An Investigation of the Mechanism of Water Molecules Interaction with Hydrophilic Disperse Substances by the NMR Method

The paper presents the results of an investigation of the linewidths and chemical shifts of, the NMR of protons of water molecules and some magnetic nuclei of counterions (Li+, F-, NH4+, H+) in aqueous dispersions of a number of ion-exchange resins and alumosilicates in solutions of high-molecular compounds. The spectra have been recorded by the high-resolution NMR type INM-4H-100 spectrometer with a 100 MHz work frequency for protons and 40 MHz for 7Li in a wide temperature range from 173 K to 373 K. The phenomenon that the shift of water ·signal versus tern- . perature variation is smaller for electrolyte solutions that for pure water, is proposed to be utilized for the evaluation of the hydratation numbers of ions in electrolyte solutions. The activation energy of molecular motion at low temperatures, calculated, from temperature dependence of the linewidth is 8-16 kcal moi-1 and it is in good agreement with the results obtained by other techniques. A model of interaction of water molecules between each other and with the active centres ·Of hydrophilic disperse systems has been proposed. The peculiarities of the interaction of water molecules with ions of various electron structure have been elucidated. The hydratation numbers of counterions have been determined and compared with those for equeous solutions of corresponding salts. The special features of water molecules on the interface at low temperatures have been discussed. The role of hydrogen bonds in the determination of the freezing temperature of water has been elucidated

Synergistic effects research in the system of complex emulsifier

Вивчено поведінку молекул моно- і диефірів олеїнової кислоти та моно- і диефірів стеаринової кислоти у суміші з поліетиленгліколем-400 на межі поділу фаз олія-вода при виробництві косметичних емульсій. Запропоновано використання 0,5%мас. високодисперсного порошку глауконіту, що концентрується на міжфазній межі з утворенням міцної просторової коагуляційної структури для стійкості дисперсної системи.Изучено поведение молекул моно- и диэфиров олеиновой кислоты и моно- и диэфиров стеариновой кислоты в смеси с полиэтиленгликолем-400 на границе раздела фаз масло-вода при производстве косметических эмульсий. Предложено использование 0,5% масс высокодисперсного порошка глауконита, который концентрируется на межфазной границе с образованием прочной пространственной коагуляционной структуры для стойкости дисперсной системы.It was studied the behavior of molecules mono- and diesters of oleic acid and monoand diesters of stearic acid in a mixture of polyethylene glycol 400 at phase interface of oil-water in the production of cosmetic emulsions. The use of 0,5% by weight. high-dispersive powder of glauconite, which concentrates at interfaces with formation of a strong spatial coagulation structure for stability of dispersed system

Effect of Preventive Supplementation with Zinc and other Micronutrients on Non-Malarial Morbidity in Tanzanian Pre-School Children: A Randomized Trial.

The efficacy of preventive zinc supplementation against diarrhea and respiratory illness may depend on simultaneous supplementation with other micronutrients. We aimed to assess the effect of supplementation with zinc and multiple micronutrients on diarrhea and other causes of non-malarial morbidity. Rural Tanzanian children (n = 612) aged 6-60 months and with height-for-age z-score < -1.5 SD were randomized to daily supplementation with zinc (10 mg) alone, multi-nutrients without zinc, multi-nutrients with zinc, or placebo. Children were followed for an average of 45 weeks. During follow-up, we recorded morbidity episodes. We found no evidence that concurrent supplementation with multi-nutrients influenced the magnitude of the effect of zinc on rates of diarrhea, respiratory illness, fever without localizing signs, or other illness (guardian-reported illness with symptoms involving skin, ears, eyes and abscesses, but excluding trauma or burns). Zinc supplementation reduced the hazard rate of diarrhea by 24% (4%-40%). By contrast, multi-nutrients seemed to increase this rate (HR; 95% CI: 1.19; 0.94-1.50), particularly in children with asymptomatic Giardia infection at baseline (2.03; 1.24-3.32). Zinc also protected against episodes of fever without localizing signs (0.75; 0.57-0.96), but we found no evidence that it reduced the overall number of clinic visits. We found no evidence that the efficacy of zinc supplements in reducing diarrhea rates is enhanced by concurrent supplementation with other micronutrients. By reducing rates of fever without localizing signs, supplementation with zinc may reduce inappropriate drug use with anti-malarial medications and antibiotics. ClinicalTrials.gov NCT00623857

The Structure of Ca2+ Sensor Case16 Reveals the Mechanism of Reaction to Low Ca2+ Concentrations

Here we report the first crystal structure of a high-contrast genetically encoded circularly permuted green fluorescent protein (cpGFP)-based Ca2+ sensor, Case16, in the presence of a low Ca2+ concentration. The structure reveals the positioning of the chromophore within Case16 at the first stage of the Ca2+-dependent response when only two out of four Ca2+-binding pockets of calmodulin (CaM) are occupied with Ca2+ ions. In such a “half Ca2+-bound state”, Case16 is characterized by an incomplete interaction between its CaM-/M13-domains. We also report the crystal structure of the related Ca2+ sensor Case12 at saturating Ca2+ concentration. Based on this structure, we postulate that cpGFP-based Ca2+ sensors can form non-functional homodimers where the CaM-domain of one sensor molecule binds symmetrically to the M13-peptide of the partner sensor molecule. Case12 and Case16 behavior upon addition of high concentrations of free CaM or M13-peptide reveals that the latter effectively blocks the fluorescent response of the sensor. We speculate that the demonstrated intermolecular interaction with endogenous substrates and homodimerization can impede proper functioning of this type of Ca2+ sensors in living cells

Verification of high-energy transport codes on the basis of activation data

Nuclide production cross sections measured at ITEP for the targets of nat-Cr, 56-Fe, nat-Ni, 93-Nb, 181-Ta, nat-W, nat-Pb, 209-Bi irradiated by protons with energies from 40 to 2600 MeV were used to estimate the predictive accuracy of several popular high-energy transport codes. A general agreement of the ITEP data with the data obtained by other groups, including the numerous GSI data measured by the inverse kinematics method was found. Simulations of the measured data were performed with the MCNPX (Bertini and ISABEL options), CEM03.02, INCL4.2+ABLA, INCL4.5+ABLA07, PHITS, and CASCADE.07 codes. Deviation factors between the calculated and experimental cross sections have been estimated for each target and for the whole energy range covered by our measurements. Two-dimensional diagrams of deviation factor values were produced for estimating the predictive power of every code for intermediate, not measured masses of nuclei-targets and bombarding energies of protons. Further improvements of all tested here codes are recommended. In addition, new measurements at ITEP of nuclide yields from a 208-Pb target irradiated by 500 MeV protons are presented. A good agreement between these new data and the GSI measurements obtained by the inverse kinematics method was foundComment: 31 pages, 18 figures, 6 tables, only pdf, LANL Report LA-UR-11-02704, Los Alamos (2011), submitted to Phys. Rev.

Rapid De Novo Evolution of X Chromosome Dosage Compensation in Silene latifolia, a Plant with Young Sex Chromosomes

Evidence for dosage compensation in Silene latifolia, a plant with 10-million-year-old sex chromosomes, reveals that dosage compensation can evolve rapidly in young XY systems and is not an animal-specific phenomenon

Protection against Diarrhea Associated with Giardia intestinalis Is Lost with Multi-Nutrient Supplementation: A Study in Tanzanian Children

Giardia intestinalis is a well-known cause of diarrhea in industrialized countries. In children in developing countries, asymptomatic infections are common and their role as cause of diarrhea has been questioned. In a cohort of rural Tanzanian pre-school children, we assessed the association between the presence of Giardia at baseline and subsequent diarrhea risk. The study was conducted in the context of a randomised trial assessing the effect of supplementation with zinc and other micro-nutrients on malaria, and half of the children daily received a multi-nutrient supplement. Surprisingly, we found that the presence of Giardia at baseline was associated with a substantial reduction in diarrhea risk. Multivariate statistical analysis showed that this protection could not be explained by differences in age or walking distance to the dispensary between children with and without Giardia. Because we cannot exclude that children differed in other (unmeasured) characteristics, we cannot draw firm conclusions about the causality of the observed association, but our findings support the view that the parasite is not an important cause of diarrhea in highly endemic settings. Striking was that the Giardia-associated protection was lost when children received multi-nutrients. Our data do not provide information about the mechanisms involved, but suggest that multi-nutrients may influence the compositionor pathogenicity of intestinal biota

Characterizing Ligand-Gated Ion Channel Receptors with Genetically Encoded Ca++ Sensors

We present a cell based system and experimental approach to characterize agonist and antagonist selectivity for ligand-gated ion channels (LGIC) by developing sensor cells stably expressing a Ca2+ permeable LGIC and a genetically encoded Förster (or fluorescence) resonance energy transfer (FRET)-based calcium sensor. In particular, we describe separate lines with human α7 and human α4β2 nicotinic acetylcholine receptors, mouse 5-HT3A serotonin receptors and a chimera of human α7/mouse 5-HT3A receptors. Complete concentration-response curves for agonists and Schild plots of antagonists were generated from these sensors and the results validate known pharmacology of the receptors tested. Concentration-response relations can be generated from either the initial rate or maximal amplitudes of FRET-signal. Although assaying at a medium throughput level, this pharmacological fluorescence detection technique employs a clonal line for stability and has versatility for screening laboratory generated congeners as agonists or antagonists on multiple subtypes of ligand-gated ion channels. The clonal sensor lines are also compatible with in vivo usage to measure indirectly receptor activation by endogenous neurotransmitters

Genetic characterisation of farmed rainbow trout in Norway: intra- and inter-strain variation reveals potential for identification of escapees

<p>Abstract</p> <p>Background</p> <p>The rainbow trout (<it>Oncorhynchus mykiss</it>) is one of the most important aquaculture species in the world, and Norway is one of the largest producers. The present study was initiated in response to a request from the Norwegian police authority to identify the farm of origin for 35 escaped rainbow trout captured in a fjord. Eleven samples, each consisting of approximately 47 fish, were collected from the three farms operating in the fjord where the escapees were captured. In order to gain a better general understanding of the genetic structure of rainbow trout strains used in Norwegian aquaculture, seven samples (47 fish per sample) were collected from six farms located outside the region where the escapees were captured. All samples, including the escapees, were genotyped with 12 microsatellite loci.</p> <p>Results</p> <p>All samples displayed considerable genetic variability at all loci (mean number of alleles per locus per sample ranged from 5.4–8.6). Variable degrees of genetic differentiation were observed among the samples, with pair-wise <it>F</it>_STvalues ranging from 0–0.127. Self-assignment tests conducted among the samples collected from farms outside the fjord where the escapees were observed gave an overall correct assignment of 82.5%, demonstrating potential for genetic identification of escapees. In the "real life" assignment of the 35 captured escapees, all were excluded from two of the samples included as controls in the analysis, and 26 were excluded from the third control sample. In contrast, only 1 of the escapees was excluded from the 11 pooled samples collected on the 3 farms operating in the fjord.</p> <p>Conclusion</p> <p>Considerable genetic variation exists within and among rainbow trout strains farmed in Norway. Together with modern statistical methods, this will provide commercial operators with a tool to monitor breeding and fish movements, and management authorities with the ability to identify the source of escapees. The data generated in this study were used by the Norwegian police to initiate an investigation of the company operating the three farms in the fjord where escapees were observed.</p