Detection of the hyaluronan receptor CD44 in the bovine oviductal epithelium

Hyaluronan is involved in fundamental reproductive events such as sperm storage in the female reproductive tract, fertilization, and early embryo development, these functions are presumably mediated by its major cell surface receptor, CD44. The present study was conducted to investigate the presence and localization of CD44 in the bovine oviductal epithelium, using immunohistochemical and Western blot methods on tissue sections and epithelial cell extracts collected from the uterotubal junction (UTJ), isthmus, and ampulla of animals in the oestrus or luteal phase of the oestrous cycle. While positive immunolabelling for CD44 was found on the ad-luminal surface and supra-nuclear region of epithelial cells in all tubal segments investigated, in the UTJ, there were epithelial cells in which the entire cytoplasm positively stained. We found no differences in terms of CD44-positive staining between the different stages of the oestrous cycle. Presence of CD44 was detected by Western blotting in the tubal epithelium as a single band at 200 kDa. Although it appeared in all tubal segments, the expression of CD44 protein was more accentuated in the sperm reservoir (UTJ) than in the other segments. This is the first time CD44 has been detected in the epithelium of the tubal sperm reservoir in cattle, suggesting a pathway for the action of hyaluronan in this segment.     

ENDOSCOPIC ULTRASONOGRAPHY FOR THE DIAGNOSIS OF INTRATHORACIC LESIONS IN TWO DOGS

Endoscopic ultrasound was developed initially in humans to overcome limitations of conventional ultrasound in examining certain internal organs due to intervening bone or air-filled structures. Endoscopic ultrasound has been used most widely in investigation of the gastrointestinal tract in humans, but many intrathoracic applications as well as endoscopic ultrasound-guided techniques have recently been described. Mediastinal and pulmonary structures can be examined with endoscopic ultrasound since a high frequency ultrasound probe can be brought into close contact with the areas of interest via a transesophageal approach. The purpose of this report is to describe the application of endoscopic ultrasound as an aid in the diagnosis of intrathoracic disease in the dog. Two dogs, one with a history of prior esophageal foreign body extraction, the other with apathy, weakness and dyspnea were referred for further investigation. Both dogs had caudal intrathoracic soft tissue opacities diagnosed radiographically, but their origin and nature were difficult to determine. Conventional ultrasound was limiting in both dogs due to their location and superimposition of gas-filled structures. With endosonography lesions were characterized more completely. We have found endoscopic ultrasound to be an elegant diagnostic tool for the investigation of radiographically detected intrathoracic lesions in the dog whose origins are difficult to determine or do not lend themselves to investigation by conventional ultrasound. Endoscopic ultrasound provides valuable diagnostic information complementary to that provided radiographically which aids in therapeutic planning. Endoscopic ultrasound was also more sensitive for detecting mediastinal lymphadenomegaly than radiography in one of the dogs. An additional advantage of endoscopic ultrasound is the fact that US-guided tissue sampling can be performed during the examination.     

玉米大垅双行高产密植全程机械化技术推广应用

介绍花生大垅双行种植模式的特点以及机械作业技术要点。     

树干液流监测系统的研制

树干液流速率是判断根系水分吸收和蒸腾作用强弱的关键指标,被普遍应用于树木蒸腾耗水研究,常用的植物液流仪普遍是价格高昂、采样数据类型单一的进口设备,因此亟待研发集多因素于一体的树干液流监测系统。基于树干液流及气象和土壤因子建立树干液流监测系统,其采用基于热扩散技术的TDP液流计监测枝干液流,采用多类型传感器实现气象和土壤因素数据的收集,系统平台采用PHP+HTML+MySQL作为开发语言和设计工具。与对照植物液流仪对比,二者电压差、液流速率相关系数分别为0.834 3、0.876 5。选取环境因子对全天、日间、黑夜时段的白玉兰液流速率进行相关性分析,发现不同时段环境因子对液流速率的影响程度不同。此外,建立液流速率与环境因子的多元线性回归模型,其中全天时段的回归模型拟合程度较好,R²为0.674。该系统具有性价比高、监测指标多、各指标数据可视化等特点,可用于研究林木液流速率和环境因子的时空变化规律。     

基于小波分形的电能质量暂态扰动多分辨率分析

电能质量暂态扰动会给敏感负荷带来重大损失.采用小波变换的多分辨率分析思想,利用分形理论从图形模式辨识的角度出发对电能质量暂态扰动进行分类、辨析.首先采用计算简单的计盒维数对波形图像进行初步分析,随后根据盒的分布密度进行分段划分,将含暂态扰动的信息段从波形中提取出来,并根据多分辨率分析的思想对重点波形段进行分形及小波分析提取信号特征.仿真结果证明,该方法对电能质量扰动的暂态识别具有较好的适应性及稳健性,可以在噪声环境下识别小幅度的电能质量扰动,具有检测速度快、可并发执行的特点.     

我馆参考咨询服务的现状与发展对策探讨

对作者所在图书馆的参考咨询工作的现状进行了分析,并就参考咨询工作发展对笨进行了探讨。     

High-selectivity, high-flux silica membranes for gas separation

Process improvements in silica membrane fabrication, especially the use of clean-room techniques, resulted in silica membranes without detectable mesoscopic defects, resulting in significantly improved transport properties. Supported membranes calcined at 400 degreesC were 30 nanometers in thickness, showed a H2 permeance at 200 degreesC of 2 x 10(-6) moles per square meter per second per Pascal (mol m-2 s-1 Pa-1), and had a CH4 permeance more than 500 times smaller. Molecules larger than CH4 were completely blocked. Silica membranes calcined at 600 degreesC showed no detectable CH4 flux, with a H2 permeance of 5 x 10(-7) (mol m-2 s-1 Pa-1) at 200 degreesC. These results signify an important step toward the industrial application of these membranes such as purification of H2 and natural gas as well as the selective removal of CO2.     

林业科技发展带给园林建设的启示

随着城市的发展和人们对生态环境的保护意识的提高,许多国家非常重视林业科技的发展和园林建设。探讨了21世纪林业科技的发展的8个方面,包括近自然林业理论和生态林业学说的兴起;森林培育学的进一步发展;林业生物技术的重大突破;森林生态与环境的研究;防治荒漠化;森林病虫害防治技术的发展;森林旅游业的发展。结合中国的园林发展现状,提出园林建设要紧密联系林业科技发展动态,多方面借鉴林业科研成果。     

白肋烟品种对比试验

为筛选更适合重庆市万州地区的优良品种,本试验通过对6个白肋烟品种进行田间对比试验。结果表明:1)除品种达白1号和达白2号生育期比对照稍迟外,其余品种的生育期与CK相当,达白1号、50927、9026、106126的生长势强于CK,各品种的株高和叶数均高于CK。2)从抗病性看,50927和9026病害发生于CK相当,其余品种抗病性均优于CK。3)以品种50927产量最高,为180.13kg/667m2,其次是106126;以品种9026产值最高,为2224.68元/667m2,其次是50927;上中等烟比例以达白2号最高。4)从农艺性状和经济性状的多方面比较分析,50927、9026和106126较适宜于在万州进行进一步的扩大示范,以筛选适合万州生态、生产条件的白肋烟品种。     

龙眼长跗萤叶甲成虫耐寒性及卵的发育起点温度和有效积温的研究

为了分析龙眼长跗萤叶甲成虫耐寒性及其卵发育情况,对龙眼长跗萤叶甲成虫过冷却点和冰点及卵的发育起点温度和有效积温进行了测定.该研究用RW热敏电阻+数字万用电表过冷却点测定仪、超低温冰箱、计算机自动记录检测该虫成虫的过冷却点和冰点,应用自然温度饲养观察并计算了叶甲卵的发育情况.结果表明:成虫的雌虫体过冷却点-13.38～-5.56℃,平均-10.75℃;体液冰点为-10.41～.2.32℃,平均-6.5℃.雄虫体过冷却点为-11.22～-5.56℃,平均-8.88℃;体液冰为-7.71～-0.7℃,平均-3.80℃.雌虫的耐寒性强于雄虫.龙眼长跗萤叶甲卵在常温条件下,其发育起点温度是(15.8±0.7)℃,有效积温是(142.5±9.5)日度,卵发育速率与温度关系公式为:V=[T-(15.8±0.7)]/(142.5±9.5).由研究结果推测目前广西龙眼栽种区都可能成为此虫发生分布区和潜在发生分布区.