检索结果-南通市图书馆

面向人脸属性编辑的三阶段对抗扰动生成主动防御算法

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

计算机学报 2024年第3期47卷 677-689页

作者：陈北京张海涛李玉茹南京信息工程大学教育部数字取证工程研究中心南京210044 南京信息工程大学江苏省大气环境与装备技术协同创新中心南京210044 南京信息工程大学计算机学院、网络空间安全学院南京210044

针对恶意人脸属性编辑行为,基于取证的被动防御技术只能对篡改行为进行取证并不能防止其产生,从而难以消除恶意篡改行为已经造成的损失.因此,主动防御技术应运而生,其可以破坏属性编辑的输出从而避免人脸被篡改使用.然而,现有两阶段训... 详细信息

针对恶意人脸属性编辑行为,基于取证的被动防御技术只能对篡改行为进行取证并不能防止其产生,从而难以消除恶意篡改行为已经造成的损失.因此,主动防御技术应运而生,其可以破坏属性编辑的输出从而避免人脸被篡改使用.然而,现有两阶段训练人脸篡改主动防御框架存在迁移性和扰动鲁棒性不足的问题,为此本文通过优化两阶段训练架构及损失函数和引入一个辅助分类器,提出一种三阶段对抗扰动主动防御框架.本文首先修改两阶段训练架构中的代理目标模型并基于此设计了训练扰动生成器的属性编辑损失,以提升代理模型的重建性能和属性约束能力,从而减少对代理模型的过拟合;其次,在训练阶段引入辅助分类器对代理模型提取的编码后特征进行源属性分类并基于此设计训练扰动生成器的辅助分类器损失,从而将原本的两阶段交替训练改为代理目标模型、辅助分类器和扰动生成器的三阶段交替训练,期望通过对抗攻击辅助分类器以促进对篡改模型的主动防御;最后,在扰动生成器的训练中,引入攻击层以促进对抗扰动对滤波和JPEG压缩的鲁棒性.实验结果验证,本文提出的框架能够比现有框架更好地将主动防御从白盒的代理目标模型迁移到黑盒的属性编辑模型,黑盒性能提升16.17%,且生成的对抗扰动较基线算法具有更强的鲁棒性,针对JPEG压缩的性能(PSNR)提升13.91%,针对高斯滤波提升17.76%.

关键词：人脸属性编辑主动防御对抗攻击辅助分类器交替训练

在线全文

学校读者我要写书评

暂无评论

艾绒中酸性黄36快速检测方法研究

中国现代应用药学 2024年第11期41卷 1524-1528页

作者：赵培敬陈林宋颖李中娥黄涵南阳市产品质量检验检测中心河南南阳473061 东北林业大学哈尔滨150040

目的建立艾绒中非法添加色素酸性黄36的快速检测方法。方法利用酸性黄36为酸碱指示剂,在pH值1.2(红)~2.3(黄)内变色的原理,以15%硫酸溶液为显色剂,对艾绒乙醇提取液进行初筛,再采用HPLC对初筛可疑阳性样品进行验证,最后采用LC-MS进行确... 详细信息

目的建立艾绒中非法添加色素酸性黄36的快速检测方法。方法利用酸性黄36为酸碱指示剂,在pH值1.2(红)~2.3(黄)内变色的原理,以15%硫酸溶液为显色剂,对艾绒乙醇提取液进行初筛,再采用HPLC对初筛可疑阳性样品进行验证,最后采用LC-MS进行确认,检验所建立的理化快检方法的准确性。结果应用建立的酸性黄36快检方法在67批艾绒样品中检出3批阳性样品,经HPLC和LC-MS确认后,结果一致。结论所建立的方法准确、快速、便捷,可用于艾绒中酸性黄36的快速检测。

关键词：艾绒酸性黄36 快检方法 HPLC-DAD LC-MS/MS

Effects of Headgroups and Serum on Gene Transfection of Alkaline Amino Acid Based Cationic lipids

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2009年第1期25卷 69-71页

作者： li li YANG Yang NIE yu HE Bin GU zhong-wei National Engineering Research Center for Biomaterials Sichuan University Chengdu 610064 P. R. China

Three cationic lipids with lysylated（1）, histidylated（2）, and arginylated（3） headgroups and cholesterol hydrophobic moiety were synthesized. The average sizes of liposomes and lipoplexes were around 100 and 160 nm, respectively. The gene transfection efficiency of the three lipoplexes loaded with pGL3 or pORF-LacZ was compared on 293T cells in the presence or the absence of serum. The transfection efficiency of the three lipoplexes in a serum-free medium was 2 to 3-fold higher than that of dioleoyl-trimethylammonium propane（DOTAP）. In the presence of serum, however, most of the lipoplexes showed lower transfection activities; only lipoplex 3 retained its high transfection efficiency.

关键词： Cationic lipids Alkaline amino acids Serum Gene delivery Transfection efficiency

Risk factors for local recurrence following neoadjuvant chemoradiotherapy for rectal cancers

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2013年第32期19卷 5227-5237页

作者： Jia-yuan Peng zhong-Nan li yu Wang Department of Surgery Shanghai Sixth People’s HospitalShanghai Jiao Tong University

Local recurrence(LR)has an adverse impact on rectal cancer *** chemoradiotherapy(nCRT)is increasingly administered to patients with progressive cancers to improve the ***,LR still remains a problem and its pattern can ***,new risk factors have emerged in the context of nCRT in addition to the traditional risk factors in patients receiving non-neoadjuvant *** risk factors are decisive when reviewing treatment *** review aims to elucidate the distinctive risk factors related to LR of rectal cancers in patients receiving nCRT and to clarify their clinical significance.A search was conducted on PubMed to identify original studies investigating patients with rectal cancer receiving *** of interest,especially potential risk factors for LR in patients with nCRT,were then *** clinical importance of these risk factors is *** cancer cells,lymph-nodes and tumor response were found to be major risk *** cancer cells decide the status of resection *** excision following nCRT is promising in ypT0-1N0M0 *** of lateral lymph nodes should be considered in advanced lowlying *** better tumor response resulted in a relatively lower recurrence rate,the evidence available is insufficient to justify a non-operative approach in clinical complete responders to *** cannot be totally avoided by current multidisciplinary *** related risk factors resulting from nCRT should be considered when making decisions regarding treatment selection.

关键词： Local recurrence Rectal cancer Neoadjuvant chemoradiotherapy

沙眼衣原体pORF5蛋白通过激活PI3K/Akt信号通路抑制细胞凋亡

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国免疫学杂志 2018年第3期34卷 321-324,330页

作者：卜继常邹燕聂倩雷文波周洲陆春雪陈超群李忠玉南华大学医学院病原生物学研究所/特殊病原体防控湖南省重点实验室衡阳421001

目的:探讨沙眼衣原体(Chlamydia trachomatis,Ct)pORF5蛋白对细胞凋亡的影响,并进一步分析其分子机制,为阐明Ct致病机制提供实验依据。方法:p GEX-6p/pORF5重组质粒转化XL1-blue大肠杆菌,IPTG诱导表达GST-pORF5融合蛋白,融合蛋白经谷胱... 详细信息

目的:探讨沙眼衣原体(Chlamydia trachomatis,Ct)pORF5蛋白对细胞凋亡的影响,并进一步分析其分子机制,为阐明Ct致病机制提供实验依据。方法:p GEX-6p/pORF5重组质粒转化XL1-blue大肠杆菌,IPTG诱导表达GST-pORF5融合蛋白,融合蛋白经谷胱甘肽琼脂糖凝胶4B纯化及蛋白酶切除GST标签后得到pORF5蛋白。用不同浓度的pORF5蛋白刺激HeLa细胞,Western blot检测不同时间Bax和Bcl-2的表达水平以及PI3K/Akt磷酸化水平,Hoechst 33342及流式细胞技术分析细胞凋亡情况;HeLa细胞经PI3K/Akt特异性抑制剂LY294002预处理1 h后,再用pORF5蛋白刺激24 h,测定细胞凋亡率,并进一步分析凋亡相关蛋白Bax和Bcl-2的表达水平及PI3K/Akt磷酸化水平。结果:凋亡相关蛋白Bax和Bcl-2的表达变化与pORF5蛋白浓度呈现一定的浓度和时间依赖性,当pORF5蛋白浓度达10μg/ml时,Bax表达下调,Bcl-2的表达上调,当升高至15μg/ml时,Bax和Bcl-2的表达量变化最明显;15μg/ml的pORF5蛋白刺激HeLa细胞24 h,Bax和Bcl-2表达变化最明显;流式细胞检测结果显示:pORF5蛋白刺激组较TNF-α处理组和未处理组细胞凋亡率分别降低了27.3%(P<0.01)和8.4%(P<0.05);Akt在pORF5蛋白刺激15 min后发生磷酸化,30 min后磷酸化水平达到峰值,用PI3K抑制剂LY294002预处理Hela细胞后,发现Akt的磷酸化显著减少,Bax蛋白表达明显上调,Bcl-2表达明显下调;LY294002处理组细胞凋亡率相比于对照组增加了13.0%(P<0.01)。结论:pORF5蛋白通过激活PI3K/Akt信号通路调节Bcl-2和Bax蛋白的表达抑制细胞凋亡。

关键词：沙眼衣原体 pORF5蛋白细胞凋亡 PI3K/Akt信号通路

Collisions Between Lumps/Rogue Waves and Solitons for A(3+1)-Dimensional Generalized Variable-Coefficient Shallow Water Wave Equation

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2022年第5期36卷 808-813页

作者： WU Xiao-yu DU zhong School of Science Beijing Forestry UniversityBeijing 100083China Department of Mathematics and Physics North China Electric Power UniversityBaoding 071003China

In this paper,we investigate a(3+1)-dimensional generalized variable-coefficient shallow water wave equation,which can be used to describe the flow below a pressure surface in oceanography and atmospheric *** the Kadomtsev−Petviashvili hierarchy reduction,we obtain the semi-rational solutions which describe the lumps and rogue waves interacting with the kink *** find that the lump appears from one kink soliton and fuses into the other on the x−y and x−t ***,on the x−z plane,the localized waves in the middle of the parallel kink solitons are in two forms:lumps and line rogue *** effects of the variable coefficients on the two forms are *** dispersion coefficient influences the speed of solitons,while the background coefficient influences the background’s height.

关键词： variable-coefficient shallow water wave equation lumps linear rogue waves Kadomtsev-Petviashvili hierarchy reduction

Multiple immune function impairments in diabetic patients and their effects on COVID-19

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2021年第24期9卷 6969-6978页

作者： zhong-Hua Lu Wei-li yu yun Sun Department of Critical Care Medicine The Second Affiliated HospitalAnhui Medical UniversityHefei 230601Anhui ProvinceChina

Coronavirus disease 2019(COVID-19),which is caused by severe acute respiratory syndrome coronavirus 2,poses a significant threat to public health worldwide,and diabetes is considered a risk factor for the rapid progression and poor prognosis of *** immune function is a clinical feature of COVID-19 patients,and diabetes patients have defects in innate and adaptive immune functions,which may be an important reason for the rapid progression and poor prognosis of COVID-19 in patients with *** review the possible multiple effects of immune impairment in diabetic patients on the immune responses to COVID-19 to provide guidance for the diagnosis and treatment of diabetic patients with COVID-19.

关键词： COVID-19 Diabetes Immune function SARS-CoV-2

基于牵引网电压和空载电压的多储能系统区间能量管理策略

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

电工技术学报 2024年第15期39卷 4583-4598页

作者：钟志宏李炎米佳雨林飞杨中平北京交通大学电气工程学院北京100044

近年来,随着“双碳”政策的推动,储能技术在城市轨道交通中的应用愈发广泛,呈现出点到线的发展趋势。当一条线路中有多站安装储能装置时,想要进一步提升储能系统的节能效果,必须要解决不同站储能装置的充放电策略个性化设计,以及多储能... 详细信息

近年来,随着“双碳”政策的推动,储能技术在城市轨道交通中的应用愈发广泛,呈现出点到线的发展趋势。当一条线路中有多站安装储能装置时,想要进一步提升储能系统的节能效果,必须要解决不同站储能装置的充放电策略个性化设计,以及多储能间协调控制这两个问题。因此,该文提出一种基于实时牵引网电压和空载电压的多储能系统区间能量管理策略。该策略基于多个牵引变电站的空载电压和牵引网电压,对能量管理区间内的列车状态和列车剩余功率进行辨识,基于此计算区间内储能装置的充放电阈值基准值初值及基准值变化的斜率。为进一步提升节能和稳压效果,该策略基于充放电周期、牵引网电压超限频次及储能系统的荷电状态(SOC)等参数,对基准值及其更新斜率进行实时校正。该文在北京地铁的实际线路中进行了验证,结果表明,相较于基于本站空载电压的能量管理策略,提出的策略在降低系统能耗和稳定牵引网电压方面都具有显著的改善效果。

关键词：城轨交通空载电压多储能能量管理协调控制

High Temperature and Risk of Cause-Specific Mortality in China,2013−2018

在线全文

学校读者我要写书评

暂无评论

China CDC weekly 2020年第23期2卷 408-412,I0001-I0003页

作者： yu zhong Chen Chen Qing Wang Tiantian li China CDC Key Laboratory of Environment and Population Health National Institute of Environmental HealthChinese Center for Disease Control and PreventionBeijingChina

Summary What is already known about this topic?High temperature is a well-recognized public health threat and may increase mortality risks,especially mortality risks involving diseases of the circulatory *** is added by this report?Using a six-year time series analysis,the differences of daily mean,maximum,minimum temperature were explored in assessing the health effects of high temperatures in nationwide and at climatic-zone level,and population groups susceptible to high temperatures were *** are the implications for public health practice?This study suggests that the daily mean temperature is the optimal indicator for high temperature exposure in heat-related health risk assessments and early *** policy measures of heat-related public health protection should be made considering regional distribution,sensitive diseases,and vulnerable populations.

关键词： nationwide high policy