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For the deficiencies of AgSnO2 contact material, the first-principle based on the density functional theory was used to study the electrical and mechanical properties of pure SnO2, Ni doped SnO2, Mo doped SnO2 and Ni-Mo co-doped SnO2 . The parameters of every model, including the formation energy, energy band structure, density of state, elastic constant were obtained by the CASTEP module of Materials Studio software. According to the formation energy, the doped models can exist stably. After doped, every mode's valence band top and conduction band bottom are at the same point so the doped models are still the direct bandgap semiconductor materials. The Ni-doped SnO2 is P-type doped semiconductor material, and the Modoped is the N-type as well as Ni-Mo co-doped SnO2 . With the introduction of the new impurity levels, the band gap is narrowed. Compared with the band structure of pure SnO2, the doped models have a rising valence band and a declining conduction band so they have a smaller band gap, and the Ni-Mo co-doped SnO2 has the smallest band gap. With the reduced energy for carrier transition, the electrical performance of SnO2 is improved largely. What's more, the shear modulus, volume modulus and hardness are obtained by the elastic constants. The hardness of Ni-Mo co-doped SnO2 decreases significantly and its toughness is enhanced, which is conductive to the subsequent processing and forming of AgSnO2 contact material. The Ni- Mo co-doped SnO2 has the smallest universal elastic anisotropy index so the contact materials are not easy to form cracks. According to the calculation results, it turns out that the co-doping of Ni-Mo can improve the electrical and mechanical properties of SnO2 better than single element doping, which provides theoretical guidance for the further development and research of contact materials. [ABSTRACT FROM AUTHOR]

For the deficiencies of AgSnO2 contact material, the first-principle based on the density functional theory was used to study the electrical and mechanical properties of pure SnO2, Ni doped SnO2, Mo doped SnO2 and Ni-Mo co-doped SnO2 . The parameters of every model, including the formation energy, energy band structure, density of state, elastic constant were obtained by the CASTEP module of Materials Studio software. According to the formation energy, the doped models can exist stably. After doped, every mode's valence band top and conduction band bottom are at the same point so the doped models are still the direct bandgap semiconductor materials. The Ni-doped SnO2 is P-type doped semiconductor material, and the Modoped is the N-type as well as Ni-Mo co-doped SnO2 . With the introduction of the new impurity levels, the band gap is narrowed. Compared with the band structure of pure SnO2, the doped models have a rising valence band and a declining conduction band so they have a smaller band gap, and the Ni-Mo co-doped SnO2 has the smallest band gap. With the reduced energy for carrier transition, the electrical performance of SnO2 is improved largely. What's more, the shear modulus, volume modulus and hardness are obtained by the elastic constants. The hardness of Ni-Mo co-doped SnO2 decreases significantly and its toughness is enhanced, which is conductive to the subsequent processing and forming of AgSnO2 contact material. The Ni- Mo co-doped SnO2 has the smallest universal elastic anisotropy index so the contact materials are not easy to form cracks. According to the calculation results, it turns out that the co-doping of Ni-Mo can improve the electrical and mechanical properties of SnO2 better than single element doping, which provides theoretical guidance for the further development and research of contact materials. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effect of calmodulin (CaM) and its mutants on binding to voltage-gated Na channel isoleucine-glutamine domain (Na V 1.2 IQ)., Methods: The cDNA of Na V 1.2 IQ was constructed by PCR technique, CaM mutants CaM 12 , CaM 34 and CaM 1234 were constructed with Quickchange TM site-directed mutagenesis kit (QIAGEN). The binding of Na V 1.2 IQ to CaM and CaM mutants under calcium and calcium free conditions were detected by pull-down assay., Results: Na V 1.2 IQ and CaM were bound to each other at different calcium concentrations, while GST alone did not bind to CaM. The binding affinity of CaM and Na V 1.2 IQ at [Ca 2+ ]-free was greater than that at 100 nmol/L [Ca 2+ ] ( P < 0.05). In the absence of calcium, the binding amount of CaM wild-type to Na V 1.2 IQ was greater than that of its mutant, and the binding affinity of CaM 1234 to Na V 1.2 IQ was the weakest among the three mutants ( P < 0.05)., Conclusions: The binding ability of CaM and CaM mutants to Na V 1.2 IQ is Ca 2+ -dependent. This study has revealed a new mechanism of Na V 1.2 regulated by CaM, which would be useful for the study of ion channel related diseases.

Objective: To explore the mechanism of hypertonic salt solution (HS) alleviates lung injury of rats at the early stage of severe scald., Methods: Thirty-two female Sprague-Dawley (SD) rats were randomly assigned to sham group, lactated Ringer solution (LR) group, HS200 group (200 mmol/L HS group, 1 L 200 mmol/L HS contained 955 mL LR and 45 mL 10% NaCl) and HS400 group (400 mmol/L HS group, 1 L 400 mmol/L HS contained 846 mL LR and 154 mL 10% NaCl), with 8 rats in each group. A 30% total body surface area (TBSA) III degree scalded model was reproduced by scalded on the back with 98 centigrade boiling water for 12 seconds, whereas those in the sham group were exposed to 37 centigrade water without liquid resuscitation. Rats in the three drug intervention groups were resuscitated with LR, 200 mmol/L HS and 400 mmol/L HS by caudal vein according to the Parkland formula, respectively. All rats were sacrificed at 8 hours after scald injury to harvest abdominal aorta blood and lung tissues. Interleukins (IL-6, IL-10 and IL-17) in serum were determined by enzyme-linked immunosorbent assay (ELISA). Samples from the lung tissue were used to measure malondialdehyde (MDA) and superoxide dismutase (SOD) levels by ultraviolet spectrophotometer. Expressions of p38 mitogen-activated protein kinase (p38MAPK) and extracellular regulated protein kinase 1/2 (ERK1/2) in the lung were determined by Western Blot. The lung tissue was stained with hematoxylin and eosin (HE), and the pathological changes were observed with a light microscope., Results: Compared with the sham group, the lung tissues in the LR group were damage obviously, which accompanied with more inflammatory cell infiltration, cell edema and pulmonary septum thickening, and the levels of IL-6, IL-10, IL-17 in serum and MDA content, the phosphorylation of p38MAPK and ERK1/2 in lung tissues were increased whereas the activity of SOD was decreased. Compared with the LR group, the lung injury was significantly alleviated, the levels of IL-6, IL-17 in serum and MDA content and the phosphorylation of p38MAPK and ERK1/2 were decreased, and the levels of IL-10 and SOD were increased in both HS groups with a dose-dependent manner. There were significant difference in above parameters between HS400 group and LR group [serum IL-6 (ng/L): 3.76±0.12 vs. 6.72±0.90, serum IL-10 (ng/L): 33.76±3.71 vs. 16.77±3.19, serum IL-17 (ng/L): 103.52±2.78 vs. 124.96±4.96, lung MDA (nmol/mg): 5.59±0.24 vs. 7.09±0.39, lung SOD (U/mg): 226.7±3.9 vs. 172.7±3.4, lung phosphorylation of p38MAPK (p-p38MAPK)/p38MAPK: 0.15±0.09 vs. 0.35±0.19, lung phosphorylation of ERK1/2 (p-ERK1/2)/ERK1/2: 0.27±0.01 vs. 0.70±0.01, all P < 0.01]., Conclusions: HS protected against lung injury induced by severe burns in rats with a dose-dependent manner, and it was better than LR, and its possible mechanism was related with reducing the expression of p38MAPK and ERK1/2 pathway in lung tissue, increasing the level of anti-inflammatory cytokines and decreasing the release of pro-inflammatory cytokines, thus inhibiting excessive inflammation and oxidative stress injury in lung.

Objective: To investigate the clinical effect of Meek technique skin graft in treating exceptionally large area burns., Methods: The clinical data were retrospectively analysed from 10 cases of exceptionally large area burns treated with Meek technique skin graft from April 2009 to February 2010 (Meek group), and were compared with those from 10 cases of exceptionally large area burns treated with the particle skin with large sheet of skin allograft transplantation from January 2002 to December 2006 (particle skin group). In Meek group, there were 8 males and 2 females with an average age of 34.5 years (range, 5-55 years), including 6 cases of flame burns, 2 cases of hot liquid burns, 1 case of electrical burn, and 1 case of high-temperature dust burn. The burn area was 82.6% +/- 3.1% of total body surface area (TBSA). The most were deep II degree to III degree burns. The time from burn to hospitalization was (3.5 +/- 1.3) hours. In particle skin group, there were 8 males and 2 females with an average age of 36.8 years (range, 18-62 years), including 5 cases of flame burns, 2 cases of hot liquid burns, and 3 cases of gunpowder explosion injury. The burn area was 84.1% +/- 7.4% of TBSA. The most were deep II degree to III degree burns. The time from burn to hospitalization was (4.9 +/- 2.2) hours. There was no significant difference in general data between 2 groups (P > 0.05)., Results: The skin graft survival rate, the time of skin fusion, the systemic wound healing time, and the treatment cost of 1% of burn area were 91.23% +/- 5.61%, (11.14 +/- 2.12) days, (38.89 +/- 10.36) days, and (5113.28 +/- 552.44) yuan in Meek group, respectively; and were 78.65% +/- 12.29%, (18.37 +/- 4.63) days, (48.73 +/- 16.92) days, and (7386.36 +/- 867.64) yuan in particle skin group; showing significant differences between 2 groups (P < 0.05)., Conclusion: Meek technique skin graft has good effect in treating exceptionally large area burns with the advantages of high survival rate of skin graft, short time of skin fusion, and low treatment cost of 1% of burn area.