全文获取类型
收费全文 | 1390篇 |
免费 | 122篇 |
专业分类
林业 | 120篇 |
农学 | 39篇 |
基础科学 | 2篇 |
264篇 | |
综合类 | 99篇 |
农作物 | 62篇 |
水产渔业 | 122篇 |
畜牧兽医 | 660篇 |
园艺 | 37篇 |
植物保护 | 107篇 |
出版年
2024年 | 3篇 |
2023年 | 15篇 |
2022年 | 16篇 |
2021年 | 62篇 |
2020年 | 64篇 |
2019年 | 59篇 |
2018年 | 64篇 |
2017年 | 55篇 |
2016年 | 61篇 |
2015年 | 49篇 |
2014年 | 74篇 |
2013年 | 66篇 |
2012年 | 116篇 |
2011年 | 137篇 |
2010年 | 65篇 |
2009年 | 66篇 |
2008年 | 89篇 |
2007年 | 78篇 |
2006年 | 71篇 |
2005年 | 72篇 |
2004年 | 58篇 |
2003年 | 54篇 |
2002年 | 39篇 |
2001年 | 12篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 2篇 |
1997年 | 7篇 |
1996年 | 4篇 |
1995年 | 7篇 |
1994年 | 6篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1988年 | 3篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1976年 | 1篇 |
1969年 | 1篇 |
1966年 | 1篇 |
1962年 | 1篇 |
1961年 | 1篇 |
1959年 | 1篇 |
1958年 | 3篇 |
1955年 | 1篇 |
1941年 | 1篇 |
排序方式: 共有1512条查询结果,搜索用时 15 毫秒
991.
Intercultural studies about the methods of use and perceptions of traditional remedies in Europe are strategically important in understanding how pharmaceutical means in our multicultural modern societies are differently accepted by diverse ethnic groups. In this survey, we analysed the biological means traditionally used in the ethnomedicine of three Arb?resh? (ethnic Albanians) communities in the Vulture area (northern Lucania, southern Italy). The majority of remedies are represented by plants belonging to 54 botanical taxa. A few of the recorded species have a traditional therapeutic use that has never previously been reported in southern Italy. Other means-especially used in the past-are comprised of mineral, animal and industrial derived materials. In specific cases, some of these materials and even plants are neither applied externally or internally, but are instead utilised as symbolic ritual objects in spiritual healing ceremonies. Ethnopharmacological and anthropological considerations about these usages are discussed. 相似文献
992.
Ondej kor Ludmila Bicanov Birgitt Wolfesberger Andrea Fuchs‐Baumgartinger Barbara Ruetgen Marie trbov Ilse Schwendenwein Miriam Kleiter 《Veterinary and comparative oncology》2021,19(1):201-208
In humans B‐symptoms refer to systemic symptoms of lymphoma such as fever, weight loss, and night sweats and influence the prognosis of patients. In canine lymphoma, substage B is used to describe any clinical sign observed. Aim of the retrospective study was to compare the prognostic value of substage B with B‐symptoms to predict treatment response and survival in canine nodal diffuse large B‐cell lymphoma. Affected dogs treated with CHOP chemotherapy between 2008 and 2019 were included. B‐symptoms were defined by weight loss greater than 10% of normal weight, fever and the occurrence of unexplained resting tachypnoea substituted human night sweats. Substage B was defined as any symptoms but lymphadenopathy. Fifty‐five cases were included. B‐symptoms were present in 20/55 (36%) and substage B in 40/55 (74%) patients. No significant associations between B‐symptoms or substage B and weight, sex, breed, WHO stage and lymphoma grade were found. Treatment response was negatively associated with both substage B (P = .02) and B‐symptoms (P = .001). B‐symptoms significantly decreased progression free survival (PFS) (95 vs 330 days, P = .001) and lymphoma specific survival (LSS) (160 vs 462 days, P = .001). Data showed that B‐symptoms might be a more reliable prognostic indicator than substage B in canine nodal diffuse large B‐cell lymphoma. Prospective studies assessing B‐symptoms in a larger cohort of patients and in other common lymphoma types are warranted. The abstract was presented at the fourth meeting of the European Canine Lymphoma Network Group in Lugano, 22 June 2019 and published in the proceeding of the meeting on the page 26. 相似文献
993.
Pablo E. Otero Marta Romano Andrea S. Zaccagnini Santiago E. Fuensalida Natali Verdier Fernanda Sanchez Diego A. Portela 《Veterinary anaesthesia and analgesia》2021,48(3):432-441
ObjectiveTo describe the sonoanatomy of the abdominal wall in live cats and to compare the distribution pattern of two versus three ultrasound-guided transversus abdominis plane (TAP) injections using clinically applicable volumes of lidocaine–dye solution in cat cadavers.Study designProspective anatomical study.AnimalsA total of eight client-owned healthy cats and eight cat cadavers.MethodsUltrasound anatomy of the abdominal wall, landmarks and sites for needle access were determined in live cats. Ultrasound-guided TAP injections were performed in eight thawed cat cadavers. Volumes of 0.25 or 0.16 mL kg?1 per point of a lidocaine–dye solution were injected using either two [subcostal and preiliac (SP)] or three [subcostal, retrocostal and preiliac (SRP)] injection points, respectively. Each cadaver was then dissected to determine the injectate distribution and the number of thoracolumbar nerves stained with each approach. The target nerves were defined as the ventromedial branches of the thoracic nerves 10 (T10), T11, T12, T13 and lumbar nerves 1 (L1) and L2.ResultsSonoanatomy was consistent with anatomy upon dissection and the TAP was identified in all cadavers. A total of 16 subcostal, 16 preiliac and nine retrocostal TAP injections were performed. The overall staining success rate of the target nerves was 66.7% and 92.6% for the SP and SPR approaches, respectively (p = 0.02). The ventromedial branches of T10, T11, T12, T13, L1 and L2 were stained in 57.1%, 100.0%, 85.7%, 28.6%, 42.9% and 85.7%, and in 66.7%, 100.0%, 100.0%, 100.0%, 88.9% and 100.0% of the cases with the SP and SRP approaches, respectively.Conclusions and clinical relevanceThe SRP approach allowed a broader distribution around the target nerves, whereas a staining gap was observed at T13 and L1 with the SP approach. Further studies are necessary to investigate the analgesic effect of these approaches in a clinical setting. 相似文献
994.
Giuseppe Mandolino Andrea Carboni Manuela Bagatta V.M. Cristiana Moliterni Paolo Ranalli 《Euphytica》2002,126(2):211-218
DNA from female and male hemp (Cannabis sativa L.) plants belonging to nine different varieties were screened with180 RAPD primers in a search for sex-associated DNA markers.
About 1500bands were produced in total, nine primers were found yielding one or two DNA bands amplified in all nine male DNA
bulks and absent in all female DNA bulks. These putatively male-associated markers were then scored in three different F1progenies,
deriving from a cross between a common male parent and three different female plants. The sex of the progeny was accurately
scored on the basis of the floral phenotype, and the presence of the nine male-associated markers was verified by RAPD analysis.
In all three progenies examined, all the male plants showed the DNA markers previously identified by bulk segregant analysis
(BSA) on the hemp varieties, while all the female plants lacked them. The fact that the association between these markers
and the staminate phenotype is found when examining male plants of distantly related varieties, and that such linkage is never
broken when different progenies are examined, strongly supports the hypothesis that the markers found are physically located
on the Y chromosome, in a region excluded from recombination during meiosis. Another marker was shown to be present in the
male parent, in all the male plants of each progeny, and in 50% of the female progenies, while it was absent in the female
parent; the possible occurrence of markers deriving from multiple amplification sites of the genome is discussed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
995.
Summary Callus induction, callus growth and organogenetic processes were investigated in hypocotyl and stem cultures of four species of Amaranthus each of which comprised several varieties. Callus formation occurred in almost all the varieties in 100% of explants. The combinations of naphtaleneacetic acid plus benzylaminopurine or 2,4-dichlorophenoxyacetic acid plus Kinetin were very effective in causing callus formation; the results for callus growth in presence of the same growth regulator combinations revealed in some cases significant differences among the varieties.As far organogenesis-based on a few varieties-only A. caudatus and A. hypochondriacus responded well forming shoots from callus when cultured in presence of indoleacetic acid plus Kinetin and/or indoleacetic acid plus benzylaminopurine. Root regeneration was also observed in several varieties. Complete plantlets were obtained from rooted shoots.The results are discussed in relation to hormonal effect and the genotype importance. 相似文献
996.
997.
998.
999.
Leonor Corrales-Retana Francesca Ciucci Giuseppe Conte Laura Casarosa Marcello Mele Andrea Serra 《Journal of animal physiology and animal nutrition》2021,105(2):326-335
The omega-3 fatty acid (FA) enrichment of yolk is a key means one of the main objectives to improve the nutraceutical properties of eggs. We evaluated the effect of the dietary inclusion of extruded linseed fed to laying hens on the fatty acid composition of the polar and non-polar lipid classes of the eggs. Two groups of 36 Lohmann White Leghorn layers (65 weeks old) were each fed one of two different diets for a period of 12 weeks. The two diets consisted of a conventional cereal-based diet concentrate (C) and a diet concentrate containing 5% linseed (L). The inclusion of linseed in the diet increased the content of α-linolenic (C18:3n-3), eicosapentaenoic (C20:5n-3) and docosahexaenoic (C22:6n-3) acids in neutral lipids, while a concomitant decrease in arachidonic acid (C20:4n-6) was observed. As regards the polar fraction, the fatty acid composition was slightly affected by the dietary treatments except for C18:0 (+1.14 fold), C18:2n-6 (+1.23 fold), C18:3n-3 (+2.8 fold) and C22:6n-3 (+1.41 fold). Principal component analysis demonstrated that very long-chain FAs were more representative of polar lipids, except for C20:5n-3, while neutral lipids were characterized by dietary n-3 FA (C18:3n-3). 相似文献
1000.
Bordoni R Mezzelani A Consolandi C Frosini A Rizzi E Castiglioni B Salati C Marmiroli N Marchelli R Rossi Bernardi L Battaglia C De Bellis G 《Journal of agricultural and food chemistry》2004,52(5):1049-1054
We have applied the ligation detection reaction (LDR) combined with a universal array approach to the detection and quantitation of the polymerase chain reaction (PCR) amplified cry1A(b) gene from Bt-176 transgenic maize. We demonstrated excellent specificity and high sensitivity. Down to 0.5 fmol (nearly 60 pg) of PCR amplified transgenic material was unequivocally detected with excellent linearity within the 0.1-2.0% range with respect to wild-type maize. We suggest the feasibility of extending the LDR/universal array format to detect in parallel several transgenic sequences that are being developed for food applications. 相似文献