首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   74篇
  免费   2篇
林业   4篇
基础科学   1篇
综合类   2篇
水产渔业   24篇
畜牧兽医   45篇
  2022年   1篇
  2020年   1篇
  2019年   2篇
  2018年   2篇
  2016年   1篇
  2015年   1篇
  2014年   3篇
  2013年   4篇
  2012年   3篇
  2011年   2篇
  2010年   2篇
  2008年   2篇
  2007年   4篇
  2006年   4篇
  2005年   5篇
  2004年   1篇
  2003年   13篇
  2001年   7篇
  2000年   3篇
  1999年   4篇
  1998年   1篇
  1997年   3篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1984年   1篇
  1983年   1篇
  1969年   1篇
排序方式: 共有76条查询结果,搜索用时 546 毫秒
1.
Atopic dermatitis (AD) is thought to be caused by immunologic abnormalities expressed as a Th1/Th2 cytokine imbalance in both humans and dogs. Several studies have focused on the therapeutic effects of IFNγ in human AD with successful results; however, the mechanism of action of IFNγ is not fully understood. We investigated the effect of recombinant canine interferon gamma (rCaIFNγ) on 10 dogs with AD and evaluated the ratio of IL‐4 mRNA to IFNγ mRNA in peripheral blood mononuclear cells, serum total IgE levels, and histological changes in skin. After six injections of rCaIFNγ over a span of 2 weeks, seven of the 10 dogs showed improvement, and six of these seven dogs exhibited decreased IL‐4:IFNγ mRNA ratios. Two of the three cases that did not improve had increased IL‐4:IFNγ mRNA ratios. Total serum IgE levels were significantly decreased in nine of 10 cases. The number of IgE‐positive cells detected by immunostaining and the number of mast cells in skin biopsy samples were decreased. A reduction of epidermal cell layers was demonstrated by histopathology after treatment. These results demonstrated that rCaIFNγ may be a novel safe and effective therapeutic option for the treatment of canine AD, and the mechanism of action of rCaIFNγ may be related to the modulation of Th2 cytokines to Th1 cytokines with the reduction of serum IgE production. Funding: Self‐funded.  相似文献   
2.
One hundred dogs that were positive for canine distemper virus antigen and inclusion bodies in the tonsils were examined for the distribution of inclusion bodies in various tissues. Inclusion bodies were found in the lungs (70 dogs), brains (20 dogs), urinary bladders (73 dogs), stomachs (78 dogs), spleens (77 dogs), and lymph nodes (81 dogs) of the dogs. Based on these results, the tonsils may be the most suitable tissue for detection of inclusion bodies in canine distemper.  相似文献   
3.
气动真空发生器系统背压与抽吸性能关系分析   总被引:1,自引:0,他引:1  
对气动系统中常用的真空发生器样机,采用有限体积法对其内部流场进行数值计算,分析了背压不同时内部压力分布和吸入流速改变情况。以此为基础,测量系统背压升高时吸入流量变化量,绘制了背压与吸入流量关系曲线,提出了通过判断系统背压防止逆流现象的方法。在真空发生器系统的设计和应用中,需要在理论计算的基础上,根据试验得出系统正常工作的背压范围,防止逆流现象,保证系统工作。  相似文献   
4.
OBJECTIVE: To determine effects of hypercapnia on arrhythmias in ducks anesthetized with halothane. ANIMALS: 12 ducks, 6 to 8 months old, weighing 1.1 to 1.6 kg. PROCEDURES: Each duck was anesthetized with a 1.5% mixture of halothane in oxygen, and anesthetic depth was stabilized during a 20-minute period. We added CO2 to the inspired oxygen to produce CO2 partial pressures of 40, 60, and 80 mm Hg in the inspired gas mixture.The CO2 partial pressure was increased in a stepwise manner. When arrhythmias were not evident during inhalation of the gas mixture at a specific CO2 partial pressure, the CO2 partial pressure was maintained for 10 minutes before a sample was collected for blood gas analysis. When arrhythmias were detected, a sample for blood gas analysis was collected after the CO2 partial pressure was maintained for at least 2 minutes, and CO2 inhalation then was terminated. RESULTS: During the stabilization period, PaCO2 (mean +/- SD) was 33 +/- 5 mm Hg,and arrhythmias were not detected. In 6 ducks, arrhythmias such as unifocal and multifocal premature ventricular contractions developed during inhalation of CO2. Mean PaCO2 at which arrhythmias developed was 67 +/- 12 mm Hg. In 5 of 6 ducks with arrhythmias, the arrhythmias disappeared after CO2 inhalation was terminated. CONCLUSION AND CLINICAL RELEVANCE: Analysis of data from this study indicated that hypercapnia can lead to arrhythmias in ducks during halothane-induced anesthesia. Thus, ventilatory support to maintain normocapnia is important for managing ducks anesthetized with halothane.  相似文献   
5.
Forty-six isolates of Taylorella equigenitalis were analysed by pulsed-field gel electrophoresis (PFGE) after separate digestion of the genomic DNA with ApaI and with NotI. The isolates had been obtained from horses in six European countries and were classified into 18 genotypes. In Belgium, 2 genotypes were detected in 2 isolates, in England 9 among 15, in Finland 2 in 2, in France 2 among 10, in Sweden 3 among 5, and in Switzerland 3 among 12. Two English isolates and 4 French isolates gave identical PFGE profiles to those of Kentucky 188 from the United States. A common genotype was found in 5 isolates from Belgium and England and also in 10 isolates from France and Switzerland. The analysis of genomic DNA from 12 isolates of T. equigenitalis obtained from male horses in France, Sweden and Switzerland gave no evidence of a sex-related difference in the genomic DNA. Genomic DNA from 11 streptomycin (STM)-susceptible isolates obtained in Sweden and Switzerland were classified into four genotypes by PFGE. Each of the six genotypes determined among the 17 isolates from these two countries had single phenotypes for resistance or susceptibility to STM.  相似文献   
6.
Accumulation of lipids and hyalinosis in the splenic arteries of aged dogs are frequently detected by routine histopathologic examinations. The purpose of this study was to pinpoint the localization of canine apolipoprotein B-100 (CApoB-100) and immunoglobulins (IgA, IgM, IgG) in the splenic arteries of aging dogs (n = 80) through the use of immunohistochemical techniques. CApoB-100 deposits were found in the subendothelial space, extracellular matrix, and atheromatous lesions in the tunica media of the arteries in dogs > or = 6 years of age. Foamy cytoplasm of the infiltrated macrophages was also CApoB-100 immunopositive. In dogs > or = 10 years of age, almost all central arteries were CApoB-100 immunopositive. Hyaline deposits within the wall were characterized by immunopositivity against canine IgA, IgM, IgG, and albumin. Lipid accumulation in splenic arteries may be an age-related lesion and a precursor of the atheromatous plaques associated with splenic hemorrhage and infarcts later in life. In addition, deposition of immunoglobulins, probably mediated by immune complexes, may play an important role in the development of canine vascular diseases similar to human disease.  相似文献   
7.
A malignant pheochromocytoma with multiple metastases was diagnosed in a 7-year-old male wolfdog that resulted from a cross between an eastern timber wolf (Canis lupus lycaon) and an Alaskan malamute. A yellowish white neoplastic mass approximately 10 cm diameter was found in the right adrenal gland. The neoplasm penetrated through the wall of the caudal vena cava. A diagnosis of pheochromocytoma was established by histopathologic and immunohistochemical procedures. Immunohistochemically, the neoplastic cells expressed chromogranin A, substance P, synaptophysin, Leu-7, protein gene product 9.5, methionine-enkephalin, S100 protein, and galanin. Multiple metastatic tumors were found in the kidneys, spleen, lungs, heart, and liver.  相似文献   
8.
A pleomorphic adenoma of the lacrimal gland in a dog   总被引:1,自引:0,他引:1  
A 13-year-old female mongrel dog had a pleomorphic adenoma of the lacrimal gland in the right upper orbit. The tumor measured 3.8 x 3.0 x 3.3 cm, appeared white, round, and firm, and pressed the right globe and surrounding tissues. Histopathologically, the tumor had a thin connective tissue capsule and was composed of tubules with two cell types, some resembling luminal epithelial cells making up the tubular structures and the other of myoepithelial cells. Epithelial tubules were disposed in an adenomatous fashion and separated from each other by proliferating pleomorphic myoepithelial cells. Immunohistochemically, large numbers of the luminal epithelial cells revealed an immunopositive reaction against keratin/cytokeratin (AE1/AE3), and some epithelial cells reacted against cytokeratin 14. Spindle-shaped myoepithelial cells revealed an immunopositive reaction against cytokeratin 14, alpha-smooth muscle actin, and vimentin. A small number of myoepithelial cells reacted against desmin. S-100 protein immunopositivity was frequently found in luminal epithelial cells and rarely in the pleomorphic myoepithelial cells. Glial fibrillary acidic protein positivity was commonly found in myoepithelial cells, myxoid matrices, and intracystic materials, but not in luminal epithelial cells.  相似文献   
9.
Repeated injections of salmon pituitary extract (20 mg per fish per week) induced vitellogenesis in feminized, cultivated Japanese eels (Anguilla japonica). Oocytes were attained at the migratory nucleus stage after 11 or 12 injections. Addition of 17,20-dihydroxy-4-pregnen-3-one (DHP) into the incubation medium induced germinal vesicle breakdown (GVBD) in the oocytes at the migratory nucleus stage. An injection of DHP (2 µg g-1 BW), given 24h after an injection of salmon pituitary extract (20 mg fish-1), succeeded in inducing maturation and ovulation in females which contained occytes at the migratory nucleus stage. Most fish ovulated 15–18h following the DHP injection. Eggs that were ovulated within 15h after the DHP injection showed high fertility and hatchability, but eggs ovulated 18 or 21h after the DHP injection, showed considerably lower fertility and hatchability. A delay between ovulation and stripping of the eggs rapidly decreased both the fertility and hatchability within 6–9h after ovulation, indicating that artificial fertilization must be carried out immediately after ovulation. Repeated injections of human chorionic gonadotropin (hCG) at a concentration of 1 IU g-1 BW week-1 induced spermatogenesis, spermiation, and the acquisition of potential for sperm motility in cultivated males. Most males spermiated after the fifth or sixth injection of hCG, and the milt weight gradually increased and remained constant (1–2 g) from the 11th to 31th injection. Sperm motility peaked 24h after each weekly injection, and decreased from the 3rd day after the injection. Potassium ions are an essential constituent for the maintenance of motility in the eel spermatozoa. Artificial seminal plasma containing 15.2 mM KCl is applicable as a milt diluent. Using these techniques developed for female and male eels, we have succeeded in obtaining many fertilized eggs from cultivated eels.  相似文献   
10.
ABSTRACT:   The fine structure of the alimentary canal in preleptocephali produced by artificially matured Japanese eel was examined. At 1 day posthatch (dph), the alimentary canal was found only above the dorsal side of the yolk mass, and the epithelium was composed of a single layer of epithelial cells. By 5 dph, the alimentary canal was divided into three segments based on the structure of the epithelial cells: foregut, midgut and hindgut, corresponding to the future esophagus, intestine and rectum, respectively. After 7 dph, the epithelium in the foregut was surrounded by a circular muscle layer, suggesting a role in the transportation of food materials. The epithelial cells of the midgut exhibited well-developed membranous structures, which are deduced to be invaginations of the cytoplasmic membrane. Pinocytotic invaginations and vacuoles were observed in the epithelial cells of the hindgut; this observation suggests that this region is involved in the uptake of food. Significant changes in morphological features of the epithelial cells in each segment were observed until 7 dph; however, these were not evident between 7 dph and 13 dph. Consequently, the differentiation of the alimentary canal was completed by 7 dph, and preleptocephalus had developed the ability to absorb food by 7 dph.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号