全文获取类型
收费全文 | 279篇 |
免费 | 38篇 |
国内免费 | 2篇 |
专业分类
林业 | 12篇 |
45篇 | |
综合类 | 59篇 |
农作物 | 5篇 |
水产渔业 | 7篇 |
畜牧兽医 | 178篇 |
园艺 | 1篇 |
植物保护 | 12篇 |
出版年
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 8篇 |
2016年 | 3篇 |
2015年 | 8篇 |
2014年 | 6篇 |
2013年 | 13篇 |
2012年 | 8篇 |
2011年 | 24篇 |
2010年 | 15篇 |
2009年 | 12篇 |
2008年 | 12篇 |
2007年 | 11篇 |
2006年 | 11篇 |
2005年 | 5篇 |
2004年 | 9篇 |
2003年 | 7篇 |
2002年 | 6篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 9篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1992年 | 7篇 |
1991年 | 11篇 |
1990年 | 7篇 |
1989年 | 13篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1973年 | 3篇 |
1970年 | 3篇 |
1967年 | 2篇 |
1945年 | 2篇 |
1931年 | 2篇 |
1930年 | 2篇 |
1928年 | 3篇 |
排序方式: 共有319条查询结果,搜索用时 15 毫秒
131.
Pathogenic bacteria and fungi associated with external ocular diseases in dogs: 131 cases (1981-1986) 总被引:1,自引:0,他引:1
P A Gerding S A McLaughlin M W Troop 《Journal of the American Veterinary Medical Association》1988,193(2):242-244
Medical records of 131 dogs with external ocular diseases were reviewed. Bacteriologic culture of swab specimens from 151 eyes revealed 100 eyes (66.2%) were considered positive for potentially pathogenic microorganisms. Of 127 species of microorganisms (bacterial and fungal) isolated, 50 (39.3%) were Staphylococcus spp (S intermedius, 17.3%). Streptococcus spp were the next most frequently isolated organism at 32 (25.2%), (Str canis, 16.5%). beta-Hemolytic streptococci (17%) were isolated more frequently than were alpha-hemolytic streptococci (9%), and coagulase-positive staphylococcal species (29%) were isolated almost 3 times as often as were coagulase-negative species (11%). Fungal and yeast organisms were isolated from 4.6% of the eyes. In vitro, most Staphylococcus spp were susceptible to cephalothin, bacitracin, and gentamicin, whereas most Streptococcus spp were susceptible to chloramphenicol, erythromycin, carbenicillin, and cephalothin. Pseudomonas spp were sensitive to tobramycin, gentamicin, and amikacin. 相似文献
132.
Control of nematode parasites with reduced reliance on the use of anthelmintics was studied in 16 ewes with suckling twin lambs on contaminated pasture in Denmark. Ewes and lambs were treated with albendazole at turn-out 3 May. Ewes were removed from the groups on 26 July, and lambs were slaughtered on 11 October. The animals were allocated to 4 groups of 8 lambs and their 4 ewes. Group TS was treated with albendazole at weeks 3, 6 and 8 after turnout and set-stocked; group TM was similarly treated but moved to clean pasture in conjunction with the last drenching; group US was untreated and set-stocked, and group UM was left untreated but moved to clean pasture week 8 after turn-out. Supplementary feed was offered in June and August due to scarcity of pasture. Strategic treatments of ewes and lambs weeks 3, 6 and 8 after turn-out, with or without a move to clean pasture, were highly effective in controlling nematode infections for most of the season. This was reflected in better weight gains and carcass characteristics in the treated compared to untreated lambs, resulting in an average increase in the value of the product by 36%. The effect of moving without treatment (UM) on faecal egg counts was limited but peak pasture infectivity was reduced to less than 10% compared to the set-stocked group and weight gains of lambs were significantly better despite poor feed availability in late season. The study showed that under set-stocked conditions repeated anthelmintic treatments of both ewes and lambs in early season may ensure sufficient nematode control whereas moving animals to clean pasture without dosing was less efficient. The latter may, however, still be a viable option in organic and other production systems where routine use of anthelmintics is banned, particularly if weaning and moving are combined or a second move is performed. 相似文献
133.
McLaughlin BG Adams PS Cornell WD Elkins AD 《The Canadian veterinary journal. La revue veterinaire canadienne》1985,26(12):368-372
Four cases of canine distemper were detected by the presence of numerous cytoplasmic inclusions in various circulating blood cells. Fluorescent antibody techniques and electron microscopy confirmed the identity of the viral inclusions. The cases occurred in the same geographic area and within a short time span. All four dogs had been vaccinated against canine distemper, but stress or other factors may have compromised their immune status. The possibility of an unusually virulent virus strain was also considered. 相似文献
134.
Ferguson D Crowe M McLaughlin L Gaschen F 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2011,25(4):831-837
Background: Cycad palms are commonly used in landscaping and ingestion by dogs can cause disease or death. Objectives: Determine the morbidity and case fatality of cycad palm toxicosis in dogs from Louisiana, and examine putative prognostic factors. Animals: Thirty‐four client‐owned dogs with confirmed cycad palm toxicosis between 2003 and 2010. Methods: Retrospective cohort study. Search of all medical records for animals with cycad palm toxicosis. Results: Seventeen of 34 (50%) dogs died or were euthanized as a direct consequence of cycad intoxication. There were no differences in presenting signs and physical examination findings between survivors and nonsurvivors. Nonsurvivors had higher serum alanine transaminase activity (median 196 U/L; range 16–4,123 versus 113.5; 48–1,530) and total bilirubin concentration (0.5 mg/dL; 0.1–6.2 versus 0.25; 0–1.7) upon presentation, and their initial serum concentrations of albumin (2.9 g/dL; 1.4–4.1 versus 3.3; 2.2–3.9) were lower than those of survivors. Nadir serum albumin concentration was also lower in nonsurvivors (1.9; 1.4–3.7 versus 3.2; 1.8–3.5). A higher proportion of nonsurvivors had prolonged coagulation times, prothrombin time. and partial thromboplastin time. In a multivariate model, administration of charcoal at initial presentation was associated with longer survival (heart rate [HR] 0.019, 95% CI 0.001–0.644), while high serum aspartate aminotransferase activity was a negative prognostic factor (HR 118.2, 95% CI 2.89–4,826). Conclusions and Clinical Importance: Cycad intoxication is associated with a higher case fatality than previously published. Several laboratory parameters might help differentiating potential nonsurvivors from survivors. Administration of charcoal as part of the emergency treatment appears to have a protective effect. 相似文献
135.
A'Hearn MF Belton MJ Delamere WA Feaga LM Hampton D Kissel J Klaasen KP McFadden LA Meech KJ Melosh HJ Schultz PH Sunshine JM Thomas PC Veverka J Wellnitz DD Yeomans DK Besse S Bodewits D Bowling TJ Carcich BT Collins SM Farnham TL Groussin O Hermalyn B Kelley MS Kelley MS Li JY Lindler DJ Lisse CM McLaughlin SA Merlin F Protopapa S Richardson JE Williams JL 《Science (New York, N.Y.)》2011,332(6036):1396-1400
Understanding how comets work--what drives their activity--is crucial to the use of comets in studying the early solar system. EPOXI (Extrasolar Planet Observation and Deep Impact Extended Investigation) flew past comet 103P/Hartley 2, one with an unusually small but very active nucleus, taking both images and spectra. Unlike large, relatively inactive nuclei, this nucleus is outgassing primarily because of CO(2), which drags chunks of ice out of the nucleus. It also shows substantial differences in the relative abundance of volatiles from various parts of the nucleus. 相似文献
136.
McLaughlin BG O'brien JL 《The Canadian veterinary journal. La revue veterinaire canadienne》1986,27(3):109-111
A case of mycotic encephalitis in a horse with guttural pouch mycosis is described. A liquid pellet feed binder contaminated with Aspergillus sp. and erroneously mixed in a feed concentrate was a possible source of infection. 相似文献
137.
Efficacy of a live Pasteurella multocida vaccine for the prevention of experimentally induced bovine pneumonic pasteurellosis 总被引:1,自引:0,他引:1
M M Chengappa B G McLaughlin W L Kadel R L Maddux S C Greer 《Veterinary microbiology》1989,21(2):147-154
Seventeen Holstein-Friesian calves weighing an average of 139.8 +/- 13.5 (mean +/- standard deviation) kg were used in a study to determine the efficacy of a live vaccine containing of Pasteurella multocida A:3 and Pasteurella haemolytica A:1. Eleven calves received the vaccine by intramuscular injection in the right shoulder, whereas six calves received vaccine diluent and served as non-vaccinated controls. Fourteen days following vaccination (Day 15) all calves were inoculated deep intranasally with 3.6 X 10(7) TCID50 bovine herpes virus-1. On Day 16, calves were stressed by transports, and on Day 17 calves were challenged intratracheally with P. multocida A:3. On Day 22 calves were euthanized and necropsied, and tissues were collected for pathological and microbiological evaluations. Scores were assigned to each calf based on the severity of observed clinical signs. Macroscopic lung lesions were expressed as percentage of tissue involved relative to the total lung tissue of a calf. Plasma fibrinogen concentration, rectal temperature, serum antibody level, microscopic appearance of lung, and microbiologic results were also recorded for analyses. The control calves had significantly higher clinical-sign scores (P less than 0.05) and more severe gross lesions (P less than 0.05) than the vaccinated calves. Although the vaccinated calves had a slight increase of immunoglobulins M and G classes, the differences were not statistically significant (P greater than 0.05, P greater than 0.05). The results of the study indicate that the live Pasteurella vaccine is effective against experimental P. multocida infection in calves. 相似文献
138.
The reason why cows carrying the mutation of complex vertebral malformation (CVM) show poor reproductive capability although they carry only one mutant allele is still not fully understood. Monitoring the progesterone profiles during oestrous cycle and early pregnancy in carrier cows might help explain their lowered reproductive capability. Progesterone concentration was measured in 19 CVM carrier cows and 21 control cows during oestrous cycle and early pregnancy. Milk samples were collected from all cows starting on the day of artificial insemination until day 45 post‐AI. Progesterone was measured in skim milk using enzyme‐linked immunosorbent assay (ELISA). Progesterone concentration was significantly reduced on day 7 (p < 0.05) and day 9 (p < 0.01) post‐insemination in conceived CVM carrier cows when compared with that in control conceived cows. The mean progesterone concentration during early pregnancy was significantly lower (p < 0.05) in conceived cows with CVM than that of control cows in the same period. However, the mean progesterone concentration did not differ significantly (p = 0.072) in CVM cows that showed fertilization failure or embryonic death than that of control cows. Additionally, of 13 conceived control cows, eight cows (61.5%) showed normal luteal function. In contrast, of nine conceived CVM cows, only four cows (44.4%) showed normal luteal function. The conception rate was 47.4% in CVM carrier cows and 61.9% in control cows, but this difference did not reach significance. In conclusion, progesterone concentration might be lowered during early pregnancy in conceived CVM cows compared with that in control cows. 相似文献
139.
The objectives of the present study were to investigate the relationship between the morphological status of cumulus cells surrounding canine oocytes after maturation culture and the meiotic stage of the oocytes. In addition, the effect of the removal of cumulus cells from canine cumulus-oocyte complexes (COCs) during maturation culture on their meiotic competence was examined. Canine COCs were collected from bitches at the anoestrous and dioestrous stages and only COCs with >110 microm in vitelline diameter were cultured in medium 199 with 10% canine serum for 72 h. In the first experiment, the relation between the morphological status of cumulus cells surrounding oocytes cultured for 72 h and their meiotic stages was examined. At the end of maturation culture, the proportions of intact, partially nude and completely nude oocytes were 65.2%, 22.9% and 11.9%, respectively. The proportion of maturation to metaphase II of completely nude oocytes was highest among the oocytes with different morphological status of cumulus cells. In the second experiment, the cumulus cells were partially or completely removed from COCs at 48 h after the start of maturation culture and the oocytes were cultured for a further 24 h. The proportion of oocytes reaching metaphase II in the completely denuded oocytes was significantly higher than that in the control oocytes without the removal treatment of cumulus cells. The results indicate that morphological status of cumulus cells surrounding oocytes may be related to the nuclear maturation of canine oocytes, and the removal of cumulus cells from COCs during maturation culture can promote the completion of oocyte meiotic maturation. 相似文献
140.
Effect of different mini‐volume colloid centrifugation configurations on flow cytometrically sorted sperm recovery efficiency and quality using a computer‐assisted semen analyzer 下载免费PDF全文
LB Ferré JL Chitwood C Fresno HH Ortega ME Kjelland PJ Ross 《Reproduction in domestic animals》2018,53(1):26-33
Straws of sex‐sorted sperm are usually packaged at a low concentration (e.g., ~2.1 × 106 sperm/ml) and cost significantly more than unsorted conventional semen from the same sire. In order to maximize the efficiency of using sex‐sorted sperm under in vitro fertilization conditions, the selection of an appropriate sperm separation technique is essential. In this study, the effect of using different silane‐coated silica colloid dilutions and layering configurations during centrifugation of sex‐sorted sperm was examined over an extended period of incubation time. Sperm recovery and viability after centrifugation using the colloid separation technique were measured along with several sperm motility parameters using CASA. For this purpose, frozen and thawed sex‐sorted sperm samples were centrifuged using mini‐volume single‐layer (40%, 60% and 80%) and mini‐volume two‐layer (45%/90%, 40%/80% and 30%/60%) separation configurations using PureSperm®. A single layer of 40% PureSperm® recovered significantly more sex‐sorted sperm (78.07% ± 2.28%) followed by a single layer of 80% PureSperm® (68.43% ± 2.33%). The lowest sperm recovery was obtained using a two‐layer PureSperm® dilution of 45%/90% (47.57% ± 2.33%). Single‐layer centrifugation recovered more sorted sperm (68.67% ± 1.74%) than two layer (53.74% ± 1.74%) (p < .0001). A single layer of 80% PureSperm® exhibited the highest sorted sperm viability (72.01% ± 2.90%) after centrifugation (p < .05). The mini‐volume single layer of 80% PureSperm® was determined to be an effective alternative to a two‐layer centrifugation configuration for sex‐sorted sperm selection. In addition, single‐layer colloid dilution of 80% performed either as well as or significantly outperformed the other treatments, as well as the control, with regard to motility (MOT) for all time periods of analysis. 相似文献