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排序方式: 共有85条查询结果,搜索用时 578 毫秒
1.
This retrospective study evaluates the effectiveness of nonsurgical treatment using antibiotics to treat hematogenous septic arthritis in five dogs. Giant-breed dogs were over-represented, with all dogs <1 year of age. Synovial fluid cultures were positive in all cases, with common bacterial species isolated that included Streptococcus B-haemolytic spp., Pasteurella multocida, and Staphylococcus intermedius. Dogs treated with appropriate duration and selection of antibiotics had clinical resolution with no residual deficits. This report and a previous clinical report demonstrate that hematogenous septic arthritis can be successfully treated nonsurgically with antibiotic therapy. 相似文献
2.
Evolution of human influenza A viruses over 50 years: rapid, uniform rate of change in NS gene 总被引:34,自引:0,他引:34
D A Buonagurio S Nakada J D Parvin M Krystal P Palese W M Fitch 《Science (New York, N.Y.)》1986,232(4753):980-982
Variation in influenza A viruses was examined by comparison of nucleotide sequences of the NS gene (890 bases) of 15 human viruses isolated over 53 years (1933 to 1985). Changes in the genes accumulate with time, and an evolutionary tree based on the maximum parsimony method can be constructed. The evolutionary rate is approximately 2 X 10(-3) substitution per site per year in the NS genes, which is about 10(6) times the evolutionary rate of germline genes in mammals. This uniform and rapid rate of evolution in the NS gene is a good molecular clock and is compatible with the hypothesis that positive selection is operating on the hemagglutinin (or perhaps some other viral genes) to preserve random mutations in the NS gene. 相似文献
3.
Evolution in inbred strains of mice appears rapid 总被引:11,自引:0,他引:11
Genetic variation at 97 loci in ten commonly used inbred strains of mice is greatly in excess of that expected under current assumptions. Evidence against all of the readily apparent explanations is presented and the possibility of early selection for heterozygosity or of conversion is suggested. The common ancestor of these strains is estimated to have occurred about 150 years ago. 相似文献
4.
The structure of morphine monohemisuccinate 总被引:1,自引:0,他引:1
5.
Eighteen codons in the HA1 domain of the hemagglutinin genes of human influenza A subtype H3 appear to be under positive selection to change the amino acid they encode. Retrospective tests show that viral lineages undergoing the greatest number of mutations in the positively selected codons were the progenitors of future H3 lineages in 9 of 11 recent influenza seasons. Codons under positive selection were associated with antibody combining site A or B or the sialic acid receptor binding site. However, not all codons in these sites had predictive value. Monitoring new H3 isolates for additional changes in positively selected codons might help identify the most fit extant viral strains that arise during antigenic drift. 相似文献
6.
Hemin lyses malaria parasites 总被引:8,自引:0,他引:8
Malaria parasites isolated from mouse erythrocytes are lysed by ferriprotoporphyrin IX chloride (hemin) or by a chloroquine-hemin complex in amounts that could be produced by release of less than 0.1 percent of the heme in erythrocytic hemoglobin. This effect of hemin may explain the protection against malaria provided by thalassemia and other conditions causing intracellular denaturation of hemoglobin. The toxicity of the chloroquine-hemin complex may explain the selective antimalarial action of chloroquine. 相似文献
7.
R.D. Montgomery D.V.M. M.S. R.B. Fitch D.V.M. M.S. J.T. Hathcock D.V.M. M.S. R.F. Laprade M.D. M.E. Wilson R.T. P.D. Garrett D.V.M. M.S. 《Veterinary radiology & ultrasound》1995,36(4):276-282
The intercondylar fossa is believed to play an important role in the pathology of cranial cruciate ligament rupture and therefore has received considerable attention in the last decade. Accurate radiographic imaging of the intercondylar fossa requires that the central x-ray beam pass through the center of the intercondylar "tunnel". The anatomy of the canine intercondylar fossa is similar to humans, however, the orientations of the intercondylar fossa's differ. Consequently, the positioning techniques described for humans are not appropriate for the dog. To pass through the center of the dog, intercondylar fossa, the central x-ray beam should be 12° (S.D. 1.7°) caudal from the femoral diaphysis in the sagittal plane and obliqued caudolateral to craniomedial 7° (S.D. 0.60°) (caudo78°proximo7° lateralcraniodistomedial oblique). Cross table positioning was used with the hip flexed and the radiograph cassette placed on the cranial surface of the stifle. However, superimposition of the tuber ischii and soft tissues caudal to the femur made 15° to 20° the best angle obtainable. There was not a significant difference (p = 0.17) in the notch width index between a 12° versus 20° angle of the central x-ray beam caudal to the femoral diaphysis, both with 7° of external rotation of the stifle. The notch width index of 0.252 obtained from radiographic measurements was not significantly different from measurements obtained grossly of 0.254 (n = 26; p = 0.69). Failure to oblique the central x-ray beam caused a significant (p = 0.0008) decrease in the apparent fossa width radiographically. 相似文献
8.
Randall B. Fitch DVM MS John T. Hathcock DVM MS Ronald D. Montgomery DVM MS 《Veterinary radiology & ultrasound》1996,37(4):266-274
The role of the intercondylar fossa in cranial cruciate ligament injury has gained notable attention in humans and it's role is now being questioned in animals. Controversy exists regarding the accuracy of radiographs and computed tomography (CT) in evaluating the intercondylar fossa. This study compared radiographic and CT evaluation with gross evaluation of the intercondylar fossa. Six greyhounds were evaluated before notchplasty, immediately after notchplasty and 6 months after notchplasty in stable and unstable stifles. A fossa width index was used for comparison because it negates the effects of patient size and radiographic magnification. The fossa width index is calculated by dividing the width of the intercondylar fossa by the total condylar width.
The fossa width indices of dogs determined from radiographs and CT were not significantly different before notchplasty except for the cranial fossa width indices which were more inconsistent and tended to underestimate the size when compared to gross measurements. At six months, both stable and unstable stifles had refilling of the notchplasty, but the unstable stifles had significantly greater refilling resulting in no significant enlargement in intercondylar fossa size as compared to the prenotchplasty size. Osteophytes that occurred within the intercondylar fossa were less radiopaque and more easily visualized by computed tomography. Computed tomography provided several advantages, including clearer visualization of the intercondylar fossa, avoiding superimposition of the intercondylar fossa by caudal thigh muscles or tuber ischii and the ability to analyze the cranial and caudal components of the intercondylar fossa separately. 相似文献
The fossa width indices of dogs determined from radiographs and CT were not significantly different before notchplasty except for the cranial fossa width indices which were more inconsistent and tended to underestimate the size when compared to gross measurements. At six months, both stable and unstable stifles had refilling of the notchplasty, but the unstable stifles had significantly greater refilling resulting in no significant enlargement in intercondylar fossa size as compared to the prenotchplasty size. Osteophytes that occurred within the intercondylar fossa were less radiopaque and more easily visualized by computed tomography. Computed tomography provided several advantages, including clearer visualization of the intercondylar fossa, avoiding superimposition of the intercondylar fossa by caudal thigh muscles or tuber ischii and the ability to analyze the cranial and caudal components of the intercondylar fossa separately. 相似文献
9.
10.
Aaron C. Rhodes Cecily Fitch Samuel B. St. Clair 《Strength and Conditioning Journal》2019,72(3):454-460
Aspen is a foundation species that provides vital habitat for hundreds of plant and animal species. However, changing ungulate herbivory regimes may be altering recruitment success and resilience of aspen forests. The objective of this observational study was to quantify the impacts of ungulate herbivory on aspen recruitment potential. We sampled 36 aspen dominant stands on the Fishlake National Forest in Utah for browse of apical meristems, suckering density (< 180 cm in height), and recruitment density (≥ 180 cm). Our analysis indicated that for each 10% of apical meristems browsed, annual vertical and radial growth rates and recruitment density were reduced by 1.2 cm, 0.02 mm, and 17 ha? 1, respectively. In contrast, aspen suckering density increased by 1 230 suckers ha? 1, with each 10% browse of apical meristems. This suggests that ungulates contribute to aspen suckers persisting in the understory for longer periods and may alter recruitment success of aspen stands. Aspen that were under high ungulate browse pressure were associated with lower growth rates and persisted for twice as long in the understory. For example, a 5-yr-old sucker was predicted to be 115 cm without browse of apical meristems and 60 cm with 100% browse of apical meristems. Further, aspens of the same height with 100% browse of apical meristems were nearly 4 yr older on average than aspens with no evidence of browse of apical meristems. Approximately 34% of aspen suckers had persisted in the understory < 100 cm for ≥ 6 yr, and 7% of suckers had persisted in the understory for ≥ 10 yr. Our results suggest that high rates of meristem removal are correlated with increased aspen suckering yet reduced aspen growth and recruitment. 相似文献