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   180篇
  免费   17篇
  国内免费   1篇
农学   2篇
  9篇
综合类   26篇
农作物   8篇
水产渔业   1篇
畜牧兽医   145篇
园艺   2篇
植物保护   5篇
  2023年   1篇
  2022年   1篇
  2021年   1篇
  2020年   4篇
  2019年   4篇
  2018年   7篇
  2017年   5篇
  2016年   10篇
  2015年   5篇
  2014年   5篇
  2013年   14篇
  2012年   2篇
  2011年   2篇
  2010年   3篇
  2009年   17篇
  2008年   6篇
  2007年   3篇
  2006年   6篇
  2005年   4篇
  2004年   5篇
  2003年   2篇
  2002年   3篇
  2001年   2篇
  2000年   1篇
  1999年   6篇
  1998年   10篇
  1997年   9篇
  1996年   4篇
  1995年   3篇
  1994年   1篇
  1993年   5篇
  1992年   2篇
  1991年   8篇
  1990年   7篇
  1989年   7篇
  1988年   4篇
  1983年   2篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1972年   1篇
  1971年   3篇
  1968年   1篇
  1967年   2篇
  1963年   4篇
  1948年   1篇
  1939年   1篇
  1893年   1篇
排序方式: 共有198条查询结果,搜索用时 0 毫秒
41.
AIM: To describe the Chlamydia psittaci genotypes in samples from native and introduced birds from New Zealand by analysis of the sequence variation of the ompA gene.

METHODS: DNA was extracted from samples collected from a non-random sample of birds; either swabs from live asymptomatic birds or birds with clinical signs, or formalin-fixed, paraffin-embedded (FFPE) samples from historical post-mortem cases. The presence of C. psittaci in all samples had been confirmed using a quantitative PCR assay. The C. psittaci ompA gene was amplified and sequenced from samples from 26 native and introduced infected birds comprising 12 different species. These sequences were compared to published available C. psittaci genotypes.

RESULTS: Genotypes A and C of C. psittaci were identified in the samples. Genotype A was identified in samples from nine birds, including various native and introduced species. Genotype C was identified in samples from 16 different waterfowl species, and a mixed infection of both genotypes was found in a kaka (Nestor meridionalis). In native birds, C. psittaci infection was confirmed in seven new host species.

CONCLUSIONS AND CLINICAL RELEVANCE: Two genotypes (A and C) of C. psittaci were found in samples from a wider range of both native and introduced species of birds in New Zealand than previously reported. Both genotypes have been globally associated with significant disease in birds and humans. These initial results suggest the host range of C. psittaci in New Zealand birds is under-reported. However, the prevalence of C. psittaci infection in New Zealand, and the associated impact on avian and public health, remains to be determined. There are biosecurity implications associated with the importation of birds to New Zealand if there is a limited diversity of C. psittaci genotypes present.  相似文献   
42.
The objective of this study was to estimate the prevalence of and risk factors for pathological conditions of the reproductive organs in stray dogs under tropical conditions. Three hundred and eighteen dogs were examined post-mortem in the period from 1 July 2002 to 30 June 2003. Before killing, a blood sample (from the cephalic vein) for testosterone assay was taken. Pathological conditions of the reproductive organs were found in 135 of the dogs (42.5%) and in 175 of the testes (64.8%). The most frequent pathologies found were testicular degeneration, cryptorchidism, testicular hypoplasia and testicular tumours (in 15.1%, 6.6%, 6.6% and 5.4% of the dogs and 15.1, 4.6, 6.0 and 3.5 of the testes, respectively). Transmissible venereal tumour (TVT) was seen in 5.4% of the dogs. Testicular degeneration was more common in old dogs and underweight dogs (p < 0.05). Testicular tumours were 14.3 times more common in cryptorchid dogs. Age was another important factor for the development of testicular tumours (p < 0.05). Lower levels of testosterone concentration (p < 0.05) were observed in dogs with advanced testicular degeneration (0.7 +/- 0.8 nM), dogs with hypoplastic testicles (0.8 +/- 0.9 nM) and dogs with one degenerated and one retained testis or with bilateral cryptorchidism (1.2 +/- 0.9 nM) compared to dogs with one or two normal testes (7.0 +/- 5.5 nM). Testicular volume and weight were significantly lower in degenerated, hypoplastic and retained testes compared with the contralateral normal testis. Some spermatogenic activity was found in three of the retained testes, producing oligozoospermic smears with a high percentage of sperm abnormalities. No comparable epidemiological data about male pathological conditions of the reproductive organs in the dog is available. The prevalence found in this study, yet, appears high.  相似文献   
43.
44.
Protein fractions of cerebral spinal fluid samples were analyzed in an effort to find a reliable, minimally invasive and cost effective method of diagnosing cervical vertebral myelopathy. There were six separate protein fractions analyzed by electrophoresis. In this study we specifically looked for a post beta spike in horses with spinal cord compression. There was no correlation in our study between horses with a post beta spike and CVM as diagnosed by a myelogram.  相似文献   
45.
One hundred and twenty‐six suckled crossbred cows (Bos taurus × Bos indicus), with body condition score ≥3 (1–5 point scale), were employed in the present study to evaluate the effectiveness of intravaginal progestin‐releasing sponges (IVS) for shortening anoestrous interval. Fifty‐four cows were assigned to control group. Seventy‐two cows were treated with IVS impregnated with 250 mg of medroxy‐acetate‐progesterone (MAP) as follows: day 0, IVS plus 5 mg of 17β‐E and 50 mg of MAP i.m.; day 6, 500 IU of equine chorionic gonadotropin and 25 mg prostaglandin F i.m.; day 8, IVS withdrawal and day 9, 1 mg 17β‐E i.m. Cows were also grouped according to postpartum days (dpp) at treatment: MAP <70 days (n = 25); control <70 days (n = 22); MAP >70 days (n = 47); control >70 days (n = 32). From IVS removal, cows were detected in oestrus and inseminated. Cows not detected in oestrus were timed artificial insemination 72 h after sponge removal. Treatment effect on oestrous rate (ER), conception rate (CR), pregnancy rate (PR) and treatment to conception intervals (TCI) and calving to conception intervals (CCI) were evaluated. The ER, CR and PR were analysed using proc logistic , while TCI and CCI with proc glm of SAS. The groups MAP <70 days and MAP >70 days showed higher (p < 0.01) ER than control <70 days and control >70 days (84.0% and 76.6% vs 31.8% and 31.3% respectively). The PR was higher (p < 0.01) in MAP <70 days vs control <70 days (64.0% vs 22.7%) and also higher (p < 0.05) in MAP >70 days vs control <70 days (40.4% vs 18.8%). The TCI and CCI were shorter (p < 0.01) in MAP <70 days vs control <70 days (36.0 and 95.8 days; 95.3 and 158.6 days respectively). In conclusion, only cows treated with IVS before 70 dpp had a CCI shorter than 100 days, consequently this treatment shortened postpartum anoestrous interval in crossbred dual purpose cattle.  相似文献   
46.
47.
The response of rainbow trout (Oncorhynchus mykiss, Walbaum) towards probiotics present in the feed was investigated by examining the proteome of serum as a measure of the acute phase response (APR). Proteomic analysis by two-dimensional electrophoresis (2D) concurrently with mass spectrometry was used to detect APR related proteins in rainbow trout serum following feeding with probiotics Aeromonas sobria GC2 and Bacillus sp. JB-1. Three candidate proteins increased following use of GC2, and were putatively identified as NADH dehydrogenase, dystrophin and mKIAA0350. Conversely, one of the proteins, which were induced following use of JB-1 was identified as transferrin.  相似文献   
48.
A 13‐year‐old Romanov sheep presented for evaluation of vaginal discharge, depression and anorexia. Blood work demonstrated mature neutrophilia and marked hyperlactatemia. Transrectal and transabdominal ultrasound revealed echogenic fluid (pus) within the uterus. Purulent uterine fluid culture yield Escherichia coli. A diagnosis of pyometra was made. After medical treatment without clinical improvement, an exploratory laparotomy was performed, and a 360‐degree uterine left horn torsion was identified with the pyometra and multiple corpora lutea on both ovaries. Ovariohysterectomy was performed and the ewe recovered uneventfully.  相似文献   
49.
SUMMARY Vascular leakage induced by intradermal injection of histamine, bradykinin and serotonin alone and co-injected with prostaglandin E2 was measured in Greyhounds using 125Iodine-labelled human serum albumin (125I-HSA) as a marker in the blood. Histamine and bradykinin produced dose-dependent vascular leakage. At equimolar concentrations, histamine was more than twice as potent as bradykinin. Serotonin did not induce vascular leakage and was irritant. Prostaglandin E2 did not induce significant vascular leakage (maximum 5μL) when injected alone, but when co-injected with histamine and bradykinin, the vascular leakage of both histamine and bradykinin was increased. This effect was more pronounced if lower concentrations of histamine and bradykinin were injected. The induced vascular leakage was greatest during the first five minutes of lesion development for histamine, during the second five minutes of lesion development for bradykinin, and the synergistic effect of prostaglandin E2 was maximal during the third five minute period of lesion development.  相似文献   
50.
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