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   45篇
  免费   4篇
林业   3篇
  1篇
综合类   14篇
水产渔业   1篇
畜牧兽医   28篇
园艺   1篇
植物保护   1篇
  2023年   1篇
  2021年   1篇
  2020年   2篇
  2018年   1篇
  2016年   2篇
  2015年   3篇
  2014年   2篇
  2013年   2篇
  2012年   1篇
  2011年   1篇
  2010年   2篇
  2008年   2篇
  2007年   1篇
  2006年   1篇
  2005年   2篇
  2004年   2篇
  2003年   1篇
  2001年   1篇
  2000年   1篇
  1998年   2篇
  1997年   1篇
  1995年   1篇
  1991年   5篇
  1988年   1篇
  1987年   2篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
  1979年   1篇
  1978年   1篇
  1967年   1篇
  1940年   1篇
  1925年   1篇
排序方式: 共有49条查询结果,搜索用时 15 毫秒
41.
42.
Human senescence patterns-late onset of mortality increase, slow mortality acceleration, and exceptional longevity-are often described as unique in the animal world. Using an individual-based data set from longitudinal studies of wild populations of seven primate species, we show that contrary to assumptions of human uniqueness, human senescence falls within the primate continuum of aging; the tendency for males to have shorter life spans and higher age-specific mortality than females throughout much of adulthood is a common feature in many, but not all, primates; and the aging profiles of primate species do not reflect phylogenetic position. These findings suggest that mortality patterns in primates are shaped by local selective forces rather than phylogenetic history.  相似文献   
43.
Chloramphenicol 1. Hazards of use and the current regulatory environment   总被引:1,自引:0,他引:1  
Chloramphenicol is a broad-spectrum antibiotic which has enjoyed extensive use in both medical and veterinary practice. Shortly after its introduction in the late 1940s, the use of chloramphenicol was associated with the induction of an idiosyncratic form of aplastic anaemia in man. This rare and unpredictable adverse effect has since been associated not only with systemic use but with topical applications, as well as occupational exposure. Recognition of the small risk of a potentially fatal adverse reaction, together with the risk of selection of chloramphenicol-resistant pathogens, has led to restrictions on the veterinary uses of chloramphenicol. In Australia at present, the use of chloramphenicol is only permitted in small animals. Its use is specifically prohibited in food-producing animals, including horses.  相似文献   
44.
45.
Marsupostrongylus spp. are the metastrongyloid nematodes most commonly associated with verminous pneumonia in Australian marsupials. Currently, there is a scarcity of information regarding this parasite in the common brushtail possum (Trichosurus vulpecula). Thirty-four free-living possums submitted to two wildlife hospitals in Sydney, Australia, between 2008 and 2015 were diagnosed with verminous pneumonia on postmortem examination. The majority of possums presented ill with multiple comorbidities. However, only five cases had clinical signs of respiratory disease. Necropsy and histopathology revealed extensive lung lesions characterised by diffuse, mixed interstitial infiltrates of macrophages, lymphocytes and plasma cells with mild to marked concentrations of eosinophils. Bronchopneumonia, pulmonary oedema, interstitial fibrosis, atelectasis and type II pneumocyte hyperplasia were also present in most cases. Adult nematodes, first-stage larvae and embryonating eggs were present in the large airways and alveolar spaces. The parasites were definitively identified as Marsupostrongylus spp. in eight cases with presumptive diagnoses based on histopathological characteristics reached in a further 26 cases. Twenty-nine of the 34 affected possums were adults with no sex predisposition. A review of the brushtail possum records at Taronga Wildlife Hospital from 1999 to 2015 revealed no lungworm infections were reported in the 45 possums examined before 2008. However, between 2008 and 2015, 30 of 47 possums (63.8%) examined were diagnosed with metastrongyloid lungworms. This case series is the first detailed report of Marsupostrongylus nematodes in common brushtail possums and highlights the clinical and pathological features, along with epidemiological findings.  相似文献   
46.
Adipose tissue (AT) expresses adipokines, which are involved in the regulation of energy expenditure, lipid metabolism and insulin sensitivity. Visceral (v.c.) and subcutaneous (s.c.) depots largely differ concerning their metabolic characteristics as to the control of lipolysis and the sensitivity to insulin. The adipokines adiponectin, leptin and visfatin influence lipolysis and insulin sensitivity. Signalling by G‐protein coupled receptor 41 (GPR 41) stimulates leptin release via activation by short‐chain fatty acids. We hypothesized that the metabolic differences between v.c. and s.c. fat depots may also apply to the expression of adiponectin, its receptors, leptin, visfatin, insulin receptor (IR) and GPR 41. Therefore, we aimed to compare the mRNA expression of adiponectin, leptin and visfatin, of the adiponectin receptors 1 and 2 (AdipoR1/2) and IR as well of GPR 41 between several s.c. and v.c. fat depots in sheep. Samples from 10 rams were collected at slaughter (40 kg BW) from three s.c. depots, i.e. close to sternum (s.c.S), close to withers (s.c.W), and at the base of tail (s.c.T), and from two v.c. depots, i.e. from perirenal (v.c.P) and omental (v.c.O) fat. The mRNAs of both adiponectin receptors, as well as IR and putative GPR 41, were higher expressed in v.c. fat than in s.c. fat (p ≤ 0.05). Leptin mRNA abundance was greater in s.c. than in v.c. fat (mean ± SEM: s.c.: 2.55 ± 0.81; v.c.: 0.66 ± 0.21) and also differed among the five separately measured fat depots. Our results show differences in mRNA abundance for leptin, AdipoR1 and R2, as well as for IR and GPR 41 in s.c. compared with v.c. fat, thus confirming the need for individual consideration of distinct fat depots, when aiming to characterize adipose functions in ruminants.  相似文献   
47.
Diethylstilboestrol is a non-steroidal orally active oestrogen that in the past has been widely used in a variety of conditions in both medical and veterinary fields. In recognition of potential systemic availability to man of DES in the tissues of treated food-producing animals, together with an understanding of the potential teratogenic and carcinogenic toxicity of DES in man, the veterinary use of DES has been restricted to oral use in small animals only. Use of DES is prohibited in all food-producing animals.  相似文献   
48.
Positive relationships between circulating leptin concentrations and body fat content have been established in sheep when covering a rather broad range of age and/or body weight. The usefulness of leptin measurements for predicting carcass fat has yet to be evaluated specifically in fattening lambs. We therefore measured plasma leptin concentrations in 56 male lambs half and half Merino Mutton and Blackheaded Mutton. Subcutaneous fat thickness was measured by ultrasound 1 day before the lambs were slaughtered at 35 or 45 kg live weight. Carcass composition was determined by tissue dissection. The coefficients of correlations between leptin and the different amounts in fat depots ranged from 0.40 to 0.56 within the two live weight groups, and from 0.53 to 0.64 when taking the two groups together. Carcass fat percentage was estimated by leptin concentrations with the same accuracy (R2 = 0.34) as with ultrasound fat thickness. The accuracy was higher for leptin in the 35 kg-group whereas the accuracy was higher for ultrasound fat thickness in the 45 kg-group (R2 = 0.26 vs. 0.31). A combination of leptin and ultrasound fat thickness clearly enhanced the precision of estimation in all groups. Further investigations on the influence of factors such as breed, gender, duration of feed withdrawal or photoperiod on the association between leptin and carcass composition are necessary before the suitability of plasma leptin concentration for practical application can be evaluated.  相似文献   
49.
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