全文获取类型
收费全文 | 360篇 |
免费 | 8篇 |
国内免费 | 1篇 |
专业分类
林业 | 6篇 |
农学 | 3篇 |
基础科学 | 2篇 |
22篇 | |
综合类 | 65篇 |
农作物 | 15篇 |
水产渔业 | 6篇 |
畜牧兽医 | 230篇 |
园艺 | 7篇 |
植物保护 | 13篇 |
出版年
2022年 | 3篇 |
2020年 | 9篇 |
2019年 | 3篇 |
2018年 | 6篇 |
2017年 | 9篇 |
2016年 | 5篇 |
2015年 | 7篇 |
2014年 | 8篇 |
2013年 | 20篇 |
2012年 | 5篇 |
2011年 | 8篇 |
2010年 | 10篇 |
2009年 | 7篇 |
2008年 | 12篇 |
2007年 | 11篇 |
2006年 | 10篇 |
2005年 | 5篇 |
2004年 | 12篇 |
2003年 | 6篇 |
2002年 | 8篇 |
2001年 | 13篇 |
2000年 | 9篇 |
1999年 | 9篇 |
1998年 | 18篇 |
1997年 | 4篇 |
1996年 | 9篇 |
1995年 | 7篇 |
1994年 | 8篇 |
1993年 | 8篇 |
1992年 | 5篇 |
1991年 | 11篇 |
1990年 | 7篇 |
1989年 | 11篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1981年 | 6篇 |
1979年 | 3篇 |
1978年 | 7篇 |
1977年 | 8篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 3篇 |
1972年 | 2篇 |
1968年 | 4篇 |
1967年 | 2篇 |
1965年 | 4篇 |
1963年 | 2篇 |
排序方式: 共有369条查询结果,搜索用时 15 毫秒
251.
252.
Lehnert SA Byrne KA Reverter A Nattrass GS Greenwood PL Wang YH Hudson NJ Harper GS 《Journal of animal science》2006,84(12):3239-3250
Gene expression profiles of LM from beef cattle that underwent significant postweaning undernutrition were studied using complementary DNA (cDNA) microarrays. After 114 d of undernutrition, the RNA from LM showed 2- to 6-fold less expression of many genes from the classes of muscle structural proteins, muscle metabolic enzymes, and extracellular matrix compared with animals on a rapid growth diet. The expression levels of these genes had mostly returned to pretreatment levels after 84 d of realimentation. The gene expression changes associated with undernutrition and BW loss showed an emphasis on downregulation of gene expression specific to fast-twitch fibers, typical of starving mammals, with a preferential atrophy of glycolytic fast-twitch fibers. We also identified a small group of genes that showed 2- to 5-fold elevated expression in LM after 114 d of undernutrition. Putative roles for these genes in atrophying skeletal muscle are regulation of myogenic differentiation (CSRP3), maintenance of mesenchymal stem cells (CYR61), modulation of membrane function (TM4SF2), prevention of oxidative damage (SESN1), and regulation of muscle protein degradation (SQSTM1). A significant increase in stearoyl-CoA desaturase (SCD) gene expression was observed in atrophying muscle, suggesting either that increased fatty acid synthesis is part of the tissue response to caloric restriction, or that SCD plays another role in energy metabolism in the mixed cellular environment of bovine skeletal muscle. 相似文献
253.
Judith A. Hudson DVM Stephen T. Simpson DVM MS Donald F. Buxton DVM PHD Robert E. Cartee DVM MS Janet E. Steiss DVM PND 《Veterinary radiology & ultrasound》1990,31(2):50-58
The brains of 23 canine patients and six random-source dogs were examined ultrasonographically through the bregmatic fontanelle or a surgical craniotomy. Fifteen dogs had abnormal neurologic signs; the others were normal on neurologic examination. Untrasound results were compared with signalment, clinical signs, electroencephalography, computed tomography, radiology and histopathology. The purposes of the study were to demonstrate the use of ultrasound for the diagnosis of canine hydrocephalus and to determine whether there is a relationship between ventricular size and clinical signs. Lateral ventricles were considered enlarged if lateral ventricular height, ventricle-mantle ratio, or ventricle-hemisphere ratio, at the level of or caudal to the interthalamic adhesion in the transverse plane, exceeded 0.35 cm, 0.25 or 0.19, respectively. Of the 29 dogs examined, 14 had enlarged lateral ventricles and abnormal neurologic signs. Five dogs had enlarged lateral ventricles but appeared neurologically normal (occult hydrocephalus). Correlation was poor between ventricular size and clinical signs. 相似文献
254.
Equine gastrointestinal motility is a central issue in cases of equine colic, post operative convalescence and alimentary conditions encountered in practice. There are significant syndromes of intestinal dysmotility in the horse such as obstructive disorders and post operative ileus that are still poorly understood. This review describes the various areas of research that aim to elucidate the pathogenesis of intestinal hypo- or hypermotility by research methods, which include studies at the cellular level, and those that employ in vitro or in vivo techniques of evaluating the physiology and mechanical means of ingesta transit through the alimentary tract. The review discusses future directions for studies which will hopefully lead to better understanding and appropriate measures for diagnosis, therapy and prevention of ileus and other motility disorders. 相似文献
255.
D F Wolfe P W Mysinger R S Hudson R L Carson 《Journal of the American Veterinary Medical Association》1987,190(10):1313-1314
A 4-year-old Limousin bull sustained a rupture of the ventral aspect of the tunica albuginea of the penis, 20 cm distal to the distal bend of the sigmoid flexure. The corpus spongiosum penis and urethra apparently ruptured at the same time. 相似文献
256.
Kurobe T MacConnell E Hudson C McDowell TS Mardones FO Hedrick RP 《Journal of aquatic animal health》2011,23(1):9-18
Iridovirus infections of the integument were associated with disease and mortality among hatchery-reared populations of juvenile pallid sturgeon Scaphirhynchus albus and shovelnose sturgeon S. platorynchus from the Missouri River. Virus-infected cells in the integument of fins and body were greatly enlarged, possessed pleomorphic and eccentric nuclei, and exhibited an amphophilic to eosinophilic staining of the cytoplasm in hematoxylin-and-eosin-stained sections. Virus particles found in the host cell cytoplasm were composed of an outer hexagonal capsid measuring 254 nm in diameter and surrounding a dense nucleoid. Despite numerous attempts, the virus could not be propagated on routine cell lines used in fish viral diagnostics or from established cell lines from white sturgeon Acipenser transmontanus, pallid sturgeon, or shovelnose sturgeon. Bath exposures of healthy juvenile pallid sturgeon to a crude extract or a 0.45-microm-filtered extract from the fins of infected fish resulted in transmission of the virus and mortality. At water temperatures of 15 degrees C, the first deaths occurred at approximately 1 month; mortality peaked between 50 and 60 d postexposure, after which surviving fish recovered. Presence of the virus was confirmed among dead and moribund pallid sturgeon by both histology and detection of viral DNA by polymerase chain reaction methods. Feeding of infected tissues and cohabitation with virus-infected shovelnose sturgeon also resulted in successful virus transmission to juvenile pallid sturgeon. Virus infections among experimentally exposed pallid sturgeon that recovered from clinical episodes persisted for at least 8.5 months, and these apparently healthy fish transmitted the virus and disease to juvenile pallid sturgeon by cohabitation. The newly described Missouri River sturgeon iridovirus (MRSIV) as found in pallid sturgeon and shovelnose sturgeon shares many properties with a group of iridoviruses associated with serious skin and gill infections in several species of sturgeon. 相似文献
257.
Edmund J Leigh Edward Mackillop Ian D Robertson Lola C Hudson 《Veterinary radiology & ultrasound》2008,49(2):113-121
The purpose of this study was to produce an magnetic resonsnce (MR) image atlas of clinically relevant brain anatomy and to relate this neuroanatomy to clinical signs. The brain of a large mixed breed dog was imaged in transverse, sagittal, and dorsal planes using a 1.5 T MR unit and the following pulse sequences: Turbo (fast) spin echo (TSE) T2, T1, and T2- weighted spatial and chemical shift-encoded excitation sequence. Relevant neuroanatomic structures were identified using anatomic texts, sectioned cadaver heads, and previously published atlases. Major subdivisions of the brain were mapped and the neurologic signs of lesions in these divisions were described. TSE T2-weighted images were found to be the most useful for identifying clinically relevant neuroanatomy. Relating clinical signs to morphology as seen on MR will assist veterinarians to better understand clinically relevant neuroanatomy in MR images. 相似文献
258.
Amanda Michelle torres Panta Ana Flvia Bezerra da Silva Rodrigo Tenrio Padilha Hudson Henrique Vieira Correia Davide Rondina Jos Ricardo Figueiredo Deborah de Melo Magalhes Padilha 《Reproduction in domestic animals》2019,54(3):480-485
This study aimed to examine the in vitro culture of secondary preantral follicles, using reused ovaries, to compare both the 2D and 3D methods of in vitro culture of preantral follicles, and the system of medium replacement. Twenty‐five pairs of ovaries from mixed‐breed goats were used for the experiment. Follicular puncture of antral follicles was performed for in vitro production. After this procedure, the secondary preantral follicles were submitted to a microdissection procedure. The isolated preantral follicles were randomly divided into three treatments: (a) Two‐dimensional culture with partial replacement of medium during culture (2D PR), (b) Three‐dimensional culture with addition of medium during culture (3D AD) and (c) Three‐dimensional culture with partial replacement of medium (3D PR). The culture period was 18 days. All treatments at the end of the in vitro culture period (18 days) presented a follicular survival rate which ranged from 59% to 70%, demonstrating that it was possible to perform an experiment with preantral follicles using ovaries that had previously been used in another reproductive biotechnique. The 3D AD treatment showed a survival percentage and follicular diameter higher than the 2D PR treatment, however, it did not differ from the 3D PR treatment. In conclusion, experiments employing the use of preantral follicles can be performed with success after the ovaries have been used for experiments with antral follicles. Moreover, the three‐dimensional system with the addition of medium is recommended for in vitro culture of preantral follicles, since this system is more practical and financially feasible. 相似文献
259.
S Lampotang EB Liem D Lizdas S Cantwell JH Modell 《Veterinary anaesthesia and analgesia》2003,30(2):118-119
Gases are transparent and the piping layout in anesthesia machines is not obvious, making it hard to understand anesthesia machine function, potential failure modes, and recovery from faults. We experimented with an approach that simplified the layout of the anesthesia machine piping by removing extraneous details and making gases not only visible, but also color-coded. More than 15 anesthesia machine controls were represented by icons that a user can adjust by clicking on the icon with a pointing device and subsequently observing the effect of his/her intervention on anesthesia machine function in real time. We simulated two anesthesia machine failures and also supported non-English languages and non-US gas color codes. Further, we initiated an experiment in Web philanthropy by deliberately choosing to make the educational module accessible without charge and selected the Web as the preferred medium for dissemination of the Virtual Anesthesia Machine (VAM) viewable at http://www.anest.ufl.edu/vam . Originally designed for use in human anesthesiology, a significant percentage (about 30%) of the 54 000 international visitors, as tracked by an independent third-party Web traffic monitoring service, for the period 9/00–5/02, were from the veterinary field. VAM is being used as part of the curriculum in veterinary programs in the US and overseas and has been well received by the global anesthesia community (human and veterinary). 相似文献
260.
OBJECTIVE: To examine shedding of cell-free and cell-associated feline immunodeficiency virus (FIV) in semen of domestic cats during acute infection. ANIMALS: 7 specific-pathogen-free sexually intact male cats. PROCEDURE: 6 cats were inoculated IV with 5 x 10(6) 50% tissue culture infective doses of FIV-NCSU1, and 1 cat served as an uninfected (control) cat. Infection was confirmed in the 6 cats. Periodically for up to 16 weeks after inoculation, cats were anesthetized and ejaculates obtained by use of electroejaculation. Virus was isolated from filtered seminal plasma and washed seminal cells by co-cultivation with a feline CD4+ T-cell line. Seminal cell lysates were also examined for a 582-base pair segment of FIV gag provirus DNA, using a nested polymerase chain reaction amplification. RESULTS: During the acute phase of FIV infection, virus was evident in semen of 5 inoculated cats. Five cats had virus-positive seminal plasma and 3 had virus-positive cellular constituents during the study. Virus was isolated from 8/22 (36%) seminal plasma samples and 2/17 (18%) seminal cell specimens. Provirus DNA was detected in 5/24 (21%) seminal cell lysates. Cell-free virus was isolated as early as 6 weeks after inoculation, whereas cell-associated virus was isolated as early as 12 weeks after inoculation. Provirus DNA was detected in seminal cells from one cat as early as 1 week after inoculation. CONCLUSIONS AND CLINICAL RELEVANCE: Cell-free and cell-associated FIV are shed in semen of cats early during the course of infection. Samples obtained before seroconversion may contain virus. Virus shedding in ejaculates varies between and within cats during acute infection. 相似文献