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11.
To better understand the interaction between Mycoplasma bovis and its bovine host, we have characterized the immune response generated during an experimental lung infection with M. bovis. Proliferation ([3H]-thymidine blastogenesis) and Th1/Th2 cytokine production were used to monitor peripheral cellular immune responses. Flow cytometry analysis was used to determine T-cell subset activity by CD25 expression. Humoral immune response was monitored by the identification of antigen-specific IgG1 and IgG2 isotypes over time. Herein, we show that M. bovis antigen stimulates activation of CD4+ and CD8+ cells in vitro in a manner consistent with memory, and that gammadelta-T cells are activated by antigen in a manner consistent with innate immunity. In addition, the percentage of cells producing IFN-gamma during recall response is equal to that of IL-4 producing cells. Serological analysis shows M. bovis stimulates increased production of antigen-specific IgG1 while very little IgG2 is produced. We therefore submit that experimental lung infection of cattle with M. bovis results in a Th2-skewed immune response. 相似文献
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Jamie M Bush Doreene R Hyatt Denise Bolte Karamjeet Pandher 《Journal of veterinary diagnostic investigation》2006,18(6):594-596
A 700-pound, 9-month-old Angus heifer from a feedlot presented with acute neurologic signs, characterized by circling, posterior weakness, and nonresponsiveness, followed by death. Histologically, the frontal lobe and the thalamus contained multiple foci of liquefaction that contained numerous degenerative neutrophils and foamy macrophages. Some of these foci were centered on blood vessels that contained fibrin thrombi and exhibited varying degrees of fibrinoid necrosis of the vessel wall. There was adjacent axonal degeneration and neuronal necrosis characterized by pronounced cytoplasmic eosinophilia, peripheralization of the nuclei, and loss of Nissl substance. Aerobic culture of the brain yielded moderate growth of Vibrio species, which was determined to be Vibrio cholerae by polymerase chain reaction analysis of a 438-base pair fragment of the 16 S ribosomal RNA gene. V. cholerae are motile, gram-negative, curved rod-shaped bacteria. Some strains of V. cholerae are important food- and water-borne bacterial pathogens that produce an often fatal diarrhea in humans. This is the first known case report of V. cholerae meningoencephalitis and cerebral abscessation in a bovine. 相似文献
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John M Sykes Michael M Garner Leah L Greer Nancy P Lung Rob L Coke Frank Ridgley Mitch Bush Richard J Montali Ben Okimoto Robert Schmidt Jack L Allen Bruce A Rideout Patricia A Pesavento Edward C Ramsay 《Journal of zoo and wildlife medicine》2007,38(2):300-308
Oral eosinophilic granulomas were diagnosed in 16 tigers (Panthera tigris). All lesions were located on the hard or soft palate and typically consisted of flat or slightly raised circular ulcers. Histologic features of these lesions were essentially identical to those seen in oral eosinophilic granulomas of domestic cats and dogs. No clinical signs were noted in eight cases, though various degrees of inappetence, excessive salivation, and dysphagia were noted in the other eight tigers. Six cases were not treated. Treatment for the remaining 10 cases centered on corticosteroids and additional treatments included surgical removal, cryotherapy, antibiotics, and chlorpheniramine. Treatment with corticosteroids did appear to be effective in some cases, though lesions would worsen after cessation of therapy and no cases were cured. In addition, three cases developed complications possibly related to this corticosteroid therapy. The etiology of these lesions remains unknown, though an underlying allergic condition is likely. 相似文献
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Using phenotypic variation to determine conservation value: application of a novel approach to Arctic charr 总被引:1,自引:1,他引:0
Abstract – There is a very high degree of discrete variation in phenotype between populations of Arctic charr. This takes the form of variation not only in morphometric and meristic characters traditionally used to distinguish species, but also in characteristics of life-history, behaviour, coloration and ecology. This variability has a number of consequences, one of these is that there is a strong case for the conservation of populations with extreme phenotypes. However, if variation is discrete between populations but continuous across many populations, this poses difficulties in separating those populations of high conservation value from those of lower conservation value. In this paper we describe a statistical technique which enables populations on the extreme edges of the range of phenotypic variation to be identified and apply this to the morphometric characters of charr from 25 populations from across Scotland and Ireland. The technique enables the identification of any proportion of the most extreme phenotypes. When applied to our data, one population (Loch More) was in the top 2 percentile of the most extreme phenotypes from across the range of all populations included. Three populations were within the top 10% most extreme phenotypes (Lochs More, Uaine and Earn) and a further five within the top 20% (previously mentioned lochs plus Lochs Eck, Merkland, Uaine, Talla and Lough Nalughraman). This technique can potentially be used on any species and on any suite of characteristics as an objective measure of conservation value of a population within a continuous phenotypic range. 相似文献
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Association of blood cholesterol with occurrence of fat necrosis in cows and tall fescue summer toxicosis in steers 总被引:2,自引:0,他引:2
J A Stuedemann T S Rumsey J Bond S R Wilkinson L P Bush D J Williams A B Caudle 《American journal of veterinary research》1985,46(9):1990-1995
Factors associated with fat necrosis in cows and tall-fescue summer toxicosis in steers were studied. In the cow study, fescue pastures were fertilized, using 3 rates of N: high N (703 to 483 kg and 0 kg of N/ha/year from broiler litter in 1972 to 1974 and 1975, respectively), moderate N, and low N (224 and 74 kg of N/ha/yr from NH4NO3, 1972 to 1975, respectively). Bermuda grass pastures were fertilized at 2 rates of N: moderate N and low N (280 and 20 kg of N/ha/year from NH4NO3, 1972 to 1975, respectively). Fat necrosis developed only in cows grazing tall fescue, with an occurrence of 60%, 8%, and 3% for high-N, moderate-N, and low-N pastures, respectively. Cows grazing the high-N fescue, and to some extent those grazing the moderate-N fescue, had clinical signs of summer fescue toxicosis. Plasma cholesterol concentrations were lowest in cattle grazing the high-N fescue, averaging 114 mg/dl, followed by 134 and 127 mg/dl in cattle grazing the moderate-N and low-N fescue, respectively. In the steer grazing study, 24 paddocks of 0.49 ha each were seeded with tall-fescue lines G1-307 or G1-306 or with tall-fescue cultivars, KY-31 or Kenhy. All paddocks were fertilized with 170 kg of N/ha/year. Serum cholesterol concentrations were lower in steers grazing on G1-307 than in steers grazing on G1-306 or cultivars. Serum total lipids followed a similar trend, with a positive correlation (r = 0.49) between cholesterol and total lipids.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Astaxanthin Normalizes Epigenetic Modifications of Bovine Somatic Cell Cloned Embryos and Decreases the Generation of Lipid Peroxidation 下载免费PDF全文
Astaxanthin is an extremely common antioxidant scavenging reactive oxygen species (ROS) and blocking lipid peroxidation. This study was conducted to investigate the effects of astaxanthin supplementation on oocyte maturation, and development of bovine somatic cell nuclear transfer (SCNT) embryos. Cumulus–oocyte complexes were cultured in maturation medium with astaxanthin (0, 0.5, 1.0, or 1.5 mg/l), respectively. We found that 0.5 mg/l astaxanthin supplementation significantly increased the proportion of oocyte maturation. Oocytes cultured in 0.5 mg/l astaxanthin supplementation were used to construct SCNT embryos and further cultured with 0, 0.5, 1.0 or 1.5 mg/l astaxanthin. The results showed that the supplementation of 0.5 mg/l astaxanthin significantly improved the proportions of cleavage and blastulation, as well as the total cell number in blastocysts compared with the control group, yet this influence was not concentration dependent. Chromosomal analyses revealed that more blastomeres showed a normal chromosomal complement in 0.5 mg/l astaxanthin treatment group, which was similar to that in IVF embryos. The methylation levels located on the exon 1 of the imprinted gene H19 and IGF2, pluripotent gene OCT4 were normalized, and global DNA methylation, H3K9 and H4K12 acetylation were also improved significantly, which was comparable to that in vitro fertilization (IVF) embryos. Moreover, we also found that astaxanthin supplementation significantly decreased the level of lipid peroxidation. Our findings showed that the supplementation of 0.5 mg/l astaxanthin to oocyte maturation medium and embryo culture medium improved oocyte maturation, SCNT embryo development, increased chromosomal stability and normalized the epigenetic modifications, as well as inhibited overproduction of lipid peroxidation. 相似文献
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