The occurrence of Ebola virus (EBOV) in West Africa during 2013–2015 is unprecedented. Early reports suggested that in this outbreak EBOV is mutating twice as fast as previously observed, which ...indicates the potential for changes in transmissibility and virulence and could render current molecular diagnostics and countermeasures ineffective. We have determined additional full-length sequences from two clusters of imported EBOV infections into Mali, and we show that the nucleotide substitution rate (9.6 × 10–4 substitutions per site per year) is consistent with rates observed in Central African outbreaks. In addition, overall variation among all genotypes observed remains low. Thus, our data indicate that EBOV is not undergoing rapid evolution in humans during the current outbreak. This finding has important implications for outbreak response and public health decisions and should alleviate several previously raised concerns.
The storage of hydrogen in underground reservoirs comprises a potential solution for balancing the fluctuating energy production from wind and solar power plants. In this concept, electrolysers are ...used to transform excessively produced electrical energy into chemical energy in the form of hydrogen. The resulting large volumes of hydrogen are temporarily stored in subsurface formations purely or in mixture with other gases. In times of high energy demand, the chemical energy is transformed back into electricity by fuel cells or engine generators. Key aspects in the development period and the subsequent cyclic operations of such a storage are the hydrodynamic behavior of hydrogen and its interaction with residual fluids in the reservoir. Mathematically, the behavior can be described by a compositional two-phase flow model with water and gas as phases and all relevant chemical species as components (H
2
, H
2
O, CH
4
, CO
2
, N
2
, H
2
S, etc.). The spatial variation of the gas phase composition between injected and initial gas leads to density and viscosity contrasts which influence the displacement process. The mixing of gases with different compositions is governed by molecular diffusion or mechanical dispersion dependent on the flow velocity. In the present paper, a numerical case study in a depleted gas reservoir was performed. The storage was charged with hydrogen for 5 years. Subsequently, 5 years of seasonal cyclic operation were simulated to predict injection and production rates, pressure response and composition of the produced gas stream .
Recently, n-type Si solar cells featuring tunnel-oxide-passivated contacts have achieved remarkable conversion efficiencies of up to 24.9%. Different approaches concerning the doped Si layer, which ...can be amorphous, polycrystalline, or partially crystalline, have been presented over the past few years. In this paper, carrier-selective electron contacts featuring tunnel oxides are investigated by means of numerical device simulation. The influence of 1) the Si layer material, 2) the Si layer doping, 3) an additional in-diffusion in the absorber, 4) the surface recombination velocity at the oxide interface, and 5) the oxide thickness and the tunneling mass are investigated by means of an open-circuit voltage analysis, as well as a fill factor (FF) analysis. With the fundamental understanding generated in this paper, we are able to explain the excellent device performance of solar cells with carrier-selective contacts featuring tunnel oxides.
Advances in Laparoscopic Colorectal Surgery Parker, James Michael; Feldmann, Timothy F; Cologne, Kyle G
The Surgical clinics of North America,
06/2017, Letnik:
97, Številka:
3
Journal Article
Recenzirano
Laparoscopic colorectal surgery has now become widely adopted for the treatment of colorectal neoplasia, with steady increases in utilization over the past 15 years. Common minimally invasive ...techniques include multiport laparoscopy, single-incision laparoscopy, and hand-assisted laparoscopy, with the choice of technique depending on several patient and surgeon factors. Laparoscopic colorectal surgery involves a robust learning curve, and fellowship training often lays the foundation for a high-volume laparoscopic practice. This article provides a summary of the various techniques for laparoscopic colorectal surgery, including operative steps, the approach to difficult patients, and the learning curve for proficiency.
A central quantity to assess the high quality of monocrystalline silicon (on scales beyond mere purity) is the minority charge carrier lifetime. We demonstrate that the lifetime in high purity float ...zone material can be improved beyond existing observations, thanks to a deeper understanding of grown-in defects and how they can be permanently annihilated. In a first step we investigate the influence of several process sequences on the lifetime by applying a low temperature superacid passivation treatment. We find that a pre-treatment consisting of an oxidation at 1050 °C followed by a POCl3 diffusion at 900 °C can improve the lifetime by deactivating or eliminating grown-in defects. Then, pre-treated wafers of different float zone materials are passivated with three state-of-the-art layer stacks. Very high effective lifetime values are measured, thereby demonstrating the high quality of the surface passivation schemes and the pre-treated silicon wafers. The measured effective lifetimes exceed previous records, and we report an effective lifetime of 225 ms measured on a 200 µm thick 100 Ω cm n-type silicon wafer symmetrically passivated with a layer stack of a thin thermally grown oxide and a polycrystalline layer (the TOPCon layer stack).
•Effective lifetimes in FZ silicon wafers are often limited by grown in defects. We investigate ways to mitigate them.•Combination of oxidation @1050 °C and POCl3 diffusion @900 °C results in very high bulk lifetimes in FZ silicon wafers.•Samples after bulk stabilisation are passivated with Al2O3, ONO stack & TOPCon stack.•Lifetimes of ONO samples are improved with additional corona charge.•Extremely high effective lifetimes are measured. 1 Ω cm p-/ n-type: 5.3 ms / 15 ms; 100 Ω cm p-/ n-type: 95 ms / 225 ms.
The ribonucleoprotein (RNP) complex of Ebola virus (EBOV) is known to be a multiprotein/RNA structure, however, knowledge is rather limited regarding the actual protein–protein interactions involved ...in its formation. Here we show that singularly expressed VP35 and VP30 are present throughout the cytoplasm, while NP forms prominent cytoplasmic inclusions and L forms smaller perinuclear inclusions. We could demonstrate the existence of NP–VP35, NP–VP30 and VP35–L interactions, similar to those described for Marburg virus (MARV) based on the redistribution of protein partners into NP and L inclusion bodies. Significantly, a novel VP30–L interaction was also identified and found to form as part of an NP–VP30–L bridge structure, similar to that formed by VP35. The identification of these interactions allows a preliminary model of the EBOV RNP complex structure to be proposed, and may provide insight into filovirus transcriptional regulation.
Besides passivation of the c-Si absorber, provided mainly by the undoped buffer layer, the net doping of the silicon thin films plays a major role in the performance of silicon-based heterojunction ...(SHJ) solar cells. However, junction engineering is complex as high net doping often interferes with the interface passivation and the optical properties of the silicon thin films. We show that injection-level-dependent open-circuit voltage (Suns- Voc) measurements are a simple and valuable method for the characterization and optimization of the doped amorphous silicon (a-Si:H) layers. It is shown by experiment and device simulations that at high illumination intensities the Suns- Voc characteristic exhibits a strong signature of defect recombination within the a-Si:H, which is determined by the a-Si:H doping and the interfacial transparent conducting oxide (TCO) properties. This fact is exploited for a qualitative interpretation of the interplay between a-Si:H and the interfacial TCO properties. As a clear correlation between the Suns- Voc characteristic and the maximum power point conditions of the devices exists, fill factor (FF) losses attributed to the doped a-Si:H and the interfacial TCO properties can 1) be easily predicted in the early stage of device optimization on simple test structures, or 2) these FF losses can be identified and distinguished from other FF losses in the final device.
Ebola viruses are zoonotic pathogens with the potential of causing severe viral hemorrhagic fever in humans and nonhuman primates. Bats have been identified as a reservoir for Ebola viruses but it ...remains unclear if transmission to an end host involves intermediate hosts. Recently, one of the Ebola species has been found in Philippine pigs raising concerns regarding animal health and food safety. Diagnostics have so far focused on human application, but enhanced pig surveillance and diagnostics, particularly in Asia, for Ebola virus infections seem to be needed to establish reasonable guidelines for public and animal health and food safety. Livestock vaccination against Ebola seems currently not justified but proper preparedness may include experimental vaccine approaches.
The occurrence and fate of residues from the therapeutic use of the non-steroidal anti-inflammatory drug metamizole have been studied in investigations of sewage effluents from a military hospital, ...municipal sewers and a sewage treatment plant (STP) in Berlin, Germany. The loads of the metabolites aminoantipyrin (AA), 4-acetylaminoantipyrin (AAA) and 4-formyl-aminoantipyrin (FAA), rapidly formed after the application of metamizole, were predicted from pharmacokinetic data and based on the evaluation of extensive data sets of on the administration in hospitals and private households. In parallel, the actual concentrations were measured within three field trials.
For the military hospital, the estimated average annual discharges of AA/AAA and FAA were 10.5 and 3.2
kg, respectively. For the STP, annual loads of 333 and 133 kg were determined for AA/AAA and FAA, respectively. During sewage treatment, an average decrease of 26% of the loads was measured for AA/AAA whereas no changes were observed for FAA. Generally, the prediction of the loads resulted in an overestimation of the residue levels compared to those measured in the respective sewers. Thus, modeling of predicted loads or concentrations alone will not be sufficient for a realistic assessment.
Concerns for human or other mammals’ health are not expected from the occurrence of metamizole residues in the aquatic system measured at concentrations up to 7
μg
l
−1 in STP effluents. However, a rest of uncertainty remains as it was not possible to derive a no observed effect level for the induction of rare but potentially fatal toxicological side effects reported for metamizole.
The c-myb proto-oncogene encodes a transcription factor that is highly expressed in the progenitor cells of the hematopoietic system, where it regulates the expression of genes important for lineage ...determination, cell proliferation and differentiation. There is strong evidence that deregulation of c-myb expression is involved in the development of human tumors, particularly of certain types of leukemia, and breast and colon cancer. The c-Myb protein is therefore an interesting therapeutic target. Here, we have investigated the potential of natural sesquiterpene lactones (STLs), a class of compounds that are active constituents of a variety of medicinal plants, to suppress Myb-dependent gene expression. We have developed a test system that allows screening of compounds for their ability to interfere with the activation of Myb target genes. Using this assay system, we have identified the STL mexicanin-I as the first cell-permeable, low-molecular-weight inhibitor of Myb-induced gene expression.
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