SiC MOSFETs (silicon carbide metal-oxide semiconductor field-effect transistors) are replacing Si insulated gate bipolar transistors in many power conversion applications due to their superior ...performance. However, ruggedness and reliability of SiC MOSFETs are still big concern for their widespread applications in the market, especially in safety-critical applications. The objective of this study is to provide a comprehensive picture on the ruggedness and reliability of commercial SiC MOSFETs, discover their failure or degradation mechanism, and propose some possible mitigation methods through both literature survey and in-depth analysis. The ruggedness of SiC MOSFETs discussed here includes short-circuit (SC) ruggedness, avalanche ruggedness, and their failure mechanism. The reliability issues include gate oxide reliability, degradation under high-temperature bias stress, repetitive SC stress, avalanche stress, power cycling stress, body diode's surge current stress, and their degradation mechanism. Furthermore, this study discusses methods and solutions to improve their ruggedness and reliability.
Noroviruses (NoVs) and rotaviruses (RVs), the two most important causes of viral acute gastroenteritis, are found to recognise histo-blood group antigens (HBGAs) as receptors or ligands for ...attachment. Human HBGAs are highly polymorphic containing ABO, secretor and Lewis antigens. In addition, both NoVs and RVs are highly diverse in how they recognise these HBGAs. Structural analysis of the HBGA-binding interfaces of NoVs revealed a conserved central binding pocket (CBP) interacting with a common major binding saccharide (MaBS) of HBGAs and a variable surrounding region interacting with additional minor binding saccharides. The conserved CBP indicates a strong selection of NoVs by the host HBGAs, whereas the variable surrounding region explains the diverse recognition patterns of different HBGAs by NoVs and RVs as functional adaptations of the viruses to human HBGAs. Diverse recognition of HBGAs has also been found in bacterial pathogen Helicobacter pylori. Thus, exploratory research into whether such diverse recognitions also occur for other viral and bacterial pathogens that recognise HBGAs is warranted.
Primary lung cancer is one of the most common malignant tumors in China. Approximately 60% of lung cancer patients have distant metastasis at the initial diagnosis, so it is necessary to find new ...tumor markers for early diagnosis and individualized treatment. Tumor markers contribute to the early diagnosis of lung cancer and play important roles in early detection and treatment, as well as in precision medicine, efficacy monitoring, and prognosis prediction. The pathological diagnosis of lung cancer in small biopsy specimens determines whether there are tumor cells in the biopsy and tumor type. Because biopsy is traumatic and the compliance of patients with multiple biopsies is poor, liquid biopsy has become a hot research direction. Liquid biopsies are advantageous because they are nontraumatic, easy to obtain, reflect the overall state of the tumor, and allow for real-time monitoring. At present, liquid biopsies mainly include circulating tumor cells, circulating tumor DNA, exosomes, microRNA, circulating RNA, tumor platelets, and tumor endothelial cells. This review introduces the research progress and clinical application prospect of liquid biopsy technology for lung cancer.
This study presents an analytical investigation based on thermodynamic simulation aimed at achieving a holistic management of the phase assemblages of alkali-activated materials (AAMs) and gaining ...insights into the designing of precursors. Gibbs free energy minimization method was conducted on AAMs spanning the compositional envelopes at (metastable) thermodynamic equilibrium. The stability regions and quantities of simulated phases were identified in the SiO2-CaO-Al2O3 ternary contour diagrams, yielding the overall relationships between the chemical components of precursors, phase assemblages and pH in pore solution. The analytical results are in good agreement with the available experimental observations that the main precipitation regions of C-(N-)A-S-H appear at CaO/SiO2 = ~1.0 and relatively low Al regions while N-A-S-H phases generally dominate the Ca-deficient regions of the contour diagrams. Strätlingite mainly occurs at intermediate levels of Si, Al and Ca. Katoite and AFm phases form at Al2O3/CaO = ~3.0 under Si-deficient conditions. The findings also suggest the precipitation regions of a product may span a range of pH of aqueous solution, making it possible to simultaneously control pH and maintain the precipitation amount of the phase. The application of this work in designing precursors can achieve a more precise control of the phase assemblages for AAMs.
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•A holistic management of the solid phases of alkali-activated materials (AAMs) can be achieved by thermodynamic modelling.•Gibbs free energy minimization method was conducted on AAMs spanning the relevant compositional envelopes.•SiO2-CaO-Al2O3 ternary contour diagrams show the precipitation regions and quantities of each solid phase in AAMs.•The relationships between chemical components of precursors, hydrate assemblages and pH in pore solution were explored.•A more precise control of the phase assemblages can be achieved for AAMs based on this work.
Acute coronary syndromes (ACS) remain life-threatening disorders, which are associated with high morbidity and mortality. Dual antiplatelet therapy with aspirin and clopidogrel has been shown to ...reduce cardiovascular events in patients with ACS. However, there is substantial inter-individual variability in the response to clopidogrel treatment, in addition to prolonged recovery of platelet reactivity as a result of irreversible binding to P2Y12 receptors. This high inter-individual variability in treatment response has primarily been associated with genetic polymorphisms in the genes encoding for cytochrome (CYP) 2C19, which affect the pharmacokinetics of clopidogrel. While the US Food and Drug Administration has issued a boxed warning for CYP2C19 poor metabolizers because of potentially reduced efficacy in these patients, results from multivariate analyses suggest that additional factors, including age, sex, obesity, concurrent diseases and drug-drug interactions, may all contribute to the overall between-subject variability in treatment response. However, the extent to which each of these factors contributes to the overall variability, and how they are interrelated, is currently unclear. The objective of this review article is to provide a comprehensive update on the different factors that influence the pharmacokinetics and pharmacodynamics of clopidogrel and how they mechanistically contribute to inter-individual differences in the response to clopidogrel treatment.
The discovery of human histo-blood group antigens (HBGAs) as receptors or ligands of noroviruses (NoVs) raises a question about the potential role of host factors in the evolution and diversity of ...NoVs. Recent structural analysis of selected strains in the two major genogroups of human NoVs (GI and GII) demonstrated highly conserved HBGA binding interfaces within the two groups but not between them, indicating convergent evolution of GI and GII NoVs. GI and GII NoVs are probably introduced to humans from different non-human hosts with the HBGAs as a common niche. Each genogroup has further diverged into multiple sub-lineages (genotypes) through selections by the polymorphic HBGAs of the hosts. An elucidation of such pathogen–host interaction, including determination of the phenotypes of NoV–HBGAs interaction for each genotype, is important in understanding the epidemiology, classification and disease control and prevention of NoVs. A model of this multi-selection of NoVs by HBGAs is proposed.
Increasing amounts of data also showed that many bacterial and other viral pathogens rely on a carbohydrate receptor for infection 17. ...the requirement of a carbohydrate receptor could be a ...convergent factor in the evolution of these bacterial and viral pathogens.\n One possibility is that a functional co-receptor necessary for norovirus replication is missing in the cell culture, although failures of additional downstream steps of viral replication also may be the reason. In the laboratory a single residue mutation around receptor-binding interfaces can result in a change of HBGA binding patterns 8, 29. ...it would be of significance to explore whether the consensus receptor binding patterns can switch between two genotypes in nature and whether GII.4 noroviruses will continue to dominate or will be replaced by other genotypes in future epidemics.
A NiCl2-promoted 2 + 2 + 1 carboannulation of 1,7-enynes with internally oxidative cyclobutanone oximes to produce canyo-functionalized 4H-cyclopentacquinolin-4-ones is disclosed. Through C–C/N–O ...bond cleavage and C–H functionalization, the process enables one-carbon incorporation using cyclobutanone oximes to achieve 2 + 2 + 1 carboannulation of 1,7-enynes, which is highlighted by allowing the formation of four new bonds with high selectivity and broad substrate scope.
Intraoral scanning has benefits over conventional impression making, but whether scanning is sufficiently accurate for multiple implants is unclear.
The purpose of this in vitro study was to compare ...the trueness of digital scans acquired by using intraoral scanners from a small range to a complete arch with the conventional impression technique and to determine the influence of 2 different evaluation methods (best-fit algorithm versus absolute linear deviation) on the outcomes of accuracy assessment.
A mandibular model with 8 implants (A-H) around an edentulous arch was used as the master model. Open-format standard tessellation language (STL) data sets (1 reference file from a highly accurate dental laboratory scanner, 10 files from an intraoral scanner, and 10 files from digitized conventional impressions at room temperature) were imported to a metrology software program, and 5 groups of scanning ranges (AB, FGH, CDEF, BCDEFG, and ABCDEFGH) were identified simulating different clinical situations. Two evaluation methods—root mean square values calculated from the best-fit algorithm and average value of linear discrepancies from absolute linear deviation—were used to describe the trueness values. The impacts of different scanning or impression methods, ranges, and evaluation methods were tested by using a 3-way ANOVA. The effect of the scanning range on accuracy was further identified with 1-way ANOVA. The paired-sample t test was used to determine the differences of trueness values between the 2 methods in different groups.
The trueness values of the implant impressions were significantly affected by different scanning or impression methods (P<.001), evaluation methods (P<.001), and scanning ranges (P<.001) as independent variables. With use of the best-fit algorithm, deviations from the digital scans were significantly greater than those from the conventional impressions in cross-arch situations (groups CDEF, BCDEFG, and ABCDEFGH). With use of the absolute linear deviation method, statistically significant lower accuracy was found when larger areas were encountered (groups BCDEFG and ABCDEFGH). Use of the absolute linear deviation method resulted in a higher mean score of inaccuracy than that from the best-fit algorithm method in most situations.
Scanning or impression methods, ranges, and evaluation methods affected the dimensional accuracy (trueness) of scans or impressions with multiple implants. Digital scans had worse trueness values compared with those made with the conventional splinting open-tray technique when cross-arch implant impressions were acquired.
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