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11.
Torben Greve 《Acta veterinaria Scandinavica》1980,21(1):26
Fourteen true repeat breeders with entirely normal oestrous cyclicity more than 1 year after calving and 14 control donor cows were superovulated with PMSG (2000 i.u.) and flushed non-surgically 6–8 days after the superovulatory heat. The superovulatory response was identical for the 2 groups such as assessed by the number of corpora lutea (9.4 ± 1.8 C.L. per repeat breeder and 9.1 ± 1.5 per control cow), occurrence of ovarian overstimulation (polycysts), presence of a non-countable amount of corpora lutea, negative outcome of the flushings and the number of recovered embryos (5.8 ± 1.0 embryos per repeat breeder and 6.0 ± 1.8 embryos per control cow). The most pronounced difference between the 2 categories of animals was related to the fertilization rate of embryos. In the repeat breeder group only 2.4 embryos per cow or 41 % were fertilized, whereas the control animals attained a fertilization rate of 4.9 embryos or 82 %. Since most factors liable to interfere with the fertilization process were identical for both groups (age, breed, nutritional and management conditions, semen quality, dose, AI-technician e.g.), it is believed that intraovarian, follicular, or follicular-dynamic conditions were responsible for producing a high proportion of non-fertilizable oocytes. 相似文献
12.
Rolshausen PE Greve LC Labavitch JM Mahoney NE Molyneux RJ Gubler WD 《Phytopathology》2008,98(2):222-229
Eutypa lata is a vascular pathogen of woody plants. In the present study we (i) determined which component(s) of the cell wall polymers were degraded in naturally infected grapevines and in artificially inoculated grape wood blocks; (ii) compared the pattern of wood decay in the tolerant grape cv. Merlot versus the susceptible cv. Cabernet Sauvignon; and (iii) identified secondary metabolites and hydrolytic enzymes expressed by E. lata during wood degradation. Biochemical analyses and a cytochemical study indicated that glucose-rich polymers were primary targets of E. lata. Structural glucose and xylose of the hemicellulose fraction of the plant cell wall and starch were depleted in infected woods identically in both cultivars. Moreover, the more tolerant cv. Merlot always had more lignin in the wood than the susceptible cv. Cabernet Sauvignon, indicating that this polymer may play a role in disease resistance. In vitro assays demonstrated the production by E. lata of oxidases, glycosidases and starch degrading enzymes. Phytotoxic secondary metabolites were also produced but our data suggest that they may bind to the wood. Finally, we demonstrated that free glucose in liquid cultures repressed primary but not secondary metabolism. 相似文献
13.
The present investigation was undertaken to study the effect of addition of dbc AMP on bovine oocyte maturation and fertilization in vitro. The bovine oocytes isolated from 2–8 mm follicles were cultured for 26 h in TCM-199. The maturation rate (71.4 %) did not significantly increase after supplementation of the culture medium with dbc AMP (86.3 %.) or FSH + hCG (86.3 %). The in vitro fertilization rate of oocytes based on sperm penetration and presence of sperm tail in the ooplasm increased significantly in the dbc AMP (34.7 %) and the dbc AMP + FSH + hCG (33.9 %) treated groups when compared with untreated controls (17.9 %). However, dbc AMP treated oocytes were not able to secure the formation of male pronucleus 20 h after in vitro fertilization, while in oocytes matured in dbc AMP free medium both pronuclei were present in approximately 15 % of the penetrated oocytes. Also, the sperm head decondensation was blocked or slowed down by the dbc AMP treatment. It is concluded (1) that dbc AMP may improve the condition for the interaction of oocytes with spermatozoa, and (2) that the ooplasm of such dbc AMP treated oocytes apparently is not able to decandense the sperm head and transform it to the male pronucleus. 相似文献
14.
Dairy cows were heat synchronized with two injections of cloprostenol (PG1/PG2) with an interval of 13 days and inseminated 72 hours after PG2. The total pregnancy rate obtained was 42% The probability of achieving luteal phase at PG2, the probability of undergoing luteolysis after PG2 and the probability of achieving pregnancy were all equal whether the cows were in luteal phase, follicular phase, had follicular cysts or small ovaries at PG1. Close correlations were found between the signs of heat at the insemination and the interval from calving to PG1 to the pregnancy rates. 相似文献
15.
S L Marks A K Cook R Reader P H Kass A P Théon C Greve Q R Rogers 《American journal of veterinary research》1999,60(6):755-763
OBJECTIVE: To determine effects of glutamine-supplemented and glutamine-free amino acid-based purified diets, compared with a dry expanded diet, on intestinal structure and function in a model that used cats with methotrexate-induced enteritis. ANIMALS: 18 adult specific-pathogen-free cats. PROCEDURE: 12 cats were given intragastric feedings of an amino acid-based purified diet supplemented with glutamine (7% [wt:wt]) or an isonitrogenous amount of glycine and alanine; 6 cats consumed a dry expanded diet. After 21 days, cats received methotrexate (MTX; 11 mg/kg of body weight, IV). Intestinal permeability testing was performed immediately before and 66 hours after MTX administration. Celiotomy was performed 72 hours after MTX administration for aseptic removal of mesenteric lymph nodes, collection of full-thickness intestinal biopsy specimens, determination of intestinal cellular proliferation, and collection of aortic and portal venous blood samples for determination of arteriovenous amino acid concentrations across the intestine. RESULTS: Administration of MTX was associated with severe enterotoxicosis manifested as diarrhea (8/12 cats), vomiting (12/12), and positive results for bacterial culture of mesenteric lymph nodes (12/12) in cats receiving the purified diets, independent of glutamine supplementation. Diet did not affect villus tip length and villus surface area in the small intestine or cellular proliferation. Administration of MTX was associated with significantly increased intestinal permeability, which was not attenuated by glutamine supplementation. CONCLUSIONS: Feeding of a glutamine-supplemented amino acid-based purified diet was unable to preserve intestinal function in cats with MTX-induced enteritis. CLINICAL RELEVANCE: Intestinal morphologic alterations correlate poorly with intestinal function as measured by means of bacterial translocation and intestinal permeability. 相似文献
16.
17.
A. Taghizadeh‐Toosi J. E. Olesen K. Kristensen L. Elsgaard H. S. Østergaard M. H. Greve B. T. Christensen 《European Journal of Soil Science》2014,65(5):730-740
To establish a national inventory of soil organic carbon (SOC) stocks and their change over time, soil was sampled in 1986, 1997 and 2009 in a Danish nation‐wide 7‐km grid and analysed for SOC content. The average SOC stock in 0–100‐cm depth soil was 142 t C ha?1, with 63, 41 and 38 t C ha?1 in the 0–25, 25–50 and 50–100 cm depths, respectively. Changes at 0–25 cm were small. During 1986–97, SOC in the 25–50‐cm layer increased in sandy soils while SOC decreased in loam soils. In the subsequent period (1997–2009), most soils showed significant losses of SOC. From 1986 to 2009, SOC at 0–100 cm decreased in loam soils and tended to increase in sandy soils. This trend is ascribed to dairy farms with grass leys being abundant on sandy soils while cereal cropping dominates on loamy soils. A statistical model including soil type, land use and management was applied separately to 0–25, 25–50 and 50–100 cm depths to pinpoint drivers for SOC change. In the 0–25 cm layer, grass leys added 0.95 t C ha?1 year?1 and autumn‐sown crops with straw incorporation added 0.40 t C ha?1 year?1. Cattle manure added 0.21 t C ha?1 year?1. Most interestingly, grass leys contributed 0.58 t C ha?1 year?1 at 25–50 cm, confirming that inventories based only on top‐soils are incomplete. We found no significant effects in 50–100 cm. Our study indicates a small annual loss of 0.2 t C ha?1 from the 0–100 cm soil layer between 1986 and 2009. 相似文献
18.
Traditionally and when using objective gait analysis, horses with and without lameness are most frequently assessed trotting in straight lines in hand. Valuable information can be gained from assessment on the lunge and ridden in walk, trot and canter. No studies have quantified lameness during all aforementioned conditions and gaits at once, despite the rapid recent development in equine gait analysis methods. Objective methodologies, previously confined to gait laboratories, are currently being expanded to field technologies using accelerometers and inertial measurement units (IMUs). This publication aims to describe normal gait and the spectrum of pain-related gait abnormalities and other musculoskeletal adaptations to pain that can be observed in walk, trot and canter during in hand and ridden assessment in straight lines and on a circle on hard and soft surfaces. In addition, it aims to describe briefly how IMUs have been used and areas for further research in the light of what we know from subjective lameness examinations and what is possible with IMUs. 相似文献
19.
Alsos IG Eidesen PB Ehrich D Skrede I Westergaard K Jacobsen GH Landvik JY Taberlet P Brochmann C 《Science (New York, N.Y.)》2007,316(5831):1606-1609
The ability of species to track their ecological niche after climate change is a major source of uncertainty in predicting their future distribution. By analyzing DNA fingerprinting (amplified fragment-length polymorphism) of nine plant species, we show that long-distance colonization of a remote arctic archipelago, Svalbard, has occurred repeatedly and from several source regions. Propagules are likely carried by wind and drifting sea ice. The genetic effect of restricted colonization was strongly correlated with the temperature requirements of the species, indicating that establishment limits distribution more than dispersal. Thus, it may be appropriate to assume unlimited dispersal when predicting long-term range shifts in the Arctic. 相似文献
20.