 790-94. Concentrations of vegetative cells in chicken increased 2 to 3logCFU/g during the SIT profiles. Similar results were found for non-heated and heated spores in chicken, whereas in pork C. perfringens 790-94 increased less than 1logCFU/g. At 53°C C. perfringens 790-94 was log-linearly inactivated. Observed and predicted concentrations of C. perfringens, at the time when 53°C (log(N53)) was reached, were used to evaluate the new growth model and three available predictive models previously published for C. perfringens growth during cooling rather than during SIT profiles. Model performance was evaluated by using mean deviation (MD), mean absolute deviation (MAD) and the acceptable simulation zone (ASZ) approach with a zone of ±0.5logCFU/g. The new model showed best performance with MD=0.27logCFU/g, MAD=0.66logCFU/g and ASZ=67%. The two growth models that performed best, were used together with a log-linear inactivation model and D53-values from the present study to simulate the behaviour of C. perfringens under the fast and slow SIT profiles investigated in the present study. Observed and predicted concentrations were compared using a new fail-safe acceptable zone (FSAZ) method. FSAZ was defined as the predicted concentration of C. perfringens plus 0.5logCFU/g. If at least 85% of the observed log-counts were below the FSAZ, the model was considered fail-safe. The two models showed similar performance but none of them performed satisfactorily for all conditions. It is recommended to use the models without a lag phase until more precise lag time models become available. Copyright © 2016 Elsevier B.V. All rights reserved.

The Dependency in the Elasticity of the Saccharomyces cerevisiae Cell Wall upon Cell Viability and Membrane Integrity

NASA Astrophysics Data System (ADS)

McPherson, Dacia; Zhu, Chenhui; Yi, Youngwoo; Clark, Noel

2007-03-01

In this study the elastic spring constant of the yeast cell wall is probed with the atomic force microscope (AFM) under variable conditions. Cells were sequentially analyzed in rich growth medium (YPD), a 0.8 M NaCl rich growth medium solution and an injection of 0.01% sodium azide solution. Cells in late log phase, which have variable diameters within three to five microns, were immobilized on a patterned silicon substrate with holes approximately 3.8um in diameter and 1.5um deep that was functionalized with polyethylenimine prior to cell application. Force curves were taken moving laterally across the cell in one dimension after exposure to each medium. Spring constants of the cells, calculated from force curves, displayed a positional dependency and marked differences in high osmolarity medium and after the injection of sodium azide. This study demonstrates the ability of the AFM to investigate changes in cell morphology and correlate those findings to underlying physiological processes.

Cell and Molecular Biology of Ataxia Telangiectasia Heterozygous Human Mammary Epithelial Cells Irradiated in Culture

NASA Technical Reports Server (NTRS)

Richmond, Robert C.

2001-01-01

Autologous isolates of cell types from obligate heterozygotes with the autosomal disorder ataxia-telangiectasia (A-T)were used to begin a tissue culture model for assessing pathways of radiation-induced cancer formation in this target tissue. This was done by establishing cultures of stromal fibroblasts and long-term growth human mammary epithelial cells (HMEC) in standard 2-dimensional tissue culture in order to establish expression of markers detailing early steps of carcinogenesis. The presumptive breast cancer susceptibility of A-T heterozygotes as a sequel to damage caused by ionizing radiation provided reason to study expression of markers in irradiated HMEC. Findings from our study with HMEC have included determination of differences in specific protein expression amongst growth phase (e.g., log vs stationary) and growth progression (e.g., pass 7 vs pass 9), as well as differences in morphologic markers within populations of irradiated HMEC (e.g., development of multinucleated cells).

Isolation of total RNA from yeast cell cultures.

PubMed

Ares, Manuel

2012-10-01

This article describes two procedures for isolating total RNA from yeast cell cultures. The first allows the convenient isolation of total RNA from early log-phase cultures (vegetative cells). RNA isolated in this way is intact and sufficiently pure for use in microarray experiments, primer extension, and RNase protection mapping. With additional treatment to remove contaminating genomic DNA, the preparation is suitable for reverse transcription-polymerase chain reaction (RT-PCR), quantitative PCR (qPCR), cDNA library construction, high-throughput sequencing of RNA, or other manipulations. However, compared to vegetative cells, the isolation of RNA from cells late in meiosis (asci and ascospores) requires additional effort. This is because a tough cell wall composed of heavily cross-linked polysaccharides and proteins is built around the four spores during meiosis and ascospore development. Therefore, an alternative protocol is presented for extracting RNA from cells late in meiosis. This alternative may also be preferable for cells from stationary cultures or from yeast strains and other fungal species isolated from the environment.

Distribution or adsorption: the major dilemma in reversed-phase HPLC

NASA Astrophysics Data System (ADS)

Deineka, V. I.

2008-06-01

A method is suggested for analyzing the dependences obtained for different compositions of mobile eluent system phases, their slopes and intercepts, log k( i, B) = a + b log k ( i, A), where a is the intercept for the A and B stationary phases and b is the proportionality factor. An analysis requires parallel investigation of sorbate retention on at least three stationary phases with different lengths of grafted hydrocarbon radicals. The dependence of correlation parameters on the sorbate retention mechanism is discussed. It is shown that the hypothetical dependences coincide with the experimental dependences for surface sorption of resveratrol and volume distribution of triglycerides.

Log-correlated random-energy models with extensive free-energy fluctuations: Pathologies caused by rare events as signatures of phase transitions

NASA Astrophysics Data System (ADS)

Cao, Xiangyu; Fyodorov, Yan V.; Le Doussal, Pierre

2018-02-01

We address systematically an apparent nonphysical behavior of the free-energy moment generating function for several instances of the logarithmically correlated models: the fractional Brownian motion with Hurst index H =0 (fBm0) (and its bridge version), a one-dimensional model appearing in decaying Burgers turbulence with log-correlated initial conditions and, finally, the two-dimensional log-correlated random-energy model (logREM) introduced in Cao et al. [Phys. Rev. Lett. 118, 090601 (2017), 10.1103/PhysRevLett.118.090601] based on the two-dimensional Gaussian free field with background charges and directly related to the Liouville field theory. All these models share anomalously large fluctuations of the associated free energy, with a variance proportional to the log of the system size. We argue that a seemingly nonphysical vanishing of the moment generating function for some values of parameters is related to the termination point transition (i.e., prefreezing). We study the associated universal log corrections in the frozen phase, both for logREMs and for the standard REM, filling a gap in the literature. For the above mentioned integrable instances of logREMs, we predict the nontrivial free-energy cumulants describing non-Gaussian fluctuations on the top of the Gaussian with extensive variance. Some of the predictions are tested numerically.

Behavior of Lactobacillus plantarum and Saccharomyces cerevisiae in fresh and thermally processed orange juice.

PubMed

Alwazeer, Duried; Cachon, Remy; Divies, Charles

2002-10-01

Lactobacillus plantarum and Saccharomyces cerevisiae are acid-tolerant microorganisms that are able to spoil citrus juices before and after pasteurization. The growth of these microorganisms in orange juice with and without pasteurization was investigated. Two samples of orange juice were inoculated with ca. 10(5) CFU/ml of each microorganism. Others were inoculated with ca. 10(7) CFU/ml of each microorganism and then thermally treated. L. plantarum populations were reduced by 2.5 and <1 log10 CFU/ml at 60 degrees C for 40 s and at 55 degrees C for 40 s, respectively. For the same treatments, S. cerevisiae populations were reduced by >6 and 2 log10 CFU/ml, respectively. Samples of heated and nonheated juice were incubated at 15 degrees C for 20 days. Injured populations of L. plantarum decreased by ca. 2 log10 CFU/ml during the first 70 h of storage, but those of S. cerevisiae did not decrease. The length of the lag phase after pasteurization increased 6.2-fold for L. plantarum and 1.9-fold for S. cerevisiae, and generation times increased by 41 and 86%, respectively. The results of this study demonstrate the differences in the capabilities of intact and injured cells of spoilage microorganisms to spoil citrus juice and the different thermal resistance levels of cells. While L. plantarum was more resistant to heat treatment than S. cerevisiae was, growth recovery after pasteurization was faster for the latter microorganism.

Lipophilicity of some guaianolides isolated from two endemic subspecies of Amphoricarpos neumayeri (Asteraceae) from Montenegro.

PubMed

Atrrog, Abubaker A B; Natić, Maja; Tosti, Tomislav; Milojković-Opsenica, Dusanka; Dordević, Iris; Tesević, Vele; Jadranin, Milka; Milosavljević, Slobodan; Lazić, Milan; Radulović, Sinisa; Tesić, Zivoslav

2009-03-01

In this study 10 guaianolide-type sesquiterpene gamma-lactones named amphoricarpolides, isolated from the aerial parts of two endemic subspecies of Amphoricarpos neumayeri (ssp. neumayeri and ssp. murbeckii Bosnjak), were investigated by means of reversed-phase thin-layer chromatography. Methanol-water and tetrahydrofuran-water binary mixtures were used as mobile phase in order to determine lipophilicity parameters R (0) (M) and C(0). Some of the investigated compounds were screened for their cytotoxic activity against HeLa and B16 cells. Chromatographically obtained lipophilicity parameters were correlated with calculated logP values and IC(50) values. Principal component analysis identified the dominant pattern in the chromatographically obtained data. 2008 John Wiley & Sons, Ltd.

Prediction and mechanism elucidation of analyte retention on phospholipid stationary phases (IAM-HPLC) by in silico calculated physico-chemical descriptors.

PubMed

Russo, Giacomo; Grumetto, Lucia; Barbato, Francesco; Vistoli, Giulio; Pedretti, Alessandro

2017-03-01

The present study proposes a method for an in silico calculation of phospholipophilicity. Phospholipophilicity is intended as the measure of analyte affinity for phospholipids; it is currently assessed by HPLC measures of analyte retention on phosphatidylcholine-like stationary phases (IAM - Immobilized Artificial Membrane) resulting in log k W IAM values. Due to the amphipathic and electrically charged nature of phospholipids, retention on these stationary phases results from complex mechanisms, being affected not only by lipophilicity (as measured by n-octanol/aqueous phase partition coefficients, log P) but also by the occurrence of polar and/or electrostatic intermolecular interaction forces. Differently from log P, to date no method has been proposed for in silico calculation of log k W IAM . The study is aimed both at shedding new light into the retention mechanism on IAM stationary phases and at offering a high-throughput method to achieve such values. A wide set of physico-chemical and topological properties were taken into account, yielding a robust final model including four in silico calculated parameters (lipophilicity, hydrophilic/lipophilic balance, molecular size, and molecule flexibility). The here presented model was based on the analysis of 205 experimentally determined values, taken from the literature and measured by a single research group to minimize the interlaboratory variability; such model is able to predict phospholipophilicity values on both the two IAM stationary phases to date marketed, i.e. IAM.PC.MG and IAM.PC.DD2, with a fairly good degree (r 2 =0.85) of accuracy. The present work allowed the development of a free on-line service aimed at calculating log k W IAM values of any molecule included in the PubChem database, which is freely available at http://nova.disfarm.unimi.it/logkwiam.htm. Copyright © 2016 Elsevier B.V. All rights reserved.

Fate of Escherichia coli O157 Cells Inoculated into Lightly Pickled Chinese Cabbage during Processing, Storage and Incubation in Artificial Gastric Juice.

PubMed

Inatsu, Yasuhiro; Ohata, Yukiko; Ananchaipattana, Chiraporn; Latiful Bari, Md; Hosotani, Yukie; Kawasaki, Susumu

2016-01-01

Fate of Escherichia coli O157 cells was evaluated when inoculated into each step after production of lightly pickled Chinese cabbage. The efficacy of surface sterilization by 100 mg/L of chlorine water for 10 min on raw leaves (6.0 log CFU/g) was 2.2 log CFU/g reduction. No meaningful change of the population of E. coli O157 (3.5 log CFU/g to 1.5 log MPN/g) contaminated into 19 kinds of products was observed. These results indicated the difficulty of estimating the viable count of the cells between contaminated on farms and further processing and storage steps. The population of E. coli O157 (3 log CFU/g to 1 log MPN/g) inoculated into the Chinese cabbage products was reduced less than 0.6 log CFU/g after 2 h-incubation at 37℃ in artificial gastric juice. Prevention from initial contamination of E. coli O157 on the ingredients of Chinese cabbage products is important to reduce the risk of food poisoning because the reduction of the bacterial counts after processing and consumption are limited.

THE CROSS-RESISTANCE TO PENICILLIN AND RADIATION OF ESCHERICHIA COLI B (in Hungarian)

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

Kutas, V.

The radiosensitivity of cultures resistant to 1500 IU/ml, 2000 IU/ml, 2500 IU/ml of penicillin, produced from strain E. coli B was examined. Cultures in the log-phase were streaked in monocellular layers on the agar surface and x irradiation was applied. As a result of penicillin treatment cell filaments consisting of several members were formed. Measuring the effect of ionizing radiation by the percentage survival, the cultures resistant to penicillin proved to be considerably more radioresistant than the parent strain B, non-treated with penicillin. (auth)

Enhancing DNA electro-transformation efficiency on a clinical Staphylococcus capitis isolate.

PubMed

Cui, Bintao; Smooker, Peter M; Rouch, Duncan A; Deighton, Margaret A

2015-02-01

Clinical staphylococcus isolates possess a stronger restriction-modification (RM) barrier than laboratory strains. Clinical isolates are therefore more resistant to acceptance of foreign genetic material than laboratory strains, as their restriction systems more readily recognize and destroy foreign DNA. This stronger barrier consequently restricts genetic studies to a small number of domestic strains that are capable of accepting foreign DNA. In this study, an isolate of Staphylococcus capitis, obtained from the blood of a very low birth-weight baby, was transformed with a shuttle vector, pBT2. Optimal conditions for electro-transformation were as follows: cells were harvested at mid-log phase, electro-competent cells were prepared; cells were pre-treated at 55°C for 1min; 3μg of plasmid DNA was mixed with 70-80μL of competent cells (3-4×10(10)cells/mL) at 20°C in 0.5M sucrose, 10% glycerol; and electroporation was conducted using 2.1kV/cm field strength with a 0.1cm gap. Compared to the conventional method, which involves DNA electroporation of Staphylococcus aureus RN4220 as an intermediate strain to overcome the restriction barrier, our proposed approach exhibits a higher level (3 log10 units) of transformation efficiency. Heat treatment was used to temporarily inactivate the recipient RM barrier. Other important parameters contributing to improved electro-transformation efficiency were growth stage for cell harvesting, the quantity of DNA, the transformation temperature and field strength. The approach described here may facilitate genetic manipulations of this opportunistic pathogen. Copyright © 2014 Elsevier B.V. All rights reserved.

Logging costs for management planning for young-growth coast Douglas-fir.

Treesearch

.Roger D. Fight; Chris B. LeDoux; Tom L. Ortman

1984-01-01

Logging cost equations are provided that can be used for analyses of silvicultural regimes. These equations include costs for all phases of logging from felling to loading onto a truck. They are presented by various components so that the user can substitute other values if some components do not seem applicable. Where appropriate these costs vary by size of trees...

Safety and immunogenicity of a live attenuated mumps vaccine: a phase I clinical trial.

PubMed

Liang, Yan; Ma, Jingchen; Li, Changgui; Chen, Yuguo; Liu, Longding; Liao, Yun; Zhang, Ying; Jiang, Li; Wang, Xuan-Yi; Che, Yanchun; Deng, Wei; Li, Hong; Cui, Xiaoyu; Ma, Na; Ding, Dong; Xie, Zhongping; Cui, Pingfang; Ji, Qiuyan; Wang, JingJing; Zhao, Yuliang; Wang, Junzhi; Li, Qihan

2014-01-01

Mumps, a communicable, acute and previously well-controlled disease, has had recent and occasional resurgences in some areas. A randomized, double-blind, controlled and multistep phase I study of an F-genotype attenuated mumps vaccine produced in human diploid cells was conducted. A total of 300 subjects were enrolled and divided into 4 age groups: 16-60 years, 5-16 years, 2-5 years and 8-24 months. The groups were immunized with one injection per subject. Three different doses of the F-genotype attenuated mumps vaccine, A (3.5 ± 0.25 logCCID50), B (4.25 ± 0.25 logCCID50) and C (5.0 ± 0.25 logCCID50), as well as a placebo control and a positive control of a licensed A-genotype vaccine (S79 strain) were used. The safety and immunogenicity of this vaccine were compared with those of the controls. The safety evaluation suggested that mild adverse reactions were observed in all groups. No serious adverse event (SAE) was reported throughout the trial. The immunogenicity test showed a similar seroconversion rate of the neutralizing and ELISA antibody in the 2- to 5-year-old and 8- to 24-month-old groups compared with the seroconversion rate in the positive control. The GMT of the neutralizing anti-F-genotype virus antibodies in the vaccine groups was slightly higher than that in the positive control group. The F-genotype attenuated mumps vaccine evaluated in this clinical trial was demonstrated to be safe and have effective immunogenicity vs. control.

Chromatographic behaviour predicts the ability of potential nootropics to permeate the blood-brain barrier.

PubMed

Farsa, Oldřich

2013-01-01

The log BB parameter is the logarithm of the ratio of a compound's equilibrium concentrations in the brain tissue versus the blood plasma. This parameter is a useful descriptor in assessing the ability of a compound to permeate the blood-brain barrier. The aim of this study was to develop a Hansch-type linear regression QSAR model that correlates the parameter log BB and the retention time of drugs and other organic compounds on a reversed-phase HPLC containing an embedded amide moiety. The retention time was expressed by the capacity factor log k'. The second aim was to estimate the brain's absorption of 2-(azacycloalkyl)acetamidophenoxyacetic acids, which are analogues of piracetam, nefiracetam, and meclofenoxate. Notably, these acids may be novel nootropics. Two simple regression models that relate log BB and log k' were developed from an assay performed using a reversed-phase HPLC that contained an embedded amide moiety. Both the quadratic and linear models yielded statistical parameters comparable to previously published models of log BB dependence on various structural characteristics. The models predict that four members of the substituted phenoxyacetic acid series have a strong chance of permeating the barrier and being absorbed in the brain. The results of this study show that a reversed-phase HPLC system containing an embedded amide moiety is a functional in vitro surrogate of the blood-brain barrier. These results suggest that racetam-type nootropic drugs containing a carboxylic moiety could be more poorly absorbed than analogues devoid of the carboxyl group, especially if the compounds penetrate the barrier by a simple diffusion mechanism.

Comparison of bacteriophage and enteric virus removal in pilot scale activated sludge plants.

PubMed

Arraj, A; Bohatier, J; Laveran, H; Traore, O

2005-01-01

The aim of this experimental study was to determine comparatively the removal of two types of bacteriophages, a somatic coliphage and an F-specific RNA phage and of three types of enteric viruses, hepatitis A virus (HAV), poliovirus and rotavirus during sewage treatment by activated sludge using laboratory pilot plants. The cultivable simian rotavirus SA11, the HAV HM 175/18f cytopathic strain and poliovirus were quantified by cell culture. The bacteriophages were quantified by plaque formation on the host bacterium in agar medium. In each experiment, two pilots simulating full-scale activated sludge plants were inoculated with viruses at known concentrations, and mixed liquor and effluent samples were analysed regularly. In the mixed liquor, liquid and solid fractions were analysed separately. The viral behaviour in both the liquid and solid phases was similar between pilots of each experiment. Viral concentrations decreased rapidly following viral injection in the pilots. Ten minutes after the injections, viral concentrations in the liquid phase had decreased from 1.0 +/- 0.4 log to 2.2 +/- 0.3 log. Poliovirus and HAV were predominantly adsorbed on the solid matters of the mixed liquor while rotavirus was not detectable in the solid phase. In our model, the estimated mean log viral reductions after 3-day experiment were 9.2 +/- 0.4 for rotavirus, 6.6 +/- 2.4 for poliovirus, 5.9 +/- 3.5 for HAV, 3.2 +/- 1.2 for MS2 and 2.3 +/- 0.5 for PhiX174. This study demonstrates that the pilots are useful models to assess the removal of infectious enteric viruses and bacteriophages by activated sludge treatment. Our results show the efficacy of the activated sludge treatment on the five viruses and suggest that coliphages could be an acceptable indicator of viral removal in this treatment system.

PHAGE FORMATION IN STAPHYLOCOCCUS MUSCAE CULTURES

PubMed Central

Price, Winston H.

1949-01-01

1. A non-dialyzable fraction from fresh bakers' yeast stimulates the formation of S. muscae virus in cells in synthetic medium in the log phase of multiplication. 2. A similar fraction was not found in calf thymus, pancreas, or liver. 3. The active substance in this fraction has been partially purified. 4. This substance is taken up by the cells. In the absence of virus the added substance is metabolized to a form no longer available for virus formation. 5. A purified yeast fraction, which stimulates adaptive enzyme formation in yeast, has been found to stimulate virus formation in the S. muscae system. 6. The similarities between the yeast fraction that stimulates adaptive enzyme formation and the yeast fraction that stimulates virus formation are discussed. PMID:18123312

A branching process model for the analysis of abortive colony size distributions in carbon ion-irradiated normal human fibroblasts.

PubMed

Sakashita, Tetsuya; Hamada, Nobuyuki; Kawaguchi, Isao; Hara, Takamitsu; Kobayashi, Yasuhiko; Saito, Kimiaki

2014-05-01

A single cell can form a colony, and ionizing irradiation has long been known to reduce such a cellular clonogenic potential. Analysis of abortive colonies unable to continue to grow should provide important information on the reproductive cell death (RCD) following irradiation. Our previous analysis with a branching process model showed that the RCD in normal human fibroblasts can persist over 16 generations following irradiation with low linear energy transfer (LET) γ-rays. Here we further set out to evaluate the RCD persistency in abortive colonies arising from normal human fibroblasts exposed to high-LET carbon ions (18.3 MeV/u, 108 keV/µm). We found that the abortive colony size distribution determined by biological experiments follows a linear relationship on the log-log plot, and that the Monte Carlo simulation using the RCD probability estimated from such a linear relationship well simulates the experimentally determined surviving fraction and the relative biological effectiveness (RBE). We identified the short-term phase and long-term phase for the persistent RCD following carbon-ion irradiation, which were similar to those previously identified following γ-irradiation. Taken together, our results suggest that subsequent secondary or tertiary colony formation would be invaluable for understanding the long-lasting RCD. All together, our framework for analysis with a branching process model and a colony formation assay is applicable to determination of cellular responses to low- and high-LET radiation, and suggests that the long-lasting RCD is a pivotal determinant of the surviving fraction and the RBE.

Global Analysis of Mannitol 2-Dehydrogenase in Lactobacillus reuteri CRL 1101 during Mannitol Production through Enzymatic, Genetic and Proteomic Approaches.

PubMed

Ortiz, Maria Eugenia; Bleckwedel, Juliana; Fadda, Silvina; Picariello, Gianluca; Hebert, Elvira M; Raya, Raúl R; Mozzi, Fernanda

2017-01-01

Several plants, fungi, algae, and certain bacteria produce mannitol, a polyol derived from fructose. Mannitol has multiple industrial applications in the food, pharmaceutical, and medical industries, being mainly used as a non-metabolizable sweetener in foods. Many heterofermentative lactic acid bacteria synthesize mannitol when an alternative electron acceptor such as fructose is present in the medium. In previous work, we reported the ability of Lactobacillus reuteri CRL 1101 to efficiently produce mannitol from sugarcane molasses as carbon source at constant pH of 5.0; the activity of the enzyme mannitol 2-dehydrogenase (MDH) responsible for the fructose conversion into mannitol being highest during the log cell growth phase. Here, a detailed assessment of the MDH activity and relative expression of the mdh gene during the growth of L. reuteri CRL 1101 in the presence of fructose is presented. It was observed that MDH was markedly induced by the presence of fructose. A direct correlation between the maximum MDH enzyme activity and a high level of mdh transcript expression during the log-phase of cells grown in a fructose-containing chemically defined medium was detected. Furthermore, two proteomic approaches (2DE and shotgun proteomics) applied in this study confirmed the inducible expression of MDH in L. reuteri. A global study of the effect of fructose on activity, mdh gene, and protein expressions of MDH in L. reuteri is thus for the first time presented. This work represents a deep insight into the polyol formation by a Lactobacillus strain with biotechnological potential in the nutraceutics and pharmaceutical areas.

Global Analysis of Mannitol 2-Dehydrogenase in Lactobacillus reuteri CRL 1101 during Mannitol Production through Enzymatic, Genetic and Proteomic Approaches

PubMed Central

Ortiz, Maria Eugenia; Bleckwedel, Juliana; Fadda, Silvina; Picariello, Gianluca; Hebert, Elvira M.; Raya, Raúl R.

2017-01-01

Several plants, fungi, algae, and certain bacteria produce mannitol, a polyol derived from fructose. Mannitol has multiple industrial applications in the food, pharmaceutical, and medical industries, being mainly used as a non-metabolizable sweetener in foods. Many heterofermentative lactic acid bacteria synthesize mannitol when an alternative electron acceptor such as fructose is present in the medium. In previous work, we reported the ability of Lactobacillus reuteri CRL 1101 to efficiently produce mannitol from sugarcane molasses as carbon source at constant pH of 5.0; the activity of the enzyme mannitol 2-dehydrogenase (MDH) responsible for the fructose conversion into mannitol being highest during the log cell growth phase. Here, a detailed assessment of the MDH activity and relative expression of the mdh gene during the growth of L. reuteri CRL 1101 in the presence of fructose is presented. It was observed that MDH was markedly induced by the presence of fructose. A direct correlation between the maximum MDH enzyme activity and a high level of mdh transcript expression during the log-phase of cells grown in a fructose-containing chemically defined medium was detected. Furthermore, two proteomic approaches (2DE and shotgun proteomics) applied in this study confirmed the inducible expression of MDH in L. reuteri. A global study of the effect of fructose on activity, mdh gene, and protein expressions of MDH in L. reuteri is thus for the first time presented. This work represents a deep insight into the polyol formation by a Lactobacillus strain with biotechnological potential in the nutraceutics and pharmaceutical areas. PMID:28060932

Contribution of Stress Responses to Antibiotic Tolerance in Pseudomonas aeruginosa Biofilms

PubMed Central

Franklin, Michael J.; Williamson, Kerry S.; Folsom, James P.; Boegli, Laura; James, Garth A.

2015-01-01

Enhanced tolerance of biofilm-associated bacteria to antibiotic treatments is likely due to a combination of factors, including changes in cell physiology as bacteria adapt to biofilm growth and the inherent physiological heterogeneity of biofilm bacteria. In this study, a transcriptomics approach was used to identify genes differentially expressed during biofilm growth of Pseudomonas aeruginosa. These genes were tested for statistically significant overlap, with independently compiled gene lists corresponding to stress responses and other putative antibiotic-protective mechanisms. Among the gene groups tested were those associated with biofilm response to tobramycin or ciprofloxacin, drug efflux pumps, acyl homoserine lactone quorum sensing, osmotic shock, heat shock, hypoxia stress, and stationary-phase growth. Regulons associated with Anr-mediated hypoxia stress, RpoS-regulated stationary-phase growth, and osmotic stress were significantly enriched in the set of genes induced in the biofilm. Mutant strains deficient in rpoS, relA and spoT, or anr were cultured in biofilms and challenged with ciprofloxacin and tobramycin. When challenged with ciprofloxacin, the mutant strain biofilms had 2.4- to 2.9-log reductions in viable cells compared to a 0.9-log reduction of the wild-type strain. Interestingly, none of the mutants exhibited a statistically significant alteration in tobramycin susceptibility compared to that with the wild-type biofilm. These results are consistent with a model in which multiple genes controlled by overlapping starvation or stress responses contribute to the protection of a P. aeruginosa biofilm from ciprofloxacin. A distinct and as yet undiscovered mechanism protects the biofilm bacteria from tobramycin. PMID:25870065

Clinical Significance of Quantitative HBsAg Titres and its Correlation With HBV DNA Levels in the Natural History of Hepatitis B Virus Infection.

PubMed

Karra, Vijay K; Chowdhury, Soumya J; Ruttala, Rajesh; Polipalli, Sunil K; Kar, Premashis

2016-09-01

Quantification of serum hepatitis B antigen (HBsAg) is an important test that marks active infection with hepatitis B and helps in the prediction of the clinical outcome and management of hepatitis B virus (HBV) infection. Correlation with HBV DNA quantitative levels may help in developing strategies for antiviral treatment. This study is aimed to evaluate HBsAg titres in various phase of HBV infection in HBsAg positive patients, and its correlation with HBV DNA viral load levels. 976 HBV related patients were analysed in this retrospective cross-sectional study. Patients were categorised on the basis of the phase of HBV infection: immune tolerant phase (IT, n  = 123), immune clearance phase (IC, n  = 192), low-replicative phase (LR, n  = 476), and HBeAg-negative hepatitis (ENH, n  = 185). HBsAg titres were quantified and correlated with HBV-DNA levels and clinical parameters. Median HBsAg titres were different between each phases of HBV infection ( P  < 0.001): (4.62 log10 IU/ml), IC (3.88 log10 IU/ml), LR (2.76 log10 IU/ml) and ENH (2.94 log10 IU/ml). HBsAg and HBV DNA levels showed significant correlation in the whole group ( r  = 0.694, P  < 0.001), and this was also observed in different phases of HBV infection. Strong correlation in IT phase ( r  = 0.603, P  < 0.001) and IC phase ( r  = 0.523, P  < 0.001), moderate in LR phase ( r  = 0.362, P  < 0.001) and weak in ENH ( r  = 0.110, P  = 0.04). No correlation was observed between serum HBsAg levels and biochemical parameters. The study demonstrated significant difference in the median baseline values of serum HBsAg titres in different phases of HBV infection and provides additional information in understanding the natural history of HBV-infection.

Investigation of the factors influencing the survival of Bifidobacterium longum in model acidic solutions and fruit juices.

PubMed

Nualkaekul, Sawaminee; Salmeron, Ivan; Charalampopoulos, Dimitris

2011-12-01

The survival of Bifidobacterium longum NCIMB 8809 was studied during refrigerated storage for 6weeks in model solutions, based on which a mathematical model was constructed describing cell survival as a function of pH, citric acid, protein and dietary fibre. A Central Composite Design (CCD) was developed studying the influence of four factors at three levels, i.e., pH (3.2-4), citric acid (2-15g/l), protein (0-10g/l), and dietary fibre (0-8g/l). In total, 31 experimental runs were carried out. Analysis of variance (ANOVA) of the regression model demonstrated that the model fitted well the data. From the regression coefficients it was deduced that all four factors had a statistically significant (P<0.05) negative effect on the log decrease [log10N0 week-log10N6 week], with the pH and citric acid being the most influential ones. Cell survival during storage was also investigated in various types of juices, including orange, grapefruit, blackcurrant, pineapple, pomegranate and strawberry. The highest cell survival (less than 0.4log decrease) after 6weeks of storage was observed in orange and pineapple, both of which had a pH of about 3.8. Although the pH of grapefruit and blackcurrant was similar (pH ∼3.2), the log decrease of the former was ∼0.5log, whereas of the latter was ∼0.7log. One reason for this could be the fact that grapefruit contained a high amount of citric acid (15.3g/l). The log decrease in pomegranate and strawberry juices was extremely high (∼8logs). The mathematical model was able to predict adequately the cell survival in orange, grapefruit, blackcurrant, and pineapple juices. However, the model failed to predict the cell survival in pomegranate and strawberry, most likely due to the very high levels of phenolic compounds in these two juices. Copyright © 2011 Elsevier Ltd. All rights reserved.

Application of perfluorinated acids as ion-pairing reagents for reversed-phase chromatography and retention-hydrophobicity relationships studies of selected beta-blockers.

PubMed

Flieger, J

2010-01-22

The addition of the homologous series of perfluorinated acids-trifluoroacetic acid (TFAA), pentafluoropropionic acid (PFPA), heptafluorobutyric acid (HFBA) to mobile phases for reversed-phase high-performance liquid chromatography (RP-HPLC) of beta-blockers was tested. Acidic modifiers were responsible for acidification of mobile phase (pH 3) ensuring the protonation of the beta-blockers and further ion pairs creation. The effect of the type and concentration of mobile phase additives on retention parameters, the efficiency of the peaks, their symmetry and separation selectivity of the beta-blockers mixture were all studied. It appeared that at increasing acid concentration, the retention factor, for all compounds investigated, increased to varying degrees. It should be stressed that the presence of acids more significantly affected the retention of the most hydrophobic beta-blockers. Differences in hydrophobicity of drugs can be maximized through variation of the hydrophobicity of additives. Thus, the relative increase in the retention depends on either concentration and hydrophobicity of the anionic mobile phase additive or hydrophobicity of analytes. According to QSRR (quantitative structure retention relationship) methodology, chromatographic lipophilicity parameters: isocratic log k and log k(w) values (extrapolated retention to pure water) were correlated with the molecular (log P(o/w)) and apparent (log P(app)) octanol-water partition coefficients obtained experimentally by countercurrent chromatography (CCC) or predicted by Pallas software. The obtained, satisfactory retention-hydrophobicity correlations indicate that, in the case of the basic drugs examined in RP-HPLC systems modified with perfluorinated acids, the retention is mainly governed by their hydrophobicity. Copyright 2009 Elsevier B.V. All rights reserved.

The development of a full-digital and networkable multi-media based highway information system : phase 1

DOT National Transportation Integrated Search

1999-07-26

This report covers the development of a Multimedia Based Highway Information System (MMHIS). MMHIS extends the capabilities of current photo logging facilities. Photographic logging systems used by highway agencies provide engineers with information ...

Effect of Zn2+ on halohydrin dehalogenase expression and accumulation through multi-parameter correlation research with Escherichia coli P84A/MC1061

PubMed Central

Li, Xiao; Luo, Yu-Di; Pan, Dong-Rui; Shi, Xiao-Dan; Tan, Ya-Li; Li, Zhi-Hong

2017-01-01

ABSTRACT Using 5 Zn2+ supplementation strategies in a 50 L batch bioreactor named FUS-50L(A), possible correlations among Zn2+ content and addition timing, physiologic activity (PA), halohydrin dehalogenase (HheC) accumulation of Escherichia coli P84A/MC1061 were systematically investigated. First, Zn2+ was confirmed as the significant factor, and its optimal concentration for HheC expression was 3.87 mg/L through fermentation experiments in shaking flasks. Second, based on experimental results from the different strategies, it was found that PA, nutrient consumption rate (NCR) and specific growth rate (μ) for E. coli P84A/MC1061 were promoted in the log phase (4–8 h) under appropriate Zn2+ concentrations in the lag phase and late log phase. Furthermore cell biomass was also increased to a higher level and the maximum HheC activity (i.e. HheCmax) was increased by 9.80%, and the time to reach HheCmax was reduced from 16 to 12 hours. Furthermore, appropriate supplementation of Zn2+ caused higher μ for E. coli P84A/MC1061, which resulted in more rapid accumulation of increased acetic acid concentrations, leading to higher acetic acid consumption avoiding any negative effects on producing HheC because of carbon source being exhausted prematurely and acetic acid being consumed rapidly. PMID:28282255

Effect of drug lipophilicity on in vitro release rate from oil vehicles using nicotinic acid esters as model prodrug derivatives.

PubMed

Weng Larsen, S; Engelbrecht Thomsen, A E; Rinvar, E; Friis, G J; Larsen, C

2001-03-23

The rate constants for transfer of a homologous series of nicotinic acid esters from oil vehicles to aqueous buffer phases were determined using a rotating dialysis cell. The chemical stability of butyl nicotinate has been investigated at 60 degrees C over pH range 0.5--10. Maximum stability occurs at pH 4--5 and an inflection point was seen around the pK(a). For the nicotinic acid esters, a linear correlation was established between the first-order rate constant related to attainment of equilibrium, k(obs) and the apparent partition coefficient, P(app): log k(obs)=-0.83log P(app)+0.26 (k(obs) in h(-1), n=9). For hexyl nicotinate with a true partition coefficient of 4 it was possible to determine k(obs) by decreasing pH in the aqueous release medium to 2.05. Thus, under the latter experimental conditions estimation of the relative release rates for the esters were performed. The ratio between the specific rate constant k(ow), related to the transport from oil vehicle to aqueous phase, for ethyl and hexyl nicotinate was 139. The hydrophobic substituent constant for a methylene group, pi(CH(2)), was determined for nicotinic acid esters in different oil/buffer partitioning systems to 0.54--0.58. Addition of hydroxypropyl-beta-cyclodextrin to the aqueous release medium did not enhance the transport rate of the esters from the oil phase.

Differences in the toxicity of six Gambierdiscus (Dinophyceae) species measured using an in vitro human erythrocyte lysis assay.

PubMed

Holland, William C; Litaker, R Wayne; Tomas, Carmelo R; Kibler, Steven R; Place, Allen R; Davenport, Erik D; Tester, Patricia A

2013-04-01

This study examined the toxicity of six Gambierdiscus species (Gambierdiscus belizeanus, Gambierdiscus caribaeus, Gambierdiscus carolinianus, Gambierdiscus carpenteri, Gambierdiscus ribotype 2 and Gambierdiscus ruetzleri) using a human erythrocyte lysis assay. In all, 56 isolates were tested. The results showed certain species were significantly more toxic than others. Depending on the species, hemolytic activity consistently increased by ∼7-40% from log phase growth to late log - early stationary growth phase and then declined in mid-stationary growth phase. Increasing growth temperatures from 20 to 31 °C for clones of G. caribaeus showed only a slight increase in hemolytic activity between 20 and 27 °C. Hemolytic activity in the G. carolinianus isolates from different regions grown over the same 20-31 °C range remained constant. These data suggest that growth temperature is not a significant factor in modulating the inter-isolate and interspecific differences in hemolytic activity. The hemolytic activity of various isolates measured repeatedly over a 2 year period remained constant, consistent with the hemolytic compounds being constitutively produced and under strong genetic control. Depending on species, greater than 60-90% of the total hemolytic activity was initially associated with the cell membranes but diffused into solution over a 24 h assay incubation period at 4 °C. These findings suggest that hemolytic compounds produced by Gambierdiscus isolates were held in membrane bound vesicles as reported for brevetoxins produced by Karenia brevis. Gambierdiscus isolates obtained from other parts of the world exhibited hemolytic activities comparable to those found in the Caribbean and Gulf of Mexico confirming the range of toxicities is similar among Gambierdiscus species worldwide. Experiments using specific inhibitors of the MTX pathway and purified MTX, Gambierdiscus whole cell extracts, and hydrophilic cell extracts containing MTX, were consistent with MTX as the primary hemolytic compound produced by Gambierdiscus species. While the results from inhibition studies require validation by LC-MS analysis, the available data strongly suggest differences in hemolytic activity observed in this study reflect maitotoxicity. Published by Elsevier Ltd.

In vitro characterization of Leishmania (Viannia) braziliensis isolates from patients with different responses to Glucantime(®) treatment from Northwest Paraná, Brazil.

PubMed

Fernandes, Andrea Claudia Bekner Silva; Pedroso, Raíssa Bocchi; de Mello, Tatiane França Perles; Donatti, Lucélia; Venazzi, Eneide Aparecida Sabaini; Demarchi, Izabel Galhardo; Aristides, Sandra Mara Alessi; Lonardoni, Maria Valdrinez Campana; Silveira, Thaís Gomes Verzignassi

2016-08-01

Leishmaniasis is a group of diseases that presents various clinical manifestations. Many studies have shown that the parasite plays an important role in the clinical manifestations and prognosis of this disease. The cutaneous and mucosal forms of American tegumentary leishmaniasis (ATL) are associated with Leishmania (Viannia) braziliensis, which exhibits intraspecific genetic polymorphisms and various clinical manifestations. The present study focused on four different L. braziliensis strains that were isolated from patients with distinct Glucantime(®) treatment responses. The isolates were described based on their molecular, biological, and infective characteristics. Growth patterns in culture medium and different grow phases were analyzed, MID-Logarithimic (Mid-LOG), Logarithimic (LOG) and Stationary (STAT) phases. Complement resistance was evaluated using guinea pig serum. Infection to murine peritoneal macrophages, cytokine and nitric oxide were analyzed. Ultrastructural features were determined by transmission electron microscopy, and molecular characteristics were determined based on random amplified polymorphic DNA (RAPD). All of the L. braziliensis isolates showed typical growth and similar complement sensitivity patterns. Markedly lower infectivity indexes were observed for all strains in the LOG phase, with different cytokine profiles. The ultrastructure analysis revealed distinct differences between the MID-LOG, LOG, and STAT phases. The RAPD results showed a divergence between the isolates of the L. braziliensis. The in vitro characterization of L. braziliensis isolates from humans with different treatment responses using various parameters enabled us to observe differences among the isolates. Molecular and in vivo characterizations are currently under study to improve understanding of the parasite-host interaction that can imply in the clinical manifestation differences. Copyright © 2016 Elsevier Inc. All rights reserved.

Log Normal Distribution of Cellular Uptake of Radioactivity: Statistical Analysis of Alpha Particle Track Autoradiography

PubMed Central

Neti, Prasad V.S.V.; Howell, Roger W.

2008-01-01

Recently, the distribution of radioactivity among a population of cells labeled with 210Po was shown to be well described by a log normal distribution function (J Nucl Med 47, 6 (2006) 1049-1058) with the aid of an autoradiographic approach. To ascertain the influence of Poisson statistics on the interpretation of the autoradiographic data, the present work reports on a detailed statistical analyses of these data. Methods The measured distributions of alpha particle tracks per cell were subjected to statistical tests with Poisson (P), log normal (LN), and Poisson – log normal (P – LN) models. Results The LN distribution function best describes the distribution of radioactivity among cell populations exposed to 0.52 and 3.8 kBq/mL 210Po-citrate. When cells were exposed to 67 kBq/mL, the P – LN distribution function gave a better fit, however, the underlying activity distribution remained log normal. Conclusions The present analysis generally provides further support for the use of LN distributions to describe the cellular uptake of radioactivity. Care should be exercised when analyzing autoradiographic data on activity distributions to ensure that Poisson processes do not distort the underlying LN distribution. PMID:16741316

A novel evaluation method for extrapolated retention factor in determination of n-octanol/water partition coefficient of halogenated organic pollutants by reversed-phase high performance liquid chromatography.

PubMed

Han, Shu-ying; Liang, Chao; Qiao, Jun-qin; Lian, Hong-zhen; Ge, Xin; Chen, Hong-yuan

2012-02-03

The retention factor corresponding to pure water in reversed-phase high performance liquid chromatography (RP-HPLC), k(w), was commonly obtained by extrapolation of retention factor (k) in a mixture of organic modifier and water as mobile phase in tedious experiments. In this paper, a relationship between logk(w) and logk for directly determining k(w) has been proposed for the first time. With a satisfactory validation, the approach was confirmed to enable easy and accurate evaluation of k(w) for compounds in question with similar structure to model compounds. Eight PCB congeners with different degree of chlorination were selected as a training set for modeling the logk(w)-logk correlation on both silica-based C(8) and C(18) stationary phases to evaluate logk(w) of sample compounds including seven PCB, six PBB and eight PBDE congeners. These eight model PCBs were subsequently combined with seven structure-similar benzene derivatives possessing reliable experimental K(ow) values as a whole training set for logK(ow)-logk(w) regressions on the two stationary phases. Consequently, the evaluated logk(w) values of sample compounds were used to determine their logK(ow) by the derived logK(ow)-logk(w) models. The logK(ow) values obtained by these evaluated logk(w) were well comparable with those obtained by experimental-extrapolated logk(w), demonstrating that the proposed method for logk(w) evaluation in this present study could be an effective means in lipophilicity study of environmental contaminants with numerous congeners. As a result, logK(ow) data of many PCBs, PBBs and PBDEs could be offered. These contaminants are considered to widely exist in the environment, but there have been no reliable experimental K(ow) data available yet. Copyright © 2011 Elsevier B.V. All rights reserved.

The role of cell size in density gradient electrophoretic separation of mouse leukemia cells according to position in the cell cycle

NASA Technical Reports Server (NTRS)

Plank, L. D.; Kunze, M. E.; Todd, P. W.

1985-01-01

Cultured mouse leukemia cells line L5178Y were subjected to upward electrophoresis in a density gradient and the slower migrating cell populations were enriched in G2 cells. It is indicated that this cell line does not change electrophoretic mobility through the cell cycle. The possibility that increased sedimentation downward on the part of the larger G2 cells caused this separation was explored. Two different cell populations were investigated. The log phase population was found to migrate upward faster than the G2 population, and a similar difference between their velocities and calculated on the basis of a 1 um diameter difference between the two cell populations. The G2 and G1 enriched populations were isolated by Ficoll density gradient sedimentation. The bottom fraction was enriched in G2 cells and the top fraction was enriched with G1 cells, especially when compared with starting materials. The electrophoretic mobilities of these two cell populations did not differ significantly from one another. Cell diameter dependent migration curves were calculated and were found to be different. Families of migration curves that differ when cell size is considered as a parameter are predicted.

Monitoring alkylphenols in water using the polar organic chemical integrative sampler (POCIS): Determining sampling rates via the extraction of PES membranes and Oasis beads.

PubMed

Silvani, Ludovica; Riccardi, Carmela; Eek, Espen; Papini, Marco Petrangeli; Morin, Nicolas A O; Cornelissen, Gerard; Oen, Amy M P; Hale, Sarah E

2017-10-01

Polar organic chemical integrative samplers (POCIS) have previously been used to monitor alkylphenol (AP) contamination in water and produced water. However, only the sorbent receiving phase of the POCIS (Oasis beads) is traditionally analyzed, thus limiting the use of POCIS for monitoring a range of APs with varying hydrophobicity. Here a "pharmaceutical" POCIS was calibrated in the laboratory using a static renewal setup for APs (from 2-ethylphenol to 4-n-nonylphenol) with varying hydrophobicity (log K ow between 2.47 and 5.76). The POCIS sampler was calibrated over its 28 day integrative regime and sampling rates (R s ) were determined. Uptake was shown to be a function of AP hydrophobicity where compounds with log K ow  < 4 were preferentially accumulated in Oasis beads, and compounds with log K ow  > 5 were preferentially accumulated in the PES membranes. A lag phase (over a 24 h period) before uptake in to the PES membranes occurred was evident. This work demonstrates that the analysis of both POCIS phases is vital in order to correctly determine environmentally relevant concentrations owing to the fact that for APs with log K ow  ≤ 4 uptake, to the PES membranes and the Oasis beads, involves different processes compared to APs with log K ow  ≥ 4. The extraction of both the POCIS matrices is thus recommended in order to assess the concentration of hydrophobic APs (log K ow  ≥ 4), as well as hydrophilic APs, most effectively. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Chromatographic Behaviour Predicts the Ability of Potential Nootropics to Permeate the Blood-Brain Barrier

PubMed Central

Farsa, Oldřich

2013-01-01

The log BB parameter is the logarithm of the ratio of a compound’s equilibrium concentrations in the brain tissue versus the blood plasma. This parameter is a useful descriptor in assessing the ability of a compound to permeate the blood-brain barrier. The aim of this study was to develop a Hansch-type linear regression QSAR model that correlates the parameter log BB and the retention time of drugs and other organic compounds on a reversed-phase HPLC containing an embedded amide moiety. The retention time was expressed by the capacity factor log k′. The second aim was to estimate the brain’s absorption of 2-(azacycloalkyl)acetamidophenoxyacetic acids, which are analogues of piracetam, nefiracetam, and meclofenoxate. Notably, these acids may be novel nootropics. Two simple regression models that relate log BB and log k′ were developed from an assay performed using a reversed-phase HPLC that contained an embedded amide moiety. Both the quadratic and linear models yielded statistical parameters comparable to previously published models of log BB dependence on various structural characteristics. The models predict that four members of the substituted phenoxyacetic acid series have a strong chance of permeating the barrier and being absorbed in the brain. The results of this study show that a reversed-phase HPLC system containing an embedded amide moiety is a functional in vitro surrogate of the blood-brain barrier. These results suggest that racetam-type nootropic drugs containing a carboxylic moiety could be more poorly absorbed than analogues devoid of the carboxyl group, especially if the compounds penetrate the barrier by a simple diffusion mechanism. PMID:23641330

Effects of solvent composition in the normal-phase liquid chromatography of alkylphenols and naphthols

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

Hurtubise, R.J.; Hussain, A.; Silver, H.F.

1981-11-01

The normal-phase liquid chromatographic models of Scott, Snyder, and Soczewinski were considered for a ..mu..-Bondapak NH/sub 2/ stationary phase. n-Heptane:2-propanol and n-heptane:ethyl acetate mobile phases of different compositions were used. Linear relationships were obtained from graphs of log K' vs. log mole fraction of the strong solvent for both n-heptane:2-propanol and n-heptane:ethyl acetate mobile phases. A linear relationship was obtained between the reciprocal of corrected retention volume and % wt/v of 2-propanol but not between the reciprocal of corrected retention volume and % wt/v of ethyl acetate. The slopes and intercept terms from the Snyder and Soczewinski models were foundmore » to approximately describe interactions with ..mu..-Bondapak NH/sub 2/. Capacity factors can be predicted for the compounds by using the equations obtained from mobile phase composition variation experiments.« less

Longitudinal qPCR Study of the Dynamics of L. crispatus, L. iners, A. vaginae, (Sialidase Positive) G. vaginalis, and P. bivia in the Vagina

PubMed Central

Lopes dos Santos Santiago, Guido; Tency, Inge; Verstraelen, Hans; Verhelst, Rita; Trog, Marijke; Temmerman, Marleen; Vancoillie, Leen; Decat, Ellen; Cools, Piet; Vaneechoutte, Mario

2012-01-01

Background To obtain more detailed understanding of the causes of disturbance of the vaginal microflora (VMF), a longitudinal study was carried out for 17 women during two menstrual cycles. Methods Vaginal swabs were obtained daily from 17 non-pregnant, menarchal volunteers. For each woman, Gram stains were scored, the quantitative changes of 5 key vaginal species, i.e. Atopobium vaginae, Lactobacillus crispatus, L. iners, (sialidase positive) Gardnerella vaginalis and Prevotella bivia were quantified with qPCR and hydrogen-peroxide production was assessed on TMB+ agar. Results Women could be divided in 9 subjects with predominantly normal VMF (grades Ia, Ib and Iab, group N) and 8 with predominantly disturbed VMF (grades I-like, II, III and IV, group D). VMF was variable between women, but overall stable for most of the women. Menses were the strongest disturbing factor of the VMF. L. crispatus was present at log7–9 cells/ml in grade Ia, Iab and II VMF, but concentrations declined 100-fold during menses. L. crispatus below log7 cells/ml corresponded with poor H2O2-production. L. iners was present at log 10 cells/ml in grade Ib, II and III VMF. Sialidase negative G. vaginalis strains (average log5 cells/ml) were detected in grade I, I-like and IV VMF. In grade II VMF, predominantly a mixture of both sialidase negative and positive G. vaginalis strains (average log9 cells/ml) were present, and predominantly sialidase positive strains in grade III VMF. The presence of A. vaginae (average log9 cells/ml) coincided with grade II and III VMF. P. bivia (log4–8 cells/ml) was mostly present in grade III vaginal microflora. L. iners, G. vaginalis, A. vaginae and P. bivia all increased around menses for group N women, and as such L. iners was considered a member of disturbed VMF. Conclusions This qPCR-based study confirms largely the results of previous culture-based, microscopy-based and pyrosequencing-based studies. PMID:23028904

Fragment-based approach to calculate hydrophobicity of anionic and nonionic surfactants derived from chromatographic retention on a C18 stationary phase.

PubMed

Hammer, Jort; Haftka, Joris J-H; Scherpenisse, Peter; Hermens, Joop L M; de Voogt, Pim W P

2017-02-01

To predict the fate and potential effects of organic contaminants, information about their hydrophobicity is required. However, common parameters to describe the hydrophobicity of organic compounds (e.g., octanol-water partition constant [K OW ]) proved to be inadequate for ionic and nonionic surfactants because of their surface-active properties. As an alternative approach to determine their hydrophobicity, the aim of the present study was therefore to measure the retention of a wide range of surfactants on a C 18 stationary phase. Capacity factors in pure water (k' 0 ) increased linearly with increasing number of carbon atoms in the surfactant structure. Fragment contribution values were determined for each structural unit with multilinear regression, and the results were consistent with the expected influence of these fragments on the hydrophobicity of surfactants. Capacity factors of reference compounds and log K OW values from the literature were used to estimate log K OW values for surfactants (log KOWHPLC). These log KOWHPLC values were also compared to log K OW values calculated with 4 computational programs: KOWWIN, Marvin calculator, SPARC, and COSMOThermX. In conclusion, capacity factors from a C 18 stationary phase are found to better reflect hydrophobicity of surfactants than their K OW values. Environ Toxicol Chem 2017;36:329-336. © 2016 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC. © 2016 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC.

Structure-activity relationships for novel drug precursor N-substituted-6-acylbenzothiazolon derivatives: A theoretical approach

NASA Astrophysics Data System (ADS)

Sıdır, Yadigar Gülseven; Sıdır, İsa

2013-08-01

In this study, the twelve new modeled N-substituted-6-acylbenzothiazolon derivatives having analgesic analog structure have been investigated by quantum chemical methods using a lot of electronic parameters and structure-activity properties; such as molecular polarizability (α), dipole moment (μ), EHOMO, ELUMO, q-, qH+, molecular volume (Vm), ionization potential (IP), electron affinity (EA), electronegativity (χ), molecular hardness (η), molecular softness (S), electrophilic index (ω), heat of formation (HOF), molar refractivity (MR), octanol-water partition coefficient (log P), thermochemical properties (entropy (S), capacity of heat (Cv)); as to investigate activity relationships with molecular structure. The correlations of log P with Vm, MR, ω, EA, EHOMO - ELUMO (ΔE), HOF in aqueous phase, χ, μ, S, η parameters, respectively are obtained, while the linear relation of log P with IP, Cv, HOF in gas phase are not observed. The log P parameter is obtained to be depending on different properties of compounds due to their complexity.

Comparative analysis of growth-phase-dependent gene expression in virulent and avirulent Streptococcus pneumoniae using a high-density DNA microarray.

PubMed

Ko, Kwan Soo; Park, Sulhee; Oh, Won Sup; Suh, Ji-Yoeun; Oh, Taejeong; Ahn, Sungwhan; Chun, Jongsik; Song, Jae-Hoon

2006-02-28

The global pattern of growth-dependent gene expres-sion in Streptococcus pneumoniae strains was evalu-ated using a high-density DNA microarray. Total RNAs obtained from an avirulent S. pneumoniae strain R6 and a virulent strain AMC96-6 were used to compare the expression patterns at seven time points (2.5, 3.5, 4.5, 5.5, 6.0, 6.5, and 8.0 h). The expression profile of strain R6 changed between log and station-ary growth (the Log-Stat switch). There were clear differences between the growth-dependent gene ex-pression profiles of the virulent and avirulent pneumo-coccal strains in 367 of 1,112 genes. Transcripts of genes associated with bacterial competence and capsular polysaccharide formation, as well as clpP and cbpA, were higher in the virulent strain. Our data suggest that late log or early stationary phase may be the most virulent phase of S. pneumoniae.

Bacteriophage T4 Infection of Stationary Phase E. coli: Life after Log from a Phage Perspective

PubMed Central

Bryan, Daniel; El-Shibiny, Ayman; Hobbs, Zack; Porter, Jillian; Kutter, Elizabeth M.

2016-01-01

Virtually all studies of phage infections investigate bacteria growing exponentially in rich media. In nature, however, phages largely encounter non-growing cells. Bacteria entering stationary phase often activate well-studied stress defense mechanisms that drastically alter the cell, facilitating its long-term survival. An understanding of phage-host interactions in such conditions is of major importance from both an ecological and therapeutic standpoint. Here, we show that bacteriophage T4 can efficiently bind to, infect and kill E. coli in stationary phase, both in the presence and absence of a functional stationary-phase sigma factor, and explore the response of T4-infected stationary phase cells to the addition of fresh nutrients 5 or 24 h after that infection. An unexpected new mode of response has been identified. “Hibernation” mode is a persistent but reversible dormant state in which the infected cells make at least some phage enzymes, but halt phage development until appropriate nutrients become available before producing phage particles. Our evidence indicates that the block in hibernation mode occurs after the middle-mode stage of phage development; host DNA breakdown and the incorporation of the released nucleotides into phage DNA indicate that the enzymes of the nucleotide synthesizing complex, under middle-mode control, have been made and assembled into a functional state. Once fresh glucose and amino acids become available, the standard lytic infection process rapidly resumes and concentrations of up to 1011 progeny phage (an average of about 40 phage per initially present cell) are produced. All evidence is consistent with the hibernation-mode control point lying between middle mode and late mode T4 gene expression. We have also observed a “scavenger” response, where the infecting phage takes advantage of whatever few nutrients are available to produce small quantities of progeny within 2 to 5 h after infection. The scavenger response seems able to produce no more than an average of one phage per originally available cell, and few if any further progeny are produced by cells in this mode even if fresh nutrients are made available later. PMID:27660625

Correlations between chromatographic parameters and bioactivity predictors of potential herbicides.

PubMed

Janicka, Małgorzata

2014-08-01

Different liquid chromatography techniques, including reversed-phase liquid chromatography on Purosphere RP-18e, IAM.PC.DD2 and Cosmosil Cholester columns and micellar liqud chromatography with a Purosphere RP-8e column and using buffered sodium dodecyl sulfate-acetonitrile as the mobile phase, were applied to study the lipophilic properties of 15 newly synthesized phenoxyacetic and carbamic acid derivatives, which are potential herbicides. Chromatographic lipophilicity descriptors were used to extrapolate log k parameters (log kw and log km) and log k values. Partitioning lipophilicity descriptors, i.e., log P coefficients in an n-octanol-water system, were computed from the molecular structures of the tested compounds. Bioactivity descriptors, including partition coefficients in a water-plant cuticle system and water-human serum albumin and coefficients for human skin partition and permeation were calculated in silico by ACD/ADME software using the linear solvation energy relationship of Abraham. Principal component analysis was applied to describe similarities between various chromatographic and partitioning lipophilicities. Highly significant, predictive linear relationships were found between chromatographic parameters and bioactivity descriptors. © The Author [2013]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Lipophilicity assessment of basic drugs (log P(o/w) determination) by a chromatographic method.

PubMed

Pallicer, Juan M; Sales, Joaquim; Rosés, Martí; Ràfols, Clara; Bosch, Elisabeth

2011-09-16

A previously reported chromatographic method to determine the 1-octanol/water partition coefficient (log P(o/w)) of organic compounds is used to estimate the hydrophobicity of bases, mainly commercial drugs with diverse chemical nature and pK(a) values higher than 9. For that reason, mobile phases buffered at high pH to avoid the ionization of the solutes and three different columns (Phenomenex Gemini NX, Waters XTerra RP-18 and Waters XTerra MS C(18)) with appropriate alkaline-resistant stationary phases have been used. Non-ionizable substances studied in previous works were also included in the set of compounds to evaluate the consistency of the method. The results showed that all the columns provide good estimations of the log P(o/w) for most of the compounds included in this study. The Gemini NX column has been selected to calculate log P(o/w) values of the set of studied drugs, and really good correlations between the determined log P(o/w) values and those considered as reference were obtained, proving the ability of the procedure for the lipophilicity assessment of bioactive compounds with very different structures and functionalities. Copyright © 2011 Elsevier B.V. All rights reserved.

Unsymmetric Mono- and Dinuclear Platinum(IV) Complexes Featuring an Ethylene Glycol Moiety: Synthesis, Characterization, and Biological Activity

PubMed Central

Pichler, Verena; Heffeter, Petra; Valiahdi, Seied M.; Kowol, Christian R.; Egger, Alexander; Berger, Walter; Jakupec, Michael A.; Galanski, Markus; Keppler, Bernhard K.

2014-01-01

Eight novel mononuclear and two dinuclear platinum(IV) complexes were synthesized and characterized by elemental analysis, one- and two-dimensional NMR spectroscopy, mass spectrometry, and reversed-phase HPLC (log kw) and in one case by X-ray diffraction. Cytotoxicity of the compounds was studied in three human cancer cell lines (CH1, SW480, and A549) by means of the MTT assay, featuring IC50 values to the low micromolar range. Furthermore a selected set of compounds was investigated in additional cancer cell lines (P31 and P31/cis, A2780 and A2780/cis, SW1573, 2R120, and 2R160) with regard to their resistance patterns, offering a distinctly different scheme compared to cisplatin. To gain further insights into the mode of action, drug uptake, DNA synthesis inhibition, cell cycle effects, and induction of apoptosis were determined for two characteristic substances. PMID:23194425

Novel medium-throughput technique for investigating drug-cyclodextrin complexation by pH-metric titration using the partition coefficient method.

PubMed

Dargó, Gergő; Boros, Krisztina; Péter, László; Malanga, Milo; Sohajda, Tamás; Szente, Lajos; Balogh, György T

2018-05-05

The present study was aimed to develop a medium-throughput screening technique for investigation of cyclodextrin (CD)-active pharmaceutical ingredient (API) complexes. Dual-phase potentiometric lipophilicity measurement, as gold standard technique, was combined with the partition coefficient method (plotting the reciprocal of partition coefficients of APIs as a function of CD concentration). A general equation was derived for determination of stability constants of 1:1 CD-API complexes (K 1:1,CD ) based on solely the changes of partition coefficients (logP o/w N -logP app N ), without measurement of the actual API concentrations. Experimentally determined logP value (-1.64) of 6-deoxy-6[(5/6)-fluoresceinylthioureido]-HPBCD (FITC-NH-HPBCD) was used to estimate the logP value (≈ -2.5 to -3) of (2-hydroxypropyl)-ß-cyclodextrin (HPBCD). The results suggested that the amount of HPBCD can be considered to be inconsequential in the octanol phase. The decrease of octanol volume due to the octanol-CD complexation was considered, thus a corrected octanol-water phase ratio was also introduced. The K 1:1,CD values obtained by this developed method showed a good accordance with the results from other orthogonal methods. Copyright © 2018 Elsevier B.V. All rights reserved.

MONITOIRNG OF A CONTROLLED DNAPL SPILL USING A PROTOTYPE DIELECTRIC LOGGING TOOL

EPA Science Inventory

The U. S. Geological Survey (USGS) utilized their prototype dielectric logging tool to monitor a controlled Dense Non-Aqueous Phase Liquid (DNAPL) spill into a large tank located at the University of California Richmond Field Station (RFS) containing multiple sand and clayey sand...

Evaluation of the phase ratio for three C18 high performance liquid chromatographic columns.

PubMed

Caiali, Edvin; David, Victor; Aboul-Enein, Hassan Y; Moldoveanu, Serban C

2016-02-26

For a chromatographic column, phase ratio Φ is defined as the ratio between the volume of the stationary phase Vst and the void volume of the column V0, and it is an important parameter characterizing the HPLC process. Although apparently simple, the evaluation of Φ presents difficulties because there is no sharp boundary between the mobile phase and the stationary phase. In addition, the boundary depends not only on the nature of the stationary phase, but also on the composition of the mobile phase. In spite of its importance, phase ratio is seldom reported for commercially available HPLC columns and the data typically provided by the vendors about the columns do not provide key information that would allow the calculation of Φ based on Vst and V0 values. A different procedure for the evaluation of Φ is based on the following formula: log k'j=a log Kow,j+log Φ, where k'j is the retention factor for a compound j that must be a hydrocarbon, Kow,j is the octanol/water partition coefficient, and a is a proportionality constant. Present study describes the experimental evaluation of Φ based on the measurement of k'j for the compounds in the homologous series between benzene and butylbenzene for three C18 columns: Gemini C18, Luna C18 both with 5 μm particles, and a Chromolith Performance RP-18. The evaluation was performed for two mobile phase systems at different proportions of methanol/water and acetonitrile/water. The octanol/water partition coefficients were obtained from the literature. The results obtained in the study provide further support for the new procedure for the evaluation of phase ratio. Copyright © 2016 Elsevier B.V. All rights reserved.

Microbiological quality and somatic cell count in bulk milk of dromedary camels (Camelus dromedarius): descriptive statistics, correlations, and factors of variation.

PubMed

Nagy, P; Faye, B; Marko, O; Thomas, S; Wernery, U; Juhasz, J

2013-09-01

The objectives of the present study were to monitor the microbiological quality and somatic cell count (SCC) of bulk tank milk at the world's first large-scale camel dairy farm for a 2-yr period, to compare the results of 2 methods for the enumeration of SCC, to evaluate correlation among milk quality indicators, and to determine the effect of specific factors (year, season, stage of lactation, and level of production) on milk quality indicators. The study was conducted from January 2008 to January 2010. Total viable count (TVC), coliform count (CC), California Mastitis Test (CMT) score, and SCC were determined from daily bulk milk samples. Somatic cell count was measured by using a direct microscopic method and with an automatic cell counter. In addition, production parameters [total daily milk production (TDM, kg), number of milking camels (NMC), average milk per camel (AMC, kg)] and stage of lactation (average postpartum days, PPD) were recorded for each test day. A strong correlation (r=0.33) was found between the 2 methods for SCC enumeration; however, values derived using the microscopic method were higher. The geometric means of SCC and TVC were 394×10(3) cells/mL and 5,157 cfu/mL during the observation period, respectively. Somatic cell count was >500×10(3) cells/mL on 14.6% (106/725) and TVC was >10×10(3) cfu/mL on 4.0% (30/742) of the test days. Both milk quality indicators had a distinct seasonal pattern. For log SCC, the mean was lowest in summer and highest in autumn. The seasonal pattern of log TVC was slightly different, with the lowest values being recorded during the spring. The monthly mean TVC pattern showed a clear difference between years. Coliform count was <10 cfu/mL in most of the samples (709/742, 95.6%). A positive correlation was found between log SCC and log TVC (r=0.32), between log SCC and CMT score (r=0.26), and between log TVC and CC in yr 1 (r=0.30). All production parameters and stage of lactation showed strong seasonal variation. Log SCC was negatively correlated with TDM (r=-0.35), AMC (r=-0.37), and NMC (r=-0.15) and positively correlated with PPD (r=0.40). Log TVC had a negative correlation with AMC (r=-0.40) but a positive correlation with NMC (r=0.32), TDM (r=0.16), and PPD (r=0.45). The linear mixed model with stepwise variable selection showed that the main sources of log SCC variation were PPD, TDM, PPD × season, and season. For log TVC, the same factors and year contributed to the variation. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

HST/COS detection of a Ne VIII absorber towards PG 1407+265: an unambiguous tracer of collisionally ionized hot gas?

NASA Astrophysics Data System (ADS)

Hussain, T.; Muzahid, S.; Narayanan, A.; Srianand, R.; Wakker, B. P.; Charlton, J. C.; Pathak, A.

2015-01-01

We report the detection of Ne VIII in a zabs = 0.599 61 absorber towards the QSO PG1407+265 (zem= 0.94). Besides Ne VIII, absorption from H I Lyman series lines (H I λ1025-λ915), several other low (C II, N II, O II and S II), intermediate (C III, N III, N IV, O III, S IV and S V) and high (S VI, O VI and Ne VIII) ionization metal lines are detected. Disparity in the absorption line kinematics between different ions implies that the absorbing gas comprises of multiple ionization phases. The low and the intermediate ions (except S V) trace a compact (˜410 pc), metal-rich (Z ˜ Z⊙) and overdense (log nH ˜ -2.6) photoionized region that sustained star formation for a prolonged period. The high ions, Ne VIII and O VI, can be explained as arising in a low density (-5.3 ≤ log nH ≤ -5.0), metal-rich (Z ≳ Z⊙) and diffuse (˜180 kpc) photoionized gas. The S V, S VI and C IV [detected in the Faint Object Spectrograph (FOS) spectrum] require an intermediate photoionization phase with -4.2 < log nH < -3.5. Alternatively, a pure collisional ionization model, as used to explain the previous known Ne VIII absorbers, with 5.65 < log T < 5.72, can reproduce the S VI, O VI and Ne VIII column densities simultaneously in a single phase. However, even such models require an intermediate phase to reproduce any observable S V and/or C IV. Therefore, we conclude that when multiple phases are present, the presence of Ne VIII is not necessarily an unambiguous indication of collisionally ionized hot gas.

Effect of Pseudomonas graminis strain CPA-7 on the ability of Listeria monocytogenes and Salmonella enterica subsp. enterica to colonize Caco-2 cells after pre-incubation on fresh-cut pear.

PubMed

Collazo, Cyrelys; Abadías, Maribel; Colás-Medà, Pilar; Iglesias, María Belén; Granado-Serrano, Ana Belén; Serrano, José; Viñas, Inmaculada

2017-12-04

To further gain insight into the mechanism by which the biopreservative bacterium Pseudomonas graminis CPA-7 develops its antimicrobial activity, we have examined the effect that the prior interaction stablished by this bacterium and two foodborne pathogens on fresh-cut pear, has on their capacity to colonize human epithelial cells (Caco-2 cell line) which is crucial for establishing infection. CPA-7 inhibited the growth of L. monocytogenes and S. enterica subsp. enterica ser. Enteritidis by 5.5 and 3.1 log 10 , respectively, after 7d of interaction at 10°C. Furthermore, CPA-7 attenuated the adherence of S. enterica to Caco-2 cells by 0.8 log 10 regardless of the pre-adaptation on the fruit. Conversely, the adhesiveness of L. monocytogenes was not influenced by the interaction with the antagonist but it was reduced by 0.5 log 10 after incubation on the food matrix. Pathogen-antagonist-food matrix interaction was associated to a significant reduction of the relative invasiveness of both pathogens, by 1.3 log 10 in the case of L. monocytogenes and to an undetectable level (below 5CFU/g fruit) for S. enterica. CPA-7 can adhere to and internalize into intestinal epithelium which enables it for competition. Its adherence positively correlates to the multiplicity of infection (MOI) with respect to Caco-2 cells, increasing by 0.6 log 10 in an MOI range of 0.1:1 to 100:1. For the same levels of inoculum, internalized cells could only be detected after 7d of pre-adaptation in the fruit (pH4.5-5.0). However, the combination of gastrointestinal digestion and habituation on the fruit resulted in a significant reduction of CPA-7 populations (by 2 log 10 more after 7d of incubation than on inoculation day) as well as in the decrease of its adhesiveness (by 0.8 log 10 ) and invasiveness (to undetectable levels). Copyright © 2017 Elsevier B.V. All rights reserved.

Overall Survival and Updated Results for Sunitinib Compared With Interferon Alfa in Patients With Metastatic Renal Cell Carcinoma

PubMed Central

Motzer, Robert J.; Hutson, Thomas E.; Tomczak, Piotr; Michaelson, M. Dror; Bukowski, Ronald M.; Oudard, Stéphane; Negrier, Sylvie; Szczylik, Cezary; Pili, Roberto; Bjarnason, Georg A.; Garcia-del-Muro, Xavier; Sosman, Jeffrey A.; Solska, Ewa; Wilding, George; Thompson, John A.; Kim, Sindy T.; Chen, Isan; Huang, Xin; Figlin, Robert A.

2009-01-01

Purpose A randomized, phase III trial demonstrated superiority of sunitinib over interferon alfa (IFN-α) in progression-free survival (primary end point) as first-line treatment for metastatic renal cell carcinoma (RCC). Final survival analyses and updated results are reported. Patients and Methods Seven hundred fifty treatment-naïve patients with metastatic clear cell RCC were randomly assigned to sunitinib 50 mg orally once daily on a 4 weeks on, 2 weeks off dosing schedule or to IFN-α 9 MU subcutaneously thrice weekly. Overall survival was compared by two-sided log-rank and Wilcoxon tests. Progression-free survival, response, and safety end points were assessed with updated follow-up. Results Median overall survival was greater in the sunitinib group than in the IFN-α group (26.4 v 21.8 months, respectively; hazard ratio [HR] = 0.821; 95% CI, 0.673 to 1.001; P = .051) per the primary analysis of unstratified log-rank test (P = .013 per unstratified Wilcoxon test). By stratified log-rank test, the HR was 0.818 (95% CI, 0.669 to 0.999; P = .049). Within the IFN-α group, 33% of patients received sunitinib, and 32% received other vascular endothelial growth factor–signaling inhibitors after discontinuation from the trial. Median progression-free survival was 11 months for sunitinib compared with 5 months for IFN-α (P < .001). Objective response rate was 47% for sunitinib compared with 12% for IFN-α (P < .001). The most commonly reported sunitinib-related grade 3 adverse events included hypertension (12%), fatigue (11%), diarrhea (9%), and hand-foot syndrome (9%). Conclusion Sunitinib demonstrates longer overall survival compared with IFN-α plus improvement in response and progression-free survival in the first-line treatment of patients with metastatic RCC. The overall survival highlights an improved prognosis in patients with RCC in the era of targeted therapy. PMID:19487381

ViriChip: a solid phase assay for detection and identification of viruses by atomic force microscopy

NASA Astrophysics Data System (ADS)

Nettikadan, Saju R.; Johnson, James C.; Vengasandra, Srikanth G.; Muys, James; Henderson, Eric

2004-03-01

Bionanotechnology can be viewed as the integration of tools and concepts in nanotechnology with the attributes of biomolecules. We report here on an atomic force microscopy-immunosensor assay (AFMIA) that couples AFM with solid phase affinity capture of biological entities for the rapid detection and identification of group B coxsackievirus particles. Virus identification is based on type-specific immunocapture and the morphological properties of the captured viruses as obtained by the AFM. Representatives of the six group B coxsackieviruses have been specifically captured from 1 µl volumes of clarified cell lysates, body fluids and environmental samples. Concentration and kinetic profiles for capture indicate that detection is possible at 103 TCID50 µl-1 and the dynamic range of the assay spans three logs. The results demonstrate that the melding of a nanotechnological tool (AFM) with biotechnology (solid phase immunocapture of virus particles) can create a clinically relevant platform, useful for the detection and identification of enterovirus particles in a variety of samples.

Gene Methylation and Cytological Atypia in Random Fine Needle Aspirates for Assessment of Breast Cancer Risk

PubMed Central

Hafeez, Sidra; Bujanda, Zoila Lopez; Chatterton, Robert T.; Jacobs, Lisa K.; Khouri, Nagi F.; Ivancic, David; Kenney, Kara; Shehata, Christina; Jeter, Stacie C.; Wolfman, Judith A.; Zalles, Carola M.; Huang, Peng

2016-01-01

Methods to determine individualized breast cancer risk lack sufficient sensitivity to select women most likely to benefit from preventive strategies. Alterations in DNA methylation occur early in breast cancer. We hypothesized that cancer-specific methylation markers could enhance breast cancer risk assessment. We evaluated 380 women without a history of breast cancer. We determined their menopausal status or menstrual cycle phase, risk of developing breast cancer (Gail model), and breast density, and obtained random fine needle aspiration (rFNA) samples for assessment of cytopathology and cumulative methylation index (CMI). Eight methylated gene markers were identified through whole genome methylation analysis and included novel and previously established breast cancer detection genes. We performed correlative and multivariate linear regression analyses to evaluate DNA methylation of a gene panel as a function of clinical factors associated with breast cancer risk. CMI and individual gene methylation were independent of age, menopausal status or menstrual phase, lifetime Gail risk score, and breast density. CMI and individual gene methylation for the eight genes increased significantly (p<0.001) with increasing cytological atypia. The findings were verified with multivariate analyses correcting for age, log (Gail), log (percent density), rFNA cell number and BMI. Our results demonstrate a significant association between cytological atypia and high CMI, which does not vary with menstrual phase or menopause and is independent of Gail risk and mammographic density. Thus CMI is an excellent candidate breast cancer risk biomarker, warranting larger prospective studies to establish its utility for cancer risk assessment. PMID:27261491

Short communication: bulk tank total bacterial count in dairy sheep: factors of variation and relationship with somatic cell count.

PubMed

Gonzalo, C; Carriedo, J A; Beneitez, E; Juárez, M T; De La Fuente, L F; San Primitivo, F

2006-02-01

A total of 9,353 records for bulk tank total bacterial count (TBC) were obtained over 1 yr from 315 dairy ewe flocks belonging to the Sheep Improvement Consortium (CPO) in Castilla-León (Spain). Analysis of variance showed significant effects of flock, breed, month within flock, dry therapy, milking type and installation, and logSCC on logTBC. Flock and month within flock were important variation factors as they accounted for 22.0 and 22.1% of the variance, respectively. Considerable repeatability values were obtained for both random factors. Hand milking and bucket-milking machines elicited highest logTBC (5.31), whereas parlor systems with looped milkline (5.01) elicited the lowest logTBC. The implementation of dry therapy practice (5.12) showed significantly lower logTBC than when not used (5.25). Variability in logTBC among breeds ranged from 5.24 (Awassi) to 5.07 (Churra). However, clinical outbreaks of contagious agalactia did not increase TBC significantly. A statistically significant relationship was found between logTBC and logSCC, the correlation coefficient between the variables being r = 0.23. Programs for improving milk hygiene should be implemented for both total bacterial count and somatic cell count variables at the same time.

Effect of sonically induced deflocculation on the efficiency of ozone mediated partial sludge disintegration for improved production of biogas.

PubMed

Sowmya Packyam, G; Kavitha, S; Adish Kumar, S; Kaliappan, S; Yeom, Ick Tae; Rajesh Banu, J

2015-09-01

In this study, ultrasonication was used for sludge deflocculation, followed by cell disintegration using ozone. The effect of this phase separated sono-ozone pretreatment is evaluated based on extra polymeric substances release, deoxyribonucleic acid (DNA) in the medium, solubilization of intra cellular components and suspended solids (SS) reduction. Ultrasonically induced deflocculation was optimized at an energy dosage of 76.4(log 1.88)kJ/kg TS. During cell disintegration (ozone dosage 0.0011 mgO3/mgSS), chemical oxygen demand solubilization (COD) and SS reduction of sonic mediated ozone pretreated sludge were 25.4% and 17.8% comparatively higher than ozone pretreated sludge, respectively. Further, biogas production potential of control (raw), flocculated (ozone pretreated), and deflocculated (sonic mediated ozone pretreated) sludges were observed to be 0.202, 0.535 and 0.637 L/(gVS), respectively. Thus, the phase separated pretreatment at lower ultrasonic specific energy and low dose ozone proved to enhance the anaerobic biodegradability efficiently. Copyright © 2015 Elsevier B.V. All rights reserved.

Temporal trends in postseroconversion CD4 cell count and HIV load: the Concerted Action on Seroconversion to AIDS and Death in Europe Collaboration, 1985-2002.

PubMed

Dorrucci, Maria; Rezza, Giovanni; Porter, Kholoud; Phillips, Andrew

2007-02-15

To determine whether early postseroconversion CD4 cell counts and human immunodeficiency virus (HIV) loads have changed over time. Our analysis was based on 22 cohorts of people with known dates of seroconversion from Europe, Australia, and Canada (Concerted Action on Seroconversion to AIDS and Death in Europe Collaboration). We focused on individuals seroconverting between 1985 and 2002 who had the first CD4 cell count (n=3687) or HIV load (n=1584) measured within 2 years of seroconversion and before antiretroviral use. Linear regression models were used to assess time trends in postseroconversion CD4 cell count and HIV load. Trends in time to key thresholds were also assessed, using survival analysis. The overall median initial CD4 cell count was 570 cells/ microL (interquartile range [IQR], 413-780 cells/ microL). The median initial HIV load was 35,542 copies/mL (IQR, 7600-153,050 copies/mL; on log(10) scale, 3.9-5.2 log(10) copies/mL). The postseroconversion CD4 cell count changed by an average of -6.33 cells/ microL/year (95% confidence interval [CI], -8.47 to -4.20 cells/ microL/year; P<.001), whereas an increase was observed in log(10) HIV load (+0.044 log(10) copies/mL/year; 95% CI, +0.034 to +0.053 log(10) copies/mL/year). These trends remained after adjusting for potential confounders. The probability of progressing to a CD4 cell count of <500 cells/ microL by 24 months from seroconversion increased from 0.66 (95% CI, 0.63-0.69) for individuals who seroconverted before 1991 to 0.80 (95% CI, 0.75-0.84) for those who seroconverted during 1999-2002. These data suggest that, in Europe, there has been a trend of decrease in the early CD4 cell count and of increase in the early HIV load. Additional research will be necessary to determine whether similar trends exist in other geographical areas.

Hepatitis B core-related antigen (HBcrAg) levels in the natural history of hepatitis B virus infection in a large European cohort predominantly infected with genotypes A and D.

PubMed

Maasoumy, B; Wiegand, S B; Jaroszewicz, J; Bremer, B; Lehmann, P; Deterding, K; Taranta, A; Manns, M P; Wedemeyer, H; Glebe, D; Cornberg, M

2015-06-01

Hepatitis B core-related antigen (HBcrAg) has been suggested as an additional marker of hepatitis B virus (HBV) infection. HBcrAg combines the antigenic reactivity resulting from denatured hepatitis B e antigen (HBeAg), HBV core antigen and an artificial core-related protein (p22cr). In Asian patients, high levels of HBcrAg have been suggested to be an independent risk factor for hepatocellular carcinoma, while low levels could guide safe cessation of treatment with nucleos(t)ide analogues. We here studied HBcrAg levels in different phases of HBV infection in a large European cohort predominantly infected with genotypes A and D: HBeAg-positive immune tolerance (n = 30), HBeAg-positive immune clearance (IC) (n = 60), HBeAg-negative hepatitis (ENH) (n = 50), HBeAg-negative inactive/quiescent carrier phase (c) (n = 109) and acute hepatitis B (n = 8). Median HBcrAg levels were high in the immune tolerance and immune clearance phases (8.41 and 8.11 log U/mL, respectively), lower in ENH subjects (4.82 log U/mL) but only 2.00 log U/mL in ENQ subjects. Correlation between HBcrAg and HBV DNA varied among the different phases of HBV infection, while HBcrAg moderately correlated with hepatitis B surface antigen in all phases. ENQ patients had HBcrAg levels <3 log U/mL in 79%, in contrast to only 12% in the ENH group. HBcrAg levels vary significantly during the different phases of HBV infection. HBcrAg may serve as valuable marker for virus replication and reflect the transcriptional activity of intrahepatic cccDNA. In HBeAg-negative patients, HBcrAg may help to distinguish between inactive carriers (ENQ) and those with active disease (ENH). Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Association between feline immunodeficiency virus (FIV) plasma viral RNA load, concentration of acute phase proteins and disease severity.

PubMed

Kann, Rebecca K C; Seddon, Jennifer M; Kyaw-Tanner, Myat T; Henning, Joerg; Meers, Joanne

2014-08-01

Veterinarians have few tools to predict the rate of disease progression in FIV-infected cats. In contrast, in HIV infection, plasma viral RNA load and acute phase protein concentrations are commonly used as predictors of disease progression. This study evaluated these predictors in cats naturally infected with FIV. In older cats (>5 years), log10 FIV RNA load was higher in the terminal stages of disease compared to the asymptomatic stage. There was a significant association between log10 FIV RNA load and both log10 serum amyloid A concentration and age in unwell FIV-infected cats. This study suggests that viral RNA load and serum amyloid A warrant further investigation as predictors of disease status and prognosis in FIV-infected cats. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Application of reversed-phase ion-pair chromatography for universal estimation of octanol-water partition coefficients of acid, basic and amphoteric drugs].

PubMed

Zhu, Hui; Yang, Ri-Fang; Yun, Liu-Hong; Jiang, Yu; Li, Jin

2009-09-01

This paper is to establish a reversed-phase ion-pair chromatography (RP-IPC) method for universal estimation of the octanol/water partition coefficients (logP) of a wide range of structurally diverse compounds including acidic, basic, neutral and amphoteric species. The retention factors corresponding to 100% water (logk(w)) were derived from the linear part of the logk'/phi relationship, using at least four isocratic logk' values containing different organic compositions. The logk(w) parameters obtained were close to the corresponding logP values obtained with the standard "shake flask" methods. The mean deviation for test drugs is 0.31. RP-IPC with trifluoroacetic acid as non classic ion-pair agents can be applicable to determine the logP values for a variety of drug-like molecules with increased accuracy.

Partitioning of total mercury and methylmercury to the colloidal phase in freshwaters.

PubMed

Babiarz, C L; Hurley, J P; Hoffmann, S R; Andren, A W; Shafer, M M; Armstrong, D E

2001-12-15

Using tangential flow ultrafiltration, total mercury (HgT) and methylmercury (MeHg) concentrations in the colloidal phase (0.4 microm-10 kDa) were determined for 15 freshwaters located in the upper Midwest (Minnesota, Michigan, and Wisconsin) and the Southern United States (Georgia and Florida). Unfiltered concentrations were typical of those reported for freshwater and ranged from 0.9 to 27.1 ng L(-1) HgT and from 0.08 to 0.86 ng L(-1) MeHg. For some rivers, HgT and MeHg in the colloidal phase comprised up to 72% of the respective unfiltered concentration. On average, however, HgT and MeHg concentrations were evenly distributed between the particulate (>0.4 microm), colloidal, and dissolved (<10 kDa) phases. The pool of Hg in the colloidal phase decreased with increasing specific conductance. Results from experiments on freshwaters with artificially elevated specific conductance suggest that HgT and MeHg may partition to different subfractions of colloidal material. The colloidal-phase HgT correlation with filtered organic carbon (OC(F)) was generally poor (r2 < 0.14; p > 0.07), but the regression of MeHg with OC(F) was strong, especially in the upper Midwest (r2 = 0.78; p < 0.01). On a mass basis, colloidal-phase Hg concentrations were similar to those of unimpacted sediments in the Midwest. Mercury to carbon ratios averaged 352 pg of HgT/mg of C and 25 pg of MeHg/mg of C and were not correlated to ionic strength. The log of the partition coefficient (log K(D)) for HgT and MeHg ranged from 3.7 to 6.4 and was typical of freshwater values determined using a 0.4 microm cutoff between the particulate phase and the dissolved phase. Log K(D) calculated using the <10 kDa fraction as "dissolved" ranged from 4.3 to 6.6 and had a smaller standard deviation about the mean. In addition, our data support the "particle concentration effect" (PCE) hypothesis that the association of Hg with colloids in the filter-passing fraction can lower the observed log K(D). The similarity between colloidal and particulate-phase partition coefficients suggests that colloidal mass and not preferential colloidal partitioning drives the PCE.

Effect of oxygen stress on growth and survival of Clostridium perfringens, Campylobacter jejuni, and Listeria monocytogenes under different storage conditions.

PubMed

Al-Qadiri, Hamzah; Sablani, Shyam S; Ovissipour, Mahmoudreza; Al-Alami, Nivin; Govindan, Byju; Rasco, Barbara

2015-04-01

This study investigated the growth and survival of three foodborne pathogens (Clostridium perfringens, Campylobacter jejuni, and Listeria monocytogenes) in beef (7% fat) and nutrient broth under different oxygen levels. Samples were tested under anoxic (<0.5%), microoxic (6 to 8%), and oxic (20%) conditions during storage at 7 °C for 14 days and at 22 °C for 5 days. Two initial inoculum concentrations were used (1 and 2 log CFU per g of beef or per ml of broth). The results show that C. perfringens could grow in beef at 22 °C, with an increase of approximately 5 log under anoxic conditions and a 1-log increase under microoxic conditions. However, C. perfringens could not survive in beef held at 7 °C under microoxic and oxic storage conditions after 14 days. In an anoxic environment, C. perfringens survived in beef samples held at 7 °C, with a 1-log reduction. A cell decline was observed at 2 log under these conditions, with no surviving cells at the 1-log level. However, the results show that C. jejuni under microoxic conditions survived with declining cell numbers. Significant increases in L. monocytogenes (5 to 7 log) were observed in beef held at 22 °C for 5 days, with the lowest levels recovered under anoxic conditions. L. monocytogenes in refrigerated storage increased by a factor of 2 to 4 log. It showed the greatest growth under oxic conditions, with significant growth under anoxic conditions. These findings can be used to enhance food safety in vacuum-packed and modified atmosphere-packaged food products.

Pretreatment of low dose radiation reduces radiation-induced apoptosis in mouse lymphoma (EL4) cells.

PubMed

Kim, J H; Hyun, S J; Yoon, M Y; Ji, Y H; Cho, C K; Yoo, S Y

1997-06-01

Induction of an adaptive response to ionizing radiation in mouse lymphoma (EL4) cells was studied by using cell survival fraction and apoptotic nucleosomal DNA fragmentation as biological end points. Cells in early log phase were pre-exposed to low dose of gamma-rays (0.01 Gy) 4 or 20 hrs prior to high dose gamma-ray (4, 8 and 12 Gy for cell survival fraction analysis; 8 Gy for DNA fragmentation analysis) irradiation. Then cell survival fractions and the extent of DNA fragmentation were measured. Significant adaptive response, increase in cell survival fraction and decrease in the extent of DNA fragmentation were induced when low and high dose gamma-ray irradiation time interval was 4 hr. Addition of protein or RNA synthesis inhibitor, cycloheximide or 5,6-dichloro-1-beta-d-ribofuranosylbenzimidazole (DRFB), respectively during adaptation period, the period from low dose gamma-ray irradiation to high dose gamma-ray irradiation, was able to inhibit the induction of adaptive response, which is the reduction of the extent DNA fragmentation in irradiated EL4 cells. These data suggest that the induction of adaptive response to ionizing radiation in EL4 cells required both protein and RNA synthesis.

Visualization and quantification of two-phase flow in transparent miniature packed beds

NASA Astrophysics Data System (ADS)

Zhu, Peixi; Papadopoulos, Kyriakos D.

2012-10-01

Optical microscopy was used to visualize the flow of two phases [British Petroleum (BP) oil and an aqueous surfactant phase] in confined space, three-dimensional, transparent, natural porous media. The porous media consisted of water-wet cryolite grains packed inside cylindrical, glass microchannels, thus producing microscopic packed beds. Primary drainage of BP oil displacing an aqueous surfactant phase was studied at capillary numbers that varied between 10-6 and 10-2. The confinement space had a significant effect on the flow behavior. Phenomena of burst motion and capillary fingering were observed for low capillary numbers due to the domination of capillary forces. It was discovered that breakthrough time and capillary number bear a log-log scale linear relationship, based on which a generalized correlation between oil travel distance x and time t was found empirically.

Visualization and quantification of two-phase flow in transparent miniature packed beds.

PubMed

Zhu, Peixi; Papadopoulos, Kyriakos D

2012-10-01

Optical microscopy was used to visualize the flow of two phases [British Petroleum (BP) oil and an aqueous surfactant phase] in confined space, three-dimensional, transparent, natural porous media. The porous media consisted of water-wet cryolite grains packed inside cylindrical, glass microchannels, thus producing microscopic packed beds. Primary drainage of BP oil displacing an aqueous surfactant phase was studied at capillary numbers that varied between 10(-6) and 10(-2). The confinement space had a significant effect on the flow behavior. Phenomena of burst motion and capillary fingering were observed for low capillary numbers due to the domination of capillary forces. It was discovered that breakthrough time and capillary number bear a log-log scale linear relationship, based on which a generalized correlation between oil travel distance x and time t was found empirically.

Application of calcium oxide (CaO, heated scallop-shell powder) for the reduction of Listeria monocytogenes biofilms on eggshell surfaces.

PubMed

Park, S Y; Jung, S-J; Kang, I; Ha, S-D

2018-05-01

This study investigated bactericidal activity of 0.05 to 0.50% calcium oxide (CaO) against planktonic cells in tryptic soy broth (TSB) and biofilms of Listeria monocytogenes on eggshell surfaces. The bactericidal activity of CaO against planktonic cells and biofilms of L. monocytogens significantly (P < 0.05) increased log reductions with increasing concentrations of CaO. Exposure to 0.05 to 0.50% CaO for one min reduced planktonic cells in TSB cell suspensions by 0.47 to 3.86 log10CFU/mL and biofilm cells on the shell surfaces by 0.14 to 2.32 log10CFU/cm2. The Hunter colors of eggshells ("L" for lightness, "a" for redness, and "b" for yellowness), shell thickness (puncture force), and sensory quality (egg taste and yolk color) were not changed by 0.05 to 0.50% CaO treatment. The nonlinear Weibull model was used to calculate CR = 3 values as the CaO concentration of 3 log (99.9%) reduction for planktonic cells (R2 = 0.96, RMSE = 0.26) and biofilms (R2 = 0.95, RMSE = 0.18) of L. monocytogens. The CR = 3 value, 0.31% CaO for planktonic cells, was significantly (P < 0.05) lower than 0.57% CaO for biofilms. CaO could be an alternative disinfectant to reduce planktonic cells and biofilms L. monocytogenes on eggshell surface in egg processing plants.

Sludge-grown algae for culturing aquatic organisms: Part I. Algal growth in sludge extracts

NASA Astrophysics Data System (ADS)

Hung, K. M.; Chiu, S. T.; Wong, M. H.

1996-05-01

This project is aimed at studying the feasibility of using sewage sludge to prepare culture media for microalgae ( Chlorella-HKBU) and the use of the sludge-grown algae as a feed for some aquatic organisms. Part I of the project included results on preparing sludge extracts and their use on algal culture. By comparing two culturing techniques, “aeration” and “shaking,” it was noted that both lag and log phases were shortened in the aeration system. A subsequent experiment noted that algal growth subject to aeration rates of 1.0 and 1.5 liters/min had similar lag and log phases. In addition, both aeration rates had a significantly higher ( P < 0.05) final cell density than that of 0.5 liters/min. A detailed study on the variation of growth conditions on the algal growth was done. The results indicated that pH values of all the cultures declined below 5 at day 12. The removal rates of ammonia N ranged from 62% to 70%. The sludge-grown algae contained a rather substantial amount of heavy metals (µg/g): Zn 289 581, Cu 443 682, Ni 310 963, Mn 96 126, Cr 25 118, and Fe 438 653. This implied that the rather high levels of heavy metals may impose adverse effects on higher trophic organisms.

HIV-1 RNA May Decline More Slowly in Semen than in Blood following Initiation of Efavirenz-Based Antiretroviral Therapy

PubMed Central

Graham, Susan M.; Holte, Sarah E.; Dragavon, Joan A.; Ramko, Kelly M.; Mandaliya, Kishor N.; McClelland, R. Scott; Peshu, Norbert M.; Sanders, Eduard J.; Krieger, John N.; Coombs, Robert W.

2012-01-01

Objectives Antiretroviral therapy (ART) decreases HIV-1 RNA levels in semen and reduces sexual transmission from HIV-1-infected men. Our objective was to study the time course and magnitude of seminal HIV-1 RNA decay after initiation of efavirenz-based ART among 13 antiretroviral-naïve Kenyan men. Methods HIV-1 RNA was quantified (lower limit of detection, 120 copies/mL) in blood and semen at baseline and over the first month of ART. Median log10 HIV-1 RNA was compared at each time-point using Wilcoxon Signed Rank tests. Perelson’s two-phase viral decay model and nonlinear random effects were used to compare decay rates in blood and semen. Results Median baseline HIV-1 RNA was 4.40 log10 copies/mL in blood (range, 3.20–5.08 log10 copies/mL) and 3.69 log10 copies/mL in semen (range, <2.08–4.90 log10 copies/mL). The median reduction in HIV-1 RNA by day 28 was 1.90 log10 copies/mL in blood (range, 0.56–2.68 log10 copies/mL) and 1.36 log10 copies/mL in semen (range, 0–2.66 log10 copies/mL). ART led to a decrease from baseline by day 7 in blood and day 14 in semen (p = 0.005 and p = 0.006, respectively). The initial modeled decay rate was slower in semen than in blood (p = 0.06). There was no difference in second-phase decay rates between blood and semen. Conclusions Efavirenz-based ART reduced HIV-1 RNA levels more slowly in semen than in blood. Although this difference was of borderline significance in this small study, our observations suggest that there is suboptimal suppression of seminal HIV-1 RNA for some men in the early weeks of treatment. PMID:22912795

Caspar Creek Phase II: Discovering how watersheds respond to logging

Treesearch

Anonymous

1993-01-01

For the past three decades, researchers from the Pacific Southwest Research Station's Redwood Sciences Laboratory in Arcata, California, and the California Department of Forestry and Fire Protection (CDF), Jackson Demonstration Forest near Fort Bragg, have been studying the effects of logging northern California watersheds. The findings have identified the extent...

Selection, Identification, and Binding Mechanism Studies of an ssDNA Aptamer Targeted to Different Stages of E. coli O157:H7.

PubMed

Zou, Ying; Duan, Nuo; Wu, Shijia; Shen, Mofei; Wang, Zhouping

2018-06-06

Enterohemorrhagic Escherichia coli O157:H7 ( E. coli O157:H7) is known as an important food-borne pathogen related to public health. In this study, aptamers which could bind to different stages of E. coli O157:H7 (adjustment phase, log phase, and stationary phase) with high affinity and specificity were obtained by the whole cell-SELEX method through 14 selection rounds including three counter-selection rounds. Altogether, 32 sequences were obtained, and nine families were classified to select the optimal aptamer. To analyze affinity and specificity by flow cytometer, an ssDNA aptamer named Apt-5 was picked out as the optimal aptamer that recognizes different stages of E. coli O157:H7 specifically with the K d value of 9.04 ± 2.80 nM. In addition, in order to study the binding mechanism, target bacteria were treated by proteinase K and trypsin, indicating that the specific binding site is not protein on the cell membrane. Furthermore, when we treated E. coli O157:H7 with EDTA, the result showed that the binding site might be lipopolysaccharide (LPS) on the outer membrane of E. coli O157:H7.

Determination of drug lipophilicity by phosphatidylcholine-modified microemulsion high-performance liquid chromatography.

PubMed

Xuan, Xueyi; Xu, Liyuan; Li, Liangxing; Gao, Chongkai; Li, Ning

2015-07-25

A new biomembrane-mimetic liquid chromatographic method using a C8 stationary phase and phosphatidylcholine-modified (PC-modified) microemulsion mobile phase was used to estimate unionized and ionized drugs lipophilicity expressed as an n-octanol/water partition coefficient (logP and logD). The introduction of PC into sodium dodecyl sulfate (SDS) microemulsion yielded a good correlation between logk and logD (R(2)=0.8). The optimal composition of the PC-modified microemulsion liquid chromatography (PC-modified MELC) mobile phase was 0.2% PC-3.0% SDS-6.0% n-butanol-0.8% ethyl acetate-90.0% water (pH 7.0) for neutral and ionized molecules. The interactions between the analytes and system described by this chromatographic method is more similar to biological membrane than the n-octanol/water partition system. The result in this paper suggests that PC-modified MELC can serve as a possible alternative to the shake-flask method for high-throughput unionized and ionized drugs lipophilicity determination and simulation of biological processes. Copyright © 2015 Elsevier B.V. All rights reserved.

Efficient natural defense mechanisms against Listeria monocytogenes in T and B cell-deficient allogeneic bone marrow radiation chimeras. Preactivated macrophages are the main effector cells in an early phase after bone marrow transfer

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

Roesler, J.; Groettrup, E.B.; Baccarini, M.

1989-09-01

Radiation chimeras in the early phase after bone marrow transplantation are a good model to study the efficiency of the body's nonspecific defense system represented by macrophages (M phi), polymorphonuclear cells (PMN), and NK cells. These cell types are present in large numbers in spleen and liver at that time, whereas the specific immune system represented by T and B cells is functionally deficient. We previously reported enhanced activities in vitro of M phi (and PMN) from recipient animals in an early phase after allogeneic bone marrow transfer. We here demonstrate that these activities result in enhanced spontaneous resistance againstmore » Listeria monocytogenes in vivo: CFU of L. monocytogenes in spleen and liver 48 h after infection were about 1 or 2 to 4 log steps less than in untreated control mice of donor or host haplotype. This enhanced resistance decreased over the 4-mo period after marrow transfer. Preactivated M phi were identified as the most important effector cells. Isolated from spleen and peritoneal cavity, they performed enhanced killing of phagocytosed Listeria. Such preactivated M phi occurred in recipient animals after transfer of allogeneic but not of syngeneic bone marrow. The precise mechanism of M phi activation in the allogeneic radiation chimera in the complete absence of any detectable T cell function is not clear at present. However, these preactivated M phi display an important protective effect against L. monocytogenes: chimeras could eliminate Listeria without acquisition of positive delayed-type sensitivity when infected with 10(3) bacteria. An inoculum of 5 . 10(3) L. monocytogenes resulted either in prolonged survival compared with normal mice of the recipient haplotype or in definitive survival accompanied by a positive delayed-type sensitivity.« less

Oman Drilling Project Phase I Borehole Geophysical Survey

NASA Astrophysics Data System (ADS)

Matter, J. M.; Pezard, P. A.; Henry, G.; Brun, L.; Célérier, B.; Lods, G.; Robert, P.; Benchikh, A. M.; Al Shukaili, M.; Al Qassabi, A.

2017-12-01

The Oman Drilling Project (OmanDP) drilled six holes at six sites in the Samail ophiolite in the southern Samail and Tayin massifs. 1500-m of igneous and metamorphic rocks were recovered at four sites (GT1, GT2, GT3 and BT1) using wireline diamond core drilling and drill cuttings at two sites (BA1, BA2) using air rotary drilling, respectively. OmanDP is an international collaboration supported by the International Continental Scientific Drilling Program, the Deep Carbon Observatory, NSF, NASA, IODP, JAMSTEC, and the European, Japanese, German and Swiss Science Foundations, and with in-kind support in Oman from Ministry of Regional Municipalities and Water Resources, Public Authority of Mining, Sultan Qaboos University and the German University of Technology. A comprehensive borehole geophysical survey was conducted in all the OmanDP Phase I boreholes shortly after drilling in April 2017. Following geophysical wireline logs, using slim-hole borehole logging equipment provided and run by the Centre National De La Recherche Scientifique (CNRS) and the Université de Montpellier/ Géosciences Montpellier, and logging trucks from the Ministry of Regional Municipalities and Water Resources, were collected in most of the holes: electrical resistivity (dual laterolog resistivity, LLd and LLs), spectral gamma ray (K, U, and Th contents), magnetic susceptibility, total natural gamma ray, full waveform sonic (Vp and Vs), acoustic borehole wall imaging, optical borehole wall imaging, borehole fluid parameters (pressure, temperature, electrical conductivity, dissolved oxygen, pH, redox potential, non-polarized spontaneous electrical potential), and caliper (borehole diameter). In addition, spinner flowmeter (downhole fluid flow rate along borehole axis) and heatpulse flow meter logs (dowhole fluid flow rate along borehole axis) were collected in BA1 to characterize downhole fluid flow rates along borehole axis. Unfortuantely, only incomplete wireline logs are available for holes BT1, GT3 and BA2 due to hole obstruction (e.g. collapsed borehole wall). Results from the geophysical survey including preliminary log analysis will be presented for each OmanDP Phase I borehole.

Measured and Modeled Toxicokinetics in Cultured Fish Cells and Application to In Vitro - In Vivo Toxicity Extrapolation

PubMed Central

Stadnicka-Michalak, Julita; Tanneberger, Katrin; Schirmer, Kristin; Ashauer, Roman

2014-01-01

Effect concentrations in the toxicity assessment of chemicals with fish and fish cells are generally based on external exposure concentrations. External concentrations as dose metrics, may, however, hamper interpretation and extrapolation of toxicological effects because it is the internal concentration that gives rise to the biological effective dose. Thus, we need to understand the relationship between the external and internal concentrations of chemicals. The objectives of this study were to: (i) elucidate the time-course of the concentration of chemicals with a wide range of physicochemical properties in the compartments of an in vitro test system, (ii) derive a predictive model for toxicokinetics in the in vitro test system, (iii) test the hypothesis that internal effect concentrations in fish (in vivo) and fish cell lines (in vitro) correlate, and (iv) develop a quantitative in vitro to in vivo toxicity extrapolation method for fish acute toxicity. To achieve these goals, time-dependent amounts of organic chemicals were measured in medium, cells (RTgill-W1) and the plastic of exposure wells. Then, the relation between uptake, elimination rate constants, and log KOW was investigated for cells in order to develop a toxicokinetic model. This model was used to predict internal effect concentrations in cells, which were compared with internal effect concentrations in fish gills predicted by a Physiologically Based Toxicokinetic model. Our model could predict concentrations of non-volatile organic chemicals with log KOW between 0.5 and 7 in cells. The correlation of the log ratio of internal effect concentrations in fish gills and the fish gill cell line with the log KOW was significant (r>0.85, p = 0.0008, F-test). This ratio can be predicted from the log KOW of the chemical (77% of variance explained), comprising a promising model to predict lethal effects on fish based on in vitro data. PMID:24647349

Use of Log-Linear Models in Classification Problems.

DTIC Science & Technology

1981-12-01

polynomials. The second example involves infant hypoxic trauma, and many cells are empty. The existence conditions are used to find a model for which esti...mates of cell frequencies exist and are in good agreement with the ob- served data. Key Words: Classification problem, log-difference models, minimum 8...variates define k states, which are labeled consecutively. Thus, while MB define cells in their tables by an I-vector Z, we simply take Z to be a

The impact of tropical forest logging and oil palm agriculture on the soil microbiome.

PubMed

Tripathi, Binu M; Edwards, David P; Mendes, Lucas William; Kim, Mincheol; Dong, Ke; Kim, Hyoki; Adams, Jonathan M

2016-05-01

Selective logging and forest conversion to oil palm agriculture are rapidly altering tropical forests. However, functional responses of the soil microbiome to these land-use changes are poorly understood. Using 16S rRNA gene and shotgun metagenomic sequencing, we compared composition and functional attributes of soil biota between unlogged, once-logged and twice-logged rainforest, and areas converted to oil palm plantations in Sabah, Borneo. Although there was no significant effect of logging history, we found a significant difference between the taxonomic and functional composition of both primary and logged forests and oil palm. Oil palm had greater abundances of genes associated with DNA, RNA, protein metabolism and other core metabolic functions, but conversely, lower abundance of genes associated with secondary metabolism and cell-cell interactions, indicating less importance of antagonism or mutualism in the more oligotrophic oil palm environment. Overall, these results show a striking difference in taxonomic composition and functional gene diversity of soil microorganisms between oil palm and forest, but no significant difference between primary forest and forest areas with differing logging history. This reinforces the view that logged forest retains most features and functions of the original soil community. However, networks based on strong correlations between taxonomy and functions showed that network complexity is unexpectedly increased due to both logging and oil palm agriculture, which suggests a pervasive effect of both land-use changes on the interaction of soil microbes. © 2016 John Wiley & Sons Ltd.

The advantages of logarithmically scaled data for electromagnetic inversion

NASA Astrophysics Data System (ADS)

Wheelock, Brent; Constable, Steven; Key, Kerry

2015-06-01

Non-linear inversion algorithms traverse a data misfit space over multiple iterations of trial models in search of either a global minimum or some target misfit contour. The success of the algorithm in reaching that objective depends upon the smoothness and predictability of the misfit space. For any given observation, there is no absolute form a datum must take, and therefore no absolute definition for the misfit space; in fact, there are many alternatives. However, not all misfit spaces are equal in terms of promoting the success of inversion. In this work, we appraise three common forms that complex data take in electromagnetic geophysical methods: real and imaginary components, a power of amplitude and phase, and logarithmic amplitude and phase. We find that the optimal form is logarithmic amplitude and phase. Single-parameter misfit curves of log-amplitude and phase data for both magnetotelluric and controlled-source electromagnetic methods are the smoothest of the three data forms and do not exhibit flattening at low model resistivities. Synthetic, multiparameter, 2-D inversions illustrate that log-amplitude and phase is the most robust data form, converging to the target misfit contour in the fewest steps regardless of starting model and the amount of noise added to the data; inversions using the other two data forms run slower or fail under various starting models and proportions of noise. It is observed that inversion with log-amplitude and phase data is nearly two times faster in converging to a solution than with other data types. We also assess the statistical consequences of transforming data in the ways discussed in this paper. With the exception of real and imaginary components, which are assumed to be Gaussian, all other data types do not produce an expected mean-squared misfit value of 1.00 at the true model (a common assumption) as the errors in the complex data become large. We recommend that real and imaginary data with errors larger than 10 per cent of the complex amplitude be withheld from a log-amplitude and phase inversion rather than retaining them with large error-bars.

Use of NAD(P)H fluorescence measurement for on-line monitoring of metabolic state of Azohydromonas australica in poly(3-hydroxybutyrate) production.

PubMed

Gahlawat, Geeta; Srivastava, Ashok K

2013-02-01

Culture fluorescence measurement is an indirect and non-invasive method of biomass estimation to assess the metabolic state of the microorganism in a fermentation process. In the present investigation, NAD(P)H fluorescence has been used for on-line in situ characterization of metabolic changes occurring during different phases of batch cultivation of Azohydromonas australica in growth associated poly(3-hydroxybutyrate) or PHB production. A linear correlation between biomass concentration and net NAD(P)H fluorescence was obtained during early log phase (3-12 h) and late log phase (24-39 h) of PHB fermentation. After 12 h (mid log phase) cultivation PHB accumulation shot up and a drop in culture fluorescence was observed which synchronously exhibited continuous utilization of NAD(P)H for the synthesis of biomass and PHB formation simultaneously. A decrease in the observed net fluorescence value was observed again towards the end of fermentation (at 39 h) which corresponded very well with the culture starvation and substrate depletion towards the end of cultivation inside the bioreactor. It was therefore concluded that NAD(P)H fluorescence measurements could be used for indication of the time of fresh nutrient (substrate) feed during substrate limitation to further enhance the PHB production.

Autologous dendritic cells transfected with prostate-specific antigen RNA stimulate CTL responses against metastatic prostate tumors

PubMed Central

Heiser, Axel; Coleman, Doris; Dannull, Jens; Yancey, Donna; Maurice, Margaret A.; Lallas, Costas D.; Dahm, Philipp; Niedzwiecki, Donna; Gilboa, Eli; Vieweg, Johannes

2002-01-01

Autologous dendritic cells (DCs) transfected with mRNA encoding prostate-specific antigen (PSA) are able to stimulate potent, T cell–mediated antitumor immune responses in vitro. A phase I trial was performed to evaluate this strategy for safety, feasibility, and efficacy to induce T cell responses against the self-protein PSA in patients with metastatic prostate cancer. In 13 study subjects, escalating doses of PSA mRNA–transfected DCs were administered with no evidence of dose-limiting toxicity or adverse effects, including autoimmunity. Induction of PSA-specific T cell responses was consistently detected in all patients, suggesting in vivo bioactivity of the vaccine. Vaccination was further associated with a significant decrease in the log slope PSA in six of seven subjects; three patients that could be analyzed exhibited a transient molecular clearance of circulating tumor cells. The demonstration of vaccine safety, successful in vivo induction of PSA-specific immunity, and impact on surrogate clinical endpoints provides a scientific rationale for further clinical investigation of RNA-transfected DCs in the treatment of human cancer. PMID:11828001

Lethality of a Heat- and Phosphate-Catalyzed Glucose By-Product to Escherichia coli O157:H7 and Partial Protection Conferred by the rpoS Regulon

PubMed Central

Byrd, Jeffrey J.; Cheville, Ann M.; Bose, Jeffrey L.; Kaspar, Charles W.

1999-01-01

A by-product of glucose produced during sterilization (121°C, 15 lb/in2, 15 min) at neutral pH and in the presence of phosphate (i.e., phosphate-buffered saline) was bactericidal to Escherichia coli O157:H7 (ATCC 43895). Other six-carbon (fructose and galactose) and five-carbon (arabinose, ribose, and xylose) reducing sugars also produced a toxic by-product under the same conditions. Fructose and the five-carbon sugars yielded the most bactericidal activity. Glucose concentrations of 1% (wt/vol) resulted in a 99.9% decline in the CFU of stationary-phase cells per milliliter in 2 days at 25°C. An rpoS mutant (pRR10::rpoS) of strain 43895 (FRIK 816-3) was significantly (P < 0.001) more sensitive to the glucose-phosphate by-product than the parent strain, as glucose concentrations from 0.05 to 0.25% resulted in a 2- to 3-log10 reduction in CFU per milliliter in 2 days at 25°C. Likewise, log-phase cells of the wild-type strain, 43895, were significantly more sensitive (P < 0.001) to the glucose-phosphate by-product than were stationary-phase cells, which is consistent with the stability of rpoS and the regulation of rpoS-regulated genes. The bactericidal effect of the glucose-phosphate by-product was reduced when strains ATCC 43895 and FRIK 816-3 were incubated at a low temperature (4°C). Also, growth in glucose-free medium (i.e., nutrient broth) did not alleviate the sensitivity to the glucose-phosphate by-product and excludes the possibility of substrate-accelerated death as the cause of the bactericidal effect observed. The glucose-phosphate by-product was also bactericidal to Salmonella typhimurium, Shigella dysenteriae, and a Klebsiella sp. Attempts to identify the glucose-phosphate by-product were unsuccessful. These studies demonstrate the production of a glucose-phosphate by-product bactericidal to E. coli O157:H7 and the protective effects afforded by rpoS-regulated gene products. Additionally, the detection of sublethally injured bacteria may be compromised by the presence of this by-product in recovery media. PMID:10347019

Thermochemical properties of silver tellurides including empressite (AgTe) and phase diagrams for Ag-Te and Ag-Te-O

NASA Astrophysics Data System (ADS)

Voronin, Mikhail V.; Osadchii, Evgeniy G.; Brichkina, Ekaterina A.

2017-10-01

This study compiles original experimental and literature data on the thermodynamic properties (ΔfG°, S°, ΔfH°) of silver tellurides (α-Ag2Te, β-Ag2Te, Ag1.9Te, Ag5Te3, AgTe) obtained by the method of solid-state galvanic cell with the RbAg4I5 and AgI solid electrolytes. The thermodynamic data for empressite (AgTe, pure fraction from Empress Josephine Mine, Colorado USA) have been obtained for the first time by the electrochemical experiment with the virtual reaction Ag + Te = AgTe. The Ag-Te phase diagrams in the T - x and log fTe2 (gas) - 1/ T coordinates have been refined, and the ternary Ag-Te-O diagrams with Ag-Te-TeO2 (paratellurite) composition range have been calculated.

Bacterial Associates Modify Growth Dynamics of the Dinoflagellate Gymnodinium catenatum

PubMed Central

Bolch, Christopher J. S.; Bejoy, Thaila A.; Green, David H.

2017-01-01

Marine phytoplankton cells grow in close association with a complex microbial associate community known to affect the growth, behavior, and physiology of the algal host. The relative scale and importance these effects compared to other major factors governing algal cell growth remain unclear. Using algal-bacteria co-culture models based on the toxic dinoflagellate Gymnodinium catenatum, we tested the hypothesis that associate bacteria exert an independent effect on host algal cell growth. Batch co-cultures of G. catenatum were grown under identical environmental conditions with simplified bacterial communities composed of one-, two-, or three-bacterial associates. Modification of the associate community membership and complexity induced up to four-fold changes in dinoflagellate growth rate, equivalent to the effect of a 5°C change in temperature or an almost six-fold change in light intensity (20–115 moles photons PAR m-2 s-1). Almost three-fold changes in both stationary phase cell concentration and death rate were also observed. Co-culture with Roseobacter sp. DG874 reduced dinoflagellate exponential growth rate and led to a more rapid death rate compared with mixed associate community controls or co-culture with either Marinobacter sp. DG879, Alcanivorax sp. DG881. In contrast, associate bacteria concentration was positively correlated with dinoflagellate cell concentration during the exponential growth phase, indicating growth was limited by supply of dinoflagellate-derived carbon. Bacterial growth increased rapidly at the onset of declining and stationary phases due to either increasing availability of algal-derived carbon induced by nutrient stress and autolysis, or at mid-log phase in Roseobacter co-cultures potentially due to the onset of bacterial-mediated cell lysis. Co-cultures with the three bacterial associates resulted in dinoflagellate and bacterial growth dynamics very similar to more complex mixed bacterial community controls, suggesting that three-way co-cultures are sufficient to model interaction and growth dynamics of more complex communities. This study demonstrates that algal associate bacteria independently modify the growth of the host cell under non-limiting growth conditions and supports the concept that algal–bacterial interactions are an important structuring mechanism in phytoplankton communities. PMID:28469613

Image analysis for the automated estimation of clonal growth and its application to the growth of smooth muscle cells.

PubMed

Gavino, V C; Milo, G E; Cornwell, D G

1982-03-01

Image analysis was used for the automated measurement of colony frequency (f) and colony diameter (d) in cultures of smooth muscle cells, Initial studies with the inverted microscope showed that number of cells (N) in a colony varied directly with d: log N = 1.98 log d - 3.469 Image analysis generated the complement of a cumulative distribution for f as a function of d. The number of cells in each segment of the distribution function was calculated by multiplying f and the average N for the segment. These data were displayed as a cumulative distribution function. The total number of colonies (fT) and the total number of cells (NT) were used to calculate the average colony size (NA). Population doublings (PD) were then expressed as log2 NA. Image analysis confirmed previous studies in which colonies were sized and counted with an inverted microscope. Thus, image analysis is a rapid and automated technique for the measurement of clonal growth.

Evaluation of geophysical logs, Phase II, at Willow Grove Naval Air Station Joint Reserve Base, Montgomery County, Pennsylvania

USGS Publications Warehouse

Conger, Randall W.

1999-01-01

Between March and April 1998, the U.S. Navy contracted Tetra Tech NUS Inc., to drill two monitor wells in the Stockton Formation at the Willow Grove Naval Air Station Joint Reserve Base, Horsham Township, Montgomery County, Pa. The wells MG-1634 and MG-1635 were installed to monitor water levels and sample contaminants in the shallow, intermediate, and deep water-producing zones of the fractured bedrock. Chemical analyses of the samples will help determine the horizontal and vertical distribution of any contaminated ground water migrating from known contaminant sources. Wells were drilled near the Fire Training Area (Site 5). Depths of all boreholes range from 69 to 149 feet below land surface. The U.S. Geological Survey conducted borehole geophysical logging and video surveys to identify water-producing zones in newly drilled monitor wells MG-1634 and MG-1635 and in wells MG-1675 and MG-1676. The logging was conducted from March 5, 1998, to April 16, 1998. This work is a continuation of the Phase I work. Caliper logs and video surveys were used to locate fractures; inflections on fluid-temperature and fluid-resistivity logs were used to locate possible water-producing fractures. Heatpulse-flowmeter measurements were used to verify the locations of water-producing or water-receiving zones and to measure rates of flow between water-bearing fractures. Single-point-resistance and natural-gamma logs provided information on stratigraphy. After interpretation of geophysical logs, video surveys, and driller's notes, wells MG-1634 and MG-1635 were screened such that water-levels fluctuations could be monitored and discrete water samples collected from one or more water-producing zones in each borehole.

Phase 1 drilling operations at the Magma Energy Exploratory Well (LVF 51-20)

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

Finger, J.T.; Jacobson, R.D.

1990-12-01

This report describes the Phase 1 drilling operations for the Magma Energy Exploratory Well near Mammoth Lakes, California. An important part of the Department of Energy's Magma Energy Program, this well is designed to reach an ultimate depth of 20,000 feet or a bottomhole temperature of 500{degree}C, whichever comes first. There will be four drilling phases, at least a year apart, with scientific investigations in the borehole between the drilling intervals. Phase 1 of this project resulted in a 20 inch cased hole to 2558 feet, with 185 feet of coring beyond that. This document comprises a narrative of themore » daily activities, copies of the daily mud and lithologic reports, time breakdowns of rig activities, inventories of lost circulation materials, temperature logs of the cored hole, and a strip chart mud log. 2 figs.« less

Evaluation of geophysical logs, Phase II, November 1998 to May 1999, at Crossley Farms Superfund Site, Berks County, Pennsylvania

USGS Publications Warehouse

Conger, Randall W.

2000-01-01

Between November 1998 and May 1999, geophysical logging was conducted in 29 boreholes at the Crossley Farms Superfund Site, Hereford Township, Berks County, Pa., to determine the fluidproducing zones, fluid-receiving zones, zones of vertical borehole flow, and casing depth. The wells range in depth from 96 to 500 feet below land surface. Gamma logs only were collected in three bedrock wells. The geophysical logging determined the placement of well screens and packers, which allow monitoring and sampling of water-bearing zones in the fractured bedrock so that the horizontal and vertical distribution of contaminated ground water migrating from known sources could be determined. Geophysical logging included collection of caliper, video, fluid-temperature, fluid-resistivity, single-point-resistance, natural-gamma, fluid-flow, and acoustic-televiewer logs. Caliper and video logs were used to locate fractures, joints, and weathered zones. Inflections on fluidtemperature and fluid-resistivity logs indicated possible water-bearing fractures, and flowmeter measurements verified these locations. Single-point-resistance and natural-gamma logs provided information on stratigraphy. After interpretation of geophysical, video logs, and drillers notes, 24 of the wells were reconstructed such that water levels can be monitored and water samples collected from discrete water-bearing fractures in each well.

Effect of cobalt doping on structural and dielectric properties of nanocrystalline LaCrO3

NASA Astrophysics Data System (ADS)

Zarrin, Naima; Husain, Shahid

2018-05-01

Pure and Co doped Lanthanum chromite (LaCrO3) nanoparticles, LaCr1-xCoxO3 (0≤x≤0.3), have been synthesized through sol-gel process and their structural, morphological and dielectric properties have been studied. X ray diffraction patterns reveal that the samples are in single phase having orthorhombic structure with Pnma space group. Structural parameters are refined by Rietveld refinement using Fullprof software. Lattice parameters and unit cell volume are found to decrease with increase in Co doping. Crystallite size is calculated using Scherrer equation and is also found to decrease with increase in Co concentration. Surface morphology is examined using SEM-EDX analysis, which confirms the formation of regular and homogeneous samples without any impurities. The value of dielectric constant (ɛ') decreases with the increase in frequency while it enhances with the increase in Co concentration. The log (ɛ'×f) versus log (f) graphs have been plotted to verify the universal dielectric response (UDR) model. All the samples follow UDR model in the low frequency range.

Immobilization of infant fecal microbiota and utilization in an in vitro colonic fermentation model.

PubMed

Cinquin, C; Le Blay, G; Fliss, I; Lacroix, C

2004-07-01

Bacteria isolated from infant feces were immobilized in polysaccharide gel beads (2.5% gellan gum, 0.25% xanthan gum) using a two-phase dispersion process. A 52-day continuous culture was carried out in a single-stage chemostat containing precolonized beads and fed with a medium formulated to approximate the composition of infant chyme. Different dilution rates and pH conditions were tested to simulate the proximal (PCS), transverse (TCS), and distal (DCS) colons. Immobilization preserved all nine bacterial groups tested with survival rates between 3 and 56%. After 1 week fermentation, beads were highly colonized with all populations tested (excepted Staphylococcus spp. present in low numbers), which remained stable throughout the 7.5 weeks of fermentation, with variations below 1 log unit. However, free-cell populations in the circulating liquid medium, produced by immobilized cell growth, cell-release activity from gel beads, and free-cell growth, were altered considerably by culture conditions. Compared to the stabilization period, PCS was characterized by a considerable and rapid increase in Bifidobacterium spp. concentrations (7.4 to 9.6 log CFU/mL), whereas Bifidobacterium spp., Lactobacillus spp., and Clostridium spp. concentrations decreased and Staphylococcus spp. and coliforms increased during TCS and DCS. Under pseudo-steady-state conditions, the community structure developed in the chemostat reflected the relative proportions of viable bacterial numbers and metabolites generally encountered in infant feces. This work showed that a complex microbiota such as infant fecal bacteria can be immobilized and used in a continuous in vitro intestinal fermentation model to reproduce the high bacterial concentration and bacterial diversity of the feces inoculum, at least at the genera level, with a high stability during long-term experiment.

Viral dynamics and CD4+ T cell counts in subtype C human immunodeficiency virus type 1-infected individuals from southern Africa.

PubMed

Gray, Clive M; Williamson, Carolyn; Bredell, Helba; Puren, Adrian; Xia, Xiaohua; Filter, Ruben; Zijenah, Lynn; Cao, Huyen; Morris, Lynn; Vardas, Efthyia; Colvin, Mark; Gray, Glenda; McIntyre, James; Musonda, Rosemary; Allen, Susan; Katzenstein, David; Mbizo, Mike; Kumwenda, Newton; Taha, Taha; Karim, Salim Abdool; Flores, Jorge; Sheppard, Haynes W

2005-04-01

Defining viral dynamics in natural infection is prognostic of disease progression and could prove to be important for vaccine trial design as viremia may be a likely secondary end point in phase III HIV efficacy trials. There are limited data available on the early course of plasma viral load in subtype C HIV-1 infection in Africa. Plasma viral load and CD4+ T cell counts were monitored in 51 recently infected subjects for 9 months. Individuals were recruited from four southern African countries: Zambia, Malawi, Zimbabwe, and South Africa and the median estimated time from seroconversion was 8.9 months (interquartile range, 5.7-14 months). All were infected with subtype C HIV-1 and median viral loads, measured using branched DNA, ranged from 3.82-4.02 log10 RNA copies/ml from 2-24 months after seroconversion. Viral loads significantly correlated with CD4+ cell counts (r=-0.5, p<0.0001; range, 376-364 cells/mm3) and mathematical modeling defined a median set point of 4.08 log10 (12 143 RNA copies/ml), which was attained approximately 17 months after seroconversion. Comparative measurements using three different viral load platforms (bDNA, Amplicor, and NucliSens) confirmed that viremia in subtype C HIV-1-infected individuals within the first 2 years of infection did not significantly differ from that found in early subtype B infection. In conclusion, the course of plasma viremia, as described in this study, will allow a useful baseline comparator for understanding disease progression in an African setting and may be useful in the design of HIV-1 vaccine trials in southern Africa.

An in vivo requirement for the mediator subunit med14 in the maintenance of stem cell populations.

PubMed

Burrows, Jeffrey T A; Pearson, Bret J; Scott, Ian C

2015-04-14

The Mediator complex has recently been shown to be a key player in the maintenance of embryonic and induced pluripotent stem cells. However, the in vivo consequences of loss of many Mediator subunits are unknown. We identified med14 as the gene affected in the zebrafish logelei (log) mutant, which displayed a morphological arrest by 2 days of development. Surprisingly, microarray analysis showed that transcription was not broadly affected in log mutants. Indeed, log cells transplanted into a wild-type environment were able to survive into adulthood. In planarians, RNAi knockdown demonstrated a requirement for med14 and many other Mediator components in adult stem cell maintenance and regeneration. Multiple stem/progenitor cell populations were observed to be reduced or absent in zebrafish med14 mutant embryos. Taken together, our results show a critical, evolutionarily conserved, in vivo function for Med14 (and Mediator) in stem cell maintenance, distinct from a general role in transcription. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Controlling attachment and growth of Listeria monocytogenes in polyvinyl chloride model floor drains using a peroxide chemical, chitosan-arginine, or heat.

PubMed

Berrang, Mark E; Hofacre, Charles L; Frank, Joseph F

2014-12-01

Listeria monocytogenes can colonize a poultry processing plant as a resident in floor drains. Limiting growth and attachment to drain surfaces may help lessen the potential for cross-contamination of product. The objective of this study was to compare a hydrogen peroxide-peroxyacetic acid-based chemical to chitosan-arginine or heat to prevent attachment of or destroy existing L. monocytogenes on the inner surface of model floor drains. L. monocytogenes was introduced to result in about 10(9) planktonic and attached cells within untreated polyvinyl chloride model drain pipes. Treatments (0.13 % peroxide-based sanitizer, 0.1 % chitosan-arginine, or 15 s of hot water at 95 to 100°C) were applied immediately after inoculation or after 24 h of incubation. Following treatment, all pipes were incubated for an additional 24 h; planktonic and attached cells were enumerated by plate count. All treatments significantly (P < 0.05) lowered numbers of planktonic and attached cells recovered. Chitosan-arginine resulted in approximately a 6-log reduction in planktonic cells when applied prior to incubation and a 3-log reduction after the inoculum had a chance to grow. Both heat and peroxide significantly outperformed chitosan-arginine (8- to 9-log reduction) and were equally effective before and after incubation. Heat was the only treatment that eliminated planktonic L. monocytogenes. All treatments were less effective against attached cells. Chitosan-arginine provided about a 4.5-log decrease in attached cells when applied before incubation and no significant decrease when applied after growth. Like with planktonic cells, peroxide-peroxyacetic acid and heat were equally effective before or after incubation, causing decreases ranging from 7 to 8.5 log for attached L. monocytogenes. Applied at the most efficacious time, any of these techniques may lessen the potential for L. monocytogenes to remain as a long-term resident in processing plant floor drains.

Results of investigation at the Miravalles Geothermal Field, Costa Rica: Part 1, Well logging. Resultados de las investigaciones en el campo geotermico de Miravalles, Costa Rica: Parte 1, Registros de pozos (in EN;SP)

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

Dennis, B.R.; Lawton, R.G.; Kolar, J.D.

The well-logging operations performed in the Miravalles Geothermal Field in Costa Rica were conducted during two separate field trips. The Phase I program provided the deployment of a suite of high-temperature borehole instruments, including the temperature/rabbit, fluid sampler, and three-arm caliper in Well PGM-3. These same tools were deployed in Well PGM-10 along with an additional survey run with a combination fluid velocity/temperature/pressure instrument used to measure thermodynamic properties under flowing well conditions. The Phase II program complemented Phase I with the suite of tools deployed in Wells PGM-5, PGM-11, and PGM-12. 4 refs., 25 figs., 1 tab.

Three new defined proton affinities for polybasic molecules in the gas-phase: Proton microaffinity, proton macroaffinity and proton overallaffinity

NASA Astrophysics Data System (ADS)

Salehzadeh, Sadegh; Bayat, Mehdi

2006-08-01

A theoretical study on complete protonation of a series of tetrabasic molecules with general formula N[(CH 2) nNH 2][(CH 2) mNH 2][(CH 2) pNH 2] (tren, pee, ppe, tpt, epb and ppb) is reported. For first time, three kinds of gas-phase proton affinities for each polybasic molecule are defined as: 'proton microaffinity (PA n, i)', 'proton macroaffinity (PA)' and 'proton overall affinity ( PA)'. The variations of calculated logPA in the series of these molecules is very similar to that of their measured log Kn. There is also a good correlation between the calculated gas-phase proton macroaffinities and proton overallaffinities with corresponding equilibrium macroconstants and overall protonation constants in solution.

Current Log-Periodic View on Future World Market Development

NASA Astrophysics Data System (ADS)

Drożdż, S.; Kwapień, J.; Oświęcimka, P.; Speth, J.

2008-09-01

Applicability of the concept of financial log-periodicity is discussed and encouragingly verified for various phases of the world stock markets development in the period 2000-2010. In particular, a speculative forecasting scenario designed in the end of 2004, that properly predicted the world stock market increases in 2007, is updated by setting some more precise constraints on the time of duration of the present long-term equity market bullish phase. A termination of this phase is evaluated to occur in around November 2009. In particular, on the way towards this dead-line, a Spring-Summer 2008 increase is expected. On the precious metals market a forthcoming critical time signal is detected at the turn of March/April 2008 which marks a tendency for at least a serious correction to begin.

A new flexible DBD device for treating infected wounds: in vitro and ex vivo evaluation and comparison with a RF argon plasma jet

NASA Astrophysics Data System (ADS)

Boekema, B. K. H. L.; Vlig, M.; Guijt, D.; Hijnen, K.; Hofmann, S.; Smits, P.; Sobota, A.; van Veldhuizen, E. M.; Bruggeman, P.; Middelkoop, E.

2016-02-01

Cold plasma has been shown to provide a promising alternative antimicrobial treatment for wound healing. We developed and tested a flexible surface dielectric barrier discharge (DBD) and compared it to an argon gas based plasma jet operated remotely with a distance between plasma plume and sample of 8 mm. Tests were conducted using different models: on cultured cells, on ex vivo human skin and on bacteria (Pseudomonas aeruginosa) (on agar, in suspension, in collagen/elastin matrix or on ex vivo human skin), allowing us to directly compare bactericidal with safety aspects under identical conditions. Both plasma devices were highly efficient when used on bacteria in non-buffered solutions, but DBD was faster in reaching the maximum bacterial reduction. Treatment of bacteria on intact skin with DBD resulted in up to 6 log reductions in 3 min. The jet was far less efficient on intact skin. Even after 8 min treatment no more than 2 log reductions were obtained with the jet. Treatment of bacteria in burn wound models with DBD for 6 min resulted in a 4.5 log reduction. Even when using DBD for 6 min on infected burn wound models with colonizing or biofilm phase bacteria, the log reductions were 3.8 or 3.2 respectively. DBD plasma treatment for 6 min did not affect fibroblast viability, whereas a treatment for 8 min was detrimental. Similarly, treatment with DBD or plasma jet for 6 min did also not affect the metabolic activity of skin biopsies. After treatment for 8 min with DBD or plasma jet, 78% or 60% of activity in skin biopsies remained, respectively. Multiple treatments of in vitro burn wound models with surface DBD for 6 min or with plasma jet for 8 min did not affect re-epithelialization. With the flexible surface DBD plasma strip we were able to quickly inactivate large numbers of bacteria on and in skin. Under the same conditions, viability of skin cells or re-epithelialization was not affected. The DBD source has potential for treating larger wound areas.

Survival and growth of epidemically successful and nonsuccessful Salmonella enterica clones after freezing and dehydration.

PubMed

Müller, Karoline; Aabo, Søren; Birk, Tina; Mordhorst, Hanne; Bjarnadóttir, Björg; Agersø, Yvonne

2012-03-01

The spread of epidemically successful nontyphoidal Salmonella clones has been suggested as the most important cause of salmonellosis in industrialized countries. Factors leading to the emergence of success clones are largely unknown, but their ability to survive and grow after physical stress may contribute. During epidemiological studies, a mathematical model was developed that allowed estimation of a factor (q) accounting for the relative ability of Salmonella serovars with different antimicrobial resistances to survive in the food chain and cause human disease. Based on this q-factor, 26 Salmonella isolates were characterized as successful or nonsuccessful. We studied the survival and growth of stationary- and exponential-phase cells of these isolates after freezing for up to 336 days in minced meat. We also investigated survival and growth after dehydration at 10°C and 82% relative humidity (RH) and 25°C and 49% RH for 112 days. Stationary-phase cells were reduced by less than 1 log unit during 1 year of freezing, and growth was initiated with an average lag phase of 1.7 h. Survival was lower in exponentialphase cells, but lag phases tended to be shorter. High humidity and low temperature were less harmful to Salmonella than were low humidity and high temperature. Tolerance to adverse conditions was highest for Salmonella Infantis and one Salmonella Typhimurium U292 isolate and lowest for Salmonella Derby and one Salmonella Typhimurium DT170 isolate. Dehydration, in contrast to freezing, was differently tolerated by the Salmonella strains in this study, but tolerance to freezing and dehydration does not appear to contribute to the emergence of successful Salmonella clones.

Quantification of HER2/neu gene amplification by competitive pcr using fluorescent melting curve analysis.

PubMed

Lyon, E; Millson, A; Lowery, M C; Woods, R; Wittwer, C T

2001-05-01

Molecular detection methods for HER2/neu gene amplification include fluorescence in situ hybridization (FISH) and competitive PCR. We designed a quantitative PCR system utilizing fluorescent hybridization probes and a competitor that differed from the HER2/neu sequence by a single base change. Increasing twofold concentrations of competitor were coamplified with DNA from cell lines with various HER2/neu copy numbers at the HER2/neu locus. Competitor DNA was distinguished from the HER2/neu sequence by a fluorescent hybridization probe and melting curve analysis on a fluorescence-monitoring thermal cycler. The percentages of competitor to target peak areas on derivative fluorescence vs temperature curves were used to calculate copy number. Real-time monitoring of the PCR reaction showed comparable relative areas throughout the log phase and during the PCR plateau, indicating that only end-point detection is necessary. The dynamic range was over two logs (2000-250 000 competitor copies) with CVs < 20%. Three cell lines (MRC-5, T-47D, and SK-BR-3) were determined to have gene doses of 1, 3, and 11, respectively. Gene amplification was detected in 3 of 13 tumor samples and was correlated with conventional real-time PCR and FISH analysis. Use of relative peak areas allows gene copy numbers to be quantified against an internal competitive control in < 1 h.

Thermal inactivation of Escherichia coli O157:H7 in blade-tenderized beef steaks cooked on a commercial open-flame gas grill.

PubMed

Luchansky, John B; Porto-Fett, Anna C S; Shoyer, Bradley; Phebus, Randall K; Thippareddi, Harshavardhan; Call, Jeffrey E

2009-07-01

Beef subprimals were inoculated on the lean side with ca. 4.0 log CFU/g of a cocktail of rifampin-resistant (Rif(r)) Escherichia coli O157:H7 strains and then passed once through a mechanical blade tenderizer with the lean side facing upward. Inoculated subprimals that were not tenderized served as controls. Two core samples were removed from each of three tenderized subprimals and cut into six consecutive segments starting from the inoculated side. A total of six cores were also obtained from control subprimals, but only segment 1 (topmost) was sampled. Levels of E. coli O157:H7 recovered from segment 1 were 3.81 log CFU/g for the control subprimals and 3.36 log CFU/g for tenderized subprimals. The percentage of cells recovered in segment 2 was ca. 25-fold lower than levels recovered from segment 1, but E. coli O157:H7 was recovered from all six segments of the cores obtained from tenderized subprimals. In phase II, lean-side-inoculated (ca. 4.0 log CFU/g), single-pass tenderized subprimals were cut into steaks of various thicknesses (1.91 cm [0.75 in.], 2.54 cm [1.0 in.], and 3.18 cm [1.25 in.]) that were subsequently cooked on a commercial open-flame gas grill to internal temperatures of 48.8 degrees C (120 degrees F), 54.4 degrees C (130 degrees F), and 60 degrees C (140 degrees F). In general, regardless of temperature or thickness, we observed about a 2.6- to 4.2-log CFU/g reduction in pathogen levels following cooking. These data validate that cooking on a commercial gas grill is effective at eliminating relatively low levels of the pathogen that may be distributed throughout a blade-tenderized steak.

Gas/solid particulate phthalic esters (PAEs) in Masson pine (Pinus massoniana L.) needles and rhizosphere surface soils.

PubMed

Wang, Wen-xin; Fan, Chinbay Q

2014-07-15

Phthalic acid esters (PAEs) are used in many branches of industry and are produced in huge amounts throughout the world. An investigation on particulate- and gas-phase distribution of PAEs has been conducted between January 2011 and December 2012 in Nanjing (China). Masson pine (Pinus massoniana L.) needles and rhizosphere surface soils were sampled from urban to suburban/remote sites, to investigate the pine needle/soil distribution of PAEs. The results showed that the average total PAE concentration (gas+particle) was 97.0ngm(-3). The six PAE congeners considered predominantly existed in the gas phase and the average contribution of gas phase to total PAEs ranged from 75.0% to 89.1%. The PAE concentrations in rhizosphere soils and pine needles were positively correlated with their particulate- and gas-phase concentrations, respectively, which suggested that surface soils accumulated PAEs mainly through gravity deposition of particles and pine needle stomata absorbed PAEs mainly from the gas phase. The gas/particle partitioning (KP) and soil-pine needle ratio (Rs/n) were determined. Experimentally determined KP values correlated well with the subcooled liquid vapor pressures (PL). A set of interesting relationships of logRs/n-logKP-logPL was employed to explain the experimental findings of PAEs deposition to surface soils and to needles. This data set offered a unique perspective into the influence that Rs/n played in KP and correlated with PL. Copyright © 2014 Elsevier B.V. All rights reserved.

A Modified MuDPIT Separation Identified 4,488 Proteins in a System Wide Analysis of Quiescence in Yeast

PubMed Central

Webb, Kristofor J.; Xu, Tao; Park, Sung Kyu; Yates, John R.

2013-01-01

A modified multidimensional protein identification technology (MudPIT) separation was coupled to an LTQ Orbitrap Velos mass spectrometer and used to rapidly identify the near complete yeast proteome from a whole cell tryptic digest. This modified on-line two dimensional liquid chromatography separation consists of 39 strong cation exchange steps followed by a short 18.5 min reversed-phase (RP) gradient. A total of 4,269 protein identifications were made from 4,189 distinguishable protein families from yeast during log phase growth. The “Micro” MudPIT separation performed as well as a standard MudPIT separation in 40% less gradient time. The majority of the yeast proteome can now be routinely covered in less than a days’ time with high reproducibility and sensitivity. The newly devised separation method was used to detect changes in protein expression during cellular quiescence in yeast. An enrichment in the GO annotations ‘oxidation reduction’, ‘catabolic processing’ and ‘cellular response to oxidative stress’ was seen in the quiescent cellular fraction, consistent with their long lived stress resistant phenotypes. Heterogeneity was observed in the stationary phase fraction with a less dense cell population showing reductions in KEGG pathway categories of ‘Ribosome’ and ‘Proteasome’, further defining the complex nature of yeast populations present during stationary phase growth. In total 4,488 distinguishable protein families were identified in all cellular conditions tested. PMID:23540446

Foraging patterns in online searches.

PubMed

Wang, Xiangwen; Pleimling, Michel

2017-03-01

Nowadays online searches are undeniably the most common form of information gathering, as witnessed by billions of clicks generated each day on search engines. In this work we describe online searches as foraging processes that take place on the semi-infinite line. Using a variety of quantities like probability distributions and complementary cumulative distribution functions of step length and waiting time as well as mean square displacements and entropies, we analyze three different click-through logs that contain the detailed information of millions of queries submitted to search engines. Notable differences between the different logs reveal an increased efficiency of the search engines. In the language of foraging, the newer logs indicate that online searches overwhelmingly yield local searches (i.e., on one page of links provided by the search engines), whereas for the older logs the foraging processes are a combination of local searches and relocation phases that are power law distributed. Our investigation of click logs of search engines therefore highlights the presence of intermittent search processes (where phases of local explorations are separated by power law distributed relocation jumps) in online searches. It follows that good search engines enable the users to find the information they are looking for through a local exploration of a single page with search results, whereas for poor search engine users are often forced to do a broader exploration of different pages.

Foraging patterns in online searches

NASA Astrophysics Data System (ADS)

Wang, Xiangwen; Pleimling, Michel

2017-03-01

Nowadays online searches are undeniably the most common form of information gathering, as witnessed by billions of clicks generated each day on search engines. In this work we describe online searches as foraging processes that take place on the semi-infinite line. Using a variety of quantities like probability distributions and complementary cumulative distribution functions of step length and waiting time as well as mean square displacements and entropies, we analyze three different click-through logs that contain the detailed information of millions of queries submitted to search engines. Notable differences between the different logs reveal an increased efficiency of the search engines. In the language of foraging, the newer logs indicate that online searches overwhelmingly yield local searches (i.e., on one page of links provided by the search engines), whereas for the older logs the foraging processes are a combination of local searches and relocation phases that are power law distributed. Our investigation of click logs of search engines therefore highlights the presence of intermittent search processes (where phases of local explorations are separated by power law distributed relocation jumps) in online searches. It follows that good search engines enable the users to find the information they are looking for through a local exploration of a single page with search results, whereas for poor search engine users are often forced to do a broader exploration of different pages.

Gene Methylation and Cytological Atypia in Random Fine-Needle Aspirates for Assessment of Breast Cancer Risk.

PubMed

Stearns, Vered; Fackler, Mary Jo; Hafeez, Sidra; Bujanda, Zoila Lopez; Chatterton, Robert T; Jacobs, Lisa K; Khouri, Nagi F; Ivancic, David; Kenney, Kara; Shehata, Christina; Jeter, Stacie C; Wolfman, Judith A; Zalles, Carola M; Huang, Peng; Khan, Seema A; Sukumar, Saraswati

2016-08-01

Methods to determine individualized breast cancer risk lack sufficient sensitivity to select women most likely to benefit from preventive strategies. Alterations in DNA methylation occur early in breast cancer. We hypothesized that cancer-specific methylation markers could enhance breast cancer risk assessment. We evaluated 380 women without a history of breast cancer. We determined their menopausal status or menstrual cycle phase, risk of developing breast cancer (Gail model), and breast density and obtained random fine-needle aspiration (rFNA) samples for assessment of cytopathology and cumulative methylation index (CMI). Eight methylated gene markers were identified through whole-genome methylation analysis and included novel and previously established breast cancer detection genes. We performed correlative and multivariate linear regression analyses to evaluate DNA methylation of a gene panel as a function of clinical factors associated with breast cancer risk. CMI and individual gene methylation were independent of age, menopausal status or menstrual phase, lifetime Gail risk score, and breast density. CMI and individual gene methylation for the eight genes increased significantly (P < 0.001) with increasing cytological atypia. The findings were verified with multivariate analyses correcting for age, log (Gail), log (percent density), rFNA cell number, and body mass index. Our results demonstrate a significant association between cytological atypia and high CMI, which does not vary with menstrual phase or menopause and is independent of Gail risk and mammographic density. Thus, CMI is an excellent candidate breast cancer risk biomarker, warranting larger prospective studies to establish its utility for cancer risk assessment. Cancer Prev Res; 9(8); 673-82. ©2016 AACR. ©2016 American Association for Cancer Research.

Octanol/water partitioning simulation by RP-HPLC for structurally diverse acidic drugs: comparison of three columns in the presence and absence of n-octanol as the mobile phase additive.

PubMed

Giaginis, Costas; Theocharis, Stamatios; Tsantili-Kakoulidou, Anna

2013-12-01

The advantageous effect of n-octanol as a mobile phase additive for lipophilicity assessment of structurally diverse acidic drugs both in the neutral and ionized form was explored. Two RP C18 columns, ABZ+ and Aquasil, were used for the determination of logkw indices, and the results were compared with those previously reported on a base-deactivated silica column. At pH 2.5, the use of n-octanol-saturated buffer as the mobile phase aqueous component led to high-quality 1:1 correlation between logkw and logP for the ABZ+ column, while inferior statistics were obtained for Aquasil. At physiological pH, the correlations were significantly improved if strongly ionized acidic drugs were treated separately from weakly ionized ones. In the latter case, 1:1 correlations between logD7.4 and logkw(oct) indices were obtained in the presence of 0.25% n-octanol. Concerning strongly ionized compounds, adequate correlations were established under the same conditions; however, slopes were significantly lower than unity, while large negative intercepts were obtained. According to the absolute difference (diff = logD7.4 – logkw) pattern, base-deactivated silica showed a better performance than ABZ+, however, the latter seems more efficient for the lipophilicity assessment of highly lipophilic acidic compounds. Aquasil may be the column of choice if logD7.4<3 with the limitation, however, that very hydrophilic compounds cannot be measured.

Differences between co-cultures and monocultures in testing the toxicity of particulate matter derived from log wood and pellet combustion.

PubMed

Kasurinen, Stefanie; Happo, Mikko S; Rönkkö, Teemu J; Orasche, Jürgen; Jokiniemi, Jorma; Kortelainen, Miika; Tissari, Jarkko; Zimmermann, Ralf; Hirvonen, Maija-Riitta; Jalava, Pasi I

2018-01-01

In vitro studies with monocultures of human alveolar cells shed deeper knowledge on the cellular mechanisms by which particulate matter (PM) causes toxicity, but cannot account for mitigating or aggravating effects of cell-cell interactions on PM toxicity. We assessed inflammation, oxidative stress as well as cytotoxic and genotoxic effects induced by PM from the combustion of different types of wood logs and softwood pellets in three cell culture setups: two monocultures of either human macrophage-like cells or human alveolar epithelial cells, and a co-culture of these two cell lines. The adverse effects of the PM samples were compared between these setups. We detected clear differences in the endpoints between the mono- and co-cultures. Inflammatory responses were more diverse in the macrophage monoculture and the co-culture compared to the epithelial cells where only an increase of IL-8 was detected. The production of reactive oxygen species was the highest in epithelial cells and macrophages seemed to have protective effects against oxidative stress from the PM samples. With no metabolically active cells at the highest doses, the cytotoxic effects of the PM samples from the wood log combustion were far more pronounced in the macrophages and the co-culture than in the epithelial cells. All samples caused DNA damage in macrophages, whereas only beech and spruce log combustion samples caused DNA damage in epithelial cells. The organic content of the samples was mainly associated with cytotoxicity and DNA damage, while the metal content of the samples correlated with the induction of inflammatory responses. All of the tested PM samples induce adverse effects and the chemical composition of the samples determines which pathway of toxicity is induced. In vitro testing of the toxicity of combustion-derived PM in monocultures of one cell line, however, is inadequate to account for all the possible pathways of toxicity.

Differences between co-cultures and monocultures in testing the toxicity of particulate matter derived from log wood and pellet combustion

PubMed Central

Happo, Mikko S.; Rönkkö, Teemu J.; Orasche, Jürgen; Jokiniemi, Jorma; Kortelainen, Miika; Tissari, Jarkko; Zimmermann, Ralf; Hirvonen, Maija-Riitta; Jalava, Pasi I.

2018-01-01

Background In vitro studies with monocultures of human alveolar cells shed deeper knowledge on the cellular mechanisms by which particulate matter (PM) causes toxicity, but cannot account for mitigating or aggravating effects of cell-cell interactions on PM toxicity. Methods We assessed inflammation, oxidative stress as well as cytotoxic and genotoxic effects induced by PM from the combustion of different types of wood logs and softwood pellets in three cell culture setups: two monocultures of either human macrophage-like cells or human alveolar epithelial cells, and a co-culture of these two cell lines. The adverse effects of the PM samples were compared between these setups. Results We detected clear differences in the endpoints between the mono- and co-cultures. Inflammatory responses were more diverse in the macrophage monoculture and the co-culture compared to the epithelial cells where only an increase of IL-8 was detected. The production of reactive oxygen species was the highest in epithelial cells and macrophages seemed to have protective effects against oxidative stress from the PM samples. With no metabolically active cells at the highest doses, the cytotoxic effects of the PM samples from the wood log combustion were far more pronounced in the macrophages and the co-culture than in the epithelial cells. All samples caused DNA damage in macrophages, whereas only beech and spruce log combustion samples caused DNA damage in epithelial cells. The organic content of the samples was mainly associated with cytotoxicity and DNA damage, while the metal content of the samples correlated with the induction of inflammatory responses. Conclusions All of the tested PM samples induce adverse effects and the chemical composition of the samples determines which pathway of toxicity is induced. In vitro testing of the toxicity of combustion-derived PM in monocultures of one cell line, however, is inadequate to account for all the possible pathways of toxicity. PMID:29466392

COMPARISON OF THE OCTANOL-AIR PARTITION COEFFICIENT AND LIQUID-PHASE VAPOR PRESSURE AS DESCRIPTORS FOR PARTICLE/GAS PARTITIONING USING LABORATORY AND FIELD DATA FOR PCBS AND PCNS

EPA Science Inventory

The conventional Junge-Pankow adsorption model uses the sub-cooled liquid vapor pressure (pLo) as a correlation parameter for gas/particle interactions. An alternative is the octanol-air partition coefficient (Koa) absorption model. Log-log plots of the particle-gas partition c...

Seasonal pathogen removal by alternative on-site wastewater treatment systems.

PubMed

Pundsack, J; Axler, R; Hicks, R; Henneck, J; Nordman, D; McCarthy, B

2001-01-01

Subsurface-flow constructed wetlands, sand filters, and peat filters near Duluth, Minnesota, were studied to determine their seasonal performance for removing pathogens from wastewater. Influent was a high-strength septic tank effluent (mean values of 5-day biochemical oxygen demand, total nitrogen, and total phosphorus were 294, 96, and 15 mg/L, respectively) at the Natural Resources Research Institute's alternative treatment system test facility in northern Minnesota. Each treatment system was inoculated with cultures of Salmonella choleraesuis (serotype typhimurium) for 5 to 7 consecutive days in summer and winter during 1998 to 1999. After the seeding, outflow samples were taken until Salmonella counts were sustained at background levels. The removal of Salmonella was calculated for each system, although the exact removal mechanisms were not determined. During the summer, the wetlands removed 99.6 to 99.999 4% (2.4 to 5.3 log10 reduction) of the culturable Salmonella. The sand filters demonstrated a greater than 7 log10 removal of Salmonella cells, whereas the peat filters were responsible for a greater than 8 log10 loss of cells. Fewer Salomonella cells were removed by all of these systems during the winter, although the pattern of removal was similar to their summer operation. During the winter, the wetlands and sand filters removed greater than 1 log10 of culturable cells, but the peat filters were responsible for a greater than 5 log10 loss of cells. Fecal coliform removal patterns reflected those for Salmonella by treatment systems for summer and winter periods. Based on Salmonella and fecal coliform removal, the peat filters operated most effectively followed by the sand filters and the constructed wetlands.

Supercooled liquid vapour pressures and related thermodynamic properties of polycyclic aromatic hydrocarbons determined by gas chromatography.

PubMed

Haftka, Joris J H; Parsons, John R; Govers, Harrie A J

2006-11-24

A gas chromatographic method using Kováts retention indices has been applied to determine the liquid vapour pressure (P(i)), enthalpy of vaporization (DeltaH(i)) and difference in heat capacity between gas and liquid phase (DeltaC(i)) for a group of polycyclic aromatic hydrocarbons (PAHs). This group consists of 19 unsubstituted, methylated and sulphur containing PAHs. Differences in log P(i) of -0.04 to +0.99 log units at 298.15K were observed between experimental values and data from effusion and gas saturation studies. These differences in log P(i) have been fitted with multilinear regression resulting in a compound and temperature dependent correction. Over a temperature range from 273.15 to 423.15K, differences in corrected log P(i) of a training set (-0.07 to +0.03 log units) and a validation set (-0.17 to 0.19 log units) were within calculated error ranges. The corrected vapour pressures also showed a good agreement with other GC determined vapour pressures (average -0.09 log units).

Attachment of and biofilm formation by Enterobacter sakazakii on stainless steel and enteral feeding tubes.

PubMed

Kim, Hoikyung; Ryu, Jee-Hoon; Beuchat, Larry R

2006-09-01

Enterobacter sakazakii has been reported to form biofilms, but environmental conditions affecting attachment to and biofilm formation on abiotic surfaces have not been described. We did a study to determine the effects of temperature and nutrient availability on attachment and biofilm formation by E. sakazakii on stainless steel and enteral feeding tubes. Five strains grown to stationary phase in tryptic soy broth (TSB), infant formula broth (IFB), or lettuce juice broth (LJB) at 12 and 25 degrees C were examined for the extent to which they attach to these materials. Higher populations attached at 25 degrees C than at 12 degrees C. Stainless steel coupons and enteral feeding tubes were immersed for 24 h at 4 degrees C in phosphate-buffered saline suspensions (7 log CFU/ml) to facilitate the attachment of 5.33 to 5.51 and 5.03 to 5.12 log CFU/cm(2), respectively, before they were immersed in TSB, IFB, or LJB, followed by incubation at 12 or 25 degrees C for up to 10 days. Biofilms were not produced at 12 degrees C. The number of cells of test strains increased by 1.42 to 1.67 log CFU/cm(2) and 1.16 to 1.31 log CFU/cm(2) in biofilms formed on stainless steel and feeding tubes, respectively, immersed in IFB at 25 degrees C; biofilms were not formed on TSB and LJB at 25 degrees C, indicating that nutrient availability plays a major role in processes leading to biofilm formation on the surfaces of these inert materials. These observations emphasize the importance of temperature control in reconstituted infant formula preparation and storage areas in preventing attachment and biofilm formation by E. sakazakii.

Preformulation studies of EFdA, a novel nucleoside reverse transcriptase inhibitor for HIV prevention

PubMed Central

Zhang, Wei; Parniak, Michael A.; Mitsuya, Hiroaki; Sarafianos, Stefan G.; Graebing, Phillip W.; Rohan, Lisa C.

2014-01-01

4′-Ethynyl-2-fluoro-2′-deoxyadenosine (EFdA) is a novel nucleoside analog of great interest because of its superior activity against wild-type and multidrug-resistant HIV-1 strains, and favorable safety profiles in vitro and in vivo. The aim of this work was to provide preformulation information of EFdA important for delivery system development. A simple, accurate and specific reverse-phase high performance liquid chromatographic (RP-HPLC) method with UV detection was developed for quantification of EFdA. In addition, physicochemical characterizations including pH solubility profile, octanol/water partition coefficient (Log Po/w), DSC analysis, field emission scanning electron microscopy, and stability studies under various conditions were conducted. EFdA existed in planar or flake shape, with a melting point of ~130 °C, and had a pH dependent solubility. The log Po/w value of EFdA was −1.19. The compound was stable upon exposure to pH levels from 3 to 9 and showed good stability at elevated temperature (65 °C). In vitro cytotoxicity assessments were performed in two different epithelial cell lines. In cell-based studies, the EFdA selectivity index (50% cytotoxic concentration [CC50] values/50% effective concentration [EC50]) was found to be greater than 1 × 103. Permeability studies using cell- and tissue-based models showed that EFdA had an apparent permeability coefficient (Papp) <1 × 10−6cm/s and that the paracelluar pathway was the dominant transport route for EFdA. Overall, EFdA possesses favorable characteristics for further formulation development. PMID:23841536

Preformulation studies of EFdA, a novel nucleoside reverse transcriptase inhibitor for HIV prevention.

PubMed

Zhang, Wei; Parniak, Michael A; Mitsuya, Hiroaki; Sarafianos, Stefan G; Graebing, Phillip W; Rohan, Lisa C

2014-08-01

4'-Ethynyl-2-fluoro-2'-deoxyadenosine (EFdA) is a novel nucleoside analog of great interest because of its superior activity against wild-type and multidrug-resistant HIV-1 strains, and favorable safety profiles in vitro and in vivo. The aim of this work was to provide preformulation information of EFdA important for delivery system development. A simple, accurate and specific reverse-phase high performance liquid chromatographic (RP-HPLC) method with UV detection was developed for quantification of EFdA. In addition, physicochemical characterizations including pH solubility profile, octanol/water partition coefficient (Log Po/w), DSC analysis, field emission scanning electron microscopy, and stability studies under various conditions were conducted. EFdA existed in planar or flake shape, with a melting point of ∼130 °C, and had a pH dependent solubility. The log Po/w value of EFdA was -1.19. The compound was stable upon exposure to pH levels from 3 to 9 and showed good stability at elevated temperature (65 °C). In vitro cytotoxicity assessments were performed in two different epithelial cell lines. In cell-based studies, the EFdA selectivity index (50% cytotoxic concentration [CC50] values/50% effective concentration [EC50]) was found to be greater than 1 × 10(3). Permeability studies using cell- and tissue-based models showed that EFdA had an apparent permeability coefficient (Papp) <1 × 10(-6)cm/s and that the paracelluar pathway was the dominant transport route for EFdA. Overall, EFdA possesses favorable characteristics for further formulation development.

A Fast Chromatographic Method for Estimating Lipophilicity and Ionization in Nonpolar Membrane-Like Environment.

PubMed

Caron, Giulia; Vallaro, Maura; Ermondi, Giuseppe; Goetz, Gilles H; Abramov, Yuriy A; Philippe, Laurence; Shalaeva, Marina

2016-03-07

This study describes the design and implementation of a new chromatographic descriptor called log k'80 PLRP-S that provides information about the lipophilicity of drug molecules in the nonpolar environment, both in their neutral and ionized form. The log k'80 PLRP-S obtained on a polymeric column with acetonitrile/water mobile phase is shown to closely relate to log Ptoluene (toluene dielectric constant ε ∼ 2). The main intermolecular interactions governing log k'80 PLRP-S were deconvoluted using the Block Relevance (BR) analysis. The information provided by this descriptor was compared to ElogD and calclog Ptol, and the differences are highlighted. The "charge-flush" concept is introduced to describe the sensitivity of log k'80 PLRP-S to the ionization state of compounds in the pH range 2 to 12. The ability of log k'80 PLRP-S to indicate the propensity of neutral molecules and monoanions to form Intramolecular Hydrogen Bonds (IMHBs) is proven through a number of examples.

Predicting drug penetration across the blood-brain barrier: comparison of micellar liquid chromatography and immobilized artificial membrane liquid chromatography.

PubMed

De Vrieze, Mike; Lynen, Frédéric; Chen, Kai; Szucs, Roman; Sandra, Pat

2013-07-01

Several in vitro methods have been tested for their ability to predict drug penetration across the blood-brain barrier (BBB) into the central nervous system (CNS). In this article, the performance of a variety of micellar liquid chromatographic (MLC) methods and immobilized artificial membrane (IAM) liquid chromatographic approaches were compared for a set of 45 solutes. MLC measurements were performed on a C18 column with sodium dodecyl sulfate (SDS), polyoxyethylene (23) lauryl ether (Brij35), or sodium deoxycholate (SDC) as surfactant in the micellar mobile phase. IAM liquid chromatography measurements were performed with Dulbecco's phosphate-buffered saline (DPBS) and methanol as organic modifier in the mobile phase. The corresponding retention and computed descriptor data for each solute were used for construction of models to predict transport across the blood-brain barrier (log BB). All data were correlated with experimental log BB values and the relative performance of the models was studied. SDS-based models proved most suitable for prediction of log BB values, followed closely by a simplified IAM method, in which it could be observed that extrapolation of retention data to 0% modifier in the mobile phase was unnecessary.

Direct calculation of 1-octanol-water partition coefficients from adaptive biasing force molecular dynamics simulations.

PubMed

Bhatnagar, Navendu; Kamath, Ganesh; Chelst, Issac; Potoff, Jeffrey J

2012-07-07

The 1-octanol-water partition coefficient log K(ow) of a solute is a key parameter used in the prediction of a wide variety of complex phenomena such as drug availability and bioaccumulation potential of trace contaminants. In this work, adaptive biasing force molecular dynamics simulations are used to determine absolute free energies of hydration, solvation, and 1-octanol-water partition coefficients for n-alkanes from methane to octane. Two approaches are evaluated; the direct transfer of the solute from 1-octanol to water phase, and separate transfers of the solute from the water or 1-octanol phase to vacuum, with both methods yielding statistically indistinguishable results. Calculations performed with the TIP4P and SPC∕E water models and the TraPPE united-atom force field for n-alkanes show that the choice of water model has a negligible effect on predicted free energies of transfer and partition coefficients for n-alkanes. A comparison of calculations using wet and dry octanol phases shows that the predictions for log K(ow) using wet octanol are 0.2-0.4 log units lower than for dry octanol, although this is within the statistical uncertainty of the calculation.

Comparison of the Effect of Curing Ingredients Derived from Purified and Natural Sources on Inhibition of Clostridium perfringens Outgrowth during Cooling of Deli-Style Turkey Breast.

PubMed

King, Amanda M; Glass, Kathleen A; Milkowski, Andrew L; Sindelar, Jeffrey J

2015-08-01

The antimicrobial impact of purified and natural sources of both nitrite and ascorbate were evaluated against Clostridium perfringens during the postthermal processing cooling period of deli-style turkey breast. The objective of phase I was to assess comparable concentrations of nitrite (0 or 100 ppm) and ascorbate (0 or 547 ppm) from both purified and natural sources. Phase II was conducted to investigate concentrations of nitrite (50, 75, or 100 ppm) from cultured celery juice powder and ascorbate (0, 250, or 500 ppm) from cherry powder to simulate alternative curing formulations. Ground turkey breast (75% moisture, 1.2% salt, pH 6.2) treatments were inoculated with C. perfringens spores (three-strain mixture) to yield 2.5 log CFU/g. Individual 50-g portions were vacuum packaged, cooked to 71.1°C, and chilled from 54.4 to 26.7°C in 5 h and from 26.7 to 7.2°C in 10 additional hours. Triplicate samples were assayed for growth of C. perfringens at predetermined intervals by plating on tryptose-sulfite-cycloserine agar; experiments were replicated three times. In phase I, uncured, purified nitrite, and natural nitrite treatments without ascorbate had 5.3-, 4.2-, and 4.4-log increases in C. perfringens, respectively, at 15 h, but <1-log increase was observed at the end of chilling in treatments containing 100 ppm of nitrite and 547 ppm of ascorbate from either source. In phase II, 0, 50, 75, and 100 ppm of nitrite and 50 ppm of nitrite plus 250 ppm of ascorbate supported 4.5-, 3.9-, 3.5-, 2.2-, and 1.5-log increases in C. perfringens, respectively. In contrast, <1-log increase was observed after 15 h in the remaining phase II treatments supplemented with 50 ppm of nitrite and 500 ppm of ascorbate or ≥75 ppm of nitrite and ≥250 ppm of ascorbate. These results confirm that equivalent concentrations of nitrite, regardless of the source, provide similar inhibition of C. perfringens during chilling and that ascorbate enhances the antimicrobial effect of nitrite on C. perfringens at concentrations commonly used in alternative cured meats.

Application of orange essential oil as an antistaphylococcal agent in a dressing model.

PubMed

Muthaiyan, Arunachalam; Biswas, Debabrata; Crandall, Philip G; Wilkinson, Brian J; Ricke, Steven C

2012-08-16

Staphylococcus aureus is the pathogen most often and prevalently involved in skin and soft tissue infections. In recent decades outbreaks of methicillin-resistant S. aureus (MRSA) have created major problems for skin therapy, and burn and wound care units. Topical antimicrobials are most important component of wound infection therapy. Alternative therapies are being sought for treatment of MRSA and one area of interest is the use of essential oils. With the increasing interest in the use and application of natural products, we screened the potential application of terpeneless cold pressed Valencia orange oil (CPV) for topical therapy against MRSA using an in vitro dressing model and skin keratinocyte cell culture model. The inhibitory effect of CPV was determined by disc diffusion vapor assay for MRSA and vancomycin intermediate-resistant S. aureus (VISA) strains. Antistaphylococcal effect of CPV in an in vitro dressing model was tested on S. aureus inoculated tryptic soya agar plate. Bactericidal effect of CPV on MRSA and VISA infected keratinocyte cells was examined by enumeration of extra- and intra-cellular bacterial cells at different treatment time points. Cytotoxic effects on human skin cells was tested by adding CPV to the keratinocyte (HEK001) cells grown in serum free KSFM media, and observed by phase-contrast microscope. CPV vapour effectively inhibited the MRSA and VISA strains in both disc diffusion vapour assay and in vitro dressing model. Compared to untreated control addition of 0.1% CPV to MRSA infected keratinocyte decreased the viable MRSA cells by 2 log CFU/mL in 1 h and in VISA strain 3 log CFU/mL reduction was observed in 1 h. After 3 h viable S. aureus cells were not detected in the 0.2% CPV treatment. Bactericidal concentration of CPV did not show any cytotoxic effect on the human skin keratinocyte cells in vitro. At lower concentration addition of CPV to keratinocytes infected with MRSA and VISA rapidly killed the bacterial cells without causing any toxic effect to the keratinocytes. Therefore, the results of this study warrant further in vivo study to evaluate the potential of CPV as a topical antistaphylococcal agent.

A TWO-PHASE LOW-VELOCITY OUTFLOW IN THE SEYFERT 1 GALAXY Ark 564

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

Gupta, A.; Mathur, S.; Krongold, Y.

2013-05-10

The Seyfert 1 galaxy Ark 564 was observed with Chandra high-energy transmission gratings for 250 ks. We present the high-resolution X-ray spectrum that shows several associated absorption lines. The photoionization model requires two warm absorbers (WAs) with two different ionization states (log U = 0.39 {+-} 0.03 and log U = -0.99 {+-} 0.13), both with moderate outflow velocities ({approx}100 km s{sup -1}) and relatively low line of sight column densities (log N{sub H} = 20.94 and 20.11 cm{sup -2}). The high-ionization phase produces absorption lines of O VII, O VIII, Ne IX, Ne X, Mg XI, Fe XVII, andmore » Fe XVIII, while the low-ionization phase produces lines at lower energies (O VIand O VII). The pressure-temperature equilibrium curve for the Ark 564 absorber does not have the typical ''S'' shape, even if the metallicity is super-solar; as a result, the two WA phases do not appear to be in pressure balance. This suggests that the continuum incident on the absorbing gas is perhaps different from the observed continuum. We also estimated the mass outflow rate and the associated kinetic energy and find it to be at most 0.009% of the bolometric luminosity of Ark 564. Thus, it is highly unlikely that these outflows provide significant feedback required by the galaxy formation models.« less

Modelling by partial least squares the relationship between the HPLC mobile phases and analytes on phenyl column.

PubMed

Markopoulou, Catherine K; Kouskoura, Maria G; Koundourellis, John E

2011-06-01

Twenty-five descriptors and 61 structurally different analytes have been used on a partial least squares (PLS) to latent structure technique in order to study chromatographically their interaction mechanism on a phenyl column. According to the model, 240 different retention times of the analytes, expressed as Y variable (log k), at different % MeOH mobile-phase concentrations have been correlated with their theoretical most important structural or molecular descriptors. The goodness-of-fit was estimated by the coefficient of multiple determinations r(2) (0.919), and the root mean square error of estimation (RMSEE=0.1283) values with a predictive ability (Q(2)) of 0.901. The model was further validated using cross-validation (CV), validated by 20 response permutations r(2) (0.0, 0.0146), Q(2) (0.0, -0.136) and validated by external prediction. The contribution of certain mechanism interactions between the analytes, the mobile phase and the column, proportional or counterbalancing is also studied. Trying to evaluate the influence on Y of every variable in a PLS model, VIP (variables importance in the projection) plot provides evidence that lipophilicity (expressed as Log D, Log P), polarizability, refractivity and the eluting power of the mobile phase are dominant in the retention mechanism on a phenyl column. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A transcriptome-based model of central memory CD4 T cell death in HIV infection.

PubMed

Olvera-García, Gustavo; Aguilar-García, Tania; Gutiérrez-Jasso, Fany; Imaz-Rosshandler, Iván; Rangel-Escareño, Claudia; Orozco, Lorena; Aguilar-Delfín, Irma; Vázquez-Pérez, Joel A; Zúñiga, Joaquín; Pérez-Patrigeon, Santiago; Espinosa, Enrique

2016-11-22

Human central memory CD4 T cells are characterized by their capacity of proliferation and differentiation into effector memory CD4 T cells. Homeostasis of central memory CD4 T cells is considered a key factor sustaining the asymptomatic stage of Human Immunodeficiency Virus type 1 (HIV-1) infection, while progression to acquired immunodeficiency syndrome is imputed to central memory CD4 T cells homeostatic failure. We investigated if central memory CD4 T cells from patients with HIV-1 infection have a gene expression profile impeding proliferation and survival, despite their activated state. Using gene expression microarrays, we analyzed mRNA expression patterns in naive, central memory, and effector memory CD4 T cells from healthy controls, and naive and central memory CD4 T cells from patients with HIV-1 infection. Differentially expressed genes, defined by Log 2 Fold Change (FC) ≥ |0.5| and Log (odds) > 0, were used in pathway enrichment analyses. Central memory CD4 T cells from patients and controls showed comparable expression of differentiation-related genes, ruling out an effector-like differentiation of central memory CD4 T cells in HIV infection. However, 210 genes were differentially expressed in central memory CD4 T cells from patients compared with those from controls. Expression of 75 of these genes was validated by semi quantitative RT-PCR, and independently reproduced enrichment results from this gene expression signature. The results of functional enrichment analysis indicated movement to cell cycle phases G1 and S (increased CCNE1, MKI67, IL12RB2, ADAM9, decreased FGF9, etc.), but also arrest in G2/M (increased CHK1, RBBP8, KIF11, etc.). Unexpectedly, the results also suggested decreased apoptosis (increased CSTA, NFKBIA, decreased RNASEL, etc.). Results also suggested increased IL-1β, IFN-γ, TNF, and RANTES (CCR5) activity upstream of the central memory CD4 T cells signature, consistent with the demonstrated milieu in HIV infection. Our findings support a model where progressive loss of central memory CD4 T cells in chronic HIV-1 infection is driven by increased cell cycle entry followed by mitotic arrest, leading to a non-apoptotic death pathway without actual proliferation, possibly contributing to increased turnover.

Cytotoxic diterpenes from roots of Crossopetalum gaumeri, a Celastraceae species from Yucatan Peninsula.

PubMed

Miron-Lopez, Gumersindo; Bazzocchi, Isabel L; Jimenez-Diaz, Ignacio A; Moujir, Laila M; Quijano-Quiñones, Ramiro; Quijano, Leovigildo; Mena-Rejon, Gonzalo J

2014-05-01

Four new diterpenes, crossogumerins A-D (1-4) along with six known ones (5-10) were isolated from the root bark of Crossopetalum gaumeri, an endemic medicinal plant from the Yucatan Peninsula. Their structures were elucidated on the basis of 1D and 2D NMR techniques, including HMQC, HMBC, and ROESY experiments. Compounds 1-5, 8-10 were evaluated for cytotoxicity against HeLa (carcinoma of the cervix) and Hep-2 (lung carcinoma) human tumor cells lines and against normal Vero cells (African green monkey kidney) in lag and log phase of growth. Podocarpane diterpenes, crossogumerin B (2) and nimbiol (10), exhibited the highest activity against HeLa cells (IC50 values of 3.1 and 8.1 μM, respectively), but also selectivity on Vero cells (SI 22.6 and 7.5, respectively). The preliminary SAR studies suggest that an epoxy moiety in ring B and a hydrogen bond-donor group strategically positioned in the diterpene core are important requirements for cytotoxicity and selectivity. Copyright © 2014. Published by Elsevier Ltd.

Linear modeling of the soil-water partition coefficient normalized to organic carbon content by reversed-phase thin-layer chromatography.

PubMed

Andrić, Filip; Šegan, Sandra; Dramićanin, Aleksandra; Majstorović, Helena; Milojković-Opsenica, Dušanka

2016-08-05

Soil-water partition coefficient normalized to the organic carbon content (KOC) is one of the crucial properties influencing the fate of organic compounds in the environment. Chromatographic methods are well established alternative for direct sorption techniques used for KOC determination. The present work proposes reversed-phase thin-layer chromatography (RP-TLC) as a simpler, yet equally accurate method as officially recommended HPLC technique. Several TLC systems were studied including octadecyl-(RP18) and cyano-(CN) modified silica layers in combination with methanol-water and acetonitrile-water mixtures as mobile phases. In total 50 compounds of different molecular shape, size, and various ability to establish specific interactions were selected (phenols, beznodiazepines, triazine herbicides, and polyaromatic hydrocarbons). Calibration set of 29 compounds with known logKOC values determined by sorption experiments was used to build simple univariate calibrations, Principal Component Regression (PCR) and Partial Least Squares (PLS) models between logKOC and TLC retention parameters. Models exhibit good statistical performance, indicating that CN-layers contribute better to logKOC modeling than RP18-silica. The most promising TLC methods, officially recommended HPLC method, and four in silico estimation approaches have been compared by non-parametric Sum of Ranking Differences approach (SRD). The best estimations of logKOC values were achieved by simple univariate calibration of TLC retention data involving CN-silica layers and moderate content of methanol (40-50%v/v). They were ranked far well compared to the officially recommended HPLC method which was ranked in the middle. The worst estimates have been obtained from in silico computations based on octanol-water partition coefficient. Linear Solvation Energy Relationship study revealed that increased polarity of CN-layers over RP18 in combination with methanol-water mixtures is the key to better modeling of logKOC through significant diminishing of dipolar and proton accepting influence of the mobile phase as well as enhancing molar refractivity in excess of the chromatographic systems. Copyright © 2016 Elsevier B.V. All rights reserved.

Human respiratory syncytial virus load normalized by cell quantification as predictor of acute respiratory tract infection.

PubMed

Gómez-Novo, Miriam; Boga, José A; Álvarez-Argüelles, Marta E; Rojo-Alba, Susana; Fernández, Ana; Menéndez, María J; de Oña, María; Melón, Santiago

2018-05-01

Human respiratory syncytial virus (HRSV) is a common cause of respiratory infections. The main objective is to analyze the prediction ability of viral load of HRSV normalized by cell number in respiratory symptoms. A prospective, descriptive, and analytical study was performed. From 7307 respiratory samples processed between December 2014 to April 2016, 1019 HRSV-positive samples, were included in this study. Low respiratory tract infection was present in 729 patients (71.54%). Normalized HRSV load was calculated by quantification of HRSV genome and human β-globin gene and expressed as log10 copies/1000 cells. HRSV mean loads were 4.09 ± 2.08 and 4.82 ± 2.09 log10 copies/1000 cells in the 549 pharyngeal and 470 nasopharyngeal samples, respectively (P < 0.001). The viral mean load was 4.81 ± 1.98 log10 copies/1000 cells for patients under the age of 4-year-old (P < 0.001). The viral mean loads were 4.51 ± 2.04 cells in patients with low respiratory tract infection and 4.22 ± 2.28 log10 copies/1000 cells with upper respiratory tract infection or febrile syndrome (P < 0.05). A possible cut off value to predict LRTI evolution was tentatively established. Normalization of viral load by cell number in the samples is essential to ensure an optimal virological molecular diagnosis avoiding that the quality of samples affects the results. A high viral load can be a useful marker to predict disease progression. © 2018 Wiley Periodicals, Inc.

Use of biopartitioning micellar chromatography and RP-HPLC for the determination of blood-brain barrier penetration of α-adrenergic/imidazoline receptor ligands, and QSPR analysis.

PubMed

Vucicevic, J; Popovic, M; Nikolic, K; Filipic, S; Obradovic, D; Agbaba, D

2017-03-01

For this study, 31 compounds, including 16 imidazoline/α-adrenergic receptor (IRs/α-ARs) ligands and 15 central nervous system (CNS) drugs, were characterized in terms of the retention factors (k) obtained using biopartitioning micellar and classical reversed phase chromatography (log k BMC and log k wRP , respectively). Based on the retention factor (log k wRP ) and slope of the linear curve (S) the isocratic parameter (φ 0 ) was calculated. Obtained retention factors were correlated with experimental log BB values for the group of examined compounds. High correlations were obtained between logarithm of biopartitioning micellar chromatography (BMC) retention factor and effective permeability (r(log k BMC /log BB): 0.77), while for RP-HPLC system the correlations were lower (r(log k wRP /log BB): 0.58; r(S/log BB): -0.50; r(φ 0 /P e ): 0.61). Based on the log k BMC retention data and calculated molecular parameters of the examined compounds, quantitative structure-permeability relationship (QSPR) models were developed using partial least squares, stepwise multiple linear regression, support vector machine and artificial neural network methodologies. A high degree of structural diversity of the analysed IRs/α-ARs ligands and CNS drugs provides wide applicability domain of the QSPR models for estimation of blood-brain barrier penetration of the related compounds.

Logarithmic amplifiers.

PubMed

Gandler, W; Shapiro, H

1990-01-01

Logarithmic amplifiers (log amps), which produce an output signal proportional to the logarithm of the input signal, are widely used in cytometry for measurements of parameters that vary over a wide dynamic range, e.g., cell surface immunofluorescence. Existing log amp circuits all deviate to some extent from ideal performance with respect to dynamic range and fidelity to the logarithmic curve; accuracy in quantitative analysis using log amps therefore requires that log amps be individually calibrated. However, accuracy and precision may be limited by photon statistics and system noise when very low level input signals are encountered.

Could LogP be a principal determinant of biological activity in 18-crown-6 ethers? Synthesis of biologically active adamantane-substituted diaza-crowns.

PubMed

Supek, Fran; Ramljak, Tatjana Šumanovac; Marjanović, Marko; Buljubašić, Maja; Kragol, Goran; Ilić, Nataša; Smuc, Tomislav; Zahradka, Davor; Mlinarić-Majerski, Kata; Kralj, Marijeta

2011-08-01

18-crown-6 ethers are known to exert their biological activity by transporting K(+) ions across cell membranes. Using non-linear Support Vector Machines regression, we searched for structural features that influence antiproliferative activity in a diverse set of 19 known oxa-, monoaza- and diaza-18-crown-6 ethers. Here, we show that the logP of the molecule is the most important molecular descriptor, among ∼1300 tested descriptors, in determining biological potency (R(2)(cv) = 0.704). The optimal logP was at 5.5 (Ghose-Crippen ALOGP estimate) while both higher and lower values were detrimental to biological potency. After controlling for logP, we found that the antiproliferative activity of the molecule was generally not affected by side chain length, molecular symmetry, or presence of side chain amide links. To validate this QSAR model, we synthesized six novel, highly lipophilic diaza-18-crown-6 derivatives with adamantane moieties attached to the side arms. These compounds have near-optimal logP values and consequently exhibit strong growth inhibition in various human cancer cell lines and a bacterial system. The bioactivities of different diaza-18-crown-6 analogs in Bacillus subtilis and cancer cells were correlated, suggesting conserved molecular features may be mediating the cytotoxic response. We conclude that relying primarily on the logP is a sensible strategy in preparing future 18-crown-6 analogs with optimized biological activity. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Development of a bifunctional filter for prion protein and leukoreduction of red blood cell components.

PubMed

Yokomizo, Tomo; Kai, Takako; Miura, Morikazu; Ohto, Hitoshi

2015-02-01

Leukofiltration of blood components is currently implemented worldwide as a precautionary measure against white blood cell-associated adverse effects and the potential transmission of variant Creutzfeldt-Jakob disease (vCJD). A newly developed bifunctional filter (Sepacell Prima, Asahi Kasei Medical) was assessed for prion removal, leukoreduction (LR), and whether the filter significantly affected red blood cells (RBCs). Sepacell Prima's postfiltration effects on RBCs, including hemolysis, complement activation, and RBC chemistry, were compared with those of a conventional LR filter (Sepacell Pure RC). Prion removal was measured by Western blot after spiking RBCs with microsomal fractions derived from scrapie-infected hamster brain homogenate. Serially diluted exogenous prion solutions (0.05 mL), with or without filtration, were injected intracerebrally into Golden Syrian hamsters. LR efficiency of 4.44 log with the Sepacell Prima was comparable to 4.11 log with the conventional LR filter. There were no significant differences between the two filters in hemoglobin loss, hemolysis, complement activation, and RBC biomarkers. In vitro reduction of exogenously spiked prions by the filter exceeded 3 log. The titer, 6.63 (log ID50 /mL), of prefiltration infectivity of healthy hamsters was reduced to 2.52 (log ID50 /mL) after filtration. The reduction factor was calculated as 4.20 (log ID50 ). With confirmed removal efficacy for exogenous prion protein, this new bifunctional prion and LR filter should reduce the residual risk of vCJD transmission through blood transfusion without adding complexity to component processing. © 2014 AABB.

Comparison of Insulin Resistance and β-Cell Dysfunction Between the Young and the Elderly in Normal Glucose Tolerance and Prediabetes Population: A Prospective Study.

PubMed

Chen, G; Shi, L; Cai, L; Lin, W; Huang, H; Liang, J; Li, L; Lin, L; Tang, K; Chen, L; Lu, J; Bi, Y; Wang, W; Ning, G; Wen, J

2017-02-01

Insulin resistance and β-cell function are different between the young and elderly diabetes individuals, which are not well elaborated in the nondiabetic persons. The aims of this study were to compare insulin resistance and β-cell function between young and old adults from normal glucose tolerance (NGT) to prediabetes [which was subdivided into isolated impaired fasting glucose (i-IFG), isolated impaired glucose tolerance (i-IGT), and a combination of both (IFG/IGT)], and compare the prevalence of diabetes mellitus (DM) in the above prediabetes subgroups between different age groups after 3 years. A total of 1 374 subjects aged below 40 or above 60 years old with NGT or prediabetes were finally included in this study. Insulin resistance and β-cell function from homeostasis model assessment (HOMA) and interactive, 24-variable homeostatic model of assessment (iHOMA2) were compared between different age groups. The rate of transition to diabetes between different age groups in all pre-diabetes subgroups was also compared. Compared with the old groups, young i-IFG and IFG/IGT groups exhibit higher log HOMA-IR and log HOMA2-S, whereas the young i-IGT groups experienced comparable log HOMA-IR and log HOMA2-S when compared with old i-IFG and IFG/IGT groups. Three prediabetes subgroups all had similar log HOMA-B and log HOMA2-B between different age groups. In addition, the prevalence of diabetes in young i-IFG was statistically higher than that in old i-IFG after 3 years. Age is negatively related to log HOMA2-B in both age groups. Considering an age-related deterioration of β-cell function, young i-IFG, young i-IGT, and young IFG/IGT all suffered a greater impairment in insulin secretion than the old groups. Young i-IFG and IFG/IGT have more severe insulin resistance than the old groups. In addition, young i-IFG characterized with a higher incidence of DM than the old i-IFG. These disparities highlight that the prevention to slow progression from prediabetes to type 2 diabetes should be additionally focused in young prediabetes individuals, especially young i-IFG. © Georg Thieme Verlag KG Stuttgart · New York.

Log (TG)/HDL-C ratio as a predictor of decreased islet beta cell function in patients with type 2 diabetes: 6-year cohort study.

PubMed

Zhou, Meicen; Li, Zengyi; Min, Rui; Dong, Yaxiu; Sun, Qi; Li, Yuxiu

2015-09-01

The aim of the present study was to explore whether the triglyceride to high density lipoprotein cholesterol ratio [log (TG)/HDL-C] and peripheral blood leukocytes DNA telomere length could predict future islet beta cell function decreased in Chinese type 2 diabetes mellitus (T2DM) during a 6-year cohort. Sixty T2DM patients (without insulin treatment at baseline) were included in the 6-year cohort study. Peripheral blood leukocytes DNA telomere length, HbA1c, blood lipid profile, fatty fat acid, glucose, insulin and C peptide (3 h after a mixed meal) were determined. Delta C peptide area under curve (Delta CP AUC) was used to reflect change in beta cell secretion function (Delta CP AUC = baseline CP AUC - CP AUC after 6 years). Subjects were divided into slow decrease of beta cell function group (Delta CP AUCslow group) and fast decrease group (Delta CP AUCfast group) according to median of Delta CP AUC. Baseline demographic characteristics, clinical variables between two groups were compared. Correlations between baseline data and Delta CP AUC were analyzed. Baseline log (TG)/HDL-C was positively correlated with Delta CP AUC (r = 0.306, P = 0.027); log (TG)/HDL-C in Delta CP AUCfast group was higher than that in Delta CP AUCslow group (0.103 ± 0.033 vs 0.083 ± 0.030, P = 0.027). There was no significant difference in DNA telomere length between the two groups. Change in DNA telomere length over 6 years was not significantly correlated with baseline blood lipid. In Chinese T2DM patients, high baseline log (TG)/HDL-C ratio predicts fast progression of islet beta cell dysfunction. It may be a simple index to predict progression speed of islet beta cell dysfunction. © 2014 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

Fe-Ti oxide geothermometry: thermodynamic formulation and the estimation of intensive variables in silicic magmas

NASA Astrophysics Data System (ADS)

Ghiorso, Mark S.; Sack, O.

1991-10-01

A new thermodynamic formulation of the Fe-Ti oxide geothermometer/oxygen barometer is developed. The method is based upon recently calibrated models for spinel solid solutions in the quinary system (Fe2+, Mg)(Al,Fe3+,Cr)2O4-(Fe2+, Mg)2TiO4 by Sack and Ghiorso, and rhombohedral oxides in the quaternary system (Fe2+,Mg,Mn)TiO3-Fe2O3 (this paper). The formulation is internally consistent with thermodynamic models for (Fe2+,Mg)-olivine and -orthopyroxene solid solutions and end-member thermodynamic properties tabulated by Berman. The constituent expressions account for compositional and temperature dependent cation ordering and reproduce miscibility gap features in all of the component binaries. The calibration does not account for the excess Gibbs energy resulting from compositional and temperature dependent magnetic ordering in either phase. This limits application of the method to assemblages that equilibrated at temperatures above 600° C. Practical implementation of the proposed geothermometer/oxygen barometer requires minimal use of projection algorthms in accommodating compositions of naturally occurring phases. The new formulation is applied to the estimation of temperature and oxygen fugacity in a wide variety of intermediate to silicic volcanic rocks. In combination with previous work on olivine and orthopyroxene thermodynamics, equilibration pressures are computed for a subset of these volcanics that contain the assemblage quartz, oxides and either ferromagnesian silicate. The calculated log10 f O 2- T relations are reflected in coexisting ferromagnesian mineral assemblages. Volcanics with the lowest relative oxygen fugacity (Δlog10 f O 2) are characterized by the assemblage olivine-quartz, those with slightly higher Δ log10 f O 2 s, by the assemblage orthopyroxene-quartz. The sequence proceeds with the necessary phases biotite-feldspar, then hornblende-quartz-clinopyroxene, and finally at the highest Δ log10 f O 2 s, sphene-quartz-clinopyroxene. Quantitative analysis of these trends, utilizing thermodynamic data for the constituent phases, establishes that, in most cases, the T-log10 f O 2value computed from the oxides is consistent with the compositions of coexisting silicate phases, indicating that phenocryst equilibrium was achieved prior to eruption. There is, however, considerable evidence of oxide-silicate disequilibrium in samples collected from more slowly cooled domes and obsidians. In addition, T-log10 f O 2trends from volcanic rocks that contain biotite and orthopyroxene are interpreted to imply a condition of Fe2+-Mg exchange disequilibrium between orthopyroxene and coexisting ferromagnesian silicates and melt. It is suspected that many biotite-feldspar-quartz-orthopyroxene bearing low temperature volcanic rocks inherit orthopyroxene xenocrysts which crystallized earlier in the cooling history of the magma body.

An assessment of the impact of FIA's default assumptions on the estimates of coarse woody debris volume and biomass

Treesearch

Vicente J. Monleon

2009-01-01

Currently, Forest Inventory and Analysis estimation procedures use Smalian's formula to compute coarse woody debris (CWD) volume and assume that logs lie horizontally on the ground. In this paper, the impact of those assumptions on volume and biomass estimates is assessed using 7 years of Oregon's Phase 2 data. Estimates of log volume computed using Smalian...

Oxygen mapping: Probing a novel seeding strategy for bone tissue engineering.

PubMed

Westphal, Ines; Jedelhauser, Claudia; Liebsch, Gregor; Wilhelmi, Arnd; Aszodi, Attila; Schieker, Matthias

2017-04-01

Bone tissue engineering (BTE) utilizing biomaterial scaffolds and human mesenchymal stem cells (hMSCs) is a promising approach for the treatment of bone defects. The quality of engineered tissue is crucially affected by numerous parameters including cell density and the oxygen supply. In this study, a novel oxygen-imaging sensor was introduced to monitor the oxygen distribution in three dimensional (3D) scaffolds in order to analyze a new cell-seeding strategy. Immortalized hMSCs, pre-cultured in a monolayer for 30-40% or 70-80% confluence, were used to seed demineralized bone matrix (DBM) scaffolds. Real-time measurements of oxygen consumption in vitro were simultaneously performed by the novel planar sensor and a conventional needle-type sensor over 24 h. Recorded oxygen maps of the novel planar sensor revealed that scaffolds, seeded with hMSCs harvested at lower densities (30-40% confluence), exhibited rapid exponential oxygen consumption profile. In contrast, harvesting cells at higher densities (70-80% confluence) resulted in a very slow, almost linear, oxygen decrease due to gradual achieving the stationary growth phase. In conclusion, it could be shown that not only the seeding density on a scaffold, but also the cell density at the time point of harvest is of major importance for BTE. The new cell seeding strategy of harvested MSCs at low density during its log phase could be a useful strategy for an early in vivo implantation of cell-seeded scaffolds after a shorter in vitro culture period. Furthermore, the novel oxygen imaging sensor enables a continuous, two-dimensional, quick and convenient to handle oxygen mapping for the development and optimization of tissue engineered scaffolds. Biotechnol. Bioeng. 2017;114: 894-902. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Actual distribution of Cronobacter spp. in industrial batches of powdered infant formula and consequences for performance of sampling strategies.

PubMed

Jongenburger, I; Reij, M W; Boer, E P J; Gorris, L G M; Zwietering, M H

2011-11-15

The actual spatial distribution of microorganisms within a batch of food influences the results of sampling for microbiological testing when this distribution is non-homogeneous. In the case of pathogens being non-homogeneously distributed, it markedly influences public health risk. This study investigated the spatial distribution of Cronobacter spp. in powdered infant formula (PIF) on industrial batch-scale for both a recalled batch as well a reference batch. Additionally, local spatial occurrence of clusters of Cronobacter cells was assessed, as well as the performance of typical sampling strategies to determine the presence of the microorganisms. The concentration of Cronobacter spp. was assessed in the course of the filling time of each batch, by taking samples of 333 g using the most probable number (MPN) enrichment technique. The occurrence of clusters of Cronobacter spp. cells was investigated by plate counting. From the recalled batch, 415 MPN samples were drawn. The expected heterogeneous distribution of Cronobacter spp. could be quantified from these samples, which showed no detectable level (detection limit of -2.52 log CFU/g) in 58% of samples, whilst in the remainder concentrations were found to be between -2.52 and 2.75 log CFU/g. The estimated average concentration in the recalled batch was -2.78 log CFU/g and a standard deviation of 1.10 log CFU/g. The estimated average concentration in the reference batch was -4.41 log CFU/g, with 99% of the 93 samples being below the detection limit. In the recalled batch, clusters of cells occurred sporadically in 8 out of 2290 samples of 1g taken. The two largest clusters contained 123 (2.09 log CFU/g) and 560 (2.75 log CFU/g) cells. Various sampling strategies were evaluated for the recalled batch. Taking more and smaller samples and keeping the total sampling weight constant, considerably improved the performance of the sampling plans to detect such a type of contaminated batch. Compared to random sampling, stratified random sampling improved the probability to detect the heterogeneous contamination. Copyright © 2011 Elsevier B.V. All rights reserved.

Rapid determination of octanol-water partition coefficient using vortex-assisted liquid-liquid microextraction.

PubMed

Román, Iván P; Mastromichali, Anna; Tyrovola, Konstantina; Canals, Antonio; Psillakis, Elefteria

2014-02-21

Vortex-assisted liquid-liquid microextraction (VALLME) coupled with high-performance liquid chromatography (HPLC) is proposed here for the rapid determination of octanol-water partitioning coefficients (Kow). VALLME uses vortex agitation, a mild emulsification procedure, to disperse microvolumes of octanol in the aqueous phase thus increasing the interfacial contact area and ensuring faster partitioning rates. With VALLME, 2min were enough to achieve equilibrium conditions between the octanolic and aqueous phases. Upon equilibration, separation was achieved using centrifugation and the octanolic microdrop was collected and analyzed in a HPLC system. Six model compounds with logKow values ranging between ∼0.5 and 3.5 were used during the present investigations. The proposed method produced logKow values that were consistent with previously published values and the recorded uncertainty was well within the acceptable log unit range. Overall, the key features of the proposed Kow determination procedure comprised speed, reliability, simplicity, low cost and minimal solvent consumption. Copyright © 2014 Elsevier B.V. All rights reserved.

The Opportunistic Pathogen Vibrio vulnificus Produces Outer Membrane Vesicles in a Spatially Distinct Manner Related to Capsular Polysaccharide

PubMed Central

Hampton, Cheri M.; Guerrero-Ferreira, Ricardo C.; Storms, Rachel E.; Taylor, Jeannette V.; Yi, Hong; Gulig, Paul A.; Wright, Elizabeth R.

2017-01-01

Vibrio vulnificus, a bacterial species that inhabits brackish waters, is an opportunistic pathogen of humans. V. vulnificus infections can cause acute gastroenteritis, invasive septicemia, tissue necrosis, and potentially death. Virulence factors associated with V. vulnificus include the capsular polysaccharide (CPS), lipopolysaccharide, flagellum, pili, and outer membrane vesicles (OMVs). The aims of this study were to characterize the morphology of V. vulnificus cells and the formation and arrangement of OMVs using cryo-electron microscopy (cryo-EM). cryo-EM and cryo-electron tomography imaging of V. vulnificus strains grown in liquid cultures revealed the presence of OMVs (diameters of ∼45 nm for wild-type, ∼30 nm for the unencapsulated mutant, and ∼50 nm for the non-motile mutant) in log-phase growth. Production of OMVs in the stationary growth phase was limited and irregular. The spacing of the OMVs around the wild-type cells was in regular, concentric rings. In wild-type cells and a non-motile mutant, the spacing between the cell envelope and the first ring of OMVs was ∼200 nm; this spacing was maintained between subsequent OMV layers. The size, arrangement, and spacing of OMVs in an unencapsulated mutant was irregular and indicated that the polysaccharide chains of the capsule regulate aspects of OMV production and order. Together, our results revealed the distinctive organization of V. vulnificus OMVs that is affected by expression of the CPS. PMID:29163452

On the bad metallicity and phase diagrams of Fe1+δX (X =Te, Se, S, solid solutions): an electrical resistivity study

NASA Astrophysics Data System (ADS)

El Massalami, M.; Deguchi, K.; Machida, T.; Takeya, H.; Takano, Y.

2014-12-01

Based on a systematic analysis of the thermal evolution of the resistivities of Fe-based chalcogenides Fe1+δTe1-xXx (X = Se, S), it is inferred that their often observed nonmetallic resistivities are related to a presence of two resistive channels: one is a high- temperature thermally-activated process while the other is a low-temperature log-in-T process. On lowering temperature, there are often two metal-to-nonmetall crossover events: one from the high-T thermally-activated nonmetallic regime into a metal-like phase and the other from the log-in-T regime into a second metal-like phase. Based on these events, together with the magnetic and superconducting transitions, a phase diagram is constructed for each series. We discuss the origin of both processes as well as the associated crossover events. We also discuss how these resistive processes are being influenced by pressure, intercalation, disorder, doping, or sample condition and, in turn, how these modifications are shaping the associated phase diagrams.

Heat inactivation of a norovirus surrogate in cell culture lysate, abalone meat, and abalone viscera.

PubMed

Park, Shin Young; Bae, San-Cheong; Ha, Sang-Do

2015-03-01

The current study examined the effects of temperature and heat treatment duration on murine norovirus-1 (MNV-1) from both viral cell culture lysate (7-8 log10 PFU) and experimentally contaminated abalone meat and viscera (5-6 log10 PFU) as a model of human norovirus (NoV). MNV-1 titers in cell culture lysate, abalone meat, and abalone viscera were gradually reduced to 1.93-4.55, 1.79-3.00, and 2.26-3.26 log10 PFU/ml, respectively, after treatment at 70 °C for 1-10 min. Treatment at 85 °C for 1-5 min gradually reduced MNV-1 titers in abalone meat to 2.71-4.15 log10 PFU/ml. MNV-1 titers in abalone viscera were gradually reduced to 2.91-3.46 log10 PFU/ml after treatment at 85 °C for 1-3 min. No significant difference (P > 0.05) was found in MNV-1 titers in the abalone meat and viscera among treatment groups (70 °C for 5 min, 70 °C for 3 min, and 85 °C for 1 min). Complete inactivation of MNV-1 in cell culture lysate was determined at 85 °C for ≥1 min and 100 °C for ≥0.5 min. Complete inactivation of MNV-1 in abalone was determined at 100 °C for ≥0.5 min for meat, and 85 °C for 5 min and 100 °C for ≥0.5 min for viscera. At treatments at 70 °C, the Td-values (3 log reduction time) were significantly lower (P < 0.05) in the cell culture lysate (3.38) than for the abalone meat (6.07) and viscera (10.73). Td = 3 values were not significantly different (P > 0.05) between abalone meat (1.78) and abalone viscera (1.33) at treatments at 85 °C. This study suggests that 100 °C for ≥0.5 min could potentially be used to inactivate NoV in molluscan shellfishes, including viscera.

Safety, Pharmacokinetics and Efficacy of Dolutegravir in Treatment-experienced HIV-1 Infected Adolescents: Forty-eight-week Results from IMPAACT P1093.

PubMed

Viani, Rolando M; Alvero, Carmelita; Fenton, Terry; Acosta, Edward P; Hazra, Rohan; Townley, Ellen; Steimers, Debra; Min, Sherene; Wiznia, Andrew

2015-11-01

To assess the pharmacokinetics (PK), safety and efficacy of dolutegravir plus optimized background regimen in HIV-infected treatment-experienced adolescents. Children older than 12 to younger than 18 years received dolutegravir weight-based fixed doses at approximately 1.0 mg/kg once daily in a phase I/II multicenter open label 48-week study. Intensive PK evaluation was done at steady state after dolutegravir was added to a failing regimen or started at the end of a treatment interruption. Safety and HIV RNA and CD4 cell count assessments were performed through week 48. Twenty-three adolescents were enrolled and 22 (96%) completed the 48-week study visit. Median age and weight were 15 years and 52 kg, respectively. Median [interquartile range (IQR)] baseline CD4+ cell count was 466 cells/μL (297, 771). Median (IQR) baseline HIV-1 RNA log10 was 4.3 log10 copies/mL (3.9, 4.6). Dolutegravir geometric mean of the area under the plasma concentration-time curve from time of administration to 24 hours after dosing (AUC0-24) and 24 hour postdose concentration (C24) were 46.0 μg hours/mL and 0.90 μg/mL, respectively, which were within the study targets based on adult PK ranges. Virologic success with an HIV RNA <400 copies/mL was achieved in 74% [95% confidence interval (CI): 52-90%] at week 48. Additionally, 61% (95% CI: 39-80%) had an HIV RNA <50 copies/mL at week 48. Median (IQR) gain in CD4 cell count at week 48 was 84 cells/μL (-81, 238). Dolutegravir was well tolerated, with no grade 4 adverse events, serious adverse events or discontinuations because of serious adverse events. Dolutegravir achieved target PK exposures in adolescents. Dolutegravir was safe and well tolerated, providing good virologic efficacy through week 48.

Matrix diffusion coefficients in volcanic rocks at the Nevada test site: influence of matrix porosity, matrix permeability, and fracture coating minerals.

PubMed

Reimus, Paul W; Callahan, Timothy J; Ware, S Doug; Haga, Marc J; Counce, Dale A

2007-08-15

Diffusion cell experiments were conducted to measure nonsorbing solute matrix diffusion coefficients in forty-seven different volcanic rock matrix samples from eight different locations (with multiple depth intervals represented at several locations) at the Nevada Test Site. The solutes used in the experiments included bromide, iodide, pentafluorobenzoate (PFBA), and tritiated water ((3)HHO). The porosity and saturated permeability of most of the diffusion cell samples were measured to evaluate the correlation of these two variables with tracer matrix diffusion coefficients divided by the free-water diffusion coefficient (D(m)/D*). To investigate the influence of fracture coating minerals on matrix diffusion, ten of the diffusion cells represented paired samples from the same depth interval in which one sample contained a fracture surface with mineral coatings and the other sample consisted of only pure matrix. The log of (D(m)/D*) was found to be positively correlated with both the matrix porosity and the log of matrix permeability. A multiple linear regression analysis indicated that both parameters contributed significantly to the regression at the 95% confidence level. However, the log of the matrix diffusion coefficient was more highly-correlated with the log of matrix permeability than with matrix porosity, which suggests that matrix diffusion coefficients, like matrix permeabilities, have a greater dependence on the interconnectedness of matrix porosity than on the matrix porosity itself. The regression equation for the volcanic rocks was found to provide satisfactory predictions of log(D(m)/D*) for other types of rocks with similar ranges of matrix porosity and permeability as the volcanic rocks, but it did a poorer job predicting log(D(m)/D*) for rocks with lower porosities and/or permeabilities. The presence of mineral coatings on fracture walls did not appear to have a significant effect on matrix diffusion in the ten paired diffusion cell experiments.

Matrix diffusion coefficients in volcanic rocks at the Nevada test site: Influence of matrix porosity, matrix permeability, and fracture coating minerals

NASA Astrophysics Data System (ADS)

Reimus, Paul W.; Callahan, Timothy J.; Ware, S. Doug; Haga, Marc J.; Counce, Dale A.

2007-08-01

Diffusion cell experiments were conducted to measure nonsorbing solute matrix diffusion coefficients in forty-seven different volcanic rock matrix samples from eight different locations (with multiple depth intervals represented at several locations) at the Nevada Test Site. The solutes used in the experiments included bromide, iodide, pentafluorobenzoate (PFBA), and tritiated water ( 3HHO). The porosity and saturated permeability of most of the diffusion cell samples were measured to evaluate the correlation of these two variables with tracer matrix diffusion coefficients divided by the free-water diffusion coefficient ( Dm/ D*). To investigate the influence of fracture coating minerals on matrix diffusion, ten of the diffusion cells represented paired samples from the same depth interval in which one sample contained a fracture surface with mineral coatings and the other sample consisted of only pure matrix. The log of ( Dm/ D*) was found to be positively correlated with both the matrix porosity and the log of matrix permeability. A multiple linear regression analysis indicated that both parameters contributed significantly to the regression at the 95% confidence level. However, the log of the matrix diffusion coefficient was more highly-correlated with the log of matrix permeability than with matrix porosity, which suggests that matrix diffusion coefficients, like matrix permeabilities, have a greater dependence on the interconnectedness of matrix porosity than on the matrix porosity itself. The regression equation for the volcanic rocks was found to provide satisfactory predictions of log( Dm/ D*) for other types of rocks with similar ranges of matrix porosity and permeability as the volcanic rocks, but it did a poorer job predicting log( Dm/ D*) for rocks with lower porosities and/or permeabilities. The presence of mineral coatings on fracture walls did not appear to have a significant effect on matrix diffusion in the ten paired diffusion cell experiments.

Estimating pore-space gas hydrate saturations from well log acoustic data

NASA Astrophysics Data System (ADS)

Lee, Myung W.; Waite, William F.

2008-07-01

Relating pore-space gas hydrate saturation to sonic velocity data is important for remotely estimating gas hydrate concentration in sediment. In the present study, sonic velocities of gas hydrate-bearing sands are modeled using a three-phase Biot-type theory in which sand, gas hydrate, and pore fluid form three homogeneous, interwoven frameworks. This theory is developed using well log compressional and shear wave velocity data from the Mallik 5L-38 permafrost gas hydrate research well in Canada and applied to well log data from hydrate-bearing sands in the Alaskan permafrost, Gulf of Mexico, and northern Cascadia margin. Velocity-based gas hydrate saturation estimates are in good agreement with Nuclear Magneto Resonance and resistivity log estimates over the complete range of observed gas hydrate saturations.

Estimating pore-space gas hydrate saturations from well log acoustic data

USGS Publications Warehouse

Lee, Myung W.; Waite, William F.

2008-01-01

Relating pore-space gas hydrate saturation to sonic velocity data is important for remotely estimating gas hydrate concentration in sediment. In the present study, sonic velocities of gas hydrate–bearing sands are modeled using a three-phase Biot-type theory in which sand, gas hydrate, and pore fluid form three homogeneous, interwoven frameworks. This theory is developed using well log compressional and shear wave velocity data from the Mallik 5L-38 permafrost gas hydrate research well in Canada and applied to well log data from hydrate-bearing sands in the Alaskan permafrost, Gulf of Mexico, and northern Cascadia margin. Velocity-based gas hydrate saturation estimates are in good agreement with Nuclear Magneto Resonance and resistivity log estimates over the complete range of observed gas hydrate saturations.

Effect of heat-assisted pulsed electric fields and bacteriophage on enterohemorrhagic Escherichia coli O157:H7.

PubMed

Walkling-Ribeiro, Markus; Anany, Hany; Griffiths, Mansel W

2015-01-01

Pulsed electric fields (PEF), heat-assisted PEF (H-PEF), and virulent bacteriophage (VP) are non-thermal techniques for pathogen inactivation in liquids that were investigated individually, and in combination (PEF/VP, H-PEF/VP) to control enterohemorrhagic Escherichia coli (EHEC) O157:H7 in Luria-Bertani broth (LBB) and Ringer's solution (RS). Treated cells were subsequently incubated at refrigeration (4°C) and temperature-abuse conditions (12°C) for 5 days. When EHEC cells grown in LBB were subjected to non-thermal processing and subsequently stored at 12°C for 5 days, reductions in count of between 0.1 and 0.6 log cycles were observed and following storage at 4°C the decrease in counts varied between 0.2 and 1.1 log10 . For bacteria cells suspended in RS values ranged from 0.1 to ≥3.9 log cycles at both storage temperatures. The most effective treatments were H-PEF and H-PEF/VP, both producing a >3.4 log cycle reduction of cells suspended in non-nutrient RS. Analysis of EHEC recovery on selective and non-selective media indicated no occurrence of sub-lethal damage for VP, PEF/VP, and H-PEF/VP-treated cells. The findings indicate that combining PEF and lytic phage may represent a suitable alternative to conventional fluid decontamination following further process optimization. © 2014 American Institute of Chemical Engineers.

Variability of Burkholderia pseudomallei Strain Sensitivities to Chlorine Disinfection▿

PubMed Central

O'Connell, Heather A.; Rose, Laura J.; Shams, Alicia; Bradley, Meranda; Arduino, Matthew J.; Rice, Eugene W.

2009-01-01

Burkholderia pseudomallei is a select agent and the causative agent of melioidosis. Variations in previously reported chlorine and monochloramine concentration time (Ct) values for disinfection of this organism make decisions regarding the appropriate levels of chlorine in water treatment systems difficult. This study identified the variation in Ct values for 2-, 3-, and 4-log10 reductions of eight environmental and clinical isolates of B. pseudomallei in phosphate-buffered water. The greatest calculated Ct values for a 4-log10 inactivation were 7.8 mg·min/liter for free available chlorine (FAC) at pH 8 and 5°C and 550 mg·min/liter for monochloramine at pH 8 and 5°C. Ionic strength of test solutions, culture hold times in water, and cell washing were ruled out as sources of the differences in prior observations. Tolerance to FAC was correlated with the relative amount of extracellular material produced by each isolate. Solid-phase cytometry analysis using an esterase-cleaved fluorochrome assay detected a 2-log10-higher level of organisms based upon metabolic activity than did culture, which in some cases increased Ct values by fivefold. Despite strain-to-strain variations in Ct values of 17-fold for FAC and 2.5-fold for monochloramine, standard FAC disinfection practices utilized in the United States should disinfect planktonic populations of these B. pseudomallei strains by 4 orders of magnitude in less than 10 min at the tested temperatures and pH levels. PMID:19542324

Compressed quantum simulation of the Ising model.

PubMed

Kraus, B

2011-12-16

Jozsa et al. [Proc. R. Soc. A 466, 809 2009)] have shown that a match gate circuit running on n qubits can be compressed to a universal quantum computation on log(n)+3 qubits. Here, we show how this compression can be employed to simulate the Ising interaction of a 1D chain consisting of n qubits using a universal quantum computer running on log(n) qubits. We demonstrate how the adiabatic evolution can be realized on this exponentially smaller system and how the magnetization, which displays a quantum phase transition, can be measured. This shows that the quantum phase transition of very large systems can be observed experimentally with current technology. © 2011 American Physical Society

Design and analysis of linear oscillatory single-phase permanent magnet generator for free-piston stirling engine systems

NASA Astrophysics Data System (ADS)

Kim, Jeong-Man; Choi, Jang-Young; Lee, Kyu-Seok; Lee, Sung-Ho

2017-05-01

This study focuses on the design and analysis of a linear oscillatory single-phase permanent magnet generator for free-piston stirling engine (FPSE) systems. In order to implement the design of linear oscillatory generator (LOG) for suitable FPSEs, we conducted electromagnetic analysis of LOGs with varying design parameters. Then, detent force analysis was conducted using assisted PM. Using the assisted PM gave us the advantage of using mechanical strength by detent force. To improve the efficiency, we conducted characteristic analysis of eddy-current loss with respect to the PM segment. Finally, the experimental result was analyzed to confirm the prediction of the FEA.

Reconfigurable microfluidic device with discretized sidewall

PubMed Central

Oono, Masahiro; Yamaguchi, Keisuke; Rasyid, Amirul; Takano, Atsushi; Tanaka, Masato

2017-01-01

Various microfluidic features, such as traps, have been used to manipulate flows, cells, and other particles within microfluidic systems. However, these features often become undesirable in subsequent steps requiring different fluidic configurations. To meet the changing needs of various microfluidic configurations, we developed a reconfigurable microfluidic channel with movable sidewalls using mechanically discretized sidewalls of laterally aligned rectangular pins. The user can deform the channel sidewall at any time after fabrication by sliding the pins. We confirmed that the flow resistance of the straight microchannel could be reversibly adjusted in the range of 101–105 Pa s/μl by manually displacing one of the pins comprising the microchannel sidewall. The reconfigurable microchannel also made it possible to manipulate flows and cells by creating a segmented patterned culture of COS-7 cells and a coculture of human umbilical vein endothelial cells (HUVECs) and human lung fibroblasts (hLFs) inside the microchannel. The reconfigurable microfluidic device successfully maintained a culture of COS-7 cells in a log phase throughout the entire period of 216 h. Furthermore, we performed a migration assay of cocultured HUVEC and hLF spheroids within one microchannel and observed their migration toward each other. PMID:28503247

Distribution and Bioconcentration of Polycyclic Aromatic Hydrocarbons in Surface Water and Fishes

PubMed Central

Li, Haiyan; Ran, Yong

2012-01-01

To examine spatial distribution and bioconcentration of PAHs, water and fish samples were collected from Pearl River Delta in summer and spring, respectively. Particulate organic carbon, dissolved organic carbon, biodegradable DOC (BDOC), and chlorophyll a were measured. PAHs were dominated by 2- and 3-ring compounds in the water and SPM samples. Aqueous and solid-phase PAHs, respectively, showed significant correlations with total organic matter (TOC) in SPM or dissolved organic matter (DOC) in the water. The in-situ partitioning coefficients (logK oc, mL/g) for the samples were observed to be related to logK ow, implying that the hydrophobicity of PAHs is a critical factor in their distribution. It was also observed that BCF increased with the increasing K ow in the viscera of tilapia (logBCF = 0.507logK ow − 1.368, r = 0.883). However, most of the observed log BCF values in other different fish tissues at first increased with the increasing of log K ow, then reached a maximum value when logK ow is between 5 and 7, and then decreased when logK ow is higher than 7, indicating that the value of BCF may vary due to the diversity of fish species. PMID:23365526

A Phase III Clinical Trial of the Epidermal Growth Factor Vaccine CIMAvax-EGF as Switch Maintenance Therapy in Advanced Non-Small Cell Lung Cancer Patients.

PubMed

Rodriguez, Pedro C; Popa, Xitllaly; Martínez, Odeth; Mendoza, Silvia; Santiesteban, Eduardo; Crespo, Tatiana; Amador, Rosa M; Fleytas, Ricardo; Acosta, Soraida C; Otero, Yanine; Romero, Gala N; de la Torre, Ana; Cala, Mireysi; Arzuaga, Lina; Vello, Loisel; Reyes, Delmairis; Futiel, Niurka; Sabates, Teresa; Catala, Mauricio; Flores, Yoanna I; Garcia, Beatriz; Viada, Carmen; Lorenzo-Luaces, Patricia; Marrero, Maria A; Alonso, Liuba; Parra, Jenelin; Aguilera, Nadia; Pomares, Yaisel; Sierra, Patricia; Rodríguez, Gryssell; Mazorra, Zaima; Lage, Agustin; Crombet, Tania; Neninger, Elia

2016-08-01

EGFR is a well-validated target for patients with non-small cell lung cancer (NSCLC). CIMAvax-EGF is a therapeutic cancer vaccine composed of human recombinant EGF conjugated to a carrier protein and Montanide ISA51 as adjuvant. The vaccine is intended to induce antibodies against self EGFs that block EGF-EGFR interaction. To evaluate overall survival, safety, immunogenicity, and EGF concentration in serum after CIMAvax-EGF, a randomized phase III trial was done in patients with advanced NSCLC. Four to 6 weeks after first-line chemotherapy, 405 patients with stage IIIB/IV NSCLC were randomly assigned to a vaccine group, which received CIMAvax-EGF or a control group, treated with best supportive care. Long-term vaccination was very safe. Most frequent adverse reactions were grade 1 or 2 injection-site pain, fever, vomiting, and headache. Vaccination induced anti-EGF antibodies and decreased serum EGF concentration. In the safety population, median survival time (MST) was 10.83 months in the vaccine arm versus 8.86 months in the control arm. These differences were not significant according the standard log rank (HR, 0.82; P = 0.100), but according a weighted log rank (P = 0.04) that was applied once the nonproportionality of the HR was verified. Survival benefit was significant (HR, 0.77; P = 0.036) in the per-protocol setting (patients receiving at least four vaccine doses): MST was 12.43 months for the vaccine arm versus 9.43 months for the control arm. MST was higher (14.66 months) for vaccinated patients with high EGF concentration at baseline. Switch maintenance with CIMAvax-EGF was well tolerated and significantly increased MST of patients that completed induction vaccination. Baseline EGF concentration predicted survival benefit. Clin Cancer Res; 22(15); 3782-90. ©2016 AACR. ©2016 American Association for Cancer Research.

Incorporating Zataria multiflora Boiss. essential oil and sodium bentonite nano-clay open a new perspective to use zein films as bioactive packaging materials.

PubMed

Kashiri, Mahboobeh; Maghsoudlo, Yahya; Khomeiri, Morteza

2017-10-01

Active zein films with different levels of Zataria multiflora Boiss. essential oil were produced successfully. To enhance properties of this biopolymer for food packaging applications, sodium bentonite clay was used at two levels (2 and 4%). The results indicated that the addition of Z. multiflora Boiss. essential oil caused a reduction in tensile strength and Young's modulus and slight increase in the percent of elongation at break of the films. Maximum solubility in water and water vapor permeability was observed by incorporation of 10% Z. multiflora Boiss. essential oil in the zein matrix. Transmission electron microscopy micrographs of zein film were verified by the exfoliation of the layers of sodium bentonite clay in the zein matrix. Stronger films with lower water vapor permeability and water solubility were evident of good distribution of sodium bentonite clay in the zein matrix. According to the results, 2% sodium bentonite clay was selected for evaluation of nano active film properties. Water vapor permeability, UV light barrier, tensile strength, and Young's modulus values of active films were improved by incorporation of 2% sodium bentonite clay. The antibacterial activity of different contents of Z. multiflora Boiss. essential oil in vapor phase demonstrated that use of Z. multiflora Boiss. essential oil in the liquid phase was more effective than in vapor phase. The antibacterial zein-based films showed that active zein film with 5 and 10% Z. multiflora Boiss. essential oil had reductions of 1.68 log and 2.99 log, respectively, against Listeria monocytogenes and 1.39 and 3.07 log against Escherichia coli. Nano active zein film containing 10% Z. multiflora Boiss. essential oil and 2% sodium bentonite clay showed better antibacterial properties against L. monocytogenes (3.23 log) and E. coli (3.17 log).

In vitro production of Clostridium difficile spores for use in the efficacy evaluation of disinfectants: a precollaborative investigation.

PubMed

Hasan, Jafrul A; Japal, Knoxley M; Christensen, Erick R; Samalot-Freire, Luisa C

2011-01-01

Clostridium difficile is a strict anaerobic spore-forming bacterium, and an increasingly common nosocomial pathogen. The U.S. Environmental Protection Agency (EPA) is responsible for the registration of disinfectants, including products designed to treat environmental surfaces contaminated with spores of C. difficile. Product efficacy data are required for registration; however, there is a lack of methodology for generating high-quality spore suspensions for evaluating product performance. As such, a study was carried out to select a suitable C. difficile strain and to develop a stand-alone method to prepare a spore suspension that meets specific criteria necessary for quantitative testing of disinfectants. The criteria are: (1) a spore titer of > 8 log10/mL, (2) > or = 90% spores to vegetative cells, and (3) resistance of spores (determined by viability) to 2.5 M hydrochloric acid (HCl). Several strains of C. difficile (toxigenic and nontoxigenic) were grown on various media (solid and liquid) for varying lengths of time to determine the best combination of incubation conditions and media to optimize spore production and quality. Once the spore production procedure was optimized, a toxigenic strain of C. difficile [American Type Culture Collection (ATCC) 43598] was selected for use in trials to verify repeatability from one production run to the next. The spore suspension was initiated by spreading vegetative cells of C. difficile (ATCC 43598) on CDC anaerobic 5% sheep blood agar plates and incubating for 7-10 days at 36 +/- 1 degrees C under anaerobic conditions. Spores were harvested when > or = 90% of the cells converted to spores as determined by observation using phase-contrast microscopy. The spores were washed three times with saline-Tween-80, resuspended in cold deionized water, heated to 70 degrees C for 10 min, evaluated microscopically for quality, and enumerated on cycloserine-cefoxitin-fructose agar containing horse blood and taurocholate. The spore suspension was used to inoculate brushed stainless steel carriers (1 cm in diameter) with and without a soil load in accordance with the Standard Quantitative Carrier Disk Test Method (ASTM E-2197-02) to determine carrier load. Once it was determined that > 6 log10 spores/carrier could be recovered, spores were evaluated for resistance to HCI. The sporulation method presented in this report is simple and repeatable and results in spore suspension of high titer (> 8 log10/mL) and quality (> or = 90% spores to vegetative cells) that met acid resistance criteria (spores were resistant to 2.5 M HCI for 10 min). In addition, recovery from brushed stainless steel carriers with and without soil load was > 6 log10 spores/carrier. A 6 log10 performance standard was set forth in the EPA's interim guidance for generating data to support a label claim for effectiveness against C. difficile spores on hard, nonporous surfaces. This precollaborative investigation successfully demonstrated the use of a methodology for in vitro production of C. difficile spores (ATCC 43598) necessary for conducting efficacy tests. A proposal will be submitted to the AOAC INTERNATIONAL Methods Committee on Antimicrobial Efficacy Testing for a collaborative study; see Appendix.

Green chromatography separation of analytes of greatly differing properties using a polyethylene glycol stationary phase and a low-toxic water-based mobile phase.

PubMed

Šatínský, Dalibor; Brabcová, Ivana; Maroušková, Alena; Chocholouš, Petr; Solich, Petr

2013-07-01

A simple, rapid, and environmentally friendly HPLC method was developed and validated for the separation of four compounds (4-aminophenol, caffeine, paracetamol, and propyphenazone) with different chemical properties. A "green" mobile phase, employing water as the major eluent, was proposed and applied to the separation of analytes with different polarity on polyethylene glycol (PEG) stationary phase. The chromatography separation of all compounds and internal standard benzoic acid was performed using isocratic elution with a low-toxicity mobile phase consisting of 0.04% (v/v) triethylamine and water. HPLC separation was carried out using a PEG reversed-phase stationary phase Supelco Discovery HS PEG column (15 × 4 mm; particle size 3 μm) at a temperature of 30 °C and flow rate at 1.0 mL min(-1). The UV detector was set at 210 nm. In this study, a PEG stationary phase was shown to be suitable for the efficient isocratic separation of compounds that differ widely in hydrophobicity and acid-base properties, particularly 4-aminophenol (log P, 0.30), caffeine (log P, -0.25), and propyphenazone (log P, 2.27). A polar PEG stationary phase provided specific selectivity which allowed traditional chromatographic problems related to the separation of analytes with different polarities to be solved. The retention properties of the group of structurally similar substances (aromatic amines, phenolic compounds, and xanthine derivatives) were tested with different mobile phases. The proposed green chromatography method was successfully applied to the analysis of active substances and one degradation impurity (4-aminophenol) in commercial preparation. Under the optimum chromatographic conditions, standard calibration was carried out with good linearity correlation coefficients for all compounds in the range (0.99914-0.99997, n = 6) between the peak areas and concentration of compounds. Recovery of the sample preparation was in the range 100 ± 5% for all compounds. The intraday method precision was determined as RSD, and the values were lower than 1.00%.

Ternary Phase Diagrams of PBZT/Zytel 330/MSA and PBZT/Lubrizol/MSA solutions

DTIC Science & Technology

1990-01-01

8217]bisthiazole-2,6-diyl)- 1,4-phenylene (PBZT). This sytem represents a new class of rigid-rod molecular composite system that is different from all the rigid-rod...per square centimeter, I. In Equations form, this can be summarized by, -dI = a’ c Idb (15) log1O(I/Io)= logT = - abc (16) A = abc (17) where a’ is a

Automated knot detection with visual post-processing of Douglas-fir veneer images

Treesearch

C.L. Todoroki; Eini C. Lowell; Dennis Dykstra

2010-01-01

Knots on digital images of 51 full veneer sheets, obtained from nine peeler blocks crosscut from two 35-foot (10.7 m) long logs and one 18-foot (5.5 m) log from a single Douglas-fir tree, were detected using a two-phase algorithm. The algorithm was developed using one image, the Development Sheet, refined on five other images, the Training Sheets, and then applied to...

Time-resolved characterization of primary emissions from residential wood combustion appliances.

PubMed

Heringa, M F; DeCarlo, P F; Chirico, R; Lauber, A; Doberer, A; Good, J; Nussbaumer, T; Keller, A; Burtscher, H; Richard, A; Miljevic, B; Prevot, A S H; Baltensperger, U

2012-10-16

Primary emissions from a log wood burner and a pellet boiler were characterized by online measurements of the organic aerosol (OA) using a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) and of black carbon (BC). The OA and BC concentrations measured during the burning cycle of the log wood burner, batch wise fueled with wood logs, were highly variable and generally dominated by BC. The emissions of the pellet burner had, besides inorganic material, a high fraction of OA and a minor contribution of BC. However, during artificially induced poor burning BC was the dominating species with ∼80% of the measured mass. The elemental O:C ratio of the OA was generally found in the range of 0.2-0.5 during the startup phase or after reloading of the log wood burner. During the burnout or smoldering phase, O:C ratios increased up to 1.6-1.7, which is similar to the ratios found for the pellet boiler during stable burning conditions and higher than the O:C ratios observed for highly aged ambient OA. The organic emissions of both burners have a very similar H:C ratio at a given O:C ratio and therefore fall on the same line in the Van Krevelen diagram.

Optimised method to estimate octanol water distribution coefficient (logD) in a high throughput format.

PubMed

Low, Ying Wei Ivan; Blasco, Francesca; Vachaspati, Prakash

2016-09-20

Lipophilicity is one of the molecular properties assessed in early drug discovery. Direct measurement of the octanol-water distribution coefficient (logD) requires an analytical method with a large dynamic range or multistep dilutions, as the analyte's concentrations span across several orders of magnitude. In addition, water/buffer and octanol phases which have very different polarity could lead to matrix effects and affect the LC-MS response, leading to erroneous logD values. Most compound libraries use DMSO stocks as it greatly reduces the sample requirement but the presence of DMSO has been shown to underestimate the lipophilicity of the analyte. The present work describes the development of an optimised shake flask logD method using deepwell 96 well plate that addresses the issues related to matrix effects, DMSO concentration and incubation conditions and is also amenable to high throughput. Our results indicate that the equilibrium can be achieved within 30min by flipping the plate on its side while even 0.5% of DMSO is not tolerated in the assay. This study uses the matched matrix concept to minimise the errors in analysing the two phases namely buffer and octanol in LC-MS. Copyright © 2016 Elsevier B.V. All rights reserved.

Nature of the Carrier State of Bacteriophage SP-10 in Bacillus subtilis1

PubMed Central

Kawakami, Masaya; Landman, Otto E.

1968-01-01

Although the association of phage SP-10 with Bacillus subtilis W-23-Sr persists in heat- and antiserum-resistant form through the spore stage, it is unstable in vegetative cells and frequently terminates in loss of the carried phage or in lysis. On low-tonicity media, the plating efficiency of carrier cells is low. However, high concentrations of succinate or sucrose or a slowed growth rate preserve viability: on 0.48 m succinate-agar, the viable count per optical density unit is the same as that of a noncarrier control culture. Carrier clones retain phage on 0.48 m succinate-agar. At higher succinate levels, many colonies emerge free of phage; at 1 m succinate, all are cured, probably because high succinate inhibits reinfection. Growth of carrier cells in liquid medium with antiphage serum results in rapid curing; events in such cultures with and without succinate were studied quantitatively by tracing the emergence of sensitive cells, the multiplication and induction of carrier cells, and the sensitivity of carrier cells to superinfection with virulent phage. During log phase, 40 to 70% of the carrier cells became sensitive to virulent phage, although the same cells were insensitive during lag and stationary phase. Apparently, fluctuations in repressor levels are responsible. Spontaneous induction of carrier cells followed a qualitatively similar pattern, perhaps in response to changes in level of the same repressor. Production of sensitive segregants by carrier followed a different course, presumably because the repressor does not affect segregation. Many sensitive cells were found two to three divisions after inoculation in antiserum medium. This suggests that each inoculum cell contained one or only a few phage replicons. The data are compatible with the idea that the carrier state in media without antisera is maintained entirely by reinfection and without replication of phage in the latent state. Alternative models which involve replication of latent phage are not ruled out, however. PMID:4967775

Reduction of Escherichia coli O157:H7 in Biofilms Using Bacteriophage BPECO 19.

PubMed

Sadekuzzaman, Mohammad; Yang, Sungdae; Mizan, Md Furkanur Rahaman; Ha, Sang-Do

2017-06-01

Biofilm formation is a growing concern in the food industry. Escherichia coli O157:H7 is one of the most important foodborne pathogens that can persists in food and food-related environments and subsequently produce biofilms. The efficacy of bacteriophage BPECO 19 was evaluated against three E. coli O157:H7 strains in biofilms. Biofilms of the three E. coli O157:H7 strains were grown on abiotic (stainless steel, rubber, and minimum biofilm eradication concentration [MBEC TM ] device) and biotic (lettuce) surfaces at different temperatures. The effectiveness of bacteriophage BPECO 19 in reducing preformed biofilms on these surfaces was further evaluated by treating the surfaces with a phage suspension (10 8 PFU/mL) for 2 h. The results indicated that the phage treatment significantly reduced (P  < 0.05) the number of adhered cells in all the surfaces. Following phage treatment, the viability of adhered cells was reduced by ≥3 log CFU/cm 2 , 2.4 log CFU/cm 2 , and 3.1 log CFU/peg in biofilms grown on stainless steel, rubber, and the MBEC TM device, respectively. Likewise, the phage treatment reduced cell viability by ≥2 log CFU/cm 2 in biofilms grown on lettuce. Overall, these results suggested that bacteriophages such as BPECO 19 could be effective in reducing the viability of biofilm-adhered cells. © 2017 Institute of Food Technologists®.

Predictive performance of the human Cell Line Activation Test (h-CLAT) for lipophilic chemicals with high octanol-water partition coefficients.

PubMed

Takenouchi, Osamu; Miyazawa, Masaaki; Saito, Kazutoshi; Ashikaga, Takao; Sakaguchi, Hitoshi

2013-01-01

To meet the urgent need for a reliable alternative test for predicting skin sensitizing potential of many chemicals, we have developed a cell-based in vitro test, human Cell Line Activation Test (h-CLAT). However, the predictive performance for lipophilic chemicals in the h-CLAT still remains relatively unknown. Moreover, it's suggested that low water solubility of chemicals might induce false negative outcomes. Thus, in this study, we tested relatively low water soluble 37 chemicals with log Kow values above and below 3.5 in the h-CLAT. The small-scale assessment resulted in nine false negative outcomes for chemicals with log Kow values greater than 3.5. We then created a dataset of 143 chemicals by combining the existing dataset of 106 chemicals and examined the predictive performance of the h-CLAT for chemicals with a log Kow of less than 3.5; a total of 112 chemicals from the 143 chemicals in the dataset. The sensitivity and overall accuracy for the 143 chemicals were 83% and 80%, respectively. In contrast, sensitivity and overall accuracy for the 112 chemicals with log Kow values below 3.5 improved to 94% and 88%, respectively. These data suggested that the h-CLAT could successfully detect sensitizers with log Kow values up to 3.5. When chemicals with log Kow values greater than 3.5 that were deemed positive by h-CLAT were included with the 112 chemicals, the sensitivity and accuracy in terms of the resulting applicable 128 chemicals out of the 143 chemicals became 95% and 88%, respectively. The use of log Kow values gave the h-CLAT a higher predictive performance. Our results demonstrated that the h-CLAT could predict sensitizing potential of various chemicals, which contain lipophilic chemicals using a large-scale chemical dataset.

Preliminary report on geophysical well-logging activity on the Salton Sea Scientific Drilling Project, Imperial Valley, California

USGS Publications Warehouse

Paillet, Frederick L.; Morin, R.H.; Hodges, H.E.

1986-01-01

The Salton Sea Scientific Drilling Project has culminated in a 10,564-ft deep test well, State 2-14 well, in the Imperial Valley of southern California. A comprehensive scientific program of drilling, coring, and downhole measurements, which was conducted for about 5 months, has obtained much scientific information concerning the physical and chemical processes associated with an active hydrothermal system. This report primarily focuses on the geophysical logging activities at the State 2-14 well and provides early dissemination of geophysical data to other investigators working on complementary studies. Geophysical-log data were obtained by a commercial logging company and by the U.S. Geological Survey (USGS). Most of the commercial logs were obtained during three visits to the site; only one commercial log was obtained below a depth of 6,000 ft. The commercial logs obtained were dual induction, natural gamma, compensated neutron formation density, caliper and sonic. The USGS logging effort consisted of four primary periods, with many logs extending below a depth of 6,000 ft. The USGS logs obtained were temperature, caliper, natural gamma, gamma spectral, epithermal neutron, acoustic velocity, full-waveform, and acoustic televiewer. Various problems occurred throughout the drilling phase of the Salton Sea Scientific Drilling Project that made successful logging difficult: (1) borehole constrictions, possibly resulting from mud coagulation, (2) maximum temperatures of about 300 C, and (3) borehole conditions unfavorable for logging because of numerous zones of fluid loss, cement plugs, and damage caused by repeated trips in and out of the hole. These factors hampered and compromised logging quality at several open-hole intervals. The quality of the logs was dependent on the degree of probe sophistication and sensitivity to borehole-wall conditions. Digitized logs presented were processed on site and are presented in increments of 1,000 ft. A summary of the numerous factors that may be relevant to this interpretation also is presented. (Lantz-PTT)

Precipitation scavenging of polychlorinated biphenyl congeners in the great lakes region

NASA Astrophysics Data System (ADS)

Murray, Michael W.; Andren, Anders W.

Ten precipitation events were sampled in the fall of 1986 in Madison, WI and analyzed for individual congener and total polychlorinated biphenyl (PCB) levels in both the dissolved and particulate phases. Total PCB concentrations were generally at the lower end of ranges recently reported for precipitation. Operationally defined dissolved and particulate phase congener distribution patterns for the two events of highest concentration were qualitatively similar to gas-phase and particle-bound patterns for northern Wisconsin air samples. Higher than predicted dissolved-phase concentrations may indicate non-equilibrium processes during scavenging and/or sample processing, the presence of colloids and micro-particulates, and/or more efficient gas-phase transfer to hydrometeors with organic coatings. Observed organic carbon-normalized distribution coefficients increased slightly with increasing octanol-water partition coefficient, giving the relationship log Koc = 0.22 log Kow + 4.64. The data indicate that a third organic-rich colloidal phase could be influencing partitioning, and could explain the higher than expected apparent gas scavenging efficiency for PCBs from the atmosphere. Precipitation-weighted mean fluxes of PCBs in the dissolved and particulate phases were 1.2 and 1.4 μg m -2 year -1, respectively, indicating that precipitation remains a significant source of PCBs to the upper Great Lakes.

Synergistic effect of high hydrostatic pressure and natural antimicrobials on inactivation kinetics of Bacillus cereus in a liquid whole egg and skim milk mixed beverage.

PubMed

Pina-Pérez, Maria Consuelo; Silva-Angulo, Angela B; Muguerza-Marquínez, Begoña; Aliaga, D Rodrigo; López, Antonio Martínez

2009-01-01

An in-depth study was conducted in order to extend the storage life of a liquid whole egg-skim milk (LWE-SM) mixed beverage to enhance its safety and the safety of related beverages. Bacillus cereus vegetative cells (1 x 10(8) colony-forming units [CFU]/mL) were inoculated in LWE-SM beverages with or without natural antimicrobial supplements: flavonol rich-cocoa powder (cocoanOX 12%, CCX) (700 ppm), vanillin (700 ppm), anise (700 ppm), and cinnamon (700 ppm). B. cereus cells were maintained at 10 degrees C for 10 days in the different beverages to test the bacteriostatic or inhibitory effect of the aforementioned ingredients. Beverages were treated with high hydrostatic pressure (HHP) technology and stored at 10 degrees C for 15 days after treatment. All natural antimicrobials reduced the micro(max) values and increased the lag phase time of B. cereus, and Gompertz growth curves showed different inhibitory effects depending on the substance. The maximum inhibitory effect (1.330 log cycle reduction) was achieved in LWE-SM-cinnamon-supplemented beverage. The maximum inactivation achieved by HHP in LWE-SM beverage was a reduction of around 3.89 +/- 0.25 log cycles at 300 MPa for 12 minutes. When supplemented beverages were treated under the same conditions, enhanced inactivation levels were achieved. This increased inactivation can be attributed to a synergistic effect when the LWE-SM was supplemented with flavonol-rich cocoa powder, cinnamon, and vanillin. The maximum synergistic effect was observed in LWE-SM-CCX-supplemented beverage. During the refrigerated storage of B. cereus HHP-treated cells in beverages to which antimicrobials had been added, the inhibitory effect was dependent on the previously applied pressure level.

Na2O-Al2O3 system: Activity of Na2O in (α + β)- and (β + β)-alumina

NASA Astrophysics Data System (ADS)

Kale, G. M.

1992-12-01

The activity of Na2O in a biphasic mixture of (α + β)-alumina has been measured in the temperature range of 700 to 1100 K using the solid-state galvanic cell: 11663_2007_Article_BF02656462_TeX2GIFE1.gif _{(1:1)}^{Pt,CO_2 + O_2 /Na_2 CO_3 /(α + β ) - alumin a//(Y_2 O_3 )ZrO_2 //In + In_2 O_3 ,Ta,Pt} Similarly, the activity of Na2O in a (β + β’’)-alumina two-phase mixture has been measured between 700 and 1100 K employing the galvanic cell: 11663_2007_Article_BF02656462_TeX2GIFE2.gif _{(1:1)}^{Pt,CO_2 + O_2 /Na_2 CO_3 /(β + β ) - alumin a//(Y_2 O_3 )ZrO_2 //In + In_2 O_3 ,Ta,Pt} The reversible electromotive force (emf ) of both the cells was found to vary linearly with temperature over the entire temperature range of measurement. From the measured reversible emf and auxiliary thermodynamic data for In2O2, Na2O, CO2 and Na2CO3 reported in the literature, the temperature dependence of the logarithm of activity of Na2O in (α + β)-alumina is obtained: 11663_2007_Article_BF02656462_TeX2GIFE3.gif log α _{Na_2 O} (α + β ) = 1.85 - 14,750/T(K)( ± 0.015)(700 ≤slant T ≤slant 1100) For (β + β'’)-alumina, 11663_2007_Article_BF02656462_TeX2GIFE4.gif log α _{Na_2 O} (β + β ) = 3.9 - 13,000/T(K)( ± 0.015)(700 ≤slant T ≤slant 1100)

Biochemical Traits, Survival and Biological Properties of the Probiotic Lactobacillus plantarum Grown in the Presence of Prebiotic Inulin and Pectin as Energy Source

PubMed Central

Nazzaro, Filomena; Fratianni, Florinda; Orlando, Pierangelo; Coppola, Raffaele

2012-01-01

The viability of the probiotic strain Lactobacillus plantarum subsp. plantarum, after its passage through simulated gastric and pancreatic juices, was evaluated as function of its pre-growth in a medium containing the known prebiotics pectin or inulin, and was compared to glucose used as control. The presence of pectin or inulin did not markedly affect the growth (10.07 log10 colony forming units/mL and 10.28 log10 colony forming units/mL for pectin and inulin respectively versus 10.42 log10 colony forming units/mL obtained for glucose). Pectin and inulin, in contrast to glucose, induced cell stress resistance against gastrointestinal juices (Δ log101.5 and 2.4 colony forming units/mL respectively, versus Δ log10 4.0 for glucose). The data were corroborated by the analysis of the protein pattern following stress treatments which, in the case of microbial cells grown with glucose, revealed a more marked protein degradation after the double passage through simulated gastric and intestinal juices. Inulin stimulated the production of the relevant healthy bio-molecule butyrate, which amount was 30% higher respect of growth in the presence of glucose. Inulin and pectin improved cell DPPH scavenging activity, and an impressive hydrophobicity (35.28% and 34.81%, respectively) was observed with respect to the microbial growth in presence of glucose (3.39%). PMID:24281559

47 CFR 73.1820 - Station log.

Code of Federal Regulations, 2011 CFR

2011-10-01

... values): (A) Common point current. (B) When the operating power is determined by the indirect method, the efficiency factor F and either the product of the final amplifier input voltage and current or the calculated antenna input power. See § 73.51(e). (C) Antenna monitor phase or phase deviation indications. (D) Antenna...

Cytomegalovirus (CMV) DNA Quantitation in Bronchoalveolar Lavage Fluid From Hematopoietic Stem Cell Transplant Recipients With CMV Pneumonia

PubMed Central

Stevens-Ayers, Terry; Travi, Giovanna; Huang, Meei-Li; Cheng, Guang-Shing; Xie, Hu; Leisenring, Wendy; Erard, Veronique; Seo, Sachiko; Kimball, Louise; Corey, Lawrence; Pergam, Steven A; Jerome, Keith R.

2017-01-01

Abstract Background. Quantitative cytomegalovirus (CMV) DNA–specific polymerase chain reaction (PCR) analysis is widely used as a surveillance method for hematopoietic stem cell transplant (HCT) recipients. However, no CMV DNA threshold exists in bronchoalveolar lavage (BAL) to differentiate pneumonia from pulmonary shedding. Methods. We tested archived BAL fluid samples from 132 HCT recipients with CMV pneumonia and 139 controls (100 patients with non-CMV pneumonia, 18 with idiopathic pneumonia syndrome [IPS], and 21 who were asymptomatic) by quantitative CMV and β-globin DNA–specific PCR. Results. Patients with CMV pneumonia had higher median viral loads (3.9 log10 IU/mL; interquartile range [IQR], 2.6–6.0 log10 IU/mL) than controls (0 log10 IU/mL [IQR, 0–1.6 log10 IU/mL] for patients with non-CMV pneumonia, 0 log10 IU/mL [IQR, 0–1.6 log10 IU/mL] for patients with IPS, and 1.63 log10 IU/mL [IQR, 0–2.5 log10 IU/mL] for patients who were asymptomatic; P < .001 for all comparisons to patients with CMV pneumonia). Receiver operating characteristic curve analyses and predictive models identified a cutoff CMV DNA level of 500 IU/mL to differentiate between CMV pneumonia and pulmonary shedding, using current CMV pneumonia prevalence figures. However, different levels may be appropriate in settings of very high or low CMV pneumonia prevalence. The presence of pulmonary copathogens, radiographic presentation, or pulmonary hemorrhage did not alter predictive values. Conclusion. CMV DNA load in BAL can be used to differentiate CMV pneumonia from pulmonary shedding. PMID:28181657

Cytomegalovirus (CMV) DNA Quantitation in Bronchoalveolar Lavage Fluid From Hematopoietic Stem Cell Transplant Recipients With CMV Pneumonia.

PubMed

Boeckh, Michael; Stevens-Ayers, Terry; Travi, Giovanna; Huang, Meei-Li; Cheng, Guang-Shing; Xie, Hu; Leisenring, Wendy; Erard, Veronique; Seo, Sachiko; Kimball, Louise; Corey, Lawrence; Pergam, Steven A; Jerome, Keith R

2017-05-15

Quantitative cytomegalovirus (CMV) DNA-specific polymerase chain reaction (PCR) analysis is widely used as a surveillance method for hematopoietic stem cell transplant (HCT) recipients. However, no CMV DNA threshold exists in bronchoalveolar lavage (BAL) to differentiate pneumonia from pulmonary shedding. We tested archived BAL fluid samples from 132 HCT recipients with CMV pneumonia and 139 controls (100 patients with non-CMV pneumonia, 18 with idiopathic pneumonia syndrome [IPS], and 21 who were asymptomatic) by quantitative CMV and β-globin DNA-specific PCR. Patients with CMV pneumonia had higher median viral loads (3.9 log10 IU/mL; interquartile range [IQR], 2.6-6.0 log10 IU/mL) than controls (0 log10 IU/mL [IQR, 0-1.6 log10 IU/mL] for patients with non-CMV pneumonia, 0 log10 IU/mL [IQR, 0-1.6 log10 IU/mL] for patients with IPS, and 1.63 log10 IU/mL [IQR, 0-2.5 log10 IU/mL] for patients who were asymptomatic; P < .001 for all comparisons to patients with CMV pneumonia). Receiver operating characteristic curve analyses and predictive models identified a cutoff CMV DNA level of 500 IU/mL to differentiate between CMV pneumonia and pulmonary shedding, using current CMV pneumonia prevalence figures. However, different levels may be appropriate in settings of very high or low CMV pneumonia prevalence. The presence of pulmonary copathogens, radiographic presentation, or pulmonary hemorrhage did not alter predictive values. CMV DNA load in BAL can be used to differentiate CMV pneumonia from pulmonary shedding. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Development of PMA real-time PCR method to quantify viable cells of Pantoea agglomerans CPA-2, an antagonist to control the major postharvest diseases on oranges.

PubMed

Soto-Muñoz, Lourdes; Teixidó, Neus; Usall, Josep; Viñas, Inmaculada; Crespo-Sempere, Ana; Torres, Rosario

2014-06-16

Dilution plating is the quantification method commonly used to estimate the population level of postharvest biocontrol agents, but this method does not permit a distinction among introduced and indigenous strains. Recently, molecular techniques based on DNA amplification such as quantitative real-time PCR (qPCR) have been successfully applied for their high strain-specific detection level. However, the ability of qPCR to distinguish viable and nonviable cells is limited. A promising strategy to avoid this issue relies on the use of nucleic acid intercalating dyes, such as propidium monoazide (PMA), as a sample pretreatment prior to the qPCR. The objective of this study was to optimize a protocol based on PMA pre-treatment samples combined with qPCR to distinguish and quantify viable cells of the biocontrol agent P. agglomerans CPA-2 applied as a postharvest treatment on orange. The efficiency of PMA-qPCR method under the established conditions (30μM PMA for 20min of incubation followed by 30min of LED light exposure) was evaluated on an orange matrix. Results showed no difference in CFU or cells counts of viable cells between PMA-qPCR and dilution plating. Samples of orange matrix inoculated with a mixture of viable/dead cells showed 5.59log10 CFU/ml by dilution plating, 8.25log10 cells/ml by qPCR, and 5.93log10 cells/ml by PMA-qPCR. Furthermore, samples inoculated with heat-killed cells were not detected by dilution plating and PMA-qPCR, while by qPCR was of 8.16log10 cells/ml. The difference in quantification cycles (Cq) among qPCR and PMA-qPCR was approximately 16cycles, which means a reduction of 65,536 fold of the dead cells detected. In conclusion, PMA-qPCR method is a suitable tool for quantify viable CPA-2 cells, which could be useful to estimate the ability of this antagonist to colonize the orange surface. Copyright © 2014 Elsevier B.V. All rights reserved.

Fracture identification based on remote detection acoustic reflection logging

NASA Astrophysics Data System (ADS)

Zhang, Gong; Li, Ning; Guo, Hong-Wei; Wu, Hong-Liang; Luo, Chao

2015-12-01

Fracture identification is important for the evaluation of carbonate reservoirs. However, conventional logging equipment has small depth of investigation and cannot detect rock fractures more than three meters away from the borehole. Remote acoustic logging uses phase-controlled array-transmitting and long sound probes that increase the depth of investigation. The interpretation of logging data with respect to fractures is typically guided by practical experience rather than theory and is often ambiguous. We use remote acoustic reflection logging data and high-order finite-difference approximations in the forward modeling and prestack reverse-time migration to image fractures. First, we perform forward modeling of the fracture responses as a function of the fracture-borehole wall distance, aperture, and dip angle. Second, we extract the energy intensity within the imaging area to determine whether the fracture can be identified as the formation velocity is varied. Finally, we evaluate the effect of the fracture-borehole distance, fracture aperture, and dip angle on fracture identification.

Displacement chromatography on cyclodextrin silicas. IV. Separation of the enantiomers of ibuprofen.

PubMed

Farkas, G; Irgens, L H; Quintero, G; Beeson, M D; al-Saeed, A; Vigh, G

1993-08-13

A displacement chromatographic method has been developed for the preparative separation of the enantiomers of ibuprofen using a beta-cyclodextrin silica stationary phase. The retention behavior of ibuprofen was studied in detail: the log k' vs. polar organic modifier concentration, the log k' vs. pH, the log k' vs. buffer concentration and the log k' vs. 1/T relationships; also, the alpha vs. polar organic modifier concentration, the alpha vs. pH, the alpha vs. buffer concentration and the log alpha vs. 1/T relationships have been determined in order to find the carrier solution composition which results in maximum chiral selectivity and sufficient, but not excessive solute retention (1 < k' < 30). 4-tert.-Butylcyclohexanol, a structurally similar but more retained compound than ibuprofen, was selected as displacer for the separation. Even with an alpha value as small as 1.08, good preparative chiral separations were observed both in the displacement mode and in the overloaded elution mode, up to a sample load of 0.5 mg.

[Distribution of individuals by spontaneous frequencies of lymphocytes with micronuclei. Particularity and consequences].

PubMed

Serebrianyĭ, A M; Akleev, A V; Aleshchenko, A V; Antoshchina, M M; Kudriashova, O V; Riabchenko, N I; Semenova, L P; Pelevina, I I

2011-01-01

By micronucleus (MN) assay with cytokinetic cytochalasin B block, the mean frequency of blood lymphocytes with MN has been determined in 76 Moscow inhabitants, 35 people from Obninsk and 122 from Chelyabinsk region. In contrast to the distribution of individuals on spontaneous frequency of cells with aberrations, which was shown to be binomial (Kusnetzov et al., 1980), the distribution of individuals on the spontaneous frequency of cells with MN in all three massif can be acknowledged as log-normal (chi2 test). Distribution of individuals in the joined massifs (Moscow and Obninsk inhabitants) and in the unique massif of all inspected with great reliability must be acknowledged as log-normal (0.70 and 0.86 correspondingly), but it cannot be regarded as Poisson, binomial or normal. Taking into account that log-normal distribution of children by spontaneous frequency of lymphocytes with MN has been observed by the inspection of 473 children from different kindergartens in Moscow we can make the conclusion that log-normal is regularity inherent in this type of damage of lymphocytes genome. On the contrary the distribution of individuals on induced by irradiation in vitro lymphocytes with MN frequency in most cases must be acknowledged as normal. This distribution character points out that damage appearance in the individual (genomic instability) in a single lymphocytes increases the probability of the damage appearance in another lymphocytes. We can propose that damaged stem cells lymphocyte progenitor's exchange by information with undamaged cells--the type of the bystander effect process. It can also be supposed that transmission of damage to daughter cells occurs in the time of stem cells division.

Biofilms associated with poultry processing equipment.

PubMed

Lindsay, D; Geornaras, I; von Holy, A

1996-01-01

Aerobic and Gram-negative bacteria were enumerated on non-metallic surfaces and stainless steel test pieces attached to equipment surfaces by swabbing and a mechanical dislodging procedure, respectively, in a South African grade B poultry processing plant. Changes in bacterial numbers were also monitored over time on metal test pieces. The highest bacterial counts were obtained from non-metallic surfaces such as rubber fingered pluckers and plastic defeathering curtains which exceeded the highest counts found on the metal surfaces by at least 1 log CFU cm-2. Gram-negative bacterial counts on all non-metallic surface types were at least 2 log CFU cm-2 lower than corresponding aerobic plate counts. On metal surfaces, the highest microbial numbers were obtained after 14 days exposure, with aerobic plate counts ranging from 3.57 log CFU cm-2 to 5.13 log CFU cm-2, and Gram-negative counts from 0.70 log CFU cm-2 to 3.31 log CFU cm-2. Scanning electron microscopy confirmed the presence of bacterial cells on non-metallic and metallic surfaces associated with poultry processing. Rubber 'fingers', plastic curtains, conveyor belt material and stainless steel test surfaces placed on the scald tank overflow and several chutes revealed extensive and often confluent bacterial biofilms. Extracellular polymeric substances, but few bacterial cells were visible on test pieces placed on evisceration equipment, spinchiller blades and the spinchiller outlet.

Anti-prelog reduction of prochiral carbonyl compounds by Oenococcus oeni in a biphasic system.

PubMed

Hu, Jian; Xu, Yan

2006-07-01

An aqueous-organic biphasic system was established and used with whole cells of Oenococcus oeni to reduce 2-octanone to (R)-2-octanol. The conversion reached 99% when the Tris/borate buffer was increased from 50 mM to 300 mM in the aqueous phase. In addition, the conversion increased as the log P value of the organic solvent changed from 0.5 to 6.6. Under optimized conditions, the conversion of (R)-2-octanol reached 99% from 0.5 M 2-octanone with an optical purity of 99% e.e. The biphasic system allows the anti-Prelog reduction of aliphatic and aromatic ketones to furnish (R)-configurated alcohols in high optical purity as well.

ZnO Nanoparticles Treatment Induces Apoptosis by Increasing Intracellular ROS Levels in LTEP-a-2 Cells.

PubMed

Wang, Caixia; Hu, Xiaoke; Gao, Yan; Ji, Yinglu

2015-01-01

Owing to the wide use of novel nanoparticles (NPs) such as zinc oxide (ZnO) in all aspects of life, toxicological research on ZnO NPs is receiving increasing attention in these days. In this study, the toxicity of ZnO NPs in a human pulmonary adenocarcinoma cell line LTEP-a-2 was tested in vitro. Log-phase cells were exposed to different levels of ZnO NPs for hours, followed by colorimetric cell viability assay using tetrazolium salt and cell survival rate assay using trypan blue dye. Cell morphological changes were observed by Giemsa staining and light microscopy. Apoptosis was detected by using fluorescence microscopy and caspase-3 activity assay. Both intracellular reactive oxygen species (ROS) and reduced glutathione (GSH) were examined by a microplate-reader method. Results showed that ZnO NPs (≥ 0.01 μg/mL) significantly inhibited proliferation (P < 0.05) and induced substantial apoptosis in LTEP-a-2 cells after 4 h of exposure. The intracellular ROS level rose up to 30-40% corresponding to significant depletion (approximately 70-80%) in GSH content in LTEP-a-2 cells (P < 0.05), suggesting that ZnO NPs induced apoptosis mainly through increased ROS production. This study elucidates the toxicological mechanism of ZnO NPs in human pulmonary adenocarcinoma cells and provides reference data for application of nanomaterials in the environment.

Susceptibility of Salmonella enterica Isolates from Tomato Farm Environments to Fatty Acids Naturally Found on Tomato Fruit.

PubMed

Dev Kumar, Govindaraj; Micallef, Shirley A

2017-05-01

Salmonella enterica subsp. enterica can colonize tomato fruit as it interacts with fruit surface compounds. The exometabolome of tomato fruit contains a mixture of compounds, including fatty acids, which could affect Salmonella fitness. Fatty acids detected in fruit exudates were investigated for Salmonella inhibition. Pelargonic, lauric, myristic, palmitic, margaric, stearic, and oleic acids were suspended in water dissolved in dimethyl sulfoxide (DMSO) or emulsified in water and quillaja saponin to assess how bioavailability impacted Salmonella growth. The minimum inhibitory concentrations of fatty acids were determined using a resazurin assay. Quillaja saponin emulsion and DMSO solution of pelargonic acid were inhibitory to Salmonella at 31.25 mM. Lauric and myristic acid emulsions inhibited growth at 1 M concentrations in quillaja emulsions and 62.5 mM in DMSO. Lauric and myristic acids significantly affected growth of Salmonella Newport, Javiana, and Typhimurium (p ≤ 0.05). Growth curve analysis using the Baranyi model revealed reduced maxima populations for all treatments (p ≤ 0.001) and shorter lag phase durations for Salmonella Newport with lauric acid (p < 0.01) and Salmonella Javiana with lauric (p < 0.001) and myristic (p < 0.001) acids. Salmonella Newport and Javiana exhibited an accelerated growth rate with lauric acid (p < 0.001) as a result of early stationary phase transition (shorter log phase). In myristic acid-amended media, Salmonella Javiana also displayed a faster growth rate (p < 0.001). Pelargonic acid (31.25 mM) treatment of Salmonella cells resulted in a drop in culturable cells to below detection in an hour. Microscopic analysis with Cyto-dye and propidium iodide of bacterial cells treated with pelargonic acid indicated a mixture of live and dead cells, with cell lysis of some cells. A subset of cells exhibited elongation-possibly indicating filament formation, a known antibiotic stress response. The results suggest that fatty acids present in tomato fruit surface exudates may exert a restrictive effect on Salmonella growth on fruit.

Outcomes of Descemet Membrane Endothelial Keratoplasty in Eyes With a Previous Descemet Stripping Automated Endothelial Keratoplasty Graft.

PubMed

Sorkin, Nir; Showail, Mahmood; Einan-Lifshitz, Adi; Boutin, Tanguy; Borovik, Armand; Kreimei, Mohammad; Rosenblatt, Amir; Chan, Clara C; Rootman, David S

2018-06-01

To analyze the outcomes of Descemet membrane endothelial keratoplasty (DMEK) in eyes with previous Descemet stripping automated endothelial keratoplasty (DSAEK). This retrospective interventional case series included 26 eyes (26 patients) that underwent DMEK to replace a previous DSAEK graft with at least 6 months of follow-up. The outcome measures were indications for surgery, best spectacle-corrected visual acuity (BSCVA), endothelial cell density, rebubbling rate, rejection, and failure. Patient age was 71.9 ± 12.6 years. The average follow-up time after DMEK was 15.1 ± 10.6 months. Indications for DMEK were DSAEK graft failure (69%) and a DSAEK suboptimal visual outcome (31%). BSCVA of the entire cohort (n = 26) improved from 1.33 ± 0.78 logMAR preoperatively to 1.04 ± 0.78 and 1.06 ± 0.89 logMAR at 6 months postoperatively and at the last follow-up, respectively (P = 0.019 and P = 0.033). BSCVA among eyes without visual comorbidities (n = 13) improved from 0.84 ± 0.50 logMAR preoperatively to 0.55 ± 0.47 and 0.51 ± 0.49 logMAR at 6 months postoperatively and at final follow-up, respectively (P = 0.023 for both). Of these eyes, 84.6% had improvement in BSCVA at 6 months postoperatively and at last follow-up. In the subgroup of 8 eyes with DMEK for suboptimal visual outcomes after DSAEK, BSCVA improved from 0.81 ± 0.44 to 0.52 ± 0.35 logMAR at final follow-up (P = 0.024). When excluding eyes with visual comorbidities, BSCVA of this subgroup (n = 5) improved from 0.54 ± 0.32 to 0.36 ± 0.25 logMAR at final follow-up (P = 0.038). BSCVA of this subgroup at 6 months postoperatively was not significantly different from preoperative BSCVA, when including visual comorbidities (n = 8, 0.75 ± 0.60 logMAR, P = 0.79) and when excluding visual comorbidities (n = 5, 0.40 ± 0.28 logMAR, P = 0.621). Endothelial cell density decreased from 2753 ± 307 cells/mm to 1659 ± 655 cells/mm 6 months after surgery (39.7% loss, P = 0.005). Three eyes (11.5%) required rebubbling, and 5 eyes (19.2%) had secondary graft failure at 2 to 20 months. DMEK is effective for replacing previous DSAEK not only for graft failure but also for suboptimal visual outcomes.

“Direct” Gas-phase Metallicity in Local Analogs of High-redshift Galaxies: Empirical Metallicity Calibrations for High-redshift Star-forming Galaxies

NASA Astrophysics Data System (ADS)

Bian, Fuyan; Kewley, Lisa J.; Dopita, Michael A.

2018-06-01

We study the direct gas-phase oxygen abundance using the well-detected auroral line [O III]λ4363 in the stacked spectra of a sample of local analogs of high-redshift galaxies. These local analogs share the same location as z ∼ 2 star-forming galaxies on the [O III]λ5007/Hβ versus [N II]λ6584/Hα Baldwin–Phillips–Terlevich diagram. This type of analog has the same ionized interstellar medium (ISM) properties as high-redshift galaxies. We establish empirical metallicity calibrations between the direct gas-phase oxygen abundances (7.8< 12+{log}({{O}}/{{H}})< 8.4) and the N2 (log([N II]λ6584/Hα))/O3N2 (log(([O III]λ5007/Hβ)/([N II]λ6584/Hα))) indices in our local analogs. We find significant systematic offsets between the metallicity calibrations for our local analogs of high-redshift galaxies and those derived from the local H II regions and a sample of local reference galaxies selected from the Sloan Digital Sky Survey (SDSS). The N2 and O3N2 metallicities will be underestimated by 0.05–0.1 dex relative to our calibration, if one simply applies the local metallicity calibration in previous studies to high-redshift galaxies. Local metallicity calibrations also cause discrepancies of metallicity measurements in high-redshift galaxies using the N2 and O3N2 indicators. In contrast, our new calibrations produce consistent metallicities between these two indicators. We also derive metallicity calibrations for R23 (log(([O III]λλ4959,5007+[O II]λλ3726,3729)/Hβ)), O32(log([O III]λλ4959,5007/[O II]λλ3726,3729)), {log}([O III]λ5007/Hβ), and log([Ne III]λ3869/[O II]λ3727) indices in our local analogs, which show significant offset compared to those in the SDSS reference galaxies. By comparing with MAPPINGS photoionization models, the different empirical metallicity calibration relations in the local analogs and the SDSS reference galaxies can be shown to be primarily due to the change of ionized ISM conditions. Assuming that temperature structure variations are minimal and ISM conditions do not change dramatically from z ∼ 2 to z ∼ 5, these empirical calibrations can be used to measure relative metallicities in galaxies with redshifts up to z ∼ 5.0 in ground-based observations.

Optical treatment of amblyopia in older children and adults is essential prior to enrolment in a clinical trial.

PubMed

Gao, Tina Y; Anstice, Nicola; Babu, Raiju J; Black, Joanna M; Bobier, William R; Dai, Shuan; Guo, Cindy X; Hess, Robert F; Jenkins, Michelle; Jiang, Yannan; Kearns, Lisa; Kowal, Lionel; Lam, Carly S Y; Pang, Peter C K; Parag, Varsha; South, Jayshree; Staffieri, Sandra Elfride; Wadham, Angela; Walker, Natalie; Thompson, Benjamin

2018-03-01

Optical treatment alone can improve visual acuity (VA) in children with amblyopia, thus clinical trials investigating additional amblyopia therapies (such as patching or videogames) for children require a preceding optical treatment phase. Emerging therapies for adult patients are entering clinical trials. It is unknown whether optical treatment is effective for adults with amblyopia and whether an optical correction phase is required for trials involving adults. We examined participants who underwent optical treatment in the Binocular Treatment for Amblyopia using Videogames (BRAVO) clinical trial (ANZCTR ID: ACTRN12613001004752). Participants were recruited in three age groups (7 to 12, 13 to 17, or ≥18 years), and had unilateral amblyopia due to anisometropia and/or strabismus, with amblyopic eye VA of 0.30-1.00 logMAR (6/12 to 6/60, 20/40 to 20/200). Corrective lenses were prescribed based on cycloplegic refraction to fully correct any anisometropia. VA was assessed using the electronic visual acuity testing algorithm (e-ETDRS) test and near stereoacuity was assessed using the Randot Preschool Test. Participants were assessed every four weeks up to 16 weeks, until either VA was stable or until amblyopic eye VA improved to better than 0.30 logMAR, rendering the participant ineligible for the trial. Eighty participants (mean age 24.6 years, range 7.6-55.5 years) completed four to 16 weeks of optical treatment. A small but statistically significant mean improvement in amblyopic eye VA of 0.05 logMAR was observed (S.D. 0.08 logMAR; paired t-test p < 0.0001). Twenty-five participants (31%) improved by ≥1 logMAR line and of these, seven (9%) improved by ≥2 logMAR lines. Stereoacuity improved in 15 participants (19%). Visual improvements were not associated with age, presence of strabismus, or prior occlusion treatment. Two adult participants withdrew due to intolerance to anisometropic correction. Sixteen out of 80 participants (20%) achieved better than 0.30 logMAR VA in the amblyopic eye after optical treatment. Nine of these participants attended additional follow-up and four (44%) showed further VA improvements. Improvements from optical treatment resulted in one-fifth of participants becoming ineligible for the main clinical trial. Studies investigating additional amblyopia therapies must include an appropriate optical treatment only phase and/or parallel treatment group regardless of patient age. Optical treatment of amblyopia in adult patients warrants further investigation. © 2018 The Authors Ophthalmic & Physiological Optics © 2018 The College of Optometrists.

Effects of pomegranate and pomegranate-apple blend juices on the growth characteristics of Alicyclobacillus acidoterrestris DSM 3922 type strain vegetative cells and spores.

PubMed

Molva, Celenk; Baysal, Ayse Handan

2015-05-04

The present study examined the growth characteristics of Alicyclobacillus acidoterrestris DSM 3922 vegetative cells and spores after inoculation into apple, pomegranate and pomegranate-apple blend juices (10, 20, 40 and 80%, v/v). Also, the effect of sporulation medium was tested using mineral [Bacillus acidoterrestris agar (BATA) and Bacillus acidocaldarius agar (BAA)] and non-mineral containing media [potato dextrose agar (PDA) and malt extract agar (MEA)]. The juice samples were inoculated separately with approximately 10(5)CFU/mL cells or spores from different sporulation media and then incubated at 37°C for 336 h. The number of cells decreased significantly with increasing pomegranate juice concentration in the blend juices and storage time (p<0.001). Based on the results, 3.17, 3.53, and 3.72 log cell reductions were observed in 40%, 80% blend and pomegranate juices, respectively while the cell counts attained approximately 7.17 log CFU/mL in apple juice after 336 h. On the other hand, the cell growth was inhibited for a certain time, and then the numbers started to increase after 72 and 144 h in 10% and 20% blend juices, respectively. After 336 h, total population among spores produced on PDA, BATA, BAA and MEA indicated 1.49, 1.65, 1.67, and 1.28 log reductions in pomegranate juice; and 1.51, 1.38, 1.40 and 1.16 log reductions in 80% blend juice, respectively. The inhibitory effects of 10%, 20% and 40% blend juices varied depending on the sporulation media used. The results obtained in this study suggested that pomegranate and pomegranate-apple blend juices could inhibit the growth of A. acidoterrestris DSM 3922 vegetative cells and spores. Copyright © 2015 Elsevier B.V. All rights reserved.

Determination of 1-octanol-air partition coefficient using gaseous diffusion in the air boundary layer.

PubMed

Ha, Yeonjeong; Kwon, Jung-Hwan

2010-04-15

Exact determination of the partition coefficient between 1-octanol and air (K(OA)) is very important because it is a key descriptor for describing the thermodynamic partitioning between the air and organic phases. In spite of its importance, the number and quality of experimental K(OA) values for hydrophobic organic chemicals are limited because of experimental difficulties. Thus, to measure K(OA) values, a high-throughput method was developed that used liquid-phase extraction with 1-octanol drop at the tip of a microsyringe needle. The concentration in the headspace surrounding the 1 muL octanol drop was equilibrated with liquid octanol containing polycyclic aromatic hydrocarbons (PAHs). The change in concentrations of PAHs in the octanol drop was measured to obtain mass transfer rate constants, and these rate constants were then converted into K(OA) values using a film diffusion model. Thirteen polycyclic aromatic hydrocarbons with log K(OA) between 5 and 12 were chosen for the proof of the principle. Experimental determination of log K(OA) was accomplished in 30 h for PAHs with their log K(OA) less than 11. The measured log K(OA) values were very close to those obtained by various experimental and estimation methods in the literature, suggesting that this new method can provide a fast and easy determination of log K(OA) values for many chemicals of environmental interests. In addition, the applicability of the method can be extended to determine Henry's law constant for compounds with low vapor pressure and to estimate gaseous transfer rate of semivolatile compounds for environmental fate modeling.

Galaxy And Mass Assembly (GAMA): the effect of galaxy group environment on active galactic nuclei

NASA Astrophysics Data System (ADS)

Gordon, Yjan A.; Pimbblet, Kevin A.; Owers, Matt S.; Bland-Hawthorn, Joss; Brough, Sarah; Brown, Michael J. I.; Cluver, Michelle E.; Croom, Scott M.; Holwerda, Benne W.; Loveday, Jonathan; Mahajan, Smriti; Wang, Lingyu

2018-04-01

In galaxy clusters, efficiently accreting active galactic nuclei (AGNs) are preferentially located in the infall regions of the cluster projected phase-space, and are rarely found in the cluster core. This has been attributed to both an increase in triggering opportunities for infalling galaxies, and a reduction of those mechanisms in the hot, virialized, cluster core. Exploiting the depth and completeness (98 per cent at r < 19.8 mag) of the Galaxy And Mass Assembly survey (GAMA), we probe down the group halo mass function to assess whether AGNs are found in the same regions in groups as they are in clusters. We select 451 optical AGNs from 7498 galaxies with log10(M*/M⊙) > 9.9 in 695 groups with 11.53 ≤ log10(M200/M⊙) ≤ 14.56 at z < 0.15. By analysing the projected phase-space positions of these galaxies, we demonstrate that when split both radially, and into physically derived infalling and core populations, AGN position within group projected phase-space is dependent on halo mass. For groups with log10(M200/M⊙) > 13.5, AGNs are preferentially found in the infalling galaxy population with 3.6σ confidence. At lower halo masses, we observe no difference in AGN fraction between core and infalling galaxies. These observations support a model where a reduced number of low-speed interactions, ram pressure stripping and intra-group/cluster medium temperature, the dominance of which increase with halo mass, work to inhibit AGN in the cores of groups and clusters with log10(M200/M⊙) > 13.5, but do not significantly affect nuclear activity in cores of less massive structures.

Oil-bearing sediments of Gondwana glaciation in Oman

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

Levell, B.K.; Braakman, J.H.; Rutten, K.W.

1988-07-01

More than 3.5 billion bbl of oil in place have so far been discovered in reservoirs of the Al Khlata Formation of the Permian-Carboniferous lower Haushi Group in south Oman. Glacially striated pavements and boulders in exposures at Al Khlata in east-central Oman confirmed previous interpretations that the formation is, at least partly, of glacial origin. Core and wireline-log data from some 500 wells that penetrate the formation show that glacial facies are widespread in the subsurface. Shales with varvelike laminations and dropstones are present in two main layers, which extend over the larger part of south Oman and aremore » perhaps the most diagnostic facies. Diamictites are also widespread, and some, which can be correlated as sheets over thousands of square kilometers, are interpreted as true tillites. Other diamictites are interbedded with shales with varvelike laminations or unbedded siltstones and are interpreted as subaqueous glacial deposits. Ten sedimentary facies have been described in cores and outcrops. An important result of this study is a formal scheme to interpret these facies from wireline logs using quantitative analysis of density and neutron logs and qualitative information from other logs. Lateral facies relationships are complicated by syndepositional salt withdrawal and dissolution, paleorelief on the basal unconformity, and intraformational unconformities beneath regionally extensive tillites. At least three glacial phases can be recognized: an early phase, represented only by erosional remnants of diamictites, and two later phases, the last of which extended over the whole of Oman south of the Oman Mountains. Deglaciation is represented by a regional shale bed sharply overlying the diamictite sheet of this last glaciation. 19 figures, 1 table.« less

Statistical characterization of Earth’s heterogeneities from seismic scattering

NASA Astrophysics Data System (ADS)

Zheng, Y.; Wu, R.

2009-12-01

The distortion of a teleseismic wavefront carries information about the heterogeneities through which the wave propagates and it is manifestited as logarithmic amplitude (logA) and phase fluctuations of the direct P wave recorded by a seismic network. By cross correlating the fluctuations (e.g., logA-logA or phase-phase), we obtain coherence functions, which depend on spatial lags between stations and incident angles between the incident waves. We have mathematically related the depth-dependent heterogeneity spectrum to the observable coherence functions using seismic scattering theory. We will show that our method has sharp depth resolution. Using the HiNet seismic network data in Japan, we have inverted power spectra for two depth ranges, ~0-120km and below ~120km depth. The coherence functions formed by different groups of stations or by different groups of earthquakes at different back azimuths are similar. This demonstrates that the method is statistically stable and the inhomogeneities are statistically stationary. In both depth intervals, the trend of the spectral amplitude decays from large scale to small scale in a power-law fashion with exceptions at ~50km for the logA data. Due to the spatial spacing of the seismometers, only information from length scale 15km to 200km is inverted. However our scattering method provides new information on small to intermediate scales that are comparable to scales of the recycled materials and thus is complimentary to the global seismic tomography which reveals mainly large-scale heterogeneities on the order of ~1000km. The small-scale heterogeneities revealed here are not likely of pure thermal origin. Therefore, the length scale and strength of heterogeneities as a function of depth may provide important constraints in mechanical mixing of various components in the mantle convection.

Lethality of chlorine, chlorine dioxide, and a commercial fruit and vegetable sanitizer to vegetative cells and spores of Bacillus cereus and spores of Bacillus thuringiensis.

PubMed

Beuchat, Larry R; Pettigrew, Charles A; Tremblay, Mario E; Roselle, Brian J; Scouten, Alan J

2004-08-01

Chlorine, ClO2, and a commercial raw fruit and vegetable sanitizer were evaluated for their effectiveness in killing vegetative cells and spores of Bacillus cereus and spores of Bacillus thuringiensis. The ultimate goal was to use one or both species as a potential surrogate(s) for Bacillus anthracis in studies that focus on determining the efficacy of sanitizers in killing the pathogen on food contact surfaces and foods. Treatment with alkaline (pH 10.5 to 11.0) ClO2 (200 microg/ml) produced by electrochemical technologies reduced populations of a five-strain mixture of vegetative cells and a five-strain mixture of spores of B. cereus by more than 5.4 and more than 6.4 log CFU/ml respectively, within 5 min. This finding compares with respective reductions of 4.5 and 1.8 log CFU/ml resulting from treatment with 200 microg/ml of chlorine. Treatment with a 1.5% acidified (pH 3.0) solution of Fit powder product was less effective, causing 2.5- and 0.4-log CFU/ml reductions in the number of B. cereus cells and spores, respectively. Treatment with alkaline ClO2 (85 microg/ml), acidified (pH 3.4) ClO2 (85 microg/ml), and a mixture of ClO2 (85 microg/ml) and Fit powder product (0.5%) (pH 3.5) caused reductions in vegetative cell/spore populations of more than 5.3/5.6, 5.3/5.7, and 5.3/6.0 log CFU/ml, respectively. Treatment of B. cereus and B. thuringiensis spores in a medium (3.4 mg/ml of organic and inorganic solids) in which cells had grown and produced spores with an equal volume of alkaline (pH 12.1) ClO2 (400 microg/ml) for 30 min reduced populations by 4.6 and 5.2 log CFU/ml, respectively, indicating high lethality in the presence of materials other than spores that would potentially react with and neutralize the sporicidal activity of ClO2.

Effect of high-pressure processing on reduction of Listeria monocytogenes in packaged Queso Fresco.

PubMed

Tomasula, P M; Renye, J A; Van Hekken, D L; Tunick, M H; Kwoczak, R; Toht, M; Leggett, L N; Luchansky, J B; Porto-Fett, A C S; Phillips, J G

2014-03-01

The effect of high-hydrostatic-pressure processing (HPP) on the survival of a 5-strain rifampicin-resistant cocktail of Listeria monocytogenes in Queso Fresco (QF) was evaluated as a postpackaging intervention. Queso Fresco was made using pasteurized, homogenized milk, and was starter-free and not pressed. In phase 1, QF slices (12.7 × 7.6 × 1 cm), weighing from 52 to 66 g, were surface inoculated with L. monocytogenes (ca. 5.0 log10 cfu/g) and individually double vacuum packaged. The slices were then warmed to either 20 or 40°C and HPP treated at 200, 400, and 600 MPa for hold times of 5, 10, 15, or 20 min. Treatment at 600 MPa was most effective in reducing L. monocytogenes to below the detection level of 0.91 log10 cfu/g at all hold times and temperatures. High-hydrostatic-pressure processing at 40°C, 400 MPa, and hold time ≥ 15 min was effective but resulted in wheying-off and textural changes. In phase 2, L. monocytogenes was inoculated either on the slices (ca. 5.0 log10 cfu/g; ON) or in the curds (ca. 7.0 log10 cfu/g; IN) before the cheese block was formed and sliced. The slices were treated at 20°C and 600 MPa at hold times of 3, 10, and 20 min, and then stored at 4 and 10°C for 60 d. For both treatments, L. monocytogenes became less resistant to pressure as hold time increased, with greater percentages of injured cells at 3 and 10 min than at 20 min, at which the lethality of the process increased. For the IN treatment, with hold times of 3 and 10 min, growth of L. monocytogenes increased the first week of storage, but was delayed for 1 wk, with a hold time of 20 min. Longer lag times in growth of L. monocytogenes during storage at 4°C were observed for the ON treatment at hold times of 10 and 20 min, indicating that the IN treatment may have provided a more protective environment with less injury to the cells than the ON treatment. Similarly, HPP treatment for 10 min followed by storage at 4°C was the best method for suppressing the growth of the endogenous microflora with bacterial counts remaining below the level of detection for 2 out of the 3 QF samples for up to 84 d. Lag times in growth were not observed during storage of QF at 10°C. Although HPP reduced L. monocytogenes immediately after processing, a second preservation technique is necessary to control growth of L. monocytogenes during cold storage. However, the results also showed that HPP would be effective for slowing the growth of microorganisms that can shorten the shelf life of QF. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Analyzing Decision Logs to Understand Decision Making in Serious Crime Investigations.

PubMed

Dando, Coral J; Ormerod, Thomas C

2017-12-01

Objective To study decision making by detectives when investigating serious crime through the examination of decision logs to explore hypothesis generation and evidence selection. Background Decision logs are used to record and justify decisions made during serious crime investigations. The complexity of investigative decision making is well documented, as are the errors associated with miscarriages of justice and inquests. The use of decision logs has not been the subject of an empirical investigation, yet they offer an important window into the nature of investigative decision making in dynamic, time-critical environments. Method A sample of decision logs from British police forces was analyzed qualitatively and quantitatively to explore hypothesis generation and evidence selection by police detectives. Results Analyses revealed diversity in documentation of decisions that did not correlate with case type and identified significant limitations of the decision log approach to supporting investigative decision making. Differences emerged between experienced and less experienced officers' decision log records in exploration of alternative hypotheses, generation of hypotheses, and sources of evidential inquiry opened over phase of investigation. Conclusion The practical use of decision logs is highly constrained by their format and context of use. Despite this, decision log records suggest that experienced detectives display strategic decision making to avoid confirmation and satisficing, which affect less experienced detectives. Application Potential applications of this research include both training in case documentation and the development of new decision log media that encourage detectives, irrespective of experience, to generate multiple hypotheses and optimize the timely selection of evidence to test them.

Liquid-liquid distribution of ion associates of tetrabromoindate(III) with quaternary ammonium counter ions.

PubMed

Yamamoto, K; Matsumoto, A

1997-11-01

The solvent extraction of an ion associate of tetrabromoindate(III) ion, InBr(-)(4), with quaternary ammonium cations (Q(+)) has been studied. The extraction constant (K(ex)) were determined for the ion associates of InBr(-)(4) with Q(+) between an aqueous phase and several organic phases (chloroform, chlorobenzene, benzene and toluene). A linear relationship was found between log K(ex) and the total number of carbon atoms in Q(+); from the slope of the lines, the contribution of a methylene group to log K(ex) was calculated to be 0.91 for the chloroform extraction system and 0.52 for the other extraction systems. The extractability with alkyltrimethylammonium cations was larger than that with symmetrical tetraalkylammonium cations and the mean difference in log K(ex) for two cations (one of each type) with the same number of carbon atoms was about 1.3. From the extraction constant obtained, the extractability of InBr(-)(4) among metal-halogeno complex anions was in the order TlBr(-)(4) > BiI(-)(4) > AuBr(-)(4) > AuCl(-)(4) > TlCl(-)(4) > InBr(-)(4) > CuCl(-)(2).

Solubilization of polycyclic aromatic hydrocarbons in micellar nonionic surfactant solutions

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

Edwards, D.A.; Luthy, R.G.; Liu, Zhongbao

1991-01-01

Experimental data are presented on the enhanced apparent solubilities of naphthalene, phenanthrene, and pyrene resulting from solubilization in aqueous solutions of four commercial, nonionic surfactants: an alkyl polyoxyethylene (POE) type, two octylphenol POE types, and a nonylphenol POE type. Apparent solubilities of the polycyclic aromatic hydrocarbon (PAH) compounds in surfactant solutions were determined by radiolabeled techniques. Solubilization of each PAH compound commenced at the surfactant critical micelle concentration and was proportional to the concentration of surfactant in micelle form. The partitioning of organic compounds between surfactant micelles and aqueous solution is characterized by a mole fraction micelle-phase/aqueous-phase partition coefficient, K{submore » m}. Values of log K{sub m} for PAH compounds in surfactant solutions of this study range from 4.57 to 6.53. Log K{sub m} appears to be a linear function of log K{sub ow} for a given surfactant solution. A knowledge of partitioning in aqueous surfactant systems is a prerequisite to understanding mechanisms affecting the behavior of hydrophobic organic compounds in soil-water systems in which surfactants play a role in contaminant remediation or facilitated transport.« less

Structure-based design, synthesis, and biological evaluation of withaferin A-analogues as potent apoptotic inducers.

PubMed

Llanos, Gabriel G; Araujo, Liliana M; Jiménez, Ignacio A; Moujir, Laila M; Rodríguez, Jaime; Jiménez, Carlos; Bazzocchi, Isabel L

2017-11-10

Apoptosis inducers represent an attractive approach for the discovery and development of anticancer agents. Herein, we report on the development by molecular fine tuning of a withaferin A-based library of 63 compounds (2-64), 53 of them reported for the first time. Their antiproliferative evaluation on HeLa, A-549 and MCF-7 human tumor cell lines identified fifteen analogues displaying higher activity (IC 50 values ranging 0.3-4.8 μM) than the lead (IC 50 values ranging 1.3-10.1 μM) either in lag or log growth phases. SAR analysis revealed that acylation enhances cytotoxicity, suggesting the hydrophobic moiety contributes to the activity, presumably by increasing affinity and/or cell membrane permeability. Further investigation clearly indicated that compounds 3, 11, 12, and 18 induce apoptosis evidenced by chromatin condensation, phosphatidylserine externalization, and caspase-3 activation effects on HeLa cells. The potent capacity to induce apoptosis with concomitant cell loss in G2/M highlights the potential of 27-benzyl analogue (18) as an apoptotic inducer drug candidate. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Odorant responses of olfactory sensory neurons expressing the odorant receptor MOR23: A patch clamp analysis in gene-targeted mice

PubMed Central

Grosmaitre, Xavier; Vassalli, Anne; Mombaerts, Peter; Shepherd, Gordon M.; Ma, Minghong

2006-01-01

A glomerulus in the mammalian olfactory bulb receives axonal inputs from olfactory sensory neurons (OSNs) that express the same odorant receptor (OR). Glomeruli are generally thought to represent functional units of olfactory coding, but there are no data on the electrophysiological properties of OSNs that express the same endogenous OR. Here, using patch clamp recordings in an intact epithelial preparation, we directly measured the transduction currents and receptor potentials from the dendritic knobs of mouse OSNs that express the odorant receptor MOR23 along with the green fluorescent protein. All of the 53 cells examined responded to lyral, a known ligand for MOR23. There were profound differences in response kinetics, particularly in the deactivation phase. The cells were very sensitive to lyral, with some cells responding to as little as 10 nM. The dynamic range was unexpectedly broad, with threshold and saturation in individual cells often covering three log units of lyral concentration. The potential causes and biological significance of this cellular heterogeneity are discussed. Patch clamp recording from OSNs that express a defined OR provides a powerful approach to investigate the sensory inputs to individual glomeruli. PMID:16446455

Odorant responses of olfactory sensory neurons expressing the odorant receptor MOR23: a patch clamp analysis in gene-targeted mice.

PubMed

Grosmaitre, Xavier; Vassalli, Anne; Mombaerts, Peter; Shepherd, Gordon M; Ma, Minghong

2006-02-07

A glomerulus in the mammalian olfactory bulb receives axonal inputs from olfactory sensory neurons (OSNs) that express the same odorant receptor (OR). Glomeruli are generally thought to represent functional units of olfactory coding, but there are no data on the electrophysiological properties of OSNs that express the same endogenous OR. Here, using patch clamp recordings in an intact epithelial preparation, we directly measured the transduction currents and receptor potentials from the dendritic knobs of mouse OSNs that express the odorant receptor MOR23 along with the green fluorescent protein. All of the 53 cells examined responded to lyral, a known ligand for MOR23. There were profound differences in response kinetics, particularly in the deactivation phase. The cells were very sensitive to lyral, with some cells responding to as little as 10 nM. The dynamic range was unexpectedly broad, with threshold and saturation in individual cells often covering three log units of lyral concentration. The potential causes and biological significance of this cellular heterogeneity are discussed. Patch clamp recording from OSNs that express a defined OR provides a powerful approach to investigate the sensory inputs to individual glomeruli.

Effect of sodium-alginate and laminaran on Salmonella Typhimurium infection in human enterocyte-like HT-29-Luc cells and BALB/c mice.

PubMed

Kuda, Takashi; Kosaka, Misa; Hirano, Shino; Kawahara, Miho; Sato, Masahiro; Kaneshima, Tai; Nishizawa, Makoto; Takahashi, Hajime; Kimura, Bon

2015-07-10

Brown algal polysaccharides such as alginate, polymers of uronic acids, and laminaran, beta-1,3 and 1,6-glucan, can be fermented by human intestinal microbiota. To evaluate the effects of these polysaccharides on infections caused by food poisoning pathogens, we investigated the adhesion and invasion of pathogens (Salmonella Typhimurium, Listeria monocytogenes and Vibrio parahaemolyticus) in human enterocyte-like HT-29-Luc cells and in infections caused in BALB/c mice. Both sodium Na-alginate and laminaran (0.1% each) inhibited the adhesion of the pathogens to HT-29-Luc cells by approximately 70-90%. The invasion of S. Typhimurium was also inhibited by approximately 70 and 80% by Na-alginate and laminaran, respectively. We observed that incubation with Na-alginate for 18 h increased the transepithelial electrical resistance of HT-29-Luc monolayer cells. Four days after inoculation with 7 log CFU/mouse of S. Typhimurium, the faecal pathogen count in mice that were not fed polysaccharides (control mice) was about 6.5 log CFU/g while the count in mice that were fed Na-alginate had decreased to 5.0 log CFU/g. The liver pathogen count, which was 4.1 log CFU/g in the control mice, was also decreased in mice that were fed Na-alginate. In contrast, the mice that were fed laminaran exhibited a more severe infection than that exhibited by control mice. Copyright © 2015 Elsevier Ltd. All rights reserved.

Maltodextrin enhances biofilm elimination by electrochemical scaffold

PubMed Central

Sultana, Sujala T.; Call, Douglas R.; Beyenal, Haluk

2016-01-01

Electrochemical scaffolds (e-scaffolds) continuously generate low concentrations of H2O2 suitable for damaging wound biofilms without damaging host tissue. Nevertheless, retarded diffusion combined with H2O2 degradation can limit the efficacy of this potentially important clinical tool. H2O2 diffusion into biofilms and bacterial cells can be increased by damaging the biofilm structure or by activating membrane transportation channels by exposure to hyperosmotic agents. We hypothesized that e-scaffolds would be more effective against Acinetobacter baumannii and Staphylococcus aureus biofilms in the presence of a hyperosmotic agent. E-scaffolds polarized at −600 mVAg/AgCl were overlaid onto preformed biofilms in media containing various maltodextrin concentrations. E-scaffold alone decreased A. baumannii and S. aureus biofilm cell densities by (3.92 ± 0.15) log and (2.31 ± 0.12) log, respectively. Compared to untreated biofilms, the efficacy of the e-scaffold increased to a maximum (8.27 ± 0.05) log reduction in A. baumannii and (4.71 ± 0.12) log reduction in S. aureus biofilm cell densities upon 10 mM and 30 mM maltodextrin addition, respectively. Overall ~55% decrease in relative biofilm surface coverage was achieved for both species. We conclude that combined treatment with electrochemically generated H2O2 from an e-scaffold and maltodextrin is more effective in decreasing viable biofilm cell density. PMID:27782161

An "ASYMPTOTIC FRACTAL" Approach to the Morphology of Malignant Cell Nuclei

NASA Astrophysics Data System (ADS)

Landini, Gabriel; Rippin, John W.

To investigate quantitatively nuclear membrane irregularity, 672 nuclei from 10 cases of oral cancer (squamous cell carcinoma) and normal cells from oral mucosa were studied in transmission electron micrographs. The nuclei were photographed at ×1400 magnification and transferred to computer memory (1 pixel = 35 nm). The perimeter of the profiles was analysed using the "yardstick method" of fractal dimension estimation, and the log-log plot of ruler size vs. boundary length demonstrated that there exists a significant effect of resolution on length measurement. However, this effect seems to disappear at higher resolutions. As this observation is compatible with the concept of asymptotic fractal, we estimated the parameters c, L and Bm from the asymptotic fractal formula Br = Bm {1 + (r / L)c}-1 , where Br is the boundary length measured with a ruler of size r, Bm is the maximum boundary for r → 0, L is a constant, and c = asymptotic fractal dimension minus topological dimension (D - Dt) for r → ∞. Analyses of variance showed c to be significantly higher in the normal than malignant cases (P < 0.001), but log(L) and Bm to be significantly higher in the malignant cases (P < 0.001). A multivariate linear discrimination analysis on c, log(L) and Bm re-classified 76.6% of the cells correctly (84.8% of the normal and 67.5% of the tumor). Furthermore, this shows that asymptotic fractal analysis applied to nuclear profiles has great potential for shape quantification in diagnosis of oral cancer.

Low ergosterol content in yeast adh1 mutant enhances chitin maldistribution and sensitivity to paraquat-induced oxidative stress.

PubMed

Marisco, G; Saito, S T; Ganda, I S; Brendel, M; Pungartnik, C

2011-05-01

Alcohol dehydrogenases catalyse the reversible oxidation of alcohols to aldehydes or ketones, with concomitant reduction of NAD(+) or NADP(+) . Adh1p is responsible for the reduction of acetaldehyde to ethanol, while Adh2p catalyses the reverse reaction, the oxidation of ethanol to acetaldehyde. Lack of Adh1p shifts the cellular redox balance towards excess NADH/NADPH and acetaldehyde, while absence of Adh2p does the opposite. Yeast mutant adh1Δ had a slow growth rate, whereas adh2Δ grew like the isogenic wild-type (WT) during prediauxic shift fermentative metabolism. After 48 h WT and mutants reached the same number of viable cells. When exponentially growing (LOG) cells were exposed to calcofluor white, only mutant adh1Δ displayed an irregular deposition of chitin. Quantitative analyses of both LOG and stationary-phase cells showed that adh1Δ mutant contained significantly less ergosterol than cells of WT and adh2Δ mutant, whereas the erg3Δ mutant contained extremely low ergosterol pools. Both adh1Δ and adh2Δ mutants showed higher-than-WT resistance to heat shock and to H(2) O(2) but had WT resistance when exposed to ultraviolet (UV) light and the DNA cross-linking agent diepoxyoctane, indicating normal DNA repair capacity. Mutant adh1Δ was specifically sensitive to acetaldehyde and to membrane peroxidizing paraquat. Our results link the pleiotropic phenotype of adh1Δ mutants to low pools of ergosterol and to reductive stress, and introduce the two new phenotypes, resistance to heat shock and to H(2) O(2) , for the adh2Δ mutant, most probably related to increased ROS production in mitochondria, which leads to the induction of oxidative stress protection. Copyright © 2011 John Wiley & Sons, Ltd.

A simple graphical representation of selectivity in hydrophilic interaction liquid chromatography.

PubMed

Ibrahim, Mohammed E A; Liu, Yang; Lucy, Charles A

2012-10-19

This paper uses the HILIC selectivity data of Dinh et al. (J. Chromatogr. A 1218 (2011) 5880) to yield simple and easy to understand plots analogous to Neue plots for selectivity in HILIC. The plots categorize 21 previously studied HILIC phases (data from Dinh et al.), 8 additional HILIC columns and 4 reversed phase columns (our data) using selected probes for specific interactions. The relative retention of cytosine vs. uracil is used to probe the "hydrophilicity" of the HILIC phases; adenosine vs. adenine is used to probe the ability of the stationary phase to participate in hydrogen bonding; and benzyltrimethylammonium (BTMA) vs. cytosine is used to probe the cation exchange and anion exchange character of the column. Plots of kBTMA/kcytosine vs. kcytosine/kuracil successfully classify silica, amide, zwitterionic, diol and reverse phase columns in terms of their HILIC behavior. Polymeric columns including polymer substrate and polymer coated columns show low ion exchange character, but vary widely in their hydrophilicity. Alternatively a HILIC-Phase Selectivity Chart, in analogy to the Neue plot, is constructed by plotting log(kBTMA/kcytosine) vs. log(kcytosine). This plot enables classification of HILIC columns that will yield similar or significantly different separations. Copyright © 2012 Elsevier B.V. All rights reserved.

Effect of physiological age on radiation resistance of some bacteria that are highly radiation resistant. [Micrococcus radiodurans; Micrococcus sp. isolate C-3; Moraxella sp isolate 4; Escherichia coli

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

Keller, L.C.; Maxcy, R.B.

1984-05-01

Physiological age-dependent variation in radiation resistance was studied for three bacteria that are highly radiation resistant: Micrococcus radiodurans, Micrococcus sp. isolate C-3, and Moraxella sp. isolate 4. Stationary-phase cultures of M. radiodurans and isolate C-3 were much more resistant to gamma radiation than were log-phase cultures. This pattern of relative resistance was reversed for isolate 4. Resistance of isolate 4 to UV light was also greater during log phase, although heat resistance and NaCl tolerance after heat stresses were greater during stationary phase. Radiation-induced injury of isolate 4 compared with injury of Escherichia coli B suggested that the injury process,more » as well as the lethal process, was affected by growth phase. The hypothesis that growth rate affects radiation resistance was tested, and results were interpreted in light of the probable confounding effect of methods used to alter growth rates of bacteria. These results indicate that dose-response experiments should be designed to measure survival during the most resistant growth phase of the organism under study. The timing is particularly important when extrapolations of survival results might be made to potential irradiation processes for foods. 17 references.« less

Measurement of diffusion coefficients of parabens and steroids in water and 1-octanol.

PubMed

Seki, Toshinobu; Mochida, Junko; Okamoto, Maiko; Hosoya, Osamu; Juni, Kazuhiko; Morimoto, Kazuhiro

2003-06-01

Diffusion coefficients (D) of parabens and steroids in water and 1-octanol were determined by using the chromatographic broadening method at 37 degrees C, and the relationships between the D values and the physicochemical properties of the drugs were discussed. The D values in 1-octanol were lower than those in water because of the higher viscosity of 1-octanol. The D values depend on not only the molecular weight (MW), but also the lipophilicity of the drugs in water and on the ability for hydrogen-bonding in 1-octanol. When the lipophilic index (LI), calculated from the retention time using in a reverse-phase column, was used as a parameter of drug lipophilicity, the following equation was obtained for D in water (D(w)); log D(w)=-0.215.log MW-0.077.log LI-4.367. When the hydrogen bond index (HI), the logarithm of the ratio of the partition coefficient of the drugs in 1-octanol and cyclohexane, was used as an index of hydrogen-bonding, the following equation was obtained for D in 1-octanol (D(o)); log D(o)=-0.690.log MW-0.074.log HI-4.085.

Effects of chain length, chlorination degree, and structure on the octanol-water partition coefficients of polychlorinated n-alkanes.

PubMed

Hilger, Bettina; Fromme, Hermann; Völkel, Wolfgang; Coelhan, Mehmet

2011-04-01

Log octanol-water partition coefficients (log Kow) of 40 synthesized polychlorinated n-alkanes (PCAs) with different chlorination degrees were determined using reversed-phase high performance liquid chromatography (RP-HPLC). In addition, log Kow values of a technical mixture namely Cereclor 63L as well as 15 individual in house synthesized C10, C11, and C12 chloroalkanes with known chlorine positions were estimated. Based on these results, the effects of chain length, chlorination degree, and structure were explored. The estimated log Kow values ranged from 4.10 (polychlorinated n-decanes with 50.2% chlorine content) to 11.34 (polychlorinated n-octacosanes with 54.8% chlorine content) for PCAs and from 3.82 (1,2,5,6,9,10-hexachlorodecane) to 7.75 (1,1,1,3,9,11,11,11-octachlorododecane) for the individual chloroalkanes studied. The results showed that log Kow value was influenced linearly at a given chlorine content by chain length, while a polynominal effect was observed in dependence on the chlorination degree of an alkane chain. Chlorine substitution pattern influenced markedly the log Kow value of chloroalkanes.

Comparison of methods for quantitating Salmonella enterica Typhimurium and Heidelberg strain attachment to reusable plastic shipping container coupons and preliminary assessment of sanitizer efficacy.

PubMed

Shi, Zhaohao; Baker, Christopher A; Lee, Sang In; Park, Si Hong; Kim, Sun Ae; Ricke, Steven C

2016-09-01

Salmonella serovars, one of the leading contributors to foodborne illness and are especially problematic for foods that are not cooked before consumption, such as fresh produce. The shipping containers that are used to transport and store fresh produce may play a role in cross contamination and subsequent illnesses. However, methods for quantitatively attached cells are somewhat variable. The overall goal of this study was to compare conventional plating with molecular methods for quantitating attached representative strains for Salmonella Typhimurium and Heidelberg on reusable plastic containers (RPC) coupons, respectively. We attached Salmonella enterica serovar Typhimurium ATCC 14028 and serovar Heidelberg SL486 (parent and an antibiotic resistant marker strain) to plastic coupons (2.54 cm(2)) derived from previously used shipping containers by growing for 72 h in tryptic soy broth. The impact of the concentration of sanitizer on log reductions between unsanitized and sanitized coupons was evaluated by exposing attached S. Typhimurium cells to 200 ppm and 200,000 ppm sodium hypochlorite (NaClO). Differences in sanitizer effectiveness between serovars were also evaluated with attached S. Typhimurium compared to attached S. Heidelberg populations after being exposed to 200 ppm peracetic acid (PAA). Treatment with NaClO caused an average of 2.73 ± 0.23 log CFU of S. Typhimurium per coupon removed with treatment at 200 ppm while 3.36 ± 0.54 log CFU were removed at 200,000 ppm. Treatment with PAA caused an average of 2.62 ± 0.15 log CFU removed for S. Typhimurium and 1.41 ± 0.17 log CFU for S. Heidelberg (parent) and 1.61 ± 0.08 log CFU (marker). Lastly, scanning electron microscopy (SEM) was used to visualize cell attachment and coupon surface topography. SEM images showed that remaining attached cell populations were visible even after sanitizer application. Conventional plating and qPCR yielded similar levels of enumerated bacterial populations indicating a high concordance between the two methods. Therefore, qPCR could be used for the rapid quantification of Salmonella attached on RPC.

Bioconcentration of chlorinated hydrocarbons from sediment by oligochaetes

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

Connell, D.W.; Bowman, M.; Hawker, D.W.

1988-12-01

Previously published data on the accumulation of 15 chlorinated hydrocarbons from sediment by oligochaetes have been interpreted on the basis of bioconcentration from interstitial water. Calculation of the interstitial water concentration allowed determination of uptake and clearance rate constants together with bioconcentration factors (KB) for these compounds. These three factors each exhibited a systematic relationship to the octanol/water partition coefficient (KOW). The log KB versus log KOW relationship was roughly linear over the log KOW range from 4.4 to 6.4 and displayed an increasing nonlinear deviation for log KOW values greater than 6.4. These relationships are qualitatively similar to thosemore » established for other aquatic organisms where bioconcentration from water was the mechanism involved. This suggests that interstitial water may be the phase from which lipophilic compounds in sediment are bioconcentrated by oligochaetes. An expression relating the bioconcentration factor to the biotic concentration and various sediment characteristics has also been developed.« less

Two biomarker-directed randomized trials in European and Chinese patients with nonsmall-cell lung cancer: the BRCA1-RAP80 Expression Customization (BREC) studies.

PubMed

Moran, T; Wei, J; Cobo, M; Qian, X; Domine, M; Zou, Z; Bover, I; Wang, L; Provencio, M; Yu, L; Chaib, I; You, C; Massuti, B; Song, Y; Vergnenegre, A; Lu, H; Lopez-Vivanco, G; Hu, W; Robinet, G; Yan, J; Insa, A; Xu, X; Majem, M; Chen, X; de Las Peñas, R; Karachaliou, N; Sala, M A; Wu, Q; Isla, D; Zhou, Y; Baize, N; Zhang, F; Garde, J; Germonpre, P; Rauh, S; ALHusaini, H; Sanchez-Ronco, M; Drozdowskyj, A; Sanchez, J J; Camps, C; Liu, B; Rosell, R

2014-11-01

In a Spanish Lung Cancer Group (SLCG) phase II trial, the combination of BRCA1 and receptor-associated protein 80 (RAP80) expression was significantly associated with outcome in Caucasian patients with nonsmall-cell lung cancer (NSCLC). The SLCG therefore undertook an industry-independent collaborative randomized phase III trial comparing nonselected cisplatin-based chemotherapy with therapy customized according to BRCA1/RAP80 expression. An analogous randomized phase II trial was carried out in China under the auspices of the SLCG to evaluate the effect of BRCA1/RAP80 expression in Asian patients. Eligibility criteria included stage IIIB-IV NSCLC and sufficient tumor specimen for molecular analysis. Randomization to the control or experimental arm was 1 : 1 in the SLCG trial and 1 : 3 in the Chinese trial. In both trials, patients in the control arm received docetaxel/cisplatin; in the experimental arm, patients with low RAP80 expression received gemcitabine/cisplatin, those with intermediate/high RAP80 expression and low/intermediate BRCA1 expression received docetaxel/cisplatin, and those with intermediate/high RAP80 expression and high BRCA1 expression received docetaxel alone. The primary end point was progression-free survival (PFS). Two hundred and seventy-nine patients in the SLCG trial and 124 in the Chinese trial were assessable for PFS. PFS in the control and experimental arms in the SLCG trial was 5.49 and 4.38 months, respectively [log rank P = 0.07; hazard ratio (HR) 1.28; P = 0.03]. In the Chinese trial, PFS was 4.74 and 3.78 months, respectively (log rank P = 0.82; HR 0.95; P = 0.82). Accrual was prematurely closed on the SLCG trial due to the absence of clinical benefit in the experimental over the control arm. However, the BREC studies provide proof of concept that an international, nonindustry, biomarker-directed trial is feasible. Thanks to the groundwork laid by these studies, we expect that ongoing further research on alternative biomarkers to elucidate DNA repair mechanisms will help define novel therapeutic approaches. NCT00617656/GECP-BREC and ChiCTR-TRC-12001860/BREC-CHINA. © The Author 2014. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Safety and immunogenicity of a live attenuated mumps vaccine

PubMed Central

Liang, Yan; Ma, Jingchen; Li, Changgui; Chen, Yuguo; Liu, Longding; Liao, Yun; Zhang, Ying; Jiang, Li; Wang, Xuan-Yi; Che, Yanchun; Deng, Wei; Li, Hong; Cui, Xiaoyu; Ma, Na; Ding, Dong; Xie, Zhongping; Cui, Pingfang; Ji, Qiuyan; Wang, Jingjing; Zhao, Yuliang; Wang, Junzhi; Li, Qihan

2014-01-01

Background: Mumps, a communicable, acute and previously well-controlled disease, has had recent and occasional resurgences in some areas. Methods: A randomized, double-blind, controlled and multistep phase I study of an F-genotype attenuated mumps vaccine produced in human diploid cells was conducted. A total of 300 subjects were enrolled and divided into 4 age groups: 16–60 years, 5–16 years, 2–5 years and 8–24 months. The groups were immunized with one injection per subject. Three different doses of the F-genotype attenuated mumps vaccine, A (3.5 ± 0.25 logCCID50), B (4.25 ± 0.25 logCCID50) and C (5.0 ± 0.25 logCCID50), as well as a placebo control and a positive control of a licensed A-genotype vaccine (S79 strain) were used. The safety and immunogenicity of this vaccine were compared with those of the controls. Results: The safety evaluation suggested that mild adverse reactions were observed in all groups. No serious adverse event (SAE) was reported throughout the trial. The immunogenicity test showed a similar seroconversion rate of the neutralizing and ELISA antibody in the 2- to 5-year-old and 8- to 24-month-old groups compared with the seroconversion rate in the positive control. The GMT of the neutralizing anti-F-genotype virus antibodies in the vaccine groups was slightly higher than that in the positive control group. Conclusions: The F-genotype attenuated mumps vaccine evaluated in this clinical trial was demonstrated to be safe and have effective immunogenicity vs. control. PMID:24614759

Gas/particle partitioning and particle size distribution of PCDD/Fs and PCBs in urban ambient air.

PubMed

Barbas, B; de la Torre, A; Sanz, P; Navarro, I; Artíñano, B; Martínez, M A

2018-05-15

Urban ambient air samples, including gas-phase (PUF), total suspended particulates (TSP), PM 10 , PM 2.5 and PM 1 airborne particle fractions were collected to evaluate gas-particle partitioning and size particle distribution of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs). Clausius-Clapeyron equation, regressions of logKp vs logP L and logK OA, and human respiratory risk assessment were used to evaluate local or long-distance transport sources, gas-particle partitioning sorption mechanisms, and implications for health. Total ambient air levels (gas phase+particulate phase) of TPCBs and TPCDD/Fs, were 437 and 0.07pgm -3 (median), respectively. Levels of PCDD/F in the gas phase (0.004-0.14pgm -3 , range) were significantly (p<0.05) lower than those found in the particulate phase (0.02-0.34pgm -3 ). The concentrations of PCDD/Fs were higher in winter. In contrast, PCBs were mainly associated to the gas phase, and displayed maximum levels in warm seasons, probably due to an increase in evaporation rates, supported by significant and strong positive dependence on temperature observed for several congeners. No significant differences in PCDD/Fs and PCBs concentrations were detected between the different particle size fractions considered (TSP, PM 10 , PM 2.5 and PM 1 ), reflecting that these chemicals are mainly bounded to PM 1 . The toxic content of samples was also evaluated. Total toxicity (PUF+TSP) attributable to dl-PCBs (13.4fg-TEQ 05 m -3 , median) was higher than those reported for PCDD/Fs (6.26fg-TEQ 05 m -3 ). The inhalation risk assessment concluded that the inhalation of PCDD/Fs and dl-PCBs pose a low cancer risk in the studied area. Copyright © 2017 Elsevier B.V. All rights reserved.

Impact of food model (micro)structure on the microbial inactivation efficacy of cold atmospheric plasma.

PubMed

Smet, C; Noriega, E; Rosier, F; Walsh, J L; Valdramidis, V P; Van Impe, J F

2017-01-02

The large potential of cold atmospheric plasma (CAP) for food decontamination has recently been recognized. Room-temperature gas plasmas can decontaminate foods without causing undesired changes. This innovative technology is a promising alternative for treating fresh produce. However, more fundamental studies are needed before its application in the food industry. The impact of the food structure on CAP decontamination efficacy of Salmonella Typhimurium and Listeria monocytogenes was studied. Cells were grown planktonically or as surface colonies in/on model systems. Both microorganisms were grown in lab culture media in petri dishes at 20°C until cells reached the stationary phase. Before CAP treatment, cells were deposited in a liquid carrier, on a solid(like) surface or on a filter. A dielectric barrier discharge reactor generated helium-oxygen plasma, which was used to treat samples up to 10min. Although L. monocytogenes is more resistant to CAP treatment, similar trends in inactivation behavior as for S. Typhimurium are observed, with log reductions in the range [1.0-2.9] for S. Typhimurium and [0.2-2.2] for L. monocytogenes. For both microorganisms, cells grown planktonically are easily inactivated, as compared to surface colonies. More stressing growth conditions, due to cell immobilization, result in more resistant cells during CAP treatment. The main difference between the inactivation support systems is the absence or presence of a shoulder phase. For experiments in the liquid carrier, which exhibit a long shoulder, the plasma components need to diffuse and penetrate through the medium. This explains the higher efficacies of CAP treatment on cells deposited on a solid(like) surface or on a filter. This research demonstrates that the food structure influences the cell inactivation behavior and efficacy of CAP, and indicates that food intrinsic factors need to be accounted when designing plasma treatment. Copyright © 2016. Published by Elsevier B.V.

Responses of crayfish photoreceptor cells following intense light adaptation.

PubMed

Cummins, D R; Goldsmith, T H

1986-01-01

After intense orange adapting exposures that convert 80% of the rhodopsin in the eye to metarhodopsin, rhabdoms become covered with accessory pigment and appear to lose some microvillar order. Only after a delay of hours or even days is the metarhodopsin replaced by rhodopsin (Cronin and Goldsmith 1984). After 24 h of dark adaptation, when there has been little recovery of visual pigment, the photoreceptor cells have normal resting potentials and input resistances, and the reversal potential of the light response is 10-15 mV (inside positive), unchanged from controls. The log V vs log I curve is shifted about 0.6 log units to the right on the energy axis, quantitatively consistent with the decrease in the probability of quantum catch expected from the lowered concentration of rhodopsin in the rhabdoms. Furthermore, at 24 h the photoreceptors exhibit a broader spectral sensitivity than controls, which is also expected from accumulations of metarhodopsin in the rhabdoms. In three other respects, however, the transduction process appears to be light adapted: The voltage responses are more phasic than those of control photoreceptors. The relatively larger effect (compared to controls) of low extracellular Ca++ (1 mmol/l EGTA) in potentiating the photoresponses suggests that the photoreceptors may have elevated levels of free cytoplasmic Ca++. The saturating depolarization is only about 30% as large as the maximal receptor potentials of contralateral, dark controls, and by that measure the log V-log I curve is shifted downward by 0.54 log units.(ABSTRACT TRUNCATED AT 250 WORDS)

Atomic Force Microscopy Analysis of the Role of Major DNA-Binding Proteins in Organization of the Nucleoid in Escherichia coli

PubMed Central

Ohniwa, Ryosuke L.; Muchaku, Hiroki; Saito, Shinji; Wada, Chieko; Morikawa, Kazuya

2013-01-01

Bacterial genomic DNA is packed within the nucleoid of the cell along with various proteins and RNAs. We previously showed that the nucleoid in log phase cells consist of fibrous structures with diameters ranging from 30 to 80 nm, and that these structures, upon RNase A treatment, are converted into homogeneous thinner fibers with diameter of 10 nm. In this study, we investigated the role of major DNA-binding proteins in nucleoid organization by analyzing the nucleoid of mutant Escherichia coli strains lacking HU, IHF, H–NS, StpA, Fis, or Hfq using atomic force microscopy. Deletion of particular DNA-binding protein genes altered the nucleoid structure in different ways, but did not release the naked DNA even after the treatment with RNase A. This suggests that major DNA-binding proteins are involved in the formation of higher order structure once 10-nm fiber structure is built up from naked DNA. PMID:23951337

Global and Local Approaches Describing Critical Phenomena on the Developing and Developed Financial Markets

NASA Astrophysics Data System (ADS)

Grech, Dariusz

We define and confront global and local methods to analyze the financial crash-like events on the financial markets from the critical phenomena point of view. These methods are based respectively on the analysis of log-periodicity and on the local fractal properties of financial time series in the vicinity of phase transitions (crashes). The log-periodicity analysis is made in a daily time horizon, for the whole history (1991-2008) of Warsaw Stock Exchange Index (WIG) connected with the largest developing financial market in Europe. We find that crash-like events on the Polish financial market are described better by the log-divergent price model decorated with log-periodic behavior than by the power-law-divergent price model usually discussed in log-periodic scenarios for developed markets. Predictions coming from log-periodicity scenario are verified for all main crashes that took place in WIG history. It is argued that crash predictions within log-periodicity model strongly depend on the amount of data taken to make a fit and therefore are likely to contain huge inaccuracies. Next, this global analysis is confronted with the local fractal description. To do so, we provide calculation of the so-called local (time dependent) Hurst exponent H loc for the WIG time series and for main US stock market indices like DJIA and S&P 500. We point out dependence between the behavior of the local fractal properties of financial time series and the crashes appearance on the financial markets. We conclude that local fractal method seems to work better than the global approach - both for developing and developed markets. The very recent situation on the market, particularly related to the Fed intervention in September 2007 and the situation immediately afterwards is also analyzed within fractal approach. It is shown in this context how the financial market evolves through different phases of fractional Brownian motion. Finally, the current situation on American market is analyzed in fractal language. This is to show how far we still are from the end of recession and from the beginning of a new boom on US financial market or on other world leading stocks.

Improving Attachments of Non-Invasive (Type III) Electronic Data Loggers to Cetaceans

DTIC Science & Technology

2013-09-30

logged using a netbook and USB analog to digital converter. Initial testing of the SSSCup was conducted on a common dolphin (Delphinus delphis) cadaver...cell and five pressure sensors (four to measure internal cup pressure and one for atmospheric pressure). Sensor data are logged using a netbook and

Rapid-gradient HPLC method for measuring drug interactions with immobilized artificial membrane: comparison with other lipophilicity measures.

PubMed

Valko, K; Du, C M; Bevan, C D; Reynolds, D P; Abraham, M H

2000-08-01

A fast-gradient high-performance liquid chromatographic (HPLC) method has been suggested to characterize the interactions of drugs with an immobilized artificial membrane (IAM). With a set of standards, the gradient retention times can be converted to Chromatographic Hydrophobicity Index values referring to IAM chromatography (CHI(IAM)) that approximates an acetonitrile concentration with which the equal distribution of compound can be achieved between the mobile phase and IAM. The CHI(IAM) values are more suitable for interlaboratory comparison and for high throughput screening of new molecular entities than the log k(IAM) values (isocratic retention factor on IAM). The fast-gradient method has been validated against the isocratic log k(IAM) values using the linear free energy relationship solvation equations based on the data from 48 compounds. The compound set was selected to provide a wide range and the least cross-correlation between the molecular descriptors in the solvation equation: (2) where SP is a solute property (e.g., logarithm of partition coefficients, reversed-phase (RP)-HPLC retention parameters, such as log k, log k(w), etc.) and the explanatory variables are solute descriptors as follows: R(2) is an excess molar refraction that can be obtained from the measured refractive index of a compound, pi(2)(H) is the solute dipolarity/polarizability, summation operatoralpha(2)(H) and summation operatorbeta(2)(0) are the solute overall or effective hydrogen-bond acidity and basicity, respectively, and V(x) is the McGowan characteristic volume (in cm(3)/100 mol) that can be calculated for any solute simply from molecular structure using a table of atomic constants. It was found that the relative constants of the solvation equation were very similar for the CHI(IAM) and for the log k(IAM). The IAM lipophilicity scale was quite similar to the octanol/water lipophilicity scale for neutral compounds. The effect of charge on the interaction with IAM was studied by varying the mobile phase pH. Copyright 2000 Wiley-Liss, Inc.

GEMAS: prediction of solid-solution phase partitioning coefficients (Kd) for oxoanions and boric acid in soils using mid-infrared diffuse reflectance spectroscopy.

PubMed

Janik, Leslie J; Forrester, Sean T; Soriano-Disla, José M; Kirby, Jason K; McLaughlin, Michael J; Reimann, Clemens

2015-02-01

The authors' aim was to develop rapid and inexpensive regression models for the prediction of partitioning coefficients (Kd), defined as the ratio of the total or surface-bound metal/metalloid concentration of the solid phase to the total concentration in the solution phase. Values of Kd were measured for boric acid (B[OH]3(0)) and selected added soluble oxoanions: molybdate (MoO4(2-)), antimonate (Sb[OH](6-)), selenate (SeO4(2-)), tellurate (TeO4(2-)) and vanadate (VO4(3-)). Models were developed using approximately 500 spectrally representative soils of the Geochemical Mapping of Agricultural Soils of Europe (GEMAS) program. These calibration soils represented the major properties of the entire 4813 soils of the GEMAS project. Multiple linear regression (MLR) from soil properties, partial least-squares regression (PLSR) using mid-infrared diffuse reflectance Fourier-transformed (DRIFT) spectra, and models using DRIFT spectra plus analytical pH values (DRIFT + pH), were compared with predicted log K(d + 1) values. Apart from selenate (R(2)  = 0.43), the DRIFT + pH calibrations resulted in marginally better models to predict log K(d + 1) values (R(2)  = 0.62-0.79), compared with those from PSLR-DRIFT (R(2)  = 0.61-0.72) and MLR (R(2)  = 0.54-0.79). The DRIFT + pH calibrations were applied to the prediction of log K(d + 1) values in the remaining 4313 soils. An example map of predicted log K(d + 1) values for added soluble MoO4(2-) in soils across Europe is presented. The DRIFT + pH PLSR models provided a rapid and inexpensive tool to assess the risk of mobility and potential availability of boric acid and selected oxoanions in European soils. For these models to be used in the prediction of log K(d + 1) values in soils globally, additional research will be needed to determine if soil variability is accounted on the calibration. © 2014 SETAC.

Linear solvation energy relationships regarding sorption and retention properties of hydrophobic organic compounds in soil leaching column chromatography.

PubMed

Xu, Feng; Liang, Xinmiao; Lin, Bingcheng; Su, Fan; Schramm, Karl-Werner; Kettrup, Antonius

2002-08-01

The capacity factors of a series of hydrophobic organic compounds (HOCs) were measured in soil leaching column chromatography (SLCC) on a soil column, and in reversed-phase liquid chromatography on a C18 column with different volumetric fractions (phi) of methanol in methanol-water mixtures. A general equation of linear solvation energy relationships, log(XYZ) XYZ0 + mV(I)/100 + spi + bbetam + aalpham, was applied to analyze capacity factors (k'), soil organic partition coefficients (Koc) and octanol-water partition coefficients (P). The analyses exhibited high accuracy. The chief solute factors that control logKoc, log P, and logk' (on soil and on C18) are the solute size (V(I)/100) and hydrogen-bond basicity (betam). Less important solute factors are the dipolarity/polarizability (pi*) and hydrogen-bond acidity (alpham). Log k' on soil and log Koc have similar signs in four fitting coefficients (m, s, b and a) and similar ratios (m:s:b:a), while log k' on C18 and logP have similar signs in coefficients (m, s, b and a) and similar ratios (m:s:b:a). Consequently, logk' values on C18 have good correlations with logP (r > 0.97), while logk' values on soil have good correlations with logKoc (r > 0.98). Two Koc estimation methods were developed, one through solute solvatochromic parameters, and the other through correlations with k' on soil. For HOCs, a linear relationship between logarithmic capacity factor and methanol composition in methanol-water mixtures could also be derived in SLCC.

Evaluation of geophysical logs, Phase I, at Willow Grove Naval Air Station, Montgomery County, Pennsylvania

USGS Publications Warehouse

Conger, R.W.

1997-01-01

Between April and June 1997, the U.S. Navy contracted Brown and Root Environmental, Inc., to drill 20 monitor wells at the Willow Grove Naval Air Station in Horsham Township, Montgomery County, Pa. The wells were installed to monitor water levels and allow collection of water samples from shallow, intermediate, and deep water-bearing zones. Analysis of the samples will determine the horizontal and vertical distribution of any contaminated ground water migrating from known contaminant sources. Eight wells were drilled near the Fire Training Area (Site 5), five wells near the 9th Street Landfill (Site 3), four wells at the Antenna Field Landfill (Site 2), and three wells near Privet Road Compound (Site 1). Depths range from 73 to 167 feet below land surface. The U.S. Geological Survey conducted borehole-geophysical and borehole-video logging to identify water-bearing zones so that appropriate intervals could be screened in each monitor well. Geophysical logs were run on the 20 monitor wells and 1 existing well. Video logs were run on 16 wells. Caliper and video logs were used to locate fractures, inflections on fluid-temperature and fluid-resistivity logs were used to locate possible water-bearing fractures, and flowmeter measurements verified these locations. Single-point-resistance and natural-gamma logs provided information on stratigraphy. After interpretation of geophysical logs, video logs, and driller's notes, all wells were screened such that water-level fluctuations could be monitored and discrete water samples collected from one or more shallow and intermediate water-bearing zones in each borehole.

Role of serum hepatitis B virus marker quantitation to differentiate natural history phases of HBV infection.

PubMed

Wang, Li; Zou, Zhi-Qiang; Wang, Kai; Yu, Ji-Guang; Liu, Xiang-Zhong

2016-01-01

The purpose of this study was to characterize roles of serum hepatitis B virus marker quantitation in differentiation of natural phases of HBV infection. A total of 184 chronic hepatitis B (CHB) patients were analyzed retrospectively. Patients were classified into four categories: immune tolerant phase (IT, n = 36), immune clearance phase (IC, n = 81), low-replicative phase (LR, n = 31), and HBeAg-negative hepatitis phase (ENH, n = 36), based on clinical, biochemical, serological, HBV DNA level and histological data. Hepatitis B surface antigen (HBsAg) quantitation in four phases were 4.7 ± 0.2, 3.8 ± 0.5, 2.5 ± 1.2 and 3.4 ± 0.4 log10 IU/mL, respectively. There were significant differences between IT and IC (p < 0.001) and between LR and ENH phases (p < 0.001). Quantitation of hepatitis B e antigen (HBeAg) in IT and IC phases are 1317.9 ± 332.9 and 673.4 ± 562.1 S/CO, respectively (p < 0.001). Hepatitis B core antibody (HBcAb) quantitation in the four groups were 9.48 ± 3.3, 11.7 ± 2.8, 11.2 ± 2.6 and 13.2 ± 2.9 S/CO, respectively. Area under receiver operating characteristic curve (AUCs) of HBsAg and HBeAg at cutoff values of 4.41 log10 IU/mL and 1118.96 S/CO for differentiation of IT and IC phases are 0.984 and 0.828, with sensitivity 94.4 and 85.2 %, specificity 98.7 and 75 %, respectively. AUCs of HBsAg and HBcAb at cutoff values of 3.4 log10 IU/mL and 10.5 S/CO for differentiation of LR and ENT phases are 0.796 and 0.705, with sensitivity 58.1 and 85.7 %, and specificity 94.4 and 46.2 %, respectively. HBsAg quantitation has high predictive value and HBeAg quantitation has moderate predictive value for discriminating IT and IC phase. HBsAg and HBcAb quantitations have moderate predictive values for differentiation of LR and ENH phase.

Particulate emissions from the combustion of birch, beech, and spruce logs cause different cytotoxic responses in A549 cells.

PubMed

Kasurinen, Stefanie; Jalava, Pasi I; Happo, Mikko S; Sippula, Olli; Uski, Oskari; Koponen, Hanna; Orasche, Jürgen; Zimmermann, Ralf; Jokiniemi, Jorma; Hirvonen, Maija-Riitta

2017-05-01

According to the World Health Organization particulate emissions from the combustion of solid fuels caused more than 110,000 premature deaths worldwide in 2010. Log wood combustion is the most prevalent form of residential biomass heating in developed countries, but it is unknown how the type of wood logs used in furnaces influences the chemical composition of the particulate emissions and their toxicological potential. We burned logs of birch, beech and spruce, which are used commonly as firewood in Central and Northern Europe in a modern masonry heater, and compared them to the particulate emissions from an automated pellet boiler fired with softwood pellets. We determined the chemical composition (elements, ions, and carbonaceous compounds) of the particulate emissions with a diameter of less than 1 µm and tested their cytotoxicity, genotoxicity, inflammatory potential, and ability to induce oxidative stress in a human lung epithelial cell line. The chemical composition of the samples differed significantly, especially with regard to the carbonaceous and metal contents. Also the toxic effects in our tested endpoints varied considerably between each of the three log wood combustion samples, as well as between the log wood combustion samples and the pellet combustion sample. The difference in the toxicological potential of the samples in the various endpoints indicates the involvement of different pathways of toxicity depending on the chemical composition. All three emission samples from the log wood combustions were considerably more toxic in all endpoints than the emissions from the pellet combustion. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1487-1499, 2017. © 2016 Wiley Periodicals, Inc.

Effects of electrolyzed oxidizing water on reducing Listeria monocytogenes contamination on seafood processing surfaces.

PubMed

Liu, Chengchu; Duan, Jingyun; Su, Yi-Cheng

2006-02-15

The effects of electrolyzed oxidizing (EO) water on reducing Listeria monocytogenes contamination on seafood processing surfaces were studied. Chips (5 x 5 cm(2)) of stainless steel sheet (SS), ceramic tile (CT), and floor tile (FT) with and without crabmeat residue on the surface were inoculated with L. monocytogenes and soaked in tap or EO water for 5 min. Viable cells of L. monocytogenes were detected on all chip surfaces with or without crabmeat residue after being held at room temperature for 1 h. Soaking contaminated chips in tap water resulted in small-degree reductions of the organism (0.40-0.66 log cfu/chip on clean surfaces and 0.78-1.33 log cfu/chip on dirty surfaces). Treatments of EO water significantly (p<0.05) reduced L. monocytogenes on clean surfaces (3.73 log on SS, 4.24 log on CT, and 5.12 log on FT). Presence of crabmeat residue on chip surfaces reduced the effectiveness of EO water on inactivating Listeria cells. However, treatments of EO water also resulted in significant reductions of L. monocytogenes on dirty surfaces (2.33 log on SS and CT and 1.52 log on FT) when compared with tap water treatments. The antimicrobial activity of EO water was positively correlated with its chlorine content. High oxidation-reduction potential (ORP) of EO water also contributed significantly to its antimicrobial activity against L. monocytogenes. EO water was more effective than chlorine water on inactivating L. monocytogenes on surfaces and could be used as a chlorine alternative for sanitation purpose. Application of EO water following a thorough cleaning process could greatly reduce L. monocytogenes contamination in seafood processing environments.

Endothelial keratoplasty with infant donor tissue

PubMed Central

Kobayashi, Akira; Yokogawa, Hideaki; Yamazaki, Natsuko; Masaki, Toshinori; Sugiyama, Kazuhisa

2014-01-01

Here we report a case of endothelial keratoplasty with infant donor tissue obtained after brain death. A 52-year-old man with endothelial dysfunction of unknown cause in the right eye underwent non-Descemet stripping automated endothelial keratoplasty (nDSAEK) with tissue from an infant donor (2 years). Intraoperative and postoperative complications were recorded. Best corrected visual acuity and donor central endothelial cell density were recorded preoperatively and postoperatively. Infant donor tissue preparation with a microkeratome set at 300 μm was successful; the donor tissue was extremely elastic and soft compared with adult tissue. The central endothelial cell density of the infant donor tissue was as high as 4,291 cells/mm2. No complications were observed during donor tissue (8.0 mm in diameter) insertion with the double-glide technique (Busin glide with intraocular lens sheet glide) or any of the other procedures. Best corrected visual acuity improved from 1.7 logMAR (logarithm of the minimum angle of resolution; 0.02 decimal visual acuity) preoperatively to 0.2 logMAR (0.6) after 6 months and 0.1 logMAR (0.8) after 1 year. The central endothelial cell density after 6 months was 4,098 cells/mm2 (representing a 4.5% cell loss from preoperative donor cell measurements), and the central endothelial cell density after 1 year was 4,032 cells/mm2 (6.0% decrease). Infant donor tissue may be preferably used for DSAEK/nDASEK, since it may not be suitable for penetrating keratoplasty or Descemet membrane endothelial keratoplasty. PMID:25246761

Changes in diadenosine tetraphosphate levels in Physarum polycephalum with different oxygen concentrations.

PubMed Central

Garrison, P N; Mathis, S A; Barnes, L D

1989-01-01

Cellular levels of diadenosine tetraphosphate (Ap4A) were measured, by a specific high-pressure liquid chromatography method, in microplasmodia of Physarum polycephalum subjected to different degrees of hypoxia, hyperoxia, and treatment with H2O2. Ap4A levels increased three- to sevenfold under anaerobic conditions, and the microplasmodia remained viable after such treatment. Elevated levels of Ap4A returned to the basal level within 5 to 10 min upon reoxygenation of the microplasmodia. The increases in Ap4A levels were larger in stationary-phase or starved microplasmodia than in fed, log-phase microplasmodia. The maximal increase measured in log-phase microplasmodia was twofold. No significant changes in Ap4A levels occurred in microplasmodia subjected to mild hypoxia, hyperoxia, or treatment with 1 mM H2O2. These results indicate that in P. polycephalum, Ap4A may function in the metabolic response to anaerobic conditions rather than in the response to oxidative stress. PMID:2921243

Carrier Mediated Distribution System (CAMDIS): a new approach for the measurement of octanol/water distribution coefficients.

PubMed

Wagner, Bjoern; Fischer, Holger; Kansy, Manfred; Seelig, Anna; Assmus, Frauke

2015-02-20

Here we present a miniaturized assay, referred to as Carrier-Mediated Distribution System (CAMDIS) for fast and reliable measurement of octanol/water distribution coefficients, log D(oct). By introducing a filter support for octanol, phase separation from water is facilitated and the tendency of emulsion formation (emulsification) at the interface is reduced. A guideline for the best practice of CAMDIS is given, describing a strategy to manage drug adsorption at the filter-supported octanol/buffer interface. We validated the assay on a set of 52 structurally diverse drugs with known shake flask log D(oct) values. Excellent agreement with literature data (r(2) = 0.996, standard error of estimate, SEE = 0.111), high reproducibility (standard deviation, SD < 0.1 log D(oct) units), minimal sample consumption (10 μL of 100 μM DMSO stock solution) and a broad analytical range (log D(oct) range = -0.5 to 4.2) make CAMDIS a valuable tool for the high-throughput assessment of log D(oc)t. Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of surface roughness and stainless steel finish on Listeria monocytogenes attachment and biofilm formation.

PubMed

Rodriguez, Andres; Autio, Wesley R; McLandsborough, Lynne A

2008-01-01

The purpose of this study was to evaluate the effect of surface roughness (Ra) and finish of mechanically polished stainless steel (Ra = 0.26 +/- 0.05, 0.49 +/- 0.10, and 0.69 +/- 0.05 microm) and electropolished stainless steel (Ra = 0.16 +/- 0.06, 0.40 +/- 0.003, and 0.67 +/- 0.02 microm) on Listeria adhesion and biofilm formation. A four-strain cocktail of Listeria monocytogenes was used. Each strain (0.1%) was added to 200 ml of tryptic soy broth (TSB), and coupons were inserted to the mixture for 5 min. For biofilm formation, coupons with adhesive cells were incubated in 1:20 diluted TSB at 32 degrees C for 48 h. The experiment was performed by a randomized block design. Our results show that the level of Listeria present after 48 h of incubation (mean = 7 log CFU/cm2) was significantly higher than after 5 min (mean = 6.0 log CFU/cm2) (P < 0.01). No differences in initial adhesion were seen in mechanically finished (mean = 6.7 log CFU/cm2) when compared with electropolished stainless steel (mean = 6.7 log CFU/cm2) (P > 0.05). Listeria initial adhesion (values ranged from 5.9 to 6.1 log CFU/cm2) or biofilm formation (values ranged from 6.9 to 7.2 log CFU/cm2) was not significantly correlated with Ra values (P > 0.05). Image analysis with an atomic force microscope showed that bacteria did not colonize the complete surface after 48 h but were individual cells or grouped in microcolonies that ranged from 5 to 10 microm in diameter and one to three cell layers in thickness. Exopolymeric substances were observed to be associated with the colonies. According to our results, electropolishing stainless steel does not pose a significant advantage for food sanitation over mechanically finished stainless steel.

Pore-level influence of micro-fracture parameters on visco-capillary behavior of two-phase displacements in porous media

NASA Astrophysics Data System (ADS)

Rokhforouz, M. R.; Akhlaghi Amiri, H. A.

2018-03-01

In this work, coupled Cahn-Hilliard phase field and Navier-Stokes equations were solved using finite element method to address the effects of micro-fracture and its characterizations on water-oil displacements in a heterogeneous porous medium. Sensitivity studies at a wide range of viscosity ratios (M) and capillary numbers (Ca), and the resultant log Ca-log M stability phase diagram, revealed that in both media, with/without fracture, the three regimes of viscous fingering, capillary fingering and stable displacement similarly occur. However, presence of the fracture caused water channeling phenomenon which resulted in reduction of the number of active fingers and hence the final oil recovery factor. At high Ca (especially in the stable regime, with log Ca ≥ -2.5 and log M ≥ 0), recovery factor for the fractured medium was relatively identical with the non-fractured one. At log M ≥ 0, the fracture was fully swept, but flow instabilities were observed inside the fracture at lower M values, especially for log Ca > -4.6. In the case of the fractured medium at log Ca = -4.6 and log M = 0 (capillary dominant flow), it is observed that the primary breakthrough took place by a finger progressed through the matrix, not those channeled through the fracture. Geometrical properties of the fracture, including length, aperture and orientation, highly affected both displacement profile and efficiency. The fracture length inversely influenced the oil recovery factor. It was observed that there is a critical fracture width (almost half of the medium average pore diameter) at which the recovery factor of the medium during displacement is minimum, compared to the media having thinner and thicker fractures. Minor channeling effect in the media with thinner fracture and larger fracture swept volume as well as high fracture/matrix cross flow in the media with thicker fracture were detected as the main cause of this non-monotonic behavior. In the models with thick fractures (with the thickness higher than the average pore diameter), considerable trapped oil volumes were observed inside the fracture at low M values. The fracture orientation had the most impressive effect on oil recovery compared to the other studied parameters; where the oil recovery factor incremented more than 20% as the fracture rotated 90° from flow direction. Due to the dominant effect of the channeling phenomenon, the change in the medium wettability from slightly oil-wet to slightly water-wet, did not considerably affect the displacement profile in the fractured medium. However, oil recovery factor increased as the medium became more water-wet. The fracture area was fully swept by the injected water in the oil-wet and neutral-wet media. However, flow instabilities were observed inside the fracture of the water-wet medium due to counter-current imbibition between fracture/matrix. Micro-scale mechanisms of pore doublet effect, interface coalesce, snap-off and reverse movements were captured during the studied unstable displacements.

Viability-qPCR for detecting Legionella: Comparison of two assays based on different amplicon lengths.

PubMed

Ditommaso, Savina; Giacomuzzi, Monica; Ricciardi, Elisa; Zotti, Carla M

2015-08-01

Two different real-time quantitative PCR (PMA-qPCR) assays were applied for quantification of Legionella spp. by targeting a long amplicon (approx 400 bp) of 16S rRNA gene and a short amplicon (approx. 100 bp) of 5S rRNA gene. Purified DNA extracts from pure cultures of Legionella spp. and from environmental water samples were quantified. Application of the two assays to quantify Legionella in artificially contaminated water achieved that both assays were able to detect Legionella over a linear range of 10 to 10(5) cells ml(-1). A statistical analysis of the standard curves showed that both assays were linear with a good correlation coefficient (R(2) = 0.99) between the Ct and the copy number. Amplification with the reference assay was the most effective for detecting low copy numbers (1 bacterium per PCR mixture). Using selective quantification of viable Legionella by the PMA-qPCR method we obtained a greater inhibition of the amplification of the 400-bp 16S gene fragment (Δlog(10) = 3.74 ± 0.39 log(10) GU ml(-1)). A complete inhibition of the PCR signal was obtained when heat-killed cells in a concentration below 1 × 10(5) cells ml(-1) were pretreated with PMA. Analysing short amplicon sizes led to only 2.08 log reductions in the Legionella dead-cell signal. When we tested environmental water samples, the two qPCR assays were in good agreement according to the kappa index (0.741). Applying qPCR combined with PMA treatment, we also obtained a good agreement (kappa index 0.615). The comparison of quantitative results shows that both assays yielded the same quantification sensitivity (mean log = 4.59 vs mean log = 4.31). Copyright © 2015 Elsevier Ltd. All rights reserved.

Quantitative structure-retention relationships of flavonoids unraveled by immobilized artificial membrane chromatography.

PubMed

Santoro, Adriana Leandra; Carrilho, Emanuel; Lanças, Fernando Mauro; Montanari, Carlos Alberto

2016-06-10

The pharmacokinetic properties of flavonoids with differing degrees of lipophilicity were investigated using immobilized artificial membranes (IAMs) as the stationary phase in high performance liquid chromatography (HPLC). For each flavonoid compound, we investigated whether the type of column used affected the correlation between the retention factors and the calculated octanol/water partition (log Poct). Three-dimensional (3D) molecular descriptors were calculated from the molecular structure of each compound using i) VolSurf software, ii) the GRID method (computational procedure for determining energetically favorable binding sites in molecules of known structure using a probe for calculating the 3D molecular interaction fields, between the probe and the molecule), and iii) the relationship between partition and molecular structure, analyzed in terms of physicochemical descriptors. The VolSurf built-in Caco-2 model was used to estimate compound permeability. The extent to which the datasets obtained from different columns differ both from each other and from both the calculated log Poct and the predicted permeability in Caco-2 cells was examined by principal component analysis (PCA). The immobilized membrane partition coefficients (kIAM) were analyzed using molecular descriptors in partial least square regression (PLS) and a quantitative structure-retention relationship was generated for the chromatographic retention in the cholesterol column. The cholesterol column provided the best correlation with the permeability predicted by the Caco-2 cell model and a good fit model with great prediction power was obtained for its retention data (R(2)=0.96 and Q(2)=0.85 with four latent variables). Copyright © 2015 Elsevier B.V. All rights reserved.

Eradication of Pseudomonas aeruginosa cells by cathodic electrochemical currents delivered with graphite electrodes.

PubMed

Niepa, Tagbo H R; Wang, Hao; Gilbert, Jeremy L; Ren, Dacheng

2017-03-01

Antibiotic resistance is a major challenge to the treatment of bacterial infections associated with medical devices and biomaterials. One important intrinsic mechanism of such resistance is the formation of persister cells that are phenotypic variants of microorganisms and highly tolerant to antibiotics. Recently, we reported a new approach to eradicating persister cells of Pseudomonas aeruginosa using low-level direct electrochemical current (DC) and synergy with the antibiotic tobramycin. To further understand the underlying mechanism and develop this technology toward possible medical applications, we investigated the electricidal activities of non-metallic biomaterial on persister and biofilm cells of P. aeruginosa using graphite-based TGON™ 805 electrodes. We employed both single and dual chamber systems to compare electrochemical factors of TGON and stainless steel 304 electrodes. The results revealed that TGON-based treatments were highly effective against P. aeruginosa persister cells. In the single chamber system, complete eradication of planktonic persister cells (corresponding to a 7-log killing) was achieved with 70μA/cm 2 DC using TGON electrodes within 40min of treatment, while the cell viability in biofilms was reduced by 2 logs within 1h. The killing effects were dose and time dependent with higher current densities requiring less time. Moreover, reduction reactions were found more effective than oxidation reactions, confirming that metal cations are not indispensable, although they may facilitate cell killing. The findings of this study can help develop electrochemical technologies to eradicate persister and biofilm cells for more effective treatment of medical device and biomaterial associated infections. Infections associated with medical devices and biomaterials present a major challenge due to high-level tolerance of microbes to conventional antibiotics. It is well established that such tolerance is due to the formation of dormant persister cells and multicellular structures known as biofilms. Recent studies have demonstrated electrochemical treatment as a promising alternative to eradicate bacterial infections, since the killing mechanism is independent of the growth phase of bacterial cells, but relies on various electrochemical species interplaying during the treatment. The current study investigated major bactericidal properties of the electrochemical currents mediated via TGON, a carbon-based electrode material. Up to total eradication of Pseudomonas aeruginosa persister cells was achieved. The new knowledge of electrochemical properties and the bioactivity of TGON may help develop new methods/devices to eradicate bacterial infections by delivering safe levels of electrochemical currents. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Instantaneous Attributes Applied to Full Waveform Sonic Log and Seismic Data in Integration of Elastic Properties of Shale Gas Formations in Poland

NASA Astrophysics Data System (ADS)

Wawrzyniak-Guz, Kamila

2018-03-01

Seismic attributes calculated from full waveform sonic log were proposed as a method that may enhance the interpretation the data acquired at log and seismic scales. Though attributes calculated in the study were the mathematical transformations of amplitude, frequency, phase or time of the acoustic full waveforms and seismic traces, they could be related to the geological factors and/or petrophysical properties of rock formations. Attributes calculated from acoustic full waveforms were combined with selected attributes obtained for seismic traces recorded in the vicinity of the borehole and with petrophysical parameters. Such relations may be helpful in elastic and reservoir properties estimation over the area covered by the seismic survey.

Snake River Plain FORGE Well Data for INEL-1

DOE Data Explorer

Robert Podgorney

1979-03-01

Well data for the INEL-1 well located in eastern Snake River Plain, Idaho. This data collection includes caliper logs, lithology reports, borehole logs, temperature at depth data, neutron density and gamma data, full color logs, fracture analysis, photos, and rock strength parameters for the INEL-1 well. This collection of data has been assembled as part of the site characterization data used to develop the conceptual geologic model for the Snake River Plain site in Idaho, as part of phase 1 of the Frontier Observatory for Research in Geothermal Energy (FORGE) initiative. They were assembled by the Snake River Geothermal Consortium (SRGC), a team of collaborators that includes members from national laboratories, universities, industry, and federal agencies, lead by the Idaho National Laboratory (INL).

Insights on wood combustion generated proinflammatory ultrafine particles (UFP).

PubMed

Corsini, Emanuela; Ozgen, Senem; Papale, Angela; Galbiati, Valentina; Lonati, Giovanni; Fermo, Paola; Corbella, Lorenza; Valli, Gianluigi; Bernardoni, Vera; Dell'Acqua, Manuela; Becagli, Silvia; Caruso, Donatella; Vecchi, Roberta; Galli, Corrado L; Marinovich, Marina

2017-01-15

This study aimed to collect, characterize ultrafine particles (UFP) generated from the combustion of wood pellets and logs (softwood and hardwood) and to evaluate their pro-inflammatory effects in THP-1 and A549 cells. Both cell lines responded to UFP producing interleukin-8 (IL-8), with wood log UFP being more active compared to pellet UFP. With the exception of higher effect observed with beech wood log UFP in THP-1, the ability of soft or hard woods to induce IL-8 release was similar. In addition, on weight mass, IL-8 release was similar or lower compared to diesel exhaust particles (DEP), arguing against higher biological activity of smaller size particles. UFP-induced IL-8 could be reduced by SB203580, indicating a role of p38MAPK activation in IL-8 production. The higher activity of beech wood log UFP in THP-1 was not due to higher uptake or endotoxin contamination. Qualitatively different protein adsorption profiles were observed, with less proteins bound to beech UFP compared to conifer UFP or DEP, which may provide higher intracellular availability of bioactive components, i.e. levoglucosan and galactosan, toward which THP-1 were more responsive compared to A549 cells. These results contribute to our understanding of particles emitted by domestic appliances and their biological effects. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Photodynamic inactivation of Listeria innocua biofilms with food-grade photosensitizers: a curcumin-rich extract of Curcuma longa vs commercial curcumin.

PubMed

Bonifácio, D; Martins, C; David, B; Lemos, C; Neves, M G P M S; Almeida, A; Pinto, D C G A; Faustino, M A F; Cunha, Â

2018-03-22

The aim of this work is to assess the potential of curcumin in the photosensitization of biofilms of Listeria. Biofilms of Listeria innocua, were irradiated with blue light in the presence of a curcumin-rich extract of Curcuma longa or commercial curcumin. Similar experiments were conducted with planktonic cells, for comparison. A reduction of 4·9 log in the concentration of viable biofilm cells was obtained with 3·7 mg l -1 of commercial curcumin. Planktonic cells were much more susceptible (6·1 log reduction). A tetracationic porphyrin, used as a reference photosensitizer (PS), caused a very modest inactivation of the biofilm (1·1 log) and complete inactivation of the planktonic form (>8 log). Curcumin is an effective PS for the photodynamic control of Listeria biofilms and the inactivation efficiency attained with this natural compound is higher than with the porphyrin. This result may point to a better performance of type I PSs against bacterial biofilms by circumventing the limitations to singlet-oxygen diffusion imposed by the extracellular matrix. Curcumin represents a promising alternative to the control of bacteria and bacterial biofilms in food products particularly in the case of meat products in which turmeric is used as spice. © 2018 The Society for Applied Microbiology.

Behavior and biocompatibility of rabbit bone marrow mesenchymal stem cells with bacterial cellulose membrane

PubMed Central

Leite, Yulla Klinger de Carvalho; de Carvalho, Camila Ernanda Sousa; Feitosa, Matheus Levi Tajra; Alves, Michel Muálem de Moraes; Carvalho, Fernando Aécio de Amorim; Neto, Bartolomeu Cruz Viana; Miglino, Maria Angélica

2018-01-01

Background Tissue engineering has been shown to exhibit great potential for the creation of biomaterials capable of developing into functional tissues. Cellular expansion and integration depends on the quality and surface-determinant factors of the scaffold, which are required for successful biological implants. The objective of this research was to characterize and evaluate the in vitro characteristics of rabbit bone marrow mesenchymal stem cells (BM-MSCs) associated with a bacterial cellulose membrane (BCM). We assessed the adhesion, expansion, and integration of the biomaterial as well as its ability to induce macrophage activation. Finally, we evaluated the cytotoxicity and toxicity of the BCM. Methods Samples of rabbit bone marrow were collected. Mesenchymal stem cells were isolated from medullary aspirates to establish fibroblast colony-forming unit assay. Osteogenic, chondrogenic, and adipogenic differentiation was performed. Integration with the BCM was assessed by scanning electron microscopy at 1, 7, and 14 days. Cytotoxicity was assessed via the production of nitric oxide, and BCM toxicity was assessed with the MTT assay; phagocytic activity was also determined. Results The fibroblastoid colony-forming unit (CFU-F) assay showed cells with a fibroblastoid morphology organized into colonies, and distributed across the culture area surface. In the growth curve, two distinct phases, lag and log phase, were observed at 15 days. Multipotentiality of the cells was evident after induction of osteogenic, chondrogenic, and adipogenic lineages. Regarding the BM-MSCs’ bioelectrical integration with the BCM, BM-MSCs were anchored in the BCM in the first 24 h. On day 7 of culture, the cytoplasm was scattered, and on day 14, the cells were fully integrated with the biomaterial. We also observed significant macrophage activation; analysis of the MTT assay and the concentration of nitric oxide revealed no cytotoxicity of the biomaterial. Conclusion The BCM allowed the expansion and biointegration of bone marrow progenitor cells with a stable cytotoxic profile, thus presenting itself as a biomaterial with potential for tissue engineering. PMID:29736332

The biosynthesis and wall-binding of hemicelluloses in cellulose-deficient maize cells: an example of metabolic plasticity.

PubMed

de Castro, María; Miller, Janice G; Acebes, José Luis; Encina, Antonio; García-Angulo, Penélope; Fry, Stephen C

2015-04-01

Cell-suspension cultures (Zea mays L., Black Mexican sweet corn) habituated to 2,6-dichlorobenzonitrile (DCB) survive with reduced cellulose owing to hemicellulose network modification. We aimed to define the hemicellulose metabolism modifications in DCB-habituated maize cells showing a mild reduction in cellulose at different stages in the culture cycle. Using pulse-chase radiolabeling, we fed habituated and non-habituated cultures with [(3)H]arabinose, and traced the distribution of (3)H-pentose residues between xylans, xyloglucans and other polymers in several cellular compartments for 5 h. Habituated cells were slower taking up exogenous [(3)H]arabinose. Tritium was incorporated into polysaccharide-bound arabinose and xylose residues, but habituated cells diverted a higher proportion of their new [(3)H]xylose residues into (hetero) xylans at the expense of xyloglucan synthesis. During logarithmic growth, habituated cells showed slower vesicular trafficking of polymers, especially xylans. Moreover, habituated cells showed a decrease in the strong wall-binding of all pentose-containing polysaccharides studied; correspondingly, especially in log-phase cultures, habituation increased the proportion of (3)H-hemicelluloses ([(3)H]xylans and [(3)H]xyloglucan) sloughed into the medium. These findings could be related to the cell walls' cellulose-deficiency, and consequent reduction in binding sites for hemicelluloses; the data could also reflect the habituated cells' reduced capacity to integrate arabinoxylans by extra-protoplasmic phenolic cross-linking, as well as xyloglucans, during wall assembly. © 2015 Institute of Botany, Chinese Academy of Sciences.

Ground station software for receiving and handling Irecin telemetry data

NASA Astrophysics Data System (ADS)

Ferrante, M.; Petrozzi, M.; Di Ciolo, L.; Ortenzi, A.; Troso, G

2004-11-01

The on board resources, needed to perform the mission tasks, are very limited in nano-satellites. This paper proposes a software system to receive, manage and process in Real Time the Telemetry data coming from IRECIN nanosatellite and transmit operator manual commands and operative procedures. During the receiving phase, it shows the IRECIN subsystem physical values, visualizes the IRECIN attitude, and performs other suitable functions. The IRECIN Ground Station program is in charge to exchange information between IRECIN and the Ground segment. It carries out, in real time during IRECIN transmission phase, IRECIN attitude drawing, sun direction drawing, power supply received from Sun, visualization of the telemetry data, visualization of Earth magnetic field and more other functions. The received data are memorized and interpreted by a module, parser, and distribute to the suitable modules. Moreover it allows sending manual and automatic commands. Manual commands are delivered by an operator, on the other hand, automatic commands are provided by pre-configured operative procedures. Operative procedures development is realized in a previous phase called configuration phase. This program is also in charge to carry out a test session by mean the scheduler and commanding modules allowing execution of specific tasks without operator control. A log module to memorize received and transmitted data is realized. A phase to analyze, filter and visualize in off line the collected data, called post analysis, is based on the data extraction form the log module. At the same time, the Ground Station Software can work in network allowing managing, receiving and sending data/commands from different sites. The proposed system constitutes the software of IRECIN Ground Station. IRECIN is a modular nanosatellite weighting less than 2 kg, constituted by sixteen external sides with surface-mounted solar cells and three internal Al plates, kept together by four steel bars. Lithium-ions batteries are used. Attitude is determined by two three-axis magnetometers and the solar panels data. Control is provided by an active magnetic control system. The spacecraft will be spin- stabilized with the spin-axis normal to the orbit. All IRECIN electronic components are SMD technology in order to reduce weight and size. The realized Electronic board are completely developed, realized and tested at the Vitrociset S.P.A. under control of Research and Develop Group

Silver nanoparticle-E. coli colloidal interaction in water and effect on E. coli survival.

PubMed

Dror-Ehre, A; Mamane, H; Belenkova, T; Markovich, G; Adin, A

2009-11-15

Silver nanoparticles exhibit antibacterial properties via bacterial inactivation and growth inhibition. The mechanism is not yet completely understood. This work was aimed at elucidating the effect of silver nanoparticles on inactivation of Escherichia coli, by studying particle-particle interactions in aqueous suspensions. Stable, molecularly capped, positively or negatively charged silver nanoparticles were mixed at 1 to 60microgmL(-1) with suspended E. coli cells to examine their effect on inactivation of the bacteria. Gold nanoparticles with the same surfactant were used as a control, being of similar size but made up of a presumably inert metal. Log reduction of 5log(10) and complete inactivation were obtained with the silver nanoparticles while the gold nanoparticles did not show any inactivation ability. The effect of molecularly capped nanoparticles on E. coli survival was dependent on particle number. Log reduction of E. coli was associated with the ratio between the number of nanoparticles and the initial bacterial cell count. Electrostatic attraction or repulsion mechanisms in silver nanoparticle-E. coli cell interactions did not contribute to the inactivation process.

Use of propidium monoazide for the enumeration of viable Brettanomyces bruxellensis in wine and beer by quantitative PCR.

PubMed

Vendrame, Marco; Manzano, Marisa; Comi, Giuseppe; Bertrand, Julien; Iacumin, Lucilla

2014-09-01

Brettanomyces bruxellensis is a current problem in winemaking all over the world, and the question if B. bruxellensis has a positive or negative impact on wine is one of the most controversial discussions in the world. The presence of live B. bruxellensis cells represents the risk of growth and an increase in cell numbers, which is related to the potential production of volatile phenols. In this work, the optimisation of a PMA-quantitative PCR (qPCR) method to enumerate only viable cells was carried out using the standard strain B. bruxellensis DSMZ 70726. The obtained detection limits were 0.83 log CFU/mL in red wine, 0.63 log CFU/mL in white wine and 0.23 log CFU/mL in beer. Moreover, the quantification was also performed by Reverse Transcription quantitative PCR (RT-qPCR), and the results showed a higher detection limit for all of the trials. Copyright © 2014 Elsevier Ltd. All rights reserved.

Al(III), Pd(II), and Zn(II) phthalocyanines for inactivation of dental pathogen Aggregatibacter actinomycetemcomitans as planktonic and biofilm-cultures

NASA Astrophysics Data System (ADS)

Kussovski, V.; Mantareva, V.; Angelov, I.; Avramov, L.; Popova, E.; Dimitrov, S.

2012-06-01

The Gram-negative, oral bacterium Aggregatibacter actinomycetemcomitans has been implicated as the causative agent of several forms of periodontal disease in humans. The new periodontal disease treatments are emergence in order to prevent infection progression. Antimicrobial photodynamic therapy (a-PDT) can be a useful tool for this purpose. It involves the use of light of specific wavelength to activate a nontoxic photosensitizing agent in the presence of oxygen for eradication of target cells, and appears effective in photoinactivation of microorganisms. The phthalocyanine metal complexes of Pd(II)- (PdPcC) and Al(III)- (AlPc1) were evaluated as photodynamic sensitizers towards a dental pathogen A. actinomycetemcomitans in comparison to the known methylpyridyloxy-substituted Zn(II) phthalocyanine (ZnPcMe). The planktonic and biofilm-cultivated species of A. actinomycetemcomitans were treated. The photophysical results showed intensive and far-red absorbance with high tendency of aggregation for Pd(II)-phthalocyanine. The dark toxicities of both photosensitizers were negligible at concentrations used (< 0.5 log decrease of viable cells). The photodynamic response for planktonic cultured bacteria was full photoinactivation after a-PDT with ZnPcMe. In case of the newly studied complexes, the effect was lower for PdPcC (4 log) as well as for AlPc1 (1.5-2 log). As it is known the bacterial biofilms were more resistant to a-PDT, which was confirmed for A. actinomycetemcomitans biofilms with 3 log reductions of viable cells after treatment with ZnPcMe and approximately 1 log reduction of biofilms after PdPcC and AlPc1. The initial results suggest that a-PDT can be useful for effective inactivation of dental pathogen A. actinomycetemcomitans.

Passage through Tetrahymena tropicalis enhances the resistance to stress and the infectivity of Legionella pneumophila.

PubMed

Koubar, Mohamad; Rodier, Marie-Hélène; Garduño, Rafael A; Frère, Jacques

2011-12-01

Legionella pneumophila is a gram-negative bacterium prevalent in fresh water which accidentally infects humans and is responsible for the disease called legionellosis. Intracellular growth of L. pneumophila in Tetrahymena is inconsistent; in the species Tetrahymena tropicalis stationary-phase forms (SPFs) of L. pneumophila differentiate into mature intracellular forms (MIFs) without apparent bacterial replication and are expelled from the ciliate as pellets containing numerous MIFS. In the present work, we tested the impact of L. pneumophila passage through T. tropicalis. We observed that MIFs released from T. tropicalis are more resistant to various stresses than SPFs. Under our conditions, MIFs harboured a higher gentamicin resistance, maintained even after 3 months as pellets. Long-term survival essays revealed that MIFs survived better in a nutrient-poor environment than SFPs, as a reduction of only about 3 logs was observed after 4 months in the MIF population, whereas no cultivable SPFs were detected after 3 months in the same medium, corresponding to a loss of about 7 logs. We have also observed that MIFs are significantly more infectious in human pneumocyte cells compared with SPFs. These results strongly suggest a potential role of ciliates in increasing the risk of legionellosis. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

National validation study of a swab protocol for the recovery of Bacillus anthracis spores from surfaces.

PubMed

Hodges, Lisa R; Rose, Laura J; O'Connell, Heather; Arduino, Matthew J

2010-05-01

Twelve Laboratory Response Network (LRN) affiliated laboratories participated in a validation study of a macrofoam swab protocol for the recovery, detection, and quantification of viable B. anthracis (BA) Sterne spores from steel surfaces. CDC personnel inoculated steel coupons (26cm(2)) with 1-4 log(10) BA spores and recovered them by sampling with pre-moistened macrofoam swabs. Phase 1 (P1) of the study evaluated swabs containing BA only, while dust and background organisms were added to swabs in Phase 2 (P2) to mimic environmental conditions. Laboratories processed swabs and enumerated spores by culturing eluted swab suspensions and counting colonies with morphology consistent with BA. Processed swabs were placed in enrichment broth, incubated 24h, and cultured by streaking for isolation. Real-time PCR was performed on selected colonies from P2 samples to confirm the identity of BA. Mean percent recovery (%R) of spores from the surface ranged from 15.8 to 31.0% (P1) and from 27.9 to 55.0% (P2). The highest mean percent recovery was 31.0% (sd 10.9%) for P1 (4 log(10) inoculum) and 55.0% (sd 27.6%) for P2 (1 log(10) inoculum). The overall %R was higher for P2 (44.6%) than P1 (24.1%), but the overall reproducibility (between-lab variability) was lower in P2 than in P1 (25.0 vs 16.5%CV, respectively). The overall precision (within-lab variability) was close to identical for P1 and P2 (44.0 and 44.1, respectively), but varied greatly between inoculum levels. The protocol demonstrated linearity in %R over the three inoculum levels and is able to detect between 26 and 5x10(6)spores/26cm(2). Sensitivity as determined by culture was >98.3% for both phases and all inocula, suggesting that the culture method maintains sensitivity in the presence of contaminants. The enrichment broth method alone was less sensitive for sampled swabs (66.4%) during P2, suggesting that the presence of background organisms inhibited growth or isolation of BA from the broth. The addition of real-time PCR testing to the assay increased specificity from >85.4% to >95.0% in P2. Although the precision was low at the 1 log(10) inoculum level in both phases (59.0 and 50.2%), this swab processing protocol, was sensitive, specific, precise, and reproducible at 2-4 log(10)/26cm(2) spore concentrations. Published by Elsevier B.V.

[Determination and prediction for vapor pressures of organophosphate flame retardants by gas chromatography].

PubMed

Wang, Qingzhi; Zhao, Hongxia; Wang, Yan; Xie, Qing; Chen, Jingwen; Quan, Xie

2017-09-08

Organophosphate flame retardants (OPFRs) are ubiquitous in the environment. To better understand and predict their environmental transport and fate, well-defined physicochemical properties are required. Vapor pressures ( P ) of 14 OPFRs were estimated as a function of temperature ( T ) by gas chromatography (GC), while 1,1,1-trichioro-2,2-bis (4-chlorophenyl) ethane ( p,p '-DDT) was acted as a reference substance. Their log P GC values and internal energies of phase transfer (△ vap H ) ranged from -6.17 to -1.25 and 74.1 kJ/mol to 122 kJ/mol, respectively. Substitution pattern and molar volume ( V M ) were found to be capable of influencing log P GC values of the OPFRs. The halogenated alkyl-OPFRs had lower log P GC values than aryl-or alkyl-OPFRs. The bigger the molar volume was, the smaller the log P GC value was. In addition, a quantitative structure-property relationship (QSPR) model of log P GC versus different relative retention times (RRTs) was developed with a high cross-validated value ( Q 2 cum ) of 0.946, indicating a good predictive ability and stability. Therefore, the log P GC values of the OPFRs without standard substance can be predicted by using their RRTs on different GC columns.

Determination and prediction of octanol-air partition coefficients for organophosphate flame retardants.

PubMed

Wang, Qingzhi; Zhao, Hongxia; Wang, Yan; Xie, Qing; Chen, Jingwen; Quan, Xie

2017-11-01

Organophosphate flame retardants (OPFRs) have attracted wide concerns due to their toxicities and ubiquitous occurrence in the environment. In this work, Octanol-air partition coefficient (K OA ) for 14 OPFRs including 4 halogenated alkyl-, 5 aryl- and 5 alkyl-OPFRs, were estimated as a function of temperature using a gas chromatographic retention time (GC-RT) method. Their log K OA-GC values and internal energies of phase transfer (Δ OA U/kJmol -1 ) ranged from 8.03 to 13.0 and from 69.7 to 149, respectively. Substitution pattern and molar volume (V M ) were found to be capable of influencing log K OA-GC values of OPFRs. The halogenated alkyl-OPFRs had higher log K OA-GC values than aryl- or alkyl-OPFRs. The bigger the molar volume was, the greater the log K OA-GC values increased. In addition, a predicted model of log K OA-GC versus different relative retention times (RRTs) was developed with a high cross-validated value (Q 2 (cum) ) of 0.951, indicating a good predictive ability and stability. Therefore, the log K OA-GC values of the remaining OPFRs can be predicted by using their RRTs on different GC columns. Copyright © 2017 Elsevier Inc. All rights reserved.

Inactivation of Escherichia coli, Saccharomyces cerevisiae, and Lactobacillus brevis in Low-fat Milk by Pulsed Electric Field Treatment: A Pilot-scale Study

PubMed Central

Han, Bok Kung; Choi, Hyuk Joon; Kang, Shin Ho; Baick, Seung Chun

2015-01-01

We investigated the effects of a pulsed electric field (PEF) treatment on microbial inactivation and the physical properties of low-fat milk. Milk inoculated with Escherichia coli, Saccharomyces cerevisiae, or Lactobacillus brevis was supplied to a pilot-scale PEF treatment system at a flow rate of 30 L/h. Pulses with an electric field strength of 10 kV/cm and a pulse width of 30 μs were applied to the milk with total pulse energies of 50-250 kJ/L achieved by varying the pulse frequency. The inactivation curves of the test microorganisms were biphasic with an initial lag phase (or shoulder) followed by a phase of rapid inactivation. PEF treatments with a total pulse energy of 200 kJ/L resulted in a 4.5-log reduction in E. coli, a 4.4-log reduction in L. brevis, and a 6.0-log reduction in S. cerevisiae. Total pulse energies of 200 and 250 kJ/L resulted in greater than 5-log reductions in microbial counts in stored PEF-treated milk, and the growth of surviving microorganisms was slow during storage for 15 d at 4℃. PEF treatment did not change milk physical properties such as pH, color, or particle-size distribution (p<0.05). These results indicate that a relatively low electric-field strength of 10 kV/cm can be used to pasteurize low-fat milk. PMID:26877640

Inactivation of Escherichia coli, Saccharomyces cerevisiae, and Lactobacillus brevis in Low-fat Milk by Pulsed Electric Field Treatment: A Pilot-scale Study.

PubMed

Lee, Gun Joon; Han, Bok Kung; Choi, Hyuk Joon; Kang, Shin Ho; Baick, Seung Chun; Lee, Dong-Un

2015-01-01

We investigated the effects of a pulsed electric field (PEF) treatment on microbial inactivation and the physical properties of low-fat milk. Milk inoculated with Escherichia coli, Saccharomyces cerevisiae, or Lactobacillus brevis was supplied to a pilot-scale PEF treatment system at a flow rate of 30 L/h. Pulses with an electric field strength of 10 kV/cm and a pulse width of 30 μs were applied to the milk with total pulse energies of 50-250 kJ/L achieved by varying the pulse frequency. The inactivation curves of the test microorganisms were biphasic with an initial lag phase (or shoulder) followed by a phase of rapid inactivation. PEF treatments with a total pulse energy of 200 kJ/L resulted in a 4.5-log reduction in E. coli, a 4.4-log reduction in L. brevis, and a 6.0-log reduction in S. cerevisiae. Total pulse energies of 200 and 250 kJ/L resulted in greater than 5-log reductions in microbial counts in stored PEF-treated milk, and the growth of surviving microorganisms was slow during storage for 15 d at 4℃. PEF treatment did not change milk physical properties such as pH, color, or particle-size distribution (p<0.05). These results indicate that a relatively low electric-field strength of 10 kV/cm can be used to pasteurize low-fat milk.

Chromatographic and computational assessment of lipophilicity using sum of ranking differences and generalized pair-correlation.

PubMed

Andrić, Filip; Héberger, Károly

2015-02-06

Lipophilicity (logP) represents one of the most studied and most frequently used fundamental physicochemical properties. At present there are several possibilities for its quantitative expression and many of them stems from chromatographic experiments. Numerous attempts have been made to compare different computational methods, chromatographic methods vs. computational approaches, as well as chromatographic methods and direct shake-flask procedure without definite results or these findings are not accepted generally. In the present work numerous chromatographically derived lipophilicity measures in combination with diverse computational methods were ranked and clustered using the novel variable discrimination and ranking approaches based on the sum of ranking differences and the generalized pair correlation method. Available literature logP data measured on HILIC, and classical reversed-phase combining different classes of compounds have been compared with most frequently used multivariate data analysis techniques (principal component and hierarchical cluster analysis) as well as with the conclusions in the original sources. Chromatographic lipophilicity measures obtained under typical reversed-phase conditions outperform the majority of computationally estimated logPs. Oppositely, in the case of HILIC none of the many proposed chromatographic indices overcomes any of the computationally assessed logPs. Only two of them (logkmin and kmin) may be selected as recommended chromatographic lipophilicity measures. Both ranking approaches, sum of ranking differences and generalized pair correlation method, although based on different backgrounds, provides highly similar variable ordering and grouping leading to the same conclusions. Copyright © 2015. Published by Elsevier B.V.

Compensatory Muscle Activation During Unstable Overhead Squat Using a Water-filled Training Tube.

PubMed

Glass, Stephen C; Albert, Robert W

2018-05-01

Glass, SC, and Albert, RW. Compensatory muscle activation during unstable overhead squat using a water-filled training tube. J Strength Cond Res 32(5): 1230-1237, 2018-The purpose of this study was to assess compensatory muscle activation of core and support muscle during an overhead squat using a water-filled training tube. Eleven experienced weightlifting (age = 20.10 ± 0.99, mass 89.17 ± 6.88 kg) men completed 3, 30-second trials of an overhead squat using an 11.4 kg tube that was partially filled with water. A central valve allowed 3 conditions of water movement: 50% open, 100% open, and a stable(S), closed valve condition. Subjects completed 8-10 repetitions within each condition. Electromyographic (EMG) electrodes were placed over the belly of the vastus lateralis, deltoid, rectus abdominus, and paraspinal muscles and recorded during concentric and eccentric (ECC) phases. Integrated EMG were computed and converted to percent maximal voluntary contraction (%MVC). Compensatory activation was assessed using the natural log of the coefficient of variation of %MVC across repetitions. A 1-way repeated-measures analysis of variance across (phase, condition) was used. Significant compensatory muscle activation was seen in the deltoid muscle during ECC (100% open = 3.60 ± 0.50 > stable LogCV = 3.06 ± 0.45). In addition, paraspinal muscle activity was also more variable during the ECC phase (50% open LogCv = 3.28 ± 0.26 > stable = 2.77 ± 0.67). We conclude that the water-filled training tube induces compensatory muscle activation in the deltoid and paraspinal muscles during the ECC phase of the overhead squat.

Physicochemical properties of Scamorza ewe milk cheese manufactured with different probiotic cultures.

PubMed

Albenzio, M; Santillo, A; Caroprese, M; Ruggieri, D; Napolitano, F; Sevi, A

2013-05-01

The present study was undertaken to produce functional Scamorza cheese from Gentile di Puglia ewe milk by incorporating probiotic strains into the cheese matrix and to evaluate the physicochemical characteristics of Scamorza ewe milk cheese. Gentile di Puglia ewe bulk milk was used for Scamorza cheese production. Cheeses were denoted S-CO for control Scamorza cheese, S-BB for Scamorza cheese made using a mix of Bifidobacterium longum and Bifidobacterium lactis, and S-LA for Scamorza cheese made using Lactobacillus acidophilus as probiotic strain. Cheeses were analyzed at 1, 7, and 15 d of ripening. Probiotic cell recovery in cheese was 7.55 ± 0.07 log10 cfu/g and 9.09 ± 0.04 log10 cfu/g in S-LA and S-BB cheese, respectively; probiotic cheeses also displayed the highest levels of lactic microflora. Reverse-phase HPLC chromatograms of the water-soluble nitrogen fraction showed a more complex profile in S-BB, with distinctive peaks in the early-eluting zone. The matured Scamorza cheese containing the mix of B. longum and B. lactis was characterized by significantly higher levels of Gln, Ser, Arg, Ile, and Leu, whereas cheese containing Lb. acidophilus was characterized by higher levels of Tyr and Met. Total FFA content was the highest in S-LA, intermediate in S-BB, and the lowest in S-CO cheese; in particular, Scamorza cheese containing Lb. acidophilus showed the highest level of vaccenic acid, oleic acid, and total conjugated linoleic acid. Probiotic bacteria survived through the technological phases of pasta filata cheese production, maintained their specific metabolic pathways, and conferred functional properties to Scamorza ewe milk cheese. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Novel small RNA (sRNA) landscape of the starvation-stress response transcriptome of Salmonella enterica serovar typhimurium.

PubMed

Amin, Shivam V; Roberts, Justin T; Patterson, Dillon G; Coley, Alexander B; Allred, Jonathan A; Denner, Jason M; Johnson, Justin P; Mullen, Genevieve E; O'Neal, Trenton K; Smith, Jason T; Cardin, Sara E; Carr, Hank T; Carr, Stacie L; Cowart, Holly E; DaCosta, David H; Herring, Brendon R; King, Valeria M; Polska, Caroline J; Ward, Erin E; Wise, Alice A; McAllister, Kathleen N; Chevalier, David; Spector, Michael P; Borchert, Glen M

2016-01-01

Small RNAs (sRNAs) are short (∼50-200 nucleotides) noncoding RNAs that regulate cellular activities across bacteria. Salmonella enterica starved of a carbon-energy (C) source experience a host of genetic and physiological changes broadly referred to as the starvation-stress response (SSR). In an attempt to identify novel sRNAs contributing to SSR control, we grew log-phase, 5-h C-starved and 24-h C-starved cultures of the virulent Salmonella enterica subspecies enterica serovar Typhimurium strain SL1344 and comprehensively sequenced their small RNA transcriptomes. Strikingly, after employing a novel strategy for sRNA discovery based on identifying dynamic transcripts arising from "gene-empty" regions, we identify 58 wholly undescribed Salmonella sRNA genes potentially regulating SSR averaging an ∼1,000-fold change in expression between log-phase and C-starved cells. Importantly, the expressions of individual sRNA loci were confirmed by both comprehensive transcriptome analyses and northern blotting of select candidates. Of note, we find 43 candidate sRNAs share significant sequence identity to characterized sRNAs in other bacteria, and ∼70% of our sRNAs likely assume characteristic sRNA structural conformations. In addition, we find 53 of our 58 candidate sRNAs either overlap neighboring mRNA loci or share significant sequence complementarity to mRNAs transcribed elsewhere in the SL1344 genome strongly suggesting they regulate the expression of transcripts via antisense base-pairing. Finally, in addition to this work resulting in the identification of 58 entirely novel Salmonella enterica genes likely participating in the SSR, we also find evidence suggesting that sRNAs are significantly more prevalent than currently appreciated and that Salmonella sRNAs may actually number in the thousands.

Novel small RNA (sRNA) landscape of the starvation-stress response transcriptome of Salmonella enterica serovar typhimurium

PubMed Central

Amin, Shivam V.; Roberts, Justin T.; Patterson, Dillon G.; Coley, Alexander B.; Allred, Jonathan A.; Denner, Jason M.; Johnson, Justin P.; Mullen, Genevieve E.; O'Neal, Trenton K.; Smith, Jason T.; Cardin, Sara E.; Carr, Hank T.; Carr, Stacie L.; Cowart, Holly E.; DaCosta, David H.; Herring, Brendon R.; King, Valeria M.; Polska, Caroline J.; Ward, Erin E.; Wise, Alice A.; McAllister, Kathleen N.; Chevalier, David; Spector, Michael P.; Borchert, Glen M.

2016-01-01

ABSTRACT Small RNAs (sRNAs) are short (∼50–200 nucleotides) noncoding RNAs that regulate cellular activities across bacteria. Salmonella enterica starved of a carbon-energy (C) source experience a host of genetic and physiological changes broadly referred to as the starvation-stress response (SSR). In an attempt to identify novel sRNAs contributing to SSR control, we grew log-phase, 5-h C-starved and 24-h C-starved cultures of the virulent Salmonella enterica subspecies enterica serovar Typhimurium strain SL1344 and comprehensively sequenced their small RNA transcriptomes. Strikingly, after employing a novel strategy for sRNA discovery based on identifying dynamic transcripts arising from “gene-empty” regions, we identify 58 wholly undescribed Salmonella sRNA genes potentially regulating SSR averaging an ∼1,000-fold change in expression between log-phase and C-starved cells. Importantly, the expressions of individual sRNA loci were confirmed by both comprehensive transcriptome analyses and northern blotting of select candidates. Of note, we find 43 candidate sRNAs share significant sequence identity to characterized sRNAs in other bacteria, and ∼70% of our sRNAs likely assume characteristic sRNA structural conformations. In addition, we find 53 of our 58 candidate sRNAs either overlap neighboring mRNA loci or share significant sequence complementarity to mRNAs transcribed elsewhere in the SL1344 genome strongly suggesting they regulate the expression of transcripts via antisense base-pairing. Finally, in addition to this work resulting in the identification of 58 entirely novel Salmonella enterica genes likely participating in the SSR, we also find evidence suggesting that sRNAs are significantly more prevalent than currently appreciated and that Salmonella sRNAs may actually number in the thousands. PMID:26853797

Caspar Creek Watershed Study--North Fork Phase, Jackson Demonstration State Forest, Status and Plans, 1983-1990

Treesearch

Norm Henry; Karen Sendek

1985-01-01

Abstract - The California Department of Forestry and U.S. Forest Service, Pacific Southwest Forest and Range Experiment Station have been conducting a paired watershed study on Jackson Demonstration State Forest for 24 years. The South Fork watershed phase of the study involved monitoring the impacts of road construction (1967) and selective tractor logging (1971-1973...

In vitro observations on the suitability of new rifamycins for the intermittent chemotherapy of tuberculosis.

PubMed

Dickinson, J M; Mitchison, D A

1987-09-01

The bactericidal activity of six new rifamycin derivatives--rifabutin (RBU), FCE 22250 (F22), rifapentine (RPE), CGP 29861 (C29), CGP 7040 (C70) and CGP 27557 (C27) and rifampicin (RMP)--have been measured against log phase and, as a better test of sterilising activity, against stationary phase cultures of Mycobacterium tuberculosis, H37Rv. The order of activity of 1.0 and 0.2 mg/l rifamycin against log phase cultures was RMP greater than RPE & C27 greater than RBU & C29 greater than C70. The order of activity of 1.0 and 0.4 mg/l, adjusted for stability of the rifamycin, against stationary phase cultures was F22 & RMP greater than RBU greater than RPE greater than C27 & C29 greater than C70. Viable counts were done during and after pulsed exposures of 6, 24 or 96 h to C29 and RMP. The curves were similar though C29 was less bactericidal and the lag period before recovery was 1-2 days longer. F22, having high bactericidal activity against stationary organisms and a long half-life, was considered likely to be the most effective sterilising drug.

Imaging hydraulic fractures using temperature transients in the Belridge Diatomite

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

Shahin, G.T.; Johnston, R.M.

1995-12-31

Results of a temperature transient analysis of Shell`s Phase 1 and Phase 2 Diatomite Steamdrive Pilots are used to image hydraulic injection fracture lengths, angles, and heat injectivities into the low-permeability formation. The Phase 1 Pilot is a limited-interval injection test. In Phase 2, steam is injected into two 350 ft upper and lower zones through separate hydraulic fractures. Temperature response of both pilots is monitored with sixteen logging observation wells. A perturbation analysis of the non-linear pressure diffusion and heat transport equations indicates that at a permeability of about 0.1 md or less, heat transport in the Diatomite tendsmore » to be dominated by thermal diffusivity, and pressure diffusion is dominated by the ratio of thermal expansion to fluid compressibility. Under these conditions, the temperature observed at a logging observation well is governed by a dimensionless quantity that depends on the perpendicular distance between the observation well and the hydraulic fracture, divided by the square root of time. Using this dependence, a novel method is developed for imaging hydraulic fracture geometry and relative heat injectivity from the temperature history of the pilot.« less

Evaluation of geophysical logs, phase I, for Crossley Farms Superfund Site, Berks County, Pennsylvania

USGS Publications Warehouse

Conger, Randall W.

1998-01-01

Twenty-one wells were drilled at Crossley Farms Superfund Site between December 15, 1987, and May 1, 1988, to define and monitor the horizontal and vertical distribution of ground-water contamination emanating from a suspected contaminant source area (Blackhead Hill). Eight well clusters were drilled on or near the Crossley Site and three well clusters were drilled at locations hydrologically down gradient from the site. Depths of wells range from 21 to 299 feet below land surface. These wells were installed in saprolite in shallow, intermediate, and deep water-producing zones of the fractured bedrock aquifer. Borehole-geophysical and video logging were conducted between April 24, 1997, and May 8, 1997, to determine the water-producing zones, water-receiving zones, zones of vertical flow, borehole depth, and casing integrity in each well. This data and interpretation will be used to determine the location of the well intake for the existing open-hole wells, which will be retrofitted to isolate and monitor water-producing zones and prevent further cross-contamination within each open borehole, and identify wells that may need rehabilitation or replacement. Caliper and video logs were used to locate fractures, inflections on fluid-temperature and fluidresistivity logs indicated possible fluid-bearing fractures, and flowmeter measurements verified these locations. Single-point-resistance and natural-gamma logs provided information on stratigraphy. After interpretation of geophysical logs, video logs, and driller?s notes, all wells will be constructed so that water-level fluctuations can be monitored and discrete water samples collected from shallow, intermediate, and deep water-bearing zones in each well. Geophysical logs were run on seven bedrock and two deep bedrock wells. Gamma logs were run on 10 bedrock wells. Twenty-two wells were inspected visually with the borehole video camera for casing integrity.

Development of TiO2 powder-coated food packaging film and its ability to inactivate Escherichia coli in vitro and in actual tests.

PubMed

Chawengkijwanich, Chamorn; Hayata, Yasuyoshi

2008-04-30

Titanium dioxide (TiO2) has attracted a great deal of attention as a photocatalytic disinfecting material in the food and environmental industry. TiO2 has been used to inactivate a wide variety of microorganisms in many applications. In the present study, we aimed to develop a TiO2 powder-coated packaging film and clarify its ability to inactivate Escherichia coli both in vitro and in actual tests, using two different particle sizes and two types of illumination at different intensities. No inhibition effect of the testing method itself on the growth of E. coli was observed. The cells of E. coli were found to have decreased 3 log CFU/ml after 180 min of illumination by two 20 W black-light bulbs (wavelength of 300-400 nm) on TiO2-coated oriented-polypropylene (OPP) film, while E. coli decreased 1 log CFU/m with black-light illumination of uncoated OPP film. The results showed that both ultraviolet A (UVA; wavelength of 315-400 nm) alone and TiO2-coated OPP film combined with UVA reduced the number of E. coli cell in vitro, but that the reduction of E. coli cell numbers was greater by TiO2-coated OPP film combined with UVA. The antimicrobial effect of TiO2-coated film is dependent on the UVA light intensity (0, <0.05 and 1 mW/cm2) and the kind of artificial light (black-light and daylight fluorescent bulbs), but it is independent of the particle size of TiO2 coating on the surface of OPP film. The surviving cell numbers of E. coli on TiO2-coated film decreased 3 log and 0.35 log CFU/ml after 180 min of illumination by two 20 W black bulbs and two 20 W daylight fluorescent bulbs, respectively. Despite the lesser efficacy of the photocatalytic method with fluorescent lights, the survival of E. coli cells using this method was 50% of that using fluorescent lights alone. In the actual test, the number of E. coli cells from cut lettuce stored in a TiO2-coated film bag irradiated with UVA light decreased from 6.4 on Day 0 to 4.9 log CFU/g on Day 1, while that of an uncoated film bag irradiated with UVA light decreased from 6.4 to 6.1 log CFU/g after 1 day of storage. The result shows that the TiO2-coated film could reduce the microbial contamination on the surface of solid food products and thus reduce the risks of microbial growth on fresh-cut produce.

The F4/AS01B HIV-1 Vaccine Candidate Is Safe and Immunogenic, But Does Not Show Viral Efficacy in Antiretroviral Therapy-Naive, HIV-1-Infected Adults

PubMed Central

Dinges, Warren; Girard, Pierre-Marie; Podzamczer, Daniel; Brockmeyer, Norbert H.; García, Felipe.; Harrer, Thomas; Lelievre, Jean-Daniel; Frank, Ian; Colin De Verdière, Nathalie; Yeni, Guy-Patrick; Ortega Gonzalez, Enrique; Rubio, Rafael; Clotet Sala, Bonaventura; DeJesus, Edwin; Pérez-Elias, Maria Jesus; Launay, Odile; Pialoux, Gilles; Slim, Jihad; Weiss, Laurence; Bouchaud, Olivier; Felizarta, Franco; Meurer, Anja; Raffi, François; Esser, Stefan; Katlama, Christine; Koletar, Susan L.; Mounzer, Karam; Swindells, Susan; Baxter, John D.; Schneider, Stefan; Chas, Julie; Molina, Jean-Michel; Koutsoukos, Marguerite; Collard, Alix; Bourguignon, Patricia; Roman, François

2016-01-01

Abstract The impact of the investigational human immunodeficiency virus type 1 (HIV-1) F4/AS01B vaccine on HIV-1 viral load (VL) was evaluated in antiretroviral therapy (ART)-naive HIV-1 infected adults. This phase IIb, observer-blind study (NCT01218113), included ART-naive HIV-1 infected adults aged 18 to 55 years. Participants were randomized to receive 2 (F4/AS01B_2 group, N = 64) or 3 (F4/AS01B_3 group, N = 62) doses of F4/AS01B or placebo (control group, N = 64) at weeks 0, 4, and 28. Efficacy (HIV-1 VL, CD4+ T-cell count, ART initiation, and HIV-related clinical events), safety, and immunogenicity (antibody and T-cell responses) were evaluated during 48 weeks. At week 48, based on a mixed model, no statistically significant difference in HIV-1 VL change from baseline was demonstrated between F4/AS01B_2 and control group (0.073 log10 copies/mL [97.5% confidence interval (CI): −0.088; 0.235]), or F4/AS01B_3 and control group (−0.096 log10 copies/mL [97.5% CI: −0.257; 0.065]). No differences between groups were observed in HIV-1 VL change, CD4+ T-cell count, ART initiation, or HIV-related clinical events at intermediate timepoints. Among F4/AS01B recipients, the most frequent solicited symptoms were pain at injection site (252/300 doses), fatigue (137/300 doses), myalgia (105/300 doses), and headache (90/300 doses). Twelve serious adverse events were reported in 6 participants; 1 was considered vaccine-related (F4/AS01B_2 group: angioedema). F4/AS01B induced polyfunctional F4-specific CD4+ T-cells, but had no significant impact on F4-specific CD8+ T-cell and anti-F4 antibody levels. F4/AS01B had a clinically acceptable safety profile, induced F4-specific CD4+ T-cell responses, but did not reduce HIV-1 VL, impact CD4+ T-cells count, delay ART initiation, or prevent HIV-1 related clinical events. PMID:26871794

The F4/AS01B HIV-1 Vaccine Candidate Is Safe and Immunogenic, But Does Not Show Viral Efficacy in Antiretroviral Therapy-Naive, HIV-1-Infected Adults: A Randomized Controlled Trial.

PubMed

Dinges, Warren; Girard, Pierre-Marie; Podzamczer, Daniel; Brockmeyer, Norbert H; García, Felipe; Harrer, Thomas; Lelievre, Jean-Daniel; Frank, Ian; Colin De Verdière, Nathalie; Yeni, Guy-Patrick; Ortega Gonzalez, Enrique; Rubio, Rafael; Clotet Sala, Bonaventura; DeJesus, Edwin; Pérez-Elias, Maria Jesus; Launay, Odile; Pialoux, Gilles; Slim, Jihad; Weiss, Laurence; Bouchaud, Olivier; Felizarta, Franco; Meurer, Anja; Raffi, François; Esser, Stefan; Katlama, Christine; Koletar, Susan L; Mounzer, Karam; Swindells, Susan; Baxter, John D; Schneider, Stefan; Chas, Julie; Molina, Jean-Michel; Koutsoukos, Marguerite; Collard, Alix; Bourguignon, Patricia; Roman, François

2016-02-01

The impact of the investigational human immunodeficiency virus type 1 (HIV-1) F4/AS01B vaccine on HIV-1 viral load (VL) was evaluated in antiretroviral therapy (ART)-naive HIV-1 infected adults.This phase IIb, observer-blind study (NCT01218113), included ART-naive HIV-1 infected adults aged 18 to 55 years. Participants were randomized to receive 2 (F4/AS01B_2 group, N = 64) or 3 (F4/AS01B_3 group, N = 62) doses of F4/AS01B or placebo (control group, N = 64) at weeks 0, 4, and 28. Efficacy (HIV-1 VL, CD4 T-cell count, ART initiation, and HIV-related clinical events), safety, and immunogenicity (antibody and T-cell responses) were evaluated during 48 weeks.At week 48, based on a mixed model, no statistically significant difference in HIV-1 VL change from baseline was demonstrated between F4/AS01B_2 and control group (0.073 log10 copies/mL [97.5% confidence interval (CI): -0.088; 0.235]), or F4/AS01B_3 and control group (-0.096 log10 copies/mL [97.5% CI: -0.257; 0.065]). No differences between groups were observed in HIV-1 VL change, CD4 T-cell count, ART initiation, or HIV-related clinical events at intermediate timepoints. Among F4/AS01B recipients, the most frequent solicited symptoms were pain at injection site (252/300 doses), fatigue (137/300 doses), myalgia (105/300 doses), and headache (90/300 doses). Twelve serious adverse events were reported in 6 participants; 1 was considered vaccine-related (F4/AS01B_2 group: angioedema). F4/AS01B induced polyfunctional F4-specific CD4 T-cells, but had no significant impact on F4-specific CD8 T-cell and anti-F4 antibody levels.F4/AS01B had a clinically acceptable safety profile, induced F4-specific CD4 T-cell responses, but did not reduce HIV-1 VL, impact CD4 T-cells count, delay ART initiation, or prevent HIV-1 related clinical events.

Criticality and Phase Transition in Stock-Price Fluctuations

NASA Astrophysics Data System (ADS)

Kiyono, Ken; Struzik, Zbigniew R.; Yamamoto, Yoshiharu

2006-02-01

We analyze the behavior of the U.S. S&P 500 index from 1984 to 1995, and characterize the non-Gaussian probability density functions (PDF) of the log returns. The temporal dependence of fat tails in the PDF of a ten-minute log return shows a gradual, systematic increase in the probability of the appearance of large increments on approaching black Monday in October 1987, reminiscent of parameter tuning towards criticality. On the occurrence of the black Monday crash, this culminates in an abrupt transition of the scale dependence of the non-Gaussian PDF towards scale-invariance characteristic of critical behavior. These facts suggest the need for revisiting the turbulent cascade paradigm recently proposed for modeling the underlying dynamics of the financial index, to account for time varying—phase transitionlike and scale invariant-critical-like behavior.

Extreme high temperature redox kinetics in ceria: exploration of the transition from gas-phase to material-kinetic limitations

DOE PAGES

Ji, Ho-Il; Davenport, Timothy C.; Gopal, Chirranjeevi Balaji; ...

2016-07-18

The redox kinetics of undoped ceria (CeO 2-δ) are investigated by the electrical conductivity relaxation method in the oxygen partial pressure range of -4.3 ≤ log(pO 2/atm) ≤ -2.0 at 1400 °C. It is demonstrated that extremely large gas flow rates, relative to the mass of the oxide, are required in order to overcome gas phase limitations and access the material kinetic properties. Using these high flow rate conditions, the surface reaction rate constant k chem is found to obey the correlation log(k chem/cm s -1) = (0.84 ± 0.02) × log(pO 2/atm) - (0.99 ± 0.05) and increases withmore » oxygen partial pressure. This increase contrasts the known behavior of the dominant defect species, oxygen vacancies and free electrons, which decrease in concentration with increasing oxygen partial pressure. For the sample geometries employed, diffusion was too fast to be detected. At low gas flow rates, the relaxation process becomes limited by the capacity of the sweep gas to supply/remove oxygen to/from the oxide. An analytical expression is derived for the relaxation in the gas-phase limited regime, and the result reveals an exponential decay profile, identical in form to that known for a surface reaction limited process. Thus, measurements under varied gas flow rates are required to differentiate between surface reaction limited and gas flow limited behavior.« less

Exploring the Chemical Link Between Local Ellipticals and Their High-Redshift Progenitors

NASA Technical Reports Server (NTRS)

Leja, Joel; Van Dokkum, Pieter G.; Momcheva, Ivelina; Brammer, Gabriel; Skelton, Rosalind E.; Whitaker, Katherine E.; Andrews, Brett H.; Franx, Marijn; Kriek, Mariska; Van Der Wel, Arjen;

Chromatographic retention prediction and octanol-water partition coefficient determination of monobasic weak acidic compounds in ion-suppression reversed-phase liquid chromatography using acids as ion-suppressors.

PubMed

Ming, Xin; Han, Shu-ying; Qi, Zheng-chun; Sheng, Dong; Lian, Hong-zhen

2009-08-15

Although simple acids, replacing buffers, have been widely applied to suppress the ionization of weakly ionizable acidic analytes in reversed-phase liquid chromatography (RPLC), none of the previously reported works focused on the systematic studies about the retention behavior of the acidic solutes in this ion-suppression RPLC mode. The subject of this paper was therefore to investigate the retention behavior of monobasic weak acidic compounds using acetic, perchloric and phosphoric acids as the ion-suppressors. The apparent octanol-water partition coefficient (K" ow) was proposed to calibrate the octanol-water partition coefficient (K(ow)) of these weak acidic compounds, which resulted in a better linear correlation with log k(w), the logarithm of the hypothetical retention factor corresponding to neat aqueous fraction of hydroorganic mobile phase. This log K" ow-log k w linear correlation was successfully validated by the results of monocarboxylic acids and monohydrating phenols, and moreover by the results under diverse experimental conditions for the same solutes. This straightforward relationship not only can be used to effectively predict the retention values of weak acidic solutes combined with Snyder-Soczewinski equation, but also can offer a promising medium for directly measuring K(ow) data of these compounds via Collander equation. In addition, the influence of the different ion-suppressors on the retention of weak acidic compounds was also compared in this RPLC mode.

Extreme high temperature redox kinetics in ceria: exploration of the transition from gas-phase to material-kinetic limitations.

PubMed

Ji, Ho-Il; Davenport, Timothy C; Gopal, Chirranjeevi Balaji; Haile, Sossina M

2016-08-03

The redox kinetics of undoped ceria (CeO2-δ) are investigated by the electrical conductivity relaxation method in the oxygen partial pressure range of -4.3 ≤ log(pO2/atm) ≤ -2.0 at 1400 °C. It is demonstrated that extremely large gas flow rates, relative to the mass of the oxide, are required in order to overcome gas phase limitations and access the material kinetic properties. Using these high flow rate conditions, the surface reaction rate constant kchem is found to obey the correlation log(kchem/cm s(-1)) = (0.84 ± 0.02) × log(pO2/atm) - (0.99 ± 0.05) and increases with oxygen partial pressure. This increase contrasts the known behavior of the dominant defect species, oxygen vacancies and free electrons, which decrease in concentration with increasing oxygen partial pressure. For the sample geometries employed, diffusion was too fast to be detected. At low gas flow rates, the relaxation process becomes limited by the capacity of the sweep gas to supply/remove oxygen to/from the oxide. An analytical expression is derived for the relaxation in the gas-phase limited regime, and the result reveals an exponential decay profile, identical in form to that known for a surface reaction limited process. Thus, measurements under varied gas flow rates are required to differentiate between surface reaction limited and gas flow limited behavior.

Regulated Degradation of an Endoplasmic Reticulum Membrane Protein in a Tubular Lysosome in Leishmania mexicana

PubMed Central

Mullin, Kylie A.; Foth, Bernardo J.; Ilgoutz, Steven C.; Callaghan, Judy M.; Zawadzki, Jody L.; McFadden, Geoffrey I.; McConville, Malcolm J.

2001-01-01

The cell surface of the human parasite Leishmania mexicana is coated with glycosylphosphatidylinositol (GPI)-anchored macromolecules and free GPI glycolipids. We have investigated the intracellular trafficking of green fluorescent protein- and hemagglutinin-tagged forms of dolichol-phosphate-mannose synthase (DPMS), a key enzyme in GPI biosynthesis in L. mexicana promastigotes. These functionally active chimeras are found in the same subcompartment of the endoplasmic reticulum (ER) as endogenous DPMS but are degraded as logarithmically growing promastigotes reach stationary phase, coincident with the down-regulation of endogenous DPMS activity and GPI biosynthesis in these cells. We provide evidence that these chimeras are constitutively transported to and degraded in a novel multivesicular tubule (MVT) lysosome. This organelle is a terminal lysosome, which is labeled with the endocytic marker FM 4-64, contains lysosomal cysteine and serine proteases and is disrupted by lysomorphotropic agents. Electron microscopy and subcellular fractionation studies suggest that the DPMS chimeras are transported from the ER to the lumen of the MVT via the Golgi apparatus and a population of 200-nm multivesicular bodies. In contrast, soluble ER proteins are not detectably transported to the MVT lysosome in either log or stationary phase promastigotes. Finally, the increased degradation of the DPMS chimeras in stationary phase promastigotes coincides with an increase in the lytic capacity of the MVT lysosome and changes in the morphology of this organelle. We conclude that lysosomal degradation of DPMS may be important in regulating the cellular levels of this enzyme and the stage-dependent biosynthesis of the major surface glycolipids of these parasites. PMID:11514622

Thermal Inactivation of Desiccation-Adapted Salmonella spp. in Aged Chicken Litter

PubMed Central

Chen, Zhao; Diao, Junshu; Dharmasena, Muthu; Ionita, Claudia; Rieck, James

2013-01-01

Thermal inactivation of desiccation-adapted Salmonella spp. in aged chicken litter was investigated in comparison with that in a nonadapted control to examine potential cross-tolerance of desiccation-adapted cells to heat treatment. A mixture of four Salmonella serovars was inoculated into the finished compost with 20, 30, 40, and 50% moisture contents for a 24-h desiccation adaptation. Afterwards, the compost with desiccation-adapted cells was inoculated into the aged chicken litter with the same moisture content for heat treatments at 70, 75, 80, 85, and 150°C. Recovery media were used to allow heat-injured cells to resuscitate. A 5-log reduction in the number of the desiccation-adapted cells in aged chicken litter with a 20% moisture content required >6, >6, ∼4 to 5, and ∼3 to 4 h of exposure at 70, 75, 80, and 85°C, respectively. As a comparison, a 5-log reduction in the number of nonadapted control cells in the same chicken litter was achieved within ∼1.5 to 2, ∼1 to 1.5, ∼0.5 to 1, and <0.5 h at 70, 75, 80, and 85°C, respectively. The exposure time required to obtain a 5-log reduction in the number of desiccation-adapted cells gradually became shorter as temperature and moisture content were increased. At 150°C, desiccation-adapted Salmonella cells survived for 50 min in chicken litter with a 20% moisture content, whereas control cells were detectable by enrichment for only 10 min. Our results demonstrated that the thermal resistance of Salmonella in aged chicken litter was increased significantly when the cells were adapted to desiccation. This study also validated the effectiveness of thermal processing being used for producing chicken litter free of Salmonella contamination. PMID:24014540

Thermal inactivation of desiccation-adapted Salmonella spp. in aged chicken litter.

PubMed

Chen, Zhao; Diao, Junshu; Dharmasena, Muthu; Ionita, Claudia; Jiang, Xiuping; Rieck, James

2013-11-01

Thermal inactivation of desiccation-adapted Salmonella spp. in aged chicken litter was investigated in comparison with that in a nonadapted control to examine potential cross-tolerance of desiccation-adapted cells to heat treatment. A mixture of four Salmonella serovars was inoculated into the finished compost with 20, 30, 40, and 50% moisture contents for a 24-h desiccation adaptation. Afterwards, the compost with desiccation-adapted cells was inoculated into the aged chicken litter with the same moisture content for heat treatments at 70, 75, 80, 85, and 150°C. Recovery media were used to allow heat-injured cells to resuscitate. A 5-log reduction in the number of the desiccation-adapted cells in aged chicken litter with a 20% moisture content required >6, >6, ∼4 to 5, and ∼3 to 4 h of exposure at 70, 75, 80, and 85°C, respectively. As a comparison, a 5-log reduction in the number of nonadapted control cells in the same chicken litter was achieved within ∼1.5 to 2, ∼1 to 1.5, ∼0.5 to 1, and <0.5 h at 70, 75, 80, and 85°C, respectively. The exposure time required to obtain a 5-log reduction in the number of desiccation-adapted cells gradually became shorter as temperature and moisture content were increased. At 150°C, desiccation-adapted Salmonella cells survived for 50 min in chicken litter with a 20% moisture content, whereas control cells were detectable by enrichment for only 10 min. Our results demonstrated that the thermal resistance of Salmonella in aged chicken litter was increased significantly when the cells were adapted to desiccation. This study also validated the effectiveness of thermal processing being used for producing chicken litter free of Salmonella contamination.

Growth of Pseudomonas sp. TX1 on a wide range of octylphenol polyethoxylate concentrations and the formation of dicarboxylated metabolites.

PubMed

Lin, Yi-Wen; Guo, Gia-Luen; Hsieh, Hsiao-Cheng; Huang, Shir-Ly

2010-04-01

Pseudomonas sp. TX1, is able to use octylphenol polyethoxylates (OPEO(n), or Triton X-100; average n = 9.5) as a sole carbon source. It can grow on 0.05-20% of OPEO(n) with a specific growth rate of 0.34-0.44 h(-1). High-performance liquid chromatography-mass spectrometer analysis of OPEO(n) degraded metabolites revealed that strain TX1 was able to shorten the ethoxylate chain and produce octylphenol (OP). Furthermore, formation of the short carboxylate metabolites, such as carboxyoctylphenol polyethoxylates (COPEO(n), n = 2, 3) and carboxyoctylphenol polyethoxycarboxylates (COPEC(n), n = 2, 3) began at the log stage, while octylphenol polyethoxycarboxylates (OPEC(n), n = 1-3) was formed at the stationary phase. All the short-ethoxylated metabolites, OPEO(n), OPEC(n), COPEO(n), and COPEC(n), accumulated when the cells were in the stationary phase. This study is the first to demonstrate the formation of COPEO(n) and COPEC(n) from OPEO(n) by an aerobic bacterium. Copyright 2009 Elsevier Ltd. All rights reserved.

Clinical Grade Purification and Expansion of NK Cell Products for an Optimized Manufacturing Protocol

PubMed Central

Koehl, Ulrike; Brehm, Claudia; Huenecke, Sabine; Zimmermann, Stefanie-Yvonne; Kloess, Stephan; Bremm, Melanie; Ullrich, Evelyn; Soerensen, Jan; Quaiser, Andrea; Erben, Stephanie; Wunram, Claudia; Gardlowski, Tanja; Auth, Eileen; Tonn, Torsten; Seidl, Christian; Meyer-Monard, Sandrine; Stern, Martin; Passweg, Jakob; Klingebiel, Thomas; Bader, Peter; Schwabe, Dirk; Esser, Ruth

2013-01-01

Allogeneic natural killer (NK) cells are used for adoptive immunotherapy after stem cell transplantation. In order to overcome technical limitations in NK cell purification and activation, the following study investigates the impact of different variables on NK cell recovery, cytotoxicity, and T-cell depletion during good manufacturing practice (GMP)-grade NK cell selection. Forty NK cell products were derived from 54 unstimulated donor leukaphereses using immunomagnetic CD3 T-cell depletion, followed by a CD56 cell enrichment step. For T-cell depletion, either the depletion 2.1 program in single or double procedure (D2.11depl, n = 18; D2.12depl, n = 13) or the faster depletion 3.1 (D3.1, n = 9) was used on the CliniMACS instrument. Seventeen purified NK cell products were activated in vitro by IL-2 for 12 days. The whole process resulted in a median number of 7.59 × 108 CD56+CD3− cells with both purity and viability of 94%, respectively. The T-cell depletion was significantly better using D2.11depl/2depl compared to D3.1 (log 4.6/log 4.9 vs. log 3.7; p < 0.01) and double procedure in two stages led always to residual T cells below 0.1%. In contrast D3.1 was superior to D2.11depl/2depl with regard to recovery of CD56+CD3− NK cells (68% vs. 41%/38%). Concomitant monocytes and especially IL-2 activation led to increased NK cell activity against malignant target cells compared to unstimulated NK cells, which correlated with both up-regulation of natural cytotoxicity receptors and intracellular signaling. Overall, wide variations in the NK cell expansion rate and the distribution of NK cell subpopulations were found. In conclusion, our results indicate that GMP-grade purification of NK cells might be improved by a sequential processing of T-cell depletion program D2.1 and D3.1. In addition NK cell expansion protocols need to be further optimized. PMID:23730623

Comparison of sequential vs same-day simultaneous collagen cross-linking and topography-guided PRK for treatment of keratoconus.

PubMed

Kanellopoulos, Anastasios John

2009-09-01

The safety and efficacy of corneal collagen cross-linking (CXL) and topography-guided photorefractive keratectomy (PRK) using a different sequence and timing were evaluated in consecutive keratoconus cases. This study included a total of 325 eyes with keratoconus. Eyes were divided into two groups. The first group (n=127 eyes) underwent CXL with subsequent topography-guided PRK performed 6 months later (sequential group) and the second group (n=198 eyes) underwent CXL and PRK in a combined procedure on the same day (simultaneous group). Statistical differences were examined for pre- to postoperative changes in uncorrected (UCVA, logMAR) and best-spectacle-corrected visual acuity (BSCVA, logMAR), manifest refraction spherical equivalent (MRSE), keratometry (K), topography, central corneal thickness, endothelial cell count, corneal haze, and ectatic progression. Mean follow-up was 36+/-18 months (range: 24 to 68 months). At last follow-up in the sequential group, the mean UCVA improved from 0.9+/-0.3 logMAR to 0.49+/-0.25 logMAR, and mean BSCVA from 0.41+/-0.25 logMAR to 0.16+/-0.22 logMAR. Mean reduction in spherical equivalent refraction was 2.50+/-1.20 diopters (D), mean haze score was 1.2+/-0.5, and mean reduction in K was 2.75+/-1.30 D. In the simultaneous group, mean UCVA improved from 0.96+/-0.2 logMAR to 0.3+/-0.2 logMAR, and mean BSCVA from 0.39+/-0.3 logMAR to 0.11+/-0.16 logMAR. Mean reduction in spherical equivalent refraction was 3.20+/-1.40 D, mean haze score was 0.5+/-0.3, and mean reduction in K was 3.50+/-1.3 D. Endothelial cell count preoperatively and at last follow-up was unchanged (P<.05) in both groups. Statistically, the simultaneous group did better (P<.05) in all fields evaluated, with improvement in UCVA and BSCVA, a greater mean reduction in spherical equivalent refraction and keratometry, and less corneal haze. Same-day simultaneous topography-guided PRK and CXL appears to be superior to sequential CXL with later PRK in the visual rehabilitation of progressing keratoconus. Copyright 2009, SLACK Incorporated.

Experimental study and thermodynamic modeling of the phase relation in the Fe-S-Si system with implications for the distribution of S and Si in a partially solidified core

NASA Astrophysics Data System (ADS)

Tao, R.; Fei, Y.

2017-12-01

Planetary cooling leads to solidification of any initially molten metallic core. Some terrestrial cores (e.g. Mercury) are formed and differentiated under relatively reduced conditions, and they are thought to be composed of Fe-S-Si. However, there are limited understanding of the phase relations in the Fe-S-Si system at high pressure and temperature. In this study, we conducted high-pressure experiments to investigate the phase relations in the Fe-S-Si system up to 25 GPa. Experimental results show that the liquidus and solidus in this study are slightly lower than those in the Fe-S binary system for the same S concentration in liquid at same pressure. The Fe3S, which is supposed to be the stable sub-solidus S-bearing phase in the Fe-S binary system above 17 GPa, is not observed in the Fe-S-Si system at 21 GPa. Almost all S prefers to partition into liquid, while the distribution of Si between solid and liquid depends on experimental P and T conditions. We obtained the partition coefficient log(KDSi) by fitting the experimental data as a function of P, T and S concentration in liquid. At a constant pressure, the log(KDSi) linearly decreases with 1/T(K). With increase of pressure, the slopes of linear correlation between log(KDSi) and 1/T(K) decreases, indicating that more Si partitions into solid at higher pressure. In order to interpolate and extrapolate the phase relations over a wide pressure and temperature range, we established a comprehensive thermodynamic model in the Fe-S-Si system. The results will be used to constrain the distribution of S and Si between solid inner core and liquid outer core for a range of planet sizes. A Si-rich solid inner core and a S-rich liquid outer core are suggested for an iron-rich core.

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.

Disinfection efficacy over yeast biofilms of juice processing industries.

PubMed

Tarifa, María C; Lozano, Jorge E; Brugnoni, Lorena I

2018-03-01

Membrane separation systems represent a hot - spot for biofilm formation in juice industries. Sodium hypochlorite (NaOCl) has been traditionally the disinfectant of choice; however, its effectiveness over well-established biofilms is limited. In this work the study of biofilm formation on ultrafiltration membranes was proposed. The effectiveness of cleaning and disinfection procedures commonly used in juice industry was tested on the removal and killing of cells. The species used (Rhodotorula mucilaginosa, Candida krusei, Candida kefyr and Candida tropicalis) were isolated from ultrafiltration modules of a clarified apple juice industry. Industrial concentrations of NaOCl (200mgCL∙L -1 ) showed to be effective against planktonic cultures with >4 log reductions, whereas their overall efficiency against adhered cells was smaller. Recovery of viable cell counts to initial numbers was evidenced regardless of the time of colonization. The topography of the surface showed to have an impact on the efficiency of the disinfectant, presenting membranes smaller log reductions than stainless steel (~1.09-1.53logCFU). At 200mgCl∙L -1 only membrane's cross flow recovery was reached with no long-term effect over the attached cells. The overall results demonstrated the recalcitrance of these biofilms to typical cleaning and disinfection process which may confer them with a selective advantage. Copyright © 2017 Elsevier Ltd. All rights reserved.

Neuromorphic log-domain silicon synapse circuits obey bernoulli dynamics: a unifying tutorial analysis

PubMed Central

Papadimitriou, Konstantinos I.; Liu, Shih-Chii; Indiveri, Giacomo; Drakakis, Emmanuel M.

2014-01-01

The field of neuromorphic silicon synapse circuits is revisited and a parsimonious mathematical framework able to describe the dynamics of this class of log-domain circuits in the aggregate and in a systematic manner is proposed. Starting from the Bernoulli Cell Formalism (BCF), originally formulated for the modular synthesis and analysis of externally linear, time-invariant logarithmic filters, and by means of the identification of new types of Bernoulli Cell (BC) operators presented here, a generalized formalism (GBCF) is established. The expanded formalism covers two new possible and practical combinations of a MOS transistor (MOST) and a linear capacitor. The corresponding mathematical relations codifying each case are presented and discussed through the tutorial treatment of three well-known transistor-level examples of log-domain neuromorphic silicon synapses. The proposed mathematical tool unifies past analysis approaches of the same circuits under a common theoretical framework. The speed advantage of the proposed mathematical framework as an analysis tool is also demonstrated by a compelling comparative circuit analysis example of high order, where the GBCF and another well-known log-domain circuit analysis method are used for the determination of the input-output transfer function of the high (4th) order topology. PMID:25653579

Neuromorphic log-domain silicon synapse circuits obey bernoulli dynamics: a unifying tutorial analysis.

PubMed

Papadimitriou, Konstantinos I; Liu, Shih-Chii; Indiveri, Giacomo; Drakakis, Emmanuel M

2014-01-01

The field of neuromorphic silicon synapse circuits is revisited and a parsimonious mathematical framework able to describe the dynamics of this class of log-domain circuits in the aggregate and in a systematic manner is proposed. Starting from the Bernoulli Cell Formalism (BCF), originally formulated for the modular synthesis and analysis of externally linear, time-invariant logarithmic filters, and by means of the identification of new types of Bernoulli Cell (BC) operators presented here, a generalized formalism (GBCF) is established. The expanded formalism covers two new possible and practical combinations of a MOS transistor (MOST) and a linear capacitor. The corresponding mathematical relations codifying each case are presented and discussed through the tutorial treatment of three well-known transistor-level examples of log-domain neuromorphic silicon synapses. The proposed mathematical tool unifies past analysis approaches of the same circuits under a common theoretical framework. The speed advantage of the proposed mathematical framework as an analysis tool is also demonstrated by a compelling comparative circuit analysis example of high order, where the GBCF and another well-known log-domain circuit analysis method are used for the determination of the input-output transfer function of the high (4(th)) order topology.

Growth kinetics of Staphylococcus aureus on Brie and Camembert cheeses.

PubMed

Lee, Heeyoung; Kim, Kyungmi; Lee, Soomin; Han, Minkyung; Yoon, Yohan

2014-05-01

In this study, we developed mathematical models to describe the growth kinetics of Staphylococcus aureus on natural cheeses. A five-strain mixture of Staph. aureus was inoculated onto 15 g of Brie and Camembert cheeses at 4 log CFU/g. The samples were then stored at 4, 10, 15, 25, and 30 °C for 2-60 d, with a different storage time being used for each temperature. Total bacterial and Staph. aureus cells were enumerated on tryptic soy agar and mannitol salt agar, respectively. The Baranyi model was fitted to the growth data of Staph. aureus to calculate kinetic parameters such as the maximum growth rate in log CFU units (r max; log CFU/g/h) and the lag phase duration (λ; h). The effects of temperature on the square root of r max and on the natural logarithm of λ were modelled in the second stage (secondary model). Independent experimental data (observed data) were compared with prediction and the respective root mean square error compared with the RMSE of the fit on the original data, as a measure of model performance. The total growth of bacteria was observed at 10, 15, 25, and 30 °C on both cheeses. The r max values increased with storage temperature (P<0·05), but a significant effect of storage temperature on λ values was only observed between 4 and 15 °C (P<0·05). The square root model and linear equation were found to be appropriate for description of the effect of storage temperature on growth kinetics (R 2=0·894-0·983). Our results indicate that the models developed in this study should be useful for describing the growth kinetics of Staph. aureus on Brie and Camembert cheeses.

Uptake of pesticides from water by curly waterweed Lagarosiphon major and lesser duckweed Lemna minor.

PubMed

de Carvalho, Renato F; Bromilow, Richard H; Greenwood, Richard

2007-08-01

The uptake of pesticides from water by two aquatic plants, the submersed Lagarosiphon major (Ridley) Moss and the floating duckweed Lemna minor L., was measured over periods of up to 72 h. Twelve non-ionised pesticides and analogues, chosen to span a wide range of physicochemical properties, and one analogue (3,5-D) of the phenoxyacetic acid herbicide 2,4-D were studied. Concentrations of the parent compound were determined in the plants following extraction and separation by chromatography. Quantification was by liquid scintillation counting for the (14)C-labelled compounds and by high-performance liquid chromatography for the four non-radiolabelled commercial pesticides. Uptake for all compound and plant combinations had reached equilibrium by 24 h. Accumulation of compound in the plant could be described well for most non-ionised compounds by equilibration into the aqueous phase in the plant cells together with partitioning onto the plant solids, this latter process becoming dominant in Lagarosiphon for compounds with log K(ow) > 1 and in Lemna for compounds with log K(ow) > 1.8. Lipophilic compounds with log K(ow) > 4 were concentrated more than 100-fold on a fresh-weight basis. However, the uptake of isoproturon and chlorotoluron was up to threefold less than expected from their K(ow) values, and their behaviour was better explained using solvation descriptors. Uptake of the acid 3,5-D was dependent on solution pH, this compound being strongly taken up at lower pH by the process of ion trapping, as previously observed in barley roots. Aquatic vegetation can thus rapidly accumulate pesticides, and could be an important sink especially for lipophilic pesticides reaching well-vegetated waters. Copyright (c) 2007 Society of Chemical Industry

Preclinical tests of an android based dietary logging application.

PubMed

Kósa, István; Vassányi, István; Pintér, Balázs; Nemes, Márta; Kámánné, Krisztina; Kohut, László

2014-01-01

The paper describes the first, preclinical evaluation of a dietary logging application developed at the University of Pannonia, Hungary. The mobile user interface is briefly introduced. The three evaluation phases examined the completeness and contents of the dietary database and the time expenditure of the mobile based diet logging procedure. The results show that although there are substantial individual differences between various dietary databases, the expectable difference with respect to nutrient contents is below 10% on typical institutional menu list. Another important finding is that the time needed to record the meals can be reduced to about 3 minutes daily especially if the user uses set-based search. a well designed user interface on a mobile device is a viable and reliable way for a personalized lifestyle support service.

Function of the Pyruvate Oxidase-Lactate Oxidase Cascade in Interspecies Competition between Streptococcus oligofermentans and Streptococcus mutans

PubMed Central

Liu, Lei

2012-01-01

Complex interspecies interactions occur constantly between oral commensals and the opportunistic pathogen Streptococcus mutans in dental plaque. Previously, we showed that oral commensal Streptococcus oligofermentans possesses multiple enzymes for H2O2 production, especially lactate oxidase (Lox), allowing it to out-compete S. mutans. In this study, through extensive biochemical and genetic studies, we identified a pyruvate oxidase (pox) gene in S. oligofermentans. A pox deletion mutant completely lost Pox activity, while ectopically expressed pox restored activity. Pox was determined to produce most of the H2O2 in the earlier growth phase and log phase, while Lox mainly contributed to H2O2 production in stationary phase. Both pox and lox were expressed throughout the growth phase, while expression of the lox gene increased by about 2.5-fold when cells entered stationary phase. Since lactate accumulation occurred to a large degree in stationary phase, the differential Pox- and Lox-generated H2O2 can be attributed to differential gene expression and substrate availability. Interestingly, inactivation of pox causes a dramatic reduction in H2O2 production from lactate, suggesting a synergistic action of the two oxidases in converting lactate into H2O2. In an in vitro two-species biofilm experiment, the pox mutant of S. oligofermentans failed to inhibit S. mutans even though lox was active. In summary, S. oligofermentans develops a Pox-Lox synergy strategy to maximize its H2O2 formation so as to win the interspecies competition. PMID:22287002

Anaerosporomusa subterranea gen. nov., sp. nov., a spore-forming anaerobe belonging to the class Negativicutes isolated from saprolite.

PubMed

Choi, Jessica K; Shah, Madhavi; Yee, Nathan

2016-10-01

A Gram-stain-negative, spore-forming, anaerobic bacterium designated strain RU4T was isolated from a saprolite core collected from Oak Ridge, Tennessee, USA. Cells were slightly curved rods and exhibited an outer membrane exterior to a thin cell wall. Strain RU4T formed heat-resistant endospores in late-log phase and stationary phase cultures. Under anaerobic conditions, strain RU4T grew by fermenting fumarate and maleate, but did not grow on glucose, glycerol, pyruvate, lactate, succinate, citrate, formate, acetate, propionate, butyrate or valerate. Strain RU4T did not reduce sulfate or ferric iron. The main cellular fatty acids were C17 : 0 cyclo, C16 : 0 and C15 : 0. The DNA G+C content was 52 mol%. Analysis of the 16S rRNA, rpoB, recA, infB, gyrB and atpD gene sequences indicated that the isolate is related to members of the family Sporomusaceae. Based on 92 % sequence similarity of the 16S rRNA gene to its closest relatives in the family Sporomusaceae and divergent physiological traits, the newly-cultivated isolate was assigned to a novel species of a new genus, Anaerosporomusa subterranea gen. nov., sp. nov. The type strain of Anaerosporomusa subterranea is RU4T (=DSM 29728T=ATCC BAA-2723T).

Survival and High-Hydrostatic Pressure Inactivation of Foodborne Pathogens in Salmorejo, a Traditional Ready-to-Eat Food.

PubMed

Toledo Del Árbol, Julia; Pérez Pulido, Rubén; Grande, Ma José; Gálvez, Antonio; Lucas, Rosario

2015-11-01

Salmorejo is a traditional tomato-based creamy product. Because salmorejo is not heat-processed, there is a risk of contamination with foodborne pathogens from raw materials. Even though bacterial growth in salmorejo is strongly inhibited because of its acidic pH (close to 3.9), the growth and survival of 3 foodborne pathogens in this food has not been studied before. In this study, 3 cocktails consisting of Escherichia coli O157, Salmonella enterica serovar Enteritidis, and Listeria monocytogenes strains were inoculated in freshly prepared salmorejo. The food was treated by high hydrostatic pressure (HHP) at 400, 500, or 600 MPa for 8 min, or left untreated, and stored at 4 °C for 30 d. Viable cell counts were determined on selective media and also by the triple-layer agar method in order to detect sublethally injured cells. In control samples, L. monocytogenes viable cells decreased by 2.4 log cycles at day 7 and were undetectable by day 15. S. enterica cells decreased by 0.5 or 2.4 log cycles at days 7 and 15 respectively, but still were detectable at day 30. E. coli O157 cells survived much better in salmorejo, decreasing only by 1.5 log cycles at day 30. Treatments at pressures of 400 MPa or higher reduced viable counts of L. monocytogenes and S. enterica to undetectable levels. HHP treatments significantly (P < 0.05) reduced E. coli counts by approximately 5.2 to 5.4 log cycles, but also yielded surviving cells that apparently were sublethally injured. Only samples treated at 600 MPA for 8 min were devoid of detectable E. coli cells during storage. Salmorejo is a traditional, vitamin-rich food, usually produced on a small scale. HHP treatment at 600 MPa for 8 min can be an efficient nonthermal method for industrial-scale preparation of preservative-free salmorejo with improved safety against transmission of foodborne pathogens L. monocytogenes serotyes 4a and 4b, S. enterica serovar Enteritidis, and E. coli O157. © 2015 Institute of Food Technologists®

Substance abuse treatment in an urban HIV clinic: who enrolls and what are the benefits?

PubMed

Pisu, Maria; Cloud, Gretchen; Austin, Shamly; Raper, James L; Stewart, Katharine E; Schumacher, Joseph E

2010-03-01

Substance abuse treatment (SAT) is important for HIV medical care. Characteristics of those who choose SAT and effects of SAT on HIV clinical outcomes are not understood. We compared patients who enrolled and did not enroll in a SAT program offered within an HIV clinic, and evaluated the effect of SAT on CD4 T-cell counts and HIV plasma viral load (VL). Subjects were assessed and invited to enroll in SAT. Enrollees chose to receive psychological and psychiatric treatment, or motivational enhancement and relapse prevention, or residential SAT. We used logistic regressions to determine factors associated with enrollment (age, race, sex, HIV transmission risk factors, CD4 T-cell counts, and VL at assessment). A two-period (assessment and six months after SAT) data analysis was used to analyze the effect of SAT on CD4 T-cell count and log VL controlling for changes in HIV therapy. We find that, compared to Decliners (N=76), Enrollees (N=78) were more likely to be females (29.5% vs. 6.6%, OR=5.32, 95% CI 1.61-17.6), and to report injection drug use (IDU) as the HIV transmission risk factor (23.1% vs. 9.2%, OR=3.92, CI 1.38-11.1). Age (37.2 vs. 38.4), CD4 T-cell count (377.3 vs. 409.2), and log VL (3.21 vs. 2.99) at assessment were similar across the two groups (p>0.05). After six months, Enrollees and Decliners' CD4 T-cell counts increased and log VL decreased. SAT did not affect the change in CD4 T-cell count (p=0.51) or log VL (p=0.73). Similar results were found for patients with CD4 T-cell count < or =350 at assessment. In this small sample of HIV-infected patients with a limited follow-up period, women were more likely to enroll in SAT than men, and SAT reached those who needed it, e.g., IDUs. We did not find an effect of SAT on HIV clinical outcomes.

Modeling to predict growth/no growth boundaries and kinetic behavior of Salmonella on cutting board surfaces.

PubMed

Yoon, Hyunjoo; Lee, Joo-Yeon; Suk, Hee-Jin; Lee, Sunah; Lee, Heeyoung; Lee, Soomin; Yoon, Yohan

2012-12-01

This study developed models to predict the growth probabilities and kinetic behavior of Salmonella enterica strains on cutting boards. Polyethylene coupons (3 by 5 cm) were rubbed with pork belly, and pork purge was then sprayed on the coupon surface, followed by inoculation of a five-strain Salmonella mixture onto the surface of the coupons. These coupons were stored at 13 to 35°C for 12 h, and total bacterial and Salmonella cell counts were enumerated on tryptic soy agar and xylose lysine deoxycholate (XLD) agar, respectively, every 2 h, which produced 56 combinations. The combinations that had growth of ≥0.5 log CFU/cm(2) of Salmonella bacteria recovered on XLD agar were given the value 1 (growth), and the combinations that had growth of <0.5 log CFU/cm(2) were assigned the value 0 (no growth). These growth response data from XLD agar were analyzed by logistic regression for producing growth/no growth interfaces of Salmonella bacteria. In addition, a linear model was fitted to the Salmonella cell counts to calculate the growth rate (log CFU per square centimeter per hour) and initial cell count (log CFU per square centimeter), following secondary modeling with the square root model. All of the models developed were validated with observed data, which were not used for model development. Growth of total bacteria and Salmonella cells was observed at 28, 30, 33, and 35°C, but there was no growth detected below 20°C within the time frame investigated. Moreover, various indices indicated that the performance of the developed models was acceptable. The results suggest that the models developed in this study may be useful in predicting the growth/no growth interface and kinetic behavior of Salmonella bacteria on polyethylene cutting boards.

Effects of the calcium ionophore A23187 on airway responsiveness to histamine and substance P in guinea pigs.

PubMed

Uno, D; Tsukagoshi, H; Hisada, T; Iwamae, S; Mori, M

1997-03-01

We evaluated the mechanism of the airway hyperresponsiveness (AHR) induced by a calcium ionophore in guinea pigs. Airway responsiveness to intravenous histamine (HS) and substance P (SP) was measured 24 h after a 1-h exposure to aerosolized A23187 (0.03 or 0.1 mg/ml) or its vehicle (10% DMSO). Changes were assessed by calculating -logPC350HS and logPC350SP. Neutral endopeptidase (NEP) activity in the airway tissues, as well as the nitrite (NO2) levels and the cell population in bronchoalveolar lavage fluid (BALF) was determined after measurement of pulmonary function. Changes in SP-induced vascular permeability 24 h after exposure to A23187 were measured by the Evans Blue dye extravasation technique. Exposure to A23187 caused a significant AHR to SP, along with a significant increase in the number of neutrophils and epithelial cells in the BALF. While there was no significant change in NEP activity in the airway tissues, the levels of nitrite in the BALF were significantly decreased in A23187-exposed animals. Significant correlations were found between the number of epithelial cells in the BALF and logPC350SP (r = 0.477, p < 0.05) and between nitrite levels in the BALF and -logPC350SP (r = 0.491, p < 0.05) A23187 exposure did not significantly change the SP-induced airway microvascular leakage. These data suggest that A23187 exposure induced AHR to SP possibly by reducing NO levels in the airway tissues. This may be due to damaged airway epithelium and/or NO breakdown by activated inflammatory cells in the airways of these guinea pigs.

Extravascular transport of drugs in tumor tissue: effect of lipophilicity on diffusion of tirapazamine analogues in multicellular layer cultures.

PubMed

Pruijn, Frederik B; Sturman, Joanna R; Liyanage, H D Sarath; Hicks, Kevin O; Hay, Michael P; Wilson, William R

2005-02-24

The extravascular diffusion of antitumor agents is a key determinant of their therapeutic activity, but the relationships between physicochemical properties of drugs and their extravascular transport are poorly understood. It is well-known that drug lipophilicity plays an important role in transport across biological membranes, but the net effect of lipophilicity on transport through multiple layers of tumor cells is less clear. This study examines the influence of lipophilicity (measured as the octanol-water partition coefficient P) on the extravascular transport properties of the hypoxic cytotoxin tirapazamine (TPZ, 1) and a series of 13 neutral analogues, using multicellular layers (MCLs) of HT29 human colon carcinoma cells as an in vitro model for the extravascular compartment of tumors. Flux of drugs across MCLs was determined using diffusion chambers, with the concentration-time profile on both sides of the MCL measured by HPLC. Diffusion coefficients in the MCLs (D(MCL)) were inversely proportional to M(r)(0.5) (M(r), relative molecular weight), although this was a minor contributor to differences between compounds over the narrow M(r) range investigated. Differences in lipophilicity had a larger effect, with a sigmoidal dependence of D(MCL) on log P. Correcting for M(r) differences, lipophilic compounds (log P > 1.5) had ca. 15-fold higher D(MCL) than hydrophilic compounds (log P < -1). Using a pharmacokinetic/pharmacodynamic (PK/PD) model in which diffusion in the extravascular compartment of tumors is considered explicitly, we demonstrated that hypoxic cell kill is very sensitive to changes in extravascular diffusion coefficient of TPZ analogues within this range. This study shows that simple monosubstitution of TPZ can alter log P enough to markedly improve extravascular transport and activity against target cells, especially if rates of metabolic activation are also optimized.

Comparison between moving and stationary transmitter systems in induction logging

NASA Astrophysics Data System (ADS)

Poddar, M.; Caleb Dhanasekaran, P.; Prabhakar Rao, K.

1985-09-01

In a general treatment of the theory of induction logging, an exact integral representation has been obtained for the mutual impedance between a vertical dipole transmitter and a coaxial dipole receiver in a three layered earth. Based on this representation, a computer model has been devised using the traditional Slingram system of induction logging and the comparatively new Turam system, ignoring borehole effects. The model results indicate that due to its much larger response, the Turam system is in general preferable to the Slingram in mineral and groundwater investigations where formation conductivity much less than 1 S/m is generally encountered. However, if the surrounding media are conductive (more than 0.1 S/m), the Turam system suffers from large amplitude attenuation and phase rotation of the primary field caused by the conductive surrounding, and is less useful than the Slingram system which does not so suffer, unless the target bed is shallow. Because it is a more complex function of system parameters than the corresponding Slingram log, a Turam log can be conveniently interpreted only by the modern inverse method using a fast algorithm for the forward solution and a high speed digital computer.

Inactivation of Bacillus cereus by Na-chlorophyllin-based photosensitization on the surface of packaging.

PubMed

Luksiene, Z; Buchovec, I; Paskeviciute, E

2010-11-01

This study was focused on the possibility to inactivate food-borne pathogen Bacillus cereus by Na-chlorophyllin (Na-Chl)-based photosensitization in vitro and after attachment to the surface of packaging material. Bacillus cereus in vitro or attached to the packaging was incubated with Na-Chl (7·5×10(-8) to 7·5×10(-5) mol l(-1) ) for 2-60min in phosphate buffer saline. Photosensitization was performed by illuminating cells under a light with a λ of 400nm and an energy density of 20mW cm(-2) . The illumination time varied 0-5min and subsequently the total energy dose was 0-6J cm(-2) . The results show that B. cereus vegetative cells in vitro or attached to the surface of packaging after incubation with 7·5×10(-7) mol l(-1) Na-Chl and following illumination were inactivated by 7log. The photoinactivation of B. cereus spores in vitro by 4log required higher (7·5×10(-6) mol l(-1) ) Na-Chl concentration. Decontamination of packaging material from attached spores by photosensitization reached 5log at 7·5×10(-5) mol l(-1) Na-Chl concentration. Comparative analysis of different packaging decontamination treatments indicates that washing with water can diminish pathogen population on the surface by <1log, 100ppm Na-hypochlorite reduces the pathogens about 1·7log and 200ppm Na-hypochlorite by 2·2log. Meanwhile, Na-Chl-based photosensitization reduces bacteria on the surface by 4·2 orders of magnitude. Food-borne pathogen B. cereus could be effectively inactivated (7log) by Na-Chl-based photosensitization in vitro and on the surface of packaging material. Spores are more resistant than vegetative cells to photosensitization-based inactivation. Comparison of different surface decontamination treatments indicates that Na-Chl-based photosensitization is much more effective antibacterial tool than washing with water or 200ppm Na-hypochlorite. Our data support the idea that Na-Chl-based photosensitization has great potential for future application as an environment-friendly, nonthermal surface decontamination technique. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.

Growth of Listeria monocytogenes, Salmonella spp., Escherichia coli O157:H7, and Staphylococcus aureus on cheese during extended storage at 25°C.

PubMed

Leong, Wan Mei; Geier, Renae; Engstrom, Sarah; Ingham, Steve; Ingham, Barbara; Smukowski, Marianne

2014-08-01

Potentially hazardous foods require time/temperature control for safety. According to the U.S. Food and Drug Administration Food Code, most cheeses are potentially hazardous foods based on pH and water activity, and a product assessment is required to evaluate safety of storage >6 h at 21°C. We tested the ability of 67 market cheeses to support growth of Listeria monocytogenes (LM), Salmonella spp. (SALM), Escherichia coli O157:H7 (EC), and Staphylococcus aureus (SA) over 15 days at 25°C. Hard (Asiago and Cheddar), semi-hard (Colby and Havarti), and soft cheeses (mozzarella and Mexican-style), and reduced-sodium or reduced-fat types were tested. Single-pathogen cocktails were prepared and individually inoculated onto cheese slices (∼10(5) CFU/g). Cocktails were 10 strains of L. monocytogenes, 6 of Salmonella spp., or 5 of E. coli O157:H7 or S. aureus. Inoculated slices were vacuum packaged and stored at 25°C for ≤ 15 days, with surviving inocula enumerated every 3 days. Percent salt-in-the-moisture phase, percent titratable acidity, pH, water activity, and levels of indigenous/starter bacteria were measured. Pathogens did not grow on 53 cheeses, while 14 cheeses supported growth of SA, 6 of SALM, 4 of LM, and 3 of EC. Of the cheeses supporting pathogen growth, all supported growth of SA, ranging from 0.57 to 3.08 log CFU/g (average 1.70 log CFU/g). Growth of SALM, LM, and EC ranged from 1.01 to 3.02 log CFU/g (average 2.05 log CFU/g), 0.60 to 2.68 log CFU/g (average 1.60 log CFU/g), and 0.41 to 2.90 log CFU/g (average 1.69 log CFU/g), respectively. Pathogen growth varied within cheese types or lots. Pathogen growth was influenced by pH and percent salt-in-the-moisture phase, and these two factors were used to establish growth/no-growth boundary conditions for safe, extended storage (≤25°C) of pasteurized milk cheeses. Pathogen growth/no-growth could not be predicted for Swiss-style cheeses, mold-ripened or bacterial surface-ripened cheeses, and cheeses made with nonbovine milk, as insufficient data were gathered. This challenge study data can support science-based decision making in a regulatory framework.

MapMySmoke: feasibility of a new quit cigarette smoking mobile phone application using integrated geo-positioning technology, and motivational messaging within a primary care setting.

PubMed

Schick, Robert S; Kelsey, Thomas W; Marston, John; Samson, Kay; Humphris, Gerald W

2018-01-01

Approximately 11,000 people die in Scotland each year as a result of smoking-related causes. Quitting smoking is relatively easy; maintaining a quit attempt is a very difficult task with success rates for unaided quit attempts stubbornly remaining in the single digits. Pharmaceutical treatment can improve these rates by lowering the overall reward factor of nicotine. However, these and related nicotine replacement therapies do not operate on, or address, the spatial and contextual aspects of smoking behaviour. With the ubiquity of smartphones that can log spatial, quantitative and qualitative data related to smoking behaviour, there exists a person-centred clinical opportunity to support smokers attempting to quit by first understanding their smoking behaviour and subsequently sending them dynamic messages to encourage health behaviour change within a situational context. We have built a smartphone app-MapMySmoke-that works on Android and iOS platforms. The deployment of this app within a clinical National Health Service (NHS) setting has two distinct phases: (1) a 2-week logging phase where pre-quit patients log all of their smoking and craving events; and (2) a post-quit phase where users receive dynamic support messages and can continue to log craving events, and should they occur, relapse events. Following the initial logging phase, patients consult with their general practitioner (GP) or healthcare provider to review their smoking patterns and to outline a precise, individualised quit attempt plan. Our feasibility study consists of assessment of an initial app version during and after use by eight patients recruited from an NHS Fife GP practice. In addition to evaluation of the app as a potential smoking cessation aid, we have assessed the user experience, technological requirements and security of the data flow. In an initial feasibility study, we have deployed the app for a small number of patients within one GP practice in NHS Fife. We recruited eight patients within one surgery, four of whom actively logged information about their smoking behaviour. Initial feedback was very positive, and users indicated a willingness to log their craving and smoking events. In addition, two out of three patients who completed follow-up interviews noted that the app helped them reduce the number of cigarettes they smoked per day, while the third indicated that it had helped them quit. The study highlighted the use of pushed notifications as a potential technology for maintaining quit attempts, and the security of collection of data was audited. These initial results influenced the design of a planned second larger study, comprised of 100 patients, the primary objectives of which are to use statistical modelling to identify times and places of probable switches into smoking states, and to target these times with dynamic health behaviour messaging. While the health benefits of quitting smoking are unequivocal, such behaviour change is very difficult to achieve. Many factors are likely to contribute to maintaining smoking behaviour, yet the precise role of cues derived from the spatial environment remains unclear. The rise of smartphones, therefore, allows clinicians the opportunity to better understand the spatial aspects of smoking behaviour and affords them the opportunity to push targeted individualised health support messages at vulnerable times and places. ClinicalTrial.gov, NCT02932917.

Calix[4]arene-bis(t-octylbenzo-18-crown-6) as an extraordinarily effective macrocyclic receptor for the univalent thallium cation

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

Makrlik, Emanuel; Toman, Petr; Vanura, Petr

2013-01-01

From extraction experiments and -activity measurements, the exchange extraction constant corresponding to the equilibrium Tl+ (aq) + 1 Cs+ (org) 1 Tl+ (org) + Cs+ (aq) taking place in the two-phase water phenyltrifluoromethyl sulfone (abbrev. FS 13) system (1 = calix[4]arene-bis(t-octylbenzo-18-crown-6); aq = aqueous phase, org = FS 13 phase) was evaluated as log Kex (Tl+, 1 Cs+) = 1.7 0.1. Further, the extraordinarily high stability constant of the 1 Tl+ complex in FS 13 saturated with water was calculated for a temperature of 25 C: log org(1 Tl+) = 13.1 0.2. Finally, by using quantum mechanical DFT calculations, themore » most probable structure of the cationic complex species 1 Tl+ was derived. In the resulting 1 Tl+ complex, the central cation Tl+ is bound by eight bond interactions to six oxygen atoms from the respective 18-crown-6 moiety and to two carbons of the corresponding two benzene rings of the parent receptor 1 via cation interaction.« less

Interaction of the cesium cation with calix[4]arene-bis(t-octylbenzo-18-crown-6): Extraction and DFT study

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

Makrlik, Emanuel; Toman, Petr; Vanura, Petr

2013-01-01

From extraction experiments and c-activity measurements, the extraction constant corresponding to the equilibrium Cs+ (aq) + I (aq) + 1 (org),1Cs+ (org) + I (org) taking place in the two-phase water-phenyltrifluoromethyl sulfone (abbrev. FS 13) system (1 = calix[4]arene-bis(t-octylbenzo-18-crown-6); aq = aqueous phase, org = FS 13 phase) was evaluated as logKex (1Cs+, I) = 2.1 0.1. Further, the stability constant of the 1Cs+ complex in FS 13 saturated with water was calculated for a temperature of 25 C: log borg (1Cs+) = 9.9 0.1. Finally, by using quantum mechanical DFT calculations, the most probable structure of the cationic complexmore » species 1Cs+ was derived. In the resulting 1Cs+ complex, the central cation Cs+ is bound by eight bond interactions to six oxygen atoms of the respective 18-crown-6 moiety and to two carbons of the corresponding two benzene rings of the parent ligand 1 via cation p interaction.« less

Interaction of the univalent silver cation with [Gly6]-antamanide: Experimental and theoretical study

NASA Astrophysics Data System (ADS)

Makrlík, Emanuel; Böhm, Stanislav; Kvíčala, Jaroslav; Vaňura, Petr; Ruzza, Paolo

2018-03-01

On the basis of extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Ag+(aq) + 1.Na+(nb) ⇄ 1.Ag+ (nb) + Na+(aq) occurring in the two-phase water - nitrobenzene system (1 = [Gly6]-antamanide; aq = aqueous phase, nb = nitrobenzene phase) was determined as log Kex (Ag+,1·Na+) = 1.5 ± 0.1. Further, the stability constant of the 1·Ag+ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log βnb (1·Ag+) = 4.5 ± 0.2. Finally, by using quantum chemical DFT calculations, the most probable structure of the cationic complex species 1·Ag+ was derived. In the resulting complex, the "central" cation Ag+ is coordinated by four noncovalent interactions to the corresponding four carbonyl oxygen atoms of the parent ligand 1. Besides, the whole 1·Ag+ complex structure is stabilized by two intramolecular hydrogen bonds. The interaction energy of the considered 1·Ag+ complex was found to be -465.5 kJ/mol, confirming also the formation of this cationic species.

Vanadium Partitioning and Mantle Oxidation State: New Experimental Data

NASA Astrophysics Data System (ADS)

Mallmann, G.; O'Neill, H. S.

2007-12-01

Vanadium exists in multiple valences in natural basaltic melts, namely V2+, V3+, V4+ and V5+. Because most crystalline phases prefer to incorporate V3+ rather than V4+ and V5+, the crystal/silicate-melt partitioning of vanadium (DVcry/melt) tends to decrease with increasing oxygen fugacity (fO2). Such dependence has been experimentally demonstrated and used to estimate the fO2 of mantle and mantle-derived rocks. Recent modelling of V and V/Sc systematics in basalts has lead to the view that the relative fO2 of the upper mantle is constant, both through time and among the sources of different types of basaltic magmas (i.e. MORB, OIB and IAB). This is contrary to the notion given by other oxygen barometric methods on peridotites and basalts, which indicate an upper mantle heterogeneous in relative fO2. To explore further the potential of V abundances and V/Sc ratios to estimate the relative fO2 of mantle peridotites and basalts, and in particular to understand variations in mantle oxidation state better, we carried out an experimental campaign aimed at measuring DVcry/melt for all the relevant phases of the upper mantle (i.e. olivine, orthopyroxene, clinopyroxene, garnet and spinel) over a range of fO2 conditions large enough to pin down not only the behaviour of V3+ and V4+ but also V2+ and V5+. Experiments were done in 1-atm vertical tube furnaces (1300°C) and piston-cylinder apparatus (1275-1450°C and 1.5-3.2 GPa). For the high-pressure experiments, fO2 was controlled by the Re-ReOx/2 equilibrium (10-9 to 10-0.7 bar), whereas for the 1-atm experiments, fO2 was controlled by Ar-CO-CO2- O2 gas mixes (10-18 to 10-0.7 bar). Five starting compositions were used to ensure the presence of all the desired phases. Experimental products were analysed for major elements by electron microprobe and for trace elements by laser-ablation ICP-MS, which enables V to be measured precisely even at very low concentrations. Partition coefficients for all phases plot as approximately sigmoid-shaped curves in log D-log fO2 space. Details of the shape of the curve are controlled by the relative preference of each crystalline phase for a specific valence of V. For instance, orthopyroxene appears to particularly like V4+, so that the log DVopx/melt-log fO2 and log DVcpx/melt-log fO2 curves converge in the region of the diagram dominated by V4+, diverging in the regions dominated by V3+ and V5+. Contrary to previous studies, our results do not suggest a systematic increase in DVcpx/opx with decreasing fO2. Olivine and spinel, on the other hand, strongly prefer V3+ relative to V4+ and V5+ and hence for olivine and spinel the difference in partition coefficients between reducing and oxidizing conditions are more pronounced than that for pyroxenes. At high-pressure, DVgrt/melt and DVcpx/melt are very similar to each other, but the values of DVcpx/melt are about one order of magnitude higher than those obtained at 1 atm at comparable fO2. The cause of this discrepancy is being investigated.

Biofilm formation by Salmonella spp. in catfish mucus extract under industrial conditions.

PubMed

Dhowlaghar, Nitin; De Abrew Abeysundara, Piumi; Nannapaneni, Ramakrishna; Schilling, Mark W; Chang, Sam; Cheng, Wen-Hsing; Sharma, Chander S

2018-04-01

The objective of this study was to determine the effect of strain and temperature on the growth and biofilm formation of Salmonella spp. in high and low concentrations of catfish mucus extract on different food-contact surfaces at 22 °C and 10 °C. The second objective of this study was to evaluate the efficacy of disinfectants at recommended concentrations and contact times for removing Salmonella biofilms cells on a stainless steel surface containing catfish mucus extract. Growth and biofilm formation of all Salmonella strains increased with higher concentrations of catfish mucus extract at both 10 °C and 22 °C. In 15 μg/ml of catfish mucus extract inoculated with 3 log CFU/ml, the biofilm levels of Salmonella on stainless steel surface reached to 3.5 log CFU/cm 2 at 10 °C or 5.5 log CFU/cm 2 at 22 °C in 7 days. In 375 μg/ml of catfish mucus extract inoculated with 3 log CFU/ml, the biofilm levels of Salmonella on the stainless steel surface reached 4.5 log CFU/cm 2 at 10 °C and 6.5 log CFU/cm 2 at 22 °C in 7 days. No differences were observed between Salmonella strains tested for biofilm formation in catfish mucus extract on the stainless steel surface. The biofilm formation by Salmonella Blockley (7175) in catfish mucus extract was less (P < 0.05) on buna-N rubber when compared to stainless steel, polyethylene and polyurethane surfaces. Salmonella biofilm cells were not detectable on the stainless steel surface after treatment with a mixture of disinfectants but were still present when single compound disinfectants were used. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biodegradable polylactic acid polymer with nisin for use in antimicrobial food packaging.

PubMed

Jin, T; Zhang, H

2008-04-01

Biodegradable polylactic acid (PLA) polymer was evaluated for its application as a material for antimicrobial food packaging. PLA films were incorporated with nisin to for control of foodborne pathogens. Antimicrobial activity of PLA/nisin films against Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Enteritidis were evaluated in culture media and liquid foods (orange juice and liquid egg white). Scanned electron micrograph and confocal laser microscopy revealed that nisin particles were evenly distributed in PLA polymer matrix on the surface and inside of the PLA/nisin films. PLA/nisin significantly inhibited growth of L. monocytogenes in culture medium and liquid egg white. The greatest inhibition occurred at 24 h when the cell counts of L. monocytogenes in the PLA/nisin samples were 4.5 log CFU/mL less than the controls. PLA/nisin reduced the cell population of E. coli O157:H7 in orange juice from 7.5 to 3.5 log at 72 h whereas the control remained at about 6 log CFU/mL. PLA/nisin treatment resulted in a 2 log reduction of S. Enteritidis in liquid egg white at 24 degrees C. After 21 d at 4 degrees C the S. Enteritidis population from PLA/nisin treated liquid egg white (3.5 log CFU/mL) was significantly less than the control (6.8 log CFU/mL). E. coli O157:H7 in orange juice was more sensitive to PLA/nisin treatments than in culture medium. The results of this research demonstrated the retention of nisin activity when incorporated into the PLA polymer and its antimicrobial effectiveness against foodborne pathogens. The combination of a biopolymer and natural bacteriocin has potential for use in antimicrobial food packaging.

Adamantyl- and other polycyclic cage-based conjugates of desferrioxamine B (DFOB) for treating iron-mediated toxicity in cell models of Parkinson's disease.

PubMed

Telfer, Thomas J; Liddell, Jeffrey R; Duncan, Clare; White, Anthony R; Codd, Rachel

2017-04-15

The death of dopaminergic neurons is a major pathological hallmark of Parkinson's disease (PD). Elevated iron within the substantia nigra of the PD brain is thought to catalyze this neuronal death through hydroxyl radical-derived oxidative damage. Removing this excess iron presents a potential therapeutic strategy for PD. Seventeen derivatives of the non-toxic iron chelator desferrioxamine B (DFOB) were prepared by the conjugation of adamantyl- (1-4, 8-12), deconstructed adamantyl units (5-7), norborna(e)ne- (13-16) or bicyclo[2.2.2]octane-based (17) ancillary fragments to the terminal amine group. The range of experimental logP values of 1-17 (logP=0.15-2.82) was greater than water soluble DFOB (logP -2.29), with the increased hydrophobicity designed to improve cell membrane carriage to facilitate intracellular iron sequestration. The first activity screen showed compounds with methyl-substituted adamantyl (1-3), noradamantyl (5), or 1-pentylbicyclo[2.2.2]octane (17) ancillary groups significantly rescued iron-mediated oxidative stress in confluent PD-relevant SK-N-BE2-M17 neuroblastoma cells (M17 cells) exposed to 1,1'-dimethyl-4,4'-bipyridinium (paraquat, PQ) or H 2 O 2 . The second dose-dependence screen ranked 1-3 and 17 as the top candidates (EC 50 ∼10µM) in the rescue of PQ-treated M17 cells. The ancillary fragments of 1-3 and 17 clustered in a region defined by a close-to-zero dipole moment, logP values of 2-2.8 and a surface area:volume ratio of 0.60-0.61. Results of iron leaching studies indicate that the compounds may be operating via mechanisms beyond solely removing intracellular iron. The DFOB conjugates with methyl-substituted adamantyl ancillary groups (1-3) were the top and most consistent performers in this class of compound designed for PD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Survival of cold-stressed Campylobacter jejuni on ground chicken and chicken skin during frozen storage.

PubMed

Bhaduri, Saumya; Cottrell, Bryan

2004-12-01

Campylobacter jejuni is prevalent in poultry, but the effect of combined refrigerated and frozen storage on its survival, conditions relevant to poultry processing and storage, has not been evaluated. Therefore, the effects of refrigeration at 4 degrees C, freezing at -20 degrees C, and a combination of refrigeration and freezing on the survival of C. jejuni in ground chicken and on chicken skin were examined. Samples were enumerated using tryptic soy agar containing sheep's blood and modified cefoperazone charcoal deoxycholate agar. Refrigerated storage alone for 3 to 7 days produced a reduction in cell counts of 0.34 to 0.81 log10 CFU/g in ground chicken and a reduction in cell counts of 0.31 to 0.63 log10 CFU/g on chicken skin. Declines were comparable for each sample type using either plating medium. Frozen storage, alone and with prerefrigeration, produced a reduction in cell counts of 0.56 to 1.57 log10 CFU/g in ground chicken and a reduction in cell counts of 1.38 to 3.39 log10 CFU/g on chicken skin over a 2-week period. The recovery of C. jejuni following freezing was similar on both plating media. The survival following frozen storage was greater in ground chicken than on chicken skin with or without prerefrigeration. Cell counts after freezing were lower on chicken skin samples that had been prerefrigerated for 7 days than in those that had been prerefrigerated for 0, 1, or 3 days. This was not observed for ground chicken samples, possibly due to their composition. C. jejuni survived storage at 4 and -20 degrees C with either sample type. This study indicates that, individually or in combination, refrigeration and freezing are not a substitute for safe handling and proper cooking of poultry.

Effects of glucose, lactate and basic FGF as limiting factors on the expansion of human induced pluripotent stem cells.

PubMed

Horiguchi, Ikki; Urabe, Yusuke; Kimura, Keiichi; Sakai, Yasuyuki

2018-01-01

Pluripotent stem cells (PSCs) are one of the promising cell sources for tissue engineering and drug screening. However, mass production of induced pluripotent stem cells (iPSCs) is still developing. Especially, a huge amount of culture medium usage causes expensive cost in the mass production process. In this report, we reduced culture medium usage by extending interval of changing culture medium. In parallel, we also increased glucose concentration and supplied heparan sulfate to avoid depletion of glucose and bFGF, respectively. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analyses showed that reducing medium change frequency increased differentiation marker expressions but high glucose concentration downregulated these expressions. In contrast, heparan sulfate did not prevent differentiation marker expressions. According to analyses of growth rate, cell growth with extended medium change interval was decreased in later stage of log growth phase despite the existence of high glucose concentration and heparan sulfate. This result and culturing iPSCs with lactate showed that the accumulation of excreted lactate decreased the growth rate regardless of pH control. Conclusively, these experiments show that adding glucose and removing lactate are important to expand iPSCs with reduced culture medium usage. This knowledge should be useful to design economical iPSC mass production and differentiation system. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Measurements of gas and particle polycyclic aromatic hydrocarbons (PAHs) in air at urban, rural and near-roadway sites

NASA Astrophysics Data System (ADS)

Pratt, G. C.; Herbrandson, C.; Krause, M. J.; Schmitt, C.; Lippert, C. J.; McMahon, C. R.; Ellickson, K. M.

2018-04-01

We measured polycyclic aromatic hydrocarbons (PAHs) in gas and particle phases over two years using high volume samplers equipped with quartz fiber filters and XAD-4 at a rural site, an urban site, and a site adjacent to a heavily trafficked roadway. Overall results were generally as expected, in that concentrations increased from rural to urban to near-roadway sites, and PAHs with high vapor pressures (liquid subcooled, PoL) and low octanol-air partition coefficients (Koa) were mainly in the gas phase, while those with low PoL and high Koa were predominantly in the particle phase. Intermediate PAHs existed in both phases with the phase distribution following a seasonal pattern of higher gas phase concentrations in summer due to temperature effects. The overall pattern of phase distribution was consistent with PAH properties and ambient conditions and was similar at all three sites. The particle-bound fraction (ϕ) was well-described empirically by nonlinear regressions with log Koa and log PoL as predictors. Adsorption and absorption models underestimated the particle-bound fraction for most PAHs. The dual aerosol-air/soot-air model generally represented the gas-particle partitioning better than the other models across all PAHs, but there was a tendency to underestimate the range in the particle-bound fraction seen in measurements. There was a statistically insignificant tendency for higher PAHs in the particle phase at the near roadway site, and one piece of evidence that PAHs may be enriched on ultrafine particles at the near roadway site. Understanding the phase and particle size distributions of PAHs in highly polluted, high exposure microenvironments near traffic sources will help shed light on potential health effects.

Estimating tree bole and log weights from green densities measured with the Bergstrom Xylodensimeter.

Treesearch

Dale R. Waddell; Michael B. Lambert; W.Y. Pong

1984-01-01

The performance of the Bergstrom xylodensimeter, designed to measure the green density of wood, was investigated and compared with a technique that derived green densities from wood disk samples. In addition, log and bole weights of old-growth Douglas-fir and western hemlock were calculated by various formulas and compared with lifted weights measured with a load cell...

Phase 1 results from the Stirling-powered vehicle project

NASA Technical Reports Server (NTRS)

Shaltens, Richard K.

1988-01-01

The NASA Technology Utilization (TU) Office is sponsoring a multiyear, multiphase demonstration program to assess the technology developed under the DOE/NASA automotive Stirling engine (ASE) program with engines installed in various Air Force vehicles while being evaluated by independent third parties under realistic conditions. This paper reviews the operational history of Phase 1 with a Mod 1 Stirling engine installed in an Air Force multistop van in a variety of missions. Ten months of operation were with Air Force personnel at Langley Air Force Base, Virginia, where over 1100 hr and 4000 mi were logged on the Langley flight line. The Stirling-powered van operated on unleaded gasoline, JP-4 aircraft fuel, and diesel fuel at Langley Air Force Base. Two months of operation were completed with Deere and Company personnel in the Moline, Illinois area where over 175 hr and 2650 mi were logged on a Deere mail delivery route.

Synergistic effect of pulsed electric fields and CocoanOX 12% on the inactivation kinetics of Bacillus cereus in a mixed beverage of liquid whole egg and skim milk.

PubMed

Pina-Pérez, M C; Silva-Angulo, A B; Rodrigo, D; Martínez-López, A

2009-04-15

With a view to extending the shelf-life and enhancing the safety of liquid whole egg/skim milk (LWE-SM) mixed beverages, a study was conducted with Bacillus cereus vegetative cells inoculated in skim milk (SM) and LWE-SM beverages, with or without antimicrobial cocoa powder. The beverages were treated with Pulsed Electric Field (PEF) technology and then stored at 5 degrees C for 15 days. The kinetic results were modeled with the Bigelow model, Weibull distribution function, modified Gompertz equation, and Log-logistic models. Maximum inactivation registered a reduction of around 3 log cycles at 40 kV/cm, 360 micros, 20 degrees C in both the SM and LWE-SM beverages. By contrast, in the beverages supplemented with the aforementioned antimicrobial compound, higher inactivation levels were obtained under the same treatment conditions, reaching a 3.30 log(10) cycle reduction. The model affording the best fit for all four beverages was the four-parameter Log-logistic model. After 15 days of storage, the antimicrobial compound lowered Bacillus cereus survival rates in the samples supplemented with CocoanOX 12% by a 4 log cycle reduction, as compared to the untreated samples without CocoanOX 12%. This could indicate that the PEF-antimicrobial combination has a synergistic effect on the bacterial cells under study, increasing their sensitivity to subsequent refrigerated storage.

Preparation and Properties of (YCa)(TiMn)O3−δ Ceramics Interconnect of Solid Oxide Fuel Cells

PubMed Central

Liou, Yi-Cheng; Tsai, Wen-Chou; Yen, Hao-Hsuan; Chang, Yung-Chia

2015-01-01

(YCa)(TiMn)O3–δ ceramics prepared using a reaction-sintering process were investigated. Without any calcination involved, the mixture of raw materials was pressed and sintered directly. Y2Ti2O7 instead of YTiO3 formed when a mixture of Y2O3 and TiO2 with Y/Ti ratio 1/1 were sintered in air. Y2Ti2O7, YTiO2.085 and some unknown phases were detected in Y0.6Ca0.4Ti0.6Mn0.4O3–δ. Monophasic Y0.6Ca0.4Ti0.4Mn0.6O3–δ ceramics were obtained after 1400–1500 °C sintering. Dense Y0.6Ca0.4Ti0.4Mn0.6O3–δ with a density 4.69 g/cm3 was observed after 1500 °C/4 h sintering. Log σ for Y0.6Ca0.4Ti0.6Mn0.4O3–δ increased from –3.73 Scm–1 at 350 °C to –2.14 Scm–1 at 700 °C. Log σ for Y0.6Ca0.4Ti0.4Mn0.6O3–δ increased from –2.1 Scm–1 at 350 °C to –1.36 Scm–1 at 700 °C. Increasing Mn content decreased activation energy Ea and increased electrical conductivity. Reaction-sintering process is proved to be a simple and effective method to obtain (YCa)(TiMn)O3–δ ceramics for interconnects in solid oxide fuel cells. PMID:28793436

A prospective microbiome-wide association study of food sensitization and food allergy in early childhood.

PubMed

Savage, Jessica H; Lee-Sarwar, Kathleen A; Sordillo, Joanne; Bunyavanich, Supinda; Zhou, Yanjiao; O'Connor, George; Sandel, Megan; Bacharier, Leonard B; Zeiger, Robert; Sodergren, Erica; Weinstock, George M; Gold, Diane R; Weiss, Scott T; Litonjua, Augusto A

2018-01-01

Alterations in the intestinal microbiome are prospectively associated with the development of asthma; less is known regarding the role of microbiome alterations in food allergy development. Intestinal microbiome samples were collected at age 3-6 months in children participating in the follow-up phase of an interventional trial of high-dose vitamin D given during pregnancy. At age 3, sensitization to foods (milk, egg, peanut, soy, wheat, walnut) was assessed. Food allergy was defined as caretaker report of healthcare provider-diagnosed allergy to the above foods prior to age 3 with evidence of IgE sensitization. Analysis was performed using Phyloseq and DESeq2; P-values were adjusted for multiple comparisons. Complete data were available for 225 children; there were 87 cases of food sensitization and 14 cases of food allergy. Microbial diversity measures did not differ between food sensitization and food allergy cases and controls. The genera Haemophilus (log 2 fold change -2.15, P=.003), Dialister (log 2 fold change -2.22, P=.009), Dorea (log 2 fold change -1.65, P=.02), and Clostridium (log 2 fold change -1.47, P=.002) were underrepresented among subjects with food sensitization. The genera Citrobacter (log 2 fold change -3.41, P=.03), Oscillospira (log 2 fold change -2.80, P=.03), Lactococcus (log 2 fold change -3.19, P=.05), and Dorea (log 2 fold change -3.00, P=.05) were underrepresented among subjects with food allergy. The temporal association between bacterial colonization and food sensitization and allergy suggests that the microbiome may have a causal role in the development of food allergy. Our findings have therapeutic implications for the prevention and treatment of food allergy. © 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

Effect of n-octanol in the mobile phase on lipophilicity determination by reversed-phase high-performance liquid chromatography on a modified silica column.

PubMed

Benhaim, Deborah; Grushka, Eli

2008-10-31

In this study, we show that the addition of n-octanol to the mobile phase improves the chromatographic determination of lipophilicity parameters of xenobiotics (neutral solutes, acidic, neutral and basic drugs) on a Phenomenex Gemini C18 column. The Gemini C18 column is a new generation hybrid silica-based column with an extended pH range capability. The wide pH range (2-12) afforded the examination of basic drugs and acidic drugs in their neutral form. Extrapolated retention factor values, [Formula: see text] , obtained on the above column with the n-octanol-modified mobile phase were very well correlated (1:1 correlation) with literature values of logP (logarithm of the partition coefficient in n-octanol/water) of neutral compounds and neutral drugs (69). In addition, we found good linear correlations between measured [Formula: see text] values and calculated values of the logarithm of the distribution coefficient at pH 7.0 (logD(7.0)) for ionized acidic and basic drugs (r(2)=0.95). The Gemini C18 phase was characterized using the linear solvation energy relationship (LSER) model of Abraham. The LSER system constants for the column were compared to the LSER constants of n-octanol/water extraction system using the Tanaka radar plots. The comparison shows that the two methods are nearly equivalent.

Novel Desorber for Online Drilling Mud Gas Logging.

PubMed

Lackowski, Marcin; Tobiszewski, Marek; Namieśnik, Jacek

2016-01-01

This work presents the construction solution and experimental results of a novel desorber for online drilling mud gas logging. The traditional desorbers use mechanical mixing of the liquid to stimulate transfer of hydrocarbons to the gaseous phase that is further analyzed. The presented approach is based on transfer of hydrocarbons from the liquid to the gas bubbles flowing through it and further gas analysis. The desorber was checked for gas logging from four different drilling muds collected from Polish boreholes. The results of optimization studies are also presented in this study. The comparison of the novel desorber with a commercial one reveals strong advantages of the novel one. It is characterized by much better hydrocarbons recovery efficiency and allows reaching lower limits of detection of the whole analytical system. The presented desorber seems to be very attractive alternative over widely used mechanical desorbers.

Analytical approximations for effective relative permeability in the capillary limit

NASA Astrophysics Data System (ADS)

Rabinovich, Avinoam; Li, Boxiao; Durlofsky, Louis J.

2016-10-01

We present an analytical method for calculating two-phase effective relative permeability, krjeff, where j designates phase (here CO2 and water), under steady state and capillary-limit assumptions. These effective relative permeabilities may be applied in experimental settings and for upscaling in the context of numerical flow simulations, e.g., for CO2 storage. An exact solution for effective absolute permeability, keff, in two-dimensional log-normally distributed isotropic permeability (k) fields is the geometric mean. We show that this does not hold for krjeff since log normality is not maintained in the capillary-limit phase permeability field (Kj=k·krj) when capillary pressure, and thus the saturation field, is varied. Nevertheless, the geometric mean is still shown to be suitable for approximating krjeff when the variance of ln⁡k is low. For high-variance cases, we apply a correction to the geometric average gas effective relative permeability using a Winsorized mean, which neglects large and small Kj values symmetrically. The analytical method is extended to anisotropically correlated log-normal permeability fields using power law averaging. In these cases, the Winsorized mean treatment is applied to the gas curves for cases described by negative power law exponents (flow across incomplete layers). The accuracy of our analytical expressions for krjeff is demonstrated through extensive numerical tests, using low-variance and high-variance permeability realizations with a range of correlation structures. We also present integral expressions for geometric-mean and power law average krjeff for the systems considered, which enable derivation of closed-form series solutions for krjeff without generating permeability realizations.

Insights into arsenic multi-operons expression and resistance mechanisms in Rhodopseudomonas palustris CGA009

PubMed Central

Zhao, Chungui; Zhang, Yi; Chan, Zhuhua; Chen, Shicheng; Yang, Suping

2015-01-01

Arsenic (As) is widespread in the environment and causes numerous health problems. Rhodopseudomonas palustris has been regarded as a good model organism for studying arsenic detoxification since it was first demonstrated to methylate environmental arsenic by conversion to soluble or gaseous methylated species. However, the detailed arsenic resistance mechanisms remain unknown though there are at least three arsenic-resistance operons (ars1, ars2, and ars3) in R. palustris. In this study, we investigated how arsenic multi-operons contributed to arsenic detoxification in R. palustris. The expression of ars2 or ars3 operons increased with increasing environmental arsenite (As(III)) concentrations (up to 1.0 mM) while transcript of ars1 operon was not detected in the middle log-phase (55 h). ars2 operon was actively expressed even at the low concentration of As(III) (0.01 μM), whereas the ars3 operon was expressed at 1.0 μM of As(III), indicating that there was a differential regulation mechanism for the three arsenic operons. Furthermore, ars2 and ars3 operons were maximally transcribed in the early log-phase where ars2 operon was 5.4-fold higher than that of ars3 operon. A low level of ars1 transcript was only detected at 43 h (early log-phase). Arsenic speciation analysis demonstrated that R. palustris could reduce As(V) to As(III). Collectively, strain CGA009 detoxified arsenic by using arsenic reduction and methylating arsenic mechanism, while the latter might occur with the presence of higher concentrations of arsenic. PMID:26441915

The origins of post-starburst galaxies at z < 0.05

NASA Astrophysics Data System (ADS)

Pawlik, M. M.; Taj Aldeen, L.; Wild, V.; Mendez-Abreu, J.; Lahén, N.; Johansson, P. H.; Jimenez, N.; Lucas, W.; Zheng, Y.; Walcher, C. J.; Rowlands, K.

2018-06-01

Post-starburst galaxies can be identified via the presence of prominent Hydrogen Balmer absorption lines in their spectra. We present a comprehensive study of the origin of strong Balmer lines in a volume-limited sample of 189 galaxies with 0.01 < z < 0.05, log ({M}_{\\star }/{M}_{⊙})>9.5 and projected axial ratio b/a > 0.32. We explore their structural properties, environments, emission lines, and star formation histories, and compare them to control samples of star-forming and quiescent galaxies, and simulated galaxy mergers. Excluding contaminants, in which the strong Balmer lines are most likely caused by dust-star geometry, we find evidence for three different pathways through the post-starburst phase, with most events occurring in intermediate-density environments: (1) a significant disruptive event, such as a gas-rich major merger, causing a starburst and growth of a spheroidal component, followed by quenching of the star formation (70 per cent of post-starburst galaxies at 9.5< log ({M}_{\\star}/{M}_{⊙})<10.5 and 60 per cent at log ({M}_{\\star}/{M}_{⊙})>10.5); (2) at 9.5< log ({M}_{\\star}/{M}_{⊙})<10.5, stochastic star formation in blue-sequence galaxies, causing a weak burst and subsequent return to the blue sequence (30 per cent); (3) at log ({M}_{\\star}/{M}_{⊙})>10.5, cyclic evolution of quiescent galaxies which gradually move towards the high-mass end of the red sequence through weak starbursts, possibly as a result of a merger with a smaller gas-rich companion (40 per cent). Our analysis suggests that active galactic nuclei (AGNs) are 'on' for 50 per cent of the duration of the post-starburst phase, meaning that traditional samples of post-starburst galaxies with strict emission-line cuts will be at least 50 per cent incomplete due to the exclusion of narrow-line AGNs.

Biosynthesis of the Osmoprotectant Ectoine, but Not Glycine Betaine, Is Critical for Survival of Osmotically Stressed Vibrio parahaemolyticus Cells

PubMed Central

Ongagna-Yhombi, Serge Y.

2013-01-01

Vibrio parahaemolyticus is a halophile present in marine and estuarine environments, ecosystems characterized by fluctuations in salinity and temperature. One strategy to thrive in such environments is the synthesis and/or uptake of compatible solutes. The V. parahaemolyticus genome contains biosynthesis systems for both ectoine and glycine betaine, which are known to act as compatible solutes in other species. We showed that V. parahaemolyticus had a 6% NaCl tolerance when grown in M9 minimal medium with 0.4% glucose (M9G) with a >5-h lag phase. By using 1H nuclear magnetic resonance spectroscopy (1H-NMR) analysis, we determined that cells synthesized ectoine and glutamate in a NaCl-dependent manner. The most effective compatible solutes as measured by a reduction in lag-phase growth in M9G with 6% NaCl (M9G 6% NaCl) were in the order glycine betaine > choline > proline = glutamate > ectoine. However, V. parahaemolyticus could use glutamate or proline as the sole carbon source, but not ectoine or glycine betaine, which suggests that these are bona fide compatible solutes. Expression analysis showed that the ectA and betA genes were more highly expressed in log-phase cells, and expression of both genes was induced by NaCl up-shock. Under all conditions examined, the ectA gene was more highly expressed than the betA gene. Analysis of in-frame deletions in betA and ectB and in a double mutant showed that the ectB mutant was defective for growth, and this defect was rescued by the addition of glycine betaine, proline, ectoine, and glutamate, indicating that these compounds are compatible solutes for this species. The presence of both synthesis systems was the predominant distribution pattern among members of the Vibrionaceae family, suggesting this is the ancestral state. PMID:23770911

Liquid based formulations of bacteriophages for the management of waterborne bacterial pathogens in water microcosms.

PubMed

Ahiwale, Sangeeta; Tagunde, Sujata; Khopkar, Sushama; Karni, Mrudula; Gajbhiye, Milind; Kapadnis, Balasaheb

2013-11-01

Water resources are contaminated by life-threatening multidrug resistant pathogenic bacteria. Unfortunately, these pathogenic bacteria do not respond to the traditional water purification methods. Therefore, there is a need of environmentally friendly strategies to overcome the problems associated with the antimicrobial resistant bacterial pathogens. In the present study, highly potent lytic phages against multidrug-resistant Salmonella enterica serovar Paratyphi B, Pseudomonas aeruginosa and Klebsiella pneumoniae were isolated from the Pavana river water. They belonged to the Podoviridae and Siphoviridae families. These phages were purified and enriched in the laboratory. Monovalent formulations of phiSPB, BVPaP-3 and KPP phages were prepared in three different liquids viz., phage broth, saline and distilled water. The phages were stable for almost 8-10 months in the phage broth at 4 degrees C. The stability of the phages in saline and distilled water was 5-6 months at 4 degrees C. All of the phages were stable only for 4-6 months in the phage broth at 30 degrees C. The monovalent phage formulation of psiSPB was applied at MOI < 1, as disinfectant against an exponential and stationary phase cells of Salmonella enterica serovar Paratyphi B in various water microcosms. The results indicated that there was almost 80 % reduction in the log phase cells of Salmonella serovar Paratyphi B in 24 h. In stationary phase cells, the reduction was comparatively less within same period. At the same time, there was concomitant increase in the phage population by 80% in all the microcosms indicating that psiSPB phage is highly potent in killing pathogen in water. Results strongly support that the formulation of psiSPB in the phage broth in monovalent form could be used as an effective biological disinfectant for preventing transmission of water-borne bacterial pathogens, including antimicrobial resistant ones.

A Randomized, Placebo Controlled, Double Masked Phase IB Study Evaluating the Safety and Antiviral Activity of Aprepitant, a Neurokinin-1 Receptor Antagonist in HIV-1 Infected Adults

PubMed Central

Tebas, Pablo; Tuluc, Florin; Barrett, Jeffrey S.; Wagner, Wayne; Kim, Deborah; Zhao, Huaquing; Gonin, René; Korelitz, James; Douglas, Steven D.

2011-01-01

Background Neurokinin-1 receptor (NK1R) antagonists have anti-HIV activity in monocyte-derived macrophages, decrease CCR5 expression and improve natural killer cell function ex vivo. Aprepitant is a NK1R antagonist approved by FDA as an antiemetic. Methods We conducted a phase IB randomized, placebo controlled, double masked study to evaluate the safety, antiviral activity, pharmacokinetics and immune-modulatory effects of aprepitant in HIV-infected adults not receiving antiretroviral therapy, with CD4+ cell count ≥350 cells/mm3 and plasma viral load ≥2,000 copies/ml. Subjects were stratified by viral load (< vs. ≥20,000 copies/ml) and randomized within each stratum to receive aprepitant at 125 mg QD(Low), or 250 mg QD(High), or placebo(PL) for 14 days, and followed for 42 days. Results Thirty subjects were randomized and 27 completed treatment (9, 8, 10 subjects in 125 (Low), 250 (High), and PL groups). 63% were male; 37% white; mean (SD) age 43 (9.3) years. Geometric mean baseline viral load (copies/ml) for Low, High, and PL was 15,709, 33,013, and 19,450, respectively. Mean (95%CI) change in log10 viral load at day 14 for Low, High, and PL was −0.02(−0.24,+0.20), −0.05(−0.21,+0.10), and +0.04(−0.08,+0.16), respectively. The number of subjects with AEs was 4(44.4%), 5(62.5%), and 1(10%) for Low, High, and PL. No Grade 4 AEs occurred. Conclusions Adverse events of aprepitant were more common in the treated groups. At the dose used in this two-week phase IB study, aprepitant showed biological activity, but no significant antiviral activity. Trial Registration ClinicalTrials.gov NCT00428519 PMID:21931661

Effect of Fe doping on structural and impedance properties of PZTFN ceramics

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

Kumar, Arvind, E-mail: arvindmse07311209.in@gmail.com; Pal, Vijayeta; Mishra, S. K.

2016-05-06

An attempts have been made to synthesis the ceramics Pb{sub 1-3x/2} Fe{sub x}(Zr{sub 0.52}Ti{sub 0.48}){sub 1-5y/4} NbyO{sub 3} abbreviated as (PFZTN) for x = 1-6 mol% and y = 5.5 mol% by a semi-wet route. In the present paper, we have investigated the effect of Fe doping on structural and electrical properties of the PFZTN ceramics. X-ray diffraction (XRD) patterns reveal that PFZTN ceramics are single phase in nature. However, for x = 0.05 and 0.06, a secondary phase appears as discernible from the XRD profiles. Rietveld analysis of the powder diffraction data shows the presence of coexistence of tetragonal (P4mm spacemore » group) and rhombohedral phases (R3c space group) occurs near the morphotropic phase boundary (MPB) at x ≥ = 0.05. The log-log plots show that the conductivity increases with increase of temperature. The ac conductivity becomes sensitive at high frequency region and shifted towards higher frequency side with increasing temperature. It is observed that the activation energy (Ea) decreases with increasing frequency. This complex perovskite structure can be used as a multilayer ceramic capacitors and electromechanical transducers.« less

Inosine and 2'-deoxyinosine and their synthetic analogues: lipophilicity in the relation to their retention in reversed-phase liquid chromatography and the stability characteristics.

PubMed

Novotny, L; Abdel-Hamid, M; Hamza, H

2000-12-01

The purines and among them inosine synthetic nucleoside derivatives and analogues belong to a group of compounds to which the attention is being paid because of their biological activities. Relationships of their various parameters are being investigated because of their effect on biological (antineoplastic, virostatic, immunosuppressive) properties. Hydrophobicity parameters expressed as the logarithm of the partition coefficient (log P) and the capacity factor k' for naturally occurring inosine, 2'-deoxyinosine, 2'-deoxyadenosine and 2'-deoxyguanosine and for inosine synthetic analogues 5'-deoxyinosine, 5'-chloro-5'-deoxyinosine and 2',3'-dideoxyinosine were measured. The effect of methanol percentage in the mobile phase and its pH on the retention of the studied compounds in a reversed-phase system was also examined. There was a good correlation between the lipophilicity expressed as log P and capacity factor k'. It was also determined that dissociation has a marginal effect on capacity factor k' in this group of nucleoside derivatives as the k' values were almost unchanged at various pH of the mobile phase used. The stability of the all investigated compounds was investigated in basic, neutral and acidic conditions. The values of the reaction constant k1 were calculated and effects of nucleoside structural characteristic on stability are discussed.

Development of Fatigue and Crack Propagation Design and Analysis Methodology in a Corrosive Environment for Typical Mechanically-Fastened Joints. Volume 3. Phase II Documentation.

DTIC Science & Technology

1984-10-01

8217. .,.. .-- . -.- , -. .... , . - .. , -. , , . ..- . . -.- - .- -. . ..-. . . . -. . . . -.- . . . . - . . K~~ K 7--- K, log SclI I.I. Fig. A-2 True Stress Versus Plastic Strain for Cyclic Response

Effects of anticoagulant, processing delay, and assay method (branched DNA versus reverse transcriptase PCR) on measurement of human immunodeficiency virus type 1 RNA levels in plasma.

PubMed

Kirstein, L M; Mellors, J W; Rinaldo, C R; Margolick, J B; Giorgi, J V; Phair, J P; Dietz, E; Gupta, P; Sherlock, C H; Hogg, R; Montaner, J S; Muñoz, A

1999-08-01

We conducted two studies to determine the potential influence of delays in blood processing, type of anticoagulant, and assay method on human immunodeficiency virus type 1 (HIV-1) RNA levels in plasma. The first was an experimental study in which heparin- and EDTA-anticoagulated blood samples were collected from 101 HIV-positive individuals and processed to plasma after delays of 2, 6, and 18 h. HIV-1 RNA levels in each sample were then measured by both branched-DNA (bDNA) and reverse transcriptase PCR (RT-PCR) assays. Compared to samples processed within 2 h, the loss (decay) of HIV-1 RNA in heparinized blood was significant (P < 0.05) but small after 6 h (bDNA assay, -0.12 log(10) copies/ml; RT-PCR, -0.05 log(10) copies/ml) and after 18 h (bDNA assay, -0.27 log(10) copies/ml; RT-PCR, -0.15 log(10) copies/ml). Decay in EDTA-anticoagulated blood was not significant after 6 h (bDNA assay, -0.002 log(10) copies/ml; RT-PCR, -0.02 log(10) copies/ml), but it was after 18 h (bDNA assay, -0.09 log(10) copies/ml; RT-PCR, -0.09 log(10) copies/ml). Only 4% of samples processed after 6 h lost more than 50% (>/=0.3 log(10) copies/ml) of the HIV-1 RNA, regardless of the anticoagulant or the assay that was used. The second study compared HIV-1 RNA levels in samples from the Multicenter AIDS Cohort Study (MACS; samples were collected in heparin-containing tubes in 1985, had a 6-h average processing delay, and were assayed by bDNA assay) and the British Columbia Drug Treatment Program (BCDTP) (collected in EDTA- or acid citrate dextrose-containing tubes in 1996 and 1997, had a 2-h maximum processing delay, and were assayed by RT-PCR). HIV-1 RNA levels in samples from the two cohorts were not significantly different after adjusting for CD4(+)-cell count and converting bDNA assay values to those corresponding to the RT-PCR results. In summary, the decay of HIV-1 RNA measured in heparinized blood after 6 h was small (-0.05 to -0.12 log(10) copies/ml), and the minor impact of this decay on HIV-1 RNA concentrations in archived plasma samples of the MACS was confirmed by the similarity of CD4(+)-cell counts and assay-adjusted HIV-1 RNA concentrations in the MACS and BCDTP.

Screening of intact yeasts and cell extracts to reduce Scrapie prions during biotransformation of food waste.

PubMed

Huyben, David; Boqvist, Sofia; Passoth, Volkmar; Renström, Lena; Allard Bengtsson, Ulrika; Andréoletti, Olivier; Kiessling, Anders; Lundh, Torbjörn; Vågsholm, Ivar

2018-02-08

Yeasts can be used to convert organic food wastes to protein-rich animal feed in order to recapture nutrients. However, the reuse of animal-derived waste poses a risk for the transmission of infectious prions that can cause neurodegeneration and fatality in humans and animals. The aim of this study was to investigate the ability of yeasts to reduce prion activity during the biotransformation of waste substrates-thereby becoming a biosafety hurdle in such a circular food system. During pre-screening, 30 yeast isolates were spiked with Classical Scrapie prions and incubated for 72 h in casein substrate, as a waste substitute. Based on reduced Scrapie seeding activity, waste biotransformation and protease activities, intact cells and cell extracts of 10 yeasts were further tested. Prion analysis showed that five yeast species reduced Scrapie seeding activity by approximately 1 log10 or 90%. Cryptococcus laurentii showed the most potential to reduce prion activity since both intact and extracted cells reduced Scrapie by 1 log10 and achieved the highest protease activity. These results show that select forms of yeast can act as a prion hurdle during the biotransformation of waste. However, the limited ability of yeasts to reduce prion activity warrants caution as a sole barrier to transmission as higher log reductions are needed before using waste-cultured yeast in circular food systems.

Femtosecond Laser-Assisted Descemetorhexis: A Novel Technique in Descemet Membrane Endothelial Keratoplasty.

PubMed

Pilger, Daniel; von Sonnleithner, Christoph; Bertelmann, Eckart; Joussen, Antonia M; Torun, Necip

2016-10-01

To explore the feasibility of femtosecond laser-assisted descemetorhexis (DR) to facilitate Descemet membrane endothelial keratoplasty (DMEK) surgery. Six pseudophakic patients suffering from Fuchs' endothelial dystrophy underwent femtosecond laser-assisted DMEK surgery. DR was performed using the LenSx femtosecond laser, followed by manual removal of the Descemet membrane. Optical coherence tomography images were used to measure DR parameters. Patients were followed up for 1 month to examine best corrected visual acuity, endothelial cell loss, flap detachment, and structure of the anterior chamber of the eye. The diameter of the DR approximated the intended diameter closely [mean error of 34 μm (0.45%) and 54 μm (0.67%) in the x- and y-diameter, respectively] and did not require manual correction. The median visual acuity increased from 0.4 logMAR (range 0.6-0.4 logMAR) preoperative to 0.2 logMAR (range 0-0.4 logMAR) postoperative. The median endothelial cell loss was 22% (range 7%-34%). No clinically significant flap detachments were noted. All patients had clear corneas after surgery, and no side effects or damage to structures of the anterior chamber were noted. Femtosecond laser-assisted DR is a safe and precise method for facilitating DMEK surgery.

Influence of trophic conditions on exopolysaccharide production: bacterial biofilm susceptibility to chlorine and monochloramine.

PubMed

Samrakandi, M M; Roques, C; Michel, G

1997-08-01

This study examines the controversial efficacy of chlorine and monochloramine against biofilms that differ in their extracellular polysaccharide (EPS) content. The results point out a net variability of bacterial biofilm susceptibility according to the nutrients present. Chlorine and monochloramine showed an equal biocidal activity on lactose medium-grown E. coli ATCC 10536 and glycerol-ammonium nitrate medium-grown nonmucoid Pseudomonas aeruginosa biofilms. In contrast, the effect of monochloramine is greater compared with that of chlorine on E. coli and mucoid P. aeruginosa biofilms grown in sucrose and glycerol-ammonium nitrate media, respectively. In these culture conditions, treatment with 25 mg monochloramine/L for 2 h reduced culturable cells by 4.5 logs (99.997%) for E. coli and about 3 logs (99.87%) for mucoid P. aeruginosa while the similar treatment with chlorine reduced culturable cells in these biofilms by 2.2 logs (99.4%) and 1 log (10%), respectively. The decrease of chlorine disinfection efficacy on sucrose and glycerol-ammonium nitrate medium-grown biofilms is postulated to be linked to the higher polysaccharide production observed in these media. It seems likely that monochloramine produces a high leakage of material absorbing at 260 nm from sucrose medium-grown E. coli biofilm, which could indicate its better penetration into biofilms.

Organic acids for control of Salmonella in different feed materials.

PubMed

Koyuncu, Sevinc; Andersson, Mats Gunnar; Löfström, Charlotta; Skandamis, Panagiotis N; Gounadaki, Antonia; Zentek, Jürgen; Häggblom, Per

2013-04-18

Salmonella control in animal feed is important in order to protect animal and public health. Organic acids is one of the control measures used for treatment of Salmonella contaminated feed or feed ingredients. In the present study, the efficacy of formic acid (FA) and different blends of FA, propionic acid (PA) and sodium formate (SF) was investigated. Four Salmonella strains isolated from feed were assayed for their acid tolerance. Also, the effect of lower temperatures (5°C and 15°C) compared to room temperature was investigated in rape seed and soybean meal. The efficacy of acid treatments varied significantly between different feed materials. The strongest reduction was seen in pelleted and compound mash feed (2.5 log10 reduction) followed by rapeseed meal (1 log10 reduction) after 5 days exposure. However, in soybean meal the acid effects were limited (less than 0.5 log10 reduction) even after several weeks' exposure. In all experiments the survival curves showed a concave shape, with a fast initial death phase followed by reduction at a slower rate during the remaining time of the experiment.No difference in Salmonella reduction was observed between FA and a blend of FA and PA, whereas a commercial blend of FA and SF (Amasil) was slightly more efficacious (0.5-1 log10 reduction) than a blend of FA and PA (Luprocid) in compound mash feed. The Salmonella Infantis strain was found to be the most acid tolerant strain followed by, S. Putten, S. Senftenberg and S. Typhimurium. The tolerance of the S. Infantis strain compared with the S. Typhimurium strain was statistically significant (p<0.05). The lethal effect of FA on the S. Typhimurium strain and the S. Infantis strain was lower at 5°C and 15°C compared to room temperatures. Acid treatment of Salmonella in feed is a matter of reducing the number of viable bacterial cells rather than eliminating the organism. Recommendations on the use of acids for controlling Salmonella in feed should take into account the relative efficacy of acid treatment in different feed materials, the variation in acid tolerance between different Salmonella strains, and the treatment temperature.

From expert-derived user needs to user-perceived ease of use and usefulness: a two-phase mixed-methods evaluation framework.

PubMed

Boland, Mary Regina; Rusanov, Alexander; So, Yat; Lopez-Jimenez, Carlos; Busacca, Linda; Steinman, Richard C; Bakken, Suzanne; Bigger, J Thomas; Weng, Chunhua

2014-12-01

Underspecified user needs and frequent lack of a gold standard reference are typical barriers to technology evaluation. To address this problem, this paper presents a two-phase evaluation framework involving usability experts (phase 1) and end-users (phase 2). In phase 1, a cross-system functionality alignment between expert-derived user needs and system functions was performed to inform the choice of "the best available" comparison system to enable a cognitive walkthrough in phase 1 and a comparative effectiveness evaluation in phase 2. During phase 2, five quantitative and qualitative evaluation methods are mixed to assess usability: time-motion analysis, software log, questionnaires - System Usability Scale and the Unified Theory of Acceptance of Use of Technology, think-aloud protocols, and unstructured interviews. Each method contributes data for a unique measure (e.g., time motion analysis contributes task-completion-time; software log contributes action transition frequency). The measures are triangulated to yield complementary insights regarding user-perceived ease-of-use, functionality integration, anxiety during use, and workflow impact. To illustrate its use, we applied this framework in a formative evaluation of a software called Integrated Model for Patient Care and Clinical Trials (IMPACT). We conclude that this mixed-methods evaluation framework enables an integrated assessment of user needs satisfaction and user-perceived usefulness and usability of a novel design. This evaluation framework effectively bridges the gap between co-evolving user needs and technology designs during iterative prototyping and is particularly useful when it is difficult for users to articulate their needs for technology support due to the lack of a baseline. Copyright © 2013 Elsevier Inc. All rights reserved.

Installation Restoration Program. Phase 1. Records Search, McGuire AFB, New Jersey

DTIC Science & Technology

1982-11-01

Raritan- Magothy System * 3.12 Log of Base Well OD" 3-23 3.13 Well no. 1 at McGuire Missile Site 3-25 3.14 Base Well Locations 3-26 3.15 Surface Water...in the Potomac-Raritan- Magothy outcrop area has been published. This is not expected to impact base water quality in the near term. o Flooding is not a...Potamac-Raritan- Magothy System (PRM) 3-13 FIGURE 3.7 McGUIRE AFB STANDARD LOG OF McGUIRE PENETRATION. TEST MISSILE SITE I TEST BORING 46 21 DEPTH BELOW

Survival of Listeria monocytogenes in vanilla-flavored soy and dairy products stored at 8 degrees C.

PubMed

Tipparaju, Sireesha; Ravishankar, Sadhana; Slade, Peter J

2004-02-01

The survival of Listeria monocytogenes V37 in vanilla-flavored yogurt (low-fat and nonfat) and soy milk (low-fat and Plus) stored at 8 degrees C for 31 days was investigated. Commercial samples of yogurt and soy milk were used. These samples were inoculated with either 10(4) or 10(7) CFU of L. monocytogenes per ml. Sampling was carried out every 3 to 4 days initially and was then carried out weekly, for a total storage time of 31 days. Each time a sample was collected, the pH of the sample was measured. After 31 days, low-fat plain, low-fat vanilla, and nonfat plain yogurt samples inoculated with 10(4) CFU/ml showed 2.5-log reductions in viable cell populations, and nonfat vanilla yogurt showed a 3.5-log reduction. For yogurt inoculated with 10(7) CFU/ml, reductions of 2.5 log CFU/ml were observed for plain low-fat and nonfat yogurts, and reductions of 5 log CFU/ml were observed for vanilla-flavored low-fat and nonfat yogurts. In vanilla-flavored and plain low-fat and Plus soy milk samples, cell counts increased from 10(4) and 10(7) CFU/ml to 10(9) CFU/ml at 7 and 3 days of storage, respectively, at 8 degrees C. Coagulation in soy milk samples was observed when the cell population reached 10(9) CFU/ml. In soy milk, the L. monocytogenes population did not change for up to 31 days. Vanillin had an inhibitory effect on L. monocytogenes in yogurt but not in soy milk.

Retropupillary fixation of iris-claw lens in visual rehabilitation of aphakic eyes.

PubMed

Jayamadhury, G; Potti, Sudhakar; Kumar, K Vinaya; Kumar, R Madhu; Divyansh Mishra, K C; Nambula, Srinivasa Rao

2016-10-01

Surgical outcome of retropupillary fixation of iris claw lens. To evaluate the various indications, intra and post-operative complications, and visual outcome of retropupillary fixation of iris claw lens in aphakic eyes. The study design is a retrospective study at a tertiary eye care center. Review of medical records of 61 aphakic eyes of 61 patients, who were rehabilitated with retropupillary fixation of an iris claw lens, with a follow-up duration of at least 1 year. Data analysis was performed using paired t-test and Chi-square test. Mean preoperative uncorrected visual acuity was 1.66 ± 0.3 LogMAR and postoperative acuity at 1 year was 0.53 ± 0.5 LogMAR (P = 0.00001). Preoperative distant best-corrected visual acuity was 0.30 ± 0.48 LogMAR and postoperative acuity at 1 year was 0.27 ± 0.46 LogMAR (P = 0.07). Mean preoperative astigmatism was 1.43 ± 1.94 D and postoperatively was 1.85 ± 2.16 D (P = 0.0127). Mean endothelial cell count was 2353.52 ± 614 cells/mm2 preoperatively which decreased to 2200 ± 728 cells/mm2 at 1 year follow-up (P = 0.006). There was no significant difference in central macular thickness and intraocular pressure pre and post-surgery. Complications included ovalization of pupil in 9.83%, hypotony in 1.63%, toxic anterior segment syndrome in 1.63%, cystoid macular edema in 11.47%, epiretinal membrane in 3.27%, and iris atrophy in 6.55%. Iris claw is a safe and an effective method of rehabilitating aphakic eyes.

Changes in gene expression caused by insect venom immunotherapy responsible for the long-term protection of insect venom-allergic patients.

PubMed

Niedoszytko, Marek; Bruinenberg, Marcel; de Monchy, Jan; Weersma, Rinse K; Wijmenga, Cisca; Jassem, Ewa; Elberink, Joanne N G Oude

2011-06-01

Insect venom immunotherapy (VIT) is the only causative treatment of insect venom allergy (IVA). The immunological mechanism(s) responsible for long-term protection achieved by VIT are largely unknown. A better understanding is relevant for improving the diagnosis, prediction of anaphylaxis, and monitoring and simplifying treatment of IVA. To find genes that are differentially expressed during the maintenance phase of VIT and after stopping, to get clues about the pathways involved in the long-term protective effect of immunotherapy. Whole genome gene expression analysis was performed on RNA samples from 50 patients treated with VIT and 43 healthy controls. Patients were divided into three groups: (1) before the start of VIT; (2) on maintenance phase of VIT for at least 3 years still receiving injections; and (3) after VIT. Of all 48,804 probes present in the array, 48,773 transcripts had sufficient data for further analysis. The list of genes that were differentially expressed (at least log2 FC > 2; P < .05 corrected for multiple testing) during the maintenance phase of VIT as well as after successful VIT contains 89 entities. The function of these genes affects cell signaling, cell differentiation, and ion transport. This study shows that a group of genes is differentially expressed both during and after VIT in comparison with gene expression in patients before VIT. Although the results of this study should be confirmed prospectively, the relevance of these findings is supported by the fact that they are related to putative mechanisms of immunotherapy. Copyright © 2011 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

The Proteome of Shigella flexneri 2a 2457T Grown at 30 and 37 °C*

PubMed Central

Zhu, Li; Zhao, Ge; Stein, Robert; Zheng, Xuexue; Hu, Wei; Shang, Na; Bu, Xin; Liu, Xiankai; Wang, Jie; Feng, Erling; Wang, Bin; Zhang, Xuemin; Ye, Qinong; Huang, Peitang; Zeng, Ming; Wang, Hengliang

2010-01-01

To upgrade the proteome reference map of Shigella flexneri 2a 2457T, the protein expression profiles of log phase and stationary phase cells grown at 30 and 37 °C were thoroughly analyzed using multiple overlapping narrow pH range (between pH 4.0 and 11.0) two-dimensional gel electrophoresis. A total of 723 spots representing 574 protein entries were identified by MALDI-TOF/TOF MS, including the majority of known key virulence factors. 64 hypothetical proteins and six misannotated proteins were also experimentally identified. A comparison between the four proteome maps showed that most of the virulence-related proteins were up-regulated at 37 °C, and the differences were more notable in stationary phase cells, suggesting that the expressions of these virulence factors were not only controlled by temperature but also controlled by the nutrients available in the environment. The expression patterns of some virulence-related genes under the four different conditions suggested that they might also be regulated at the post-transcriptional level. A further significant finding was that the expression of the protein ArgT was dramatically up-regulated at 30 °C. The results of semiquantitative RT-PCR analysis showed that expression of argT was not regulated at the transcriptional level. Therefore, we carried out a series of experiments to uncover the mechanism regulating ArgT levels and found that the differential expression of ArgT was due to its degradation by a periplasmic protease, HtrA, whose activity, but not its synthesis, was affected by temperature. The cleavage site in ArgT was between position 160 (Val) and position 161 (Ala). These results may provide useful insights for understanding the physiology and pathogenesis of S. flexneri. PMID:20164057

The proteome of Shigella flexneri 2a 2457T grown at 30 and 37 degrees C.

PubMed

Zhu, Li; Zhao, Ge; Stein, Robert; Zheng, Xuexue; Hu, Wei; Shang, Na; Bu, Xin; Liu, Xiankai; Wang, Jie; Feng, Erling; Wang, Bin; Zhang, Xuemin; Ye, Qinong; Huang, Peitang; Zeng, Ming; Wang, Hengliang

2010-06-01

To upgrade the proteome reference map of Shigella flexneri 2a 2457T, the protein expression profiles of log phase and stationary phase cells grown at 30 and 37 degrees C were thoroughly analyzed using multiple overlapping narrow pH range (between pH 4.0 and 11.0) two-dimensional gel electrophoresis. A total of 723 spots representing 574 protein entries were identified by MALDI-TOF/TOF MS, including the majority of known key virulence factors. 64 hypothetical proteins and six misannotated proteins were also experimentally identified. A comparison between the four proteome maps showed that most of the virulence-related proteins were up-regulated at 37 degrees C, and the differences were more notable in stationary phase cells, suggesting that the expressions of these virulence factors were not only controlled by temperature but also controlled by the nutrients available in the environment. The expression patterns of some virulence-related genes under the four different conditions suggested that they might also be regulated at the post-transcriptional level. A further significant finding was that the expression of the protein ArgT was dramatically up-regulated at 30 degrees C. The results of semiquantitative RT-PCR analysis showed that expression of argT was not regulated at the transcriptional level. Therefore, we carried out a series of experiments to uncover the mechanism regulating ArgT levels and found that the differential expression of ArgT was due to its degradation by a periplasmic protease, HtrA, whose activity, but not its synthesis, was affected by temperature. The cleavage site in ArgT was between position 160 (Val) and position 161 (Ala). These results may provide useful insights for understanding the physiology and pathogenesis of S. flexneri.

Reflection coefficients of permeant molecules in human red cell suspensions.

PubMed

Owen, J D; Eyring, E M

1975-08-01

The Staverman reflection coefficient, sigma for several permeant molecules was determined in human red cell suspensions with a Durrum stopped-flow spectrophotometer. This procedure was first used with dog, cat, and beef red cells and with human red cells. The stopped-flow technique used was similar to the rapid-flow method used by those who originally reported sigma measurements in human red cells for molecules which rapidly penetrate the red cell membrane. The sigma values we obtained agreed with those previously reported for most of the slow penetrants, except malonamide, but disagreed with all the sigma values previously reported for the rapid penetrants. We were unable to calculate an "equivalent pore radius" with our sigma data. The advantages of our equipment and our experimental procedure are discussed. Our sigma data suggest that sigma is indirectly proportional to the log of the nonelectrolyte permeability coefficient, omega. Since a similar trend has been previously shown for log omega and molar volume of the permeant molecules, a correlatioo was shown between sigma and molar volume suggesting the membrane acts as a sieve.

Size effects on electrical properties of chemically grown zinc oxide nanoparticles

NASA Astrophysics Data System (ADS)

Rathod, K. N.; Joshi, Zalak; Dhruv, Davit; Gadani, Keval; Boricha, Hetal; Joshi, A. D.; Solanki, P. S.; Shah, N. A.

2018-03-01

In the present article, we study ZnO nanoparticles grown by cost effective sol–gel technique for various electrical properties. Structural studies performed by x-ray diffraction (XRD) revealed hexagonal unit cell phase with no observed impurities. Transmission electron microscopy (TEM) and particle size analyzer showed increased average particle size due to agglomeration effect with higher sintering. Dielectric constant (ε‧) decreases with increase in frequency because of the disability of dipoles to follow higher electric field. With higher sintering, dielectric constant reduced owing to the important role of increased formation of oxygen vacancy defects. Universal dielectric response (UDR) was verified by straight line fitting of log (fε‧) versus log (f) plots. All samples exhibit UDR behavior and with higher sintering more contribution from crystal cores. Impedance studies suggest an important role of boundary density while Cole–Cole (Z″ versus Z‧) plots have been studied for the relaxation behavior of the samples. Average normalized change (ANC) in impedance has been studied for all the samples wherein boundaries play an important role. Frequency dependent electrical conductivity has been understood on the basis of Jonscher’s universal power law. Jonscher’s law fits suggest that conduction of charge carrier is possible in the context of correlated barrier hopping (CBH) mechanism for lower temperature sintered sample while for higher temperature sintered ZnO samples, Maxwell–Wagner (M–W) relaxation process has been determined.

Prediction of shear wave velocity using empirical correlations and artificial intelligence methods

NASA Astrophysics Data System (ADS)

Maleki, Shahoo; Moradzadeh, Ali; Riabi, Reza Ghavami; Gholami, Raoof; Sadeghzadeh, Farhad

2014-06-01

Good understanding of mechanical properties of rock formations is essential during the development and production phases of a hydrocarbon reservoir. Conventionally, these properties are estimated from the petrophysical logs with compression and shear sonic data being the main input to the correlations. This is while in many cases the shear sonic data are not acquired during well logging, which may be for cost saving purposes. In this case, shear wave velocity is estimated using available empirical correlations or artificial intelligent methods proposed during the last few decades. In this paper, petrophysical logs corresponding to a well drilled in southern part of Iran were used to estimate the shear wave velocity using empirical correlations as well as two robust artificial intelligence methods knows as Support Vector Regression (SVR) and Back-Propagation Neural Network (BPNN). Although the results obtained by SVR seem to be reliable, the estimated values are not very precise and considering the importance of shear sonic data as the input into different models, this study suggests acquiring shear sonic data during well logging. It is important to note that the benefits of having reliable shear sonic data for estimation of rock formation mechanical properties will compensate the possible additional costs for acquiring a shear log.

Identification, structure, and characterization of an exopolysaccharide produced by Histophilus somni during biofilm formation.

PubMed

Sandal, Indra; Inzana, Thomas J; Molinaro, Antonio; De Castro, Christina; Shao, Jian Q; Apicella, Michael A; Cox, Andrew D; St Michael, Frank; Berg, Gretchen

2011-08-19

Histophilus somni, a gram-negative coccobacillus, is an obligate inhabitant of bovine and ovine mucosal surfaces, and an opportunistic pathogen responsible for respiratory disease and other systemic infections in cattle and sheep. Capsules are important virulence factors for many pathogenic bacteria, but a capsule has not been identified on H. somni. However, H. somni does form a biofilm in vitro and in vivo, and the biofilm matrix of most bacteria consists of a polysaccharide. Following incubation of H. somni under growth-restricting stress conditions, such as during anaerobiosis, stationary phase, or in hypertonic salt, a polysaccharide could be isolated from washed cells or culture supernatant. The polysaccharide was present in large amounts in broth culture sediment after H. somni was grown under low oxygen tension for 4-5 days (conditions favorable to biofilm formation), but not from planktonic cells during log phase growth. Immuno-transmission electron microscopy showed that the polysaccharide was not closely associated with the cell surface, and was of heterogeneous high molecular size by gel electrophoresis, indicating it was an exopolysaccharide (EPS). The EPS was a branched mannose polymer containing some galactose, as determined by structural analysis. The mannose-specific Moringa M lectin and antibodies to the EPS bound to the biofilm matrix, demonstrating that the EPS was a component of the biofilm. The addition of N-acetylneuraminic acid to the growth medium resulted in sialylation of the EPS, and increased biofilm formation. Real-time quantitative reverse transcription-polymerase chain reaction analyses indicated that genes previously identified in a putative polysaccharide locus were upregulated when the bacteria were grown under conditions favorable to a biofilm, compared to planktonic cells. H. somni is capable of producing a branching, mannose-galactose EPS polymer under growth conditions favorable to the biofilm phase of growth, and the EPS is a component of the biofilm matrix. The EPS can be sialylated in strains with sialyltransferase activity, resulting in enhanced density of the biofilm, and suggesting that EPS and biofilm formation may be important to persistence in the bovine host. The EPS may be critical to virulence if the biofilm state is required for H. somni to persist in systemic sites.

The influence of headspace and dissolved oxygen level on growth and haemolytic BL enterotoxin production of a psychrotolerant Bacillus weihenstephanensis isolate on potato based ready-to-eat food products.

PubMed

Samapundo, S; Everaert, H; Wandutu, J N; Rajkovic, A; Uyttendaele, M; Devlieghere, F

2011-04-01

The major objective of this study was to determine the influence of the initial headspace and dissolved O(2) level and vacuum packaging on growth and diarrhoeal enterotoxin production by Bacillus weihenstephanensis on potato based ready-to-eat food products. In general, the lower the initial headspace or dissolved O(2) level the slower the maximum growth rate (μ(max), log(10) CFU g(-1) d(-1)), the longer the lag phase duration (λ, d) and the smaller the maximum population density (N(max), log(10) CFU g(-1)) became. The slowest μ(max), the longest λ and the smallest N(max) were generally found for growth under vacuum packaging. This implies shorter shelf-lives will occur at higher initial headspace or dissolved O(2) levels as the growth of B. weihenstephanensis to the infective dose of 10(5) CFU g(-1) in such atmospheres takes a shorter time. Significant consumption of dissolved O(2) only occurred when growth shifted from the lag to the exponential phase and growth generally transitioned from the exponential to the stationary phase when the dissolved O(2) levels fell below ca. 75 ppb. Diarrhoeal enterotoxin production (determined via detection of the L2 component of haemolytic BL) was similar for growth under initial headspace O(2) levels of 1-20.9%, and was only reduced when growth took place under vacuum packaging. The reduction in L2 production when growth took place under vacuum was most probably related to the low final cell densities observed under this condition. Both growth and L2 production were inhibited over a 32-day incubation period at 7 °C by 40% CO(2) irrespective of the headspace or dissolved O(2) levels. The results illustrate the importance of residual O(2) and CO(2) on the shelf-stability and safety of modified atmosphere packaged potato based ready-to-eat food products with regards to B. weihenstephanensis. Copyright © 2010 Elsevier Ltd. All rights reserved.

C-Peptide Decline in Type 1 Diabetes Has Two Phases: An Initial Exponential Fall and a Subsequent Stable Phase.

PubMed

Shields, Beverley M; McDonald, Timothy J; Oram, Richard; Hill, Anita; Hudson, Michelle; Leete, Pia; Pearson, Ewan R; Richardson, Sarah J; Morgan, Noel G; Hattersley, Andrew T

2018-06-07

The decline in C-peptide in the 5 years after diagnosis of type 1 diabetes has been well studied, but little is known about the longer-term trajectory. We aimed to examine the association between log-transformed C-peptide levels and the duration of diabetes up to 40 years after diagnosis. We assessed the pattern of association between urinary C-peptide/creatinine ratio (UCPCR) and duration of diabetes in cross-sectional data from 1,549 individuals with type 1 diabetes using nonlinear regression approaches. Findings were replicated in longitudinal follow-up data for both UCPCR ( n = 161 individuals, 326 observations) and plasma C-peptide ( n = 93 individuals, 473 observations). We identified two clear phases of C-peptide decline: an initial exponential fall over 7 years (47% decrease/year [95% CI -51%, -43%]) followed by a stable period thereafter (+0.07%/year [-1.3, +1.5]). The two phases had similar durations and slopes in patients above and below the median age at diagnosis (10.8 years), although levels were lower in the younger patients irrespective of duration. Patterns were consistent in both longitudinal UCPCR ( n = 162; ≤7 years duration: -48%/year [-55%, -38%]; >7 years duration -0.1% [-4.1%, +3.9%]) and plasma C-peptide ( n = 93; >7 years duration only: -2.6% [-6.7%, +1.5%]). These data support two clear phases of C-peptide decline: an initial exponential fall over a 7-year period, followed by a prolonged stabilization where C-peptide levels no longer decline. Understanding the pathophysiological and immunological differences between these two phases will give crucial insights into understanding β-cell survival. © 2018 by the American Diabetes Association.

Evaluation of geophysical logs and aquifer-isolation tests, Phase III, August 2002 to March 2004, Crossley Farm superfund site, Hereford township, Berks County, Pennsylvania

USGS Publications Warehouse

Conger, Randall W.; Low, Dennis J.

2006-01-01

Between August 2002 and March 2004, geophysical logging was conducted in 23 boreholes at the Crossley Farm Superfund Site, Hereford Township, Berks County, Pa., to determine the water-producing zones, water-receiving zones, zones of vertical-borehole flow, and fracture orientation where applicable. The boreholes ranged in depth from 71 to 503 ft (feet) below land surface. The geophysical logging determined the placement of well screens and packers, which allow monitoring and sampling of water-bearing zones in the fractured bedrock so the horizontal and vertical distribution of contaminated ground water migrating from known sources could be determined. Geophysical logging included collection of caliper (22 boreholes), fluid-temperature (17 boreholes), single-pointresistance (17 boreholes), natural-gamma (17 boreholes), fluidflow (18 boreholes), and acoustic-televiewer (13 boreholes) logs. Caliper and acoustic-televiewer logs were used to locate fractures, joints, and weathered zones. Inflections on fluid-temperature and single-point-resistance logs indicated possible water-bearing zones, and flowmeter measurements verified these locations. Single-point-resistance, natural-gamma, and geologist logs provided information on stratigraphy; the geologist log also provided information on the location of possible water-producing zones.Borehole geophysical logging and heatpulse flowmetering indicated active flow in 10 boreholes. Seven of the boreholes are in ground-water discharge areas and three boreholes are in ground-water recharge areas. Heatpulse flowmetering, in conjunction with the geologist logs, indicates lithologic contacts (changes in lithology from a gneiss dominated by quartz-plagioclase-feldspar mineralogy to a gneiss dominated by hornblende mineralogy) are typically fractured, permeable, and effective transmitters of water. Single-well, aquifer-isolation (packer) tests were performed on two boreholes. Packers were set at depths ranging from 210 to 465 ft below land surface to isolate water-bearing zones at discrete intervals. Placement and inflation of the packers provided information on hydraulic heads, specific capacities, the hydraulic connection between intervals, and depth-specific water-quality samples. Upon completion of borehole geophysical logging and interpretation of geophysical logs, geologist logs, drillers notes, and packer work, 13 boreholes were reconstructed such that water levels could be monitored and water samples could be collected from discrete shallow, intermediate, and deep waterbearing fractures in each borehole. Boreholes BE-1672, BE-1674, BE-1676, and BE-1677 remained open-hole for sampling purposes. Boreholes RI-2, RI-3, and RI-4 remained openhole for injection purposes. Boreholes P-1, P-2, and P-3 remained open and were converted to pumping wells.

Contrasting Patterns of Damage and Recovery in Logged Amazon Forests From Small Footprint LiDAR Data

NASA Technical Reports Server (NTRS)

Morton, D. C.; Keller, M.; Cook, B. D.; Hunter, Maria; Sales, Marcio; Spinelli, L.; Victoria, D.; Andersen, H.-E.; Saleska, S.

2012-01-01

Tropical forests ecosystems respond dynamically to climate variability and disturbances on time scales of minutes to millennia. To date, our knowledge of disturbance and recovery processes in tropical forests is derived almost exclusively from networks of forest inventory plots. These plots typically sample small areas (less than or equal to 1 ha) in conservation units that are protected from logging and fire. Amazon forests with frequent disturbances from human activity remain under-studied. Ongoing negotiations on REDD+ (Reducing Emissions from Deforestation and Forest Degradation plus enhancing forest carbon stocks) have placed additional emphasis on identifying degraded forests and quantifying changing carbon stocks in both degraded and intact tropical forests. We evaluated patterns of forest disturbance and recovery at four -1000 ha sites in the Brazilian Amazon using small footprint LiDAR data and coincident field measurements. Large area coverage with airborne LiDAR data in 2011-2012 included logged and unmanaged areas in Cotriguacu (Mato Grosso), Fiona do Jamari (Rondonia), and Floresta Estadual do Antimary (Acre), and unmanaged forest within Reserva Ducke (Amazonas). Logging infrastructure (skid trails, log decks, and roads) was identified using LiDAR returns from understory vegetation and validated based on field data. At each logged site, canopy gaps from logging activity and LiDAR metrics of canopy heights were used to quantify differences in forest structure between logged and unlogged areas. Contrasting patterns of harvesting operations and canopy damages at the three logged sites reflect different levels of pre-harvest planning (i.e., informal logging compared to state or national logging concessions), harvest intensity, and site conditions. Finally, we used multi-temporal LiDAR data from two sites, Reserva Ducke (2009, 2012) and Antimary (2010, 2011), to evaluate gap phase dynamics in unmanaged forest areas. The rates and patterns of canopy gap formation at these sites illustrate potential issues for separating logging damages from natural forest disturbances over longer time scales. Multi-temporal airborne LiDAR data and coincident field measurements provide complementary perspectives on disturbance and recovery processes in intact and degraded Amazon forests. Compared to forest inventory plots, the large size of each individual site permitted analyses of landscape-scale processes that would require extremely high investments to study using traditional forest inventory methods.

Control of Listeria monocytogenes growth in soft cheeses by bacteriophage P100.

PubMed

Silva, Elaine Nóbrega Gibson; Figueiredo, Ana Cláudia Leite; Miranda, Fernanda Araújo; de Castro Almeida, Rogeria Comastri

2014-01-01

The purpose of this study was to determine the effect of bacteriophage P100 on strains of Listeria monocytogenes in artificially inoculated soft cheeses. A mix of L. monocytogenes 1/2a and Scott A was inoculated in Minas Frescal and Coalho cheeses (approximately 10(5) cfu/g) with the bacteriophage added thereafter (8.3 × 10(7) PFU/g). Samples were analyzed immediately, and then stored at 10 °C for seven days. At time zero, 30 min post-infection, the bacteriophage P100 reduced L. monocytogenes counts by 2.3 log units in Minas Frescal cheese and by 2.1 log units in Coalho cheese, compared to controls without bacteriophage. However, in samples stored under refrigeration for seven days, the bacteriophage P100 was only weakly antilisterial, with the lowest decimal reduction (DR) for the cheeses: 1.0 log unit for Minas Frescal and 0.8 log units for Coalho cheese. The treatment produced a statistically significant decrease in the counts of viable cells (p < 0.05) and in all assays performed, we observed an increase of approximately one log cycle in the number of viable cells of L. monocytogenes in the samples under refrigeration for seven days. Moreover, a smaller effect of phages was observed. These results, along with other published data, indicate that the effectiveness of the phage treatment depends on the initial concentration of L. monocytogenes, and that a high concentration of phages per unit area is required to ensure sustained inactivation of target pathogens on food surfaces.

Immobilized Artificial Membrane HPLC Derived Parameters vs PAMPA-BBB Data in Estimating in Situ Measured Blood-Brain Barrier Permeation of Drugs.

PubMed

Grumetto, Lucia; Russo, Giacomo; Barbato, Francesco

2016-08-01

The affinity indexes for phospholipids (log kW(IAM)) for 42 compounds were measured by high performance liquid chromatography (HPLC) on two different phospholipid-based stationary phases (immobilized artificial membrane, IAM), i.e., IAM.PC.MG and IAM.PC.DD2. The polar/electrostatic interaction forces between analytes and membrane phospholipids (Δlog kW(IAM)) were calculated as the differences between the experimental values of log kW(IAM) and those expected for isolipophilic neutral compounds having polar surface area (PSA) = 0. The values of passage through a porcine brain lipid extract (PBLE) artificial membrane for 36 out of the 42 compounds considered, measured by the so-called PAMPA-BBB technique, were taken from the literature (P0(PAMPA-BBB)). The values of blood-brain barrier (BBB) passage measured in situ, P0(in situ), for 38 out of the 42 compounds considered, taken from the literature, represented the permeability of the neutral forms on "efflux minimized" rodent models. The present work was aimed at verifying the soundness of Δlog kW(IAM) at describing the potential of passage through the BBB as compared to data achieved by the PAMPA-BBB technique. In a first instance, the values of log P0(PAMPA-BBB) (32 data points) were found significantly related to the n-octanol lipophilicity values of the neutral forms (log P(N)) (r(2) = 0.782) whereas no significant relationship (r(2) = 0.246) was found with lipophilicity values of the mixtures of ionized and neutral forms existing at the experimental pH 7.4 (log D(7.4)) as well as with either log kW(IAM) or Δlog kW(IAM) values. log P0(PAMPA-BBB) related moderately to log P0(in situ) values (r(2) = 0.604). The latter did not relate with either n-octanol lipophilicity indexes (log P(N) and log D(7.4)) or phospholipid affinity indexes (log kW(IAM)). In contrast, significant inverse linear relationships were observed between log P0(in situ) (38 data points) and Δlog kW(IAM) values for all the compounds but ibuprofen and chlorpromazine, which behaved as moderate outliers (r(2) = 0.656 and r(2) = 0.757 for values achieved on IAM.PC.MG and IAM.PC.DD2, respectively). Since log P0(in situ) refer to the "intrinsic permeability" of the analytes regardless their ionization degree, no correction for ionization of Δlog kW(IAM) values was needed. Furthermore, log P0(in situ) were found roughly linearly related to log BB values (i.e., the logarithm of the ratio brain concentration/blood concentration measured in vivo) for all the analytes but those predominantly present at the experimental pH 7.4 as anions. These results suggest that, at least for the data set considered, Δlog kW(IAM) parameters are more effective than log P0(PAMPA-BBB) at predicting log P0(in situ) values for all the analytes. Furthermore, ionization appears to affect differently, and much more markedly, BBB passage of acids (yielding anions) than that of the other ionizable compounds.

Dolutegravir versus placebo in subjects harbouring HIV-1 with integrase inhibitor resistance associated substitutions: 48-week results from VIKING-4, a randomized study.

PubMed

Akil, Bisher; Blick, Gary; Hagins, Debbie P; Ramgopal, Moti N; Richmond, Gary J; Samuel, Rafik M; Givens, Naomi; Vavro, Cindy; Song, Ivy H; Wynne, Brian; Ait-Khaled, Mounir

2015-01-01

The Phase III VIKING-3 study demonstrated that dolutegravir (DTG) 50 mg twice daily was efficacious in antiretroviral therapy (ART)-experienced subjects harbouring raltegravir- and/or elvitegravir-resistant HIV-1. VIKING-4 (ING116529) included a placebo-controlled 7-day monotherapy phase to demonstrate that short-term antiviral activity was attributable to DTG. VIKING-4 is a Phase III randomized, double-blind study in therapy-experienced adults with integrase inhibitor (INI)-resistant virus randomized to DTG 50 mg twice daily or placebo while continuing their failing regimen (without raltegravir or elvitegravir) for 7 days (clinicaltrials.gov identifier NCT01568892). At day 8, all subjects switched to open-label DTG 50 mg twice daily and optimized background therapy including ≥1 fully active drug. The primary end point was change from baseline in plasma HIV-1 RNA at day 8. The study population (n=30) was highly ART-experienced with advanced HIV disease. Patients had extensive baseline resistance to all approved antiretroviral classes. Adjusted mean change in HIV-1 RNA at day 8 was 
-1.06 log10 copies/ml for the DTG arm and 0.10 log10 copies/ml for the placebo arm (treatment difference -1.16 log10 copies/ml [-1.52, -0.80]; P<0.001). Overall, 47% and 57% of subjects had plasma HIV-1 RNA <50 and <400 copies/ml at week 24, and 40% and 53% at week 48, respectively. No discontinuations due to drug-related adverse events occurred in the study. The observed day 8 antiviral activity in this highly treatment-experienced population with INI-resistant HIV-1 was attributable to DTG. Longer-term efficacy (after considering baseline ART resistance) and safety during the open-label phase were in-line with the results of the larger VIKING-3 study.

Drug Design Relating Amebicides to Inhibition of Protein Synthesis.

DTIC Science & Technology

1977-09-01

A study of the effect of emetine on protein synthesis in E. histolytica was made on log phase amebas as compared to stationary phase amebas ...Sensitivity to emetine was maintained independently of the rate of protein synthesis. Furthermore, both stages of amebas had the same capacity to bind emetine...elongation site. Finally, evidence was obtained that the capacity to bind emetine provides a basis for conferring drug resistance in amebas . A direct

Recovery Efficiency Test Project: Phase 1, Activity report

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

Overbey, W.K. Jr.; Wilkins, D.W.; Keltch, B.

1988-04-01

This report is the second volume of the Recovery Efficiency Test Phase I Report of Activities. Volume 1 covered selection, well planning, drilling, coring, logging and completion operations. This volume reports on well testing activities, reclamation activities on the drilling site and access roads, and the results of physical and mechanical properties tests on the oriented core material obtained from a horizontal section of the well. 3 refs., 21 figs., 10 tabs.

The growth of Propionibacterium cyclohexanicum in fruit juices and its survival following elevated temperature treatments.

PubMed

Walker, Michelle; Phillips, Carol A

2007-06-01

This study investigated the growth of Propionibacterium cyclohexanicum in orange juice over a temperature range from 4 to 40 degrees C and its ability to multiply in tomato, grapefruit, apple, pineapple and cranberry juices at 30 and 35 degrees C. Survival after 10 min exposure to 50, 60, 70, 80, 85, 90 and 95 degrees C in culture medium and in orange juice was also assessed. In orange juice the organism was able to multiply by 2 logs at temperatures from 4 to 35 degrees C and survived for up to 52 days. However, at 40 degrees C viable counts were reduced after 6 days and no viable cells isolated after 17 days. The optimum growth temperature in orange juice over 6 days was 25 degrees C but over 4 days it was 35 degrees C. The growth of P. cyclohexanicum was monitored in tomato, grapefruit, cranberry, pineapple and apple juices at 30 and 35 degrees C over 29 days. Cranberry, grapefruit and apple juice did not support the growth of P. cyclohexanicum. At 30 degrees C no viable cells were detected after 8 days in cranberry juice or after 22 days in grapefruit juice while at 35 degrees C no viable cells were detected after 5 and 15 days, respectively. However, in apple juice, although a 5 log reduction occurred, viable cells could be detected after 29 days. P. cyclohexanicum was able to multiply in both tomato and pineapple juices. In tomato juice, there was a 2 log increase in viable counts after 8 days at 30 degrees C but no increase at 35 degrees C, while in pineapple juice there was a 1 log increase in numbers over 29 days with no significant difference between numbers of viable cells present at 30 and 35 degrees C. The organism survived at 50 degrees C for 10 min in culture medium without a significant loss of viability while similar treatment at 60, 70 and 80 degrees C resulted in approximately a 3-4 log reduction, with no viable cells detected after treatment at 85 or 90 or 95 degrees C but, when pre-treated at intermediate temperatures before exposure to higher temperatures, some cells survived. However, in orange juice a proportion of cells survived at 95 degrees C for 10 min without pre-treatment and there was no significant difference between numbers surviving with and without pre-treatment. The results from this study demonstrate that P. cyclohexanicum is able to grow in a number of juices, other than orange juice, and able to survive a number of high temperature procedures. Therefore, if initially present in the raw materials P. cyclohexanicum might survive the pasteurization procedures used in the fruit juice industry, contaminate and consequently spoil the final product.

Prediction of drug transport processes using simple parameters and PLS statistics. The use of ACD/logP and ACD/ChemSketch descriptors.

PubMed

Osterberg, T; Norinder, U

2001-01-01

A method of modelling and predicting biopharmaceutical properties using simple theoretically computed molecular descriptors and multivariate statistics has been investigated for several data sets related to solubility, IAM chromatography, permeability across Caco-2 cell monolayers, human intestinal perfusion, brain-blood partitioning, and P-glycoprotein ATPase activity. The molecular descriptors (e.g. molar refractivity, molar volume, index of refraction, surface tension and density) and logP were computed with ACD/ChemSketch and ACD/logP, respectively. Good statistical models were derived that permit simple computational prediction of biopharmaceutical properties. All final models derived had R(2) values ranging from 0.73 to 0.95 and Q(2) values ranging from 0.69 to 0.86. The RMSEP values for the external test sets ranged from 0.24 to 0.85 (log scale).

The Effects of L2C Signal Tracking on High-Precision Carrier Phase GPS Positioning: Implications for the Next Generation of GNSS Systems

NASA Astrophysics Data System (ADS)

Blume, F.; Berglund, H.; Estey, L.

2012-12-01

In December 2005, the L2C signal was introduced to improve the accuracy, tracking and redundancy of the GPS system for civilian users. The L2C signal also provides improved SNR data when compared with the L2P(Y) legacy signal. However, GNSS network operators have been hesitant to use the new signal as it is not well determined how positions derived from L2 carrier phase measurements are affected. L2C carrier phase is in quadrature with L2P(Y); some manufacturers correct for this when logging L2C phase while others do not. In cases where both L2C and L2P(Y) are logged simultaneously, translation software must be used carefully in order to select which phase is used in positioning. Modifications were made to UNAVCO's teqc pre-processing software to eliminate confusion, however GNSS networks such as the IGS still suffer occasional data loss due to improperly configured GPS receivers or data flow routines. To date L2C analyses have been restricted to special applications such as snow depth and soil moisture using SNR data, as some high-precision data analysis packages are not compatible with L2C. We use several different methods to determine the effect that tracking and logging L2C has on carrier phase measurements and positioning for various receiver models and configurations. Twenty-four hour zero-length baseline solutions using L2 show sub- millimeter differences in mean positions for both horizontal and vertical components. Direct comparisons of the L2 phase observable from RINEX files with and without the L2C observable show sub-millicycle differences. The magnitude of the variations increased at low elevations. The behavior of the L2P(Y) phase observations or positions from a given receiver were not affected by the enabling of L2C tracking. We find that the use of the L2C-derived carrier phase in real-time applications can be disastrous in cases where receiver brands are mixed between those that correct for quadrature and those that do not (Figure 1). Until standards are implemented for universal phase corrections in either receivers or software the use of L2C should be avoided by real-time network operators. The complexity involved in the adoption of a single new signal on an existing GPS frequency over a period of 7 years has implications for the use of multi-GNSS systems and modernized GPS in geodetic networks.

Novel Desorber for Online Drilling Mud Gas Logging

PubMed Central

Lackowski, Marcin; Tobiszewski, Marek; Namieśnik, Jacek

2016-01-01

This work presents the construction solution and experimental results of a novel desorber for online drilling mud gas logging. The traditional desorbers use mechanical mixing of the liquid to stimulate transfer of hydrocarbons to the gaseous phase that is further analyzed. The presented approach is based on transfer of hydrocarbons from the liquid to the gas bubbles flowing through it and further gas analysis. The desorber was checked for gas logging from four different drilling muds collected from Polish boreholes. The results of optimization studies are also presented in this study. The comparison of the novel desorber with a commercial one reveals strong advantages of the novel one. It is characterized by much better hydrocarbons recovery efficiency and allows reaching lower limits of detection of the whole analytical system. The presented desorber seems to be very attractive alternative over widely used mechanical desorbers. PMID:27127674

Gas-hydrate concentration estimated from P- and S-wave velocities at the Mallik 2L-38 research well, Mackenzie Delta, Canada

NASA Astrophysics Data System (ADS)

Carcione, José M.; Gei, Davide

2004-05-01

We estimate the concentration of gas hydrate at the Mallik 2L-38 research site using P- and S-wave velocities obtained from well logging and vertical seismic profiles (VSP). The theoretical velocities are obtained from a generalization of Gassmann's modulus to three phases (rock frame, gas hydrate and fluid). The dry-rock moduli are estimated from the log profiles, in sections where the rock is assumed to be fully saturated with water. We obtain hydrate concentrations up to 75%, average values of 37% and 21% from the VSP P- and S-wave velocities, respectively, and 60% and 57% from the sonic-log P- and S-wave velocities, respectively. The above averages are similar to estimations obtained from hydrate dissociation modeling and Archie methods. The estimations based on the P-wave velocities are more reliable than those based on the S-wave velocities.

Studies on Acidification of Media by Avena Stem Segments in the Presence and Absence of Gibberellic Acid 1

PubMed Central

Hebard, Frederick V.; Amatangelo, Steven J.; Dayanandan, P.; Kaufman, Peter B.

1976-01-01

The rate of acidification of media by Avena stem segments was studied with a titrimeter. GA3 increased this rate by an average of 17% if supplied to the segments 90 min prior to measurement. GA3 inhibited the rate by 15% if supplied 10 min prior to measurement. After 90 min incubation, stimulation of elongation had started; at 10 min, GA3 had not yet started to stimulate elongation in the segments. The acidification rates of the nodes (including the sheath-pulvinus), leaf sheath bases, and the internode bases of the stem segments were determined for plus and minus GA3-treated segments. The internode fraction contributes most to modification of the acidification rate, the node-pulvinus fraction less so, and the nongrowing sheath not at all. Acidification rates were measured for segments in different stages of elongation (lag, log, and plateau phases of growth). Segments in these growth stages were obtained from intact plants and from segments preincubated in sucrose and sucrose + GA3. Segments from all sources which are in the log phase of growth have the highest rates, those in the plateau phase the lowest. For lag and log growth phases, segments preincubated in sucrose + GA3 show the highest rates, those preincubated in sucrose the lowest rates. The opposite occurs for segments in the plateau phase of growth. Segments stimulated to grow by GA3 cause the pH of their incubation media to drop to pH 5.15 from an initial pH of 6.5. Nonstimulated segments cause a drop to pH 5.6. Long term growth of the segments is maximal in media buffered to pH 5 in the presence and absence of GA3. Our results support the idea that GA3 stimulates an active acidification process in Avena stem segments just after GA3 starts to stimulate growth in the segments, and that such an acidification process could play an important role in wall-loosening during active growth of the internode. PMID:16659741

Influenza viruses production: Evaluation of a novel avian cell line DuckCelt®-T17.

PubMed

Petiot, Emma; Proust, Anaïs; Traversier, Aurélien; Durous, Laurent; Dappozze, Frédéric; Gras, Marianne; Guillard, Chantal; Balloul, Jean-Marc; Rosa-Calatrava, Manuel

2018-05-24

The influenza vaccine manufacturing industry is looking for production cell lines that are easily scalable, highly permissive to multiple viruses, and more effective in term of viral productivity. One critical characteristic of such cell lines is their ability to grow in suspension, in serum free conditions and at high cell densities. Influenza virus causing severe epidemics both in human and animals is an important threat to world healthcare. The repetitive apparition of influenza pandemic outbreaks in the last 20years explains that manufacturing sector is still looking for more effective production processes to replace/supplement embryonated egg-based process. Cell-based production strategy, with a focus on avian cell lines, is one of the promising solutions. Three avian cell lines, namely duck EB66®cells (Valneva), duck AGE.CR® cells (Probiogen) and quail QOR/2E11 cells (Baxter), are now competing with traditional mammalian cell platforms (Vero and MDCK cells) used for influenza vaccine productions and are currently at advance stage of commercial development for the manufacture of influenza vaccines. The DuckCelt®-T17 cell line presented in this work is a novel avian cell line developed by Transgene. This cell line was generated from primary embryo duck cells with the constitutive expression of the duck telomerase reverse transcriptase (dTERT). The DuckCelt®-T17 cells were able to grow in batch suspension cultures and serum-free conditions up to 6.5×10 6 cell/ml and were easily scaled from 10ml up to 3l bioreactor. In the present study, DuckCelt®-T17 cell line was tested for its abilities to produce various human, avian and porcine influenza strains. Most of the viral strains were produced at significant infectious titers (>5.8 log TCID50/ml) with optimization of the infection conditions. Human strains H1N1 and H3N2, as well as all the avian strains tested (H5N2, H7N1, H3N8, H11N9, H12N5) were the most efficiently produced with highest titre reached of 9.05 log TCID50/ml for A/Panama/2007/99 influenza H3N2. Porcine strains were also greatly rescued with titres from 4 to 7 log TCID50/ml depending of the subtypes. Interestingly, viral kinetics showed maximal titers reached at 24h post-infection for most of the strains, allowing early harvest time (Time Of Harvest: TOH). The B strains present specific production kinetics with a delay of 24h before reaching the maximal viral particle release. Process optimization on H1N1 2009 human pandemic strain allowed identifying best operating conditions for production (MOI, trypsin concentration, cell density at infection) allowing improving the production level by 2 log. Our results suggest that the DuckCelt®-T17 cell line is a very promising platform for industrial production of influenza viruses and particularly for avian viral strains. Copyright © 2017 Elsevier Ltd. All rights reserved.

Coupling of Solar Energy to Hydrogen Peroxide Production in the Cyanobacterium Anacystis nidulans

PubMed Central

Roncel, Mercedes; Navarro, José A.; De la Rosa, Miguel A.

1989-01-01

Hydrogen peroxide production by blue-green algae (cyanobacteria) under photoautotrophic conditions is of great interest as a model system for the bioconversion of solar energy. Our experimental system was based on the photosynthetic reduction of molecular oxygen with electrons from water by Anacystis nidulans 1402-1 as the biophotocatalyst and methyl viologen as a redox intermediate. It has been demonstrated that the metabolic conditions of the algae in their different growth stages strongly influence the capacity for hydrogen peroxide photoproduction, and so the initial formation rate and net peroxide yield became maximum in the mid-log phase of growth. The overall process can be optimized in the presence of certain metabolic inhibitors such as iodoacetamide and p-hydroxymercuribenzoate, as well as by permeabilization of the cellular membrane after drastic temperature changes and by immobilization of the cells in inert supports such as agar and alginate. PMID:16347855

Remote Environmental Monitoring and Diagnostics in the Perishables Supply Chain - Phase 1

DTIC Science & Technology

2011-12-12

The table below displays the  raw  data from the tests. Each cell contains a number between 0  and 5 corresponding  to  the number of  successful...along  with  the  raw   temperature  data  to  the  email  addresses  specified  in  the  configuration file.    As mentioned previously, for the CAEN...the Intelleflex system.    The user also has the option to save the data log, which contains the  raw  temperature data, to  a file on the Windows

Determination of volumetric gas-liquid mass transfer coefficient of carbon monoxide in a batch cultivation system using kinetic simulations.

PubMed

Jang, Nulee; Yasin, Muhammad; Park, Shinyoung; Lovitt, Robert W; Chang, In Seop

2017-09-01

A mathematical model of microbial kinetics was introduced to predict the overall volumetric gas-liquid mass transfer coefficient (k L a) of carbon monoxide (CO) in a batch cultivation system. The cell concentration (X), acetate concentration (C ace ), headspace gas (N co and [Formula: see text] ), dissolved CO concentration in the fermentation medium (C co ), and mass transfer rate (R) were simulated using a variety of k L a values. The simulated results showed excellent agreement with the experimental data for a k L a of 13/hr. The C co values decreased with increase in cultivation times, whereas the maximum mass transfer rate was achieved at the mid-log phase due to vigorous microbial CO consumption rate higher than R. The model suggested in this study may be applied to a variety of microbial systems involving gaseous substrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biological legacies buffer local species extinction after logging

PubMed Central

Rudolphi, Jörgen; Jönsson, Mari T; Gustafsson, Lena

2014-01-01

Clearcutting has been identified as a main threat to forest biodiversity. In the last few decades, alternatives to clearcutting have gained much interest. Living and dead trees are often retained after harvest to serve as structural legacies to mitigate negative effects of forestry. However, this practice is widely employed without information from systematic before–after control-impact studies to assess the processes involved in species responses after clearcutting with retention. We performed a large-scale survey of the occurrence of logging-sensitive and red-listed bryophytes and lichens before and after clearcutting with the retention approach. A methodology was adopted that, for the first time in studies on retention approaches, enabled monitoring of location-specific substrates. We used uncut stands as controls to assess the variables affecting the survival of species after a major disturbance. In total, 12 bryophyte species and 27 lichen species were analysed. All were classified as sensitive to logging, and most species are also currently red-listed. We found that living and dead trees retained after final harvest acted as refugia in which logging-sensitive species were able to survive for 3 to 7 years after logging. Depending on type of retention and organism group, between 35% and 92% of the species occurrences persisted on retained structures. Most species observed outside retention trees or patches disappeared. Larger pre-harvest population sizes of bryophytes on dead wood increased the survival probability of the species and hence buffered the negative effects of logging. Synthesis and applications. Careful spatial planning of retention structures is required to fully embrace the habitats of logging-sensitive species. Bryophytes and lichens persisted to a higher degree in retention patches compared to solitary trees or in the clearcut area. Retaining groups of trees in logged areas will help to sustain populations of species over the clearcut phase. When possible, old logs should be moved into retention patches to provide a more beneficial environment for dead wood-dependent species. Our study also highlights the need for more before–after control-impact studies of retention forestry to explore factors influencing the survival of species after logging. PMID:25653456

Biological legacies buffer local species extinction after logging.

PubMed

Rudolphi, Jörgen; Jönsson, Mari T; Gustafsson, Lena; Bugmann, H

2014-02-01

Clearcutting has been identified as a main threat to forest biodiversity. In the last few decades, alternatives to clearcutting have gained much interest. Living and dead trees are often retained after harvest to serve as structural legacies to mitigate negative effects of forestry. However, this practice is widely employed without information from systematic before-after control-impact studies to assess the processes involved in species responses after clearcutting with retention. We performed a large-scale survey of the occurrence of logging-sensitive and red-listed bryophytes and lichens before and after clearcutting with the retention approach. A methodology was adopted that, for the first time in studies on retention approaches, enabled monitoring of location-specific substrates. We used uncut stands as controls to assess the variables affecting the survival of species after a major disturbance. In total, 12 bryophyte species and 27 lichen species were analysed. All were classified as sensitive to logging, and most species are also currently red-listed. We found that living and dead trees retained after final harvest acted as refugia in which logging-sensitive species were able to survive for 3 to 7 years after logging. Depending on type of retention and organism group, between 35% and 92% of the species occurrences persisted on retained structures. Most species observed outside retention trees or patches disappeared. Larger pre-harvest population sizes of bryophytes on dead wood increased the survival probability of the species and hence buffered the negative effects of logging. Synthesis and applications . Careful spatial planning of retention structures is required to fully embrace the habitats of logging-sensitive species. Bryophytes and lichens persisted to a higher degree in retention patches compared to solitary trees or in the clearcut area. Retaining groups of trees in logged areas will help to sustain populations of species over the clearcut phase. When possible, old logs should be moved into retention patches to provide a more beneficial environment for dead wood-dependent species. Our study also highlights the need for more before-after control-impact studies of retention forestry to explore factors influencing the survival of species after logging.

On the predictive potential of Pc5 ULF waves to forecast relativistic electrons based on their relationships over two solar cycles

NASA Astrophysics Data System (ADS)

Lam, Hing-Lan

2017-01-01

A statistical study of relativistic electron (>2 MeV) fluence derived from geosynchronous satellites and Pc5 ultralow frequency (ULF) wave power computed from a ground magnetic observatory data located in Canada's auroral zone has been carried out. The ground observations were made near the foot points of field lines passing through the GOESs from 1987 to 2009 (cycles 22 and 23). We determine statistical relationships between the two quantities for different phases of a solar cycle and validate these relationships in two different cycles. There is a positive linear relationship between log fluence and log Pc5 power for all solar phases; however, the power law indices vary for different phases of the cycle. High index values existed during the descending phase. The Pearson's cross correlation between electron fluence and Pc5 power indicates fluence enhancement 2-3 days after strong Pc5 wave activity for all solar phases. The lag between the two quantities is shorter for extremely high fluence (due to high Pc5 power), which tends to occur during the declining phases of both cycles. Most occurrences of extremely low fluence were observed during the extended solar minimum of cycle 23. The precursory attribute of Pc5 power with respect to fluence and the enhancement of fluence due to rising Pc5 power both support the notion of an electron acceleration mechanism by Pc5 ULF waves. This precursor behavior establishes the potential of using Pc5 power to predict relativistic electron fluence.

Quantitative estimation of Nipah virus replication kinetics in vitro

PubMed Central

Chang, Li-Yen; Ali, AR Mohd; Hassan, Sharifah Syed; AbuBakar, Sazaly

2006-01-01

Background Nipah virus is a zoonotic virus isolated from an outbreak in Malaysia in 1998. The virus causes infections in humans, pigs, and several other domestic animals. It has also been isolated from fruit bats. The pathogenesis of Nipah virus infection is still not well described. In the present study, Nipah virus replication kinetics were estimated from infection of African green monkey kidney cells (Vero) using the one-step SYBR® Green I-based quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) assay. Results The qRT-PCR had a dynamic range of at least seven orders of magnitude and can detect Nipah virus from as low as one PFU/μL. Following initiation of infection, it was estimated that Nipah virus RNA doubles at every ~40 minutes and attained peak intracellular virus RNA level of ~8.4 log PFU/μL at about 32 hours post-infection (PI). Significant extracellular Nipah virus RNA release occurred only after 8 hours PI and the level peaked at ~7.9 log PFU/μL at 64 hours PI. The estimated rate of Nipah virus RNA released into the cell culture medium was ~0.07 log PFU/μL per hour and less than 10% of the released Nipah virus RNA was infectious. Conclusion The SYBR® Green I-based qRT-PCR assay enabled quantitative assessment of Nipah virus RNA synthesis in Vero cells. A low rate of Nipah virus extracellular RNA release and low infectious virus yield together with extensive syncytial formation during the infection support a cell-to-cell spread mechanism for Nipah virus infection. PMID:16784519

Inactivation of ferric uptake regulator (Fur) attenuates Helicobacter pylori J99 motility by disturbing the flagellar motor switch and autoinducer-2 production.

PubMed

Lee, Ai-Yun; Kao, Cheng-Yen; Wang, Yao-Kuan; Lin, Ssu-Yuan; Lai, Tze-Ying; Sheu, Bor-Shyang; Lo, Chien-Jung; Wu, Jiunn-Jong

2017-08-01

Flagellar motility of Helicobacter pylori has been shown to be important for the bacteria to establish initial colonization. The ferric uptake regulator (Fur) is a global regulator that has been identified in H. pylori which is involved in the processes of iron uptake and establishing colonization. However, the role of Fur in H. pylori motility is still unclear. Motility of the wild-type, fur mutant, and fur revertant J99 were determined by a soft-agar motility assay and direct video observation. The bacterial shape and flagellar structure were evaluated by transmission electron microscopy. Single bacterial motility and flagellar switching were observed by phase-contrast microscopy. Autoinducer-2 (AI-2) production in bacterial culture supernatant was analyzed by a bioluminescence assay. The fur mutant showed impaired motility in the soft-agar assay compared with the wild-type J99 and fur revertant. The numbers and lengths of flagellar filaments on the fur mutant cells were similar to those of the wild-type and revertant cells. Phenotypic characterization showed similar swimming speed but reduction in switching rate in the fur mutant. The AI-2 production of the fur mutant was dramatically reduced compared with wild-type J99 in log-phase culture medium. These results indicate that Fur positively modulates H. pylori J99 motility through interfering with bacterial flagellar switching. © 2017 John Wiley & Sons Ltd.

Three feruloyl esterases in Cellulosilyticum ruminicola H1 act synergistically to hydrolyze esterified polysaccharides.

PubMed

Li, Jiabao; Cai, Shichun; Luo, Yuanming; Dong, Xiuzhu

2011-09-01

Feruloyl esterases (Faes) constitute a subclass of carboxyl esterases that specifically hydrolyze the ester linkages between ferulate and polysaccharides in plant cell walls. Until now, the described microbial Faes were mainly from fungi. In this study, we report that Cellulosilyticum ruminicola H1, a previously described fibrolytic rumen bacterium, possesses three different active feruloyl esterases, FaeI, FaeII, and FaeIII. Phylogenetic analysis classified the described bacterial Faes into two types, FaeI and FaeII in type I and FaeIII in type II. Substrate specificity assays indicated that FaeI is more active against the ester bonds in natural hemicelluloses and FaeIII preferentially attacks the ferulate esters with a small moiety, such as methyl groups, while FaeII is active on both types of substrates. Among the three feruloyl esterase genes, faeI was the only one induced significantly by xylose and xylan, while pectin appeared to moderately induce the three genes during the late log phase to stationary phase. Western blot analysis determined that FaeI and FaeIII were secreted and cytoplasmic proteins, respectively, whereas FaeII seemed to be cell associated. The addition of FaeI and FaeII but not FaeIII enhanced the activity of a xylanase on maize cob, suggesting a synergy of the former two with xylanase. Hence, we propose that the three feruloyl esterases work in concert to hydrolyze ferulate esters in natural hemicelluloses.

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

Canini, Laetitia; DebRoy, Swati; Mariño, Zoe

HCV kinetic analysis and modeling during antiviral therapy have not been performed in decompensated cirrhotic patients awaiting liver transplantation. Here, viral and host parameters were compared in patients treated with daily intravenous silibinin (SIL) monotherapy for 7 days according to the severity of their liver disease. Data were obtained from 25 patients, 12 non-cirrhotic, 8 with compensated cirrhosis and 5 with decompensated cirrhosis. The standard-biphasic model with time-varying SIL effectiveness (from 0 to ε max) was fit to viral kinetic data. Our results show that baseline viral load and age were significantly associated with the severity of liver disease (p<0.0001).more » A biphasic viral decline was observed in most patients with a higher first phase decline patients with less severe liver disease. The maximal effectiveness, ε max, was significantly (p≤0.032) associated with increasing severity of liver disease (ε max[s.e.]=0.86[0.05], ε max=0.69[0.06] and ε max=0.59[0.1]). The 2nd phase decline slope was not significantly different among groups (mean 1.88±0.15 log 10IU/ml/wk, p=0.75) as was the rate of change of SIL effectiveness (k=2.12/day[standard error, SE=0.18/day]). HCV-infected cell loss rate (δ[SE]=0.62/day[0.05/day]) was high and similar among groups. We conclude that the high loss rate of HCV-infected cells suggests that sufficient dose and duration of SIL might achieve viral suppression in advanced liver disease.« less

The effect of high-power ultrasound and gas phase plasma treatment on Aspergillus spp. and Penicillium spp. count in pure culture.

PubMed

Herceg, Z; Režek Jambrak, A; Vukušić, T; Stulić, V; Stanzer, D; Milošević, S

2015-01-01

The aim of this study was to investigate and compare two nonthermal techniques in the inactivation of moulds. High power ultrasound (20 kHz) and nonthermal gas phase plasma treatments were studied in the inactivation of selected moulds. Aspergillus spp. and Penicillium spp. were chosen as the most common mould present in or on food. Experimental design was introduced to establish and optimize working variables. For high power ultrasound, the greatest reduction of moulds (indicated by the total removal of viable cells) was obtained after ultrasound treatments at 60°C (thermosonication) for 6 and 9 min (power applied, 20-39 W). For plasma treatment, the greatest inactivation of moulds was observed for the longest treatment time (5 min) and lowest sample volume (2 ml), (AP12, AP13, PP12 and PP13). The great amount of applied energy required for achieving a partial log reduction in viable cells is the limiting factor for using high-power ultrasound. However, both treatment methods could be combined in the future to produce beneficial outcomes. This study deals with nonthermal food processing techniques and the results and findings present in this study are the root for further prospective studies. The food industry is looking for nonthermal methods that will enable food preservation, reduce deterioration of food compounds and structure and prolong food shelf life. © 2014 The Society for Applied Microbiology.

Growth condition-dependent cell surface proteome analysis of Enterococcus faecium.

PubMed

Sinnige, Jan C; de Been, Mark; Zhou, Miaomiao; Bonten, Marc J M; Willems, Rob J L; Top, Janetta

2015-11-01

The last 30 years Enterococcus faecium has become an important nosocomial pathogen in hospitals worldwide. The aim of this study was to obtain insight in the cell surface proteome of E. faecium when grown in laboratory and clinically relevant conditions. Enterococcus faecium E1162, a clinical blood stream isolate, was grown until mid-log phase in brain heart infusion medium (BHI) with, or without 0.02% bile salts, Tryptic Soy Broth with 1% glucose (TSBg) and urine, and its cell surface was "shaved" using immobilized trypsin. Peptides were identified using MS/MS. Mapping against the translated E1162 whole genome sequence identified 67 proteins that were differentially detected in different conditions. In urine, 14 proteins were significantly more and nine proteins less abundant relative to the other conditions. Growth in BHI-bile and TSBg, revealed four and six proteins, respectively, which were uniquely present in these conditions while two proteins were uniquely present in both conditions. Thus, proteolytic shaving of E. faecium cells identified differentially surface exposed proteins in different growth conditions. These proteins are of special interest as they provide more insight in the adaptive mechanisms and may serve as targets for the development of novel therapeutics against this multi-resistant emerging pathogen. All MS data have been deposited in the ProteomeXchange with identifier PXD002497 (http://proteomecentral.proteomexchange.org/dataset/PXD002497). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mitochondrial fusion increases the mitochondrial DNA copy number in budding yeast.

PubMed

Hori, Akiko; Yoshida, Minoru; Ling, Feng

2011-05-01

Mitochondrial fusion plays an important role in mitochondrial DNA (mtDNA) maintenance, although the underlying mechanisms are unclear. In budding yeast, certain levels of reactive oxygen species (ROS) can promote recombination-mediated mtDNA replication, and mtDNA maintenance depends on the homologous DNA pairing protein Mhr1. Here, we show that the fusion of isolated yeast mitochondria, which can be monitored by the bimolecular fluorescence complementation-derived green fluorescent protein (GFP) fluorescence, increases the mtDNA copy number in a manner dependent on Mhr1. The fusion event, accompanied by the degradation of dissociated electron transport chain complex IV and transient reductions in the complex IV subunits by the inner membrane AAA proteases such as Yme1, increases ROS levels. Analysis of the initial stage of mitochondrial fusion in early log-phase cells produced similar results. Moreover, higher ROS levels in mitochondrial fusion-deficient mutant cells increased the amount of newly synthesized mtDNA, resulting in increases in the mtDNA copy number. In contrast, reducing ROS levels in yme1 null mutant cells significantly decreased the mtDNA copy number, leading to an increase in cells lacking mtDNA. Our results indicate that mitochondrial fusion induces mtDNA synthesis by facilitating ROS-triggered, recombination-mediated replication and thereby prevents the generation of mitochondria lacking DNA. © 2011 The Authors. Journal compilation © 2011 by the Molecular Biology Society of Japan/Blackwell Publishing Ltd.

The prisoner's dilemma as a cancer model.

PubMed

West, Jeffrey; Hasnain, Zaki; Mason, Jeremy; Newton, Paul K

2016-09-01

Tumor development is an evolutionary process in which a heterogeneous population of cells with different growth capabilities compete for resources in order to gain a proliferative advantage. What are the minimal ingredients needed to recreate some of the emergent features of such a developing complex ecosystem? What is a tumor doing before we can detect it? We outline a mathematical model, driven by a stochastic Moran process, in which cancer cells and healthy cells compete for dominance in the population. Each are assigned payoffs according to a Prisoner's Dilemma evolutionary game where the healthy cells are the cooperators and the cancer cells are the defectors. With point mutational dynamics, heredity, and a fitness landscape controlling birth and death rates, natural selection acts on the cell population and simulated 'cancer-like' features emerge, such as Gompertzian tumor growth driven by heterogeneity, the log-kill law which (linearly) relates therapeutic dose density to the (log) probability of cancer cell survival, and the Norton-Simon hypothesis which (linearly) relates tumor regression rates to tumor growth rates. We highlight the utility, clarity, and power that such models provide, despite (and because of) their simplicity and built-in assumptions.

Separation of alkylphenols by normal-phase and reversed-phase high-performance liquid chromatography

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

Schabron, J.F.; Hurtubise, R.J.; Silver, H.F.

1978-11-01

Empirical correlation factors were developed which relate log k' values for alkylphenols, the naphthols, and two phenylphenols to structural features. Both normal-phase and reversed-phase chromatographic systems were studied. The stationary phases employed in the normal-phase work were ..mu..-Bondapak CN, ..mu..-Bondapak NH/sub 2/, and ..mu..-Porasil. The structural features which affect retention in the normal-phase chromatographic systems are the number of ortho substituents, the number of aliphatic carbons, and the number of aromatic rings. The stationary phases employed in the reversed-phase work were ..mu..-Bondapak C/sub 18/ and ..mu..-Bondapak CN. The structural features which affect retention in the reversed-phase chromatographic systems are themore » number of aliphatic carbons and the number of aromatic double bonds. On ..mu..-Bondapak C/sub 18/, the presence or absence of a nonaromatic ring is of added importance.« less

Complexation of the calcium cation with antamanide: an experimental and theoretical study

NASA Astrophysics Data System (ADS)

Makrlík, Emanuel; Böhm, Stanislav; Vaňura, Petr; Ruzza, Paolo

2015-06-01

By using extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Ca2+(aq) + 1 .Sr2+(nb) ? 1 .Ca2+(nb) + Sr2+(aq) occurring in the two-phase water-nitrobenzene system (1 = antamanide; aq = aqueous phase, nb = nitrobenzene phase) was determined as log Kex (Ca2+, 1 .Sr2+) = 1.6 ± 0.1. Further, the stability constant of the 1 .Ca2+ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log βnb (1 .Ca2+) = 10.9 ± 0.2. Finally, applying quantum mechanical density functional level of theory calculations, the most probable structure of the cationic complex species 1 .Ca2+ was derived. In the resulting complex, the 'central' cation Ca2+ is bound by six strong bonding interactions to the corresponding six carbonyl oxygen atoms of the parent ligand 1. Besides, the whole 1 .Ca2+ complex structure is stabilised by two intramolecular hydrogen bonds. The interaction energy of the considered 1 .Ca2+ complex, involving the Boys-Bernardi counterpoise corrections of the basis set superposition error, was found to be -1219.3 kJ/mol, confirming the formation of this cationic species.

Transport of organic solutes through amorphous teflon AF films.

PubMed

Zhao, Hong; Zhang, Jie; Wu, Nianqiang; Zhang, Xu; Crowley, Katie; Weber, Stephen G

2005-11-02

Fluorous media have great potential for selective extraction (e.g., as applied to organic synthesis). Fluorous polymer films would have significant advantages in fluorous separations. Stable films of Teflon AF 2400 were cast from solution. Films appear defect-free (SEM; AFM). Rigid aromatic solutes are transported (from chloroform solution to chloroform receiving phase) in a size-dependent manner (log permeability is proportional to -0.0067 times critical volume). Benzene's permeability is about 2 orders of magnitude higher than in comparable gas-phase experiments. The films show selectivity for fluorinated solutes in comparison to the hydrogen-containing control. Transport rates are dependent on the solvent making up the source and receiving phases. The effect of solvent is, interestingly, not due to changes in partition ratio, but rather it is due to changes in the solute diffusion coefficient in the film. Solvents plasticize the films. A less volatile compound, -COOH-terminated poly(hexafluoropropylene oxide) (4), plasticizes the films (T(g) = -40 degrees C). Permeabilities are decreased in comparison to 4-free films apparently because of decreased diffusivity of solutes. The slope of dependence of log permeability on critical volume is not changed, however.

Chromatographic behavior of zwitterionic enalapril-exploring the conditions for lipophilicity assessment.

PubMed

Gikas, Spyros; Tsopelas, Fotios; Giaginis, Costas; Dimitrakopoulos, John; Livadara, Theodora; Archontaki, Helen; Tsantili-Kakoulidou, Anna

2008-11-04

The chromatographic behavior of enalapril was investigated under different stationary and mobile phase conditions in an effort to unravel interferences in the underlying retention mechanism, which would affect its relation to octanol-water partitioning. Extrapolated retention factors, logk(w), were used as relevant chromatographic indices. The retention/pH profile was established and the peak split phenomenon, associated with cis/trans interconversion, was also monitored as a function of pH. The pH at maximum retention and minimum peak split occurrence was chosen for further investigation, so that the presence of zwitterionic structure was guaranteed and any effect of cis/trans interconversion could be ignored. Retention of zwitterionic enalapril was found to be very sensitive to mobile phase conditions in regard to organic modifier as well to the aqueous component. The use of morpholine-propanesulfonic acid (MOPS) as buffer and the presence of n-octanol as mobile phase additive proved critical factors for maximum suppression of secondary interactions. Nevertheless, the corresponding extrapolated retention factor was considerably larger than octanol-water logD value at the isoelectric point. However, logk(w) could be successfully converted to logD by means of a calibration equation established for ionized acidic compounds.

Higher-order aberrations of lenticular opacities.

PubMed

Sachdev, Nisha; Ormonde, Susan E; Sherwin, Trevor; McGhee, Charles N J

2004-08-01

To measure and quantify higher-order aberrations induced by different types of lenticular opacities. Department of Ophthalmology, University of Auckland, and Department of Ophthalmology, Auckland Public Hospital, Auckland, New Zealand. Patients with lenticular opacities were recruited from outpatient clinics of a major tertiary referral center for ophthalmology. Patients were included if they had clinically evident, mild to moderate lenticular opacity with no coexisting ocular pathology. Patients were examined using standard preoperative techniques with additional assessment by wavefront aberrometry (Zywave, Bausch & Lomb) and Scheimpflug photography (EAS-1000, Nidek). For comparison, 20 eyes of 10 subjects with no lenticular opacity (control group) were recruited and assessed in an identical manner. Thirty persons were recruited and 40 eyes assessed, 20 with lenticular opacities. Ten eyes had predominantly cortical opacification, and 10 had mainly nuclear opacification. In eyes with predominantly cortical opacification, the mean logMAR uncorrected visual acuity (UCVA) was 0.5 +/- 0.2 (SD) (6/18 Snellen equivalent) and the mean logMAR best spectacle-corrected visual acuity (BSCVA), 0.2 +/- 0.2 (6/9). Analysis of aberrometry data for a 6.0 mm pupil in this group revealed an increase in coma of cosine phase (Z(3), P =.06) and tetrafoil of cosine phase (Z(4), P =.07) compared to eyes in the control group. Eyes with predominantly nuclear opacification had a mean logMAR UCVA of 0.7 +/- 0.2 (6/30) and a logMAR BSCVA of 0.4 +/- 0.2 (6/15). Aberrometry data for this cohort for a 6.0 mm pupil showed a statistically greater amount of spherical aberration (Z(4)(0), P =.001) and tetrafoil of cosine phase (Z(4), P =.005; Z(4)(-4), P =.004). This pilot study suggests that different types of early lenticular opacities induce different wavefront aberration profiles. Predominantly cortical opacification produced an increase in coma and nuclear opacification induced an increase in spherical aberration compared to eyes without opacities. Both types of lenticular opacities also induced a higher amount of tetrafoil. This could explain the significant visual symptoms in patients with early cataract and relatively good high-contrast Snellen acuity.

Untapped Therapeutic Targets in the Tumor Microenvironment

DTIC Science & Technology

2017-08-01

that harbors the resistant cancer cells is simultaneously targeted. Since activated carcinoma-associated fibroblasts (CAFs) have a prominent role in...epithelial cells (IOSE) or HEYA8 epithelial ovarian cancer cells (EOC) using a Transwell membrane. Inverse -log2 values of the Robust Multi-array Average...barrier for drug transport. Thus, simultaneous targeting of CAFs and cancer cells may be necessary for chemotherapeutic accessibility. To identify

High pressure effects on the iron iron oxide and nickel nickel oxide oxygen fugacity buffers

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

Campbell, Andrew J; Danielson, Lisa; Righter, Kevin

The chemical potential of oxygen in natural and experimental samples is commonly reported relative to a specific oxygen fugacity (fO{sub 2}) buffer. These buffers are precisely known at 1 bar, but under high pressures corresponding to the conditions of the deep Earth, oxygen fugacity buffers are poorly calibrated. Reference (1 bar) fO{sub 2} buffers can be integrated to high pressure conditions by integrating the difference in volume between the solid phases, provided that their equations of state are known. In this work, the equations of state and volume difference between the metal-oxide pairs Fe-FeO and Ni-NiO were measured using synchrotronmore » X-ray diffraction in a multi-anvil press and laser heated diamond anvil cells. The results were used to construct high pressure fO{sub 2} buffer curves for these systems. The difference between the Fe-FeO and Ni-NiO buffers is observed to decrease significantly, by several log units, over 80 GPa. The results can be used to improve interpretation of high pressure experiments, specifically Fe-Ni exchange between metallic and oxide phases.« less

Proteome analysis of Lactobacillus helveticus H9 during growth in skim milk.

PubMed

Chen, Y F; Zhao, W J; Wu, R N; Sun, Z H; Zhang, W Y; Wang, J C; Bilige, M; Zhang, H P

2014-12-01

Lactobacillus helveticus H9 was isolated from traditionally fermented yak milk in Tibet (China) with the ability to produce the antihypertensive peptides Val-Pro-Pro (VPP) and Ile-Pro-Pro (IPP) during milk fermentation. To understand the changes in the protein expression of L. helveticus H9, proteome analysis was performed at 3 different growth stages, lag phase (pH 6.1), log phase (pH 5.1), and stationary phase (pH 4.5) using 2-dimensional electrophoresis (2-DE). Further analysis showed that 257 differential protein spots were found and 214 protein spots were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS). The cellular functions of the differentially expressed proteins were complex. Interestingly, the proteolytic system-related proteins aminopeptidase N (PepN), aminopeptidase E (PepE), endopeptidase O2 (PepO2), and oligopeptide transport system permease protein (OppC) were observed only on the maps of pH 5.1 and pH 4.5, which was consistent with the presence of angiotensin I-converting enzyme (ACE)-inhibitory peptides VPP and IPP during these 2 growth stages (log phase and stationary phase). These results, combined with a previous study of gene expression of the proteolytic system, led us to conclude that the Opp transport system, pepE, and pepO2 are likely related to the production of ACE-inhibitory peptides. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Grain coarsening in two-dimensional phase-field models with an orientation field

NASA Astrophysics Data System (ADS)

Korbuly, Bálint; Pusztai, Tamás; Henry, Hervé; Plapp, Mathis; Apel, Markus; Gránásy, László

2017-05-01

In the literature, contradictory results have been published regarding the form of the limiting (long-time) grain size distribution (LGSD) that characterizes the late stage grain coarsening in two-dimensional and quasi-two-dimensional polycrystalline systems. While experiments and the phase-field crystal (PFC) model (a simple dynamical density functional theory) indicate a log-normal distribution, other works including theoretical studies based on conventional phase-field simulations that rely on coarse grained fields, like the multi-phase-field (MPF) and orientation field (OF) models, yield significantly different distributions. In a recent work, we have shown that the coarse grained phase-field models (whether MPF or OF) yield very similar limiting size distributions that seem to differ from the theoretical predictions. Herein, we revisit this problem, and demonstrate in the case of OF models [R. Kobayashi, J. A. Warren, and W. C. Carter, Physica D 140, 141 (2000), 10.1016/S0167-2789(00)00023-3; H. Henry, J. Mellenthin, and M. Plapp, Phys. Rev. B 86, 054117 (2012), 10.1103/PhysRevB.86.054117] that an insufficient resolution of the small angle grain boundaries leads to a log-normal distribution close to those seen in the experiments and the molecular scale PFC simulations. Our paper indicates, furthermore, that the LGSD is critically sensitive to the details of the evaluation process, and raises the possibility that the differences among the LGSD results from different sources may originate from differences in the detection of small angle grain boundaries.

Emission characteristics and vapour/particulate phase distributions of PCDD/F in a hazardous waste incinerator under transient conditions

PubMed Central

Wang, Chao; Cen, Kefa; Ni, Mingjiang; Li, Xiaodong

2018-01-01

Polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD/F) emission characteristics and vapour/particulate phase partitions under three continued operation conditions, i.e. shut-down, start-up and after start-up, were investigated by sampling stack gas. The results indicated that the PCDD/F emission levels were 0.40–18.03 ng I-TEQ Nm−3, much higher than the annual monitoring level (0.016 ng I-TEQ Nm−3). Additionally, the PCDD/F emission levels in start-up were higher than the other two conditions. Furthermore, the PCDD/F congener profiles differed markedly between shut-down and start-up, and the chlorination degree of PCDD/F increased in shut-down and decreased evidently in start-up. Moreover, PCDD/F vapour/particulate phase distributions varied significantly under three transient conditions. The PCDD/F vapour phase proportion decreased as the shut-down process continued, then increased as the start-up process proceeded, finally more than 98% of the PCDD/F congeners were distributed in the vapour phase after start-up. The correlations between log(Cv/Cs) versus log pL0 of each PCDD/F congener in stack gas were disorganized in shut-down, and trend to a linear distribution after start-up. Besides, polychlorinated biphenyl emissions show behaviour similar to that of PCDD/F, and the lower chlorinated congeners have a stronger relationship with 2,3,7,8-PCDD/Fs, such as M1CB and D2CB. PMID:29410821

Gas/particle partitioning of 2-methyltetrols and levoglucosan at an urban site in Denver.

PubMed

Xie, Mingjie; Hannigan, Michael P; Barsanti, Kelley C

2014-01-01

In this study, a medium volume sampler incorporating quartz fiber filters (QFFs) and a polyurethane foam (PUF)/XAD/PUF sandwich (PXP) was used to collect 2-methyltetrols (isoprene tracer) and levoglucosan (biomass burning tracer) in gaseous and particle (PM2.5) phases. The measured gas/particle (G/P) partitioning coefficients (Kp,OMm) of 2-methyltetrols and levoglucosan were calculated and compared to their predicted G/P partitioning coefficients (Kp,OMt) based on an absorptive partitioning theory. The breakthrough experiments showed that gas-phase 2-methyltetrols and levoglucosan could be collected using the PXP or PUF adsorbent alone, with low breakthrough; however, the recoveries of levoglucosan in PXP samples were lower than 70% (average of 51.9–63.3%). The concentration ratios of 2-methyltetrols and levoglucosan in the gas phase to those in the particle phase were often close to or higher than unity in summer, indicating that these polar species are semi-volatile and their G/P partitioning should be considered when applying particle-phase data for source apportionment. The Kp,OMm values of 2-methyltetrols had small variability in summer Denver, which was ascribed to large variations in concentrations of particulate organic matter (5.14 ± 3.29 μg m–3) and small changes in ambient temperature (21.8 ± 4.05 °C). The regression between log Kp,OMm and log Kp,OMt suggested that the absorptive G/P partitioning theory could reasonably predict the measured G/P partitioning of levoglucosan in ambient samples.

Interference with the Mannose Binding and Epithelial Cell Adherence of Escherichia coli by Sublethal Concentrations of Streptomycin

PubMed Central

Eisenstein, Barry I.; Ofek, Itzhak; Beachey, Edwin H.

1979-01-01

When Escherichia coli was grown in sublethal concentrations of streptomycin, mannose binding activity and epithelial cell adherence of the E. coli cultures at stationary phase were significantly reduced in the drug-grown organisms. In a strain whose minimal inhibitory concentrations was 30 μg/ml, the percentage of reduction in mannose binding activity was dose related over a range of concentrations between 0.5 and 10 μg/ml streptomycin. Concomitant with the drug-induced suppression of mannose binding activity, antigenic and ultrastructural alterations on the surface of the drug-grown organisms were observed by agglutination tests and electron microscopy, respectively. The streptomycin effect was reversible, required actively growing organisms, and was most apparent in the early log-phase of growth. High doses of antibiotic were ineffective when added to cultures which had acquired mannose binding activity. An isogenic derivative with high-level resistance to streptomycin was obtained as a single-step mutation from the test E. coli strain. Whereas the isogenic mutant possessed mannose binding activity and adhering ability similar to the parent strain, it was resistant to the streptomycin-induced suppression of the two activities at enormous concentrations (up to 10,000 μg/ml) of streptomycin. Taken together the results suggest that the suppression of epithelial cell adherence and mannose binding activity of E. coli grown in sublethal concentrations of streptomycin is a result of classic mechanisms of drug action upon the bacterial ribosome. The results support the possibility that antibiotics may act through mechanisms other than inhibition of growth and bacterial killing to eradicate bacteria from mucosal surfaces. Images PMID:376556

Biodosimetry as a New Paradigm for Determination of Radiation Risks and Risk-Mitigation in Astronauts Exposed to Space Radiation

NASA Technical Reports Server (NTRS)

Richmond, Robert; Cruz, Angela; Bors, Karen

2004-01-01

Predicting risk of cancer in astronauts exposed to space radiation is challenging partly because uncertainties of absorption of dose and the processing of dose-related damage at the cellular level degrade the confidence of predicting the expression of cancer. Cellular biodosimeters that simultaneously report: 1) the quantity of absorbed dose after exposure to ionizing radiation, 2) the quality of radiation delivering that dose, and 3) the macromolecular profiles related to malignant transformation in cells absorbing that dose would therefore be useful. An approach to such a multiparametric biodosimeter will be reported, This is the demonstration of two dose-responsive field-effects of enhanced protein-expression. In one case, expression of keratin 18 (K18) in cultures of human mammary epithelial cells (HMEC) irradiated with cesium-137 gamma-rays is enhanced following exposure of log phase cells to relatively low doses of 30 to 90 cGy. K18 has been reported by a marker for tumor staging and for apoptosis. In the second case, expression of connexin 43 (Cx43) is increased in irradiated stationary phase cultures of HMEC, indicating enhanced formation of gap junctions. Gap junctions have been reported to be involved in bystander effects following irradiation. It is a biodosimeter for assessing radiogenic damage. It is suggested further that such biomolecular dosimetry may introduce a new paradigm for assessing cancer risk and risk-mitigation in individuals, a requirement for managing radiation health in astronauts during extended missions in space. This new paradigm is built upon the statistical power provided by the use of functional genomics and proteomics represented in combined gene- and protein-expression assays.

Interactive tools for inpatient medication tracking: a multi-phase study with cardiothoracic surgery patients

PubMed Central

Woollen, Janet; Prey, Jennifer; Restaino, Susan; Bakken, Suzanne; Feiner, Steven; Sackeim, Alexander; Vawdrey, David K

2016-01-01

Objective Prior studies of computing applications that support patients’ medication knowledge and self-management offer valuable insights into effective application design, but do not address inpatient settings. This study is the first to explore the design and usefulness of patient-facing tools supporting inpatient medication management and tracking. Materials and Methods We designed myNYP Inpatient, a custom personal health record application, through an iterative, user-centered approach. Medication-tracking tools in myNYP Inpatient include interactive views of home and hospital medication data and features for commenting on these data. In a two-phase pilot study, patients used the tools during cardiothoracic postoperative care at Columbia University Medical Center. In Phase One, we provided 20 patients with the application for 24–48 h and conducted a closing interview after this period. In Phase Two, we conducted semi-structured interviews with 12 patients and 5 clinical pharmacists who evaluated refinements to the tools based on the feedback received during Phase One. Results Patients reported that the medication-tracking tools were useful. During Phase One, 14 of the 20 participants used the tools actively, to review medication lists and log comments and questions about their medications. Patients’ interview responses and audit logs revealed that they made frequent use of the hospital medications feature and found electronic reporting of questions and comments useful. We also uncovered important considerations for subsequent design of such tools. In Phase Two, the patients and pharmacists participating in the study confirmed the usability and usefulness of the refined tools. Conclusions Inpatient medication-tracking tools, when designed to meet patients’ needs, can play an important role in fostering patient participation in their own care and patient-provider communication during a hospital stay. PMID:26744489

Phage Inactivation of Listeria monocytogenes on San Daniele Dry-Cured Ham and Elimination of Biofilms from Equipment and Working Environments

PubMed Central

Iacumin, Lucilla; Manzano, Marisa; Comi, Giuseppe

2016-01-01

The anti-listerial activity of generally recognized as safe (GRAS) bacteriophage Listex P100 (phage P100) was demonstrated in broths and on the surface of slices of dry-cured ham against 5 strains or serotypes (i.e., Scott A, 1/2a, 1/2b, and 4b) of Listeria monocytogenes. In a broth model system, phage P100 at a concentration equal to or greater than 7 log PFU/mL completely inhibited 2 log CFU/cm2 or 3 log CFU/cm2 of L. monocytogenes growth at 30 °C. The temperature (4, 10, 20 °C) seemed to influence P100 activity; the best results were obtained at 4 °C. On dry-cured ham slices, a P100 concentration ranging from 5 to 8 log PFU/cm2 was required to obtain a significant reduction in L. monocytogenes. At 4, 10, and 20 °C, an inoculum of 8 log PFU/cm2 was required to completely eliminate 2 log L. monocytogenes/cm2 and to reach the absence in 25 g product according to USA food law. Conversely, it was impossible to completely eradicate L. monocytogenes with an inoculum of approximately of 3.0 and 4.0 log CFU/cm2 and with a P100 inoculum ranging from 1 to 7 log PFU/cm2. P100 remained stable on dry-cured ham slices over a 14-day storage period, with only a marginal loss of 0.2 log PFU/cm2 from an initial phage treatment of approximately 8 log PFU/cm2. Moreover, phage P100 eliminated free L. monocytogenes cells and biofilms on the machinery surfaces used for dry-cured ham production. These findings demonstrate that the GRAS bacteriophage Listex P100 at level of 8 log PFU/cm2 is listericidal and useful for reducing the L. monocytogenes concentration or eradicating the bacteria from dry-cured ham. PMID:27681898

Inoculation onto solid surfaces protects Salmonella spp. during acid challenge: a model study using polyethersulfone membranes.

PubMed

Gawande, Purushottam V; Bhagwat, Arvind A

2002-01-01

Salmonellae are the most frequently reported cause of outbreaks of food-borne gastroenteritis in the United States. In clinical trials, the oral infective dose (ID) for healthy volunteers was estimated to be approximately 1 million cells. However, in reports from various outbreaks, the ID of Salmonella species associated with solid foods was estimated to be as few as 100 cells. We found that fresh-cut produce surfaces not only provided suitable solid support for pathogen attachment but also played a critical role in increasing the acid tolerance of the pathogen. However the acidic nature of certain produce played no role in making salmonellae resistant to stomach acidity. Inoculation onto fresh-cut produce surfaces, as well as onto inert surfaces, such as polyethersulfone membranes and tissue paper, increased the survival of salmonellae during acid challenge (50 mM Na-citrate, pH 3.0; 37 degrees C; 2 h) by 4 to 5 log units. Acid challenge experiments using cells inoculated onto polyethersulfone membranes provided a model system suitable for studying the underlying fundamentals of the protection that occurs when Salmonella strains are associated with solid foods. The surface-associated acid protection, which was observed in several Salmonella strains, required de novo protein synthesis and was independent of stationary-phase sigma transcription factor.

Inoculation onto Solid Surfaces Protects Salmonella spp. during Acid Challenge: a Model Study Using Polyethersulfone Membranes

PubMed Central

Gawande, Purushottam V.; Bhagwat, Arvind A.

2002-01-01

Salmonellae are the most frequently reported cause of outbreaks of food-borne gastroenteritis in the United States. In clinical trials, the oral infective dose (ID) for healthy volunteers was estimated to be approximately 1 million cells. However, in reports from various outbreaks, the ID of Salmonella species associated with solid foods was estimated to be as few as 100 cells. We found that fresh-cut produce surfaces not only provided suitable solid support for pathogen attachment but also played a critical role in increasing the acid tolerance of the pathogen. However the acidic nature of certain produce played no role in making salmonellae resistant to stomach acidity. Inoculation onto fresh-cut produce surfaces, as well as onto inert surfaces, such as polyethersulfone membranes and tissue paper, increased the survival of salmonellae during acid challenge (50 mM Na-citrate, pH 3.0; 37°C; 2 h) by 4 to 5 log units. Acid challenge experiments using cells inoculated onto polyethersulfone membranes provided a model system suitable for studying the underlying fundamentals of the protection that occurs when Salmonella strains are associated with solid foods. The surface-associated acid protection, which was observed in several Salmonella strains, required de novo protein synthesis and was independent of stationary-phase sigma transcription factor. PMID:11772613

Degradation of milk-based bioactive peptides by yogurt fermentation bacteria.

PubMed

Paul, M; Somkuti, G A

2009-09-01

To analyse the effect of cell-associated peptidases in yogurt starter culture strains Lactobacillus delbrueckii ssp. bulgaricus (LB) and Streptococcus thermophilus (ST) on milk-protein-based antimicrobial and hypotensive peptides in order to determine their survival in yogurt-type dairy foods. The 11mer antimicrobial and 12mer hypotensive milk-protein-derived peptides were incubated with mid-log cells of LB and ST, which are required for yogurt production. Incubations were performed at pH 4.5 and 7.0, and samples removed at various time points were analysed by reversed-phase high-performance liquid chromatography (RP-HPLC). The peptides remained mostly intact at pH 4.5 in the presence of ST strains and moderately digested by exposure to LB cells. Peptide loss occurred more rapidly and was more extensive after incubation at pH 7.0. The 11mer and 12mer bioactive peptides may be added at the end of the yogurt-making process when the pH level has dropped to 4.5, limiting the overall extent of proteolysis. The results show the feasibility of using milk-protein-based antimicrobial and hypotensive peptides as food supplements to improve the health-promoting qualities of liquid and semi-solid dairy foods prepared by the yogurt fermentation process.

Solubility enhancement of dioxins and PCBs by surfactant monomers and micelles quantified with polymer depletion techniques.

PubMed

Schacht, Veronika J; Grant, Sharon C; Escher, Beate I; Hawker, Darryl W; Gaus, Caroline

2016-06-01

Partitioning of super-hydrophobic organic contaminants (SHOCs) to dissolved or colloidal materials such as surfactants can alter their behaviour by enhancing apparent aqueous solubility. Relevant partition constants are, however, challenging to quantify with reasonable accuracy. Partition constants to colloidal surfactants can be measured by introducing a polymer (PDMS) as third phase with known PDMS-water partition constant in combination with the mass balance approach. We quantified partition constants of PCBs and PCDDs (log KOW 5.8-8.3) between water and sodium dodecyl sulphate monomers (KMO) and micelles (KMI). A refined, recently introduced swelling-based polymer loading technique allowed highly precise (4.5-10% RSD) and fast (<24 h) loading of SHOCs into PDMS, and due to the miniaturisation of batch systems equilibrium was reached in <5 days for KMI and <3 weeks for KMO. SHOC losses to experimental surfaces were substantial (8-26%) in monomer solutions, but had a low impact on KMO (0.10-0.16 log units). Log KMO for PCDDs (4.0-5.2) were approximately 2.6 log units lower than respective log KMI, which ranged from 5.2 to 7.0 for PCDDs and 6.6-7.5 for PCBs. The linear relationship between log KMI and log KOW was consistent with more polar and moderately hydrophobic compounds. Apparent solubility increased with increasing hydrophobicity and was highest in micelle solutions. However, this solubility enhancement was also considerable in monomer solutions, up to 200 times for OCDD. Given the pervasive presence of surfactant monomers in typical field scenarios, these data suggest that low surfactant concentrations may be effective long-term facilitators for subsurface transport of SHOCs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Campylobacter jejuni CsrA Regulates Metabolic and Virulence Associated Proteins and Is Necessary for Mouse Colonization.

PubMed

Fields, Joshua A; Li, Jiaqi; Gulbronson, Connor J; Hendrixson, David R; Thompson, Stuart A

2016-01-01

Campylobacter jejuni infection is a leading bacterial cause of gastroenteritis and a common antecedent leading to Gullian-Barré syndrome. Our previous data suggested that the RNA-binding protein CsrA plays an important role in regulating several important phenotypes including motility, biofilm formation, and oxidative stress resistance. In this study, we compared the proteomes of wild type, csrA mutant, and complemented csrA mutant C. jejuni strains in an effort to elucidate the mechanisms by which CsrA affects virulence phenotypes. The putative CsrA regulon was more pronounced at stationary phase (111 regulated proteins) than at mid-log phase (25 regulated proteins). Proteins displaying altered expression in the csrA mutant included diverse metabolic functions, with roles in amino acid metabolism, TCA cycle, acetate metabolism, and various other cell processes, as well as pathogenesis-associated characteristics such as motility, chemotaxis, oxidative stress resistance, and fibronectin binding. The csrA mutant strain also showed altered autoagglutination kinetics when compared to the wild type. CsrA specifically bound the 5' end of flaA mRNA, and we demonstrated that CsrA is a growth-phase dependent repressor of FlaA expression. Finally, the csrA mutant exhibited reduced ability to colonize in a mouse model when in competition with the wild type, further underscoring the role of CsrA in C. jejuni colonization and pathogenesis.

Campylobacter jejuni CsrA Regulates Metabolic and Virulence Associated Proteins and Is Necessary for Mouse Colonization

PubMed Central

Fields, Joshua A.; Li, Jiaqi; Gulbronson, Connor J.; Hendrixson, David R.

2016-01-01

Campylobacter jejuni infection is a leading bacterial cause of gastroenteritis and a common antecedent leading to Gullian-Barré syndrome. Our previous data suggested that the RNA-binding protein CsrA plays an important role in regulating several important phenotypes including motility, biofilm formation, and oxidative stress resistance. In this study, we compared the proteomes of wild type, csrA mutant, and complemented csrA mutant C. jejuni strains in an effort to elucidate the mechanisms by which CsrA affects virulence phenotypes. The putative CsrA regulon was more pronounced at stationary phase (111 regulated proteins) than at mid-log phase (25 regulated proteins). Proteins displaying altered expression in the csrA mutant included diverse metabolic functions, with roles in amino acid metabolism, TCA cycle, acetate metabolism, and various other cell processes, as well as pathogenesis-associated characteristics such as motility, chemotaxis, oxidative stress resistance, and fibronectin binding. The csrA mutant strain also showed altered autoagglutination kinetics when compared to the wild type. CsrA specifically bound the 5’ end of flaA mRNA, and we demonstrated that CsrA is a growth-phase dependent repressor of FlaA expression. Finally, the csrA mutant exhibited reduced ability to colonize in a mouse model when in competition with the wild type, further underscoring the role of CsrA in C. jejuni colonization and pathogenesis. PMID:27257952

An integrated remote sensing and GIS approach for monitoring areas affected by selective logging: A case study in northern Mato Grosso, Brazilian Amazon

NASA Astrophysics Data System (ADS)

Grecchi, Rosana Cristina; Beuchle, René; Shimabukuro, Yosio Edemir; Aragão, Luiz E. O. C.; Arai, Egidio; Simonetti, Dario; Achard, Frédéric

2017-09-01

Forest cover disturbances due to processes such as logging and forest fires are a widespread issue especially in the tropics, and have heavily affected forest biomass and functioning in the Brazilian Amazon in the past decades. Satellite remote sensing has played a key role for assessing logging activities in this region; however, there are still remaining challenges regarding the quantification and monitoring of these processes affecting forested lands. In this study, we propose a new method for monitoring areas affected by selective logging in one of the hotspots of Mato Grosso state in the Brazilian Amazon, based on a combination of object-based and pixel-based classification approaches applied on remote sensing data. Logging intensity and changes over time are assessed within grid cells of 300 m × 300 m spatial resolution. Our method encompassed three main steps: (1) mapping forest/non-forest areas through an object-based classification approach applied to a temporal series of Landsat images during the period 2000-2015, (2) mapping yearly logging activities from soil fraction images on the same Landsat data series, and (3) integrating information from previous steps within a regular grid-cell of 300 m × 300 m in order to monitor disturbance intensities over this 15-years period. The overall accuracy of the baseline forest/non-forest mask (year 2000) and of the undisturbed vs disturbed forest (for selected years) were 93% and 84% respectively. Our results indicate that annual forest disturbance rates, mainly due to logging activities, were higher than annual deforestation rates during the whole period of study. The deforested areas correspond to circa 25% of the areas affected by forest disturbances. Deforestation rates were highest from 2001 to 2005 and then decreased considerably after 2006. In contrast, the annual forest disturbance rates show high temporal variability with a slow decrease over the 15-year period, resulting in a significant increase of the ratio between disturbed and deforested areas. Although the majority of the areas, which have been affected by selective logging during the period 2000-2014, were not deforested by 2015, more than 70% of the deforested areas in 2015 had been at least once identified as disturbed forest during that period.

An integrated remote sensing and GIS approach for monitoring areas affected by selective logging: A case study in northern Mato Grosso, Brazilian Amazon.

PubMed

Grecchi, Rosana Cristina; Beuchle, René; Shimabukuro, Yosio Edemir; Aragão, Luiz E O C; Arai, Egidio; Simonetti, Dario; Achard, Frédéric

2017-09-01

Forest cover disturbances due to processes such as logging and forest fires are a widespread issue especially in the tropics, and have heavily affected forest biomass and functioning in the Brazilian Amazon in the past decades. Satellite remote sensing has played a key role for assessing logging activities in this region; however, there are still remaining challenges regarding the quantification and monitoring of these processes affecting forested lands. In this study, we propose a new method for monitoring areas affected by selective logging in one of the hotspots of Mato Grosso state in the Brazilian Amazon, based on a combination of object-based and pixel-based classification approaches applied on remote sensing data. Logging intensity and changes over time are assessed within grid cells of 300 m × 300 m spatial resolution. Our method encompassed three main steps: (1) mapping forest/non-forest areas through an object-based classification approach applied to a temporal series of Landsat images during the period 2000-2015, (2) mapping yearly logging activities from soil fraction images on the same Landsat data series, and (3) integrating information from previous steps within a regular grid-cell of 300 m × 300 m in order to monitor disturbance intensities over this 15-years period. The overall accuracy of the baseline forest/non-forest mask (year 2000) and of the undisturbed vs disturbed forest (for selected years) were 93% and 84% respectively. Our results indicate that annual forest disturbance rates, mainly due to logging activities, were higher than annual deforestation rates during the whole period of study. The deforested areas correspond to circa 25% of the areas affected by forest disturbances. Deforestation rates were highest from 2001 to 2005 and then decreased considerably after 2006. In contrast, the annual forest disturbance rates show high temporal variability with a slow decrease over the 15-year period, resulting in a significant increase of the ratio between disturbed and deforested areas. Although the majority of the areas, which have been affected by selective logging during the period 2000-2014, were not deforested by 2015, more than 70% of the deforested areas in 2015 had been at least once identified as disturbed forest during that period.

Incidence of Clostridium perfringens in commercially produced cured raw meat product mixtures and behavior in cooked products during chilling and refrigerated storage.

PubMed

Taormina, Peter J; Bartholomew, Gene W; Dorsa, Warren J

2003-01-01

A total of 445 whole-muscle and ground or emulsified raw pork, beef, and chicken product mixtures acquired from industry sources were monitored over a 10-month period for vegetative and spore forms of Clostridium perfringens. Black colonies that formed on Shahidi-Ferguson perfringens (SFP) agar after 24 h at 37 degrees C were considered presumptive positive. Samples that were positive after a 15-min heat shock at 75 degrees C were considered presumptive positive for spores. Of 194 cured whole-muscle samples, 1.6% were positive; spores were not detected from those samples. Populations of vegetative cells did not exceed 1.70 log10 CFU/g and averaged 1.56 log10 CFU/g. Of 152 cured ground or emulsified samples, 48.7% were positive, and 5.3% were positive for spores. Populations of vegetative cells did not exceed 2.72 log10 CFU/g and averaged 1.98 log10 CFU/g; spores did not exceed 2.00 log10 CFU/g and averaged 1.56 log10 CFU/g. Raw bologna (70% chicken), chunked ham with emulsion, and whole-muscle ham product mixtures were inoculated with C. perfringens spores (ATCC 12916, ATCC 3624, FD1041, and two product isolates) to ca. 3.0 log10 CFU/g before being subjected either to thermal processes mimicking cooking and chilling regimes determined by in-plant temperature probing or to cooking and extended chilling regimes. Populations of C. perfringens were recovered on SFP from each product at the peak cook temperatures, at 54.4, 26.7, and 7.2 degrees C, and after up to 14 days of storage under vacuum at 4.4 degrees C. In each product, populations remained relatively unchanged during chilling from 54.4 to 7.2 degrees C and declined slightly during refrigerated storage. These findings indicate processed meat products cured with sodium nitrite are not at risk for the growth of C. perfringens during extended chilling and cold storage.

Reduction of spiked porcine circovirus during the manufacture of a Vero cell-derived vaccine.

PubMed

Lackner, Cornelia; Leydold, Sandra M; Modrof, Jens; Farcet, Maria R; Grillberger, Leopold; Schäfer, Birgit; Anderle, Heinz; Kreil, Thomas R

2014-04-11

Porcine circovirus-1 (PCV1) was recently identified as a contaminant in live Rotavirus vaccines, which was likely caused by contaminated porcine trypsin. The event triggered the development of new regulatory guidance on the use of porcine trypsin which shall ensure that cell lines and porcine trypsin in use are free from PCV1. In addition, manufacturing processes of biologicals other than live vaccines include virus clearance steps that may prevent and mitigate any potential virus contamination of product. In this work, artificial spiking of down-scaled models for the manufacturing process of an inactivated pandemic influenza virus vaccine were used to investigate inactivation of PCV1 and the physico-chemically related porcine parvovirus (PPV) by formalin and ultraviolet-C (UV-C) treatment as well as removal by the purification step sucrose gradient ultracentrifugation. A PCV1 infectivity assay, using a real-time PCR infectivity readout was established. The formalin treatment (0.05% for 48h) showed substantial inactivation for both PCV1 and PPV with reduction factors of 3.0log10 and 6.8log10, respectively, whereas UV-C treatment resulted in complete PPV (≥5.9log10) inactivation already at a dose of 13mJ/cm but merely 1.7log10 at 24mJ/cm(2) for PCV1. The UV-C inactivation results with PPV were confirmed using minute virus of mice (MVM), indicating that parvoviruses are far more sensitive to UV-C than PCV1. The sucrose density gradient ultracentrifugation also contributed to PCV1 clearance with a reduction factor of 2log10. The low pH treatment during the production of procine trypsin was investigated and showed effective inactivation for both PCV1 (4.5log10) and PPV (6.4log10). In conclusion, PCV1 in general appears to be more resistant to virus inactivation than PPV. Still, the inactivated pandemic influenza vaccine manufacturing process provides for robust virus reduction, in addition to the already implemented testing for PCV1 to avoid any contaminations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Interaction of estradiol and high density lipoproteins on proliferation of the human breast cancer cell line MCF-7 adapted to grow in serum free conditions

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

Jozan, S.; Faye, J.C.; Tournier, J.F.

1985-11-27

The responsiveness of the human mammary carcinoma cell line MCF-7 to estradiol and tamoxifen treatment has been studied in different culture conditions. Cells from exponentially growing cultures were compared with cells in their initial cycles after replating from confluent cultures (''confluent-log'' cells). It has been observed that estradiol stimulation of tritiated thymidine incorporation decreases with cell density and that ''confluent-log'' cells are estrogen unresponsive for a period of four cell cycles in serum-free medium conditions. On the other hand, growth of cells replated from exponentially growing, as well as from confluent cultures, can be inhibited by tamoxifen or a combinedmore » treatment with tamoxifen and the progestin levonorgestrel. This growth inhibitory effect can be rescued by estradiol when cells are replated from exponentially growing cultures. The growth inhibitory effect cannot be rescued by estradiol alone (10(-10) to 10(-8) M) when cells are replated from confluent cultures. In this condition, the addition of steroid depleted serum is necessary to reverse the state of estradiol unresponsiveness. Serum can be replaced by high density lipoproteins but not by low density lipoproteins or lipoprotein deficient serum. The present data show that estradiol and HDL interact in the control of MCF-7 cell proliferation.« less

Impact of preheating on the behavior of Listeria monocytogenes in a broth that mimics Camembert cheese composition.

PubMed

Helloin, E; Bouttefroy, A; Gay, M; Phan Thanh, L

2003-02-01

The effect of preheating on the survival of L. monocytogenes in Richard's broth, which mimics the composition of Camembert cheese composition, was examined. Experiments were carried out to reproduce contamination of cheese with environmental heat-stressed cells of L. monocytogenes surviving hot-cleaning procedures. Cells in mid-log phase were heated for 30 min at 56 degrees C before being inoculated into Richard's broth. The pHs and temperatures of Richard's broth were chosen to recreate the conditions of curd dripping (pH 5, 25 degrees C), of the beginning of cheese ripening (pH 5, 12 degrees C), and of the beginning (pH 5, 4 degrees C) and the end (pH 7, 4 degrees C) of cheese storage. Immediately after heat treatment, the viability loss was especially high for strain 306715, which exhibited only 0.6% +/- 0.2% survival, compared with 22% +/- 8.7% for strain EGD. The percentages of the surviving heated cells that were injured were 93% +/- 8% for strain 306715 and 98% +/- 3% for strain EGD. The destruction of the surviving L. monocytogenes cells was accelerated when they encountered the pH and temperature conditions of Camembert cheese during manufacturing, ripening, and cold storage (pH 5 at 25, 12, and 4 degrees C, respectively). The multiplication of the surviving heated cells was retarded under favorable growth conditions similar to those of storage by the distributor and the consumer (pH 7 at 4 and 12 degrees C, respectively).

Protection of Lactobacillus acidophilus NRRL-B 4495 under in vitro gastrointestinal conditions with whey protein/pullulan microcapsules.

PubMed

Çabuk, Burcu; Tellioğlu Harsa, Şebnem

2015-12-01

In this research, whey protein/pullulan (WP/pullulan) microcapsules were developed in order to assess its protective effect on the viability of Lactobacillus acidophilus NRRL-B 4495 under in vitro gastrointestinal conditions. Results demonstrated that WP/pullulan microencapsulated cells exhibited significantly (p ≤ 0.05) higher resistance to simulated gastric acid and bile salt. Pullulan incorporation into protein wall matrix resulted in improved survival as compared to free cells after 3 h incubation in simulated gastric solution. Moreover WP/pullulan microcapsules were found to release over 70% of encapsulated L. acidophilus NRRL-B 4495 cells within 1 h. The effect of encapsulation during refrigerated storage was also studied. Free bacteria exhibited 3.96 log reduction while, WP/pullulan encapsulated bacteria showed 1.64 log reduction after 4 weeks of storage. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Brominated flame retardants in the urban atmosphere of Northeast China: concentrations, temperature dependence and gas-particle partitioning.

PubMed

Qi, Hong; Li, Wen-Long; Liu, Li-Yan; Song, Wei-Wei; Ma, Wan-Li; Li, Yi-Fan

2014-09-01

57 pairs of air samples (gas and particle phases) were collected using a high volume air sampler in a typical city of Northeast China. Brominated flame retardants (BFRs) including 13 polybrominated diphenyl ethers (PBDEs, including BDEs 17, 28, 47, 49, 66, 85, 99, 100, 138, 153, 154, 183, and 209) and 9 alternative BFRs (p-TBX, PBBZ, PBT, PBEB, DPTE, HBBZ, γ-HBCD, BTBPE, and DBDPE) were analyzed. The annual average total concentrations of the 13 PBDEs and the 9 alternative BFRs were 69 pg/m(3) and 180 pg/m(3), respectively. BDE 209 and γ-HBCD were the dominant congeners, according to the one-year study. The partial pressure of BFRs in the gas phase was significantly correlated with the ambient temperature, except for BDE 85, γ-HBCD and DBDPE, indicating the important influence of ambient temperature on the behavior of BFRs in the atmosphere. It was found that the gas-particle partitioning coefficients (logKp) for most low molecular weight BFRs were highly temperature dependent as well. Gas-particle partitioning coefficients (logKp) also correlated with the sub-cooled liquid vapor pressure (logPL(o)). Our results indicated that absorption into organic matter is the main control mechanism for the gas-particle partitioning of atmospheric PBDEs. Copyright © 2014 Elsevier B.V. All rights reserved.

Synergetic effects of ultrasound and slightly acidic electrolyzed water against Staphylococcus aureus evaluated by flow cytometry and electron microscopy.

PubMed

Li, Jiao; Ding, Tian; Liao, Xinyu; Chen, Shiguo; Ye, Xingqian; Liu, Donghong

2017-09-01

This study evaluated the synergetic effects of ultrasound and slightly acidic electrolyzed water (SAEW) on the inactivation of Staphylococcus aureus using flow cytometry and electron microscopy. The individual ultrasound treatment for 10min only resulted in 0.36logCFU/mL reductions of S. aureus, while the SAEW treatment alone for 10min resulted in 3.06logCFU/mL reductions. The log reductions caused by combined treatment were enhanced to 3.68logCFU/mL, which were greater than the sum of individual treatments. This phenomenon was referred to as synergistic effects. FCM analysis distinguished live and dead cells as well as revealed dynamic changes in the physiological states of S. aureus after different treatments. The combined treatment greatly reduced the number of viable but nonculturable (VBNC) bacteria to 0.07%; in contrast, a single ultrasound treatment for 10min induced the formation of VBNC cells to 45.75%. Scanning and transmission electron microscopy analysis revealed that greater damage to the appearance and ultrastructure of S. aureus were achieved after combined ultrasound-SAEW treatment compared to either treatment alone. These results indicated that combining ultrasound with SAEW is a promising sterilization technology with potential uses for environmental remediation and food preservation. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of Anticoagulant, Processing Delay, and Assay Method (Branched DNA versus Reverse Transcriptase PCR) on Measurement of Human Immunodeficiency Virus Type 1 RNA Levels in Plasma

PubMed Central

Kirstein, Lynn M.; Mellors, John W.; Rinaldo, Charles R.; Margolick, Joseph B.; Giorgi, Janis V.; Phair, John P.; Dietz, Edith; Gupta, Phalguni; Sherlock, Christopher H.; Hogg, Robert; Montaner, J. S. G.; Muñoz, Alvaro

1999-01-01

We conducted two studies to determine the potential influence of delays in blood processing, type of anticoagulant, and assay method on human immunodeficiency virus type 1 (HIV-1) RNA levels in plasma. The first was an experimental study in which heparin- and EDTA-anticoagulated blood samples were collected from 101 HIV-positive individuals and processed to plasma after delays of 2, 6, and 18 h. HIV-1 RNA levels in each sample were then measured by both branched-DNA (bDNA) and reverse transcriptase PCR (RT-PCR) assays. Compared to samples processed within 2 h, the loss (decay) of HIV-1 RNA in heparinized blood was significant (P < 0.05) but small after 6 h (bDNA assay, −0.12 log10 copies/ml; RT-PCR, −0.05 log10 copies/ml) and after 18 h (bDNA assay, −0.27 log10 copies/ml; RT-PCR, −0.15 log10 copies/ml). Decay in EDTA-anticoagulated blood was not significant after 6 h (bDNA assay, −0.002 log10 copies/ml; RT-PCR, −0.02 log10 copies/ml), but it was after 18 h (bDNA assay, −0.09 log10 copies/ml; RT-PCR, −0.09 log10 copies/ml). Only 4% of samples processed after 6 h lost more than 50% (≥0.3 log10 copies/ml) of the HIV-1 RNA, regardless of the anticoagulant or the assay that was used. The second study compared HIV-1 RNA levels in samples from the Multicenter AIDS Cohort Study (MACS; samples were collected in heparin-containing tubes in 1985, had a 6-h average processing delay, and were assayed by bDNA assay) and the British Columbia Drug Treatment Program (BCDTP) (collected in EDTA- or acid citrate dextrose-containing tubes in 1996 and 1997, had a 2-h maximum processing delay, and were assayed by RT-PCR). HIV-1 RNA levels in samples from the two cohorts were not significantly different after adjusting for CD4+-cell count and converting bDNA assay values to those corresponding to the RT-PCR results. In summary, the decay of HIV-1 RNA measured in heparinized blood after 6 h was small (−0.05 to −0.12 log10 copies/ml), and the minor impact of this decay on HIV-1 RNA concentrations in archived plasma samples of the MACS was confirmed by the similarity of CD4+-cell counts and assay-adjusted HIV-1 RNA concentrations in the MACS and BCDTP. PMID:10405379

Laboratory tank studies of a single species of phytoplankton using a remote sensing fluorosensor

NASA Technical Reports Server (NTRS)

Brown, C. A., Jr.; Jarrett, O., Jr.; Farmer, F. H.

1981-01-01

Phytoplankton were grown in the laboratory for the purpose of testing a remote fluorosensor. The fluorosensor uses a unique four-wavelength dye laser system to excite phytoplankton bearing chlorophyll and to measure the chlorophyll fluorescence generated by this excitation. Six different species were tested, one at a time, and each was grown two to four times. Fluorescence measured by the fluorosensor provides good quantitative measurement of chlorophyll concentrations for all species tested while the cultures were in log phase growth. Fluorescene cross section ratios obtained in the single species tank tests support the hypothesis that the shape of the fluorescence cross section curve remains constant with the species (differences in fluorescence cross section ratios are a basis for determining composition of phytoplankton according to color group when a multiwavelength source of excitation is used. Linear relationships exist between extracted chlorophyll concentration and fluorescence measured by the remote fluorosensor during the log phase growth of phytoplankton cultures tested.

Automatic method for evaluating the activity of sourdough strains based on gas pressure measurements.

PubMed

Wick, M; Vanhoutte, J J; Adhemard, A; Turini, G; Lebeault, J M

2001-04-01

A new method is proposed for the evaluation of the activity of sourdough strains, based on gas pressure measurements in closed air-tight reactors. Gas pressure and pH were monitored on-line during the cultivation of commercial yeasts and heterofermentative lactic acid bacteria on a semi-synthetic medium with glucose as the major carbon source. Relative gas pressure evolution was compared both to glucose consumption and to acidification and growth. It became obvious that gas pressure evolution is related to glucose consumption kinetics. For each strain, a correlation was made between maximum gas pressure variation and amount of glucose consumed. The mass balance of CO2 in both liquid and gas phase demonstrated that around 90% of CO2 was recovered. Concerning biomass production, a linear relationship was found between log colony-forming units/ml and log pressure for both yeasts and bacteria during the exponential phase; and for yeasts, relative gas pressure evolution also followed optical density variation.

Propagation of electromagnetic waves in a turbulent medium

NASA Technical Reports Server (NTRS)

Canuto, V. M.; Hartke, G. J.

1986-01-01

Theoretical modeling of the wealth of experimental data on propagation of electromagnetic radiation through turbulent media has centered on the use of the Heisenberg-Kolmogorov (HK) model, which is, however, valid only for medium to small sized eddies. Ad hoc modifications of the HK model to encompass the large-scale region of the eddy spectrum have been widely used, but a sound physical basis has been lacking. A model for large-scale turbulence that was recently proposed is applied to the above problem. The spectral density of the temperature field is derived and used to calculate the structure function of the index of refraction N. The result is compared with available data, yielding a reasonably good fit. The variance of N is also in accord with the data. The model is also applied to propagation effects. The phase structure function, covariance of the log amplitude, and variance of the log intensity are calculated. The calculated phase structure function is in excellent agreement with available data.

A Log-Scaling Fault Tolerant Agreement Algorithm for a Fault Tolerant MPI

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

Hursey, Joshua J; Naughton, III, Thomas J; Vallee, Geoffroy R

The lack of fault tolerance is becoming a limiting factor for application scalability in HPC systems. The MPI does not provide standardized fault tolerance interfaces and semantics. The MPI Forum's Fault Tolerance Working Group is proposing a collective fault tolerant agreement algorithm for the next MPI standard. Such algorithms play a central role in many fault tolerant applications. This paper combines a log-scaling two-phase commit agreement algorithm with a reduction operation to provide the necessary functionality for the new collective without any additional messages. Error handling mechanisms are described that preserve the fault tolerance properties while maintaining overall scalability.

A Single HIV-1 Cluster and a Skewed Immune Homeostasis Drive the Early Spread of HIV among Resting CD4+ Cell Subsets within One Month Post-Infection

PubMed Central

Avettand-Fenoël, Véronique; Nembot, Georges; Mélard, Adeline; Blanc, Catherine; Lascoux-Combe, Caroline; Slama, Laurence; Allegre, Thierry; Allavena, Clotilde; Yazdanpanah, Yazdan; Duvivier, Claudine; Katlama, Christine; Goujard, Cécile; Seksik, Bao Chau Phung; Leplatois, Anne; Molina, Jean-Michel; Meyer, Laurence; Autran, Brigitte; Rouzioux, Christine

2013-01-01

Optimizing therapeutic strategies for an HIV cure requires better understanding the characteristics of early HIV-1 spread among resting CD4+ cells within the first month of primary HIV-1 infection (PHI). We studied the immune distribution, diversity, and inducibility of total HIV-DNA among the following cell subsets: monocytes, peripheral blood activated and resting CD4 T cells, long-lived (naive [TN] and central-memory [TCM]) and short-lived (transitional-memory [TTM] and effector-memory cells [TEM]) resting CD4+T cells from 12 acutely-infected individuals recruited at a median 36 days from infection. Cells were sorted for total HIV-DNA quantification, phylogenetic analysis and inducibility, all studied in relation to activation status and cell signaling. One month post-infection, a single CCR5-restricted viral cluster was massively distributed in all resting CD4+ subsets from 88% subjects, while one subject showed a slight diversity. High levels of total HIV-DNA were measured among TN (median 3.4 log copies/million cells), although 10-fold less (p = 0.0005) than in equally infected TCM (4.5), TTM (4.7) and TEM (4.6) cells. CD3−CD4+ monocytes harbored a low viral burden (median 2.3 log copies/million cells), unlike equally infected resting and activated CD4+ T cells (4.5 log copies/million cells). The skewed repartition of resting CD4 subsets influenced their contribution to the pool of resting infected CD4+T cells, two thirds of which consisted of short-lived TTM and TEM subsets, whereas long-lived TN and TCM subsets contributed the balance. Each resting CD4 subset produced HIV in vitro after stimulation with anti-CD3/anti-CD28+IL-2 with kinetics and magnitude varying according to subset differentiation, while IL-7 preferentially induced virus production from long-lived resting TN cells. In conclusion, within a month of infection, a clonal HIV-1 cluster is massively distributed among resting CD4 T-cell subsets with a flexible inducibility, suggesting that subset activation and skewed immune homeostasis determine the conditions of viral dissemination and early establishment of the HIV reservoir. PMID:23691172

Influence of variation in mobile phase pH and solute pK(a) with the change of organic modifier fraction on QSRRs of hydrophobicity and RP-HPLC retention of weakly acidic compounds.

PubMed

Han, Shu-ying; Liang, Chao; Zou, Kuan; Qiao, Jun-qin; Lian, Hong-zhen; Ge, Xin

2012-11-15

The variation in mobile phase pH and ionizable solute dissociation constant (pK(a)) with the change of organic modifier fraction in hydroorganic mobile phase has seemingly been a troublesome problem in studies and applications of reversed phase high performance liquid chromatography (RP-HPLC). Most of the early studies regarding the RP-HPLC of acid-base compounds have to measure the actual pH of the mixed mobile phase rigorously, sometimes bringing difficulties in the practices of liquid chromatographic separation. In this paper, the effect of this variation on the apparent n-octanol/water partition coefficient (K(ow)″) and the related quantitative structure-retention relationship (QSRR) of logK(ow)″ vs. logk(w), the logarithm of retention factor of analytes in neat aqueous mobile phases, was investigated for weakly acidic compounds. This QSRR is commonly used as a classical method for K(ow) measurement by RP-HPLC. The theoretical and experimental derivation revealed that the variation in mobile phase pH and solute pK(a) will not affect the QSRRs of acidic compounds. This conclusion is proved to be suitable for various types of ion-suppressors, i.e., strong acid (perchloric acid), weak acid (acetic acid) and buffer salt (potassium dihydrogen phosphate/phosphoric acid, PBS). The QSRRs of logK(ow)″ vs. logk(w) were modeled by 11 substituted benzoic acids using different types of ion-suppressors in a binary methanol-water mobile phase to confirm our deduction. Although different types of ion-suppressor all can be used as mobile phase pH modifiers, the QSRR model obtained by using perchloric acid as the ion-suppressor was found to have the best result, and the slightly inferior QSRRs were obtained by using acetic acid or PBS as the ion-suppressor. Copyright © 2012 Elsevier B.V. All rights reserved.

ELISPOTs Produced by CD8 and CD4 Cells Follow Log Normal Size Distribution Permitting Objective Counting

PubMed Central

Karulin, Alexey Y.; Karacsony, Kinga; Zhang, Wenji; Targoni, Oleg S.; Moldovan, Ioana; Dittrich, Marcus; Sundararaman, Srividya; Lehmann, Paul V.

2015-01-01

Each positive well in ELISPOT assays contains spots of variable sizes that can range from tens of micrometers up to a millimeter in diameter. Therefore, when it comes to counting these spots the decision on setting the lower and the upper spot size thresholds to discriminate between non-specific background noise, spots produced by individual T cells, and spots formed by T cell clusters is critical. If the spot sizes follow a known statistical distribution, precise predictions on minimal and maximal spot sizes, belonging to a given T cell population, can be made. We studied the size distributional properties of IFN-γ, IL-2, IL-4, IL-5 and IL-17 spots elicited in ELISPOT assays with PBMC from 172 healthy donors, upon stimulation with 32 individual viral peptides representing defined HLA Class I-restricted epitopes for CD8 cells, and with protein antigens of CMV and EBV activating CD4 cells. A total of 334 CD8 and 80 CD4 positive T cell responses were analyzed. In 99.7% of the test cases, spot size distributions followed Log Normal function. These data formally demonstrate that it is possible to establish objective, statistically validated parameters for counting T cell ELISPOTs. PMID:25612115

Prediction of gas/particle partitioning of polybrominated diphenyl ethers (PBDEs) in global air: A theoretical study

NASA Astrophysics Data System (ADS)

Li, Y.-F.; Ma, W.-L.; Yang, M.

2015-02-01

Gas/particle (G/P) partitioning of semi-volatile organic compounds (SVOCs) is an important process that primarily governs their atmospheric fate, long-range atmospheric transport, and their routes of entering the human body. All previous studies on this issue are hypothetically based on equilibrium conditions, the results of which do not predict results from monitoring studies well in most cases. In this study, a steady-state model instead of an equilibrium-state model for the investigation of the G/P partitioning behavior of polybrominated diphenyl ethers (PBDEs) was established, and an equation for calculating the partition coefficients under steady state (KPS) of PBDEs (log KPS = log KPE + logα) was developed in which an equilibrium term (log KPE = log KOA + logfOM -11.91 where fOM is organic matter content of the particles) and a non-equilibrium term (log α, caused by dry and wet depositions of particles), both being functions of log KOA (octanol-air partition coefficient), are included. It was found that the equilibrium is a special case of steady state when the non-equilibrium term equals zero. A criterion to classify the equilibrium and non-equilibrium status of PBDEs was also established using two threshold values of log KOA, log KOA1, and log KOA2, which divide the range of log KOA into three domains: equilibrium, non-equilibrium, and maximum partition domain. Accordingly, two threshold values of temperature t, tTH1 when log KOA = log KOA1 and tTH2 when log KOA = log KOA2, were identified, which divide the range of temperature also into the same three domains for each PBDE congener. We predicted the existence of the maximum partition domain (the values of log KPS reach a maximum constant of -1.53) that every PBDE congener can reach when log KOA ≥ log KOA2, or t ≤ tTH2. The novel equation developed in this study was applied to predict the G/P partition coefficients of PBDEs for our Chinese persistent organic pollutants (POPs) Soil and Air Monitoring Program, Phase 2 (China-SAMP-II) program and other monitoring programs worldwide, including in Asia, Europe, North America, and the Arctic, and the results matched well with all the monitoring data, except those obtained at e-waste sites due to the unpredictable PBDE emissions at these sites. This study provided evidence that the newly developed steady-state-based equation is superior to the equilibrium-state-based equation that has been used in describing the G/P partitioning behavior over decades. We suggest that the investigation on G/P partitioning behavior for PBDEs should be based onsteady-state, not equilibrium state, and equilibrium is just a special case of steady-state when non-equilibrium factors can be ignored. We also believe that our new equation provides a useful tool for environmental scientists in both monitoring and modeling research on G/P partitioning of PBDEs and can be extended to predict G/P partitioning behavior for other SVOCs as well.

Prevalence, isolation and characterization of Bacillus cereus strains from rice of local cultivators of Sabah, Sarawak, and Peninsular Malaysia

NASA Astrophysics Data System (ADS)

Sawei, Jelin; Sani, Norrakiah Abdullah

2016-11-01

Bacillus cereus is a spore-forming, facultative anaerobic, motile microorganism that has been identified as a causative agent of two types of gastrointestinal diseases such as emetic and diarrhea. This foodborne pathogen is found in both vegetative cells and endospores form in foods such as rice either raw or cooked. The aim of this study is to investigate and determine the prevalence, characterize and identify the isolation of vegetative cells and endospores of B. cereus in thirty varieties (n=3) of raw rice from Sabah, Sarawak and Peninsular Malaysia. A total of 90 (n=90) raw rice were examined and 84 (93.33%) samples were positive to vegetative cells of B. cereus. However, only 32 (35.56%) samples were positive for endospore cells that able to germinate after samples were heated at 75°C for 15 mins. The mean log cfu/g for vegetative cells were higher range (0.00 - 4.1533) than visible endospores (0.00 - 3.7533 mean log cfu/g). Sample of raw red rice (UKMRC9) had significantly higher contamination by both vegetative cells and endospores at p<0.05, than the other raw rice samples.

Inactivation of Escherichia coli O157:H7 on stainless steel upon exposure to Paenibacillus polymyxa biofilms.

PubMed

Kim, Seonhwa; Bang, Jihyun; Kim, Hoikyung; Beuchat, Larry R; Ryu, Jee-Hoon

2013-11-01

We investigated the potential use of biofilm formed by a competitive-exclusion (CE) microorganism to inactivate Escherichia coli O157:H7 on a stainless steel surface. Five microorganisms showing inhibitory activities against E. coli O157:H7 were isolated from vegetable seeds and sprouts. The microorganism with the greatest antimicrobial activity was identified as Paenibacillus polymyxa (strain T5). In tryptic soy broth (TSB), strain T5 reached a higher population at 25 °C than at 12 or 37 °C without losing inhibitory activity against E. coli O157:H7. When P. polymyxa (6 log CFU/mL) was co-cultured with E. coli O157:H7 (2, 3, 4, or 5 log CFU/mL) in TSB at 25 °C, the number of E. coli O157:H7 decreased significantly within 24h. P. polymyxa formed a biofilm on stainless steel coupons (SSCs) in TSB at 25 °C within 24h, and cells in biofilms, compared to attached cells without biofilm formation, showed significantly increased resistance to a dry environment (43% relative humidity [RH]). With the exception of an inoculum of 4 log CFU/coupon at 100% RH, upon exposure to biofilm formed by P. polymyxa on SSCs, populations of E. coli O157:H7 (2, 4, or 6 log CFU/coupon) were significantly reduced within 48 h. Most notably, when E. coli O157:H7 at 2 log CFU/coupon was applied to SSCs on which P. polymyxa biofilm had formed, it was inactivated within 1h, regardless of RH. These results will be useful when developing strategies using biofilms produced by competitive exclusion microorganisms to inactivate foodborne pathogens in food processing environments. © 2013.

Anti-intercellular substance antibody log titres are correlated with serum concentrations of interleukin-6, interleukin-15 and tumor necrosis factor-alpha in patients with Pemphigus vulgaris relationships with peripheral blood neutrophil counts, disease severity and duration and patients' age.

PubMed

Ameglio, F; D'Auria, L; Cordiali-Fei, P; Trento, E; D'Agosto, G; Mastroianni, A; Giannetti, A; Giacalone, B

1999-01-01

Pemphigus vulgaris is a rare dermatosis of autoimmune origin, characterized by autoantibodies directed against intercellular substance (AICS) and presenting with intra-epidermal blisters and/or erosions of the skin and mucous membranes. The aim of this paper is to analyze the relationships between serum AICS titers (after log transformation) and: patients' age, disease duration and disease activity; serum cytokine (IL-6, IL-7, IL-15 and TNF-alpha) concentrations and peripheral blood cell counts (namely neutrophils, lymphocytes and natural killer cells). Fifteen consecutive subjects affected with PV were enrolled. Diagnosis was supported by histological examination as well as by direct and indirect immunofluorescence tests. Cytokine determinations were made by means of commercially available ELISA kits. This study shows for the first time that AICS titers have a significant correlation with age of PV patients (R=0.57, p=0.031) and with the disease duration (R=0.73, p=0.002). A correlation between blood neutrophils count and log (AICS) titres was observed (R=0.6, p=0.021). Furthermore, significant correlations were observed between log (AICS) titres and serum IL-15 (R=0.54, p=0.048), serum IL-6 (R=0.53, p=0.05) or serum TNF-alpha concentrations (R=0.53, p=0.05). These data, taken together, show that there are several connections between the log (AICS) titres, some proinflammatory cytokines, peripheral blood neutrophil counts and the numbers of individuals' lesions, suggesting a relationship between AICS production and lesion development.

Destruction of Listeria monocytogenes in sturgeon (Acipenser transmontanus) caviar by a combination of nisin with chemical antimicrobials or moderate heat.

PubMed

Al-Holy, M; Lin, M; Rasco, B

2005-03-01

The objective of this study was to investigate the effect of nisin in combination with heat or antimicrobial chemical treatments (such as lactic acid, chlorous acid, and sodium hypochlorite) on the inhibition of Listeria monocytogenes and total mesophiles in sturgeon (Acipenser transmontanus) caviar. The effects of nisin (250, 500, 750, and 1,000 IU/ml), lactic acid (1, 2, and 3%), chlorous acid (134 and 268 ppm), sodium hypochlorite (150 and 300 ppm), and heat at 60 degrees C for 3 min were evaluated for a five-strain mixture of L. monocytogenes and total mesophiles in sturgeon caviar containing 3.5% salt. Selected combinations of these antimicrobial treatments were also tested. Injured and viable L. monocytogenes cells were recovered using an overlay method. Treating caviar with > or =500 IU/ml nisin initially reduced L. monocytogenes by 2 to 2.5 log units. Chlorous acid (268 ppm) reduced L. monocytogenes from 7.7 log units to undetectable (<0.48 log units) after 4 days of storage at 4 degrees C. However, there were no synergistic effects observed for combinations of nisin (500 or 750 IU/ml) plus either lactic acid or chlorous acid. Lactic acid caused a slight reduction (approximately 1 log unit) in the microbial load during a 6-day period at 4 degrees C. Sodium hypochlorite was ineffective at the levels tested. Mild heating (60 degrees C for 3 min) with nisin synergistically reduced viable counts of L. monocytogenes and total mesophiles. No L. monocytogenes cells (<0.48 log units) were recovered from caviar treated with heat and nisin (750 IU/ml) after a storage period of 28 days at 4 degrees C.

Phase III Study of Cabozantinib in Previously Treated Metastatic Castration-Resistant Prostate Cancer: COMET-1.

PubMed

Smith, Matthew; De Bono, Johann; Sternberg, Cora; Le Moulec, Sylvestre; Oudard, Stéphane; De Giorgi, Ugo; Krainer, Michael; Bergman, Andries; Hoelzer, Wolfgang; De Wit, Ronald; Bögemann, Martin; Saad, Fred; Cruciani, Giorgio; Thiery-Vuillemin, Antoine; Feyerabend, Susan; Miller, Kurt; Houédé, Nadine; Hussain, Syed; Lam, Elaine; Polikoff, Jonathan; Stenzl, Arnulf; Mainwaring, Paul; Ramies, David; Hessel, Colin; Weitzman, Aaron; Fizazi, Karim

2016-09-01

Cabozantinib is an inhibitor of kinases, including MET and vascular endothelial growth factor receptors, and has shown activity in men with previously treated metastatic castration-resistant prostate cancer (mCRPC). This blinded phase III trial compared cabozantinib with prednisone in patients with mCRPC. Men with progressive mCRPC after docetaxel and abiraterone and/or enzalutamide were randomly assigned at a two-to-one ratio to cabozantinib 60 mg once per day or prednisone 5 mg twice per day. The primary end point was overall survival (OS). Bone scan response (BSR) at week 12 as assessed by independent review committee was the secondary end point; radiographic progression-free survival (rPFS) and effects on circulating tumor cells (CTCs), bone biomarkers, serum prostate-specific antigen (PSA), and symptomatic skeletal events (SSEs) were exploratory assessments. A total of 1,028 patients were randomly assigned to cabozantinib (n = 682) or prednisone (n = 346). Median OS was 11.0 months with cabozantinib and 9.8 months with prednisone (hazard ratio, 0.90; 95% CI, 0.76 to 1.06; stratified log-rank P = .213). BSR at week 12 favored cabozantinib (42% v 3%; stratified Cochran-Mantel-Haenszel P < .001). rPFS was improved in the cabozantinib group (median, 5.6 v 2.8 months; hazard ratio, 0.48; 95% CI, 0.40 to 0.57; stratified log-rank P < .001). Cabozantinib was associated with improvements in CTC conversion, bone biomarkers, and post-random assignment incidence of SSEs but not PSA outcomes. Grade 3 to 4 adverse events and discontinuations because of adverse events were higher with cabozantinib than with prednisone (71% v 56% and 33% v 12%, respectively). Cabozantinib did not significantly improve OS compared with prednisone in heavily treated patients with mCRPC and progressive disease after docetaxel and abiraterone and/or enzalutamide. Cabozantinib had some activity in improving BSR, rPFS, SSEs, CTC conversions, and bone biomarkers but not PSA outcomes. © 2016 by American Society of Clinical Oncology.

Investigating the Effect of Different Treatments with Lactic Acid Bacteria on the Fate of Listeria monocytogenes and Staphylococcus aureus Infection in Galleria mellonella Larvae

PubMed Central

Grounta, Athena; Harizanis, Paschalis; Mylonakis, Eleftherios; Nychas, George-John E.; Panagou, Efstathios Z.

2016-01-01

The use of Galleria mellonella as a model host to elucidate microbial pathogenesis and search for novel drugs and therapies has been well appreciated over the past years. However, the effect of microorganisms with functional appeal in the specific host remains scarce. The present study investigates the effect of treatment with selected lactic acid bacteria (LAB) with probiotic potential, as potential protective agents by using live or heat-killed cells at 6 and 24 h prior to infection with Listeria monocytogenes and Staphylococcus aureus or as potential therapeutic agents by using cell-free supernatants (CFS) after infection with the same pathogens. The employed LAB strains were Lactobacillus pentosus B281 and Lactobacillus plantarum B282 (isolated from table olive fermentations) along with Lactobacillus rhamnosus GG (inhabitant of human intestinal tract). Kaplan-Meier survival curves were plotted while the pathogen’s persistence in the larval hemolymph was determined by microbiological analysis. It was observed that the time (6 or 24 h) and type (live or heat-killed cells) of challenge period with LAB prior to infection greatly affected the survival of infected larvae. The highest decrease of L. monocytogenes population in the hemolymph was observed in groups challenged for 6 h with heat-killed cells by an average of 1.8 log units compared to non challenged larvae for strains B281 (p 0.0322), B282 (p 0.0325), and LGG (p 0.0356). In the case of S. aureus infection, the population of the pathogen decreased in the hemolymph by 1 log units at 8 h post infection in the groups challenged for 6 h with heat-killed cells of strains B281 (p 0.0161) and B282 (p 0.0096) and by 1.8 log units in groups challenged with heat-killed cells of LGG strain (p 0.0175). Further use of CFS of each LAB strain did not result in any significant prolonged survival but interestingly it resulted in pronounced decrease of L. monocytogenes in the hemolymph at 24 h and 48 h after infection by more than 1 log unit (p < 0.05) depending on the strain. The results of the present work support the broader use of G. mellonella larvae as a low cost in vivo tool for screening for probiotic properties. PMID:27618619