飞机机舱内的气压

正同学们,你乘坐过飞机吗?乘坐飞机时,在飞机起飞和降落的过程中,耳朵常常会感到不适,这是为什么?这与客机机舱内的气压有关。我们知道,民航客机的飞行高度一般为9000米~12000米。而大气压随高度增加而减小,万米高空的气压大约只有地面附近的30%。     

内毒素对大鼠小肠黏膜组织的影响及多价阳离子A的保护效应

旨在揭示大肠埃希菌内毒素(ET)对大鼠小肠黏膜的结构、绒毛长度、上皮内淋巴细胞(IEL)的数量和分布的影响,并探讨多价阳离子A(CA)对上述指标的保护效应。选用72只140g~150g SPF级SD大鼠随机分为3组,即对照组、ET组和CA保护组,经相应处理后分别在3、4、8、12h采集十二指肠、空肠组织作为检测样本,制备病理组织切片,HE染色并利用图像分析系统进行分析。ET组十二指肠和空肠绒毛长度在3、4、8、12h均显著低于对照组和CA保护组(P0.01),ET组十二指肠、空肠IEL数量在3、4、8、12h均显著低于对照组(P0.01);CA保护组十二指肠和空肠IEL数量在4、8、12h均显著高于ET组(P0.01)。结果显示,ET在不同程度上能够破坏小肠黏膜的正常组织结构,降低小肠绒毛长度,减少IEL的数量,从而影响小肠正常的吸收和免疫功能,而CA则能明显降低ET所导致的毒性作用,发挥其保护效应。     

奶牛子宫内膜炎继发黄体囊肿的诊治体会

<正>最近一段时间,遵化市铁厂镇的一奶牛养殖小区接连出现了牛子宫内膜炎的情况。养殖场主求助于铁厂镇畜牧兽医站,经兽医诊治,未能确诊。为此,遵化市畜牧水产局选派专家对其进行了检查分析。根据繁殖记录,病畜产后已有65 d没有发情,产后胎衣正常落下,子宫未进行处理。后发现奶牛从阴门流出脓性分泌物,病畜体温偏高,有努责现象。直肠检查,有子宫内膜炎和黄体囊肿,其它正     

P53在胆囊上皮内瘤变及胆囊癌组织中的表达及临床意义

目的:检测P53在胆囊上皮内瘤变及胆囊癌组织中的表达,探讨其在胆囊癌发展中的作用及临床意义。方法:应用免疫组化技术SP法检测54例胆囊低级别上皮内瘤变,45例高级别上皮内瘤变及39例胆囊癌标本中P53的表达。结果:P53在胆囊低级别上皮内瘤变、高级别上皮内瘤变和胆囊癌组织中的阳性表达率分别为20.37%(11/54)、44.44%(20/45)和82.05%(31/39)。随着胆囊上皮异型性增加,P53表达率明显升高,组间比较差异具有统计学意义(P0.05);各组间P53和COX-2表达呈正相关(P0.01)。结论:P53在胆囊癌变过程中起着重要作用,可作为诊断和鉴别胆囊上皮内瘤变和胆囊癌的指标。     

保证母牛高繁殖力的几项措施

正养牛业发展的好坏,关键在母牛,母牛养的好坏,关键看产犊,即看母牛繁殖力,繁殖力越高,经济效益越好。但是目前很多牛场,母牛繁殖力低下,经济效益下滑,困扰养牛业的发展。而影响母牛繁殖力的因素有多方面:如营养因素、管理因素、繁殖技术、繁殖障碍疾病等,因此要想提高母牛繁殖力,单从一两个方面去抓,是解决不了根本问题的,必须从复杂的因素中提取出既有科学性,更要有在实际生产中具有操作性,适用性的具体措施,以下是几项具     

我国人口自然增长率的影响因素分析——基于计量经济学软件STATA13.0的相关数据分析

人口是构成社会的最基本要素。由于人口过多、增长过快以及结构不尽合理等所引起的社会、经济和生态环境问题,越来越受到人们重视。采用计量经济学软件STATA13.0研究我国人口自然增长率与经济的关系,分析认为,人口增长与经济发展呈负相关。     

受橱柜和家具需求推动,美国的层积材产值在2020年将达到68亿美元

美国:根据美国弗里多尼亚集团最近的研究,橱柜和家具需求的增长继续推动着美国的装饰层积材生产以每年2.5%的速度递增,目前的年产量已经达到116亿ft~2,产值达到68亿美元。研究认为,这些装饰性面板的产量将与国内橱柜、家具、零部件、墙板和其他复合木材产品的生产同步增长。橱柜和家具是2015年层积材销售市场上的两大主力目标产品,预计橱柜市场将会以更快的速度增长。     

Investigation of Clinical Medicine for Treating Cows Endometritis in Baotou Area

In 4 dairy farms located in Baotou area, clinical medicine investigation and drug resistance of pathogenic bacteria were conducted, and then curative effects of different treatment methods were analyzed.Epidemic materials were collected from diary cows infected by endometritis, from which pathogenic bacteria were isolated using conventional microbiology technologies.Broth microdilution method was used to detect the sensitivity and resistance of pathogenic bacteria to antibiotics commonly used in clinic.On this basis, the sensitive drugs were used to treat mastitis or endometritis, the clinical curative effect of traditional treatment group was compared with that of therapeutic test group.The result of traditional treatment group showed 13 antibiotics were used to treat 160 cases of endometritis, florfenicol was most effective, penicillin was most ineffective.The results of therapeutic test group showed that Staphylococcus aureus, Escherichia coli and Streptococcus were the main pathogenic bacteria of endometritis, which were sensitive to gentamicin and cefalotin, etc.The results of statistical analysis showed that the curative effect of therapeutic test group was extremely significantly different from that of traditional treatment group(P<0.01).Sensitive drugs screened by drug sensitive test could be used to target therapy, and obtain satisfied curative effect.Moreover, this approach could avoid antibiotic abuse.     

Preliminary Study on NF-κB Signaling Pathway Regulating Brucella Intracellular Survival Molecular Mechanisms

By the infection of Brucella virulent strain and attenuated strain in mice macrophage RAW264.7,the assay was aimed to explore the relationship between NF-κB signaling pathways and Brucella virulent strain and attenuated strain in intracellular survival.Use different MOI Brucella (2308,RB51,16M and M5) to infect mice macrophage RAW264.7,after 0,4,8 and 24 h infected,cracking cell and collecting supernatant,we detected the effect of Brucella on activation of NF-κB signaling pathway by Western blotting.Different concentrations of NF-κB signaling pathway inhibitor were incubated with mice macrophage RAW264.7,with different multiplicities of infection (MOI) of Brucella infecting cells,ELISA kits to detect the expressions of TNF-α,IL-1β and IL-6 cytokine;At the same time,count the number of intracellular bacteria of CFU.The results showed that rough cattle Brucella strains RB51 could strongly activate NF-κB signaling pathway,smooth cattle Brucella strains 2308 was weak in the activation;At the same time,the activation of NF-κB signaling pathway was concentration dependent.When the MOI was 80,infection time was 8 h,NF-κB activation degrees of rough cattle Brucella strains RB51 and smooth cattle Brucella strains 2308 were the strongest,and this pathway was involved in producing TNF-α and IL-6;NF-κB signaling pathway inhibitor BAY11-7082 affected Brucella intracellular survival.So rough cattle Brucella strains RB51 intracellular survival and NF-κB signaling pathway activity were closely related.The results laid the foundation for the further study of Brucella intracellular pathogenesis,also provided scientific basis for the research of new drugs to Brucella,and prevention and treatment of brucellosis.     

正体与斜体使用规则

物种的学名属名、种名(包括亚种、变种)用拉丁文斜体,首字母大写,其余小写;属以上用拉丁文正体,首字母大写。限制性内切酶前3个字母用斜体,后面的字母和编码正体平排,例如:Bam HⅠ、Eco RⅠ、MspⅠ、Sau 3AⅠ等。氨基酸和碱基的缩写氨基酸缩写用3个字母表示时,仅第一个字母大写,其余小写,正体。碱基缩写为大写正体。