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内镜下CCEST微创干预治疗胰胆管合流异常患者35例分析
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作者 徐梦想 范震 赵敏楠 《世界华人消化杂志》 CAS 2024年第1期41-49,共9页
背景胰胆管合流异常(pancreaticobiliary maljunction,PBM)患者的共同通道(common channel,CC)过长导致Oddi括约肌的作用不直接影响到胰胆连接处,继而胰液和胆汁相互反流,造成胆道或胰腺的各种病理改变.探索内镜下微创缩短胰胆管CC通道... 背景胰胆管合流异常(pancreaticobiliary maljunction,PBM)患者的共同通道(common channel,CC)过长导致Oddi括约肌的作用不直接影响到胰胆连接处,继而胰液和胆汁相互反流,造成胆道或胰腺的各种病理改变.探索内镜下微创缩短胰胆管CC通道在PBM中的应用及其机制变得尤为重要,为患者提供又一个治疗的技术选择.目的探讨经内镜下十二指肠乳头括约肌共同通道切开术(endoscopic common channel sphinctertomy,CCEST)微创干预治疗PBM患者的临床效果及安全性.方法观察分析CCEST内镜下微创干预治疗的35例PBM患者,其中BP型19例、PB型16例,复杂型0例.35例患者均行经内镜逆行胰胆管造影(endoscopic retrograde cholangiopancreatography,ERCP)下CCEST并分析内镜下微创干预治疗对PBM患者的影响作用及并发症等情况.结果35例PBM患者中,男性12例,女性23例,平均年龄为(46±26.38)岁(3岁-89岁).所有患者均给予内镜下CCEST,以缩短共同通道.35例PBM患者中合并胆、胰管结石患者18例(51.43%),14例患者首次ERCP取石成功,成功率为78%(14/18).ERCP微创干预治疗术后1 wk,35例患者中血清生化、C-反应蛋白(C-reactive protein,CRP)指标及胆汁淀粉酶较术前均明显下降(P<0.05).5例患者出现轻度ERCP术后胰腺炎,经对症治疗后均未出现术后出血、消化道穿孔和重症胰腺炎等严重并发症.经过对35例患者(22.05±10.67)mo的随访,其中1例术后确诊胆管癌而行外科手术;有4例患者因结石复发再次行ERCP治疗,也取得满意疗效.治疗总有效率为88.6%(31/35).结论PBM起病较隐匿,ERCP可协助明确PBM诊断.CCEST通过缩短胆胰管汇合部共同通道,早期改善PBM患者胆胰管引流,是内镜微创治疗PBM患者的有效安全方法. 展开更多
关键词 胰胆管合流异常 内镜下十二指肠乳头括约肌共同通道切开术 胆胰疾病 微创治疗
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Epileptic brain network mechanisms and neuroimaging techniques for the brain network
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作者 Yi Guo Zhonghua Lin +1 位作者 zhen fan Xin Tian 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第12期2637-2648,共12页
Epilepsy can be defined as a dysfunction of the brain network,and each type of epilepsy involves different brain-network changes that are implicated diffe rently in the control and propagation of interictal or ictal d... Epilepsy can be defined as a dysfunction of the brain network,and each type of epilepsy involves different brain-network changes that are implicated diffe rently in the control and propagation of interictal or ictal discharges.Gaining more detailed information on brain network alterations can help us to further understand the mechanisms of epilepsy and pave the way for brain network-based precise therapeutic approaches in clinical practice.An increasing number of advanced neuroimaging techniques and electrophysiological techniques such as diffusion tensor imaging-based fiber tra ctography,diffusion kurtosis imaging-based fiber tractography,fiber ball imagingbased tra ctography,electroencephalography,functional magnetic resonance imaging,magnetoencephalography,positron emission tomography,molecular imaging,and functional ultrasound imaging have been extensively used to delineate epileptic networks.In this review,we summarize the relevant neuroimaging and neuroelectrophysiological techniques for assessing structural and functional brain networks in patients with epilepsy,and extensively analyze the imaging mechanisms,advantages,limitations,and clinical application ranges of each technique.A greater focus on emerging advanced technologies,new data analysis software,a combination of multiple techniques,and the construction of personalized virtual epilepsy models can provide a theoretical basis to better understand the brain network mechanisms of epilepsy and make surgical decisions. 展开更多
关键词 electrophysiological techniques EPILEPSY functional brain network functional magnetic resonance imaging functional near-infrared spectroscopy machine leaning molecular imaging neuroimaging techniques structural brain network virtual epileptic models
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影响304钢/Q235B钢复合板结合强度的因素
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作者 丁美良 邵春娟 +1 位作者 镇凡 曲锦波 《上海金属》 CAS 2024年第6期36-41,共6页
通过采用Gleeble-3800热模拟试验机模拟轧制工艺、拉伸试验和金相检验等,研究了界面粗糙度、压缩温度和压缩率对304钢/Q235B钢复合板结合强度的影响。结果表明:压缩率大于或等于20%时,粗糙界面复合板的结合强度低于光滑界面复合板;在低... 通过采用Gleeble-3800热模拟试验机模拟轧制工艺、拉伸试验和金相检验等,研究了界面粗糙度、压缩温度和压缩率对304钢/Q235B钢复合板结合强度的影响。结果表明:压缩率大于或等于20%时,粗糙界面复合板的结合强度低于光滑界面复合板;在低于或等于1200℃压缩的复合板结合强度高于在1200℃以上压缩的复合板;随着压缩率升至20%,复合板结合强度升高,压缩率大于20%时,复合板结合强度变化不大。 展开更多
关键词 复合板 结合强度 粗糙度 压缩温度 压缩率
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变形率对316L/Q420不锈钢复合板界面结构和结合性能的影响
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作者 镇凡 刘静 +3 位作者 黄峰 邵春娟 曲锦波 李小兵 《材料热处理学报》 CAS CSCD 北大核心 2023年第1期22-30,共9页
利用Gleeble-3800热模拟试验机制备了316L/Q420不锈钢复合板试样,采用拉伸试验、显微硬度仪、光学显微镜、扫描电镜、能谱仪和电子探针等研究了变形率对316L/Q420不锈钢复合板界面结构和结合性能的影响。结果表明:316L不锈钢复层组织为... 利用Gleeble-3800热模拟试验机制备了316L/Q420不锈钢复合板试样,采用拉伸试验、显微硬度仪、光学显微镜、扫描电镜、能谱仪和电子探针等研究了变形率对316L/Q420不锈钢复合板界面结构和结合性能的影响。结果表明:316L不锈钢复层组织为奥氏体,Q420基层组织为贝氏体(B)+少量针状铁素体(AF),脱碳层(DL)组织为贝氏体(B)+多边形铁素体(PF)+少量针状铁素体(AF)。界面区域由渗碳层(CL)、过渡层(TL)和脱碳层(DL)组成,各层硬度分布规律为过渡层>渗碳层>脱碳层。原始界面(OI)上存在孔洞和SiMn氧化物,随着变形率增加,其形貌由不连续线状转变为球状颗粒,比例由36%降低至4%,渗碳层、过渡层和脱碳层的厚度逐渐降低,晶粒得到细化,过渡层的硬度峰值增加,复合板的抗拉强度先增加后趋于稳定,伸长率增加。复合板界面存在元素扩散行为,随着变形率的增加,Cr、Ni、C等元素的扩散层厚度逐渐减小。 展开更多
关键词 不锈钢复合板 316L不锈钢 Q420低合金高强钢 变形率 复合板界面 结合强度
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链霉蛋白酶+西甲硅油对无痛胃镜检查效果的影响 被引量:16
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作者 黄平 张皞 +5 位作者 张筱凤 吕文 范震 黄海涛 王霞 蒋楠 《中国内镜杂志》 2021年第11期17-24,共8页
目的探讨链霉蛋白酶+西甲硅油在无痛胃镜患者检查前不同时间口服及服用后体位不同对检查效果的影响。方法选择杭州市第一人民医院门诊及住院接受无痛胃镜检查的患者740例,随机分成链霉蛋白酶+西甲硅油组(n=300)、西甲硅油组(n=240)和对... 目的探讨链霉蛋白酶+西甲硅油在无痛胃镜患者检查前不同时间口服及服用后体位不同对检查效果的影响。方法选择杭州市第一人民医院门诊及住院接受无痛胃镜检查的患者740例,随机分成链霉蛋白酶+西甲硅油组(n=300)、西甲硅油组(n=240)和对照组(盐酸利多卡因胶浆组,n=200)。观察并对比3组患者在无痛胃镜检查前5、10、15、20、25、30、45和60 min口服上述药物及服药后患者采取不同体位[坐位、立位(间断行走)和卧位(间断左右侧身)]的胃镜视野清晰度、丙泊酚使用剂量、胃镜操作时间、恶心呕吐发生率、癌前病变和早期胃癌检出率。结果链霉蛋白酶+西甲硅油组的胃镜视野清晰度、丙泊酚使用剂量、内镜操作时间和癌前病变及早期胃癌检出率明显优于西甲硅油组和对照组(P<0.01),而西甲硅油组又优于对照组(P<0.01);3组患者的恶心呕吐发生率比较,差异无统计学意义(P>0.05)。链霉蛋白酶+西甲硅油组在无痛胃镜检查前20和25 min口服链霉蛋白酶+西甲硅油后,胃镜视野清晰度更佳(P<0.05),但这两者间比较,差异无统计学意义(P>0.05)。链霉蛋白酶+西甲硅油组采取立位(间断行走)和卧位(间断左右侧身)的胃镜视野清晰度优于坐位,差异有统计学意义(χ^(2)_(1)=14.56,P1=0.000;χ^(2)_(2)=16.61,P2=0.000);采取立位(间断行走)和卧位(间断左右侧身)的胃镜视野清晰度比较,差异无统计学意义(χ^(2)_(3)=0.12,P3=0.733)。结论无痛胃镜检查前应用链霉蛋白酶+西甲硅油可有效提高胃镜视野清晰度、缩短内镜操作时间、减少丙泊酚使用剂量、提高癌前病变及早期胃癌检出率;胃镜前20和25 min服药及服药后采取立位(间断行走)及卧位(间断左右侧身)效果更佳。 展开更多
关键词 无痛胃镜 链霉蛋白酶 西甲硅油 盐酸利多卡因胶浆 服药时间 体位
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Al-V微合金化高强钢热处理工艺及组织性能研究
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作者 王云涛 丁庆丰 +4 位作者 杨安山 镇凡 王欣宏 邱君豪 张帆 《河南冶金》 2023年第5期8-11,共4页
实验室利用力学性能测试、OA、SEM分析研究了Al-V微合金化高强钢热处理工艺及组织性能,结果表明添加3%的Al后,试验钢密度降低至7.515g/cm^(3),且同规格钢板可降低重量4%以上;经900℃淬火+540℃回火热处理工艺试验钢组织为回火索氏体,具... 实验室利用力学性能测试、OA、SEM分析研究了Al-V微合金化高强钢热处理工艺及组织性能,结果表明添加3%的Al后,试验钢密度降低至7.515g/cm^(3),且同规格钢板可降低重量4%以上;经900℃淬火+540℃回火热处理工艺试验钢组织为回火索氏体,具有优异的强韧性匹配,综合力学性能满足屈服强度R_(eL)≥460MPa,抗拉强度R_(m)≥630MPa,延伸率A≥18%,-20℃KV_(2)≥80J试验技术要求。 展开更多
关键词 Al-V高强钢 热处理工艺 组织 性能
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超声内镜引导下对接技术治疗经内镜逆行胰胆管造影术失败的恶性梗阻性黄疸的疗效研究 被引量:13
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作者 张皞 黄平 +5 位作者 张筱凤 吕文 范震 黄海涛 楼颂梅 王霞 《中国内镜杂志》 北大核心 2017年第7期22-25,共4页
目的探讨超声内镜引导下对接技术(EUS-RV)治疗经内镜逆行胰胆管造影术(ERCP)失败的恶性梗阻性黄疸的疗效。方法 12例恶性梗阻性黄疸患者在ERCP不成功后改为EUS-RV治疗。观察其操作成功率、术后1周及1个月肝功能指标恢复情况、并发症发... 目的探讨超声内镜引导下对接技术(EUS-RV)治疗经内镜逆行胰胆管造影术(ERCP)失败的恶性梗阻性黄疸的疗效。方法 12例恶性梗阻性黄疸患者在ERCP不成功后改为EUS-RV治疗。观察其操作成功率、术后1周及1个月肝功能指标恢复情况、并发症发生率、住院时间及患者生存期。结果 12例患者均通过超声内镜穿刺成功,经胃穿刺者8例,经十二指肠穿刺4例,成功率为100.00%;术后1周较术前、术后1个月较术后1周肝功能指标差异有统计学意义(P<0.05);并发出血1例,经保守治疗后改善,并发症发生率8.33%;所有患者住院时间为(20.68±5.76)d;平均生存期为224 d。结论 EUS-RV创伤小、疗效好,可作为ERCP失败的恶性梗阻性黄疸患者的替代治疗。 展开更多
关键词 恶性梗阻性黄疸 超声内镜引导下对接技术 经内镜逆行胰胆管造影术失败
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聚(ε-己内酯)-多肽共聚物胶束增强抗生素的抗菌活性 被引量:2
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作者 陈灵珊 洪苑秀 +2 位作者 贺石生 范震 杜建忠 《物理化学学报》 SCIE CAS CSCD 北大核心 2021年第10期78-86,共9页
细菌感染对人类健康构成了严重威胁,而传统抗生素治疗可能导致如胃病、细菌耐药等一系列副作用。因此,亟需发展提高抗生素抗菌效率的新方法。在本文中,我们通过氨基酸环内酸酐和ε-己内酯开环聚合合成了多肽基的聚合物[PCL_(34)-b-PGA_(... 细菌感染对人类健康构成了严重威胁,而传统抗生素治疗可能导致如胃病、细菌耐药等一系列副作用。因此,亟需发展提高抗生素抗菌效率的新方法。在本文中,我们通过氨基酸环内酸酐和ε-己内酯开环聚合合成了多肽基的聚合物[PCL_(34)-b-PGA_(30)-b-P(Lys_(16)-stat-Phe_(12))]。在碱性环境中,此聚合物能够自组装成带负电荷的胶束(其zeta电位值为−26.7 mV)。通过透射电子显微镜和动态光散射可以证实组装体的胶束结构。此胶束具有药物缓释的特性,并且胶束上含有的抗菌多肽链段能够有效杀死细菌,因此该胶束能够很大程度上提高抗生素的抗菌效率。实验证实该载药胶束对革兰氏阴性菌(大肠杆菌)和革兰氏阳性菌(金黄色葡萄球菌)均具有较好的抗菌活性,最小抑菌浓度值分别为7.8和18.2μg·mL^(−1)。这种胶束包载妥布霉素的载药率和载药量分别为24.3%和5.2%。因此,胶束中实际含有的抗生素量为0.4和0.9μg·mL^(−1),小于妥布霉素的最小抑菌浓度值。总的来说,该胶束有望大幅降低抗生素的使用量,并减少临床上抗生素过量使用造成的副作用。 展开更多
关键词 抗生素 自组装 多肽 聚合物胶束 抗菌性 缓释
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光交联固化的聚合物囊泡用于降温触发的药物释放 被引量:2
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作者 廖雨瑶 范震 杜建忠 《物理化学学报》 SCIE CAS CSCD 北大核心 2021年第10期87-94,共8页
光交联固化可以使聚合物囊泡保持稳定的结构,从而使其在生物医学领域具有应用前景。升温是常用的控制药物释放的触发手段,但是其可能会导致细胞损伤,而通过降温进行药物可控释放则能够避免该问题。本文通过可逆加成断裂链转移(RAFT)聚... 光交联固化可以使聚合物囊泡保持稳定的结构,从而使其在生物医学领域具有应用前景。升温是常用的控制药物释放的触发手段,但是其可能会导致细胞损伤,而通过降温进行药物可控释放则能够避免该问题。本文通过可逆加成断裂链转移(RAFT)聚合制备了一种两亲性嵌段共聚物聚氧乙烯-嵌段-聚[(N-异丙基丙烯酰胺-无规-7-(2-甲基丙烯酰氧基乙氧基)-4-甲基香豆素)-嵌段-聚丙烯酸][PEO_(43)-b-P(NIPAM_(71)-stat-CMA_(8))-b-PAA_(13)]。该共聚物能够在水溶液中自组装形成囊泡。其中,P(NIPAM_(71)-stat-CMA_(8))嵌段形成囊泡的非均相膜,而PEO链和PAA链形成囊泡的混合冠,囊泡的内部空腔可用于包载亲水性药物。可光交联的CMA基团可增强囊泡的稳定性,而PNIPAM链段赋予了囊泡温度响应特性。温度降低时,囊泡溶胀并响应性释放所包载的药物。通过动态光散射、扫描电子显微镜和透射电子显微镜表征了囊泡的尺寸分布和形貌。为了验证囊泡载药和释药的能力,将一种水溶性抗生素包载在囊泡的空腔内,其在水溶液中释放12 h后,抗生素释放率在25℃时比在37℃时高近35%。总体而言,这种具有温度响应特性的光交联囊泡为降温触发的药物释放提供了一个范例,有望应用于降温触发药物释放领域。 展开更多
关键词 聚合物囊泡 温敏 光交联 可控释药 可逆加成断裂链转移聚合
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Effect of holding pressure on density and cooling rate of cast Al-Si alloy during additive pressure casting 被引量:4
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作者 zhen fan Wei Song +4 位作者 Hua-rui Zhang Bao-sheng Zhou Xiao-yan Wu Li-na Jia Hu Zhang 《China Foundry》 SCIE 2019年第6期363-370,共8页
The cast Al-Si alloy was fabricated using the Additive Pressure Casting(APC)method.The effects of holding pressure from 50 to 400 k Pa on the density,cooling rate,and mechanical properties of the alloy,and the corresp... The cast Al-Si alloy was fabricated using the Additive Pressure Casting(APC)method.The effects of holding pressure from 50 to 400 k Pa on the density,cooling rate,and mechanical properties of the alloy,and the corresponding mechanism were discussed.The results indicate that the application of high holding pressure(300 k Pa)enhances the feeding ability of the alloy,leading to an increase of the density.Meanwhile,the cooling rate of the alloy is increased by 100%.In addition,the tensile testing results show that the increase of holding pressure from 50 to 300 k Pa improves the tensile strength and elongation of the alloy by 6.2%and 81.3%,respectively.However,excessive holding pressure(400 k Pa)might lower the density and cooling rate of the alloy due to the feeding channels being blocked. 展开更多
关键词 HOLDING PRESSURE cast Al-Si alloy DENSITY cooling rate mechanical properties ADDITIVE PRESSURE CASTING
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控轧控冷工艺对X70级抗大变形管线钢组织与性能的影响 被引量:6
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作者 邵春娟 邵伟 +1 位作者 镇凡 曲锦波 《材料热处理学报》 EI CAS CSCD 北大核心 2020年第3期110-116,共7页
采用光学显微镜、扫描电镜及力学性能实验等研究了控轧控冷工艺对X70级管线钢的组织与力学性能的影响。结果表明:不同终轧温度下X70管线钢的显微组织主要由多边形铁素体、贝氏体和少量的珠光体组成,且随着终轧温度的升高,抗拉强度与屈... 采用光学显微镜、扫描电镜及力学性能实验等研究了控轧控冷工艺对X70级管线钢的组织与力学性能的影响。结果表明:不同终轧温度下X70管线钢的显微组织主要由多边形铁素体、贝氏体和少量的珠光体组成,且随着终轧温度的升高,抗拉强度与屈服强度降低,硬度下降,冲击韧性提高,但屈强比变化不大,并且落锤性能较差;随着终轧温度的升高,晶粒尺寸逐渐增大,铁素体体积含量增多。在不同的终冷温度下,X70管线钢的显微组织主要由多边形铁素体和贝氏体组成,并且随着终冷温度的升高,抗拉强度大幅度降低,屈服强度则呈M形波动,硬度呈线性降低,冲击吸收能量大幅度升高且落锤性能较好,屈强比缓慢升高;随着终冷温度的升高,晶粒度等级基本保持稳定,铁素体含量呈线性增加。该大变形管线钢最优的轧制工艺为控制终轧温度为840℃,终冷温度为450℃。 展开更多
关键词 终轧温度 终冷温度 组织 力学性能
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Ala-Gln improves varicocele-induced testicular injury by increasing HSP70 and antioxidant activity in male rats 被引量:4
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作者 LEI YU zhen fan +6 位作者 HONGQIANG WANG WENXIAN LI TAO JING QIANG LI SHENQIAN LI PEITAO WANG XUJUN XUAN 《BIOCELL》 SCIE 2021年第2期323-329,共7页
This worked aimed to test the hypothesis that L-alanyl-L-glutamine(Ala-Gln)improves the varicocele-induced testicular injury,which causes male infertility.For this purpose,fifty adult male Wistar rats received the var... This worked aimed to test the hypothesis that L-alanyl-L-glutamine(Ala-Gln)improves the varicocele-induced testicular injury,which causes male infertility.For this purpose,fifty adult male Wistar rats received the varicocele(VC)surgery at the left renal vein.Biomarkers were determined 2,4,and 8 weeks after VC(n=10/each detection).Four weeks after VC,rats received Ala-Gln(1.125 g/kg)treatment with and or saline for 1 week(n=10/each group).Rats in the sham group were also detected for biomarkers at 2,4,and 8 weeks(n=10/each detection).VC caused testicular injury detected by hematoxylin–eosin(H&E)staining,immunohistochemistry,and TUNEL assay.HSP70 mRNA was detected quantitative RT-PCR,SOD,and CAT by nitroblue tetrazolium(NBT)method and 8-OHDG by ELISA.The results showed that varicocele induced injury in the testes.The weight of the left testes was lower than that of the right testes in VC-bearing rats(p<0.01).The relative numbers of sustentacular and spermatogenic cells were decreased after VC(p<0.01).In sham-4 wk,VC-4wk,VC-5wk and Ala-Gln groups,the apoptosis index was 5.10±1.14,13.22±3.63,33.62±3.56 and 22.33±2.61,relative level of HSP70 mRNA 1.00±0.12,0.53±0.05,0.51±0.04 and 1.62±0.15 fold,SOD 16.4±0.23,13.4±0.17,10.01±1.06 and 19.53±2.26 U/mg protein,CAT 2.16±0.31,1.07±0.28,and 1.31±0.26 and 3.46±0.71 U/mg,8-OHDG 5.23±0.67,6.81±0.78,7.16±1.22 and 4.14±0.73 pg/μg DNA,respectively(p<0.01).Our results suggest that Ala-Gln prevented the VC-induced testicular injury.We have firstly reported that Ala-Gln protects against varicocele-induced testicular injuries by up-regulation of HSP70 and antioxidants,SOD and CAT,and down-regulation of oxidant 8-OHDG,resulting in reducing apoptosis in the testis. 展开更多
关键词 VARICOCELE Ala-Gln HSP70 SOD CAT 8-OHDG
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回火温度对低碳马氏体高强钢组织和性能的影响 被引量:4
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作者 镇凡 邵春娟 +1 位作者 陆春洁 曲锦波 《材料热处理学报》 CAS CSCD 北大核心 2022年第10期160-168,共9页
采用光学显微镜、扫描电镜、电子背散射衍射和拉伸及冲击试验等研究了回火温度对离线再加热淬火(RQ)与在线直接淬火(DQ)低碳马氏体高强钢组织和性能的影响。结果表明:两种淬火态试验钢组织均为板条马氏体,其中RQ钢中原奥氏体晶粒及板条... 采用光学显微镜、扫描电镜、电子背散射衍射和拉伸及冲击试验等研究了回火温度对离线再加热淬火(RQ)与在线直接淬火(DQ)低碳马氏体高强钢组织和性能的影响。结果表明:两种淬火态试验钢组织均为板条马氏体,其中RQ钢中原奥氏体晶粒及板条束呈等轴状,而DQ钢中呈扁平状;随着回火温度升高,马氏体板条发生合并、粗化,并逐渐消失,形成多边形铁素体;碳化物析出并聚集长大、球化。在同一回火温度下,RQ钢的屈服和抗拉强度均较DQ钢低,但伸长率较DQ钢高。同时,RQ钢比DQ钢具有更高的冲击吸收能量和更低的韧脆转变温度(DBTT);随着回火温度升高,RQ和DQ钢的伸长率和屈强比上升,屈服强度和抗拉强度下降,DBTT先升高后降低;RQ和DQ钢在200℃或500~600℃回火时具有优良的综合力学性能。 展开更多
关键词 板条马氏体 回火温度 在线直接淬火 离线再加热淬火
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Mn对低合金钢连续冷却相变规律的影响及强化机制 被引量:3
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作者 陆春洁 邵伟 +1 位作者 镇凡 曲锦波 《兵器材料科学与工程》 CAS CSCD 北大核心 2019年第2期64-69,共6页
通过热模拟试验、热轧试验,结合金相分析等研究不同Mn含量低合金钢的连续冷却相变规律,探讨Mn对低合金钢组织性能及强化机制的影响。结果表明:Mn能降低钢的相变开始温度(A_(r3))和相变结束温度(A_f),降低形成贝氏体的临界冷速,Mn的质量... 通过热模拟试验、热轧试验,结合金相分析等研究不同Mn含量低合金钢的连续冷却相变规律,探讨Mn对低合金钢组织性能及强化机制的影响。结果表明:Mn能降低钢的相变开始温度(A_(r3))和相变结束温度(A_f),降低形成贝氏体的临界冷速,Mn的质量分数每增加0.1%,可使Ar3降低8.6℃,Af降低13.3℃;随Mn含量的升高,试验钢中的铁素体晶粒尺寸逐渐减小、珠光体含量增多、试验钢的强韧性提高、,塑性稍有降低;Mn的质量分数达到1.60%时,在4℃/s低冷速下即出现大量的贝氏体组织,塑韧性均有大幅降低。细晶强化和固溶强化是试验钢的主要强化方式,其中细晶强化效果大于固溶强化效果。Mn的质量分数为0.1%时引起的屈服强度增量约为10 MPa,其中细晶强化分量约为6 MPa,固溶强化分量约为4 MPa,引起的抗拉强度增量约为13 MPa。 展开更多
关键词 MN含量 低合金钢 CCT曲线 强化机制 细晶强化 固溶强化
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A Stator Current Vector Orientation Based Multi-objective Integrative Suppressions of Flexible Load Vibration and Torque Ripple for PMSM Considering Electrical Loss 被引量:7
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作者 Yang Yu Leyao Cong +4 位作者 Xia Tian Zengqiang Mi Yang Li zhen fan Hui fan 《CES Transactions on Electrical Machines and Systems》 CSCD 2020年第3期161-171,共11页
To store energy from the grid into spiral torsion spring(STS)smoothly and efficiently via PMSM,a multi-objective control problem of flexible load’s vibration,PMSM’s torque ripple,and electrical loss is raised,where ... To store energy from the grid into spiral torsion spring(STS)smoothly and efficiently via PMSM,a multi-objective control problem of flexible load’s vibration,PMSM’s torque ripple,and electrical loss is raised,where the current studies on vibration and torque ripple are mostly addressed separately,not to mention electrical loss.This research attempts to propose a multi-objective integrative control scenario that can simultaneously solve these problems satisfactorily in a unitary nonlinear control framework.Firstly,a dynamic mathematical model of PMSM is built under stator current vector orientation,and then the model of PMSM is combined with the vibration model of STS to establish the overall system model of STS driven by PMSM with considering motor’s electrical loss.Then,a backstepping control principle-based multi-objective integrative control approach is proposed to realize the suppression of flexible load’s vibration and the reduction of PMSM’s torque ripple and electrical loss concurrently.Meanwhile,this research also designs a wide range speed identification method based on the least square algorithm with a forgetting factor.Simulation and experimental results have verified that the proposed integrative control method enables the state variables to track their respective references quickly and accurately,both torque ripple and load vibration are effectively suppressed,and the operating efficiency of the whole system is improved. 展开更多
关键词 PMSM VIBRATION Torque ripple Electrical loss Backstepping control
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Metastable state of gas hydrate during decomposition: A novel phenomenon 被引量:2
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作者 Ronghui Sun zhen fan +3 位作者 Lei Yang Yuanping Li Xin Lü Yang Miao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第4期949-954,共6页
Natural gas hydrates are solid compounds with cage-like structures formed by gas and water.An intriguing phenomenon that gas hydrates can dissociate at a low rate below the ice freezing point has been viewed as the me... Natural gas hydrates are solid compounds with cage-like structures formed by gas and water.An intriguing phenomenon that gas hydrates can dissociate at a low rate below the ice freezing point has been viewed as the metastability of hydrate.The mechanisms of hydrate metastability have been widely studied,and many mechanisms were proposed involving the self-preservation effect,supercooled water-gas-hydrate metastable equilibrium,and supersaturated liquid-gas-hydrate system etc.The metastable state of hydrate could be of crucial significance in the kinetics of hydrate formation and decomposition,heat and mass transfer during gas production processes,and the application of hydrate-based technique involving desalination,energy storage and transportation,and gas separation and sequestration.Few researches have systematically considered this phenomenon,and its mechanism remains unclear.In this work,various mechanisms and hypothesis explaining the metastable state of gas hydrates were introduced and discussed.Further studies are still required to reveal the intrinsic nature of this metastable state of gas hydrate,and this work could give some implications on the existing theory and current status of relevant efforts. 展开更多
关键词 HYDRATES DISSOCIATION METASTABILITY SELF-PRESERVATION SUPERSATURATION
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Strawberry sweetness and consumer preference are enhanced by specific volatile compounds 被引量:3
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作者 zhen fan Tomas Hasing +7 位作者 Timothy S.Johnson Drake M.Garner Michael L.Schwieterman Christopher R.Barbey Thomas A.Colquhoun Charles A.Sims Marcio F.R.Resende Vance M.Whitaker 《Horticulture Research》 SCIE 2021年第1期870-884,共15页
Breeding crops for improved flavor is challenging due to the high cost of sensory evaluation and the difficulty of connecting sensory experience to chemical composition.The main goal of this study was to identify the ... Breeding crops for improved flavor is challenging due to the high cost of sensory evaluation and the difficulty of connecting sensory experience to chemical composition.The main goal of this study was to identify the chemical drivers of sweetness and consumer liking for fresh strawberries(Fragaria×ananassa).Fruit of 148 strawberry samples from cultivars and breeding selections were grown and harvested over seven years and were subjected to both sensory and chemical analyses.Each panel consisted of at least 100 consumers,resulting in more than 15,000 sensory data points per descriptor.Three sugars,two acids and 113 volatile compounds were quantified.Consumer liking was highly associated with sweetness intensity,texture liking,and flavor intensity,but not sourness intensity.Partial least square analyses revealed 20 volatile compounds that increased sweetness perception independently of sugars;18 volatiles that increased liking independently of sugars;and 15 volatile compounds that had positive effects on both.Machine learning-based predictive models including sugars,acids,and volatiles explained at least 25%more variation in sweetness and liking than models accounting for sugars and acids only.Volatile compounds such asγ-dodecalactone;5-hepten-2-one,6-methyl;and multiple medium-chain fatty acid esters may serve as targets for breeding or quality control attributes for strawberry products.A genetic association study identified two loci controlling ester production,both on linkage group 6 A.Co-segregating makers in these regions can be used for increasing multiple esters simultaneously.This study demonstrates a paradigm for improvement of fruit sweetness and flavor in which consumers drive the identification of the most important chemical targets,which in turn drives the discovery of genetic targets for marker-assisted breeding. 展开更多
关键词 VOLATILE SUGAR ESTERS
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Correction: Strawberry sweetness and consumer preference are enhanced by specific volatile compounds 被引量:2
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作者 zhen fan Tomas Hasing +7 位作者 Timothy S.Johnson Drake M.Garner Michael L.Schwieterman Christopher R.Barbey Thomas A.Colquhoun Charles A.Sims Marcio F.R.Resende Vance M.Whitaker 《Horticulture Research》 SCIE 2021年第1期3067-3067,共1页
Since the publication of this article 1,the corresponding author discovered that an additional researcher contributed data and should be included as an author.Michael L.Schwieterman(Plenty Unlimited,Inc.,South San Fra... Since the publication of this article 1,the corresponding author discovered that an additional researcher contributed data and should be included as an author.Michael L.Schwieterman(Plenty Unlimited,Inc.,South San Francisco,CA 94080,US)has been added as the fifth author. 展开更多
关键词 VOLATILE SPECIFIC COMPOUNDS
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Enhanced Thermal Conductivity of Carbon Nanotube Arrays by Carbonizing Impregnated Phenolic Resins 被引量:1
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作者 Dongmei Hu Hongyuan Chen +5 位作者 zhenzhong Yong Minghai Chen Xiaohua Zhang Qingwen Li zhen fan Zhihai Feng 《Materials Sciences and Applications》 2013年第8期453-457,共5页
A carbonization method is reported to improve the thermal conductivity of carbon nanotube (CNT) arrays. After being impregnated with phenolic resins, CNT arrays were carbonized at a temperature up to 1400°C. As a... A carbonization method is reported to improve the thermal conductivity of carbon nanotube (CNT) arrays. After being impregnated with phenolic resins, CNT arrays were carbonized at a temperature up to 1400°C. As a result, pyrolytic carbon was formed and connected non-neighboring CNTs. The pyrolysis improved the room temperature conductivity from below 2 W/m·K up to 11.8 and 14.6 W/m·K with carbonization at 800°C and 1400°C, respectively. Besides the light mass density of 1.1 g/cm3, the C/C composites demonstrated high thermal stability and a higher conductivity up to 21.4 W/m·K when working at 500°C. 展开更多
关键词 Carbon NANOTUBE PHENOLIC RESIN PYROLYSIS Thermal CONDUCTIVITY
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Additive nanomanufacturing of lab-on-a-chip fluorescent peptide nanoparticle arrays for Alzheimer's disease diagnosis 被引量:1
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作者 Leming Sun zhen fan +3 位作者 Tao Yues Jun Yin Jianzhong FU Mingjun Zhang 《Bio-Design and Manufacturing》 2018年第3期182-194,共13页
This paper proposes an additive nanomanufacturing approach to fabricate a personalized lab-on-a-chip fluorescent peptide nanoparticles (f-PNPs) array for simultaneous multi-biomarker detection that can be used in Al... This paper proposes an additive nanomanufacturing approach to fabricate a personalized lab-on-a-chip fluorescent peptide nanoparticles (f-PNPs) array for simultaneous multi-biomarker detection that can be used in Alzheimer's disease (AD) diagnosis. We will discuss optimization techniques for the additive nanomanufacturing process in terms of reliability, yield and manufacturing efficiency. One contribution of this paper lies in utilization of additive nanomanufacturing techniques to fabricate a patient-specific customize-designed lab-on-a-chip device for personalized AD diagnosis, which remains a major challenge for biomedical engineering. Through the integrated bio-design and bio-manufacturing process, doctor's check- up and computer-aided customized design are integrated into the lab-on-a-chip array for patient-specific AD diagnosis. In addition, f-PNPs with targeting moieties for personalized AD biomarkers will be self-assembled onto the customized lab-on-a- chip through the additive nanomanufacturing process, which has not been done before. Another contribution of this research is the personalized lab-on-a-chip f-PNPs array for AD diagnosis utilizing limited human blood. Blood-based AD assessment has been described as "the holy grail" of early AD detection. This research created the computer-aided design, fabrication through additive nanomanufacturing, and validation of the f-PNPs array for AD diagnosis. This is a highly interdisciplinary research contributing to nanotechnology, biomaterials, and biomedical engineering for neurodegenerative disease. The conceptual work is preliminary with intent to introduce novel techniques to the application. Large-scale manufacturing based on the proposed framework requires extensive validation and optimization. 展开更多
关键词 NANOMANUFACTURING LAB-ON-A-CHIP Fluorescent peptide nanoparticle Alzheimer's disease DIAGNOSIS
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