全文获取类型
收费全文 | 647篇 |
免费 | 62篇 |
专业分类
林业 | 50篇 |
农学 | 4篇 |
基础科学 | 2篇 |
92篇 | |
综合类 | 58篇 |
农作物 | 18篇 |
水产渔业 | 31篇 |
畜牧兽医 | 390篇 |
园艺 | 4篇 |
植物保护 | 60篇 |
出版年
2023年 | 10篇 |
2022年 | 10篇 |
2021年 | 22篇 |
2020年 | 15篇 |
2019年 | 22篇 |
2018年 | 15篇 |
2017年 | 22篇 |
2016年 | 24篇 |
2015年 | 18篇 |
2014年 | 32篇 |
2013年 | 24篇 |
2012年 | 62篇 |
2011年 | 53篇 |
2010年 | 29篇 |
2009年 | 37篇 |
2008年 | 45篇 |
2007年 | 51篇 |
2006年 | 50篇 |
2005年 | 39篇 |
2004年 | 30篇 |
2003年 | 19篇 |
2002年 | 27篇 |
2001年 | 5篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有709条查询结果,搜索用时 187 毫秒
631.
Bruna Sayuri Fujiyama Mário Lopes da Silva Júnior Nicole Raquel Pinto Cardoso Adrianne Braga da Fonseca Rafael Gomes Viana 《Journal of plant nutrition》2013,36(19):2498-2506
AbstractInfluence of boron (B) on photosynthesis and water use has not sufficiently been evaluated in soybean despite its worldwide importance as a crop. The objective of this work was to evaluate the effects of B application on photosynthesis and water use in soybean at vegetative growth stage. A pot experiment was carried out in a greenhouse. Soybean [Glycine max (L.) Merrill cv. M8644 IPRO] was grown in a clayey Oxisol previously fertilized with 4 B rates (0, 1.5, 3.0, and 6.0?mg dm?3). Net photosynthesis rate (Pn), intercellular CO2 concentration (Ci), transpiration rate (E), stomatal conductance (gs) were measured in the second trifoliate leaf of plants at the V4 growth stage. Instantaneous water use efficiency (WUEis = Pn/E) and intrinsic water use efficiency (WUEic = Pn/gs) were calculated. B application to soil increased all these variables. The most consistent increases were in Pn, WUEis, and WUEic. The critical level of hot water extractable B in soil that maximized photosynthesis and optimized water use by soybean at vegetative growth stage was calculated to be 0.38?mg dm?3. 相似文献
632.
Fouchier RA García-Sastre A Kawaoka Y Barclay WS Bouvier NM Brown IH Capua I Chen H Compans RW Couch RB Cox NJ Doherty PC Donis RO Feldmann H Guan Y Katz J Klenk HD Kobinger G Liu J Liu X Lowen A Mettenleiter TC Osterhaus AD Palese P Peiris JS Perez DR Richt JA Schultz-Cherry S Steel J Subbarao K Swayne DE Takimoto T Tashiro M Taubenberger JK Thomas PG Tripp RA Tumpey TM Webby RJ Webster RG 《Science (New York, N.Y.)》2012,335(6067):400-401
633.
The purpose of this study was to describe the appropriate surgical technique, postoperative monitoring, and complications encountered with use of vacuum-assisted closure (VAC) in six dogs with confirmed septic peritonitis. Initial diagnosis of septic peritonitis was performed by measuring either the blood-to-fluid lactate ratio and glucose concentration differences or cytologic verification of intracellular bacteria. After appropriate surgical procedures were performed to manage the primary cause of peritoneal sepsis, a VAC was performed. Serum and abdominal fluid protein levels were measured, and all complications were noted during the postoperative period. Three of the six dogs (50%) survived to the secondary closure and were subsequent discharged, which is similar to previous studies where the abdomen was either closed primarily or treated with open abdominal drainage. No major complications occurred with bandage management during hospitalization. The results of this study support VAC as a feasible technique for managing septic peritonitis. 相似文献
634.
Liliana M. Marín M. Cristina Iazbik Sara Zaldivar‐Lopez Linda K. Lord Nicole Stingle Paulo Vilar Ana Lara‐Garcia Francisco Alvarez Kenji Hosoya Laura Nelson Antonio Pozzi Edward Cooper Mary A. McLoughlin Rebecca Ball William C. Kisseberth Cheryl A. London Robert Dudley Jonathan Dyce Melanie McMahon Phillip Lerche Richard Bednarski C. Guillermo Couto 《Journal of Veterinary Emergency and Critical Care》2012,22(3):332-340
635.
636.
Jeffrey H. Gertsch Bryan Corbett Peter S. Holck Allison Mulcahy Melanie Watts Nathan Thomas Stillwagon Amanda Morgan Casto Charles Hessel Abramson Charles Peter Aloysius Vaughan Christopher Macguire Neda Nicole Farzan Baotran Nguyen Vo Rebecca Jean Norvelle Kerstin May Jessica Elizabeth Holly Hillary Irons Aaron Michael Stutz Pradip Chapagain Siddhartha Yadav Matiram Pun Buddha Basnyat 《The Forestry Chronicle》2012,23(4):307-315
637.
Büttner N Beineke A de Buhr N Lilienthal S Merkel J Waldmann KH Valentin-Weigand P Baums CG 《Veterinary immunology and immunopathology》2012,146(3-4):191-200
Streptococcus suis diseases in pigs, most importantly meningitis, are worldwide responsible for major economic losses in the pig industry. About one fourth of invasive S. suis diseases are caused by S. suis serotype 9 strains in Europe. However, little is known about serotype 9 since most studies were performed with serotype 2. The objective of this study was to determine the immunogenicity and protective efficacy of a serotype 9 bacterin in piglets. Challenge was conducted with a reference serotype 9 strain, belonging to the same clonal complex but to a different sequence type as the bacterin strain. The bacterin induced protection against mortality but not morbidity. Eleven days post infection, 3 of 7 vaccinated survivors were not fully convalescent and had not eliminated the challenge strain from inner organs completely. In accordance with the clinical findings, the majority of piglets showed fibrinous-suppurative lesions in at least one inner organ or tissue. In contrast to the placebo group such lesions were not detected in one third of bacterin-vaccinated piglets. Determination of specific serum IgG titers revealed that the bacterin elicited seroconversion against muramidase-released protein and basic membrane lipoprotein. Furthermore, vaccination was associated with induction of opsonizing antibodies against the serotype 9 challenge strain. However, titers of opsonizing antibodies were rather low in comparison to those found in our previous serotype 2 vaccination trial. Piglets developed substantially higher titers of opsonizing antibodies after challenge. Opsonizing antibodies were absorbable with the serotype 9 challenge strain but not with an unencapsulated isogenic mutant of a serotype 2 strain indicating their specificity. The results indicate that a serotype 9 bacterin is less protective than a serotype 2 bacterin, most likely due to inducing only low titers of opsonizing antibodies. This might contribute to emergence of serotype 9 strains, in particular strains of this clonal complex, in Europe. 相似文献
638.
Cole LK Kwochka KW Hillier A Kowalski JJ Smeak DD Kelbick NT 《Veterinary dermatology》2006,17(2):128-133
The purposes of this study were to determine whether ciprofloxacin disk diffusion susceptibility test (DDT) results could be used to assess the in vitro susceptibility of otic bacterial organisms to enrofloxacin and to determine the effect of concurrent enrofloxacin administration on the DDT results for enrofloxacin and ciprofloxacin. Thirty dogs with end-stage otitis externa undergoing unilateral total ear canal ablation were enrolled. The dogs were randomized to one of four enrofloxacin-treatment groups or to the control group. Each dog in the treatment groups received two intravenous doses of enrofloxacin prior to surgical removal of the middle-ear tissue while the control group did not receive any enrofloxacin. One dog was excluded from the study as no middle-ear tissue was removed during surgery. Twenty-four dogs were in the enrofloxacin-treatment groups and five dogs were in the control group. In 12 of 29 dogs (41.4%), 14 of 82 (17.1%) of bacteria had discrepancies in DDT results for enrofloxacin and ciprofloxacin. Discrepancies between the control group and treatment groups were not significantly different even though the percentage of discrepancies for the combined treatment group was 19.4% compared to 6.7% for the control group. In this study, ciprofloxacin DDT results were not an accurate indicator of the in vitro susceptibility of enrofloxacin for bacteria isolated from the middle-ear tissue of dogs with end-stage otitis. 相似文献
639.
640.
Yasushi Okinaka Nicole T. Perna Shihui Yang Noel T. Keen Ching-Hong Yang 《Journal of General Plant Pathology》2006,72(6):360-368
Erwinia chrysanthemi 3937 is a soft-rotting plant pathogen in Enterobacteriaceae. It attacks a wide range of plant host species. Previously, we
identified dozens of E. chrysanthemi 3937 genes induced during plant infection by microarray differential display. Here, we have mutated plant-upregulated and
putatively plant-upregulated genes in E. chrysanthemi 3937 using a transposon insertion method. Of 57 mutants produced, 8 were significantly reduced in maceration in African violet
leaves. These 8 E. chrysanthemi genes are similar to Escherichia coli purU (formyltetrahydrofolate deformylase; ASAP20623) and wcaJ (undecaprenylphosphate glucosephosphotransferase; ASAP18556), Bacillus subtilis dltA (d-alanine-d-alanyl carrier protein ligase; ASAP19406), Pseudomonas syringae PSPTO2912 (ABC transporter, periplasmic glutamine-binding protein; ASAP15639), Pseudomonas aeruginosa pheC (cyclohexadienyl dehydratase; ASAP19773), P. syringae syrE (peptide synthase; ASAP19989), Vibrio vulnificus VV12303 (unknown protein; ASAP18555), and Yersinia pestis speD (S-adenosylmethionine decarboxylase; ASAP20536). In some of the genes, possible roles in virulence could be postulated based
on the functions of their homologues. This work demonstrated that a low proportion of pathogenicity-related genes were among
the plant-upregulated genes of E. chrysanthemi 3937. This study and further dissection of these putative virulence genes should lead to new insights into infection mechanisms
in pathogens. 相似文献