Interface Engineering for Atomic Layer Deposited Alumina Gate Dielectric on SiGe Substrates.

Optimization of the interface between high-k dielectrics and SiGe substrates is a challenging topic due to the complexity arising from the coexistence of Si and Ge interfacial oxides. Defective high-k/SiGe interfaces limit future applications of SiGe as a channel material for electronic devices. In this paper, we identify the surface layer structure of as-received SiGe and Al2O3/SiGe structures based on soft and hard X-ray photoelectron spectroscopy. As-received SiGe substrates have native SiOx/GeOx surface layers, where the GeOx-rich layer is beneath a SiOx-rich surface. Silicon oxide regrows on the SiGe surface during Al2O3 atomic layer deposition, and both SiOx and GeOx regrow during forming gas anneal in the presence of a Pt gate metal. The resulting mixed SiOx-GeOx interface layer causes large interface trap densities (Dit) due to distorted Ge-O bonds across the interface. In contrast, we observe that oxygen-scavenging Al top gates decompose the underlying SiOx/GeOx, in a selective fashion, leaving an ultrathin SiOx interfacial layer that exhibits dramatically reduced Dit

Interface Engineering for Atomic Layer Deposited Alumina Gate Dielectric on SiGe Substrates.

Optimization of the interface between high-k dielectrics and SiGe substrates is a challenging topic due to the complexity arising from the coexistence of Si and Ge interfacial oxides. Defective high-k/SiGe interfaces limit future applications of SiGe as a channel material for electronic devices. In this paper, we identify the surface layer structure of as-received SiGe and Al2O3/SiGe structures based on soft and hard X-ray photoelectron spectroscopy. As-received SiGe substrates have native SiOx/GeOx surface layers, where the GeOx-rich layer is beneath a SiOx-rich surface. Silicon oxide regrows on the SiGe surface during Al2O3 atomic layer deposition, and both SiOx and GeOx regrow during forming gas anneal in the presence of a Pt gate metal. The resulting mixed SiOx-GeOx interface layer causes large interface trap densities (Dit) due to distorted Ge-O bonds across the interface. In contrast, we observe that oxygen-scavenging Al top gates decompose the underlying SiOx/GeOx, in a selective fashion, leaving an ultrathin SiOx interfacial layer that exhibits dramatically reduced Dit

Second to fourth digit ratio (2D: 4D) and prostate cancer risk in the Melbourne Collaborative Cohort Study

BACKGROUND : The ratio of the lengths of index and ring fingers (2D : 4D) is a marker of prenatal exposure to sex hormones, with low 2D : 4D being indicative of high prenatal androgen action. Recent studies have reported a strong association between 2D : 4D and risk of prostate cancer. METHODS : A total of 6258 men participating in the Melbourne Collaborative Cohort Study had 2D : 4D assessed. Of these men, we identified 686 incident prostate cancer cases. Hazard ratios (HRs) and confidence intervals (CIs) were estimated for a standard deviation increase in 2D : 4D. RESULTS : No association was observed between 2D : 4D and prostate cancer risk overall (HRs 1.00; 95% CIs, 0.92–1.08 for right, 0.93–1.08 for left). We observed a weak inverse association between 2D : 4D and risk of prostate cancer for age o 60, however 95% CIs included unity for all observed ages. CONCLUSION : Our results are not consistent with an association between 2D : 4D and overall prostate cancer risk, but we cannot exclude a weak inverse association between 2D : 4D and early onset prostate cancer risk

Colossal Aggregations of Giant Alien Freshwater Fish as a Potential Biogeochemical Hotspot

The ubiquity and fascinating nature of animal aggregations are widely recognised. We report here consistent and previously undocumented occurences of aggregations of a giant alien freshwater fish, the Wels catfish (Silurus glanis). Aggregative groups were on average composed of 25 (±10 SD, ranging from 15 to 44) adults with estimated average total biomass of 651 kg (386 – 1132) and biomass density of 23 kg m−2 (14 – 40). Aggregations always occurred within the same location. No foraging, reproductive or anti-predator behaviour were observed during the aggregations. A mass-balance model estimated that these colossal aggregations of an alien species can locally release, through excretion only, up to 70 mg P m−2 h−1 and 400 mg N m−2 h−1, potentially representing the highest biogeochemical hotspots reported in freshwater ecosystems and another unexpected ecological effect of alien species

Subjective Cognitive Complaints in Participants of the Healthy Brain Ageing Study (HeBA)

Subjective cognitive complaints (SCC) have the potential for earlier detection of Alzheimer’s disease and Parkinson’s disease. Currently, the results of the completed online survey in the frame of the HeBA study reveal that 23% of the Luxembourgish participants have SCC with the SCC group having a higher prevalence rate of depression

The impact of an exercise physiologist coordinated resistance exercise program on the physical function of people receiving hemodialysis: a stepped wedge randomised control study

Background:Exercise during hemodialysis treatments improves physical function, markers of cardiovascular disease and quality of life. However, exercise programs are not a part of standard therapy in the vast majority of hemodialysis clinics internationally. Hemodialysis unit-based accredited exercise physiologists may contribute to an increased intradialytic exercise uptake and improved physical function.Methods and design: This is a stepped wedge cluster randomised controlled trial design. A total of 180 participants will be recruited from 15 community satellite hemodialysis clinics in a large metropolitan Australian city. Each clinic will represent a cluster unit. The stepped wedge design will consist of three groups each containing five randomly allocated cluster units, allocated to either 12, 24 or 36 weeks of the intervention. The intervention will consist of an accredited exercise physiologist-coordinated program consisting of six lower body resistance exercises using resistance elastic bands and tubing. The resistance exercises will include leg abduction, plantar flexion, dorsi flexion, straight-leg/bent-knee raise, knee extension and knee flexion. The resistance training will incorporate the principle of progressive overload and completed in a seated position during the first hour of hemodialysis treatment. The primary outcome measure is objective physical function measured by the 30-second sit to stand test. Secondary outcome measures include the 8-foot timed-up-and-go test, the four square step test, quality of life, cost-utility analysis, uptake and involvement in community activity, self-reported falls, fall\u27s confidence, medication use, blood pressure and morbidity (hospital admissions). Discussion: The results of this study are expected to determine the efficacy of an accredited exercise physiologist supervised resistance training on the physical function of people receiving hemodialysis and the cost-utility of exercise physiologists in hemodialysis centres. This may contribute to intradialytic exercise as standard therapy using an exercise physiologist workforce model.</div

Impacts of an Invasive Snail (Tarebia granifera) on Nutrient Cycling in Tropical Streams: The Role of Riparian Deforestation in Trinidad, West Indies

Non-native species and habitat degradation are two major catalysts of environmental change and often occur simultaneously. In freshwater systems, degradation of adjacent terrestrial vegetation may facilitate introduced species by altering resource availability. Here we examine how the presence of intact riparian cover influences the impact of an invasive herbivorous snail, Tarebia granifera, on nitrogen (N) cycling in aquatic systems on the island of Trinidad. We quantified snail biomass, growth, and N excretion in locations where riparian vegetation was present or removed to determine how snail demographics and excretion were related to the condition of the riparian zone. In three Neotropical streams, we measured snail biomass and N excretion in open and closed canopy habitats to generate estimates of mass- and area-specific N excretion rates. Snail biomass was 2 to 8 times greater and areal N excretion rates ranged from 3 to 9 times greater in open canopy habitats. Snails foraging in open canopy habitat also had access to more abundant food resources and exhibited greater growth and mass-specific N excretion rates. Estimates of ecosystem N demand indicated that snail N excretion in fully closed, partially closed, and open canopy habitats supplied 2%, 11%, and 16% of integrated ecosystem N demand, respectively. We conclude that human-mediated riparian canopy loss can generate hotspots of snail biomass, growth, and N excretion along tropical stream networks, altering the impacts of an invasive snail on the biogeochemical cycling of N

Back to Basics: Pitting Edema and the Optimization of Hypertension Treatment in Incident Peritoneal Dialysis Patients (BRAZPD)

Systemic arterial hypertension is an important risk factor for cardiovascular disease that is frequently observed in populations with declining renal function. Initiation of renal replacement therapy at least partially decreases signs of fluid overload; however, high blood pressure levels persist in the majority of patients after dialysis initiation. Hypervolemia due to water retention predisposes peritoneal dialysis (PD) patients to hypertension and can clinically manifest in several forms, including peripheral edema. The approaches to detect edema, which include methods such as bioimpedance, inferior vena cava diameter and biomarkers, are not always available to physicians worldwide. For clinical examinations, the presence of pitting located in the lower extremities and/or over the sacrum to diagnose the presence of peripheral edema in their patients are frequently utulized. We evaluated the impact of edema on the control of blood pressure of incident PD patients during the first year of dialysis treatment. Patients were recruited from 114 Brazilian dialysis centers that were participating in the BRAZPD study for a total of 1089 incident patients. Peripheral edema was diagnosed by the presence of pitting after finger pressure was applied to the edematous area. Patients were divided into 2 groups: those with and without edema according to the monthly medical evaluation. Blood arterial pressure, body mass index, the number of antihypertensive drugs and comorbidities were analyzed. We observed an initial BP reduction in the first five months and a stabilization of blood pressure levels from five to twelve months. The edematous group exhibited higher blood pressure levels than the group without edema during the follow-up. The results strongly indicate that the presence of a simple and easily detectable clinical sign of peripheral edema is a very relevant tool that could be used to re-evaluate not only the patient's clinical hypertensive status but also the PD prescription and patient compliance