兔舍内气载需氧菌和气载葡萄球菌的检测     

段会勇  王磊  柴同杰 《家畜生态》2005,(4)

本研究采用A ndersen-6级空气微生物样品收集器,选用血-葡萄糖-琼脂培养基为采样介质,对两个不同种兔舍环境空气中需氧菌总数和葡萄球菌总数进行了检测,并对葡萄球菌的菌群组成进行了分析。结果表明,两个兔舍内需氧菌含量分别为1.73~85.8×103CFU/m3、2.71~9.66×103CFU/m3空气,葡萄球菌含量分别为0.94~7.84×103CFU/m3、1.02~6.54×103CFU/m3空气。兔舍空气中葡萄球菌主要包括金黄色葡萄球菌、腐生葡萄球菌、表皮葡萄球菌、科氏葡萄球菌、头状葡萄球菌和马胃葡萄球菌,其中金黄色葡萄球菌的含量占葡萄球菌总数的26.3%~29.6%,其次是腐生葡萄球菌和表皮葡萄球菌。另外,还对需氧菌和金黄色葡萄球菌在A ndersen-6级收集器不同层级上的分布情况进行了统计分析,结果表明,约有56.4%的需氧菌和49%金黄色葡萄球菌分布在3~6层上,空气动力学直径(A erody-nam ic d iam eter,D ae)在6~0.2μm,它们能进入人、畜的气管、支气管,甚至细支气管,对饲养员和动物的呼吸道构成严重危害。  相似文献   

坡耕地暴雨结皮对作物生长发育影响的实验研究     

吴发启  范文波  郑子成  赵西宁 《干旱区资源与环境》2003,17(2):100-105

采用盆栽和小区试验的方法,经3年试验发现,坡耕地土壤结皮对作物的出苗、生长、产量和生物量等均有不同程度的影响。小麦出苗率、苗高、最大苗高、产量和生物量分别降低了22.06％、4.60％、6.86％、1.16-9.84％和0.74-6.98％;结皮虽对玉米出苗影响不大,但延长了出苗期,使产量和生物量降低了5.66—9.17％和7.17—11.25％,而且随结皮厚度、强度和地表坡度的增加,其影响更为明显。因此,通过增加地面覆盖和雨后人工耕锄以消除结皮,增加产量和保持水土。  相似文献   

The basic mechanism of increased microvascular permeability     

ZHAO Ke-sen  HUANG Qiao-bing 《园艺学报》2003,19(4):549-553

The increased microvascular permeability appears mainly in venule during inflammation, shock, and burns. Endothelial cells play an important role in venule permeability enhancement. There are two kinds of pathway for macromolecule extravasation. One is paracellular pathway and another is transcellular pathway, which are related to the formation of endothelial gap or transcellular openings seperately. The alteration of intercellular related protein, such as occludin, claudin, zona occludens (ZO), junctional adhesion molecule (JAM), VE cadherin, catenin, integrin, etc, and the alteration of endothelial cytoskeleton, such as rearrangement of actin filament, formation of stress fiber and focal adhesion, etc, involve in the pathogenesis of increased microvascular permeability.  相似文献   

中国风水侵蚀交错区分布特征分析   总被引：6，自引：1，他引：6  

邹亚荣  张增祥  王长有  赵晓丽  刘斌 《干旱区研究》2003,20(1):67-71

风水侵蚀交错带的研究 ,对景观、土地覆盖 /土地利用、全球变化等研究具有重要意义。论文以GIS技术为支撑 ,定量计算出我国风水侵蚀带。在分布特征上 ,主要分布我国北方地区 ,其中以西部沙漠 ,北部山脉沿线为重 ,这种分布与气候、地貌分界有明显联系。 49.6 %风水侵蚀复合带的降水量小于 2 0 0mm。风水侵蚀复合带的土地利用主要以草地为主 ,占 41.8% ,其次为耕地。两种类型的分布 ,草地以与其它土地利用类型交错分布为主 ;而耕地是有重心的分散分布。风水侵蚀复合带的总体侵蚀要强于全国水平。  相似文献   

不同地下水位植物蒸腾耗水特性研究   总被引：20，自引：6，他引：20  

赵明  郭志中  王耀琳  李爱德  张德魁  贾宝全 《干旱区研究》2003,20(4):286-291

在甘肃省民勤治沙站利用非称量测渗仪研究了梭梭、柠条等 10种沙区植物的蒸腾耗水特征。结果表明 ,各种植物 5a的总蒸腾量由大到小排列为 :沙枣、花棒、沙木蓼、柠条、梭梭、白皮沙拐枣 ;随植物年龄增长 ,蒸腾系数有上升的趋势 ,而蒸散系数有下降的趋势 ;在民勤沙区 6～ 9月是主要蒸腾季节 ,该时段的蒸腾量占全年蒸腾量的80 %～ 90 % ;植物的蒸腾量随年龄的增长而迅速增加 ,但增长幅度随物种不同而异。一般生长快的植物增长快 ,生长慢的植物增长慢。  相似文献   

沙漠化过程土壤种子库特征的研究   总被引：13，自引：5，他引：13  

赵丽娅  李锋瑞 《干旱区研究》2003,20(4):317-321

采用野外定点取样与室内萌发实验相结合的方法 ,研究了 4种不同类型退化沙地土壤种子库特征 ,主要结论是 :(1)土壤种子库密度随沙漠化程度的增加而下降 ,不同沙漠化发展阶段下降速率不同 ,从固定到半固定沙地是种子库密度衰减最快的时期 ;(2 )土壤种子库植物种数从固定到半流动沙地变化很小 ,半流动到流动沙地衰减速度明显加快 ,是种子库植物种数衰减最快的时期 ;(3) 4种类型退化沙地土壤种子库的种类组成以 1、2年生草本植物为主 ,所占比例 79%～ 88% ,多年生草本和灌木所占比例很小 ;(4 )土壤种子库物种多样性指数并非随着沙漠化程度的增加而下降 ,其中半流动沙地的物种多样性指数最小 ;(5 ) 4种类型退化沙地土壤种子库组成上的相似性系数变化范围为 0 .82 9～ 1.0 0 0 ,表现出较小的空间异质性。  相似文献   

Inhibitory effects of LDL-ACM complex on subcutaneous implanted tumors in nude mice()     

JIANG An-li  KANG Lu-dong  ZHAO Chun-hua  BI Wen-xiang  HU Xiao-yan  KONG Feng  XU Song-de 《园艺学报》2003,19(1):55-58

AIM: In order to evaluate the applicable value of LDL as a targeted vehicle for chemotherapeutic agents, we investigated and compared the inhibitory effects of LDL-ACM complex and free ACM on nude mice's subcutaneous implanted tumors derived from gastric cancer cell lines, SGC-7901 and NKM-45. METHODS: LDL-ACM complex was prepared and the tumor model of nude mice was established by subcutaneous implantation of SGC-7901 and NKM-45. Then, the groups of nude mice developed subcutaneous implanted tumors were received either LDL-ACM complex or free ACM. Subsequently, the tumor size, weight and leukemia cell counts were measured and the rates of tumor-inhibition and the survival were compared among the groups. RESULTS: The inhibitory effects of LDL-ACM complex on the tumors, especially on SGC-7901 implanted tumors were much more obvious than that of free ACM. It was also indicated that the action of LDL-ACM complex was mediated by LDL receptor. CONCLUSION: These results showed that LDL-ACM complex had significant inhibitory effects on the implanted tumors and the effect might be mediated by LDL receptor.  相似文献   

Effect of cocaine on caspase-3 in myocardiac cells of male rats in different age     

WANG Hong-ju  HUANG Yuan-wei  YANG Guo-sheng  ZHANG Lei 《园艺学报》2003,19(9):1193-1196

AIM: To study the effect of cocaine on caspase-3 in myocardiac cells of male rats in different age. METHODS: Three-week-old(n=16), six-week-old(n=16) and twelve-week-old (n=16) male Sprague-Dawley rats were all divided into control groups and experiment groups randomly, each group had eight animals, experiment groups were given cocaine hydrochloride (15 mg·kg^-1 body weight) subcutaneously daily for four weeks. The ratio of heart weight to body weight (HW/BW, mg/g) were measured. DNA fragmentation of myocardia cells was determined by gel electrophoresis, and caspase-3 activity in myocardia cells was tested by flow cytometry (FCM). RESULTS: In three experiment groups, the DNA isolated from myocardial cells displayed clear ladder pattern. The HW/BW and the caspase-3 activity were increased significantly than those of control groups (P<0.01). CONCLUSIONS: Cocaine induced apoptosis in rat myocardial cells. The increase in caspase-3 activity may be the one of important pathways related to the induction of apoptosis.  相似文献   

Effect of adenosine on myocardial expression of TNF-α, IL-6 mRNA in rats with pneumonia     

TAN Jian-xin  HUANG Yu-ge  HUANG Xiu-lan  HE Hui-juan  ZHAO Jia-ming 《园艺学报》2003,19(10):1403-1406

  相似文献   

额尔齐斯河流域生态系统格局及变化   总被引：8，自引：4，他引：8  

李生宇  雷加强 《干旱区研究》2002,19(2):56-61

本文首先对额尔齐斯河流域气候，地貌，水文等环境因子特征进行了评述，进而阐述了流域生态系统的特征和格局以及在自然和人为干扰作用下的变化。分析结果表明在自然干扰作用下流域生态系统的格局与流域水文情势变化相适应，处于准稳定变化状态，而在人为对流域水文情势扰动下，流域生态系统的格局间接地受到影响。从而产生新的格局，其作用的强度，持久性和生态系统的格局变化程度过错大于大于自然干扰作用下的变化。引额调水工程对额尔齐斯河流域河谷生态系统内部单元格局变化具有重要影响。  相似文献