全文获取类型
收费全文 | 271篇 |
免费 | 29篇 |
专业分类
林业 | 2篇 |
农学 | 11篇 |
42篇 | |
综合类 | 31篇 |
农作物 | 3篇 |
水产渔业 | 35篇 |
畜牧兽医 | 151篇 |
园艺 | 11篇 |
植物保护 | 14篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 8篇 |
2017年 | 7篇 |
2016年 | 12篇 |
2015年 | 10篇 |
2014年 | 12篇 |
2013年 | 34篇 |
2012年 | 18篇 |
2011年 | 17篇 |
2010年 | 11篇 |
2009年 | 7篇 |
2008年 | 15篇 |
2007年 | 10篇 |
2006年 | 19篇 |
2005年 | 14篇 |
2004年 | 7篇 |
2003年 | 8篇 |
2002年 | 10篇 |
2001年 | 9篇 |
2000年 | 6篇 |
1999年 | 10篇 |
1998年 | 3篇 |
1997年 | 5篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1955年 | 1篇 |
1940年 | 1篇 |
排序方式: 共有300条查询结果,搜索用时 15 毫秒
121.
122.
Gavin W. Glenney Patricia A. Barbash John A. Coll 《Journal of aquatic animal health》2016,28(1):46-55
A novel herpesvirus was found by molecular methods in samples of Lake Trout Salvelinus namaycush from Lake Erie, Pennsylvania, and Lake Ontario, Keuka Lake, and Lake Otsego, New York. Based on PCR amplification and partial sequencing of polymerase, terminase, and glycoprotein genes, a number of isolates were identified as a novel virus, which we have named Namaycush herpesvirus (NamHV) salmonid herpesvirus 5 (SalHV5). Phylogenetic analyses of three NamHV genes indicated strong clustering with other members of the genus Salmonivirus, placing these isolates into family Alloherpesviridae. The NamHV isolates were identical in the three partially sequenced genes; however, they varied from other salmonid herpesviruses in nucleotide sequence identity. In all three of the genes sequenced, NamHV shared the highest sequence identity with Atlantic Salmon papillomatosis virus (ASPV; SalHV4) isolated from Atlantic Salmon Salmo salar in northern Europe, including northwestern Russia. These results lead one to believe that NamHV and ASPV have a common ancestor that may have made a relatively recent host jump from Atlantic Salmon to Lake Trout or vice versa. Partial nucleotide sequence comparisons between NamHV and ASPV for the polymerase and glycoprotein genes differ by >5% and >10%, respectively. Additional nucleotide sequence comparisons between NamHV and epizootic epitheliotropic disease virus (EEDV/SalHV3) in the terminase, glycoprotein, and polymerase genes differ by >5%, >20%, and >10%, respectively. Thus, NamHV and EEDV may be occupying discrete ecological niches in Lake Trout. Even though NamHV shared the highest genetic identity with ASPV, each of these viruses has a separate host species, which also implies speciation. Additionally, NamHV has been detected over the last 4 years in four separate water bodies across two states, which suggests that NamHV is a distinct, naturally replicating lineage. This, in combination with a divergence in nucleotide sequence from EEDV, indicates that NamHV is a new species in the genus Salmonivirus.
Received April 20, 2015; accepted October 11, 2015 相似文献
123.
124.
We present a case of aggressive metastatic carcinoma in a horse that was initially presented for shoulder lameness. Although radiography and scintigraphy were useful for localising a lesion in the proximal humerus, subsequent development of non-specific signs of systemic disease prompted further evaluation. Haematology and blood biochemistry, urinalysis and ultrasonography were all instrumental in identifying renal involvement. A diagnosis of a peri-renal mass causing secondary renal failure prompted euthanasia of the horse because of the poor prognosis. Antemortem findings were supported by necropsy, with secondary lesions also identified in the spleen, liver, 8th left rib and proximal humerus. Histological examination yielded a diagnosis of undifferentiated metastatic carcinoma. 相似文献
125.
Relationships between total suspended solids (TSS) and metals (Cu, Pb and Zn) were tested and compared amongst base and high
flows of three urbanised catchments in Sydney Estuary, Australia. Significant relationships between TSS and Cu, Pb and Zn
were detected for high flows within each catchment; however, no significant relationship was detected for TSS/Zn and TSS/Cu
in one of the creeks (Whites Creek) and for TSS/Zn in another (Hawthorne Canal) in 2010 during base flow. Relationships between
metals and TSS also varied significantly in locations of intercept and slope between high and base flow and amongst catchments.
Spatial variance in TSS/metal relationships were likely caused by specific anthropogenic activities because land uses, meteorology
and geology within the study catchments were similar. Results suggest TSS may be used as a surrogate for estimating metal
loading in real time for urban catchments, once relationships between metals and TSS were established for individual catchments
and for base and high flow conditions. Moreover, no differences in TSS/metal relationships were detected between 2009 and
2010 in Hawthorne Canal during high flow conditions, suggesting that this method of real-time monitoring may be reliable for
assessing Cu, Pb and Zn loads during high flows over inter-annual periods. However, long-term consistency of TSS/metal relationships
for base flow may need testing since changes in TSS/Zn and TSS/Cu relationships were detected between 2009 and 2010 in Hawthorne
Canal. Although irregular discharges to stormwater did not conform to TSS/metal relationships, irregular discharges may be
detected in real time by increased flow during dry weather conditions, which may facilitate regulation of these conditions
that currently result in potential environmental harm to aquatic biota in Sydney Estuary. 相似文献
126.
127.
R.K. Sellon J. Fidel R. Houston P.R. Gavin 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2009,23(5):1038-1044
Objective: Determine the efficacy and safety of a linear-accelerator-based single fraction radiosurgical approach to the treatment of pituitary tumors in cats.
Design: Retrospective study.
Animals: Eleven client-owned cats referred for treatment of pituitary tumors causing neurological signs, or poorly controlled diabetes mellitus (DM) secondary either to acromegaly or pituitary-dependent hyperadrenocortism.
Procedures: Cats underwent magnetic resonance imaging (MRI) of the brain to manually plan radiation therapy. After MRI, modified radiosurgery was performed by delivering a single large dose (15 or 20 Gy) of radiation while arcing a linear-accelerator-generated radiation beam around the cat's head with the pituitary mass at the center of the beam. Eight cats were treated once, 2 cats were treated twice, and 1 cat received 3 treatments. Treated cats were evaluated for improvement in endocrine function or resolution of neurological disease by review of medical records or contact with referring veterinarians and owners.
Results: Improvement in clinical signs occurred in 7/11 (63.6%) of treated cats. Five of 9 cats with poorly regulated DM had improved insulin responses, and 2/2 cats with neurological signs had clinical improvement. There were no confirmed acute or late adverse radiation effects. The overall median survival was 25 months (range, 1–60), and 3 cats were still alive.
Conclusions and Clinical Importance: Single fraction modified radiosurgery is a safe and effective approach to the treatment of pituitary tumors in cats. 相似文献
Design: Retrospective study.
Animals: Eleven client-owned cats referred for treatment of pituitary tumors causing neurological signs, or poorly controlled diabetes mellitus (DM) secondary either to acromegaly or pituitary-dependent hyperadrenocortism.
Procedures: Cats underwent magnetic resonance imaging (MRI) of the brain to manually plan radiation therapy. After MRI, modified radiosurgery was performed by delivering a single large dose (15 or 20 Gy) of radiation while arcing a linear-accelerator-generated radiation beam around the cat's head with the pituitary mass at the center of the beam. Eight cats were treated once, 2 cats were treated twice, and 1 cat received 3 treatments. Treated cats were evaluated for improvement in endocrine function or resolution of neurological disease by review of medical records or contact with referring veterinarians and owners.
Results: Improvement in clinical signs occurred in 7/11 (63.6%) of treated cats. Five of 9 cats with poorly regulated DM had improved insulin responses, and 2/2 cats with neurological signs had clinical improvement. There were no confirmed acute or late adverse radiation effects. The overall median survival was 25 months (range, 1–60), and 3 cats were still alive.
Conclusions and Clinical Importance: Single fraction modified radiosurgery is a safe and effective approach to the treatment of pituitary tumors in cats. 相似文献
128.
Effects of season and postharvest storage on the carotenoid content of Solanum phureja potato tubers
Griffiths DW Dale MF Morris WL Ramsay G 《Journal of agricultural and food chemistry》2007,55(2):379-385
The total carotenoid content was determined of tubers from 38 Solanum phureja lines grown in field plots over 3 years. The results indicated a significant difference between years, but the ranking was similar from year to year and the interaction between season and variety was small. Postharvest storage significantly reduced the carotenoid content of the tubers, and reducing the storage temperature further lowered the carotenoid content. Examination of the individual carotenoids revealed that lutein was the most stable and least likely to be reduced, while the levels of the carotenoids derived from beta-carotene were significantly reduced during storage at either temperature. Exposure of the tubers to either mercury or sodium lights resulted in a significant increase in total carotenoid content, concomitant with elevated chlorophyll. Although both types of radiation produced a broadly similar increase in total carotenoid contents, differential effects on the individual carotenoid profile of the light-induced carotenoids were observed. 相似文献
129.
The geological record of ocean acidification 总被引:1,自引:0,他引:1
Hönisch B Ridgwell A Schmidt DN Thomas E Gibbs SJ Sluijs A Zeebe R Kump L Martindale RC Greene SE Kiessling W Ries J Zachos JC Royer DL Barker S Marchitto TM Moyer R Pelejero C Ziveri P Foster GL Williams B 《Science (New York, N.Y.)》2012,335(6072):1058-1063
Ocean acidification may have severe consequences for marine ecosystems; however, assessing its future impact is difficult because laboratory experiments and field observations are limited by their reduced ecologic complexity and sample period, respectively. In contrast, the geological record contains long-term evidence for a variety of global environmental perturbations, including ocean acidification plus their associated biotic responses. We review events exhibiting evidence for elevated atmospheric CO(2), global warming, and ocean acidification over the past ~300 million years of Earth's history, some with contemporaneous extinction or evolutionary turnover among marine calcifiers. Although similarities exist, no past event perfectly parallels future projections in terms of disrupting the balance of ocean carbonate chemistry-a consequence of the unprecedented rapidity of CO(2) release currently taking place. 相似文献
130.