An electrically driven solid state modulator

Simulation results for the design and fabrication of an electrically driven solid state modulator are presented. The design criteria has identified various trade-offs in the manufacturing of an electrically driven modulator using a p-i-n diode to be made from high purity Ge. The issues relating to the doping, layer thickness and contact material for the diode fabrication are discussed. A compromise between the high 'ON' state transmission and uniformity is required to achieve the optimum performance from the device. Using FEMLAB and ATLAS a p-i-n diode with different apertures has been simulated which clearly show the effects of non-uniformity and the requirement of a mesh-type electrode for a uniform absorption across the large device apertures

Hospital admission with non-alcoholic fatty liver disease is associated with increased all-cause mortality independent of cardiovascular risk factors

Non-alcoholic fatty liver disease (NAFLD) is common and strongly associated with the metabolic syndrome. Though NAFLD may progress to end-stage liver disease, the top cause of mortality in NAFLD is cardiovascular disease (CVD). Most of the data on liver-related mortality in NAFLD derives from specialist liver centres. It is not clear if the higher reported mortality rates in individuals with non-cirrhotic NAFLD are entirely accounted for by complications of atherosclerosis and diabetes. Therefore, we aimed to describe the CVD burden and mortality in NAFLD when adjusting for metabolic risk factors using a ‘real world’ cohort. We performed a retrospective study of patients followed-up after an admission to non-specialist hospitals with a NAFLD-spectrum diagnosis. Non-cirrhotic NAFLD and NAFLD-cirrhosis patients were defined by ICD-10 codes. Cases were age-/sex-matched with non-NAFLD hospitalised patients. All-cause mortality over 14-years follow-up after discharge was compared between groups using Cox proportional hazard models adjusted for demographics, CVD, and metabolic syndrome components. We identified 1,802 patients with NAFLD-diagnoses: 1,091 with non-cirrhotic NAFLD and 711 with NAFLD-cirrhosis, matched to 24,737 controls. There was an increasing burden of CVD with progression of NAFLD: for congestive heart failure 3.5% control, 4.2% non-cirrhotic NAFLD, 6.6% NAFLD-cirrhosis; and for atrial fibrillation 4.7% control, 5.9% non-cirrhotic NAFLD, 12.1% NAFLD-cirrhosis. Over 14-years follow-up, crude mortality rates were 14.7% control, 13.7% non-cirrhotic NAFLD, and 40.5% NAFLD-cirrhosis. However, after adjusting for demographics, non-cirrhotic NAFLD (HR 1.3 (95% CI 1.1–1.5)) as well as NAFLD-cirrhosis (HR 3.7 (95% CI 3.0–4.5)) patients had higher mortality compared to controls. These differences remained after adjusting for CVD and metabolic syndrome components: non-cirrhotic NAFLD (HR 1.2 (95% CI 1.0–1.4)) and NAFLD-cirrhosis (HR 3.4 (95% CI 2.8–4.2)). In conclusion, from a large non-specialist registry of hospitalised patients, those with non-cirrhotic NAFLD had increased overall mortality compared to controls even after adjusting for CVD

Diffusion of boron and silicon in germanium

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Diffusion of boron in germanium

Results are presented of implantation and diffusion study of boron (B) in germanium (Ge). B implantation was carried out in Ge with different energies and to different doses. High-resolution secondary ion mass spectroscopy (SIMS) was used to obtain concentration profiles after furnace annealing. The as-implanted profiles show a long tail possibly due to enhanced diffusion. A limited diffusion has been observed after furnace annealing. Using T-SUPREM, diffusivity value of 1.5 (±0.3) X 10-16 cm2/s at 850°C has been extracted. This value is two orders of magnitude lower than previously reported values. The results question the change in diffusion mechanism of B diffusion in SiGe alloys from low Ge leveIs to high Ge leveIs

An electrically driven mid-infrared solid state modulator

Detailed device fabrication and operation modelling has been undertaken for a mid-infrared, 8-14µm band modulator based on a high purity Germanium p-i-n diode. The results show the crucial importance of optimising material properties and dopant concentrations and profiles for optimum device performance. Preliminary experimental results will be presented

Length of hospital stay is shorter in South Asian patients with acute pulmonary embolism.

Pulmonary embolism (PE) is a common diagnosis in UK hospitals and confers a significant hospital stay (LOS). There is very little evidence concerning ethnic variations on LOS in patients with PE. We sought to investigate ethnic variations in LOS in a large sample of 3440 patients with PE from 2000 to 2013 across seven hospitals in the north west of UK. We found that South Asian patients have significantly lower LOS compared with Caucasian patients. We discuss possible reasons for, and implications of, this finding