Каталитические свойства и устойчивость порошковых сплавов никель–олово в процессе электрохимического выделения водорода из раствора щелочи

Ni–Sn powder alloys with a nickel content from 24.4 to 78.5 at.% and from 30.6 to 55.1 at.%, respectively, were synthesized chemically and electrochemically for the use as catalysts for the hydrogen electrochemical reduction (HER) in alkali solution. It was established that the catalytically active surface area of chemically synthesized powders was larger in comparison with electrochemically obtained ones. Ni24.4Sn75.6 powder alloy has the largest surface area. It was found that catalytic properties of chemically synthesized powders increased in the row Ni24.4Sn75.6 < Ni78.5Sn21.5 < Ni. Electrochem ically obtained alloys are inefficient as HER catalysts. It was found that Ni24.4Sn75.6 alloy is characterized by the greater re tention of catalytically active surface area during exploitation in alkali solution in comparison with Ni and Ni78.5Sn21.5 alloy. Химически и электрохимически синтезированы порошковые сплавы Ni–Sn с содержанием никеля соответственно от 24,4 до 78,5 ат.% и от 30,6 до 55,1 ат.% для применения в качестве катализаторов электрохимического восстановления водорода в растворе щелочи. Установлено, что каталитически активная площадь поверхности химически синтезированных порошков больше в сравнении с электрохимически полученными, максимальной площадью характеризуется сплав Ni24,4Sn75,6. Выявлено, что для химически синтезированных порошков каталитические свойства, оцененные по значению потенциала, при котором достигается плотность тока 10 мА/см2, возрастают в ряду Ni24,4Sn75,6 < Ni78,5Sn21,5 < Ni; электрохимически полученные сплавы являются неэффективными катализаторами. Установлено, что сплав Ni24,4Sn75,6 характеризуется большей сохранностью каталитически активной площади поверхности в процессе эксплуатации в сравнении с никелем и сплавом Ni78,5Sn21,5

Scans for signatures of selection in Russian cattle breed genomes reveal new candidate genes for environmental adaptation and acclimation

Domestication and selective breeding has resulted in over 1000 extant cattle breeds. Many of these breeds do not excel in important traits but are adapted to local environments. These adaptations are a valuable source of genetic material for efforts to improve commercial breeds. As a step toward this goal we identified candidate regions to be under selection in genomes of nine Russian native cattle breeds adapted to survive in harsh climates. After comparing our data to other breeds of European and Asian origins we found known and novel candidate genes that could potentially be related to domestication, economically important traits and environmental adaptations in cattle. The Russian cattle breed genomes contained regions under putative selection with genes that may be related to adaptations to harsh environments (e.g., AQP5, RAD50, and RETREG1). We found genomic signatures of selective sweeps near key genes related to economically important traits, such as the milk production (e.g., DGAT1, ABCG2), growth (e.g., XKR4), and reproduction (e.g., CSF2). Our data point to candidate genes which should be included in future studies attempting to identify genes to improve the extant breeds and facilitate generation of commercial breeds that fit better into the environments of Russia and other countries with similar climates

Prevalence and Determinants of QuantiFERON-Diagnosed Tuberculosis Infection in 9810 Mongolian Schoolchildren.

BACKGROUND: There is controversy regarding the potential influence of vitamin D deficiency, exposure to environmental tobacco smoke, BCG vaccination, season, and body habitus on susceptibility to Mycobacterium tuberculosis (MTB) infection. METHODS: We conducted a cross-sectional analysis to identify determinants of a positive QuantiFERON-TB Gold (QFT) assay result in children aged 6-13 years attending 18 schools in Ulaanbaatar, Mongolia. Data relating to potential risk factors for MTB infection were collected by questionnaire, physical examination, and determination of serum 25-hydroxyvitamin D (25[OH]D) concentrations. Risk ratios (RRs) were calculated with adjustment for potential confounders, and population attributable fractions (PAFs) were calculated for modifiable risk factors identified. RESULTS: Nine hundred forty-six of 9810 (9.6%) participants had a positive QFT result. QFT positivity was independently associated with household exposure to pulmonary tuberculosis (adjusted RR [aRR], 4.75 [95% confidence interval {CI}, 4.13-5.46, P < .001]; PAF, 13.1% [95% CI, 11.1%-15.0%]), vitamin D deficiency (aRR, 1.23 [95% CI, 1.08-1.40], P = .002; PAF, 5.7% [95% CI, 1.9%-9.3%]), exposure to environmental tobacco smoke (1 indoor smoker, aRR, 1.19 [95% CI, 1.04-1.35]; ≥2 indoor smokers, aRR, 1.30 [95% CI, 1.02-1.64]; P for trend = .006; PAF, 7.2% [95% CI, 2.2%-12.0%]), and increasing age (aRR per additional year, 1.14 [95% CI, 1.10-1.19], P < .001). No statistically significant independent association was seen for presence of a BCG scar, season of sampling, or body mass index. CONCLUSIONS: Vitamin D deficiency and exposure to environmental tobacco smoke are potentially modifiable risk factors for MTB infection

Каталитическая активность порошковых сплавов никель–медь в процессах электрохимического выделения водорода в растворе щелочи и щелочном растворе этанола

Ni93Cu and Ni82Cu (at%) alloys were synthesized by the method of combined chemical reduction of Ni(II) and Cu(II) with hydrazine hydrate. These alloys consist of crystalline phases of nickel, solid solution of copper in nickel. Determination by the “capacitive method” of the electrochemically active surface area of working graphite electrodes with “catalytic inks” containing Ni93Cu and Ni82Cu powders showed that it is 4 and 20 % larger than for nickel powder, respectively. It was found that powder alloys Ni93Cu and Ni82Cu are applicable as catalysts for the electrochemical process of hydrogen evolution in alkaline solutions and alkaline ethanol solution. It was determined that the catalytic activity of Ni82Cu powder alloy in the process of hydrogen evolution in the alkaline ethanol solution is higher than for nickel and Ni93Cu powders. The catalytic ability of the Ni82Cu powder alloy during cycling for 25 cycles practically does not change, in contrast to Ni and Ni93Cu.  Методом совместного химического восстановления Ni(II) и Cu(II) гидратом гидразина синтезированы сплавы Ni93Cu и Ni82Cu (ат.%), состоящие из кристаллических фаз никеля, твердого раствора меди в никеле. Определение емкостным методом электрохимически активной площади поверхности рабочих графитовых электродов с «каталитическими чернилами», содержащими порошки Ni93Cu и Ni82Cu, показало, что она на 4 и 20 % больше, чем для порошка никеля. Установлено, что порошковые сплавы Ni93Cu и Ni82Cu применимы в качестве катализаторов электрохимического процесса выделения водорода в растворах щелочей и щелочном растворе этанола. Определено, что каталитическая активность порошкового сплава Ni82Cu в процессе выделения водорода в щелочном растворе этанола выше, чем для порошков никеля и Ni93Cu. Каталитическая способность порошкового сплава Ni82Cu при циклировании в течение 25 циклов практически не меняется в отличие от Ni и Ni93Cu.

A Genome-Wide SNP Scan Reveals Novel Loci for Egg Production and Quality Traits in White Leghorn and Brown-Egg Dwarf Layers

Availability of the complete genome sequence as well as high-density SNP genotyping platforms allows genome-wide association studies (GWAS) in chickens. A high-density SNP array containing 57,636 markers was employed herein to identify associated variants underlying egg production and quality traits within two lines of chickens, i.e., White Leghorn and brown-egg dwarf layers. For each individual, age at first egg (AFE), first egg weight (FEW), and number of eggs (EN) from 21 to 56 weeks of age were recorded, and egg quality traits including egg weight (EW), eggshell weight (ESW), yolk weight (YW), eggshell thickness (EST), eggshell strength (ESS), albumen height(AH) and Haugh unit(HU) were measured at 40 and 60 weeks of age. A total of 385 White Leghorn females and 361 brown-egg dwarf dams were selected to be genotyped. The genome-wide scan revealed 8 SNPs showing genome-wise significant (P<1.51E-06, Bonferroni correction) association with egg production and quality traits under the Fisher's combined probability method. Some significant SNPs are located in known genes including GRB14 and GALNT1 that can impact development and function of ovary, but more are located in genes with unclear functions in layers, and need to be studied further. Many chromosome-wise significant SNPs were also detected in this study and some of them are located in previously reported QTL regions. Most of loci detected in this study are novel and the follow-up replication studies may be needed to further confirm the functional significance for these newly identified SNPs

Breeding for resistance to gastrointestinal nematodes - the potential in low-input/output small ruminant production systems

AbstractThe control of gastrointestinal nematodes (GIN) is mainly based on the use of drugs, grazing management, use of copper oxide wire particles and bioactive forages. Resistance to anthelmintic drugs in small ruminants is documented worldwide. Host genetic resistance to parasites, has been increasingly used as a complementary control strategy, along with the conventional intervention methods mentioned above. Genetic diversity in resistance to GIN has been well studied in experimental and commercial flocks in temperate climates and more developed economies. However, there are very few report outputs from the more extensive low-input/output smallholder systems in developing and emerging countries. Furthermore, results on quantitative trait loci (QTL) associated with nematode resistance from various studies have not always been consistent, mainly due to the different nematodes studied, different host breeds, ages, climates, natural infections versus artificial challenges, infection level at sampling periods, among others. The increasing use of genetic markers (Single Nucleotide Polymorphisms, SNPs) in GWAS or the use of whole genome sequence data and a plethora of analytic methods offer the potential to identify loci or regions associated nematode resistance. Genomic selection as a genome-wide level method overcomes the need to identify candidate genes. Benefits in genomic selection are now being realised in dairy cattle and sheep under commercial settings in the more advanced countries. However, despite the commercial benefits of using these tools, there are practical problems associated with incorporating the use of marker-assisted selection or genomic selection in low-input/output smallholder farming systems breeding schemes. Unlike anthelmintic resistance, there is no empirical evidence suggesting that nematodes will evolve rapidly in response to resistant hosts. The strategy of nematode control has evolved to a more practical manipulation of host-parasite equilibrium in grazing systems by implementation of various strategies, in which improvement of genetic resistance of small ruminant should be included. Therefore, selection for resistant hosts can be considered as one of the sustainable control strategy, although it will be most effective when used to complement other control strategies such as grazing management and improving efficiency of anthelmintics currently