A Study of Physicochemical Properties of Subcutaneous Fat of the Abdomen and its Implication in Abdominal Obesity

PubMed Central

Kumar, Pramod; Kodavoor, Srinivas Aithal; Kotian, Sushma Rama; Yathdaka, Sudhakar Narahari; Nayak, Dayanand; Souza, Anne D; Souza, Antony Sylvan D

2016-01-01

Introduction The lower abdominal obesity is more resistant to absorption as compared to that of upper abdomen. Differences in the physicochemical properties of the subcutaneous fat of the upper and lower abdomen may be responsible for this variation. There is paucity of the scientific literature on the physicochemical properties of the subcutaneous fat of abdomen. Aim The present study was undertaken to create a database of physicochemical properties of abdominal subcutaneous fat. Materials and Methods The samples of subcutaneous fat from upper and lower abdomen were collected from 40 fresh autopsied bodies (males 33, females 7). The samples were prepared for physicochemical analysis using organic and inorganic solvents. Various physicochemical properties of the fat samples analysed were surface tension, viscosity, specific gravity, specific conductivity, iodine value and thermal properties. Data was analysed by paired and independent sample t-tests. Results There was a statistically significant difference in all the physicochemical parameters between males and females except surface tension (organic) and surface tension (inorganic) of upper abdominal fat, and surface tension (organic) of lower abdominal fat. In males, viscosity of upper abdominal fat was more compared to that of lower abdomen (both organic and inorganic) unlike the specific conductivity that was higher for the lower abdominal fat as compared to that of the upper abdomen. In females there were statistically significant higher values of surface tension (inorganic) and specific gravity (organic) of the upper abdomen fat as compared to that of lower abdomen. The initial and final weight loss of the lower abdominal fat as indicated by Thermo Gravimetric Analysis was significantly more in males than in female Conclusion The difference in the physicochemical properties of subcutaneous fat between upper and lower abdomen and between males and females could be responsible for the variant behaviour of subcutaneous abdominal fat towards resorption. PMID:27437272

Self-Motion Depending on the Physicochemical Properties of Esters as the Driving Force

ERIC Educational Resources Information Center

Nakata, Satoshi; Matsuo, Kyoko; Kirisaka, Junko

2007-01-01

The self-motion of an ester boat is investigated depending on the physicochemical properties of the surface-active substance. The results show that the ester boat moves towards the higher surface tension generating as the driving force.

Supplementation of increasing amounts of linseed oil to dairy cows fed total mixed rations: effects on digestion, ruminal fermentation characteristics, protozoal populations, and milk fatty acid composition.

PubMed

Benchaar, C; Romero-Pérez, G A; Chouinard, P Y; Hassanat, F; Eugene, M; Petit, H V; Côrtes, C

2012-08-01

The effect of linseed oil (LO) supplementation on nutrient digestibility, forage (i.e., timothy hay) in sacco ruminal degradation, ruminal fermentation characteristics, protozoal populations, milk production, and milk fatty acid (FA) profile in dairy cows was investigated. Four ruminally cannulated, primiparous lactating cows were used in a 4 × 4 Latin square design (28-d periods). They were fed a total mixed ration (50:50 forage:concentrate (F:C) ratio [dry matter (DM) basis] without supplementation (control, CTL), or supplemented (wt/wt; DM basis) with LO at 2, 3, or 4%. Supplementation with LO had no effect on DM intake (19 kg/d) and apparent total-tract digestibility of nutrients (organic matter, neutral detergent fiber, acid detergent fiber, starch, and gross energy). Ruminal pH, ammonia, and total volatile FA concentrations were not changed by LO supplementation to diets. Extent of changes in volatile FA pattern and effective ruminal degradability of DM of timothy hay were minor. Neither the total numbers nor the genera distribution of protozoa was changed by the addition of increasing amounts of LO to the diet. Milk yield increased linearly (26.1, 27.3, 27.4, and 28.4 kg/d for CTL to LO4, respectively) as the amount of LO added to the diet increased. Milk fat content was not affected by LO supplementation, whereas milk protein content decreased linearly with increasing amounts of LO in the diet. Milk fat proportions of several intermediates of ruminal biohydrogenation of polyunsaturated FA (i.e., trans-10 18:1, trans-11 18:1, cis-9,trans-11 18:2, trans-11,cis-15 18:2, and cis-9,trans-11,cis-15 18:3) increased linearly with LO addition to the diet. The proportion of cis-9,cis-12 18:2 decreased linearly (2.06, 1.99, 1.91, and 1.83% for CTL to LO4, respectively) as the amount of LO in the diet increased. Milk fat content of cis-9,cis-12,cis-15 18:3 increased as the level of LO in the diet increased up to 3% but no further increase was observed when 4% of LO was fed (0.33, 0.79, 0.86, and 0.86% for CTL to LO4, respectively). A similar quadratic response to LO supplementation was also observed for cis-5,cis-8,cis-11,cis-14,cis-17 20:5 and cis-5,cis-7,cis-10,cis-13,cis-16 22:5. The results of the present study show that LO can be safely supplemented up to 4% in forage-based diets of dairy cows to enrich milk with potential health beneficial FA (i.e., n-3 FA) without causing any detrimental effects on rumen function, digestion, and milk production. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Assessment of physicochemical parameters and prevalence of virulent and multiple-antibiotic-resistant Escherichia coli in treated effluent of two wastewater treatment plants and receiving aquatic milieu in Durban, South Africa.

PubMed

Pillay, Leanne; Olaniran, Ademola O

2016-05-01

The poor operational status of some wastewater treatment plants often result in the discharge of inadequately treated effluent into receiving surface waters. This is of significant public health concern as there are many informal settlement dwellers (ISDs) that rely on these surface waters for their domestic use. This study investigated the treatment efficiency of two independent wastewater treatment plants (WWTPs) in Durban, South Africa and determined the impact of treated effluent discharge on the physicochemical and microbial quality of the receiving water bodies over a 6-month period. Presumptive Escherichia coli isolates were identified using biochemical tests and detection of the mdh gene via PCR. Six major virulence genes namely eae, hly, fliC, stx1, stx2, and rfbE were also detected via PCR while antibiotic resistance profiles of the isolates were determined using Kirby-Bauer disc diffusion assay. The physicochemical parameters of the wastewater samples ranged variously between 9 and 313.33 mg/L, 1.52 and 76.43 NTUs, and 6.30 and 7.87 for COD, turbidity, and pH respectively, while the E. coli counts ranged between 0 and 31.2 × 10(3) CFU/ml. Of the 200 selected E. coli isolates, the hly gene was found in 28 %, fliC in 20 %, stx2 in 17 %, eae in 14 %, with stx1 and rfbE in only 4 % of the isolates. Notable resistance was observed toward trimethoprim (97 %), tetracycline (56 %), and ampicillin (52.5 %). These results further highlight the poor operational status of these WWTPs and outline the need for improved water quality monitoring and enforcement of stringent guidelines.

Numerical Investigation of LO2 and LCH4 Storage Tanks on the Lunar Surface

NASA Technical Reports Server (NTRS)

Moder, Jeff; Barsi, Stephen; Kassemi, Mohammad

2008-01-01

Currently NASA is developing technologies to enable human exploration of the lunar surface for duration of up to 210 days. While trade studies are still underway, a cryogenic ascent stage using liquid oxygen (LO2) and liquid methane (LCH4) is being considered for the Altair lunar lander. For a representative Altair cryogenic ascent stage, we present a detailed storage analysis of the LO2 and LCH4 propellant tanks on the lunar surface for durations of up to 210 days. Both the LO2 and LCH4 propellant tanks are assumed to be pressurized with gaseous helium at launch. A two-phase lumped-vapor computational fluid dynamics model has been developed to account for the presence of a noncondensable gas in the ullage. The CFD model is used to simulate the initial pressure response of the propellant tanks while they are subjected to representative heat leak rates on the lunar surface. Once a near stationary state is achieved within the liquid phase, multizone model is used to extrapolate the solution farther in time. For fixed propellant mass and tank size, the long-term pressure response for different helium mass fractions in both the LO2 and LCH4 tanks is examined.

G‐LoSA: An efficient computational tool for local structure‐centric biological studies and drug design

PubMed Central

2016-01-01

Abstract Molecular recognition by protein mostly occurs in a local region on the protein surface. Thus, an efficient computational method for accurate characterization of protein local structural conservation is necessary to better understand biology and drug design. We present a novel local structure alignment tool, G‐LoSA. G‐LoSA aligns protein local structures in a sequence order independent way and provides a GA‐score, a chemical feature‐based and size‐independent structure similarity score. Our benchmark validation shows the robust performance of G‐LoSA to the local structures of diverse sizes and characteristics, demonstrating its universal applicability to local structure‐centric comparative biology studies. In particular, G‐LoSA is highly effective in detecting conserved local regions on the entire surface of a given protein. In addition, the applications of G‐LoSA to identifying template ligands and predicting ligand and protein binding sites illustrate its strong potential for computer‐aided drug design. We hope that G‐LoSA can be a useful computational method for exploring interesting biological problems through large‐scale comparison of protein local structures and facilitating drug discovery research and development. G‐LoSA is freely available to academic users at http://im.compbio.ku.edu/GLoSA/. PMID:26813336

G-LoSA: An efficient computational tool for local structure-centric biological studies and drug design.

PubMed

Lee, Hui Sun; Im, Wonpil

2016-04-01

Molecular recognition by protein mostly occurs in a local region on the protein surface. Thus, an efficient computational method for accurate characterization of protein local structural conservation is necessary to better understand biology and drug design. We present a novel local structure alignment tool, G-LoSA. G-LoSA aligns protein local structures in a sequence order independent way and provides a GA-score, a chemical feature-based and size-independent structure similarity score. Our benchmark validation shows the robust performance of G-LoSA to the local structures of diverse sizes and characteristics, demonstrating its universal applicability to local structure-centric comparative biology studies. In particular, G-LoSA is highly effective in detecting conserved local regions on the entire surface of a given protein. In addition, the applications of G-LoSA to identifying template ligands and predicting ligand and protein binding sites illustrate its strong potential for computer-aided drug design. We hope that G-LoSA can be a useful computational method for exploring interesting biological problems through large-scale comparison of protein local structures and facilitating drug discovery research and development. G-LoSA is freely available to academic users at http://im.compbio.ku.edu/GLoSA/. © 2016 The Protein Society.

Pele Erupting on Lo

NASA Technical Reports Server (NTRS)

2001-01-01

This image of Jupiter's moon, lo, was taken by the Chandra X-Ray Observatory (CXO). Shown here is the most extreme example of the effect of tidal forces as Lo is being pulled by massive Jupiter on one side and by the outer moons Europa, Callisto, and Ganymede on the other. The opposing tidal forces alternately squeeze and stretch its interior, causing the solid surface to rise and fall by about 100 meters. The enormous amount of heat and pressure generated by the resulting friction creates colossal volcanoes and fractures on the surface of this moon.

The physicochemical process of bacterial attachment to abiotic surfaces: Challenges for mechanistic studies, predictability and the development of control strategies.

PubMed

Wang, Yi; Lee, Sui Mae; Dykes, Gary

2015-01-01

Bacterial attachment to abiotic surfaces can be explained as a physicochemical process. Mechanisms of the process have been widely studied but are not yet well understood due to their complexity. Physicochemical processes can be influenced by various interactions and factors in attachment systems, including, but not limited to, hydrophobic interactions, electrostatic interactions and substratum surface roughness. Mechanistic models and control strategies for bacterial attachment to abiotic surfaces have been established based on the current understanding of the attachment process and the interactions involved. Due to a lack of process control and standardization in the methodologies used to study the mechanisms of bacterial attachment, however, various challenges are apparent in the development of models and control strategies. In this review, the physicochemical mechanisms, interactions and factors affecting the process of bacterial attachment to abiotic surfaces are described. Mechanistic models established based on these parameters are discussed in terms of their limitations. Currently employed methods to study these parameters and bacterial attachment are critically compared. The roles of these parameters in the development of control strategies for bacterial attachment are reviewed, and the challenges that arise in developing mechanistic models and control strategies are assessed.

Detection of the 2015 Gorkha earthquake-induced landslide surface deformation in Kathmandu using InSAR images from PALSAR-2 data

NASA Astrophysics Data System (ADS)

Sato, Hiroshi P.; Une, Hiroshi

2016-03-01

Previous studies reported that the 2015 Gorkha earthquake (Mw 7.8), which occurred in Nepal, triggered landslides in mountainous areas. In Kathmandu, earthquake-induced land subsidence was identified by interpreting local phase changes in interferograms produced from Advanced Land Observing Satellite-2/Phased Array type L-band Synthetic Aperture Radar-2 data. However, the associated ground deformation was not discussed in detail. We studied line-of-sight (LoS) changes from InSAR images in the SE area of Tribhuvan International Airport, Kathmandu. To obtain the change in LoS caused only by local, short-wavelength surface deformation, we subtracted the change in LoS attributed to coseismic deformation from the original change in LoS. The resulting change in LoS showed that the river terrace was driven to the bottom of the river valley. We also studied the changes in LoS in both ascending and descending InSAR images of the area along the Bishnumati River and performed 2.5D analysis. Removing the effect of coseismic deformation revealed east-west and up-down components of local surface deformation, indicating that the river terrace deformed eastward and subsided on the western riverbank of the river. On the east riverbank, the river terrace deformed westward and subsided. However, in the southern part of the river basin, the river terrace deformed westward and was uplifted. The deformation data and field survey results indicate that local surface deformation in these two areas was not caused by land subsidence but by a landslide (specifically, lateral spread).

X-ray and extreme ultraviolet spectroscopy on DIII-D

NASA Astrophysics Data System (ADS)

Victor, B. S.; Allen, S. L.; Beiersdorfer, P.; Magee, E. W.

2017-06-01

Two spectrometers were installed to measure tungsten emission in the core of DIII-D plasmas during a metal rings experimental campaign. The spectral range of the high-resolution (1340 spectral channels), variable-ruled grating X-ray and Extreme Ultraviolet Spectrometer (XEUS) extends from 10-71 dot A. The spectral range of the second spectrometer, the Long-Wavelength Extreme Ultraviolet Spectrometer (LoWEUS), measures between 31-174 dot A. Three groups of tungsten lines were identified with XEUS: W38+-W45+ from 47-63 dot A, W27+-W35+ from 45-55 dot A, and W28+-W33+ from 16-30 dot A. Emission lines from tungsten charge states W28+, W43+, W44+, and W45+ are identified and the line amplitude is presented versus time. Peak emission of W43+-W45+ occurs between core Te=2.5-3 keV, and peak emission of W28+ occurs at core Te<=1.3 keV. One group of tungsten lines, W40+-W45+, between 120-140 dot A, was identified with LoWEUS. W43+-W45+ lines measured with LoWEUS track the sawtooth cycle. Sensitivity to the sawtooth cycle and the correlation of the peak emission with core electron temperature show that these spectrometers track the on-axis tungsten emission of DIII-D plasmas.

IR Reflectance Properties Of Weakly And Strongly Absorbing Surface Films

NASA Astrophysics Data System (ADS)

Yen, Yu-Sze; Wong, James S.

1989-12-01

In an external reflection measurement, the optical properties of a surface film can give rise to a variety of spectral behavior on metallic and nonmetallic substrates. The diversity of behavior can be explained by the presence of transverse optical (TO) and longitudinal optical (LO) bands of the film in the infrared region. The excitation modes associated with these bands are directional with respect to the plane of the surface. Spectral interpretation is facilitated by understanding the roles of the TO and LO bands in reflectance spectra, the substrate selection rules for the appearance of these bands, and the relationship between the TO and LO frequencies. We will show that weakly absorbing films have a simpler optical behavior than strongly absorbing films.

Investigation of room temperature UV emission of ZnO films with different defect densities induced by laser irradiation.

PubMed

Zhao, Yan; Jiang, Yijian

2010-08-01

We studied the room temperature UV emission of ZnO films with different defect densities which is fabricated by KrF laser irradiation process. It is shown room temperature UV photoluminescence of ZnO film is composed of contribution from free-exciton (FX) recombination and its longitudinal-optical phonon replica (FX-LO) (1LO, 2LO). With increase of the defect density, the FX emission decreased and FX-LO emission increased dramatically; and the relative strengths of FX to FX-LO emission intensities determine the peak position and intensity of UV emission. What is more, laser irradiation with moderate energy density could induce the crystalline ZnO film with very flat and smooth surface. This investigation indicates that KrF laser irradiation could effectively modulate the exciton emission and surface morphology, which is important for the application of high performance of UV emitting optoelectronic devices. Copyright 2010 Elsevier B.V. All rights reserved.

Short communication: Unexpected findings on the physicochemical characterization of the silver nanoparticle surface

NASA Astrophysics Data System (ADS)

Loran, S.; Yelon, A.; Sacher, E.

2018-01-01

The bactericidal properties of silver nanoparticles (Ag NPs) have been variously attributed to the action of the NP surface and/or the Ag ions released therefrom. However, the published literature does not appear to contain any information on the physicochemical characterization of the NP surface. Herein, we report on the surprisingly reactive surface of the Ag NP, which has an almost total lack of free Ag on atmospheric exposure. Rather, an abundance of surface hydrocarbons, hydrides and oxides, as well as amines and oxidized N, argues for a reinterpretation of their bactericidal action.

Sorption of 75% DDT Water-Dispersible Powder on Different Mud Surfaces

PubMed Central

Bami, H. L.

1961-01-01

The loss of residual insecticide particles on absorbent mud surfaces due to the phenomenon of sorption has been well investigated from various physical, chemical and biological aspects. The present report describes an attempt to correlate the relative sorption capacities of representative Indian and African soils and a synthetic soil with the physicochemical characteristics of these soils and their surfaces. The investigation has further elucidated the mode of sorption of non-volatile residual insecticides on mud surfaces and the role of certain physicochemical factors. PMID:13686503

X-ray and extreme ultraviolet spectroscopy on DIII-D

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

Victor, Brian S.; Allen, Steve L.; Beiersdorfer, P.

Two spectrometers were installed to measure tungsten emission in the core of DIII-D plasmas during a metal rings experimental campaign. The spectral range of the high-resolution (1340 spectral channels), variable-ruled grating X-ray and Extreme Ultraviolet Spectrometer (XEUS) extends from10–71more » $$\\dot{A}$$ . The spectral range of the second spectrometer, the Long-Wavelength Extreme Ultraviolet Spectrometer (LoWEUS), measures between 31–174$$\\dot{A}$$ . Three groups of tungsten lines were identified with XEUS: W 38+-W 45+ from 47–63$$\\dot{A}$$ , W 27+-W 35+ from 45–55$$\\dot{A}$$ , and W 28+-W 33+ from 16–30$$\\dot{A}$$ . Emission lines from tungsten charge states W 28+, W 43+, W 44+, and W 45+ are identified and the line amplitude is presented versus time. Peak emission of W 43+-W 45+ occurs between core Te=2.5-3 keV, and peak emission of W28+ occurs at core Te 1:3 keV. One group of tungsten lines, W 40+-W 45+, between 120–140$$\\dot{A}$$ , was identified with LoWEUS. W 43+- W 45+ lines measured with LoWEUS track the sawtooth cycle. Furthermore, sensitivity to the sawtooth cycle and the correlation of the peak emission with core electron temperature show that these spectrometers track the on-axis tungsten emission of DIII-D plasmas.« less

X-ray and extreme ultraviolet spectroscopy on DIII-D

DOE PAGES

Victor, Brian S.; Allen, Steve L.; Beiersdorfer, P.; ...

2017-06-14

Two spectrometers were installed to measure tungsten emission in the core of DIII-D plasmas during a metal rings experimental campaign. The spectral range of the high-resolution (1340 spectral channels), variable-ruled grating X-ray and Extreme Ultraviolet Spectrometer (XEUS) extends from10–71more » $$\\dot{A}$$ . The spectral range of the second spectrometer, the Long-Wavelength Extreme Ultraviolet Spectrometer (LoWEUS), measures between 31–174$$\\dot{A}$$ . Three groups of tungsten lines were identified with XEUS: W 38+-W 45+ from 47–63$$\\dot{A}$$ , W 27+-W 35+ from 45–55$$\\dot{A}$$ , and W 28+-W 33+ from 16–30$$\\dot{A}$$ . Emission lines from tungsten charge states W 28+, W 43+, W 44+, and W 45+ are identified and the line amplitude is presented versus time. Peak emission of W 43+-W 45+ occurs between core Te=2.5-3 keV, and peak emission of W28+ occurs at core Te 1:3 keV. One group of tungsten lines, W 40+-W 45+, between 120–140$$\\dot{A}$$ , was identified with LoWEUS. W 43+- W 45+ lines measured with LoWEUS track the sawtooth cycle. Furthermore, sensitivity to the sawtooth cycle and the correlation of the peak emission with core electron temperature show that these spectrometers track the on-axis tungsten emission of DIII-D plasmas.« less

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

Rizal, Umesh, E-mail: umeshrizal680@gmail.com; Swain, Bibhu P., E-mail: bibhu.s@smit.smu.edu.in; Swain, Bhabani S., E-mail: bsswain@kookmin.ac.kr

Gallium nitride nanowires (GaN-NWs) of diameters ranging from 20 to 80 nm were grown on the p-type Si substrate by Thermal Chemical Vapor Deposition (TCVD) using Iron (Fe) catalyst via VLS mechanism. Raman and FTIR spectra reveal the presence of broad transverse optic (TO) and longitudinal optic (LO) phonon peak spreads over 500-600 cm{sup −1} and 720 cm{sup −1} respectively. The detail deconvolution of integrated transverse and longitudinal phonon analysis reveals phonon confinement brought out by incorporation of hydrogen atom. The red shifts of TO and LO phonon peak position indicates nanosized effect. I{sub A1(LO)}/I{sub A1(TO)} increases from 0.073 to 1.0 and theirmore » respective fwhm{sub A1(LO)}/fwhm{sub A1(TO)} also increases from 0.71 to 1.31 with increasing H{sub 2} flow rate. E{sub 1}(LO) - E{sub 1}(TO) and A{sub 1}(LO) - A{sub 1}(TO) increases from 173.83 to 190.73 and 184.89 to 193.22 respectively. Apart from this usual TO and LO phonon, we have found Surface Optic (SO) phonon at 671 cm{sup −1} in FTIR spectra. The intensity of PL peak increases with increasing H{sub 2} dilution reveals efficient passivation of defect centre at surface of GaN-NWs.« less

Collagen hydrogels incorporated with surface-aminated mesoporous nanobioactive glass: Improvement of physicochemical stability and mechanical properties is effective for hard tissue engineering.

PubMed

El-Fiqi, Ahmed; Lee, Jae Ho; Lee, Eun-Jung; Kim, Hae-Won

2013-12-01

Collagen (Col) hydrogels have poor physicochemical and mechanical properties and are susceptible to substantial shrinkage during cell culture, which limits their potential applications in hard tissue engineering. Here, we developed novel nanocomposite hydrogels made of collagen and mesoporous bioactive glass nanoparticles (mBGns) with surface amination, and addressed the effects of mBGn addition (Col:mBG = 2:1, 1:1 and 1:2) and its surface amination on the physicochemical and mechanical properties of the hydrogels. The amination of mBGn was shown to enable chemical bonding with collagen molecules. As a result, the nanocomposite hydrogels exhibited a significantly improved physicochemical and mechanical stability. The hydrolytic and enzymatic degradation of the Col-mBGn hydrogels were slowed down due to the incorporation of mBGn and its surface amination. The mechanical properties of the hydrogels, specifically the resistance to loading as well as the stiffness, significantly increased with the addition of mBGn and its aminated form, as assessed by a dynamic mechanical analysis. Mesenchymal stem cells cultivated within the Col-mBGn hydrogels were highly viable, with enhanced cytoskeletal extensions, due to the addition of surface aminated mBGn. While the Col hydrogel showed extensive shrinkage (down to ∼20% of initial size) during a few days of culture, the shrinkage of the mBGn-added hydrogel was substantially reduced, and the aminated mBGn-added hydrogel had no observable shrinkage over 21 days. Results demonstrated the effective roles of aminated mBGn in significantly improving the physicochemical and mechanical properties of Col hydrogel, which are ultimately favorable for applications in stem cell culture for bone tissue engineering. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

NANOSILVER MOVEMENT THROUGH BIOLOGICAL BARRIERS RELATES TO PHYSICOCHEMICAL PROPERTIES

EPA Science Inventory

Linking the physicochemical (PC) properties of engineered nanomaterials (NM) to their biological activity is critical for identifying their (toxic) mode of action, and developing appropriate and effective risk assessment guidelines. Particle surface charge (zeta potential), surfa...

Long-term stability study of clofarabine injection concentrate and diluted clofarabine infusion solutions.

PubMed

Kaiser, Jeanette; Krämer, Irene

2012-06-01

The aim of this study was to investigate the physicochemical stability of clofarabine (CAFdA) injection concentrate and ready-to-use CAFdA infusion solutions over a prolonged period of 28 days. To determine the stability of CAFdA infusion solutions, the injection concentrate (Evoltra®, 1 mg/mL, Genzyme) was diluted either with 0.9% sodium chloride or 5% glucose infusion solution. The resulting concentrations of 0.2 mg/mL or 0.6 mg/mL, respectively, were chosen to represent the lower and upper limit of the ordinary concentration range. Test solutions were stored under refrigeration (2-8°C) or at room temperature either light protected or exposed to light. CAFdA concentrations and pH values were determined at different time intervals throughout a 28-day storage period. Compatibility of diluted CAFdA infusion solutions (0.1-0.4 mg/mL) with different container materials (polyvinyl chloride (PVC), glass, and polypropylene/polyethylene (PP/PE)) was tested over a 48-h storage period. CAFdA concentrations were measured by a stability-indicating reversed phase high-performance liquid chromatography (HPLC) assay with ultraviolet detection. CAFdA injection concentrate and CAFdA infusion solutions remained physicochemically stable (>90% CAFdA) for 4 weeks. Results are independent of storage conditions, drug concentrations (0.2, 0.6, and 1.0 mg/mL) and diluents (0.9% sodium chloride, 5% glucose infusion solution). Adsorption of CAFdA to container material can be excluded. CAFdA injection concentrate and diluted infusion solutions in commonly used vehicles are stable for at least 28 days either refrigerated or at room temperature. Physicochemical stability favors pharmacy-based centralized preparation. Due to microbiological reasons, strict aseptic handling and storage of the products under refrigeration is recommended.

Relationship between boundary layer heights and growth rates with ground-level ozone in Houston, Texas

NASA Astrophysics Data System (ADS)

Haman, C. L.; Couzo, E.; Flynn, J. H.; Vizuete, W.; Heffron, B.; Lefer, B. L.

2014-05-01

Measurements and predictions of ambient ozone (O3), planetary boundary layer (PBL) height, the surface energy budget, wind speed, and other meteorological parameters were made near downtown Houston, Texas, and were used to investigate meteorological controls on elevated levels of ground-level O3. Days during the study period (1 April 2009 to 31 December 2010 for measurements and 15 April 2009 to 17 October 2009 for modeled) were classified into low (LO3) and high ozone (HO3) days. The majority of observed high HO3 days occurred in a postfrontal environment. Observations showed there is not a significant difference in daily maximum PBL heights on HO3 and LO3 days. Modeling results showed large differences between maximum PBL heights on HO3 and LO3 days. Nighttime and early morning observed and modeled PBL heights are consistently lower on HO3 days than on LO3 days. The observed spring LO3 days had the most rapid early morning PBL growth (~350 m h-1) while the fall HO3 group had the slowest (~200 m h-1). The predicted maximum average hourly morning PBL growth rates were greater on HO3 (624 m h-1) days than LO3 days (361 m h-1). Observed turbulent mixing parameters were up to 2-3 times weaker on HO3 days, which indicate large-scale subsidence associated with high-pressure systems (leading to clear skies and weak winds) substantially suppresses mixing. Lower surface layer ventilation coefficients were present in the morning on HO3 days in the spring and fall, which promotes the accumulation of O3 precursors near the surface.

Donor-Derived Regulatory Dendritic Cell Infusion Maintains Donor-Reactive CD4+CTLA4hi T Cells in Non-Human Primate Renal Allograft Recipients Treated with CD28 Co-Stimulation Blockade.

PubMed

Ezzelarab, Mohamed B; Lu, Lien; Shufesky, William F; Morelli, Adrian E; Thomson, Angus W

2018-01-01

Donor-derived regulatory dendritic cell (DCreg) infusion before transplantation, significantly prolongs renal allograft survival in non-human primates. This is associated with enhanced expression of the immunoregulatory molecules cytotoxic T-lymphocyte-associated antigen (Ag) 4 (CTLA4) and programmed cell death protein 1 (PD1) by host donor-reactive T cells. In rodents and humans, CD28 co-stimulatory pathway blockade with the fusion protein CTLA4:Ig (CTLA4Ig) is associated with reduced differentiation and development of regulatory T cells (Treg). We hypothesized that upregulation of CTLA4 by donor-reactive CD4 + T cells in DCreg-infused recipients treated with CTLA4Ig, might be associated with higher incidences of donor-reactive CD4 + T cells with a Treg phenotype. In normal rhesus monkeys, allo-stimulated CD4 + CTLA4 hi , but not CD4 + CTLA4 med/lo T cells exhibited a regulatory phenotype, irrespective of PD1 expression. CTLA4Ig significantly reduced the incidence of CD4 + CTLA4 hi , but not CD4 + CTLA4 med/lo T cells following allo-stimulation, associated with a significant reduction in the CD4 + CTLA4 hi /CD4 + CTLA4 med/lo T cell ratio. In CTLA4Ig-treated renal allograft recipient monkeys, there was a marked reduction in circulating donor-reactive CD4 + CTLA4 hi T cells. In contrast, in CTLA4Ig-treated monkeys with DCreg infusion, no such reduction was observed. In parallel, the donor-reactive CD4 + CTLA4 hi /CD4 + CTLA4 med/lo T cell ratio was reduced significantly in graft recipients without DCreg infusion, but increased in those given DCreg. These observations suggest that pre-transplant DCreg infusion promotes and maintains donor-reactive CD4 + CTLA4 hi T cells with a regulatory phenotype after transplantation, even in the presence of CD28 co-stimulation blockade.

Donor-Derived Regulatory Dendritic Cell Infusion Maintains Donor-Reactive CD4+CTLA4hi T Cells in Non-Human Primate Renal Allograft Recipients Treated with CD28 Co-Stimulation Blockade

PubMed Central

Ezzelarab, Mohamed B.; Lu, Lien; Shufesky, William F.; Morelli, Adrian E.; Thomson, Angus W.

2018-01-01

Donor-derived regulatory dendritic cell (DCreg) infusion before transplantation, significantly prolongs renal allograft survival in non-human primates. This is associated with enhanced expression of the immunoregulatory molecules cytotoxic T-lymphocyte-associated antigen (Ag) 4 (CTLA4) and programmed cell death protein 1 (PD1) by host donor-reactive T cells. In rodents and humans, CD28 co-stimulatory pathway blockade with the fusion protein CTLA4:Ig (CTLA4Ig) is associated with reduced differentiation and development of regulatory T cells (Treg). We hypothesized that upregulation of CTLA4 by donor-reactive CD4+ T cells in DCreg-infused recipients treated with CTLA4Ig, might be associated with higher incidences of donor-reactive CD4+ T cells with a Treg phenotype. In normal rhesus monkeys, allo-stimulated CD4+CTLA4hi, but not CD4+CTLA4med/lo T cells exhibited a regulatory phenotype, irrespective of PD1 expression. CTLA4Ig significantly reduced the incidence of CD4+CTLA4hi, but not CD4+CTLA4med/lo T cells following allo-stimulation, associated with a significant reduction in the CD4+CTLA4hi/CD4+CTLA4med/lo T cell ratio. In CTLA4Ig-treated renal allograft recipient monkeys, there was a marked reduction in circulating donor-reactive CD4+CTLA4hi T cells. In contrast, in CTLA4Ig-treated monkeys with DCreg infusion, no such reduction was observed. In parallel, the donor-reactive CD4+CTLA4hi/CD4+CTLA4med/lo T cell ratio was reduced significantly in graft recipients without DCreg infusion, but increased in those given DCreg. These observations suggest that pre-transplant DCreg infusion promotes and maintains donor-reactive CD4+CTLA4hi T cells with a regulatory phenotype after transplantation, even in the presence of CD28 co-stimulation blockade. PMID:29520267

Drug-Mediated Intracellular Donation of Nitric Oxide Potently Inhibits 5-Lipoxygenase: A Possible Key to Future Antileukotriene Therapy.

PubMed

Roos, Jessica; Peters, Marcus; Maucher, Isabelle V; Kühn, Benjamin; Fettel, Jasmin; Hellmuth, Nadine; Brat, Camilla; Sommer, Benita; Urbschat, Anja; Piesche, Matthias; Vogel, Anja; Proschak, Ewgenij; Blöcher, René; Buscató, Estella; Häfner, Ann-Kathrin; Matrone, Carmela; Werz, Oliver; Heidler, Juliana; Wittig, Ilka; Angioni, Carlo; Geisslinger, Gerd; Parnham, Michael J; Zacharowski, Kai; Steinhilber, Dieter; Maier, Thorsten J

2018-05-10

5-Lipoxygenase (5-LO) is the key enzyme of leukotriene (LT) biosynthesis and is critically involved in a number of inflammatory diseases such as arthritis, gout, bronchial asthma, atherosclerosis, and cancer. Because 5-LO contains critical nucleophilic amino acids, which are sensitive to electrophilic modifications, we determined the consequences of a drug-mediated intracellular release of nitric oxide (NO) on 5-LO product formation by human granulocytes and on 5-LO-dependent pulmonary inflammation in vivo. Clinically relevant concentrations of NO-releasing nonsteroidal anti-inflammatory drugs and other agents releasing NO intracellularly suppress 5-LO product synthesis in isolated human granulocytes via direct S-nitrosylation of 5-LO at the catalytically important cysteines 416 and 418. Furthermore, suppression of 5-LO product formation was observed in ionophore-stimulated human whole blood and in an animal model of pulmonary inflammation. Here, we report for the first time that drugs releasing NO intracellularly are efficient 5-LO inhibitors in vitro and in vivo at least equivalent to approved 5-LO inhibitors. Our findings provide a novel mechanistic strategy for the development of a new class of drugs suppressing LT biosynthesis by site-directed nitrosylation. The results may also help to better understand the well-recognized anti-inflammatory clinically relevant actions of NO-releasing drugs. Furthermore, our study describes in detail a novel molecular mode of action of NO. Rebound Track: This work was rejected during standard peer review and rescued by Rebound Peer Review (Antioxid Redox Signal 16: 293-296, 2012) with the following serving as open reviewers: Angel Lanas, Hartmut Kühn, Joan Clària, Orina Belton. Antioxid. Redox Signal. 28, 1265-1285.

Proximate composition and physicochemical properties of European beaver (Castor fiber L.) meat.

PubMed

Florek, Mariusz; Drozd, Leszek; Skałecki, Piotr; Domaradzki, Piotr; Litwińczuk, Anna; Tajchman, Katarzyna

2017-01-01

The proximate composition of meat from young and mature European beaver and physicochemical properties during storage were investigated. The young beaver meat contains 20.52g of protein and 1.86g of fat in 100g, while mature animals 22.16g and 0.73g. Index of nutritional quality for protein ranged from 2.03 to 2.24. Storage had a greater impact on the physicochemical properties of beaver meat than animal age and muscle type. The meat of mature beavers was significantly (P<0.05) darker (L*=28.51) in comparison with young animals (L*=30.79) and contained significantly (P<0.01) more total pigments. However, the negative b* values (between -2.05 and -2.19) indicated a bluish tint on the surface of beaver meat. The significantly (P<0.05) lower drip loss and cooking loss showed semimembranosus (0.65% and 17.89%) compared to longissimus thoracis et lumborum muscle (0.84% and 19.58%). Significantly (P<0.01) lower values of TBARS, drip loss and cooking loss were determined in meat at 24h (0.15mgMDAkg -1 , 0.59% and 15.99%) in comparison with stored for 7days (0.46mgMDAkg -1 , 0.90% and 21.49%). Generally, storage for 7days improved meat water holding capacity and tenderness. W-B shear force and shear energy of beaver meat decreased from 51.4N and 0.21J at 24h to 33.2N and 0.11J at 7days. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rational engineering of physicochemical properties of nanomaterials for biomedical applications with nanotoxicological perspectives.

PubMed

Navya, P N; Daima, Hemant Kumar

2016-01-01

Innovative engineered nanomaterials are at the leading edge of rapidly emerging fields of nanobiotechnology and nanomedicine. Meticulous synthesis, unique physicochemical properties, manifestation of chemical or biological moieties on the surface of materials make engineered nanostructures suitable for a variety of biomedical applications. Besides, tailored nanomaterials exhibit entirely novel therapeutic applications with better functionality, sensitivity, efficiency and specificity due to their customized unique physicochemical and surface properties. Additionally, such designer made nanomaterials has potential to generate series of interactions with various biological entities including DNA, proteins, membranes, cells and organelles at nano-bio interface. These nano-bio interactions are driven by colloidal forces and predominantly depend on the dynamic physicochemical and surface properties of nanomaterials. Nevertheless, recent development and atomic scale tailoring of various physical, chemical and surface properties of nanomaterials is promising to dictate their interaction in anticipated manner with biological entities for biomedical applications. As a result, rationally designed nanomaterials are in extensive demand for bio-molecular detection and diagnostics, therapeutics, drug and gene delivery, fluorescent labelling, tissue engineering, biochemical sensing and other pharmaceuticals applications. However, toxicity and risk associated with engineered nanomaterials is rather unclear or not well understood; which is gaining considerable attention and the field of nanotoxicology is evolving promptly. Therefore, this review explores current knowledge of articulate engineering of nanomaterials for biomedical applications with special attention on potential toxicological perspectives.

Rational engineering of physicochemical properties of nanomaterials for biomedical applications with nanotoxicological perspectives

NASA Astrophysics Data System (ADS)

Navya, P. N.; Daima, Hemant Kumar

2016-02-01

Innovative engineered nanomaterials are at the leading edge of rapidly emerging fields of nanobiotechnology and nanomedicine. Meticulous synthesis, unique physicochemical properties, manifestation of chemical or biological moieties on the surface of materials make engineered nanostructures suitable for a variety of biomedical applications. Besides, tailored nanomaterials exhibit entirely novel therapeutic applications with better functionality, sensitivity, efficiency and specificity due to their customized unique physicochemical and surface properties. Additionally, such designer made nanomaterials has potential to generate series of interactions with various biological entities including DNA, proteins, membranes, cells and organelles at nano-bio interface. These nano-bio interactions are driven by colloidal forces and predominantly depend on the dynamic physicochemical and surface properties of nanomaterials. Nevertheless, recent development and atomic scale tailoring of various physical, chemical and surface properties of nanomaterials is promising to dictate their interaction in anticipated manner with biological entities for biomedical applications. As a result, rationally designed nanomaterials are in extensive demand for bio-molecular detection and diagnostics, therapeutics, drug and gene delivery, fluorescent labelling, tissue engineering, biochemical sensing and other pharmaceuticals applications. However, toxicity and risk associated with engineered nanomaterials is rather unclear or not well understood; which is gaining considerable attention and the field of nanotoxicology is evolving promptly. Therefore, this review explores current knowledge of articulate engineering of nanomaterials for biomedical applications with special attention on potential toxicological perspectives.

Large differences in peak oxygen uptake do not independently alter changes in core temperature and sweating during exercise.

PubMed

Jay, Ollie; Bain, Anthony R; Deren, Tomasz M; Sacheli, Matthew; Cramer, Matthew N

2011-09-01

The independent influence of peak oxygen uptake (Vo(₂ peak)) on changes in thermoregulatory responses during exercise in a neutral climate has not been previously isolated because of complex interactions between Vo(₂ peak), metabolic heat production (H(prod)), body mass, and body surface area (BSA). It was hypothesized that Vo(₂ peak) does not independently alter changes in core temperature and sweating during exercise. Fourteen males, 7 high (HI) Vo(₂ peak): 60.1 ± 4.5 ml·kg⁻¹·min⁻¹; 7 low (LO) Vo(₂ peak): 40.3 ± 2.9 ml·kg⁻¹·min⁻¹ matched for body mass (HI: 78.2 ± 6.1 kg; LO: 78.7 ± 7.1 kg) and BSA (HI: 1.97 ± 0.08 m²; LO: 1.94 ± 0.08 m²), cycled for 60-min at 1) a fixed heat production (FHP trial) and 2) a relative exercise intensity of 60% Vo(₂ peak) (REL trial) at 24.8 ± 0.6°C, 26 ± 10% RH. In the FHP trial, H(prod) was similar between the HI (542 ± 38 W, 7.0 ± 0.6 W/kg or 275 ± 25 W/m²) and LO (535 ± 39 W, 6.9 ± 0.9 W/kg or 277 ± 29 W/m²) groups, while changes in rectal (T(re): HI: 0.87 ± 0.15°C, LO: 0.87 ± 0.18°C, P = 1.00) and aural canal (T(au): HI: 0.70 ± 0.12°C, LO: 0.74 ± 0.21°C, P = 0.65) temperature, whole-body sweat loss (WBSL) (HI: 434 ± 80 ml, LO: 440 ± 41 ml; P = 0.86), and steady-state local sweating (LSR(back)) (P = 0.40) were all similar despite relative exercise intensity being different (HI: 39.7 ± 4.2%, LO: 57.6 ± 8.0% Vo(2 peak); P = 0.001). At 60% Vo(2 peak), H(prod) was greater in the HI (834 ± 77 W, 10.7 ± 1.3 W/kg or 423 ± 44 W/m²) compared with LO (600 ± 90 W, 7.7 ± 1.4 W/kg or 310 ± 50 W/m²) group (all P < 0.001), as were changes in T(re) (HI: 1.43 ± 0.28°C, LO: 0.89 ± 0.19°C; P = 0.001) and T(au) (HI: 1.11 ± 0.21°C, LO: 0.66 ± 0.14°C; P < 0.001), and WBSL between 0 and 15, 15 and 30, 30 and 45, and 45 and 60 min (all P < 0.01), and LSR(back) (P = 0.02). The absolute esophageal temperature (T(es)) onset for sudomotor activity was ∼0.3°C lower (P < 0.05) in the HI group, but the change in T(es) from preexercise values before sweating onset was similar between groups. Sudomotor thermosensitivity during exercise were similar in both FHP (P = 0.22) and REL (P = 0.77) trials. In conclusion, changes in core temperature and sweating during exercise in a neutral climate are determined by H(prod), mass, and BSA, not Vo(₂ peak).

Numerical Investigation of Physicochemical Processes Occurring During Water Evaporation in the Surface Layer Pores of a Forest Combustible Material

NASA Astrophysics Data System (ADS)

Zhdanova, A. O.; Kuznetsov, G. V.; Strizhak, P. A.

2014-07-01

A numerical investigation of the physicochemical processes occurring during water evaporation from the pores of the surface layer of a forest combustible material has been carried out. The characteristic features of the suppression of the thermal decomposition reaction of a combustible material with water filling fullyits pores and formation of a water fi lm over its surface have been determined. The characteristic times of suppression of thermal decomposition reactions under various environmental conditions and the thickness and kinds of forest combustible material (birch leaves, pine and spruce needles, etc.) have been established.

Physicochemical pretreatments and hydrolysis of furfural residues via carbon-based sulfonated solid acid.

PubMed

Ma, Bao Jun; Sun, Yuan; Lin, Ke Ying; Li, Bing; Liu, Wan Yi

2014-03-01

Potential commercial physicochemical pretreatment methods, NaOH/microwave and NaOH/ultrasound were developed, and the carbon-based sulfonated solid acid catalysts were prepared for furfural residues conversion into reducing sugars. After the two optimum pretreatments, both the content of cellulose increased (74.03%, 72.28%, respectively) and the content of hemicellulose (94.11%, 94.17% of removal rate, respectively) and lignin (91.75%, 92.09% of removal rate, respectively) decreased in furfural residues. The reducing sugar yields of furfural residues with the two physicochemical pretreatments on coal tar-based solid acid reached 33.94% and 33.13%, respectively, higher than that pretreated via NaOH alone (27%) and comparable to that pretreated via NaOH/H2O2 (35.67%). The XRD patterns, IR spectra and SEM images show microwave and ultrasound improve the pretreatment effect. The results demonstrate the carbon-based sulfonated solid acids and the physicochemical pretreatments are green, effective, low-cost for furfural residues conversion. Copyright © 2014 Elsevier Ltd. All rights reserved.

Irradiated vacuum-packed lamb meat stored under refrigeration: microbiology, physicochemical stability and sensory acceptance.

PubMed

Fregonesi, R P; Portes, R G; Aguiar, A M M; Figueira, L C; Gonçalves, C B; Arthur, V; Lima, C G; Fernandes, A M; Trindade, M A

2014-06-01

Reducing spoilage and indicator bacteria is important for microbiological stability in meat and meat products. The objective was to evaluate the effect of different doses of gamma radiation on the shelf-life of lamb meat, vacuum-packed and stored under refrigeration, by assessing the microbiological safety, physicochemical stability and sensory quality. Lamb loin cuts (Longissimus dorsi) were irradiated with 1.5kGy and 3.0kGy. The samples, including control, were stored at 1±1°C during 56days. Samples were analyzed on zero, 14, 28, 42 and 56days by their microbiological and physicochemical characteristics. Sensory quality was carried out on day zero. The results showed a reduction (p<0.05) in the microbial load of the irradiated samples. The acceptance of lamb loins was not affected (p>0.05) by the radiation doses. Thus gamma irradiation at 3.0kGy was effective in reducing the content of microorganisms, without harming the physicochemical characteristics evaluated. Copyright © 2014 Elsevier Ltd. All rights reserved.

Torso geometry reconstruction and body surface electrode localization using three-dimensional photography.

PubMed

Perez-Alday, Erick A; Thomas, Jason A; Kabir, Muammar; Sedaghat, Golriz; Rogovoy, Nichole; van Dam, Eelco; van Dam, Peter; Woodward, William; Fuss, Cristina; Ferencik, Maros; Tereshchenko, Larisa G

We conducted a prospective clinical study (n=14; 29% female) to assess the accuracy of a three-dimensional (3D) photography-based method of torso geometry reconstruction and body surface electrodes localization. The position of 74 body surface electrocardiographic (ECG) electrodes (diameter 5mm) was defined by two methods: 3D photography, and CT (marker diameter 2mm) or MRI (marker size 10×20mm) imaging. Bland-Altman analysis showed good agreement in X (bias -2.5 [95% limits of agreement (LoA) -19.5 to 14.3] mm), Y (bias -0.1 [95% LoA -14.1 to 13.9] mm), and Z coordinates (bias -0.8 [95% LoA -15.6 to 14.2] mm), as defined by the CT/MRI imaging, and 3D photography. The average Hausdorff distance between the two torso geometry reconstructions was 11.17±3.05mm. Thus, accurate torso geometry reconstruction using 3D photography is feasible. Body surface ECG electrodes coordinates as defined by the CT/MRI imaging, and 3D photography, are in good agreement. Copyright © 2017 Elsevier Inc. All rights reserved.

Surface Craft Motion Parameter Estimation Using Multipath Delay Measurements from Hydrophones

DTIC Science & Technology

2011-12-01

the sensor is cd . The slant range of the source from the sensor at time t is given by 21222 ])([)( cc RtvtR +−= τ ( 1 ) where 2122 ])[( crtc dhhR...Surface Craft Motion Parameter Estimation Using Multipath Delay Measurements from Hydrophones Kam W. Lo # 1 and Brian G. Ferguson #2 # Maritime...Eveleigh, NSW 2015 Australia 1 kam.lo@dsto.defence.gov.au 2 brian.ferguson@dsto.defence.gov.au Abstract— An equation-error (EE) method is

Physico-chemical induced modification of seed germination and early development in artichoke (Cynara scolymus L.) using low energy plasma technology

NASA Astrophysics Data System (ADS)

Hosseini, Seyed Iman; Mohsenimehr, Soad; Hadian, Javad; Ghorbanpour, Mansour; Shokri, Babak

2018-01-01

In this study, low pressure non-thermal radiofrequency nitrogen plasma at very low power has been used to treat the artichoke seeds on the powered cathode for the first time. The influence of treatment time on the surface physical properties, germination rate, seedling growth, and enzyme activity of the seeds has been investigated. Results showed that plasma treatment considerably improved the germination rate and seedling growth. The root length grew by 28.5% and 50% and root dry weight increased by 13% and 53%, respectively, for 10 and 15 min of treatment. The same trend has been found for the shoot growth parameters although the greater stimulatory efficacy on root has been obtained. The nitrogen plasma treatment substantially made the seeds' surface hydrophilic which leads to 36.9% improvement in seed's water uptake at 15 min of treatment. Our study showed the activity of peroxidase and catalase enzymes slightly increased after the plasma treatment.

Physicochemical properties of surface charge-modified ZnO nanoparticles with different particle sizes

PubMed Central

Kim, Kyoung-Min; Choi, Mun-Hyoung; Lee, Jong-Kwon; Jeong, Jayoung; Kim, Yu-Ri; Kim, Meyoung-Kon; Paek, Seung-Min; Oh, Jae-Min

2014-01-01

In this study, four types of standardized ZnO nanoparticles were prepared for assessment of their potential biological risk. Powder-phased ZnO nanoparticles with different particle sizes (20 nm and 100 nm) were coated with citrate or L-serine to induce a negative or positive surface charge, respectively. The four types of coated ZnO nanoparticles were subjected to physicochemical evaluation according to the guidelines published by the Organisation for Economic Cooperation and Development. All four samples had a well crystallized Wurtzite phase, with particle sizes of ∼30 nm and ∼70 nm after coating with organic molecules. The coating agents were determined to have attached to the ZnO surfaces through either electrostatic interaction or partial coordination bonding. Electrokinetic measurements showed that the surface charges of the ZnO nanoparticles were successfully modified to be negative (about −40 mV) or positive (about +25 mV). Although all the four types of ZnO nanoparticles showed some agglomeration when suspended in water according to dynamic light scattering analysis, they had clearly distinguishable particle size and surface charge parameters and well defined physicochemical properties. PMID:25565825

Ion-ion correlation, solvent excluded volume and pH effects on physicochemical properties of spherical oxide nanoparticles.

PubMed

Ovanesyan, Zaven; Aljzmi, Amal; Almusaynid, Manal; Khan, Asrar; Valderrama, Esteban; Nash, Kelly L; Marucho, Marcelo

2016-01-15

One major source of complexity in the implementation of nanoparticles in aqueous electrolytes arises from the strong influence that biological environments has on their physicochemical properties. A key parameter for understanding the molecular mechanisms governing the physicochemical properties of nanoparticles is the formation of the surface charge density. In this article, we present an efficient and accurate approach that combines a recently introduced classical solvation density functional theory for spherical electrical double layers with a surface complexation model to account for ion-ion correlation and excluded volume effects on the surface titration of spherical nanoparticles. We apply the proposed computational approach to account for the charge-regulated mechanisms on the surface chemistry of spherical silica (SiO2) nanoparticles. We analyze the effects of the nanoparticle size, as well as pH level and electrolyte concentration of the aqueous solution on the nanoparticle's surface charge density and Zeta potential. We validate our predictions for 580Å and 200Å nanoparticles immersed in acid, neutral and alkaline mono-valent aqueous electrolyte solutions against experimental data. Our results on mono-valent electrolyte show that the excluded volume and ion-ion correlations contribute significantly to the surface charge density and Zeta potential of the nanoparticle at high electrolyte concentration and pH levels, where the solvent crowding effects and electrostatic screening have shown a profound influence on the protonation/deprotonation reactions at the liquid/solute interface. The success of this approach in describing physicochemical properties of silica nanoparticles supports its broader application to study other spherical metal oxide nanoparticles. Copyright © 2015 Elsevier Inc. All rights reserved.

Advanced oxygen-hydrocarbon rocket engine study

NASA Technical Reports Server (NTRS)

Obrien, C. J.; Ewen, R. L.

1981-01-01

This study identifies and evaluates promising LO2/HC rocket engine cycles, produces a consistent and reliable data base for vehicle optimization and design studies, demonstrates the significance of propulsion system improvements, and selects the critical technology areas necessary to realize an improved surface to orbit transportation system. Parametric LO2/HC engine data were generated over a range of thrust levels from 890 to 6672 kN (200K to 1.5M 1bF) and chamber pressures from 6890 to 34500 kN (1000 to 5000 psia). Engine coolants included RP-1, refined RP-1, LCH4, LC3H8, LO2, and LH2. LO2/RP-1 G.G. cycles were found to be not acceptable for advanced engines. The highest performing LO2/RP-1 staged combustion engine cycle utilizes LO2 as the coolant and incorporates an oxidizer rich preburner. The highest performing cycle for LO2/LCH4 and LO2/LC3H8 utilizes fuel cooling and incorporates both fuel and oxidizer rich preburners. LO2/HC engine cycles permitting the use of a third fluid LH2 coolant and an LH2 rich gas generator provide higher performance at significantly lower pump discharge pressures. The LO2/HC dual throat engine, because of its high altitude performance, delivers the highest payload for the vehicle configuration that was investigated.

Optimization of an organic yogurt based on sensorial, nutritional, and functional perspectives.

PubMed

Karnopp, Ariadne Roberto; Oliveira, Katherine Guimarães; de Andrade, Eriel Forville; Postingher, Bruna Mara; Granato, Daniel

2017-10-15

The effects of purple grape juice (PGJ), grape skin flour (GSF), and oligofructose (OLI) on proximate composition, total phenolic content (TPC), antioxidant activity (AA), sensory, physicochemical, and textural properties of yogurts were analyzed using response surface methodology. Multiple regression models were proposed and results showed that PGJ increased the viscosity, AA, and TPC, while GSF increased the ash and total fiber contents of yogurts. GSF and OLI increased the hardness and consistency. A simultaneous optimization was performed to maximize TPC, ash and fibers contents, and sensory acceptance: a yogurt containing 1.7% GSF and 8.0% PGJ had a high fiber (5.60±0.13%) and ash (0.76±0.02%) contents, TPC (28.32±2.10mg GAE/100g), AA toward DPPH (57.85±1.36mg AAE/100g), and total reducing capacity (28.86±5.19mg QE/100g). The optimized yogurt had 79% acceptability index, indicating the use of PGJ and GSF is a feasible alternative to increase the functional properties of yogurts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Physicochemical properties of sugar palm starch film: Effect of concentration and plasticizer type

NASA Astrophysics Data System (ADS)

Prasetyo, D. J.; Apriyana, W.; Jatmiko, T. H.; Hernawan; Hayati, S. N.; Rosyida, V. T.; Pranoto, Y.; Poeloengasih, C. D.

2017-07-01

In order to find the best formula for capsule shell production, this present work dealt with exploring physicochemical properties of sugar palm (Arenga pinnata) starch film as a function of different kinds and various concentrations of plasticizers. The films were prepared by casting method at different formula: starch 9-11%, glycerol or sorbitol 35-45% and polyethylene-glycol 400 (PEG 400) 5-9%. Appearance, thickness, retraction ratio, moisture content, swelling behavior and solubility of the film in water were analyzed. Both glycerol and sorbitol are compatible with starch matrix. On the contrary, PEG 400 did not form a film with suitable characteristics. The result reveals that glycerol- and sorbitol-plasticized films appeared translucent, homogenous, smooth and slightly brown in all formulas. Different type and concentration of plasticizers altered the physicochemical of film in different ways. The sorbitol-plasticized film had lower moisture content (≤ 10%) than that of glycerol-plasticized film (≥ 18%). In contrast, film plasticized with sorbitol showed higher solubility in water (28-35%) than glycerol-plasticized film (22-28%). As the concentration of both plasticizers increased, there was an increasing tendency on thickness and solubility in water. Conversely, retraction ratio and swelling degree decreased when both plasticizers concentration increased. In conclusion, the sorbitol-plasticized film showed a potency to be developed as hard capsule material.

Physicochemical properties and analysis of Malaysian palm fatty acid distilled

NASA Astrophysics Data System (ADS)

Jumaah, Majd Ahmed; Yusoff, Mohamad Firdaus Mohamad; Salimon, Jumat

2018-04-01

Palm fatty acid distillate (PFAD) is cheap and valuable byproduct of edible oil processing industries. This study was carried out to determine the physicochemical properties of Malaysian palm fatty acid distilled (PFAD). The physicochemical properties showed that the free fatty acid (FFA %), acid value, iodine value, saponification value, unsaponifiable matter, hydroxyl value, specific gravity at 28°C, moisture content, viscosity at 40°C and colour at 28°C values were 87.04± 0.1 %, 190.6± 1 mg/g, 53.3±0.2 mg/g, 210.37±0.8 mg/g, 1.5±0.1%, 47±0.2 mg/g, 0.87 g/ml, 0.63 %, 30 cSt and yellowish respectively. Gas chromatography (GC) was used to determine the fatty acid (FA) composition in PFAD. The fatty acids were found to be comprised mostly with 48.9 % palmitic acid (C16:0), 37.4 % oleic acid (C18:1), 9.7 % linoleic acid (C18:2), 2.7 % stearic acid (C18:0) and 1.1 % myristic acid (C14:0). The analysis of high performance liquid chromatography (HPLC) has resulted with 99.2 % of FFA, while diacylglycerol and monoacylglycerol were 0.69 and 0.062 % respectively.

Screening for oxidative damage by engineered nanomaterials: a comparative evaluation of FRAS and DCFH

NASA Astrophysics Data System (ADS)

Pal, Anoop K.; Hsieh, Shu-Feng; Khatri, Madhu; Isaacs, Jacqueline A.; Demokritou, Philip; Gaines, Peter; Schmidt, Daniel F.; Rogers, Eugene J.; Bello, Dhimiter

2014-02-01

Several acellular assays are routinely used to measure oxidative stress elicited by engineered nanomaterials (ENMs), yet little comparative evaluations of such methods exist. This study compares for the first time the performance of the dichlorofluorescein (DCFH) assay which measures reactive oxygen species (ROS) generation, to that of the ferric-reducing ability of serum (FRAS) assay, which measures biological oxidant damage in serum. A diverse set of 28 commercially important and extensively characterized ENMs were tested on both the assays. Intracellular oxidative stress was also assessed on a representative subset of seven ENMs in THP-1 (phorbol 12-myristate 13-acetate matured human monocytes) cells. Associations between assay responses and ENM physicochemical properties were assessed via correlation and regression analysis. DCFH correlated strongly with FRAS after dose normalization for mass ( R 2 = 0.78) and surface area ( R 2 = 0.68). Only 10/28 ENMs were positive in DCFH versus 21/28 in FRAS. Both assays were strongly associated with specific surface area and transition metal content. Qualitatively, a similar response ranking was observed for acellular FRAS and intracellular reduced:oxidized glutathione ratio (GSH:GSSG) in cells. Quantitatively, weak correlation was found between intracellular GSSG and FRAS or DCFH ( R 2 < 0.25) even after calculating effective dose to cells. The FRAS assay was more sensitive than DCFH, especially for ENMs with low to moderate oxidative damage potential, and may serve as a more biologically relevant substitute for acellular ROS measurements of ENMs. Further in vitro and in vivo validations of FRAS against other toxicological endpoints with larger datasets are recommended.

Correlation between physicochemical properties of modified clinoptilolite and its performance in the removal of ammonia-nitrogen.

PubMed

Dong, Yingbo; Lin, Hai; He, Yinhai

2017-03-01

The physicochemical properties of the 24 modified clinoptilolite samples and their ammonia-nitrogen removal rates were measured to investigate the correlation between them. The modified clinoptilolites obtained by acid modification, alkali modification, salt modification, and thermal modification were used to adsorb ammonia-nitrogen. The surface area, average pore width, macropore volume, mecropore volume, micropore volume, cation exchange capacity (CEC), zeta potential, silicon-aluminum ratios, and ammonia-nitrogen removal rate of the 24 modified clinoptilolite samples were measured. Subsequently, the linear regression analysis method was used to research the correlation between the physicochemical property of the different modified clinoptilolite samples and the ammonia-nitrogen removal rate. Results showed that the CEC was the major physicochemical property affecting the ammonia-nitrogen removal performance. According to the impacts from strong to weak, the order was CEC > silicon-aluminum ratios > mesopore volume > micropore volume > surface area. On the contrary, the macropore volume, average pore width, and zeta potential had a negligible effect on the ammonia-nitrogen removal rate. The relational model of physicochemical property and ammonia-nitrogen removal rate of the modified clinoptilolite was established, which was ammonia-nitrogen removal rate = 1.415[CEC] + 173.533 [macropore volume] + 0.683 [surface area] + 4.789[Si/Al] - 201.248. The correlation coefficient of this model was 0.982, which passed the validation of regression equation and regression coefficients. The results of the significance test showed a good fit to the correlation model.

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

Pawlowski, L.; Lacy, W.J.; Dlugosz, J.J.

This book contains the Proceedings from an International Conference on Chemistry for the Protection of the Environment held in Lublin, Poland, September 4-7, 1989. It opens with a tribute to Andre Van Haute who was a member of the Committee on the title subject and who died in 1989. This is followed by a preface by the editors and 70 chapters, which are grouped under the following headings: General Problems; Monitoring Methods for Surface and Ground water and Analysis of Pollutants; Pathways of Chemicals in the Environment; Physicochemical Treatment: Ion Exchange; Physicochemical Treatment: Coagulation, Flocculation and Sorption; Physicochemical Treatment: Oxidation-Reductionmore » Processes; Physicochemical Treatment; Membrane Processes; and Miscellaneous Methods for Removal of Pollutants. There is a brief subject index.« less

A Biophysico-Computational Perspective of Breast Cancer Pathogenesis and Treatment Response

DTIC Science & Technology

2011-03-01

modification maps. Nat Rev Genet 8, 286-298 (2007). 51 Lo , P. K. & Sukumar, S. Epigenomics and breast cancer. Pharmacogenomics 9, 1879-1902 (2008). 52...P e rc e n t c e ll d e a th *** *** *** 0 7 14 21 28 0 100 200 300 400 Vector N-CoR2 Time after IR (days) C o lo n y s iz e ( m ) *** *** *** MDA...orchestrated processes.  In this respect, HOXA9 plays an important role in skeletal (41),  uro - genital tract (42), kidney (43), and mammary gland development

Data on changes in red wine phenolic compounds, headspace aroma compounds and sensory profile after treatment of red wines with activated carbons with different physicochemical characteristics.

PubMed

Filipe-Ribeiro, Luís; Milheiro, Juliana; Matos, Carlos C; Cosme, Fernanda; Nunes, Fernando M

2017-06-01

Data in this article presents the changes on phenolic compounds, headspace aroma composition and sensory profile of a red wine spiked with 4-ethylphenol and 4-ethylguaiacol and treated with seven activated carbons with different physicochemical characteristics, namely surface area, micropore volume and mesopore volume ("Reduction of 4-ethylphenol and 4-ethylguaiacol in red wine by activated carbons with different physicochemical characteristics: impact on wine quality" Filipe-Ribeiro et al. (2017) [1]). Data on the physicochemical characteristics of the activated carbons are shown. Statistical data on the sensory expert panel consistency by General Procrustes Analysis is shown. Statistical data is also shown, which correlates the changes in chemical composition of red wines with the physicochemical characteristics of activated carbons used.

CD4+ T Cells Coexpressing CD134 (OX40) Harbor Significantly Increased Levels of Human Herpesvirus 6B DNA Following Umbilical Cord Blood Transplantation.

PubMed

Pritchett, Joshua C; Green, Jaime S; Thomm, Angela M; Knox, Konstance K; Verneris, Michael R; Lund, Troy C

2016-12-15

Human herpesvirus 6B (HHV-6B) commonly reactivates after umbilical cord blood transplantation (UCBT) and is associated with delayed engraftment, fever, rash, and central nervous system dysfunction. Recently, CD134 (OX40) has been implicated as a potential viral entry receptor. We evaluated CD4 + CD134 + / neg-lo and CD8 + CD134 + / neg-lo cells at day 28 after UCBT in 20 subjects with previously documented HHV-6 reactivation and persistent viremia. Analysis of CD4 + CD134 + cells as compared to CD4 + CD134 neg-lo cells showed 0.308 versus 0.129 copies of HHV-6B/cell (P = .0002). CD8 + CD134 +/neg-lo cells contained little to no HHV-6B copies. Following UCBT, CD4 + CD134 + cells harbor significantly increased levels of HHV-6B, suggesting that CD134 (OX40) may facilitate viral entry. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Some physicochemical properties of surface layer soils shelterbelts in agricultural landscape

NASA Astrophysics Data System (ADS)

Jaskulska, R.; Szajdak, L.

2009-04-01

Shelterbelts belong to very efficient biogeochemical barriers. They decrease the migration of chemical compounds between ecosystems. The investigations were carried out in the Chlapowski's Agroecological Park in Turew situated 40 km South-West of Poznań, Poland. This area is located on loamy soils, which contains 70% cultivated fields and 14% shelterbelts and small afforestations. The shelterbelts represent different ages and the content of plants as well as humus quantity in surface layer. The first one is 100-year-old shelterbelt, where predominant species is Crataegus monogyna Jacq., Quercus rober L., and Fraxinus excelsior (L.) and is characterized by a well-developed humus level. The other one is 14-year-old shelterbelt. It includes 13 species of trees and revealed a small amount of humus. The soil under both shelterbelts is mineral, grey-brown podzolic in surface layer compound from light loamy sands and weakly loamy sands. The soil samples were taken from surface layer (0-20 cm). pH 1N KCl, hydrolytic acidity, cation-exchange capacity, total proper area, total organic carbon and dissociation constants were determined in soils. The study showed that the soil under shelterbelts revealed acidic properties. It was observed that soils of 100-year-old shelterbelt characterizing lowest values pH = 4.2 revealed highest values of hydrolytic acidity equaled to 7.8 cmol(+)ṡkg-1. The physicochemical properties of investigated soils shoved specific surface areas (22.8 m2ṡg-1), cationic sorptive capacity (12.9 cmol(+)ṡkg-1). TOC (1.6%) 100-year-old shelterbelt was higher than in 14-year-old shelterbelt. The dissociation constants were determined by potentiometric titration. This investigation revealed that the pK value was the highest in the humus of 100-year-old shelterbelt (pKa = 3.1). However, soils of 14-year-old shelterbelt characterized by the lovest pK equaled to 2.8. The surface layer soils shelterbelts in agricultural landscape with good humus development are the most acidic of the soils studied. Most values of acidity, full specific surface areas and sorption capacity are specific to the surface layer of 100-year-old shelterbelt with the highest total organic carbon content. This work was supported by a grant No. 2295/B/P01/2008/35 founded by Polish Ministry of Education.

The contribution of proprioceptive information to postural control in elderly and patients with Parkinson's disease with a history of falls.

PubMed

Bekkers, Esther M J; Dockx, Kim; Heremans, Elke; Vercruysse, Sarah; Verschueren, Sabine M P; Mirelman, Anat; Nieuwboer, Alice

2014-01-01

Proprioceptive deficits negatively affect postural control but their precise contribution to postural instability in Parkinson's disease (PD) is unclear. We investigated if proprioceptive manipulations differentially affect balance, measured by force plates, during quiet standing in 13 PD patients and 13 age-matched controls with a history of falls. Perceived limits of stability (LoS) were derived from the differences between maximal center of pressure (CoP) displacement in anterior-posterior (AP) and medio-lateral (ML) direction during a maximal leaning task. Task conditions comprised standing with eyes open (EO) and eyes closed (EC): (1) on a stable surface; (2) an unstable surface; and (3) with Achilles tendon vibration. CoP displacements were calculated as a percentage of their respective LoS. Perceived LoS did not differ between groups. PD patients showed greater ML CoP displacement than elderly fallers (EF) across all conditions (p = 0.043) and tended to have higher postural sway in relation to the LoS (p = 0.050). Both groups performed worse on an unstable surface and during tendon vibration compared to standing on a stable surface with EO and even more so with EC. Both PD and EF had more AP sway in all conditions with EC compared to EO (p < 0.001) and showed increased CoP displacements when relying on proprioception only compared to standing with normal sensory input. This implies a similar role of the proprioceptive system in postural control in fallers with and without PD. PD fallers showed higher ML sway after sensory manipulations, as a result of which these values approached their perceived LoS more closely than in EF. We conclude that despite a similar fall history, PD patients showed more ML instability than EF, irrespective of sensory manipulation, but had a similar reliance on ankle proprioception. Hence, we recommend that rehabilitation and fall prevention for PD should focus on motor rather than on sensory aspects.

Physico-chemical stability of eribulin mesylate containing concentrate and ready-to-administer solutions.

PubMed

Spindeldreier, Kirsten; Thiesen, Judith; Lipp, Hans-Peter; Krämer, Irene

2014-06-01

The aim of this study was to determine the stability of commercially available eribulin mesylate containing injection solution as well as diluted ready-to-administer solutions stored under refrigeration or at room temperature. Stability was studied by a novel developed stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) assay with ultraviolet detection (detection wavelength 200 nm). Triplicate test solutions of eribulin mesylate containing injection concentrate (0.5 mg/mL) and with 0.9% sodium chloride solution diluted ready-to-administer preparations (0.205 mg/mL eribulin mesylate in polypropylene (PP) syringes, 0.020 mg/mL eribulin mesylate in polypropylene/polyethylene (PE) bags) were stored protected from light either at room temperature (25) or under refrigeration (2-8). Samples were withdrawn on day 0 (initial), 1, 3, 5, 7, 14, 21 and 28 of storage and assayed. Physical stability was determined by measuring the pH value once a week and checking for visible precipitations or colour changes. The stability tests revealed that concentrations of eribulin mesylate remained unchanged over a period of 28 days irrespective of concentration, container material or storage temperature. Neither colour changes nor visible particles have been observed. The pH value varied slightly over time but remained in the stability favourable range of 5-9. Eribulin mesylate injection (0.5 mg/mL) is physico-chemically stable over a period of 28 days after first puncture of the vial. After dilution with 0.9% NaCl vehicle solution, ready-to-administer eribulin mesylate injection solutions (0.205 mg/mL in PP syringe) and infusion solutions (0.02 mg/mL in prefilled PP/PE bags) are physico-chemically stable for a period of at least four weeks either refrigerated or stored at room temperature. For microbiological reasons storage under refrigeration is recommended.

Physicochemical variation of mica surface by low energy ion beam irradiation

NASA Astrophysics Data System (ADS)

Bhowmik, Dipak; Karmakar, Prasanta

2018-05-01

We report the transformation of smooth and hydrophilic mica surface to a patterned and hydrophobic surface by 12 keV Ar+ and N+ ion bombardment at oblique ion incidence. Periodic ripple pattern has been found on the mica surface when nitrogen like lighter or argon like heavier ions are bombarded at an angle 60° with respect to the surface normal. During ion bombardment the different components of multi-elemental mica are eroded at different rate; as a result surface chemistry is changed, as well as a surface ripple pattern is developed on the surface due to the generation of surface instabilities. The change of surface chemistry and presence of pattern change the hydrophilic nature of the mica surface. X-ray photoelectron spectroscopy (XPS) study of irradiated mica surface shows that the upper K atoms are sputtered most. The vertical and lateral dimensions of the surface patterns are controlled by varying the ion fluence. Contact angle measurement of un-irradiated and irradiated mica surface shows a certain change from hydrophilicity to hydrophobicity. The physicochemical changes of mica surface due to Ar+ and N+ ion bombardment have been discussed.

Rho-associated kinase (ROCK) inhibition reverses low cell activity on hydrophobic surfaces.

PubMed

Tian, Yu Shun; Kim, Hyun Jung; Kim, Hyun-Man

2009-08-28

Hydrophobic polymers do not offer an adequate scaffold surface for cells to attach, migrate, proliferate, and differentiate. Thus, hydrophobic scaffolds for tissue engineering have traditionally been physicochemically modified to enhance cellular activity. However, modifying the surface by chemical or physical treatment requires supplementary engineering procedures. In the present study, regulation of a cell signal transduction pathway reversed the low cellular activity on a hydrophobic surface without surface modification. Inhibition of Rho-associated kinase (ROCK) by Y-27632 markedly enhanced adhesion, migration, and proliferation of osteoblastic cells cultured on a hydrophobic polystyrene surface. ROCK inhibition regulated cell-cycle-related molecules on the hydrophobic surface. This inhibition also decreased expression of the inhibitors of cyclin-dependent kinases such as p21(cip1) and p27(kip1) and increased expression of cyclin A and D. These results indicate that defective cellular activity on the hydrophobic surface can be reversed by the control of a cell signal transduction pathway without physicochemical surface modification.

Power-Combined GaN Amplifier with 2.28-W Output Power at 87 GHz

NASA Technical Reports Server (NTRS)

Fung, King Man; Ward, John; Chattopadhyay, Goutam; Lin, Robert H.; Samoska, Lorene A.; Kangaslahti, Pekka P.; Mehdi, Imran; Lambrigtsen, Bjorn H.; Goldsmith, Paul F.; Soria, Mary M.;

3D Visualization of Urban Area Using Lidar Technology and CityGML

NASA Astrophysics Data System (ADS)

Popovic, Dragana; Govedarica, Miro; Jovanovic, Dusan; Radulovic, Aleksandra; Simeunovic, Vlado

2017-12-01

3D models of urban areas have found use in modern world such as navigation, cartography, urban planning visualization, construction, tourism and even in new applications of mobile navigations. With the advancement of technology there are much better solutions for mapping earth’s surface and spatial objects. 3D city model enables exploration, analysis, management tasks and presentation of a city. Urban areas consist of terrain surfaces, buildings, vegetation and other parts of city infrastructure such as city furniture. Nowadays there are a lot of different methods for collecting, processing and publishing 3D models of area of interest. LIDAR technology is one of the most effective methods for collecting data due the large amount data that can be obtained with high density and geometrical accuracy. CityGML is open standard data model for storing alphanumeric and geometry attributes of city. There are 5 levels of display (LoD0, LoD1, LoD2, LoD3, LoD4). In this study, main aim is to represent part of urban area of Novi Sad using LIDAR technology, for data collecting, and different methods for extraction of information’s using CityGML as a standard for 3D representation. By using series of programs, it is possible to process collected data, transform it to CityGML and store it in spatial database. Final product is CityGML 3D model which can display textures and colours in order to give a better insight of the cities. This paper shows results of the first three levels of display. They consist of digital terrain model and buildings with differentiated rooftops and differentiated boundary surfaces. Complete model gives us a realistic view of 3D objects.

Mining for osteogenic surface topographies: In silico design to in vivo osseo-integration.

PubMed

Hulshof, Frits F B; Papenburg, Bernke; Vasilevich, Aliaksei; Hulsman, Marc; Zhao, Yiping; Levers, Marloes; Fekete, Natalie; de Boer, Meint; Yuan, Huipin; Singh, Shantanu; Beijer, Nick; Bray, Mark-Anthony; Logan, David J; Reinders, Marcel; Carpenter, Anne E; van Blitterswijk, Clemens; Stamatialis, Dimitrios; de Boer, Jan

2017-08-01

Stem cells respond to the physicochemical parameters of the substrate on which they grow. Quantitative material activity relationships - the relationships between substrate parameters and the phenotypes they induce - have so far poorly predicted the success of bioactive implant surfaces. In this report, we screened a library of randomly selected designed surface topographies for those inducing osteogenic differentiation of bone marrow-derived mesenchymal stem cells. Cell shape features, surface design parameters, and osteogenic marker expression were strongly correlated in vitro. Furthermore, the surfaces with the highest osteogenic potential in vitro also demonstrated their osteogenic effect in vivo: these indeed strongly enhanced bone bonding in a rabbit femur model. Our work shows that by giving stem cells specific physicochemical parameters through designed surface topographies, differentiation of these cells can be dictated. Copyright © 2017 Elsevier Ltd. All rights reserved.

Physicochemical characterization of porcine bone-derived grafting material and comparison with bovine xenografts for dental applications.

PubMed

Lee, Jung Heon; Yi, Gyu Sung; Lee, Jin Woong; Kim, Deug Joong

2017-12-01

The physicochemical properties of a xenograft are very important because they strongly influence the bone regeneration capabilities of the graft material. Even though porcine xenografts have many advantages, only a few porcine xenografts are commercially available, and most of their physicochemical characteristics have yet to be reported. Thus, in this work we aimed to investigate the physicochemical characteristics of a porcine bone grafting material and compare them with those of 2 commercially available bovine xenografts to assess the potential of xenogenic porcine bone graft materials for dental applications. We used various characterization techniques, such as scanning electron microscopy, the Brunauer-Emmett-Teller adsorption method, atomic force microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and others, to compare the physicochemical properties of xenografts of different origins. The porcine bone grafting material had relatively high porosity (78.4%) and a large average specific surface area (SSA; 69.9 m 2 /g), with high surface roughness (10-point average roughness, 4.47 µm) and sub-100-nm hydroxyapatite crystals on the surface. Moreover, this material presented a significant fraction of sub-100-nm pores, with negligible amounts of residual organic substances. Apart from some minor differences, the overall characteristics of the porcine bone grafting material were very similar to those of one of the bovine bone grafting material. However, many of these morphostructural properties were significantly different from the other bovine bone grafting material, which exhibited relatively smooth surface morphology with a porosity of 62.0% and an average SSA of 0.5 m 2 /g. Considering that both bovine bone grafting materials have been successfully used in oral surgery applications in the last few decades, this work shows that the porcine-derived grafting material possesses most of the key physiochemical characteristics required for its application as a highly efficient xenograft material for bone replacement.

Acellular assessments of engineered-manufactured nanoparticle biological surface reactivity

EPA Science Inventory

It is critical to assess the surface properties and reactivity of engineered-manufactured nanoparticles (NPs) as these will influence their interactions with biological systems, biokinetics and toxicity. We examined the physicochemical properties and surface reactivity of metal o...

Tolerance of the frequency deviation of LO sources at a MIMO system

NASA Astrophysics Data System (ADS)

Xiao, Jiangnan; Li, Xingying; Zhang, Zirang; Xu, Yuming; Chen, Long; Yu, Jianjun

2015-11-01

We analyze and simulate the tolerance of frequency offset at a W-band optical-wireless transmission system. The transmission system adopts optical polarization division multiplexing (PDM), and multiple-input multiple-output (MIMO) reception. The transmission signal adopts optical quadrature phase shift keying (QPSK) modulation, and the generation of millimeter-wave is based on the optical heterodyning technique. After 20-km single-mode fiber-28 (SMF-28) transmission, tens of Gb/s millimeter-wave signal is delivered. At the receiver, two millimeter-wave signals are down-converted into electrical intermediate-frequency (IF) signals in the analog domain by mixing with two electrical local oscillators (LOs) with different frequencies. We investigate the different frequency LO effect on the 2×2 MIMO system performance for the first time, finding that the process during DSP of implementing frequency offset estimation (FOE) before cascaded multi-modulus-algorithm (CMMA) equalization can get rid of the inter-channel interference (ICI) and improve system bit-error-ratio (BER) performance in this type of transmission system.

Active membrane having uniform physico-chemically functionalized ion channels

DOEpatents

Gerald, II, Rex E; Ruscic, Katarina J; Sears, Devin N; Smith, Luis J; Klingler, Robert J; Rathke, Jerome W

2012-09-24

The present invention relates to a physicochemically-active porous membrane for electrochemical cells that purports dual functions: an electronic insulator (separator) and a unidirectional ion-transporter (electrolyte). The electrochemical cell membrane is activated for the transport of ions by contiguous ion coordination sites on the interior two-dimensional surfaces of the trans-membrane unidirectional pores. One dimension of the pore surface has a macroscopic length (1 nm-1000 .mu.m) and is directed parallel to the direction of an electric field, which is produced between the cathode and the anode electrodes of an electrochemical cell. The membrane material is designed to have physicochemical interaction with ions. Control of the extent of the interactions between the ions and the interior pore walls of the membrane and other materials, chemicals, or structures contained within the pores provides adjustability of the ionic conductivity of the membrane.

Effect of physicochemical action on the aggregative properties of detonation-synthesized nanodiamonds

NASA Astrophysics Data System (ADS)

Fan, Z. W.; Ilnitska, H.; Lysakovskyi, V.; Ivakhnenko, S.; Kovalenko, T.

2018-01-01

The results of researches of physicochemical action on aggregate properties of nanodiamond are presented. The kinetics of aggregation of nanodiamond powder was studied as a function of time, temperature, and pH of the solution. The effect of the sp2-sp3 hybridization ratio of carbon in nanodiamond powders on their aggregation was studied. It is shown that the presence of non-diamond carbon in detonation synthesis nanodiamond powders leads to the increase of the mean diameters of particles, i.e., their agglomeration. The theoretical justification of the aggregation mechanism is proposed. It is shown that it is possible to control aggregative properties of nanodiamond powders by physicochemical influences, e.g., gas-phase thermal treatment to reduce the size of agglomerates and to create a well-developed reconstructed surface of diamond particles with a low content of functional groups on their surface.

Effect of casein and inulin addition on physico-chemical characteristics of low fat camel dairy cream.

PubMed

Ziaeifar, Leila; Labbafi Mazrae Shahi, Mohsen; Salami, Maryam; Askari, Gholam R

2018-05-21

The effect of the addition of the camel casein fraction on some physico-chemical properties of low fat camel milk cream was studied. Oil-in-water emulsions, 25, 30, and 35 (w/w) fat, were prepared using inulin, camel skim milk, milk fat and variable percentages of casein (1, 2, and 3% w/w). The droplet size, ζ-potential, surface protein concentration, viscosity and surface tension of low fat dairy creams was measured. Cream containing 2% (w/w) casein had better stability. The modifications in physico-chemical properties appeared to be driven by changes in particle size distribution caused by droplet aggregation. The cream containing 2% casein leads to a gradual decrease in droplet size, as the particle size decreased, apparent viscosity increased. When casein concentration increased, ζ-potential decreased due to combination of c terminal (negative charge) with the surface of fat particles but steric repulsion improved textural properties. Cream with 30% fat and 2% casein had the best result. Copyright © 2018 Elsevier B.V. All rights reserved.

Evolution of Starspots on LO Pegasi

NASA Astrophysics Data System (ADS)

Harmon, Robert; Bloodgood, Felise; Martin, Alec; Pellegrin, Kyle

2018-01-01

LO Pegasi is a young solar analog, a K main-sequence star that rotates with a period of 10.1538 hr. The rapid rotation yields a strong stellar dynamo associated with large starspots on the surface, which are regions where the magnetic field inhibits the convective transport of energy from below, so that the spots are cooler and thus darker than the surrounding photosphere. The star thus exhibits rotational modulation of its light curve as the starspots are carried into and out of view of Earth. CCD images of LO Peg were acquired at Perkins Observatory in Delaware, OH through standard B, V, R, and I photometric filters from 2017 June 1 to July 20. After subtracting dark frames and flat fielding the images, differential aperture photometry was performed to yield light curves through each of the four filters. The resulting light curves that were then analyzed via the Light-curve Inversion program created by one of us (Harmon) to produce surface maps. Our observations indicated that LO Pegasi’s light curve changed in both amplitude and shape between 2017 June and July, while its maximum brightness did not change. We present maps corresponding to these two distinct light curves, along with maps for data acquired from 2006-2016.

Design of Electron-Beam Controlled Switches.

DTIC Science & Technology

1982-11-24

I- HYBRID (OPENING/CLOSING) LO LSW E EBCS(O) 11111 C ESCS(C) T TJL (a) !z 0 TIME E OPEN I IM 0 TIM Fig. 2 - Circuit diagram illustrating the...34 l i iN l II -ItB "i ’ : i = i . • ’ " -.. ~...2 .. .. . * INDUCTIVE (OPENING) (a)(a) LO LSW , io E EBCS(O) III1t RL ___T (a) "ii’ (b) ) IJ.: z 0...switch pressure is given by Eq. (28) with EJ - 20 kV/cm, f. - 2 x lOs cm/V-s for N2-0 2 and ko - 0.25 (Eq. (26)): P -1700 Torr 2.3 atm. (33) The switch

Protein-Protein Interaction Site Predictions with Three-Dimensional Probability Distributions of Interacting Atoms on Protein Surfaces

PubMed Central

Chen, Ching-Tai; Peng, Hung-Pin; Jian, Jhih-Wei; Tsai, Keng-Chang; Chang, Jeng-Yih; Yang, Ei-Wen; Chen, Jun-Bo; Ho, Shinn-Ying; Hsu, Wen-Lian; Yang, An-Suei

2012-01-01

Protein-protein interactions are key to many biological processes. Computational methodologies devised to predict protein-protein interaction (PPI) sites on protein surfaces are important tools in providing insights into the biological functions of proteins and in developing therapeutics targeting the protein-protein interaction sites. One of the general features of PPI sites is that the core regions from the two interacting protein surfaces are complementary to each other, similar to the interior of proteins in packing density and in the physicochemical nature of the amino acid composition. In this work, we simulated the physicochemical complementarities by constructing three-dimensional probability density maps of non-covalent interacting atoms on the protein surfaces. The interacting probabilities were derived from the interior of known structures. Machine learning algorithms were applied to learn the characteristic patterns of the probability density maps specific to the PPI sites. The trained predictors for PPI sites were cross-validated with the training cases (consisting of 432 proteins) and were tested on an independent dataset (consisting of 142 proteins). The residue-based Matthews correlation coefficient for the independent test set was 0.423; the accuracy, precision, sensitivity, specificity were 0.753, 0.519, 0.677, and 0.779 respectively. The benchmark results indicate that the optimized machine learning models are among the best predictors in identifying PPI sites on protein surfaces. In particular, the PPI site prediction accuracy increases with increasing size of the PPI site and with increasing hydrophobicity in amino acid composition of the PPI interface; the core interface regions are more likely to be recognized with high prediction confidence. The results indicate that the physicochemical complementarity patterns on protein surfaces are important determinants in PPIs, and a substantial portion of the PPI sites can be predicted correctly with the physicochemical complementarity features based on the non-covalent interaction data derived from protein interiors. PMID:22701576

Optically Sectioned Imaging of Microvasculature of In-Vivo and Ex-Vivo Thick Tissue Models with Speckle-illumination HiLo Microscopy and HiLo Image Processing Implementation in MATLAB Architecture

NASA Astrophysics Data System (ADS)

Suen, Ricky Wai

The work described in this thesis covers the conversion of HiLo image processing into MATLAB architecture and the use of speckle-illumination HiLo microscopy for use of ex-vivo and in-vivo imaging of thick tissue models. HiLo microscopy is a wide-field fluorescence imaging technique and has been demonstrated to produce optically sectioned images comparable to confocal in thin samples. The imaging technique was developed by Jerome Mertz and the Boston University Biomicroscopy Lab and has been implemented in our lab as a stand-alone optical setup and a modification to a conventional fluorescence microscope. Speckle-illumination HiLo microscopy combines two images taken under speckle-illumination and standard uniform-illumination to generate an optically sectioned image that reject out-of-focus fluorescence. The evaluated speckle contrast in the images is used as a weighting function where elements that move out-of-focus have a speckle contrast that decays to zero. The experiments shown here demonstrate the capability of our HiLo microscopes to produce optically-sectioned images of the microvasculature of ex-vivo and in-vivo thick tissue models. The HiLo microscope were used to image the microvasculature of ex-vivo mouse heart sections prepared for optical histology and the microvasculature of in-vivo rodent dorsal window chamber models. Studies in label-free surface profiling with HiLo microscopy is also presented.

Hydrophobicity and Charge Shape Cellular Metabolite Concentrations

PubMed Central

Bar-Even, Arren; Noor, Elad; Flamholz, Avi; Buescher, Joerg M.; Milo, Ron

2011-01-01

What governs the concentrations of metabolites within living cells? Beyond specific metabolic and enzymatic considerations, are there global trends that affect their values? We hypothesize that the physico-chemical properties of metabolites considerably affect their in-vivo concentrations. The recently achieved experimental capability to measure the concentrations of many metabolites simultaneously has made the testing of this hypothesis possible. Here, we analyze such recently available data sets of metabolite concentrations within E. coli, S. cerevisiae, B. subtilis and human. Overall, these data sets encompass more than twenty conditions, each containing dozens (28-108) of simultaneously measured metabolites. We test for correlations with various physico-chemical properties and find that the number of charged atoms, non-polar surface area, lipophilicity and solubility consistently correlate with concentration. In most data sets, a change in one of these properties elicits a ∼100 fold increase in metabolite concentrations. We find that the non-polar surface area and number of charged atoms account for almost half of the variation in concentrations in the most reliable and comprehensive data set. Analyzing specific groups of metabolites, such as amino-acids or phosphorylated nucleotides, reveals even a higher dependence of concentration on hydrophobicity. We suggest that these findings can be explained by evolutionary constraints imposed on metabolite concentrations and discuss possible selective pressures that can account for them. These include the reduction of solute leakage through the lipid membrane, avoidance of deleterious aggregates and reduction of non-specific hydrophobic binding. By highlighting the global constraints imposed on metabolic pathways, future research could shed light onto aspects of biochemical evolution and the chemical constraints that bound metabolic engineering efforts. PMID:21998563

Characterisation of nanomaterial hydrophobicity using engineered surfaces

NASA Astrophysics Data System (ADS)

Desmet, Cloé; Valsesia, Andrea; Oddo, Arianna; Ceccone, Giacomo; Spampinato, Valentina; Rossi, François; Colpo, Pascal

2017-03-01

Characterisation of engineered nanomaterials (NMs) is of outmost importance for the assessment of the potential risks arising from their extensive use. NMs display indeed a large variety of physico-chemical properties that drastically affect their interaction with biological systems. Among them, hydrophobicity is an important property that is nevertheless only slightly covered by the current physico-chemical characterisation techniques. In this work, we developed a method for the direct characterisation of NM hydrophobicity. The determination of the nanomaterial hydrophobic character is carried out by the direct measurement of the affinity of the NMs for different collectors. Each collector is an engineered surface designed in order to present specific surface charge and hydrophobicity degrees. Being thus characterised by a combination of surface energy components, the collectors enable the NM immobilisation with surface coverage in relation to their hydrophobicity. The experimental results are explained by using the extended DLVO theory, which takes into account the hydrophobic forces acting between NMs and collectors.

Effects of excipients on the tensile strength, surface properties and free volume of Klucel® free films of pharmaceutical importance

NASA Astrophysics Data System (ADS)

Gottnek, Mihály; Süvegh, Károly; Pintye-Hódi, Klára; Regdon, Géza

2013-08-01

The physicochemical properties of polymers planned to be applied as mucoadhesive films were studied. Two types of Klucel® hydroxypropylcellulose (LF and MF) were used as film-forming polymers. Hydroxypropylcellulose was incorporated in 2 w/w% with glycerol and xylitol as excipients and lidocaine base as an active ingredient at 5, 10 or 15 w/w% of the mass of the film-forming polymer. The free volume changes of the films were investigated by positron annihilation lifetime spectroscopy, the mechanical properties of the samples were measured with a tensile strength tester and contact angles were determined to assess the surface properties of the films. It was found that the Klucel® MF films had better physicochemical properties than those of the LF films. Klucel® MF as a film-forming polymer with lidocaine base and both excipients at 5 w/w% exhibited physicochemical properties and good workability. The excipients proved to exert strong effects on the physicochemical properties of the tested systems and it is very important to study them intensively in preformulation studies in the pharmaceutical technology in order to utilise their benefits and to avoid any disadvantageous effects.

Ehf Multiple Beam Antennas.

DTIC Science & Technology

1981-09-21

acknowledge and thank A. R. Hislop and D. L. Saul, Code 9262, for their work on tbh mixer design and D. L. Chappelle and K. S. Maynard, Code 8124, for...MTT-28, p 555-563, June 1980 . 33 (a) Mixer matrix, 7 boards, 6-5 mixers, 1-7 mixers. (b) LO power split to boards, 7-way. rN’ o, Ro (c) N-way power...1966. 9. Saleh, A.A.M., Planar Electrically Symmetric N-Way Hybrid Power Dividers/ Combiners, IEEE T-MTT-28, p 555-563, June 1980 . 55

Dissimilatory perchlorate reduction: a review.

PubMed

Bardiya, Nirmala; Bae, Jae-Ho

2011-05-20

In the United States anthropogenic activities are mainly responsible for the wide spread perchlorate contamination of drinking water, surface water, groundwater, and soil. Even at microgram levels, perchlorate causes toxicity to flora and fauna and affects growth, metabolism and reproduction in humans and animals. Reports of antithyroid effects of perchlorate and its detection in common food items have raised serious public health concerns, leading to extensive decontamination efforts in recent years. Several physico-chemical removal and biological decontamination processes are being developed. Although promising, ion exchange is a non-selective and incomplete process as it merely transfers perchlorate from water to the resin. The perchlorate-laden spent resins (perchlorate 200-500 mg L(-1)) require regeneration resulting in production of concentrated brine (6-12% NaCl) or caustic waste streams. On the contrary, biological reduction completely degrades perchlorate into O(2) and innocuous Cl(-). High reduction potential of ClO(4)(-)/Cl(-) (E° =∼ 1.28 V) and ClO(3)(-)/Cl(-) pairs (E° =1.03 V) makes these contaminants thermodynamically ideal e(-) acceptors for microbial reduction. In recent years unique dissimilatory perchlorate reducing bacteria have been isolated and detailed studies pertaining to their microbiological, biochemical, genetics and phylogenetic aspects have been undertaken which is the subject of this review article while the various physico-chemical removal and biological reduction processes have been reviewed by others. Copyright © 2010 Elsevier GmbH. All rights reserved.

Agreement Between Autorefraction and Subjective Refraction in Keraring-Implanted Keratoconic Eyes.

PubMed

Al-Tuwairqi, Waleed S; Ogbuehi, Kelechi C; Razzouk, Haya; Alanazi, Mana A; Osuagwu, Uchechukwu L

2017-03-01

To assess the agreement between subjective refraction and autorefraction and to explore the relationship between the magnitude of higher order aberration, and visual acuity and refraction, before and after keraring implantation. This prospective, randomized, interventional study enrolled 27 subjects (mean age 28.1±6.5 years) with keratoconus. Noncycloplegic refraction was performed subjectively by one clinician and with an autorefractor by another clinician, before and 6 months after surgery. The limit of agreement (LoA) between methods was assessed, and the relationships between the corrected distance visual acuity, logMAR on the one hand and refraction measurements and higher-order aberrations on the other, were examined. The agreement in mean spherical equivalent refraction (MSER) between methods was good postoperatively but poor preoperatively. The autorefractor gave a more myopic refraction than subjective refraction preoperatively (-3.28±3.06 D; LoA -9.27 to +2.71 D, P<0.0001) and postoperatively (-0.63±1.64 D; LoA -3.85 to +2.58 D, P=0.055), and returned higher negative cylinders preoperatively (-1.10±1.17 D; LoA -3.40 to +1.19 D, P<0.0001) and postoperatively (-1.08±1.27 D; LoA -3.60 to +1.41 D, P<0.0001) in keratoconic eyes. The difference in MSER between methods was significantly related to the refractive error at both visits (P<0.05) and to the magnitude of higher-order aberrations in keratoconic eyes preoperatively (P<0.05). The logMAR visual acuity achieved subjectively worsened as the magnitude of higher-order aberrations increased preoperatively (P<0.001). The autorefractor returns values that are significantly more myopic in MSER and higher negative cylinders than subjective refraction, preoperatively, but the MSER was similar between devices postoperatively. The autorefactor seems a valid starting point for subjective refraction in keratoconic eyes treated with keraring, but the cylinder should be corrected by about +1 D. The instruments agree more in less myopic than high myopic eyes.

Effect of a new regeneration process by adsorption-coagulation and flocculation on the physicochemical properties and the detergent efficiency of regenerated cleaning solutions.

PubMed

Blel, Walid; Dif, Mehdi; Sire, Olivier

2015-05-15

Reprocessing soiled cleaning-in-place (CIP) solutions has large economic and environmental costs, and it would be cheaper and greener to recycle them. In food industries, recycling of CIP solutions requires a suitable green process engineered to take into account the extreme physicochemical conditions of cleaning while not altering the process efficiency. To this end, an innovative treatment process combining adsorption-coagulation with flocculation was tested on multiple recycling of acid and basic cleaning solutions. In-depth analysis of time-course evolutions was carried out in the physicochemical properties (concentration, surface tension, viscosity, COD, total nitrogen) of these solutions over the course of successive regenerations. Cleaning and disinfection efficiencies were assessed based on both microbiological analyses and organic matter detachment and solubilization from fouled stainless steel surfaces. Microbiological analyses using a resistant bacterial strain (Bacillus subtilis spores) highlighted that solutions regenerated up to 20 times maintained the same bactericidal efficiency as de novo NaOH solutions. The cleanability of stainless steel surfaces showed that regenerated solutions allow better surface wettability, which goes to explain the improved detachment and solubilization found on different types of organic and inorganic fouling. Copyright © 2015 Elsevier Ltd. All rights reserved.

In vitro characterization of CD133lo cancer stem cells in Retinoblastoma Y79 cell line.

PubMed

Nair, Rohini M; Balla, Murali Ms; Khan, Imran; Kalathur, Ravi Kiran Reddy; Kondaiah, Paturu; Vemuganti, Geeta K

2017-11-21

Retinoblastoma (Rb), the most common childhood intraocular malignant tumor, is reported to have cancer stem cells (CSCs) similar to other tumors. Our previous investigation in primary tumors identified the small sized cells with low CD133 (Prominin-1) and high CD44 (Hyaluronic acid receptor) expression to be putative Rb CSCs using flow cytometry (FSC lo /SSC lo /CD133 lo /CD44 hi ). With this preliminary data, we have now utilized a comprehensive approach of in vitro characterization of Y79 Rb cell line following CSC enrichment using CD133 surface marker and subsequent validation to confirm the functional properties of CSCs. The cultured Rb Y79 cells were evaluated for surface markers by flow cytometry and CD133 sorted cells (CD133 lo /CD133 hi ) were compared for CSC characteristics by size/percentage, cell cycle assay, colony formation assay, differentiation, Matrigel transwell invasion assay, cytotoxicity assay, gene expression using microarray and validation by semi-quantitative PCR. Rb Y79 cell line shared the profile (CD133, CD90, CXCR4 and ABCB1) of primary tumors except for CD44 expression. The CD133 lo cells (16.1 ± 0.2%) were FSC lo /SSC lo , predominantly within the G0/G1 phase, formed larger and higher number of colonies with ability to differentiate to CD133 hi cells, exhibited increased invasive potential in a matrigel transwell assay (p < 0.05) and were resistant to Carboplatin treatment (p < 0.001) as compared to CD133 hi cells. The CD133 lo cells showed higher expression of several embryonic stem cell genes (HOXB2, HOXA9, SALL1, NANOG, OCT4, LEFTY), stem cells/progenitor genes (MSI2, BMI1, PROX1, ABCB1, ABCB5, ABCG2), and metastasis related gene- MACC1, when compared to the CD133 hi cells. This study validates the observation from our earlier primary tumor study that CSC properties in Rb Y79 cell line are endowed within the CD133 lo population, evident by their characteristics- i.e. small sized, dormant in nature, increased colony forming ability, differentiation to CD133 hi cells, higher invasiveness potential, drug resistance and primitive gene expression pattern. These findings provide a proof of concept for methodological characterization of the retinoblastoma CSCs with future implications for improved diagnostic and treatment strategies.

Influence of selected physicochemical parameters on microbiological activity of mucks.

NASA Astrophysics Data System (ADS)

Całka, A.; Sokołowska, Z.; Warchulska, P.; Dąbek-Szreniawska, M.

2009-04-01

One of the basic factor decided about soil fertility are microorganisms that together with flora, determine trend and character of biochemical processes as well totality of fundamental transformations connected with biogeochemistry and physicochemical properties of soil. Determination of general bacteria number, quantity of selected groups of microorganisms and investigation of respiration intensity let estimate microbiological activity of soil. Intensity of microbiological processes is directly connected with physicochemical soil parameters. In that case, such structural parameters as bulk density, porosity, surface or carbon content play significant role. Microbiological activity also changes within the bounds of mucks with different stage of humification and secondary transformation. Knowledge of relations between structural properties, microorganism activity and degree of transformation and humification can lead to better understanding microbiological processes as well enable to estimate microbiological activity at given physicochemical conditions and at progressing process of soil transformation. The study was carried out on two peaty-moorsh (muck) soils at different state of secondary transformation and humification degree. Soil samples were collected from Polesie Lubelskie (layer depth: 5 - 25 cm). Investigated mucks originated from soils formed from low peatbogs. Soil sample marked as I belonged to muck group weakly secondary transformed. Second sample (II) represented soil group with middle stage of secondary transformation. The main purpose of the research was to examine the relations between some physicochemical and surface properties and their biological activity. Total number and respiration activity of microorganisms were determined. The effectiveness of utilizing the carbon substances from the soil by the bacteria increased simultaneously with the transformation state of the peat-muck soils. Quantity of organic carbon decreased distinctly in the soil at the higher stage of secondary transformation and it influenced quantity and activity of soil microorganisms. Bulk density and surface increased with increasing secondary transformation degree. On the other hand, porosity decreased with increasing secondary transformation index. Process of secondary transformation influenced the soil environment for the microbes by changing the physicochemical properties. This way it influenced the number of microorganisms and caused changes of biological activity in the soils.

The Contribution of Proprioceptive Information to Postural Control in Elderly and Patients with Parkinson’s Disease with a History of Falls

PubMed Central

Bekkers, Esther M. J.; Dockx, Kim; Heremans, Elke; Vercruysse, Sarah; Verschueren, Sabine M. P.; Mirelman, Anat; Nieuwboer, Alice

2014-01-01

Proprioceptive deficits negatively affect postural control but their precise contribution to postural instability in Parkinson’s disease (PD) is unclear. We investigated if proprioceptive manipulations differentially affect balance, measured by force plates, during quiet standing in 13 PD patients and 13 age-matched controls with a history of falls. Perceived limits of stability (LoS) were derived from the differences between maximal center of pressure (CoP) displacement in anterior–posterior (AP) and medio-lateral (ML) direction during a maximal leaning task. Task conditions comprised standing with eyes open (EO) and eyes closed (EC): (1) on a stable surface; (2) an unstable surface; and (3) with Achilles tendon vibration. CoP displacements were calculated as a percentage of their respective LoS. Perceived LoS did not differ between groups. PD patients showed greater ML CoP displacement than elderly fallers (EF) across all conditions (p = 0.043) and tended to have higher postural sway in relation to the LoS (p = 0.050). Both groups performed worse on an unstable surface and during tendon vibration compared to standing on a stable surface with EO and even more so with EC. Both PD and EF had more AP sway in all conditions with EC compared to EO (p < 0.001) and showed increased CoP displacements when relying on proprioception only compared to standing with normal sensory input. This implies a similar role of the proprioceptive system in postural control in fallers with and without PD. PD fallers showed higher ML sway after sensory manipulations, as a result of which these values approached their perceived LoS more closely than in EF. We conclude that despite a similar fall history, PD patients showed more ML instability than EF, irrespective of sensory manipulation, but had a similar reliance on ankle proprioception. Hence, we recommend that rehabilitation and fall prevention for PD should focus on motor rather than on sensory aspects. PMID:25505395

Phonon Raman spectra of colloidal CdTe nanocrystals: effect of size, non-stoichiometry and ligand exchange

PubMed Central

2011-01-01

Resonant Raman study reveals the noticeable effect of the ligand exchange on the nanocrystal (NC) surface onto the phonon spectra of colloidal CdTe NC of different size and composition. The oleic acid ligand exchange for pyridine ones was found to change noticeably the position and width of the longitudinal optical (LO) phonon mode, as well as its intensity ratio to overtones. The broad shoulder above the LO peak frequency was enhanced and sharpened after pyridine treatment, as well as with decreasing NC size. The low-frequency mode around 100 cm-1 which is commonly related with the disorder-activated acoustical phonons appears in smaller NCs but is not enhanced after pyridine treatment. Surprisingly, the feature at low-frequency shoulder of the LO peak, commonly assigned to the surface optical phonon mode, was not sensitive to ligand exchange and concomitant close packing of the NCs. An increased structural disorder on the NC surface, strain and modified electron-phonon coupling is discussed as the possible reason of the observed changes in the phonon spectrum of ligand-exchanged CdTe NCs. PACS: 63.20.-e, 78.30.-j, 78.67.-n, 78.67.Bf PMID:21711581

Low-thrust chemical propulsion system propellant expulsion and thermal conditioning study

NASA Technical Reports Server (NTRS)

Merino, F.; Wakabayashi, I.; Pleasant, R. L.; Hill, M.

1982-01-01

Thermal conditioning systems for satisfying engine net positive suction pressure (NPSP) requirements, and propellant expulsion systems for achieving propellant dump during a return-to-launch site (RTLS) abort were studied for LH2/LO2 and LCH4/LO2 upper stage propellant combinations. A state-of-the-art thermal conditioning system employing helium injection beneath the liquid surface shows the lowest weight penalty for LO2 and LCH4. A technology system incorporating a thermal subcooler (heat exchanger) for engine NPSP results in the lowest weight penalty for the LH2 tank. A preliminary design of two state-of-the-art and two new technology systems indicates a weight penalty difference too small to warrant development of a LH2 thermal subcooler. Analysis results showed that the LH2/LO2 propellant expulsion system is optimized for maximum dump line diameters, whereas the LCH4/LO2 system is optimized for minimum dump line diameter (LCH4) and maximum dump line diameter (LO2). The primary uncertainty is the accurate determination of two-phase flow rates through the dump system; experimentation is not recommended because this uncertainty is not considered significant.

Predicting and analyzing DNA-binding domains using a systematic approach to identifying a set of informative physicochemical and biochemical properties

PubMed Central

2011-01-01

Background Existing methods of predicting DNA-binding proteins used valuable features of physicochemical properties to design support vector machine (SVM) based classifiers. Generally, selection of physicochemical properties and determination of their corresponding feature vectors rely mainly on known properties of binding mechanism and experience of designers. However, there exists a troublesome problem for designers that some different physicochemical properties have similar vectors of representing 20 amino acids and some closely related physicochemical properties have dissimilar vectors. Results This study proposes a systematic approach (named Auto-IDPCPs) to automatically identify a set of physicochemical and biochemical properties in the AAindex database to design SVM-based classifiers for predicting and analyzing DNA-binding domains/proteins. Auto-IDPCPs consists of 1) clustering 531 amino acid indices in AAindex into 20 clusters using a fuzzy c-means algorithm, 2) utilizing an efficient genetic algorithm based optimization method IBCGA to select an informative feature set of size m to represent sequences, and 3) analyzing the selected features to identify related physicochemical properties which may affect the binding mechanism of DNA-binding domains/proteins. The proposed Auto-IDPCPs identified m=22 features of properties belonging to five clusters for predicting DNA-binding domains with a five-fold cross-validation accuracy of 87.12%, which is promising compared with the accuracy of 86.62% of the existing method PSSM-400. For predicting DNA-binding sequences, the accuracy of 75.50% was obtained using m=28 features, where PSSM-400 has an accuracy of 74.22%. Auto-IDPCPs and PSSM-400 have accuracies of 80.73% and 82.81%, respectively, applied to an independent test data set of DNA-binding domains. Some typical physicochemical properties discovered are hydrophobicity, secondary structure, charge, solvent accessibility, polarity, flexibility, normalized Van Der Waals volume, pK (pK-C, pK-N, pK-COOH and pK-a(RCOOH)), etc. Conclusions The proposed approach Auto-IDPCPs would help designers to investigate informative physicochemical and biochemical properties by considering both prediction accuracy and analysis of binding mechanism simultaneously. The approach Auto-IDPCPs can be also applicable to predict and analyze other protein functions from sequences. PMID:21342579

Characterization of the surface properties of wheat spikelet components

USDA-ARS?s Scientific Manuscript database

The physicochemical surface properties of wheat spikelet components were determined. The water and water:acetone (1:1, v/v) contact angle for the glumes and lemmas of two wheat cultivars were measured. The results demonstrate that the surface chemistry and ultrastructure of glume and lemma tissues...

Surface functionalization of magnetic nanoparticles formed by self-associating hydrophobized oxidized dextrans

NASA Astrophysics Data System (ADS)

Farber, Shimon; Ickowicz, Diana E.; Melnik, Kristie; Yudovin-Farber, Ira; Recko, Daniel; Rampersaud, Arfaan; Domb, Abraham J.

2014-06-01

Magnetic iron oxide nanoparticles surface covered with oleic acid layer followed by a second layer of hydrophobized oxidized dextran aldehyde were prepared and tested for physico-chemical properties and ligand- and cell-specific binding. It was demonstrated that oleic acid-iron oxide nanoparticles coated with an additional layer of hydrophobized oxidized dextran were dispersible in buffer solutions and possess surface aldehyde active groups available for further binding of ligands or markers via imine or amine bond formation. Hydrophobized dextrans were synthesized by periodate oxidation and conjugation of various alkanamines to oxidized dextran by imination. Physico-chemical properties, as separation using magnetic field, magnetite concentration, and particle diameter, of the prepared magnetic samples are reported. The biotin-binding protein, neutravidin, was coupled to the particle surface by a simple reductive amination procedure. The particles were used for specific cell separation with high specificity.

Physico-chemical foundations underpinning microarray and next-generation sequencing experiments

PubMed Central

Harrison, Andrew; Binder, Hans; Buhot, Arnaud; Burden, Conrad J.; Carlon, Enrico; Gibas, Cynthia; Gamble, Lara J.; Halperin, Avraham; Hooyberghs, Jef; Kreil, David P.; Levicky, Rastislav; Noble, Peter A.; Ott, Albrecht; Pettitt, B. Montgomery; Tautz, Diethard; Pozhitkov, Alexander E.

2013-01-01

Hybridization of nucleic acids on solid surfaces is a key process involved in high-throughput technologies such as microarrays and, in some cases, next-generation sequencing (NGS). A physical understanding of the hybridization process helps to determine the accuracy of these technologies. The goal of a widespread research program is to develop reliable transformations between the raw signals reported by the technologies and individual molecular concentrations from an ensemble of nucleic acids. This research has inputs from many areas, from bioinformatics and biostatistics, to theoretical and experimental biochemistry and biophysics, to computer simulations. A group of leading researchers met in Ploen Germany in 2011 to discuss present knowledge and limitations of our physico-chemical understanding of high-throughput nucleic acid technologies. This meeting inspired us to write this summary, which provides an overview of the state-of-the-art approaches based on physico-chemical foundation to modeling of the nucleic acids hybridization process on solid surfaces. In addition, practical application of current knowledge is emphasized. PMID:23307556

Data on physicochemical properties of active films derived from plantain flour/PCL blends developed under reactive extrusion conditions.

PubMed

Gutiérrez, Tomy J; Alvarez, Vera A

2017-12-01

The data given below relates to the research paper entitled: "Eco-friendly films prepared from plantain flour/PCL blends under reactive extrusion conditions using zirconium octanoate as a catalyst", recently published by our research group [1]. This article provides information concerning the physicochemical properties of the above-mentioned film systems: thickness, density, opacity, moisture content and surface moisture.

Modified atmosphere packaging of precooked vegetables: effect on physicochemical properties and sensory quality.

PubMed

Barbosa, Carla; Alves, M Rui; Rocha, Susana; Oliveira, M Beatriz P P

2016-03-01

This study aims at verifying the effect of three modified atmosphere packaging (MAP) conditions, all with high CO2 and residual or low O2 contents (%O2/%CO2: 0/40; 2.5/40 and 2.5/60), on the quality preservation of several species of precooked vegetables (cabbage, carrots, green beans and bell peppers). The study was carried out for different storage periods (up to 28 days and 6 sampling periods). Physicochemical parameters (pH, acidity, moisture and ash contents, antioxidant activity, colour, and texture), microbial growth, organoleptic properties and consumer acceptability were assessed. Concerning physicochemical parameters and microbial growth only slight changes without any consistent tendency were observed. This was also confirmed by the trained panel that could not discriminate samples with different storage times. Best preservation conditions were obtained with 0%O2/40%CO2, promoting a shelf life extension of almost 12 days more comparing to commercial conditions presently used. Copyright © 2015 Elsevier Ltd. All rights reserved.

Physicochemical mechanisms of plasma-liquid interactions within plasma channels in liquid

NASA Astrophysics Data System (ADS)

Franclemont, Joshua; Fan, Xiangru; Mededovic Thagard, Selma

2015-10-01

The goal of this study is to advance the fundamental understanding of the physical and chemical mechanisms by which excited radical species produced by electrical plasmas directly in water, OH radicals especially, induce chemical changes in aqueous organic compounds and to exploit this for the development and optimization of drinking and wastewater plasma-based treatment systems. To achieve this goal, this study measured and correlated the production rate of hydrogen peroxide (H2O2) with physicochemical properties of 11 organic compounds. The observed individual correlations between the investigated physicochemical properties and the resulting H2O2 concentrations were used to develop an equation that would allow predicting the measured H2O2 concentration from physicochemical properties of a compound. Results reveal that the production rate of H2O2 directly depends on the surface tension of the solution and compounds’ bulk liquid concentration, hydrophobicity (K ow value), and molecular volume. Other properties such as vapor pressure, Henry’s constant, enthalpy of vaporization, ionization energy, electron affinity, and molecular dipole moment do not affect the H2O2 chemistry. K ow value and surface tension of the solution determine the compound’s concentration at the plasma interface. Once at the interface, the molecular volume determines the rate at which the molecule will react with OH radicals.

Tamoxifen-loaded lecithin organogel (LO) for topical application: Development, optimization and characterization.

PubMed

Bhatia, Amit; Singh, Bhupinder; Raza, Kaisar; Wadhwa, Sheetu; Katare, Om Prakash

2013-02-28

Lecithin organogels (LOs) are semi-solid systems with immobilized organic liquid phase in 3-D network of self-assembled gelators. This paper attempts to study the various attributes of LOs, starting from selection of materials, optimization of influential components to LO specific characterization. After screening of various components (type of gelators, organic and aqueous phase) and construction of phase diagrams, a D-optimal mixture design was employed for the systematic optimization of the LO composition. The response surface plots were constructed for various response variables, viz. viscosity, gel strength, spreadability and consistency index. The optimized LO composition was searched employing overlay plots. Subsequent validation of the optimization study employing check-point formulations, located using grid search, indicated high degree of prognostic ability of the experimental design. The optimized formulation was characterized for morphology, drug content, rheology, spreadability, pH, phase transition temperatures, and physical and chemical stability. The outcomes of the study were interesting showing high dependence of LO attributes on the type and amount of phospholipid, Poloxamer™, auxillary gelators and organic solvent. The optimized LO was found to be quite stable, easily applicable and biocompatible. The findings of the study can be utilized for the development of LO systems of other drugs for the safer and effective topical delivery. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Preparation and physicochemical characterization of spray-dried and jet-milled microparticles containing bosentan hydrate for dry powder inhalation aerosols.

PubMed

Lee, Hyo-Jung; Kang, Ji-Hyun; Lee, Hong-Goo; Kim, Dong-Wook; Rhee, Yun-Seok; Kim, Ju-Young; Park, Eun-Seok; Park, Chun-Woong

2016-01-01

The objectives of this study were to prepare bosentan hydrate (BST) microparticles as dry powder inhalations (DPIs) via spray drying and jet milling under various parameters, to comprehensively characterize the physicochemical properties of the BST hydrate microparticles, and to evaluate the aerosol dispersion performance and dissolution behavior as DPIs. The BST microparticles were successfully prepared for DPIs by spray drying from feeding solution concentrations of 1%, 3%, and 5% (w/v) and by jet milling at grinding pressures of 2, 3, and 4 MPa. The physicochemical properties of the spray-dried (SD) and jet-milled (JM) microparticles were determined via scanning electron microscopy, atomic force microscopy, dynamic light scattering particle size analysis, Karl Fischer titration, surface analysis, pycnometry, differential scanning calorimetry, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The in vitro aerosol dispersion performance and drug dissolution behavior were evaluated using an Anderson cascade impactor and a Franz diffusion cell, respectively. The JM microparticles exhibited an irregular corrugated surface and a crystalline solid state, while the SD microparticles were spherical with a smooth surface and an amorphous solid state. Thus, the in vitro aerosol dispersion performance and dissolution behavior as DPIs were considerably different due to the differences in the physicochemical properties of the SD and JM microparticles. In particular, the highest grinding pressures under jet milling exhibited excellent aerosol dispersion performance with statistically higher values of 56.8%±2.0% of respirable fraction and 33.8%±2.3% of fine particle fraction and lower mass median aerodynamic diameter of 5.0±0.3 μm than the others ( P <0.05, analysis of variance/Tukey). The drug dissolution mechanism was also affected by the physicochemical properties that determine the dissolution kinetics of the SD and JM microparticles, which were well fitted into the Higuchi and zero-order models, respectively.

[Study on preparation and physicochemical properties of surface modified sintered bone].

PubMed

Li, Jingfeng; Zheng, Qixin; Guo, Xiaodong

2012-06-01

The aim of this study is to investigate a new method for preparing a biomimetic bone material-surface modified sintered bovine cancellous bone, and to improve its bioactivity as a tissue engineering bone. The prepared sintered bovine cancellous bones with the same size were randomly divided into two groups, immersing in 1 and 1. 5 times simulated body fluid (SBF), respectively. The three time periods of soak time were 7, 14, and 21 days. After sintered bone was dried, the surface morphology of sintered bone and surface mineralization composition were observed under scanning electron microscopy (SEM). By comparing the effect of surface modification of sintered bone materials, we chose the most ideal material and studied its pore size, the rate of the porosity, the compress and bend intensity. And then the material and the sintered bone material without surface modification were compared. The study indicated that sintered bone material immersed in SBF (1.5 times) for 14 days showed the best effect of surface modification, retaining the original physico-chemical properties of sintered bone.

Early vs late age at onset frontotemporal dementia and frontotemporal lobar degeneration.

PubMed

Seo, Sang Won; Thibodeau, Marie-Pierre; Perry, David C; Hua, Alice; Sidhu, Manu; Sible, Isabel; Vargas, Jose Norberto S; Gaus, Stephanie E; Rabinovici, Gil D; Rankin, Katherine D; Boxer, Adam L; Kramer, Joel H; Rosen, Howard J; Gorno-Tempini, Maria Luisa; Grinberg, Lea T; Huang, Eric J; DeArmond, Stephen J; Trojanowski, John Q; Miller, Bruce L; Seeley, William W

2018-03-20

To examine clinicopathologic correlations in early vs late age at onset frontotemporal dementia (FTD) and frontotemporal lobar degeneration (FTLD). All patients were clinically evaluated and prospectively diagnosed at the UCSF Memory and Aging Center. Two consecutive series were included: (1) patients with a clinically diagnosed FTD syndrome who underwent autopsy (cohort 1) and (2) patients with a primary pathologic diagnosis of FTLD, regardless of the clinical syndrome (cohort 2). These series were divided by age at symptom onset (cutoff 65 years). In cohort 1, 48 (25.3%) were 65 years or older at symptom onset. Pathologic causes of behavioral variant FTD (bvFTD) were similar in the early age at onset (EO) and late age at onset (LO) bvFTD groups. In corticobasal syndrome (CBS), however, the most common pathologic substrate differed according to age at onset: progressive supranuclear palsy (42.9%) in LO-CBS and Alzheimer disease (AD; 40.7%) in EO-CBS. In cohort 2, 57 (28.4%) were classified as LO-FTLD. Regarding FTLD major molecular classes, FTLD with transactive response DNA-binding protein of 43 kDa was most common in EO-FTLD (44.4%), whereas FTLD-tau (58.3%) was most common in LO-FTLD. Antemortem diagnosis of a non-FTD syndrome, usually AD-type dementia, was more frequent in LO-FTLD than EO-FTLD (19.3% vs 7.7%, p = 0.017). LO-FTLD was also associated with more prevalent comorbid pathologic changes. Of these, moderate to severe AD neuropathologic change and argyrophilic grain disease were overrepresented among patients who received an antemortem diagnosis of AD-type dementia. Patients with FTD and FTLD often develop symptoms after age 65, and age at onset represents an important consideration when making antemortem neuropathologic predictions. © 2018 American Academy of Neurology.

Proceedings of the NASTRAN (Tradename) Users’ Colloquium (8th) Held in Greenbelt, Maryland on 30-31 October 1979

DTIC Science & Technology

1980-05-01

36 wing were replaced by a six foot extension and winglet on the 28/29 wing (see Figures 1 & 2). The outward appearance of the 28/29 wing in the...in NASA TMX-3428 (Ref. 1). This model was later updated in the outboard section with the six foot extension and winglet attachment structure. Sizing...incorporated to provide stiffness and an internal lo3d path for forces developed by the winglet , since the winglet was mounted very near the trailing

Effect of gamma irradiation and storage time on microbial growth and physicochemical characteristics of pumpkin (Cucurbita Moschata Duchesne ex Poiret) puree.

PubMed

Gliemmo, María F; Latorre, María E; Narvaiz, Patricia; Campos, Carmen A; Gerschenson, Lía N

2014-01-01

The effect of gamma irradiation (0-2 kGy) and storage time (0-28 days) on microbial growth and physicochemical characteristics of a packed pumpkin puree was studied. For that purpose, a factorial design was applied. The puree contained potassium sorbate, glucose and vanillin was stored at 25°C . Gamma irradiation diminished and storage time increased microbial growth. A synergistic effect between both variables on microbial growth was observed. Storage time decreased pH and color of purees. Sorbate content decreased with storage time and gamma irradiation. Mathematical models of microbial growth generated by the factorial design allowed estimating that a puree absorbing 1.63 kGy would have a shelf-life of 4 days. In order to improve this time, some changes in the applied hurdles were assayed. These included a thermal treatment before irradiation, a reduction of irradiation dose to 0.75 kGy and a decrease in storage temperature at 20°C . As a result, the shelf-life of purees increased to 28 days.

Physicochemical analysis of full-fat, reduced-fat, and low-fat artisan-style goat cheese.

PubMed

Sánchez-Macías, D; Fresno, M; Moreno-Indias, I; Castro, N; Morales-delaNuez, A; Alvarez, S; Argüello, A

2010-09-01

The objective of this study was to examine the physicochemical properties of cheese elaborated via traditional artisan methods using goat milk containing 5, 1.5, or 0.4% fat and ripened for 1, 7, 14, or 28 d. Seventy-two cheeses were produced (2 batches x 3 fat levels x 4 ripening times x triplicate). Proximal composition, pH, texture analysis, and color were recorded in each cheese. Protein and moisture were increased in cheese, and fat and fat in DM were decreased with decreasing fat in milk. Internal and external pH was higher in low-fat and reduced-fat cheese, and pH values decreased during the first 2 wk of ripening but increased slightly on d 28. Cheese fracturability, cohesiveness, masticability, and hardness increased with decreasing fat, whereas elasticity and adhesiveness decreased. Cheese lightness and red and yellow indexes decreased with decreasing fat content; during ripening, lightness decreased further but yellow index increased. Copyright (c) 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Influence of succinylation on physicochemical property of yak casein micelles.

PubMed

Yang, Min; Yang, Jitao; Zhang, Yuan; Zhang, Weibing

2016-01-01

Succinylation is a chemical-modification method that affects the physicochemical characteristics and functional properties of proteins. This study assessed the influence of succinylation on the physicochemical properties of yak casein micelles. The results revealed that surface hydrophobicity indices decreased with succinylation. Additionally, denaturation temperature and denaturation enthalpy decreased with increasing succinylation level, except at 82%. The buffering properties of yak casein micelles were affected by succinylation. It was found that chemical modification contributed to a slight shift of the buffering peak towards a lower pH value and a markedly increase of the maximum buffering values of yak casein micelles at pH 4.5-6.0 and pH < 3. Succinylation increased yak casein micellar hydration and whiteness values. The findings obtained from this study will provide the basic information on the physicochemical properties of native and succinylated yak casein micelles. Copyright © 2015 Elsevier Ltd. All rights reserved.

Unique battery with an active membrane separator having uniform physico-chemically functionalized ion channels and a method making the same

DOEpatents

Gerald, II, Rex E.; Ruscic, Katarina J [Chicago, IL; Sears, Devin N [Spruce Grove, CA; Smith, Luis J [Natick, MA; Klingler, Robert J [Glenview, IL; Rathke, Jerome W [Homer Glen, IL

2012-02-21

The invention relates to a unique battery having an active, porous membrane and method of making the same. More specifically the invention relates to a sealed battery system having a porous, metal oxide membrane with uniform, physicochemically functionalized ion channels capable of adjustable ionic interaction. The physicochemically-active porous membrane purports dual functions: an electronic insulator (separator) and a unidirectional ion-transporter (electrolyte). The electrochemical cell membrane is activated for the transport of ions by contiguous ion coordination sites on the interior two-dimensional surfaces of the trans-membrane unidirectional pores. The membrane material is designed to have physicochemical interaction with ions. Control of the extent of the interactions between the ions and the interior pore walls of the membrane and other materials, chemicals, or structures contained within the pores provides adjustability of the ionic conductivity of the membrane.

Effects of the physicochemical properties of gold nanostructures on cellular internalization

PubMed Central

Zhang, Jinchao; Wang, Paul C.; Liang, Xing-Jie

2015-01-01

Unique physicochemical properties of Au nanomaterials make them potential star materials in biomedical applications. However, we still know a little about the basic problem of what really matters in fabrication of Au nanomaterials which can get into biological systems, especially cells, with high efficiency. An understanding of how the physicochemical properties of Au nanomaterials affect their cell internalization is of significant interest. Studies devoted to clarify the functions of various properties of Au nanostructures such as size, shape and kinds of surface characteristics in cell internalization are under way. These fundamental investigations will give us a foundation for constructing Au nanomaterial-based biomedical devices in the future. In this review, we present the current advances and rationales in study of the relationship between the physicochemical properties of Au nanomaterials and cell uptake. We also provide a perspective on the Au nanomaterial-cell interaction research. PMID:26813673

Physico-chemical properties and cytotoxic effects of sugar-based surfactants: Impact of structural variations.

PubMed

Lu, Biao; Vayssade, Muriel; Miao, Yong; Chagnault, Vincent; Grand, Eric; Wadouachi, Anne; Postel, Denis; Drelich, Audrey; Egles, Christophe; Pezron, Isabelle

2016-09-01

Surfactants derived from the biorefinery process can present interesting surface-active properties, low cytotoxicity, high biocompatibility and biodegradability. They are therefore considered as potential sustainable substitutes to currently used petroleum-based surfactants. To better understand and anticipate their performances, structure-property relationships need to be carefully investigated. For this reason, we applied a multidisciplinary approach to systematically explore the effect of subtle structural variations on both physico-chemical properties and biological effects. Four sugar-based surfactants, each with an eight carbon alkyl chain bound to a glucose or maltose head group by an amide linkage, were synthesized and evaluated together along with two commercially available standard surfactants. Physico-chemical properties including solubility, Krafft point, surface-tension lowering and critical micellar concentration (CMC) in water and biological medium were explored. Cytotoxicity evaluation by measuring proliferation index and metabolic activity against dermal fibroblasts showed that all surfactants studied may induce cell death at low concentrations (below their CMC). Results revealed significant differences in both physico-chemical properties and cytotoxic effects depending on molecule structural features, such as the position of the linkage on the sugar head-group, or the orientation of the amide linkage. Furthermore, the cytotoxic response increased with the reduction of surfactant CMC. This study underscores the relevance of a methodical and multidisciplinary approach that enables the consideration of surfactant solution properties when applied to biological materials. Overall, our results will contribute to a better understanding of the concomitant impact of surfactant structure at physico-chemical and biological levels. Copyright © 2016 Elsevier B.V. All rights reserved.

[The influence of N-, S-containing chinasolone derivatives (NC-224) on the biochemical and physicochemical parameters of membrane endoplasmatic reticulum and nuclear chromatine fractions of rats liver cells in conditions of its injury by tetrachloromethane].

PubMed

Gubs'kyî, Iu I; Goriushko, G G; Belenichev, I F; Kovalenko, S I; Litvinova, N V; Marchenko, O M; Kurapova, T M; Babenko, L P; Velychko, O M

2010-01-01

Using biochemical and physicochemical methods of investigation in vivo, the effect of the substance NC-224, N-, S-chinasolone-derivative, on the lipoperoxidation activity in rat liver endoplasmatic reticulum membranes and nuclear chromatin fractions under tetrachloromethane intoxication have been studied. It was shown that NC-224 has pronounced antioxidant activity which is the biochemical basis of the substance membrane- and genome-protective effects and its ability to restore physicochemical properties of the surface and hydrophobic zones of hepatocyte membranes and structural parameter nuclear chromatin fractions in the conditions of chemical liver injury.

A comparison of thermoregulatory responses to exercise between mass-matched groups with large differences in body fat

PubMed Central

Dervis, Sheila; Coombs, Geoff B.; Chaseling, Georgia K.; Filingeri, Davide; Smoljanic, Jovana

2015-01-01

We sought to determine 1) the influence of adiposity on thermoregulatory responses independently of the confounding biophysical factors of body mass and metabolic heat production (Hprod); and 2) whether differences in adiposity should be accounted for by prescribing an exercise intensity eliciting a fixed Hprod per kilogram of lean body mass (LBM). Nine low (LO-BF) and nine high (HI-BF) body fat males matched in pairs for total body mass (TBM; LO-BF: 88.7 ± 8.4 kg, HI-BF: 90.1 ± 7.9 kg; P = 0.72), but with distinctly different percentage body fat (%BF; LO-BF: 10.8 ± 3.6%; HI-BF: 32.0 ± 5.6%; P < 0.001), cycled for 60 min at 28.1 ± 0.2°C, 26 ± 8% relative humidity (RH), at a target Hprod of 1) 550 W (FHP trial) and 2) 7.5 W/kg LBM (LBM trial). Changes in rectal temperature (ΔTre) and local sweat rate (LSR) were measured continuously while whole body sweat loss (WBSL) and net heat loss (Hloss) were estimated over 60 min. In the FHP trial, ΔTre (LO-BF: 0.66 ± 0.21°C, HI-BF: 0.87 ± 0.18°C; P = 0.02) was greater in HI-BF, whereas mean LSR (LO-BF 0.52 ± 0.19, HI-BF 0.43 ± 0.15 mg·cm−2·min−1; P = 0.19), WBSL (LO-BF 586 ± 82 ml, HI-BF 559 ± 75 ml; P = 0.47) and Hloss (LO-BF 1,867 ± 208 kJ, HI-BF 1,826 ± 224 kJ; P = 0.69) were all similar. In the LBM trial, ΔTre (LO-BF 0.82 ± 0.18°C, HI-BF 0.54 ± 0.19°C; P < 0.001), mean LSR (LO-BF 0.59 ± 0.20, HI-BF 0.38 ± 0.12 mg·cm−2·min−1; P = 0.04), WBSL (LO-BF 580 ± 106 ml, HI-BF 381 ± 68 ml; P < 0.001), and Hloss (LO-BF 1,884 ± 277 kJ, HI-BF 1,341 ± 184 kJ; P < 0.001) were all greater at end-exercise in LO-BF. In conclusion, high %BF individuals demonstrate a greater ΔTre independently of differences in mass and Hprod, possibly due to a lower mean specific heat capacity or impaired sudomotor control. However, thermoregulatory responses of groups with different adiposity levels should not be compared using a fixed Hprod in watts per kilogram lean body mass. PMID:26702025

A comparison of thermoregulatory responses to exercise between mass-matched groups with large differences in body fat.

PubMed

Dervis, Sheila; Coombs, Geoff B; Chaseling, Georgia K; Filingeri, Davide; Smoljanic, Jovana; Jay, Ollie

2016-03-15

We sought to determine 1) the influence of adiposity on thermoregulatory responses independently of the confounding biophysical factors of body mass and metabolic heat production (Hprod); and 2) whether differences in adiposity should be accounted for by prescribing an exercise intensity eliciting a fixed Hprod per kilogram of lean body mass (LBM). Nine low (LO-BF) and nine high (HI-BF) body fat males matched in pairs for total body mass (TBM; LO-BF: 88.7 ± 8.4 kg, HI-BF: 90.1 ± 7.9 kg; P = 0.72), but with distinctly different percentage body fat (%BF; LO-BF: 10.8 ± 3.6%; HI-BF: 32.0 ± 5.6%; P < 0.001), cycled for 60 min at 28.1 ± 0.2 °C, 26 ± 8% relative humidity (RH), at a target Hprod of 1) 550 W (FHP trial) and 2) 7.5 W/kg LBM (LBM trial). Changes in rectal temperature (ΔTre) and local sweat rate (LSR) were measured continuously while whole body sweat loss (WBSL) and net heat loss (Hloss) were estimated over 60 min. In the FHP trial, ΔTre (LO-BF: 0.66 ± 0.21 °C, HI-BF: 0.87 ± 0.18 °C; P = 0.02) was greater in HI-BF, whereas mean LSR (LO-BF 0.52 ± 0.19, HI-BF 0.43 ± 0.15 mg·cm(-2)·min(-1); P = 0.19), WBSL (LO-BF 586 ± 82 ml, HI-BF 559 ± 75 ml; P = 0.47) and Hloss (LO-BF 1,867 ± 208 kJ, HI-BF 1,826 ± 224 kJ; P = 0.69) were all similar. In the LBM trial, ΔTre (LO-BF 0.82 ± 0.18 °C, HI-BF 0.54 ± 0.19 °C; P < 0.001), mean LSR (LO-BF 0.59 ± 0.20, HI-BF 0.38 ± 0.12 mg·cm(-2)·min(-1); P = 0.04), WBSL (LO-BF 580 ± 106 ml, HI-BF 381 ± 68 ml; P < 0.001), and Hloss (LO-BF 1,884 ± 277 kJ, HI-BF 1,341 ± 184 kJ; P < 0.001) were all greater at end-exercise in LO-BF. In conclusion, high %BF individuals demonstrate a greater ΔTre independently of differences in mass and Hprod, possibly due to a lower mean specific heat capacity or impaired sudomotor control. However, thermoregulatory responses of groups with different adiposity levels should not be compared using a fixed Hprod in watts per kilogram lean body mass. Copyright © 2016 the American Physiological Society.

The physicochemical and thermal properties of Malaysian high free fatty acid crude palm oil

NASA Astrophysics Data System (ADS)

Bahadi, Murad Awadh; Salimon, Jumat; Japir, Abd-Wali M.

2016-11-01

This study was carried out to determine the physicochemical properties and the thermal behavior of Malaysian high free fatty acid crude palm oil (HFFA-CPO). The physicochemical properties showed that the free fatty acid (FFA %), acid value, iodine value, saponification value, unsaponifiable matter, hydroxyl value, specific gravity, refractive index at 28°C, moisture content, viscosity at 28°C and colour at 28°C values were 9.4±0.1 %, 21.3±0.1 mg/g, 50.6±0.2 mg/g, 203.1±0.1 mg/g, 0.7±0.1%, 43.4±0.2 mg/g, 0.878 g/ml, 1.4669, 0.6 %, 52 cP and 50R-40Y respectively. Gas chromatography (GC) was used to determine the fatty acid (FA) composition in HFFA-CPO. The fatty acids were found to be comprised mostly with 45.7 % palmitic acid (C16:0), 39.5 % oleic acid (C18:1), 9.4 % linoleic acid (C18:2) and 4.3 % stearic acid (C18:0). The analysis of triacylglycerol components with high performance liquid chromatography (HPLC) has resulted with 3.5 % triunsaturated (OOO, OLL and OLO), 32.7 % monosaturated (POO, PLO, SOO and PLL), 35.7 % disaturated (MLP, PPL, PPO, POS and SOS) and 2.32 % trisaturated fatty acids (PPP and PPS). The differential scanning calorimetry (DSC) showed that the crystallization of TAG displayed two major exothermic regions of HFFA-CPO with the di and trisaturated TAG at 23.11°C and the di and triunsaturated TAG at 9.31 °C. The melting curve displayed multiple endothermic peak regions at 25.13 °C and 35.31 °C could be attributed to the di and trisaturated TAGs. While the peaks at 0.95 °C, 6.94 °C and 9.77 °C could be attributed to the mono, di and triunsaturated TAGs.

Medicinal foodstuffs. XXVII. Saponin constituents of gotu kola (2): structures of new ursane- and oleanane-type triterpene oligoglycosides, centellasaponins B, C, and D, from Centella asiatica cultivated in Sri Lanka.

PubMed

Matsuda, H; Morikawa, T; Ueda, H; Yoshikawa, M

2001-10-01

Ursane- and oleanane-type triterpene oligoglycosides, centellasaponins B, C, and D, were isolated from the aerial parts of Centella asiatica (L.) Urban cultivated in Sri Lanka together with madecassoside, asiaticoside, asiaticoside B, and sceffoleoside A. The chemical structures of centellasaponins B, C, and D were determined on the basis of chemical and physicochemical evidence to be madecassic acid 28-O-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside, madasiatic acid 28-O-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside, and 3beta,6beta,23-trihydroxyolean-12-en-28-oic acid 28-O-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside, respectively.

Effect of heat-moisture treatment on the structural, physicochemical, and rheological characteristics of arrowroot starch.

PubMed

Pepe, Larissa S; Moraes, Jaqueline; Albano, Kivia M; Telis, Vânia R N; Franco, Célia M L

2016-04-01

The effect of heat-moisture treatment on structural, physicochemical, and rheological characteristics of arrowroot starch was investigated. Heat-moisture treatment was performed with starch samples conditioned to 28% moisture at 100 ℃ for 2, 4, 8, and 16 h. Structural and physicochemical characterization of native and modified starches, as well as rheological assays with gels of native and 4 h modified starches subjected to acid and sterilization stresses were performed. Arrowroot starch had 23.1% of amylose and a CA-type crystalline pattern that changed over the treatment time to A-type. Modified starches had higher pasting temperature and lower peak viscosity while breakdown viscosity practically disappeared, independently of the treatment time. Gelatinization temperature and crystallinity increased, while enthalpy, swelling power, and solubility decreased with the treatment. Gels from modified starches, independently of the stress conditions, were found to have more stable apparent viscosities and higher G' and G″ than gels from native starch. Heat-moisture treatment caused a reorganization of starch chains that increased molecular interactions. This increase resulted in higher paste stability and strengthened gels that showed higher resistance to shearing and heat, even after acid or sterilization conditions. A treatment time of 4 h was enough to deeply changing the physicochemical properties of starch. © The Author(s) 2015.

Instrumental studies on silicone oil adsorption to the surface of intraocular lenses

NASA Astrophysics Data System (ADS)

Kim, Chun Ho; Joo, Choun-Ki; Chun, Heung Jae; Yoo, Bok Ryul; Noh, Dong Il; Shim, Young Bock

2012-12-01

The purpose of this study was to examine the degree of adherence of silicone oil to various intraocular lenses (IOLs) through comparison of the physico-chemical properties of the oil and IOLs. Four kinds of IOLs comprising various biomaterials were examined: PMMA (720A™), PHEMA (IOGEL 1103™), Acrysof (MA60BM™), and silicone (SI30NB™). Each lens was immersed in silicone oil or carboxylated silicone (CS-PDMS) oil for 72 h. For determination of the changes in chemical and elemental compositions on the surfaces of IOLs caused by the contact with silicone oil, IOLs were washed and rinsed with n-pentane to remove as much of the adsorbed silicone oil as possible, then subjected to Fourier transform infrared spectroscopic (FTIR) and X-ray photoelectron spectroscopic (XPS) analyses. The results of FTIR studies strongly indicate that washing with n-pentane completely removed the adhered silicone oil on the surfaces of PHEMA and Acrysof IOLs, whereas the residual silicone oil was detected on the surfaces of PMMA and silicone IOLs. XPS studies showed that silicone oil coverage of PMMA lenses was 12%, even after washing with n-pentane. In the case of silicone IOLs, the relative O1s peak area of carboxyl group in the residual CS-PDMS oil was found to be ˜2.7%. Considering that 2.8% carboxyl group-substituted silicone oil was used in the present study, CS-PDMS oil covered the entire surface of the silicone IOLs.

A study on the electrical, optical, and physicochemical properties of poly(MMA-co-MAA)/ poly(3,4-ethylenedioxythiophene) hybrid thin films.

PubMed

Han, Yong-Hyeon; Kim, Hyeong Eun; Hwangbo, Kyung-Hee; Yim, Jin-Heong; Cho, Kuk Young

2013-08-01

Poly(3,4-ethylenedioxythiophene) (PEDOT) has good properties as a conductive polymer such as high conductivity, optical transmittance, and chemical stability, while offering relatively weak physicochemical properties. The main purpose of this paper is to improve physicochemical properties such as solvent resistance and pencil hardness of PEDOT. Carboxyl groups in the poly(MMA-co-MAA) polymer chains can effectively crosslink each other in the presence of aziridine, resulting in physicochemically robust PEDOT/poly(MMA-co-MAA) hybrid conductive films. The electrical conductivity, optical properties, and physicochemical properties of the hybrid conductive film were compared by varying the solid content and poly(MMA-co-MAA) portion in the coating precursor solution. From the results, the transparency and surface resistance of the hybrid film show a tendency to decrease with increasing solid content in the coating precursor. Moreover, solvent resistance and hardness were dramatically enhanced by hybridization of PEDOT and crosslinked poly(MMA-co-MAA) due to curing reactions between carboxyl groups. The chemical composition of 30 wt-% of poly(MMA-co-MAA) (MMA:MAA mole ratio 9:1) and 3 wt-% - 5 wt-% of aziridine yields the best physicochemical properties of poly(MMA-co-MAA)/PEDOT hybrid thin films.

Functional Assessment of Skeletal Muscle Regeneration Utilizing Homologous Extracellular Matrix as Scaffolding

DTIC Science & Technology

2010-01-01

as a biologic scaffold material. Biomaterials 28, 3587, 2007. 24. Conconi, M.T., De Coppi, P., Bellini, S., Zara , G., Sabatti, M., Marzaro, M., Zanon...full-thickness ab- dominal wall defects. Tissue Eng 12, 1929, 2006. 26. Gamba, P.G., Conconi, M.T., Lo Piccolo, R., Zara , G., Spi- nazzi, R., and

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

Radzihovsky, Leo

Motivated by a realization of imbalanced Feshbach-resonant atomic Fermi gases, we formulate a low-energy theory of the Fulde-Ferrell and the Larkin-Ovchinnikov (LO) states and use it to analyze fluctuations, stability, and phase transitions in these enigmatic finite momentum-paired superfluids. Focusing on the unidirectional LO pair-density-wave state, which spontaneously breaks the continuous rotational and translational symmetries, we show that it is characterized by two Goldstone modes, corresponding to a superfluid phase and a smectic phonon. Because of the liquid-crystalline ''softness'' of the latter, at finite temperature the three-dimensional state is characterized by a vanishing LO order parameter, quasi-Bragg peaks in themore » structure and momentum distribution functions, and a ''charge''-4, paired-Cooper-pairs, off-diagonal long-range order, with a superfluid-stiffness anisotropy that diverges near a transition into a nonsuperfluid state. In addition to conventional integer vortices and dislocations, the LO superfluid smectic exhibits composite half-integer vortex-dislocation defects. A proliferation of defects leads to a rich variety of descendant states, such as the charge-4 superfluid and Fermi-liquid nematics and topologically ordered nonsuperfluid states, that generically intervene between the LO state and the conventional superfluid and the polarized Fermi liquid at low and high imbalance, respectively. The fermionic sector of the LO gapless superconductor is also quite unique, exhibiting a Fermi surface of Bogoliubov quasiparticles associated with the Andreev band of states, localized on the array of the LO domain walls.« less

Adsorption of hyaluronic acid on solid supports: role of pH and surface chemistry in thin film self-assembly.

PubMed

Choi, Jae-Hyeok; Kim, Seong-Oh; Linardy, Eric; Dreaden, Erik C; Zhdanov, Vladimir P; Hammond, Paula T; Cho, Nam-Joon

2015-06-15

Owing to its biocompatibility, resistance to biofouling, and desirable physicochemical and biological properties, hyaluronic acid (HA) has been widely used to modify the surface of various materials. The role of various physicochemical factors in HA adsorption remains, however, to be clarified. Herein, we employed quartz crystal microbalance with dissipation (QCM-D) in order to investigate HA adsorption at different pH conditions onto three substrates-silicon oxide, amine-terminated self-assembled monolayer (SAM) on gold, and carboxylic acid-terminated SAM on gold. The QCM-D experiments indicated specific pH conditions where either strong or weak HA adsorption occurs. The morphology of the adsorbed HA layers was investigated by atomic force microscopy (AFM), and we identified that strong HA adsorption produced a complete, homogenous and smooth HA layer, while weak HA adsorption resulted in rough and inhomogeneous HA layers. The observed specifics of the kinetics of HA adsorption, including a short initial linear phase and subsequent long non-linear phase, were described by using a mean-field kinetic model taking HA diffusion limitations and reconfiguration in the adsorbed state into account. The findings extend the physicochemical background of design strategies for improving the use of passive HA adsorption for surface modification applications. Copyright © 2015 Elsevier Inc. All rights reserved.

Predicting Cell Association of Surface-Modified Nanoparticles Using Protein Corona Structure - Activity Relationships (PCSAR).

PubMed

Kamath, Padmaja; Fernandez, Alberto; Giralt, Francesc; Rallo, Robert

2015-01-01

Nanoparticles are likely to interact in real-case application scenarios with mixtures of proteins and biomolecules that will absorb onto their surface forming the so-called protein corona. Information related to the composition of the protein corona and net cell association was collected from literature for a library of surface-modified gold and silver nanoparticles. For each protein in the corona, sequence information was extracted and used to calculate physicochemical properties and statistical descriptors. Data cleaning and preprocessing techniques including statistical analysis and feature selection methods were applied to remove highly correlated, redundant and non-significant features. A weighting technique was applied to construct specific signatures that represent the corona composition for each nanoparticle. Using this basic set of protein descriptors, a new Protein Corona Structure-Activity Relationship (PCSAR) that relates net cell association with the physicochemical descriptors of the proteins that form the corona was developed and validated. The features that resulted from the feature selection were in line with already published literature, and the computational model constructed on these features had a good accuracy (R(2)LOO=0.76 and R(2)LMO(25%)=0.72) and stability, with the advantage that the fingerprints based on physicochemical descriptors were independent of the specific proteins that form the corona.

PRince: a web server for structural and physicochemical analysis of protein-RNA interface.

PubMed

Barik, Amita; Mishra, Abhishek; Bahadur, Ranjit Prasad

2012-07-01

We have developed a web server, PRince, which analyzes the structural features and physicochemical properties of the protein-RNA interface. Users need to submit a PDB file containing the atomic coordinates of both the protein and the RNA molecules in complex form (in '.pdb' format). They should also mention the chain identifiers of interacting protein and RNA molecules. The size of the protein-RNA interface is estimated by measuring the solvent accessible surface area buried in contact. For a given protein-RNA complex, PRince calculates structural, physicochemical and hydration properties of the interacting surfaces. All these parameters generated by the server are presented in a tabular format. The interacting surfaces can also be visualized with software plug-in like Jmol. In addition, the output files containing the list of the atomic coordinates of the interacting protein, RNA and interface water molecules can be downloaded. The parameters generated by PRince are novel, and users can correlate them with the experimentally determined biophysical and biochemical parameters for better understanding the specificity of the protein-RNA recognition process. This server will be continuously upgraded to include more parameters. PRince is publicly accessible and free for use. Available at http://www.facweb.iitkgp.ernet.in/~rbahadur/prince/home.html.

Predicting Salmonella populations from biological, chemical, and physical indicators in Florida surface waters.

PubMed

McEgan, Rachel; Mootian, Gabriel; Goodridge, Lawrence D; Schaffner, Donald W; Danyluk, Michelle D

2013-07-01

Coliforms, Escherichia coli, and various physicochemical water characteristics have been suggested as indicators of microbial water quality or index organisms for pathogen populations. The relationship between the presence and/or concentration of Salmonella and biological, physical, or chemical indicators in Central Florida surface water samples over 12 consecutive months was explored. Samples were taken monthly for 12 months from 18 locations throughout Central Florida (n = 202). Air and water temperature, pH, oxidation-reduction potential (ORP), turbidity, and conductivity were measured. Weather data were obtained from nearby weather stations. Aerobic plate counts and most probable numbers (MPN) for Salmonella, E. coli, and coliforms were performed. Weak linear relationships existed between biological indicators (E. coli/coliforms) and Salmonella levels (R(2) < 0.1) and between physicochemical indicators and Salmonella levels (R(2) < 0.1). The average rainfall (previous day, week, and month) before sampling did not correlate well with bacterial levels. Logistic regression analysis showed that E. coli concentration can predict the probability of enumerating selected Salmonella levels. The lack of good correlations between biological indicators and Salmonella levels and between physicochemical indicators and Salmonella levels shows that the relationship between pathogens and indicators is complex. However, Escherichia coli provides a reasonable way to predict Salmonella levels in Central Florida surface water through logistic regression.

Predicting Salmonella Populations from Biological, Chemical, and Physical Indicators in Florida Surface Waters

PubMed Central

McEgan, Rachel; Mootian, Gabriel; Goodridge, Lawrence D.; Schaffner, Donald W.

2013-01-01

Coliforms, Escherichia coli, and various physicochemical water characteristics have been suggested as indicators of microbial water quality or index organisms for pathogen populations. The relationship between the presence and/or concentration of Salmonella and biological, physical, or chemical indicators in Central Florida surface water samples over 12 consecutive months was explored. Samples were taken monthly for 12 months from 18 locations throughout Central Florida (n = 202). Air and water temperature, pH, oxidation-reduction potential (ORP), turbidity, and conductivity were measured. Weather data were obtained from nearby weather stations. Aerobic plate counts and most probable numbers (MPN) for Salmonella, E. coli, and coliforms were performed. Weak linear relationships existed between biological indicators (E. coli/coliforms) and Salmonella levels (R2 < 0.1) and between physicochemical indicators and Salmonella levels (R2 < 0.1). The average rainfall (previous day, week, and month) before sampling did not correlate well with bacterial levels. Logistic regression analysis showed that E. coli concentration can predict the probability of enumerating selected Salmonella levels. The lack of good correlations between biological indicators and Salmonella levels and between physicochemical indicators and Salmonella levels shows that the relationship between pathogens and indicators is complex. However, Escherichia coli provides a reasonable way to predict Salmonella levels in Central Florida surface water through logistic regression. PMID:23624476

Doped indium nitride thin film by sol-gel spin coating method

NASA Astrophysics Data System (ADS)

Lee, Hui San; Ng, Sha Shiong; Yam, Fong Kwong

2017-12-01

In this study, magnesium doped indium nitride (InN:Mg) thin films grown on silicon (100) substrate were prepared via sol-gel spin coating method followed by nitridation process. A custom-made tube furnace was used to perform the nitridation process. Through this method, the low dissociation temperature issue of InN:Mg thin films can be solved. The deposited InN:Mg thin films were investigated using various techniques. The X-rays diffraction results revealed that two intense diffraction peaks correspond to wurtzite structure InN (100), and InN (101) were observed at 29° and 33.1° respectively. Field emission scanning electron microscopy images showed that the surface of the films exhibits densely packed grains. The elemental composition of the deposited thin films was analyzed using energy dispersive X-rays spectroscopy. The detected atomic percentages for In, N, and Mg were 43.22 %, 3.28 %, and 0.61 % respectively. The Raman spectra showed two Raman- and infrared-active modes of E2 (High) and A1 (LO) of the wurtzite InN. The band gap obtained from the Tauc plot showed around 1.74 eV. Lastly, the average surface roughness measured by AFM was around 0.133 µm.

Tillage impact on herbicide loss by surface runoff and lateral subsurface flow

USDA-ARS?s Scientific Manuscript database

There is worldwide interest in conservation tillage practices because they can reduce surface runoff, agrichemical, and sediment loss from farm fields. Since these practices typically increase infiltration, their use may increase subsurface transport of water-soluble contaminants. Thus, to assess lo...

Bacterial Adhesion under Static and Dynamic Conditions

PubMed Central

Rijnaarts, Huub H. M.; Norde, Willem; Bouwer, Edward J.; Lyklema, Johannes; Zehnder, Alexander J. B.

1993-01-01

The deposition of various pseudomonads and coryneform bacteria with different hydrophobicities (water contact angles) and negative cell surface charges on negatively charged Teflon and glass surfaces was investigated. The levels of deposition varied between 5.0 × 104 and 1.6 × 107 cells cm-2 and between 5.0 × 104 and 3.6 × 107 cells cm-2 for dynamic column and static batch systems, respectively, indicating that there was a wide variation in physicochemical interactions. Batch and column results were compared in order to better distinguish between hydrodynamic and other system-dependent influences and method-independent physicochemical interactions. Despite the shorter suspension-solid contact time in columns (1 h) than in batch systems (4 h), the level of deposition (expressed as the number of cells that adhered) divided by the applied ambient cell concentration was 4.12 ± 1.63 times higher in columns than in batch sytems for 15 of 22 strain-surface combinations studied. This demonstrates that transport of microbial particles from bulk liquid to surfaces is more efficient in dynamic columns (transport dominated by convection and diffusion) than in static batch systems (transport by diffusion only). The relative constancy of this ratio for the 15 combinations shows that physicochemical interactions affect adhesion similarly in the two systems. The deviating deposition behavior of the other seven strain-surface combinations could be attributed to method-dependent effects resulting from specific cell characteristics (e.g., to the presence of capsular polymers, to an ability to aggregate, to large cell sizes, or to a tendency to desorb after passage through an air-liquid interface). Images PMID:16349063

Mechanisms of carbon nanotube-induced pulmonary fibrosis: a physicochemical characteristic perspective.

PubMed

Duke, Katherine S; Bonner, James C

2018-05-01

Carbon nanotubes (CNTs) are engineered nanomaterials (ENMs) with numerous beneficial applications. However, they could pose a risk to human health from occupational or consumer exposures. Rodent models demonstrate that exposure to CNTs via inhalation, instillation, or aspiration results in pulmonary fibrosis. The severity of the fibrogenic response is determined by various physicochemical properties of the nanomaterial such as residual metal catalyst content, rigidity, length, aggregation status, or surface charge. CNTs are also increasingly functionalized post-synthesis with organic or inorganic agents to modify or enhance surface properties. The mechanisms of CNT-induced fibrosis involve oxidative stress, innate immune responses of macrophages, cytokine and growth factor production, epithelial cell injury and death, expansion of the pulmonary myofibroblast population, and consequent extracellular matrix accumulation. A comprehensive understanding of how physicochemical properties affect the fibrogenic potential of various types of CNTs should be considered in combination with genetic variability and gain or loss of function of specific genes encoding secreted cytokines, enzymes, or intracellular cell signaling molecules. Here, we cover the current state of the literature on mechanisms of CNT-exposed pulmonary fibrosis in rodent models with a focus on physicochemical characteristics as principal drivers of the mechanisms leading to pulmonary fibrosis. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Respiratory Disease Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials. © 2017 Wiley Periodicals, Inc.

Influence of Epicuticular Physicochemical Properties on Porcine Rotavirus Adsorption to 24 Leafy Green Vegetables and Tomatoes

PubMed Central

Palma-Salgado, Sindy Paola; Storm, Andrew Page; Feng, Hao; Juvik, John A.; Nguyen, Thanh H.

2015-01-01

Foodborne diseases are a persistent problem in the United States and worldwide. Fresh produce, especially those used as raw foods like salad vegetables, can be contaminated, causing illness. In this study, we determined the number of rotaviruses adsorbed on produce surfaces using group A porcine rotaviruses and 24 cultivars of leafy vegetables and tomato fruits. We also characterized the physicochemical properties of each produce’s outermost surface layer, known as the epicuticle. The number of rotaviruses found on produce surfaces varied among cultivars. Three-dimensional crystalline wax structures on the epicuticular surfaces were found to significantly contribute to the inhibition of viral adsorption to the produce surfaces (p = 0.01). We found significant negative correlations between the number of rotaviruses adsorbed on the epicuticular surfaces and the concentrations of alkanes, fatty acids, and total waxes on the epicuticular surfaces. Partial least square model fitting results suggest that alkanes, ketones, fatty acids, alcohols, contact angle and surface roughness together can explain 60% of the variation in viral adsorption. The results suggest that various fresh produce surface properties need to be collectively considered for efficient sanitation treatments. Up to 10.8% of the originally applied rotaviruses were found on the produce surfaces after three washing treatments, suggesting a potential public health concern regarding rotavirus contamination. PMID:26181904

Organochlorine pesticide residues in surface water from Sichuan Basin to Aba Prefecture profile, east of the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Liu, Hongxia; Hu, Ying; Qi, Shihua; Xing, Xinli; Zhang, Yuan; Yang, Dan; Qu, Chengkai

2015-06-01

Organochlorine pesticides (OCPs) found in rivers from the Sichuan Basin to Aba Prefecture profile were analyzed to assess possible health risks to adults and children who use the river as a source of drinking water. OCP concentrations in surface water ranged between 22.29-274.28 ng·L-1. Compared with other published data around the world, OCP levels in this study were moderate. Among all OCPs, hexachlorobenzene (HCB) and hexachlorocyclohexanes (HCHs) were the predominant compounds. Higher concentrations of OCPs were attributed close to the agricultural fields of the Sichuan Basin, current OCPs inputs, and long-range atmospheric transport from abroad. Various spatial patterns of OCPs in the profile might be affected by the usage and physicochemical properties of the pesticides, in addition to the adjacent geographical environment. The health risk assessment indicated that most OCPs had little impact on human health according to the acceptable risk level for carcinogens (10-6) recommended by the US EPA. However, carcinogenic effects caused by heptachlor, Aldrin, HCB, and α-HCH might occur in drinking water. The risk of negative impacts caused by OCPs is much higher for children than for adults.

The Localized Scleroderma Skin Severity Index and Physician Global Assessment of Disease Activity: A Work in Progress Toward Development of Localized Scleroderma Outcome Measures

PubMed Central

ARKACHAISRI, THASCHAWEE; VILAIYUK, SOAMARAT; LI, SUZANNE; O’NEIL, KATHLEEN M.; POPE, ELENA; HIGGINS, GLORIA C.; PUNARO, MARILYNN; RABINOVICH, EGLA C.; ROSENKRANZ, MARGALIT; KIETZ, DANIEL A.; ROSEN, PAUL; SPALDING, STEVEN J.; HENNON, TERESA R.; TOROK, KATHRYN S.; CASSIDY, ELAINE; MEDSGER, THOMAS A.

2013-01-01

Objective To develop and evaluate a Localized Scleroderma (LS) Skin Severity Index (LoSSI) and global assessments’ clinimetric property and effect on quality of life (QOL). Methods A 3-phase study was conducted. The first phase involved 15 patients with LS and 14 examiners who assessed LoSSI [surface area (SA), erythema (ER), skin thickness (ST), and new lesion/extension (N/E)] twice for inter/intrarater reliability. Patient global assessment of disease severity (PtGA-S) and Children’s Dermatology Life Quality Index (CDLQI) were collected for intrarater reliability evaluation. The second phase was aimed to develop clinical determinants for physician global assessment of disease activity (PhysGA-A) and to assess its content validity. The third phase involved 2 examiners assessing LoSSI and PhysGA-A on 27 patients. Effect of training on improving reliability/validity and sensitivity to change of the LoSSI and PhysGA-A was determined. Results Interrater reliability was excellent for ER [intraclass correlation coefficient (ICC) 0.71], ST (ICC 0.70), LoSSI (ICC 0.80), and PhysGA-A (ICC 0.90) but poor for SA (ICC 0.35); thus, LoSSI was modified to mLoSSI. Examiners’ experience did not affect the scores, but training/practice improved reliability. Intrarater reliability was excellent for ER, ST, and LoSSI (Spearman’s rho = 0.71–0.89) and moderate for SA. PtGA-S and CDLQI showed good intrarater agreement (ICC 0.63 and 0.80). mLoSSI correlated moderately with PhysGA-A and PtGA-S. Both mLoSSI and PhysGA-A were sensitive to change following therapy. Conclusion mLoSSI and PhysGA-A are reliable and valid tools for assessing LS disease severity and show high sensitivity to detect change over time. These tools are feasible for use in routine clinical practice. They should be considered for inclusion in a core set of LS outcome measures for clinical trials. PMID:19833758

The Determinants of Costs and Length of Stay for Hip Fracture Patients

PubMed Central

Castelli, Adriana; Daidone, Silvio; Jacobs, Rowena; Kasteridis, Panagiotis; Street, Andrew David

2015-01-01

Background and Purpose An ageing population at greater risk of proximal femoral fracture places an additional clinical and financial burden on hospital and community medical services. We analyse the variation in i) length of stay (LoS) in hospital and ii) costs across the acute care pathway for hip fracture from emergency admission, to hospital stay and follow-up outpatient appointments. Patients and Methods We analyse patient-level data from England for 2009/10 for around 60,000 hip fracture cases in 152 hospitals using a random effects generalized linear multi-level model where the dependent variable is given by the patient’s cost or length of stay (LoS). We control for socio-economic characteristics, type of fracture and intervention, co-morbidities, discharge destination of patients, and quality indicators. We also control for provider and social care characteristics. Results Older patients and those from more deprived areas have higher costs and LoS, as do those with specific co-morbidities or that develop pressure ulcers, and those transferred between hospitals or readmitted within 28 days. Costs are also higher for those having a computed tomography (CT) scan or cemented arthroscopy. Costs and LoS are lower for those admitted via a 24h emergency department, receiving surgery on the same day of admission, and discharged to their own homes. Interpretation Patient and treatment characteristics are more important as determinants of cost and LoS than provider or social care factors. A better understanding of the impact of these characteristics can support providers to develop treatment strategies and pathways to better manage this patient population. PMID:26204450

Diffusion length of positrons and positronium investigated using a positronbeam with longitudinal geometry

NASA Astrophysics Data System (ADS)

van Petegem, S.; Dauwe, C.; van Hoecke, T.; de Baerdemaeker, J.; Segers, D.

2004-09-01

Positronium emission from single crystalline Al2O3 , MgO and vitreous a-SiO2 surfaces was studied as a function of the positron implantation energy E by means of Doppler broadening spectroscopy and Compton-to-peak ratio analysis. When the Ge-detector is in-line with the positron beam, the emission of para-positronium yields a red-shifted fly-away peak with intensity IpPse . An analysis of IpPse versus E for Al2O3 and MgO where no Ps is formed in the bulk (fPs=0) results in positron diffusion lengths L+(Al2O3)=(18±1)nm and L+(MgO)=(14±1)nm , and efficiencies for the emission of Ps by picking up of a surface electron of fpu(Al2O3)=(0.28±0.2) and fpu(MgO)=(0.24±0.2) . For a-SiO2 the bulk Ps fraction is fPs(a-SiO2)=(0.72±0.01) , fpu(a-SiO2)=(0.12±0.01) and the diffusion lengths of positrons, para-positronium and ortho-positronium are L+(SiO2)=(8±2)nm , LpPs(SiO2)=(14.5±2)nm and LoPs(SiO2)=(11±2)=nm . Depending on the specimen-detector geometry the emission of Ps at low implantation energy may cause either an increase or a decrease of the width of the annihilation line shape at low implantation energies.

Seasonal variations in physico-chemical characteristics of Tuticorin coastal waters, southeast coast of India

NASA Astrophysics Data System (ADS)

Balakrishnan, S.; Chelladurai, G.; Mohanraj, J.; Poongodi, J.

2017-07-01

Physico-chemical parameters were determined along the Vellapatti, Tharuvaikulam and Threspuram coastal waters, southeast coast of India. All the physico-chemical parameters such as sea surface temperature, salinity, pH, total alkalinity, total suspended solids, dissolved oxygen and nutrients like nitrate, nitrite, inorganic phosphate and reactive silicate were studied for a period of 12 months (June 2014-May 2015). Sea surface temperature varied from 26.4 to 29.7 °C. Salinity varied from 26.1 and 36.2 ‰, hydrogen ion concentration ranged between 8.0 and 8.5. Variation in dissolved oxygen content was from 4.125 to 4.963 mg l-1. Total alkalinity ranged from 64 to 99 mg/l. Total suspended solids ranged from 24 to 97 mg/l. Concentrations of nutrients, viz. nitrates (2.047-4.007 μM/l), nitrites (0.215-0.840 μM/l), phosphates (0.167-0.904 µM/l), total phosphorus (1.039-3.479 μM/l), reactive silicates (3.737-8.876 μM/l) ammonia (0.078-0.526 μM/l) and also varied independently.

Physicochemical properties of natural actomyosin from threadfin bream (Nemipterus spp.) induced by high hydrostatic pressure.

PubMed

Zhou, Aimei; Lin, Liying; Liang, Yan; Benjakul, Soottawat; Shi, Xiaoling; Liu, Xin

2014-08-01

Changes of physicochemical properties in natural actomyosin (NAM) from threadfin bream (Nemipterus spp.) induced by high hydrostatic pressure (200, 400, 600MPa for 10, 30, 50min) were studied. The increase in turbidity of NAM was coincidental with the decrease in protein solubility with increasing pressure and time, suggesting the formation of protein aggregates. SDS-PAGE showed that polymerisation and degradation of myosin heavy chain were induced by high pressure. Ca(2+)-ATPase activity of NAM treated by high pressure was lost, suggesting the denaturation of myosin and the dissociation of actomyosin complex. Surface hydrophobicity of NAM increased when the pressure and pressurization time increased, indicating that the exposed hydrophobic residues increased upon application of high pressure. Decrease in total sulfhydryl content and increase in surface-reactive sulfhydryl content of NAM samples were observed with the extension of pressurizing time, indicating the formation of disulphide bonds through oxidation of SH groups or disulphide interchanges. The above changes of physicochemical properties suggested conformational changes of NAM from muscle of threadfin bream induced by high hydrostatic pressure. Copyright © 2014 Elsevier Ltd. All rights reserved.

Physicochemical characterization of ultrasmall superparamagnetic iron oxide particles (USPIO) for biomedical application as MRI contrast agents

PubMed Central

Di Marco, Mariagrazia; Sadun, Claudia; Port, Marc; Guilbert, Irene; Couvreur, Patrick; Dubernet, Catherine

2007-01-01

Ultrasmall superparamagnetic iron oxide (USPIO) particles are maghemite or magnetite nanoparticles currently used as contrast agent in magnetic resonance imaging. The coatings surrounding the USPIO inorganic core play a major role in both the in vitro stability and, over all, USPIO’s in vivo fate. Different physicochemical properties such as final size, surface charge and coating density are key factors in this respect. Up to now no precise structure – activity relationship has been described to predict entirely the USPIOs stability, as well as their pharmacokinetics and their safety. This review is focused on both the classical and the latest available techniques allowing a better insight in the magnetic core structure and the organic surface of these particles. Concurrently, this work clearly shows the difficulty to obtain a complete physicochemical characterization of USPIOs particles owing to their small dimensions, reaching the analytical resolution limits of many commercial instruments. An extended characterization is therefore necessary to improve the understanding of the properties of USPIOs when dispersed in an aqueous environment and to set the specifications and limits for their conception. PMID:18203428

Interfacial tensiometry and dilational surface visco-elasticity of biological liquids in medicine.

PubMed

Fainerman, V B; Trukhin, D V; Zinkovych, Igor I; Miller, R

2018-05-01

Dynamic surface tensions and dilational visco-elasticity are easy accessible parameters of liquids. For human body liquids, such as urine, blood serum, amniotic fluid, gastric juice, saliva and others, these parameters are very characteristic for the health status of people. In case of a disease the composition of certain liquids specifically changes and the measured characteristics of dynamic surface tension of the dilational surface elasticity and viscosity reflect these changes in a clear way. Thus, this kind of physico-chemical measurements represent sensitive tools for evaluating the severity of a disease and can serve as control tool for the efficiency of applied therapies. The overview summarises the results of a successful work over about 25years on this subject and gives specific insight into a number of diseases for which the diagnostics as well as the therapy control have been significantly improved by the application of physico-chemical experimental techniques. Copyright © 2017 Elsevier B.V. All rights reserved.

Fabrication of Gold Nanoparticles for targeted therapy in pancreatic cancer**

PubMed Central

Patra, Chitta Ranjan; Bhattacharya, Resham; Mukhopadhyay, Debabrata; Mukherjee, Priyabrata

2009-01-01

The targeted delivery of a drug should result in enhanced therapeutic efficacy with low to minimal side effects. This is a widely accepted concept, but limited in application due to lack of available technologies and process of validation. Biomedical nanotechnology can play an important role in this respect. Biomedical nanotechnology is a burgeoning field with myriads of opportunities and possibilities for advancing medical science and disease treatment. Cancer nanotechnology (1–100 nm size range) is expected to change the very foundations of cancer treatment, diagnosis and detection. Nanomaterials, especially gold nanoparticles (AuNPs) have unique physicochemical properties, such as ultra small size, large surface area to mass ratio, and high surface reactivity, presence of surface plasmon resonance (SPR) bands, biocompatibility and ease of surface functionalization. In this review, we will discuss how the unique physico-chemical properties of gold nanoparticles may be utilized for targeted drug delivery in pancreatic cancer leading to increased efficacy of traditional chemotherapeutics. PMID:19914317

Superficial physicochemical properties of polyurethane biomaterials as osteogenic regulators in human mesenchymal stem cells fates.

PubMed

Shahrousvand, Mohsen; Sadeghi, Gity Mir Mohamad; Shahrousvand, Ehsan; Ghollasi, Marzieh; Salimi, Ali

2017-08-01

All of the cells' interactions are done through their surfaces. Evaluation of surface physicochemical scaffolds along with other factors is important and determines the fate of stem cells. In this work, biodegradable and biocompatible polyester/polyether based polyurethanes (PUs) were synthesized by polycaprolactone diol (PCL) and poly (tetra methylene ether) glycol (PTMEG) as the soft segment. To assess better the impact of surface parameters such as stiffness and roughness effects on osteogenic differentiation of the human mesenchymal stem cell (hMSC), the dimension effect of substrates was eliminated and two-dimensional membranes were produced by synthesized polyurethane. Surface and bulk properties of prepared 2D membranes such as surface chemistry, roughness, stiffness and tensile behavior were evaluated by Attenuated total reflectance Fourier transform infrared (ATR-FTIR), atomic force microscopy (AFM) and tensile behavior. The prepared 2D PU films had suitable hydrophilicity, biodegradability, water absorption, surface roughness and bulk strength. The hMSCs showed greater osteogenesis expression in PU substrates with more roughness and stiffness than others. The results demonstrated that surface parameters along with other differentiation cues have a synergistic effect on stem cells fates. Copyright © 2017 Elsevier B.V. All rights reserved.

Physicochemical and antibacterial characterization of ionocity Ag/Cu powder nanoparticles

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

Nowak, A., E-mail: ana.maria.nowak@gmail.com; Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów; Szade, J.

Metal ion in bimetallic nanoparticles has shown vast potential in a variety of applications. In this paper we show the results of physical and chemical investigations of powder Ag/Cu nanoparticles obtained by chemical synthesis. Transmission electron microscopy (TEM) experiment indicated the presence of bimetallic nanoparticles in the agglomerated form. The average size of silver and copper nanoparticles is 17.1(4) nm (Ag) and 28.9(2) nm (Cu) basing on the X-ray diffraction (XRD) data. X-ray photoelectron (XPS) and Raman spectroscopies revealed the existence of metallic silver and copper as well as Cu{sub 2}O and CuO being a part of the nanoparticles. Moreover,more » UV–Vis spectroscopy showed surface alloy of Ag and Cu while Time of Flight Secondary Ion Mass Spectroscopy (ToF-SIMS) and Energy Dispersive X-ray Spectroscopy (EDX) showed heterogeneously distributed Ag structures placed on spherical Cu nanoparticles. The tests of antibacterial activity show promising killing/inhibiting growth behaviour for Gram positive and Gram negative bacteria. - Highlights: • Ag/Cu nanoparticles were obtained in the powder form. • The average size of nanoparticles is 17.1(4) nm (Ag) and 28.9(2) nm (Cu). • Ag/Cu powder nanoparticle shows promising antibacterial properties.« less

Does a Relationship Exist Between Lower Body Power and Balance Scores Among Older Adults?

PubMed

Shim, Andrew; Harr, Brady; Waller, Mike

2018-03-12

Falls are the second-leading cause of unintentional injury and death worldwide. To determine if a relationship exists between lower body power scores and center of pressure (CoP) and limits of stability (LoS) scores. A one-shot case study design (n = 13) was selected for the investigation. All participants were assessed stability scores via computerized posturography to determine CoP and LoS balance scores. Participants stood on a perturbed surface with their eyes open and closed. An experimental stair ramp with a switch mat timing device was used to determine lower body power scores in watts. There was a strong correlation (r = 0.725, p = 0.005) between the posterior (LoS) plane and relative peak power. An intraclass R revealed a strong correlation among the three trials (R = 0.831) performed on the stair ramp. Muscle power output and LoS scores have moderate to strong correlations with balance scores in older adults.

76 FR 50152 - Airworthiness Directives; Lycoming Engines (L)O-360, (L)IO-360, AEIO-360, O-540, IO-540, AEIO-540...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-12

...-B2C5 Piper PA-24 ``235'' Pawnee O-540-B4B5 Embraer EMB-710 Corioca Maule MX-7-235 Star Rocket, M-6-235 Super Rocket, M-7-235 Super Rocket Piper PA-28 ``235'' Cherokee S.O.C.A.T.A 235GT Rallye, 235C Rallye O... Rocket, M-6-235 Super Rocket, M-7-235 Super Rocket O-540-J3A5 Robin R-3000/235 O-540-J3A5D Piper PA-28...

Salivary protein adsorption and Streptococccus gordonii adhesion to dental material surfaces.

PubMed

Schweikl, Helmut; Hiller, Karl-Anton; Carl, Ulrich; Schweiger, Rainer; Eidt, Andreas; Ruhl, Stefan; Müller, Rainer; Schmalz, Gottfried

2013-10-01

The initial adhesion of microorganisms to clinically used dental biomaterials is influenced by physico-chemical parameters like hydrophobicity and pre-adsorption of salivary proteins. Here, polymethyl methacrylate (PMMA), polyethylene (PE), polytetrafluoroethylene (PTFE), silicone (Mucopren soft), silorane-based (Filtek Silorane) and methacrylate-based (Tetric EvoCeram) dental composites, a conventional glassionomer cement as well as cobalt-chromium-molybdenum (Co28Cr6Mo) and titanium (Ti6Al4V) were tested for adsorption of salivary proteins and adhesion of Streptococcus gordonii DL1. Wettability of material surfaces precoated with salivary proteins or left in phosphate-buffered saline was determined by the measurement of water contact angles. Amounts of adsorbed proteins were determined directly on material surfaces after biotinylation of amino groups and detection by horseradish peroxidase-conjugated avidin-D. The same technique was used to analyze for the binding of biotinylated bacteria to material surfaces. The highest amount of proteins (0.18μg/cm(2)) adsorbed to hydrophobic PTFE samples, and the lowest amount (0.025μg/cm(2)) was detected on silicone. The highest number of S. gordonii (3.2×10(4)CFU/mm(2)) adhered to the hydrophilic glassionomer cement surface coated with salivary proteins, and the lowest number (4×10(3)CFU/mm(2)) was found on the hydrophobic silorane-based composite. Hydrophobicity of pure material surfaces and the number of attached microorganisms were weakly negatively correlated. No such correlation between hydrophobicity and the number of bacteria was detected when surfaces were coated with salivary proteins. Functional groups added by the adsorption of specific salivary proteins to material surfaces are more relevant for initial bacterial adhesion than hydrophobicity as a physical property. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Feasibility study of determining axial stress in ferromagnetic bars using reciprocal amplitude of initial differential susceptibility obtained from static magnetization by permanent magnets

NASA Astrophysics Data System (ADS)

Deng, Dongge; Wu, Xinjun

2018-03-01

An electromagnetic method for determining axial stress in ferromagnetic bars is proposed. In this method, the tested bar is under the static magnetization provided by permanent magnets. The tested bar do not have to be magnetized up to the technical saturation because reciprocal amplitude of initial differential susceptibility (RAIDS) is adopted as the feature parameter. RAIDS is calculated from the radial magnetic flux density Br Lo = 0.5 at the Lift-off Lo = 0.5 mm, radial magnetic flux density Br Lo = 1 at the Lift-off Lo = 1 mm and axial magnetic flux density Bz Lo = 1 at the Lift-off Lo = 1 mm from the surface of the tested bar. Firstly, the theoretical derivation of RAIDS is carried out according to Gauss' law for magnetism, Ampere's Law and the Rayleigh relation in Rayleigh region. Secondly, the experimental system is set up for a 2-meter length and 20 mm diameter steel bar. Thirdly, an experiment is carried out on the steel bar to analyze the relationship between the obtained RAIDS and the axial stress. Experimental results show that the obtained RAIDS decreases almost linearly with the increment of the axial stress inside the steel bar in the initial elastic region. The proposed method has the potential to determine tensile axial stress in the slender cylindrical ferromagnetic bar.

Environmental Stress-mediated EPS Production Shape Microbial Activity on Various Hydrated Rough Surfaces

NASA Astrophysics Data System (ADS)

Wang, G.; Liu, L.; Chen, G.

2016-12-01

The complex environmental physical and chemical processes and interplay with the associating biological responses are keys to understanding the environmental microbiology ensconced in environmental remediation, water quality control, food safety, nutrient cycling, and etc., yet remain poorly understood. Using experimental micromodels, we study how environmental conditions (e.g., hydration fluctuation, nutrient limitation, pH variation, etc.) affect microbial extracellular polymeric substances (EPS) production and their configuration within various hydrated surfaces, and impacts on microbial motility, surface attachment, aggregation, and other bioremediation activities. To elucidate the potential mechanisms underlying the complex bio-physicochemical processes, we developed an individual-based and spatio-temporally resolved modeling platform that explicitly considers microscale aqueous-phase configuration and nutrient transport/diffusion and associated biophysical processes affecting individual microbial cell life history. We quantitatively explore the effects of the above microscale environmental processes on bio-physicochemical interactions affecting microbial growth, motility, surface attachment and aggregation, and shaping population interactions and functions. Simulation scenarios of microbial induced pollutant (e.g., roxarsone) biotransformation on various hydrated rough surfaces will also be present.

Influence of physicochemical properties of laser-modified polystyrene on bovine serum albumin adsorption and rat C6 glioma cell behavior.

PubMed

Wang, Xuefeng; Ohlin, C André; Lu, Qinghua; Hu, Jun

2006-09-15

Biomaterial surface modification is an efficient way of improving cell-material interactions. In this study, sub-micrometer laser-induced periodic surface structures (LIPSS) were produced on polystyrene by laser irradiation. FT-IR analysis confirmed that this treatment also led to surface oxidation and anisotropic orientation of the produced carbonyl groups. As a consequence, the surface energy of the laser-treated polystyrene was 1.45 times that of the untreated polystyrene, as measured by contact-angle goniometry. Protein adsorption and rat C6 glioma cell behavior on the two substrates were investigated, showing that the changed physicochemical properties of laser-modified polystyrene surface led to an increase in the quantity of adsorbed bovine serum albumin and significantly affected the behavior of rat C6 glioma cells. In the early stages of cell spreading, cells explored their microenvironment using filopodium as the main sensor. Moreover, cells actively aligned themselves along the direction of LIPSS gradually and cell attachment and proliferation were significantly enhanced. 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006.

Influences of iron and calcium carbonate on wastewater treatment performances of algae based reactors.

PubMed

Zhao, Zhimiao; Song, Xinshan; Wang, Wei; Xiao, Yanping; Gong, Zhijie; Wang, Yuhui; Zhao, Yufeng; Chen, Yu; Mei, Mengyuan

2016-09-01

The influences of iron and calcium carbonate (CaCO3) addition in wastewater treatments reactors performance were investigated. Adding different concentrations of Fe(3+) (5, 10, 30 and 50mmol/m(3)), iron and CaCO3 powder led to changes in algal characteristics and physico-chemical and microbiological properties. According to the investigation results, nutrient removal efficiency in algae based reactors was obviously increased by the addition of 10mmol/m(3) Fe(3+), iron (5mmol/m(3)) and CaCO3 powder (0.2gm(-3)) and the removal efficiencies of BOD5, TN, and TP in Stage 2 were respectively increased by 28%, 8.9%, and 22%. The improvements in physico-chemical performances were verified by microbial community tests (bacteria quantity, activity and community measured in most probable number, extracellular enzymes activity, and Biolog Eco Plates). Microbial variations indicated the coexistence of Fe ions and carbonate-bicarbonate, which triggered the synergistic effect of physico-chemical action and microbial factors in algae based reactors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Physicochemical properties and oral bioavailability of ursolic acid nanoparticles using supercritical anti-solvent (SAS) process.

PubMed

Yang, Lei; Sun, Zhen; Zu, Yuangang; Zhao, Chunjian; Sun, Xiaowei; Zhang, Zhonghua; Zhang, Lin

2012-05-01

The objective of the study was to prepare ursolic acid (UA) nanoparticles using the supercritical anti-solvent (SAS) process and evaluate its physicochemical properties and oral bioavailability. The effects of four process variables, pressure, temperature, drug concentration and drug solution flow rate, on drug particle formation during SAS process, were investigated. Particles with mean particle size ranging from 139.2±19.7 to 1039.8±65.2nm were obtained by varying the process parameters. The UA was characterised by scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, thermal gravimetric analysis, specific surface area, dissolution test and bioavailability test. It was concluded that physicochemical properties and bioavailability of crystalline UA could be improved by physical modification, such as particle size reduction and generation of amorphous state using SAS process. Further, SAS process was a powerful methodology for improving the physicochemical properties and bioavailability of UA. Copyright © 2011 Elsevier Ltd. All rights reserved.

Michael acceptor containing drugs are a novel class of 5-lipoxygenase inhibitor targeting the surface cysteines C416 and C418.

PubMed

Maucher, Isabelle V; Rühl, Michael; Kretschmer, Simon B M; Hofmann, Bettina; Kühn, Benjamin; Fettel, Jasmin; Vogel, Anja; Flügel, Karsten T; Manolikakes, Georg; Hellmuth, Nadine; Häfner, Ann-Kathrin; Golghalyani, Vahid; Ball, Ann-Katrin; Piesche, Matthias; Matrone, Carmela; Geisslinger, Gerd; Parnham, Michael J; Karas, Michael; Steinhilber, Dieter; Roos, Jessica; Maier, Thorsten J

2017-02-01

Recently, we published that nitro-fatty acids (NFA) are potent electrophilic molecules which inhibit 5-lipoxygenase (5-LO) by interacting catalytically with cysteine residues next to a substrate entry channel. The electrophilicity is derived from an intramolecular Michael acceptor moiety consisting of an electron-withdrawing group in close proximity to a double bond. The potential of the Michael acceptor moiety to interact with functionally relevant cysteines of proteins potentially renders them effective and sustained enzyme activity modulators. We screened a large library of naturally derived and synthetic electrophilic compounds to investigate whether other types of Michael acceptor containing drugs suppress 5-LO enzyme activity. The activity was measured by assessing the effect on the 5-LO product formation of intact human polymorphonuclear leukocytes. We demonstrated that a number of structurally different compounds were suppressive in the activity assays and showed that Michael acceptors of the quinone and nitro-alkene group produced the strongest inhibition of 5-LO product formation. Reactivity with the catalytically relevant cysteines 416 and 418 was confirmed using mutated recombinant 5-LO and mass spectrometric analysis (MALDI-MS). In the present study, we show for the first time that a number of well-recognized naturally occurring or synthetic anti-inflammatory compounds carrying a Michael acceptor, such as thymoquinone (TQ), the paracetamol metabolite NAPQI, the 5-LO inhibitor AA-861, and bardoxolone methyl (also known as RTA 402 or CDDO-methyl ester) are direct covalent 5-LO enzyme inhibitors that target the catalytically relevant cysteines 416 and 418. Copyright © 2016 Elsevier Inc. All rights reserved.

Diagnosing the Nature of Land-Atmosphere Coupling: A Case Study of Dry/Wet Extremes in the U. S. Southern Great Plains

NASA Technical Reports Server (NTRS)

Santanello, Joseph A. Jr.; Peters-Lidard, Christa D.; Kennedy, Aaron; Kumar, Sujay V.

2012-01-01

Land-atmosphere (L-A) interactions play a critical role in determining the diurnal evolution of land surface and planetary boundary layer (PBL) temperature and moisture states and fluxes. In turn, these interactions regulate the strength of the connection between surface moisture and precipitation in a coupled system. To address model deficiencies, recent studies have focused on development of diagnostics to quantify the strength and accuracy of the land- PBL coupling at the process-level. In this paper, a diagnosis of the nature and impacts of local land-atmosphere coupling (LoCo) during dry and wet extreme conditions is presented using a combination of models and observations during the summers of 2006 and 2007 in the U.S. Southern Great Plains. A range of diagnostics exploring the links and feedbacks between soil moisture and precipitation are applied to the dry/wet regimes exhibited in this region, and in the process a thorough evaluation of nine different land-PBL scheme couplings is conducted under the umbrella of a high-resolution regional modeling testbed. Results show that the sign and magnitude of errors in land surface energy balance components are sensitive to the choice of land surface model, regime type, and running mode. In addition, LoCo diagnostics show that the sensitivity of L-A coupling is stronger towards the land during dry conditions, while the PBL scheme coupling becomes more important during the wet regime. Results also demonstrate how LoCo diagnostics can be applied to any modeling system (e.g. reanalysis products) in the context of their integrated impacts on the process-chain connecting the land surface to the PBL and in support of hydrological anomalies.

Diagnosing the Nature of Land-Atmosphere Coupling: A Case Study of Dry/Wet Extremes in the U.S. Southern Great Plains

NASA Technical Reports Server (NTRS)

Santanello, Joseph A., Jr.; Peters-Lidard, Christa D.; Kennedy, Aaron; Kumar, Sujay V.

2012-01-01

Land-atmosphere (L-A) interactions play a critical role in determining the diurnal evolution of land surface and planetary boundary layer (PBL) temperature and moisture states and fluxes. In turn, these interactions regulate the strength of the connection between surface moisture and precipitation in a coupled system. To address model deficiencies, recent studies have focused on development of diagnostics to quantify the strength and accuracy of the land-PBL coupling at the process level. In this paper, a diagnosis of the nature and impacts of local land-atmosphere coupling (LoCo) during dry and wet extreme conditions is presented using a combination of models and observations during the summers of 2006 and 2007 in the U.S. southern Great Plains. A range of diagnostics exploring the links and feedbacks between soil moisture and precipitation is applied to the dry/wet regimes exhibited in this region, and in the process, a thorough evaluation of nine different land-PBL scheme couplings is conducted under the umbrella of a high-resolution regional modeling test bed. Results show that the sign and magnitude of errors in land surface energy balance components are sensitive to the choice of land surface model, regime type, and running mode. In addition, LoCo diagnostics show that the sensitivity of L-A coupling is stronger toward the land during dry conditions, while the PBL scheme coupling becomes more important during the wet regime. Results also demonstrate how LoCo diagnostics can be applied to any modeling system (e.g., reanalysis products) in the context of their integrated impacts on the process chain connecting the land surface to the PBL and in support of hydrological anomalies.

Response surface model for predicting chronic toxicity of cadmium to Paronychiurus kimi (Collembola), with a special emphasis on the importance of soil characteristics in the reproduction test.

PubMed

Son, Jino; Shin, Key-il; Cho, Kijong

2009-11-01

A central composite design (CCD) was employed to investigate the effects of organic matter (OM) content and soil pH on the reproduction, and chronic toxicity (28-d EC(50-reproduction)) of cadmium for Paronychiurus kimi after 28days exposure in a standard artificial soil. Two statistical models were developed, one describing reproduction in control artificial soils as a function of OM content and pH, and the other describing cadmium toxicity to the same soil parameters. In the reproduction model, pH was the most important factor, followed by two quadratic factors of OM(2) and pH(2). The parameter pH alone could explain 75.5% of the response variation. The reproduction model will allow us to predict a mean reproduction in the non-treated control soils that contain various combinations of OM content and different pH values. In the chronic toxicity model, only the linear factor of the OM content and pH significantly (p<0.05) affect cadmium toxicity, which explains the 78.9% and 14.9% of total response variance, respectively. Therefore, the final polynomial regression describing the chronic toxicity of cadmium to P. kimi is as follows: predicted 28-d EC(50) of cadmium (mgkg(-1))=-21.231+2.794 x OM+4.874 x pH. The present study show that soil characteristics, which can alter the toxicity of cadmium, can also act as stressors themselves in regards to the reproduction of P. kimi. Based on the physico-chemical characteristics of the test media, the response surface model developed in this study can be used to provide initial toxicity information for cadmium within a region of interest in terms of OM content and pH, and may lead to more scientific based risk assessment for metals.

Effect of additional of Hoodia Gordonii and seaweed powder on the sensory and physicochemical properties of brown rice bar

NASA Astrophysics Data System (ADS)

Hajal, Masturah Ebni; Ghani, Maaruf Abd; Daud, Norlida Mat

2015-09-01

Awareness of the nutritional content of food has increased with the emergence of various health products in the market. Cereal bar is one of the beneficial foods among consumer that concern on their healthy food. This study was conducted to develop a brown rice bar that contain active ingredients (H. gordonii and seaweed powder) and to determine the effect on sensory evaluation and physicochemical properties (colour, texture and proximate analysis) of this product. This study consisted of two phases in which the first phase consisted of development of ten formulations including control. All of the formulations were undergo analysis of colour, texture and sensory evaluation. Based on the sensory evaluation, Control (H. gordonii: 0%, seaweed: 0%) and two best formulations that consist of formulation 6 (H. gordonii: 1.6%; seaweed: 2.8%) and formulation 9 (H. gordonii: 2.4%, seaweed: 2.8%) were chosen to undergo the second phase which is proximate analysis. Base on the result, were significant different (p<0.05) on proximate analysis except for the protein and moisture content. Therefore, it can be concluded that H. gordonii is a good source of fiber when adding in a bar.

Optical and Atomic Force Microscopy Characterization of PbI2 Quantum Dots

NASA Technical Reports Server (NTRS)

Mu, R.; Tung, Y. S.; Ueda, A.; Henderson, D. O.

1997-01-01

Lead iodide (PbI2) clusters were synthesized from the chemical reaction of NaI (or KI) with Pb(NO3)2 in H2O, D2O, CH3OH, and C3H7OH media. The observation of the absorption features above 350 nm with the help of integrating sphere accessory strongly suggests the quantum dot formation of PbI2 in solution. Spectral comparison between the synthesized PbI2 clusters in solution and PbI2 nanophase by impregnation of PbI2 in four different pore-sized porous silica indicates that the PbI2 cluster size in solution is less than 2.5 nm in lateral dimension. Atomic force microscopy (AFM) measurements show that the PbL clusters deposited onto three different molecularly flat surfaces are single-layered. The measured height is 1.0 - 0.1 nm. The swollen layer thickness can be attributed to the intralayer contraction from the strong lateral interaction among PbI2 molecules, which is supported by ab initio calculation. Raman scattering measurement of LO and TO modes of PbI2 in bulk and in the confined state were also conducted in 50-150 cu cm region. The observed three bands at 74, %, 106 1/cm are assigned to TO2, LO2, and LO, mode, respectively. The relatively small red-shift in LO modes may be caused by the surface phonon polaritons of PbI2 nanophase in the porous silica.

Nanometer Scale Titanium Surface Texturing Are Detected by Signaling Pathways Involving Transient FAK and Src Activations

PubMed Central

Zambuzzi, Willian F.; Bonfante, Estevam A.; Jimbo, Ryo; Hayashi, Mariko; Andersson, Martin; Alves, Gutemberg; Takamori, Esther R.; Beltrão, Paulo J.; Coelho, Paulo G.; Granjeiro, José M.

2014-01-01

Background It is known that physico/chemical alterations on biomaterial surfaces have the capability to modulate cellular behavior, affecting early tissue repair. Such surface modifications are aimed to improve early healing response and, clinically, offer the possibility to shorten the time from implant placement to functional loading. Since FAK and Src are intracellular proteins able to predict the quality of osteoblast adhesion, this study evaluated the osteoblast behavior in response to nanometer scale titanium surface texturing by monitoring FAK and Src phosphorylations. Methodology Four engineered titanium surfaces were used for the study: machined (M), dual acid-etched (DAA), resorbable media microblasted and acid-etched (MBAA), and acid-etch microblasted (AAMB). Surfaces were characterized by scanning electron microscopy, interferometry, atomic force microscopy, x-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy. Thereafter, those 4 samples were used to evaluate their cytotoxicity and interference on FAK and Src phosphorylations. Both Src and FAK were investigated by using specific antibody against specific phosphorylation sites. Principal Findings The results showed that both FAK and Src activations were differently modulated as a function of titanium surfaces physico/chemical configuration and protein adsorption. Conclusions It can be suggested that signaling pathways involving both FAK and Src could provide biomarkers to predict osteoblast adhesion onto different surfaces. PMID:24999733

Fate of Listeria spp. on parsley leaves grown in laboratory and field cultures.

PubMed

Dreux, N; Albagnac, C; Carlin, F; Morris, C E; Nguyen-The, C

2007-11-01

To investigate the population dynamics of Listeria monocytogenes and Listeria innocua on the aerial surfaces of parsley. Under 100% relative humidity (RH) in laboratory and regardless of the inoculum tested (10(3)-10(8) CFU per leaf), counts of L. monocytogenes EGDe, LO28, LmP60 and L. innocua CIP 80-12 tended towards approx. 10(5) CFU per leaf. Under low RH, Listeria spp. populations declined regardless to the inoculum size (10(4)-10(8) CFU per leaf). L. innocua CIP 80-12 survived slightly better than L. monocytogenes in the laboratory and was used in field cultures. Under field cultures, counts of L. innocua decreased more rapidly than in the laboratory, representing a decrease of 9 log(10) in 2 days in field conditions compared to a decrease of 4.5 log(10) in 8 days in the laboratory. Counts of L. innocua on tunnel parsley cultures were always higher (at least by 100 times) than those on unprotected parsley culture. Even with a high inoculum and under protected conditions (i.e. plastic tunnels), population of L. monocytogenes on the surface of parsley on the field would decrease by several log(10) scales within 2 days. Direct contamination of aerial surfaces of parsley with L. monocytogenes (i.e. through contaminated irrigation water) will not lead to contaminated produce unless it occurs very shortly before harvest.

Spray drying of lipid-based systems loaded with Camellia sinensis polyphenols.

PubMed

Secolin, Vanessa A; Souza, Claudia R F; Oliveira, Wanderley P

2017-03-01

In this work, spray-dried lipid systems based on soy phosphatidylcholine, cholesterol and lauroyl polyoxylglycerides for entrapping Green tea polyphenols were produced. The aim was to study the effects of the encapsulating composition and spray drying conditions on the system performance and physicochemical product properties. The spray dryer powder production yield falls around 50.7 ± 2.8%, which is typical for lab scale spray dryers. Wrinkled and rounded particles, with low surface porosities were generated, independent of the drying carriers (trehalose or lactose) used. The product showed high encapsulation efficiency of Green tea polyphenols, which was promptly redispersible in water. It presented low density, and good compressive and flow properties. The results herein reported confirm the feasibility of the entrapment of Green tea polyphenols in lipid-based compositions by spray drying in presence of the drying carriers evaluated. The spray-dried microparticles show high potential to be used as additive in food, nutraceutical and pharmaceutical products.

Effect of silver additive on physicochemical properties of hydroxyapatite applied to reconstructive surgery

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

Zhuk, I. V., E-mail: zhukiv1993@mail.ru; Rasskazova, L. A., E-mail: ly-2207@mail.ru; Korotchenko, N. M., E-mail: korotch@mail.ru

The effect of silver adding to hydroxyapatite (HA) in its solubility in physiological solution and biological activity was investigated. Samples of HA containing silver (AgHA) obtained by liquid-phase method in the conditions of microwave exposure. Solubility (C{sub Ca}{sup 2+}·10{sup 3}, mol/l) of the powders AgHA was determined by chemical methods according trilonometric titration of the calcium ions in physiological solution at 25 and 37 °C. To investigate the biological activity of the samples, a series of experiments on the formation of the calcium-phosphate layer on the surface of the SBF-solution at 37 °C for 28 days. Electronic micrographs of samplesmore » taken at the end of each 7 days of the experiment, indicate the formation of calcium-phosphate layer (CPL) in the samples, the kinetics of which is shown as a function of cumulative concentrations of calcium and magnesium ions from time.« less

Bioinspired anchoring AgNPs onto micro-nanoporous TiO2 orthopedic coatings: Trap-killing of bacteria, surface-regulated osteoblast functions and host responses.

PubMed

Jia, Zhaojun; Xiu, Peng; Li, Ming; Xu, Xuchen; Shi, Yuying; Cheng, Yan; Wei, Shicheng; Zheng, Yufeng; Xi, Tingfei; Cai, Hong; Liu, Zhongjun

2016-01-01

The therapeutic applications of silver nanoparticles (AgNPs) against biomedical device-associated infections (BAI), by local delivery, are encountered with risks of detachment, instability and nanotoxicity in physiological milieus. To firmly anchor AgNPs onto modified biomaterial surfaces through tight physicochemical interactions would potentially relieve these concerns. Herein, we present a strategy for hierarchical TiO2/Ag coating, in an attempt to endow medical titanium (Ti) with anticorrosion and antibacterial properties whilst maintaining normal biological functions. In brief, by harnessing the adhesion and reactivity of bioinspired polydopamine, silver nanoparticles were easily immobilized onto peripheral surface and incorporated into interior cavity of a micro/nanoporous TiO2 ceramic coating in situ grown from template Ti. The resulting coating protected the substrate well from corrosion and gave a sustained release of Ag(+) up to 28 d. An interesting germicidal effect, termed "trap-killing", was observed against Staphylococcus aureus strain. The multiple osteoblast responses, i.e. adherence, spreading, proliferation, and differentiation, were retained normal or promoted, via a putative surface-initiated self-regulation mechanism. After subcutaneous implantation for a month, the coated specimens elicited minimal, comparable inflammatory responses relative to the control. Moreover, this simple and safe functionalization strategy manifested a good degree of flexibility towards three-dimensional sophisticated objects. Expectedly, it can become a prospective bench to bedside solution to current challenges facing orthopedics. Copyright © 2015 Elsevier Ltd. All rights reserved.

In vitro cellular responses to silicon carbide nanoparticles: impact of physico-chemical features on pro-inflammatory and pro-oxidative effects

NASA Astrophysics Data System (ADS)

Pourchez, Jérémie; Forest, Valérie; Boumahdi, Najih; Boudard, Delphine; Tomatis, Maura; Fubini, Bice; Herlin-Boime, Nathalie; Leconte, Yann; Guilhot, Bernard; Cottier, Michèle; Grosseau, Philippe

2012-10-01

Silicon carbide is an extremely hard, wear resistant, and thermally stable material with particular photoluminescence and interesting biocompatibility properties. For this reason, it is largely employed for industrial applications such as ceramics. More recently, nano-sized SiC particles were expected to enlarge their use in several fields such as composite supports, power electronics, biomaterials, etc. However, their large-scaled development is restricted by the potential toxicity of nanoparticles related to their manipulation and inhalation. This study aimed at synthesizing (by laser pyrolysis or sol-gel methods), characterizing physico-chemical properties of six samples of SiC nanopowders, then determining their in vitro biological impact(s). Using a macrophage cell line, toxicity was assessed in terms of cell membrane damage (LDH release), inflammatory effect (TNF-α production), and oxidative stress (reactive oxygen species generation). None of the six samples showed cytotoxicity while remarkable pro-oxidative reactions and inflammatory response were recorded, whose intensity appears related to the physico-chemical features of nano-sized SiC particles. In vitro data clearly showed an impact of the extent of nanoparticle surface area and the nature of crystalline phases (α-SiC vs. β-SiC) on the TNF-α production, a role of surface iron on free radical release, and of the oxidation state of the surface on cellular H2O2 production.

Novel nano coordination polymer based synthesis of porous ZnO hexagonal nanodisk for higher gas sorption and photocatalytic activities

NASA Astrophysics Data System (ADS)

Rakibuddin, M.; Ananthakrishnan, Rajakumar

2016-01-01

Zinc(II)-based nano co-ordination polymers (NCPs) are first prepared at room temperature from three different isomers of dihydroxysalophen (DHS) ligand with Zn(OAc)2·2H2O and 1,4-benzenedicarboxylic acid (BDC) in DMF solvent. Facile calcinations of [Zn (DHS) (BDC)]·nH2O (shortly denoted as Zn(II)-based NCP) at ambient conditions produces porous ZnO hexagonal nanodisks. Moreover, a novel approach has been introduced to observe the effect of ligand of the NCP on the physico-chemical properties of the as-synthesized ZnO. The porous ZnO nanodisks are characterized by FT-IR, PXRD, TEM, FESEM, EDX and BET analysis, and the results exhibit that they possess different sizes, surface areas and porosities. Nitrogen gas sorption capacity and photocatalytic activities of the as-prepared ZnO nanodisks are also checked, and it is noticed that they differ in these physico-chemical properties due to having different porosities and surface areas. A comparative study is also done with commercially available ZnO; interestingly, the commercial ZnO exhibited lower surface area, gas sorption and photocatalytic activity compared to the ZnO nanodisks. Hence, preparation of the ZnO through the NCP route and tuning their physico-chemical properties would offer new directions in synthesis of various nano metal oxides of unique properties.

Diagnosing the Nature of Land-Atmosphere Coupling During the 2006-7 Dry/Wet Extremes in the U.S. Southern Great Plains

NASA Technical Reports Server (NTRS)

Santanello, Joseph A., Jr.; Peters-Lidard, Christa D.; Kumar, Sujay V.; Dong, Xiquan; Kennedy, Aaron D.

2011-01-01

Land-atmosphere interactions play a critical role in determining the. diurnal evolution of both planetary boundary layer (PBL) and land surface temperature and moisture states. The degree of coupling between the land surface and PBL in numerical weather prediction and climate models remains largely unexplored and undiagnosed due to the complex interactions and feedbacks present across a range of scales. Further, uncoupled systems or experiments (e.g., the Project for Intercomparison of Land Parameterization Schemes, PILPS) may lead to inaccurate water and energy cycle process understanding by neglecting feedback processes such as PBL-top entrainment. In this study, a framework for diagnosing local land-atmosphere coupling (LoCo) is presented using a coupled mesoscale model with a suite of PBL and land surface model (LSM) options along with observations during the summers of 200617 in the U.S. Southern Great Plains. Specifically, the Weather Research and Forecasting (WRF) model has been coupled to NASA's Land Information System (LIS), which provides a flexible and high-resolution representation and initialization of land surface physics and states. A range of diagnostics exploring the links and feedbacks between soil moisture and precipitation are examined for the dry/wet extremes of this region, along with the sensitivity of PBL-LSM coupling to perturbations in soil moisture. As such, this methodology provides a potential pathway to study factors controlling local land-atmosphere coupling (LoCo) using the LIS-WRF system, which is serving as a testbed for LoCo experiments to evaluate coupling diagnostics within the community.

Acemetacin cocrystal structures by powder X-ray diffraction

PubMed Central

Bolla, Geetha

2017-01-01

Cocrystals of acemetacin drug (ACM) with nicotinamide (NAM), p-aminobenzoic acid (PABA), valerolactam (VLM) and 2-pyridone (2HP) were prepared by melt crystallization and their X-ray crystal structures determined by high-resolution powder X-ray diffraction. The powerful technique of structure determination from powder data (SDPD) provided details of molecular packing and hydrogen bonding in pharmaceutical cocrystals of acemetacin. ACM–NAM occurs in anhydrate and hydrate forms, whereas the other structures crystallized in a single crystalline form. The carboxylic acid group of ACM forms theacid–amide dimer three-point synthon R 3 2(9)R 2 2(8)R 3 2(9) with three different syn amides (VLM, 2HP and caprolactam). The conformations of the ACM molecule observed in the crystal structures differ mainly in the mutual orientation of chlorobenzene fragment and the neighboring methyl group, being anti (type I) or syn (type II). ACM hydrate, ACM—NAM, ACM–NAM-hydrate and the piperazine salt of ACM exhibit the type I conformation, whereas ACM polymorphs and other cocrystals adopt the ACM type II conformation. Hydrogen-bond interactions in all the crystal structures were quantified by calculating their molecular electrostatic potential (MEP) surfaces. Hirshfeld surface analysis of the cocrystal surfaces shows that about 50% of the contribution is due to a combination of strong and weak O⋯H, N⋯H, Cl⋯H and C⋯H interactions. The physicochemical properties of these cocrystals are under study. PMID:28512568

Slip-additive migration, surface morphology, and performance on injection moulded high-density polyethylene closures.

PubMed

Dulal, Nabeen; Shanks, Robert; Gengenbach, Thomas; Gill, Harsharn; Chalmers, David; Adhikari, Benu; Pardo Martinez, Isaac

2017-11-01

The amount and distribution of slip agents, erucamide, and behenamide, on the surface of high-density polyethene, is determined by integral characteristics of slip agent structure and polymer morphology. A suite of surface analysis techniques was applied to correlate physicochemical properties with slip-additive migration behaviour and their surface morphology. The migration, surface morphology and physicochemical properties of the slip additives, crystallinity and orientation of polyethene spherulites and interaction between slip additives and high-density polyethene influence the surface characteristics. The high-density polyethene closures were produced with erucamide and behenamide separately and stored until they produced required torque. Surface composition was determined employing spectroscopy and gas chromatography. The distribution of additives was observed under optical, scanning electron and atomic force microscopes. The surface energy, crystallinity and application torque were measured using contact angle, differential scanning calorimeter and a torque force tester respectively. Each slip additive produced a characteristic amide peak at 1645cm -1 in infrared spectroscopy and peaks of oxygen and nitrogen in X-ray photoelectron spectroscopy, suggesting their presence on the surface. The erucamide produced placoid scale-like structures and behenamide formed denticulate structures. The surface erucamide and behenamide responsible for reducing the torque was found to be 15.7µg/cm 2 and 1.7µg/cm 2 . Copyright © 2017 Elsevier Inc. All rights reserved.

High-intensity exercise training does not influence body weight but improves lipid oxidation in obese adults: a 6-week RCT.

PubMed

Jabbour, Georges; Iancu, Horia-Daniel

2017-01-01

This study examined the effects of 6 weeks of high-intensity training (HIT) on lipid oxidation (LO) rates during incremental exercises in obese adults. Twenty-four obese adults were randomised into a no-exercise control group (n=12; body mass index=33.3 (4.8) kg.m -2 ) and a HIT group (18 sessions of 6×6 s of supramaximal cycling and 2 min passive intervals; n=12; body mass index=33.2 (2.8)kg.m -2 ). The percentage of LO contribution was computed at rest and for all workloads (25, 50, 75, 100 and 125 W) in both groups before and after training via a graded maximal cycling test. After training, the HIT group showed significantly higher LO at rest and at 25, 50 and 75 W compared with baseline (p<0.01) and the control group (p<0.01). Moreover, for the training group, the homoeostasis model assessment of insulin resistance (HOMA-IR) index decreased significantly from the baseline value (p<0.01) and the control group value (p<0.01). The increases in LO observed at rest and stages 25, 50 and 75 W were positively correlated with the declines in the HOMA-IR index (r=0.87, r=0.83, r=0.91 and r=0.88; p<0.01). In obese adults, HIT increased lipid contributions to energy release at rest and in response to incremental exercise, while there were no changes in participants' aerobic capacity. This supports the hypothesis that metabolic changes rather than improved aerobic capacity are important to improve LO. ISRCTN66508384. Stage: post-results.

Validation of accelerometer cut points in toddlers with and without cerebral palsy.

PubMed

Oftedal, Stina; Bell, Kristie L; Davies, Peter S W; Ware, Robert S; Boyd, Roslyn N

2014-09-01

The purpose of this study was to validate uni- and triaxial ActiGraph cut points for sedentary time in toddlers with cerebral palsy (CP) and typically developing children (TDC). Children (n = 103, 61 boys, mean age = 2 yr, SD = 6 months, range = 1 yr 6 months-3 yr) were divided into calibration (n = 65) and validation (n = 38) samples with separate analyses for TDC (n = 28) and ambulant (Gross Motor Function Classification System I-III, n = 51) and nonambulant (Gross Motor Function Classification System IV-V, n = 25) children with CP. An ActiGraph was worn during a videotaped assessment. Behavior was coded as sedentary or nonsedentary. Receiver operating characteristic-area under the curve analysis determined the classification accuracy of accelerometer data. Predictive validity was determined using the Bland-Altman analysis. Classification accuracy for uniaxial data was fair for the ambulatory CP and TDC group but poor for the nonambulatory CP group. Triaxial data showed good classification accuracy for all groups. The uniaxial ambulatory CP and TDC cut points significantly overestimated sedentary time (bias = -10.5%, 95% limits of agreement [LoA] = -30.2% to 9.1%; bias = -17.3%, 95% LoA = -44.3% to 8.3%). The triaxial ambulatory and nonambulatory CP and TDC cut points provided accurate group-level measures of sedentary time (bias = -1.5%, 95% LoA = -20% to 16.8%; bias = 2.1%, 95% LoA = -17.3% to 21.5%; bias = -5.1%, 95% LoA = -27.5% to 16.1%). Triaxial accelerometers provide useful group-level measures of sedentary time in children with CP across the spectrum of functional abilities and TDC. Uniaxial cut points are not recommended.

Occurrence of enteric viruses in reclaimed and surface irrigation water: relationship with microbiological and physicochemical indicators.

PubMed

López-Gálvez, F; Truchado, P; Sánchez, G; Aznar, R; Gil, M I; Allende, A

2016-10-01

To assess the prevalence of enteric viruses in different irrigation water sources and in the irrigated produce, and the possible links with microbiological and physicochemical water characteristics. The prevalence and levels of Escherichia coli, Norovirus (NoV) genogroup I (GI) and II (GII), as well as Hepatitis A virus were assessed in three types of water: surface water (surface-W), reclaimed water subjected to secondary treatment (secondary-W) and reclaimed water subjected to tertiary treatment (tertiary-W), as well as in zucchini irrigated with these irrigation water sources. Chemical oxygen demand (COD), turbidity, total suspended solids, alkalinity and maximum filterable volume (MFV) were also measured in the water. Higher prevalence of NoV in secondary-W (GI 100%, GII 55·6%) and tertiary-W (GI 91·7%, GII 66·7%) compared with surface-W (GI 58·4%, GII 22·2%) was observed. Nov GI showed positive correlation with E. coli (Spearman's correlation coefficient = 0·68, P < 0·01), and with some physicochemical parameters such as COD (0·52, P < 0·01), turbidity (0·52, P < 0·01) and MFV (0·54, P < 0·01). Escherichia coli and enteric viruses were not detected in zucchini. There is a potential risk of contamination of crops with NoV when reclaimed water is used for irrigation. Increase the knowledge on the prevalence of enteric viruses in different irrigation water sources, and its consequences for fresh produce safety. © 2016 The Society for Applied Microbiology.

On the influence of various physicochemical properties of the CNTs based implantable devices on the fibroblasts' reaction in vitro.

PubMed

Benko, Aleksandra; Frączek-Szczypta, Aneta; Menaszek, Elżbieta; Wyrwa, Jan; Nocuń, Marek; Błażewicz, Marta

2015-11-01

Coating the material with a layer of carbon nanotubes (CNTs) has been a subject of particular interest for the development of new biomaterials. Such coatings, made of properly selected CNTs, may constitute an implantable electronic device that facilitates tissue regeneration both by specific surface properties and an ability to electrically stimulate the cells. The goal of the presented study was to produce, evaluate physicochemical properties and test the applicability of highly conductible material designed as an implantable electronic device. Two types of CNTs with varying level of oxidation were chosen. The process of coating involved suspension of the material of choice in the diluent followed by the electrophoretic deposition to fabricate layers on the surface of a highly biocompatible metal-titanium. Presented study includes an assessment of the physicochemical properties of the material's surface along with an electrochemical evaluation and in vitro biocompatibility, cytotoxicity and apoptosis studies in contact with the murine fibroblasts (L929) in attempt to answer the question how the chemical composition and CNTs distribution in the layer alters the electrical properties of the sample and whether any of these properties have influenced the overall biocompatibility and stimulated adhesion of fibroblasts. The results indicate that higher level of oxidation of CNTs yielded materials more conductive than the metal they are deposited on. In vitro study revealed that both materials were biocompatible and that the cells were not affected by the amount of the functional group and the morphology of the surface they adhered to.

CXCR6 marks a novel subset of T-bet(lo)Eomes(hi) natural killer cells residing in human liver.

PubMed

Stegmann, Kerstin A; Robertson, Francis; Hansi, Navjyot; Gill, Upkar; Pallant, Celeste; Christophides, Theodoros; Pallett, Laura J; Peppa, Dimitra; Dunn, Claire; Fusai, Giuseppe; Male, Victoria; Davidson, Brian R; Kennedy, Patrick; Maini, Mala K

2016-05-23

Natural killer cells (NK) are highly enriched in the human liver, where they can regulate immunity and immunopathology. We probed them for a liver-resident subset, distinct from conventional bone-marrow-derived NK. CXCR6+ NK were strikingly enriched in healthy and diseased liver compared to blood (p < 0.0001). Human hepatic CXCR6+ NK had an immature phenotype (predominantly CD56(bright)CD16-CD57-), and expressed the tissue-residency marker CD69. CXCR6+ NK produced fewer cytotoxic mediators and pro-inflammatory cytokines than the non-liver-specific CXCR6- fraction. Instead CXCR6+ NK could upregulate TRAIL, a key death ligand in hepatitis pathogenesis. CXCR6 demarcated liver NK into two transcriptionally distinct populations: T-bet(hi)Eomes(lo)(CXCR6-) and T-bet(lo)Eomes(hi)(CXCR6+); the latter was virtually absent in the periphery. The small circulating CXCR6+ subset was predominantly T-bet(hi)Eomes(lo), suggesting its lineage was closer to CXCR6- peripheral than CXCR6+ liver NK. These data reveal a large subset of human liver-resident T-bet(lo)Eomes(hi) NK, distinguished by their surface expression of CXCR6, adapted for hepatic tolerance and inducible anti-viral immunity.

Evaluation for Loss of Lubrication Performance of Black Oxide, Superfinished, and As-Ground Surfaces for Use in Rotorcraft Transmissions

DTIC Science & Technology

2016-09-01

2.3.2 Loss -of-Lubrication Protocol 5 2.3.3 Friction Mapping Protocol 7 2.4 Test Matrices 9 3. Results and Discussion 10 3.1 Load Capacity 10...protocols used to simulate relevant contact conditions are the load capacity (LC), loss -of-lubrication (LoL), and mapping protocols. 2.3.1 Load ...Entrainment velocity (m/s) Slip (%) Skew (°) Load (N) Contact stress (GPa) LoL 16 –100 0 100 1.29 2.3.2.2 Low-Speed Loss -of-Lubrication

Chlorothalonil and 2,4-D Losses in Surface Water Discharge From a Managed Turf Watershed

USDA-ARS?s Scientific Manuscript database

Managed turf sites (golf courses) are the most intensively managed landscapes in the urban environment. Yet, long-term watershed scale studies documenting the environmental transport of agrichemicals applied to these systems are rare. The objective of this study was to quantify the surface runoff lo...

Multidrug resistance reversal and apoptosis induction in human colon cancer cells by some flavonoids present in citrus plants.

PubMed

Wesołowska, Olga; Wiśniewski, Jerzy; Sroda-Pomianek, Kamila; Bielawska-Pohl, Aleksandra; Paprocka, Maria; Duś, Danuta; Duarte, Noélia; Ferreira, Maria-José U; Michalak, Krystyna

2012-11-26

Multidrug resistance (MDR) of cancer cells constitutes one of the main reasons for chemotherapy failure. The search for nontoxic modulators that reduce MDR is a task of great importance. An ability to enhance apoptosis of resistant cells would also be beneficial. In the present study, the MDR reversal and apoptosis-inducing potency of three flavonoids produced by Citrus plants, namely, naringenin (1a), aromadendrin (2), and tangeretin (3), and the methylated naringenin derivatives (1b, 1c), have been studied in sensitive (LoVo) and multidrug-resistant (LoVo/Dx) human colon adenocarcinoma cells. Cytotoxicity of methoxylated flavonoids was higher as compared to hydroxylated analogues. Only 3 turned out to inhibit P-glycoprotein, as demonstrated by a rhodamine 123 accumulation assay. It also increased doxorubicin accumulation in LoVo/Dx cells and enabled doxorubicin to enter cellular nuclei. In addition, 3 was found to be an effective MDR modulator in resistant cells by sensitizing them to doxorubicin. Tangeretin-induced caspase-3 activation and elevated surface phosphatidylserine exposure demonstrated its apoptosis-inducing activity in LoVo/Dx cells, while the other flavonoids evaluated were not active. Additionally, 3 was more toxic to resistant rather than to sensitive cancer cells. Its apoptosis-inducing activity was also higher in LoVo/Dx than in LoVo cells. It was concluded that the activity of 3 against multidrug-resistant cancer cells may be enhanced by its apoptosis-inducing activity.

Evaluation of physicochemical and biological properties of chitosan/poly (vinyl alcohol) polymer blend membranes and their correlation for Vero cell growth.

PubMed

Sharma, Parul; Mathur, Garima; Dhakate, Sanjay R; Chand, Subhash; Goswami, Navendu; Sharma, Sanjeev K; Mathur, Ashwani

2016-02-10

The blend membranes with varying weight ratios of chitosan/poly (vinyl alcohol) (CS/PVA) (1:0, 1:1, 1:2.5, 1.5:1, 1.5: 2.5) were prepared using solvent casting method and were evaluated for their potential application in single-use membrane bioreactors (MBRs). The physicochemical properties of the prepared membranes were investigated for chemical interactions (FTIR), surface morphology (SEM), water uptake, protein sorption (qe), ammonia sorption and growth kinetics of Vero cells. CS/PVA blend membrane having weight ratio of 1.5:1 had shown enhanced membrane flexibility, reduced water uptake, less protein sorption and no ammonium sorption compared to CS membrane. This blend membrane also showed comparatively enhanced higher specific growth rate (0.82/day) of Vero cells. Improved physicochemical properties and growth kinetics obtrude CS/PVA (1.5:1) as a potential surface for adhesion and proliferation with possible application in single use membrane bioreactors. Additionally, new insight explaining correlation between water holding (%) of CS/PVA (1.5:1) blend membrane and doubling time (td) of Vero cells is proposed. Copyright © 2015 Elsevier Ltd. All rights reserved.

PPAR γ is highly expressed in F4/80hi adipose tissue macrophages and dampens adipose-tissue inflammation

PubMed Central

Bassaganya-Riera, Josep; Misyak, Sarah; Guri, Amir J.; Hontecillas, Raquel

2009-01-01

Macrophage infiltration into adipose tissue is a hallmark of obesity. We recently reported two phenotypically distinct subsets of adipose tissue macrophages (ATM) based on the surface expression of the glycoprotein F4/80 and responsiveness to treatment with a peroxisome proliferator-activated receptor (PPAR) γ agonist. Hence, we hypothesized that F4/80hi and F4/80lo ATM differentially express PPAR γ. This study phenotypically and functionally characterizes F4/80hi and F4/80lo ATM subsets during obesity. Changes in gene expression were also examined on sorted F4/80lo and F4/80hi ATM by quantitative real-time RT-PCR. We show that while F4/80lo macrophages predominate in adipose tissue of lean mice, obesity causes accumulation of both F4/80lo and F4/80hi ATM. Moreover, accumulation of F4/80hi ATM in adipose tissue is associated with impaired glucose tolerance. Phenotypically, F4/80hi ATM express greater amounts of CD11c, MHC II, CD49b, and CX3CR1 and produce more TNF-α, MCP-1, and IL-10 than F4/80lo ATM. Gene expression analyses of the sorted populations revealed that only the F4/80lo population produced IL-4, whereas the F4/80hi ATM expressed greater amounts of PPAR γ, δ, CD36 and toll-like receptor-4. In addition, the deficiency of PPAR γ in immune cells favors expression of M1 and impairs M2 macrophage marker expression in adipose tissue. Thus, PPAR γ is differentially expressed in F4/80hi versus F4/80low ATM subsets and its deficiency favors a predominance of M1 markers in WAT. PMID:19423085

PPAR gamma is highly expressed in F4/80(hi) adipose tissue macrophages and dampens adipose-tissue inflammation.

PubMed

Bassaganya-Riera, Josep; Misyak, Sarah; Guri, Amir J; Hontecillas, Raquel

2009-01-01

Macrophage infiltration into adipose tissue is a hallmark of obesity. We recently reported two phenotypically distinct subsets of adipose tissue macrophages (ATM) based on the surface expression of the glycoprotein F4/80 and responsiveness to treatment with a peroxisome proliferator-activated receptor (PPAR) gamma agonist. Hence, we hypothesized that F4/80(hi) and F4/80(lo) ATM differentially express PPAR gamma. This study phenotypically and functionally characterizes F4/80(hi) and F4/80(lo) ATM subsets during obesity. Changes in gene expression were also examined on sorted F4/80(lo) and F4/80(hi) ATM by quantitative real-time RT-PCR. We show that while F4/80(lo) macrophages predominate in adipose tissue of lean mice, obesity causes accumulation of both F4/80(lo) and F4/80(hi) ATM. Moreover, accumulation of F4/80(hi) ATM in adipose tissue is associated with impaired glucose tolerance. Phenotypically, F4/80(hi) ATM express greater amounts of CD11c, MHC II, CD49b, and CX3CR1 and produce more TNF-alpha, MCP-1, and IL-10 than F4/80(lo) ATM. Gene expression analyses of the sorted populations revealed that only the F4/80(lo) population produced IL-4, whereas the F4/80(hi) ATM expressed greater amounts of PPAR gamma, delta, CD36 and toll-like receptor-4. In addition, the deficiency of PPAR gamma in immune cells favors expression of M1 and impairs M2 macrophage marker expression in adipose tissue. Thus, PPAR gamma is differentially expressed in F4/80(hi) versus F4/80(low) ATM subsets and its deficiency favors a predominance of M1 markers in WAT.

Physicochemical Properties and Oxidative Storage Stability of Milled Roselle (Hibiscus sabdariffa L.) Seeds.

PubMed

Juhari, Nurul Hanisah; Petersen, Mikael Agerlin

2018-02-11

Milled Roselle ( Hibiscus sabdariffa L.) seeds of the UMKL cultivar were analyzed for proximate composition, water and oil absorption capacity, and the influence of storage conditions on storage stability. The storage stability was determined under four types of conditions: light/oxygen (air) (LO), light/nitrogen (LN), darkness/oxygen (air) (DO), and darkness/nitrogen (DN) while monitoring for seven consecutive months. During the storage period, the formation of volatiles was determined using dynamic headspace sampling and Gas Chromatography-Mass Spectrometry (GC-MS) analysis. In total, 85 volatiles were identified, mainly aldehydes, alcohols, ketones, furans, and acids indicating lipid oxidation. It is recommended that milled Roselle seeds should be flushed with nitrogen and stored in darkness. Under these conditions, the seeds can be stored for at least three months without changes in volatile profile. This is important to ensure the good quality of milled Roselle seeds for further commercialization.

Influence of the physico-chemical properties of CeO 2-ZrO 2 mixed oxides on the catalytic oxidation of NO to NO 2

NASA Astrophysics Data System (ADS)

Atribak, Idriss; Guillén-Hurtado, Noelia; Bueno-López, Agustín; García-García, Avelina

2010-10-01

Commercial and home-made Ce-Zr catalysts prepared by co-precipitation were characterised by XRD, Raman spectroscopy, N 2 adsorption at -196 °C and XPS, and were tested for NO oxidation to NO 2. Among the different physico-chemical properties characterised, the surface composition seems to be the most relevant one in order to explain the NO oxidation capacity of these Ce-Zr catalysts. As a general trend, Ce-Zr catalysts with a cerium-rich surface, that is, high XPS-measured Ce/Zr atomic surface ratios, are more active than those with a Zr-enriched surface. The decrease in catalytic activity of the Ce-Zr mixed oxided upon calcinations at 800 °C with regard to 500 °C is mainly attributed to the decrease in Ce/Zr surface ratio, that is, to the surface segregation of Zr. The phase composition (cubic or t'' for Ce-rich compositions) seems not to be a direct effect on the catalytic activity for NO oxidation in the range of compositions tested. However, the formation of a proper solid solution prevents important surface segregation of Zr upon calcinations at high temperature. The effect of the BET surface area in the catalytic activity for NO oxidation of Ce-Zr mixed oxides is minor in comparison with the effect of the Ce/Zr surface ratio.

Ease fabrication of PCR modular chip for portable DNA detection kit

NASA Astrophysics Data System (ADS)

Whulanza, Yudan; Aditya, Rifky; Arvialido, Reyhan; Utomo, Muhammad S.; Bachtiar, Boy M.

2017-02-01

Engineering a lab-on-a-chip (LoC) to perform the DNA polymerase chain reaction (PCR) for malaria detection is the ultimate goal of this study. This paper investigates the ability to fabricate an LoC kit using conventional method to achieve the lowest production cost by using existing fabrication process. It has been known that majority of LoC was made of polydimethylsiloxane (PDMS) which in this study was realized through a contact mold process. CNC milling process was utilized to create channel features in the range of 150-250 µm on the mold. Characterization on the milling process was done to understand the shrinkage/contraction between mold to product, roughness and also angle of contact of PDMS surface. Ultimately, this paper also includes analysis on flow measurement and heat distribution of an assembled LoC PCR kit. The results show that the achieved dimension of microchannel is 227 µm wide with a roughness of 0.01 µm. The flow measurement indicates a deviation with simulation in the range of 10%. A heat distribution through the kit is achieved following the three temperature zones as desired.

Characterization of the surface properties of wheat spikelet components grown under different regimes and the biocontrol yeast Cryptococcus flavescens

USDA-ARS?s Scientific Manuscript database

The physicochemical surfaces properties of wheat (Triticum aestivum L) spikelet components have been characterized under different environmental growing regimes. Wheat samples grown in a greenhouse environment were compared with samples produced in the field for two wheat cultivars (Freedom and Pion...

Physicochemical and microbiological stability of azathioprine in InOrpha suspending agent studied under various conditions.

PubMed

Amin, Alexandre; Bourget, Philippe; Vidal, Fabrice; Cartier, François; Beauvais, Raphaëlle; Afonso, Veronica Do Nascimento

2015-01-01

Azathioprine is an antineoplastic antimetabolite drug currently used as an immunosuppressive agent after organ transplantation and for several dysimmunitary diseases. The usual daily dose ranges from 1 to 5 mg/kg orally. Azathioprine is marketed in France under the trade name Imurel in tablet form for oral administration that contains either 25 mg or 50 mg of the active ingredient. This Galenic formulation is not suitable for pediatric use and often requires a grinding operation or a dose fractionation to facilitate administration. In addition to a potential risk of imprecision in the administered dose, tablet grinding might unnecessarily expose nurses and families to a toxic compound. To overcome this problem, the objective of this study was to develop and evaluate the physicochemical and microbiological stabilities of azathioprine in a sugar-free, alcohol-free, and paraben-free InOrpha suspending agent. The studied samples were formulated into a 10-mg/mL suspension and stored in 24 plastic bottles of 60 mL at two different temperature conditions (between 2 degrees C to 8 degrees C and room temperature). Two series of 12 samples were tested for physicochemical stability using high-performance liquid chromatography as well as for a microbiological status for 35 days (daily opening of the bottles from day 0 of compounding) and for 56 days, upon daily flask opening (first opening at day 28 from compounding and daily opening for 28 consecutive days). The high-performance liquid chromatography method developed is linear, accurate, precise, and robust. In addition, a forced degradation study validated the selectivity and the specificity requirements of the method validated as stability indicating. At room temperature storage, high-performance liquid chromatography analysis showed that tested samples had concentrations ranging from 90% to 110% of the initial concentration throughout the course of the study. Microbiological status remained stable during the 56 days of investigation. Based on the data collected, the study led to the development of a new Galenic formulation of azathioprine that is suitable for pediatric use and can be safely stored at room temperature for 28 days (before and after opening for a maximum of 56 consecutive days).

Effects of ion- and electron-beam treatment on surface physicochemical properties of polylactic acid

NASA Astrophysics Data System (ADS)

Pukhova, I. V.; Savkin, K. P.; Laput, O. A.; Lytkina, D. N.; Botvin, V. V.; Medovnik, A. V.; Kurzina, I. A.

2017-11-01

We describe our investigations of the surface physicochemical and mechanical properties of polylactic acid modified by silver, argon and carbon ion implantation to doses of 1 × 1014, 1 × 1015 and 1 × 1016 ions/cm2 at energies of 20 keV (for C and Ar) and 40 keV (for Ag), and by electron beam treatment with pulse-width of 100-300 μs in 50 μs increments at a beam energy 8 keV. Carbonyl bonds (sbnd Cdbnd O) related IR peak was reduced after ion and electron beam irradiation. Molecular weight of PLA decreases twice and does not depend on the nature of the bombarding particles. The microhardness of treated samples decreases by a factor of 1.3, and the surface conductivity increases by 6 orders of magnitude after ion implantation, and increases only modestly after electron beam treatment. Atomic force microscopy shows that surface roughness increases with irradiation dose. Samples irradiated with Ag to a dose of 1 × 1016 ions/cm2 show the greatest roughness of 190 nm.

Differences between tethered polyelectrolyte chains adsorbed onto bare mica and hydrophobically modified mica, comparison with theory.

NASA Astrophysics Data System (ADS)

Balastre, Marc; Tamashiro, Mario N.; Hernandez, Ernesto; Pincus, Philip; Tirrell, Matthew

2001-03-01

End-grafted polymers generated from the adsorption of asymmetric diblock copolymers on solid surface play an important role in many areas of science and technology. While the small insoluble block acts as an anchor, the charged soluble block confers useful properties to the surface. This study looks at tethered layers of poly(styrene sulfonate)/poly(t-butyl styrene) (PtBS-PSS) adsorbed on both mica (hydrophilic) and octadecyltriethoxysilane (OTE) modified mica (hydrophobic). Normal compressing forces at two different constant grafting densities (bare and modified mica) were measured with the surface force apparatus and compared with theoretical prediction. The effect of salt concentration (Cs) upon the thickness of the self-assembled layers (Lo) was measured in each case. For adsorption of diblock copolymers onto OTE the resulting scaling relationship is much closer to the brush theory, Lo Cs-1/3. This result suggests that the adsorbed amount on mica is not high enough to form a brush.

An analytical study of reduced-gravity flow dynamics

NASA Technical Reports Server (NTRS)

Bradshaw, R. D.; Kramer, J. L.; Zich, J. L.

1976-01-01

Addition of surface tension forces to a marker-and-cell code and the performance of four incompressible fluid simulations in reduced gravity, were studied. This marker-and-cell code has a variable grid capability with arbitrary curved boundaries and time dependent acceleration fields. The surface tension logic includes a spline fit of surface marker particles as well as contact angle logic for straight and curved wall boundaries. Three types of flow motion were simulated with the improved code: impulsive settling in a model Centaur LH2 tank, continuous settling in a model and full scale Centaur LO2 tank and mixing in a Centaur LH2 tank. The impulsive settling case confirmed a drop tower analysis which indicated more orderly fluid collection flow patterns with this method providing a potential savings in settling propellants. In the LO2 tank, fluid collection and flow simulation into the thrust barrel were achieved. The mixing simulation produced good results indicating both the development of the flow field and fluid interface behavior.

Contribution of engineered nanomaterials physicochemical properties to mast cell degranulation

NASA Astrophysics Data System (ADS)

Johnson, Monica M.; Mendoza, Ryan; Raghavendra, Achyut J.; Podila, Ramakrishna; Brown, Jared M.

2017-03-01

The rapid development of engineered nanomaterials (ENMs) has grown dramatically in the last decade, with increased use in consumer products, industrial materials, and nanomedicines. However, due to increased manufacturing, there is concern that human and environmental exposures may lead to adverse immune outcomes. Mast cells, central to the innate immune response, are one of the earliest sensors of environmental insult and have been shown to play a role in ENM-mediated immune responses. Our laboratory previously determined that mast cells are activated via a non-FcɛRI mediated response following silver nanoparticle (Ag NP) exposure, which was dependent upon key physicochemical properties. Using bone marrow-derived mast cells (BMMCs), we tested the hypothesis that ENM physicochemical properties influence mast cell degranulation. Exposure to 13 physicochemically distinct ENMs caused a range of mast degranulation responses, with smaller sized Ag NPs (5 nm and 20 nm) causing the most dramatic response. Mast cell responses were dependent on ENMs physicochemical properties such as size, apparent surface area, and zeta potential. Surprisingly, minimal ENM cellular association by mast cells was not correlated with mast cell degranulation. This study suggests that a subset of ENMs may elicit an allergic response and contribute to the exacerbation of allergic diseases.

BIOSURFACES: A NONSCALE OVERVIEW

EPA Science Inventory

Biosurfaces: A Nanoscale Overview.
Environmental surfaces (mineral, organic, biological, and composite) determine the physicochemical and biological properties of soils and control the chemical reactivity, fate, transport and transformation of nutrients and chemical contaminan...

Variation of Water Quality Parameters with Siltation Depth for River Ichamati Along International Border with Bangladesh Using Multivariate Statistical Techniques

NASA Astrophysics Data System (ADS)

Roy, P. K.; Pal, S.; Banerjee, G.; Biswas Roy, M.; Ray, D.; Majumder, A.

2014-12-01

River is considered as one of the main sources of freshwater all over the world. Hence analysis and maintenance of this water resource is globally considered a matter of major concern. This paper deals with the assessment of surface water quality of the Ichamati river using multivariate statistical techniques. Eight distinct surface water quality observation stations were located and samples were collected. For the samples collected statistical techniques were applied to the physico-chemical parameters and depth of siltation. In this paper cluster analysis is done to determine the relations between surface water quality and siltation depth of river Ichamati. Multiple regressions and mathematical equation modeling have been done to characterize surface water quality of Ichamati river on the basis of physico-chemical parameters. It was found that surface water quality of the downstream river was different from the water quality of the upstream. The analysis of the water quality parameters of the Ichamati river clearly indicate high pollution load on the river water which can be accounted to agricultural discharge, tidal effect and soil erosion. The results further reveal that with the increase in depth of siltation, water quality degraded.

Diagnosing the Sensitivity of Local Land-Atmosphere Coupling via the Soil Moisture-Boundary Layer Interaction

NASA Technical Reports Server (NTRS)

Santanello, Joseph A., Jr.; Peters-Lidard, Christa D.; Kumar, Sujay V.

2011-01-01

The inherent coupled nature of earth s energy and water cycles places significant importance on the proper representation and diagnosis of land atmosphere (LA) interactions in hydrometeorological prediction models. However, the precise nature of the soil moisture precipitation relationship at the local scale is largely determined by a series of nonlinear processes and feedbacks that are difficult to quantify. To quantify the strength of the local LA coupling (LoCo), this process chain must be considered both in full and as individual components through their relationships and sensitivities. To address this, recent modeling and diagnostic studies have been extended to 1) quantify the processes governing LoCo utilizing the thermodynamic properties of mixing diagrams, and 2) diagnose the sensitivity of coupled systems, including clouds and moist processes, to perturbations in soil moisture. This work employs NASA s Land Information System (LIS) coupled to the Weather Research and Forecasting (WRF) mesoscale model and simulations performed over the U.S. Southern Great Plains. The behavior of different planetary boundary layers (PBL) and land surface scheme couplings in LIS WRF are examined in the context of the evolution of thermodynamic quantities that link the surface soil moisture condition to the PBL regime, clouds, and precipitation. Specifically, the tendency toward saturation in the PBL is quantified by the lifting condensation level (LCL) deficit and addressed as a function of time and space. The sensitivity of the LCL deficit to the soil moisture condition is indicative of the strength of LoCo, where both positive and negative feedbacks can be identified. Overall, this methodology can be applied to any model or observations and is a crucial step toward improved evaluation and quantification of LoCo within models, particularly given the advent of next-generation satellite measurements of PBL and land surface properties along with advances in data assimilation schemes.

Flow cytometric analysis of regulatory T cells during hyposensitization of acquired allergic contact dermatitis.

PubMed

Fraser, Kathleen; Abbas, Mariam; Hull, Peter R

2014-01-01

We previously demonstrated that repeated intradermal steroid injections administered at weekly intervals into positive patch-test sites induce hyposensitization and desensitization. To examine changes in CD4CD25CD127lo/ regulatory T cells during the attenuation of the patch-test response. Ten patients with known allergic contact dermatitis were patch tested weekly for 10 weeks. The patch-test site was injected intradermally with 2 mg triamcinolone. At weeks 1 and 7, a biopsy was performed on the patch-test site in 6 patients, and flow cytometry was performed assessing CD4CD25CD127lo/ regulatory T cells. Secondary outcomes were clinical score, reaction size, erythema, and temperature. Statistical analysis included regression, correlation, and repeated-measures analysis of variance. The percentage of CD4CD25CD127lo/ regulatory T cells, measured by flow cytometry, increased from week 1 to week 7 by an average of 19.2%. The average grade of patch-test reaction decreased from +++ (vesicular reaction) to ++ (palpable erythema). The mean drop in temperature following treatment was 0.28°C per week. The mean area decreased 8.6 mm/wk over 10 weeks. Intradermal steroid injections of weekly patch-test reactions resulted in hyposensitization of the allergic contact dermatitis reaction. CD4CD25CD127lo/ regulatory T cells showed a tendency to increase; however, further studies are needed to determine if this is significant.

Structural Prediction and In Silico Physicochemical Characterization for Mouse Caltrin I and Bovine Caltrin Proteins

PubMed Central

Grasso, Ernesto J.; Sottile, Adolfo E.; Coronel, Carlos E.

2016-01-01

It is known that caltrin (calcium transport inhibitor) protein binds to sperm cells during ejaculation and inhibits extracellular Ca2+ uptake. Although the sequence and some biological features of mouse caltrin I and bovine caltrin are known, their physicochemical properties and tertiary structure are mainly unknown. We predicted the 3D structures of mouse caltrin I and bovine caltrin by molecular homology modeling and threading. Surface electrostatic potentials and electric fields were calculated using the Poisson–Boltzmann equation. Several different bioinformatics tools and available web servers were used to thoroughly analyze the physicochemical characteristics of both proteins, such as their Kyte and Doolittle hydropathy scores and helical wheel projections. The results presented in this work significantly aid further understanding of the molecular mechanisms of caltrin proteins modulating physiological processes associated with fertilization. PMID:27812283

The first report of the physicochemical structure of chitin isolated from Hermetia illucens.

PubMed

Waśko, Adam; Bulak, Piotr; Polak-Berecka, Magdalena; Nowak, Katarzyna; Polakowski, Cezary; Bieganowski, Andrzej

2016-11-01

This is the first report on the physicochemical properties of chitin obtained from larvae and imagoes of black soldier flies (Hermetia illucens). Scanning electron microscopy revealed differences in surface morphologies of the two types of chitin. The crystalline index values of chitins from adult flies and larvae were 24.9% and 35%, respectively. This is a trait that differentiates these biopolymers from chitins extracted from other sources described so far. X-ray diffraction patterns and IR spectroscopy revealed that both types of samples of chitin were in an α crystalline form. Also, the results of elemental analysis, thermal stabilities and FTIR spectroscopy of the chitins from larvae and adults of H. illucens were similar, which points to a general similarity in their physicochemical structure. Copyright © 2016 Elsevier B.V. All rights reserved.

Surface modification of biomaterials using plasma immersion ion implantation and deposition

PubMed Central

Lu, Tao; Qiao, Yuqin; Liu, Xuanyong

2012-01-01

Although remarkable progress has been made on biomaterial research, the ideal biomaterial that satisfies all the technical requirements and biological functions is not available up to now. Surface modification seems to be a more economic and efficient way to adjust existing conventional biomaterials to meet the current and ever-evolving clinical needs. From an industrial perspective, plasma immersion ion implantation and deposition (PIII&D) is an attractive method for biomaterials owing to its capability of treating objects with irregular shapes, as well as the control of coating composition. It is well acknowledged that the physico-chemical characteristics of biomaterials are the decisive factors greatly affecting the biological responses of biomaterials including bioactivity, haemocompatibility and antibacterial activity. Here, we mainly review the recent advances in surface modification of biomaterials via PIII&D technology, especially titanium alloys and polymers used for orthopaedic, dental and cardiovascular implants. Moreover, the variations of biological performances depending on the physico-chemical properties of modified biomaterials will be discussed. PMID:23741609

Study of heat-moisture treatment of potato starch granules by chemical surface gelatinization.

PubMed

Bartz, Josiane; da Rosa Zavareze, Elessandra; Dias, Alvaro Renato Guerra

2017-08-01

Native potato starch was subjected to heat-moisture treatment (HMT) at 12%, 15%, 18%, 21%, and 24% of moisture content at 110 °C for 1 h, and the effects on morphology, structure, and thermal and physicochemical properties were investigated. To reveal the internal structure, 30% and 50% of the granular surface were removed by chemical surface gelatinization in concentrated LiCl solution. At moisture contents of 12% and 15%, HTM reduced the gelatinization temperatures and relative crystallinity of the starches, while at moisture contents of 21% and 24 % both increased. The alterations on morphology, X-ray pattern, physicochemical properties, and increase of amylose content were more intense with the increase of moisture content of HMT. The removal of granular layers showed that the changes promoted by HMT occur throughout the whole granule and were pronounced at the core or peripheral region, depending of the moisture content applied during HMT. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Cellulolytic Enzymes Production via Solid-State Fermentation: Effect of Pretreatment Methods on Physicochemical Characteristics of Substrate.

PubMed

Brijwani, Khushal; Vadlani, Praveen V

2011-01-01

We investigated the effect of pretreatment on the physicochemical characteristics-crystallinity, bed porosity, and volumetric specific surface of soybean hulls and production of cellulolytic enzymes in solid-state fermentation of Trichoderma reesei and Aspergillus oryzae cultures. Mild acid and alkali and steam pretreatments significantly increased crystallinity and bed porosity without significant change inholocellulosic composition of substrate. Crystalline and porous steam-pretreated soybean hulls inoculated with T. reesei culture had 4 filter paper units (FPU)/g-ds, 0.6 IU/g-ds β-glucosidase, and 45 IU/g-ds endocellulase, whereas untreated hulls had 0.75 FPU/g-ds, 0.06 IU/g-ds β-glucosidase, and 7.29 IU/g-ds endocellulase enzyme activities. In A. oryzae steam-pretreated soybean hulls had 47.10 IU/g-ds endocellulase compared to 30.82 IU/g-ds in untreated soybean hulls. Generalized linear statistical model fitted to enzyme activity data showed that effects of physicochemical characteristics on enzymes production were both culture and enzyme specific. The paper shows a correlation between substrate physicochemical properties and enzyme production.

[Determination of polyphenolic complex in wines by electrochemical methods and using the enzymes tyrosinase and laccase].

PubMed

Shleev, S V; Chekanova, S A; Koroleva, O V; Stepanova, E V; Telegin, Iu A; Sen'kina, Z E

2004-01-01

Several red wines were studied to find a correlation between physicochemical parameters characterizing the antioxidant status of wine and total content of phenols in samples. The content of dissolved oxygen (its value varied from 0.75 to 3.28 mg/ml), pH (3.10-3.63), redox potential (-186 to -106 mV), mass concentration of free and total sulfur dioxide (10-30 and 36-200 mg/dm3, respectively), absorption spectra, and total phenol content were determined. The wines fell into two main groups-with a relatively low (1850-2050 mg/dm3) and high (2300-2900 mg/dm3) contents of polyphenols. It was demonstrated that physicochemical parameters (except for the content of sulfur dioxide) correlate with the total phenol content in the wines studied.

Hydrogeology and analysis of ground-water withdrawal in the Mendenhall-D'Lo area, Simpson County, Mississippi

USGS Publications Warehouse

Strom, E.W.; Oakley, W.T.

1995-01-01

The cities of Mendenhall and D'Lo, located in Simpson County, rely on ground water for their public supply and industrial needs. Most of the ground water comes from an aquifer of Miocene age. A study began in 1991 to describe the hydrogeology, analyze effects of ground-water withdrawal by making a drawdown map, and estimate the effects increased ground-water withdrawal might have on water levels in the Miocene age aquifer in the Mendenhall-D'Lo area. The most significant withdrawals of ground water in the study area are from 10 wells screened in the lower sand of the Catahoula Formation of Miocene age. Analysis of the effect of withdrawals from the 10 wells was made using the Theis non- equilibrium equation and applying the principle of superposition. Analysis of 1994 conditions was based on the pumpage history and aquifer properties deter- mined for each well. The drawdown surface resulting from the analysis indicates three general cones of depression. One cone is in the northwestern D'Lo area, one in the south-central Mendenhall area, and one about 1-1/2 miles east of Mendenhall. Calculated drawdown ranges from 21 to 47 feet. Potential drawdown-surface maps were made for 10 years and 20 years beyond 1994 using a constant pumpage. The map made for 10 years beyond 1994 indicates an average total increase in drawdown of about 5.3 feet. The map made for 20 years beyond 1994 indicates an average total increase in drawdown of about 7.3 feet.

Activation of Osteoblastic Function on Titanium Surface with Titanium-Doped Hydroxyapatite Nanoparticle Coating: An In Vitro Study.

PubMed

Nakazawa, Masahiro; Yamada, Masahiro; Wakamura, Masato; Egusa, Hiroshi; Sakurai, Kaoru

Titanium-doped hydroxyapatite (TiHA) nanoparticles contain titanium atoms in the hydroxyapatite lattice, which can physicochemically functionalize the titanium surface without modification of the surface topography. This study aimed to evaluate the physicochemical properties of machined or microroughened titanium surfaces coated with TiHA nanoparticles and the functions of osteoblasts cultured on them. Titanium disks with commercially available surface topography, such as machined or sandblasted, large-grit, and acid-etched (SLA) surfaces, were coated with TiHA. The disks with original or TiHA-coated surfaces were evaluated in topography, wettability, and chemical composition. Osteoblastic cells from rat femurs were cultured on the disks and evaluated in proliferation and differentiation. TiHA coating changed from hydrophobicity to hydrophilicity on both machined and SLA surfaces. Calcium and phosphate atoms were detected all over the surface with TiHA coating regardless of the surface topography. However, the considerable change in the inherent surface topographies was not observed on both types of surfaces after TiHA coating. Osteoblastic proliferative activity at day 4 was increased by TiHA coating on both types of surfaces. TiHA coating did not enhance expressions of bone matrix-related genes such as osteocalcin, osteopontin, bone sialoprotein, alkaline phosphatase, and collagen I. However, depositions of collagen, osteocalcin, and calcium in the culture at days 7 and 20 were increased on both types of surface topographies with TiHA coating. TiHA coating enhanced extracellular matrix formation on smooth and microroughened titanium surfaces by increasing osteoblastic proliferative activity without the deterioration of differentiation through hydrophilic and chemical functionalization.

Effect of thyme/cumin essential oils and butylated hydroxyl anisole/butylated hydroxyl toluene on physicochemical properties and oxidative/microbial stability of chicken patties.

PubMed

Sariçoban, Cemalettin; Yilmaz, Mustafa Tahsin

2014-02-01

In this study, effects of thyme/cumin essential oils (EO) and butylated hydroxyl anisole (BHA)/butylated hydroxyl toluene (BHT) on physicochemical properties and storage stability of chicken patties were compared in different storage periods (0, 3, 7, 14, 21, and 28 d). It was found that there were significant (P < 0.05) differences between physicochemical properties of patty samples treated with EO and the synthetic antioxidants. The EO showed similar performance to those of BHA and BHT in limiting TBARS values of chicken patty samples. Similarity in performance was also the case for microbial stability (total aerobic mesophilic, psychrotrophic, lactic acid, and coliform bacteria as well as molds and yeasts); namely, their effects were significant (P < 0.05). Effect of thyme EO was significant (P < 0.05) and remarkable, not allowing any coliform bacteria to grow in the samples. Given that EO were obtained from natural sources, the data suggested that the EO might be more useful than their synthetic counterparts, BHA and BHT, as additives for chicken patties to maintain oxidative/microbial stability and increase shelf life.

Gum arabic based composite edible coating on green chillies

NASA Astrophysics Data System (ADS)

Valiathan, Sreejit; Athmaselvi, K. A.

2018-04-01

Green chillies were coated with a composite edible coating composed of gum arabic (5%), glycerol (1%), thyme oil (0.5%) and tween 80 (0.05%) to preserve the freshness and quality of green chillies and thus reduce the cost of preservation. In the present work, the chillies were coated with the composite edible coating using the dipping method with three dipping times (1, 3 and 5 min). The physicochemical parameters of the coated and control chillies stored at room temperature (28±2ºC) were evaluated at regular intervals of storage. There was a significant difference (p≤0.05) in the physicochemical properties between the control chillies and coated chillies with 1, 3 and 5 min dipping times. The coated green chillies showed significantly (p≤0.05) lower weight loss, phenolic acid production, capsaicin production and significantly (p≤0.05) higher retention of ascorbic acid, total chlorophyll content, colour, firmness and better organoleptic properties. The composite edible coating of gum arabic and thyme oil with 3 min dipping was effective in preserving the desirable physico-chemical and organoleptic properties of the green chillies up to 12 days, compared to the uncoated chillies that had a shelf life of 6 days at room temperature.

Chemical, Physicochemical, Nutritional, Microbiological, Sensory and Rehydration Characteristics of Instant Whole Beans (Phaseolus vulgaris).

PubMed

Ulloa, José Armando; Ibarra-Zavala, Silvia Jazmin; Ramírez-Salas, Silvia Patricia; Rosas-Ulloa, Petra; Ramírez-Ramírez, José Carmen; Ulloa-Rangel, Blanca Estela

2015-03-01

Instant whole beans obtained by drying at 25 °C were evaluated for their chemical, physicochemical, nutritional, microbiological, sensory and rehydration characteristics. The proximal composition of instant whole beans was typical of this kind of food, whereas a w and L* , a* and b* values were 0.639, 98.55, -0.28 and -1.52, respectively. In instant whole beans, 75% of the essential amino acids had a value greater or equal to the reference standard for adult humans; the protein quality in terms of chemical score was 95%. Microbiological counts of aerobic mesophilic bacteria, moulds, yeasts and total coliforms of rehydrated instant whole beans were <10 CFU/g, whereas the scores for colour, flavour, texture and overall acceptability were 7.22, 7.68, 7.24 and 7.34, respectively, on a 1-9 hedonic scale. The logarithmic and Pilosof models showed close fits (R 2 >0.99) to the experimental data for drying of cooked beans and rehydration of instant whole beans, respectively. In the light of the chemical, physicochemical, nutritional, microbiological, sensory and rehydration characteristics of instant whole beans found in this study, drying at 25 °C is recommended for the production of such food.

Influence of storage temperature and time on the physicochemical and bioactive properties of roselle-fruit juice blends in plastic bottle

PubMed Central

Mgaya-Kilima, Beatrice; Remberg, Siv Fagertun; Chove, Bernard Elias; Wicklund, Trude

2014-01-01

Roselle-fruit juice blends were made from roselle extract and mango, papaya, and guava juices at the ratio of 80:20, 60:40, 40:60, and 20:80, % roselle: fruit juice, respectively. The blends were pasteurized at 82.5°C for 20 min and stored in 100 mL plastic bottles at 28 and 4°C for 6 months. The effects of storage time and temperature on physicochemical and bioactive properties were evaluated. Total soluble solids, pH, and reducing sugars increased significantly (P < 0.05) in some blends while titratable acidity decrease with increasing storage time. Vitamin C, total monomeric anthocyanins (TMA), total phenols (TPC), and antioxidant activity (ferric reducing ability of plasma, FRAP) in all roselle-fruit blends (40% roselle) decreased significantly (P < 0.05) at 28 and 4°C as storage progressed. Vitamin C in all roselle-fruit blends (40% roselle) decreased from 58–55% to 43–42% when stored at 28 and 4°C, respectively. TMA losses were 86–65% at 28°C and 75–53% at 4°C while TPC losses were 66–58% at 28°C and 51–22% at 4°C. Loss of antioxidant capacity (FRAP) was 18–46% at 28°C and 17–35% at 4°C. A principal component analysis (PCA) differentiated roselle-juice fruit blends into two clusters with two principle components PC1 and PC2, which explained 97 and 3% (blends stored at ambient temperature) and 96 and 4% (blends stored at refrigerated temperature) of the variation, respectively. PC1 differentiated roselle-guava juice blends which were characterized by vitamin C, TPC, FRAP, and pH, while PC2 from another cluster of roselle-mango and roselle-papaya juice blends and was characterized by TSS, RS, and color parameters (L* a* b*). However, TMA was the main variable with the highest effect on all roselle-fruit juice blends regardless of the storage time and temperature. PMID:24804077

Comment on "The surface of lo: A new model" by Bruce Hapke

USGS Publications Warehouse

McEwen, A.S.; Lunine, J.I.

1990-01-01

Hapke (1989, Icarus 79, 56-74) proposed that the surface of Io is dominantly basaltic with thin coatings of polysulfur oxide, S2O, ad SO,2. However, observations and models of the active volcanism indicate that volatiles such as sulfur and SO2 must be more abundant than envisioned by Hapke. ?? 1990.

A Key Major Guideline for Engineering Bioactive Multicomponent Nanofunctionalization for Biomedicine and Other Applications: Fundamental Models Confirmed by Both Direct and Indirect Evidence

PubMed Central

Scherrieble, Andreas; Bahrizadeh, Shiva; Avareh Sadrabadi, Fatemeh; Hedayat, Laleh

2017-01-01

This paper deals with the engineering multicomponent nanofunctionalization process considering fundamental physicochemical features of nanostructures such as surface energy, chemical bonds, and electrostatic interactions. It is pursued by modeling the surface nanopatterning and evaluating the proposed technique and the models. To this end, the effects of surface modifications of nanoclay on surface interactions, orientations, and final features of TiO2/Mt nanocolloidal textiles functionalization have been investigated. Various properties of cross-linkable polysiloxanes (XPs) treated samples as well as untreated samples with XPs have been compared to one another. The complete series of samples have been examined in terms of bioactivity and some physical properties, given to provide indirect evidence on the surface nanopatterning. The results disclosed a key role of the selected factors on the final features of treated surfaces. The effects have been thoroughly explained and modeled according to the fundamental physicochemical features. The developed models and associated hypotheses interestingly demonstrated a full agreement with all measured properties and were appreciably confirmed by FESEM evidence (direct evidence). Accordingly, a guideline has been developed to facilitate engineering and optimizing the pre-, main, and post-multicomponent nanofunctionalization procedures in terms of fundamental features of nanostructures and substrates for biomedical applications and other approaches. PMID:29333437

Radio Supernovae: Circum-Stellar Investigation (C.S.I.) of Supernova Progenitor Stars

DTIC Science & Technology

2009-02-24

agreement with the National Science Foundation. 4 −1.5 −1 −0.5 0 0.5 1 1.5 2 2.5 3 3.5 Log Time (Years since Explosion) 22 23 24 25 26 27 28 29 Lo g...formation of pulsar wind-nebula in other SN observations where VLBI measurements are not feasible. 3 The Future of Radio Supernovae Current observing

Phase Diversity and Polarization Augmented Techniques for Active Imaging

DTIC Science & Technology

2007-03-01

build up a system model for use in algorithm development. 32 IV. Conventional Imaging and Atmospheric Turbulence With an understanding of scalar...28, 59, 115 Cholesky Factorization, 14, 42 C2n, see Turbulence Coherent Image Model, 36 Complete Data, see EM Algorithm Complex Coherence...Data, see EM Algorithm Homotopic, 62 Impulse Response, 34, 44 Incoherent Image Model, 36 Incomplete Data, see EM Algorithm Lo- Turbulence Outer Scale

The Supply Effectiveness of Cooperative Logistics.

DTIC Science & Technology

1979-06-01

comparisins need special attention. One- Wav ANOVA The critical item data were run on the computer using the subprogram One-Way (lo:422-425) to...thesis midi -proposal, LSSR 3-79B, Air Force Institute of Technology, Wright-Patterson AFB OH, February 1979. 6. Christenson, Linda. Supply Systems...Pricing Procedures." Unpublished thesis midi -proposal. LSSR 8-79B, Air Force Institute of Technology, Wright-Patterson AFB OH, February 1979. 28

Effects of a nanoceria fuel additive on the physicochemical properties of diesel exhaust particles.

PubMed

Zhang, Junfeng Jim; Lee, Ki-Bum; He, Linchen; Seiffert, Joanna; Subramaniam, Prasad; Yang, Letao; Chen, Shu; Maguire, Pierce; Mainelis, Gediminas; Schwander, Stephan; Tetley, Teresa; Porter, Alexandra; Ryan, Mary; Shaffer, Milo; Hu, Sheng; Gong, Jicheng; Chung, Kian Fan

2016-10-12

Nanoceria (i.e., CeO 2 nanoparticles) fuel additives have been used in Europe and elsewhere to improve fuel efficiency. Previously we have shown that the use of a commercial fuel additive Envirox™ in a diesel-powered electricity generator reduced emissions of diesel exhaust particle (DEP) mass and other pollutants. However, such additives are currently not permitted for use in on-road vehicles in North America, largely due to limited data on the potential health impact. In this study, we characterized a variety of physicochemical properties of DEPs emitted from the same engine. Our methods include novel techniques such as Raman spectrometry for analyzing particle surface structure and an assay for DEP oxidative potential. Results show that with increasing Envirox™ concentrations in the fuel (0×, 0.1×, 1×, and 10× of manufacturer recommended 0.5 mL Envirox™ per liter fuel), DEP sizes decreased from 194.6 ± 20.1 to 116.3 ± 14.8 nm; the zeta potential changed from -28.4 mV to -22.65 mV; DEP carbon content decreased from 91.8% to 79.4%; cerium and nitrogen contents increased from 0.3% to 6.5% and 0.2% to 0.6%, respectively; the ratio of organic carbon (OC) to elemental carbon (EC) increased from 22.9% to 38.7%; and the ratio of the disordered carbon structure to the ordered carbon structure (graphitized carbon) in DEPs decreased. Compared to DEPs emitted from 0×, 0.1×, and 1× fuels, DEPs from the 10× fuel had a lower oxidative potential likely due to the increased ceria content because pure ceria nanoparticles exhibited the lowest oxidative potential compared to all the DEPs. Since the physicochemical parameters tested here are among the determinants of particle toxicity, our findings imply that adding ceria nanoparticles into diesel may alter the toxicity of DEPs. The findings from the present study, hence, can help future studies that will examine the impact of nanoceria additives on DEP toxicities.

Spatial assessment of soil organic carbon and physicochemical properties in a horticultural orchard at arid zone of India using geostatistical approaches.

PubMed

Singh, Akath; Santra, Priyabrata; Kumar, Mahesh; Panwar, Navraten; Meghwal, P R

2016-09-01

Soil organic carbon (SOC) is a major indicator of long-term sustenance of agricultural production system. Apart from sustaining productivity, SOC plays a crucial role in context of climate change. Keeping in mind these potentials, spatial variation of SOC contents of a fruit orchard comprising several arid fruit plantations located at arid region of India is assessed in this study through geostatistical approaches. For this purpose, surface and subsurface soil samples from 175 locations from a fruit orchard spreading over 14.33 ha area were collected along with geographical coordinates. SOC content and soil physicochemical properties of collected soil samples were determined followed by geostatistical analysis for mapping purposes. Average SOC stock density of the orchard was 14.48 Mg ha(-1) for 0- to 30-cm soil layer ranging from 9.01 Mg ha(-1) in Carissa carandas to 19.52 Mg ha(-1) in Prosopis cineraria block. Range of spatial variation of SOC content was found about 100 m, while two other soil physicochemical properties, e.g., pH and electrical conductivity (EC) also showed similar spatial trend. This indicated that minimum sampling distance for future SOC mapping programme may be kept lower than 100 m for better accuracy. Ordinary kriging technique satisfactorily predicted SOC contents (in percent) at unsampled locations with root-mean-squared residual (RMSR) of 0.35-0.37. Co-kriging approach was found slightly superior (RMSR = 0.26-0.28) than ordinary kriging for spatial prediction of SOC contents because of significant correlations of SOC contents with pH and EC. Uncertainty of SOC estimation was also presented in terms of 90 % confidence interval. Spatial estimates of SOC stock through ordinary kriging or co-kriging approach were also found with low uncertainty of estimation than non-spatial estimates, e.g., arithmetic averaging approach. Among different fruit block plantations of the orchard, the block with Prosopis cineraria ('khejri') has higher SOC stock density than others.

Interaction of colloidal nanoparticles with their local environment: the (ionic) nanoenvironment around nanoparticles is different from bulk and determines the physico-chemical properties of the nanoparticles

PubMed Central

Pfeiffer, Christian; Rehbock, Christoph; Hühn, Dominik; Carrillo-Carrion, Carolina; de Aberasturi, Dorleta Jimenez; Merk, Vivian; Barcikowski, Stephan; Parak, Wolfgang J.

2014-01-01

The physico-chemical properties of colloidal nanoparticles (NPs) are influenced by their local environment, as, in turn, the local environment influences the physico-chemical properties of the NPs. In other words, the local environment around NPs has a profound impact on the NPs, and it is different from bulk due to interaction with the NP surface. So far, this important effect has not been addressed in a comprehensive way in the literature. The vicinity of NPs can be sensitively influenced by local ions and ligands, with effects already occurring at extremely low concentrations. NPs in the Hückel regime are more sensitive to fluctuations in the ionic environment, because of a larger Debye length. The local ion concentration hereby affects the colloidal stability of the NPs, as it is different from bulk owing to Debye Hückel screening caused by the charge of the NPs. This can have subtle effects, now caused by the environment to the performance of the NP, such as for example a buffering effect caused by surface reaction on ultrapure ligand-free nanogold, a size quenching effect in the presence of specific ions and a significant impact on fluorophore-labelled NPs acting as ion sensors. Thus, the aim of this review is to clarify and give an unifying view of the complex interplay between the NP's surface with their nanoenvironment. PMID:24759541

Physicochemical characterizations of nano-palm oil fuel ash

NASA Astrophysics Data System (ADS)

Rajak, Mohd Azrul Abdul; Majid, Zaiton Abdul; Ismail, Mohammad

2015-07-01

Palm Oil Fuel Ash (POFA) is known as a good supplementary cementing material due to its siliceous-rich content. The application of nanotechnology in the pozzolanic materials could invent new functions in the efficiency of physical and chemical properties of materials. Thus, the present study aims to generate nano-sized POFA and characterize the physicochemical properties of nano-palm oil fuel ash (nPOFA). The nPOFA was prepared by mechanically grinding micro POFA using a high intensity ball milling for 6 hours. The physicochemical properties of nPOFA were characterized via X-Ray Fluoresence (XRF), Scanning Emission microscopy- Energy Dispersive X-Ray (SEM-EDX), Transmission Electron Microscope (TEM) and X-Ray Diffraction (XRD). The particle size of nPOFA acquired from TEM analysis was in the range of 20 nm to 90 nm, while the average crystallite size calculated from XRD diffractogram was 61.5 nm. The resulting nPOFA has a BET surface area of 145.35 m2/g, which is more than 85% increment in surface area compared to micro-sized POFA. The morphology and elemental studies showed the presence of spherical as well as irregularly shaped and fine nPOFA particles contains with high silicon content. The presence of α-quartz as the major phase of the nPOFA was identified through XRD analysis. The study concludes that nPOFA has the potential as a supplementary cementing material due to the high silica content, high surface area and the unique behaviors of nano-structured particles.

Noninvasive evaluation of global and regional left ventricular function using computed tomography and magnetic resonance imaging: a meta-analysis.

PubMed

Kaniewska, Malwina; Schuetz, Georg M; Willun, Steffen; Schlattmann, Peter; Dewey, Marc

2017-04-01

To compare the diagnostic accuracy of computed tomography (CT) in the assessment of global and regional left ventricular (LV) function with magnetic resonance imaging (MRI). MEDLINE, EMBASE and ISI Web of Science were systematically reviewed. Evaluation included: ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and left ventricular mass (LVM). Differences between modalities were analysed using limits of agreement (LoA). Publication bias was measured by Egger's regression test. Heterogeneity was evaluated using Cochran's Q test and Higgins I 2 statistic. In the presence of heterogeneity the DerSimonian-Laird method was used for estimation of heterogeneity variance. Fifty-three studies including 1,814 patients were identified. The mean difference between CT and MRI was -0.56 % (LoA, -11.6-10.5 %) for EF, 2.62 ml (-34.1-39.3 ml) for EDV and 1.61 ml (-22.4-25.7 ml) for ESV, 3.21 ml (-21.8-28.3 ml) for SV and 0.13 g (-28.2-28.4 g) for LVM. CT detected wall motion abnormalities on a per-segment basis with 90 % sensitivity and 97 % specificity. CT is accurate for assessing global LV function parameters but the limits of agreement versus MRI are moderately wide, while wall motion deficits are detected with high accuracy. • CT helps to assess patients with coronary artery disease (CAD). • MRI is the reference standard for evaluation of left ventricular function. • CT provides accurate assessment of global left ventricular function.

An Investigation of Laser Induced Surface Damage in glass.

DTIC Science & Technology

1985-06-01

ROA-RI60 669 RN INVESTIGATION OF LASER INDUCED SURFACE DAMAG IN In1 1 6lo GLASS (U) NAVAL POSTGRADUATE SCHOOL MONTEREY CA R D UYAK JUN 85IUNCLASSIFIED...ii -0 NAVAL POSTGRADUATE SCHOOL Monterey, California bor OCT THESIS AN INVESTIGATION OF LASER INDUCED SURFACE DAMAGE IN GLASS by )Richard David Uyak ,L...Subtitle) EPORT 6 PERIOD COVERED %An Investigation of Laser Induced Master’s Thesis Surface Damage in Glass June 1985S. PERFORMING ORG. REPORT MUMMER 7

Large Eddy Simulations of Surface Winds Above Water Waves: Effects of Wind-Wave Alignment and Wave Age

DTIC Science & Technology

2008-06-30

LLJ Cz tD LL LO Lij LO CO ur LL S, -1 LLA U) LIJ LIJ > CC < \\1 Ln LIJ o4 LL LLJ I 1q LO cr- Lj 0 ca C) w Li U)>) w...0 LL >Cc CCo0g o l Aoebez I- C,0) o 1,1u AplliqeqoJ d A!ilnwno (1)cq P C\\!-0 0 0 0 0 >WIN NUNN Z ,, ....... ,,0 U)) i tD z C) II iii. .i i i...t ~ ~ IL ,u UJ 4- •3:: 0 bb -0 𔃾o 4-4 0 t0 0 CL 4vJ .C E C L ’ 2t 0u bO~I uj U , b. U DO LU > LL 𔄁 0 LLJ w t 1*0 CC -~4-J Iuo a- E "

CAN IBEX DETECT INTERSTELLAR NEUTRAL HELIUM OR OXYGEN FROM ANTI-RAM DIRECTIONS?

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

Galli, A.; Wurz, P.; Park, J.

To better constrain the parameters of the interstellar neutral flow, we searched the Interstellar Boundary EXplorer (IBEX)-Lo database for helium and oxygen from the interstellar medium in the anti-ram direction in the three years (2009–2011) with the lowest background rates. We found that IBEX-Lo cannot observe interstellar helium from the anti-ram direction because the helium energy is too low for indirect detection by sputtering off the IBEX-Lo conversion surface. Our results show that this sputtering process has a low energy threshold between 25 and 30 eV, whereas the energy of the incident helium is only 10 eV for these observations.more » Interstellar oxygen, on the other hand, could in principle be detected in the anti-ram hemisphere, but the expected magnitude of the signal is close to the detection limit imposed by counting statistics and by the magnetospheric foreground.« less

Treatment of Arctic wastewater by chemical coagulation, UV and peracetic acid disinfection.

PubMed

Chhetri, Ravi Kumar; Klupsch, Ewa; Andersen, Henrik Rasmus; Jensen, Pernille Erland

2017-02-16

Conventional wastewater treatment is challenging in the Arctic region due to the cold climate and scattered population. Thus, no wastewater treatment plant exists in Greenland, and raw wastewater is discharged directly to nearby waterbodies without treatment. We investigated the efficiency of physicochemical wastewater treatment, in Kangerlussuaq, Greenland. Raw wastewater from Kangerlussuaq was treated by chemical coagulation and UV disinfection. By applying 7.5 mg Al/L polyaluminium chloride (PAX XL100), 73% of turbidity and 28% phosphate was removed from raw wastewater. E. coli and Enterococcus were removed by 4 and 2.5 log, respectively, when UV irradiation of 0.70 kWh/m 3 was applied to coagulated wastewater. Furthermore, coagulated raw wastewater in Denmark, which has a chemical quality similar to Greenlandic wastewater, was disinfected by peracetic acid or UV irradiation. Removal of heterotrophic bacteria by applying 6 and 12 mg/L peracetic acid was 2.8 and 3.1 log, respectively. Similarly, removal of heterotrophic bacteria by applying 0.21 and 2.10 kWh/m 3 for UV irradiation was 2.1 and greater than 4 log, respectively. Physicochemical treatment of raw wastewater followed by UV irradiation and/or peracetic acid disinfection showed the potential for treatment of arctic wastewater.

[Physicochemical and microbiological evaluation of 3 commercial guava jams (Psidium guajava L.)].

PubMed

López, R; Ramírez, A O; Graziani de Fariñas, L

2000-09-01

Four different production batches were taken from each brand. Samples were purchased from retail markets in Maracay, Cagua and Turmero. (Venezuela). The average physical and chemical values were: vacuum = 38.81 cm Hg; pH = 3.28; titrable acidity (%citric acid) = 0.59%; degree Brix = 67.24; reducing sugars = 55.28%; total sugars = 62.28, and the color parameters a = +14.44, b = +8.77 and L = 17.09. Molds, yeast and aerobic plate counts were lower than 10 UFC/g; it reveals an excellent microbiological quality of the product. The studied jams degree Brix and acidity fulfil COVENIN (1) requirements for jam products, but not pH range. In agreement with variance analysis, there were highly significance differences between the samples and among the shares of each sample for all physical and chemical properties evaluated.

Dynamics of vortex penetration, jumpwise instabilities, and nonlinear surface resistance of type-II superconductors in strong rf fields

NASA Astrophysics Data System (ADS)

Gurevich, A.; Ciovati, G.

2008-03-01

We consider the nonlinear dynamics of a single vortex in a superconductor in a strong rf magnetic field B0sinωt . Using the London theory, we calculate the dissipated power Q(B0,ω) and the transient time scales of vortex motion. For the linear Bardeen-Stephen viscous drag force, vortex velocities reach unphysically high values during vortex penetration through the oscillating surface barrier. It is shown that penetration of a single vortex through the ac surface barrier always involves penetration of an antivortex and the subsequent annihilation of the vortex-antivortex pairs. Using the nonlinear Larkin-Ovchinnikov (LO) viscous drag force at higher vortex velocities v(t) results in a jumpwise vortex penetration through the surface barrier and a significant increase of the dissipated power. We calculate the effect of dissipation on the nonlinear vortex viscosity η(v) and the rf vortex dynamics and show that it can also result in the LO-type behavior, instabilities, and thermal localization of penetrating vortex channels. We propose a thermal feedback model of η(v) , which not only results in the LO dependence of η(v) for a steady-state motion, but also takes into account retardation of the temperature field around a rapidly accelerating vortex and a long-range interaction with the surface. We also address the effect of pinning on the nonlinear rf vortex dynamics and the effect of trapped magnetic flux on the surface resistance Rs calculated as a function of rf frequency and field. It is shown that trapped flux can result in a temperature-independent residual resistance Ri at low T and a hysteretic low-field dependence of Ri(B0) , which can decrease as B0 is increased, reaching a minimum at B0 much smaller than the thermodynamic critical field Bc . We propose that cycling of the rf field can reduce Ri due to rf annealing of the magnetic flux which is pumped out by the rf field from a thin surface layer of the order of the London penetration depth.

Presence of Fluorescent Carbon Nanoparticles in Baked Lamb: Their Properties and Potential Application for Sensors.

PubMed

Wang, Haitao; Xie, Yisha; Liu, Shan; Cong, Shuang; Song, Yukun; Xu, Xianbing; Tan, Mingqian

2017-08-30

The presence of nanoparticles in food has drawn much attention in recent years. Fluorescent carbon nanoparticles are a new class of nanostructures; however, the distribution and physicochemical properties of such nanoparticles in food remain unclear. Herein, the presence of fluorescent carbon nanoparticles in baked lamb was confirmed, and their physicochemical properties were investigated. The fluorescent carbon nanoparticles from baked lamb emit strong blue fluorescence under ultraviolet light with a 10% fluorescent quantum yield. The nanoparticles are roughly spherical in appearance with a diameter of around 2.0 nm. Hydroxyl, amino, and carboxyl groups exist on the surface of nanoparticles. In addition, the nanoparticles could serve as a fluorescence sensor for glucose detection through an oxidation-reduction reaction. This work is the first report on fluorescent carbon nanoparticles present in baked lamb, which provides valuable insight into the physicochemical properties of such nanoparticles and their potential application in sensors.

Understanding the Interaction of Peptides and Proteins with Abiotic Surfaces: Towards Water-Free Biologics

DTIC Science & Technology

2018-02-03

peptides immobilized on abiotic surfaces depends upon a) the chemical and physical nature of the abiotic surface; b) the physicochemical properties of... dependent model of protein aggregation, aggregation proceeds only after a lag phase in which the concentration of energetically unfavorable nuclei reaches...time dependent kinetics or dynamics at such interfaces. This paper focuses on these three most important advantages of SFG and reviews some of the

Richards-Gebaur AFB, Missouri Limited Surface Observations Climatic Summary (LISOCS). Parts A, C-F.

DTIC Science & Technology

1985-07-01

Pressure" summaries for METAR stations. Table of Contents: AWS Form 2 "Station History " Part 1: Weather Conditions Part 2: Surface Winds Part 3...LOCATION AND INSTRUMENTATION HISTORY NUNiER TYPE 4T THIS LOCATION ELEVATION ABOVE NSL 065 or GEVORWICALL LOCATION I AIME Of LATITUDE LO4CI3 U01 PER

Validation of thigh-based accelerometer estimates of postural allocation in 5-12 year-olds.

PubMed

van Loo, Christiana M T; Okely, Anthony D; Batterham, Marijka J; Hinkley, Trina; Ekelund, Ulf; Brage, Søren; Reilly, John J; Jones, Rachel A; Janssen, Xanne; Cliff, Dylan P

2017-03-01

To validate activPAL3™ (AP3) for classifying postural allocation, estimating time spent in postures and examining the number of breaks in sedentary behaviour (SB) in 5-12 year-olds. Laboratory-based validation study. Fifty-seven children completed 15 sedentary, light- and moderate-to-vigorous intensity activities. Direct observation (DO) was used as the criterion measure. The accuracy of AP3 was examined using a confusion matrix, equivalence testing, Bland-Altman procedures and a paired t-test for 5-8y and 9-12y. Sensitivity of AP3 was 86.8%, 82.5% and 85.3% for sitting/lying, standing, and stepping, respectively, in 5-8y and 95.3%, 81.5% and 85.1%, respectively, in 9-12y. Time estimates of AP3 were equivalent to DO for sitting/lying in 9-12y and stepping in all ages, but not for sitting/lying in 5-12y and standing in all ages. Underestimation of sitting/lying time was smaller in 9-12y (1.4%, limits of agreement [LoA]: -13.8 to 11.1%) compared to 5-8y (12.6%, LoA: -39.8 to 14.7%). Underestimation for stepping time was small (5-8y: 6.5%, LoA: -18.3 to 5.3%; 9-12y: 7.6%, LoA: -16.8 to 1.6%). Considerable overestimation was found for standing (5-8y: 36.8%, LoA: -16.3 to 89.8%; 9-12y: 19.3%, LoA: -1.6 to 36.9%). SB breaks were significantly overestimated (5-8y: 53.2%, 9-12y: 28.3%, p<0.001). AP3 showed acceptable accuracy for classifying postures, however estimates of time spent standing were consistently overestimated and individual error was considerable. Estimates of sitting/lying were more accurate for 9-12y. Stepping time was accurately estimated for all ages. SB breaks were significantly overestimated, although the absolute difference was larger in 5-8y. Surveillance applications of AP3 would be acceptable, however, individual level applications might be less accurate. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Exploratory multivariate modeling and prediction of the physico-chemical properties of surface water and groundwater

NASA Astrophysics Data System (ADS)

Ayoko, Godwin A.; Singh, Kirpal; Balerea, Steven; Kokot, Serge

2007-03-01

SummaryPhysico-chemical properties of surface water and groundwater samples from some developing countries have been subjected to multivariate analyses by the non-parametric multi-criteria decision-making methods, PROMETHEE and GAIA. Complete ranking information necessary to select one source of water in preference to all others was obtained, and this enabled relationships between the physico-chemical properties and water quality to be assessed. Thus, the ranking of the quality of the water bodies was found to be strongly dependent on the total dissolved solid, phosphate, sulfate, ammonia-nitrogen, calcium, iron, chloride, magnesium, zinc, nitrate and fluoride contents of the waters. However, potassium, manganese and zinc composition showed the least influence in differentiating the water bodies. To model and predict the water quality influencing parameters, partial least squares analyses were carried out on a matrix made up of the results of water quality assessment studies carried out in Nigeria, Papua New Guinea, Egypt, Thailand and India/Pakistan. The results showed that the total dissolved solid, calcium, sulfate, sodium and chloride contents can be used to predict a wide range of physico-chemical characteristics of water. The potential implications of these observations on the financial and opportunity costs associated with elaborate water quality monitoring are discussed.

The influence of nanoscopically thin silver films on bacterial viability and attachment.

PubMed

Ivanova, Elena P; Hasan, Jafar; Truong, Vi Khanh; Wang, James Y; Raveggi, Massimo; Fluke, Christopher; Crawford, Russell J

2011-08-01

The physicochemical and bactericidal properties of thin silver films have been analysed. Silver films of 3 and 150 nm thicknesses were fabricated using a magnetron sputtering thin-film deposition system. X-ray photoelectron and energy dispersive X-ray spectroscopy and atomic force microscopy analyses confirmed that the resulting surfaces were homogeneous, and that silver was the most abundant element present on both surfaces, being 45 and 53 at.% on the 3- and 150-nm films, respectively. Inductively coupled plasma time of flight mass spectroscopy (ICP-TOF-MS) was used to measure the concentration of silver ions released from these films. Concentrations of 0.9 and 5.2 ppb were detected for the 3- and 150-nm films, respectively. The surface wettability of the films remained nearly identical for both film thicknesses, displaying a static water contact angle of 95°, while the surface free energy of the 150-nm film was found to be slightly greater than that of the 3-nm film, being 28.8 and 23.9 mN m(-1), respectively. The two silver film thicknesses exhibited statistically significant differences in surface topographic profiles on the nanoscopic scale, with R (a), R (q) and R (max) values of 1.4, 1.8 and 15.4 nm for the 3-nm film and 0.8, 1.2 and 10.7 nm for the 150-nm film over a 5 × 5 μm scanning area. Confocal scanning laser microscopy and scanning electron microscopy revealed that the bactericidal activity of the 3-nm silver film was not significant, whereas the nanoscopically smoother 150-nm silver film exhibited appreciable bactericidal activity towards Pseudomonas aeruginosa ATCC 9027 cells and Staphylococcus aureus CIP 65.8 cells, obtaining up to 75% and 27% sterilisation effect, respectively.

The effect of n- and p-type doping on coherent phonons in GaN.

PubMed

Ishioka, Kunie; Kato, Keiko; Ohashi, Naoki; Haneda, Hajime; Kitajima, Masahiro; Petek, Hrvoje

2013-05-22

The effect of doping on the carrier-phonon interaction in wurtzite GaN is investigated by pump-probe reflectivity measurements using 3.1 eV light in near resonance with the fundamental band gap of 3.39 eV. Coherent modulations of the reflectivity due to the E2 and A1(LO) modes, as well as the 2A1(LO) overtone are observed. Doping of acceptor and donor atoms enhances the dephasing of the polar A1(LO) phonon via coupling with plasmons, with the effect of donors being stronger. Doping also enhances the relative amplitude of the coherent A1(LO) phonon with respect to that of the high-frequency E2 phonon, though it does not affect the relative intensity in Raman spectroscopic measurements. We attribute this enhanced coherent amplitude to the transient depletion field screening (TDFS) excitation mechanism, which, in addition to impulsive stimulated Raman scattering (ISRS), contributes to the generation of coherent polar phonons even for sub-band gap excitation. Because the TDFS mechanism requires photoexcitation of carriers, we argue that the interband transition is made possible at a surface with photon energies below the bulk band gap through the Franz-Keldysh effect.

Physicochemical signatures of natural surfactant sea films from coastal Middle Adriatic stations

NASA Astrophysics Data System (ADS)

Frka, Sanja; Pogorzelski, Stanislaw; Kozarac, Zlatica; Ćosović, Božena

2013-04-01

Boundary layers between different environmental compartments represent critical interfaces for biological, chemical and physical processes. The sea surface microlayer (SSM) as a top layer of the sea surface represents natural interface between the atmosphere and ocean. Although < 1 mm in thickness the SML plays a key role in the global biogeochemical cycling because all gaseous, liquid and particulate materials must pass through this interface when exchanging between the ocean and the atmosphere. The SSM thus represents a very important driver enhancing air-water exchange processes. A variety of natural and anthropogenic organic compounds, particularly those which are surface active (SA) are generally enriched in the SML. It is widely acknowledged that the SSM is complex matrix of SA organics as carbohydrates, proteins, lipids and humic substances. Although lipid material is much less abundant than carbohydrates and proteins in the SML, their contribution to surface activity may be disproportionately large. The surfactant films at the air-sea interface change its physicochemical properties reducing air-sea exchange possesses by impeding molecular diffusion across the interface and influencing the hydrodynamic characteristics of water motion at the interface. Various biological, chemical and physical processes lead to the alteration of the film chemical composition, surface physical properties, surface concentration and spatial distribution of film-forming components. Instead of analyzing its chemical composition, it should be possible to scale the SML surface pressure-area (π-A) isotherms in terms of structural parameters which appear to be a sensitive and quantitative measure of the film physicochemical composition, surface concentration and miscibility of its film-forming components. We will present a large data set obtained by electrochemical and monolayer techniques, accompanied with the novel scaling approach for physicochemical characterization of SA substances of the natural microlayers from coastal Middle Adriatic stations including saline Rogoznica Lake and Krka river estuarine station. Higher primary production during late spring-early autumn is reflected in the presence of microlayers of higher surfactant activity containing on average molecules of lower molecular masses (Mw=0.65±0.27 kDa) and higher miscibility (y=6.46±1.33) and elasticity (E=18.33±2.02 mN/m) modulus in comparison to structural parameters (average Mw=2.15±1.58 kDa; y=3.51±1.46; E=6.41±1.97 mN/m) obtained for microlayers from period of lower organic matter production. Higher inhibition effect on the reduction process of cadmium ions is observed for natural microlayers abundant with SA material from more productive period. This kind of distribution is explained as the consequence of competitive adsorption of hydrophobic lipid-like substances of lower Mw which highly influence the surface structural properties of natural air-water interface forming there segregated surface films during more productive period. This study will offer different perspective on contemporary SML concept taking into account the lipids that act as end-members highly influencing seasonal change of SA concentration and surface structural properties of natural films at the air-water interface.

Effect of enzymatic depolymerization on physicochemical and rheological properties of guar gum.

PubMed

Mudgil, Deepak; Barak, Sheweta; Khatkar, B S

2012-09-01

Depolymerization of guar gum using enzymatic hydrolysis was performed to obtain depolymerized guar gum having functional application as soluble dietary fiber. Enzymatic hydrolysis of guar gum significantly affected the physicochemical and rheological characteristics of guar gum. The depolymerized guar gum showed a significant increase in crystallinity index from 3.86% to 13.2% and flow behavior index from 0.31 to 1.7 as compared to native guar gum. Remarkable decrease in intrinsic viscosity and consistency index was also observed from 9 to 0.28 and 4.04 to 0.07, respectively. Results revealed that enzymatic hydrolysis of guar gum resulted in a polysaccharide with low degree of polymerization, viscosity and consistency which could make it useful for incorporation in food products as dietary fiber without affecting the rheology, consistency and texture of the products. Copyright © 2012 Elsevier Ltd. All rights reserved.

Physicochemical and Sensory Characteristics of Sponge Cakes with Rubus coreanus Powder

PubMed Central

Lee, Jun Ho

2015-01-01

To develop new type of sponge cake, the effects of partial (0~40%) replacement with Rubus coreanus powder (RCP) on the quality characteristics of sponge cakes were investigated. The pH level and moisture content ranged from 4.05~8.23 and 28.49~36.59, respectively, and significantly decreased upon addition of RCP (P<0.05). Baking loss rate and cake firmness significantly increased with higher RCP content in the formulation, whereas morphological characteristics of cakes such as height, volume, and symmetry indices significantly decreased (P<0.05). For crumb color values, L*- and b*-values significantly decreased while a*-value significantly increased as a result of RCP substitution (P<0.05). Hedonic sensory results indicated that sponge cakes supplemented with 30~40% RCP showed the most favorable acceptance scores for most of the sensory attributes evaluated. Overall, Rubus coreanus sponge cake could be developed with comparable physicochemical qualities without sacrificing consumer acceptability. PMID:26451358

Physicochemical and Sensory Characteristics of Sponge Cakes with Rubus coreanus Powder.

PubMed

Lee, Jun Ho

2015-09-01

To develop new type of sponge cake, the effects of partial (0~40%) replacement with Rubus coreanus powder (RCP) on the quality characteristics of sponge cakes were investigated. The pH level and moisture content ranged from 4.05~8.23 and 28.49~36.59, respectively, and significantly decreased upon addition of RCP (P<0.05). Baking loss rate and cake firmness significantly increased with higher RCP content in the formulation, whereas morphological characteristics of cakes such as height, volume, and symmetry indices significantly decreased (P<0.05). For crumb color values, L*- and b*-values significantly decreased while a*-value significantly increased as a result of RCP substitution (P<0.05). Hedonic sensory results indicated that sponge cakes supplemented with 30~40% RCP showed the most favorable acceptance scores for most of the sensory attributes evaluated. Overall, Rubus coreanus sponge cake could be developed with comparable physicochemical qualities without sacrificing consumer acceptability.

Emerging Concern from Short-Term Textile Leaching: A Preliminary Ecotoxicological Survey.

PubMed

Lofrano, G; Libralato, G; Carotenuto, M; Guida, M; Inglese, M; Siciliano, A; Meriç, S

2016-11-01

Textile dyes and their residues gained growing attention worldwide. Textile industry is a strong water consumer potentially releasing xenobiotics from washing and rinsing procedures during finishing processes. On a decentralised basis, also final consumers generate textile waste streams. Thus, a procedure simulating home washing with tap water screened cotton textiles leachates (n = 28) considering physico-chemical (COD, BOD 5 , and UV absorbance) and ecotoxicological data (Daphnia magna, Pseudokirchneriella subcapitata and Lepidium sativum). Results evidenced that: (i) leachates presented low biodegradability levels; (ii) toxicity in more than half leachates presented slight acute or acute effects; (iii) the remaining leachates presented "no effect" suggesting the use of green dyes/additives, and/or well established finishing processes; (iv) no specific correlations were found between traditional physico-chemical and ecotoxicological data. Further investigations will be necessary to identify textile residues, and their potential interactions with simulated human sweat in order to evidence potential adverse effects on human health.

Effect of Pressure on Conductivity in Poly(Ethylene Oxide) Complexed with Alkali Metal Salts.

DTIC Science & Technology

1983-05-01

I. ill thii ai lIion o lim ;oPlb - :11 orde e to I i u PIil I I 𔃺. !IO ent, dynawical where lo~ isutll-r:lail coii’,iii:Sililty. Iiif cdl IV. it IC...iacek :,w-:.,i (e n mpr:]v 1)Dr .Janet Ostero ung

Generation of food-grade lactococcal starters which produce the lantibiotics lacticin 3147 and lacticin 481.

PubMed

O'Sullivan, Lisa; Ryan, Maire P; Ross, R Paul; Hill, Colin

2003-06-01

Transconjugant lactococcal starters which produce both lantibiotics lacticin 3147 and lacticin 481 were generated via conjugation of large bacteriocin-encoding plasmids. A representative of one of the resultant strains proved more effective at killing Lactobacillus fermentum and inhibiting the growth of Listeria monocytogenes LO28H than either of the single bacteriocin-producing parental strains, demonstrating the potential of these transconjugants as protection cultures for food safety applications.

Low LBNP Tolerance in Men is Associated With Attenuated Activation of The Renin-Angiotensin System

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Petersen, T. W.; Gabrielsen, A.; Pump, B.; Bie, P.; Christensen, N.-J.; Warberg, J.; Videbaeck, R.; Simonson, S. R.; Norsk, P.

1999-01-01

Vasoactive hormone concentrations [epinephrine (pE), norepinephrine (pNE), angiotensin II (pATII), vasopressin (pVP), endothelin 1 (pET1)] and plasma renin activity (pRA) were measured during lower body negative pressure (LBNP) to test the hypothesis that responsiveness of the renin-angiotensin system is related to LBNP tolerance. Healthy men (2,822 cal/day(exp -1), 2 mmol*kg(exp -1)*day(exp -1)) Na(+)) were exposed to 30 minutes of progressive LBNP to -50 mmHg. LBNP was uneventful for seven men (25 +/- 2 years, HiTol group), but eight men (26 +/- 3 years) reached pre-syncope after 11 +/- 1 minutes (P < 0.001, LoTol group). Mean arterial pressure was unchanged. Central venous pressure and left atrial diameter decreased in both groups (5-6 mmHg by approx. 30%, P < 0.05). Control [hormone] were similar but, pRA differed between groups (LoTol 0.6 +/- 0.1, HiTol 1.2 +/- 0.1 ng Ang1/(ml(exp -1)*h(exp -1)), P < 0.05). LBNP increased (P < 0.05) pRA and pATII more in HiTol (9.9 +/- 2.2 ng Ang1/(ml(exp -1)*h(exp -1)) and 58 +/- 12 pg/ml(exp -1)) than LoTol (4.3 +/- 0.9 ng Ang1/(ml*h) and 28 +/- 6 pg/ml(exp -1)). In contrast, pVP was higher (P < 0.05) in LoTol than in HiTol. The response of the renin-angiotensin system seems linked to the occurrence of pre-syncope, and measurement of resting pRA may be predictive.

First-order kinetic gas generation model parameters for wet landfills.

PubMed

Faour, Ayman A; Reinhart, Debra R; You, Huaxin

2007-01-01

Landfill gas collection data from wet landfill cells were analyzed and first-order gas generation model parameters were estimated for the US EPA landfill gas emissions model (LandGEM). Parameters were determined through statistical comparison of predicted and actual gas collection. The US EPA LandGEM model appeared to fit the data well, provided it is preceded by a lag phase, which on average was 1.5 years. The first-order reaction rate constant, k, and the methane generation potential, L(o), were estimated for a set of landfills with short-term waste placement and long-term gas collection data. Mean and 95% confidence parameter estimates for these data sets were found using mixed-effects model regression followed by bootstrap analysis. The mean values for the specific methane volume produced during the lag phase (V(sto)), L(o), and k were 33 m(3)/Megagrams (Mg), 76 m(3)/Mg, and 0.28 year(-1), respectively. Parameters were also estimated for three full scale wet landfills where waste was placed over many years. The k and L(o) estimated for these landfills were 0.21 year(-1), 115 m(3)/Mg, 0.11 year(-1), 95 m(3)/Mg, and 0.12 year(-1) and 87 m(3)/Mg, respectively. A group of data points from wet landfills cells with short-term data were also analyzed. A conservative set of parameter estimates was suggested based on the upper 95% confidence interval parameters as a k of 0.3 year(-1) and a L(o) of 100 m(3)/Mg if design is optimized and the lag is minimized.

[Study on triterpenoid saponins in the rhizome of Anemone hofengensis].

PubMed

Han, Lin-Tao; Li, Ming-Ming; Huang, Fang; Hou, An-Wei

2013-10-01

To study the triterpenoid saponins in the rhizome of Anemone hofengensis. The constituents were separated with various chromatographic techniques and their structures were elucidated by physicochemical properties and spectral data. Five compounds were isolated and identified as 3-O-alpha-L-rhamnopyranosyl-(1 --> 2)-alpha-L-arabino-pyranosyl-oleanolic acid (1), 3-O-alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-glucopyranosyl-(1 --> 2)-alpha-L-rhamnopyranosyl-oleanolic acid 28-O-alpha-L-rhamnopyranosyl-(1 --> 4) -beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranoside (2), 3-O-alpha-L-rhamnopyranosyl-(1 --> 2) [beta-D-glucopyranosyl-(1 --> 4)]-alpha-L-rhamnopyranosyl-oleanolic acid-28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-gluco-pyranoside (3), 3-O-beta-D-glucopyranosyl-(1 --> 2)-beta-D-xylopyranosyl-oleanolic acid 28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranoside (4), oleanolic acid-28-O-alpha-L-rhamnopyra-nosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranoside (5). Compound 1 - 5 are isolated from this plant for the first time.

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

Kumar, Pragati, E-mail: pkumar.phy@gmail.com; Agarwal, Avinash; Saxena, Nupur

The influence of swift heavy ion irradiation (SHII) on surface phonon mode (SPM) and green emission in nanocrystalline CdS thin films grown by chemical bath deposition is studied. The SHII of nanocrystalline CdS thin films is carried out using 70 MeV Ni ions. The micro Raman analysis shows that asymmetry and broadening in fundamental longitudinal optical (LO) phonon mode increases systematically with increasing ion fluence. To analyze the role of phonon confinement, spatial correlation model (SCM) is fitted to the experimental data. The observed deviation of SCM to the experimental data is further investigated by fitting the micro Raman spectra usingmore » two Lorentzian line shapes. It is found that two Lorentzian functions (LFs) provide better fitting than SCM fitting and facilitate to identify the contribution of SPM in the observed distortion of LO mode. The behavior of SPM as a function of ion fluence is studied to correlate the observed asymmetry (Γ{sub a}/Γ{sub b}) and full width at half maximum of LO phonon mode and to understand the SHII induced enhancement of SPM. The ion beam induced interstitial and surface state defects in thin films, as observed by photoluminescence (PL) spectroscopy studies, may be the underlying reason for enhancement in SPM. PL studies also show enhancement in green luminescence with increase in ion fluence. PL analysis reveals that the variation in population density of surface state defects after SHII is similar to that of SPM. The correlation between SPM and luminescence and their dependence on ion irradiation fluence is explained with the help of thermal spike model.« less

Assessing anthropogenic impact on boreal lakes with historical fish species distribution data and hydrogeochemical modeling.

PubMed

Valinia, Salar; Englund, Göran; Moldan, Filip; Futter, Martyn N; Köhler, Stephan J; Bishop, Kevin; Fölster, Jens

2014-09-01

Quantifying the effects of human activity on the natural environment is dependent on credible estimates of reference conditions to define the state of the environment before the onset of adverse human impacts. In Europe, emission controls that aimed at restoring ecological status were based on hindcasts from process-based models or paleolimnological reconstructions. For instance, 1860 is used in Europe as the target for restoration from acidification concerning biological and chemical parameters. A more practical problem is that the historical states of ecosystems and their function cannot be observed directly. Therefore, we (i) compare estimates of acidification based on long-term observations of roach (Rutilus rutilus) populations with hindcast pH from the hydrogeochemical model MAGIC; (ii) discuss policy implications and possible scope for use of long-term archival data for assessing human impacts on the natural environment and (iii) present a novel conceptual model for interpreting the importance of physico-chemical and ecological deviations from reference conditions. Of the 85 lakes studied, 78 were coherently classified by both methods. In 1980, 28 lakes were classified as acidified with the MAGIC model, however, roach was present in 14 of these. In 2010, MAGIC predicted chemical recovery in 50% of the lakes, however roach only recolonized in five lakes after 1990, showing a lag between chemical and biological recovery. Our study is the first study of its kind to use long-term archival biological data in concert with hydrogeochemical modeling for regional assessments of anthropogenic acidification. Based on our results, we show how the conceptual model can be used to understand and prioritize management of physico-chemical and ecological effects of anthropogenic stressors on surface water quality. © 2014 The Authors Global Change Biology Published by John Wiley & Sons Ltd.

Assessing anthropogenic impact on boreal lakes with historical fish species distribution data and hydrogeochemical modeling

PubMed Central

Valinia, Salar; Englund, Göran; Moldan, Filip; Futter, Martyn N; Köhler, Stephan J; Bishop, Kevin; Fölster, Jens

2014-01-01

Quantifying the effects of human activity on the natural environment is dependent on credible estimates of reference conditions to define the state of the environment before the onset of adverse human impacts. In Europe, emission controls that aimed at restoring ecological status were based on hindcasts from process-based models or paleolimnological reconstructions. For instance, 1860 is used in Europe as the target for restoration from acidification concerning biological and chemical parameters. A more practical problem is that the historical states of ecosystems and their function cannot be observed directly. Therefore, we (i) compare estimates of acidification based on long-term observations of roach (Rutilus rutilus) populations with hindcast pH from the hydrogeochemical model MAGIC; (ii) discuss policy implications and possible scope for use of long-term archival data for assessing human impacts on the natural environment and (iii) present a novel conceptual model for interpreting the importance of physico-chemical and ecological deviations from reference conditions. Of the 85 lakes studied, 78 were coherently classified by both methods. In 1980, 28 lakes were classified as acidified with the MAGIC model, however, roach was present in 14 of these. In 2010, MAGIC predicted chemical recovery in 50% of the lakes, however roach only recolonized in five lakes after 1990, showing a lag between chemical and biological recovery. Our study is the first study of its kind to use long-term archival biological data in concert with hydrogeochemical modeling for regional assessments of anthropogenic acidification. Based on our results, we show how the conceptual model can be used to understand and prioritize management of physico-chemical and ecological effects of anthropogenic stressors on surface water quality. PMID:24535943

Surface physicochemical properties at the micro and nano length scales: role on bacterial adhesion and Xylella fastidiosa biofilm development.

PubMed

Lorite, Gabriela S; Janissen, Richard; Clerici, João H; Rodrigues, Carolina M; Tomaz, Juarez P; Mizaikoff, Boris; Kranz, Christine; de Souza, Alessandra A; Cotta, Mônica A

2013-01-01

The phytopathogen Xylella fastidiosa grows as a biofilm causing vascular occlusion and consequently nutrient and water stress in different plant hosts by adhesion on xylem vessel surfaces composed of cellulose, hemicellulose, pectin and proteins. Understanding the factors which influence bacterial adhesion and biofilm development is a key issue in identifying mechanisms for preventing biofilm formation in infected plants. In this study, we show that X. fastidiosa biofilm development and architecture correlate well with physicochemical surface properties after interaction with the culture medium. Different biotic and abiotic substrates such as silicon (Si) and derivatized cellulose films were studied. Both biofilms and substrates were characterized at the micro- and nanoscale, which corresponds to the actual bacterial cell and membrane/ protein length scales, respectively. Our experimental results clearly indicate that the presence of surfaces with different chemical composition affect X. fastidiosa behavior from the point of view of gene expression and adhesion functionality. Bacterial adhesion is facilitated on more hydrophilic surfaces with higher surface potentials; XadA1 adhesin reveals different strengths of interaction on these surfaces. Nonetheless, despite different architectural biofilm geometries and rates of development, the colonization process occurs on all investigated surfaces. Our results univocally support the hypothesis that different adhesion mechanisms are active along the biofilm life cycle representing an adaptation mechanism for variations on the specific xylem vessel composition, which the bacterium encounters within the infected plant.

Surface Physicochemical Properties at the Micro and Nano Length Scales: Role on Bacterial Adhesion and Xylella fastidiosa Biofilm Development

PubMed Central

Lorite, Gabriela S.; Janissen, Richard; Clerici, João H.; Rodrigues, Carolina M.; Tomaz, Juarez P.; Mizaikoff, Boris; Kranz, Christine; de Souza, Alessandra A.; Cotta, Mônica A.

2013-01-01

The phytopathogen Xylella fastidiosa grows as a biofilm causing vascular occlusion and consequently nutrient and water stress in different plant hosts by adhesion on xylem vessel surfaces composed of cellulose, hemicellulose, pectin and proteins. Understanding the factors which influence bacterial adhesion and biofilm development is a key issue in identifying mechanisms for preventing biofilm formation in infected plants. In this study, we show that X. fastidiosa biofilm development and architecture correlate well with physicochemical surface properties after interaction with the culture medium. Different biotic and abiotic substrates such as silicon (Si) and derivatized cellulose films were studied. Both biofilms and substrates were characterized at the micro- and nanoscale, which corresponds to the actual bacterial cell and membrane/ protein length scales, respectively. Our experimental results clearly indicate that the presence of surfaces with different chemical composition affect X. fastidiosa behavior from the point of view of gene expression and adhesion functionality. Bacterial adhesion is facilitated on more hydrophilic surfaces with higher surface potentials; XadA1 adhesin reveals different strengths of interaction on these surfaces. Nonetheless, despite different architectural biofilm geometries and rates of development, the colonization process occurs on all investigated surfaces. Our results univocally support the hypothesis that different adhesion mechanisms are active along the biofilm life cycle representing an adaptation mechanism for variations on the specific xylem vessel composition, which the bacterium encounters within the infected plant. PMID:24073256

Influence of ROI definition on the heart-to-mediastinum ratio in planar 123I-MIBG imaging.

PubMed

Klene, Christiane; Jungen, Christiane; Okuda, Koichi; Kobayashi, Yuske; Helberg, Annabelle; Mester, Janos; Meyer, Christian; Nakajima, Kenichi

2018-02-01

Iodine-123-metaiodobenzylguanidine ( 123 I-MIBG) imaging with estimation of the heart-to-mediastinum ratio (HMR) has been established for risk assessment in patients with chronic heart failure. Our aim was to evaluate the effect of different methods of ROI definition on the renderability of HMR to normal or decreased sympathetic innervation. The results of three different methods of ROI definition (clinical routine (CLI), simple standardization (STA), and semi-automated (AUT) were compared. Ranges of 95% limits of agreement (LoA) of inter-observer variabilities were 0.28 and 0.13 for STA and AUT, respectively. Considering a HMR of 1.60 as the lower limit of normal, 13 of 32 (41%) for method STA and 5 of 32 (16%) for method AUT of all HMR measurements could not be classified to normal or pathologic. Ranges of 95% LoA of inter-method variabilities were 0.72 for CLI vs AUT, 0.65 for CLI vs STA, and 0.31 for STA vs AUT. Different methods of ROI definition result in different ranges of the LoA of the measured HMR with relevance for rendering the results to normal or pathological innervation. We could demonstrate that standardized protocols can help keep methodological variabilities limited, narrowing the gray zone of renderability.

Pre- and post-discharge factors influencing early readmission to acute psychiatric wards: implications for quality-of-care indicators in psychiatry.

PubMed

Donisi, Valeria; Tedeschi, Federico; Salazzari, Damiano; Amaddeo, Francesco

2016-01-01

This study aims to describe the association between pre- and post-discharge factors and early readmission to acute psychiatric wards in a well-integrated community-based psychiatric service. The analysis consisted of all the hospital discharge records containing a psychiatric diagnosis in 2011 from four Italian acute inpatient wards. Socio-demographic, clinical, admission and aftercare variables were investigated as possible predictors of readmission at 7, 30 and 90 days after discharge and were analyzed, controlling for dependency among same-patient observations. Previous psychiatric history was the most important predictor of readmissions. The socio-demographic and clinical characteristics of patients did not clearly influence readmission. Length of stay (LoS) was significant for readmission at 7 days even after controlling for other predictors and for same-patient dependence, in particular, for patients with previous admissions. Results suggest a protective role of a LoS higher than 28 days. In general, having a contact in community services did not turn out as protective from early readmission. This paper contributes to increase the knowledge about factors that may predict the risk of early readmission. Implications for quality assessment in psychiatry emerged: readmission seems actionable by LoS and not by community follow-up. Copyright © 2016 Elsevier Inc. All rights reserved.

Removal of pharmaceuticals, perfluoroalkyl substances and other micropollutants from wastewater using lignite, Xylit, sand, granular activated carbon (GAC) and GAC+Polonite® in column tests - Role of physicochemical properties.

PubMed

Rostvall, Ande; Zhang, Wen; Dürig, Wiebke; Renman, Gunno; Wiberg, Karin; Ahrens, Lutz; Gago-Ferrero, Pablo

2018-06-15

This study evaluated the performance of five different sorbents (granular activated carbon (GAC), GAC + Polonite ® (GAC + P), Xylit, lignite and sand) for a set of 83 micropollutants (MPs) (pharmaceuticals, perfluoroalkyl substances (PFASs), personal care products, artificial sweeteners, parabens, pesticide, stimulants), together representing a wide range of physicochemical properties. Treatment with GAC and GAC + P provided the highest removal efficiencies, with average values above 97%. Removal rates were generally lower for Xylit (on average 74%) and lignite (on average 68%), although they proved to be highly efficient for a few individual MPs. The average removal efficiency for sand was only 47%. It was observed that the MPs behaved differently depending on their physicochemical properties. The physicochemical properties of PFASs (i.e. molecular weight, topological molecular surface area, log octanol water partition coefficient (K ow ) and distribution coefficient between octanol and water (log D)) were positively correlated to observed removal efficiency for the sorbents Xylit, lignite and sand (p < 0.05), indicating a strong influence of perfluorocarbon chain length and associated hydrophobic characteristics. In contrast, for the other MPs the ratio between apolar and polar surface area (SA/SP) was positively correlated with the removal efficiency, indicating that hydrophobic adsorption may be a key feature of their sorption mechanisms. GAC showed to be the most promising filter medium to improve the removal of MPs in on-site sewage treatment facilities. However, more studies are needed to evaluate the removal of MPs in field trials. Copyright © 2018 Elsevier Ltd. All rights reserved.

Combination of Functional Nanoengineering and Nanosecond Laser Texturing for Design of Superhydrophobic Aluminum Alloy with Exceptional Mechanical and Chemical Properties.

PubMed

Boinovich, Ludmila B; Modin, Evgeny B; Sayfutdinova, Adeliya R; Emelyanenko, Kirill A; Vasiliev, Alexander L; Emelyanenko, Alexandre M

2017-10-24

Industrial application of metallic materials is hindered by several shortcomings, such as proneness to corrosion, erosion under abrasive loads, damage due to poor cold resistance, or weak resistance to thermal shock stresses, etc. In this study, using the aluminum-magnesium alloy as an example of widely spread metallic materials, we show that a combination of functional nanoengineering and nanosecond laser texturing with the appropriate treatment regimes can be successfully used to transform a metal into a superhydrophobic material with exceptional mechanical and chemical properties. It is demonstrated that laser chemical processing of the surface may be simultaneously used to impart multimodal roughness and to modify the composition and physicochemical properties of a thick surface layer of the substrate itself. Such integration of topographical and physicochemical modification leads to specific surface nanostructures such as nanocavities filled with hydrophobic agent and hard oxynitride nanoinclusions. The combination of superhydrophobic state, nano- and micro features of the hierarchical surface, and the appropriate composition of the surface textured layer allowed us to provide the surface with the outstanding level of resistance of superhydrophobic coatings to external chemical and mechanical impacts. In particular, experimental data presented in this study indicate high resistance of the fabricated coatings to pitting corrosion, superheated water vapor, sand abrasive wear, and rapid temperature cycling from liquid nitrogen to room temperatures, without notable degradation of superhydrophobic performance.

Interaction of PM2.5 airborne particulates with ZnO and TiO2 nanoparticles and their effect on bacteria.

PubMed

Baysal, Asli; Saygin, Hasan; Ustabasi, Gul Sirin

2017-12-21

A significant knowledge gap in nanotechnology is the absence of standardized protocols for examining and comparison the effect of metal oxide nanoparticles on different environment media. Despite the large number of studies on ecotoxicity of nanoparticles, most of them disregard the particles physicochemical transformation under real exposure conditions and interaction with different environmental components like air, soil, water, etc. While one of the main exposure ways is inhalation and/or atmosphere for human and environment, there is no investigation between airborne particulates and nanoparticles. In this study, some metal oxide nanoparticle (ZnO and TiO 2 ) transformation and behavior in PM2.5 air particulate media were examined and evaluated by the influence on nanoparticle physicochemical properties (size, surface charge, surface functionalization) and on bacterium (Gram-positive Bacillus subtilis, Staphylococcus aureus/Gram-negative Escherichia coli, Pseudomonas aeruginosa bacteria) by testing in various concentrations of PM2.5 airborne particulate media to contribute to their environmental hazard and risk assessment in atmosphere. PM2.5 airborne particulate media affected their toxicity and physicochemical properties when compared the results obtained in controlled conditions. ZnO and TiO 2 surfaces were functionalized mainly with sulfoxide groups in PM2.5 air particulates. In addition, tested particles were not observed to be toxic in controlled conditions. However, these were observed inhibition in PM2.5 airborne particulates media by the exposure concentration. These observations and dependence of the bacteria viability ratio explain the importance of particulate matter-nanoparticle interaction.

Physicochemical characterizations of nano-palm oil fuel ash

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

Rajak, Mohd Azrul Abdul, E-mail: azrulrajak88@gmail.com; Preparatory Centre of Science and Technology, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah; Majid, Zaiton Abdul, E-mail: zaiton@kimia.fs.utm.my

2015-07-22

Palm Oil Fuel Ash (POFA) is known as a good supplementary cementing material due to its siliceous-rich content. The application of nanotechnology in the pozzolanic materials could invent new functions in the efficiency of physical and chemical properties of materials. Thus, the present study aims to generate nano-sized POFA and characterize the physicochemical properties of nano-palm oil fuel ash (nPOFA). The nPOFA was prepared by mechanically grinding micro POFA using a high intensity ball milling for 6 hours. The physicochemical properties of nPOFA were characterized via X-Ray Fluoresence (XRF), Scanning Emission microscopy- Energy Dispersive X-Ray (SEM-EDX), Transmission Electron Microscope (TEM)more » and X-Ray Diffraction (XRD). The particle size of nPOFA acquired from TEM analysis was in the range of 20 nm to 90 nm, while the average crystallite size calculated from XRD diffractogram was 61.5 nm. The resulting nPOFA has a BET surface area of 145.35 m{sup 2}/g, which is more than 85% increment in surface area compared to micro-sized POFA. The morphology and elemental studies showed the presence of spherical as well as irregularly shaped and fine nPOFA particles contains with high silicon content. The presence of α-quartz as the major phase of the nPOFA was identified through XRD analysis. The study concludes that nPOFA has the potential as a supplementary cementing material due to the high silica content, high surface area and the unique behaviors of nano-structured particles.« less

Assessment of surface water quality of inland valleys for cropping in SW Nigeria

NASA Astrophysics Data System (ADS)

Aboyeji, O. S.; Ogunkoya, O. O.

2017-05-01

Inland valley agro-ecosystems which are a category of wetlands have potential for sustainable crop production relative to uplands. A major challenge to their utilisation in the study area is their heterogeneity in hydrology, morphology, soil types and agro-economy. The study assessed the surface water quality of three typologies of the agro-ecosystems—amphitheatre-like valley-heads (Am), valley-side (VS), and low depression (LD)—for cropping. Surface water of six sites were sampled during the wet and dry seasons. The physicochemical properties and metal concentrations of the samples were analysed. Descriptive statistics and water quality indices were used to assess the suitability of the waters of the agro-ecosystems for cropping. Results showed that the valleys have neutral to slightly alkaline waters. Values of physicochemical parameters are generally within the acceptable range for cropping. The concentration of major cations varied across the inland valley types, but exhibited similar characteristics within each valley. The dominance of the major cations is in the order of Na > Ca > K > Mg. ANOVA results indicated that there is no significant difference in the concentration of heavy metals across the valleys ( F = 2.044, p = 0.138, α = 0.05). Generally, most of the physicochemical parameters and trace metals have low concentrations and are non-toxic to plants. Values of water quality indices (sodium adsorption ratio, soluble sodium percentage, total dissolved solids and permeability index) indicated that the concentrations of minerals in waters across the valley typologies are generally within permissible limits for cropping.

Modification of surface characteristic and tribo-electric properties of polymers by DBD plasma in atmospheric air

NASA Astrophysics Data System (ADS)

Bekkara, Mohammed Fethi; Dascalescu, Lucien; Benmimoun, Youcef; Zeghloul, Thami; Tilmatine, Amar; Zouzou, Noureddine

2018-01-01

The aim of this paper is to quantify the effects of dielectric barrier discharge (DBD) exposure on the physico-chemical and tribo-electric properties of polymers. The study was conducted in atmospheric air on polypropylene, polyethylene and polyvinyl-chloride. These three types of polymers are widely used in industry. The polymers were characterized by means of an optical profilometer, a fourier-transform infrared (FTIR) spectrometer and an electric charge measurement system. The latter is composed of a Faraday pail connected to an electrometer. The profilometer analyses showed that the DBD plasma treatment has increased the surface roughness of the three polymers. FTIR revealed that oxygen atoms and polar groups were grafted on their surfaces, thereby conferring them a hydrophilic character. The short (2 sec) DBD plasma treatment has considerably improved the electrostatic charge acquired by the polymers during electrostatic tribo-charging, while longer exposures conferred the polymer anti-static properties and decreased its tribo-charging capability. The correlation between the results of the physico-chemical analyses and the tribo-electric behavior has been discussed.

Mediator-free interaction of glucose oxidase, as model enzyme for immobilization, with Al-doped and undoped ZnO thin films laser-deposited on polycarbonate supports.

PubMed

V T K P, Fidal; Inguva, Saikumar; Krishnamurthy, Satheesh; Marsili, Enrico; Mosnier, Jean-Paul; T S, Chandra

2017-01-01

Al doped and undoped ZnO thin films were deposited by pulsed-laser deposition on polycarbonate sheets. The films were characterized by optical transmission, Hall effect measurement, XRD and SEM. Optical transmission and surface reflectometry studies showed good transparency with thicknesses ∼100nm and surface roughness of 10nm. Hall effect measurements showed that the sheet carrier concentration was -1.44×10 15 cm -2 for AZO and -6×10 14 cm -2 for ZnO. The films were then modified by drop-casting glucose oxidase (GOx) without the use of any mediators. Higher protein concentration was observed on ZnO as compared to AZO with higher specific activity for ZnO (0.042Umg -1 ) compared to AZO (0.032Umg -1 ), and was in agreement with cyclic voltemmetry (CV). X-ray photoelectron spectroscopy (XPS) suggested that the protein was bound by dipole interactions between AZO lattice oxygen and the amino group of the enzyme. Chronoamperometry showed sensitivity of 5.5μAmM -1 cm -2 towards glucose for GOx/AZO and 2.2μAmM -1 cm -2 for GOx/ZnO. The limit of detection (LoD) was 167μM of glucose for GOx/AZO, as compared to 360μM for GOx/ZnO. The linearity was 0.28-28mM for GOx/AZO whereas it was 0.6-28mM for GOx/ZnO with a response time of 10s. Possibly due to higher enzyme loading, the decrease of impedance in presence of glucose was larger for GOx/ZnO as compared to GOx/AZO in electrochemical impedance spectroscopy (EIS). Analyses with clinical blood serum samples showed that the systems had good reproducibility and accuracy. The characteristics of novel ZnO and AZO thin films with GOx as a model enzyme, should prove useful for the future fabrication of inexpensive, highly sensitive, disposable electrochemical biosensors for high throughput diagnostics. Copyright © 2016 Elsevier Inc. All rights reserved.

Applications of metal nanoparticles in environmental cleanup

EPA Science Inventory

Iron nanoparticles (INPs) are one of the fastest-developing fields. INPs have a number of key physicochemical properties, such as high surface area, reactivity, optical and magnetic properties, and oxidation and reduction capacities, that make them attractive for water purificati...

Consumption of Fresh Yellow Onion Ameliorates Hyperglycemia and Insulin Resistance in Breast Cancer Patients During Doxorubicin-Based Chemotherapy: A Randomized Controlled Clinical Trial.

PubMed

Jafarpour-Sadegh, Farnaz; Montazeri, Vahid; Adili, Ali; Esfehani, Ali; Rashidi, Mohammad-Reza; Pirouzpanah, Saeed

2017-09-01

Doxorubicin has been found to be associated with insulin resistance in animal models. Onion, a so-called functional food, is noted to affect the insulin signaling pathway of diabetes in vitro. To our knowledge, this is the first study to investigate the effects of consuming fresh yellow onions on insulin-related indices compared with a low-onion-containing diet among breast cancer (BC) patients treated with doxorubicin. This parallel-design, randomized, triple-blind, controlled clinical trial was conducted on 56 eligible BC patients (aged 30-63 years), diagnosed with invasive ductal carcinoma. Following their second cycle of chemotherapy, subjects were assigned in a stratified-random allocation to receive body mass index-dependent 100 to 160 g/d of onion as high onion group (HO; n = 28) or 30 to 40 g/d small onions in low onion group (LO; n = 28) for 8 weeks intervention. Participants, care givers, and those who assessed laboratory analyses were blinded to the assignments (IRCT Registry No.: IRCT2012103111335N1). The compliance level of participants in the analysis was as high as 87.85%. A total of 23 available cases was analyzed in each group. The daily use of HO resulted in a significant decrease in serum fasting blood glucose and insulin levels in comparison with LO, over the period of study ( P < .001). Posttreatment with HO showed a significant decrease in homeostasis model of assessment-insulin resistance relative to changes in the LO group ( P < .05). A comparison of the changes that occurred throughout pre- and postdose treatments indicated improved quantitative insulin sensitivity check index ( P < .05) and controls on C-peptide in the HO group ( P < .05). The present study demonstrated the effectiveness of onion to ameliorate hyperglycemia and insulin resistance in BC during doxorubicin-based chemotherapy.

Consumption of Fresh Yellow Onion Ameliorates Hyperglycemia and Insulin Resistance in Breast Cancer Patients During Doxorubicin-Based Chemotherapy: A Randomized Controlled Clinical Trial

PubMed Central

Jafarpour-Sadegh, Farnaz; Montazeri, Vahid; Adili, Ali; Esfehani, Ali; Rashidi, Mohammad-Reza; Pirouzpanah, Saeed

2016-01-01

Purpose. Doxorubicin has been found to be associated with insulin resistance in animal models. Onion, a so-called functional food, is noted to affect the insulin signaling pathway of diabetes in vitro. To our knowledge, this is the first study to investigate the effects of consuming fresh yellow onions on insulin-related indices compared with a low–onion-containing diet among breast cancer (BC) patients treated with doxorubicin. Methods. This parallel-design, randomized, triple-blind, controlled clinical trial was conducted on 56 eligible BC patients (aged 30-63 years), diagnosed with invasive ductal carcinoma. Following their second cycle of chemotherapy, subjects were assigned in a stratified-random allocation to receive body mass index–dependent 100 to 160 g/d of onion as high onion group (HO; n = 28) or 30 to 40 g/d small onions in low onion group (LO; n = 28) for 8 weeks intervention. Participants, care givers, and those who assessed laboratory analyses were blinded to the assignments (IRCT Registry No.: IRCT2012103111335N1). Results. The compliance level of participants in the analysis was as high as 87.85%. A total of 23 available cases was analyzed in each group. The daily use of HO resulted in a significant decrease in serum fasting blood glucose and insulin levels in comparison with LO, over the period of study (P < .001). Posttreatment with HO showed a significant decrease in homeostasis model of assessment-insulin resistance relative to changes in the LO group (P < .05). A comparison of the changes that occurred throughout pre- and postdose treatments indicated improved quantitative insulin sensitivity check index (P < .05) and controls on C-peptide in the HO group (P < .05). Conclusions. The present study demonstrated the effectiveness of onion to ameliorate hyperglycemia and insulin resistance in BC during doxorubicin-based chemotherapy. PMID:27352956

A lunar transportation system

NASA Technical Reports Server (NTRS)

1986-01-01

Due to large amounts of oxygen required for space travel, a method of mining, transporting, and storing this oxygen in space would facilitate further space exploration. The following project deals specifically with the methods for transporting liquid oxygen from the lunar surface to the Lunar Orbit (LO) space station, and then to the Lower Earth Orbit (LEO) space station. Two vehicles were designed for operation between the LEO and LO space stations. The first of these vehicles is an aerobraked design vehicle. The Aerobrake Orbital Transfer Vehicle (OTV) is capable of transporting 5000 lbm of payload to LO while returning to LEO with 60,000 lbm of liquid oxygen, and thus meet mission requirements. The second vehicle can deliver 18,000 lbm of payload to LO and is capable of bringing 60,000 lbm of liquid oxygen back to LEO. A lunar landing vehicle was also designed for operation between LO and the established moon base. The use of an electromagnetic railgun as a method for launching the lunar lander was also investigated. The feasibility of the railgun is doubtful at this time. A system of spheres was also designed for proper storing and transporting of the liquid oxygen. The system assumes a safe means for transferring the liquid oxygen from tank to tank is operational. A sophisticated life support system was developed for both the OTV and the lunar lander. This system focuses on such factors as the vehicle environment, waste management, water requirements, food requirements, and oxygen requirements.

Chemical, Physicochemical, Nutritional, Microbiological, Sensory and Rehydration Characteristics of Instant Whole Beans (Phaseolus vulgaris)

PubMed Central

Ibarra-Zavala, Silvia Jazmin; Ramírez-Salas, Silvia Patricia; Rosas-Ulloa, Petra; Ramírez-Ramírez, José Carmen; Ulloa-Rangel, Blanca Estela

2015-01-01

Summary Instant whole beans obtained by drying at 25 °C were evaluated for their chemical, physicochemical, nutritional, microbiological, sensory and rehydration characteristics. The proximal composition of instant whole beans was typical of this kind of food, whereas aw and L*, a* and b* values were 0.639, 98.55, –0.28 and –1.52, respectively. In instant whole beans, 75% of the essential amino acids had a value greater or equal to the reference standard for adult humans; the protein quality in terms of chemical score was 95%. Microbiological counts of aerobic mesophilic bacteria, moulds, yeasts and total coliforms of rehydrated instant whole beans were <10 CFU/g, whereas the scores for colour, flavour, texture and overall acceptability were 7.22, 7.68, 7.24 and 7.34, respectively, on a 1–9 hedonic scale. The logarithmic and Pilosof models showed close fits (R2>0.99) to the experimental data for drying of cooked beans and rehydration of instant whole beans, respectively. In the light of the chemical, physicochemical, nutritional, microbiological, sensory and rehydration characteristics of instant whole beans found in this study, drying at 25 °C is recommended for the production of such food. PMID:27904331

Monitoring and assessment of water health quality in the Tajan River, Iran using physicochemical, fish and macroinvertebrates indices.

PubMed

Aazami, Jaber; Esmaili-Sari, Abbas; Abdoli, Asghar; Sohrabi, Hormoz; Van den Brink, Paul J

2015-01-01

Nowadays, aquatic organisms are used as bio-indicators to assess ecological water quality in western regions, but have hardly been used in an Iranian context. We, therefore, evaluated the suitability of several indices to assess the water quality for an Iranian case study. Measured data on biotic (fish and macroinvertebrates) and abiotic elements (28 physicochemical and habitat parameters), were used to calculate six indices for assessment of water quality and the impact of human activities in the Tajan river, Iran. GIS, uni- and multivariate statistics were used to assess the correlations between biological and environmental endpoints. The results showed that ecological condition and water quality were reduced from up- to downstream. The reduced water quality was revealed by the biotic indices better than the abiotic ones which were linked to a variety of ecological water quality scales. The fish index showed a strong relationship with long-term database of physicochemical parameters (12 years (94%)), whereas macroinvertebrates index is more correlated with short-term data (76%). Meanwhile, the biotic and abiotic elements in this study were also classified well by PCA. Pulp and wood plants and sand mining are indicated to have the most negative effects on the river ecosystem.

Beef heifer growth and reproductive performance following two levels of pasture allowance during the fall grazing period.

PubMed

Bailey, B L; Griggs, T C; Rayburn, E B; Krause, K M

2014-08-01

The objective of this study was to compare heifer growth and reproductive performance following 2 levels of stockpiled fall forage allowance of orchardgrass (30.5%) and tall fescue (14.1%). Spring-born heifers (n = 203 and BW = 246 ± 28.9 kg) of primarily Angus background were allocated to 2 grazing treatments during the fall period (November 12 to December 17 in yr 1, November 7 to January 4 in yr 2, and November 7 to January 14 in yr 3) each replicated 3 times per year for 3 yr. Treatments consisted of daily pasture DM allowance of 3.5% of BW (LO) or daily pasture DM allowance of 7.0% of BW (HI) under strip-grazing management. Throughout the winter feeding period, mixed grass-legume haylage and soybean hulls were fed. Heifers were grazed as 1 group under continuous stocking after the winter period. Heifers in the LO group gained less than heifers in the HI group during the fall grazing period (0.12 vs. 0.40 kg/d; P < 0.0001). For each 1 10 g increase in NDF/kg fall pasture (DM basis), fall ADG decreased 0.14 kg (P = 0.01). During winter feeding, ADG was 0.30 and 0.39 kg/d for LO vs. HI heifers, respectively (P = 0.0008). During the spring grazing period (April 16 to May 24 in yr 1, April 22 to May 26 in yr 2, and April 5 to May 16 in yr 3), LO heifers had numerically greater ADG than HI heifers (1.38 vs. 1.30 kg/d; P = 0.64). Hip height (122.7 vs. 121.4 cm; P = 0.0055), BCS (5.8 vs. 5.6; P = 0.0057), and BW (356 vs. 335 kg; P < 0.0001) at the end of spring grazing was greater for HI than LO heifers. Heifers in the LO group compensated with greater summer ADG than heifers in the HI group (0.74 vs. 0.66 kg/d; P = 0.03). Total ADG from treatment initiation (November) through pregnancy diagnosis (August) was greater for HI than LO heifers (0.61 vs. 0.55 kg/d; P < 0.001) as was BW at pregnancy diagnosis (415 vs. 402 kg; P = 0.0055). Percentage of heifers reaching puberty by the time of AI was 34% for both groups (P = 0.93). Percentage of heifers becoming pregnant to AI tended (P = 0.13) to be greater for HI (44%) than for LO heifers (32%). Fall ADG across treatment groups affected the probability of a heifer becoming pregnant by AI (P = 0.01). Percentage pregnant by natural service (61% for LO vs. 59% for HI; P = 0.80) and final pregnancy rate (74% for LO vs. 77% for HI; P = 0.61) was not different for the 2 groups. These results indicate that altering fall forage allowance may delay the majority of BW gain until late in heifer development without negatively affecting overall pregnancy rates.

User’s Guide to the SOLAR Bibliography File

DTIC Science & Technology

1974-12-30

Corporation "lO Colorado Avenue Santa Monica, California 90406 10. PROGRAM ELEMENT. PROJECT, TASK AREA i WORK UNIT NUMQCRS ARPA Order 2254... Program Code 5D30 It CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT OATF. 30 December 1974 13 NUML’EH OF PAGES 28 n MONITORING...yet been produced, its StlUCture has be» n specified and codmc ot the programs neede«! to build it nas begun. is»lhis

Generation of Food-Grade Lactococcal Starters Which Produce the Lantibiotics Lacticin 3147 and Lacticin 481

PubMed Central

O'Sullivan, Lisa; Ryan, Maire P.; Ross, R. Paul; Hill, Colin

2003-01-01

Transconjugant lactococcal starters which produce both lantibiotics lacticin 3147 and lacticin 481 were generated via conjugation of large bacteriocin-encoding plasmids. A representative of one of the resultant strains proved more effective at killing Lactobacillus fermentum and inhibiting the growth of Listeria monocytogenes LO28H than either of the single bacteriocin-producing parental strains, demonstrating the potential of these transconjugants as protection cultures for food safety applications. PMID:12788782

Foreign Military Sales: A Growing Concern. Departments of State and Defense

DTIC Science & Technology

1976-06-01

See p. 27.) --Implications of providing lo1.stical sup- port for de ~ense articles sold to foreign countries. (Seep. 28.) --Recovery of full cost ...items. we have taken exception to De - f~nse’s decision to exclude certain costs in its FMS pricing. ~ From November 1969 to December 1~75, we issued 10...Force readiness Follow-on support Recovering costs of sal~s Legislation to control growing arms sales \\ Opportunities identified by GAO for

Large scale analysis of protein-binding cavities using self-organizing maps and wavelet-based surface patches to describe functional properties, selectivity discrimination, and putative cross-reactivity.

PubMed

Kupas, Katrin; Ultsch, Alfred; Klebe, Gerhard

2008-05-15

A new method to discover similar substructures in protein binding pockets, independently of sequence and folding patterns or secondary structure elements, is introduced. The solvent-accessible surface of a binding pocket, automatically detected as a depression on the protein surface, is divided into a set of surface patches. Each surface patch is characterized by its shape as well as by its physicochemical characteristics. Wavelets defined on surfaces are used for the description of the shape, as they have the great advantage of allowing a comparison at different resolutions. The number of coefficients to describe the wavelets can be chosen with respect to the size of the considered data set. The physicochemical characteristics of the patches are described by the assignment of the exposed amino acid residues to one or more of five different properties determinant for molecular recognition. A self-organizing neural network is used to project the high-dimensional feature vectors onto a two-dimensional layer of neurons, called a map. To find similarities between the binding pockets, in both geometrical and physicochemical features, a clustering of the projected feature vector is performed using an automatic distance- and density-based clustering algorithm. The method was validated with a small training data set of 109 binding cavities originating from a set of enzymes covering 12 different EC numbers. A second test data set of 1378 binding cavities, extracted from enzymes of 13 different EC numbers, was then used to prove the discriminating power of the algorithm and to demonstrate its applicability to large scale analyses. In all cases, members of the data set with the same EC number were placed into coherent regions on the map, with small distances between them. Different EC numbers are separated by large distances between the feature vectors. A third data set comprising three subfamilies of endopeptidases is used to demonstrate the ability of the algorithm to detect similar substructures between functionally related active sites. The algorithm can also be used to predict the function of novel proteins not considered in training data set. 2007 Wiley-Liss, Inc.

Native and Reconstituted Plasma Lipoproteins in Nanomedicine: Physicochemical Determinants of Nanoparticle Structure, Stability, and Metabolism

PubMed Central

Pownall, Henry J.; Rosales, Corina; Gillard, Baiba K.; Ferrari, Mauro

2016-01-01

Although many acute and chronic diseases are managed via pharmacological means, challenges remain regarding appropriate drug targeting and maintenance of therapeutic levels within target tissues. Advances in nanotechnology will overcome these challenges through the development of lipidic particles, including liposomes, lipoproteins, and reconstituted high-density lipoproteins (rHDL) that are potential carriers of water-soluble, hydrophobic, and amphiphilic molecules. Herein we summarize the properties of human plasma lipoproteins and rHDL, identify the physicochemical determinants of lipid transfer between phospholipid surfaces, and discuss strategies for increasing the plasma half-life of lipoprotein- and liposome-associated molecules. PMID:27826368

Measuring Low-PRF Pulsed Signals with a Standard HP 8510B Vector Network Analyzer Within Milliseconds (Het Meten van Lage-PRF Gepulste Signalen met een Standaard HP 8510B Vector Network Analyzer Binnen Enkele Milliseconden)

DTIC Science & Technology

1990-08-01

reference signal 25 5 A METHOD FOR MEASURING LOW-PRF PULSED SIGNALS 28 5.1 Using a NWA with a smaller BPF 28 5.2 Using the HP 8510B external trigger...2nd LO 11Q 3MHz BPF lOkHz BPF Fig. 4: Receiver block diagram The receiver is a double conversion superheterodyne with a 10 kHz wide BandPass Filter... BPF ) in the second IF. This 10 kHz filter is the component that dictates how the HP 8510B responds to pulsed signals. For the pulsed-RF test signal

A zeta potential value determines the aggregate's size of penta-substituted [60]fullerene derivatives in aqueous suspension whereas positive charge is required for toxicity against bacterial cells.

PubMed

Deryabin, Dmitry G; Efremova, Ludmila V; Vasilchenko, Alexey S; Saidakova, Evgeniya V; Sizova, Elena A; Troshin, Pavel A; Zhilenkov, Alexander V; Khakina, Ekaterina A; Khakina, Ekaterina E

2015-08-08

The cause-effect relationships between physicochemical properties of amphiphilic [60]fullerene derivatives and their toxicity against bacterial cells have not yet been clarified. In this study, we report how the differences in the chemical structure of organic addends in 10 originally synthesized penta-substituted [60]fullerene derivatives modulate their zeta potential and aggregate's size in salt-free and salt-added aqueous suspensions as well as how these physicochemical characteristics affect the bioenergetics of freshwater Escherichia coli and marine Photobacterium phosphoreum bacteria. Dynamic light scattering, laser Doppler micro-electrophoresis, agarose gel electrophoresis, atomic force microscopy, and bioluminescence inhibition assay were used to characterize the fullerene aggregation behavior in aqueous solution and their interaction with the bacterial cell surface, following zeta potential changes and toxic effects. Dynamic light scattering results indicated the formation of self-assembled [60]fullerene aggregates in aqueous suspensions. The measurement of the zeta potential of the particles revealed that they have different surface charges. The relationship between these physicochemical characteristics was presented as an exponential regression that correctly described the dependence of the aggregate's size of penta-substituted [60]fullerene derivatives in salt-free aqueous suspension from zeta potential value. The prevalence of DLVO-related effects was shown in salt-added aqueous suspension that decreased zeta potential values and affected the aggregation of [60]fullerene derivatives expressed differently for individual compounds. A bioluminescence inhibition assay demonstrated that the toxic effect of [60]fullerene derivatives against E. coli cells was strictly determined by their positive zeta potential charge value being weakened against P. phosphoreum cells in an aquatic system of high salinity. Atomic force microscopy data suggested that the activity of positively charged [60]fullerene derivatives against bacterial cells required their direct interaction. The following zeta potential inversion on the bacterial cells surface was observed as an early stage of toxicity mechanism that violates the membrane-associated energetic functions. The novel data about interrelations between physicochemical parameters and toxic properties of amphiphilic [60]fullerene derivatives make possible predicting their behavior in aquatic environment and their activity against bacterial cells.

STS-133/ET-137 Tanking Test Photogrammetry Assessment

NASA Technical Reports Server (NTRS)

Oliver, Stanley T.

2012-01-01

Following the launch scrub of Space Shuttle mission STS-133 on November 5, 2010, an anomalous condition of cracked and raised thermal protection system (TPS) foam was observed on the External Tank (ET). Subsequent dissection of the affected TPS region revealed cracks in the feet of two Intertank (IT) metallic stringers. An extensive investigation into the cause(s) and corrective action(s) for the cracked stringers was initiated, involving a wide array of material and structural tests and nondestructive evaluations, with the intent to culminate into the development of flight rational. One such structural test was the instrumented tanking test performed on December 17, 2010. The tanking test incorporated two three-dimensional optical displacement measurement systems to measure full-field outer surface displacements of the TPS surrounding the affected region that contained the stringer cracks. The results showed that the radial displacement and rotation of the liquid oxygen (LO2) tank flange changed significantly as the fluid level of the LO2 approached and passed the LO2 tank flange.

Temperature effect on the coupling between coherent longitudinal phonons and plasmons in n -type and p -type GaAs

NASA Astrophysics Data System (ADS)

Hu, Jianbo; Zhang, Hang; Sun, Yi; Misochko, Oleg V.; Nakamura, Kazutaka G.

2018-04-01

The coupling between longitudinal optical (LO) phonons and plasmons plays a fundamental role in determining the performance of doped semiconductor devices. In this work, we report a comparative investigation into the dependence of the coupling on temperature and doping in n - and p -type GaAs by using ultrafast coherent phonon spectroscopy. A suppression of coherent oscillations has been observed in p -type GaAs at lower temperature, strikingly different from n -type GaAs and other materials in which coherent oscillations are strongly enhanced by cooling. We attribute this unexpected observation to a cooling-induced elongation of the depth of the depletion layer which effectively increases the screening time of the surface field due to a slow diffusion of photoexcited carriers in p -type GaAs. Such an increase breaks the requirement for the generation of coherent LO phonons and, in turn, LO phonon-plasmon coupled modes because of their delayed formation in time.

Effects of multi-walled carbon nanotube materials on Ruditapes philippinarum under climate change: The case of salinity shifts.

PubMed

De Marchi, Lucia; Neto, Victor; Pretti, Carlo; Figueira, Etelvina; Chiellini, Federica; Morelli, Andrea; Soares, Amadeu M V M; Freitas, Rosa

2018-06-01

The toxicity of carbon nanotubes (CNTs) is closely related to their physico-chemical characteristics as well as the physico-chemical parameters of the media where CNTs are dispersed. In a climate change scenario, changes in seawater salinity are becoming a topic of concern particularly in estuarine and coastal areas. Nevertheless, to our knowledge no information is available on how salinity shifts may alter the sensitivity (in terms of biochemical responses) of bivalves when exposed to different CNTs. For this reason, a laboratory experiment was performed exposing the Manila clam Ruditapes philippinarum, one of the most dominant bivalves of the estuarine and coastal lagoon environments, for 28 days to unfunctionalized multi-walled carbon nanotube MWCNTs (Nf-MWCNTs) and carboxylated MWCNTs (f-MWCNTs), maintained at control salinity (28) and low salinity 21. Concentration-dependent toxicity was demonstrated in individuals exposed to both MWCNT materials and under both salinities, generating alterations of energy reserves and metabolism, oxidative status and neurotoxicity compared to non-contaminated clams. Moreover, our results showed greater toxic impacts induced in clams exposed to f-MWCNTs compared to Nf-MWCNTs. In the present study it was also demonstrated how salinity shifts altered the toxicity of both MWCNT materials as well as the sensitivity of R. philippinarum exposed to these contaminates in terms of clam metabolism, oxidative status and neurotoxicity. Copyright © 2018 Elsevier B.V. All rights reserved.

Effect of corona discharge plasma jet on surface-borne microorganisms and sprouting of broccoli seeds.

PubMed

Kim, Je-Wook; Puligundla, Pradeep; Mok, Chulkyoon

2017-01-01

Different pathogenic microorganisms have been reported to cause sprouts-associated outbreaks. In order to sterilise and enhance the germination of seeds, non-thermal plasma has been increasingly investigated in the field of agricultural science as an alternative to the traditional pre-sowing seed treatments. This work aimed to evaluate the effect of corona discharge plasma jet (CDPJ) on disinfection of the natural bio-contaminants of broccoli seed and also studied the plasma effect on sprout seed germination rate and physico-chemical properties of sprouts. Aerobic bacteria, moulds and yeasts, B. cereus, E. coli, Salmonella spp. were detected on the broccoli seed surface. After 0-3 min treatment using CDPJ, the detected microorganisms were reduced in the range of 1.2-2.3 log units. Inactivation patterns were better explained using pseudo-first-order kinetics. The plasma treatment of seeds up to 2 min exhibited a positive effect on germination rate, seedling growth. The physico-chemical and sensory characteristics of sprouts were unaffected due to the CDPJ treatment of their respective seeds. Corona discharge plasma jet can potentially be used for microbial decontamination of broccoli seeds. In addition, the plasma treatment of broccoli sprout seeds has enabled a significant enhancement in their germination rate and seedling growth without compromising physico-chemical and sensory characteristics of their corresponding sprouts. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Physico-Chemical Conversion of Lignocellulose: Inhibitor Effects and Detoxification Strategies: A Mini Review.

PubMed

Kim, Daehwan

2018-02-01

A pretreatment of lignocellulosic biomass to produce biofuels, polymers, and other chemicals plays a vital role in the biochemical conversion process toward disrupting the closely associated structures of the cellulose-hemicellulose-lignin molecules. Various pretreatment steps alter the chemical/physical structure of lignocellulosic materials by solubilizing hemicellulose and/or lignin, decreasing the particle sizes of substrate and the crystalline portions of cellulose, and increasing the surface area of biomass. These modifications enhance the hydrolysis of cellulose by increasing accessibilities of acids or enzymes onto the surface of cellulose. However, lignocellulose-derived byproducts, which can inhibit and/or deactivate enzyme and microbial biocatalysts, are formed, including furan derivatives, lignin-derived phenolics, and carboxylic acids. These generation of compounds during pretreatment with inhibitory effects can lead to negative effects on subsequent steps in sugar flat-form processes. A number of physico-chemical pretreatment methods such as steam explosion, ammonia fiber explosion (AFEX), and liquid hot water (LHW) have been suggested and developed for minimizing formation of inhibitory compounds and alleviating their effects on ethanol production processes. This work reviews the physico-chemical pretreatment methods used for various biomass sources, formation of lignocellulose-derived inhibitors, and their contributions to enzymatic hydrolysis and microbial activities. Furthermore, we provide an overview of the current strategies to alleviate inhibitory compounds present in the hydrolysates or slurries.

A new microcolumn flotation cell for determining the wettability and floatability of minerals.

PubMed

Ozkan, A; Yekeler, M

2003-05-15

Flotation is one of the most important physicochemical processes for mineral separations and other recovery operations. Flotation machines have been developed since the beginning of the 19th century and are still under intensive research and development. The cell we devised is a combination of the Canadian column flotation cell and the Partridge-Smith cell. The materials used for the construction of the new cell are cheap and use available laboratory accessories and aquarium materials. The cell functions well in terms of its scale, control, and sample requirement. It can be used both in the laboratory for research and in classrooms for demonstrations of experiments. Some of the data obtained by the flotation method using this cell are in good agreement with data measured independently on the same minerals by the contact angles method. The critical values of surface tension of wetting (gamma(c)) for talc, sulfur, and chemically treated surfaces of calcite and barite obtained by the contact angle measurements were 31, 26, 30.5, and 31.2 mN/m, respectively. On the other hand, the gamma(c) values of those minerals, obtained using our new designed flotation cell, were 30, 28, 31.4, and 34.5 mN/m, respectively. The measurements obtained in our experiment are also comparable to those previously published for the same minerals.

Origins of life and biochemistry under high-pressure conditions.

PubMed

Daniel, Isabelle; Oger, Philippe; Winter, Roland

2006-10-01

Life on Earth can be traced back to as far as 3.8 billion years (Ga) ago. The catastrophic meteoritic bombardment ended between 4.2 and 3.9 Ga ago. Therefore, if life emerged, and we know it did, it must have emerged from nothingness in less than 400 million years. The most recent scenarios of Earth accretion predict some very unstable physico-chemical conditions at the surface of Earth, which, in such a short time period, would impede the emergence of life from a proto-biotic soup. A possible alternative would be that life originated in the depth of the proto-ocean of the Hadean Earth, under high hydrostatic pressure. The large body of water would filter harmful radiation and buffer physico-chemical variations, and therefore would provide a more stable radiation-free environment for pre-biotic chemistry. After a short introduction to Earth history, the current tutorial review presents biological and physico-chemical arguments in support of high-pressure origin for life on Earth.

Physicochemical properties and in vitro digestibility of sorghum starch altered by high hydrostatic pressure.

PubMed

Liu, Hang; Fan, Huanhuan; Cao, Rong; Blanchard, Christopher; Wang, Min

2016-11-01

A nonthermal processing technology, high hydrostatic pressure (HHP) treatment, was investigated to assess its influence on the physicochemical properties and in vitro digestibility of sorghum starch (SS). There was no change in the 'A'-type crystalline pattern of SS after the pressure treatments at 120-480MPa. However, treatment at 600MPa produced a pattern similar to 'B'-type crystalline. HHP treatment also resulted in SS granules with rough surfaces. Measured amylose content, water absorption capacity, alkaline water retention, pasting temperature and thermostability increased with increasing pressure levels, while the oil absorption capacity, swelling power, relative crystallinity and viscosity decreased. Compared with native starch, HHP-modified SS samples had lower in vitro hydrolysis, reduced amount of rapidly digestible starch, as well as increased levels of slowly digestible starch and resistant starch. These results indicate that HHP treatment is an effective modification method for altering in vitro digestibility and physicochemical properties of SS. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of high hydrostatic pressure and retrogradation treatments on structural and physicochemical properties of waxy wheat starch.

PubMed

Hu, Xiao-Pei; Zhang, Bao; Jin, Zheng-Yu; Xu, Xue-Ming; Chen, Han-Qing

2017-10-01

In this study, the effects of high hydrostatic pressure and retrogradation (HHPR) treatments on in vitro digestibility, structural and physicochemical properties of waxy wheat starch were investigated. The waxy wheat starch slurries (10%, w/v) were treated with high hydrostatic pressures of 300, 400, 500, 600MPa at 20°C for 30min, respectively, and then retrograded at 4°C for 4d. The results indicated that the content of slowly digestible starch (SDS) in HHPR-treated starch samples increased with increasing pressure level, and it reached the maximum (31.12%) at 600MPa. HHPR treatment decreased the gelatinization temperatures, the gelatinization enthalpy, the relative crystallinity and the peak viscosity of the starch samples. Moreover, HHPR treatment destroyed the surface and interior structures of starch granules. These results suggest that the in vitro digestibility, physicochemical, and structural properties of waxy wheat starch are effectively modified by HHPR. Copyright © 2017 Elsevier Ltd. All rights reserved.

Physicochemical Drivers of Microbial Community Structure in Sediments of Lake Hazen, Nunavut, Canada.

PubMed

Ruuskanen, Matti O; St Pierre, Kyra A; St Louis, Vincent L; Aris-Brosou, Stéphane; Poulain, Alexandre J

2018-01-01

The Arctic is undergoing rapid environmental change, potentially affecting the physicochemical constraints of microbial communities that play a large role in both carbon and nutrient cycling in lacustrine environments. However, the microbial communities in such Arctic environments have seldom been studied, and the drivers of their composition are poorly characterized. To address these gaps, we surveyed the biologically active surface sediments in Lake Hazen, the largest lake by volume north of the Arctic Circle, and a small lake and shoreline pond in its watershed. High-throughput amplicon sequencing of the 16S rRNA gene uncovered a community dominated by Proteobacteria, Bacteroidetes, and Chloroflexi, similar to those found in other cold and oligotrophic lake sediments. We also show that the microbial community structure in this Arctic polar desert is shaped by pH and redox gradients. This study lays the groundwork for predicting how sediment microbial communities in the Arctic could respond as climate change proceeds to alter their physicochemical constraints.

Fiber orientation measurements by diffusion tensor imaging improve hydrogen-1 magnetic resonance spectroscopy of intramyocellular lipids in human leg muscles

PubMed Central

Valaparla, Sunil K.; Gao, Feng; Daniele, Giuseppe; Abdul-Ghani, Muhammad; Clarke, Geoffrey D.

2015-01-01

Abstract. Twelve healthy subjects underwent hydrogen-1 magnetic resonance spectroscopy (H1-MRS) acquisition (15×15×15  mm3), diffusion tensor imaging (DTI) with a b-value of 600  s mm−2, and fat-water magnetic resonance imaging (MRI) using the Dixon method. Subject-specific muscle fiber orientation, derived from DTI, was used to estimate the lipid proton spectral chemical shift. Pennation angles were measured as 23.78 deg in vastus lateralis (VL), 17.06 deg in soleus (SO), and 8.49 deg in tibialis anterior (TA) resulting in a chemical shift between extramyocellular lipids (EMCL) and intramyocellular lipids (IMCL) of 0.15, 0.17, and 0.19 ppm, respectively. IMCL concentrations were 8.66±1.24  mmol kg−1, 6.12±0.77  mmol kg−1, and 2.33±0.19  mmol kg−1 in SO, VL, and TA, respectively. Significant differences were observed in IMCL and EMCL pairwise comparisons in SO, VL, and TA (p<0.05). Strong correlations were observed between total fat fractions from H1-MRS and Dixon MRI for VL (r=0.794), SO (r=0.655), and TA (r=0.897). Bland-Altman analysis between fat fractions (FFMRS and FFMRI) showed good agreement with small limits of agreement (LoA): bias=−0.21% (LoA: −1.12% to 0.69%) in VL, bias=0.025% (LoA: −1.28% to 1.33%) in SO, and bias=−0.13% (LoA: −0.74% to 0.47%) in TA. The results of this study demonstrate the variation in muscle fiber orientation and lipid concentrations in these three skeletal muscle types. PMID:26158115

Effect of comanagement with internal medicine on hospital stay of patients admitted to the Service of Otolaryngology.

PubMed

Montero Ruiz, Eduardo; Rebollar Merino, Ángela; Rivera Rodríguez, Teresa; García Sánchez, Marta; Agudo Alonso, Rosa; Barbero Allende, José Maria

2015-01-01

Patients admitted to the Department of Otolaryngology (ENT) are increasing in age, comorbidity and complexity, leading to increased consultations/referrals to Internal Medicine (IM). An alternative to consultations/referrals is co-management. We studied the effect of co-management on length of stay (LoS) in hospital for patients admitted to ENT. This was a retrospective observational study including patients ≥14 years old discharged from ENT between 1/1/2009 and 30/06/2013, with co-management from May/2011. We analysed age, sex, type of admission, whether the patient was operated, administrative weight associated with DRG, total number of discharge diagnoses, Charlson comorbidity index (CCI), deaths, readmissions and LoS. There were statistically significant differences between both groups in age (4.5 years; 95% confidence interval [95% CI] 2.8-6.3), emergency admissions (odds ratio [OR] 1.4; 95% CI 1.1-1.8), administrative weight (0.3637; 95% CI 0.0710-0.6564), number of diagnoses (1.3; 95% CI 1-1.6), CCI (0.4; 95% CI 0.2-0.6) and deaths (OR 4.1; 95% CI 1.1-15.7). On adjustment, co-management reduced ENT LoS in hospital by 28.6%, 0.8 days (95% CI 0.1-1.6%; P=.038). This reduction represents an ENT savings of at least €165,893. Co-management patients admitted to ENT are increasing in age, comorbidity and complexity. Co-management is associated with reduced LoS and costs in ENT, similar to those observed in other surgical services. Copyright © 2014 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

Low LBNP Tolerance in Men is Associated With Attenuated Activation of Renin-Angiotensin System

NASA Technical Reports Server (NTRS)

Greenleaf, John E.; Petersen, T. W.; Gabrielsen, A.; Pump, B.; Bie, P.; Christensen, N.-J.; Warberg, J.; Videbaeck, R.; Simonson, S. R.; Norsk, P.;

Development and Application of a New Learning Object for Teaching Operative Dentistry Using Augmented Reality.

PubMed

Espejo-Trung, Luciana Cardoso; Elian, Silvia Nagib; Luz, Maria Aparecia Alves De Cerqueira

2015-11-01

Learning objects (LOs) associated with augmented reality have been used as attractive new technologic tools in the educational process. However, the acceptance of new LOs must be verified with the purpose of using these innovations in the learning process in general. The aim of this study was to develop a new LO and investigate the acceptance of gold onlay in teaching preparation design at a dental school in Brazil. Questionnaires were designed to assess, first, the users' computational ability and knowledge of computers (Q1) and, second, the users' acceptance of the new LO (Q2). For both questionnaires, the internal consistency index was calculated to determine whether the questions were measuring the same construct. The reliability of Q2 was measured with a retest procedure. The LO was tested by dental students (n=28), professors and postgraduate students in dentistry and prosthetics (n=30), and dentists participating in a continuing education or remedial course in dentistry and/or prosthetics (n=19). Analyses of internal consistency (Kappa coefficient and Cronbach's alpha) demonstrated a high degree of confidence in the questionnaires. Tests for simple linear regressions were conducted between the response variable (Q2) and the following explanative variables: the Q1 score, age, gender, and group. The results showed wide acceptance regardless of the subjects' computational ability (p=0.99; R2=0), gender (p=0.27; R2=1.6%), age (p=0.27; R2=0.1%), or group (p=0.53; R2=1.9%). The methodology used enabled the development of an LO with a high index of acceptance for all groups.

Catalytic oxidation of 1,2-DCBz over V2O5/TiO2-CNTs: effect of CNT diameter and surface functional groups.

PubMed

Du, Cuicui; Wang, Qiulin; Peng, Yaqi; Lu, Shengyong; Ji, Longjie; Ni, Mingjiang

2017-02-01

A series of V 2 O 5 /TiO 2 -carbon nanotube (CNT) catalysts were prepared and tested to decompose gaseous 1,2-dichlorobenzene (1,2-DCBz). Several physicochemical methods, including nitrogen adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and H 2 temperature-programmed reduction (TPR) were employed to characterise their physicochemical properties. To better understand the effect of CNT properties on the reactivity of V 2 O 5 /TiO 2 -CNT catalysts, the 1,2-DCBz residue remaining in the off-gas and on the catalyst surface were both collected and analysed. The results indicate that the outer diameter and the surface functional groups (hydroxide radical and carboxyl) of CNTs significantly influence upon the catalytic activity of CNT-containing V 2 O 5 /TiO 2 catalysts: the CNT outer diameter mainly affects the aggregation of CNTs and the π-π interaction between the benzene ring and CNTs, while the introduction of -OH and -COOH groups by acid treatment can further enlarge specific surface area (SSA) and contribute to a higher average oxidation state of vanadium (V aos ) and supplemental surface chemisorbed oxygen (O ads ). In addition, the enhanced mobility of lattice oxygen (O latt) also improves the oxidation ability of the catalysts.

Physicochemical properties and biodegradability of organically functionalized colloidal silica particles in aqueous environment.

PubMed

Schneider, Mandy; Meder, Fabian; Haiß, Annette; Treccani, Laura; Rezwan, Kurosch; Kümmerer, Klaus

2014-03-01

Engineered sub-micron particles are being used in many technical applications, leading to an increasing introduction into the aquatic environment. Only a few studies have dealt with the biodegradability of non-functionalized organic particles. In fact the knowledge of organically surface functionalized colloids is nearly non-existent. We have investigated the biodegradability of organically surface functionalized silica (SiO2) particles bearing technically relevant groups such as amino-, carboxyl-, benzyl-, sulfonate-, chloro-, and phosphatoethyl-derivatized alkyls. Essential physicochemical properties including zeta potential, isoelectric point, morphology, surface area, porosity, surface density, and elemental composition of the particles were investigated, followed by biodegradability testing using the Closed Bottle Test (OECD 301D). None of the particles met the biodegradability threshold value of 60%. Only a slight biodegradation was revealed for SiO2-Benzyl (13.7±6.7%) and for SiO2-3-Chlorpropane (10.8±1.5%). For the other particles biodegradability was below the normal background fluctuation of 5%. The results were different of those obtained from structurally similar chemicals not being functionalized on the particle surface and from general rules of structure-biodegradation prediction of organic molecules. Therefore, our results suggest that the attachment of the organic groups heavily reduces their biodegradability, increases their residence time and possibility for adverse effects to environmental species. Copyright © 2013 Elsevier Ltd. All rights reserved.

Urban rainwater runoff quantity and quality - A potential endogenous resource in cities?

PubMed

Angrill, Sara; Petit-Boix, Anna; Morales-Pinzón, Tito; Josa, Alejandro; Rieradevall, Joan; Gabarrell, Xavier

2017-03-15

Rainwater harvesting might help to achieve self-sufficiency, but it must comply with health standards. We studied the runoff quantity and quality harvested from seven urban surfaces in a university campus in Barcelona according to their use (pedestrian or motorized mobility) and materials (concrete, asphalt and slabs). An experimental rainwater harvesting system was used to collect the runoff resulting from a set of rainfall events. We estimated the runoff coefficient and initial abstraction of each surface and analyzed the physicochemical and microbiological properties, and hydrocarbon and metal content of the samples. Rainfall intensity, surface material and state of conservation were essential parameters. Because of low rainfall intensity and surface degradation, the runoff coefficient was variable, with a minimum of 0.41. Concrete had the best quality, whereas weathering and particulate matter deposition led to worse quality in asphalt areas. Physicochemical runoff quality was outstanding when compared to superficial and underground water. Microorganisms were identified in the samples (>1 CFU/100 mL) and treatment is required to meet human consumption standards. Motorized traffic mostly affects the presence of metals such as zinc (31.7 μg/L). In the future, sustainable mobility patterns might result in improved rainwater quality standards. Copyright © 2016 Elsevier Ltd. All rights reserved.

Electroosmotic flow and ionic conductance in a pH-regulated rectangular nanochannel

NASA Astrophysics Data System (ADS)

Sadeghi, Morteza; Saidi, Mohammad Hassan; Sadeghi, Arman

2017-06-01

Infinite series solutions are obtained for electrical potential, electroosmotic velocity, ionic conductance, and surface physicochemical properties of long pH-regulated rectangular nanochannels of low surface potential utilizing the double finite Fourier transform method. Closed form expressions are also obtained for channels of large height to width ratio for which the depthwise variations vanish. Neglecting the Stern layer impact, the effects of EDL (Electric Double Layer) overlap, multiple ionic species, and association/dissociation reactions on the surface are all taken into account. Moreover, finite-element-based numerical simulations are conducted to account for the end effects as well as to validate the analytical solutions. We show that, with the exception of the migratory ionic conductivity, all the physicochemical parameters are strong functions of the channel aspect ratio. Accordingly, a slit geometry is not a good representative of a rectangular channel when the width is comparable to the height. It is also observed that the distribution of the electrical potential is not uniform over the surface of a charge-regulated channel. In addition, unlike ordinary channels for which an increase in the background salt concentration is always accompanied by higher flow rates, quite the opposite may be true for a pH-regulated duct at higher salt concentrations.

Spatial and temporal assessment of surface water quality in the Arka River, Akkar, Lebanon.

PubMed

Daou, Claude; Nabbout, Rony; Kassouf, Amine

2016-12-01

Surface water quality monitoring constitutes a crucial and important step in any water quality management system. Twenty-three physicochemical and microbiological parameters were assessed in surface water samples collected from the Arka River located in the Akkar District, north of Lebanon. Eight sampling locations were considered along the river and seven sampling campaigns were performed in order to evaluate spatial and temporal influences. The extraction of relevant information from this relatively large data set was done using principal component analysis (PCA), being a very well established chemometric tool in this field. In a first step, extracted PCA loadings revealed the implication of several physicochemical parameters in the discriminations and trends highlighted by PCA scores, mainly due to soil leaching and seawater intrusion. However, further investigations showed the implication of organic and bacterial parameters in the discrimination of stations in the Akkar flatland. These discriminations probably refer to anthropogenic pollution coming from the agricultural area and the surrounding villages. Specific ultraviolet absorption (SUVA) indices confirmed these findings since values decreased for samples collected across the villages and the flatland, indicating an increase in anthropogenic dissolved organic matter. This study will hopefully help the national and local authorities to ameliorate the surface water quality management, enabling its proper use for irrigation purposes.

On the nature of cavities on protein surfaces: application to the identification of drug-binding sites.

PubMed

Nayal, Murad; Honig, Barry

2006-06-01

In this article we introduce a new method for the identification and the accurate characterization of protein surface cavities. The method is encoded in the program SCREEN (Surface Cavity REcognition and EvaluatioN). As a first test of the utility of our approach we used SCREEN to locate and analyze the surface cavities of a nonredundant set of 99 proteins cocrystallized with drugs. We find that this set of proteins has on average about 14 distinct cavities per protein. In all cases, a drug is bound at one (and sometimes more than one) of these cavities. Using cavity size alone as a criterion for predicting drug-binding sites yields a high balanced error rate of 15.7%, with only 71.7% coverage. Here we characterize each surface cavity by computing a comprehensive set of 408 physicochemical, structural, and geometric attributes. By applying modern machine learning techniques (Random Forests) we were able to develop a classifier that can identify drug-binding cavities with a balanced error rate of 7.2% and coverage of 88.9%. Only 18 of the 408 cavity attributes had a statistically significant role in the prediction. Of these 18 important attributes, almost all involved size and shape rather than physicochemical properties of the surface cavity. The implications of these results are discussed. A SCREEN Web server is available at http://interface.bioc.columbia.edu/screen. 2006 Wiley-Liss, Inc.

[Studies on triterpenoid saponins in the rhizome of Anemone flaccida].

PubMed

Han, Lin-Tao; Huang, Fang

2009-07-01

To study the triterpenoid saponins in the rhizome of Anemone flaccida. The constituents were separated with various chromatographic techniques and their structures were elucidated by means of physicochemical properties and the analysis of their spectral datas. Five compounds were isolated and identified as 3-O-beta-D-glucuronypyranosyl-oleanolic acid-28-O-alpha-L-rhamnopyranosyl (1 --> 4)-beta-D-glucopyranosyl(1 --> 6)-beta-D-glucopyra noside (1), 3-O-beta-D-glucuronypyranosyl-oleanolic acid-28-O-beta-D-glucopyranosyl (1 --> 6)-beta-D-glucopyranoside (2), 3-O-alpha-L-rhamnopyranosy (1 --> 2)-beta-D-glucopyranosyl-oleanolic acid-28-O-alpha-L-rhamnopyranosyl (1 --> 4)-beta-D-glucopyranosyl (1 --> 6)-beta-D-glucopyranoside (3), 3-O-alpha-L-rhamnopyranosyl (1 --> 2)-alpha-L-arabinopyrano-syl-oleanolic acid-28-O-alpha-L-rhamnopyranosyl (1 -->4)-beta-D-glucopyranosyl (1 --> 6)-beta-D-glucopyranoside (4), 3-O-alpha-L-rhamnopyranosyl (1 --> 2)-beta-D-xylopyranosyl-oleanolic acid-28-O-alpha-L-rhamnopyranosyl (1 --> 4)-beta-D-glucopyranosyl (1 --> 6)-beta-D-glucopyranoside (5). Compound 1 - 4 are isolated from this plant for the first time. Compound 1,2 are isolated from this genus for the first time.

New polyacetylenes glycoside from Eclipta prostrate with DGAT inhibitory activity.

PubMed

Meng, Xiao; Li, Ban-Ban; Lin, Xin; Jiang, Yi-Yu; Zhang, Le; Li, Hao-Ze; Cui, Long

2018-06-08

One new polyacetylene glycoside eprostrata Ⅰ (1), together with seven known compounds (2-8), were isolated from Eclipta prostrata. Their structures were elucidated on the basis of spectroscopic and physico-chemical analyses. All the isolates were evaluated inhibitory activity on DGAT in an in vitro assay. Compounds 1-8 were found to exhibit inhibitory activity of DGAT1 with IC 50 values ranging from 74.4 ± 1.3 to 101.1 ± 1.1 μM.

Reproducibility of the measurement of central corneal thickness in healthy subjects obtained with the optical low coherence reflectometry pachymeter and comparison with the ultrasonic pachymetry.

PubMed

Garza-Leon, Manuel; Plancarte-Lozano, Eduardo; Valle-Penella, Agustín Del; Guzmán-Martínez, María de Lourdes; Villarreal-González, Andrés

2018-01-01

Corneal pachymetry is widely used for refractive surgery and follow up in keratoconus, accurate measurement is essential for a safe surgery. To assess intraobserver reliability of central corneal thickness (CCT) measurements using optical low-coherence reflectometry (OLCR) technology and its agreement with ultrasonic pachymeter (US). Randomized and prospective comparative evaluation of diagnostic technology. One randomly healthy eye of subjects was scanned three times with both devices. Intraobserver within-subject standard deviation (Sw), coefficient of variation (CVw) and intraclass correlation coefficient (ICC) were obtained for reliability analysis; for study agreement, data were analyzed using the paired-sample t test and the Bland-Altman LoA method. The mean of three scans of each equipment was used to assess the LoA. The study enrolled 30 eyes of 30 subjects with average age of 28.70 ± 8.06 years. For repeatability, the Sw were 3.41 and 5.96 µ, the intraobserver CVw was 2 and 4% and ICC 0.991 and 0.988, for OLCR and US respectively. The mean CCT difference between OLCR and US was 8.90 ± 9.03 µ (95% confidence interval: 5.52-2.27 µ), and the LoA was 35.40 µ. OLCR technology provided reliable intraobserver CCT measurements. Both pachymetry measurements may be used interchangeably with minimum calibration adjustment. Copyright: © 2018 Permanyer.

Effects of carbohydrate availability on sustained shivering I. Oxidation of plasma glucose, muscle glycogen, and proteins.

PubMed

Haman, François; Peronnet, François; Kenny, Glen P; Doucet, Eric; Massicotte, Denis; Lavoie, Carole; Weber, Jean-Michel

2004-01-01

Carbohydrates (CHO) can play an important thermogenic role during shivering, but the effect of their availability on the use of other oxidative fuels is unclear. Using indirect calorimetry and tracer methods ([U-13C]glucose ingestion), we have determined the specific contributions of plasma glucose, muscle glycogen, proteins, and lipids to total heat production (Hprod) in men exposed to cold for 2-h (liquid-conditioned suit perfused with 10 degrees C water). Measurements were made after low-CHO diet and exercise (Lo) and high-CHO diet without exercise (Hi). The size of CHO reserves had no effect on Hprod but a major impact on fuel selection before and during shivering. In the cold, a complete shift from lipid oxidation for Lo (53, 28, and 19% Hprod for lipids, CHO, and proteins, respectively) to CHO-based metabolism for Hi (23, 65, and 12% Hprod for lipids, CHO, and proteins, respectively) was observed. Plasma glucose oxidation remains a minor fuel under all conditions (<13% Hprod), falling to 7% Hprod for Lo. Therefore, adjusting plasma glucose oxidation to compensate for changes in muscle glycogen oxidation is not a strategy used for maintaining heat production. Instead, proteins and lipids share responsibility for this compensation. We conclude that humans can show remarkable flexibility in oxidative fuel selection to ensure that heat production is not compromised during sustained cold exposure.

Physical and chemical characterization of waste wood derived biochars

USDA-ARS?s Scientific Manuscript database

Biochar, a solid byproduct generated during waste biomass pyrolysis or gasification in the absence (or near-absence) of oxygen, has recently garnered interest for both agricultural and environmental management purposes owing to its unique physicochemical properties, such as its high surface area and...

Emergence of life from multicomponent mixtures of chemicals: the case for experiments with cycling physicochemical gradients.

PubMed

Spitzer, Jan

2013-04-01

The emergence of life from planetary multicomponent mixtures of chemicals is arguably the most complicated and least understood natural phenomenon. The fact that living cells are non-equilibrium systems suggests that life can emerge only from non-equilibrium chemical systems. From an astrobiological standpoint, non-equilibrium chemical systems arise naturally when solar irradiation strikes rotating surfaces of habitable planets: the resulting cycling physicochemical gradients persistently drive planetary chemistries toward "embryonic" living systems and an eventual emergence of life. To better understand the factors that lead to the emergence of life, I argue for cycling non-equilibrium experiments with multicomponent chemical systems designed to represent the evolving chemistry of Hadean Earth ("prebiotic soups"). Specifically, I suggest experimentation with chemical engineering simulators of Hadean Earth to observe and analyze (i) the appearances and phase separations of surface active and polymeric materials as precursors of the first "cell envelopes" (membranes) and (ii) the accumulations, commingling, and co-reactivity of chemicals from atmospheric, oceanic, and terrestrial locations.

Effect of micronization on the physicochemical properties of insoluble dietary fiber from citrus (Citrus junos Sieb. ex Tanaka) pomace.

PubMed

Ye, Fayin; Tao, Bingbing; Liu, Jia; Zou, Yan; Zhao, Guohua

2016-04-01

The aim of this work was to study the effect of micronization (mechanical and jet grindings) on the physicochemical properties of the insoluble dietary fiber from citrus pomace in comparison with ordinary grinding. The results showed that micronization treatment effectively pulverized the IDF-CP powders to micron scale and significantly increased the soluble dietary fiber content (p < 0.05). Compared with mechanical grinding, jet grinding was more effective in size reduction and resulted in IDF-CP powders with narrower particle size distributions. Micronized IDF-CP powders had smaller particle size, smoother surface, higher fluidity, cation-exchange capacity, and metal cation binding capacity values, but lower water holding capacity, oil holding capacity, and swelling capacity values. These functional properties were significantly dependent on surface area and particle size (D0.5). The present study suggested that micronization treatments could modify functional properties of IDF-CP powders, which promotes their use in food applications. © The Author(s) 2015.

Optimization of olive oil based O/W nanoemulsions prepared through ultrasonic homogenization: A response surface methodology approach.

PubMed

Mehmood, Tahir; Ahmad, Asif; Ahmed, Anwaar; Ahmed, Zaheer

2017-08-15

The present study was conducted to prepare co-surfactant free, olive-oil based alpha tocopherol nanoemulsions, using a food grade non-ionic surfactant. Response surface methodology (RSM) was used to determine the effects of independent variables (ultrasonic homogenization time, olive oil concentrations and surfactant contents) on different physico-chemical characteristics of O/W nanoemulsions. This study was carried out using a central composite design. The coefficients of determination were greater than 0.900 for all response variables and there were significant effects of independent variables on all responses. The optimum levels of independent variables for the preparation of nanoemulsions were 3min. ultrasonic homogenization time, 4% olive oil content and 2.08% surfactant concentration. The physico-chemical responses at these levels were 151.68nm particle size, 7.17% p-anisidine and 88.64% antioxidant activity. These results will help in design of nanoemulsions with optimum independent variables. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of precipitants on Ni-Al2O3 catalysts prepared by a co-precipitation method for internal reforming in molten carbonate fuel cells

PubMed Central

Jung, You-Shick; Yoon, Wang-Lai; Seo, Yong-Seog; Rhee, Young-Woo

2012-01-01

Ni-Al2O3 catalysts are prepared via the co-precipitation method using various precipitants: urea, Na2CO3, NaOH, K2CO3, KOH and NH4OH. The effects of the precipitants on the physicochemical properties and catalytic activities of the Ni-Al2O3 catalysts are investigated. The Ni50-urea catalyst displays the largest specific surface area and the highest pore volume. This catalyst also exhibits the highest Ni dispersion and the largest Ni surface area. Ni50-urea catalyst prepared with urea as precipitant and Ni50-K2CO3 catalyst prepared with K2CO3 as precipitant exhibit high pore volumes and good catalytic activities for methane steam reforming. The Ni50-urea catalyst exhibits the best physicochemical properties and shows good catalytic activity and a strong resistance to electrolyte contamination. PMID:22962548

Simultaneous production and co-mixing of microparticles of nevirapine with excipients by supercritical antisolvent method for dissolution enhancement.

PubMed

Sanganwar, Ganesh P; Sathigari, Sateeshkumar; Babu, R Jayachandra; Gupta, Ram B

2010-01-31

Microparticles of a poorly water-soluble model drug, nevirapine (NEV) were prepared by supercritical antisolvent (SAS) method and simultaneously deposited on the surface of excipients such as lactose and microcrystalline cellulose in a single step to reduce drug-drug particle aggregation. In the proposed method, termed supercritical antisolvent-drug excipient mixing (SAS-DEM), drug particles were precipitated in supercritical CO(2) vessel containing excipient particles in suspended state. Drug/excipient mixtures were characterized for surface morphology, crystallinity, drug-excipient physico-chemical interactions, and molecular state of drug. In addition, the drug content uniformity and dissolution rate were determined. A highly ordered NEV-excipient mixture was produced. The SAS-DEM treatment was effective in overcoming drug-drug particle aggregation and did not affect the crystallinity or physico-chemical properties of NEV. The produced drug/excipient mixture has a significantly faster dissolution rate as compared to SAS drug microparticles alone or when physically mixed with the excipients. Copyright 2009 Elsevier B.V. All rights reserved.

SEM visualization of glycosylated surface molecules using lectin-coated microspheres

NASA Technical Reports Server (NTRS)

Duke, J.; Janer, L.; Campbell, M.

1985-01-01

There are several techniques currently used to localize glycosylated surface molecules by scanning electron microscopy (Grinnell, 1980; Molday, 1976; Linthicum and Sell, 1975; Nicolson, 1974; Lo Buglio, et al, 1972). A simple and rapid method, using a modification of Grinnell's technique is reported here. Essentially, microspheres coated with Concavalin A are used to bind to glycosylated regions of the palatal shelf epithelium and are visualized in the scanning electron microscope (SEM).

The continuity of bacterial and physicochemical evolution: theory and experiments.

PubMed

Spitzer, Jan

2014-01-01

The continuity of chemical and biological evolution, incorporating life's emergence, can be explored experimentally by energizing 'dead' bacterial biomacromolecules with nutrients under cycling physicochemical gradients. This approach arises from three evolutionary principles rooted in physical chemistry: (i) broken bacterial cells cannot spontaneously self-assemble into a living state without the supply of external energy - 2nd law of thermodynamics, (ii) the energy delivery must be cycling - the primary mechanism of chemical evolution at rotating planetary surfaces under solar irradiation, (iii) the cycling energy must act on chemical mixtures of high molecular diversity and crowding - provided by dead bacterial populations. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Effect of inulin and glycerol supplementation on physicochemical properties of probiotic frozen yogurt.

PubMed

Muzammil, Hafiz Shehzad; Rasco, Barbara; Sablani, Shyam

2017-01-01

The present study was designed to investigate the effects of inulin and glycerol supplementation on physicochemical properties of probiotic frozen yogurt. Frozen yogurt was prepared with different types of probiotic ( Lactobacillus acidophilus and Bifidobacterium lactis ) along with yogurt starter culture ( Streptococcus thermophilus and Lactobacillus bulgaricus ). The frozen yogurt mixture was supplemented with inulin (2%, 4%, and 6%) and glycerol (1%, 2%, 3%, and 4%). The results showed that inulin 4% and 6% supplementation increased the overrun by 3% and 5% and the glass transition temperature by 3.3% and 2.8%, and decreased the hardness by 7% and 11%, respectively. Inulin supplementation did not have a significant effect on ice crystal size ( p  > 0.05). Glycerol supplementation increased the stickiness from 2.4% to 18.7%, and decreased the hardness from 8.0% to 14.5% and the glass transition temperature from 2.4% to 34.5%, respectively. Glycerol supplementation did not have a significant effect on overrun or melting rate ( p  > 0.05).

Influence of type of amphora on physico-chemical properties and antioxidant capacity of 'Falanghina' white wines.

PubMed

Baiano, Antonietta; Varva, Gabriella; De Gianni, Antonio; Viggiani, Ilaria; Terracone, Carmela; Del Nobile, Matteo Alessandro

2014-03-01

The present research was aimed to evaluate the effects of ageing and type of container on physico-chemical indices and on antioxidant compounds of 'Falanghina' wines. Wines were stored for 12months in raw, glazed, and engobe amphorae, and in stainless steel tanks. Lactic, acetic, citric, succinic, and hydroxycinnamoyl tartaric acids, and the antioxidant capacity (DPPH assay) were not affected by the type of container for the duration of the ageing. Flavonoids decreased by about 85% in all the containers. The concentrations of flavans reactive with vanilline were reduced by 100% in raw and glazed amphorae, 23% in engobe amphorae, and 59% in stainless steel tanks. The hydroxycinnamoyl tartaric acids decreased by about 11% in raw and engobe amphorae and by ∼22% in glazed amphorae and in stainless steel tanks. During the whole ageing time, the decrease of the antioxidant capacity ranged from 28% (raw amphorae) to 43% (stainless steel tanks). Copyright © 2013 Elsevier Ltd. All rights reserved.

Physico-chemical and chemical properties of some coconut coir dusts for use as a peat substitute for containerised ornamental plants.

PubMed

Abad, Manuel; Noguera, Patricia; Puchades, Rosa; Maquieira, Angel; Noguera, Vicente

2002-05-01

Selected physico-chemical and chemical characteristics of 13 coconut coir dust (mesocarp pithy tissue plus short-length fibres) samples from Asia, America and Africa were evaluated as peat alternatives. All properties studied differed significantly between and within sources, and from the control Sphagnum peat. pH of coir dust was slightly acidic, whereas salinity varied dramatically between 39 and 597 mS m(-1) in the saturated media extract. The cation exchange capacity and carbon/nitrogen (C/N) ratio ranged from 31.7 to 95.4 cmol(c) kg(-1) and from 75 to 186, respectively. Most carbon was found as lignin and cellulose. The concentrations of available nitrogen, calcium, magnesium and micro-elements were low, while those of phosphorus and potassium were remarkably high (0.28-2.81 mol m(-3) and 2.97-52.66 mol m(-3) for P and K, respectively). Saline ion concentrations, especially chloride and sodium, were also high.

Characterization of specialized flocculent yeasts to improve sparkling wine fermentation.

PubMed

Tofalo, R; Perpetuini, G; Di Gianvito, P; Arfelli, G; Schirone, M; Corsetti, A; Suzzi, G

2016-06-01

Flocculent wine yeasts were characterized for the expression of FLO1, FLO5, FLO8, AMN1 and RGA1 genes, growth kinetics and physicochemical properties of the cell surface during a 6-month sparkling wine fermentation period. The expression of FLO1, FLO5, FLO8, AMN1 and RGA1 genes was determined by RT-qPCR. The physicochemical characterization of yeast surface properties was evaluated by the microbial adhesion to solvents method. FLO5 gene was the most expressed one and a linear correlation with the flocculent degree was found. Flocculent strains were more hydrophobic than the commercial wine strain EC1118. Gene expressions and the ability to face secondary wine fermentation conditions were strain dependent. The importance of FLO5 gene in developing the high flocculent characteristic of wine yeasts was highlighted. Cell surface properties depended on the time of fermentation. Better knowledge about the expression of some genes encoding the flocculent phenotype which could be useful to select suitable starter cultures to improve sparkling wine technology was achieved. A step forward in understanding the complexity and strain-specific nature of flocculation phenotype was done. © 2016 The Society for Applied Microbiology.

A new synthesis route to high surface area sol gel bioactive glass through alcohol washing

PubMed Central

M. Mukundan, Lakshmi; Nirmal, Remya; Vaikkath, Dhanesh; Nair, Prabha D.

2013-01-01

Bioactive glass is one of the widely used bone repair material due to its unique properties like osteoconductivity, osteoinductivity and biodegradability. In this study bioactive glass is prepared by the sol gel process and stabilized by a novel method that involves a solvent instead of the conventional calcinations process. This study represents the first attempt to use this method for the stabilization of bioactive glass. The bioactive glass stabilized by this ethanol washing process was characterized for its physicochemical and biomimetic property in comparison with similar composition of calcined bioactive glass. The compositional similarity of the two stabilized glass powders was confirmed by spectroscopic and thermogravimetric analysis. Other physicochemical characterizations together with the cell culture studies with L929 fibroblast cells and bone marrow mesenchymal stem cells proved that the stabilization was achieved with the retention of its inherent bioactive potential. However an increase in the surface area of the glass powder was obtained as a result of this ethanol washing process and this add up to the success of the study. Hence the present study exhibits a promising route for high surface area bioactive glass for increasing biomimicity. PMID:23512012

Effects of argon sputtering and UV-ozone radiation on the physico-chemical surface properties of ITO

NASA Astrophysics Data System (ADS)

Che, Hui; El Bouanani, M.

2018-01-01

X-ray photoelectron spectroscopy (XPS) and Ultraviolet Photoelectron Spectroscopy (UPS) were used to evaluate and determine the effects of 1 KeV Ar+ irradiation (sputtering) on the surface chemical composition and work function of Indium Thin Oxide (ITO). While Ar+ sputtering removes carbon-based surface contaminants, it also modifies the Sn-rich surface of ITO and leads to a reduction of the oxidation state of Sn from Sn4+ to Sn2+. The decrease in the work function of ITO is directly correlated to the decrease of Sn atomic concentration in the Sn-rich top surface layer and the reduction of the oxidation state of surface Sn.

PROPERTY CHANGES IN AQUEOUS SOLUTIONS DUE TO SURFACTANT TREATMENT OF PCE: IMPLICATIONS TO GEOPHYSICAL MEASUREMENTS

EPA Science Inventory

Select physicochemical properties of aqueous solutions composed of surfactants, dye, and

perchloroethylene (PCE) were evaluated through a response surface quadratic design

model of experiment. Nine surfactants, which are conventionally used in the

remediation...

Water Quality Response to Changes in Agricultural Land Use Practices at Headwater Streams in Georgia

EPA Science Inventory

Poorly managed agricultural watersheds may be one of the most important contributors to high levels of bacterial and sediment loadings in surface waters. We investigated two cattle farms with differing management schemes to compare how physicochemical and meteorological parameter...

Equilibrium and kinetic models for colloid release under transient solution chemistry conditions

USDA-ARS?s Scientific Manuscript database

We present continuum models to describe colloid release in the subsurface during transient physicochemical conditions. Our modeling approach relates the amount of colloid release to changes in the fraction of the solid surface area that contributes to retention. Equilibrium, kinetic, equilibrium and...

COLD WATER PATCHES IN WARM STREAMS: PHYSICOCHEMICAL CHARACTERISTICS AND THE INFLUENCE OF SHADING

EPA Science Inventory

Discrete coldwater patches within the surface waters of summer-warm streams afford potential thermal refuge for coldwater fishes during periods of heat stress. This analysis focused on reach-scale heterogeneity in water temperatures as influenced by local influx of cooler subsur...

Tracheal-innominate artery fistula caused by the endotracheal tube tip: case report and investigation of a fatal complication of prolonged intubation.

PubMed

Siobal, M; Kallet, R H; Kraemer, R; Jonson, E; Lemons, D; Young, D; Campbell, A R; Schecter, W; Tang, J

2001-10-01

A patient with extensive burns was intubated with an 8.0 mm internal diameter endotracheal tube (ETT) equipped with a subglottic suction port (Mallinckrodt HiLo Evac). The ETT was secured to a left upper molar with wire sutures throughout the hospitalization course to ensure airway stability. On the 40th day of intubation, the patient exsanguinated and died from a tracheo-innominate artery fistula. Postmortem examination revealed a 1 cm lesion of the left anterior tracheal wall at the position of the ETT tip. The prolonged stationary position of the ETT was considered the primary factor responsible for the fistula. Yet tracheo-innominate artery fistula normally is associated with high cuff pressures rather than with the tube tip. The special ETT construction required for the subglottic suction feature was suspected to have increased tube rigidity and may have played a contributory role. The rigidity of the Mallinckrodt HiLo Evac was measured with a mechanical model and compared to 5 other commercially-available ETTs. Rigidity was expressed as the force generated by the ETT tip when the tube curvature was altered by 5 cm and 10 cm of flexion from its resting position. The mean force exerted by the Mallinckrodt HiLo Evac was 10.1 +/- 2.8 g at 5 cm of flexion and 17.7 +/- 5.1 g at 10 cm of flexion. This was significantly greater than all other ETT brands tested (by one-way analysis of variance and Student-Newman-Kuels test, p < 0.05). This case of fatal tracheo-innominate artery fistula formation associated with an ETT tip was unusual because of the extended duration of endotracheal intubation and the complexity of the patient's airway management problems. Our data suggest that the higher rigidity of the HiLo Evac ETT may have contributed to fistula development at the tube tip. However, we do not believe that the higher rigidity of the HiLo Evac ETT necessarily poses any greater risk than other ETTs under normal circumstances, in which the tube tip is not fixed in a stationary position for an extended period.

Lab-on-a-bubble: direct and indirect assays with portable Raman instrumentation

NASA Astrophysics Data System (ADS)

Carron, Keith; Schmit, Virginia; Scott, Brandon; Martoglio, Richard

2012-10-01

Lab-on-a-Bubble (LoB) is a new method for SERS (Surface Enhanced Raman Scattering) assays that combines separationand concentration of the assay results. A direct LoB assay is comprised of gold nanoparticles coupled directly to the ~30 μm diameter buoyant silica bubble. The direct LoB method was evaluated with cyanide and 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB). An indirect assay uses the same ~ 30 μm diameter buoyant silica bubble and a silica coated SERS reporter. Both the bubble and SERS reporter are coated with a coupling agent for the analyte. The assay measures the amount of SERS reporter coupled to the bubble through a sandwich created by the analyte. The couling agent could consist of an immunological coupling agent (antibody) or a nucleic acid coupling agent (single strand DNA). The indirect LoB method was examined with Cholera toxin (CT) and antibodies against the β subunit. An LOD of ~ 170 pptrillion was measured for cyanide and a limit of detection of 1100 ng was found for CT. Instrumentation for the assay and a novel technique of dynamic SERS (DSERS) will also be discussed. The instrument is a small hand-held Raman device called the CBEx (Chemical Biological Explosive) with a novel raster system to detect heterogeneous or light sensitive materials. DSERS is a mathematical algorithm which eliminates background interference in SERS measurements with colloidal nanoparticles.

Effectiveness of roundhouse kick in elite Taekwondo athletes.

PubMed

Thibordee, Sutima; Prasartwuth, Orawan

2014-06-01

The roundhouse kick is a powerful attack in Taekwondo. Most athletes intently perform this kick for scoring in competition. Therefore, kinematic and kinetic analyzes of this kick were the topics of interest; however, they were separately investigated and rarely recorded for impact force. Our objectives were to investigate knee and ankle joint kinematics and electromyographic (EMG) activity of leg muscle and compare them between high-impact (HI) and low-impact (LO) kicks. Sixteen male black-belt Taekwondo athletes performed five roundhouse kicks at their maximal effort. Electrogoniometer sensors measured angular motions of ankle and knee joints. Surface EMG activities were recorded for tibialis anterior, gastrocnemius medialis, rectus femoris, and biceps femoris muscles. Based on maximal impact forces, the athletes were classified into HI and LO groups. All athletes in both groups showed greater activation of rectus femoris than other muscles. The HI group only showed significantly less plantarflexion angles than the LO group during preimpact and impact phases (P<0.05). During the impact phase, the HI group demonstrated significantly greater biceps femoris activation than the LO group (P<0.05). In conclusion, rectus femoris activation could predominantly contribute to the powerful roundhouse kicks. Moreover, high biceps femoris co-activation and optimal angle of ankle plantarflexion of about 35° could help achieve the high impact force. Copyright © 2014 Elsevier Ltd. All rights reserved.

Implications of interfacial characteristics of food foaming agents in foam formulations.

PubMed

Rodríguez Patino, Juan M; Carrera Sánchez, Cecilio; Rodríguez Niño, Ma Rosario

2008-08-05

The manufacture of food dispersions (emulsions and foams) with specific quality attributes depends on the selection of the most appropriate raw materials and processing conditions. These dispersions being thermodynamically unstable require the use of emulsifiers (proteins, lipids, phospholipids, surfactants etc.). Emulsifiers typically coexist in the interfacial layer with specific functions in the processing and properties of the final product. The optimum use of emulsifiers depends on our knowledge of their interfacial physico-chemical characteristics - such as surface activity, amount adsorbed, structure, thickness, topography, ability to desorb (stability), lateral mobility, interactions between adsorbed molecules, ability to change conformation, interfacial rheological properties, etc. -, the kinetics of film formation and other associated physico-chemical properties at fluid interfaces. These monolayers constitute well defined systems for the analysis of food colloids at the micro- and nano-scale level, with several advantages for fundamental studies. In the present review we are concerned with the analysis of physico-chemical properties of emulsifier films at fluid interfaces in relation to foaming. Information about the above properties would be very helpful in the prediction of optimised formulations for food foams. We concluded that at surface pressures lower than that of monolayer saturation the foaming capacity is low, or even zero. A close relationship was observed between foaming capacity and the rate of diffusion of the foaming agent to the air-water interface. However, the foam stability correlates with the properties of the film at long-term adsorption.

A methodological approach to characterize the resilience of aquatic ecosystems with application to Lake Annecy, France

NASA Astrophysics Data System (ADS)

Pinault, J.-L.; Berthier, F.

2007-01-01

We propose a methodological approach to characterize the resilience of aquatic ecosystems with respect to the evolution of environmental parameters as well as their aptitude to adapt to forcings. This method that is applied to Lake Annecy, France, proceeds in three stages. First, according to the depth, variations of physicochemical parameters versus time are separated into three components related to (1) energy transfer through the surface of the lake, (2) the flow of rivers and springs that feed the lake, and (3) long-term evolution of the benthic zone as a consequence of mineral and organic matter loads. Second, dynamics of the lake are deduced by analyzing the physicochemical parameter components related to the three boundary conditions. Third, a stochastic process associated with the transfer models aims to characterize the resilience of the lakes according to forcings. For Lake Annecy, whose dynamics are representative of oligotrophic stratified lakes controlled by decarbonation processes where turnover and mixing occurring once a year in winter, the major consequence is the impoverishment of dissolved oxygen in deep water in autumn due to a temperature increase of the surface water in summer. The simulation raises relevant questions about whether a connection exists between physicochemical parameters and global warming, which should not induce harmful consequences on water quality and biodiversity in deep water. This methodological approach is general since it does not use any physical conceptual model to predict the hydrosystem behavior but uses directly observed data.

Swirling cavitation improves the emulsifying properties of commercial soy protein isolate.

PubMed

Yang, Feng; Liu, Xue; Ren, Xian'e; Huang, Yongchun; Huang, Chengdu; Zhang, Kunming

2018-04-01

Since emulsifying properties are important functional properties of soy protein, many physical, chemical, and enzymatic methods have been applied to treat soy protein to improve emulsifying properties. In this study, we investigated the effects of swirling cavitation at different pressures and for different times on emulsifying and physicochemical properties of soy protein isolate (SPI). The SPI treated with swirling cavitation showed a significant decrease in particle size and increase in solubility. Emulsions formed from treated SPI had higher emulsifying activity and emulsifying stability indexes, smaller oil droplet sizes, lower flocculation indexes, higher adsorbed proteins, lower interfacial protein concentrations, and lower creaming indexes than those formed from untreated SPI, indicating that swirling cavitation improved the emulsifying properties of the SPI. Furthermore, swirling cavitation treatment significantly enhanced the surface hydrophobicity, altered the disulfide bond and exposed sulfhydryl group contents of the SPI. The secondary structure of the SPI was also influenced by swirling cavitation, with an increase in β-sheet content and a decrease in α-helix, β-turn, and random coil contents. In addition, several significant correlations between physicochemical and emulsifying properties were revealed by Pearson correlation analysis, suggesting that the physicochemical changes observed in treated SPI, including the decreased particle size, increased solubility and surface hydrophobicity, and enhanced β-sheet formation, may explain the improved emulsifying properties of the isolate. Thus, our findings implied that swirling cavitation treatment may be an effective technique to improve the emulsifying properties of SPI. Copyright © 2017 Elsevier B.V. All rights reserved.

Natural Minerals Coated by Biopolymer Chitosan: Synthesis, Physicochemical, and Adsorption Properties

NASA Astrophysics Data System (ADS)

Budnyak, T. M.; Yanovska, E. S.; Kichkiruk, O. Yu.; Sternik, D.; Tertykh, V. A.

2016-11-01

Natural minerals are widely used in treatment technologies as mineral fertilizer, food additive in animal husbandry, and cosmetics because they combine valuable ion-exchanging and adsorption properties together with unique physicochemical and medical properties. Saponite (saponite clay) of the Ukrainian Podillya refers to the class of bentonites, a subclass of layered magnesium silicate montmorillonite. Clinoptilolits are aluminosilicates with carcase structure. In our work, we have coated biopolymer chitosan on the surfaces of natural minerals of Ukrainian origin — Podilsky saponite and Sokyrnitsky clinoptilolite. Chitosan mineral composites have been obtained by crosslinking of adsorbed biopolymer on saponite and clinoptilolite surface with glutaraldehyde. The obtained composites have been characterized by the physicochemical methods such as thermogravimetric/differential thermal analyses (DTA, DTG, TG), differential scanning calorimetry, mass analysis, nitrogen adsorption/desorption isotherms, scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy to determine possible interactions between the silica and chitosan molecule. The adsorption of microquantities of cations Cu(II), Zn(II), Fe(III), Cd(II), and Pb(II) by the obtained composites and the initial natural minerals has been studied from aqueous solutions. The sorption capacities and kinetic adsorption characteristics of the adsorbents were estimated. It was found that the obtained results have shown that the ability of chitosan to coordinate heavy metal ions Zn(II), Cu(II), Cd(II), and Fe(III) is less or equal to the ability to retain ions of these metals in the pores of minerals without forming chemical bonds.

Biofriendly nanocomposite containers with inhibition properties for the protection of metallic surfaces.

PubMed

Vakhitov, T R; Katnov, V E; Grishin, P V; Stepin, S N; Grigoriev, D O

2017-03-01

An attempt to combine two 'green' compounds in nanocomposite microcontainers in order to increase protection properties of waterborne acryl-styrene copolymer (ASC) coatings has been made. N -lauroylsarcosine (NLS) served as a corrosion inhibitor, and linseed oil (LO) as a carrier-forming component. LO is compatible with this copolymer and can impart to the coating self-healing properties. For the evaluation of the protective performance, three types of coatings were compared. In the first two, NLS was introduced in the coating formulation in the forms of free powder and micro-containers filled with LO, correspondingly. The last one was a standard ASC coating without inhibitor at all. Low-carbon steel substrates were coated by these formulations by spraying and subjected subsequently to the neutral salt spray test according to DIN ISO 9227. Results of these tests as well as the data obtained by electrochemical study suggest that such containers can be used for the improvement of adhesion of ASC-based coatings to the substrate and for the enhancement of their protective performance upon integrity damage, whereas the barrier properties of intact coatings were decreased.

Effective electron mass and phonon modes in n-type hexagonal InN

NASA Astrophysics Data System (ADS)

Kasic, A.; Schubert, M.; Saito, Y.; Nanishi, Y.; Wagner, G.

2002-03-01

Infrared spectroscopic ellipsometry and micro-Raman scattering are used to study vibrational and electronic properties of high-quality hexagonal InN. The 0.22-μm-thick highly n-conductive InN film was grown on c-plane sapphire by radio-frequency molecular-beam epitaxy. Combining our results from the ellipsometry data analysis with Hall-effect measurements, the isotropically averaged effective electron mass in InN is determined as 0.14m0. The resonantly excited zone center E1 (TO) phonon mode is observed at 477 cm-1 in the ellipsometry spectra. Despite the high electron concentration in the film, a strong Raman mode occurs in the spectral range of the unscreened A1(LO) phonon. Because an extended carrier-depleted region at the sample surface can be excluded from the ellipsometry-model analysis, we assign this mode to the lower branch of the large-wave-vector LO-phonon-plasmon coupled modes arising from nonconserving wave-vector scattering processes. The spectral position of this mode at 590 cm-1 constitutes a lower limit for the unscreened A1(LO) phonon frequency.

In vitro biocompatibility of the surface ion modified NiTi alloy

NASA Astrophysics Data System (ADS)

Gudimova, Ekaterina Yu.; Meisner, Ludmila L.; Lotkov, Aleksander I.; Matveeva, Vera A.; Meisner, Stanislav N.; Matveev, Andrey L.; Shabalina, Olga I.

2016-11-01

This paper presents the results of the chemical, topographic and structural properties of the NiTi alloy surface and their changes after surface treatments by ion implantation techniques with use of ions Ta+ and Si+. The influence of physicochemical properties of the surface ion modified NiTi alloy was studied on in vitro cultured mesenchymal stem cells of the rats' bone marrow. It is shown that the ion surface modification improves histocompatibility of the NiTi alloy and leads to increase of proliferative activity of mesenchymal stem cells on its surface. It was experimentally found that a major contribution to viability improvement mesenchymal stem cells of rat marrow has the chemical composition and the microstructure of the surface area.

Friction behavior and other material properties of nickel-titanium and titanium-molybdenum archwires following electrochemical surface refinement.

PubMed

Meier, Miriam Julia; Bourauel, Christoph; Roehlike, Jan; Reimann, Susanne; Keilig, Ludger; Braumann, Bert

2014-07-01

The aim of this work was to investigate whether electrochemical surface treatment of nickel-titanium (NiTi) and titanium-molybdenum (TiMo) archwires (OptoTherm and BetaTitan; Ortho-Dent Specials, Kisdorf, Germany) reduces friction inside the bracket-archwire complex. We also evaluated further material properties and compared these to untreated wires. The material properties of the surface-treated wires (Optotherm/LoFrix and BetaTitan/LoFrix) were compared to untreated wires made by the same manufacturer (see above) and by another manufacturer (Neo Sentalloy; GAC, Bohemia, NY, USA). We carried out a three-point bending test, leveling test, and friction test using an orthodontic measurement and simulation system (OMSS). In addition, a pure bending test was conducted at a special test station, and scanning electron micrographs were obtained to analyze the various wire types for surface characteristics. Finally, edge beveling and cross-sectional dimensions were assessed. Force losses due to friction were reduced by 10 percentage points (from 36 to 26%) in the NiTi and by 12 percentage points (from 59 to 47%) in the TiMo wire specimens. Most of the other material properties exhibited no significant changes after surface treatment. While the three-point bending tests revealed mildly reduced force levels in the TiMo specimens due to diameter losses of roughly 2%, these force levels remained almost unchanged in the NiTi specimens. Compared to untreated NiTi and TiMo archwire specimens, the surface-treated specimens demonstrated reductions in friction loss by 10 and 12 percentage points, respectively.

Physicochemical characterization of engineered nanoparticles under physiological conditions: effect of culture media components and particle surface coating.

PubMed

Fatisson, Julien; Quevedo, Ivan R; Wilkinson, Kevin J; Tufenkji, Nathalie

2012-03-01

The use of engineered nanoparticles (ENPs) in commercial products has increased substantially over the last few years. Some research has been conducted in order to determine whether or not such materials are cytotoxic, but questions remain regarding the role that physiological media and sera constituents play in ENP aggregation or stabilization. In this study, several characterization methods were used to evaluate the particle size and surface potential of 6 ENPs suspended in a number of culture media and in the presence of different culture media constituents. Dynamic light scattering (DLS) and fluorescence correlation spectroscopy (FCS) were employed for size determinations. Results were interpreted on the basis of ENP surface potentials evaluated from particle electrophoretic mobilities (EPM). Measurements made after 24h of incubation at 37°C showed that the cell culture medium constituents had only moderate impact on the physicochemical properties of the ENP, although incubation in bovine serum albumin destabilized the colloidal system. In contrast, most of the serum proteins increased colloidal stabilization. Moreover, the type of ENP surface modification played a significant role in ENP behavior whereby the complexity of interactions between the ENPs and the medium components generally decreased with increasing complexity of the particle surface. This investigation emphasizes the importance of ENP characterization under conditions that are representative of cell culture media or physiological conditions for improved assessments of nanoparticle cytotoxicity. Copyright © 2011 Elsevier B.V. All rights reserved.

Toward the Understanding of MNEI Sweetness from Hydration Map Surfaces

PubMed Central

De Simone, Alfonso; Spadaccini, Roberta; Temussi, Piero A.; Fraternali, Franca

2006-01-01

The binding mechanism of sweet proteins to their receptor, a G-protein-coupled receptor, is not supported by direct structural information. In principle, the key groups responsible for biological activity (glucophores) can be localized on a small structural unit (sweet finger) or spread on a larger surface area. A recently proposed model, called “wedge model”, implies a large surface of interaction with the receptor. To explore this model in greater detail, it is necessary to examine the physicochemical features of the surfaces of sweet proteins, since their interaction with the receptor, with respect to that of small sweeteners, is more dependent on general physicochemical properties of the interface, such as electrostatic potential and hydration. In this study, we performed exhaustive molecular dynamics simulations in explicit water of the sweet protein MNEI and of its structural mutant G-16A, whose sweetness is one order of magnitude lower than that of MNEI. Solvent density and self-diffusion calculated from molecular dynamics simulations suggest a likely area of interaction delimited by four stretches arranged as a tetrahedron whose shape is complementary to that of a cavity on the surface of the receptor, in agreement with the wedge model. The suggested area of interaction is amazingly consistent with known mutagenesis data. In addition, the asymmetric hydration of the only helix in both proteins hints at a specific role for this secondary structure element in orienting the protein during the binding process. PMID:16461400

NaCl strongly modifies the physicochemical properties of aluminum hydroxide vaccine adjuvants.

PubMed

Art, Jean-François; Vander Straeten, Aurélien; Dupont-Gillain, Christine C

2017-01-30

The immunostimulation capacity of most vaccines is enhanced through antigen adsorption on aluminum hydroxide (AH) adjuvants. Varying the adsorption conditions, i.e. pH and ionic strength (I), changes the antigen adsorbed amount and therefore the ability of the vaccine to stimulate the immune system. Vaccine formulations are thus resulting from an empirical screening of the adsorption conditions. This work aims at studying the physicochemical effects of adjusting the ionic strength of commercial AH adjuvant particles suspensions with sodium chloride (NaCl). X-ray photoelectron spectroscopy data show that AH particles surface chemical composition is neither altered by I adjustment with NaCl nor by deposition on gold surfaces. The latter result provides the opportunity to use AH-coated gold surfaces as a platform for advanced surface analysis of adjuvant particles, e.g. by atomic force microscopy (AFM). The morphology of adjuvant particles recovered from native and NaCl-treated AH suspensions, as studied by scanning electron microscopy and AFM, reveals that AH particles aggregation state is significantly altered by NaCl addition. This is further confirmed by nitrogen adsorption experiments: I adjustment to 150mM with NaCl strongly promotes AH particles aggregation leading to a strong decrease of the developed specific surface area. This work thus evidences the effect of NaCl on AH adjuvant structure, which may lead to alteration of formulated vaccines and to misinterpretation of data related to antigen adsorption on adjuvant particles. Copyright © 2016 Elsevier B.V. All rights reserved.

PARTICLE NUMBER AND SURFACE CHARGE PREDICT THE BIOLOGICAL ACTIVATION OF HUMAN BRONCHIAL EPITHELIAL CELLS EXPOSED TO PARTICULATE MATTER.

EPA Science Inventory

Exposure to particulate matter (PM) produces a uniform degree of mortality in exposed populations, in spite of its diverse sources. This suggests a common mechanism of action to explain its initial toxicity. The present study relates certain physicochemical characteristics (i.e.,...

Average [O II] nebular emission associated with Mg II absorbers: dependence on Fe II absorption

NASA Astrophysics Data System (ADS)

Joshi, Ravi; Srianand, Raghunathan; Petitjean, Patrick; Noterdaeme, Pasquier

2018-05-01

We investigate the effect of Fe II equivalent width (W2600) and fibre size on the average luminosity of [O II] λλ3727, 3729 nebular emission associated with Mg II absorbers (at 0.55 ≤ z ≤ 1.3) in the composite spectra of quasars obtained with 3 and 2 arcsec fibres in the Sloan Digital Sky Survey. We confirm the presence of strong correlations between [O II] luminosity (L_{[O II]}) and equivalent width (W2796) and redshift of Mg II absorbers. However, we show L_{[O II]} and average luminosity surface density suffer from fibre size effects. More importantly, for a given fibre size, the average L_{[O II]} strongly depends on the equivalent width of Fe II absorption lines and found to be higher for Mg II absorbers with R ≡W2600/W2796 ≥ 0.5. In fact, we show the observed strong correlations of L_{[O II]} with W2796 and z of Mg II absorbers are mainly driven by such systems. Direct [O II] detections also confirm the link between L_{[O II]} and R. Therefore, one has to pay attention to the fibre losses and dependence of redshift evolution of Mg II absorbers on W2600 before using them as a luminosity unbiased probe of global star formation rate density. We show that the [O II] nebular emission detected in the stacked spectrum is not dominated by few direct detections (i.e. detections ≥3σ significant level). On an average, the systems with R ≥ 0.5 and W2796 ≥ 2 Å are more reddened, showing colour excess E(B - V) ˜ 0.02, with respect to the systems with R < 0.5 and most likely trace the high H I column density systems.

Results of Experimental Investigations to Determine External Tank Protuberance Loads Using a 0.03-Scale Model of the Space Shuttle Launch Configuration (Model 47-OTS) in the NASA/ARC Unitary Plan Wind Tunnel, Volume 2

NASA Technical Reports Server (NTRS)

Houlihan, S. R.

1992-01-01

Data were obtained on a 3-percent model of the Space Shuttle launch vehicle in the NASA/Ames Research Center 11x11-foot and 9x7-foot Unitary Plan Wind Tunnels. This test series has been identified as IA19OA/B and was conducted from 7 Feb. 1980 to 19 Feb. 1980 (IA19OA) and from 17 March 1980 to 19 March 1980 and from 8 May 1980 to 30 May 1980 (IA19OB). The primary test objective was to obtain structural loads on the following external tank protuberances: (1) LO2 feedline; (2) GO2 pressure line; (3) LO2 antigeyser line; (4) GH2 pressure line; (5) LH2 tank cable tray; (6) LO2 tank cable tray; (7) Bipod; (8) ET/SRB cable tray; and (9) Crossbeam/Orbiter cable tray. To fulfill these objectives the following steps were taken: Eight 3-component balances were used to measure forces on various sections of 1 thru 6 above; 315 pressure orifices were distributed over all 9 above items. The LO2 feedline was instrumented with 96 pressure taps and was rotated to four positions to yield 384 pressure measurements. The LO2 antigeyser line was instrumented with 64 pressure taps and was rotated to two positions to yield 128 pressure measurements; Three Chrysler miniature flow direction probes were mounted on a traversing mechanism on the tank upper surface centerline to obtain flow field data between the forward and aft attach structures; and Schlieren photographs and ultraviolet flow photographs were taken at all test conditions. Data from each of the four test phases are presented.

Results of experimental investigations to determine external tank protuberance loads using a 0.03-scale model of the Space Shuttle launch configuration (model 47-OTS) in the NASA/ARC unitary plan wind tunnel, volume 1

NASA Technical Reports Server (NTRS)

Houlihan, S. R.

1992-01-01

Data were obtained on a 3-percent model of the Space Shuttle launch vehicle in the NASA/Ames Research Center 11x11-foot and 9x7-foot Unitary Plan Wind Tunnels. This test series has been identified as IA190A/B and was conducted from 7 Feb. 1980 to 19 Feb. 1980 (IA190A) and from 17 March 1980 to 19 March 1980 and from 8 May 1980 to 30 May 1980 (IA190B). The primary test objective was to obtain structural loads on the following external tank protuberances: (1) LO2 feedline, (2) GO2 pressure line, (3) LO2 antigeyser line, (4) GH2 pressure line, (5) LH2 tank cable tray, (6) LO2 tank cable tray, (7) Bipod, (8) ET/SRB cable tray, and (9) Crossbeam/Orbiter cable tray. To fulfill these objectives the following steps were taken: (1) Eight 3-component balances were used to measure forces on various sections of 1 thru 6 above. (2) 315 pressure orifices were distributed over all 9 above items. The LO2 feedline was instrumented with 96 pressure taps and was rotated to four positions to yield 384 pressure measurements. The LO2 antigeyser line was instrumented with 64 pressure taps and was rotated to two positions to yield 128 pressure measurements. (3) Three Chrysler miniature flow direction probes were mounted on a traversing mechanism on the tank upper surface centerline to obtain flow field data between the forward and aft attach structures. (4) Schlieren photographs and ultraviolet flow photographs were taken at all test conditions. Data from each of the four test phases are presented.

Supplementation of methionine and selection of highly digestible rumen undegradable protein to improve nitrogen efficiency for milk production.

PubMed

Noftsger, S; St-Pierre, N R

2003-03-01

Metabolizable protein (MP) supply and amino acid balance were manipulated through selection of highly digestible rumen-undegradable protein (RUP) sources and methionine (Met) supplementation. Effects on production efficiency and N utilization of lactating dairy cows were determined. Thirty-two multiparous (647 kg) and 28 primiparous (550 kg) Holstein cows were assigned during the fourth week of lactation to one of four dietary treatments. Treatments were 1) 18.3% crude protein (CP) with low estimated intestinal digestibility of RUP (HiCP-LoDRUP), 2) 18.3% CP with high digestibility RUP (HiCP-HiDRUP), 3) 16.9% CP with high digestibility RUP (LoCP-HiDRUP), and 4) 17.0% CP with high digestibility RUP and supplemental Met (LoCP-HiDRUP + Met). Diets were balanced to have equal concentrations of net energy for lactation (NE(L)), acid detergent fiber (ADF), neutral detergent fiber (NDF), and ash. Milk yields (40.8, 46.2, 42.9, 46.6 kg/d), protein percentages (2.95, 2.98, 2.99, 3.09%), and fat percentages (3.42, 3.64, 3.66, 3.73%) are reported here for HiCP-LoDRUP, HiCP-HiDRUP, LoCP-HiDRUP, and LoCP-HiDRUP + Met, respectively. Milk urea N and BUN decreased when feeding a lower CP diet. Efficiency of use of N for milk protein production was higher when feeding higher digestibility RUP, especially with the LoCP-HiDRUP + Met diet. A digestibility study followed the production trial, with six cows per treatment group continuing on the same treatment for an additional week. The experimental periods were 5 d long, with 1 d of adjustment and 4 d of total collection of urine and feces. Dry matter intake, milk production, milk protein production, and N digestibility were not significantly different among treatments during the collection trial, whereas N intake and N absorbed increased with the higher CP diets. The quantity of N in feces did not change with diet, but quantity of N in urine decreased in the low CP diets. Milk N as a percentage of intake N and milk N as a percentage of N absorbed showed a trend toward increasing as CP concentration in the diet decreased. The supplementation of Met did not improve the efficiency of N utilization during the digestibility study, in contrast to what was estimated during the production trial. Supplementing the highly digestible RUP source with rumen available and rumen escape sources of Met resulted in maximal milk and protein production and maximum N efficiency by cows during the production trial, indicating that postruminal digestibility of RUP and amino acid balance can be more important than total RUP supplementation.

Glycosyl-Nucleolipids as new bioinspired amphiphiles.

PubMed

Latxague, Laurent; Patwa, Amit; Amigues, Eric; Barthélémy, Philippe

2013-09-30

Four new Glycosyl-NucleoLipid (GNL) analogs featuring either a single fluorocarbon or double hydrocarbon chains were synthesized in good yields from azido thymidine as starting material. Physicochemical studies (surface tension measurements, differential scanning calorimetry) indicate that hydroxybutanamide-based GNLs feature endothermic phase transition temperatures like the previously reported double chain glycerol-based GNLs. The second generation of GNFs featuring a free nucleobase reported here presents a better surface activity (lower glim) compared to the first generation of GNFs.

Layer-by-layer buildup of polysaccharide-containing films: Physico-chemical properties and mesenchymal stem cells adhesion.

PubMed

Kulikouskaya, Viktoryia I; Pinchuk, Sergei V; Hileuskaya, Kseniya S; Kraskouski, Aliaksandr N; Vasilevich, Irina B; Matievski, Kirill A; Agabekov, Vladimir E; Volotovski, Igor D

2018-03-22

Layer-by-Layer assembled polyelectrolyte films offer the opportunity to control cell attachment and behavior on solid surfaces. In the present study, multilayer films based on negatively charged biopolymers (pectin, dextran sulfate, carboxymethylcellulose) and positively charged polysaccharide chitosan or synthetic polyelectrolyte polyethyleneimine has been prepared and evaluated. Physico-chemical properties of the formed multilayer films, including their growth, morphology, wettability, stability, and mechanical properties, have been studied. We demonstrated that chitosan-containing films are characterized by the linear growth, the defect-free surface, and predominantly viscoelastic properties. When chitosan is substituted for the polyethyleneimine in the multilayer system, the properties of the formed films are significantly altered: the rigidity and surface roughness increases, the film growth acquires the exponential character. The multilayer films were subsequently used for culturing mesenchymal stem cells. It has been determined that stem cells effectively adhered to chitosan-containing films and formed on them the monolayer culture of fibroblast-like cells with high viability. Our results show that cell attachment is a complex process which is not only governed by the surface functionality because one of the key parameter effects on cell adhesion is the stiffness of polyelectrolyte multilayer films. We therefore propose our Layer-by-Layer films for applications in tissue engineering. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2018. © 2018 Wiley Periodicals, Inc.

Theophylline cocrystals prepared by spray drying: physicochemical properties and aerosolization performance.

PubMed

Alhalaweh, Amjad; Kaialy, Waseem; Buckton, Graham; Gill, Hardyal; Nokhodchi, Ali; Velaga, Sitaram P

2013-03-01

The purpose of this work was to characterize theophylline (THF) cocrystals prepared by spray drying in terms of the physicochemical properties and inhalation performance when aerosolized from a dry powder inhaler. Cocrystals of theophylline with urea (THF-URE), saccharin (THF-SAC) and nicotinamide (THF-NIC) were prepared by spray drying. Milled THF and THF-SAC cocrystals were also used for comparison. The physical purity, particle size, particle morphology and surface energy of the materials were determined. The in vitro aerosol performance of the spray-dried cocrystals, drug-alone and a drug-carrier aerosol, was assessed. The spray-dried particles had different size distributions, morphologies and surface energies. The milled samples had higher surface energy than those prepared by spray drying. Good agreement was observed between multi-stage liquid impinger and next-generation impactor in terms of assessing spray-dried THF particles. The fine particle fractions of both formulations were similar for THF, but drug-alone formulations outperformed drug-carrier formulations for the THF cocrystals. The aerosolization performance of different THF cocrystals was within the following rank order as obtained from both drug-alone and drug-carrier formulations: THF-NIC>THF-URE>THF-SAC. It was proposed that micromeritic properties dominate over particle surface energy in terms of determining the aerosol performance of THF cocrystals. Spray drying could be a potential technique for preparing cocrystals with modified physical properties.

Effect of stone coverage on soil erosion

NASA Astrophysics Data System (ADS)

Jomaa, S.; Barry, D. A.; Heng, B. P.; Brovelli, A.; Sander, G. C.; Parlange, J.

2010-12-01

Soil surface coverage has a significant impact on water infiltration, runoff and soil erosion yields. In particular, surface stones protect the soils from raindrop detachment, they retard the overland flow therefore decreasing its sediment transport capacity, and they prevent surface sealing. Several physical and environmental factors control to what extent stones on the soil surface modify the erosion rates and the related hydrological response. Among the most important factors are the moisture content of the topsoil, stone size, emplacement, coverage density and soil texture. Owing to the different inter-related processes, there is ambiguity concerning the quantitative effect of stones, and process-based understanding is limited. Experiments were performed (i) to quantify how stone features affect sediment yields, (ii) to understand the local effect of isolated surface stones, that is, the changes of the soil particle size distribution in the vicinity of a stone and (iii) to determine how stones attenuate the development of surface sealing and in turn how this affects the local infiltration rate. A series of experiments using the EPFL 6-m × 2-m erosion flume were conducted at different rainfall intensities (28 and 74 mm h-1) and stone coverage (20 and 40%). The total sediment concentration, the concentration of the individual size classes and the flow discharge were measured. In order to analyze the measurements, the Hairsine and Rose (HR) erosion model was adapted to account for the shielding effect of the stone cover. This was done by suitably adjusting the parameters based on the area not covered by stones. It was found that the modified HR model predictions agreed well with the measured sediment concentrations especially for the long time behavior. Changes in the bulk density of the topsoil due to raindrop-induced compaction with and without stone protection revealed that the stones protect the upper soil surface against the structural seals resulting in negligible changes in the bulk density during the erosion event. Since the main process contributing to surface sealing development is the compaction due to the raindrop kinetic energy and associated physico-chemical changes, the protection provided by the stone cover is consistent with the area-averaging approach used in applying the HR model.

Physicochemical properties of β-carotene emulsions stabilized by chlorogenic acid-lactoferrin-glucose/polydextrose conjugates.

PubMed

Liu, Fuguo; Wang, Di; Xu, Honggao; Sun, Cuixia; Gao, Yanxiang

2016-04-01

In this study, the influence of chlorogenic acid (CA)-lactoferrin (LF)-glucose (Glc) conjugate and CA-LF-polydextrose (PD) conjugate on the physicochemical characteristics of β-carotene emulsions was investigated. Novel emulsifiers were formed during Maillard reaction between CA-LF conjugate and Glc/PD. The physicochemical properties of β-carotene emulsions were characterized by droplet size, ζ-potential, rheological behavior, transmission changes during centrifugal sedimentation and β-carotene degradation. Results showed that the covalent attachment of Glc or PD to CA-LF conjugate effectively increased the hydrophilicity of the oil droplets surfaces and strengthened the steric repulsion between the oil droplets. Glucose was better than polydextrose for the conjugation with CA-LF conjugate to stabilize β-carotene emulsions. In comparison with LF and CA-LF-Glc/PD mixtures, CA-LF-Glc/PD ternary conjugates exhibited better emulsifying properties and improved physical stability of β-carotene emulsions during the freeze-thaw treatment. In addition, CA-LF-Glc/PD conjugates significantly enhanced chemical stability of β-carotene in the emulsions against ultraviolet light exposure. Copyright © 2015 Elsevier Ltd. All rights reserved.

Spatial variation of physicochemical and bacteriological parameters elucidation with GIS in Rangat Bay, Middle Andaman, India

NASA Astrophysics Data System (ADS)

Dheenan, P. S.; Jha, Dilip Kumar; Vinithkumar, N. V.; Ponmalar, A. Angelin; Venkateshwaran, P.; Kirubagaran, R.

2014-01-01

The purpose of this study was to determine the concentration, distribution of bacteria and physicochemical property of surface seawater in Rangat Bay, Middle Andaman, Andaman Islands (India). The bay experiences tidal variations. Perhaps physicochemical properties of seawater in Rangat Bay were found not to vary significantly. The concentration of faecal streptococci was high (2.2 × 103 CFU/100 mL) at creek and harbour area, whereas total coliforms were high (7.0 × 102 CFU/100 mL) at mangrove area. Similarly, total heterotrophic bacterial concentration was high (5.92 × 104 CFU/100 mL) in mangrove and harbour area. The Vibrio cholerae and Vibrio parahaemolyticus concentration was high (4.2 × 104 CFU/100 mL and 9 × 103 CFU/100 mL) at open sea. Cluster analysis showed grouping of stations in different tidal periods. The spatial maps clearly depicted the bacterial concentration pattern in the bay. The combined approach of multivariate analysis and spatial mapping techniques was proved to be useful in the current study.

Influence of surface heterogeneity in electroosmotic flows—Implications in chromatography, fluid mixing, and chemical reactions in microdevices

NASA Astrophysics Data System (ADS)

Adrover, Alessandra; Giona, Massimiliano; Pagnanelli, Francesca; Toro, Luigi

2007-04-01

We analyze the influence of surface heterogeneity, inducing a random ζ-potential at the walls in electroosmotic incompressible flows. Specifically, we focus on how surface heterogeneity modifies the physico-chemical processes (transport, chemical reaction, mixing) occurring in microchannel and microreactors. While the macroscopic short-time features associated with solute transport (e.g. chromatographic patterns) do not depend significantly on ζ-potential heterogeneity, spatial randomness in the surface ζ-potential modifies the spectral properties of the advection-diffusion operator, determining different long-term properties of transport/reaction phenomena compared to the homogeneous case. Examples of physical relevance (chromatography, infinitely fast reactions) are addressed.

Measurement of Surface Interfacial Tension as a Function of Temperature Using Pendant Drop Images

NASA Astrophysics Data System (ADS)

Yakhshi-Tafti, Ehsan; Kumar, Ranganathan; Cho, Hyoung J.

2011-10-01

Accurate and reliable measurements of surface tension at the interface of immiscible phases are crucial to understanding various physico-chemical reactions taking place between those. Based on the pendant drop method, an optical (graphical)-numerical procedure was developed to determine surface tension and its dependency on the surrounding temperature. For modeling and experimental verification, chemically inert and thermally stable perfluorocarbon (PFC) oil and water was used. Starting with geometrical force balance, governing equations were derived to provide non-dimensional parameters which were later used to extract values for surface tension. Comparative study verified the accuracy and reliability of the proposed method.

Preparation of zeolite supported TiO{sub 2}, ZnO and ZrO{sub 2} and the study on their catalytic activity in NO{sub x} reduction and 1-pentanol dehydration

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

Fatimah, Is

Preparation of zeolite supported TiO{sub 2}, ZnO and ZrO{sub 2} and their catalytic activity was studied. Activated natural zeolite from Indonesia was utilized for the preparation and catalytic activity test on NO{sub x} reduction by NH{sub 3} and also 1-pentanol dehydration were examined. Physicochemical characterization of materials was studied by x-ray diffraction (XRD) measurement, scanning electron microscope, solid acidity determination and also gas sorption analysis. The results confirmed that the preparation gives some improvements on physicochemical characters suitable for catalysis mechanism in those reactions. Solid acidity and specific surface area contributed significantly to the activity.

Variations of physicochemical properties in Kalpakkam coastal waters, east coast of India, during southwest to northeast monsoon transition period.

PubMed

Satpathy, Kamala Kanta; Mohanty, Ajit K; Sahu, Gouri; Sarkar, Santosh K; Natesan, Usha; Venkatesan, R; Prasad, M V R

2010-12-01

A significant variation in physicochemical properties of the Kalpakkam coastal waters, eastern part of India, was observed during the event of southwest to northeast monsoon transition. Increase in nitrate, total nitrogen, and silicate concentrations were noticed during post-transition period. Ammonia concentration was at peak during transition period as compared to pre- and post-transition periods. Hypo-saline condition (~23 psu) was observed during post-transition as the surface water salinity decreased by ~10 psu from the pre-transitional values. Turbidity, suspended particulate matter, phosphate and total phosphorous values decreased marginally, coinciding with northward to southward current reversal. A drastic decrease (eightfold) in chlorophyll-a concentration was observed in the coastal water during post-transition period.

[Physicochemical properties of Guanting Reservoir sediment and its land application].

PubMed

Su, De-Chun; Hu, Yu-Feng; Song, Chong-Wei; Wu, Fei-Long; Liu, Pei-Bin

2007-06-01

Surface sediment of Guanting Reservoir was dredged up and dewatered in field, and pollutant and physicochemical characterizations were mensurated. The stabilization and agricultural land use of the sediment was also studied in the field. Results showed that the sediments have a higher clay content, bulk density (1.89 g x cm(-3)) and lower porosity (23.8%), higher deoxidize material and available nitrogen, phosphorus concentration. Heavy metal and organochlorinated pesticides concentration was lower than the class II of national standard for soil. Stabilized the sediment with sand soil and straw could improve the physical property and decrease the concentration of deoxidize material and available nitrogen, phosphorus. Stabilized sediment could be a suitable medium for alfalfa, tree and corn growth and used for agricultural land.

Detonation Initiation and Evolution in Spray- Fueled Pulsed Detonation Rocket Engines

DTIC Science & Technology

2007-06-28

shock by an nth fluid particle during the induction time is characterized by Z" = Uro ’, where o;,, is the induction time for that particle and o7, is a...12.5 15 z 15 s=20 25. 28 e 10 5 - 0 2.5 5 75 10 12.5 15 z 20 s=3.0, 31, 32 15- I- + E! lo 02.5 T 01251 2 T s 3.3.3.4, 3.5 20 10 F.... 0 25 5 75 10 12.5

Advanced Operational Aviation Medicine Course (6th), Held at Centre de Medecine Aeronautique, Brussels, Belgium, 24-28 March 1980,

DTIC Science & Technology

1981-05-01

accolk au 10 bruit, decrescendo et laisse libre la miso et la tilisystole. 2) les souffles cardiopulsaonaires (souffle de Potaist) rencontris plus...climicion do so faire rapidement une id~e de Is diatensibilitL6 dui sya-A tome artLriel. IV - ZTUD88 CHROI0CARDIOGUAPIQLMS Pilque lea intervallos dui...nombro do trois, continuant d’atno pratiqudost .Lo test do Maator, Il consist. A fairs gravir A une cadence doonnd in scabeau do doux marches pendant

"Breath figures" on leaf surfaces-formation and effects of microscopic leaf wetness.

PubMed

Burkhardt, Juergen; Hunsche, Mauricio

2013-01-01

"Microscopic leaf wetness" means minute amounts of persistent liquid water on leaf surfaces which are invisible to the naked eye. The water is mainly maintained by transpired water vapor condensing onto the leaf surface and to attached leaf surface particles. With an estimated average thickness of less than 1 μm, microscopic leaf wetness is about two orders of magnitude thinner than morning dewfall. The most important physical processes which reduce the saturation vapor pressure and promote condensation are cuticular absorption and the deliquescence of hygroscopic leaf surface particles. Deliquescent salts form highly concentrated solutions. Depending on the type and concentration of the dissolved ions, the physicochemical properties of microscopic leaf wetness can be considerably different from those of pure water. Microscopic leaf wetness can form continuous thin layers on hydrophobic leaf surfaces and in specific cases can act similar to surfactants, enabling a strong potential influence on the foliar exchange of ions. Microscopic leaf wetness can also enhance the dissolution, the emission, and the reaction of specific atmospheric trace gases e.g., ammonia, SO2, or ozone, leading to a strong potential role for microscopic leaf wetness in plant/atmosphere interaction. Due to its difficult detection, there is little knowledge about the occurrence and the properties of microscopic leaf wetness. However, based on the existing evidence and on physicochemical reasoning it can be hypothesized that microscopic leaf wetness occurs on almost any plant worldwide and often permanently, and that it significantly influences the exchange processes of the leaf surface with its neighboring compartments, i.e., the plant interior and the atmosphere. The omission of microscopic water in general leaf wetness concepts has caused far-reaching, misleading conclusions in the past.

Spatially resolved surface-related exciton polariton dynamics in a single ZnO tetrapod

NASA Astrophysics Data System (ADS)

Sun, Fangfang; Sun, Liaoxin; Zhang, Bo; Wang, Hailong

2018-02-01

The band-edge emission lifetime in a single ZnO tetrapod is studied by using the time-resolved confocal micro-photoluminescence (TR- μPL) spectroscopic technique at room temperature. By performing μPL and TR- μPL mapping along the tapered arm of tetrapod, we observe whispering gallery mode (WGM) polaritons and find that the predominant radiative lifetime of exciton polaritons decreases linearly with increasing the surface-to-volume ratio of the sample. This behavior is ascribed to the surface electric field induced enhancement of the radiative decay rate of the exciton-like polaritons coupling with LO phonons.

Texturing of continuous LOD meshes with the hierarchical texture atlas

NASA Astrophysics Data System (ADS)

Birkholz, Hermann

2006-02-01

For the rendering of detailed virtual environments, trade-offs have to be made between image quality and rendering time. An immersive experience of virtual reality always demands high frame-rates with the best reachable image qual-ity. Continuous Level of Detail (cLoD) triangle-meshes provide an continuous spectrum of detail for a triangle mesh that can be used to create view-dependent approximations of the environment in real-time. This enables the rendering with a constant number of triangles and thus with constant frame-rates. Normally the construction of such cLoD mesh representations leads to the loss of all texture information of the original mesh. To overcome this problem, a parameter domain can be created, in order to map the surface properties (colour, texture, normal) to it. This parameter domain can be used to map the surface properties back to arbitrary approximations of the original mesh. The parameter domain is often a simplified version of the mesh to be parameterised. This limits the reachable simplification to the domain mesh which has to map the surface of the original mesh with the least possible stretch. In this paper, a hierarchical domain mesh is presented, that scales between very coarse domain meshes and good property-mapping.

Simulated Rainfall-Driven Dissolution of TNT, Tritonal, Comp B and Octol Particles

DTIC Science & Technology

2009-01-01

Comp B a b s t r a c t Live-fire military training can deposit millimeter- sized particles of high explosives (HE) on surface soils when rounds do not...might dissolve under the action of rainfall and to use the data to verify a model that predicts HE dissolution as a function of particle size , particle...Detonations scatter HE particles broadly over surface soils. High-order detonations scatter lm- size HE particles and low-order (LO) detonations scatter

[Characterization of an extracellular glycolipid from Lentinus edodes (Berk.) Sing [Lentinula edodes (Berk.) Pegler

PubMed

Tsivileva, O M; Nikitina, V E; Makarov, O E

2008-01-01

Submerged mycelium of a xylotrophic basidiomycete Lentinus edodes produces an extracellular glycolipid, S3, associated with a lectin. Galactose glycan residue, as well as the lipid pool composition, which includes nonhydroxylated short-chain fatty acids, is uncommon for basidiomycetes. The glycolipid consists of D-galactopyranose (15% of S3 contains galactose sulfate) acylated by octadecanoic and nonadecanoic fatty acid residues (28 and 72%, respectively). The glycolipid structure and composition are confirmed by physicochemical analysis. The glycolipid is assumed to be a regulator of lectin activity.

Impact of supplemental protein source offered to primiparous heifers during gestation on I. Average daily gain, feed intake, calf birth body weight, and rebreeding in pregnant beef heifers.

PubMed

Summers, A F; Meyer, T L; Funston, R N

2015-04-01

A 3-yr study was conducted to determine the effect of supplemental protein source on ADG, feed intake, calf birth BW, and subsequent pregnancy rate in pregnant beef heifers. Crossbred, Angus-based, AI-pregnant heifers (yr 1, n = 38; yr 2, n = 40; and yr 3, n = 36) were stratified by BW (450 ± 10 kg) and placed in a Calan Broadbent individual feeding system at approximately d 142 of gestation. Following a 25-d adaptation period, an 84-d feeding trial was conducted. Heifers were offered ad libitum grass hay (8 to 11% CP, DM basis) and no supplement (CON), 0.83 kg/d distillers-based supplement (HI), or 0.83 kg/d dried corn gluten-based supplement (LO). Supplements were formulated to be isocaloric, isonitrogenous (28% CP, DM basis), and equal in lipid content but differed in RUP, with HI (59% RUP) having greater levels of RUP than LO (34% RUP). Dry matter intake was also calculated based on feed NE values to account for different energy levels of the supplement compared with the control diet. Control heifers tended (P = 0.09) to consume less total DM than either supplement treatment. However, forage-only DMI was greater (P < 0.01) for CON heifers (9.94 ± 0.12 kg) compared with HI or LO heifers (8.50 and 8.34 ± 0.12 kg, respectively). Net energy DMI was less (P < 0.01) for CON heifers (4.98 ± 0.23 kg) compared with HI or LO heifers (5.43 and 5.35 ± 0.23 kg, respectively). Control heifers gained less (P < 0.01; 0.59 ± 0.14 kg/d) than either HI (0.82 ± 0.14 kg/d) or LO heifers (0.78 ± 0.14 kg/d), resulting in lower (501 ± 9 kg) BW (P < 0.01) than HI (519 ± 9 kg) heifers at the end of the feeding period. Calf birth BW was similar (P = 0.99) among treatments. At prebreeding, CON heifers weighed less (P < 0.03) than LO heifers. Cow BW was similar (P = 0.48) among treatments at pregnancy diagnosis, and final pregnancy rate was also similar (87%; P = 0.22). Protein supplementation increased ADG in pregnant heifers; however, calf birth BW and subsequent pregnancy rates were similar.

Polymeric membrane materials for artificial organs.

PubMed

Kawakami, Hiroyoshi

2008-01-01

Many polymeric materials have already been used in the field of artificial organs. However, the materials used in artificial organs are not necessarily created with the best material selectivity and materials design; therefore, the development of synthesized polymeric membrane materials for artificial organs based on well-defined designs is required. The approaches to the development of biocompatible polymeric materials fall into three categories: (1) control of physicochemical characteristics on material surfaces, (2) modification of material surfaces using biomolecules, and (3) construction of biomimetic membrane surfaces. This review will describe current issues regarding polymeric membrane materials for use in artificial organs.

Surface physicochemical properties and decay of the low-lying isomer in the 229Th nucleus

NASA Astrophysics Data System (ADS)

Borisyuk, P. V.; Kurel'chuk, U. N.; Vasil'ev, O. S.; Troyan, V. I.; Lebedinskii, Yu Yu; Tkalya, E. V.

2018-05-01

The effect of the 229Th nucleus proximity to the CsI surface on the decay probability of its anomalously low lying isomeric level is studied. Results of experimental and theoretical studies show that the CsI surface does not produce chemical bonding with Th and does not noticeably change its valence shells. Hence, it is an optimal substrate for measuring the probability of the 229Th isomer state decay via internal electron conversion. The half-life of the 229Thm isomer in the thorium atom is calculated for neutral chemical environment.

The Influence of the Surface Neutralization of Active Impurities on the Field-Electron Emission Properties of p-Type Silicon Crystals

NASA Astrophysics Data System (ADS)

Yafarov, R. K.

2017-12-01

Correlation dependences between variations of the structural-phase composition, morphology characteristics, and field-electron-emission (FEE) properties of surface-structured p-type silicon singlecrystalline (100)-oriented wafers have been studied during their stepwise high-dose carbon-ion-beam irradiation. It is established that the stepwise implantation of carbon decreases the FEE threshold and favors an increase in the maximum FEE-current density by more than two orders of magnitude. Physicochemical mechanisms involved in this modification of the properties of near-surface layers of silicon under carbon-ion implantation are considered.

New approach to accuracy verification of 3D surface models: An analysis of point cloud coordinates.

PubMed

Lee, Wan-Sun; Park, Jong-Kyoung; Kim, Ji-Hwan; Kim, Hae-Young; Kim, Woong-Chul; Yu, Chin-Ho

2016-04-01

The precision of two types of surface digitization devices, i.e., a contact probe scanner and an optical scanner, and the trueness of two types of stone replicas, i.e., one without an imaging powder (SR/NP) and one with an imaging powder (SR/P), were evaluated using a computer-aided analysis. A master die was fabricated from stainless steel. Ten impressions were taken, and ten stone replicas were prepared from Type IV stone (Fujirock EP, GC, Leuven, Belgium). The precision of two types of scanners was analyzed using the root mean square (RMS), measurement error (ME), and limits of agreement (LoA) at each coordinate. The trueness of the stone replicas was evaluated using the total deviation. A Student's t-test was applied to compare the discrepancies between the CAD-reference-models of the master die (m-CRM) and point clouds for the two types of stone replicas (α=.05). The RMS values for the precision were 1.58, 1.28, and 0.98μm along the x-, y-, and z-axes in the contact probe scanner and 1.97, 1.32, and 1.33μm along the x-, y-, and z-axes in the optical scanner, respectively. A comparison with m-CRM revealed a trueness of 7.10μm for SR/NP and 8.65μm for SR/P. The precision at each coordinate (x-, y-, and z-axes) was revealed to be higher than the one assessed in the previous method (overall offset differences). A comparison between the m-CRM and 3D surface models of the stone replicas revealed a greater dimensional change in SR/P than in SR/NP. Copyright © 2015 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

14 CFR 77.28 - Military airport imaginary surfaces.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Military airport imaginary surfaces. 77.28 Section 77.28 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... above the established airfield elevation. (3) Outer horizontal surface. A plane, located 500 feet above...

Physico-chemical changes of ZnO nanoparticles with different size and surface chemistry under physiological pH conditions.

PubMed

Gwak, Gyeong-Hyeon; Lee, Won-Jae; Paek, Seung-Min; Oh, Jae-Min

2015-03-01

We studied the physico-chemical properties of ZnO nanoparticles under physiological pH conditions (gastric, intestinal and plasma) as functions of their size (20 and 70 nm) and surface chemistry (pristine, L-serine, or citrate coating). ZnO nanoparticles were dispersed in phosphate buffered saline under physiological pH conditions and aliquots were collected at specific time points (0.5, 1, 4, 10 and 24 h) for further characterization. The pH values of the aqueous ZnO colloids at each condition were in the neutral to slightly basic range and showed different patterns depending on the original size and surface chemistry of the ZnO nanoparticles. The gastric pH condition was found to significantly dissolve ZnO nanoparticles up to 18-30 wt%, while the intestinal or plasma pH conditions resulted in much lower dissolution amounts than expected. Based on the X-ray diffraction patterns and X-ray absorption spectra, we identified partial phase transition of the ZnO nanoparticles from wurtzite to Zn(OH)2 under the intestinal and plasma pH conditions. Using scanning electron microscopy, we verified that the overall particle size and morphology of all ZnO nanoparticles were maintained regardless of the pH. Copyright © 2015 Elsevier B.V. All rights reserved.

Evaluation of the physicochemical characteristics of crospovidone that influence solid dispersion preparation.

PubMed

Nakanishi, Sayaka; Fujii, Makiko; Sugamura, Yuka; Suzuki, Ayako; Shibata, Yusuke; Koizumi, Naoya; Watanabe, Yoshiteru

2011-07-15

A solid dispersion (SD) powder of indomethacin (IM) with crospovidone (CrosPVP) shows useful characteristics for manufacturing dosage forms. Four types of commercial CroPVP, Polyplasdone XL (XL) used as the initial carrier, Polyplasdone XL10 and INF-10 manufactured by milling XL, and Kollidon CL (CL) marketed by another company, were compared. The limit of the IM-CrosPVP weight ratio with which an SD can be prepared (maximum IM content) was calculated on the basis of the heat of fusion of physical mixtures of IM and CrosPVP with various weight ratios. When Polyplasdones were used, the maximum IM content increased with the specific surface area of the CrosPVP. When CL was used, however, it was about half of that obtained with XL, even though the difference between XL and CL was not observed in the physicochemical characteristics (particle size, specific surface area, flowability, glass transition temperature, IR spectra, and solid state NMR spectra). As determined by pore size distribution measurement, the volume of pore of which size is larger than the particle size of IM was less in CL than in XL. Therefore, the effective surface area of CrosPVP that comes in contact with IM is important for the preparation of the SD. Copyright © 2011 Elsevier B.V. All rights reserved.

Conversion of CH4/CO2 to syngas over Ni-Co/Al2O3-ZrO2 nanocatalyst synthesized via plasma assisted co-impregnation method: Surface properties and catalytic performance

NASA Astrophysics Data System (ADS)

Rahemi, Nader; Haghighi, Mohammad; Akbar Babaluo, Ali; Fallah Jafari, Mahdi; Khorram, Sirous

2013-09-01

Ni/Al2O3 catalyst promoted by Co and ZrO2 was prepared by co-impregnation method and treated with glow discharge plasma. The catalytic activity of the synthesized nanocatalysts has been tested toward conversion of CH4/CO2 to syngas. The physicochemical characterizations like XRD, EDX, FESEM, TEM, BET, FTIR, and XPS show that plasma treatment results in smaller particle size, more surface concentration, and uniform morphology. The dispersion of nickel in plasma-treated nanocatalyst was also significantly improved, which was helpful for controlling the ensemble size of active phase atoms on the support surface. Improved physicochemical properties caused 20%-30% enhancement in activity of plasma-treated nanocatalyst that means to achieve the same H2 or CO yield, the plasma-treated nanocatalyst needed about 100 °C lower reaction temperature. The H2/CO ratio got closer to 1 at higher temperatures and finally at 850 °C H2/CO = 1 is attained for plasma-treated nanocatalyst. Plasma-treated nanocatalyst due to smaller Ni particles and strong interaction between active phase and support has lower tendency to keep carbon species on its structure and hence excellent stability can be observed for this catalyst.

Possibilities of surface waters monitoring at mining areas using UAV

NASA Astrophysics Data System (ADS)

Lisiecka, Ewa; Motyka, Barbara; Motyka, Zbigniew; Pierzchała, Łukasz; Szade, Adam

2018-04-01

The selected, remote measurement methods are discussed, useful for determining surface water properties using mobile unmanned aerial platforms (UAV). The possibilities of using this type of solutions in the scope of measuring spatial, physicochemical and biological parameters of both natural and anthropogenic water reservoirs, including flood polders, water-filled pits, settling tanks and mining sinks were analyzed. Methods of remote identification of the process of overgrowing this type of ecosystems with water and coastal plant formations have also been proposed.

Self-organization of multifunctional surfaces--the fingerprints of light on a complex system.

PubMed

Reinhardt, Hendrik; Kim, Hee-Cheol; Pietzonka, Clemens; Kruempelmann, Julia; Harbrecht, Bernd; Roling, Bernhard; Hampp, Norbert

2013-06-25

Nanocomposite patterns and nanotemplates are generated by a single-step bottom-up concept that introduces laser-induced periodic surface structures (LIPSS) as a tool for site-specific reaction control in multicomponent systems. Periodic intensity fluctuations of this photothermal stimulus inflict spatial-selective reorganizations, dewetting scenarios and phase segregations, thus creating regular patterns of anisotropic physicochemical properties that feature attractive optical, electrical, magnetic, and catalytic properties. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Which Environmental Factors Predict Seasonal Variation in the Coral Health of Acropora digitifera and Acropora spicifera at Ningaloo Reef?

PubMed Central

Hinrichs, Saskia; Patten, Nicole L.; Feng, Ming; Strickland, Daniel; Waite, Anya M.

2013-01-01

The impact of physico-chemical factors on percent coral cover and coral health was examined on a spatial basis for two dominant Acropora species, A. digitifera and A. spicifera, at Ningaloo Reef (north-western Australia) in the southeast Indian Ocean. Coral health was investigated by measuring metabolic indices (RNA/DNA ratio and protein concentration), energy levels (lipid ratio) and autotrophic indices (chlorophyll a (chl a) and zooxanthellae density) at six stations during typical seasons (austral autumn 2010 (March and April), austral winter 2010 (August)) and during an extreme La Niña event in summer 2011 (February). These indices were correlated with 15 physico-chemical factors (measured immediately following coral sampling) to identify predictors for health indices. Variations in metabolic indices (protein concentration and RNA/DNA ratio) for A. spicifera were mainly explained by nitrogen, temperature and zooplankton concentrations under typical conditions, while for A. digitifera, light as well as phytoplankton, in particular picoeukaryotes, were important, possibly due to higher energy requirement for lipid synthesis and storage in A. digitifera. Optimum metabolic values occurred for both Acropora species at 26–28°C when autotrophic indices (chl a and zooxanthellae density) were lowest. The extreme temperature during the La Niña event resulted in a shift of feeding modes, with an increased importance of water column plankton concentrations for metabolic rates of A. digitifera and light and plankton for A. spicifera. Our results suggest that impacts of high sea surface temperatures during extreme events such as La Niña may be mitigated via reduction on metabolic rates in coral host. The high water column plankton concentrations and associated low light levels resulted in a shift towards high symbiont densities, with lower metabolic rates and energy levels than the seasonal norm for the coral host. PMID:23637770

Just What Is It That Makes Silver Nanoprisms So Different, So Appealing?

ERIC Educational Resources Information Center

Panzarasa, Guido

2015-01-01

Thanks to their unique physicochemical properties (e.g., surface plasmon resonance), noble metal nanoparticles are at the cornerstone of nanotechnology. Silver triangular nanoprisms are presented here as an ideal playground to introduce students to nanochemistry concepts such as the formation of shape-controlled nanostructures. Not only a reliable…

Coupling online effects-based monitoring with physicochemical, optical, and spectroscopy methods to assess quality at a surface water intake

EPA Science Inventory

Effects-based monitoring of water quality is a proven approach to monitoring the status of a water source. Only biological material can integrate factors which dictate toxicity. Online Toxicity Monitors (OTMs) provide a means to digitize sentinel organism responses to dynamic wa...

PREPARATION, CHARACTERIZATION AND ACTIVITY OF AL2O3-SUPPORTED V2O5 CATALYSTS

EPA Science Inventory

A series of activated alumina supported vanadium oxide catalysts with various V2O5 loadings ranging from 5 to 25 wt% has been prepared by wet impregnation technique. A combination of various physico-chemical techniques such as BET surface areas, oxygen chemisorption, X-ray diffra...

The influence of ArF excimer laser micromachining on physicochemical properties of bioresorbable poly(L-lactide)

NASA Astrophysics Data System (ADS)

Stepak, Bogusz D.; Antończak, Arkadiusz J.; Szustakiewicz, Konrad; Pezowicz, Celina; Abramski, Krzysztof M.

2016-03-01

The main advantage of laser processing is a non-contact character of material removal and high precision attainable thanks to low laser beam dimensions. This technique enables forming a complex, submillimeter geometrical shapes such as vascular stents which cannot be manufactured using traditional techniques e.g. injection moulding or mechanical treatment. In the domain of nanosecond laser sources, an ArF excimer laser appears as a good candidate for laser micromachining of bioresorbable polymers such as poly(L-lactide). Due to long pulse duration, however, there is a risk of heat diffusion and accumulation in the material. In addition, due to short wavelength (193 nm) photochemical process can modify the chemical composition of ablated surfaces. The motivation for this research was to evaluate the influence of laser micromachining on physicochemical properties of poly(L-lactide). We performed calorimetric analysis of laser machined samples by using differential scanning calorimetry (DSC). It allowed us to find the optimal process parameters for heat affected zone (HAZ) reduction. The chemical composition of the ablated surface was investigated by FTIR in attenuated total reflectance (ATR) mode.

Production and evaluation of Ighu from selected cassava varieties using a motorized shredder—a response surface analysis

PubMed Central

Iwe, Madu O; Agiriga, Ann N

2013-01-01

Cassava varieties, TME419, TMS30572, and TMS98/0505, were planted and harvested at 3-month intervals of 10, 13, and 16 months, respectively. A central composite response surface design was used to study the effects of the variables cassava variety, harvesting time, and shredding aperture on selected physicochemical properties of Ighu samples. Regression models showed that the experimental variables had significant (P ≤ 0.05) effects on the hydrogen cyanide, moisture content, thickness, and width of dry Ighu. Minimum values obtainable for the physicochemical properties were 8.1195 mg/kg (10-month, 3-mm shredding aperture from TMS98/0505), 7.58% (13-month, 3-mm shredding aperture from TME419), 0.19 mm (13-month, 3-mm shredding aperture and from TMS30572), and 0.99 mm (16-month, 3-mm shredding aperture from TME419) for hydrogen cyanide, moisture content, thickness, and width, respectively. In addition, Ighu produced from 3-mm shredding aperture (TMS30572) at 10-month harvest was the most preferred of all the samples. PMID:24804057

Physico-chemical properties and gasification reactivity of co-pyrolysis char from different rank of coal blended with lignocellulosic biomass: Effects of the cellulose.

PubMed

Wu, Zhiqiang; Wang, Shuzhong; Luo, Zhengyuan; Chen, Lin; Meng, Haiyu; Zhao, Jun

2017-07-01

In this paper, the influence of cellulose on the physicochemical properties and the gasification reactivity of co-pyrolysis char was investigated. A specific surface area analyzer and an X-ray diffraction system were used to characterize the pore structure and the micro-crystalline structure of char. Fractal theory and deconvolution method were applied to quantitatively investigate the influence of cellulose on the structure of co-pyrolysis char. The results indicate that the improvements in the pore structure due to the presence of cellulose are more pronounced in the case of anthracite char with respect to bituminous char. Cellulose promotes the ordering of micro-scale structure and the uniformity of both anthracite and bituminous char, while the negative synergetic effect was observed during gasification of co-pyrolysis char. The exponential relationships between fractal dimension and specific surface area were determined, along with the relations between the gasification reactivity index and the microcrystalline structure parameter. Copyright © 2017 Elsevier Ltd. All rights reserved.

Enhanced surface functionality and microbial fuel cell performance of chitosan membranes through phosphorylation.

PubMed

Holder, Shima L; Lee, Ching-Hwa; Popuri, Srinivasa R; Zhuang, Meng-Xin

2016-09-20

The effects of plasticization and cross-linking on the performance of chitosan as promising proton exchange membranes (PEMs) for bioelectricity generation in microbial fuel cells (MFCs) were investigated. The physico-chemical properties of chitosan (CS), sorbitol-chitosan (S-CS), phosphorylated-chitosan (CS-P) and phosphorylated-sorbitol-chitosan (S-CS-P) membranes were investigated by FESEM-EDS, FTIR-ATR, XRD, TGA, tensile strength and sorption studies. The performance of the fabricated PEMs was assessed by power density and cation exchange capacity (CEC). Maximum power densities achieved were 130.03, 20.76, 94.59 and 7.42mW/m(2) for CS-P, S-CS-P, S-CS and CS membranes respectively. Phosphorylation of the CS membranes increased CEC and tensile strength, attributed to an increase in bonded amide and phosphate ionic surface groups. Further, 49.07% COD removal from municipal wastewater was achieved with CS-P membranes. Thus, through chemical modifications, the physico-chemical and mechanical properties of natural abundant biopolymer chitosan can be enhanced for its use as an environmentally sustainable PEM in MFC technology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cytotoxicity screening of 23 engineered nanomaterials using a test matrix of ten cell lines and three different assays

PubMed Central

2011-01-01

Background Engineered nanomaterials display unique properties that may have impact on human health, and thus require a reliable evaluation of their potential toxicity. Here, we performed a standardized in vitro screening of 23 engineered nanomaterials. We thoroughly characterized the physicochemical properties of the nanomaterials and adapted three classical in vitro toxicity assays to eliminate nanomaterial interference. Nanomaterial toxicity was assessed in ten representative cell lines. Results Six nanomaterials induced oxidative cell stress while only a single nanomaterial reduced cellular metabolic activity and none of the particles affected cell viability. Results from heterogeneous and chemically identical particles suggested that surface chemistry, surface coating and chemical composition are likely determinants of nanomaterial toxicity. Individual cell lines differed significantly in their response, dependent on the particle type and the toxicity endpoint measured. Conclusion In vitro toxicity of the analyzed engineered nanomaterials cannot be attributed to a defined physicochemical property. Therefore, the accurate identification of nanomaterial cytotoxicity requires a matrix based on a set of sensitive cell lines and in vitro assays measuring different cytotoxicity endpoints. PMID:21345205

Understanding the effect of alkyl chains of gemini cations on the physicochemical and cellular properties of polyurethane micelles.

PubMed

Pan, Zhicheng; Fang, Danxuan; Song, Yuanqing; Song, Nijia; Ding, Mingming; Li, Jiehua; Luo, Feng; Li, Jianshu; Tan, Hong; Fu, Qiang

2018-06-06

Cationic gemini quaternary ammonium (GQA) has been used as a cell internalization promoter to improve the permeability of the cell membrane and enhance the cellular uptake. However, the effect of the alkyl chain length on the cellular properties of nanocarriers has not been elucidated yet. In this study, we developed a series of polyurethane micelles containing GQAs with various alkyl chain lengths. The alteration of the gemini alkyl chain length was found to change the distribution of GQA surfactants in the micellar structure and affect the surface charge exposure, stability, and the protein absorption properties of nanocarriers. Moreover, we also clarified the role of the alkyl chain length in tumor cell internalization and macrophage uptake of polyurethane micelles. This work provides a new understanding on the effect of the GQA alkyl chain length on the physicochemical and biological properties of nanomedicines, and offers guidance on the rational design of effective drug delivery systems where the issue of functional group exposure at the micellar surface should be considered.

A plant derived multifunctional tool for nanobiotechnology based on Tomato bushy stunt virus.

PubMed

Grasso, Simone; Lico, Chiara; Imperatori, Francesca; Santi, Luca

2013-06-01

Structure, size, physicochemical properties and production strategies make many plant viruses ideal protein based nanoscaffolds, nanocontainers and nano-building blocks expected to deliver a multitude of applications in different fields such as biomedicine, pharmaceutical chemistry, separation science, catalytic chemistry, crop pest control and biomaterials science. Functionalization of viral nanoparticles through modification by design of their external and internal surfaces is essential to fully exploit the potentiality of these objects. In the present paper we describe the development of a plant derived multifunctional tool for nanobiotechnology based on Tomato bushy stunt virus. We demonstrate the ability of this system to remarkably sustain genetic modifications and in vitro chemical derivatizations of its outer surface, which resulted in the successful display of large chimeric peptides fusions and small chemical molecules, respectively. Moreover, we have defined physicochemical conditions for viral swelling and reversible viral pore gating that we have successfully employed for foreign molecules loading and retention in the inner cavity of this plant virus nanoparticles system. Finally, a production and purification strategy from Nicotiana benthamiana plants has been addressed and optimized.

Physical and chemical characterization of waste wood derived biochars.

PubMed

Yargicoglu, Erin N; Sadasivam, Bala Yamini; Reddy, Krishna R; Spokas, Kurt

2015-02-01

Biochar, a solid byproduct generated during waste biomass pyrolysis or gasification in the absence (or near-absence) of oxygen, has recently garnered interest for both agricultural and environmental management purposes owing to its unique physicochemical properties. Favorable properties of biochar include its high surface area and porosity, and ability to adsorb a variety of compounds, including nutrients, organic contaminants, and some gases. Physical and chemical properties of biochars are dictated by the feedstock and production processes (pyrolysis or gasification temperature, conversion technology and pre- and post-treatment processes, if any), which vary widely across commercially produced biochars. In this study, several commercially available biochars derived from waste wood are characterized for physical and chemical properties that can signify their relevant environmental applications. Parameters characterized include: physical properties (particle size distribution, specific gravity, density, porosity, surface area), hydraulic properties (hydraulic conductivity and water holding capacity), and chemical and electrochemical properties (organic matter and organic carbon contents, pH, oxidation-reduction potential and electrical conductivity, zeta potential, carbon, nitrogen and hydrogen (CHN) elemental composition, polycyclic aromatic hydrocarbons (PAHs), heavy metals, and leachable PAHs and heavy metals). A wide range of fixed carbon (0-47.8%), volatile matter (28-74.1%), and ash contents (1.5-65.7%) were observed among tested biochars. A high variability in surface area (0.1-155.1g/m(2)) and PAH and heavy metal contents of the solid phase among commercially available biochars was also observed (0.7-83 mg kg(-1)), underscoring the importance of pre-screening biochars prior to application. Production conditions appear to dictate PAH content--with the highest PAHs observed in biochar produced via fast pyrolysis and lowest among the gasification-produced biochars. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of groundwater quality and suitability for irrigation and drinking purposes in southwest Punjab, India using hydrochemical approach

NASA Astrophysics Data System (ADS)

Sharma, Diana Anoubam; Rishi, Madhuri S.; Keesari, Tirumalesh

2017-10-01

Groundwater samples from alluvial aquifers of Bathinda district, southwest Punjab were measured for physicochemical parameters as well as major ion chemistry to evaluate the groundwater suitability for drinking and irrigation purposes and to present the current hydrochemical status of groundwater of this district. Temporal variations were analyzed by comparing the pre- and post-monsoon groundwater chemistry. Most of the samples showed contamination: F- (72 %), Mg2+ (22 %), SO4 2- (28 %), TH (25 %), NO3 - (22 %), HCO3 - (22 %) and TDS (11 %) during pre-monsoon and F- (50 %), Mg2+ (39 %), SO4 2- (22 %), TH (28 %), NO3 - (22 %) and TDS (28 %) during post-monsoon above permissible limits for drinking, while rest of the parameters fall within the limits. Irrigation suitability was checked using sodium absorption ratio (SAR), residual sodium carbonate (RSC), percent sodium (Na%) and permeability index (PI). Most of the samples fall under good to suitable category during pre-monsoon period, but fall under doubtful to unsuitable category during post-monsoon period. Presence of high salt content in groundwater during post-monsoon season reflects leaching of salts present in the unsaturated zone by infiltrating precipitation. Hydrochemical data was interpreted using Piper's trilinear plot and Chadha's plot to understand the various geochemical processes affecting the groundwater quality. The results indicate that the order of cation dominance is Na+ > Mg2+ > Ca2+, while anion dominance is in the order Cl- > HCO3 - > SO4 2-. The geochemistry of groundwater of this district is mainly controlled by the carbonate and silicate mineral dissolution and ion exchange during pre-monsoon and leaching from the salts deposited in vadose zone during post-monsoon. The main sources of contamination are soluble fertilizers and livestock wastes. This study is significant as the surface water resources are limited and the quality and quantity of groundwater are deteriorating with time due to anthropogenic inputs.

Kaempferol loaded lecithin/chitosan nanoparticles: preparation, characterization, and their potential applications as a sustainable antifungal agent.

PubMed

Ilk, Sedef; Saglam, Necdet; Özgen, Mustafa

2017-08-01

Flavonoid compounds are strong antioxidant and antifungal agents but their applications are limited due to their poor dissolution and bioavailability. The use of nanotechnology in agriculture has received increasing attention, with the development of new formulations containing active compounds. In this study, kaempferol (KAE) was loaded into lecithin/chitosan nanoparticles (LC NPs) to determine antifungal activity compared to pure KAE against the phytopathogenic fungus Fusarium oxysporium to resolve the bioavailability problem. The influence of formulation parameters on the physicochemical properties of KAE loaded lecithin chitosan nanoparticles (KAE-LC NPs) were studied by using the electrostatic self-assembly technique. KAE-LC NPs were characterized in terms of physicochemical properties. KAE has been successfully encapsulated in LC NPs with an efficiency of 93.8 ± 4.28% and KAE-LC NPs showed good physicochemical stability. Moreover, in vitro evaluation of the KAE-LC NP system was made by the release kinetics, antioxidant and antifungal activity in a time-dependent manner against free KAE. Encapsulated KAE exhibited a significantly inhibition efficacy (67%) against Fusarium oxysporium at the end of the 60 day storage period. The results indicated that KAE-LC NP formulation could solve the problems related to the solubility and loss of KAE during use and storage. The new nanoparticle system enables the use of smaller quantities of fungicide and therefore, offers a more environmentally friendly method of controlling fungal pathogens in agriculture.

Salt microspheres and potassium chloride usage for sodium reduction: Case study with sushi.

PubMed

Đorđević, Đani; Buchtová, Hana; Macharáčková, Blanka

2018-01-01

The aim of the study was to estimate possibilities of salt substitutes usage in the preparation of two sushi types (nigiri and maki) prepared with different seafood (salmon: Salmo salar, tuna: Thunnus albacares, and shrimp: Pleoticus muelleri). Potassium chloride (Mary samples), Soda-Lo (hollowed microsphere of regular salt crystals), and regular salt (sodium chloride) were used in the experiment. Sushi samples (n = 1960) were evaluated by 40 trained panelists who noticed that maki shrimp samples prepared with Mary salt had higher bitterness (21.48 ± 28.01) in comparison with 2% sodium chloride (7.91 ± 8.80). The saltiness was lower in nigiri tuna prepared with Mary (49.59 ± 17.47) than 2% sodium chloride (61.11 ± 15.75). The study clearly showed the possibility of lowering sodium content in sushi meal with the usage of salt substitutes, with emphasis that Soda-Lo should be considered as a better option due to the retention of sensory properties in sushi samples prepared with this salt substitute.

Finite volume effects in the chiral extrapolation of baryon masses

NASA Astrophysics Data System (ADS)

Lutz, M. F. M.; Bavontaweepanya, R.; Kobdaj, C.; Schwarz, K.

2014-09-01

We perform an analysis of the QCD lattice data on the baryon octet and decuplet masses based on the relativistic chiral Lagrangian. The baryon self-energies are computed in a finite volume at next-to-next-to-next-to-leading order (N3LO), where the dependence on the physical meson and baryon masses is kept. The number of free parameters is reduced significantly down to 12 by relying on large-Nc sum rules. Altogether we describe accurately more than 220 data points from six different lattice groups, BMW, PACS-CS, HSC, LHPC, QCDSF-UKQCD and NPLQCD. Values for all counterterms relevant at N3LO are predicted. In particular we extract a pion-nucleon sigma term of 39-1+2 MeV and a strangeness sigma term of the nucleon of σsN=84-4+28 MeV. The flavor SU(3) chiral limit of the baryon octet and decuplet masses is determined with (802±4) and (1103±6) MeV. Detailed predictions for the baryon masses as currently evaluated by the ETM lattice QCD group are made.

14 CFR 77.28 - Military airport imaginary surfaces.

Code of Federal Regulations, 2010 CFR

2010-01-01

... (CONTINUED) AIRSPACE OBJECTS AFFECTING NAVIGABLE AIRSPACE Obstruction Standards § 77.28 Military airport.... These surfaces connect the primary surfaces, the first 200 feet of the clear zone surfaces, and the...

Mechanochemical synthesis and physico-chemical investigations of new materials for gas sensors

NASA Astrophysics Data System (ADS)

Shubenkova, E. G.

2018-01-01

Solid solutions of the InSb-ZnTe semiconductor system containing up to 20 mol.% of ZnTe were synthesized for the first time. The role of mechanochemical treatment in the process of obtaining solid solutions of this system is shown. Solid solutions in the InSb-ZnTe system have been identified by Raman spectroscopy, and the optical properties of its components have been studied. On the basis of an analysis of the anti-stokes spectral radiation distribution the solid solutions formation was identified both on the dependence of the spectral distribution maximum’s shift on the composition of the InSb1-x-ZnTex system, and by estimating the radiation intensity of the initial binary semiconductors at frequencies corresponding to the LO- and TO- vibrations of the binary compounds crystal lattice. The values of the band gap for InSb, (InSb)0.95(ZnTe)0.05 and (InSb)0.9(ZnTe)0.1 were calculated, their values were 0.22 eV, 0.30 eV and 0.38 eV, respectively.

New Direction of NASA Exploration Life Support

NASA Technical Reports Server (NTRS)

Chambliss, Joe; Lawson, B. Michael; Barta, Daniel J.

2006-01-01

NASA's activities in life support Research and Technology Development (R&TD) have changed in both focus and scope following implementation of recommendations from the Exploration System Architecture Study (ESAS). The limited resources available and the compressed schedule to conduct life support R&TD have required that future efforts address the needs of the Crew Exploration Vehicle (CEV), the Lunar Surface Access Module (LSAM) and Lunar Outpost (LO). Advanced Life Support (ALS) efforts related to long duration planetary bases have been deferred or canceled. This paper describes the scope of the new Exploration Life Support (ELS) project; how it differs from ALS, and how it supports critical needs for the CEV, LSAM and LO. In addition, this paper provides rationale for changes in the scope and focus of technical content within ongoing life support R&TD activities.

Processing effects on physicochemical properties of creams formulated with modified milk fat.

PubMed

Bolling, J C; Duncan, S E; Eigel, W N; Waterman, K M

2005-04-01

Type of thermal process [high temperature, short time pasteurization (HTST) or ultra-high temperature pasteurization (UHT)] and homogenization sequence (before or after pasteurization) were examined for influence on the physicochemical properties of natural cream (20% milk fat) and creams formulated with 20% low-melt, fractionated butteroil emulsified with skim milk, or buttermilk and butter-derived aqueous phase. Homogenization sequence influenced physicochemical makeup of the creams. Creams homogenized before pasteurization contained more milk fat surface material, higher phospholipid levels, and less protein at the milk fat interface than creams homogenized after pasteurization. Phosphodiesterase I activity was higher (relative to protein on lipid globule surface) when cream was homogenized before pasteurization. Creams formulated with skim milk and modified milk fat had relatively more phospholipid adsorbed at the milk fat interface. Ultra-high-temperature-pasteurized natural and reformulated creams were higher in viscosity at all shear rates investigated compared with HTST-pasteurized creams. High-temperature, short time-pasteurized natural cream was more viscous than HTST-pasteurized reformulated creams at most shear rates investigated. High-temperature, short time-pasteurized creams had better emulsion stability than UHT-pasteurized creams. Cream formulated with buttermilk had creaming stability most comparable to natural cream, and cream formulated with skim milk and modified butteroil was least stable to creaming. Most creams feathered in a pH range of 5.00 to 5.20, indicating that they were moderately stable to slightly unstable emulsions. All processing sequences yielded creams within sensory specifications with the exception of treatments homogenized before UHT pasteurization and skim milk formulations homogenized after UHT pasteurization.

Advances in the surface modification techniques of bone-related implants for last 10 years

PubMed Central

Qiu, Zhi-Ye; Chen, Cen; Wang, Xiu-Mei; Lee, In-Seop

2014-01-01

At the time of implanting bone-related implants into human body, a variety of biological responses to the material surface occur with respect to surface chemistry and physical state. The commonly used biomaterials (e.g. titanium and its alloy, Co–Cr alloy, stainless steel, polyetheretherketone, ultra-high molecular weight polyethylene and various calcium phosphates) have many drawbacks such as lack of biocompatibility and improper mechanical properties. As surface modification is very promising technology to overcome such problems, a variety of surface modification techniques have been being investigated. This review paper covers recent advances in surface modification techniques of bone-related materials including physicochemical coating, radiation grafting, plasma surface engineering, ion beam processing and surface patterning techniques. The contents are organized with different types of techniques to applicable materials, and typical examples are also described. PMID:26816626

Effect of inulin and glycerol supplementation on physicochemical properties of probiotic frozen yogurt

PubMed Central

Muzammil, Hafiz Shehzad; Rasco, Barbara; Sablani, Shyam

2017-01-01

ABSTRACT The present study was designed to investigate the effects of inulin and glycerol supplementation on physicochemical properties of probiotic frozen yogurt. Frozen yogurt was prepared with different types of probiotic (Lactobacillus acidophilus and Bifidobacterium lactis) along with yogurt starter culture (Streptococcus thermophilus and Lactobacillus bulgaricus). The frozen yogurt mixture was supplemented with inulin (2%, 4%, and 6%) and glycerol (1%, 2%, 3%, and 4%). The results showed that inulin 4% and 6% supplementation increased the overrun by 3% and 5% and the glass transition temperature by 3.3% and 2.8%, and decreased the hardness by 7% and 11%, respectively. Inulin supplementation did not have a significant effect on ice crystal size (p > 0.05). Glycerol supplementation increased the stickiness from 2.4% to 18.7%, and decreased the hardness from 8.0% to 14.5% and the glass transition temperature from 2.4% to 34.5%, respectively. Glycerol supplementation did not have a significant effect on overrun or melting rate (p > 0.05). PMID:28326004

Ochratoxin A removal by Saccharomyces cerevisiae strains: effect of wine-related physicochemical factors.

PubMed

Petruzzi, Leonardo; Sinigaglia, Milena; Corbo, Maria Rosaria; Beneduce, Luciano; Bevilacqua, Antonio

2013-07-01

This study investigated the effect of some physicochemical parameters on the removal of ochratoxin A (OTA) by yeasts. Two wild strains of Saccharomyces cerevisiae (W47 and Y28) were used to assess OTA removal under various conditions of temperature, pH, ethanol content and incubation time. All samples were analysed for OTA concentration by enzyme-linked immunosorbent assay (ELISA). In addition, yeast oenological traits were investigated: qualitative and technological traits were assessed on appropriate laboratory media, while the main products of microfermentation (sugars, ethanol, glycerol, acetic acid) were evaluated by Fourier transform infrared spectroscopy (FTIR). The results showed OTA reduction by 36-42% in cultures containing 100 g L⁻¹ ethanol incubated at pH 3.5 and 37 °C. OTA removal was affected by contact time, pH and ethanol content, as it was increased at low pH and by 100 g L⁻¹ ethanol. Moreover, the phenomenon was reversible, as OTA was lowest after 4 days, then it was partially released in the medium. © 2012 Society of Chemical Industry.

Enhanced spectrophotometric determination of Losartan potassium based on its physicochemical interaction with cationic surfactant

NASA Astrophysics Data System (ADS)

Abdel-Fattah, Laila; Abdel-Aziz, Lobna; Gaied, Mariam

2015-02-01

In this study, a simple and sensitive spectrophotometric method was developed for determination of Losartan potassium (LST K), an angiotensin-II receptor (type AT1) antagonist, in presence of cationic surfactant cetyltrimethylammonium bromide (CTAB). The physicochemical interaction of LST K with CTAB was investigated. The effect of cationic micelles on the spectroscopic and acid-base properties of LST K was studied at pH 7.4. The binding constant (Kb) and the partition coefficient (Kx) of LST K-CTAB were 1.62 × 105 M-1 and 1.38 × 105; respectively. The binding of LST K to CTAB micelles implied a shift in drug acidity constant (ΔpKa = 0.422). The developed method is linear over the range 0.5-28 μg mL-1. The accuracy was evaluated and was found to be 99.79 ± 0.509% and the relative standard deviation for intraday and interday precision was 0.821 and 0.963; respectively. The method was successfully applied to determine LST K in pharmaceutical formulations.

Improved Physicochemical Properties of Yogurt Fortified with Fish Oil/γ-Oryzanol by Nanoemulsion Technology.

PubMed

Zhong, Jinfeng; Yang, Rong; Cao, Xiaoyi; Liu, Xiong; Qin, Xiaoli

2018-01-02

Fish oil has several dietary benefits, but its application in food formulations is limited because of its poor water-solubility, easy oxidation and strong odor. The purposes of this study were to produce a fish oil/γ-oryzanol nanoemulsion and to evaluate the effect of adding this nanoemulsion on the physicochemical and sensory characteristics of yogurts. Adding fish oil/γ-oryzanol nanoemulsion resulted in a significant reduction in the acidity and syneresis of yogurt. Yogurt with the nanoemulsion had significantly lower peroxide value (0.28 mmol/L after 21 days) and higher retention of eicosapentaenoic acid and docosahexaenoic acid contents (decreased to 95% and 94% of its initial value, respectively) than yogurt with fish oil/γ-oryzanol (peroxide value = 0.65 mmol/L; eicosapentaenoic acid and docosahexaenoic acid contents decreased to 72% and 53% of its initial value, respectively). Fish oil/γ-oryzanol nanoemulsion incorporated into yogurt had closer sensory attributes scores to plain yogurt. This study may have important implications for the application of fish oil/γ-oryzanol nanoemulsion in yogurt.

Insights into the structural and physicochemical properties of small granular starches from two hydrophyte duckweeds, Spirodela oligorrhiza and Lemna minor.

PubMed

Chen, Lei; Yu, Changjiang; Ma, Yubin; Xu, Hua; Wang, Shumin; Wang, Yu; Liu, Xingxun; Zhou, Gongke

2016-11-29

The structure and physicochemical properties of starches from two hydrophyte duckweeds, Spirodela oligorrhiza and Lemna minor, were investigated and compared in this study. The amylose content and average size of starches were determined to be 20.85%, 4.70 μm and 27.77%, 6.17 μm for Spirodela oligorrhiza and Lemna minor, respectively. The average chain length of two duckweed starches was measured to be around DP 28. The chain length distribution was observed to be greatly different from other reported starches for the high proportion of long chains (DP ≥ 37) over 50%. Wide-angle X-ray diffraction profiles of the two starch samples displayed typical B-type diffraction pattern. The gelatinization enthalpy-changes (ΔH gel ) of two starch samples was about 10.40 J/g for two duckweed starches. The present results suggested the potential utilization of small granular starches from duckweed in functional foods and dietary supplement products. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enhanced spectrophotometric determination of Losartan potassium based on its physicochemical interaction with cationic surfactant.

PubMed

Abdel-Fattah, Laila; Abdel-Aziz, Lobna; Gaied, Mariam

2015-02-05

In this study, a simple and sensitive spectrophotometric method was developed for determination of Losartan potassium (LST K), an angiotensin-II receptor (type AT1) antagonist, in presence of cationic surfactant cetyltrimethylammonium bromide (CTAB). The physicochemical interaction of LST K with CTAB was investigated. The effect of cationic micelles on the spectroscopic and acid-base properties of LST K was studied at pH 7.4. The binding constant (Kb) and the partition coefficient (Kx) of LST K-CTAB were 1.62×10(5) M(-1) and 1.38×10(5); respectively. The binding of LST K to CTAB micelles implied a shift in drug acidity constant (ΔpKa=0.422). The developed method is linear over the range 0.5-28 μg mL(-1). The accuracy was evaluated and was found to be 99.79±0.509% and the relative standard deviation for intraday and interday precision was 0.821 and 0.963; respectively. The method was successfully applied to determine LST K in pharmaceutical formulations. Copyright © 2014 Elsevier B.V. All rights reserved.

Environmental and health risks of chlorine trifluoride (ClF3), an alternative to potent greenhouse gases in the semiconductor industry.

PubMed

Tsai, Wen-Tien

2011-06-15

The first accident involving chlorine trifluoride (ClF(3)) in the history of semiconductor fabrication processes occurred on 28 July 2006 at Hsinchu (Taiwan), resulting in a large release of the highly reactive material and causing the chemical burn to several workers. ClF(3) is used primarily as an in situ cleaning gas in the manufacture of semiconductor silicon-wafer devices in replacement of perfluorocompounds (PFCs) because they have the high potential to contribute significantly to the global warming. This article aimed at reviewing ClF(3) in the physicochemical properties, the industrial uses, and the environmental implications on the basis of its toxicity, reactivity, health hazards and exposure limits. The health hazards of probable decomposition/hydrolysis products from ClF(3) were also evaluated based on their basic physicochemical properties and occupational exposure limits. The occupational exposure assessment was further discussed to understand potentially hazardous risks caused by hydrogen fluoride and fluorides from the decomposition/hydrolysis products of ClF(3). Copyright © 2010 Elsevier B.V. All rights reserved.

Diagnosing the Nature of Land-Atmosphere Coupling During the 2006-7 Dry/Wet Extremes in the U. S. Southern Great Plains

NASA Technical Reports Server (NTRS)

Santanello, Joseph A.; Peters-Lidard, Christa D.; Kennedy, Aaron D.; Kumar, Sujay; Dong, Xiquan

2011-01-01

Land-atmosphere (L-A) interactions play a critical role in determining the diurnal evolution of land surface and planetary boundary layer (PBL) temperature and moisture states and fluxes. In turn, these interactions regulate the strength of the connection between surface moisture and precipitation in a coupled system. To address deficiencies in numerical weather prediction and climate models due to improper treatment of L-A interactions, recent studies have focused on development of diagnostics to quantify the strength and accuracy of the land-PBL coupling at the process-level. In this study, a diagnosis of the nature and impacts of local land-atmosphere coupling (LoCo) during dry and wet extreme conditions is presented using a combination of models and observations during the summers of2006-7 in the U.S. Southern Great Plains. Specifically, the Weather Research and Forecasting (WRF) model has been coupled to NASA's Land Information System (LIS), which provides a flexible and high resolution representation and initialization of land surface physics and states. A range of diagnostics exploring the links and feedbacks between soil moisture and precipitation are examined for the dry/wet regimes of this region, along with the behavior and accuracy of different land-PBL scheme couplings under these conditions. Results demonstrate how LoCo diagnostics can be applied to coupled model components in the context of their integrated impacts on the process-chain connecting the land surface to the PBL and support of hydrological anomalies.

Study on surface morphology and physicochemical properties of raw and activated South African coal and coal fly ash

NASA Astrophysics Data System (ADS)

Mishra, S. B.; Langwenya, S. P.; Mamba, B. B.; Balakrishnan, M.

South African coal and coal fly ash were selected as the raw materials to be used for study of their morphology and physicochemical properties and their respective activated carbons for adsorption applications. Coal and fly ash were individually steam activated at a temperature range of 550-1000 °C for 1 h in a muffle furnace using cylindrical stainless steel containers. Scanning electron micrographs revealed a change in surface morphology with more mineral matter available on the surface of the coal particles due to increased devolatilization. However, in the case of fly ash, the macerals coalesced to form agglomerates and the presence of unburnt carbon constituted pores of diameter between 50 and 100 nm. The BET surface area of coal improved significantly from 5.31 to 52.12 m 2/g whereas in case of fly ash the surface area of the raw sample which was originally 0.59 m 2/g and upon activation increased only up to 2.04 m 2/g. The chemical composition of the fly ash confirmed that silica was the major component which was approximately 60% by weight fraction. The impact of this study was to highlight the importance of using raw materials such as coal and a waste product, in the form of coal ash, in order to produce affordable activated carbon that can be used in drinking water treatment. This would therefore ensure that the quality of water supplied to communities for drinking is not contaminated especially by toxic organic compounds.

Some physicochemical aspects of water-soluble mineral flotation.

PubMed

Wu, Zhijian; Wang, Xuming; Liu, Haining; Zhang, Huifang; Miller, Jan D

2016-09-01

Some physicochemical aspects of water-soluble mineral flotation including hydration phenomena, associations and interactions between collectors, air bubbles, and water-soluble mineral particles are presented. Flotation carried out in saturated salt solutions, and a wide range of collector concentrations for effective flotation of different salts are two basic aspects of water-soluble mineral flotation. Hydration of salt ions, mineral particle surfaces, collector molecules or ions, and collector aggregates play an important role in water-soluble mineral flotation. The adsorption of collectors onto bubble surfaces is suggested to be the precondition for the association of mineral particles with bubbles. The association of collectors with water-soluble minerals is a complicated process, which may include the adsorption of collector molecules or ions onto such surfaces, and/or the attachment of collector precipitates or crystals onto the mineral surfaces. The interactions between the collectors and the minerals include electrostatic and hydrophobic interactions, hydrogen bonding, and specific interactions, with electrostatic and hydrophobic interactions being the common mechanisms. For the association of ionic collectors with minerals with an opposite charge, electrostatic and hydrophobic interactions could have a synergistic effect, with the hydrophobic interactions between the hydrophobic groups of the previously associated collectors and the hydrophobic groups of oncoming collectors being an important attractive force. Association between solid particles and air bubbles is the key to froth flotation, which is affected by hydrophobicity of the mineral particle surfaces, surface charges of mineral particles and bubbles, mineral particle size and shape, temperature, bubble size, etc. The use of a collector together with a frother and the use of mixed surfactants as collectors are suggested to improve flotation. Copyright © 2016 Elsevier B.V. All rights reserved.

Physicochemical characteristics of ambient particles settling upon leaf surfaces of urban plants in Beijing.

PubMed

Wang, Lei; Liu, Lian-you; Gao, Shang-yu; Hasi, Eerdun; Wang, Zhi

2006-01-01

Particulate pollution is a serious health problem throughout the world, exacerbating a wide range of respiratory and vascular illnesses in urban areas. Urban plants play an important role in reducing particulate pollution. Physicochemical characteristics of ambient particles settling upon leaf surfaces of eleven roadside plants at four sites of Beijing were studies. Results showed that density of particles on the leaf surfaces greatly varied with plant species and traffic condition. Fraxinus chinensis, Sophora japonica, A ilanthus altissima, Syringa oblata and Prunus persica had larger densities of particles among the tall species. Due to resuspension of road dust, the densities of particles of Euonymus japonicus and Parthenocissus quinquefolia with low sampling height were 2-35 times to other taller tree species. For test plant species, micro-roughness of leaf surfaces and density of particles showed a close correlation. In general, the larger micro-roughness of leaf surfaces is, the larger density of particles is. Particles settling upon leaf surfaces were dominantly PM, (particulate matter less than 10 microm in aerodynamic diameter; 98.4%) and PM25 (particulate matter less than 2.5 microm in aerodynamic diameter; 64.2%) which were closely relative to human health. Constant elements of particles were C, O, K, Ca, Si, Al, Mg, Na, Fe, S, Cl and minerals with higher content were SiO2, CaCO3, CaMg(CO3)2, NaCI and 2CaSO4 x H20, SiO2. CaCO3 and CaMg(CO3)2 mainly came from resuspension of road dust. 2CaSO4 x H20 was produced by the reaction between CaCO3 derived from earth dust or industrial emission and SO2, H2SO4 or sulfate. NaCl was derived from sea salt.

Physicochemical and functional properties of dietary fiber from maca (Lepidium meyenii Walp.) liquor residue.

PubMed

Chen, Jinjin; Zhao, Qingsheng; Wang, Liwei; Zha, Shenghua; Zhang, Lijun; Zhao, Bing

2015-11-05

Using maca (Lepidium meyenii) liquor residue as the raw material, dietary fiber (DF) was prepared by chemical (MCDF) and enzymatic (MEDF) methods, respectively, of which the physicochemical and functional properties were comparatively studied. High contents of DF were found in MCDF (55.63%) and MEDF (81.10%). Both fibers showed good functional properties, including swelling capacity, water holding capacity, oil holding capacity, glucose adsorption capacity and glucose retardation index. MEDF showed better functional properties, which could be attributed to its higher content of DF, more irregular surface and more abundant monosaccharide composition. The results herein suggest that maca DF prepared by enzymatic method from liquor residue is a good functional ingredient in food products. Copyright © 2015 Elsevier Ltd. All rights reserved.

Morphological and physical - chemical issues of metal nanostructures used in medical field

NASA Astrophysics Data System (ADS)

Duceac, L. D.; Velenciuc, N.; Dobre, E. C.

2016-06-01

In recent years applications of nanotechnology integrated into nanomedicine and bio-nanotechnology have attracted the attention of many researchers from different fields. Processes from chemical engineering especially nanostructured materials play an important role in medical and pharmaceutical development. Fundamental researches focused on finding simple, easily accomplished synthesis methods, morphological aspects and physico-chemical advanced characterization of nanomaterials. More over, by controlling synthesis conditions textural characteristics and physicochemical properties such as particle size, shape, surface, porosity, aggregation degree and composition can be tailored. Low cytotoxicity and antimicrobial effects of these nanostructured materials makes them be applied in medicine field. The major advantage of metal based nanoparticles is the use either for their antimicrobial properties or as drug-carriers having the potential to be active at low concentrations against infectious agents.

Study on the infrared radiation performance of Tourmaline composite and its effect on the diesel characteristic

NASA Astrophysics Data System (ADS)

Liao, Jian Bin; Yu, Hong Liang; Sun, Di; Ma, Fong Yuan

2017-09-01

The black tourmaline, magnesium tourmaline, and spinel were ground into powder, and the infrared radiation material was prepared by adding the ceramic powder, clay and the other material into the tourmaline powder according to a certain proportion. The infrared radiation property was tested and analyzed, the diesel was infrared radiation activated by the composite material, and the physicochemical property of fuel oil was analyzed pre-test and post-test. The result shows that the infrared absorption spectrum of the black tourmaline of different particle size is stable. After the diesel oil was infrared radiation activated by tourmaline composite materials, the physicochemical property of diesel oil was changed, the activation energy decreased, the viscosity and surface tension of fuel oil were reduced.

Engineered Nanomaterials: Their Physicochemical Characteristics and How to Measure Them.

PubMed

Atluri, Rambabu; Jensen, Keld Alstrup

2017-01-01

Numerous types of engineered nanomaterials (ENMs) are commercially available and developments move towards producing more advanced nanomaterials with tailored properties. Such advanced nanomaterials may include chemically doped or modified derivatives with specific surface chemistries; also called higher generation or multiconstituent nanomaterials. To fully enjoy the benefits of nanomaterials, appropriate characterisation of ENMs is necessary for many aspects of their production, use, testing and reporting to regulatory bodies. This chapter introduces both structural and textural properties of nanomaterials with a focus on demonstrating the information that can be achieved by analysis of primary physicochemical characteristics and how such information is critical to understand or assess the possible toxicity of engineered nanomaterials. Many of characterization methods are very specific to obtain particular characteristics and therefore the most widely used techniques are explained and demonstrated.

A physicochemical mechanism of chemical gas sensors using an AC analysis.

PubMed

Moon, Jaehyun; Park, Jin-Ah; Lee, Su-Jae; Lee, Jeong-Ik; Zyung, Taehyong; Shin, Eui-Chol; Lee, Jong-Sook

2013-06-21

Electrical modeling of the chemical gas sensors was successfully applied to TiO2 nanofiber gas sensors by developing an equivalent circuit model where the junction capacitance as well as the resistance can be separated from the comparable stray capacitance. The Schottky junction impedance exhibited a characteristic skewed arc described by a Cole-Davidson function, and the variation of the fit and derived parameters with temperature, bias, and NO2 gas concentration indicated definitely a physicochemical sensing mechanism based on the Pt|TiO2 Schottky junctions against the conventional supposition of the enhanced sensitivity in nanostructured gas sensors with high grain boundary/surface area. Analysis on a model Pt|TiO2|Pt structure also confirmed the characteristic impedance response of TiO2 nanofiber sensors.

Key fuel properties and engine performances of diesel-ethanol blends, using tetrahydrofuran as surfactant additive

NASA Astrophysics Data System (ADS)

Molea, A.; Visuian, P.; Barabás, I.; Suciu, R. C.; Burnete, N. V.

2017-10-01

In this paper there were presented researches related to preparation and characterization of physicochemical properties of diesel-ethanol blends stabilized with tetrahydrofuran as surfactant, in order to be used as fuels in compression ignition engines. The main spray characteristics and engine performances of these blends were evaluated by using AVL Fire software. In the first stage of the studies, commercial diesel was mixed with ethanol, in different concentrations (between 2% and 15% v/v), followed by the addition of tetrahydrofuran (THF) until the blends were miscible, i.e. the blends were stabilized. The experiments were done at room temperature (22 °C). The obtained blends were characterized in order to determine the chemical composition and physicochemical properties, i.e. density, kinematic viscosity, surface tension. UV-Vis spectroscopy was utilized in order to determine a semi-quantitative evaluation regarding the chemical composition of the prepared blends and chemical interaction between diesel, ethanol and THF. Based on the determined properties, the fuel spray characteristics, engine performances and emission characteristics were evaluated by simulation using the AVL Fire software. The obtained results regarding physicochemical properties of blends were compared with diesel. Some improvements were observed when operating with the prepared blends compared to diesel with respect to engine performances and emission characteristics. Based on physicochemical evaluation and computer simulation, it was demonstrated that diesel-ethanol-tetrahydrofuran blends can be used as alternative fuel in compression ignition engines.

Mass Transfer Behavior of Perfluorinated Chemicals in Saturated Clay-rich Sands: A Laboratory-based Study on Fate and Transport in Groundwater and Sediments

NASA Astrophysics Data System (ADS)

Greenberg, R. R.; Tick, G. R.; Abbott, J. B., III; Carroll, K. C.

2017-12-01

Perfluoroalkyl substances (PFAS) are a class of emerging contaminants that pose a threat to the human health and the quality of groundwater, surface water, and drinking water supplies. This study aims to elucidate the primary physicochemical factors controlling the fate and transport of the PFAS contaminants, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), in groundwater. Physicochemical processes of intercalation, adsorption, and desorption were investigated for the retention of PFAS at different initial aqueous-phase concentrations in modified-natural sediments composed of sand (40/50 accusand; foc = 0.04% unmodified) with low, medium, and high organic carbon contents (foc = 10, 20, and 50%) and various pre-conditioned clay-fractions. Diffusional mass-transfer limitations were evaluated based on initial PFAS concentration, specific clay structure, and resulting contaminant intercalation (d-spacing changes). A series of short- (48 hr), medium- (7 day) and long-term (30 day) batch and column experiments were conducted to determine physicochemical processes as a function of compound chemistry, sediment geochemistry, sorbent crystalline structure, and contaminant/sediment contact-time. Physicochemical parameters, PFAS concentrations, and sediment characterization were conducted using high performance liquid chromatography (HPLC), X-ray diffraction (XRD), and furnace combustion analytical techniques. The results of PFAS contaminant transport, under the different conditions tested, provide a scientific contribution with application to the development of improved risk assessments, predictions of fate and transport, and more effective remediation strategies for emerging perfluorinated contaminants in soil and groundwater.

Variations in Physicochemical Properties of a Traditional Mercury-Based Nanopowder Formulation: Need for Standard Manufacturing Practices

PubMed Central

Kamath, S. U.; Pemiah, B.; Rajan, K. S.; Krishnaswamy, S.; Sethuraman, S.; Krishnan, U. M.

2014-01-01

Rasasindura is a mercury-based nanopowder synthesized using natural products through mechanothermal processing. It has been used in the Ayurvedic system of medicine since time immemorial for various therapeutic purposes such as rejuvenation, treatment of syphilis and in genital disorders. Rasasindura is said to be composed of mercury, sulphur and organic moieties derived from the decoction of plant extracts used during its synthesis. There is little scientific understanding of the preparation process so far. Though metallic mercury is incorporated deliberately for therapeutic purposes, it certainly raises toxicity concerns. The lack of gold standards in manufacturing of such drugs leads to a variation in the chemical composition of the final product. The objective of the present study was to assess the physicochemical properties of Rasasindura samples of different batches purchased from different manufacturers and assess the extent of deviation and gauge its impact on human health. Modern characterization techniques were employed to analyze particle size and morphology, surface area, zeta potential, elemental composition, crystallinity, thermal stability and degradation. Average particle size of the samples observed through scanning electron microscope ranged from 5-100 nm. Mercury content was found to be between 84 and 89% from elemental analysis. Despite batch-to-batch and manufacturer-to-manufacturer variations in the physicochemical properties, all the samples contained mercury in the form of HgS. These differences in the physicochemical properties may ultimately impact its biological outcome. PMID:25593382

Preparation of active antibacterial LDPE surface through multistep physicochemical approach II: graft type effect on antibacterial properties.

PubMed

Bílek, František; Sulovská, Kateřina; Lehocký, Marián; Sáha, Petr; Humpolíček, Petr; Mozetič, Miran; Junkar, Ita

2013-02-01

Three monomers (allylamine, N-allylmethylamine and N,N-dimethylallylamine) were used for grafting onto air plasma activated LDPE surface. Antibacterial agent triclosan was anchored on such substrates. Influence of graft type on the antibacterial properties was determined. Increase of antibacterial activity and amount of deposited antibacterial agent for N-allylmethylamine and N,N-dimethylallylamine monomers were examined. Surface characteristics were measured by means of static contact angle measurement with surface energy evaluation, ATR-FTIR spectroscopy, XPS and SEM characterization analysis. Antibacterial properties were tested in vitro by inhibition zone method on agar plates for Staphylococcus aureus and Escherichia coli strains. Copyright © 2012 Elsevier B.V. All rights reserved.

Physicochemical characterization and biocompatibility of alginate-polycation microcapsules designed for islet transplantation

NASA Astrophysics Data System (ADS)

Tam, Susan Kimberly

Microencapsulation represents a method for immunoprotecting transplanted therapeutic cells or tissues from graft rejection using a physical barrier. This approach is advantageous in that it eliminates the need to induce long-term immunosuppression and allows the option of transplanting non-cadaveric cell sources, such as animal cells and stem cell-derived tissues. The microcapsules that we have investigated are designed to immunoprotect islets of Langerhans (i.e. clusters of insulin-secreting cells), with the goal of treating insulin-dependent diabetes. With the aid of techniques for physicochemical analysis, this research focused on understanding which properties of the microcapsule are the most important for determining its biocompatibility. The objective of this work was to elucidate correlations between the chemical make-up, physicochemical properties, and in vivo biocompatibility of alginate-based microcapsules. Our approach was based on the hypothesis that the immune response to the microcapsules is governed by, and can therefore be controlled by, specific physicochemical properties of the microcapsule and its material components. The experimental work was divided into five phases, each associated with a specific aim : (1) To prove that immunoglobulins adsorb to the surface of alginate-polycation microcapsules, and to correlate this adsorption with the microcapsule chemistry. (2) To test interlaboratory reproducibility in making biocompatible microcapsules, and evaluate the suitability of our materials and fabrication protocols for subsequent studies. (3) To determine which physicochemical properties of alginates affect the in vivo biocompatibility of their gels. (4) To determine which physiochemical properties of alginate-polycation microcapsules are most important for determining their in vivo biocompatibility (5) To determine whether a modestly immunogenic membrane hinders or helps the ability of the microcapsule to immunoprotect islet xenografts in diabetic mice. To achieve these aims, extensive physicochemical analyses of the alginates and microcapsules were carried out. Among the properties of the alginates that were investigated include their purity (LAL assay, microBCA), chemical composition (nuclear magnetic resonance, NMR), elemental composition (x-ray photoelectron spectroscopy, XPS), and hydrophilicity (contact angle technique). As for the microcapsules, we also examined their surface chemical composition (XPS), hydrophilicity, as well as alginate-polycation interactions (Fourier transform infrared spectroscopy, FTIR), and membrane strength (osmotic swelling). The results of this research led to a number of important conclusions about the biocompatibility of alginates and alginate-based microcapsules. First of all, purifying an alginate does not guarantee its biocompatibility. Indeed, we provided evidence that both the alginate chemical composition (i.e. relative content of mannuronate and guluronate) and its intrinsic viscosity influence the extent of host cell adhesion to alginate gel beads. Using a biocompatible alginate, we then provided evidence that microcapsule biocompatibility is greatly compromised by its polycationic membrane. We showed that this membrane is responsible for the adsorption of opsonizing proteins in vitro and the adhesion of immune cells in vivo. That said, the severity of inflammatory response to the membrane can vary, and this depended on the microcapsule design, including the choice of alginate and polycation type. Results of our physicochemical analyses suggested that the most important factor determining biocompatibility is the ability of the polycation to diffuse into, and subsequently bind to, the alginate gel core. Moreover, adding a final coating of alginate had no significant effect on reversing the effects of the membrane on various microcapsule properties (surface composition, hydrophobicity, stability), nor did this coating reduce its immunogenicity. Although we repeatedly provided evidence that the microcapsule membrane is the main problem for biocompatibility, we also demonstrated that the severity of this problem can vary according to the fabrication details. This is an important note, as it confirms the possibility of achieving optimal microcapsule biocompatibility if the interactions between the alginate and polycation are ideal. (Abstract shortened by UMI.)

Blocking CD147 induces cell death in cancer cells through impairment of glycolytic energy metabolism

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

Baba, Miyako; Inoue, Masahiro; Itoh, Kazuyuki

2008-09-12

CD147 is a multifunctional transmembrane protein and promotes cancer progression. We found that the anti-human CD147 mouse monoclonal antibody MEM-M6/1 strongly induces necrosis-like cell death in LoVo, HT-29, WiDr, and SW620 colon cancer cells and A2058 melanoma cells, but not in WI-38 and TIG-113 normal fibroblasts. Silencing or overexpression of CD147 in LoVo cells enhanced or decreased the MEM-M6/1 induced cell death, respectively. CD147 is known to form complex with proton-linked monocarboxylate transporters (MCTs), which is critical for lactate transport and intracellular pH (pHi) homeostasis. In LoVo cells, CD147 and MCT-1 co-localized on the cell surface, and MEM-M6/1 inhibited themore » association of these molecules. MEM-M6/1 inhibited lactate uptake, lactate release, and reduced pHi. Further, the induction of acidification was parallel to the decrease of the glycolytic flux and intracellular ATP levels. These effects were not found in the normal fibroblasts. As cancer cells depend on glycolysis for their energy production, CD147 inhibition might induce cell death specific to cancer cells.« less

Titanium Surface Chemical Composition Interferes in the Pseudomonas aeruginosa Biofilm Formation.

PubMed

Nunes Filho, Antonio; Aires, Michelle de Medeiros; Braz, Danilo Cavalcante; Hinrichs, Ruth; Macedo, Alexandre José; Alves, Clodomiro

2018-02-01

Bacterial adhesion on three different surfaces: untreated Ti, plasma nitriding, and plasma carbonitriding Ti substrates were investigated. The samples were placed in bacterial cultures of Pseudomonas aeruginosa to assess biofilm formation. The correlation between the amount of bacteria attached to the surface after a lapse of time with nanotopography and physicochemical properties was performed. TiN showed the highest capacity to avoid bacterial adhesion, while presenting intermediate roughness and wettability. Although the surface of TiCN had the highest surface roughness and low contact angle (high wettability), bacterial adhesion was intermediate on this sample. Untreated Ti, even though presenting a smooth surface and low wettability, had the highest tendency to form biofilms. © 2018 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Immunogenicity of amino acids 1-150 of Streptococcus GapC displayed on the surface of Escherichia coli.

PubMed

Song, Baifen; Yang, Xijing; Sun, Hunan; Yu, Liquan; Ma, Jinzhu; Wu, Zhijun; Cui, Yudong

2017-04-01

Streptococcus is one of the main pathogens that cause bovine mastitis. They includes into S.agalactiae, S.dysgalactiae, and S.uberis. The GapC protein is a virulence factor that is expressed on the surface of Streptococcus species. GapC is highly antigenic and immunization with GapC confers cross-protection against all three species. Our previous data showed that amino acids 1-150 of GapC (GapC 1-150 ) of S. dysgalactiae conferred similar immunoprotection compared to full-length GapC. Thus, the present study aimed to construct a recombinant Escherichia coli XL1-Blue strain that displayed GapC 1-150 on its surface, and to investigate the immunogenicity of the surface-localized GapC 1-150 . To do so, the ompA gene of the E. coli XL1-Blue strain was replaced with the lpp'-ompA-gapC1 1-150 or lpp'-ompA genes by λ Red recombination, the former of which fused GapC 1-150 to an Lpp lipoprotein signal peptide and amino acids 1-159 of OmpA; the recombinant strains were named XL1-Blue/LOG76 and XL1-Blue/LO11, respectively. GapC 1-150 was confirmed to localize to the surface of the XL1-Blue/LOG76 strain by an indirect enzyme-linked immunosorbent assay (ELISA), a fluorescence-activated cell sorter analysis, and laser-scanning confocal microscopy. Then, ICR mice were immunized intramuscularly with the XL1-Blue/LOG76 or XL1-Blue/LO11 strains, or recombinant GapC 1-150 . The sera of the immunized mice were collected and the anti-GapC 1-150 antibody levels were detected by ELISA. Lymphocytes secreting interleukin (IL)-4 and interferon-γ were detected by an enzyme-linked ImmunoSpot assay, as was the level of IL-17A level in the supernatant of cultured splenic lymphocytes. The mice immunized with the XL1-Blue/LOG76 strain or GapC 1-150 exhibited better cellular and humoral immunity. Lastly, the immunized mice were challenged with S. uberis, S. dysgalactiae, and S. agalactiae strains, and mice that were immunized with the XL1-Blue/LOG76 strain were better protected than those that were immunized with the XL1-Blue/LO11 strain. These results indicate that it is feasible to display GapC 1-150 on the E. coli surface as a vaccine against Streptococcus species. Copyright © 2017. Published by Elsevier Ltd.

Pattern recognition of concrete surface cracks and defects using integrated image processing algorithms

NASA Astrophysics Data System (ADS)

Balbin, Jessie R.; Hortinela, Carlos C.; Garcia, Ramon G.; Baylon, Sunnycille; Ignacio, Alexander Joshua; Rivera, Marco Antonio; Sebastian, Jaimie

2017-06-01

Pattern recognition of concrete surface crack defects is very important in determining stability of structure like building, roads or bridges. Surface crack is one of the subjects in inspection, diagnosis, and maintenance as well as life prediction for the safety of the structures. Traditionally determining defects and cracks on concrete surfaces are done manually by inspection. Moreover, any internal defects on the concrete would require destructive testing for detection. The researchers created an automated surface crack detection for concrete using image processing techniques including Hough transform, LoG weighted, Dilation, Grayscale, Canny Edge Detection and Haar Wavelet Transform. An automatic surface crack detection robot is designed to capture the concrete surface by sectoring method. Surface crack classification was done with the use of Haar trained cascade object detector that uses both positive samples and negative samples which proved that it is possible to effectively identify the surface crack defects.

Different cell responses induced by exposure to maghemite nanoparticles.

PubMed

Luengo, Yurena; Nardecchia, Stefania; Morales, María Puerto; Serrano, M Concepción

2013-12-07

Recent advances in nanotechnology have permitted the development of a wide repertoire of inorganic magnetic nanoparticles (NPs) with extensive promise for biomedical applications. Despite this remarkable potential, many questions still arise concerning the biocompatible nature of NPs when in contact with biological systems. Herein, we have investigated how controlled changes in the physicochemical properties of iron oxide NPs at their surface (i.e., surface charge and hydrodynamic size) affect, first, their interaction with cell media components and, subsequently, cell responses to NP exposure. For that purpose, we have prepared iron oxide NPs with three different coatings (i.e., dimercaptosuccinic acid - DMSA, (3-aminopropyl)triethoxysilane - APS and dextran) and explored the response of two different cell types, murine L929 fibroblasts and human Saos-2 osteoblasts, to their exposure. Interestingly, different cell responses were found depending on the NP concentration, surface charge and cell type. In this sense, neutral NPs, as those coated with dextran, induced negligible cell damage, as their cellular internalization was significantly reduced. In contrast, surface-charged NPs (i.e., those coated with DMSA and APS) caused significant cellular changes in viability, morphology and cell cycle under certain culture conditions, as a result of a more active cellular internalization. These results also revealed a particular cellular ability to detect and remember the original physicochemical properties of the NPs, despite the formation of a protein corona when incubated in culture media. Overall, conclusions from these studies are of crucial interest for future biomedical applications of iron oxide NPs.

Relationship between complement activation, cellular uptake and surface physicochemical aspects of novel PEG-modified nanocapsules.

PubMed

Mosqueira, V C; Legrand, P; Gulik, A; Bourdon, O; Gref, R; Labarre, D; Barratt, G

2001-11-01

The aim of our work was to examine the relationship between modifications of the surface of nanocapsules (NC) by adsorption or covalent grafting of poly(ethylene oxide) (PEG), and changes in their phospholipid (PL) content on complement activation (C3 cleavage) and on uptake by macrophages. The physicochemical characterization of the NC included an investigation of their properties, such as surface charge, size, hydrophilicity, morphology and homogeneity. This is the first time that such properties have been correlated with biological interactions for NC, a novel carrier system with a structure more complex than nanospheres. C3 crossed immunoelectrophoresis revealed the reduced activation for NC with longer PEG chain and higher density, although all formulations induced C3 cleavage to a lesser or greater extent. NC bearing PEG covalently bound to the surface were weaker activators of complement than plain PLA [poly(D,L-lactide)] NC or nanospheres (NS). Furthermore, the fluorescent/confocal microscopy of J774A1 cells in contact with NC reveal a dramatically reduced interaction with PEG-bearing NC. However, the way in which PEG was attached (covalent or adsorbed) seemed to affect the mechanism of uptake. Taken together, these results suggest that the low level of protein binding to NC covered with a high density of 20kDa PEG chains is likely to be due to the steric barriers surrounding these particles, which prevents protein adsorption and reduces their interaction with macrophages.

Conjugated fatty acids and methane production by rumen microbes when incubated with linseed oil alone or mixed with fish oil and/or malate.

PubMed

Li, Xiang Z; Gao, Qing S; Yan, Chang G; Choi, Seong H; Shin, Jong S; Song, Man K

2015-08-01

We hypothesized that manipulating metabolism with fish oil and malate as a hydrogen acceptor would affect the biohydrogenation process of α-linolenic acid by rumen microbes. This study was to examine the effect of fish oil and/or malate on the production of conjugated fatty acids and methane (CH4 ) by rumen microbes when incubated with linseed oil. Linseed oil (LO), LO with fish oil (LO-FO), LO with malate (LO-MA), or LO with fish oil and malate (LO-FO-MA) was added to diluted rumen fluid, respectively. The LO-MA and LO-FO-MA increased pH and propionate concentration compared to the other treatments. LO-MA and LO-FO-MA reduced CH4 production compared to LO. LO-MA and LO-FO-MA increased the contents of c9,t11-conjugated linoleic acid (CLA) and c9,t11,c15-conjugated linolenic acid (CLnA) compared to LO. The content of malate was rapidly reduced while that of lactate was reduced in LO-MA and LO-FO-MA from 3 h incubation time. The fold change of the quantity of methanogen related to total bacteria was decreased at both 3 h and 6 h incubation times in all treatments compared to the control. Overall data indicate that supplementation of combined malate and/or fish oil when incubated with linseed oil, could depress methane generation and increase production of propionate, CLA and CLnA under the conditions of the current in vitro study. © 2015 Japanese Society of Animal Science.

Land-margin ecosystem hydrologic data for the coastal Everglades, Florida, water years 1996-2012

USGS Publications Warehouse

Anderson, Gordon H.; Smith, Thomas J.; Balentine, Karen M.

2014-01-01

Mangrove forests and salt marshes dominate the landscape of the coastal Everglades (Odum and McIvor, 1990). However, the ecological effects from potential sea-level rise and increased water flows from planned freshwater Everglades restoration on these coastal systems are poorly understood. The National Park Service (NPS) proposed the South Florida Global Climate Change Project (SOFL-GCC) in 1990 to evaluate climate change and the effect from rising sea levels on the coastal Everglades, particularly at the marsh/mangrove interface or ecotone (Soukup and others, 1990). A primary objective of SOFL-GCC project was to monitor and synthesize the hydrodynamics of the coastal Everglades from the upstream freshwater marsh to the downstream estuary mangrove. Two related hypotheses were set forward (Nuttle and Cosby, 1993): 1. There exists hydrologic conditions (tide, local rainfall, and upstream water deliveries), which characterize the location of the marsh/mangrove ecotone along the marine and terrestrial hydrologic gradient; and 2. The marsh/mangrove ecotone is sensitive to fluctuations in sea level and freshwater inflow from inland areas. Hydrologic monitoring of the SOFL-GCC network began in 1995 after startup delays from Hurricane Andrew (August 1992) and organizational transfers from the NPS to the National Biological Survey (October 1993) and the merger with the U.S. Geological Survey (USGS) Biological Research Division in 1996 (Smith, 2004). As the SOFL-GCC project progressed, concern by environmental scientists and land managers over how the diversion of water from Everglades National Park would affect the restoration of the greater Everglades ecosystem. Everglades restoration scenarios were based on hydrodynamic models, none of which included the coastal zone (Fennema and others, 1994). Modeling efforts were expanded to include the Everglades coastal zone (Schaffranek and others, 2001) with SOFL-GCC hydrologic data assisting the ecological modeling needs. In 2002, as a response for a more interdisciplinary science approach to understanding the coastal Everglades ecological system, the SOFL-GCC hydrology project was integrated into the “Dynamics of Land-Margin Ecosystems: Historical Change, Hydrology, Vegetation, Sediment, and Climate” study (Smith and others, 2002). Data from the ongoing study has been useful in providing an empirical hydrologic baseline for the greater Everglades ecosystem restoration science and management needs. The hydrology network consisted of 13 hydrologic gaging stations installed in the southwestern coastal region of Everglades National Park along three transects: Shark River (Shark or SH) transect, Lostmans River (Lostmans or LO) transect, and Chatham River (Chatham or CH) transect (fig. 1). There were five paired surface-water/groundwater gaging stations on the Shark transect (SH1, SH2, SH3, SH4, and SH5) and one stage gaging station (BSC) in the Big Sable Creek; four paired surface-water/groundwater gaging stations on the Lostmans transect (LO1, LO2, LO3, and LO4); and three paired surface-water/groundwater gaging stations on the Chatham transect (CH1, CH2, and CH3). Both surface-water and groundwater levels, salinities, and temperatures were monitored at the paired gaging stations. Rainfall was recorded at marsh and open canopy gaging stations. This report details the study introduction, method, and description of data collected, which are accessible through the final instantaneous hydrologic dataset stored in the USGS South Florida Information Access (SOFIA) South Florida Hydrology Database website, http://sofia.usgs.gov/exchange/sfl_hydro_data/location.html#brdlandmargin.

REPORT ON THE GEOELECTRICAL DETECTION OF SURFACTANT ENHANCED AQUIFER REMEDIATION OF PCE: PROPERTY CHANGES IN AQUEOUS SOLUTIONS DUE TO SURFACTANT TREATMENT OF PERCHLOROETHYLENE: IMPLICATIONS TO GEOPHYSICAL MEASUREMENTS

EPA Science Inventory

Select physicochemical properties of nine surfactants which are conventionally used in the remediation of perchloroethylene (PCE, a.k.a. tetrachloroethene) were evaluated with varying concentrations of PCE and indicator dyes in aqueous solutions using a response surface quadrati...

Allspice, garlic, and oregano plant essential oils in tomato films inactive the foodborne pathogens Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes

USDA-ARS?s Scientific Manuscript database

Edible films containing plant essential oils are gaining importance as potential antibacterial formulations to extend product shelf-life and reduce risk of pathogen growth on food surfaces. An evaluation of both antimicrobial and physicochemical properties of edible films is important for applicati...

Allspice, garlic and oregano plant essential oils in tomato films inactivate the foodborne pathogens, Escherichia coli O157:h7, Salmonella enterica and Listeria monocytogenes

USDA-ARS?s Scientific Manuscript database

Edible films containing plant essential oils arc gaining importance as potential antibacterial formulations to extend product shelf life and reduce risk of pathogen growth on food surfaces. An evaluation of both antimicrobial and physicochemical properties of edible films is important for applicatio...

EFFECTS OF REVERSE OSMOSIS ISOLATION ON REACTIVITY OF NATURALLY OCCURRING DISSOLVED ORGANIC MATTER IN PHYSICOCHEMICAL PROCESSES. (R828045)

EPA Science Inventory

A field reverse osmosis system was used to isolate dissolved organic matter (DOM) from two lacustrine and two riverine surface water sources. The rejection of DOM was on the order of 99% and did not vary significantly with pressure. A simple mass balance model using a single m...

Benthic bacterial diversity in submerged sinkhole ecosystems.

PubMed

Nold, Stephen C; Pangborn, Joseph B; Zajack, Heidi A; Kendall, Scott T; Rediske, Richard R; Biddanda, Bopaiah A

2010-01-01

Physicochemical characterization, automated ribosomal intergenic spacer analysis (ARISA) community profiling, and 16S rRNA gene sequencing approaches were used to study bacterial communities inhabiting submerged Lake Huron sinkholes inundated with hypoxic, sulfate-rich groundwater. Photosynthetic cyanobacterial mats on the sediment surface were dominated by Phormidium autumnale, while deeper, organically rich sediments contained diverse and active bacterial communities.

Investigating Oxidative Stress and Inflammatory Responses Elicited by Silver Nanoparticles Using High-Throughput Reporter Genes in HepG2 Cells: Effect of Size, Surface Coating, and Intracellular Uptake

EPA Science Inventory

Abstract Silver nanoparticles (Ag NP) have been shown to generate reactive oxygen species; however, the association between physicochemical characteristics of nanoparticles and cellular stress responses elicited by exposure has not been elucidated. Here, we examined three key...

Modelling of the physico-chemical behaviour of clay minerals with a thermo-kinetic model taking into account particles morphology in compacted material.

NASA Astrophysics Data System (ADS)

Sali, D.; Fritz, B.; Clément, C.; Michau, N.

2003-04-01

Modelling of fluid-mineral interactions is largely used in Earth Sciences studies to better understand the involved physicochemical processes and their long-term effect on the materials behaviour. Numerical models simplify the processes but try to preserve their main characteristics. Therefore the modelling results strongly depend on the data quality describing initial physicochemical conditions for rock materials, fluids and gases, and on the realistic way of processes representations. The current geo-chemical models do not well take into account rock porosity and permeability and the particle morphology of clay minerals. In compacted materials like those considered as barriers in waste repositories, low permeability rocks like mudstones or compacted powders will be used : they contain mainly fine particles and the geochemical models used for predicting their interactions with fluids tend to misjudge their surface areas, which are fundamental parameters in kinetic modelling. The purpose of this study was to improve how to take into account the particles morphology in the thermo-kinetic code KINDIS and the reactive transport code KIRMAT. A new function was integrated in these codes, considering the reaction surface area as a volume depending parameter and the calculated evolution of the mass balance in the system was coupled with the evolution of reactive surface areas. We made application exercises for numerical validation of these new versions of the codes and the results were compared with those of the pre-existing thermo-kinetic code KINDIS. Several points are highlighted. Taking into account reactive surface area evolution during simulation modifies the predicted mass transfers related to fluid-minerals interactions. Different secondary mineral phases are also observed during modelling. The evolution of the reactive surface parameter helps to solve the competition effects between different phases present in the system which are all able to fix the chemical elements mobilised by the water-minerals interaction processes. To validate our model we simulated the compacted bentonite (MX80) studied for engineered barriers for radioactive waste confinement and mainly composed of Na-Ca-montmorillonite. The study of particles morphology and reactive surfaces evolutions reveals that aqueous ions have a complex behaviour, especially when competitions between various mineral phases occur. In that case, our model predicts a preferential precipitation of finest particles, favouring smectites instead of zeolites. This work is a part of a PhD Thesis supported by Andra, the French Radioactive Waste Management Agency.

Physico-chemical characterization of functionalized polypropylenic fibers for prosthetic applications

NASA Astrophysics Data System (ADS)

Nisticò, Roberto; Faga, Maria Giulia; Gautier, Giovanna; Magnacca, Giuliana; D'Angelo, Domenico; Ciancio, Emanuele; Piacenza, Giacomo; Lamberti, Roberta; Martorana, Selanna

2012-08-01

Polypropylene (PP) fibers can be manufactured to form nets which can find application as prosthesis in hernioplasty. One of the most important problem to deal with when nets are applied in vivo consists in the reproduction of bacteria within the net fibers intersections. This occurs right after the application of the prosthesis, and causes infections, thus it is fundamental to remove bacteria in the very early stage of the nets application. This paper deals with the physico-chemical characterization of such nets, pre-treated by atmospheric pressure plasma dielectric barrier discharge apparatus (APP-DBD) and functionalized with an antibiotic drug such as chitosan. The physico-chemical characterization of sterilized nets, before and after the functionalization with chitosan, was carried out by means of scanning electron microscopy (SEM) coupled with EDS spectroscopy, FTIR spectroscopy, drop shape analysis (DSA), X-ray diffraction and thermal analyses (TGA and DSC). The aim of the work is to individuate a good strategy to characterize this kind of materials, to understand the effects of polypropylene pre-treatment on functionalization efficiency, to follow the materials ageing in order to study the effects of the surface treatment for in vivo applications.

Molecular Modeling and Physicochemical Properties of Supramolecular Complexes of Limonene with α- and β-Cyclodextrins.

PubMed

Dos Passos Menezes, Paula; Dos Santos, Polliana Barbosa Pereira; Dória, Grace Anne Azevedo; de Sousa, Bruna Maria Hipólito; Serafini, Mairim Russo; Nunes, Paula Santos; Quintans-Júnior, Lucindo José; de Matos, Iara Lisboa; Alves, Péricles Barreto; Bezerra, Daniel Pereira; Mendonça Júnior, Francisco Jaime Bezerra; da Silva, Gabriel Francisco; de Aquino, Thiago Mendonça; de Souza Bento, Edson; Scotti, Marcus Tullius; Scotti, Luciana; de Souza Araujo, Adriano Antunes

2017-02-01

This study evaluated three different methods for the formation of an inclusion complex between alpha- and beta-cyclodextrin (α- and β-CD) and limonene (LIM) with the goal of improving the physicochemical properties of limonene. The study samples were prepared through physical mixing (PM), paste complexation (PC), and slurry complexation (SC) methods in the molar ratio of 1:1 (cyclodextrin:limonene). The complexes prepared were evaluated with thermogravimetry/derivate thermogravimetry, infrared spectroscopy, X-ray diffraction, complexation efficiency through gas chromatography/mass spectrometry analyses, molecular modeling, and nuclear magnetic resonance. The results showed that the physical mixing procedure did not produce complexation, but the paste and slurry methods produced inclusion complexes, which demonstrated interactions outside of the cavity of the CDs. However, the paste obtained with β-cyclodextrin did not demonstrate complexation in the gas chromatographic technique because, after extraction, most of the limonene was either surface-adsorbed by β-cyclodextrin or volatilized during the procedure. We conclude that paste complexation and slurry complexation are effective and economic methods to improve the physicochemical character of limonene and could have important applications in pharmacological activities in terms of an increase in solubility.

[Triterpenoid saponins from flower bud of Jasminum officinale var. grandiflorum].

PubMed

Zhao, Gui-Qin; Dong, Jun-Xing

2008-01-01

To study the chemical constituent bud of the flowers of Jasminum officinale var. grandiflorum. The compounds were isolated and purified by recrystallization and chromatography on silica gel and Sephadex LH - 20 column. Their structures were elucidated on the basis of physicochemical properties and spectral analysis. Six triterpenoid saponins were identified as 3-O-alpha-L-rhamnopyranosyl (1 --> 2)-beta-D-xylopyranosyl- hederagenin-28-O-beta-D-galactopyranosyl (1 --> 6)-beta-D-galactopyranosyl ester (1), hederagenin-3-O-beta-D-glucopyranosyl (1 --> 3)-alpha-L-arabinopyranoside (2), 2alpha, 3beta, 23-trihydroxyolean-12-en-28-oic-O-beta-D-glucopyranosyl ester (3), hederagenin-3-O-beta-D-xylopyranosyl (1 --> 3)-alpha-L-rhamnopyranosyl (1 --> 2)-alpha-L-arabinopyranoside (4), 2alpha, 3beta, 23-trihydroxyolean-12-en-28-oic-O-alpha-L-rhamnopyranosyl (1 --> 4)-beta-D-glucopyranosyl (1 --> 6)-beta-D-glucopyranosyl ester (5), hederagenin-3-O-alpha-L-rhamnopyranosyl (1 --> 2)-alpha-L-arabinopyranoside (6). Compound 1 is a new compound. Compounds 2, 3, 4, 5, 6 were isolated from the genus Jasminum for the first time.

Environmental Assessment of Short-Term Construction Projects at the 150th Fighter Wing, New Mexico Air National Guard, Kirtland Air Force Base, New Mexico

DTIC Science & Technology

2003-01-01

level scs Soil Conservation Service DOD Department of Defense SF square foot DOPAA Description of the Proposed SHPO State Historic Preservation...relatively level and most of the area has already been developed. Consequently, most surface soils have been previously disturbed or paved over. Surface... soils arc well drained sands and lo<\\ffiS with slight to moderate hazard of wind and water erosion. As a tenant organization. Nl’vtANG is required to

Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) PARM tape user's guide

NASA Technical Reports Server (NTRS)

Han, D.; Gloersen, P.; Kim, S. T.; Fu, C. C.; Cebula, R. P.; Macmillan, D.

1992-01-01

The Scanning Multichannel Microwave Radiometer (SMMR) instrument, onboard the Nimbus-7 spacecraft, collected data from Oct. 1978 until Jun. 1986. The data were processed to physical parameter level products. Geophysical parameters retrieved include the following: sea-surface temperatures, sea-surface windspeed, total column water vapor, and sea-ice parameters. These products are stored on PARM-LO, PARM-SS, and PARM-30 tapes. The geophysical parameter retrieval algorithms and the quality of these products are described for the period between Nov. 1978 and Oct 1985. Additionally, data formats and data availability are included.

Hydrographic Data from the Pilot Study of the Coastal Transition Zone (CTZ) Program, 15-28 June 1987

DTIC Science & Technology

1989-04-01

8217i Wi Ui L6 LOlaa to LO to 0 a. ’U ’𔃺I’ N W Oa ON4’𔃺 C40 W4010404 r4 10 r% r - ’ : r a . ) - ’ : - : 0 ’n p 4 44 * t*- Ka 0I 0A I 0A 000)In "i pq m...OR 97331 Dr. Robert L. Smith 1 Dr. Adriana Huyer 1 Dr. P. Michael Kosro I Dr. Mark R. Abbott 1 Dr. John S. Allen I Dr. Tim Cowles 1 Dr. David Kadco

Lo que Piensan los Estudiantes y Profesores Sobre la Calidad de la Educacion Superior. Estudio Comparativo en 5 Instituciones de Educacion Superior--dos publicas y tres privadas--en Guadalajara, Jalisco, Mexico (What Students and Faculties Think about the Quality of Higher Education. Comparative Study of 5 Higher Education Institutions--Two Public and Three Private--in Guadalajara, Jalisco, Mexico).

ERIC Educational Resources Information Center

Yanez, Maria Lorena Hernandez

This study, written in Spanish, compared attitudes of students (N=302) and faculty (N=28) at five institutions of higher education (two public and three private) in Guadalajara, Jalisco, Mexico. The study explored first, whether respondents believed there are significant quality differences between private and public universities and, second, what…

Structure Activity Relationship Studies of Flavonoids as Potent Inhibitors of Human Platelet 12-hLO, Reticulocyte 15-hLO-1 and Prostate Epithelial 15-hLO-2

PubMed Central

Vasquez-Martinez, Yesseny; Ohri, Rachana V.; Kenyon, Victor; Holman, Theodore R.; Sepúlveda-Boza, Silvia

2007-01-01

Human lipoxygenase (hLO) isozymes have been implicated in a number of disease states and have attracted much attention with respect to their inhibition. One class of inhibitors, the flavonoids, have been shown to be potent lipoxygenase inhibitors but their study has been restricted to those compounds found in nature, which have limited structural variability. We have therefore carried out a comprehensive study to determine the structural requirements for flavonoid potency and selectivity against platelet 12-hLO, reticulocyte 15-hLO-1 and prostate epithelial 15-hLO-2. We conclude from this study that catechols are essential for high potency, that isoflavones and isoflavanones tend to select against 12-hLO, that isoflavans tend to select against 15-hLO-1, but few flavonoids target 15-hLO-2. PMID:17869117

Root water transport of Helianthus annuus L. under iron oxide nanoparticle exposure.

PubMed

Martínez-Fernández, Domingo; Barroso, Didac; Komárek, Michael

2016-01-01

The application of nanomaterials in commercially available products is increasing rapidly for agriculture, phytoremediation and biotechnology. Since plants suppose the first sink for the accumulation of nanoparticles from the environment, emerging studies have focused on the general consequences for plants and their effects on the biomass production. However, effects on the root surface, as well as blockage of nutrients and water uptake by the roots, may also occur. This experiment was designed to prove if the plant water relations can be affected by the adsorption of nanoparticles on the root surface, causing a consequent stress for the plants. With this goal, plants of Helianthus annuus were previously grown in a hydroponic culture, and at age of 55 days, their roots were exposed to three different concentrations of nanomaghemite (NM) in the hydroponic solution for 5 days: control without NM; 50 and 100 mg l(-1) NM. The main effect was related to the reduction of the root hydraulic conductivity (Lo) and the nutrients uptake. The concentrations of the macronutrients Ca, K, Mg and S in the shoot were reduced relative to the control plants, which resulted in lower contents of chlorophyll pigments. Although stress was not detected in the plants, after the analysis of stress markers like the accumulation of proline or ascorbate in the tissues, reduction of the root functionality by nanoparticles has been identified here, manifested as the effect of NM on Lo. The treatment with 50 mg l(-1) NM significantly reduced the Lo, by up to 57% of its control value, and it was reduced by up to 26% at 100 mg l(-1) NM. These results will be an important factor to take into account with regard to the applicability of NM for long-term use in crops, particularly during privative water conditions.

Effects of repeated withdrawal from alcohol on recovery of cognitive impairment under abstinence and rate of relapse.

PubMed

Loeber, Sabine; Duka, Theodora; Welzel Márquez, Helga; Nakovics, Helmut; Heinz, Andreas; Mann, Karl; Flor, Herta

2010-01-01

Several authors suggest that withdrawal from alcohol could cause neurotoxic lesions in the frontal lobe and thereby affect cognitive function. In line with this, previous studies have demonstrated greater cognitive impairment of alcohol-dependent patients with two or more previous detoxifications (Hi-detox) compared with patients with less than two detoxifications (Lo-detox). The aim of the present study was to investigate whether repeated withdrawal from alcohol affects recovery of cognitive function and is related to relapse. Forty-eight alcohol-dependent patients (Hi-detox: n = 31, Lo-detox: n = 17) and 36 healthy controls underwent a comprehensive neuropsychological test-battery. Patients were tested after completion of detoxification (T1) and 3 (T2, n = 35) and 6 (T3, n = 28) months after discharge. Healthy controls were tested at T1 (n = 36) and T2 (n = 16). Drinking behaviour was assessed at all times. Patients performed significantly worse than controls at T1 as well as T2 with regard to attention/executive function. Recovery of attention/executive function was observed within the second 3 months after discharge, but the Hi-detox group performed worse than the Lo-detox group. No association with relapse was observed. This study provides first evidence, that repeated withdrawal from alcohol might be associated with reduced brain plasticity as indicated by a delay of recovery from impairment of attention/executive function. However, little evidence was found for a direct influence of cognitive impairment on treatment success.

14 CFR Appendix E to Part 420 - Tables for Explosive Site Plan

Code of Federal Regulations, 2010 CFR

2010-01-01

.... Table E-2—Liquid Propellant Explosive Equivalents Propellant combinations Explosive equivalent LO2/LH2 The larger of: 8W2/3 where W is the weight of LO2/LH2, or14% of W. LO2/LH2 + LO2/RP-1 Sum of (20% for LO2/RP-1) + the larger of: 8W2/3 where W is the weight of LO2/LH2, or14% of W. LO2/R-1 20% of W up to...

Robust Exploration and Commercial Missions to the Moon Using LANTR Propulsion and Lunar Liquid Oxygen Derived from FeO-Rich Pyroclastic Deposits

NASA Technical Reports Server (NTRS)

Borowski, Stanley K.; Ryan, Stephen W.; Burke, Laura M.; McCurdy, David R.; Fittje, James E.; Joyner, Claude R.

2017-01-01

Studies conducted by NASA and its contractors (early 1980s early 1990s) indicated a substantial benefit from using lunar-derived propellants specifically lunar-derived LO2 (LLO2) or LUNOX in a lunar space transportation system (LTS). With a LTS using LO2/LH2 chemical rockets, approx. 6 kilograms (kg) of mass in low Earth orbit (LEO) is required to place 1 kg of payload on the lunar surface (LS). Of this 6 kg, approx. 70% (4.2 kg) is propellant and 6/7th of this mass (3.6 kg) is oxygen assuming an O/H MR 6:1. Since the cost of placing a kilogram of mass on the LS is approx. 6X the cost of delivering it to LEO, the ability to produce and utilize LUNOX or lunar-derived LO2 and hydrogen (LLH2) from lunar polar ice (LPI) deposits can provide significant mission leverage. Providing LUNOX for use in fuel cells, life support systems and LO2/LH2 chemical rockets used on lunar landing vehicles (LLVs), can allow high value cargo (people, manufacturing and scientific equipment, etc.) to be transported to LEO, then to the Moon instead of bulk LO2 propellant. Oxygen is abundant in the lunar regolith (approx. 43% by mass) and can be extracted using a variety of techniques, such as hydrogen reduction of ilmenite (FeOTiO2) or FeO-rich volcanic glass (orange soil) discovered during the Apollo 17 mission to Taurus-Littrow. While considerable interest has been expressed about mining and processing LPI for rocket propellant, ground truth must first be established to quantify the physical state of the ice (e.g., its vertical thickness and areal extent, levels of soil contamination, etc.) and the deep, extremely cold (approx. 26-100 K) permanently shadowed craters where the ice resides.

Physicochemical modifications accompanying UV laser induced surface structures on poly(ethylene terephthalate) and their effect on adhesion of mesenchymal cells.

PubMed

Rebollar, Esther; Pérez, Susana; Hernández, Margarita; Domingo, Concepción; Martín, Margarita; Ezquerra, Tiberio A; García-Ruiz, Josefa P; Castillejo, Marta

2014-09-07

This work reports on the formation of different types of structures on the surface of polymer films upon UV laser irradiation. Poly(ethylene terephthalate) was irradiated with nanosecond UV pulses at 193 and 266 nm. The polarization of the laser beam and the irradiation angle of incidence were varied, giving rise to laser induced surface structures with different shapes and periodicities. The irradiated surfaces were topographically characterized by atomic force microscopy and the chemical modifications induced by laser irradiation were inspected via micro-Raman and fluorescence spectroscopies. Contact angle measurements were performed with different liquids, and the results evaluated in terms of surface free energy components. Finally, in order to test the influence of surface properties for a potential application, the modified surfaces were used for mesenchymal stem cell culture assays and the effect of nanostructure and surface chemistry on cell adhesion was evaluated.

L' upwelling de la côte atlantique du Maroc entre 1994 et 1998

NASA Astrophysics Data System (ADS)

Makaoui, Ahmed; Orbi, Abdelattif; Hilmi, Karim; Zizah, Soukaina; Larissi, Jamila; Talbi, Mohammed

2005-12-01

The pelagic ecosystem of the Moroccan Atlantic coast is influenced by the spatiotemporal variability of upwelling. The changes in the physicochemical and biological parameters as well as their interrelationship and regrouping by the principal components analysis allowed us to subdivide the Atlantic coast in four active areas: two areas located at the north of Cape Juby (28°N), characterised by a summery activity and two areas located at the south, active permanently, with a variable intensity. To cite this article: A. Makaoui et al., C. R. Geoscience 337 (2005).

Hepatic dendritic cell subsets in the mouse.

PubMed

Jomantaite, Ieva; Dikopoulos, Nektarios; Kröger, Andrea; Leithäuser, Frank; Hauser, Hansjörg; Schirmbeck, Reinhold; Reimann, Jörg

2004-02-01

The CD11c(+) cell population in the non-parenchymal cell population of the mouse liver contains dendritic cells (DC), NK cells, B cells and T cells. In the hepatic CD11c(+) DC population from immunocompetent or immunodeficient [recombinase-activating gene-1 (RAG1)(-/-)] C57BL/6 mice (rigorously depleted of T cells, B cells and NK cells), we identified a B220(+) CD11c(int) subset of 'plasmacytoid' DC, and a B220(-) CD11c(+) DC subset. The latter DC population could be subdivided into a major, immature (CD40(lo) CD80(lo) CD86(lo) MHC class II(lo)) CD11c(int) subset, and a minor, mature (CD40(hi) CD80(hi) CD86(hi) MHC class II(hi)) CD11c(hi) subset. Stimulated B220(+) but not B220(-) DC produced type I interferon. NKT cell activation in vivo increased the number of liver B220(-) DC three- to fourfold within 18 h post-injection, and up-regulated their surface expression of activation marker, while it contracted the B220(+) DC population. Early in virus infection, the hepatic B220(+) DC subset expanded, and both, the B220(+) as well as B220(-) DC populations in the liver matured. In vitro, B220(-) but not B220(+) DC primed CD4(+) or CD8(+)T cells. Expression of distinct marker profiles and functions, and distinct early reaction to activation signals hence identify two distinct B220(+) and B220(-) subsets in CD11c(+) DC populations freshly isolated from the mouse liver.

Diagnosing the Nature of Land-Atmosphere Coupling: A Case Study of Dry/Wet Extremes

NASA Technical Reports Server (NTRS)

Santanello, Joseph A., Jr.; Peters-Lidard, Christa; Kennedy, Aaron D.

2012-01-01

Land-atmosphere (L-A) interactions play a critical role in determining the diurnal evolution of land surface and planetary boundary layer (PBL) temperature and moisture states and fluxes. In turn, these interactions regulate the strength of the connection between surface moisture and precipitation in a coupled system. To address deficiencies in numerical weather prediction and climate models due to improper treatment of L-A interactions, recent studies have focused on development of diagnostics to quantify the strength and accuracy of the land-PBL coupling at the process-level. In this study, a diagnosis of the nature and impacts oflocalland-atmosphere coupling (LoCo) during dry and wet extreme conditions is presented using a combination of models and observations during the summers of2006-7 in the U.S. Southern Great Plains. Specifically, the Weather Research and Forecasting (WRF) model has been coupled to NASA's Land Information System (LIS), which provides a flexible and high-resolution representation and initialization of land surface physics and states. A range of diagnostics exploring the links and feedbacks between soil moisture and precipitation are examined for the dry/wet regimes of this region, along with the behavior and accuracy of different land-PBL scheme couplings under these conditions. In addition, we examine the impact of improved specification ofland surface states, anomalies, and fluxes that are obtained through the use of a hew optimization and uncertainty module in LIS, on the L-A coupling in WRF forecasts. Results demonstrate how LoCo diagnostics can be applied to coupled model components in the context of their integrated impacts on the process-chain connecting the land surface to the PBL and support of hydrological anomalies.

Study on the synthesis and physicochemical properties of starch acetate with low substitution under microwave assistance.

PubMed

Lin, Derong; Zhou, Wei; Zhao, Jingjing; Lan, Weijie; Chen, Rongming; Li, Yutong; Xing, Baoshan; Li, Zhuohao; Xiao, Mengshi; Wu, Zhijun; Li, Xindan; Chen, Rongna; Zhang, Xingwen; Chen, Hong; Zhang, Qing; Qin, Wen; Li, Suqing

2017-10-01

In this study, synthesis and physicochemical properties of starch acetate with low substitution under microwave were studied. A three-level-three-factorial Central Composite Design using Response Surface Methodology (RSM) was employed to optimize the reaction conditions. The optimal parameters are as follows: amount of acetic anhydride of 12%, radiation time of 11min, and microwave power of 100W. These optimal conditions predicted by RSM were confirmed that the degree of substitution (DS) of acetate starch is 0.0691mg/g and the physical and chemical properties of natural corn starch (NCS) and corn starch acetate (ACS) were further studied.The transparency, water separation, water absorption, expansion force, and solubility of ACS low substitution are better than NCS, while the NCS's hydrolysis percentage is higher than ACS, which indicate that the modified corn starch has better performance than native corn starch. The surface morphology of the corn starch acetate was examined by scanning electron microscope (SEM), which showed that it had a smooth surface and a spherical and polygonal shape. However, samples' shape is irregular. Crystal structure was observed by X-ray diffraction, and the ACS can determine the level of microwave technology that can destroy the extent of the crystal and amorphous regions. Fourier transform infrared (FTIR) spectroscopy shows that around 1750cm -1 carbonyl signal determines acetylation bonding successfully. Copyright © 2017 Elsevier B.V. All rights reserved.

Impact of protein modification on the protein corona on nanoparticles and nanoparticle-cell interactions.

PubMed

Treuel, Lennart; Brandholt, Stefan; Maffre, Pauline; Wiegele, Sarah; Shang, Li; Nienhaus, G Ulrich

2014-01-28

Recent studies have firmly established that cellular uptake of nanoparticles is strongly affected by the presence and the physicochemical properties of a protein adsorption layer around these nanoparticles. Here, we have modified human serum albumin (HSA), a serum protein often used in model studies of protein adsorption onto nanoparticles, to alter its surface charge distribution and investigated the consequences for protein corona formation around small (radius ∼5 nm), dihydrolipoic acid-coated quantum dots (DHLA-QDs) by using fluorescence correlation spectroscopy. HSA modified by succinic anhydride (HSAsuc) to generate additional carboxyl groups on the protein surface showed a 3-fold decreased binding affinity toward the nanoparticles. A 1000-fold enhanced affinity was observed for HSA modified by ethylenediamine (HSAam) to increase the number of amino functions on the protein surface. Remarkably, HSAsuc formed a much thicker protein adsorption layer (8.1 nm) than native HSA (3.3 nm), indicating that it binds in a distinctly different orientation on the nanoparticle, whereas the HSAam corona (4.6 nm) is only slightly thicker. Notably, protein binding to DHLA-QDs was found to be entirely reversible, independent of the modification. We have also measured the extent and kinetics of internalization of these nanoparticles without and with adsorbed native and modified HSA by HeLa cells. Pronounced variations were observed, indicating that even small physicochemical changes of the protein corona may affect biological responses.

Novel hybrid materials for preparation of bone tissue engineering scaffolds.

PubMed

Lewandowska-Łańcucka, Joanna; Fiejdasz, Sylwia; Rodzik, Łucja; Łatkiewicz, Anna; Nowakowska, Maria

2015-09-01

The organic-inorganic hybrid systems based on biopolymer hydrogels with dispersed silica nanoparticles were obtained and characterized in terms of their physicochemical properties, cytocompatibility and bioactivity. The hybrid materials were prepared in a form of collagen and collagen-chitosan sols to which the silica nanoparticles of two different sizes were incorporated. The ability of these materials to undergo in situ gelation under physiological temperature was assessed by microviscosity and gelation time determination based on steady-state fluorescence anisotropy measurements. The effect of silica nanoparticles addition on the physicochemical properties (surface wettability, swellability) of hybrid materials was analyzed and compared with those characteristic for pristine collagen and collagen-chitosan hydrogels. Biological studies indicate that surface wettability determined in terms of contact angle for all of the hybrids prepared is optimal and thus can provide satisfactory adhesion of fibroblasts. Cytotoxicity test results showed high metabolic activity of mouse as well as human fibroblast cell lines cultured on hybrid materials. The composition of hybrids was optimized in terms of concentration of silica nanoparticles. The effect of silica on the formation of bone-like mineral structures on exposition to simulated body fluid was determined. SEM images revealed mineral phase formation not only at the surfaces but also in the whole volumes of all hybrid materials developed suggesting their usefulness for bone tissue engineering. EDS and FTIR analyses indicated that these mineral phases consist of apatite-like structures.

Spatial and Temporal Correlates of Greenhouse Gas Diffusion from a Hydropower Reservoir in the Southern United States

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

Mosher, Jennifer; Fortner, Allison M.; Phillips, Jana Randolph

Emissions of CO 2 and CH 4 from freshwater reservoirs constitute a globally significant source of atmospheric greenhouse gases (GHGs), but knowledge gaps remain with regard to spatiotemporal drivers of emissions. We document the spatial and seasonal variation in surface diffusion of CO 2 and CH 4 from Douglas Lake, a hydropower reservoir in Tennessee, USA. Monthly estimates across 13 reservoir sites from January to November 2010 indicated that surface diffusions ranged from 236 to 18,806 mg m -2 day -1 for CO 2 and 0 to 0.95 mg m -2 day -1 for CH 4. Next, we developed statisticalmore » models using spatial and physicochemical variables to predict surface diffusions of CO 2 and CH 4. Models explained 22.7 and 20.9% of the variation in CO 2 and CH4 diffusions, respectively, and identified pH, temperature, dissolved oxygen, and Julian day as the most informative important predictors. These findings provide baseline estimates of GHG emissions from a reservoir in eastern temperate North America a region for which estimates of reservoir GHGs emissions are limited. Our statistical models effectively characterized non-linear and threshold relationships between physicochemical predictors and GHG emissions. Further refinement of such models will aid in predicting current GHG emissions in unsampled reservoirs and forecasting future GHG emissions.« less

Spatial and Temporal Correlates of Greenhouse Gas Diffusion from a Hydropower Reservoir in the Southern United States

DOE PAGES

Mosher, Jennifer; Fortner, Allison M.; Phillips, Jana Randolph; ...

2015-10-29

Emissions of CO 2 and CH 4 from freshwater reservoirs constitute a globally significant source of atmospheric greenhouse gases (GHGs), but knowledge gaps remain with regard to spatiotemporal drivers of emissions. We document the spatial and seasonal variation in surface diffusion of CO 2 and CH 4 from Douglas Lake, a hydropower reservoir in Tennessee, USA. Monthly estimates across 13 reservoir sites from January to November 2010 indicated that surface diffusions ranged from 236 to 18,806 mg m -2 day -1 for CO 2 and 0 to 0.95 mg m -2 day -1 for CH 4. Next, we developed statisticalmore » models using spatial and physicochemical variables to predict surface diffusions of CO 2 and CH 4. Models explained 22.7 and 20.9% of the variation in CO 2 and CH4 diffusions, respectively, and identified pH, temperature, dissolved oxygen, and Julian day as the most informative important predictors. These findings provide baseline estimates of GHG emissions from a reservoir in eastern temperate North America a region for which estimates of reservoir GHGs emissions are limited. Our statistical models effectively characterized non-linear and threshold relationships between physicochemical predictors and GHG emissions. Further refinement of such models will aid in predicting current GHG emissions in unsampled reservoirs and forecasting future GHG emissions.« less

Implementation of the effects of physicochemical properties on the foliar penetration of pesticides and its potential for estimating pesticide volatilization from plants.

PubMed

Lichiheb, Nebila; Personne, Erwan; Bedos, Carole; Van den Berg, Frederik; Barriuso, Enrique

2016-04-15

Volatilization from plant foliage is known to have a great contribution to pesticide emission to the atmosphere. However, its estimation is still difficult because of our poor understanding of processes occurring at the leaf surface. A compartmental approach for dissipation processes of pesticides applied on the leaf surface was developed on the base of experimental study performed under controlled conditions using laboratory volatilization chamber. This approach was combined with physicochemical properties of pesticides and was implemented in SURFATM-Pesticides model in order to predict pesticide volatilization from plants in a more mechanistic way. The new version of SURFATM-Pesticide model takes into account the effect of formulation on volatilization and leaf penetration. The model was evaluated in terms of 3 pesticides applied on plants at the field scale (chlorothalonil, fenpropidin and parathion) which display a wide range of volatilization rates. The comparison of modeled volatilization fluxes with measured ones shows an overall good agreement for the three tested compounds. Furthermore the model confirms the considerable effect of the formulation on the rate of the decline in volatilization fluxes especially for systemic products. However, due to the lack of published information on the substances in the formulations, factors accounting for the effect of formulation are described empirically. A sensitivity analysis shows that in addition to vapor pressure, the octanol-water partition coefficient represents important physicochemical properties of pesticides affecting pesticide volatilization from plants. Finally the new version of SURFATM-Pesticides is a prospecting tool for key processes involved in the description of pesticide volatilization from plants. Copyright © 2016 Elsevier B.V. All rights reserved.

Topsoil structure stability in a restored floodplain: Impacts of fluctuating water levels, soil parameters and ecosystem engineers.

PubMed

Schomburg, A; Schilling, O S; Guenat, C; Schirmer, M; Le Bayon, R C; Brunner, P

2018-10-15

Ecosystem services provided by floodplains are strongly controlled by the structural stability of soils. The development of a stable structure in floodplain soils is affected by a complex and poorly understood interplay of hydrological, physico-chemical and biological processes. This paper aims at analysing relations between fluctuating groundwater levels, soil physico-chemical and biological parameters on soil structure stability in a restored floodplain. Water level fluctuations in the soil are modelled using a numerical surface-water-groundwater flow model and correlated to soil physico-chemical parameters and abundances of plants and earthworms. Causal relations and multiple interactions between the investigated parameters are tested through structural equation modelling (SEM). Fluctuating water levels in the soil did not directly affect the topsoil structure stability, but indirectly through affecting plant roots and soil parameters that in turn determine topsoil structure stability. These relations remain significant for mean annual days of complete and partial (>25%) water saturation. Ecosystem functioning of a restored floodplain might already be affected by the fluctuation of groundwater levels alone, and not only through complete flooding by surface water during a flood period. Surprisingly, abundances of earthworms did not show any relation to other variables in the SEM. These findings emphasise that earthworms have efficiently adapted to periodic stress and harsh environmental conditions. Variability of the topsoil structure stability is thus stronger driven by the influence of fluctuating water levels on plants than by the abundance of earthworms. This knowledge about the functional network of soil engineering organisms, soil parameters and fluctuating water levels and how they affect soil structural stability is of fundamental importance to define management strategies of near-natural or restored floodplains in the future. Copyright © 2018 Elsevier B.V. All rights reserved.

Optimization of solvent extraction of shea butter (Vitellaria paradoxa) using response surface methodology and its characterization.

PubMed

Ajala, E O; Aberuagba, F; Olaniyan, A M; Onifade, K R

2016-01-01

Shea butter (SB) was extracted from its kernel by using n-hexane as solvent in an optimization study. This was to determine the optima operating variables that would give optimum yield of SB and to study the effect of solvent on the physico-chemical properties and chemical composition of SB extracted using n-hexane. A Box-behnken response surface methodology (RSM) was used for the optimization study while statistical analysis using ANOVA was used to test the significance of the variables for the process. The variables considered for this study were: sample weight (g), solvent volume (ml) and extraction time (min). The physico-chemical properties of SB extracted were determined using standard methods and Fourier Transform Infrared Spectroscopy (FTIR) for the chemical composition. The results of RSM analysis showed that the three variables investigated have significant effect (p < 0.05) on the %yield of SB, with R(2) - 0.8989 which showed good fitness of a second-order model. Based on this model, optima operating variables for the extraction process were established as: sample weight of 30.04 g, solvent volume of 346.04 ml and extraction time of 40 min, which gave 66.90 % yield of SB. Furthermore, the result of the physico-chemical properties obtained for the shea butter extracted using traditional method (SBT) showed that it is a more suitable raw material for food, biodiesel production, cosmetics, medicinal and pharmaceutical purposes than shea butter extracted using solvent extraction method (SBS). Fourier Transform Infrared Spectroscopy (FTIR) results obtained for the two samples were similar to what was obtainable from other vegetable oil.

Fatty acid composition, physicochemical properties, antioxidant and cytotoxic activity of apple seed oil obtained from apple pomace.

PubMed

Walia, Mayanka; Rawat, Kiran; Bhushan, Shashi; Padwad, Yogendra S; Singh, Bikram

2014-03-30

Apple pomace is generated in huge quantities in juice-processing industries the world over and continuous efforts are being made for its inclusive utilization. In this study, apple seeds separated from industrial pomace were used for extraction of oil. The fatty acid composition, physicochemical and antioxidant as well as in vitro anticancer properties of extracted oil were studied to assess its suitability in food and therapeutic applications. The fatty acid composition of seed oil revealed the dominance of oleic (46.50%) and linoleic acid (43.81%). It had high iodine (121.8 g I 100 g⁻¹) and saponification value (184.91 mg KOH g⁻¹ oil). The acid value, refractive index and relative density were 4.28 mg KOH g⁻¹, 1.47 and 0.97 mg mL⁻¹, respectively. The antioxidant potential (IC₅₀) of apple seed oil was 40.06 µg mL⁻¹. Cytotoxicity of apple seed oil against CHOK1, SiHa and A549 cancer cell lines ranged between 0.5 ± 0.06% and 88.6 ± 0.3%. The physicochemical properties of apple seed oil were comparable with edible food oil, indicating its better stability and broad application in the food and pharmaceutical industries. Apple seed oil could be a good source of natural antioxidants. Also, the in vitro cytotoxic activity against specific cell lines exhibited its potential as an anticancer agent. © 2013 Society of Chemical Industry.

Effects of gamma irradiation on the shelf-life of a dairy-like product

NASA Astrophysics Data System (ADS)

Odueke, Oluwakemi B.; Chadd, Stephen A.; Baines, Richard N.; Farag, Karim W.; Jansson, Jonathan

2018-02-01

This study was aimed to assess the effect of irradiation on the shelf-life of pseudo-dairy food product consisting of different concentration levels of the structural and energy-giving caloric component macronutrients (protein, fat and carbohydrate). Gamma irradiated products (1 kGy, 3 kGy, 5 kGy and 10 kGy) were compared to the current procedure used by the industry of non-irradiated dairy products. The study looked at the impact of different treatments on storage quality in respect to physicochemical (pH, acidity, macronutrients), and microbiological properties [total viable count (TVC)]. The products were aseptically packaged in plastic containers and analysed at regular weekly intervals up until 100 days during refrigerated storage at 4 ± 1 °C. The storage period did not bring about any significant change in physicochemical properties of the products throughout the period of study while the TVC displayed a linear regression for irradiated products stored at 4 ± 1 °C as well as the control (non-irradiated). At the end of the shelf-life trial (benchmarked at log 4.3 CFU/g), the total viable count did not exceed log 3.94 CFU/g for samples treated at 10 kGy after 100 days of analysis. These observations indicated that the product could be safely stored aerobically for > 100days (10 and 5 kGy), 56days at (3 kGy), 42 days at (1 kGy) for the irradiated samples' and 14-28 days for the non-irradiated samples without much change in physicochemical and microbiological properties using refrigerated storage.

Estimation of direct and indirect impacts of fireworks on the physicochemical characteristics of atmospheric fine and coarse particles

NASA Astrophysics Data System (ADS)

Tian, Y.-Z.; Wang, J.; Peng, X.; Shi, G.-L.; Feng, Y.-C.

2014-05-01

To quantify total, direct and indirect impacts of fireworks individually, size-resolved PM samples were collected before, during, and after a Chinese folk-custom festival (Chinese New Year) in a megacity in China. Through chemical analysis and morphology characterization, strong influence of fireworks on physicochemical characteristics of PM10 and PM2.5 was observed. Concentrations of many species exhibited an increasing trend during heavy-firework period, especially for K+, Mg2+ and Cr; and the results of non-sea-salt ions demonstrated anthropogenic influence on them. Then, source apportionment was conducted by receptor models and Peak Analysis. Total influence of fireworks was quantified by PMF, showing that fireworks contributed rather higher fractions (23.40% to PM10 and 29.66% to PM2.5) during heavy-firework period than those during light-firework period (4.28% to PM10 and 7.18% to PM2.5). Profiles of total fireworks obtained by two independent methods (PMF and Peak Analysis) were consistent, with higher abundances of K+, Al, Si, Ca and OC. Finally, individual contributions of direct and indirect impacts of fireworks were quantified by CMB. The percentage contributions of resuspended dust, biomass combustion and direct-fireworks were 36.82, 14.08 and 44.44% for PM10 and 34.89, 16.60 and 52.54% for PM2.5, in terms of the total fireworks. The quantification of total, direct and indirect impacts of fireworks to ambient PM gives an original contribution to understand the physicochemical characteristics and mechanisms of such high-intensity anthropogenic activities.

Effects of engineered nanoparticles on the innate immune system.

PubMed

Liu, Yuanchang; Hardie, Joseph; Zhang, Xianzhi; Rotello, Vincent M

2017-12-01

Engineered nanoparticles (NPs) have broad applications in industry and nanomedicine. When NPs enter the body, interactions with the immune system are unavoidable. The innate immune system, a non-specific first line of defense against potential threats to the host, immediately interacts with introduced NPs and generates complicated immune responses. Depending on their physicochemical properties, NPs can interact with cells and proteins to stimulate or suppress the innate immune response, and similarly activate or avoid the complement system. NPs size, shape, hydrophobicity and surface modification are the main factors that influence the interactions between NPs and the innate immune system. In this review, we will focus on recent reports about the relationship between the physicochemical properties of NPs and their innate immune response, and their applications in immunotherapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Formulation and evaluation of herbal anti-acne moisturizer.

PubMed

Rasheed, Arun; Shama, Shaik Neelufar; Joy, Jyothi Mulanjananiyil; Reddy, Bobbu Sravya; Roja, Chirra

2012-10-01

The moisture content present in human skin makes it look young and the use of moisturizer results in fastening the moisture with a surface film of oil. Acne vulgaris is one of the most commonly seen diseases among the youth. The present study is focused on the use of herbs as moisturizer for acne treatment. The anti-acne moisturizer was formulated from herbal crude extracts and investigated the physico-chemical parameters as well as antibacterial activity of the formulation. The study revealed that ethanol extract of Andrographis paniculata, Glycyrrhiza glabra, Ocimum sanctum, Azadiracta indica and Green tea possessed the potential for inhibiting acne. It was observed that the optimal formula of anti-acne moisturizer was satisfactorily effective to control acne inducing bacteria i.e., Staphylococcus epidermis and Propionibacterium. The physico-chemical parameters of the formulation were also optimal with no signs of irritation.

Techniques for physicochemical characterization of nanomaterials

PubMed Central

Lin, Ping-Chang; Lin, Stephen; Wang, Paul C.; Sridhar, Rajagopalan

2014-01-01

Advances in nanotechnology have opened up a new era of diagnosis, prevention and treatment of diseases and traumatic injuries. Nanomaterials, including those with potential for clinical applications, possess novel physicochemical properties that have an impact on their physiological interactions, from the molecular level to the systemic level. There is a lack of standardized methodologies or regulatory protocols for detection or characterization of nanomaterials. This review summarizes the techniques that are commonly used to study the size, shape, surface properties, composition, purity and stability of nanomaterials, along with their advantages and disadvantages. At present there are no FDA guidelines that have been developed specifically for nanomaterial based formulations for diagnostic or therapeutic use. There is an urgent need for standardized protocols and procedures for the characterization of nanoparticles, especially those that are intended for use as theranostics. PMID:24252561

Refractance Window™ drying of haskap berry--preliminary results on anthocyanin retention and physicochemical properties.

PubMed

Celli, Giovana Bonat; Khattab, Rabie; Ghanem, Amyl; Brooks, Marianne Su-Ling

2016-03-01

The goal of this work was to determine the anthocyanin retention and physicochemical properties of haskap powder prepared by Refractance Window™ (RW) drying. In general, the RW-dried powder particles had a smooth surface with similar thickness, consistent with the preparation method, and had a solubility of 75.63% in water. The RW-dried powder (consisting of 98% haskap berries) retained approximately 93.8% of anthocyanins from the original frozen fruits, as assessed by the pH-differential method. This result is in good agreement with HPLC analysis that indicated 92.9% retention. Three anthocyanins were identified in frozen berries and RW-dried powder: cyanidin 3-glucoside, cyanidin 3-rutinoside, and peonidin 3-glucoside. Surprisingly, cyanidin 3-rutinoside exhibited the lowest retention. Copyright © 2015 Elsevier Ltd. All rights reserved.

Intranasal delivery: physicochemical and therapeutic aspects.

PubMed

Costantino, Henry R; Illum, Lisbeth; Brandt, Gordon; Johnson, Paul H; Quay, Steven C

2007-06-07

Interest in intranasal (IN) administration as a non-invasive route for drug delivery continues to grow rapidly. The nasal mucosa offers numerous benefits as a target issue for drug delivery, such as a large surface area for delivery, rapid drug onset, potential for central nervous system delivery, and no first-pass metabolism. A wide variety of therapeutic compounds can be delivered IN, including relatively large molecules such as peptides and proteins, particularly in the presence of permeation enhancers. The current review provides an in-depth discussion of therapeutic aspects of IN delivery including consideration of the intended indication, regimen, and patient population, as well as physicochemical properties of the drug itself. Case examples are provided to illustrate the utility of IN dosing. It is anticipated that the present review will prove useful for formulation scientists considering IN delivery as a delivery route.

Physicochemical Parameters Affecting the Electrospray Ionization Efficiency of Amino Acids after Acylation

PubMed Central

2017-01-01

Electrospray ionization (ESI) is widely used in liquid chromatography coupled to mass spectrometry (LC–MS) for the analysis of biomolecules. However, the ESI process is still not completely understood, and it is often a matter of trial and error to enhance ESI efficiency and, hence, the response of a given set of compounds. In this work we performed a systematic study of the ESI response of 14 amino acids that were acylated with organic acid anhydrides of increasing chain length and with poly(ethylene glycol) (PEG) changing certain physicochemical properties in a predictable manner. By comparing the ESI response of 70 derivatives, we found that there was a strong correlation between the calculated molecular volume and the ESI response, while correlation with hydrophobicity (log P values), pKa, and the inverse calculated surface tension was significantly lower although still present, especially for individual derivatized amino acids with increasing acyl chain lengths. Acylation with PEG containing five ethylene glycol units led to the largest gain in ESI response. This response was maximal independent of the calculated physicochemical properties or the type of amino acid. Since no actual physicochemical data is available for most derivatized compounds, the responses were also used as input for a quantitative structure–property relationship (QSPR) model to find the best physicochemical descriptors relating to the ESI response from molecular structures using the amino acids and their derivatives as a reference set. A topological descriptor related to molecular size (SPAN) was isolated next to a descriptor related to the atomic composition and structural groups (BIC0). The validity of the model was checked with a test set of 43 additional compounds that were unrelated to amino acids. While prediction was generally good (R2 > 0.9), compounds containing halogen atoms or nitro groups gave a lower predicted ESI response. PMID:28737384

Physicochemical characterisation of fluids and soft foods frequently mixed with oral drug formulations prior to administration to children.

PubMed

Kersten, E; Barry, A; Klein, S

2016-03-01

Oral drug administration to children poses specific pharmaceutical challenges that are often not seen to the same extent in adults, and whose occurrence may also be age dependent. When an age-appropriate dosage form is not available, manipulation of adult dosage forms (e.g., splitting and crushing of tablets or opening of capsules) has been reported as a means to facilitate administration to children. To enhance swallowability and/or mask an unpleasant taste of the dosage form to be administered, crushed/split tablets or the contents of capsules are often mixed with food or drinks or suspended in a vehicle prior to administration. However, it seems that the risks and benefits of an approach whereby the dosage form is modified prior to administration in this manner are everything but clear. The aim of the present study was to gain an overview of the physicochemical properties of a number of fluids, soft foods and suspension vehicles that are commonly reported to be mixed with oral medications before administration to children to improve patient acceptability. For this purpose, physicochemical parameters of 15 different fluids, soft foods and suspension vehicles were measured. These included pH, buffer capacity, osmolality, surface tension and viscosity. Results of the study clearly show the differences in physicochemical properties of the test candidates. It is thus obvious that the type of fluid/food mixed with a drug product before administration may have a significant impact on bioavailability of the drug administered. Therefore, a risk-based assessment of such practices considering API properties, formulation features and physicochemical properties of the fluids and foods intended to be co-administered with the dosage form, in conjunction with the anatomical and physiological maturity of the gastro-intestinal tract in the intended paediatric population, should be an essential part of paediatric oral formulation development.

Impact of supplemental protein source offered to primiparous heifers during gestation on II. Progeny performance and carcass characteristics.

PubMed

Summers, A F; Blair, A D; Funston, R N

2015-04-01

A 3-yr study using primiparous crossbred beef heifers (n = 114) was conducted to determine the effects of protein supplement during late gestation on progeny performance and carcass characteristics. Pregnant heifers were stratified by heifer development system, initial BW, and AI service sire and placed in an individual feeding system. Heifers were offered meadow hay (8 to 11% CP) from early November to mid-February and provided no supplement (CON; n = 37), 0.83 kg/d (DM basis) of a dried distillers grains with solubles-based supplement (HI; n = 39), or 0.83 kg/d (DM basis) of a dried corn gluten feed-based supplement (LO; n = 38). Supplements were designed to be isonitrogenous (28% CP) and isocaloric but to differ in RUP with HI (59% RUP) having greater levels of RUP than LO (34% RUP). After the individual feeding period, heifers were placed in a drylot for calving. All heifers were bred using a fixed-timed AI protocol and pairs were moved to a commercial ranch in the Nebraska Sandhills for summer grazing. Calf weaning BW did not differ (P = 0.14) based on maternal diet. However, feedlot entry BW was greater (P = 0.03) for HI compared with CON calves. Average daily gain during the initial feedlot phase tended (P = 0.10) to be greatest for calves born to CON dams and lowest for calves born to LO dams. However, overall ADG was similar (P = 0.50) for the entire feedlot period. Residual feed intake during the reimplant and total feeding period was improved in calves born to supplemented dams in yr 2 and 3 compared with calves born to CON dams. There was no difference in final BW among treatments (P = 0.71). Hot carcass weight was similar (P = 0.72) among treatments; however, steers had greater (P < 0.01) HCW than heifers. Furthermore, percent empty body fat and 12th rib fat thickness were lowest (P = 0.05 and P = 0.04) for calves born to LO dams. Tenderness measured by Warner-Bratzler shear force was increased (P = 0.03) in longissimus samples from calves from CON dams compared to calves from LO dams. Similarly, crude fat levels tended to be greater (P = 0.07) for calves from CON dams compared with calves from LO dams. Based on these data, providing RUP supplements, similar to those used in this study, to primiparous heifers in late gestation consuming ad libitum grass hay resulted in increased initial feedlot BW for HI compared to CON calves, improved feed efficiency, and altered carcass characteristics in calves born to supplemented compared with CON dams.

Surface properties of catheters, stents and bacteria associated with urinary tract infections

NASA Astrophysics Data System (ADS)

Reid, Gregor; Busscher, Henk J.; Sharma, Sunaina; Mittelman, Marc W.; McIntyre, Stewart

Applications of surface and physico-chemical techniques to the clinical setting, in particular related to the urogenital tract, have been sporadic, often concentrating on aspects of biocompatibility and interactions of blood cells with materials. In an era where billions of such devices are implanted annually, it is important to utilize such techniques to improve our understanding of material-host interactions. In an effort to encourage further such interactive investigations, this review will illustrate some practical biomedical examples where utilization of sophisticated surface-science techniques has provided valuable insight into interfacial events between host components, micro-organisms and material surfaces. Techniques to reduce bacterial infection and encrustations will be discussed, and suggestions given for future lines of enquiry.

Retinotopic Maps, Spatial Tuning, and Locations of Human Visual Areas in Surface Coordinates Characterized with Multifocal and Blocked fMRI Designs

PubMed Central

Henriksson, Linda; Karvonen, Juha; Salminen-Vaparanta, Niina; Railo, Henry; Vanni, Simo

2012-01-01

The localization of visual areas in the human cortex is typically based on mapping the retinotopic organization with functional magnetic resonance imaging (fMRI). The most common approach is to encode the response phase for a slowly moving visual stimulus and to present the result on an individual's reconstructed cortical surface. The main aims of this study were to develop complementary general linear model (GLM)-based retinotopic mapping methods and to characterize the inter-individual variability of the visual area positions on the cortical surface. We studied 15 subjects with two methods: a 24-region multifocal checkerboard stimulus and a blocked presentation of object stimuli at different visual field locations. The retinotopic maps were based on weighted averaging of the GLM parameter estimates for the stimulus regions. In addition to localizing visual areas, both methods could be used to localize multiple retinotopic regions-of-interest. The two methods yielded consistent retinotopic maps in the visual areas V1, V2, V3, hV4, and V3AB. In the higher-level areas IPS0, VO1, LO1, LO2, TO1, and TO2, retinotopy could only be mapped with the blocked stimulus presentation. The gradual widening of spatial tuning and an increase in the responses to stimuli in the ipsilateral visual field along the hierarchy of visual areas likely reflected the increase in the average receptive field size. Finally, after registration to Freesurfer's surface-based atlas of the human cerebral cortex, we calculated the mean and variability of the visual area positions in the spherical surface-based coordinate system and generated probability maps of the visual areas on the average cortical surface. The inter-individual variability in the area locations decreased when the midpoints were calculated along the spherical cortical surface compared with volumetric coordinates. These results can facilitate both analysis of individual functional anatomy and comparisons of visual cortex topology across studies. PMID:22590626

The observation of the physicochemical change of rock under freeze-thawing experiment: CLSM, XRD and ICP analysis

NASA Astrophysics Data System (ADS)

Choi, J.; Chae, B.; Chon, C.; Jeong, J.

2013-12-01

Abstract : In order to understand the progress of the physical weathering of rock sample, we managed freeze-thawing experiment at temperature of up to 40C from -20C taking into account of South Korea. In this study, the time was held by two hours the temperature of the maximum (40C) and minimum (-20C) and the experiments were carried out at intervals of one hour rising and falling. We have run the experiment about 120 cycle with the cycle of -20C from 40C experiment. We measured the physical properties of rock samples after each 20 cycle has elapsed by using confocal laser scanning microscope (CLSM) and observed changes in roughness of rock samples surface. We also analyzed the mineral of rock sample using the XRD analysis and observing the change in chemical composition of solution used in the experiment by using ICP analysis. Through the above process, we observed physico-chemical changes in the rock sample due to freeze-thaw cycles. To analysis of the line roughness parameter we used set by the 10 vertical and horizontal cross section line on the surface and surface roughness parameter was analyzed by using the area on the surface. Through such a process, while the freeze-thawing experiment is advanced, it was studied how the physical roughness and chemical composition were changed. As a result, it was possible to observe a change in the mineral component of the particular dissolved in the solution and it was able to observe the characteristic changes of the parameters of the roughness of the lines and surfaces.

Synthesis of activated carbon from oil fly ash for removal of H2S from gas stream

NASA Astrophysics Data System (ADS)

Aslam, Zaheer; Shawabkeh, Reyad A.; Hussein, Ibnelwaleed A.; Al-Baghli, Nadhir; Eic, Mladen

2015-02-01

Activated carbon (AC) is made from waste oil fly ash (OFA) which is produced in large quantities from power generation plants through combustion of heavy fuel oil. OFA contains ∼80% carbon that makes it suitable for producing AC by physicochemical treatments using a mixture of HNO3, H2SO4, and H3PO4 acids to remove non-carbonaceous impurities. The acid treated OFA is then activated by CO2 at 990 °C. The physico-chemical treatments of OFA have increased the surface area from 4 to 375 m2/g. Surface morphology and pore volume of AC are characterized by combined SEM and EDX techniques. Elemental analysis shows that sulfur content is reduced from 7.1 wt% in untreated OFA to 0.51 wt% for the treated OFA. The AC is further treated with HNO3 and NH4OH solutions in order to attach the carboxylic and amine groups on the surface, respectively. FTIR characterization is used to confirm the presence of the functional groups on the surface of AC at different stages of its development. The performance of functionalized AC samples is tested for the removal of H2S from a synthetic natural gas by carrying out breakthrough experiments. The results from these tests have shown maximum adsorption capacity of 0.3001 mg/g for NH4OH functionalized activated carbon with 86.43% regeneration efficiency. The ammonium hydroxide treated AC is found to be more effective for H2S removal than acid treated AC as confirmed by breakthrough experiments. The results indicate that the presence of more acidic functionalities on the surface reduces the H2S adsorption efficiency from the gas mixture.

Quantifying, Visualizing, and Monitoring Lead Optimization.

PubMed

Maynard, Andrew T; Roberts, Christopher D

2016-05-12

Although lead optimization (LO) is by definition a process, process-centric analysis and visualization of this important phase of pharmaceutical R&D has been lacking. Here we describe a simple statistical framework to quantify and visualize the progression of LO projects so that the vital signs of LO convergence can be monitored. We refer to the resulting visualizations generated by our methodology as the "LO telemetry" of a project. These visualizations can be automated to provide objective, holistic, and instantaneous analysis and communication of LO progression. This enhances the ability of project teams to more effectively drive LO process, while enabling management to better coordinate and prioritize LO projects. We present the telemetry of five LO projects comprising different biological targets and different project outcomes, including clinical compound selection, termination due to preclinical safety/tox, and termination due to lack of tractability. We demonstrate that LO progression is accurately captured by the telemetry. We also present metrics to quantify LO efficiency and tractability.

A Partial Exploration of the Potential Energy Surfaces of SCN and HSCN: Implications for the Enzyme-Mediated Detoxification of Cyanide

DTIC Science & Technology

2009-01-01

its role in toxicology , Tox. Sci. 78 (2004) 185–188. [6] (a) B.H. Sorbo, Crystalline rhodanese. I. Purification and physicochemical exam- ination, Acta...the devel- opment of quantitative structure–activity relationships ( QSARs ). pKa-values of phenols and aromatic and aliphatic carboxylic acids, Chemosphere 19 (1989) 1595.

Molecular interactions in a surfactant-water-polyacrylamide system, according to densimetry, viscometry, conductometry, and spectroscopy data

NASA Astrophysics Data System (ADS)

Harutyunyan, R. S.

2013-08-01

Molecular interactions in a surfactant-polyacrylamide-water system are investigated. It is established that the interactions affect such physicochemical parameters of the system as viscosity, density, surface tension, conductivity, and critical micelle concentration. It is shown that in a polyacrylamide-water system, raising the polyacrylamide concentration to 0.02% causes conformational changes in its macromolecule.

Benthic Bacterial Diversity in Submerged Sinkhole Ecosystems▿ †

PubMed Central

Nold, Stephen C.; Pangborn, Joseph B.; Zajack, Heidi A.; Kendall, Scott T.; Rediske, Richard R.; Biddanda, Bopaiah A.

2010-01-01

Physicochemical characterization, automated ribosomal intergenic spacer analysis (ARISA) community profiling, and 16S rRNA gene sequencing approaches were used to study bacterial communities inhabiting submerged Lake Huron sinkholes inundated with hypoxic, sulfate-rich groundwater. Photosynthetic cyanobacterial mats on the sediment surface were dominated by Phormidium autumnale, while deeper, organically rich sediments contained diverse and active bacterial communities. PMID:19880643

An Experimental Study in the Mechanical Response of Polymer Modified Geopolymers

DTIC Science & Technology

2012-04-01

Compressive and Bending Strength of Fly ash Geopolymers ... 22 LIST OF TABLES Page Table 1. Chemical Composition of Aluminosilicates in Mass... geopolymer matrix composites .” Ceramic Transactions, 153, 227-250. 3. Davidovits J., 1991. “ Geopolymers , inorganic polymeric materials.” Journal of...Understanding the relationship between geopolymer composition , microstructure and mechanical properties.” Colloids and Surfaces.A, Physicochemical

Geochemistry of Dissolved Trace Metals in the Waters of Bahia Magdalena, Baja California Sur, Pacific Coast, Mexico

NASA Astrophysics Data System (ADS)

Suresh Babu, S.

2016-12-01

Forty two samples were acquired from the surface and bottom water profiles along 5 transects spread over Bahia Magdalena lagoon, Baja California Sur to assess the behavior of trace metals in a high influenced upwelling region on the Pacific coast. To elaborate the fate of metals, also the physico-chemical parameters (pH, temperature, salinity, conductivity, dissolved oxygen). Determination of the concentrations of trace metals (Fe, Mn, Cr, Cu, Co, Pb, Ni, Zn, Cd As, Hg) were measured using Atomic absorption spectrometry. The results demonstrated high values of As, Ni and Co which is attributed to the local geology and phosphate deposits. Low values of Fe and Mn are attested to the oxic conditions of the lagoon which are responsible for the oxidation of Fe and Mn. The region witnesses raised temperatures (28.92ºC) and salinities of 35.2 PSU for its arid climatic conditions and high rates of evaporation. In general, the region presented minor quantities of dissolved trace metals due to dispersion and high intense interaction with the open sea. The results were also compared with other studies to understand the enrichment pattern in this side of the pacific coast which experiences various geothermal activities and upwelling phenomenon.

Optimization and physicochemical characterization of a triamcinolone acetonide-loaded NLC for ocular antiangiogenic applications.

PubMed

Araújo, J; Gonzalez-Mira, E; Egea, M A; Garcia, M L; Souto, E B

2010-06-30

The purpose of this study was to develop a novel nanostructured lipid carrier (NLC) for the intravitreal-targeting delivery of triamcinolone acetonide (TA) by direct ocular instillation. A five-level central composite rotable design was used to study the influence of four different variables on the physicochemical characteristics of NLCs. The analysis of variance (ANOVA) statistical test was used to assess the optimization of NLC production parameters. The systems were produced by high pressure homogenization using Precirol ATO5 and squalene as solid and liquid lipids respectively, and Lutrol F68 as surfactant. Homogenization at 600 bar for 3 cycles of the optimized formulation resulted in the production of small NLC (mean diameter < 200 nm) with a homogeneous particle size distribution (polydispersity index (PI) approximately 0.1), of negatively charged surface (approximately |45| mV) and high entrapment efficiency (approximately 95%). Surface morphology was assessed by SEM which revealed fairly spherical shape. DSC, WAXS and FT-IR analyses confirmed that TA was mostly entrapped into the NLC, characterized by an amorphous matrix. In vivo Draize test showed no signs of ocular toxicity. 2010 Elsevier B.V. All rights reserved.

The physicochemical properties of a spray dried glutinous rice starch biopolymer.

PubMed

Laovachirasuwan, Pornpun; Peerapattana, Jomjai; Srijesdaruk, Voranuch; Chitropas, Padungkwan; Otsuka, Makoto

2010-06-15

Glutinous rice starch (GRS) is a biopolymer used widely in the food industry but not at all in the pharmaceutical industry. There are several ways to modify this biopolymer. Physical modification is simple and cheap because it requires no chemicals or biological agents. The aim of this study was to characterize the physicochemical properties of a spray dried glutinous rice starch (SGRS) produced from pregelatinized GRS. The surface morphology changed from an irregular to concave spherical shape as revealed by Scanning Electron Microscopy (SEM). SGRS was almost amorphous as determined by X-ray Diffraction (XRD) spectroscopy. The water molecules became linked through hydrogen bonds to the exposed hydroxyl group of amorphous SGRS as determined by Near Infrared (NIR) spectroscopy. Then, SGRS formed a colloid gel matrix with water and developed a highly viscous gelatinous form as determined using Differential Scanning Calorimetry (DSC) and a stress control type rheometer. In addition, SGRS can swell and produce a gelatinous surface barrier like a hydrophilic matrix biopolymer which controls drug release. Therefore, a novel application of SGRS is as a sustained release modifier for direct compression tablets in the pharmaceutical industry. Copyright 2010 Elsevier B.V. All rights reserved.

Autogenous teeth used for bone grafting: a comparison with traditional grafting materials.

PubMed

Kim, Young-Kyun; Kim, Su-Gwan; Yun, Pil-Young; Yeo, In-Sung; Jin, Seung-Chan; Oh, Ji-Su; Kim, Heung-Joong; Yu, Sun-Kyoung; Lee, Sook-Young; Kim, Jae-Sung; Um, In-Woong; Jeong, Mi-Ae; Kim, Gyung-Wook

2014-01-01

This study evaluated the surface structures and physicochemical characteristics of a novel autogenous tooth bone graft material currently in clinical use. The material's surface structure was compared with a variety of other bone graft materials via scanning electron microscope (SEM). The crystalline structure of the autogenous tooth bone graft material from the crown (AutoBT crown) and root (AutoBT root), xenograft (BioOss), alloplastic material (MBCP), allograft (ICB), and autogenous mandibular cortical bone were compared using x-ray diffraction (XRD) analysis. The solubility of each material was measured with the Ca/P dissolution test. The results of the SEM analysis showed that the pattern associated with AutoBT was similar to that from autogenous cortical bones. In the XRD analysis, AutoBT root and allograft showed a low crystalline structure similar to that of autogenous cortical bones. In the CaP dissolution test, the amount of calcium and phosphorus dissolution in AutoBT was significant from the beginning, while displaying a pattern similar to that of autogenous cortical bones. In conclusion, autogenous tooth bone graft materials can be considered to have physicochemical characteristics similar to those of autogenous bones. Copyright © 2014 Elsevier Inc. All rights reserved.

Influences of oceanographic features on the distribution and abundance of yellowfin tuna, Thunnus albacares, larvae in the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Cornic, M.; Rooker, J. R.

2016-02-01

Summer ichthyoplankton surveys were conducted in the northern Gulf of Mexico (NGoM) from 2007-2010 to characterize patterns of distribution and abundance of yellowfin tuna (Thunnus albacares) larvae in this region. Yellowfin tuna larvae were moderately abundant representing 9% of the overall Thunnus larvae collected (18765) and had a percent occurrence ranging from 13 to 57% among surveys. Interannual variations were detected with highest mean densities observed in 2009 (2.2 larvae per 1000m3) and the lowest mean densities observed in 2008 (0.7 larvae per 1000 m3). Generalized additive models were used to investigate the influence of oceanographic conditions on abundance of yellowfin tuna larvae. Increased densities were associated with high sea surface temperatures, positive sea surface heights, and intermediate salinities, revealing that these physicochemical conditions may be favorable for yellowfin tuna larvae. These results indicate that the NGoM is an important spawning and/or nursery habitat for yellowfin tuna and suggest that mesoscale features and physicochemical characteristics of water masses may impact distribution and abundance of yellowfin tuna larvae in the NGoM.

Interaction of High Flash Point Electrolytes and PE-Based Separators for Li-Ion Batteries

PubMed Central

Hofmann, Andreas; Kaufmann, Christoph; Müller, Marcus; Hanemann, Thomas

2015-01-01

In this study, promising electrolytes for use in Li-ion batteries are studied in terms of interacting and wetting polyethylene (PE) and particle-coated PE separators. The electrolytes are characterized according to their physicochemical properties, where the flow characteristics and the surface tension are of particular interest for electrolyte–separator interactions. The viscosity of the electrolytes is determined to be in a range of η = 4–400 mPa∙s and surface tension is finely graduated in a range of γL = 23.3–38.1 mN∙m−1. It is verified that the technique of drop shape analysis can only be used in a limited matter to prove the interaction, uptake and penetration of electrolytes by separators. Cell testing of Li|NMC half cells reveals that those cell results cannot be inevitably deduced from physicochemical electrolyte properties as well as contact angle analysis. On the other hand, techniques are more suitable which detect liquid penetration into the interior of the separator. It is expected that the results can help fundamental researchers as well as users of novel electrolytes in current-day Li-ion battery technologies for developing and using novel material combinations. PMID:26343636

Physicochemical properties of protein-modified silver nanoparticles in seawater

NASA Astrophysics Data System (ADS)

Zhong, Hangyue

2013-10-01

This study investigated the physicochemical properties of silver nanoparticles stabilized with casein protein in seawater. UV?vis spectrometry, dynamic light scattering (DLS), and transmission electron microscopy (TEM) were applied to measure the stability of silver nanoparticles in seawater samples. The obtained results show an increased aggregation tendency of silver nanoparticles in seawater, which could be attributed its relatively high cation concentration that could neutralize the negatively charges adsorbed on the surface of silver nanoparticles and reduce the electrostatic repulsion forces between nanoparticles. Similarly, due to the surface charge screening process, the zeta potential of silver nanoparticles in seawater decreased. This observation further supported the aggregation behavior of silver nanoparticles. This study also investigated the dissolution of silver nanoparticles in seawater. Result shows that the silver nanoparticle dissolution in DI water is lower than in seawater, which is attributed to the high Cl? concentration present in seawater. As Cl? can react with silver and form soluble AgCl complex, dissolution of silver nanoparticles was enhanced. Finally, this study demonstrated that silver nanoparticles are destabilized in seawater condition. These results may be helpful in understanding the environmental risk of discharged silver nanoparticles in seawater conditions.

Applications of nanomaterials as vaccine adjuvants

PubMed Central

Zhu, Motao; Wang, Rongfu; Nie, Guangjun

2014-01-01

Vaccine adjuvants are applied to amplify the recipient's specific immune responses against pathogen infection or malignancy. A new generation of adjuvants is being developed to meet the demands for more potent antigen-specific responses, specific types of immune responses, and a high margin of safety. Nanotechnology provides a multifunctional stage for the integration of desired adjuvant activities performed by the building blocks of tailor-designed nanoparticles. Using nanomaterials for antigen delivery can provide high bioavailability, sustained and controlled release profiles, and targeting and imaging properties resulting from manipulation of the nanomaterials’ physicochemical properties. Moreover, the inherent immune-regulating activity of particular nanomaterials can further promote and shape the cellular and humoral immune responses toward desired types. The combination of both the delivery function and immunomodulatory effect of nanomaterials as adjuvants is thought to largely benefit the immune outcomes of vaccination. In this review, we will address the current achievements of nanotechnology in the development of novel adjuvants. The potential mechanisms by which nanomaterials impact the immune responses to a vaccine and how physicochemical properties, including size, surface charge and surface modification, impact their resulting immunological outcomes will be discussed. This review aims to provide concentrated information to promote new insights for the development of novel vaccine adjuvants. PMID:25483497

A blueprint for the synthesis and characterisation of thin graphene oxide with controlled lateral dimensions for biomedicine

NASA Astrophysics Data System (ADS)

Filipe Rodrigues, Artur; Newman, Leon; Lozano, Neus; Mukherjee, Sourav P.; Fadeel, Bengt; Bussy, Cyrill; Kostarelos, Kostas

2018-07-01

Graphene-based materials (GBMs) have ignited a revolution in material science and technology, with electronic, optical and mechanical properties that are of relevant interest for a wide range of applications. To support the development of these enabling technologies, a global research effort has been invested to assess their hazard and biocompatibility. Different production methods have however generated a diverse collection of GBMs with different physicochemical properties, leading to a variety of biological outcomes that are still not fully understood. To better understand the biological interactions of GBMs with biological systems and allow the design of safer materials, a thorough physicochemical characterisation is therefore highly recommended. The aim of the present work was to produce a blueprint for the synthesis and characterisation of non-pyrogenic graphene oxide (GO) flakes with three different controlled lateral dimensions, which could be further used for either hazard assessment or biomedical proof-of-concept studies. A battery of techniques used to characterise the physicochemical properties of the GO samples included atomic force microscopy, transmission electron microscopy, Fourier-transformed infra-red spectroscopy, x-ray photoelectron spectroscopy and Raman spectroscopy. The combination of these different techniques confirmed that only the lateral dimension varied among the GO materials produced, without significant change in any other of their fundamental physicochemical properties, such as the thickness or surface chemistry. The proposed systematic approach in GO batch production for biology will hopefully contribute to a better understanding of the material properties that govern their interactions with biological systems and offer a blueprint towards standardisation of biologically relevant 2D materials.

Infrared rectification in a nanoantenna-coupled metal-oxide-semiconductor tunnel diode.

PubMed

Davids, Paul S; Jarecki, Robert L; Starbuck, Andrew; Burckel, D Bruce; Kadlec, Emil A; Ribaudo, Troy; Shaner, Eric A; Peters, David W

2015-12-01

Direct rectification of electromagnetic radiation is a well-established method for wireless power conversion in the microwave region of the spectrum, for which conversion efficiencies in excess of 84% have been demonstrated. Scaling to the infrared or optical part of the spectrum requires ultrafast rectification that can only be obtained by direct tunnelling. Many research groups have looked to plasmonics to overcome antenna-scaling limits and to increase the confinement. Recently, surface plasmons on heavily doped Si surfaces were investigated as a way of extending surface-mode confinement to the thermal infrared region. Here we combine a nanostructured metallic surface with a heavily doped Si infrared-reflective ground plane designed to confine infrared radiation in an active electronic direct-conversion device. The interplay of strong infrared photon-phonon coupling and electromagnetic confinement in nanoscale devices is demonstrated to have a large impact on ultrafast electronic tunnelling in metal-oxide-semiconductor (MOS) structures. Infrared dispersion of SiO2 near a longitudinal optical (LO) phonon mode gives large transverse-field confinement in a nanometre-scale oxide-tunnel gap as the wavelength-dependent permittivity changes from 1 to 0, which leads to enhanced electromagnetic fields at material interfaces and a rectified displacement current that provides a direct conversion of infrared radiation into electric current. The spectral and electrical signatures of the nanoantenna-coupled tunnel diodes are examined under broadband blackbody and quantum-cascade laser (QCL) illumination. In the region near the LO phonon resonance, we obtained a measured photoresponsivity of 2.7 mA W(-1) cm(-2) at -0.1 V.

Human CD34(lo)CD133(lo) fetal liver cells support the expansion of human CD34(hi)CD133(hi) hematopoietic stem cells.

PubMed

Yong, Kylie Su Mei; Keng, Choong Tat; Tan, Shu Qi; Loh, Eva; Chang, Kenneth Te; Tan, Thiam Chye; Hong, Wanjin; Chen, Qingfeng

2016-09-01

We have recently discovered a unique CD34(lo)CD133(lo) cell population in the human fetal liver (FL) that gives rise to cells in the hepatic lineage. In this study, we further characterized the biological functions of FL CD34(lo)CD133(lo) cells. Our findings show that these CD34(lo)CD133(lo) cells express markers of both endodermal and mesodermal lineages and have the capability to differentiate into hepatocyte and mesenchymal lineage cells by ex vivo differentiation assays. Furthermore, we show that CD34(lo)CD133(lo) cells express growth factors that are important for human hematopoietic stem cell (HSC) expansion: stem cell factor (SCF), insulin-like growth factor 2 (IGF2), C-X-C motif chemokine 12 (CXCL12), and factors in the angiopoietin-like protein family. Co-culture of autologous FL HSCs and allogenic HSCs derived from cord blood with CD34(lo)CD133(lo) cells supports and expands both types of HSCs.These findings are not only essential for extending our understanding of the HSC niche during the development of embryonic and fetal hematopoiesis but will also potentially benefit adult stem cell transplantations in clinics because expanded HSCs demonstrate the same capacity as primary cells to reconstitute the human immune system and mediate long-term hematopoiesis in vivo. Together, CD34(lo)CD133(lo) cells not only serve as stem/progenitor cells for liver development but are also an essential component of the HSC niche in the human FL.

[Effects of different hypoxic training modes on activities of mitochondrial antioxidants and respiratory chain complex in skeletal muscle after exhaustive running in rat].

PubMed

Li, Jie; Zhang, Yao-Bin

2011-02-25

The present study was aimed to investigate the effect of hypoxic training on mitochondrial antioxidants and activities of respiratory chain complexes in mitochondria of skeletal muscle in rats. Forty healthy male Wistar rats were randomized to 5 groups (n=8): living low-training low (LoLo), living high-training high (HiHi), living high-training low (HiLo), living low-training high (LoHi), and living high-exercise high-training low (HiHiLo). All the animals were subjected to 5-week training in normoxic (atmospheric pressure=632 mmHg, altitude of about 1 500 m) or hypoxic environment (atmospheric pressure=493 mmHg, simulated altitude of about 3 500 m). Before exhaustive running, the animals stayed in normoxia for 3 d. Skeletal muscles were prepared immediately after exhaustive running. Muscle mitochondria were extracted by differential centrifugation. Spectrophotometric analysis was used to evaluate activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), malondialdehyde (MDA) level and respiratory chain complex (C) I-III activities in muscle homogenate and mitochondria. Results showed that SOD, GSH-Px, CAT activities and MDA level in skeletal muscle homogenate in HiHi and HiHiLo groups were significantly increased (P<0.05 or P<0.01) compared with those in LoLo group. Muscle mitochondrial MDA level in HiHi and HiHiLo groups was significantly lower (P<0.01), while activities of SOD, GSH-Px and CAT were remarkably higher (P<0.01) than those in LoLo group. Meanwhile, C I-III activities in HiHi and HiHiLo groups were increased significantly (P<0.01), and C II activity in HiLo group also was increased remarkably (P<0.01) compared with those in LoLo group. These results suggest that HiHiLo might be an ideal hypoxic training mode.

Molecular simulations of heterogeneous ice nucleation. I. Controlling ice nucleation through surface hydrophilicity

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

Cox, Stephen J.; Kathmann, Shawn M.; Slater, B.

2015-05-14

Ice formation is one of the most common and important processes on earth and almost always occurs at the surface of a material. A basic understanding of how the physicochemical properties of a material’s surface affect its ability to form ice has remained elusive. Here, we use molecular dynamics simulations to directly probe heterogeneous ice nucleation at a hexagonal surface of a nanoparticle of varying hydrophilicity. Surprisingly, we find that structurally identical surfaces can both inhibit and promote ice formation and analogous to a chemical catalyst, it is found that an optimal interaction between the surface and the water existsmore » for promoting ice nucleation.We use our microscopic understanding of the mechanism to design a modified surface in silico with enhanced ice nucleating ability. C 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.« less

Bio-Inspired Functional Surfaces Based on Laser-Induced Periodic Surface Structures

PubMed Central

Müller, Frank A.; Kunz, Clemens; Gräf, Stephan

2016-01-01

Nature developed numerous solutions to solve various technical problems related to material surfaces by combining the physico-chemical properties of a material with periodically aligned micro/nanostructures in a sophisticated manner. The utilization of ultra-short pulsed lasers allows mimicking numerous of these features by generating laser-induced periodic surface structures (LIPSS). In this review paper, we describe the physical background of LIPSS generation as well as the physical principles of surface related phenomena like wettability, reflectivity, and friction. Then we introduce several biological examples including e.g., lotus leafs, springtails, dessert beetles, moth eyes, butterfly wings, weevils, sharks, pangolins, and snakes to illustrate how nature solves technical problems, and we give a comprehensive overview of recent achievements related to the utilization of LIPSS to generate superhydrophobic, anti-reflective, colored, and drag resistant surfaces. Finally, we conclude with some future developments and perspectives related to forthcoming applications of LIPSS-based surfaces. PMID:28773596

Nano-objects as biomaterials: immense opportunities, significant challenges and the important use of surface analytical methods

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

Baer, Donald R.; Shutthanandan, Vaithiyalingam

Nano-sized objects are increasingly important as biomaterials and their surfaces play critical roles in determining their beneficial or deleterious behaviors in biological systems. Important characteristics of nanomaterials that impact their application in many areas are described with a strong focus on the importance of particle surfaces and surface characterization. Understanding aspects of the inherent nature of nano-objects and the important role that surfaces play in these applications is a universal need for any research or product development using such materials in biological applications. The role of surface analysis methods in collecting critical information about the nature of particle surfaces andmore » physicochemical properties of nano-objects is described along with the importance of including sample history and analysis results in a record of provenance information regarding specific batches of nano-objects.« less

Bio-Inspired Functional Surfaces Based on Laser-Induced Periodic Surface Structures.

PubMed

Müller, Frank A; Kunz, Clemens; Gräf, Stephan

2016-06-15

Nature developed numerous solutions to solve various technical problems related to material surfaces by combining the physico-chemical properties of a material with periodically aligned micro/nanostructures in a sophisticated manner. The utilization of ultra-short pulsed lasers allows mimicking numerous of these features by generating laser-induced periodic surface structures (LIPSS). In this review paper, we describe the physical background of LIPSS generation as well as the physical principles of surface related phenomena like wettability, reflectivity, and friction. Then we introduce several biological examples including e.g., lotus leafs, springtails, dessert beetles, moth eyes, butterfly wings, weevils, sharks, pangolins, and snakes to illustrate how nature solves technical problems, and we give a comprehensive overview of recent achievements related to the utilization of LIPSS to generate superhydrophobic, anti-reflective, colored, and drag resistant surfaces. Finally, we conclude with some future developments and perspectives related to forthcoming applications of LIPSS-based surfaces.

Nanoparticles-cell association predicted by protein corona fingerprints

NASA Astrophysics Data System (ADS)

Palchetti, S.; Digiacomo, L.; Pozzi, D.; Peruzzi, G.; Micarelli, E.; Mahmoudi, M.; Caracciolo, G.

2016-06-01

In a physiological environment (e.g., blood and interstitial fluids) nanoparticles (NPs) will bind proteins shaping a ``protein corona'' layer. The long-lived protein layer tightly bound to the NP surface is referred to as the hard corona (HC) and encodes information that controls NP bioactivity (e.g. cellular association, cellular signaling pathways, biodistribution, and toxicity). Decrypting this complex code has become a priority to predict the NP biological outcomes. Here, we use a library of 16 lipid NPs of varying size (Ø ~ 100-250 nm) and surface chemistry (unmodified and PEGylated) to investigate the relationships between NP physicochemical properties (nanoparticle size, aggregation state and surface charge), protein corona fingerprints (PCFs), and NP-cell association. We found out that none of the NPs' physicochemical properties alone was exclusively able to account for association with human cervical cancer cell line (HeLa). For the entire library of NPs, a total of 436 distinct serum proteins were detected. We developed a predictive-validation modeling that provides a means of assessing the relative significance of the identified corona proteins. Interestingly, a minor fraction of the HC, which consists of only 8 PCFs were identified as main promoters of NP association with HeLa cells. Remarkably, identified PCFs have several receptors with high level of expression on the plasma membrane of HeLa cells.In a physiological environment (e.g., blood and interstitial fluids) nanoparticles (NPs) will bind proteins shaping a ``protein corona'' layer. The long-lived protein layer tightly bound to the NP surface is referred to as the hard corona (HC) and encodes information that controls NP bioactivity (e.g. cellular association, cellular signaling pathways, biodistribution, and toxicity). Decrypting this complex code has become a priority to predict the NP biological outcomes. Here, we use a library of 16 lipid NPs of varying size (Ø ~ 100-250 nm) and surface chemistry (unmodified and PEGylated) to investigate the relationships between NP physicochemical properties (nanoparticle size, aggregation state and surface charge), protein corona fingerprints (PCFs), and NP-cell association. We found out that none of the NPs' physicochemical properties alone was exclusively able to account for association with human cervical cancer cell line (HeLa). For the entire library of NPs, a total of 436 distinct serum proteins were detected. We developed a predictive-validation modeling that provides a means of assessing the relative significance of the identified corona proteins. Interestingly, a minor fraction of the HC, which consists of only 8 PCFs were identified as main promoters of NP association with HeLa cells. Remarkably, identified PCFs have several receptors with high level of expression on the plasma membrane of HeLa cells. Electronic supplementary information (ESI) available: Table S1. Cell viability (%) and cell association of the different nanoparticles used. Table S2. Total number of identified proteins on the different nanoparticles used. Tables S3-S18. Top 25 most abundant corona proteins identified in the protein corona of nanoparticles NP2-NP16 following 1 hour incubation with HP. Table S19. List of descriptors used. Table S20. Potential targets of protein corona fingerprints with its own interaction score (mentha) and the expression median value in Hela cells. Fig. S1 and S2. Effect of exposure to human plasma on size and zeta potential of NPs. Fig. S3. Predictive modeling of nanoparticle-cell association. See DOI: 10.1039/c6nr03898k

Radionuclides as natural tracers of the interaction between groundwater and surface water in the River Andarax, Spain.

PubMed

Navarro-Martinez, Francisco; Salas Garcia, Alejandro; Sánchez-Martos, Francisco; Baeza Espasa, Antonio; Molina Sánchez, Luis; Rodríguez Perulero, Antonio

2017-12-01

The identification of specific aquifers that supply water to river systems is fundamental to understanding the dynamics of the rivers' hydrochemistry, particularly in arid and semiarid environments where river flow may be discontinuous. There are multiple methods to identify the source of river water. In this study of the River Andarax, in the Southeast of Spain, an analysis of natural tracers (physico-chemical parameters, uranium, radium and radon) in surface water and groundwater indicates that chemical parameters and uranium clearly identify the areas where there is groundwater-surface water interaction. The concentration of uranium found in the river defines two areas: the headwaters with U concentrations of 2 μg L -1 and the lower reaches, with U of 6 μg L -1 . Furthermore, variation in the 234 U/ 238 U isotopic ratio allowed us to detect the influence that groundwater from the carbonate aquifer has on surface water in the headwaters of the river, where the saline content is lower and the water has a calcium bicarbonate facies. The concentration of 226 Ra and 222 Rn are low in the surface waters: <1.6 × 10 -6  μg L -1 and <5.1 × 10 -12  μg L -1 , respectively. There is a slight increase in the lower reaches where the water has a permanent flow, greater salinity and a calcium-magnesium-sulphate facies. All this is favoured by the influence of groundwater from the detritic aquifer on the surface waters. The results of this study indicate the utility in the use of physico-chemical and radiological data conjointly as tracers of groundwater-surface water interaction in semiarid areas where the lithology of aquifers is diverse (carbonate and detritic) and where evaporitic rocks are present. Copyright © 2017 Elsevier Ltd. All rights reserved.

Infusion of SMAP Data into Offline and Coupled Models: Evaluation, Calibration, and Assimilation

NASA Astrophysics Data System (ADS)

Lawston, P.; Santanello, J. A., Jr.; Dennis, E. J.; Kumar, S.

2017-12-01

The impact of the land surface on the water and energy cycle is modulated by its coupling to the planetary boundary layer (PBL), and begins at the local scale. A core component of the local land-atmosphere coupling (LoCo) effort requires understanding the `links in the chain' between soil moisture and precipitation, most notably through surface heat fluxes and PBL evolution. To date, broader (i.e. global) application of LoCo diagnostics has been limited by observational data requirements of the coupled system (and in particular, soil moisture) that are typically only met during localized, short-term field campaigns. SMAP offers, for the first time, the ability to map high quality, near-surface soil moisture globally every few days at a spatial resolution comparable to current modeling efforts. As a result, there are numerous potential avenues for SMAP model-data fusion that can be explored in the context of improving understanding of L-A interaction and NWP. In this study, we assess multiple points of intersection of SMAP products with offline and coupled models and evaluate impacts using process-level diagnostics. Results will inform upon the importance of high-resolution soil moisture mapping for improved coupled prediction and model development, as well as reconciling differences in modeled, retrieved, and measured soil moisture. Specifically, NASA model (LIS, NU-WRF) and observation (SMAP, NLDAS-2) products are combined with in-situ standard and IOP measurements (soil moisture, flux, and radiosonde) over the ARM-SGP. An array of land surface model spinups (via LIS-Noah) are performed with varying atmospheric forcing, greenness fraction, and soil layering permutations. Calibration of LIS-Noah soil hydraulic parameters is then performed using an array of in-situ soil moisture and flux and SMAP products. In addition, SMAP assimilation is performed in LIS-Noah both at the scale of the observation (36 and 9km) and the model grid (1km). The focus is on the consistency in calibrated parameters, impact of soil drydown dynamics and soil layers, and terrestrial (soil moisture-flux) coupling. The impacts of these various spinup runs and initialization of NU-WRF coupled forecasts then follows with a focus on weather (ambient, PBL, and precipitation) using LoCo metrics.

The influence of secondary processing on the structural relaxation dynamics of fluticasone propionate.

PubMed

Depasquale, Roberto; Lee, Sau L; Saluja, Bhawana; Shur, Jagdeep; Price, Robert

2015-06-01

This study investigated the structural relaxation of micronized fluticasone propionate (FP) under different lagering conditions and its influence on aerodynamic particle size distribution (APSD) of binary and tertiary carrier-based dry powder inhaler (DPI) formulations. Micronized FP was lagered under low humidity (LH 25 C, 33% RH [relative humidity]), high humidity (HH 25°C, 75% RH) for 30, 60, and 90 days, respectively, and high temperature (HT 60°C, 44% RH) for 14 days. Physicochemical, surface interfacial properties via cohesive-adhesive balance (CAB) measurements and amorphous disorder levels of the FP samples were characterized. Particle size, surface area, and rugosity suggested minimal morphological changes of the lagered FP samples, with the exception of the 90-day HH (HH90) sample. HH90 FP samples appeared to undergo surface reconstruction with a reduction in surface rugosity. LH and HH lagering reduced the levels of amorphous content over 90-day exposure, which influenced the CAB measurements with lactose monohydrate and salmeterol xinafoate (SX). CAB analysis suggested that LH and HH lagering led to different interfacial interactions with lactose monohydrate but an increasing adhesive affinity with SX. HT lagering led to no detectable levels of the amorphous disorder, resulting in an increase in the adhesive interaction with lactose monohydrate. APSD analysis suggested that the fine particle mass of FP and SX was affected by the lagering of the FP. In conclusion, environmental conditions during the lagering of FP may have a profound effect on physicochemical and interfacial properties as well as product performance of binary and tertiary carrier-based DPI formulations.

Properties of Basil and Lavender Essential Oils Adsorbed on the Surface of Hydroxyapatite.

PubMed

Predoi, Daniela; Groza, Andreea; Iconaru, Simona Liliana; Predoi, Gabriel; Barbuceanu, Florica; Guegan, Regis; Motelica-Heino, Mikael Stefan; Cimpeanu, Carmen

2018-04-24

The research conducted in this study presented for the first time results of physico-chemical properties and in vitro antimicrobial activity of hydroxyapatite plant essential oil against Gram-positive bacteria (methicillin-resistant Staphylococcus aureus (MRSA) and S. aureus 0364) and Gram-negative bacteria ( Escherichia coli ATCC 25922). The samples were studied by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy to determine the morphology and structure of the nanocomposites of hydroxyapatite coated with basil (HAp-B) and lavender (HAp-L) essential oils (EOs). The values of the BET specific surface area (S BET ), total pore volume (V P ) and pore size (D P ) were determined. The results for the physico-chemical properties of HAp-L and HAp-B revealed that lavender EOs were well adsorbed on the surface of hydroxyapatite, whereas basil EOs showed a poor adsorption on the surface of hydroxyapatite. We found that the lavender EOs hydroxyapatite (HAp-L) exhibited a very good inhibitory growth activity. The value of the minimum inhibitory concentration (MIC) related to growth bacteria was 0.039 mg/mL for MRSA, 0.02 mg/mL for S. aureus and 0.039 mg/mL E. coli ATCC 25922. The basil EO hydroxyapatite (HAp-B) showed poor inhibition of bacterial cell growth. The MIC value was 0.625 mg/mL for the HAp-B sample in the presence of the MRSA bacteria, 0.313 mg/mL in the presence of S. aureus and 0.078 mg/mL for E. coli ATCC 25922.

Silver-doped nanocomposite carbon coatings (Ag-DLC) for biomedical applications - Physiochemical and biological evaluation

NASA Astrophysics Data System (ADS)

Bociaga, Dorota; Komorowski, Piotr; Batory, Damian; Szymanski, Witold; Olejnik, Anna; Jastrzebski, Krzysztof; Jakubowski, Witold

2015-11-01

The formation of bacteria biofilm on the surface of medical products is a major clinical issue nowadays. Highly adaptive ability of bacteria to colonize the surface of biomaterials causes a lot of infections. This study evaluates samples of the AISI 316 LVM with special nanocomposite silver-doped (by means of ion implantation) diamond-like carbon (DLC) coating prepared by hybrid RF/MS PACVD (radio frequency/magnetron sputtering plasma assisted chemical vapour deposition) deposition technique in order to improve the physicochemical and biological properties of biomaterials and add new features such as antibacterial properties. The aim of the following work was to evaluate antimicrobial efficacy and biocompatibility of gradient a-C:H/Ti + Ag coatings in relation to the physiochemical properties of the surface and chemical composition of coating. For this purpose, samples were tested in live/dead test using two cell strains: human endothelial cells (Ea.hy926) and osteoblasts-like cells (Saos-2). For testing bactericidal activity of the coatings, an exponential growth phase of Escherichia coli strain DH5α was used as a model microorganism. Surface condition and its physicochemical properties were investigated using SEM, AFM and XPS. Examined coatings showed a uniformity of silver ions distribution in the amorphous DLC matrix, good biocompatibility in contact with mammalian cells and an increased level of bactericidal properties. What is more, considering very good mechanical parameters of these Ag including gradient a-C:H/Ti coatings, they constitute an excellent material for biomedical application in e.g. orthopedics or dentistry.

Biological response to purification and acid functionalization of carbon nanotubes

NASA Astrophysics Data System (ADS)

Figarol, Agathe; Pourchez, Jérémie; Boudard, Delphine; Forest, Valérie; Tulliani, Jean-Marc; Lecompte, Jean-Pierre; Cottier, Michèle; Bernache-Assollant, Didier; Grosseau, Philippe

2014-07-01

Acid functionalization has been considered as an easy way to enhance the dispersion and biodegradation of carbon nanotubes (CNT). However, inconsistencies between toxicity studies of acid functionalized CNT remain unexplained. This could be due to a joint effect of the main physicochemical modifications resulting from an acid functionalization: addition of surface acid groups and purification from catalytic metallic impurities. In this study, the impact on CNT biotoxicity of these two physiochemical features was assessed separately. The in vitro biological response of RAW 264.7 macrophages was evaluated after exposure to 15-240 µg mL-1 of two types of multi-walled CNT. For each type of CNT (small: 20 nm diameter, and big: 90 nm diameter), three different surface chemical properties were studied (total of six CNT samples): pristine, acid functionalized and desorbed. Desorbed CNT were purified by the acid functionalization but presented a very low amount of surface acid groups due to a thermal treatment under vacuum. A Janus effect of acid functionalization with two opposite impacts is highlighted. The CNT purification decreased the overall toxicity, while the surface acid groups intensified it when present at a specific threshold. These acid groups especially amplified the pro-inflammatory response. The threshold mechanism which seemed to regulate the impact of acid groups should be further studied to determine its value and potential link to the other physicochemical state of the CNT. The results suggest that, for a safer-design approach, the benefit-risk balance of an acid functionalization has to be considered, depending on the CNT primary state of purification. Further research should be conducted in this direction.

Assessment of the quality of groundwater for drinking purposes in the Upper West and Northern regions of Ghana.

PubMed

Saana, Sixtus Bieranye Bayaa Martin; Fosu, Samuel Asiedu; Sebiawu, Godfred Etsey; Jackson, Napoleon; Karikari, Thomas

2016-01-01

Underground water is an important natural resource serving as a reliable source of drinking water for many people worldwide, especially in developing countries. Underground water quality needs to be given a primary research and quality control attention due to possible contamination. This study was therefore designed to determine the physico-chemical and bacteriological quality of borehole water in the Upper West and Northern regions of Ghana. The study was conducted in seven districts in Ghana (including six in the Upper West region and one in the Northern region). The bacterial load of the water samples was determined using standard microbiological methods. Physico-chemical properties including pH, total alkalinity, temperature, turbidity, true colour, total dissolved solids (TDS), electrical conductivity, total hardness, calcium hardness, magnesium hardness, total iron, calcium ion, magnesium ion, chloride ion, fluoride ion, aluminium ion, arsenic, ammonium ions, nitrate and nitrite concentrations were determined. The values obtained were compared with the World Health Organization (WHO) standards for drinking water. The recorded pH, total alkalinity and temperature ranges were 6.14-7.50, 48-240 mg/l and 28.8-32.8 °C, respectively. Furthermore, the mean concentrations of iron, calcium, magnesium, chloride, fluoride, aluminium, arsenic, ammonium, nitrate and nitrite were 0.06, 22.11, 29.84, 13.97, 0.00, 0.00, 0.00, 0.01, 2.09 and 0.26 mg/l, respectively. Turbidity, true colour, TDS and electrical conductivity of the water samples ranged from 0.13 to 105 NTU, 5 to 130 HU, 80.1 to 524 mg/l and 131 to 873 µS/cm, respectively. In addition, the mean total hardness value was found to be 178.07 mg/l whereas calcium hardness and magnesium hardness respectively were 55.28 and 122.79 mg/l. Only 14% of the water samples tested positive for faecal coliforms. The study revealed that only a few of the values for the bacteriological and physico-chemical parameters of the water samples were above the tolerable limits recommended by the WHO. This calls for regular monitoring and purification of boreholes to ensure good water quality.

Assessment of Fenton's reagent and ozonation as pre-treatments for increasing the biodegradability of aqueous diethanolamine solutions from an oil refinery gas sweetening process.

PubMed

Durán-Moreno, A; García-González, S A; Gutiérrez-Lara, M R; Rigas, F; Ramírez-Zamora, R M

2011-02-28

The aim of this work was to evaluate the efficiency of three chemical oxidation processes for increasing the biodegradability of aqueous diethanolamine solutions (aqueous DEA solutions), to be used as pre-treatments before a biological process. The raw aqueous DEA solution, sourced from a sour gas sweetening plant at a Mexican oil refinery, was first characterized by standardized physico-chemical methods. Then experiments were conducted on diluted aqueous DEA solutions to test the effects of Fenton's reagent, ozone and ozone-hydrogen peroxide on the removal of some physicochemical parameters of these solutions. Lastly, biodegradability tests based on Dissolved Organic Carbon Die Away OECD301-A, were carried out on a dilution of the raw aqueous DEA solution and on the treated aqueous DEA solutions, produced by applying the best experimental conditions determined during the aforementioned oxidation tests. Experimental results showed that for aqueous DEA solutions treated with Fenton's reagent, the best degradation rate (70%) was obtained at pH 2.8, with Fe(2+) and H(2)O(2) at doses of 1000 and 10,000 mg/L respectively. In the ozone process, the best degradation (60%) was observed in aqueous DEA solution (100 mg COD/L), using 100 mg O(3)/L at pH 5. In the ozone-hydrogen peroxide process, no COD or DOC removals were observed. The diluted spent diethanolamine solution showed its greatest increase in biodegradability after a reaction period of 28 days when treated with Fenton's reagent, but after only 15 days in the case of ozonation. Copyright © 2011 Elsevier B.V. All rights reserved.

Reconstituted yogurt from yogurt cultured milk powder mix has better overall characteristics than reconstituted yogurt from commercial yogurt powder.

PubMed

Song, Lijie; Aryana, Kayanush J

2014-10-01

For manufacture of commercial yogurt powder, yogurt has to go through a drying process, which substantially lowers the yogurt culture counts, so the potential health benefits of the yogurt culture bacteria are reduced. Also, upon reconstitution, commercial yogurt powder does not taste like yogurt and has an off-flavor. The objective was to study the microbial, physicochemical, and sensory characteristics of reconstituted yogurt from yogurt cultured milk powder (YCMP) mix and reconstituted yogurt from commercial yogurt powder (CYP). The CYP reconstituted yogurt was the control and YCMP mix reconstituted yogurt was the treatment. Microbial and physicochemical characteristics of the CYP reconstituted yogurt and YCMP mix reconstituted yogurt were analyzed daily for the first week and then weekly for a period of 8 wk. Sensory consumer testing of CYP reconstituted yogurt and YCMP mix reconstituted yogurt was conducted with 100 consumers. At 56 d, YCMP mix reconstituted yogurt had 5 log cfu/mL higher counts of Streptococcus thermophilus than the control (CYP reconstituted yogurt). Also, Lactobacillus bulgaricus counts of YCMP mix reconstituted yogurt were 6.55 log cfu/mL at 28 d and were 5.35 log cfu/mL at 56 d, whereas the CYP reconstituted yogurt from 28 d onwards had a count of <10 cfu/mL. The YCMP mix reconstituted yogurt also had significantly higher apparent viscosity and sensory scores for appearance, color, aroma, taste, thickness, overall liking, consumer acceptability, and purchase intent than CYP reconstituted yogurt. Overall, YCMP mix reconstituted yogurt had more desirable characteristics than CYP reconstituted yogurt. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Enhanced light scattering of the forbidden longitudinal optical phonon mode studied by micro-Raman spectroscopy on single InN nanowires.

PubMed

Schäfer-Nolte, E O; Stoica, T; Gotschke, T; Limbach, F A; Sutter, E; Sutter, P; Grützmacher, D; Calarco, R

2010-08-06

In the literature, there are controversies on the interpretation of the appearance in InN Raman spectra of a strong scattering peak in the energy region of the unscreened longitudinal optical (LO) phonons, although a shift caused by the phonon-plasmon interaction is expected for the high conductance observed in this material. Most measurements on light scattering are performed on ensembles of InN nanowires (NWs). However, it is important to investigate the behavior of individual nanowires and here we report on micro-Raman measurements on single nanowires. When changing the polarization direction of the incident light from parallel to perpendicular to the wire, the expected reduction of the Raman scattering was observed for transversal optical (TO) and E(2) phonon scattering modes, while a strong symmetry-forbidden LO mode was observed independently on the laser polarization direction. Single Mg- and Si-doped crystalline InN nanowires were also investigated. Magnesium doping results in a sharpening of the Raman peaks, while silicon doping leads to an asymmetric broadening of the LO peak. The results can be explained based on the influence of the high electron concentration with a strong contribution of the surface accumulation layer and the associated internal electric field.

77 FR 50185 - LoCorr Fund Management, LLC and LoCorr Investment Trust; Notice of Application

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-20

... Fund Management, LLC and LoCorr Investment Trust; Notice of Application August 14, 2012. AGENCY.... Applicants: LoCorr Fund Management, LLC (``LFM'' or the ``Adviser'') and LoCorr Investment Trust (the ``Trust... Mary Kay Frech, Branch Chief, at (202) 551-6821 (Division of Investment Management, Office of...

MORPH-II, a software package for the analysis of scanning-electron-micrograph images for the assessment of the fractal dimension of exposed stone surfaces

USGS Publications Warehouse

Mossotti, Victor G.; Eldeeb, A. Raouf

2000-01-01

Turcotte, 1997, and Barton and La Pointe, 1995, have identified many potential uses for the fractal dimension in physicochemical models of surface properties. The image-analysis program described in this report is an extension of the program set MORPH-I (Mossotti and others, 1998), which provided the fractal analysis of electron-microscope images of pore profiles (Mossotti and Eldeeb, 1992). MORPH-II, an integration of the modified kernel of the program MORPH-I with image calibration and editing facilities, was designed to measure the fractal dimension of the exposed surfaces of stone specimens as imaged in cross section in an electron microscope.

Towards Automatic Processing of Virtual City Models for Simulations

NASA Astrophysics Data System (ADS)

Piepereit, R.; Schilling, A.; Alam, N.; Wewetzer, M.; Pries, M.; Coors, V.

2016-10-01

Especially in the field of numerical simulations, such as flow and acoustic simulations, the interest in using virtual 3D models to optimize urban systems is increasing. The few instances in which simulations were already carried out in practice have been associated with an extremely high manual and therefore uneconomical effort for the processing of models. Using different ways of capturing models in Geographic Information System (GIS) and Computer Aided Engineering (CAE), increases the already very high complexity of the processing. To obtain virtual 3D models suitable for simulation, we developed a tool for automatic processing with the goal to establish ties between the world of GIS and CAE. In this paper we introduce a way to use Coons surfaces for the automatic processing of building models in LoD2, and investigate ways to simplify LoD3 models in order to reduce unnecessary information for a numerical simulation.

Surface roughness in XeF{sub 2} etching of a-Si/c-Si(100)

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

Stevens, A.A.E.; Beijerinck, H.C.W.

2005-01-01

Single wavelength ellipsometry and atomic force microscopy (AFM) have been applied in a well-calibrated beam-etching experiment to characterize the dynamics of surface roughening induced by chemical etching of a {approx}12 nm amorphous silicon (a-Si) top layer and the underlying crystalline silicon (c-Si) bulk. In both the initial and final phase of etching, where either only a-Si or only c-Si is exposed to the XeF{sub 2} flux, we observe a similar evolution of the surface roughness as a function of the XeF{sub 2} dose proportional to D(XeF{sub 2}){sup {beta}} with {beta}{approx_equal}0.2. In the transition region from the pure amorphous to themore » pure crystalline silicon layer, we observe a strong anomalous increase of the surface roughness proportional to D(XeF{sub 2}){sup {beta}} with {beta}{approx_equal}1.5. Not only the growth rate of the roughness increases sharply in this phase, also the surface morphology temporarily changes to a structure that suggests a cusplike shape. Both features suggest that the remaining a-Si patches on the surface act effectively as a capping layer which causes the growth of deep trenches in the c-Si. The ellipsometry data on the roughness are corroborated by the AFM results, by equating the thickness of the rough layer to 6 {sigma}, with {sigma} the root-mean-square variation of the AFM's distribution function of height differences. In the AFM data, the anomalous behavior is reflected in a too small value of {sigma} which again suggests narrow and deep surface features that cannot be tracked by the AFM tip. The final phase morphology is characterized by an effective increase in surface area by a factor of two, as derived from a simple bilayer model of the reaction layer, using the experimental etch rate as input. We obtain a local reaction layer thickness of 1.5 monolayer consistent with the 1.7 ML value of Lo et al. [Lo et al., Phys. Rev. B 47, 648 (1993)] that is also independent of surface roughness.« less

Diagnosing, Measuring and Monitoring Microbiologically Influenced Corrosion (MIC)

DTIC Science & Technology

2011-01-01

ESEM to study marine biofilms on stainless steel surfaces. They observed a gelatinous layer in which bacteria and microalgae were embedded...calculate corrosion rales, but rather changes due lo the presence of a biofilm . Angell el al. (1995) used a concentric ring 304 stainless steel electrode...Telegdi el al. (1998) used AFM to image biofilm formation , extracellular polymer production and subsequent corrosion. Many of the conclusions about

Infrared Spectra and Binding Energies of Chemical Warfare Nerve Agent Simulants on the Surface of Amorphous Silica

DTIC Science & Technology

2013-06-24

Limited TPD of Water from Zeolite Linde 4A. Thermochim. Acta 1998, 319 (1), 177−184. (43) Palermo, A.; Löffler, D. G. Kinetics of Water Desorption...from Pelletized 4A and 5A Zeolites . Thermochim. Acta 1990, 159, 171−176. (44) Gorte, R. J. Design Parameters for Temperature Programmed Desorption from

Different storage conditions influence biocompatibility and physicochemical properties of iron oxide nanoparticles.

PubMed

Zaloga, Jan; Janko, Christina; Agarwal, Rohit; Nowak, Johannes; Müller, Robert; Boccaccini, Aldo R; Lee, Geoffrey; Odenbach, Stefan; Lyer, Stefan; Alexiou, Christoph

2015-04-24

Superparamagnetic iron oxide nanoparticles (SPIONs) have attracted increasing attention in many biomedical fields. In magnetic drug targeting SPIONs are injected into a tumour supplying artery and accumulated inside the tumour with a magnet. The effectiveness of this therapy is thus dependent on magnetic properties, stability and biocompatibility of the particles. A good knowledge of the effect of storage conditions on those parameters is of utmost importance for the translation of the therapy concept into the clinic and for reproducibility in preclinical studies. Here, core shell SPIONs with a hybrid coating consisting of lauric acid and albumin were stored at different temperatures from 4 to 45 °C over twelve weeks and periodically tested for their physicochemical properties over time. Surprisingly, even at the highest storage temperature we did not observe denaturation of the protein or colloidal instability. However, the saturation magnetisation decreased by maximally 28.8% with clear correlation to time and storage temperature. Furthermore, the biocompatibility was clearly affected, as cellular uptake of the SPIONs into human T-lymphoma cells was crucially dependent on the storage conditions. Taken together, the results show that the particle properties undergo significant changes over time depending on the way they are stored.

Comparative study on the processing of armour steels with various unconventional technologies

NASA Astrophysics Data System (ADS)

Herghelegiu, E.; Schnakovszky, C.; Radu, M. C.; Tampu, N. C.; Zichil, V.

2017-08-01

The aim of the current paper is to analyse the suitability of three unconventional technologies - abrasive water jet (AWJ), plasma and laser - to process armour steels. In view of this, two materials (Ramor 400 and Ramor 550) were selected to carry out the experimental tests and the quality of cuts was quantified by considering the following characteristics: width of the processed surface at the jet inlet (Li), width of the processed surface at the jet outlet (Lo), inclination angle (a), deviation from perpendicularity (u), surface roughness (Ra) and surface hardness. It was fond that in terms of cut quality and environmental impact, the best results are offered by abrasive water jet technology. However, it has the lowest productivity comparing to the other two technologies.

75 FR 56660 - Removal of an Alias of an Existing Specially Designated National Listing

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-16

... has been amended as: LAW, Steven (a.k.a. CHUNG, Lo Ping; a.k.a. LAW, Stephen; a.k.a. LO, Ping Han; a.k.a. LO, Ping Hau; a.k.a. LO, Ping Zhong; a.k.a. LO, Steven; a.k.a. NAING, Htun Myint; a.k.a. NAING...

High similarity in physicochemical properties of chitin and chitosan from nymphs and adults of a grasshopper.

PubMed

Erdogan, Sevil; Kaya, Murat

2016-08-01

This is the first study to explain the differences in the physicochemical properties of chitin and chitosan obtained from the nymphs and adults of Dociostaurus maroccanus using the same method. Fourier transform infrared spectroscopy, thermogravimetric analysis and x-ray diffraction analysis results demonstrated that the chitins from both the adults and nymphs were in the α-form. The chitin contents of the adults (14%) and nymphs (12%) were of the same order of magnitude. The crystalline index values of chitins from the adult and nymph grasshoppers were 71% and 74%, respectively. Thermal stabilities of the chitins and chitosans from adult and nymph grasshoppers were close to each other. Both the adult (7.2kDa) and nymph (5.6kDa) chitosans had low molar masses. Environmental scanning electron microscopy revealed that the surface morphologies of both chitins consisted of nanofibers and nanopores together, and they were very similar to each other. Consequently, it was determined that the physicochemical properties of the chitins and chitosans from adults and nymphs of D. maroccanus were not very different, so it can be hypothesized that the development of the chitin structure in the nymph has almost been completed and the nymph chitin has the same characteristics as the adult. Copyright © 2016 Elsevier B.V. All rights reserved.

Human health no-effect levels of TiO2 nanoparticles as a function of their primary size

NASA Astrophysics Data System (ADS)

Laurent, Alexis; Harkema, Jack R.; Andersen, Elisabeth W.; Owsianiak, Mikołaj; Vea, Eldbjørg B.; Jolliet, Olivier

2017-04-01

As engineered nanomaterials are increasingly introduced on the market into a broad range of commodities or nanoproducts, there is a need for operational, reliable tool, enabling to consistently assess the risks and impacts associated with the releases of nanoparticles. The lack of a developed metric that accurately represents their toxic effects while capturing the influence of the most relevant physicochemical properties is one of the major impediments. Here, we investigate the relationships between the toxic responses of nano-sized and micro-sized particles in in vivo toxicological studies and their physicochemical properties. Our results for TiO2 particles indicate statistically significant associations between the primary particle size and their toxicity responses for combined inhalation and ingestion exposure routes, although the numerical values should be considered with care due to the inability to encompass influences from other relevant physicochemical properties like surface coatings. These findings allow for expressing mass-based adverse effect levels as a continuous function of the primary size of particles. This meaningful, exploratory metric can thus be used for screening purposes and pave the way for reaching adaptive, robust risk assessments of nanomaterials, e.g. for setting up consistent threshold levels, as well as consistent life cycle assessments of nanoproducts. We provide examples of such applications.

Physico-chemical characteristics and protein adsorption potential of hydroxyapatite particles: influence on in vitro biocompatibility of ceramics after sintering.

PubMed

Rouahi, M; Champion, E; Gallet, O; Jada, A; Anselme, K

2006-01-15

Through the example of two HA ceramics prepared from two HA powders (HAD and HAL), we explored the relation between the physico-chemical qualities of the initial HA powder and the final HA ceramic and their influence on the protein adsorption and cell response to the final HA ceramics. The powders were characterized by XRD, FT-IR, zeta potential, and specific surface area (SSA). Their protein adsorption potential was tested after immersion in culture medium +15% of fetal calf serum. These results were correlated with the protein adsorption potential of the two ceramics (cHAD and cHAL) prepared from the HAD and HAL powders respectively and to the cell attachment after 4, 24 and 72 h on the ceramics. From our results, it appears that a relation can be established between the physico-chemical characteristics of the initial HA powders and the final biological response to the sintered ceramics prepared from these powders. An inverse relation exists between the SSA and the protein adsorption capacity of HA powders and the protein adsorption and cell attachment on HA ceramics. This inverse relation is related to phenomenon occurring during the sintering phase and the formation of inter-granular micro-porosity.

Physicochemical and morphological properties of plasticized poly(vinyl alcohol)-agar biodegradable films.

PubMed

Madera-Santana, T J; Freile-Pelegrín, Y; Azamar-Barrios, J A

2014-08-01

The effects of the addition of glycerol (GLY) on the physicochemical and morphological properties of poly(vinyl alcohol) (PVA)-agar films were reported. PVA-agar films were prepared by solution cast method, and the addition of GLY in PVA-agar films altered the optical properties, resulting in a decrease in opacity values and in the color difference (ΔE) of the films. Structural characterization using Fourier transformation infrared (FTIR) spectroscopy and X-ray diffraction (XRD) indicated that the presence of GLY altered the intensity of the bands (from 1200 to 800cm(-1)) and crystallinity. The characterization of the thermal properties indicated that an increase in the agar content produces a decrease in the melting temperature and augments the heat of fusion. Similar tendencies were observed in plasticized films, but at different magnification. The formulation that demonstrated the lowest mechanical properties contained 25wt.% agar, whereas the formulation that contained 75wt.% agar demonstrated a significant improvement. The water vapor transmission rate (WVTR) and surface morphology analysis demonstrated that the structure of PVA-agar films is reorganized upon GLY addition. The physicochemical properties of PVA-agar films using GLY as a plasticizer provide information for the application of this formulation as packaging material for specific food applications. Copyright © 2014 Elsevier B.V. All rights reserved.

Description and comparative study of physico-chemical parameters of the teleost fish skin mucus.

PubMed

Guardiola, Francisco A; Cuartero, María; Del Mar Collado-González, María; Arizcún, Marta; Díaz Baños, F Guillermo; Meseguer, José; Cuesta, Alberto; Esteban, María A

2015-01-01

The study of mucosal surfaces, and in particular the fish skin and its secreted mucus, has been of great interest recently among immunologists. Measurement of the viscosity and other physico-chemical parameters (protein concentration, pH, conductivity, redox potential, osmolality and density) of the skin mucus can help to understand its biological functions. We have used five marine species of teleost: gilthead seabream (Sparus aurata L.), European sea bass (Dicentrarchus labrax L.), shi drum (Umbrina cirrosa L.), common dentex (Dentex dentex L.) and dusky grouper (Epinephelus marginatus L.), all of them with commercial interest in the aquaculture of the Mediterranean area. Mucus showed a direct shear- and temperature-dependent viscosity, with a non-Newtonian behavior, which differed however between two groups: one with higher viscosity (D. labrax, U. cirrosa, D. dentex) and the other with lower viscosity (S. aurata, E. marginatus). In addition, there was a clear interrelation between density and osmolality, as well as between density and temperature. Taking into account that high values of viscosity should improve the barrier effect against pathogens but low values of viscosity are needed for good locomotion characteristics, our results may help elucidate the relationship between physico-chemical and biological parameters of skin mucus, and disease susceptibility.

Extraction condition optimization and effects of drying methods on physicochemical properties and antioxidant activities of polysaccharides from comfrey (Symphytum officinale L.) root.

PubMed

Shang, Hongmei; Zhou, Haizhu; Duan, Mengying; Li, Ran; Wu, Hongxin; Lou, Yujie

2018-06-01

This study was designed to investigate the extraction conditions of polysaccharides from comfrey (Symphytum officinale L.) root (CRPs) using response surface methodology (RSM). The effects of three variables including liquid-solid ratio, extraction time and extraction temperature on the extraction yield of CRPs were taken into consideration. Moreover, the effects of drying methods including hot air drying (HD), vacuum drying (VD) and freeze drying (FD) on the physicochemical properties and antioxidant activities of CRPs were evaluated. The optimal conditions to extract the polysaccharides were as follows: liquid-solid ratio (15mL/g), extraction time (74min), and extraction temperature (95°C), allowed a maximum polysaccharides yield of 22.87%. Different drying methods had significant effects on the physicochemical properties of CRPs such as the chemical composition (contents of total polysaccharides and uronic acid), relative viscosity, solubility and molecular weight. CRPs drying with FD method showed stronger reducing power and radical scavenging capacities against DPPH and ABTS radicals compared with CRPs drying with HD and VD methods. Therefore, freeze drying served as a good method for keeping the antioxidant activities of polysaccharides from comfrey root. Copyright © 2018 Elsevier B.V. All rights reserved.