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   72篇
  免费   4篇
综合类   10篇
畜牧兽医   59篇
园艺   7篇
  2023年   1篇
  2022年   4篇
  2021年   2篇
  2020年   1篇
  2019年   2篇
  2017年   4篇
  2015年   6篇
  2014年   4篇
  2013年   6篇
  2012年   4篇
  2011年   3篇
  2010年   4篇
  2009年   6篇
  2008年   2篇
  2007年   4篇
  2006年   3篇
  2005年   1篇
  2004年   4篇
  2003年   3篇
  2002年   2篇
  2000年   3篇
  1999年   1篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1993年   1篇
排序方式: 共有76条查询结果,搜索用时 15 毫秒
1.
2.
3.
AIM: In order to observe the myocardial differentiation capacity of the dedifferentiated fat (DFAT) cells treated with vitamin C in vitro. METHODS: DFAT cells were dedifferentiated from the mature rat adipocytes with ceiling adherent culture. The DFAT cells of passage 3 were used in the study. Vitamin C and/or neonatal rat heart tissue lysate were added into the culture medium to induce myocardial differentiation for 3 weeks. The cell morphology was observed under microscope. The myocardial-specific markers, such as cTnT, GATA-4 and NKx2.5, were examined by the methods of immunofluorescence, PCR and Western blot. RESULTS: Mature rat adipocytes dedifferentiated into fibroblast-like DFAT cells after ceiling adherent culture. The DFAT cells spontaneously differentiated into cardiomyocyte-like cells under normal culture condition with a low incidence. After treated with neonatal rat heart cell lysate, the DFAT cells became cardiomyocyte-like cells that had bigger size, longer shape and myotubule-structure. The expression of cTnT, GATA-4 and NKx2.5 was remarkably increased at both mRNA and protein levels as compared with the normal cultured DFAT cells. The expression of cTnT, GATA-4 and NKx2.5 was further increased in DFAT cells after treating with vitamin C. No spontaneous beating cell was observed. CONCLUSION: Vitamin C enhances the differentiation of DFAT cells into cardiomyocyte-like cells.  相似文献   
4.
5.
研究6头健康新生犊牛3日龄和10日龄时血液营养代谢成分和激素水平的昼夜动态变化结果表明:血糖(Glu)的平均水平夜间较昼间高.进食后血糖明显升高,10日龄较3日龄时进食反应显著;α-氨基氮(α-NH2.N)昼夜间差别不大,进食后.先稍降.而后升高;胰岛素(Ins)夜间高于昼间.进食可引起Ins升高,其升高程度随日龄增长明显加强;胰高血糖素(GC)清晨至中午分泌水平较低.至夜晚20:00-22:00时出现分泌高峰;皮质醇(Cort)分泌峰值出现在午夜至凌晨,随年龄增长.有后移的趋势;生长激素(GH)夜间较昼间高,在凌晨02:00-06:00时出现连续性分泌高峰。说明犊牛在生后3日龄时某些生理节律性已建立,而且呈现一定的年龄性变化规律。  相似文献   
6.
Many experimental infection studies with bovine immunodeficiency virus (BIV) have been conducted, but neither virus transmission under natural conditions nor longitudinal clinical effects of naturally occurring infections in non-experimental populations are well explored. We tested the hypotheses that BIV is transmitted across the placenta during gestation and that intragestionally infected calves are at increased risk of neonatal disease. A cohort of 59 dairy cows on one farm were enrolled at parturition and the BIV serostatus of the cows and their pre-colostral calves determined with an indirect fluorescent-antibody assay. Moreover, the enrolled calves were monitored thrice weekly for specific clinical signs through the duration of the 30 day neonatal period and the occurrence of clinical signs analyzed for association with calf pre-colostral BIV serostatus and dam BIV serostatus. Confounding due to calf passive immunity and season of birth were also explored. Forty percent of seropositive cows (14/35) gave birth to seropositive calves but no seropositive calves (0/19) were born to seronegative dams (estimated relative risk 16, 95% exact confidence interval 2.6–5.8×1029). Calf pre-colostral BIV serostatus was not associated with the occurrence or frequency of clinical signs — but dam BIV serostatus was associated with the odds of occurrence of calf hyperthermia and with the frequency of occurrence of calf hyperthermia and hyperventilatory events. This study is inconclusive about the effects of prenatal BIV infection on neonatal health — but it does provide evidence for the natural occurrence of transplacental BIV infection.  相似文献   
7.
Of 17 foals born on a Thoroughbred breeding farm between March and April 1995, infection with equine herpesvirus type 1 (EHV-1) was associated with neonatal morbidity in 5 foals, 3 of which died or were euthanized. Morbidity and mortality were associated with pulmonary inflammation, and EHV-1 was identified in the lungs of the 3 foals that died. All neonatal EHV-1 infections occurred in foals of mares housed in the same pasture and barn. No other clinical manifestations of EHV-1 infection (eg, abortion, neurologic disease, or respiratory disease) occurred during this outbreak. Three foals were treated with acyclovir (1 died, 2 survived), which may have influenced the clinical outcome in the surviving foals.  相似文献   
8.
In order to identify variables obtained at admission that could be used to predict survival in septicemic foals, medical records of 65 foals diagnosed with septicemia were reviewed. Initially, variables were analyzed independently (univariate analysis) for association with survival. Of the physical examination and historical data examined using univariate analysis, the ability to stand at admission, respiratory rate ≥ 60 breaths per minute (bpm), and normal-appearing mucous membranes were significantly associated with survival. Foals with history of induced parturition were significantly less likely to survive. The following hematologic and serum biochemical variables determined at admission were significantly associated with survival: white blood cell count a 6,000 cells/μL, neutrophil count <4,000 cells/μL, serum albumin concentration <2.2 g/dL, serum glucose concentration <120 mg/ dL, blood pH ≥ 7.35, and positive base excess. The administration of plasma at admission was significantly associated with survival. Stepwise multiple logistic regression analysis was performed to evaluate the association between survival and variables identified as significantly associated with survival in bivariate analysis. The final multivariate model selected included the variables standing, duration of clinical signs (24-hour intervals) prior to admission, respiratory rate a 60 bpm, neutropenia (> 4,000 cells/μL), and neonatal age category. The probability of survival was significantly increased for foals that were standing, had a respiratory rate a 60 bpm, and that had a neutrophil count <4,000 cells/μL at admission. Probability of survival was significantly decreased for foals that had a longer duration of clinical signs prior to admission. For each 24 hours of duration, the estimated risk of death was increased by 5.8-fold.  相似文献   
9.
Summary

An outbreak of coccidiosis on two Belgian farms is described. Diarrhea started in piglets at 9 or 10 days of life. Zero to three pigs died per litter. The morbidity rate varied from 70 to 90 per cent. Histological examination of the intestines revealed shortening of villi and different stages of the life cycle of coccidia were seen in the enterocytes. Virological examination was negative for corona‐, corona‐like, and rota‐virus. A haemolytic E. coli strain was isolated in one case. As for treatment, good results were obtained by the adding of 1 kg amproleum pre‐mix per ton sow feed. Scouring pigs were treated orally with 2 cc of an amprol solution once a day. The diarrhea stopped one day after treatment.  相似文献   
10.
本试验旨在研究不同日粮赖氨酸水平对新生仔猪生长性能、氮利用及体沉积的影响,探讨新生仔猪赖氨酸的需要量.选取4日龄、平均体重为(1-90±0.05)kg的杜×长×大三元杂新生仔猪46头,其中40头按窝别和体重分成5组,每组4个重复,每个重复2头猪,另外6头在试验开始时屠宰,测定体成分;各组日粮赖氨酸水平分别为1.27%(对照组)、1.37%、1.47%、1.57%及1.67%,饲养至21日龄.结果表明:1)1.47%~1.67%组仔猪21日龄体重、15~21日龄及4~21日龄平均日增重显著高于对照组(P<0.05),以1.57%组平均日增重最大.1.57%组和1.67%组在15~21日龄及4~21日龄的平均日采食量显著高于对照组(P<0.05).1.37%~1.67%组的仔猪料重比均显著低于对照组(P<0.05).2)1.47%~1.67%组仔猪氮的生物学价值显著高于1.27%~1.37%组(P<0.05).3)日粮赖氨酸水平未显著影响能量和脂肪沉积(P>0.05);随日粮赖氨酸水平的提高,蛋白质的每日沉积量增加,147%~1.67%组显著高于1.27%~1.37%组(P<0.05),以1.67%组最大.综合各项测定指标得出,4~21日龄仔猪日粮赖氨酸适宜水平为1.57%,即赖氨酸含量为73.1 g/kg CP或0.85 g/MJ DE;仔猪每日赖氨酸需要量为2.43 g/d.  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