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   57篇
  免费   3篇
  国内免费   1篇
农学   1篇
  4篇
综合类   4篇
农作物   1篇
畜牧兽医   46篇
植物保护   5篇
  2023年   1篇
  2021年   1篇
  2020年   3篇
  2018年   1篇
  2017年   1篇
  2016年   3篇
  2014年   3篇
  2013年   4篇
  2012年   1篇
  2011年   1篇
  2009年   1篇
  2007年   1篇
  2006年   3篇
  2005年   1篇
  2003年   1篇
  2002年   4篇
  2000年   2篇
  1999年   1篇
  1998年   4篇
  1997年   5篇
  1995年   3篇
  1994年   3篇
  1993年   5篇
  1992年   3篇
  1991年   1篇
  1990年   3篇
  1989年   1篇
排序方式: 共有61条查询结果,搜索用时 0 毫秒
51.
Objective To compare the effectiveness of combined selenium and α-tocopherol acetate treatments in preventing lupinosis-associated myopathy in sheep.
Design Measurement of plasma muscle and liver enzymes, and histopathological examination of muscle and liver in the treatment groups.
Procedure The treatments were: subcutaneous injections of selenomethionine and vitamin E (sc(SeM+E)) , an intraruminal selenium pellet and oral doses of vitamin E and intramuscular injections of selenomethionine combined with either oral doses of vitamin E (imSeM+orE) or intramuscular injections of vitamin E in an oily carrier. Another group received no supplements, while a control group was given selenium pellets on day 0 and fortnightly oral doses of vitamin E from day 0 to 72. To produce lupinosis-associated myopathy, the sheep were fed a diet low in vitamin E and given repeated injections of a crude extract of Diaphorthe toxica. Groups sc(SeM+E) and imSeM+orE were stressed by dosing with protected polyunsaturated fatty acids from day 56 onwards.
Results Lupinosis-associated myopathy was induced in all unsupplemented sheep. In these sheep the storage of Se increased and that of vitamin E decreased. The subcutaneous treatment was highly effective in preventing lupinosis-associated myopathy and also produced the highest vitamin E concentrations in plasma and liver. Supplemental vitamin E was more efficacious than supplemental Se. Concentrations of vitamin E in the livers of sheep given intramuscular vitamin E were higher than expected based on plasma concentrations. Oral doses of vitamin E proved the least effective method of increasing concentrations in liver. Lupinosis did not affect Se concentrations in liver or muscle.
Conclusion The sc(SeM+E) treatment is highly effective in preventing lupinosis-associated myopathy but needs to be further assessed when selenium and vitamin E are both limiting in the diet.  相似文献   
52.
AIMS: To review results of the ventral approach for mandibular and sublingual sialoadenectomy for the treatment of sialocoeles associated with the mandibular and sublingual salivary glands in the dog, and to determine rates of recurrence and complication following this procedure.

METHODS: Thirty-nine dogs with 41 sialocoeles that underwent surgical intervention were retrospectively evaluated with respect to signalment, aetiology, location of sialocoeles, duration of clinical signs, treatment prior to referral, post-operative use of antibiotics and drains, complications, and recurrence.

RESULTS: The mean age at the time of surgery was 5.1 (SD 3.8) years, and duration of clinical signs 6.6 (SD 10.6) months. Long-term follow-up was available for 31 dogs; the minimum was 8 months and mean 47.7 (SD 25.8) months post-surgery. There was no recurrence of sialocoeles following the ventral approach for mandibular and sublingual sialoadenectomy. Post- operatively, 6/35 (17%) cases developed a seroma at the surgical site. No breed or sex predisposition was determined. The cause of the sialocoele was unknown in 36/41 (88%) cases.

CONCLUSIONS AND CLINICAL RELEVANCE: Excellent clinical results were achieved with a low rate of complications using the ventral approach for mandibular and sublingual siaload- enectomy. The ventral approach is recommended to minimise the risk of recurrence of sialocoeles.  相似文献   
53.
Fourteen dogs with enlarged gallbladders and immobile stellate or finely striated bile patterns on ultrasound are described. Smaller breeds and older dogs were overrepresented, with 4/14 Cocker Spaniels. Most dogs presented for nonspecific clinical signs such as vomiting, anorexia and lethargy. Abdominal pain, icterus and hyperthermia were the most common findings on physical examination. All dogs except one had serum elevation of total bilirubin and/or alkaline phosphatase, alanine aminotransferase and gamma glutamyl transferase. All dogs were diagnosed with a gallbladder mucocele upon histologic and/or macroscopic evaluation. Ultrasonographically, mucoceles are characterized by the appearance of the stellate or finely striated bile patterns and differ from biliary sludge by the absence of gravity dependent bile movement. On ultrasound, gallbladder wall thickness and wall appearance were variable and nonspecific. The cystic or common bile duct were normal sized in 5 dogs although all 5 had evidence of biliary obstruction at surgery or necropsy. Loss of gallbladder wall integrity and/or gallbladder rupture were present in 50% of the dogs, all located in the fundus. Gallbladder wall discontinuity on ultrasound indicated rupture whereas neither bile patterns predicted the likelihood of gallbladder rupture. Pericholecystic hyperechoic fat or fluid were suggestive of but not diagnostic for a gallbladder rupture. Cholecystectomy appears to be an appropriate treatment for mucoceles, if not to treat a gallbladder rupture, at least in most dogs to prevent it since gallbladder wall necrosis was identified by histology in 9 of 10 dogs. Mucosal hyperplasia was present in all gallbladders examined histologically. Positive aerobic bacterial culture was obtained from bile in 6 of 9 dogs. Cholecystitis was diagnosed histologically in 5 dogs and 4 dogs had signs of gallbladder infection solely upon bacterial bile culture. Gallbladder infection was not present with all the mucoceles suggesting that biliary stasis and mucosal hyperplasia may be the primary factors involved in mucocele formation. Based on the results of our study, we suggest two alternate courses of action in the presence of a distended gallbladder with an immobile ultrasonographic stellate or finely striated bile pattern: a cholecystectomy when clinical or biochemical signs of hepatobiliary disease are present or a medical treatment (antibiotics and choleretics) and patient monitoring by follow-up ultrasound examinations when the patient does not have clinical or biochemical abnormalities. An aerobic bile culture should be obtained in all patients, by ultrasound-guided fine needle aspirate or at surgery.  相似文献   
54.
55.
56.
Natriuretic peptides (NPs) are known to regulate reproductive events in polyovulatory species, but their function and regulation in monovulatory species remain to be fully characterized. Using a well‐established in vivo model, we found that bovine granulosa cells from follicles near the deviation stage express mRNA for the three NP receptors (NPR1, NPR2 and NPR3), but not for NP precursors (NPPA, NPPB and NPPC). The abundance of NPR3 mRNA was higher in dominant compared to subordinate follicles at the expected time of follicular deviation. After deviation, mRNA for all NP receptors was significantly more abundant in the dominant follicle. Intrafollicular inhibition of oestrogen receptors downregulated NPR1 mRNA in dominant follicles. In granulosa cells from preovulatory follicles, NPPC mRNA increased at 3 and 6 h after systemic GnRH treatment, but decreased at 12 and 24 h to similar levels observed in samples collected at 0 h. After GnRH treatment, NPR1 mRNA was upregulated at 24 h, NPR3 mRNA gradually decreased after 3 h, while NPR2 mRNA was not regulated. The mRNA expression of the enzyme FURIN increased at 24 h after GnRH treatment. These findings revealed that the expression of mRNA encoding important components of the NP system is regulated in bovine granulosa cells during follicular deviation and in response to GnRH treatment, which suggests a role of NP system in the modulation of these processes in monovulatory species.  相似文献   
57.
58.
Genetic diversity in 90 Indian soybean cultivars was assessed using 45 SSR markers distributed on 20 soybean chromosomes. Forty-five SSR markers generated 232 alleles with an average of five alleles/locus. The observed frequencies of the 232 alleles ranged from 0.01 to 0.94 with an average of 0.19. The polymorphic information content (PIC) value of the SSR markers varied from 0.10 to 0.83 with an average of 0.61 and about 71% markers have a PIC value of >0.5. In this study, 54 rare alleles including 19 genotype specific alleles were also identified. The observed hetrozygosity for SSR markers ranged from 0 to 0.11 with a mean of 0.10. Cluster analysis grouped the 90 soybean cultivars into three major clusters and principal coordinates analysis (PCoA) results were similar to those of the cluster analysis. A combination of eight SSR markers successfully differentiated all 90 soybean cultivars. The population structure analysis distributed the 90 soybean genotypes into two populations with mean alpha (α) value of 0.1873. In AMOVA analysis, proportion of variation within population was high (88%), whereas only 12% occurred among populations. In cluster and structure analyses, most of the genotypes with similar pedigree were grouped together. Soybean cultivars DS228, MACS-13, LSb-1, Hardee, Improved Pelican, and Pusa-24 were the six most genetically distinct cultivars identified. The study reported a moderate genetic diversity in Indian soybean cultivars and findings would be useful to the soybean breeders in selecting genetically distinct parents for a soybean improvement program.  相似文献   
59.
The aim of the present work was to evaluate the breed and season effects on scrotal circumference (SC) and semen characteristics of 28 mature hair sheep rams kept under tropical conditions. SCs, sperm concentration (SPC) and abnormal sperm were significantly affected by breed effect (p < 0.001). The season effect was significant in SPC (p < 0.0001) while ejaculate volume, mass motility and SPC were affected by breed × season interaction effect (p < 0.001). It can be concluded that the magnitude of the breed and season effects were not sufficient to affect the reproductive capacity of hair sheep rams throughout the year.  相似文献   
60.
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