Metal Semiconductor Contact between Gold and Boron Carbide

We have investigated the interaction of gold (Au) with the semiconductor boron carbide through X-ray photoemission and heterojunction diode fabrication. The plasma enhanced chemical vapor deposition (PECVD) hydrogenated semiconducting boron carbide films, deposited from closo-1,7-dicarbadodecaborane (metacarborane, m-B10C2H12), shows a shift in the binding energies of the core level photoemission features when gold is deposited on the surface. The shifting of the B 1s level is smaller than for the C 1s level and the non-uniform nature of the shifts indicates a strong, complex and reversible gold chemical interaction with the surface, particularly with the C sites. The capacitance-voltage, C(V), and current versus voltage, I(V), results for the metacarborane film deposited on p-type Si(100) yield a carrier scattering time of 50 ns which is significantly smaller than the 35 ms for the PECVD orthocarborane boron carbide films

The chromium site in doped glassy lithium tetraborate

Using extended X-ray absorption fine structure (EXAFS) spectroscopy, we find that Cr substitutes primarily in the Liþ site as a dopant in lithium tetraborate Li2B4O7 glasses, in this case 98.4Li2B4O7e1.6Cr2O3 or nominally Li1.98Cr0.025B4O7. This strong preference for a single site is nonetheless accompanied by site distortions and some site disorder, helping explain the optical properties of chromium doped Li2B4O7 glasses. The resulting O coordination shell has a contraction of the Cr-O bond lengths as compared to the Li-O bond lengths. There is also an increase in the O coordination number

The chromium site in doped glassy lithium tetraborate

Using extended X-ray absorption fine structure (EXAFS) spectroscopy, we find that Cr substitutes primarily in the Liþ site as a dopant in lithium tetraborate Li2B4O7 glasses, in this case 98.4Li2B4O7e1.6Cr2O3 or nominally Li1.98Cr0.025B4O7. This strong preference for a single site is nonetheless accompanied by site distortions and some site disorder, helping explain the optical properties of chromium doped Li2B4O7 glasses. The resulting O coordination shell has a contraction of the Cr-O bond lengths as compared to the Li-O bond lengths. There is also an increase in the O coordination number

Safety and Immunogenicity of Different Immunization Regimens of CVD 103-HgR Live Oral Cholera Vaccine in Soldiers and Civilians in Thailand

Attenuated Vibrio cholerae oral vaccineCVD 103-HgR was well tolerated by 324 Thai soldiers and civilians. Most receiveda single 5 × 108 cfu dose, while 40 each receivedone or two 5 × 109 cfu doses. Vibriocidal antibody (the best correlate of immunity) seroconversion was lower in soldiers than civilians (P < .001). Increasing the vaccinedose to 5 × 109 cfu raised the geometric mean titer (P < .001).Asecond 5 × 109 cfu dose one weeklater did not notably increase seroconversions. Likelihood of seroconversionwas inverselycorrelated with baseline vibriocidal titer (P < .001). CVD 103-HgR caused seroconversion in most subjects with baseline titers ⩽1:40, including 100% of civilians after one 5 × 108 cfu dose, 79% of soldiers after one 5 × 109 cfu dose, and 45% of soldiers after one 5 × 108 cfu dose. In persons with elevatedbaseline titers, vibriocidal antibody seroconversion is not a sensitive measure of whether vaccine has boosted intestinal immunity; for such subjects,other measurements must be used. Study regimens in endemic areas should use a single 5 × 109 cfu dos

Possible Detection of Low Energy Solar Neutrons Using Boron Based Materials

Solar neutrons have been detected aboard the International Space Station (ISS), using lithium tetraborate and boron carbide detector elements. We find that evidence of a solar neutron flux, as detected in a neutron calorimeter following subtraction of the proton background, with an energy of about 2 to 4 MeV. This solar neutron flux is likely no more than 250 to 375 neutrons cm−2sec−1, with a lower bound of 50–75 neutrons cm−2sec−1 at one au

Higher Dimensional Cylindrical or Kasner Type Electrovacuum Solutions

We consider a D dimensional Kasner type diagonal spacetime where metric functions depend only on a single coordinate and electromagnetic field shares the symmetries of spacetime. These solutions can describe static cylindrical or cosmological Einstein-Maxwell vacuum spacetimes. We mainly focus on electrovacuum solutions and four different types of solutions are obtained in which one of them has no four dimensional counterpart. We also consider the properties of the general solution corresponding to the exterior field of a charged line mass and discuss its several properties. Although it resembles the same form with four dimensional one, there is a difference on the range of the solutions for fixed signs of the parameters. General magnetic field vacuum solution are also briefly discussed, which reduces to Bonnor-Melvin magnetic universe for a special choice of the parameters. The Kasner forms of the general solution are also presented for the cylindrical or cosmological cases.Comment: 16 pages, Revtex. Text and references are extended, Published versio

Cell Cycle Phase Regulates Glucocorticoid Receptor Function

The glucocorticoid receptor (GR) is a member of the nuclear hormone receptor superfamily of ligand-activated transcription factors. In contrast to many other nuclear receptors, GR is thought to be exclusively cytoplasmic in quiescent cells, and only translocate to the nucleus on ligand binding. We now demonstrate significant nuclear GR in the absence of ligand, which requires nuclear localisation signal 1 (NLS1). Live cell imaging reveals dramatic GR import into the nucleus through interphase and rapid exclusion of the GR from the nucleus at the onset of mitosis, which persists into early G1. This suggests that the heterogeneity in GR distribution is reflective of cell cycle phase

Clinical Outcomes With a Repositionable Self-Expanding Transcatheter Aortic Valve Prosthesis: The International FORWARD Study

Background Clinical outcomes in large patient populations from real-world clinical practice with a next-generation self-expanding transcatheter aortic valve are lacking. Objectives This study sought to document the clinical and device performance outcomes of transcatheter aortic valve replacement (TAVR) with a next-generation, self-expanding transcatheter heart valve (THV) system in patients with severe symptomatic aortic stenosis (AS) in routine clinical practice. Methods The FORWARD (CoreValve Evolut R FORWARD) study is a prospective, single-arm, multinational, multicenter, observational study. An independent clinical events committee adjudicated safety endpoints based on Valve Academic Research Consortium-2 definitions. An independent echocardiographic core laboratory evaluated all echocardiograms. From January 2016 to December 2016, TAVR with the next-generation self-expanding THV was attempted in 1,038 patients with symptomatic, severe AS at 53 centers on 4 continents. Results Mean age was 81.8 ± 6.2 years, 64.9% were women, the mean Society of Thoracic Surgeons Predicted Risk of Mortality was 5.5 ± 4.5%, and 33.9% of patients were deemed frail. The repositioning feature of the THV was applied in 25.8% of patients. A single valve was implanted in the proper anatomic location in 98.9% of patients. The mean aortic valve gradient was 8.5 ± 5.6 mm Hg, and moderate or severe aortic regurgitation was 1.9% at discharge. All-cause mortality was 1.9%, and disabling stroke occurred in 1.8% at 30 days. The expected-to-observed early surgical mortality ratio was 0.35. A pacemaker was implanted in 17.5% of patients. Conclusions TAVR using the next-generation THV is clinically safe and effective for treating older patients with severe AS at increased operative risk. (CoreValve Evolut R FORWARD Study [FORWARD]; NCT02592369

Estrogen regulation of apoptosis: how can one hormone stimulate and inhibit?

The link between estrogen and the development and proliferation of breast cancer is well documented. Estrogen stimulates growth and inhibits apoptosis through estrogen receptor-mediated mechanisms in many cell types. Interestingly, there is strong evidence that estrogen induces apoptosis in breast cancer and other cell types. Forty years ago, before the development of tamoxifen, high-dose estrogen was used to induce tumor regression of hormone-dependent breast cancer in post-menopausal women. While the mechanisms by which estrogen induces apoptosis were not completely known, recent evidence from our laboratory and others demonstrates the involvement of the extrinsic (Fas/FasL) and the intrinsic (mitochondria) pathways in this process. We discuss the different apoptotic signaling pathways involved in E2 (17β-estradiol)-induced apoptosis, including the intrinsic and extrinsic apoptosis pathways, the NF-κB (nuclear factor-kappa-B)-mediated survival pathway as well as the PI3K (phosphoinositide 3-kinase)/Akt signaling pathway. Breast cancer cells can also be sensitized to estrogen-induced apoptosis through suppression of glutathione by BSO (L-buthionine sulfoximine). This finding has implications for the control of breast cancer with low-dose estrogen and other targeted therapeutic drugs