若干引进牧草品种的适应性研究

对美国引进的6个牧草种、21个品种进行了适应性和产量比较试验,结果表明:苇状羊茅Festuca arundinacea和冰草Agropyron cristatum的干草总产量较高,其中,苇状羊茅品种Cajun的总产量最高;紫花苜蓿Medicago sativa的干草总产量居于中等水平,在参试的紫花苜蓿品种中,WL323的干草总产量最高;无芒雀麦的产量最低.苇状羊茅、冰草和紫花苜蓿在北京及其周边地区有很好的适应性和推广价值.     

我国西部地区水电开发问题探讨

水能资源是我国西部地区的优势资源，由于历史和政策的原因，开发利用程度相对较低，资源优势没有形成产业优势。在分析西部水能资源分布特点和开发现状的基础上，结合西部大开发和西电东送战略，提出目前水电产业存在的市场、政策和资金方面问题，探讨了加快西部水电开发的对策和建议。     

内蒙古杭锦旗北部盐碱田温湿盐动态与生产利用

为探析水-热-盐关系以及植被对盐碱田改良的意义,利用2008年8月2日-8月6日在内蒙古杭锦旗黄河灌区盐碱田进行的试验观测数据,主要通过方差分析与典型相关分析方法对3个样地(裸地、紫花苜蓿地和玉米地)土壤温度(0-30cm土层)、湿度(0-20cm土层)、盐度(0-100cm土层)的动态变化进行了分析。结果表明,3个样地的温(度)-湿(度)-盐(度)动态基本呈现裸地苜蓿地玉米地的格局;0-5cm地温与耕作层(0-20cm)的土壤水分具有显著相关关系,是0-30cm土层内地温驱动水盐动态的主要热力因子;植物能够减少土壤表层积盐,并可以降低碱化度;苜蓿地比玉米地具有更低的钠吸附比值。在盐碱地区选择耐盐碱牧草品种开展草田轮作,有益于盐碱土壤的改良与利用。     

松嫩草原羊草与其主要伴生种竞争与共存研究

基于对松嫩草原优势物种羊草(Leymus chi-nensis)及其主要伴生种的空间分布格局、植物种间关系对割草的响应,以及羊草、芦苇(Phragmites communis)对营养和胁迫的适应性与种间关系的研究,探讨了植物竞争和共存的潜在机制。     

Estriolum Treatment in the Bitch: A Risk for Uterine Infection?

Purulent vaginal discharge in a bitch in which ovariohysterectomy has been performed is often caused by inflammation of the uterine stump. The inflammation is due to either cystic endometrial hyperplasia (CEH) induced primarily by progesterone from remnant ovarian tissue or exogenous progestagens, or it is due to the presence of unabsorbed suture material. This report describes a 9-year-old Irish setter with hemopurulent vaginal discharge and non-pruritic symmetrical alopecia, which had undergone ovariohysterectomy 3.5 years ago and which had been treated with estriolum daily for the past 2.5 years because of urinary incontinence. Vaginoscopy revealed hemopurulent discharge throughout the vagina and vestibule. Cytological examination of ultrasound-guided fine-needle aspiration biopsies of a large mass in the hypogastricum, which appeared to be the uterine cervical stump, revealed septic purulent inflammation. The concentration of plasma progesterone was low and the concentration of plasma 17-ß oestradiol did not increase after gonadotrophin-releasing hormone administration. No remnant ovarian tissue was found by abdominal ultrasonography, laparotomy, or histological examination of mesovarian pedicles. Laparotomy revealed uterine stump empyema. Histological examination of the surgically removed mass excluded both CEH and unabsorbed suture material as the cause of the stump empyema. Instead, it is hypothesized that the long-term treatment with estriolum was a causative factor. This suggests that bitches treated with estriolum should be examined regularly.     

东北马鹿肌肉生长抑制素基因序列的克隆、编码氨基酸序列及结构特征分析

以与东北马鹿物种最近的牛(Bos taurus cattle,序列号为AB076403)的肌肉生长抑制素(myostatin,MSTN)基因序列为模版,根据该基因保守序列进行引物设计,扩增产物连接入pMD18-T载体,克隆出3个外显子片段.根据5′-GU-AG-3′规则和同源基因比对拼接出带有部分5′、3′末端的cDNA,并采用生物信息学技术对编码氨基酸序列进行蛋白质同源性比较和二级、三级结构等分析.结果表明:所获序列全长为1 128 bp,编码375个氨基酸;具有较明显的螺旋、片层和无规卷曲等二级结构;有1个较明显的跨膜区和1个疏水区,并发现明显的信号肽和糖基化位点.三级结构同源建模预测结果显示与Human Activin A的相似性为42%.结果说明东北马鹿和其他哺乳类生物的肌肉生长抑制素基因之间关系密切,并同属于TGF-β家族.     

Meniscal Mineralization in Domestic Cats

Objective: To (1) determine prevalence of radiographically detectable meniscal mineralization in domestic cats and (2) to evaluate the association between meniscal mineralization and degenerative joint disease (DJD). Study Design: Prospective study. Animals: Client‐owned cats (n=100) and 30 feline cadavers. Methods: Randomly selected client‐owned cats were used to determine the prevalence of meniscal mineralization. Stifles from feline cadavers were used to evaluate the relationship between meniscal mineralization (using high‐resolution X‐ray), radiographic DJD, and cartilage damage. Menisci were evaluated histologically. Results: Forty‐six percent of the client‐owned cats had meniscal mineralization detected in 1 or both stifles. Pain scores were not significantly different between stifles with meniscal mineralization and those with no radiographic pathology (P=.38). Thirty‐four of 57 cadaver stifles had meniscal mineralization, which was always located in the cranial horn of the medial meniscus. Percentage mineralization of the menisci was significantly correlated with the cartilage damage score of the medial femoral (r²=0.6; P<.0001) and tibial (r²=0.5; P<.0001) condyles as well as with the total joint cartilage damage (r²=0.36; P<.0001) score and DJD score (r²=0.8; P<.0001). Conclusion: Meniscal mineralization is a common condition in domestic cats and seems to indicate medial compartment DJD. Clinical Relevance: Clinical significance of meniscal mineralization is uncertain. Further work is needed to determine if the meniscal mineralization is a cause, or a consequence of joint degeneration.     

Probing the Local Effects of Magnetic Impurities on Superconductivity

The local effects of isolated magnetic adatoms on the electronic properties of the surface of a superconductor were studied with a low-temperature scanning tunneling microscope. Tunneling spectra obtained near magnetic adsorbates reveal the presence of excitations within the superconductor's energy gap that can be detected over a few atomic diameters around the impurity at the surface. These excitations are locally asymmetric with respect to tunneling of electrons and holes. A model calculation based on the Bogoliubov-de Gennes equations can be used to understand the details of the local tunneling spectra.     

玉屏风多糖脂质体的制备及表征研究

优选玉屏风多糖脂质体的最佳工艺并对其进行表征验证。采用逆向蒸发法制备玉屏风多糖脂质体,以膜材比、脂药比和超声时间为考察因素,包封率为评价指标,采用L9(34)正交试验设计优选制备条件,以超速离心法测定包封率,体外释药试验验证,纳米颗粒分析仪和透射电镜测定其粒径大小与形态。制备玉屏风多糖脂质体的最佳工艺为膜材比8∶1,脂药比4∶1,超声时间90s,包封率88.38%,24h累积释放率73.45%,平均粒径132.65nm。制备的玉屏风多糖脂质体具有较高的包封率与良好的缓释作用,粒径和形态较均匀,重现性好。     

西藏野生动物资源及其监测体系的探讨

结合西藏2000年野生动物资源监测调查，对监测调查结果进行了分析与评价，在此基础上，对建立西藏野生动物资源监测体系进行了探讨。