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基于ⅢF A/V规范和Avalon系统的大学图书馆视听数据库建设研究
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作者 张毅 熊泽泉 +1 位作者 胡晓明 陈丹 《图书馆杂志》 北大核心 2024年第1期50-58,49,共10页
随着中国网络基础设施的不断改善,视听媒体在年轻一代中非常流行,给以文本资源为主的图书馆带来了挑战。本研究旨在探究国内外大学图书馆视听资源数据库建设的现状,借鉴ⅢF规范在图像资源管理方面的成功经验和各种视听保存社区的实践,... 随着中国网络基础设施的不断改善,视听媒体在年轻一代中非常流行,给以文本资源为主的图书馆带来了挑战。本研究旨在探究国内外大学图书馆视听资源数据库建设的现状,借鉴ⅢF规范在图像资源管理方面的成功经验和各种视听保存社区的实践,提出基于ⅢF A/V规范与开源软件的中国大学图书馆视听资源管理方法。通过分析华东师范大学图书馆在视听资源保存、流媒体发布、时间轴气泡注释、转录、视听结构化和开放共享方面的实践,进行实证研究。 展开更多
关键词 视听数据库 f A/v Avalon媒体系统 视听可视化
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BCR-ABL阴性MPN患者JAK2 V617F基因突变及其与疾病类型、血管性疾病的关系
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作者 张晓南 孟君霞 武永强 《河南医学研究》 CAS 2024年第11期1939-1943,共5页
目的 研究断裂点簇集区/Abelson白血病病毒(BCR-ABL)阴性骨髓增殖性肿瘤(MPN)患者Janus激酶2(JAK2)V617F基因突变情况及其与疾病类型、血管性疾病的关系。方法 选取2020年5月至2023年5月濮阳市安阳地区医院收治的79例BCR-ABL阴性MPN患... 目的 研究断裂点簇集区/Abelson白血病病毒(BCR-ABL)阴性骨髓增殖性肿瘤(MPN)患者Janus激酶2(JAK2)V617F基因突变情况及其与疾病类型、血管性疾病的关系。方法 选取2020年5月至2023年5月濮阳市安阳地区医院收治的79例BCR-ABL阴性MPN患者为研究对象,另选取同期健康体检人群80例为对照组,于入院第1天采集外周血检测血常规和凝血功能,采用荧光定量聚合酶链反应技术(PCR)技术检测JAK2 V617F基因突变率和突变负荷,根据疾病类型和是否合并血管性疾病将患者分组并比较各组检测结果,采用多因素logistic回归分析研究血管性疾病影响因素。结果 MPN组JAK2 V617F基因突变率高于对照组(P<0.05);真性红细胞增多症(PV)组、原发血小板增多症(ET)组和原发性骨髓纤维化(PMF)组JAK2 V617F突变率分别为92.31%、57.78%和62.50%,ET组和PMF组突变率均低于PV组(P<0.05),3组突变负荷差异无统计学意义(P>0.05);血管性疾病组JAK2 V617F基因突变率和突变负荷均高于非血管性疾病组(P<0.05);血管性疾病组年龄、骨髓增殖性肿瘤总症状评估问卷(MPN-10)评分、纤维蛋白原(Fib)和D-二聚体(D-D)水平高于非血管性疾病组(P<0.05),两组性别、疾病分类、血红蛋白(Hb)、白细胞(WBC)、血小板(PLT)、活化部分凝血激酶时间(APTT)和斑块厚度(PT)差异无统计学意义(P>0.05)。JAK2 V617F基因突变阳性组Fib和D-D水平均高于JAK2 V617F基因突变阴性组(P<0.05);MPN并发血管性疾病危险因素包括年龄、D-D、JAK2 V617F突变阳性和JAK2 V617F突变负荷(P<0.05)。结论 BCR-ABL阴性MPN患者JAK2 V617F基因突变率较高,且JAK2 V617F基因突变可能引起凝血异常,与疾病类型和血管性疾病均存在密切联系。 展开更多
关键词 骨髓增殖性肿瘤 JAK2 v617f基因 突变负荷 血管性疾病
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JAK2V617F突变性原发性血小板增多症并缺血性卒中10例临床特征分析
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作者 詹自雄 陈宏 蓝梅平 《当代医学》 2024年第8期157-161,共5页
目的分析JAK2V617F突变性原发性血小板增多症(ET)并缺血性卒中的临床特征。方法回顾性分析2013年7月至2021年5月福建省立医院收治的7例及武平县医院收治的3例JAK2V617F突变性ET合并缺血性卒中患者的临床资料,分析患者临床特征(临床表现... 目的分析JAK2V617F突变性原发性血小板增多症(ET)并缺血性卒中的临床特征。方法回顾性分析2013年7月至2021年5月福建省立医院收治的7例及武平县医院收治的3例JAK2V617F突变性ET合并缺血性卒中患者的临床资料,分析患者临床特征(临床表现、实验室检测、骨髓细胞学)、影像学及治疗转归情况。结果10例JAK2V617F突变性ET合并缺血性卒中患者中,多发性脑梗死7例,单发性脑梗死2例,短暂性脑缺血发作1例。MRI显示3例患者病灶存在出血转化。9例脑梗死患者行血管评估,7例存在大动脉中重度狭窄或者闭塞。1例超急性期就诊者给予阿替普酶静脉溶栓后症状好转。二级预防:6例使用抗血小板、联合骨髓增生抑制剂,病情改善;3例起初仅用抗血小板治疗,病情反复,加用羟基脲治疗后2例病情改善。结论JAK2V617F突变性ET常引起大动脉粥样硬化狭窄性、多发性脑梗死且病灶较易出血,在抗血小板的基础上加用骨髓增生抑制剂可能有利于预防病情复发。 展开更多
关键词 原发性血小板增多症 JAK2v617f突变 卒中 影像学
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LAIR-1通过阻断JAK2 V617F突变的人HEL细胞JAK/STAT和PI3K/AKT/mTOR信号通路抑制其增殖并促进其凋亡 被引量:1
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作者 樊翠 张娅薇 +3 位作者 杨蕊 吴肖婕 周嘉迪 薛江楠 《细胞与分子免疫学杂志》 CAS CSCD 北大核心 2024年第3期207-214,共8页
目的研究人白细胞相关免疫球蛋白样受体1(LAIR-1)对Janus激酶2(JAK2)V617F突变的人急性髓系白血病HEL细胞JAK/信号转导子与转录激活子(STAT)和磷脂酰肌醇3激酶/蛋白激酶B/哺乳动物雷帕霉素靶蛋白(PI3K/AKT/mTOR)信号通路的调节作用,以... 目的研究人白细胞相关免疫球蛋白样受体1(LAIR-1)对Janus激酶2(JAK2)V617F突变的人急性髓系白血病HEL细胞JAK/信号转导子与转录激活子(STAT)和磷脂酰肌醇3激酶/蛋白激酶B/哺乳动物雷帕霉素靶蛋白(PI3K/AKT/mTOR)信号通路的调节作用,以及对细胞增殖和凋亡的影响。方法采用反转录PCR和基因测序鉴定JAK2 V617F突变;应用免疫共沉淀和Western blot法鉴定LAIR-1募集的蛋白酪氨酸磷酸酶(PTP)种类;采用CCK-8法检测HEL细胞的增殖;采用异硫氰酸荧光素标记的膜联素Ⅴ/碘化丙啶(annexinⅤ-FITC/PI)双标记结合流式细胞术检测HEL细胞的凋亡率;采用Western blot法检测JAK/STAT和PI3K/AKT/mTOR通路蛋白酪氨酸磷酸化水平及细胞周期蛋白D1(cyclin D1)、Bcl2相关X蛋白(BAX)和B细胞淋巴瘤因子2(Bcl2)的蛋白表达。结果在JAK2 V617F突变的HEL细胞中,LAIR-1与其配体胶原蛋白结合后可募集含Src同源域2磷酸酶2(SHP-2);LAIR-1可以下调HEL细胞JAK2、STAT1、STAT3、STAT5、AKT和mTOR的蛋白酪氨酸磷酸化水平,并能够显著抑制cyclin D1和Bcl2的表达,而对BAX的表达水平未见显著影响;LAIR-1能够明显抑制HEL细胞的增殖,促进HEL细胞凋亡。结论在JAK2 V617F突变的人白血病HEL细胞中,LAIR-1可通过募集SHP-2抑制JAK/STAT和PI3K/AKT/mTOR信号通路的活化,进而抑制HEL细胞的增殖,促进细胞凋亡。 展开更多
关键词 骨髓增殖性肿瘤 白细胞相关免疫球蛋白样受体1(LAIR-1) JAK2 v617f突变 Janus激酶(JAK) 信号转导子与转录激活子(STAT) 磷脂酰肌醇3激酶(PI3K) 蛋白激酶B(AKT)
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JAK2V617F基因突变阳性骨髓增殖性肿瘤相关门静脉海绵样变性1例
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作者 石翠翠 徐正婕 +1 位作者 周惠清 范建高 《实用肝脏病杂志》 CAS 2023年第3期443-444,共2页
骨髓增殖性肿瘤(myeloproliferative neoplasms,MPN)导致血细胞增加、血液高凝,是非肝硬化门静脉海绵样变性的重要病因。JAK2V617F基因突变可以帮助诊断MPN。我们报道1例JAK2V617F基因突变阳性的MPN患者发生门静脉海绵样变性(cavernous ... 骨髓增殖性肿瘤(myeloproliferative neoplasms,MPN)导致血细胞增加、血液高凝,是非肝硬化门静脉海绵样变性的重要病因。JAK2V617F基因突变可以帮助诊断MPN。我们报道1例JAK2V617F基因突变阳性的MPN患者发生门静脉海绵样变性(cavernous transformation of the portal vein,CTPV)。该例患者脾脏显著肿大,一方面是由于骨髓增殖性疾病本身的原因,另一方面是由于PVCT、门脉高压和脾脏淤血造成,表现为外周血血细胞计数基本在正常范围,亦是血细胞增殖和脾脏对血细胞的处理增加的共同作用的结果。抗凝治疗效果差,而应以预防食管曲张静脉破裂出血(EVB)为主。 展开更多
关键词 门静脉海绵样变性 骨髓增殖性肿瘤 JAK2 v617f基因突变 病例报道
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基于改进V/f控制和虚拟振荡器的光储微网黑启动控制策略
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作者 赵靖英 高天傲 张文煜 《电子测量技术》 北大核心 2023年第20期7-15,共9页
针对光储电站黑启动过程中存在的母线电压冲击过大、多光伏逆变器相位不同步等问题,研究光储微电网结构和微源控制方式,提出变d轴母线电压参考值的改进V/f控制策略。基于构网型虚拟振荡器,设计三相电路多并联逆变器并网自同步控制拓扑... 针对光储电站黑启动过程中存在的母线电压冲击过大、多光伏逆变器相位不同步等问题,研究光储微电网结构和微源控制方式,提出变d轴母线电压参考值的改进V/f控制策略。基于构网型虚拟振荡器,设计三相电路多并联逆变器并网自同步控制拓扑和策略。建立微电网仿真模型,提出不同工况下黑启动过程母线升压、光伏逆变器相位同步、微电网功率平衡实验方案。结果表明,基于提出的控制策略和拓扑,不同工况下弱电网黑启动过程的母线电压冲击减低,冲击电压由额定电压的5%降至2%以内;并联逆变器相位不同步程度减少,多逆变器最大相位差降至1%以内;储能单元0.03 s内可快速响应光伏功率和负载变化,黑启动过程平稳实现。 展开更多
关键词 光储微电网 黑启动 v/f控制 虚拟振荡器 控制拓扑 控制策略
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卵巢癌预后不良基因ATP6V1F、GINS1、GINS4的筛选
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作者 饶玉梅 王欣欣 《河南医学研究》 CAS 2023年第9期1586-1593,共8页
目的 筛选卵巢癌预后不良的分子生物学标志。方法 从GEO数据库获得卵巢癌GSE14001、GSE14407数据集,用在线分析工具GEO2R、Venn筛选得到卵巢癌和正常卵巢组织差异表达基因(DEGs),对DEGs进行富集分析,构建蛋白互作网络(PPI),以及构建网... 目的 筛选卵巢癌预后不良的分子生物学标志。方法 从GEO数据库获得卵巢癌GSE14001、GSE14407数据集,用在线分析工具GEO2R、Venn筛选得到卵巢癌和正常卵巢组织差异表达基因(DEGs),对DEGs进行富集分析,构建蛋白互作网络(PPI),以及构建网络模块得到关键基因,利用Kaplan Meier plotter网站分析关键基因与卵巢癌患者总生存期之间关系,应用GEPIA数据库分析DEGs在卵巢和卵巢癌组织中表达,应用The Human Protein Atlas数据库获取筛选基因的免疫组化结果,对比它们在卵巢和卵巢癌组织间的表达差异。结果 得到211个DEGs,92个上调和119个下调。差异基因生物学过程主要涉及侧枝发芽的正向调控、乏氧反应、间充质-上皮细胞信号传导;细胞组分主要集中在质膜顶、细胞表面、细胞外外泌体等部位;分子功能主要涉及丝氨酸型内肽酶活性、金属内肽酶活性、受体活性等;信号通路富集于白细胞跨内皮细胞迁移、细胞黏附通路、癌症通路等信号通路。得到35个候选基因,其中14个基因高表达、8个基因低表达与患者总生存期相关(P<0.05)。其中ATP6V1F、GINS1、GINS4基因在卵巢癌组织中在RNA水平和蛋白质水平表达均高于正常组织(P<0.05)。GNB3在卵巢癌组织中RNA水平表达低于正常组织,而在蛋白质水平恰好相反(P<0.05)。结论 ATP6V1F、GINS1、GINS4有可能是卵巢癌预后不良的新分子标志物。 展开更多
关键词 卵巢癌 ATP6v1f GINS1 GINS4 生物信息学
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石煤含氟酸浸液中V(Ⅴ)-Fe(Ⅲ)-F-H_(2)O系钒铁分离热力学研究 被引量:1
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作者 赖永传 杨鑫龙 +3 位作者 孙建之 尚鹤 莫晓兰 温建康 《中南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2023年第5期1703-1712,共10页
针对石煤含氟酸浸液中钒铁分离问题,计算并绘制298.15 K下V(Ⅴ)-Fe(Ⅲ)-F-H_(2)O系热力学平衡图,分析含钒离子、含铁离子随总钒浓度、总铁浓度、总氟浓度的变化规律。研究结果表明,随着pH由0升高至3.00,由于氟离子与VO_(2)^(+)、Fe^(3+... 针对石煤含氟酸浸液中钒铁分离问题,计算并绘制298.15 K下V(Ⅴ)-Fe(Ⅲ)-F-H_(2)O系热力学平衡图,分析含钒离子、含铁离子随总钒浓度、总铁浓度、总氟浓度的变化规律。研究结果表明,随着pH由0升高至3.00,由于氟离子与VO_(2)^(+)、Fe^(3+)的配位作用,含钒物种由阳离子转变为阴离子,含铁物种由阳离子转变为中性分子,此时可实现钒铁有效分离。定义pH_(50%)为含钒阴离子摩尔分数50%时的pH,溶液中总钒浓度升高、总铁浓度升高,均导致pH50%升高,总氟浓度升高,pH_(50%)则降低。采用N235阴离子萃取剂分离含氟溶液中的钒铁,当溶液中总钒浓度为0.05 mol/L、总铁浓度为0.05 mol/L、总氟浓度为0.50 mol/L时,溶液萃取pH升高,钒铁分离系数βV/Fe增加,当pH为1.97时,钒铁分离系数β_(V/Fe)可达122.86,钒铁达到有效分离,与热力学分析结果一致。 展开更多
关键词 石煤 v(Ⅴ)-fe(Ⅲ)-f-H_(2)O系 热力学平衡 pH_(50%) 阴离子萃取剂
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KVPO_(4)F/carbon nanocomposite with highly accessible active sites and robust chemical bonds for advanced potassium-ion batteries 被引量:1
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作者 Jianzhi Xu Liping Duan +3 位作者 Jiaying Liao Haowei Tang Jun Lin Xiaosi Zhou 《Green Energy & Environment》 SCIE EI CAS CSCD 2023年第5期1469-1478,共10页
KVPO_(4)F(KVPF)has been extensively investigated as the potential cathode material for potassium-ion batteries(PIBs)owing to its high theoretical capacity,superior operating voltage,and three-dimensional Kt conduction... KVPO_(4)F(KVPF)has been extensively investigated as the potential cathode material for potassium-ion batteries(PIBs)owing to its high theoretical capacity,superior operating voltage,and three-dimensional Kt conduction pathway.Nevertheless,the electrochemical behavior of KVPF is limited by the inherent poor electronic conductivity of the phosphate framework and unstable electrode/electrolyte interface.To address the above issues,this work proposes an infiltration-calcination method to confine the in-situ grown KVPF into the mesoporous carbon CMK-3(denoted KVPF@CMK-3).The assembled KVPF@CMK-3 nanocomposite features three-dimensional interconnected carbon channels,which not only offer abundant active sites and significantly accelerate K t/electron transport,but also prevent the growth of KVPF nanoparticle agglomerates,hence stabilizing the structure of the material.Additionally,V–F–C bonds are created at the interface of KVPF and CMK-3,which reduce the loss of F and stabilize the electrode interface.Thus,when tested as a cathode material for PIBs,the KVPF@CMK-3 nanocomposite delivers superior reversible capacitiy(103.2 mAh g^(-1) at 0.2 C),outstanding rate performance(90.1 mAh g^(-1) at 20 C),and steady cycling performance(92.2 mAh g^(-1) at 10 C and with the retention of 88.2%after 500 cycles).Moreover,its potassium storage mechanism is further examined by ex-situ XRD and ex-situ XPS techniques.The above synthetic strategy demonstrates the potential of KVPF@CMK-3 to be applied as the cathode for PIBs. 展开更多
关键词 Potassium-ion batteries CATHODE KvPO_(4)f CMK-3 vf–C bond
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JAK2V617F突变背景下骨髓增殖性肿瘤临床表型异质性的研究进展
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作者 相丹红(综述) 黄健(审校) 《中国临床新医学》 2023年第5期521-525,共5页
费城染色体阴性骨髓增殖性肿瘤(MPNs)是一组以造血干细胞克隆性增殖为主要特征的慢性血液肿瘤。JAK2V617F突变常见于MPNs,是诊断标准之一,其通过突变频率影响MPNs表型异质性。此外,信号通路、表观遗传学修饰、免疫异常、生活方式和其他... 费城染色体阴性骨髓增殖性肿瘤(MPNs)是一组以造血干细胞克隆性增殖为主要特征的慢性血液肿瘤。JAK2V617F突变常见于MPNs,是诊断标准之一,其通过突变频率影响MPNs表型异质性。此外,信号通路、表观遗传学修饰、免疫异常、生活方式和其他一些因素也参与JAK2V617F相关的MPNs的异质性。该文对JAK2V617F影响MPNs表型的研究进展作一综述。 展开更多
关键词 骨髓增殖性肿瘤 JAK2v617f 表型异质性
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EfficientNetV2 Model for Plant Disease Classification and Pest Recognition
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作者 R.S.Sandhya Devi V.RVijay Kumar P.Sivakumar 《Computer Systems Science & Engineering》 SCIE EI 2023年第5期2249-2263,共15页
Plant disease classification and prevention of spreading of the disease at earlier stages based on visual leaves symptoms and Pest recognition through deep learning-based image classification is in the forefront of re... Plant disease classification and prevention of spreading of the disease at earlier stages based on visual leaves symptoms and Pest recognition through deep learning-based image classification is in the forefront of research.To perform the investigation on Plant and pest classification,Transfer Learning(TL)approach is used on EfficientNet-V2.TL requires limited labelled data and shorter training time.However,the limitation of TL is the pre-trained model network’s topology is static and the knowledge acquired is detrimentally overwriting the old parameters.EfficientNet-V2 is a Convolutional Neural Network(CNN)model with significant high speed learning rates across variable sized datasets.The model employs a form of progressive learning mechanism which expands the network topology gradually over the course of training process improving the model’s learning capacity.This provides a better interpretability of the model’s understanding on the test domains.With these insights,our work investigates the effectiveness of EfficienetV2 model trained on a class imbalanced dataset for plant disease classification and pest recognition by means of combining TL and progressive learning approach.This Progressive Learning for TL(PL-TL)is used in our work consisting of 38 classes of PlantVillage dataset of crops and fruit species,5 classes of cassava leaf diseases and another dataset with around 102 classes of crop pest images downloaded from popular dataset platforms,though it is not a benchmark dataset.To test the predictability rate of the model in classifying leaf diseases with similar visual symptoms,Mix-up data augmentation technique is used at the ratio of 1:4 on corn and tomato classes which has high probability of misinterpretation of disease classes.Also,the paper compares the TL approach performed on the above mentioned three types of data set using well established CNN based Inceptionv3,and Vision Transformer a non-CNN model.It clearly depicts that EfficientNetV2 has an outstanding performance of 99.5%,97.5%,80.1%on Cassava,PlantVillage and IP102 datasets respectively at a faster rate irrespective of the data size and class distribution as compared to Inception-V3 and ViT models.The performance metrics in terms of accuracy,precision,f1-score is also studied. 展开更多
关键词 Image classification transfer learning efficientNetv2 mix-up data augmentation inception v3
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红细胞增多症SOCS3 mRNA的表达情况及其与JAK2 V617F点突变的相关性研究
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作者 刘珊 邢晶晶 +1 位作者 李志赏 王冬梅 《分子诊断与治疗杂志》 2023年第12期2105-2108,2112,共5页
目的研究真性红细胞增多症(PV)细胞因子信号传导抑制蛋白(SOCS3)mRNA的表达情况及其与JAK2 V617F点突变的相关性。方法选取2017年3月至2019年2月间衡水市人民医院收治的PV患者192例作为观察组,根据JAK2 V617F点突变情况将其分为突变阳性... 目的研究真性红细胞增多症(PV)细胞因子信号传导抑制蛋白(SOCS3)mRNA的表达情况及其与JAK2 V617F点突变的相关性。方法选取2017年3月至2019年2月间衡水市人民医院收治的PV患者192例作为观察组,根据JAK2 V617F点突变情况将其分为突变阳性组(130例)和突变阴性组(62例),选择同期健康体检者90名作为对照组。比较三组血清SOCS3 mRNA表达水平,并计算SOCS3 mRNA诊断PV患者JAK2 V617F点突变的敏感度、特异度、阳性预测值、阴性预测值及准确度,同时采用单因素和多因素Logistic回归分析PV患者JAK2 V617F点突变的影响因素。结果三组SOCS3 mRNA表达水平:突变阳性组>突变阴性组>对照组,差异有统计学意义(P<0.05);SOCS3 mRNA诊断PV患者JAK2 V617F点突变的敏感度为91.76%,特异度为92.00%,准确度为92.86%,阳性预测值为90.22%,阴性预测值为93.15%;单因素分析结果显示,JAK2 V617F突变阳性组与突变阴性组的性别、年龄、WBC、Hb、红细胞压积、PLT、SOCS3mRNA比较差异均有统计学意义(P<0.05);Logistic多因素回归分析结果显示,SOCS3 mRNA>0.25 nmol/L、Hb>170 g/L、红细胞压积>55%、PLT>420×109/L均为影响PV患者JAK2 V617F点突变的独立危险因素(P<0.05)。结论PV患者JAK2 V617F点突变受多种因素影响,SOCS3 mRNA表达水平增高为其独立危险因素,SOCS3 mRNA表达水平可为临床早期诊断PV患者JAK2 V617F点突变提供指导方向。 展开更多
关键词 真性红细胞增多症 SOCS3 mRNA JAK2v617f点突变
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A framework for end-to-end RSVP context transfer in mobile IPv6 被引量:1
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作者 刘楚达 钱德沛 +2 位作者 刘轶 李艳萍 肖凯平 《Journal of Central South University of Technology》 EI 2005年第5期584-590,共7页
A framework for end-to-end RSVP context transfer in Mobile IPv6(MIPv6) based on the architecture of F-HMIPv6 is proposed in this paper. The scheme provides an end-to-end RSVP context transfer for real-time application... A framework for end-to-end RSVP context transfer in Mobile IPv6(MIPv6) based on the architecture of F-HMIPv6 is proposed in this paper. The scheme provides an end-to-end RSVP context transfer for real-time applications to overcome the weakness of Context Transfer Protocol which can not meet the need of end-to-end QoS mechanisms because contexts are only transferred between Access Routers(ARs), therefore they can promptly get the same forwarding process, minimize the handover service disruption, and avoid initiating the end-to-end RSVP signaling from scratch after an MN performs handovers. It may also reduce the signaling overhead and handover latencies by adopting the F-HMIPv6architecture. The performance of the approach is compared with the re-initiating RSVP signaling to re-establish QoS states using network simulator, and the numerical results show that the scheme has the less latency and packet loss than that of the re-initiating approach. 展开更多
关键词 计算机 手提式电脑 网络 RSvP 机动性
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Is the Equity Transfer Agreement of a Chinese-Foreign Contractual Joint Venture Valid? A Case Comment on Xianyuan v.Zhongxin
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作者 陈思如 《海外英语》 2011年第6X期368-370,共3页
Under Chinese law, when parties have signed an equity transfer agreement of the Chinese-Foreign contractual joint venture, they need to report to the examination and approval authority for approval. However, due to im... Under Chinese law, when parties have signed an equity transfer agreement of the Chinese-Foreign contractual joint venture, they need to report to the examination and approval authority for approval. However, due to imperfection of and conflicts among laws and regulations as well as misunderstanding of the above system, it is always difficult for judges to determine the validity of such equity transfer agreement under the administrative approval system. Among the three categories of FIEs provided in Chinese law 1, scholars have had a comprehensive discussion over equity transfer agreement involving Sino-Foreign Equity Joint Venture Enterprises, but this case is concerned with the equity transfer agreement of a Chinese-Foreign contractual joint venture. In this case, the People's Supreme Court holds that the equity transfer agreement that has not undergone the approval procedures are not valid but not void. Furthermore, the parties that are bound to submit the agreement to the approval authority shall perform their duties of this kind. 展开更多
关键词 equity transfer AGREEMENT Chinese-foreign CONTRACTUAL joint venture a CASE COMMENT on Xianyuan v. Zhongxin
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计算宣传下基于F-V模型的社交机器人“5D”宣传策略研究——以战争情境中的推特文本为例
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作者 荣婷 孙佳倩 《新媒体与社会》 2023年第3期187-206,394,共21页
计算宣传时代,社交机器人在社交媒体舆论操纵与引导中的应用为国际宣传提供了新范式。本文以“契合度验证”模型(Fitness-Validation Model)和“5D”宣传策略为理论基础,选取推特中关于俄乌冲突的四个话题下的3506条社交机器人推文作为... 计算宣传时代,社交机器人在社交媒体舆论操纵与引导中的应用为国际宣传提供了新范式。本文以“契合度验证”模型(Fitness-Validation Model)和“5D”宣传策略为理论基础,选取推特中关于俄乌冲突的四个话题下的3506条社交机器人推文作为分析对象,研究发现俄乌双方的社交机器人为实现说服或劝阻的舆论干扰目的,采取了通过提示有利内容推动受众认同建构的误导(Deceive)策略、转移话题焦点促成态度契合的转移(Divert)策略、提供对冲信息引导新思维建构的中断(Disrupt)策略、调动感情共振促成态度认同的引诱(Decoy)策略以及通过强势提供信息以扰乱既有信息环境的干扰(Disturb)策略五种宣传策略类型。本研究通过透析冲突背景下社交机器人的宣传策略与规律,为我国把握新技术加持下的网络舆论战新形态、有效应对复杂严峻的国际舆论环境具有重要的前瞻意义。 展开更多
关键词 计算宣传 社交机器人 f-v模型 “5D”宣传策略
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Mass and heat transfer mechanism in wood during radio frequency/vacuum drying and numerical analysis
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作者 Xiaoran Jia Jingyao Zhao Yingchun Cai 《Journal of Forestry Research》 SCIE CAS CSCD 2017年第1期205-213,共9页
The mass and heat transfer mechanisms during radio frequency/vacuum (RF/V) drying of square-edged timber were analyzed and discussed in detail, and a new one-dimensional mathematical model to describe the transport ... The mass and heat transfer mechanisms during radio frequency/vacuum (RF/V) drying of square-edged timber were analyzed and discussed in detail, and a new one-dimensional mathematical model to describe the transport phenomena of mass and heat during continuous RF/V drying was derived from conservation equations based on the mass and heat transfer theory of porous materials The new model provided a relatively fast and efficient way to simulate vacuum drying behavior assisted by dielectric heating. Its advantages compared with the conventional models include: (1) Each independent vari- able has a separate control equation and is solved inde- pendently by converting the partial differential equation into a difference equation with the finite volume method; (2) The calculated data from different parts of the specimen can be displayed in the evolution curves, and the change law of the,parameters can be better described. After analyzing the calculated results, most of the important phenomena observed during RF/V drying were adequately described by this model. 展开更多
关键词 Bulk flow Mathematical model Numerical analysis Rf/v drying transfer mechanism
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Acute upper gastrointestinal bleeding due to portal hypertension in a patient with primary myelofibrosis:A case report
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作者 Yu Chen Bing-Bing Kong +3 位作者 He Yin Hao Liu Sheng Wu Ting Xu 《World Journal of Clinical Cases》 SCIE 2024年第15期2621-2626,共6页
BACKGROUND Acute upper gastrointestinal bleeding is a common medical emergency that has a 10%hospital mortality rate.According to the etiology,this disease can be divided into acute varicose veins and nonvaricose vein... BACKGROUND Acute upper gastrointestinal bleeding is a common medical emergency that has a 10%hospital mortality rate.According to the etiology,this disease can be divided into acute varicose veins and nonvaricose veins.Bleeding from esophageal varices is a life-threatening complication of portal hypertension.Portal hypertension is a clinical syndrome defined as a portal venous pressure that exceeds 10 mmHg.Cirrhosis is the most common cause of portal hypertension,and thrombosis of the portal system not associated with liver cirrhosis is the second most common cause of portal hypertension in the Western world.Primary myeloproliferative disorders are the main cause of portal venous thrombosis,and somatic mutations in the Janus kinase 2 gene(JAK2 V617F)can be found in approximately 90% of polycythemia vera,50% of essential thrombocyrosis and 50% of primary myelofibrosis.CASE SUMMARY We present a rare case of primary myelofibrosis with gastrointestinal bleeding as the primary manifestation that presented as portal-superior-splenic mesenteric vein thrombosis.Peripheral blood tests revealed the presence of the JAK2 V617F mutation.Bone marrow biopsy ultimately confirmed the diagnosis of myelofibrosis(MF-2 grade).CONCLUSION In patients with acute esophageal variceal bleeding due to portal hypertension and vein thrombosis without cirrhosis,the possibility of myeloproliferative neoplasms should be considered,and the JAK2 mutation test should be performed. 展开更多
关键词 Acute esophageal variceal bleeding Portal hypertension MYELOfIBROSIS JAK2 v617f mutation Case report
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Density Functional Studies of the Reaction of Ytterbium Monocation with Fluoromethane:C-F Bond Activation and Electron-Transfer Reactivity
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作者 Dong Ju ZHANG Cheng Bu LIU 《Chinese Chemical Letters》 SCIE CAS CSCD 2002年第4期359-362,共4页
The potential energy surface and reaction mechanism corresponding to the reaction of ytterbium monocation with fluoromethane, which represents a prototype of the activation of C-F bond in fluorohydrocarbons by bare la... The potential energy surface and reaction mechanism corresponding to the reaction of ytterbium monocation with fluoromethane, which represents a prototype of the activation of C-F bond in fluorohydrocarbons by bare lanthanide cations, have been investigated for the first time by using density functional theory. A direct fluorine abstraction mechanism was revealed, and the related thermochemistry data were determined. The electron-transfer reactivity of the reaction was analyzed using the two-state model, and a strongly avoided crossing behavior on the transition state region was shown. The present results support the reaction mechanism inferred from early experimental data and the related thermochemistry data can provide a guide for further experimental researches. 展开更多
关键词 C-f bond activation electron transfer ytterbium monocation fluoromethane DfT
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Fourth-Order Compact Formulation for the Resolution of Heat Transfer in Natural Convection of Water-Cu Nanofluid in a Square Cavity with a Sinusoidal Boundary Thermal Condition
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作者 Mostafa Zaydan Naoufal Yadil +2 位作者 Zoubair Boulahia Abderrahim Wakif Rachid Sehaqui 《World Journal of Nano Science and Engineering》 2016年第2期70-89,共20页
In the present work, we numerically study the laminar natural convection of a nanofluid confined in a square cavity. The vertical walls are assumed to be insulated, non-conducting, and impermeable to mass transfer. Th... In the present work, we numerically study the laminar natural convection of a nanofluid confined in a square cavity. The vertical walls are assumed to be insulated, non-conducting, and impermeable to mass transfer. The horizontal walls are differentially heated, and the low is maintained at hot condition (sinusoidal) when the high one is cold. The objective of this work is to develop a new height accurate method for solving heat transfer equations. The new method is a Fourth Order Compact (F.O.C). This work aims to show the interest of the method and understand the effect of the presence of nanofluids in closed square systems on the natural convection mechanism. The numerical simulations are performed for Prandtl number ( ), the Rayleigh numbers varying between  and for different volume fractions varies between 0% and 10% for the nanofluid (water + Cu). 展开更多
关键词 NANOfLUID Heat transfer Natural Convection fourth-Order Compact (f.O.C) formulation Numerical Performance Sinusoidal Boundary Thermal Condition
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新型感应电机V/F控制系统稳定性方法 被引量:13
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作者 陈伟 杨荣峰 +2 位作者 于泳 徐壮 徐殿国 《电机与控制学报》 EI CSCD 北大核心 2009年第A01期11-14,共4页
针对感应电机V/F控制系统在空载或轻裁时存在一个持续振荡的稳定性问题,提出一种改善感应电机V/F控制系统稳定性的方法。根据感应电机的数学模型,研究了系统振荡与无功电流波动之间的关系。并基于定子电压定向对电流进行分解,通过... 针对感应电机V/F控制系统在空载或轻裁时存在一个持续振荡的稳定性问题,提出一种改善感应电机V/F控制系统稳定性的方法。根据感应电机的数学模型,研究了系统振荡与无功电流波动之间的关系。并基于定子电压定向对电流进行分解,通过控制无功电流恒定调节输出电压来抑制电机振荡,提高系统的稳定性。实验结果表明:该方法不依赖电机参数,鲁棒性高,使系统在0~50Hz内都能平稳运行,电机的振荡得到了抑制,有效地提高了系统的稳定性。 展开更多
关键词 振荡抑制 无功电流 定子电压定向 v/f控制
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