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   86篇
  免费   6篇
  国内免费   1篇
林业   5篇
农学   2篇
  10篇
综合类   2篇
农作物   1篇
水产渔业   18篇
畜牧兽医   47篇
园艺   1篇
植物保护   7篇
  2022年   1篇
  2021年   4篇
  2020年   1篇
  2019年   2篇
  2018年   1篇
  2017年   4篇
  2016年   5篇
  2015年   3篇
  2014年   7篇
  2013年   3篇
  2012年   5篇
  2011年   6篇
  2010年   1篇
  2009年   2篇
  2008年   5篇
  2007年   8篇
  2006年   6篇
  2005年   6篇
  2004年   6篇
  2003年   9篇
  2002年   6篇
  2000年   1篇
  1996年   1篇
排序方式: 共有93条查询结果,搜索用时 46 毫秒
51.
To examine whether an angiotensin converting enzyme (ACE) inhibitor, benazepril, can be transformed to the active metabolite, benazeprilat, by severely injured liver of dogs with ascitic heartworm disease, benazepril hydrochloride was administered orally to dogs once daily for 7 consecutive days at a dose rate of 0.29 mg/kg to 0.63 mg/kg of body weight, and plasma benazepril and benazeprilat concentrations were determined on the 1st and 7th administration days. In 7 dogs with ascitic pulmonary heartworm disease, plasma benazeprilat concentrations tended to be higher than in 7 control dogs both on the 1st and 7th administration days. The peak concentration and area under the concentration-time curve tended to be greater in dogs of the ascites group than in control dogs, but the statistics could not detect significant differences in the time to peak concentration and t(1/2) between the control and ascites groups. Plasma ACE activities decreased after administration of benazepril. In dogs with ascitic heartworm disease, benazepril was readily transformed to benazeprilat by the liver, and was effective for suppression of plasma ACE activity.  相似文献   
52.
The relationship among nutritional status, systemic insulin-like growth factor-I (IGF-I) and ovarian function early postpartum were investigated. A total of 27 Holstein-Friesian cows, 10 that cycled normally within 20 days postpartum, 5 diagnosed with follicular cysts, 8 with persistent corpus luteum (CL) after the first ovulation postpartum and 4 with inactive ovaries were used for the study. Blood samples were collected 1-3 times per week, for 60 days pre- and postpartum, for IGF-I, progesterone, estradiol, free fatty acids (FFA), blood urea nitrogen (BUN), and aspartate aminotransferase (AST) determination. Inactive ovary and cystic cows had a higher body condition score before calving and lost more condition than normal or persistent CL cows. Immediately postpartum, IGF-I levels were higher and rose sharply in cows that cycled normally than in cystic, inactive ovary or persistent CL cows. At calving and early postpartum, FFA was higher in inactive ovary and cystic than in normal and persistent CL cows. There was a significant strong positive relationship between IGF-I and BUN, and strong negative relationships between IGF-I and FFA and AST in all groups. There was a positive relationship between serum IGF-I and estradiol in normal cystic and inactive ovary cows. This study found that overconditioned cows during the dry period or at calving, lost more body condition postpartum. These cows also had a deeper and longer period of negative energy balance (NEB), poor liver function and low circulating IGF-I concentrations early postpartum. Such cows were likely to have poor reproductive function as seen in development of cystic ovaries, persistent CL and inactive ovary. Changes in serum IGF-I early postpartum may help predict both nutritional and reproductive status in dairy cattle.  相似文献   
53.
Six Wagyu (Japanese Black) steers fitted with a ruminal cannula were used in a split‐plot design experiment comprising a 3 × 3 Latin square design (whole plot) and a randomized blocks design (subplot) to determine the effect of the treatment of potato pulp (PP) with urea and the effect of inclusion levels of PP silage in feed supplement on digestibility, ruminal in situ degradation and ruminal fermentation. The whole plot consisted of 20%, 50% and 80% PP silage (dry matter (DM) basis), with PP silage replacing formula feed. The subplot included untreated or 0.5% (on an as‐fed basis) urea‐treated PP. The treatment of PP with urea showed no effect on DM intake and digestibility. The percentage of the rapidly degradable DM fraction of the urea‐treated PP silage was higher (P < 0.01) and the percentage of its slowly degradable DM fraction was lower (P < 0.01) than for the untreated PP silage. Ruminal ammonia concentration was greater (P < 0.01) for steers fed urea‐treated PP silage than that for steers fed the untreated PP silage. The treatment of PP with urea caused a decrease in the molar proportion of acetate and an increase in the proportion of propionate in ruminal fluid after feeding. The rate of DM degradations in hay (linear, P < 0.01) and in PP silage decreased (linear, P < 0.01) as the inclusion level of PP silage increased. Increasing the inclusion level of PP silage in supplement decreased the effective degradability of DM in hay (linear, P < 0.05) and in PP silage (linear, P < 0.05). An increase in the amount of PP silage increased the molar proportion of acetate (linear, P < 0.01) and decreased the butyrate proportion (linear, P < 0.05) in ruminal fluid. The results suggest that urea treatment of PP facilitates microbial access to starch of PP silage in the rumen and that surplus level of PP silage in supplement have adverse effect on ruminal digestion.  相似文献   
54.
The Exaltation of Newcastle disease virus (END) phenomenon is induced by the inhibition of type I interferon in pestivirus-infected cells in vitro, via proteasomal degradation of cellular interferon regulatory factor (IRF)-3 with the property of the viral autoprotease protein Npro. Reportedly, the amino acid residues in the zinc-binding TRASH motif of Npro determine the difference in characteristics between END-phenomenon-positive (END+) and END-phenomenon-negative (END) classical swine fever viruses (CSFVs). However, the basic mechanism underlying this function in bovine viral diarrhea virus (BVDV) has not been elucidated from the genomic differences between END+ and END viruses using reverse genetics till date. In the present study, comparison of complete genome sequences of a pair of END+ and END viruses isolated from the same virus stock revealed that there were only four amino acid substitutions (D136G, I2623V, D3148G and D3502Y) between two viruses. Based on these differences, viruses with and without mutations at these positions were generated using reverse genetics. The END assay, measurements of induced type I interferon and IRF-3 detection in cells infected with these viruses revealed that the aspartic acid at position 136 in the zinc-binding TRASH motif of Npro was required to inhibit the production of type I interferon via the degradation of cellular IRF-3, consistently with CSFV.  相似文献   
55.
A 4-months-old calf of Japanese black cattle was diagnosed with orotic aciduria by gas-chromatography/mass-spectrometry (GC/MS). Until now orotic aciduria had not been reported in Japanese black cattle. The animal showed repeated diarrhea. The hematocrit was low, and microcytes and acanthocytes were observed in blood smears. The calf had lower serum total protein concentrations with a higher blood ammonia concentration. Needle-shaped crystals of orotic acid were observed in urinary sediments. Sequence homologous analysis with cattle uridine monophosphate synthase DNA indicated silent mutation in the affected calf.  相似文献   
56.
Serial sera from four mongrel cats experimentally inoculated with infectious larvae of Dirofilaria immitis were analyzed by immunoblot patterns against a phosphate buffered saline-extract of D. immitis. Antigen-specific protein bands detected indicate that the low molecular weight bands of 36, 32, 22, 19 and 14 kDa, are predictable for positive adult worm infection, suggesting diagnostic usefulness for adult D. immitis infection in cats.  相似文献   
57.
To elucidate the cause of growth retardation, 14 cattle with renal tubular dysplasia (RTD) were investigated by determining serum growth hormone (GH) and insulin-like growth factor (IGF)-1 concentrations. Compared with 6 healthy cattle, the baseline, maximum, area under the curve and peak amplitude of serum GH concentrations were higher or tended to be higher. Serum IGF-1 concentrations were lower normal or lower in cattle with RTD than in healthy cattle. Serum IGF-1 concentrations correlated significantly with body weight and chest girth, but not with serum GH and creatinine concentrations. Growth retardation in RTD might be associated partially with GH resistance.  相似文献   
58.
Endocrine patterns were compared in 2 strains of Japanese black cattle with growth retardation; MHO- and HSK-paternal strains (MHO and HSK cattle, respectively). MHO cattle (n=8) displayed lower serum concentrations of insulin-like growth factor-1 (IGF-1), triiodothyronine (T3), thyroxine (T4), and cortisol (31.1+/-20.7 ng/ml, 73.9+/-51.9 ng/dl, and 2.9+/-2.9 microg/dl, 1.3+/-0.7 microg/dl, respectively) than those in both HSK cattle (n=5) (64.9+/-47.6 ng/ml, 97.8+/-40.7 ng/dl, 4.1+/-2.1 microg/dl and 1.8+/-1.1 microg/dl, respectively), and the controls (n=6) (314.7+/-197.2 ng/ml, 140.2+/-21.3 ng/dl, 5.8+/-1.7 microg/dl, and 3.0+/-1.4 microg/dl, respectively). The area under the concentration curve of growth hormone (GH-AUC 0-600 min) in MHO cattle (22210+/-18951 ng.min/ml) tended to be greater than those in HSK (7887+/-6340 ng.min/ml) and the controls (2811+/-1275 ng.min/ml). MHO cattle showed a high GH-AUC0-600 min in contrast to a low serum IGF-1 concentration, as well as lower serum T3, T4, and cortisol concentrations. HSK cattle exhibited the same secretory patterns, but much more moderately. Growth retardation in Japanese black cattle exhibits some variations based on pedigree.  相似文献   
59.
Recent studies have shown significant associations between prepartum energy status and postpartum fertility in dairy cows; therefore, the assessment of energy status by blood metabolites and metabolic hormones and suitable improvement of management during the prepartum period may enhance reproductive performance. Rumen fill score (RFS) is associated with feed intake; however, it is unknown whether RFS is also related to blood parameters. Therefore, this study investigated the relationship between RFS and energy status during the prepartum period, and their associations with conception at first artificial insemination (AI) after parturition. In 42 multiparous Holstein cows, RFS assessment and blood sampling were carried out twice a week during 3 weeks of the peripartum period. Ovarian cycles until AI were evaluated by measuring milk progesterone levels. Before calving, positive correlations were observed between RFS and total cholesterol, and RFS did not change in pregnant cows at first AI after parturition, whereas in non‐pregnant cows, RFS decreased gradually as the calving day approached. After calving, non‐pregnant cows showed lower energy status compared with pregnant cows, and some non‐pregnant cows showed anovulation and cessation of estrous cycle. In conclusion, RFS during the close‐up dry period is related to real‐time energy status, and is associated with postpartum energy status and conception at first AI in dairy cows. © 2016 Japanese Society of Animal Science  相似文献   
60.
Ex ovo culture of avian embryos can be applied not only to embryology but also to various fields of basic research such as embryo manipulation, toxicology, and regenerative medicine. The windowing method, which facilitates various manipulations and observations by opening a hole in one part of the eggshell, and culture systems using surrogate eggshells, are widely used. Despite this, biology lessons in high schools cover shell-less culture systems, which involve the development of avian embryos in artificial vessels, such as rice bowls, without using surrogate eggshells. However, as embryo development stops at its early stages in this method, it is not possible to continuously observe the development of the embryo. This led to attempts to develop an embryo culture method using a complete artificial culture vessel that does not use surrogate eggshells, and Kamihira et al. (1998) succeeded in hatching quail embryos in an artificial culture vessel using polytetrafluoroethylene membranes. In addition, Tahara succeeded in hatching chick embryos in artificial culture vessels that used cling film made of polymethylpentene and reported their detailed methodology (Tahara and Obara, 2014). These technologies are being applied not only to school education but also to various fields of research.  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