在孟加拉国腹泻儿童中很少查出肠结肠炎耶尔辛氏菌

肠结肠炎耶尔辛氏致病菌,已被确认为腹泻和类似阑尾炎综合症的病原。在欧洲和美国虽然巳报导了许多耶尔辛氏菌病例,但在热带腹泻疾病中其作用一直没有正确的估价。在孟加拉国早期的调查中,有一份报告宣称无耶尔辛氏菌;而另一报道显示从死于腹泻的患者分离出一株肠结肠炎耶尔辛氏菌血清O:7,8型菌株。本文的目的是进一步探讨关于热带地区,患腹泻和类似阑尾炎综合症患者耶尔辛氏菌的感染率。 在9个月期间(1984年1—9月),于达卡的国际腹泻疾病研究中心(ICDDR,B),孟加拉医院就诊的病人中采集了1450份大便标本。选择对象为7岁以下体检或病史证明有发热和腹泻的儿童。在这个医院对80例死于腹泻进行尸解的病人中,采集了小肠和结肠的内容物。另在达卡的一个教会医院阑尾切除术中收集的31份阑尾标本也进行了检验。把每一份稀大便或小肠内容物放入蛋白胨水中,将标本的一部分用碱处理后,在选择琼脂培养基或麦凯康氏     

Geometric integration methods for general nonlinear dynamic equation based on Magnus and Fer expansions

Ithasbeenknownforalongtimethatthesolu tionofthefollowingdifferentialequation :U· =A(t)U ,　U(t0 ) =I ,(1)whereA (t)standsforasufficientlysmoothn×nmatrixorlinearoperator ,canlocallybewrittenintheform[1]U(t ,t0 ) =eΩ(t,t0 ) ,(2 )whereΩisobtainedasaninfiniteseriesΩ(t ,t0 ) =∑∞k =1Ωk(t,t0 ) . (3)Eqs .(2 )and (3)constitutetheso calledMagnusex pansionofthesolutionofthedifferentialequation(1) .EachtermΩkintheseries (3)isamultiplein tegralofcombinationsofnestedcommutators ,anditcanbeobtain…     

An eSnake model for medical image segmentation

Deformable model is a curve or a surface drivenpartial differential equations (PDE) method for imagesegmentation and pattern recognition. Two types ofdeformable models have been developed previously.One is the parametric deformable model proposed byKass et al.[1], which formulates the curve explicitlyin the parametric form. The other is the geometricdeformable model, which implicitly characterizes thecurve by a level set function developed by Osher,Sethian and implement…     

Petrological implication of wagnerite-Ma5bc in the quartzofeldspathic gneiss, Larsemann Hills, East Antarctica

Mg dominantmineralsofwagnerite triplite group,i.e.(Mg,Fe,Mn)2(PO4)(F,OH),arerelativelyrare,buthavebeenfoundinawidevariety ofgeologicenvironments,includingmetamorphic rocksofallgrades[1]suchasquartz carbonateveinsof hydrothermalorigin,pegmatites,kyanite quartzite,micaschist,sillimanitegneiss,andmagnetiteores.Uptonow,wagneriteispresentmainlyasthe Ma2bcpolytype,anaccessorymineralincalcium poorrocks[2,5]inwhichapatite,ifpresent,oftenoc cursasretrograderimaroundwagnerite.Henriques[6]reportedasma…     

A mathematical model for solid liquid and mass transfer coupling and numerical simulation for hydraulic fracture in rock salt

Thehydraulicfracturingtechniqueiswidelyused intheoilengineering,naturalgasexploiting,under groundheatextractingandothermineralresources mining,etc.withwelldevelopedhydraulicfracture modelsforordinaryrocks[1—3].Inthefieldofsolu tionminingofsaltdeposit,thistechniqueisusedto producefracturealongtheplanelayerofthedeposit,thustoconnecttheinjectionandtargetwells[4,5].However,duetothespecialphysicalandmechanical characteristicsofrocksalt,executinghydraulicfrac tureinrocksaltdepositisdifferentfromtha…     

An FPGA Implementation of GF(p) Elliptic Curve Cryptographic Coprocessor

0　IntroductionE lliptic Curve Cryptosystems have emerged as a promis ing new area in public key cryptography since it wasfirst introduced in the mid 1980’s[1,2]. Compared with otherestablished public key cryptosystems, the main attraction ofell…     

数值学报（2003年第12卷）

本书是由英国剑桥大学出版、发行的不定期专题论文集，每年出版一卷，登载数值分析、计算方法及其应用等方面的高水平创造性研究论文或综述报告，论文作者多为当代相关领域的国际性学术带头人。     

软件工程知识的获取

本书是由新加坡世界科技出版公司出版的《软件工程与知识工程丛书》的第14卷。未来的软件系统将分布在整个网络上，并具有专门从事不同活动的代理。每一个代理都具有不同程度上的自治。软件开发机构将会依靠这些代理，利用不同的程序开发过程来生产软件程序。本书从遗传编程的角度讨论了具体的不同之处。作者试图通过设计一个用于演化程序的软件工程环境系统（SWEEP），来使我们对于开发多代理、多过程的未来的洞察力变得更为具体。SWEEP系统使用遗传编程在软件的创建与修改中起了中心的作用。此外，还对度量学特别注意，探索了可通用性、程序肿胀和有效程序长度问题。