6 research outputs found
Microwave diagnostic system of the Uragan-2М torsatron
The construction of microwave sections together with results of loss calculation in the microwave lines for different frequencies are presented. The construction of microwave lead-ins is also described. The whole system has been well-tested on the Uragan-2M torsatron in conditions of SHF and RF cleaning at a low magnetic field, and of pulse regime with a higher magnetic field up to 6 kOe. The results of testing are illustrated by temporal evolutions of plasma density and by digitalized signals from the detector.Представлено конструкції НВЧ-трактів з розрахунком втрат в лініях на різних частотах і конструкції НВЧ- введень. НВЧ-комплекс, що описано, був випробуваний на торсатроні Ураган-2М в режимах НВЧ- і ВЧ- чищення при низькій напруженості магнітного поля, а також в імпульсному режимі з магнітним полем до 6 кЕ. Результати вимірювань ілюструються часовими залежностями густини і цифровими сигналами, отриманими з детектора.Представлены конструкции СВЧ-трактов с расчетом потерь в линиях на различных частотах и конструкции СВЧ-вводов. Описанный СВЧ-комплекс испытан на торсатроне Ураган-2М в режимах СВЧ- и ВЧ- чистки при низкой напряженности магнитного поля, а также в импульсном режиме с магнитным полем до 6 кЭ. Результаты измерений иллюстрируются временными зависимостями плотности и цифровыми сигналами, полученными с детектора
Meta-analysis of type 2 Diabetes in African Americans Consortium
Type 2 diabetes (T2D) is more prevalent in African Americans than in Europeans. However, little is known about the genetic risk in African Americans despite the recent identification of more than 70 T2D loci primarily by genome-wide association studies (GWAS) in individuals of European ancestry. In order to investigate the genetic architecture of T2D in African Americans, the MEta-analysis of type 2 DIabetes in African Americans (MEDIA) Consortium examined 17 GWAS on T2D comprising 8,284 cases and 15,543 controls in African Americans in stage 1 analysis. Single nucleotide polymorphisms (SNPs) association analysis was conducted in each study under the additive model after adjustment for age, sex, study site, and principal components. Meta-analysis of approximately 2.6 million genotyped and imputed SNPs in all studies was conducted using an inverse variance-weighted fixed effect model. Replications were performed to follow up 21 loci in up to 6,061 cases and 5,483 controls in African Americans, and 8,130 cases and 38,987 controls of European ancestry. We identified three known loci (TCF7L2, HMGA2 and KCNQ1) and two novel loci (HLA-B and INS-IGF2) at genome-wide significance (4.15 × 10(-94)<P<5 × 10(-8), odds ratio (OR) = 1.09 to 1.36). Fine-mapping revealed that 88 of 158 previously identified T2D or glucose homeostasis loci demonstrated nominal to highly significant association (2.2 × 10(-23) < locus-wide P<0.05). These novel and previously identified loci yielded a sibling relative risk of 1.19, explaining 17.5% of the phenotypic variance of T2D on the liability scale in African Americans. Overall, this study identified two novel susceptibility loci for T2D in African Americans. A substantial number of previously reported loci are transferable to African Americans after accounting for linkage disequilibrium, enabling fine mapping of causal variants in trans-ethnic meta-analysis studies.Peer reviewe
Feasibility of one-crystal GaAs artificial pyroelectric array
Multifunction properties of GaAs and other III-V semi-insulating crystals could be expanded by the artificial decreasing of their electric response symmetry that could be transformed from piezo- into a pyroelectric class. Artificial pyroelectricity of III-V type semiconductors forms a basis for one-crystal pyroelectric sensor. The voltage sensitivity of GaAs (111)-cut is the similar to PZT pyroelectric ceramics, so GaAs wafer could be used as a thermal-to-electric transducer in a new microelectronic device named pyrotransistor. The last is uncooling far infrared (IR) detector based on MESFET technology
Osmoregulation in children with cystic fibrosis
Hyponatremia is not rare in cystic fibrosis and might be due to several mechanisms. An endocrine and renal imbalance in water and salt homeostasis was suggested. To address this hypothesis, we assessed the urinary concentrating and diluting ability in 12 cystic fibrosis patients (6 females, 6 males) and in two control groups: 14 children with pneumonia (9 females, 5 males) and in 13 healthy children (9 females, 4 males). Renal concentrating ability was evaluated following overnight water deprivation. Urine osmolality was not significantly different between groups. Renal diluting ability was assessed by means of a water-load test. This provoked a decrease in urine osmolality, as well as an increase in diuresis and solute-free water excretion. These changes were comparable among groups. Conclusion: Children with cystic fibrosis show a preserved renal concentrating and diluting capacity. A generalized endocrine and renal imbalance in water and salt homeostasis therefore appears unlikely.What is Known:\u2022Hyponatremia sometimes occurs in cystic fibrosis.What is New:\u2022Osmoregulation is normal in cystic fibrosis
Pleiotropic genes for metabolic syndrome and inflammation
Metabolic syndrome (MetS) has become a health and financial burden worldwide. The MetS definition captures clustering of risk factors that predict higher risk for diabetes mellitus and cardiovascular disease. Our study hypothesis is that additional to genes influencing individual MetS risk factors, genetic variants exist that influence MetS and inflammatory markers forming a predisposing MetS genetic network. To test this hypothesis a staged approach was undertaken. (a) We analyzed 17 metabolic and inflammatory traits in more than 85,500 participants from 14 large epidemiological studies within the Cross Consortia Pleiotropy Group. Individuals classified with MetS (NCEP definition), versus those without, showed on average significantly different levels for most inflammatory markers studied. (b) Paired average correlations between 8 metabolic traits and 9 inflammatory markers from the same studies as above, estimated with two methods, and factor analyses on large simulated data, helped in identifying 8 combinations of traits for follow-u
A Meta-analysis of Gene Expression Signatures of Blood Pressure and Hypertension
10.1371/journal.pgen.1005035PLoS Genetics113e100503