Viral gastroenteritis It is thought that viruses are responsible for up to 3/4 of all infective diarrhoeas Viral gastroenteritis is the second most common viral illness after upper respiratory tract infection

Categories of Respiratory Viruses Orthomyxoviridae: Influenza virus Paramyxoviridae: Parainfluenza virus, Mumps virus; Measles, Respiratory syneytical virus Togaviridae: Rubella virus Coronaviridae: corona irus, sars virus Adenoviridae: human Adenovirus picornaviridae: Rhino virus;

What does a pathogen have to do? Infect (infest) a host Reproduce(replicate) itself Ensure that its progeny are transmitted to another host

Spirochetes Gram negative Long, thin, helical, motile axial filaments locomotion between peptidoglycan layer/outer membrane runs parallel

Mycoplasmas a group of the smallest organisms that can be free living in nature, Pass bacterial filter and also grow on laboratory media. More than 80 species, belong to Mycoplasmatales of mollicute. 3 families can be divided:

brucella The genus Brucella consists of six species four of which cause human brucellosis Afj 鲁菌病: Brucella melitensis羊布鲁菌, Brucella suis猪布鲁菌, Brucella abortus 牛布鲁菌, and brucella canis犬布鲁菌 Are all intracellular organisms .B neotomaeB ovis

MYCOBACTERIUM THIS GENUS IS COMPOSED OF. Strictly aerobic, acid-fast rods, does not Stain well (gram stain indeterminant) DNA has high g+c content, unique cell wall, Mycolic acid carbon chain length c60 Relatively slow growth(two groups) A. RAPID GROWERS (Visible colonies in <5 days B SLOW GROWERS (Visible colonies in 5 days)

Actinomyces Israelii Anaeslundii a Gram positive sulfur granule; Related to decay tooth and peridentitis

Vibrio sp Gram-negative rods Curves or comma shaped Non-spore forming Highly motile-single polar flagella Associated with salt water Oxidase positive

1.3 流体流动的基本方程 1.3.1 基本概念 1.3.2 质量衡算方程 1.3.3 运动方程 一、作用在流体上的力 二、运动方程 三、N-S方程 四、欧拉方程 五、不可压缩流体稳定层流时的N-S 方程若干解