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   84篇
  免费   30篇
林业   5篇
  6篇
综合类   6篇
农作物   1篇
水产渔业   3篇
畜牧兽医   91篇
园艺   1篇
植物保护   1篇
  2023年   1篇
  2022年   1篇
  2021年   1篇
  2020年   3篇
  2019年   3篇
  2018年   5篇
  2017年   3篇
  2016年   9篇
  2015年   7篇
  2014年   3篇
  2013年   6篇
  2012年   3篇
  2011年   5篇
  2010年   3篇
  2009年   1篇
  2008年   9篇
  2007年   1篇
  2006年   3篇
  2005年   5篇
  2004年   2篇
  2003年   6篇
  2002年   3篇
  2001年   2篇
  2000年   2篇
  1999年   4篇
  1998年   2篇
  1997年   3篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1991年   5篇
  1990年   1篇
  1989年   2篇
  1987年   1篇
  1984年   1篇
  1972年   1篇
  1968年   1篇
排序方式: 共有114条查询结果,搜索用时 15 毫秒
51.
Although rare, guttural pouch mycosis is a potentially life-threatening disease in the horse. The disease is most commonly treated surgically. One surgical option is occlusion of the internal carotid artery with a combination of ligation and use of a balloon tipped venous thrombectomy catheter. Complications of such treatment are rarely reported. This case series of five individuals describes the appearance, diagnosis and management of medium (>2 weeks) and long-term (>10 years) complications (including abscess formation, draining sinuses and wound dehiscence) of internal carotid artery occlusion with a venous thrombectomy catheter and management of these surgical site infections. The clinical presentations included swelling and/or discharging tracts in the parotid region. In one horse, an osseous reaction of the basisphenoid bone and penetration of the contralateral guttural pouch by the implant were identified by computed tomography. In all five horses, the surgical site infections were successfully resolved following removal of the venous thrombectomy catheter.  相似文献   
52.
The use of vesicles co‐incubated with plasmids showed to improve the efficiency of cytoplasmic injection of transgenes in cattle. Here, this technique was tested as a simplified alternative for transgenes delivery in porcine zygotes. To this aim, cytoplasmic injection of the plasmid alone was compared to the injection with plasmids co‐incubated with vesicles both in diploid parthenogenic and IVF zygotes. The plasmid pcx‐egfp was injected circular (CP) at 3, 30 and 300 ng/μl and linear (LP) at 30 ng/μl. The experimental groups using parthenogenetic zygotes were as follows: CP naked at 3 ng/μl (N = 105), 30 ng/μl (N = 95) and 300 ng/μl (N = 65); Sham (N = 105); control not injected (N = 223); LP naked at 30 ng/μl (N = 78); LP vesicles (N = 115) and Sham vesicles (N = 59). For IVF zygotes: LP naked (N = 44) LP vesicles (N = 94), Sham (N = 59) and control (N = 79). Cleavage, blastocyst and GFP+ rates were analysed by Fisher's test (p < 0.05). The parthenogenic CP naked group showed lower cleavage respect to control (p < 0.05). The highest concentration of plasmids to allow development to blastocyst stage was 30 ng/μl. There were no differences in DNA fragmentation between groups. The parthenogenic LP naked group resulted in high GFP rates (46%) and also allowed the production of GFP blastocysts (33%). The cytoplasmic injection with LP vesicles into parthenogenic zygotes allowed 100% GFP blastocysts. Injected IVF showed higher cleavage rates than control (p < 0.05). In IVF zygotes, only the use of vesicles produced GFP blastocysts. The use of vesicles co‐incubated with plasmids improves the transgene expression efficiency for cytoplasmic injection in porcine zygotes and constitutes a simple technique for easy delivery of plasmids.  相似文献   
53.
Nest structures of six termite species, four with epigeous (above-ground) and two with subterranean nests were analysed to find out how their building and feeding habits could be related to their nests phosphorus status compared with control soils. Termite nest structure was found to affect significantly the P status in savanna soils: mounds of the African Trinervitermes geminatus and the South American Nasutitermes ephratae (both grass-feeders) displayed a greater amount of available P, especially in the inner part of the nest, than the surrounding soil. The abundant quantities of dead grass material stored in the mound can explain the available soil P increase. A similar increase in P availability was also found for the soil-feeder Cubitermes severus. In mounds of Macrotermes bellicosus, on the other hand, there was a drastic increase in P sorption (and a corresponding decrease in available P) compared to adjacent soils, which was attributed to the building strategy of this species. M. bellicosus selected clay from subsoil to build its nest structure. The data obtained for the subterranean species Ancistrotermes cavithorax and Microtermes toumodiensis indicated also that there is an increase in P sorption in mounds when compared with associated topsoils. Consequently, the nest structures of only certain termite species should be considered, and utilised, as a soil amendment in place of fertilisers. This impact on the P cycle in savannas seems to be related to the termite feeding status and to the type of material utilised in nest building. This should be taken into account before using termite nest material in soil fertility status improvement.  相似文献   
54.
Nest structures of two termite species (Trinervitermes spp.) with epigeal (above-ground) mounds were analyzed to compare their nutrient status with that of adjacent soils. To take into account soil variability, the observations and samplings were made in three toposequences of different and representative West African savanna soils. The data showed the high degree of adaptation of these termite species to a large range of soil types and environments. Mounds of Trinervitermes geminatus and Trinervitermes trinervius, both grass-feeders, contained more clay, organic matter (OM), and exchangeable cations than the surrounding surface layer soil. The storage of OM and exchangeable cations was determined for T. geminatus nests and compared to the surrounding soil. Despite substantial nutrient storage in mounds, its total weight appeared low when compared to the nutrient storage in the surrounding 0–15 cm of soil surface layer. This illustrates how contradictory points of view on the use of termite mounds in agriculture need to be clarified using a classical approach that takes into account data by species; and this also evaluates the contribution of different termite mounds to nutrient fluxes and storage and the exact stocking rate of living mounds.  相似文献   
55.
A device that injects a planar, spike input of tracer and accommodates irregular stream cross-sections was designed and field tested. The injector is based on a modular support and electrical system that can easily be modified in the field. The tracer is distributed to the water from self-emptying packets made of latex tubing. These packets resist premature breakage and contribute no litter to the stream. The packets empty after applying a current to the electrical system. Instream assembly of the tracer injector is possible from a boat. A two-dimensional input of tracer significantly shortens the initial mixing period for streams that are wide and deep. During the initial period, the tracer cloud becomes well-mixed vertically and laterally. After the initial period is satisfied, the variance of the tracer cloud grows linearly with time, and longitudinal dispersion can be measured easily. The use of a plane source injector significantly reduces the duration of the initial period.  相似文献   
56.
Reports of tracheal injuries in horses are rare compared with those in small animals and humans. Although uncommon, tracheal injuries can be life threatening if they progress or are not treated. Different treatments have been described depending on the severity of the problem. This report describes the successful surgical treatment of three cases of closed tracheal lacerations through an intraluminal surgical approach.  相似文献   
57.
58.
Currently, mesenchymal stem cells (MSCs) are used in veterinary clinical applications. Bone marrow and adipose tissue are the most common sources of stem cells derived from adult animals. However, cord blood which is collected non‐invasively is an alternative source of stem cells other than bone marrow and adipose tissue. Moreover, high availability and lower immunogenicity of umbilical cord blood (UCB) haematopoietic stem cells compared to other sources of stem cell therapy such as bone marrow have made them a considerable source for cell therapy, but MSCs is not highly available in cord blood and their immunogenicity is poorly understood. In this study, the cells with spindle morphology from 7 of 9 bovine UCB samples were isolated and cultured. These mesenchymal stromal cells were successfully differentiated to osteocytes, chondrocytes and adipocytes. In addition, Oct‐4 and SH3 were determined by RT‐PCR assay. It is the first report of isolation, culture, characterization and differentiation of bovine umbilical stem cells.  相似文献   
59.
Reports of alimentary tract foreign bodies have been rarely reported in the equine literature. This Case Report concerns a mare who presented persistent fever and mild signs of colic. A metallic foreign body was found near to the diaphragm on radiographic and ultrasonographic examinations. A thoracotomy was subsequently performed by means of a 7th rib resection and a diaphragmatic incision made in order to remove the intra‐abdominal abscess containing a metallic foreign body. Peritonitis was the major complication and was managed during hospitalisation by multiple lavage‐drainage procedure of the abdominal cavity. Long‐term outcome (3 years) was good.  相似文献   
60.
Although alterations in biomarkers of cartilage turnover in synovial fluid (SF) have been demonstrated in horses with osteochondrosis (OC), there have been few investigations of such alterations in animals <1 year old. In this study tarsocrural SF samples from foals aged 18, 22 and 52 weeks of age were assessed for: (1) ‘turnover’ biomarkers of type II collagen (CPII and C2C) and proteoglycan (CS846 and glycosaminoglycans [GAG]); (2) matrix metalloproteinase (MMP) activity; (3) insulin-like growth factor (IGF)-1; (4) transforming growth factor (TGF)-β1; (5) prostaglandin (PG) E2; and (6) leukotriene B4.Using a linear mixed model, the concentration of biomarkers was compared between animals that developed or did not develop radiographic evidence of OC at 24 or 48 weeks of age. The CPII:C2C ratio tended to be higher in OC-affected joints compared to controls at all ages, and this difference was statistically significant at 22 weeks of age. The concentrations of CS846 and IGF-1, and the CS846:GAG ratio were reduced in OC-affected joints relative to controls at 18 weeks of age only. At 52 weeks of age, the PGE2 concentration was lower in joints with OC. Overall, there appears to be a consistent anabolic shift in type II collagen turnover in juvenile joints affected by OC. Aberrant proteoglycan turnover is not a hallmark of the late repair of this lesion but reduced concentrations of IGF-1 in SF may be associated with early-stage lesions.  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