Phase Transition Sensitive Schottky Barriers In Ga-Si(P) Contacts

Investigation and understanding of Schottky diodes continue to be interesting both for basic as well as technological points of view. Even now the evolutionary aspects of such contacts are not very clearly understood. In this paper it is shown that in respect of interfacial strain contribution to the barrier heights of such contacts semiconductor – liquid metal contacts are relatively better placed than solid semiconductor-solid metal contacts. Results on Ga-Si(p) contact are discussed in this paper to show phase sensitive contribution to the barrier height of such Schottky contacts. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3099

The effect of ethnicity on appendicular bone mass in white, coloured and Indian schoolchildren

Ethnic differences in the incidence and prevalence of osteoporosis have been shown throughout the world. In South Africa the prevalence of osteoporosis is much higher in whites than in blacks. This is surprising, since factors that might predispose to reduce bone mass are more preponderant in black communities. The present research was undertaken to detertnine whether differences in bone mass during the period of bone accretion could explain the difference in the incidence of osteoporosis. In this paper we report on differences in appendicular bone Inass between white, coloured and Indian children and teenagers (6 - 18 years) from Johannesburg. The effects of weight, height, puberty and skinfold thickness on bone mass were also assessed. The bone width (BW) of white boys was greater than that of Indian boys, while the bone mineral content (BMC) and BMC/BW were greater in white boys than in both Indian and coloured boys. After adjustment for differences in weight and height, the BW of coloured boys was significantly greater than that of white boys, while all differences in BMC and BMC/BW becaIne non-significant. For girls there were no significant differences in bone mass measurements, but after adjustment for height and weight coloured girls had significantly greater BMC and BMC/BW than either white or Indian girls. This greater weight- and height-adjusted bone mass in coloured girls is consistent with the impression of a lower incidence of osteoporosis in coloured women than in white women

Feshbach resonances, molecular bound states, and prospects of ultracold-molecule formation in mixtures of ultracold K and Cs

We consider the possibilities for producing ultracold mixtures of K and Cs and forming KCs molecules by magnetoassociation. We carry out coupled-channel calculations of the interspecies scattering length for KCs39, KCs41, and KCs40 and characterize Feshbach resonances due to s-wave and d-wave bound states, with widths ranging from below 1 nG to 5 G. We also calculate the corresponding bound-state energies as a function of magnetic field. We give a general discussion of the combinations of intraspecies and interspecies scattering lengths needed to form low-temperature atomic mixtures and condensates and identify promising strategies for cooling and molecule formation for all three isotopic combinations of K and Cs

Decoherence in rf SQUID Qubits

We report measurements of coherence times of an rf SQUID qubit using pulsed microwaves and rapid flux pulses. The modified rf SQUID, described by an double-well potential, has independent, in situ, controls for the tilt and barrier height of the potential. The decay of coherent oscillations is dominated by the lifetime of the excited state and low frequency flux noise and is consistent with independent measurement of these quantities obtained by microwave spectroscopy, resonant tunneling between fluxoid wells and decay of the excited state. The oscillation's waveform is compared to analytical results obtained for finite decay rates and detuning and averaged over low frequency flux noise.Comment: 24 pages, 13 figures, submitted to the journal Quantum Information Processin

Interleukin-7 deficiency in rheumatoid arthritis: consequences for therapy-induced lymphopenia

We previously demonstrated prolonged, profound CD4+ T-lymphopenia in rheumatoid arthritis (RA) patients following lymphocyte-depleting therapy. Poor reconstitution could result either from reduced de novo T-cell production through the thymus or from poor peripheral expansion of residual T-cells. Interleukin-7 (IL-7) is known to stimulate the thymus to produce new T-cells and to allow circulating mature T-cells to expand, thereby playing a critical role in T-cell homeostasis. In the present study we demonstrated reduced levels of circulating IL-7 in a cross-section of RA patients. IL-7 production by bone marrow stromal cell cultures was also compromised in RA. To investigate whether such an IL-7 deficiency could account for the prolonged lymphopenia observed in RA following therapeutic lymphodepletion, we compared RA patients and patients with solid cancers treated with high-dose chemotherapy and autologous progenitor cell rescue. Chemotherapy rendered all patients similarly lymphopenic, but this was sustained in RA patients at 12 months, as compared with the reconstitution that occurred in cancer patients by 3–4 months. Both cohorts produced naïve T-cells containing T-cell receptor excision circles. The main distinguishing feature between the groups was a failure to expand peripheral T-cells in RA, particularly memory cells during the first 3 months after treatment. Most importantly, there was no increase in serum IL-7 levels in RA, as compared with a fourfold rise in non-RA control individuals at the time of lymphopenia. Our data therefore suggest that RA patients are relatively IL-7 deficient and that this deficiency is likely to be an important contributing factor to poor early T-cell reconstitution in RA following therapeutic lymphodepletion. Furthermore, in RA patients with stable, well controlled disease, IL-7 levels were positively correlated with the T-cell receptor excision circle content of CD4+ T-cells, demonstrating a direct effect of IL-7 on thymic activity in this cohort

[Accepted Manuscript] A Systematic Review on Harmful Alcohol Use Among Civilian Populations Affected by Armed Conflict in Low- and Middle-Income Countries.

There are currently over 55 million refugees and internally displaced persons due to armed conflict. In addition, there are around 150 million more conflict-affected residents who remain in their home communities. Armed conflict poses a number of potential risks for harmful alcohol use. The objective of the study was to systematically examine evidence on harmful alcohol use among conflict-affected populations in low- and middle-income countries. A systematic review methodology was used following PRISMA guidelines. Quantitative studies were selected with outcomes relating to harmful alcohol use among conflict-affected populations in low- and middle-income countries. Seven bibliographic databases and a range of gray literature sources were searched. Descriptive analysis was applied and a quality assessment conducted using the Newcastle-Ottawa Quality Assessment Scale. The search yielded 10,037 references of which 22 studies met inclusion criteria. Twenty-one of the studies used a cross-sectional design, and 1 used a case series design. Evidence on risk factors for harmful alcohol use was weak overall. Factors associated with harmful alcohol use were male gender, older age, cumulative trauma event exposure, and depression. There were no studies on the effectiveness of interventions for harmful alcohol use. The strength of evidence was also limited by the generally moderate quality of the studies. Substantially more evidence is required to understand the scale of conflict-associated harmful alcohol use, key risk factors, association of alcohol use with physical and mental disorders, and effectiveness of interventions to address harmful alcohol use in conflict-affected populations

Subtyping sub-Saharan esophageal squamous cell carcinoma by comprehensive molecular analysis

Esophageal squamous cell carcinoma (ESCC) is endemic in regions of sub-Saharan Africa (SSA), where it is the third most common cancer. Here, we describe whole-exome tumor/normal sequencing and RNA transcriptomic analysis of 59 patients with ESCC in Malawi. We observed similar genetic aberrations as reported in Asian and North American cohorts, including mutations of TP53, CDKN2A, NFE2L2, CHEK2, NOTCH1, FAT1, and FBXW7. Analyses for nonhuman sequences did not reveal evidence for infection with HPV or other occult pathogens. Mutational signature analysis revealed common signatures associated with aging, cytidine deaminase activity (APOBEC), and a third signature of unknown origin, but signatures of inhaled tobacco use, aflatoxin and mismatch repair were notably absent. Based on RNA expression analysis, ESCC could be divided into 3 distinct subtypes, which were distinguished by their expression of cell cycle and neural transcripts. This study demonstrates discrete subtypes of ESCC in SSA, and suggests that the endemic nature of this disease reflects exposure to a carcinogen other than tobacco and oncogenic viruses