期刊文献+
共找到510篇文章
< 1 2 26 >
每页显示 20 50 100
An Active Deception Defense Model Based on Address Mutation and Fingerprint Camouflage
1
作者 Wang Shuo Chu Jiang +3 位作者 Pei Qingqi Shao Feng Yuan Shuai Zhong Xiaoge 《China Communications》 SCIE CSCD 2024年第7期212-223,共12页
The static and predictable characteristics of cyber systems give attackers an asymmetric advantage in gathering useful information and launching attacks.To reverse this asymmetric advantage,a new defense idea,called M... The static and predictable characteristics of cyber systems give attackers an asymmetric advantage in gathering useful information and launching attacks.To reverse this asymmetric advantage,a new defense idea,called Moving Target Defense(MTD),has been proposed to provide additional selectable measures to complement traditional defense.However,MTD is unable to defeat the sophisticated attacker with fingerprint tracking ability.To overcome this limitation,we go one step beyond and show that the combination of MTD and Deception-based Cyber Defense(DCD)can achieve higher performance than either of them.In particular,we first introduce and formalize a novel attacker model named Scan and Foothold Attack(SFA)based on cyber kill chain.Afterwards,we develop probabilistic models for SFA defenses to provide a deeper analysis of the theoretical effect under different defense strategies.These models quantify attack success probability and the probability that the attacker will be deceived under various conditions,such as the size of address space,and the number of hosts,attack analysis time.Finally,the experimental results show that the actual defense effect of each strategy almost perfectly follows its probabilistic model.Also,the defense strategy of combining address mutation and fingerprint camouflage can achieve a better defense effect than the single address mutation. 展开更多
关键词 address mutation deception defense fingerprint camouflage moving target defense probabilistic model
下载PDF
Novel MIP gene mutation causes autosomal-dominant congenital cataract
2
作者 Jing-Lan Ni Hua-Ming Wen +4 位作者 Xiao-Sheng Huang Qian-Wen Li Jia-Min Cai Bao-Jian Fan Jun Zhao 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第3期454-465,共12页
●AIM:To identify disease-causative mutations in families with congenital cataract.●METHODS:Two Chinese families with autosomaldominant congenital cataract(ADCC)were recruited and underwent comprehensive eye examinat... ●AIM:To identify disease-causative mutations in families with congenital cataract.●METHODS:Two Chinese families with autosomaldominant congenital cataract(ADCC)were recruited and underwent comprehensive eye examinations.Gene panel next-generation sequencing of common pathogenic genes of congenital cataract was performed in the proband of each family.Sanger sequencing was used to valid the candidate gene mutations and sequence the other family members for co-segregation analysis.The effect of sequence changes on protein structure and function was predicted through bioinformatics analysis.Major intrinsic protein(MIP)-wildtype and MIP-G29R plasmids were constructed and microinjected into zebrafish single-cell stage embryos.Zebrafish embryonic lens phenotypes were screened using confocal microscopy.●RESULTS:A novel heterozygous mutation(c.85G>A;p.G29R)in the MIP gene was identified in the proband of one family.A known heterozygous mutation(c.97C>T;p.R33C;rs864309693)in MIP was found in the proband of another family.In-silico prediction indicated that the novel mutation might affect the MIP protein function.Zebrafish embryonic lens was uniformly transparent in both wild-type PCS2+MIP and mutant PCS2+MIP.●CONCLUSION:Two missense mutations in the MIP gene in Chinese cataract families are identified,and one of which is novel.These findings expand the genetic spectrum of MIP mutations associated with cataracts.The functional studies suggest that the novel MIP mutation might not be a gain-of-function but a loss-of-function mutation. 展开更多
关键词 congenital cataract major intrinsic protein missense mutation zebrafish model
下载PDF
Shale Fracturability Graphic Template Based onMixed Analytic Hierar-chy Process andMutation Theory
3
作者 Sichen Li Dehua Liu +1 位作者 Liang Cheng Pan Ma 《Energy Engineering》 EI 2024年第7期1921-1943,共23页
Due to the depletion of conventional energy reserves,there has been a global shift towards non-conventional energy sources.Shale oil and gas have emerged as key alternatives.These resources have dense and heterogeneou... Due to the depletion of conventional energy reserves,there has been a global shift towards non-conventional energy sources.Shale oil and gas have emerged as key alternatives.These resources have dense and heterogeneous reservoirs,which require hydraulic fracturing to extract.This process depends on identifying optimal fracturing layers,also known as‘sweet spots’.However,there is currently no uniform standard for locating these sweet spots.This paper presents a new model for evaluating fracturability that aims to address the current gap in the field.The model utilizes a hierarchical analysis approach and a mutation model,and is distinct in its use of original logging data to generate a fracturability evaluation map.Using this paper’s shale fracturing sweet spot evaluation method based on a two-step mutation model,four wells in different blocks of Fuling and Nanchuan Districts in China were validated,and the results showed that the proportion of high-yielding wells on the sweet spot line could reach 97.6%,while the proportion of low-producing wells was only 78.67%.Meanwhile,the evaluation results of the model were compared with the microseismic data,and the matching results were consistent. 展开更多
关键词 Shale reservoir hydraulic fracturing analytic hierarchy process mutation model microseismic
下载PDF
A multilevel pan-cancer map links gene mutations to cancer hallmarks
4
作者 Theo A.Knijnenburg Tycho Bismeijer +1 位作者 Lodewyk F.A.Wessels llya Shmulevich 《Chinese Journal of Cancer》 SCIE CAS CSCD 2015年第10期439-449,共11页
Background:A central challenge in cancer research is to create models that bridge the gap between the molecular level on which interventions can be designed and the cellular and tissue levels on which the disease phen... Background:A central challenge in cancer research is to create models that bridge the gap between the molecular level on which interventions can be designed and the cellular and tissue levels on which the disease phenotypes are manifested.This study was undertaken to construct such a model from functional annotations and explore its use when integrated with large-scale cancer genomics data.Methods:We created a map that connects genes to cancer hallmarks via signaling pathways.We projected gene mutation and focal copy number data from various cancer types onto this map.We performed statistical analyses to uncover mutually exclusive and co-occurring oncogenic aberrations within this topology.Results:Our analysis showed that although the genetic fingerprint of tumor types could be very different,there were less variations at the level of hallmarks,consistent with the idea that different genetic alterations have similar functional outcomes.Additionally,we showed how the multilevel map could help to clarify the role of infrequently mutated genes,and we demonstrated that mutually exclusive gene mutations were more prevalent in pathways,whereas many co-occurring gene mutations were associated with hallmark characteristics.Conclusions:Overlaying this map with gene mutation and focal copy number data from various cancer types makes it possible to investigate the similarities and differences between tumor samples systematically at the levels of not only genes but also pathways and hallmarks. 展开更多
关键词 CANCER systems biology CANCER hallmarks Gene mutations MULTILEVEL model
下载PDF
Discrete Evolutionary Genetics: Multiplicative Fitnesses and the Mutation-Fitness Balance
5
作者 Thierry Huillet Servet Martinez 《Applied Mathematics》 2011年第1期11-22,共12页
We revisit the multi-allelic mutation-fitness balance problem especially when fitnesses are multiplicative. Using ideas arising from quasi-stationary distributions, we analyze the qualitative differences between the f... We revisit the multi-allelic mutation-fitness balance problem especially when fitnesses are multiplicative. Using ideas arising from quasi-stationary distributions, we analyze the qualitative differences between the fitness-first and mutation-first models, under various schemes of the mutation pattern. We give some stochastic domination relations between the equilibrium states resulting from these models. 展开更多
关键词 EVOLUTIONARY GENETICS FITNESS LANDSCAPE Selection mutation Stochastic models Quasi-Stationarity
下载PDF
<i>In silico</i>analysis of influence of the missense mutation P629S on the molecular interaction and 3D properties of PIK3R5
6
作者 Jameela Shinwari Asma I. Tahir +1 位作者 Saeed Bohlega Nada AlTassan 《Advances in Biological Chemistry》 2013年第4期408-417,共10页
PIK3R5 is the regulatory subunit of Phosphoinositide 3-kinase γ (PI3Kγ) that is responsible for phosphory-lating membrane lipids to activate the AKT pathway. PIK3R5 binds Gβγ and facilitates the interaction with p... PIK3R5 is the regulatory subunit of Phosphoinositide 3-kinase γ (PI3Kγ) that is responsible for phosphory-lating membrane lipids to activate the AKT pathway. PIK3R5 binds Gβγ and facilitates the interaction with p110γ catalytic subunit (PIK3CG) during PI3Kγ activation. The identification of PIK3R5 P629S mutation in AOA2 patients indicated a potential defect in the AKT pathway resulting from impaired PIK3R5 interaction with Gβγ and PIK3CG, defective AKT pathway can result in cerebellar cell death causing neurological symptoms. Our in silico macromolecular docking of the wild type and mutant PIK3R5 protein models with ligand revealed an energy requirement to maintain the mutant complexes compared to no energy required to maintain the wild type complexes, in addition, the mutant structures were loose compared to rigid wild type structures, such structural changes may impair the molecular function of the PIK3R5 and hence affect the AKT pathway. 展开更多
关键词 PIK3R5 MISSENSE mutation Protein modelling PROTEIN-PROTEIN DOCKING PIK3CG Gβγ
下载PDF
Presenilin mutations and their impact on neuronal differentiation in Alzheimer’s disease
7
作者 Mercedes A.Hernández-Sapiéns Edwin E.Reza-Zaldívar +6 位作者 Ana L.Márquez-Aguirre Ulises Gómez-Pinedo Jorge Matias-Guiu Ricardo R.Cevallos Juan C.Mateos-Díaz Víctor J.Sánchez-González Alejandro A.Canales-Aguirre 《Neural Regeneration Research》 SCIE CAS CSCD 2022年第1期31-37,共7页
The presenilin genes(PSEN1 and PSEN2)are mainly responsible for causing early-onset familial Alzheimer’s disease,harboring~300 causative mutations,and representing~90%of all mutations associated with a very aggressiv... The presenilin genes(PSEN1 and PSEN2)are mainly responsible for causing early-onset familial Alzheimer’s disease,harboring~300 causative mutations,and representing~90%of all mutations associated with a very aggressive disease form.Presenilin 1 is the catalytic core of theγ-secretase complex that conducts the intramembranous proteolytic excision of multiple transmembrane proteins like the amyloid precursor protein,Notch-1,N-and E-cadherin,LRP,Syndecan,Delta,Jagged,CD44,ErbB4,and Nectin1a.Presenilin 1 plays an essential role in neural progenitor maintenance,neurogenesis,neurite outgrowth,synaptic function,neuronal function,myelination,and plasticity.Therefore,an imbalance caused by mutations in presenilin 1/γ-secretase might cause aberrant signaling,synaptic dysfunction,memory impairment,and increased Aβ42/Aβ40 ratio,contributing to neurodegeneration during the initial stages of Alzheimer’s disease pathogenesis.This review focuses on the neuronal differentiation dysregulation mediated by PSEN1 mutations in Alzheimer’s disease.Furthermore,we emphasize the importance of Alzheimer’s disease-induced pluripotent stem cells models in analyzing PSEN1 mutations implication over the early stages of the Alzheimer’s disease pathogenesis throughout neuronal differentiation impairment. 展开更多
关键词 familial Alzheimer’s disease familial Alzheimer’s disease-induced pluripotent stem cells models induced pluripotent stem cells neurogenesis neuronal differentiation Notch presenilin 1 PSEN1 mutations γ-secretase complex
下载PDF
Evidence of Mutational Heterogeneity of the ALDH7A1 Gene in Tunisian Families: Molecular and Insilico Investigations
8
作者 Abdelaziz Tlili Marwa kharrat +4 位作者 Emna Mkaouar-Rebai Nadia Hamida-Hentati Sawssan Ben Romdhan Nourhene Fendri-Kriaa Faiza Fakhfakh 《材料科学与工程(中英文B版)》 2016年第4期196-200,共5页
下载PDF
复杂多方向威胁下的导弹预警雷达优化部署方法
9
作者 刘伟 刘昌云 +3 位作者 郭相科 樊良优 何晟 兰昊 《北京航空航天大学学报》 EI CAS CSCD 北大核心 2024年第4期1392-1404,共13页
针对现有导弹预警雷达部署相对独立、协同困难,难以满足大规模对抗场景的现状,从远程预警雷达、跟踪识别雷达、机动式预警雷达不同的任务特点出发,建立应对复杂多方向威胁的多型导弹预警雷达优化部署模型,在满足最优覆盖、协同交接、目... 针对现有导弹预警雷达部署相对独立、协同困难,难以满足大规模对抗场景的现状,从远程预警雷达、跟踪识别雷达、机动式预警雷达不同的任务特点出发,建立应对复杂多方向威胁的多型导弹预警雷达优化部署模型,在满足最优覆盖、协同交接、目标识别等任务约束下,解决雷达协同部署问题。针对所提模型设计了一种基于云自适应的分区优化离散粒子群(CPBPSO)算法,通过设计分区编码策略缩减算法求解空间、加入云自适应变异算子提高算法全局寻优和局部跳出能力,使算法更适用于导弹预警雷达部署问题的处理。实例验证了所提模型在求解单方向、多方向威胁场景部署问题的可行性,对比分析了CPBPSO算法的有效性,基本满足导弹预警雷达最优化协同部署的需求。 展开更多
关键词 导弹预警雷达 协同预警 优化部署模型 云自适应变异 粒子群算法
下载PDF
1956—2019年元谋干热河谷潜在蒸散发的变化及影响因素
10
作者 罗志锋 何真敏 +3 位作者 欧朝蓉 齐丹卉 彭凌霄 孙永玉 《东北林业大学学报》 CAS CSCD 北大核心 2024年第5期89-93,118,共6页
为探究元谋干热河谷地区潜在蒸散发变化特征及其影响因子,通过应用彭曼蒙特斯模型、曼-肯德尔突变检验、气候倾向率和距平相关方法,分时段分析1956—2019年逐日气象要素值。结果表明:元谋干热河谷地区潜在蒸散发整体呈极显著下降的趋势... 为探究元谋干热河谷地区潜在蒸散发变化特征及其影响因子,通过应用彭曼蒙特斯模型、曼-肯德尔突变检验、气候倾向率和距平相关方法,分时段分析1956—2019年逐日气象要素值。结果表明:元谋干热河谷地区潜在蒸散发整体呈极显著下降的趋势,年度潜在蒸散发在1982年发生突变;各季潜在蒸散发变化明显,变化速率从大到小依次为3—5月、12月—次年2月、6—8月、9—11月;除1956—1982年12月—次年2月,1982—2019年9—11月、12月—次年2月潜在蒸散发有所增长外,剩下时段都呈减少趋势,1982年为各季的突变点。潜在蒸散发转折点为1982年;1982年前,年度潜在蒸散发距平占主导;1982年后,负距平占据主导,2008、2015年发生两次较大的波动。元谋干热河谷地区年潜在蒸散发变化主要取决于日照时间、气温和平均相对湿度;各季潜在蒸散发主要是由各气象要素共同作用的结果,且具有季节性差异;1982年以前,6—8月、9—11月潜在蒸散发的减少和12月—次年2月潜在蒸散发的增加仅与平均风速的减弱有关。 展开更多
关键词 元谋干热河谷 潜在蒸散发 彭曼蒙特斯模型 曼-肯德尔突变检验
下载PDF
先天性无虹膜1家系临床特征及基因检测分析
11
作者 李伟候 刘丹宁 《陆军军医大学学报》 CAS CSCD 北大核心 2024年第11期1277-1283,共7页
目的分析先天性无虹膜1家系遗传学特点,了解PAX6基因突变特点及临床表型的差异。方法收集该家系的病史及临床资料,进行全外显子基因测序检查及数据分析,应用同源建模服务器SWISS-MODEL构建对应的蛋白质模型进行分析。结果本家系中4名发... 目的分析先天性无虹膜1家系遗传学特点,了解PAX6基因突变特点及临床表型的差异。方法收集该家系的病史及临床资料,进行全外显子基因测序检查及数据分析,应用同源建模服务器SWISS-MODEL构建对应的蛋白质模型进行分析。结果本家系中4名发病者均因虹膜缺失存在畏光、睁眼困难症状,相同临床表型为无虹膜、白内障、黄斑中心凹发育不良,还存在个体差异表型。基因检测结果显示:4名发病者均为PAX6基因上c.442_452del:p.M148Afs*48的杂合缺失移码变异,该变异在物种间高度保守。同源建模结果提示突变的PAX6基因最终导致蛋白质构象发生差异变化。结论新发现的PAX6基因变异在发病的家系成员中表型不完全相同,通过同源建模分析增加了对PAX6异常表达导致蛋白质结构异常的认识,遗传学检查可对该家系提供遗传学证据。 展开更多
关键词 PAX6基因 基因突变 先天性无虹膜 同源建模
下载PDF
Ⅰ型胶原编码基因突变致成骨不全症动物模型
12
作者 姜运怡 张浩 章振林 《中华骨质疏松和骨矿盐疾病杂志》 CSCD 北大核心 2024年第2期168-175,共8页
成骨不全症(osteogenesis Imperfecta,OI)是一类以低骨量、骨脆性及骨骼畸形为特征的单基因遗传性骨病,研究其病理生理学机制和有效治疗方法的关键是动物模型的应用。绝大部分OI由编码Ⅰ型胶原相关基因突变引起,本文总结了COL1A1和COL1A... 成骨不全症(osteogenesis Imperfecta,OI)是一类以低骨量、骨脆性及骨骼畸形为特征的单基因遗传性骨病,研究其病理生理学机制和有效治疗方法的关键是动物模型的应用。绝大部分OI由编码Ⅰ型胶原相关基因突变引起,本文总结了COL1A1和COL1A2突变的主要动物模型,这些模型是研究致病机制、开发和测试新的治疗策略的宝贵工具。未来的研究将运用CRISPR/Cas9等新型基因编辑技术,结合多种生物类别,优化和拓展OI动物模型,更好地模拟人类疾病,有助于对OI及其治疗方法的深入探索。 展开更多
关键词 成骨不全症 动物模型 Ⅰ型胶原 基因突变
下载PDF
地质突变条件下基于组合模型的围岩等级和TBM掘进参数预测
13
作者 满轲 曹子祥 +4 位作者 刘晓丽 宋志飞 柳宗旭 刘汭琳 武立文 《河海大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第1期55-62,共8页
为了提高硬岩隧道掘进机(TBM)施工的安全性和智能化,基于TBM掘进数据,提出了一种将双向长短期记忆(BiLSTM)网络与支持向量机回归(SVR)算法相结合的可以同时进行围岩等级和TBM掘进参数预测的组合模型(BiLSTM-SVR模型)。实例验证结果表明:... 为了提高硬岩隧道掘进机(TBM)施工的安全性和智能化,基于TBM掘进数据,提出了一种将双向长短期记忆(BiLSTM)网络与支持向量机回归(SVR)算法相结合的可以同时进行围岩等级和TBM掘进参数预测的组合模型(BiLSTM-SVR模型)。实例验证结果表明:BiLSTM-SVR模型对围岩等级的预测准确度较高,均方根误差均小于0.0265、平均绝对百分比误差均小于0.95%;BiLSTM-SVR掘进参数预测中,推力和扭矩的预测准确度最高,净掘进速度和开挖比能的预测准确度最低;BiLSTM-SVR模型比BiLSTM模型和SVR模型的掘进参数预测准确度有较大的提高,因此进行单一模型的组合可以有效提高模型预测的准确度和鲁棒性。 展开更多
关键词 TBM 地质突变 围岩等级 掘进参数 BiLSTM-SVR模型
下载PDF
夫西地酸联合黄芩素对金黄色葡萄球菌的体内外抗菌作用研究
14
作者 冯倩倩 陈淼 +3 位作者 何嘉丽 张晨宇 徐荣 陈春林 《中国抗生素杂志》 CAS CSCD 北大核心 2024年第1期90-99,共10页
目的研究夫西地酸(fusidic acid,FA)联合黄芩素(baicalein,BE)在体内和体外对13株金黄色葡萄球菌的抗菌特性。方法采用微量肉汤稀释法和微量棋盘法测定最小抑菌浓度(minimum inhibitory concentration,MIC)和部分抑菌浓度指数(fractiona... 目的研究夫西地酸(fusidic acid,FA)联合黄芩素(baicalein,BE)在体内和体外对13株金黄色葡萄球菌的抗菌特性。方法采用微量肉汤稀释法和微量棋盘法测定最小抑菌浓度(minimum inhibitory concentration,MIC)和部分抑菌浓度指数(fractional inhibitory concentration index,FICI)。采用FICI评价综合效果,采用时间-杀菌曲线法测定杀菌效果。利用琼脂二倍稀释法对5株金黄色葡萄球菌的防耐药突变浓度(mutant prevention concentration,MPC)和防耐药突变选择窗(mutant selective window,MSW)进行测定,比较夫西地酸单独应用及联用黄芩素后防耐药突变窗的变化。使用金黄色葡萄球菌感染肺炎小鼠模型进行体内实验,测定FA和BE单独和联合治疗后生命体征、肺脏指数、菌落定植数和血清炎症因子的变化。结果研究发现,FA与BE组合的协同效应为53.8%,相加效应为30.8%,无关效应为15.4%。此外,研究人员观察到,当FA与BE以特定浓度(分别为1MIC和1/2MIC)结合时,在24h后对3株金黄色葡萄球菌(SA-ATCC29213、MRSA-ATCC43300和MRSA-210702212)均有杀菌作用。FA对这些菌株的MPCs为128~256μg/mL,而MSWs为64~256μg/mL。而当BE加入混合物时,菌株的MPCs降低到16~32μg/mL,MSWs降低了8~16倍,说明BE提高了FA对这些菌株的抗菌活性。FA和BE的组合对金黄色葡萄球菌肺炎小鼠的生命体征影响很小。小鼠肺脏指数、肺部金黄色葡萄球菌定植数、血清中炎症因子等实验结果表明,FA和BE组合对金黄色葡萄球菌的影响很小,但联合用药组对小鼠肺炎的治疗效果明显优于单药组。结论FA单独应用时,MSW较宽,联用BE后,FA的MSW明显缩小。FA联合BE有协同杀菌效应,治疗小鼠金葡菌肺炎效果较单药组好。 展开更多
关键词 夫西地酸 黄芩素 金黄色葡萄球菌 防耐药突变窗 小鼠肺炎模型
下载PDF
Computed tomography radiogenomics:A potential tool for prediction of molecular subtypes in gastric stromal tumor
15
作者 Xiao-Nan Yin Zi-Hao Wang +6 位作者 Li Zou Cai-Wei Yang Chao-Yong Shen Bai-Ke Liu Yuan Yin Xi-Jiao Liu Bo Zhang 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第4期1296-1308,共13页
BACKGROUND Preoperative knowledge of mutational status of gastrointestinal stromal tumors(GISTs)is essential to guide the individualized precision therapy.AIM To develop a combined model that integrates clinical and c... BACKGROUND Preoperative knowledge of mutational status of gastrointestinal stromal tumors(GISTs)is essential to guide the individualized precision therapy.AIM To develop a combined model that integrates clinical and contrast-enhanced computed tomography(CE-CT)features to predict gastric GISTs with specific genetic mutations,namely KIT exon 11 mutations or KIT exon 11 codons 557-558 deletions.METHODS A total of 231 GIST patients with definitive genetic phenotypes were divided into a training dataset and a validation dataset in a 7:3 ratio.The models were constructed using selected clinical features,conventional CT features,and radiomics features extracted from abdominal CE-CT images.Three models were developed:ModelCT sign,modelCT sign+rad,and model CTsign+rad+clinic.The diagnostic performance of these models was evaluated using receiver operating characteristic(ROC)curve analysis and the Delong test.RESULTS The ROC analyses revealed that in the training cohort,the area under the curve(AUC)values for model_(CT sign),model_(CT sign+rad),and modelCT_(sign+rad+clinic)for predicting KIT exon 11 mutation were 0.743,0.818,and 0.915,respectively.In the validation cohort,the AUC values for the same models were 0.670,0.781,and 0.811,respectively.For predicting KIT exon 11 codons 557-558 deletions,the AUC values in the training cohort were 0.667,0.842,and 0.720 for model_(CT sign),model_(CT sign+rad),and modelCT_(sign+rad+clinic),respectively.In the validation cohort,the AUC values for the same models were 0.610,0.782,and 0.795,respectively.Based on the decision curve analysis,it was determined that the model_(CT sign+rad+clinic)had clinical significance and utility.CONCLUSION Our findings demonstrate that the combined modelCT_(sign+rad+clinic)effectively distinguishes GISTs with KIT exon 11 mutation and KIT exon 11 codons 557-558 deletions.This combined model has the potential to be valuable in assessing the genotype of GISTs. 展开更多
关键词 Gastrointestinal stromal tumor Radiomics Gene mutation Computed tomography model
下载PDF
基于铜死亡相关的铁死亡基因构建预测肝癌患者预后的模型
16
作者 谭天华 宋京海 《现代中西医结合杂志》 CAS 2024年第5期597-601,608,共6页
目的构建基于铜死亡相关的铁死亡基因的预后模型,评估其在肝癌患者中的预测能力,并探讨与免疫功能和肿瘤突变负荷的关系。方法使用TCGA(The Cancer Genome Atlas)数据库分析370例肝癌患者的与铜死亡相关的铁死亡基因和生存数据,并将数... 目的构建基于铜死亡相关的铁死亡基因的预后模型,评估其在肝癌患者中的预测能力,并探讨与免疫功能和肿瘤突变负荷的关系。方法使用TCGA(The Cancer Genome Atlas)数据库分析370例肝癌患者的与铜死亡相关的铁死亡基因和生存数据,并将数据集随机分为训练组和测试组。通过Lasso回归和Cox模型的构建,筛选出与铜死亡相关的铁死亡基因进行风险模型构建。进行单因素和多因素Cox回归分析来验证风险模型对肝癌预后影响的独立性,并分析风险模型与免疫功能和肿瘤突变负荷的关系。结果在多变量Cox回归数据中选择EIF2S1、G6PD、NRAS这3个与铜死亡相关的铁死亡基因,训练组中EIF2S1、G6PD、NRAS与生存期独立相关(P均<0.05),以该3个基因构建风险模型。Kaplan-Meier分析结果显示,与低风险组比较,高风险组患者的生存期较短(P<0.05),生存率较低(P<0.05)。单因素Cox回归分析显示,铜死亡相关的铁死亡基因构建的风险模型中HR为1.734,95%CI为1.494~2.034,P<0.001。多因素Cox回归分析显示,铜死亡相关的铁死亡基因构建的风险模型中HR为1.661,95%CI为1.397~1.976,P<0.001。ROC曲线分析显示,风险模型预测肝癌患者第1,3,5年生存期的曲线下面积(AUC)分别为0.760,0.663和0.636。运用该风险模型进行Kaplan-Meier生存曲线分析显示,与早期肝癌患者相比,晚期肝癌患者生存期更短(P<0.05),生存率更低(P<0.05)。在高风险组和低风险组中,TypeⅡIFN Response、Parainflammation、APC co-stimulation、CCR、Check-point和MHC classⅠ这6个免疫功能的表达存在统计学差异(P均<0.05)。高肿瘤突变负荷组的肝癌患者生存期明显低于低肿瘤突变负荷组的患者(P<0.05)。结论基于与铜死亡相关的铁死亡基因的风险模型能够有效区分肝癌患者的预后,且铜死亡相关的铁死亡基因与免疫功能和肿瘤突变负荷密切相关。 展开更多
关键词 铜死亡 铁死亡 肝癌 基因 预后 风险模型 免疫功能 肿瘤突变负荷
下载PDF
基于突变理论的泥岩隧道稳定性及极限位移确定
17
作者 曹明星 严松宏 杜嘉轩 《兰州交通大学学报》 CAS 2024年第1期8-15,共8页
为了分析第三系富水砂泥岩隧道的稳定性和极限位移的确定,应用突变理论尖点突变模型推导了隧道拱顶下沉的突变判别方程。采用数值模拟对隧道进行开挖,通过改变围岩应力释放系数,找出围岩相应节点塑性应变、速度和加速度的突变点,进而来... 为了分析第三系富水砂泥岩隧道的稳定性和极限位移的确定,应用突变理论尖点突变模型推导了隧道拱顶下沉的突变判别方程。采用数值模拟对隧道进行开挖,通过改变围岩应力释放系数,找出围岩相应节点塑性应变、速度和加速度的突变点,进而来判断隧道极限位移值。得出第一部开挖,围岩应力释放率为75%时,塑性应变加速度出现突变点,拱顶下沉为17.06 cm;第二部开挖时,围岩应力释放率为75%时,塑性应变加速度出现突变点,拱顶下沉为19.77 cm;第三部开挖时,围岩应力释放率为65%时,塑性应变加速度出现突变点,拱顶下沉为24.77 cm;第四部开挖时,围岩应力释放率为60%时,塑性应变加速度出现突变点,拱顶下沉为25.52 cm;第五部开挖时,围岩应力释放率为50%时,塑性应变加速度出现突变点,拱顶下沉为25.87 cm;第六部开挖时,围岩应力释放率为45%时,塑性应变加速度出现突变点,拱顶下沉为25.93 cm。 展开更多
关键词 砂泥岩 数值模拟 尖点突变模型 应力释放 隧道极限位移
下载PDF
基于ACBO-GM联合方法的高维变量结构模型修正
18
作者 夏志远 王友 +2 位作者 唐柏鉴 周广东 史慧媛 《噪声与振动控制》 CSCD 北大核心 2024年第4期8-14,21,共8页
工程结构模型修正常面临变量维度高、非线性程度强等现实问题,其模型修正的精度和效率受到严重影响,为改善这一不足,提出基于改进物体碰撞算法(Advanced Colliding Bodies Optimization,ACBO)和高斯白噪声扰动(Gaussian-white-noise Mut... 工程结构模型修正常面临变量维度高、非线性程度强等现实问题,其模型修正的精度和效率受到严重影响,为改善这一不足,提出基于改进物体碰撞算法(Advanced Colliding Bodies Optimization,ACBO)和高斯白噪声扰动(Gaussian-white-noise Mutation,GM)的联合修正方法。在联合方法中,ACBO实现从传统的“一对一”到“优对多”的碰撞模式的转变,GM则用于保证碰撞过程中种群的多样性,可有效提升结构模型修正效率。基于一系列测试函数,对比分析标准物体碰撞算法(Colliding Bodies Optimization,CBO)和联合优化方法的优化性能;给出基于ACBO-GM联合方法的修正流程,并将其应用于钢框架修正算例和悬臂梁修正实例,对比研究基于联合修正方法与基于遗传算法(Genetic Algorithm,GA)的修正精度和效率。研究表明,ACBO-GM联合优化方法在精度和效率方面都明显优于传统的CBO方法,该优化方法的可行性得到验证;基于ACBO-GM联合方法在钢框架和悬臂梁两个工程结构修正案例中的应用,其修正精度均与基于GA方法的精度一致,但修正效率显著优于基于GA的修正方法。 展开更多
关键词 振动与波 改进物体碰撞算法 高斯白噪声扰动 模型修正 联合优化方法 遗传算法
下载PDF
结直肠癌与铜死亡相关基因的相关性研究
19
作者 周玲 唐梅文 +4 位作者 谢佳涛 陈文隆 钟丰羽 许琦 古文姝 《实用中医内科杂志》 2024年第1期41-45,I0006-I0009,共9页
目的探讨结直肠癌(colorectal cancer,CRC)与新型铜死亡相关生物标志物的相关性,为治疗CRC患者预后提供理论支持。方法在研究中,CRC患者的LncRNA表达谱、临床数据以及突变数据下载来自癌症基因组图谱(TCGA)CRC数据库,使用R4.1.1软件筛... 目的探讨结直肠癌(colorectal cancer,CRC)与新型铜死亡相关生物标志物的相关性,为治疗CRC患者预后提供理论支持。方法在研究中,CRC患者的LncRNA表达谱、临床数据以及突变数据下载来自癌症基因组图谱(TCGA)CRC数据库,使用R4.1.1软件筛选出与铜死亡相关LncRNA,通过单因素Cox回归分析得到与CRC预后相关的铜死亡LncRNA,采用LASSO Cox回归及交叉验证及多因素Cox分析得出的最显著的LncRNA构建最优预后模型。根据得到的风险评分,将纳入的结直肠癌患者划分为高风险组和低风险组。对构建的模型进行Kaplan-Meier进行生存(OS)及无进展生存期差异分析。同时建立ROC曲线对模型进行验证并建立临床分组验证。随后对差异基因进行基因本体论(GO)、京都基因和基因组百科全书(KEGG)分析。我们还计算了泛癌数据中TMB状态与基因表达之间的相关性,筛选出对CRC治疗的敏感药物。结果获得36个铜死亡预后相关的LncRNA,且使用LASSO Cox回归及交叉验证及多变量Cox分析从上述36个具有预后意义的铜死亡相关的LncRNA中筛选出17个显著相关的LncRNA(DEGs)。接着使用Kaplan-Meier生存分析、无进展生存期及风险差异分析,证明高低风险组是有差异的(P<0.05),ROC曲线显示该预后模型曲线下面积在1年内为0.749,2年内为0.705,3年内为0.710。GO分析结果显示这些交集基因在生物过程主要富集于细胞二价无机阳离子同源等,细胞成分主要富集在含胶原蛋白的细胞外基质,在分子功能主要富集在受体配体a等。KEGG提示主要富集在细胞因子-细胞因子受体相互作用和吞噬体等通路。肿瘤突变负荷的生存分析和药物敏感性是有差异的。结论通过生物信息学方法,构建了17个与铜死亡相关基因的预后模型,可能奠定了结直肠癌患者的个体化治疗和评估的基础。 展开更多
关键词 结直肠癌 TCGA 铜死亡 预后模型 肿瘤突变 潜在药物选择
下载PDF
一种新的导致遗传性凝血因子Ⅶ缺陷症的基因突变分析
20
作者 王莹宇 张永根 陈文柏 《中国实验血液学杂志》 CAS CSCD 北大核心 2024年第3期857-861,共5页
目的:对一例遗传性凝血因子Ⅶ(FⅦ)缺陷症的患者及其家系进行基因分析,探讨其分子发病机制。方法:使用Sysmex-CS5100全自动血凝分析仪检测先证者及其家系成员(共3代8人)的凝血酶原时间(PT)、活化部分凝血活酶时间、凝血酶时间、D-二聚... 目的:对一例遗传性凝血因子Ⅶ(FⅦ)缺陷症的患者及其家系进行基因分析,探讨其分子发病机制。方法:使用Sysmex-CS5100全自动血凝分析仪检测先证者及其家系成员(共3代8人)的凝血酶原时间(PT)、活化部分凝血活酶时间、凝血酶时间、D-二聚体、纤维蛋白降解产物以及血浆FⅦ的活性(FⅦ:C)水平;PCR法扩增先证者凝血因子Ⅶ基因(F7)所有外显子和侧翼序列,PCR产物纯化后测序,发现突变位点则反向测序给予证实;使用Clustal W软件对突变位点进行保守性分析;应用Mutation Taster和Poly Phen-2在线生物学软件评估突变氨基酸对FⅦ蛋白结构与功能的危害性;运用Swiss软件对突变建模分析。结果:凝血常规检查结果显示,先证者PT单独性延长至42.5 s;FⅦ:C明显降低,仅为2%;同样先证者外婆、母亲和妹妹的FⅦ:C都有轻度降低,分别为49%、51%和42%;父亲各指标均在正常参考范围。基因分析结果显示,先证者F7基因第6号外显子c DNA的646位发生G>A杂合突变,导致FⅦ催化区的156位甘氨酸被替换为丝氨酸(p.Gly156Ser)。F7其他外显子和侧翼序列的测序结果均正常。其外婆、母亲和妹妹均携带c.646G>A杂合突变,父亲为正常野生型。模型构建显示p.Gly156Ser突变使该位点氨基酸极性发生改变并出现侧链,从而使蛋白的不稳定性增加,可能影响所在结构域的催化活性。同时,Mutation Taster和Poly Phen-2两个在线生物信息学软件也高分预测该突变具有致病性。结论:该遗传性凝血因子Ⅶ缺陷症患者FⅦ蛋白p.Gly156Ser错义突变与血浆FⅦ:C水平降低有关。 展开更多
关键词 遗传性凝血因子Ⅶ缺陷症 PCR 基因突变 模型分析
下载PDF
上一页 1 2 26 下一页 到第
使用帮助 返回顶部