目的探讨在急性阑尾炎患儿诊断中,超声征象的特点及诊断意义。方法以81例急性阑尾炎患儿为研究对象,将81例急性阑尾炎患儿依病理检测结果分为2组:进展性阑尾炎患儿34例(41.98%),单纯性阑尾炎患儿47例(58.02%)。通过超声检测的间接征象...目的探讨在急性阑尾炎患儿诊断中,超声征象的特点及诊断意义。方法以81例急性阑尾炎患儿为研究对象,将81例急性阑尾炎患儿依病理检测结果分为2组:进展性阑尾炎患儿34例(41.98%),单纯性阑尾炎患儿47例(58.02%)。通过超声检测的间接征象、直接征象,以及病理检查资料,并借助ROC曲线分析超声征象联合应用的曲线下面积(area under curve,AUC),进行综合分析,对患儿超声检查结果进行评分。结果进展组患儿超声检测的管壁连续性中断/层次清晰度不高、管腔积液、阑尾周围或腹腔积液、阑尾周围高回声、盲肠、回肠壁增厚检出率均高于单纯组(P<0.05);进展组超声间接征象、直接征象、联合征象评分均高于单纯组(P<0.05);ROC(receiver oprating characteristic)曲线下,联合征象诊断灵敏度、特异度、阳性预测值和阴性预测值分别为98.77%、97.53%、98.77%、96.30%均高于间接征象、直接征象,AUC为0.902高于间接征象、直接征象(P<0.05)。结论超声检测征象联合诊断,能够为急性阑尾炎患儿的早期诊断提供客观证据,且还可实现对疾病动态监测,从而有利于临床治疗方案的制定。展开更多
Dual-metal gate and gate–drain underlap designs are introduced to reduce the ambipolar current of the device based on the C-shaped pocket TFET(CSP-TFET).The effects of gate work function and gate–drain underlap leng...Dual-metal gate and gate–drain underlap designs are introduced to reduce the ambipolar current of the device based on the C-shaped pocket TFET(CSP-TFET).The effects of gate work function and gate–drain underlap length on the DC characteristics and analog/RF performance of CSP-TFET devices,such as the on-state current(I_(on)),ambipolar current(I_(amb)),transconductance(g_(m)),cut-off frequency(f_(T))and gain–bandwidth product(GBP),are analyzed and compared in this work.Also,a combination of both the dual-metal gate and gate–drain underlap designs has been proposed for the C-shaped pocket dual metal underlap TFET(CSP-DMUN-TFET),which contains a C-shaped pocket area that significantly increases the on-state current of the device;this combination design substantially reduces the ambipolar current.The results show that the CSP-DMUN-TFET demonstrates an excellent performance,including high I_(on)(9.03×10^(-4)A/μm),high I_(on)/I_(off)(~10^(11)),low SS_(avg)(~13 mV/dec),and low I_(amb)(2.15×10^(-17)A/μm).The CSP-DMUN-TFET has the capability to fully suppress ambipolar currents while maintaining high on-state currents,making it a potential replacement in the next generation of semiconductor devices.展开更多
This paper reports a low-damage interface treatment process for Al N/Ga N high electron mobility transistor(HEMT)and demonstrates the excellent power characteristics of radio-frequency(RF) enhancementmode(E-mode) Al N...This paper reports a low-damage interface treatment process for Al N/Ga N high electron mobility transistor(HEMT)and demonstrates the excellent power characteristics of radio-frequency(RF) enhancementmode(E-mode) Al N/Ga N HEMT. An RF E-mode device with 2.9-nm-thick Al N barrier layer fabricated by remote plasma oxidation(RPO) treatment at 300℃. The device with a gate length of 0.12-μm has a threshold voltage(Vth) of 0.5 V, a maximum saturation current of 1.16 A/mm, a high Ion/Ioff ratio of 1×108, and a 440-m S/mm peak transconductance. During continuous wave(CW) power testing, the device demonstrates that at 3.6 GHz, a power added efficiency is 61.9% and a power density is 1.38 W/mm, and at 30 GHz, a power added efficiency is 41.6% and a power density is 0.85 W/mm. Furthermore, the RPO treatment improves the mobility of RF E-mode Al N/Ga N HEMT. All results show that the RPO processing method has good applicability to scaling ultrathin barrier E-mode Al N/Ga N HEMT for 5G compliable frequency ranging from sub-6 GHz to Ka-band.展开更多
膀胱副神经节瘤(paraganglioma of urinary bladder,PUB)起源于膀胱壁肌层交感神经的嗜铬组织,属于神经内分泌肿瘤,约占所有嗜铬细胞瘤的1%,女性发病率高于男性[1],发病年龄以20~40岁多发。根据肿瘤是否分泌儿茶酚胺,PUB可分为功能性和...膀胱副神经节瘤(paraganglioma of urinary bladder,PUB)起源于膀胱壁肌层交感神经的嗜铬组织,属于神经内分泌肿瘤,约占所有嗜铬细胞瘤的1%,女性发病率高于男性[1],发病年龄以20~40岁多发。根据肿瘤是否分泌儿茶酚胺,PUB可分为功能性和非功能性,典型功能性PUB临床表现为排尿时出现头痛、冷汗、心悸、晕厥症状。本例是因出现严重血尿就诊的妊娠期患者,术前临床资料和影像学检查难以诊断,最终通过术后病理确诊。展开更多
文摘目的探讨在急性阑尾炎患儿诊断中,超声征象的特点及诊断意义。方法以81例急性阑尾炎患儿为研究对象,将81例急性阑尾炎患儿依病理检测结果分为2组:进展性阑尾炎患儿34例(41.98%),单纯性阑尾炎患儿47例(58.02%)。通过超声检测的间接征象、直接征象,以及病理检查资料,并借助ROC曲线分析超声征象联合应用的曲线下面积(area under curve,AUC),进行综合分析,对患儿超声检查结果进行评分。结果进展组患儿超声检测的管壁连续性中断/层次清晰度不高、管腔积液、阑尾周围或腹腔积液、阑尾周围高回声、盲肠、回肠壁增厚检出率均高于单纯组(P<0.05);进展组超声间接征象、直接征象、联合征象评分均高于单纯组(P<0.05);ROC(receiver oprating characteristic)曲线下,联合征象诊断灵敏度、特异度、阳性预测值和阴性预测值分别为98.77%、97.53%、98.77%、96.30%均高于间接征象、直接征象,AUC为0.902高于间接征象、直接征象(P<0.05)。结论超声检测征象联合诊断,能够为急性阑尾炎患儿的早期诊断提供客观证据,且还可实现对疾病动态监测,从而有利于临床治疗方案的制定。
基金Project supported by the National Natural Science Foundation of China(Grant Nos.52177185 and 62174055)。
文摘Dual-metal gate and gate–drain underlap designs are introduced to reduce the ambipolar current of the device based on the C-shaped pocket TFET(CSP-TFET).The effects of gate work function and gate–drain underlap length on the DC characteristics and analog/RF performance of CSP-TFET devices,such as the on-state current(I_(on)),ambipolar current(I_(amb)),transconductance(g_(m)),cut-off frequency(f_(T))and gain–bandwidth product(GBP),are analyzed and compared in this work.Also,a combination of both the dual-metal gate and gate–drain underlap designs has been proposed for the C-shaped pocket dual metal underlap TFET(CSP-DMUN-TFET),which contains a C-shaped pocket area that significantly increases the on-state current of the device;this combination design substantially reduces the ambipolar current.The results show that the CSP-DMUN-TFET demonstrates an excellent performance,including high I_(on)(9.03×10^(-4)A/μm),high I_(on)/I_(off)(~10^(11)),low SS_(avg)(~13 mV/dec),and low I_(amb)(2.15×10^(-17)A/μm).The CSP-DMUN-TFET has the capability to fully suppress ambipolar currents while maintaining high on-state currents,making it a potential replacement in the next generation of semiconductor devices.
基金Project supported by the Fundamental Research Funds for the National Key Research and Development Program, China (Grant No. 2020YFB1807403)the National Natural Science Foundation of China (Grant Nos. 62174125, 62188102, and 62131014)。
文摘This paper reports a low-damage interface treatment process for Al N/Ga N high electron mobility transistor(HEMT)and demonstrates the excellent power characteristics of radio-frequency(RF) enhancementmode(E-mode) Al N/Ga N HEMT. An RF E-mode device with 2.9-nm-thick Al N barrier layer fabricated by remote plasma oxidation(RPO) treatment at 300℃. The device with a gate length of 0.12-μm has a threshold voltage(Vth) of 0.5 V, a maximum saturation current of 1.16 A/mm, a high Ion/Ioff ratio of 1×108, and a 440-m S/mm peak transconductance. During continuous wave(CW) power testing, the device demonstrates that at 3.6 GHz, a power added efficiency is 61.9% and a power density is 1.38 W/mm, and at 30 GHz, a power added efficiency is 41.6% and a power density is 0.85 W/mm. Furthermore, the RPO treatment improves the mobility of RF E-mode Al N/Ga N HEMT. All results show that the RPO processing method has good applicability to scaling ultrathin barrier E-mode Al N/Ga N HEMT for 5G compliable frequency ranging from sub-6 GHz to Ka-band.
文摘膀胱副神经节瘤(paraganglioma of urinary bladder,PUB)起源于膀胱壁肌层交感神经的嗜铬组织,属于神经内分泌肿瘤,约占所有嗜铬细胞瘤的1%,女性发病率高于男性[1],发病年龄以20~40岁多发。根据肿瘤是否分泌儿茶酚胺,PUB可分为功能性和非功能性,典型功能性PUB临床表现为排尿时出现头痛、冷汗、心悸、晕厥症状。本例是因出现严重血尿就诊的妊娠期患者,术前临床资料和影像学检查难以诊断,最终通过术后病理确诊。
