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   12篇
  免费   1篇
基础科学   1篇
水产渔业   4篇
畜牧兽医   8篇
  2022年   1篇
  2021年   1篇
  2020年   2篇
  2019年   2篇
  2017年   1篇
  2016年   1篇
  2014年   1篇
  2011年   1篇
  2007年   1篇
  1996年   1篇
  1991年   1篇
排序方式: 共有13条查询结果,搜索用时 15 毫秒
1.
Cadavers were compared with live anesthetized dogs for their effectiveness as models for surgical training of veterinary medical students. One group of students was trained using cadavers, and a peer group was trained using live anesthetized dogs. Both groups then performed an intestinal anastomosis using a live subject. The time to completion of the procedure was recorded. The anastomoses and celiotomy closures were evaluated. Each anastomosis was isolated and pressure tested. Reviewers blindly scored each surgical team's performance based on actual inspection of the surgical site and on viewing videotapes of the procedure. The participants' attitudes toward the use of live animals in teaching and research were documented before and after training. No statistically significant differences could be detected between the two groups. The results suggest that some substitution of cadavers for live dogs in surgical training might be feasible.  相似文献   
2.
The present investigation aimed to evaluate the effect of dietary chitosan supplementation on growth performance, body composition, immune response and histopathology of Nile tilapia, and also the in vitro antibacterial activity of chitosan against Streptococcus agalactiae (S. agalactiae). About 180 fish (average body weight 39.3 ± 0.3 g) were randomly divided into three groups according to chitosan supplementation: control group (basal diet without chitosan), Ch3 group (3 g chitosan/kg diet) and Ch5 group (5 g chitosan/kg diet). Growth performance parameters and body proximate composition were measured before infection but biochemical parameters and lysozyme and antibacterial activities before and after experimental infection. Results of the present investigation showed dietary chitosan (5 g chitosan/kg diet) significantly (p < .05) improved growth performance parameters, body composition (dry matter, crude protein, ether extract, ash, and carbohydrate) and serum biochemistry (total protein, albumin, globulin, with no effect on AST, ALT, urea and creatinine) before infection in Ch5 group than the control. After infection, liver enzymes (serum AST and ALT) were maintained lower in fish fed Ch3 or Ch5 than the control. Serum lysozyme and bactericidal activities significantly increased (p < .05) in chitosan groups before and after the challenge. The mortality rate was markedly reduced in the Ch3 group and prohibited in the Ch5 group after the experimental infection. In conclusion, feeding 3 or 5 g chitosan/kg diet increased the growth rate and improved FCR of Nile tilapia. In addition, it reduced mortality by its antibacterial and immunostimulant effects.  相似文献   
3.
Histological examination of the peripheral circulation of the ovary of 18 females of the one‐humped camel revealed a series of blood vessels with special structures. Throttle or occlusive artery was recorded in the ovarian zona vasculosa and in the cortex, and it showed an intimal cushion‐like thickening made up of intimal bolsters that formed of smooth muscle fibres and glomus cells. The smooth muscle cells of the tunica media and the tunica adventitia of throttle artery pursued a circumferential pattern. Anastomosis arteriovenosa included simple bridge‐like anastomotic vessels between arteria and venae, and glomus vessels of typical structure were demonstrated. Glomus organs were recorded in the ovary and were comprised of the tortuous glomus vessels and the related afferent and efferent vessels. Glomus cell complexes also were commonly occur at the cortex ovarii that possessed an extremely convoluted course with a hyperplastic wall and a narrow lumen. Atypical glomus vessels were demonstrated within the ovarian zona vasculosa, and the wall of these vessels was relatively thick and consisted of double tunica media with an intimal bolster. Some vessels contained an intimal bolster device of exclusively glomus cell structure (glomus bolster) with a tunica elastic interna demarcated it from the glomus cell media. Some venae represented several layers of longitudinally arranged smooth muscle fibres in the tunica media. Other venae showed wall with variable thickness. Venae with double muscular tunica media were recorded in the medulla. Some venae showed double internal elastic lamina. Also, venae with thick adventitia contained dispersed smooth muscle fibres were determined. Spirally oriented arteriole and venule were demonstrated within the cortex and medulla ovarii. Gestation sclerosis was demonstrated in ovarian zona vasculosa of pregnant females.  相似文献   
4.
This study was designed to investigate the hormonal and metabolic factors associated with placental retention in buffaloes with respect to the roles of oxidative stress biomarkers and serotonin receptors. Blood samples were collected at weeks 3, 2 and 1 pre-partum and at calving from 37 buffaloes; thirty normally dropped their placentae (Non-RFM group) and 7 dropped their placentae after 12 hr post-calving (RFM group). Serum progesterone (P4), oestradiol, cortisol, non-esterified fatty acids (NEFA), beta-hydroxybutyric acid (BHBA), antioxidant/oxidant biomarkers and mineral concentrations were assessed. Histopathology and histochemistry were implemented to detect collagen in foetal placental tissues. Immunohistochemistry for serotonin receptors in placental tissues was performed. Significant elevations in P4, cortisol, NEFA, BHBA and oxidative biomarkers concentrations were observed in the RFM group. However, oestradiol, antioxidants and mineral concentrations were significantly lower in RFM buffaloes than Non-RFM group. Histopathological examination revealed degenerative changes and necrosis in retained placental tissue compared with that in normal placental tissues. Serotonin receptors were significantly expressed with collagen condensation in retained placental tissues. Furthermore, inferior reproductive performance was pronounced in the retained group. In conclusion, retained foetal membranes in buffaloes were associated with hormonal imbalance, metabolic perturbation, oxidative stress, serotonin receptor upregulation and markedly reduced fertility indices.  相似文献   
5.
This paper provides the methodology and results of a cross-scale diagnostic performance assessment program of the irrigation water management in the old lands of the Nile Delta of Egypt. The analysis was done at three levels; main canal level, branch canals level and on-farm level of the Meet Yazid command (82,740 ha) for the year 2008?C2009 to highlight areas for improvement. At the main canal level the annual average percentage of irrigation water returning to drains and groundwater was 53% of the total water supplied. Since Meet Yazid lies at tail end of the delta, and there is groundwater salinity, opportunities for reuse are increasingly limited moving north to Lake Burullus. This would indicate opportunities for real water savings. The results of monthly relative water supply of the main canal indicated mismatch between demand and supply especially during the winter months, and when supply is low farmers do reuse drainage or groundwater. Also, the assessment of the three branch canals showed non-uniformity of water distribution and mismatch between demand and supply even when comparing improved and non-improved canals. At the on-farm level in paddy fields, the amount of irrigation flows to drains and saline sinks varied from 0.46 to 0.71 of inflow. In spite of these values of non-uniformity and low depleted fraction, the relative evapotranspiration (ratio of actual to potential) evaporation was uniformly high, indicating most crops of most farmers were not water stressed, which is also confirmed by the high yield values. The average values of productivity per unit water depleted by ETact were 1.04 and 1.05 kg/m3 for rice and wheat fields, respectively, with yields of rice and wheat at 8 and 6 t per ha respectively. On farm and tertiary improvements alone will not yield real water savings, as excess water in the main canal and drains will continue to flow out of the system. Rather the focus should first be on supplies to the main canal, accompanied by more precise on farm and water delivery practices at branch and tertiary levels, and ensuring that environmental flows are met. There is an added advantage of focusing on this tail end region of Egypt that this response would lessen vulnerability to reuse of polluted and saline water.  相似文献   
6.
In this study, the expression and distribution of monocarboxyolate transporter 1 (MCT1) along the intestines (duodenum, jejunum, ileum, cecum, colon and rectum) of dogs were investigated at both the mRNA and protein levels. The expression of MCT1 protein and its distribution were confirmed by Western blotting and immunohistochemical staining using the antibody for MCT1. We identified mRNA coding for MCT1 and a 43-kDa band of MCT1 protein in all regions from the duodenum to the rectum. Immunoreactive staining for MCT1 was also observed in epithelial cells throughout the intestines. MCT1 immunoreactivity was greater in the large intestine than in the small intestine. MCT1 protein was predominantly expressed on the basolateral membranes along intestinal epithelial cells, suggesting that MCT1 may play an important role in lactate efflux and transport of short-chain fatty acids (SCFAs) to the bloodstream across the basolateral membranes of the dog intestine.  相似文献   
7.
Fish Physiology and Biochemistry - The current study investigated how different fasting and refeeding regimes would impact Nile tilapia growth performance, histopathological examination, and gene...  相似文献   
8.
Fish Physiology and Biochemistry - The trials of finding non-conventional and alternative aquafeed ingredients are increasing. In this sense, this study evaluated the influence of coconut oil on...  相似文献   
9.
10.

In this study, we investigated the effects of probiotic, acidifier and synbiotic supplementation on growth performance, mortality rate, intestinal gene expressions, fecal shedding, and organs colonization induced by Escherichia coli in broiler chickens. Six experimental groups were included; negative control group (NC), positive control group (PC), probiotic group (PR), acidifier group (AC), synbiotic group (SY) and colistin sulfate group (CS). Chickens in groups NC and PC were fed a basal diet, while chickens in groups PR, AC, SY, and CS were fed a basal diet containing probiotic, acidifier, synbiotic and colistin sulfate, respectively from the 1st day to the 28th day of age. At 7 days of age, all groups (not NC) were orally challenged with 0.5 ml (1.0?×?109 CFU/ml) E. coli O78. The dietary supplementation of acidifier and synbiotic were sufficient to quell the devastating effects of E. coli infection in broilers. Growth performances represented by body weight gain, feed intake and feed conversion ratio were significantly improved as well as, mortalities were prevented whilst the ileal pro-inflammatory gene expressions (IL-6, IL-8, IL-13, TLR-4, IFN-γ, LITAF, AvBD-2, and AvBD-9) were significantly downregulated and the anti-inflammatory cytokine (IL-10) was significantly increased. In addition, E. coli fecal shedding and organs colonization was significantly diminished. It was concluded that the addition of both acidifier and synbiotic to the diet of broilers infected with E. coli could modulate the intestinal inflammatory responses induced by E. coli infection and minimized the inflammation-induced damage which resulted in improvement in growth performance, prevention of mortalities and reduction of E. coli environmental contamination.

  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