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101.
Hepatoblastomas are neoplasms that originate from putative pluripotential stem cells of the liver. A hepatic mass from an 8-year-old Abyssinian cat was composed of cords and sheets of neoplastic cells, with scattered rosettes and small ductal structures. Most neoplastic cells had a pale eosinophilic cytoplasm and a round to ovoid nucleus. The tumor also had short spindle cells with an oval nucleus. Immunohistochemically, neoplastic cells were weakly positive for embryonic hepatocellular markers, such as alpha-fetoprotein and cytokeratin (CK) 8/18, but negative for the hepatocellular marker Hepatocyte Paraffin 1. The cells were also positive for CD56/neural cell adhesion molecule and for the biliary epithelial markers CK 7, CK 8/18, CK CAM5.2, and vimentin, but negative for CK 20. Some neoplastic cells expressed neuroectodermal or neuroendocrine markers, such as protein gene product 9.5 and synaptophysin, but were negative for chromogranin A and not argyrophilic by the Grimelius technique. The cat died soon after the biopsy without clinical improvement.  相似文献   
102.
Cryptosporidium is an important protozoan parasite that causes diarrhea in neonates and young bovines. The objective of the present study was to determine the frequency of Cryptosporidium infection in animals of dairy farms of the Metropolitan Region (Santiago), Chile. Fecal samples of 205 newborn calves with diarrhea were studied and used for comparing the efficiency of two microscopic staining methods for diagnosis of the parasite, the auramine (AU) and a modified Ziehl-Neelsen (ZN) procedure. Out of the 205 fecal samples, we detected oocysts in 115 (56.1%) with AU and 102 (49.8%) with ZN. Comparison of results obtained with the two microscopic techniques showed significant difference (p<0.05), AU being more sensitive. On the other hand, concordance between the two methods was almost perfect (kappa value of 0.83). The results with these two operator dependent methods were confirmed using an operator independent immunochromatographic (IC) method. The IC method also enabled us to determine the identity of the parasite species as that of Cryptosporidium parvum. Identification of the parasite species was further corroborated by performing a Cryptosporidium species-specific polymerase chain reaction (PCR) test on few samples taken at random. Overall, the results showed a high number of infected animals suggesting the parasite C. parvum as a major parasitic disease agent of neonatal calves with diarrhea in dairy farms of the Metropolitan Region (Santiago) of Chile.  相似文献   
103.
To investigate the effects of rearing practices of commercial broiler chickens on the incidence of antimicrobial resistance in commensal Escherichia coli isolates, fecal E. coli isolates obtained in 4 farms were screened for anitimicrobial resistance. Ten E. coli isolates were recovered from each of the fecal samples collected from 10 birds in the farms at the ages of 2 days, 14-17 days, and 47-50 days. In 2 out of the 4 farms, no antimicrobials were used during the rearing period. In the other two farms, following collection of the fecal samples at 14 and 15 days of age, oxytetracycline (OTC), sulfadimethoxine (SDMX), and tylosin were given to birds on one farm and SDMX was used in the other. Isolates resistant to ampicillin and OTC that were obtained from an untreated flock at different sampling times were closely related to each other by pulsed-field gel electrophoresis patterns (PFGE) of XbaI-digested chromosomal DNA. PFGE analysis together with in vitro conjugation experiments suggested that diversity of resistance phenotypes within a clone may be resulted from the acquisition and loss of R-plasmids in an untreated and a treated flock. The numbers of resistance phenotypes observed among fecal isolates increased during the growth of the chickens in all the farms. The results in the present study suggest that persistence of commensal E. coli strains resistant to antimicrobials even in the absence of antimicrobial administration. It is also hypothesized that horizontal transmission of resistance determinants resulted in the emergence of different resistance phenotypes in those farms.  相似文献   
104.
The recently emerging three-dimensional (3D) displays in the electronic shops imitate depth illusion by overlapping two parallax 2D images through either polarized glasses that viewers are required to wear or lenticular lenses fixed directly on the display. Holography, on the other hand, provides real 3D imaging, although usually limiting colors to monochrome. The so-called rainbow holograms--mounted, for example, on credit cards--are also produced from parallax images that change color with viewing angle. We report on a holographic technique based on surface plasmons that can reconstruct true 3D color images, where the colors are reconstructed by satisfying resonance conditions of surface plasmon polaritons for individual wavelengths. Such real 3D color images can be viewed from any angle, just like the original object.  相似文献   
105.
Antibodies to the nonstructural protein (NS1) of A/equine/Miami/1/63 (H3N8) influenza virus were detected exclusively in the sera of mice experimentally infected with A/Aichi/2/68 (H3N2) and horses infected with A/equine/Kentucky/1/81 (H3N8) or A/equine/La Plata/1/93 (H3N8), but not in those of the animals immunized with the inactivated viruses, by enzyme-linked immunosorbent assay (ELISA) using a recombinant NS1 as antigen. The results indicate that the present method is useful for serological diagnosis to distinguish horses infected with equine H3 influenza viruses from those immunized with the inactivated vaccine.  相似文献   
106.
We report the first genetic linkage map of the Japanese flounder (Paralichthys olivaceus) constructed with 111 microsatellite markers and 352 AFLP fragments. The parental male linkage map consisted of 25 linkage groups while the female map consisted of 27 groups, with an average resolution of 8 and 6.6 cM, respectively. We have identified linkage among 96% of the markers and the total map length was estimated to be around 1000–1200 cM. This study reports the first low-density linkage map for the Japanese flounder and describes differences in sex recombination. Recombination rates were higher in male flounder compared to the female (7.4:1), a rare condition among vertebrates. This map is a starting point for the mapping of single loci and quantitative traits in flatfish species.  相似文献   
107.
A male golden retriever of unknown age presented with multiple cutaneous and subcutaneous masses from the left elbow to the digits. Histopathologically, multiple tumor foci had formed from the dermis to the subcutaneous tissue. Tumor foci consisted of a vascular structure, alveolar structure and solid proliferative area. The borders among these areas were not clear. Some neoplastic cells resembled a mature endothelium, while others were large pleomorphic cells. Immunohistochemically, the tumor cells were usually strongly positive for CD31 and often positive for PROX-1, the lymphatic endothelial cell marker. Based on these findings, the tumor was diagnosed as a hemangiosarcoma with lymphatic differentiation.  相似文献   
108.
Antigenic variation among equine H 3 N 8 influenza virus hemagglutinins   总被引:1,自引:0,他引:1  
To provide information on the antigenic variation of the hemagglutinins (HA) among equine H 3 influenza viruses, 26 strains isolated from horses in different areas in the world during the 1963-1996 period were analyzed using a panel of monoclonal antibodies recognizing at least 7 distinct epitopes on the H 3 HA molecule of the prototype strain A/equine/Miami/1/63 (H 3 N 8). The reactivity patterns of the virus strains with the panel indicate that antigenic drift of the HA has occurred with the year of isolation, but less extensively than that of human H 3 N 2 influenza virus isolates, and different antigenic variants co-circulate. To assess immunogenicity of the viruses, antisera from mice vaccinated with each of the 7 representative inactivated viruses were examined by neutralization and hemagglutination-inhibition tests. These results emphasize the importance of monitoring the antigenic drift in equine influenza virus strains and to introduce current isolates into vaccine. On the basis of the present results, equine influenza vaccine strain A/equine/Tokyo/2/71 (H 3 N 8) was replaced with A/equine/La Plata/1/93 (H 3 N 8) in 1996 in Japan. The present results of the antigenic analysis of the 26 strains supported the results of a phylogenetic analysis, that viruses belonging to each of the Eurasian and American equine influenza lineages have independently evolved. However, the current vaccine in Japan consists of two American H 3 N 8 strains; A/equine/Kentucky/1/81 and A/equine/La Plata/1/93. It is also therefore recommended that a representative Eurasian strain should be included as a replacement of A/equine/Kentucky/1/81.  相似文献   
109.
The potential of near infrared spectroscopy (NIRS; 1,100 to 2,400 nm) to measure fat, total protein, and lactose content of nonhomogenized milk during milking and the influence of individual characteristics of each cow's milk on the accuracy of determination were studied. Milk fractions were taken during milking, twice per month, for 6 mo. Samples were taken every 2nd and 4th wk at the morning and the evening milkings. Teatcups were removed at each 3 L of milk yield as determined with a fractional sampling milk meter. A total of 260 milk samples were collected and analyzed with an NIRSystem 6500 spectrophotometer with 1-mm sample thickness. Partial least squares (PLS) regression was used to develop calibration models for the examined milk components. The comparison with the reference method was based on standard error of cross validation (SECV). The obtained SECV varied from .107 to .138% for fat content, from .092 to .125% for total protein, and from .066 to .096% for lactose content, and the accuracy of the reference method (AOAC, 1990, method No 972.16) was .05% for all measured milk components. The obtained models had lower SECV when an individual cow's spectral data were used for calibration. The reduction of SECV for each cow's individual calibration, when compared with SECV for the set of all samples, differed with the different constituents. For fat content determination, the reduction reached 22.46%, for protein 26.40%, and for lactose 31.25%. This phenomena was investigated and explained by principle component analysis (PCA) and by comparing loading of PLS factors that account for the most spectral variations for each cow and the measured milk components, respectively. The results of this study indicated that NIRS (1,100 to 2,500 nm, 1-mm sample thickness) was satisfactory for nonhomogenized milk compositional analysis of milk fractions taken in the process of milking.  相似文献   
110.
Insulin/insulin-like growth factor (IGF)-like signaling plays important roles in the aging processes of various animals. However, little is known about this signaling in rotifers, which have been used as a model animal in aging studies. Here we report that the aqueous extracts of the rotifer Brachionus plicatilis show activity similar to that of insulin/IGFs. Rotifers were cultured under four different feeding regimens (fed, starved for about ten days, or re-fed for 30 and 120 min after starvation), and then their aqueous extracts were added to culture media of rat L6 myoblasts. Treatment with these extracts increased the phosphorylation levels of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) and two Akt substrates of approximately 48 and 60 kDa, and these phosphorylations were diminished when cells were preincubated with specific inhibitors of their upstream kinases (MAPK/ERK kinase and phosphoinositide 3-kinase, respectively). Furthermore, the extracts from fed rotifers provoked higher phosphorylation levels of MAPK/ERK and Akt substrates than the extract from starved rotifers, suggesting that the production of substance(s) with insulin/IGF-like activity is stimulated upon feeding in the rotifer.  相似文献   
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