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   51篇
  免费   2篇
农学   1篇
  8篇
综合类   1篇
农作物   6篇
水产渔业   11篇
畜牧兽医   17篇
植物保护   9篇
  2022年   2篇
  2021年   4篇
  2020年   6篇
  2019年   6篇
  2018年   2篇
  2017年   2篇
  2016年   7篇
  2015年   5篇
  2013年   4篇
  2012年   3篇
  2011年   4篇
  2008年   1篇
  2006年   1篇
  2004年   1篇
  2003年   2篇
  1998年   1篇
  1993年   1篇
  1990年   1篇
排序方式: 共有53条查询结果,搜索用时 74 毫秒
11.
A method for measuring protein synthesis has been developed for small juvenile fish. A flooding dose of [3H] phenylalanine (Houlihan et al. 1988b) was added to the water containing the animals. Using juvenile tilapia O. mossambicus of approximately 15 mg, stability of the phenylalanine free pool specific radioactivity was achieved within 10 h. A linear increase in the whole body specific radioactivity of protein-bound phenylalanine occurred 3 h after [3H] phenylalanine was added to the water. In larger animals the flooding dose was injected into the peritoneum, and stable free pool phenylalanine specific radioactivities were achieved over 2 h. In the small fish the rate of protein synthesis exhibited a diurnal pattern. Scaling relationships for growth, protein synthesis and protein degradation were similar. The energy cost of protein synthesis in small juvenile animals, determined from the difference before and after the addition of the protein synthesis inhibitor cycloheximide, was close to the theoretical minimal cost.  相似文献   
12.
The present work aimed to describe the normal computed tomography (CT) and cross‐sectional anatomy of the nasal and paranasal sinuses in sheep and to correlate these features with the relevant clinical practices. Twenty apparent healthy heads of Egyptian native breed of sheep (Baladi sheep) of both sexes were used for studying these sinuses. CT images and their closely identical cross sections of the same head were selected and serially labelled in a progression from the rostral nasal region to the caudal aspect of the head using cheek teeth as landmarks. The current investigation reported seven sinuses in sheep, including maxillary, frontal, lacrimal and sphenoidal as paranasal, as well as dorsal and middle conchal and ethmoidal as nasal with unnoticeable palatine and ventral nasal conchal sinuses. The boundaries, extension, structure and communications of these sinuses were fully described. The current study provided anatomical guidelines for surgical interference in the frontal and maxillary sinuses during trephination, dehorning and sinuscopy. Also, an acceptable anatomical explanation was reported in this study for the high incidence of maxillary sinusitis than other sinuses. CT and cross‐sectional anatomy could be used as helpful database for diagnosis and clinical interference of the nasal and paranasal sinuses in sheep.  相似文献   
13.
Heterochromia iridis in water buffaloes (Bubalus bubalis)   总被引:1,自引:0,他引:1  
This study included 45 unaffected animals and 593 animals affected with heterochromia irides, and 85 enucleated eyeballs with heterochromia irides. The classification of heterochromia irides, morphology of normal and heterochromic irides, and the histology, ultrastructure, and scanning electron microscopy are presented. The incidence of heterochromia irides in water buffaloes was 7.62% affecting either one or both eyes. Both complete and partial heterochromia irides occurred. Complete heterochromia iridis is more frequent than the partial form in either bilateral or unilateral cases. The pupil has a dumb-bell-shape appearance. Granula iridica occurred at the upper (100%) and lower (30%) pupillary margins and originated from the posterior pigmented epithelium. In heterochromia irides, the melanocytes is absent in the anterior border and stromal layers, and iridal thickness appeared thinner than that of normal eyes.  相似文献   
14.
15.
16.
Abstract

Phytoremediation is a natural approach to use plants for decontaminating soil. A pot-culture factorial experiment in completely randomized design was conducted to evaluate the effects of four levels [0, 25, 50, and 100?mg/kg] of chromium (Cr) with three levels [0, 0.5, and 1-M solution) of plant defense inducer salicylic acid (SA) on growth, physiological processes, and biochemical responses of Malabar spinach (Basella alba). Results showed that Cr significantly decreased vine length (VL), leaf number (LN), leaf area (LA), fresh- (FBM), and dry-biomass (DBM), root length (RL), and dry-matter ratio (DMR). Cr also significantly decreased SPAD (chlorophyll contents), by 9% to 29% and net photosynthesis (Pn) rates, by 36% to 71%, but increased transpiration (E) rates, by 1.5 to 2.7 times and stomatal conductance (C), by 1.7 to 3.5 times, as compared with the control. Proline contents increased with an associated decrease in oxidative enzyme activities such as peroxidase, (POD) and catalase, (CAT) with increasing Cr levels. Cr significantly reduced the Dry Matter Ratio (DMR) (12% to 42%) and LA (10% to 35%), RL -stress (11% to 27%), and SPAD (10% to 28%) stress tolerance indices. The integrated stress tolerance index (ISTIndex) of Malabar spinach was reduced (by 6% to 23%) by Cr stress, as compared to the control. SA application, in contrast, partially alleviated the severity of Cr toxicity effects on VL, LN, LA, FBM, DBM, RL, and DMR and increased the SPAD (by 12%), Photosynthesis Net (Pn) (by 53% to 68%), and stomatal conductance (C) (by 35% to 50%), respectively. Furthermore, SA increased plant stress tolerance indices by increasing antioxidant enzymatic functions. SA application recovered the ISTIndex at all Cr levels, and the recovery effect on plants was more pronounced by 0.5-M SA than by other SA treatments. The mechanism of stress tolerance as induced by SA application may help plants to better survive and maintain growth in presence of higher Cr contents in soil. Results suggested that SA, as a plant defense inducer, can be exploited for improving Cr phytoremediation potential of Malabar spinach to decontaminate soil.  相似文献   
17.
Tropical Animal Health and Production - This study was performed to investigate the effect of feeding different levels of date pits (DP) to growing Japanese quails on growth performance, diet...  相似文献   
18.
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   
19.
Mycobacterium avium subsp. paratuberculosis (Map), the etiologic agent of Johne's disease (JD) in ruminants, has been implicated in the pathogenesis of Crohn's disease (CD) in humans. We developed a bovine ileal cannulation model to facilitate comparison of the immune response to Map and the mechanisms of pathogenesis in cattle and humans. Initial studies showed a T cannula could be maintained for up to a year in calves without inducing inflammation or adversely affecting intestinal function. Map introduced through the cannula established a persistent low level of infection without inflammation. Infection elicited an immune response to Map antigens detectable by flow cytometry. Further studies now show the cannulation model can be used with cows during the later stage of infection, affording access to the target tissue at all stages of infection. The studies also revealed no difference in infectivity or immunogenicity of isolates of Map obtained from cattle or humans with CD. Comparison of the immune response to Map during the early and late stages of infection using PCR, flow cytometry and QRT-PCR, showed the immune response early in the disease process is dominated by CD4 T cells. A CD8 response is delayed but comparable at later stages of infection. Genes for pro-inflammatory cytokines IFN-γ and the recently identified genes encoding IL-17 and IL-22 are up regulated in infected animals. These findings reveal that both human and bovine isolates of Map can establish infection and induce similar immune responses in a bovine model. They also reveal the cytokine responses elicited in cattle are similar to those implicated in CD pathogenesis.  相似文献   
20.
The pharmacokinetics of acetaminophen was investigated following oral dosing to Shiba goats in order to evaluate the properties of gastric emptying. Acetaminophen was intravenously and orally administered at 30 mg/kg body weight to goats using a crossover design with a 3-week washout period. The stability of acetaminophen in rumen juice was also assessed. Acetaminophen concentrations were measured by HPLC. Since acetaminophen was stable in rumen juice for 24 hr, the extremely low bioavailability (16%) was attributed to its hepatic extensive first-pass effect. The mean absorption time and absorption half-life were unexpectedly short (4.93 and 3.35 hr, respectively), indicating its marked absorption from the forestomach, which may have been due to its smaller molecular weight. Therefore, acetaminophen was considered to be unsuitable for evaluating gastric emptying in Shiba goats.  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