目的:分析血清中Caspase酶切割细胞角蛋白18的裂解产物CCCK-18与单纯硬膜外血肿并脑疝患者术后继发性脑梗死发生发展的关系,评价CCCK-18对继发性脑梗死的早期预测能力及临床决策价值。方法:回顾性分析206例单纯硬膜外血肿并脑疝患者术...目的:分析血清中Caspase酶切割细胞角蛋白18的裂解产物CCCK-18与单纯硬膜外血肿并脑疝患者术后继发性脑梗死发生发展的关系,评价CCCK-18对继发性脑梗死的早期预测能力及临床决策价值。方法:回顾性分析206例单纯硬膜外血肿并脑疝患者术前血清CCCK-18浓度与术后继发性脑梗死占位体积的潜在关系。结果:术后继发脑梗死49例(23.78%),其中占位体积>20 mL 32例(15.53%)纳入大面积脑梗死组;占位体积<20 mL 17例(8.25%)纳入小面积脑梗死组,无脑梗死157例(76.21%)纳入无脑梗死组。大面积脑梗死组患者术前CCCK-18浓度显著高于小面积脑梗死组和无脑梗死组(均P<0.001)。术前血清CCCK-18水平与继发性脑梗死的占位体积呈线性相关(P<0.001)。受试者工作曲线分析提示术前血清CCCK-18水平对术后继发性大面积脑梗死的曲线下面积为0.814(P<0.001),以241 U/L为预测界值的准确度达到83.50%。多因素logistic回归分析表明,CCCK-18>241 U/L是单纯硬膜外血肿并脑疝患者术后继发大面积脑梗死的独立危险因素(P<0.001)。术后随访6个月,术前血清CCCK-18>241 U/L患者的格拉斯哥预后量表(GOS)评分明显低于CCCK-18<241 U/L的患者(P<0.001)。结论:术前血清CCCK-18增高与单纯硬膜外血肿致脑疝患者术后继发性大面积脑梗死密切相关,可作为辅助决策此类患者去骨瓣减压手术模式并预估长期神经功能预后的生物标志物。展开更多
A GaN-based enhancement-mode(E-Mode)metal-insulator-semiconductor(MIS)high electron mobility transistor(HEMT)with a 2 nm/5 nm/1.5nm-thin GaN/AlGaN/AlN barrier is presented.We find that the formation of a two-dimension...A GaN-based enhancement-mode(E-Mode)metal-insulator-semiconductor(MIS)high electron mobility transistor(HEMT)with a 2 nm/5 nm/1.5nm-thin GaN/AlGaN/AlN barrier is presented.We find that the formation of a two-dimensional electron gas(2DES)in the GaN/AlGaN/AlN/GaN heterostructure can be controlled by the presence of the plasma-enhanced chemical-vapor deposition(PECVD)Si_(3)N_(4) on the barrier layer,and the degree of decrease in sheet resistance R_(sh) is dependent on the Si_(3)N_(4) thickness.We choose 13 nm Si_(3)N_(4) as the gate insulator to decrease gate current and to improve the threshold voltage of devices.With selective etching of the passivation Si_(3)N_(4) under gate and over fluorine plasma treatment,the MIS-HEMT exhibits a high threshold voltage of 1.8 V.The maximum drain current Id,max and the maximum transconductance are 810 mA/mm and 190 mS/mm,respectively.The devices show a wide operation range of 4.5 V.展开更多
We report the studies of In0.15Al0.85N/AlN/GaN metal-insulator-semiconductor(MIS)high electron mobility transistors with a field plate(FP)and a plasma-enhanced chemical vapor deposition(PECVD)SiN layer as the gate die...We report the studies of In0.15Al0.85N/AlN/GaN metal-insulator-semiconductor(MIS)high electron mobility transistors with a field plate(FP)and a plasma-enhanced chemical vapor deposition(PECVD)SiN layer as the gate dielectric as well as the surface passivation layer(FP-MIS HEMTs).Compared with conventional In0.15Al0.85N/AlN/GaN high electron mobility transistors(HEMTs)of the same dimensions,the FP-MIS HEMTs exhibit a maximum drain current of 1211 mA/mm,a breakdown voltage of 120 V,an effective suppression of current collapse,about one order of magnitude reduction in reverse gate leakage,as well as more than five orders of magnitude reduction in forward gate leakage.These results confirm the potential of PECVD SiN in the application of the InAlN/AlN/GaN FP-MIS HEMTs.展开更多
文摘目的:分析血清中Caspase酶切割细胞角蛋白18的裂解产物CCCK-18与单纯硬膜外血肿并脑疝患者术后继发性脑梗死发生发展的关系,评价CCCK-18对继发性脑梗死的早期预测能力及临床决策价值。方法:回顾性分析206例单纯硬膜外血肿并脑疝患者术前血清CCCK-18浓度与术后继发性脑梗死占位体积的潜在关系。结果:术后继发脑梗死49例(23.78%),其中占位体积>20 mL 32例(15.53%)纳入大面积脑梗死组;占位体积<20 mL 17例(8.25%)纳入小面积脑梗死组,无脑梗死157例(76.21%)纳入无脑梗死组。大面积脑梗死组患者术前CCCK-18浓度显著高于小面积脑梗死组和无脑梗死组(均P<0.001)。术前血清CCCK-18水平与继发性脑梗死的占位体积呈线性相关(P<0.001)。受试者工作曲线分析提示术前血清CCCK-18水平对术后继发性大面积脑梗死的曲线下面积为0.814(P<0.001),以241 U/L为预测界值的准确度达到83.50%。多因素logistic回归分析表明,CCCK-18>241 U/L是单纯硬膜外血肿并脑疝患者术后继发大面积脑梗死的独立危险因素(P<0.001)。术后随访6个月,术前血清CCCK-18>241 U/L患者的格拉斯哥预后量表(GOS)评分明显低于CCCK-18<241 U/L的患者(P<0.001)。结论:术前血清CCCK-18增高与单纯硬膜外血肿致脑疝患者术后继发性大面积脑梗死密切相关,可作为辅助决策此类患者去骨瓣减压手术模式并预估长期神经功能预后的生物标志物。
基金Supported by the Fundamental Research Funds for the Central Universities under Grant Nos JY10000904009 and K50510250006and the National Natural Science Foundation of China under Grant Nos 60736033 and 61106106.
文摘A GaN-based enhancement-mode(E-Mode)metal-insulator-semiconductor(MIS)high electron mobility transistor(HEMT)with a 2 nm/5 nm/1.5nm-thin GaN/AlGaN/AlN barrier is presented.We find that the formation of a two-dimensional electron gas(2DES)in the GaN/AlGaN/AlN/GaN heterostructure can be controlled by the presence of the plasma-enhanced chemical-vapor deposition(PECVD)Si_(3)N_(4) on the barrier layer,and the degree of decrease in sheet resistance R_(sh) is dependent on the Si_(3)N_(4) thickness.We choose 13 nm Si_(3)N_(4) as the gate insulator to decrease gate current and to improve the threshold voltage of devices.With selective etching of the passivation Si_(3)N_(4) under gate and over fluorine plasma treatment,the MIS-HEMT exhibits a high threshold voltage of 1.8 V.The maximum drain current Id,max and the maximum transconductance are 810 mA/mm and 190 mS/mm,respectively.The devices show a wide operation range of 4.5 V.
基金the National Natural Science Foundation of China under Grant No 61204085the Aeronautical Science Foundation of China under Grant No 20122481002the Fundamental Research Funds for the Central Universities under Grant No K5051225013.
文摘We report the studies of In0.15Al0.85N/AlN/GaN metal-insulator-semiconductor(MIS)high electron mobility transistors with a field plate(FP)and a plasma-enhanced chemical vapor deposition(PECVD)SiN layer as the gate dielectric as well as the surface passivation layer(FP-MIS HEMTs).Compared with conventional In0.15Al0.85N/AlN/GaN high electron mobility transistors(HEMTs)of the same dimensions,the FP-MIS HEMTs exhibit a maximum drain current of 1211 mA/mm,a breakdown voltage of 120 V,an effective suppression of current collapse,about one order of magnitude reduction in reverse gate leakage,as well as more than five orders of magnitude reduction in forward gate leakage.These results confirm the potential of PECVD SiN in the application of the InAlN/AlN/GaN FP-MIS HEMTs.
