检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

解释结核分枝杆菌DNA指纹簇

国际结核病与肺部疾病杂志 2000年第1期3卷 4-9页

作者： J.R.Glynn J.Bauer A.S.deBoer m.W.Borgdorff p.e.m.fine p.Godfrey-Faussett e.Vynnycky 丁北川 Department of Infectious and Tropical Diseases London School of Hygiene and Tropical Medicine Keppel St LondonUK Department of mycobacteriology Statens Serum Institut Copenhagen Denmark National Institute of public Health and the environment Bilthoven Royal Netherlands Tuberculosis Association The Hague The Netherlands Department of Infectious and Tropical Diseases London School of Hygiene and Tropical Medicine Keppel St London UK european Concerted Actionon molecular epidemiology Control of Tuberculosis

许多研究已在其结核分枝杆菌分离株共享DNA指纹的基础上定义了患者簇。成簇相当于最近的传播,并且对伴随结核分枝杆菌正在高度传播人群亚组来说,与成簇有关的因素已作为指标被找出。在进行和解释这些研究中值得考虑的提醒应予以注意。例... 详细信息

许多研究已在其结核分枝杆菌分离株共享DNA指纹的基础上定义了患者簇。成簇相当于最近的传播,并且对伴随结核分枝杆菌正在高度传播人群亚组来说,与成簇有关的因素已作为指标被找出。在进行和解释这些研究中值得考虑的提醒应予以注意。例如,根据标志物的稳定性和长时间在人群中的菌株数量,某些并非近期传播的原因使菌株组可能完全相同。如果病例对特定人群是新移民或在研究中不是所有人群中的病例都被包括的话,确定由近期传播引发的病例可能不作为成簇被见到。所见的成簇数量将根据研究持续的时间。在研究的设计、所包括病例的比例、补充和所使用成簇的界定上,研究应给出精确的资料。成簇的数据应至少被年龄、性别和移民状况分开。为了最大的获得信息,研究应涉及一个人群中所有病例的高比例、与传统的流行病学接触调查结合进行(如果可能的话)、并且提供人群中结核病发病资料和患者的年龄、性别、人类免疫缺损病毒状况、耐药性及社会和种族组资料。关键词:结核病;分子流行病学;DNA指纹;RFLp;传播;

关键词：结核分枝杆菌 tuberculosis DNA指纹 mycobacterium 成簇流行病学 Tropic 菌株结核病时间窗口

在非洲农村将接触结核病作为发生结核病的一个危险因素的评价与评估

在线全文

学校读者我要写书评

暂无评论

国际结核病与肺部疾病杂志 2008年第4期3卷 158-163页

作者： A.C.Crampin S.Floyd B.m.Ngwira V.mwinuka J.N.mwaungulu K.Branson p.e.m.fine J.R.Glynn 张晓进何广学 Karonga prevention Study ChilumbaMalawi London School of Hygiene and Tropical medicine LondonUK

背景:马拉维的一个农村地区目的:确定非精确回顾法对估算确诊结核病病例接触者发生结核病的影响。方法:对实验室确诊的结核病例与社区对照组进行病例对照研究,对一个结核病数据库内准备访谈的结核病患者的亲属、家庭成员和地区接触者进... 详细信息

背景:马拉维的一个农村地区目的:确定非精确回顾法对估算确诊结核病病例接触者发生结核病的影响。方法:对实验室确诊的结核病例与社区对照组进行病例对照研究,对一个结核病数据库内准备访谈的结核病患者的亲属、家庭成员和地区接触者进行比较。估算有接触史是患结核病的一个危险因素并确定接触者的有关的因素。结果:95%的被确定的接触者是已知的结核病病例。访谈的接触者占确定的接触者的比例为75%,病例组和对照组相似。先前有接触史在病例组是对照组的2倍。数据库信息的加入并没有影响比值比,但是增加了有接触史者患病的比例。远期发生的病例多为涂片阳性、男性和HIV阴性结核病患者。与涂片阳性患者有近期接触的结核病患者占12.5%。结论:确定的接触者报告显示较小的回顾偏倚,可以估算结核病接触者与结核病的相对危险度。被确定为接触者的HIV阳性病例较低可能反映降低了传染力。

关键词：结核接触者马拉维流行病学 hiv

非洲农村某高HIV流行地区利用两涂片与三涂片法诊断培阳肺结核病人的效果比较

在线全文

学校读者我要写书评

暂无评论

国际结核病与肺部疾病杂志 2002年第4期 142-146页

作者： A.C.Crampin S.Floyd F.mwaungulu G.Black R.Ndhlovu e.mwaiyeghele J.R.Glynn D.K.Warndorff p.e.m.fine 贺晓新 Karonga prevention Study Chilumba Malawi Department of Infectious and Tropical Diseases London School of Hygiene and Tropical Medicine London UK mRC Laboratories Fajarao The Gambia Karonga prevention Study Chilumba Malawi Department of Infectious and Tropical Diseases London-School of Hygieneand Tropical Medicine London UK mRC Laboratories Fajara The Gambia Department of Infectious and Tropical Diseases London School of Hygiene and Tropical Medicine London UK

地点:北马拉维Karonga地区。目的:比较在高HIV流行条件下两涂片法与三涂片法诊断肺结核的灵敏度和特异度。设计:共对1992例可疑肺结核病人进行了检查,这些病人都有在2-7天内进行的三涂片检查结果以及至少一份标本的培养检查结果。涂... 详细信息

地点:北马拉维Karonga地区。目的:比较在高HIV流行条件下两涂片法与三涂片法诊断肺结核的灵敏度和特异度。设计:共对1992例可疑肺结核病人进行了检查,这些病人都有在2-7天内进行的三涂片检查结果以及至少一份标本的培养检查结果。涂片先以金胺染色并在荧光显微镜下观察,阳性者再行萋尼氏染色并在光学显微镜下观察确诊。培养检查采用L(?)wenstein-Jensen培养基接种法。标本的真阴性和真阳性根据培养检查结果而定。对两涂片法和三涂片法的诊断灵敏度、特异度以及阴性和阳性预测值进行了比较。结果:与培养结果相比,三涂片法的灵敏度、特异度以及阳性和阴性预测值分别是70％、98％、92％和92％。头两份标本的涂片检查可以给出相似的结果。在三涂片法发现的阳性病例中,两涂片法至少可以发现其中的97％。就具有HIV检查结果的病例而言,两涂片法诊断培阳病例的灵敏度与三涂片法相同。结论:在本研究条件下,应用荧光显微镜和光学显微镜,采用两涂片法替代三涂片法只略微降低了诊断灵敏度,但也稍微提高了诊断特异度;而且上述结果不受HIV感染状态的影响。考虑到误诊的高昂成本,提高诊断的特异度具有重要意义。在结核病控制实践中,由于采用两涂片法代替三涂片法可以节约大量时间。

关键词：结核病诊断痰涂片检查 HIV 非洲

在线全文

学校读者我要写书评

暂无评论

美国页岩油气地质特征及勘探开发进展

石油勘探与开发 2024年第4期51卷 807-828页

作者： mCmAHON T p LARSON T e ZHANG T SHUSTeR m 美国德克萨斯大学奥斯汀分校杰克逊地质科学学院经济地质局奥斯汀78758-4445德克萨斯州美国

基于美国页岩油气勘探开发历程的回顾,对主要页岩盆地的地质演化、主要页岩层系的油气地质特征及勘探开发进展进行系统梳理和总结。美国重要页岩盆地的富烃页岩主要发育于6个地质时期:中奥陶世、中—晚泥盆世、早石炭世(中—晚密西西比... 详细信息

基于美国页岩油气勘探开发历程的回顾,对主要页岩盆地的地质演化、主要页岩层系的油气地质特征及勘探开发进展进行系统梳理和总结。美国重要页岩盆地的富烃页岩主要发育于6个地质时期:中奥陶世、中—晚泥盆世、早石炭世(中—晚密西西比世)、早二叠世、晚侏罗世和晚白垩世(塞诺曼期—土伦期),构造沉积环境主要包括克拉通内盆地、前陆盆地和被动大陆边缘盆地。古生界富烃页岩主要分布于以下6个盆地:阿巴拉契亚盆地(尤蒂卡页岩和马塞勒斯页岩)、阿纳达科盆地(伍德福德页岩)、威利斯顿盆地(巴肯页岩)、阿卡马盆地(费耶特维尔页岩)、沃思堡盆地(巴内特页岩)和二叠盆地(狼营组和斯帕瑞组/骨泉组页岩)。中生界富烃页岩主要发育在西墨西哥湾盆地(海恩斯维尔组和鹰滩组)和落基山盆地群(以丹佛和粉河盆地的尼尔布拉勒组页岩为主)。通过对各页岩区带的详细分析发现,页岩的岩相和矿物成分存在差异,“页岩储层”并非只是页岩,很多情况下页岩油气还产自粉砂岩和碳酸盐岩等多种岩石类型。美国的页岩油气资源丰富,页岩油地质资源量超过0.246×1012 t,页岩气地质资源量超过290×1012 m3。在开启“页岩革命”的水平井水力压裂技术出现之前,美国经过了长达20年的勘探开发实践和理论技术积累。自2007年至2023年,美国页岩油气产量从约11.2×104t/d油当量增加到超过300.0×104t/d油当量,2017年页岩油气产量超过了常规油气,2023年在油气总产量中的占比增加到60%以上。页岩油气的开发主要得益于钻完井技术的改进,“立体开发”的攻关,以及重复压裂、提高原油采收率和“U”形井等技术的应用。基于美国丰富的页岩资源基础和技术的不断进步,页岩油气的产量将继续为全美的油气生产做出更大贡献。

关键词：美国页岩油页岩气页岩储层非常规储层油气产量资源评价

Impact of device resistances in the performance of graphene‑based terahertz photodetectors

同方期刊数据库

同方期刊数据库更多评论

在线全文

学校读者我要写书评

暂无评论

Frontiers of Optoelectronics 2024年第2期17卷 87-97页

作者： O.Castelló Sofía m.López Baptista K.Watanabe T.Taniguchi e.Diez J.e.Velázquez-pérez Y.m.meziani J.m.Caridad J.A.Delgado-Notario Department of Applied physics University of Salamanca37008 SalamancaSpain Unidad de excelencia en Luz y materia estructurada(LUmeS) University of Salamanca37008 SalamancaSpain Research Center for electronic and Optical materials National Institute for Materials Science1-1 NamikiTsukuba 305-0044Japan Research Center for materials Nanoarchitectonics National Institute for Materials Science1-1 NamikiTsukuba 305-0044Japan Nanotechnology Group USAL-NanolabUniversity of Salamanca37008 SalamancaSpain

In recent years,graphene field-effect-transistors(GFeTs)have demonstrated an outstanding potential for terahertz(THz)photodetection due to their fast response and *** features are essential to enable emerging THz applications,including 6G wireless communications,quantum information,bioimaging and ***,the overall performance of these photodetectors may be utterly compromised by the impact of internal resistances presented in the device,so-called access or parasitic *** this work,we provide a detailed study of the influence of internal device resistances in the photoresponse of high-mobility dual-gate GFeT *** dual-gate architectures allow us to fine tune(decrease)the internal resistance of the device by an order of magnitude and consequently demonstrate an improved responsivity and noise-equivalent-power values of the photodetector,*** results can be well understood by a series resistance model,as shown by the excellent agreement found between the experimental data and theoretical *** findings are therefore relevant to understand and improve the overall performance of existing high-mobility graphene photodetectors.

关键词： Graphene THz photodetector Field-effect transistor plasmonic

enhanced quantum resources via two distant atom-cavity systems under the influence of atomic dissipation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical physics 2024年第2期76卷 62-73页

作者： m Setodeh Kheirabady m K Tavassoly m Rafeie e Ghasemian Laser and Optics Group Faculty of PhysicsYazd UniversityYazd 89195-741Iran Department of electrical engineering Faculty of Intelligent Systems Engineering and Data SciencePersian Gulf UniversityBushehrIran

Quantum resources such as entanglement and coherence are the holy grail for modern quantum technologies. Although the unwanted environmental effects tackle quantum information processing tasks, suprisingly these key quantum resources may be protected and even enhanced by the implementation of some special hybrid open quantum systems. Here, we aim to show how a dissipative atom-cavity-system can be accomplished to generate enhanced quantum *** do so, we consider a couple of dissipative cavities, where each one contains two effective two-level atoms interacting with a single-mode cavity field. In practical applications, a classical laser field may be applied to drive each atomic subsystem. After driving the system, a Bell-state measurement is performed on the output of the system to quantify the entanglement and coherence. The obtained results reveal that the remote entanglement and coherence between the atoms existing inside the two distant cavities are not only enhanced, but can be stabilized, even under the action of dissipation. In contrast, the local entanglement between two atoms inside each dissipative cavity attenuates due to the presence of unwanted environmental ***, the local coherence may show the same behavior as the remote ***, the system provides the steady state entanglement in various interaction regimes,particularly in the strong atom-cavity coupling and with relatively large detuning. more interestingly, our numerical analyses demonstrate that the system may show a memory effect due to the fact that the death and revival of the entanglement take place during the interaction. Our proposed model may find potential applications for the implementation of long distance quantum networks. In particular, it facilitates the distribution of quantum resources between the nodes of large-scale quantum networks for secure communication.

关键词： remote entanglement and coherence atomic dissipation steady state entanglement Bell-statemeasurement

BaTiO3 solid solutions co-doped with Gd3+ and eu3+:Synthesis,structural evolution and dielectric properties

在线全文

学校读者我要写书评

暂无评论

Journal of Rare earths 2024年第10期42卷 1920-1926页

作者： R.martínez-López m.pérez-Labra J.A.Romero-Serrano F.R.Barrientos-Hernández m.Reyes-pérez m.I.Valenzuela-Carrillo G.Urbano-Reyes V.e.Reyes-Cruz G.I.Dávila-pulido Academic Area of earth Sciences and materials Autonomous University of Hidalgo State metallurgy and materials Department ESIQIE-IPNUPALM Autonomous University of Coahuila Boulevard Adolfo López Mateos S/n

In this paper,the synthesis,structural evolution,and dielectric properties of BaTiO3solid solutions codoped with rare earth elements(Gd3+and eu3+) prepared using the solid-state reaction method are *** pure precursor powders of BaCl3,TiO2,Gd2O3,and eu2O3were mixed in stoichiometric proportions,ground in an agate mortar before being uniaxially pressed at 250 mpa and sintered at 1300℃ in air atmosphere for 6 h to obtain Ba1-3xGd2xTi1-3xeu4xO3（x=0,0.0015,0.01 and0.1）.X-ray diffraction（XRD） and Rietveld's refinement results reveal the crystal phase ferroelectric tetragonal BaTiO3for the samples with x=0,0.0015 and 0.01, as well as a consistent increment in the lattice parameters caused by the *** solubility limit of Gd3+and eu3+in the BaTiO3structure is reached for the sample with x>0.01,and the orthorhombic eu2TiO5and monoclinic BaTi2O5secondary phases were *** Raman results show the characteristic peaks of ferroelectric tetragonal BaTiO3around 716 cm-1（LO of A1 symmetry）,515 cm-1（TO of A1 symmetry）,and 305 cm-1（B1）.The maximum relative permittivity measured at 1 kHz was recorded to be 6151.8 for the sample with x=0.0015,and a decrease in the Curie temperature to 105℃ with respect to the undoped sample was *** punctual microanalysis for the samples with x=0.0015,0.01,and 0.1 reveals grains composed of Ba,Ti,O,Gd,and eu homogeneously distributed in the *** Ba/Ti ratios for samples with x=0.0015,0.01 and 0.1 are 2.86,2.91,and 0.68,respectively,indicating substitution at the Ti site for samples with x=0.0015 and 0.01 and a substitution at the Ba site for the sample with x=0.1.

关键词： BaTiO3 Doping europium Gadolinium Rare earths Synthesis

Novel Framework for an Intrusion Detection System Using multiple Feature Selection methods Based on Deep Learning

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2024年第4期29卷 948-958页

作者： A.e.m.eljialy mohammed Yousuf Uddin Sultan Ahmad Department of Information Systems College of Computer Engineering and SciencesPrince Sattam Bin Abdulaziz UniversityAlkharjSaudi Arabia Department of Computer Science College of Computer Engineering and SciencesPrince Sattam Bin Abdulaziz UniversityAlkharjSaudi Arabiaand also with University Center for Research and Development(UCRD)Department of Computer Science and EngineeringChandigarh UniversityPunjabIndia

Intrusion detection systems (IDSs) are deployed to detect anomalies in real time. They classify a network’s incoming traffic as benign or anomalous (attack). An efficient and robust IDS in software-defined networks is an inevitable component of network security. The main challenges of such an IDS are achieving zero or extremely low false positive rates and high detection rates. Internet of Things (IoT) networks run by using devices with minimal resources. This situation makes deploying traditional IDSs in IoT networks unfeasible. machine learning (mL) techniques are extensively applied to build robust IDSs. many researchers have utilized different mL methods and techniques to address the above challenges. The development of an efficient IDS starts with a good feature selection process to avoid overfitting the mL model. This work proposes a multiple feature selection process followed by classification. In this study, the Software-defined networking (SDN) dataset is used to train and test the proposed model. This model applies multiple feature selection techniques to select high-scoring features from a set of features. Highly relevant features for anomaly detection are selected on the basis of their scores to generate the candidate dataset. multiple classification algorithms are applied to the candidate dataset to build models. The proposed model exhibits considerable improvement in the detection of attacks with high accuracy and low false positive rates, even with a few features selected.

关键词： random forest feature selection decision tree software-defined network logistic regression intrusion detection system XGB classifier AdaBoost

evaluation of the seismic behavior of reinforced concrete structures with flat slab-column gravity frame and shear walls through nonlinear analysis methods

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

earthquake engineering and engineering Vibration 2024年第3期23卷 713-726页

作者： m.A.Najafgholipour S.Heidarian Radbakhsh e.erfani Department of Civil and environmental engineering Shiraz University of TechnologyShiraz ***Iran Department of Building Civiland Environmental EngineeringConcordia UniversityMontréal H3G 1M8Canada

This paper presents an investigation of the seismic behavior of reinforced concrete(RC)structures in which shear walls are the main lateral load-resisting elements and the participation of flat slab floor systems is not considered in the seismic design *** this regard,the behavior of six prototype structures(with different heights and plan layouts)is investigated through nonlinear static and time history analyses,implemented in the OpenSees *** results of the analyses are presented in terms of the behavior of the slab-column connections and their mode of failure at different loading ***,the global response of the buildings is discussed in terms of some parameters,such as lateral overstrength due to the gravity flat slab-column *** to the nonlinear static analyses,in structures in which the slab-column connections were designed only for gravity loads,the slab-column connections exhibited a punching mode of failure even in the early stages of ***,the punching failure was eliminated in structures in which a minimum transverse reinforcement recommended in ACI 318(2019)was provided in the slabs at joint ***,despite neglecting the contribution of gravity flat slab-column frames in the lateral load resistance of the structures,a relatively significant overstrength was imposed on the structures by the gravity frames.

关键词： RC flat slab-column frames seismic behavior nonlinear analysis time history analysis