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Pulsed laser annealing (PLA, 527 nm, 200-ns pulse, Nd:YLF laser) was used to activate phosphorous-implanted C-face SiC and repair lattice damage. The electrical and structural characteristics of the implanted material surface were analyzed before and after PLA. Electrical activation was confirmed by the circular transfer length method. The implanted layer was characterized by x-ray diffraction. The change in strain can be attributed to the recovery of lattice damage induced by laser annealing. Transmission electron microscopy (TEM) showed that amorphous 4H-SiC structure was transformed to crystalline structure by PLA. The defect evolution was investigated using TEM images and diffraction patterns.

In this work, a method was investigated to extract trench sidewall and trench bottom capacitances of a SiC trench metal–oxide–semiconductor (MOS) structure. Five groups of 4H-SiC trench MOS capacitors were designed and fabricated, with various trench bottom widths and trench mesa widths. High-frequency capacitance–voltage (HFCV) measurements at 100 kHz were performed on these trench MOS structures. The relationships between trench MOS capacitances and the widths of trench bottom as well as trench mesa were studied. As expected, under the same bias voltage, the measured trench MOS capacitances were proportional to the trench bottom widths and trench mesa widths. Based on this, the contributions of capacitances from the bottom, mesa, and sidewall of trench in trench MOS structure were studied systematically. The oxide thicknesses at different locations in trench were extracted. The ${C}$ – ${V}$ characteristics of the MOS capacitors from trench sidewall and trench bottom could also be deduced, from which the flat-band voltage and the charges in oxide of these two MOS capacitors could be subsequently calculated and analyzed. This method provides a convenient and precise technology to monitor process control in SiC trench MOSFETs manufacturing.

In this study, we aimed to investigate the associations between Sirt6, macrophages and diabetic nephropathy (DN). Immunohistochemical, western blot and RT-qPCR analyses were performed to detect the expression levels of Sirt6, the markers of podocytes and monocytes and related inflammatory factors in the tissues of rats with streptozocin-induced DN. A series of cell experiments in isolated culture or the co-culture of macrophages and podocytes were conducted to examine the effects of the overexpression of Sirt6 on macrophage transformation, podocyte apoptosis and associated genes, and analyses were performed using RT-qPCR, flow cytometry and western blot analysis, where appropriate. In the rat model of DN, injured podocytes were represented by the decreased protein expression levels of Nephrin and Sirt6, and by an increased Desmin expression. Additionally, the M1 phenotype transformation of macrophages was evidenced by the increased expression levels of CD86, tumor necrosis factor (TNF)-α and inducible nitric oxide synthase (iNOS), and by the decreased expression levels of CD206, Sirt6, interleukin (IL)-4 and IL-10. In vitro assays of macrophages and podocytes demonstrated that glucose promoted macrophage M1 transformation and podocyte apoptosis in a dose-dependent manner and attenuated Sirt6 expression. Macrophages transformed into the M2 phenotype following the overexpression of Sirt6 by the successful transfection of macrophages with a Sirt6 overexpression plasmid. Sirt6 was also overexpressed in podocytes. In a Transwell co-culture system, the overexpression of Sirt6 in macrophages (but not the overexpression of Sirt6 in podocytes) protected the podocytes from high-glucose-induced injury. However, the apoptosis of the podocytes overexpressing Sirt6 (induced by transfection with a Sirt6 overexpression plasmid) still increased when these podocytes were co-cultured with macrophages in high-glucose medium. These protective effects were evidenced by the inhibition of apoptosis, the upregulation of the expression levels of Bcl-2 and CD206, as well as by the decreased expression levels of Bax and CD86. On the whole, the findings of this study suggest that Sirt6 protects podocytes against injury in a mimicked diabetic kidney microenvironment by activating M2 macrophages, indicating that Sirt6 can act as an immune response regulatory factor in DN-associated renal inflammatory injury.

Carboxymethyl cellulose (CMC) and glycerol were added by immersing neutralized collagen fiber paste into CMC/glycerol aqueous solutions with different mass ratios, forming composite films. CMC decreased the glycerol adsorption by 49.5%. The presence of CMC formed rougher film surface and more compact internal structure. Glycerol increased the distances between collagen molecules and decreased the relative triple helix contents. The tensile strength and Young's modulus of film in dry condition maximum respectively increased by 125% and 277% with the immersion in CMC (1.5%)/glycerol (4%) solution, compared to the sample immersed into pure glycerol solution, but mechanical properties decreased at high glycerol content. Besides, lower wet mechanical strength was observed as the addition of CMC, corresponding to the higher water swelling ratio of film. CMC also improved the shrinkage stability under boiling and the thermostability of film at a fixed glycerol level, but higher glycerol content caused the decrease of denaturation temperature of film.

The solubility (WS) of gelatin films in water limits its packaging application of high moisture content foods. Crosslinking by transglutaminase (TGase) and addition of zein were reported to reduce WS of gelatin films, but it is a challenge to incorporate TGase in a system of two immiscible materials of gelatin (water soluble) and zein (ethanol soluble) as well as in the environment of low pH when aqueous acetic acid is used to as a commonly used solvent. Zein in ethanol was added to gelatin in aqueous solution at a controlled rate. The final concentration of ethanol was 8.5% and this film forming solution provided the optimal pH for TGase while keeping both proteins soluble. Crosslinking was confirmed by the formation of higher molecular weight protein in SDS-PAGE. The optimum crosslinking degree (65%) was with 95% gelatin/5% zein. Tensile strength of the TGase treated films was improved from 5 to 36 times and proportional to the gelatin-zein crosslinking degree, while water solubility (~98% insoluble in water) depended on the type of crosslinking. The presence of zein improved the thermal properties (melting temperature increased up to 19 °C) but reduced the transparency as compare to pure gelatin film. TGase modified gelatin/zein composite films with improved water insolubility, water vaper permeability and mechanical properties are potential candidates for high moisture food packaging application.

Superjunction technology is believed to reach the optimal specific on-resistance and breakdown voltage trade-off. It has become a mainstream technology in silicon high-voltage metal oxide semiconductor field effect transistor devices. Numerous efforts have been conducted to employ the same concept in silicon carbide devices. These works are summarized here.

To survey antibiotic resistance of clinical isolates of Acinetobacter baumannii in Changsha and to investigate molecular epidemiological characteristics of carbapenem-resistant Acinetobacter baumannii.A total of 205 non-duplicated, clinical isolates of Acinetabacter baumannii from 10 general hospitals in Changsha were collected from March 2010 to December 2010. The K-B disk diffusion method was applied for the drug-susceptibility test; a modified, double-disk synergy test was used to detect metallo-β-lactamase (MBL), and a modified Hodge test was used for the screening of carbapenemase. PCR was used to amplify carbapenemase genes (including OXA-23, OXA-24, OXA-51, IMP-1, and VIM-2) and the positive products were sequenced. Enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) was used for DNA typing and test of homology.Of the 18 antibiotics tested, 14 had a high rate of resistance (50% of the isolates tested), with piperacillin the highest (80.5% of strains), and cefoperazone/sulbactam the lowest (2.5%). In total, 115 carbapenem-resistant Acinetobacter baumannii strains were confirmed, but their MBL phenotype and genes were all negative. Seventy-one positive strains were detected by the modified Hodge test, among which 64 strains were OXA-23-positive. All the 115 strains were positive for the amplification of the OXA-51 gene, and no strain was found which carried OXA-24 or OXA-58 gene. Seven genomic types were included in the 115 Acinetobacter baumannii. The major prevalence types were Type B ( 72 strains) and Type A (19 strains).Multiple drug resistance of clinically isolated Acinetobacter baumannii is a serious problem in Changsha. Production of OXA-23 and OXA-51 carbapenemases is an important mechanism of resistance to carbapenem antibiotics, and there is prevalence of the same clones in these carbapenem-resistant strains.