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Effects of adding different concentrations of melatonin (10?7, 10?9 and 10?11 M) to maturation (Experiment 1; Control, IVM  + 10?7, IVM  + 10?9, IVM  + 10?11) and culture media (Experiment 2; Control, IVC  + 10?7, IVC  + 10?9, IVC  + 10?11) were evaluated on in vitro bovine embryonic development. The optimal concentration of melatonin (10?9 M) from Experiments 1–2 was tested in both maturation and/or culture media of Experiment 3 (Control, IVM  + 10?9, IVC  + 10?9, IVM /IVC  + 10?9). In Experiment 1, maturated oocytes from Control and IVM  + 10?9 treatments showed increased glutathione content, mitochondrial membrane potential and percentage of Grade I blastocysts (40.6% and 43%, respectively). In Experiment 2, an increase in the percentage of Grade I blastocysts was detected in IVC  + 10?7 (43.5%; 56.7%) and IVC  + 10?9 (47.4%; 57.4%). Moreover, a lower number and percentage of apoptotic cells in blastocysts were observed in the IVC  + 10?9 group compared to Control (3.8 ± 0.6; 3.6% versus 6.1 ± 0.6; 5.3%). In Experiment 3, the IVC  + 10?9 treatment increased percentage of Grade I blastocysts with a lower number of apoptotic cells compared to IVM /IVC  + 10?9 group (52.6%; 3.0 ± 0.5 versus 46.0%; 5.4 ± 1.0). The IVC  + 10?9 treatment also had a higher mRNA expression of antioxidant gene (SOD 2) compared to the Control, as well as the heat shock protein (HSPB 1) compared to the IVM  + 10?9. Reactive oxygen species production was greater in the IVM /IVC  + 10?9 treatment group. In conclusion, the 10?9 M concentration of melatonin and the in vitro production phase in which it is used directly affected embryonic development and quality.  相似文献   
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Effect of cold-induced changes in respiratory pattern on pulmonary particle deposition was investigated in 10 male Holstein calves between the ages of 1 and 3 months. Deposition of intranasally instilled fluorescence-enhanced Pasteurella haemolytica was significantly higher (P less than 0.05) for cold-exposed calves and appears to be caused by the cold-induced respiratory pattern change. Deposition was greater in apical and mediastinal lung lobes, but the reason for this preferential deposition is uncertain. Nasal mucus velocity was measured in 4 nonanesthetized calves at ambient temperature of 2 to 4 C and 16 to 18 C, using tantalum-paraffin oil droplets and serial radiography. Nasal mucus velocity was 24% lower during cold exposure. In addition, the effect of mucosal temperature on tracheal mucus velocity was determined in excised tracheas from 7 calves. A direct relationship existed between mucosal temperature and tracheal mucus velocity within the mucosal temperature range studied (35.0 to 39.5 C). Tracheal air temperature measurements in calves at ambient temperatures of -10.4 C (n = 4) and 18.5 C (n = 5) indicated that conditioning of inspired air is not complete at the tracheal level during extreme cold exposure. Therefore, cold air may directly influence tracheal mucociliary clearance. It is speculated that cold exposure increases pulmonary deposition of pathogens, while simultaneously decreasing mucociliary clearance of the upper airways, thus predisposing cold-exposed calves to respiratory tract infection.  相似文献   
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采用宏观、微观等观察手段对断裂的发动机缸盖螺栓进行分析。分析结果表明,缸盖螺栓断裂是由于氢脆延迟断裂而造成的。针对断裂原因分析了氢脆产生的原因并提出了预防措施。  相似文献   
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Lime sulphur is a common topical treatment for dermatophytosis in animals. Until recently, a single veterinary lime sulphur formulation was available. The purpose of this study was to compare the efficacy of eight lime sulphur products for in vitro growth inhibition of Microsporum canis using the isolated infected spore model. Infective M. canis spores were isolated from hairs collected from untreated cats. Hairs were macerated in Triton‐X solution and isolated according to a previously published protocol. Equal volumes of spore suspension and lime sulphur solutions were incubated for 5 min and plated onto modified BBL? Mycosel? agar (Becton, Dickinson and Company; Sparks, MD, USA) plates. Five plates were inoculated for each sample solution. Distilled water and bleach were used as controls. Colony forming units were counted daily for 21 days; positive control plates contained >300 colony forming units/plate. Seven of the products were supplied as concentrates and they were tested at the manufacturer’s recommended dilution, twice label concentration and half label concentration. A prediluted product SulfaDip® (Trask Research, Inc.; Daluca, GA, USA) was tested at the label and half label concentration. All veterinary products formed recommended treatment dilutions of 3% sulphurated lime solution except one (LymDyp®, IVX Animal Health Inc.; St Joseph, MO, USA), which formed a 2.4% sulphurated lime solution. Results of the study showed complete growth inhibition of M. canis spores by all products at all dilutions tested. These results indicate that all tested lime sulphur‐containing products were equivalent. Field studies are needed to test product equivalency in vivo.  相似文献   
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The aim of the present work was to estimate the basic wood density of Mimosa tenuiflora by using near-infrared spectroscopy (NIRS). Fifty-eight wood samples representing sapwood, heartwood and pith were evaluated by gravimetric method and NIRS together with wavelength selection methods. A comparison was made among several multivariate calibration techniques and algorithms for preprocessing and variable selection of data, including full-spectrum partial least squares (PLS), interval PLS, backward interval PLS, synergy interval PLS, genetic algorithm-PLS and successive projections algorithm for interval partial least squares (iSPA–PLS). Finally, the results obtained using iSPA–PLS model for the root mean square error of calibration and prediction were 0.0383 and 0.0166 g/cm3, respectively. A t-test was performed to compare the results of the models with each other and with a reference method. NIRS and iSPA–PLS can be used to predict basic density of Mimosa tenuiflora [Willd.] Poiret wood samples rapidly. In addition, the basic density could also be predicted with only 17 wavelengths in the range from 2,090 to 2,208 nm that should allow for measurement of this parameter using handheld NIR spectrometer.  相似文献   
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Recent debate concerning health problems in pedigree animals has highlighted gaps in current knowledge of the prevalence, severity and welfare implications of deleterious inherited traits within the pedigree-dog population. In this second part of a two-part review, inherited disorders in the top 50 UK Kennel Club registered breeds were researched using systematic searches of existing databases. A set of inclusion and exclusion criteria, including an evidence strength scale (SEHB), were applied to search results. A total of 312 non-conformation linked inherited disorders was identified, with German shepherd dogs and Golden retrievers associated with the greatest number of disorders. The most commonly reported mode of inheritance was autosomal recessive (71%; 57 breed-disorder combinations), and the most common primarily affected body system was the nervous sensory system. To provide a true assessment of the scale of inherited disorders in the pedigree dogs studied more effort is required to collect accurate prevalence data.  相似文献   
9.
Feline and canine atopic dermatitis are thought to have a similar immunopathogenesis. As with dogs, detection of allergen‐specific IgE in cat serum merely supports a diagnosis of feline atopy based on compatible history, clinical signs and elimination of other pruritic dermatoses. In this study, a rapid screening immunoassay (Allercept® E‐Screen 2nd Generation; Heska AG, Fribourg, Switzerland; ES2G) was compared with a complete‐panel serum allergen‐specific IgE assay (Allercept®; Heska AG; CP) in healthy cats with no history of skin disease and in atopic cats. The latter had no diagnosis of external parasitism, infection, food hypersensitivity or other skin disease explaining their pruritus, and expressed cutaneous reaction patterns typically associated with feline allergic skin disease (head, neck or pinnal pruritus, miliary dermatitis, self‐induced alopecia, eosinophilic granuloma complex). The proportion of cats positive on either the ES2G or the CP assays was not significantly different between the atopic and healthy cat groups. There was, however, strong agreement between the results of the ES2G and CP assay; overall, the two tests were in agreement for 43 of 49 (88%) serum samples. There was also strong agreement when individual allergen groups were evaluated (agreement noted: indoor, 41 of 49 samples; grasses/weeds, 37 of 49 samples; and trees, 41 of 49 samples). These results indicate that although neither test is diagnostic for feline atopic dermatitis, the screening assay is beneficial for predicting the results of a complete‐panel serum allergen‐specific IgE assay in cats.  相似文献   
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