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211.
Q fever is a zoonotic disease considered as emerging or re-emerging in many countries. It is caused by Coxiella burnetii, a bacterium developing spore-like forms that are highly resistant to the environment. The most common animal reservoirs are livestock and the main source of infection is by inhalation of contaminated aerosols. Although the culture process for Coxiella is laborious, advances on the knowledge of the life cycle of the bacterium have been made. New tools have been developed to (i) improve the diagnosis of Q fever in humans and animals, and especially animal shedders, (ii) perform epidemiological studies, and (iii) prevent the disease through the use of vaccines. This review summarizes the state of the knowledge on the bacteriology and clinical manifestations of Q fever as well as its diagnosis, epidemiology, treatment and prevention in order to understand what factors are responsible for its emergence or re-emergence. 相似文献
212.
Q fever is a widespread zoonosis caused by Coxiella burnetii. Infected animals, shedding bacteria by different routes, constitute contamination sources for humans and the environment. To study Coxiella excretion, pregnant goats were inoculated by the subcutaneous route in a site localized just in front of the shoulder at 90 days of gestation with 3 doses of bacteria (10(8), 10(6) or 10(4) i.d.). All the goats aborted whatever the dose used. Coxiella were found by PCR and immunofluorescence tests in all placentas and in several organs of at least one fetus per goat. At abortion, all the goats excreted bacteria in vaginal discharges up to 14 days and in milk samples up to 52 days. A few goats excreted Coxiella in their feces before abortion, and all goats, excreted bacteria in their feces after abortion. Antibody titers against Coxiella increased from 21 days post inoculation to the end of the experiment. For a Q fever diagnostic, detection by PCR and immunofluorescence tests of Coxiella in parturition products and vaginal secretions at abortion should be preferred to serological tests. 相似文献
213.
Protection evaluation against Chlamydophila abortus challenge by DNA vaccination with a dnaK-encoding plasmid in pregnant and non-pregnant mice 总被引:1,自引:0,他引:1
Mice were intramuscularly immunized with a dnaK-encoding DNA plasmid. The protective effect of DNA immunization against Chlamydophila abortus infection was studied in pregnant and non-pregnant mice models. In non-pregnant mice, the dnaK vaccine induced a specific humoral response with the predominant IgG2a isotype, which failed to have in vitro neutralizing properties. No delayed-type hypersensitivity reaction was observed and the spleens of dnaK vaccinated-mice were not protected against C. abortus challenge. In pregnant mice, the dnaK vaccine induced a non-specific partial protection from abortion. This may be due to the immunogenic properties of the CpG motifs of bacterial DNA present in the vaccinal plasmid backbone. Nevertheless, spleens of dnaK vaccinated-pregnant mice were not protected. 相似文献
214.
The effects of Drechslera spp. (causing a leaf-spotting disease) and ryegrass mosaic virus (RMV) on the dry-matter herbage yield of Lolium perenne (cv. S24) were assessed from 1977 to 1979 in a field experiment. The effect of Drechslera spp. on quality, i.e. water-soluble carbohydrate and nitrogen content and in vitro digestibility, was evaluated in 1977, when their incidence was greatest. Plots were sprayed regularly with chlorothalonil to control Drechslera spp. and endosulfan to control the eriophyid mite vector of RMV. Four harvests were taken each year and diseases were assessed immediately beforehand. Drechslera spp. were also assessed midway between harvests and Puccinia coronata was recorded in autumn 1978 and 1979. Although yield was increased where chlorothalonil and endosulfan had been applied, this increase could not be entirely attributed to the control of foliar diseases. Drechslera spp. did not affect crop quality. 相似文献
215.
Watkins C McKellar A Jensen K George A Jones D Sharp MJ Stevenson K Hopkins J 《Veterinary research communications》2008,32(8):647-657
This report describes the development of small DNA microarrays of fully defined genes suitable for projects requiring detailed
analysis of gene expression in sheep and/or cattle. Two arrays have been developed; the first is a small reference microarray
(RIGRA) that has been used to validate experimental design and methodology; the second, a larger array (RIGUA) containing
probes for 516 ruminant immuno-inflammatory genes, each represented by non-overlapping 75mer oligonucleotides. Experiments
used to validate this microarray were: (1) a comparison of gene expression profiles from sheep broncho-alveolar macrophages
before and after in vitro activation with lipopolysaccharide (LPS), using the RIGRA; (2) the differential gene expression between five in vitro unstimulated sheep keratinocyte cultures; (3) LPS/interferon γ stimulated and unstimulated blood monocytes purified from
Holstein-Friesians (Bos taurus) and Sahiwals (Bos indicus) cattle using the RIGUA. Real-time, quantitative RT-PCR was used to validate the gene expression profiles obtained with the
RIGUA microarrays. The potential for using such an immunological tool in understanding the relative gene expression corresponding
to immune-inflammatory responses of sheep and cattle is discussed.
Supplementary information for this article may be found at (login: watkins and password: PuBm7t) 相似文献
216.
217.
Ståhl K Kampa J Alenius S Persson Wadman A Baule C Aiumlamai S Belák S 《Veterinary research》2007,38(3):517-523
During a study on Bovine Viral Diarrhoea (BVD) epidemiology in Thailand, a pestivirus was detected in serum from a calf. Comparative nucleotide sequence analysis showed that this virus was closely related to a recently described atypical pestivirus (D32/00_'HoBi') that was first isolated from a batch of foetal calf serum collected in Brazil. The results from virus neutralisation tests performed on sera collected from cattle in the herd of the infected calf, showed that these cattle had markedly higher antibody titres against the atypical pestivirus 'HoBi' than against Bovine Viral Diarrhoea Virus types 1 and 2, or Border Disease Virus. The results also supported, consequently, the results from the molecular analysis, and demonstrated that a 'HoBi'-like pestivirus had been introduced to, and was now circulating in the herd. This study is the first to report a natural infection in cattle with a virus related to this atypical pestivirus, and it suggests that this group of pestiviruses may already be spread in cattle populations. The findings have implications for BVD control and for the biosafety of vaccines and other biological products produced with foetal calf serum. Consequently, these atypical pestiviruses should be included in serological assays, and any diagnostic assay aimed at detection of pestiviruses in biological products or animals should be tested for its ability to detect them. 相似文献
218.
Creamer LK Bienvenue A Nilsson H Paulsson M van Wanroij M Lowe EK Anema SG Boland MJ Jiménez-Flores R 《Journal of agricultural and food chemistry》2004,52(25):7660-7668
Changes in the structure and chemistry of beta-lactoglobulin (beta-LG) play an important role in the processing and functionality of milk products. In model beta-LG systems, there is evidence that the aggregates of heated beta-LG are held together by a mixture of intermolecular non-covalent association and heat-induced non-native disulfide bonds. Although a number of non-native disulfide bonds have been identified, little is known about the initial inter- and intramolecular disulfide bond rearrangements that occur as a result of heating. These interchange reactions were explored by examining the products of heat treatment to determine the novel disulfide bonds that form in the heated beta-LG aggregates. The native protein and heat-induced aggregates were hydrolyzed by trypsin, and the resulting peptides, before and after reduction with dithiothreitol, were separated by high-performance liquid chromatography and their identities confirmed by electrospray ionization mass spectrometry. Comparisons of these peptide patterns showed that some of the Cys160 was in the reduced form in heated beta-LG aggregates, indicating that the Cys160-Cys66 disulfide bond had been broken during heating. This finding suggests that disulfide bond interchange reactions between beta-LG non-native monomers, or polymers, and other proteins could occur largely via Cys160. 相似文献
219.
Red koji has been recognized as a cholesterol-lowering diet supplement because of it contains fungi metabolites, monacolins, which reduce cholesterol synthesis by inhibiting HMG-CoA reductase. In this study, water extracts of red koji were loaded onto a C(18) cartridge, and the acetonitrile eluate was collected as test fraction. Red koji water extracts and its C(18) cartridge acetonitrile eluent had total phenols concentrations of 5.57 and 1.89 mg/g of red koji and condensed tannins concentrations of 2.71 and 1.20 mg/g of red koji, respectively. Both exhibited an antioxidant activity and an inhibitory activity to mushroom tyrosinase. The higher antioxidant activity of the red koji acetonitrile eluent was due to the existence of a high percentage of condensed tannins. The results from the kinetic study for inhibition of mushroom tyrosinase by red koji extracts showed that the compounds in the extracts competitively inhibited the oxidation of tyrosine catalyzed by mushroom tyrosinase with an ID(50) of 5.57 mg/mL. 相似文献
220.