全文获取类型
收费全文 | 733篇 |
免费 | 43篇 |
专业分类
776篇 |
出版年
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 7篇 |
2016年 | 11篇 |
2015年 | 20篇 |
2014年 | 30篇 |
2013年 | 36篇 |
2012年 | 51篇 |
2011年 | 41篇 |
2010年 | 27篇 |
2009年 | 21篇 |
2008年 | 45篇 |
2007年 | 43篇 |
2006年 | 46篇 |
2005年 | 34篇 |
2004年 | 41篇 |
2003年 | 42篇 |
2002年 | 44篇 |
2001年 | 10篇 |
2000年 | 15篇 |
1999年 | 9篇 |
1998年 | 7篇 |
1997年 | 16篇 |
1996年 | 8篇 |
1995年 | 8篇 |
1994年 | 11篇 |
1993年 | 7篇 |
1992年 | 17篇 |
1991年 | 13篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 10篇 |
1987年 | 8篇 |
1986年 | 12篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1975年 | 2篇 |
1974年 | 3篇 |
1964年 | 5篇 |
1962年 | 2篇 |
1961年 | 2篇 |
排序方式: 共有776条查询结果,搜索用时 15 毫秒
51.
Sun L Tamaki H Ishimaru T Teruya T Ohta Y Katsuyama N Chinen I 《Bioscience, biotechnology, and biochemistry》2004,68(12):2613-2615
Seven-week old female rats fed restricted foods including the fish oils Docosahesaenoic Acid (DHA) and Eicosapentaenoic Acid (EPA) and perilla oil with food intake decreased by 50%, had increases of fracture force and bone mineral density (BMD) and decreases in levels of Deoxypiridinoline (Dpd) and Calcium (Ca) in the urine, compared with those of rats with osteoporosis due to restricted soy bean oil food intake. Therefore, the fish oils DHA and EPA and perilla oil depressed excretion of urinary Ca and inhibited osteoporosis due to restricted food intake. 相似文献
52.
Tamaki H Sun L Ohta Y Katsuyama N Ishimaru T Chinen I 《Bioscience, biotechnology, and biochemistry》2004,68(7):1578-1580
Running at 0.7 km/h for 10 min every day inhibited development of osteoporosis caused by protein deficient (PD) food intake. Urine alkaline phosphatase (ALP), a marker of bone formation osteoporosis, was not elevated in rats fed PD, when the osteoporosis was inhibited by running. Estrogen supplementation increased bone-breaking energy (BBE), but did not increase bone mineral density (BMD), and did not decrease urinary ALP levels. 相似文献
53.
54.
A new species of <Emphasis Type="Italic">Sebastes</Emphasis> (Scorpaeniformes: Scorpaenidae) from the Pacific coast of southern Japan 总被引:1,自引:1,他引:0
A new rockfish, Sebastes kiyomatsui, is described on the basis of 13 specimens from the Pacific coast of southern Japan. The new species resembles S. scythropus in having two sharp preorbital and robust preocular, supraocular, and postocular spines, but differs from the latter in having a black blotch on the opercle not extending to the subopercle, indistinct crimson marks on the body, blackish region of the oral cavity reaching to the prevomer and palatine, blackish tongue, a small ridge on the upper edge of the lachrymal, somewhat larger orbit, somewhat lower caudal peduncle, and seven lower unbranched pectoral fin rays. Sebastes kiyomatsui is a deep water (ca. 250m) inhabitant. 相似文献
55.
The phylogenetic relationships of all 16 genera (plus Psenes pellucidus) of the suborder Stromateoidei were estimated cladistically based on 43 osteological, myological, and external characters. Thirty equally parsimonious trees were obtained. Based on the strict consensus tree, Centrolophidae was nonmonophyletic, Psenopsis being placed as a sister group of a clade comprising Amarsipus, Ariomma, nomeids, Tetragonurus, and stromateids. Schedophilus formed a sister group relationship with Seriolella. The relationships among the Centrolophus, Hyperoglyphe, Icichthys, Tubbia, Schedophilus+Seriolella clade, and Psenopsis+Amarsipus+Ariomma+nomeids+Tetragonurus+stromateids clade were unresolved. Amarsipus, which is unique within the suborder in lacking a pharyngeal sac, was nested within the stromateoid clade, being a sister group of the clade including Ariomma, nomeids, Tetragonurus, and stromateids. The absence of a pharyngeal sac in Amarsipus was interpreted as a reversal, its presence in the Stromateoidei therefore being considered as a synapomorphy. Ariomma was placed as the sister group of a clade comprising nomeids, Tetragonurus, and stromateids. Monophyly of the Nomeidae and Stromateidae were supported by 2 and 11 synapomorphies, respectively. 相似文献
56.
Yano S Kazuno H Sato T Suzuki N Emura T Wierzba K Yamashita J Tada Y Yamada Y Fukushima M Asao T 《Bioorganic & medicinal chemistry》2004,12(13):3443-3450
A series of novel 6-methylene-bridged uracil derivatives have been optimized for clinical use as the inhibitors of human thymidine phosphorylase (TP). We describe their synthesis and evaluation. Introduction of a guanidino or an amidino group enhanced the in vitro inhibitory activity of TP comparing with formerly reported inhibitor 1. Their selectivity for TP based on uridine phosphorylase inhibitory activity was also evaluated. Compound 2 (TPI) has been selected for clinical evaluation based on its strong TP inhibition and excellent modulation of 2'-deoxy-5-(trifluoromethyl)uridine (F(3)dThd) pharmacokinetics. As a result, TAS-102 (a combination of F(3)dThd and TPI) is currently in phase 1 clinical studies. 相似文献
57.
Naka KK Tweddel AC Parthimos D Henderson A Goodfellow J Frenneaux MP 《American journal of physiology. Heart and circulatory physiology》2003,284(3):H970-H978
The time course of acute changes in large artery distensibility immediately and for 60 min following maximum treadmill exercise in normal subjects was characterized by simultaneously measuring upper and lower limb pulse wave velocity (PWV). A new oscillometric technique was used, which has proven to be sensitive to changes in distensibility induced by acute changes in vascular tone independently of blood pressure. The observed changes in PWV are attributable to changes in vascular tone corresponding to recovery from a systemic net constrictor response and a local net dilator response to exercise with persisting postexercise vasodilatation. They are inadequately explained by associated changes in blood pressure and cannot be attributed to changes in heart rate or viscosity. Modeled as a system of n coupled linear differential equations, the minimum (and adequate) order required to reproduce these patterns was n = 1 for the upper and n = 2 for the exercising lower limb. The economy of the solution suggests entrainment among the multiple interactive mechanisms governing vasomotor control. 相似文献
58.
59.
Synthesis and structure-activity relationships of 1-phenylpyrazoles as xanthine oxidase inhibitors 总被引:1,自引:0,他引:1
Ishibuchi S Morimoto H Oe T Ikebe T Inoue H Fukunari A Kamezawa M Yamada I Naka Y 《Bioorganic & medicinal chemistry letters》2001,11(7):879-882
A series of 1-phenylpyrazoles was evaluated for inhibitory activity against xanthine oxidase in vitro. Of the compounds prepared, 1-(3-cyano-4-neopentyloxyphenyl)pyrazole-4-carboxylic acid (Y-700) had the most potent enzyme inhibition and displayed longer-lasting hypouricemic action than did allopurinol in a rat model of hyperuricemia induced by the uricase inhibitor potassium oxonate. 相似文献
60.
Aims: To validate an assessment of qualities of complete dentures that may relate to functional success. Subjects: A consecutive sample of 131 complete denture wearers took part in the study. Setting: a Greek department of prosthetic dentistry. Intervention : All participants and their dentures underwent clinical examination. Design: The Functional Assessment of Dentures (FAD) 10‐item criteria1 describing clinical factors of denture quality was used. The rationale for selecting these particular criteria was to include a range of clinical factors to produce an overall assessment of complete dentures. The 10‐item scale was examined for Internal Consistency and Construct Validity providing a summated rating scale whose total score could be used as an index for the quality of dentures. Results: Both intra‐ and inter‐examiner agreement for all 10 dichotomous scale criteria were all good or very good; the intra‐examiner Kappa values were 0.72 to 0.91 and the inter‐ examiner values were 0.72 to 0.99. Statistical analysis revealed that a 7‐item summated rating scale could be constructed which has marginally better internal consistency (reliability) and Construct Validity with fewer questions. Conclusions: The FAD criteria1 can be used to give good repeatability. The adjustments made to the original summation scale, if confirmed by new studies, would further increase the practical utility of a FAD index for general dentists. In due course with data from future studies, discrimination on weighting of items will be appropriate to relate the impact of denture quality on quality of life. 相似文献