Terahertz Detection by Asymmetric Dual Grating Gate Bilayer Graphene FETs with Integrated Bowtie Antenna.

An asymmetric dual-grating gate bilayer graphene-based field effect transistor (ADGG-GFET) with an integrated bowtie antenna was fabricated and its response as a Terahertz (THz) detector was experimentally investigated. The device was cooled down to 4.5 K, and excited at different frequencies (0.15, 0.3 and 0.6 THz) using a THz solid-state source. The integration of the bowtie antenna allowed to obtain a substantial increase in the photocurrent response (up to 8 nA) of the device at the three studied frequencies as compared to similar transistors lacking the integrated antenna (1 nA). The photocurrent increase was observed for all the studied values of the bias voltage applied to both the top and back gates. Besides the action of the antenna that helps the coupling of THz radiation to the transistor channel, the observed enhancement by nearly one order of magnitude of the photoresponse is also related to the modulation of the hole and electron concentration profiles inside the transistor channel by the bias voltages imposed to the top and back gates. The creation of local n and p regions leads to the formation of homojuctions (np, pn or pp+) along the channel that strongly affects the overall photoresponse of the detector. Additionally, the bias of both back and top gates could induce an opening of the gap of the bilayer graphene channel that would also contribute to the photocurrent.

[Mortality and use of healthcare resources in elderly patients in Seville: Differences between institutionalised patients and those included in a home care program]. / Mortalidad y uso de recursos sanitarios en pacientes ancianos en la provincia de Sevilla: diferencias entre pacientes institucionalizados y en atención domiciliaria.

OBJECTIVES: Society is ageing, and as a consequence, the population with increased frailty and comorbidity is growing. The aim is to analyse the mortality and its potential factors, as well as the use of healthcare resources in elderly patients, and to study the differences between institutionalised patients and those included in a home care program. MATERIALS AND METHODS: An observational, longitudinal and prospective cohort study was conducted in Seville during 2016. The study subjects consisted of 1314 elderly patients (1061 institutionalised and 253 at home). The variables studied included mortality and its potential factors, and the use of healthcare resources. RESULTS: No differences were found in mortality between institutionalised and home care program patients (RR=1.044; 95% CI; 0.74-1.46; P=.799). The leading cause of death was circulatory diseases followed by respiratory diseases. Among the factors explaining the mortality, it is important to highlight: age, dependency and admissions in the hospital or the emergency department. The patient's functional independence is associated with a higher survival rate. Differences were found between both groups in the number of calls to the Critical Care and Emergency Services (P=.022) or the primary care doctor (P<.001) and in the hospital admissions (P<.001), the first 2differences being higher in home care program patients, and the latter in institutionalised patients. CONCLUSIONS: There are no differences between groups either in the mortality or in the cause of death. Age, functional dependency and admissions in the hospital are factors which explain the mortality. The use of healthcare resources is higher in patients at home.

Comparison of the viscoelastic properties of human abdominal and breast adipose tissue and its incidence on breast reconstruction surgery. A pilot study.

BACKGROUND: Breast cancer is the leading malignant tumor in women in the world. Reconstruction after mastectomy plays a key role in the physical and psychological recuperation, being the abdominal skin and adipose tissue the best current option for the DIEP surgery. The aim of the surgery is to obtain a reconstructed breast which looks and behaves naturally. Therefore, it would be useful to characterize the mechanical behaviour of the adipose tissue in the abdomen and breast to compare their mechanical properties, also investigating possible regional differences. METHODS: Experimental tests have been carried out in breast and abdominal adipose tissue samples, obtaining their viscoelastic properties. The specimens have been subjected to uniaxial compression relaxation tests and a mechanical behaviour model has been fitted to the experimental curves. Afterwards, statistical analyses have been used to detect differences between different individuals' abdominal fat tissue and finally between different areas of the same individual's breast and abdominal adipose tissue. FINDINGS: Several conclusions could be extracted from the results: 1) inter-individual differences may exist in the abdominal adipose tissue; 2) the breast fat could be regarded as a unique tissue from the mechanical point of view; 3) significant differences were detected between the superficial breast and all the locations of the abdomen, except for the superficial lateral one and 4) the mechanical properties of the abdominal adipose tissue seem to change with the depth. These conclusions can be of great value for DIEP surgeries and other surgeries in which the adipose tissue is involved.