21 research outputs found
Low incidence of SARS-CoV-2, risk factors of mortality and the course of illness in the French national cohort of dialysis patients
Binary blazed reflection grating for UV/VIS/NIR/SWIR spectral range
We report on the design and fabrication of a reflection grating for hyperspectral applications operating in the range from 340 nm to 1040 nm wavelength. The blazed grating is based on an effective medium approach, where the desired functionality is realized using a binary surface relief structure. For each period, a gradient in size of the local grating features mimics an interface which adds a linear phase profile to the illuminating beam-thus introducing diffraction. The surface relief structure is composed of 2D structures-pillars with diameters from 200 nm to 350 nm to voids with diameters from 300nm to 120 nm. Overall, an entire number of ∼50 such features are arranged to establish an overall unit cell of the grating over a length of 30 μm. By purposeful design of size, shape and arrangement of the sub-wavelength features such gratings offer novel opportunities in tailoring the spectral response, i.e. particular broadband efficiency or the enhancement of the efficiency in specific sub-domains of the spectrum. We will present measured performance results of a grating covering a circular area of 80mm in diameter manufactured on a 4inch-wafer. Finally, we will give an outlook on how such structures can be applied to curved surfaces and even ultra-broadband operation
Extreme tolerance to cadmium and high resistance to copper, nickel and zinc in different Acidiphilium strains
Interaction of metals and microbes is widespread in nature,
and causes diverse changes in the earth's biosphere including formation and solubilization of minerals (Ehrlich 1981; Poole and Gadd 1989). Several metals are essential for growth,metabolism and differentiation of both prokaryotic and eukaryotic cells whereas the majority of them are not known to have any indispensable biological functions (Gadd 1992). The growth requirement for essential heavy metals is normally very low, and at a few mmol l-' or lower concentrations many of these heavy metals, both essential and non-essential, show
toxicity in a wide range of living systems (Fergusson 1990). However, natural tolerance to one or more of these metals occurs in many bacteria with sufficiently high frequencies even in the absence of frequent exposure to any obvious source of metals which may facilitate selection of resistant cells in a population (Silver and Misra 1988). As an example, we report here the extremely high natural tolerance to Cd, and resistance to Cu, Ni and Zn in some Acidiphilium strains which are Gram-negative, aerobic, mesophilic, acidophilic heterotrophs of acidic mine environment (Harrison 1981),and had been cultured in the laboratory for several years in simple medium devoid of any heavy metal
Determinants Encoding Resistance to Several Heavy Metals in Newly Isolated Copper-Resistant Bacteria
Indications for islet or pancreatic transplantation: Statement of the TREPID working group on behalf of the Societe francophone du diabete (SFD), Societe francaise d'endocrinologie (SFE), Societe francophone de transplantation (SFT) and Societe francaise de nephrologie - dialyse - transplantation (SFNDT)
While either pancreas or pancreatic islet transplantation can restore endogenous insulin secretion in patients with diabetes, no beta-cell replacement strategies are recommended in the literature. For this reason, the aim of this national expert panel statement is to provide information on the different kinds of beta-cell replacement, their benefit-risk ratios and indications for each type of transplantation, according to type of diabetes, its control and association with end-stage renal disease. Allotransplantation requires immunosuppression, a risk that should be weighed against the risks of poor glycaemic control, diabetic lability and severe hypoglycaemia, especially in cases of unawareness. Pancreas transplantation is associated with improvement in diabetic micro- and macro-angiopathy, but has the associated morbidity of major surgery. Islet transplantation is a minimally invasive radiological or mini-surgical procedure involving infusion of purified islets via the hepatic portal vein, but needs to be repeated two or three times to achieve insulin independence and long-term functionality. Simultaneous pancreas-kidney and pancreas after kidney transplantations should be proposed for kidney recipients with type 1 diabetes with no surgical, especially cardiovascular, contraindications. In cases of high surgical risk, islet after or simultaneously with kidney transplantation may be proposed. Pancreas, or more often islet, transplantation alone is appropriate for non-uraemic patients with labile diabetes. Various factors influencing the therapeutic strategy are also detailed in this report. (C) 2018 Published by Elsevier Masson SAS