全文获取类型
收费全文 | 8486篇 |
免费 | 864篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 60篇 |
儿科学 | 306篇 |
妇产科学 | 214篇 |
基础医学 | 1285篇 |
口腔科学 | 146篇 |
临床医学 | 844篇 |
内科学 | 1790篇 |
皮肤病学 | 101篇 |
神经病学 | 639篇 |
特种医学 | 225篇 |
外科学 | 1013篇 |
综合类 | 170篇 |
一般理论 | 6篇 |
预防医学 | 822篇 |
眼科学 | 86篇 |
药学 | 762篇 |
中国医学 | 8篇 |
肿瘤学 | 888篇 |
出版年
2022年 | 43篇 |
2021年 | 116篇 |
2020年 | 86篇 |
2019年 | 94篇 |
2018年 | 146篇 |
2017年 | 96篇 |
2016年 | 128篇 |
2015年 | 138篇 |
2014年 | 215篇 |
2013年 | 340篇 |
2012年 | 487篇 |
2011年 | 543篇 |
2010年 | 264篇 |
2009年 | 275篇 |
2008年 | 454篇 |
2007年 | 521篇 |
2006年 | 509篇 |
2005年 | 477篇 |
2004年 | 502篇 |
2003年 | 445篇 |
2002年 | 497篇 |
2001年 | 121篇 |
2000年 | 152篇 |
1999年 | 147篇 |
1998年 | 131篇 |
1997年 | 122篇 |
1996年 | 118篇 |
1995年 | 96篇 |
1994年 | 108篇 |
1993年 | 98篇 |
1992年 | 109篇 |
1991年 | 125篇 |
1990年 | 105篇 |
1989年 | 104篇 |
1988年 | 114篇 |
1987年 | 79篇 |
1986年 | 75篇 |
1985年 | 81篇 |
1984年 | 77篇 |
1983年 | 84篇 |
1982年 | 81篇 |
1981年 | 66篇 |
1980年 | 70篇 |
1979年 | 65篇 |
1978年 | 62篇 |
1977年 | 51篇 |
1976年 | 45篇 |
1975年 | 43篇 |
1973年 | 49篇 |
1972年 | 43篇 |
排序方式: 共有9365条查询结果,搜索用时 15 毫秒
51.
Photic evoked responses were recorded from the striate cortex of Long-Evans hooded intact, monocular visual deprivation (MD) and MD treated with NGF rats. The averaged visual evoked responses (AVER) were obtained from both hemispheres and provided comparison after binocular photic stimuli between the contralateral and the ipsilateral striate cortex with relation to the MD eye. One month of monocular visual deprivation at the critical period of development resulted in marked reduction of the amplitudes of AVER components as compared to the control recordings (P < 0.001). These changes of the AVER could be prevented by NGF infusion to lateral ventricle at the dosage of 2.0–2.4 μg/day for four weeks during the monocular deprivation. In conclusion, the change of AVER amplitudes induced by monocular visual deprivation during the critical period of development can be prevented by NGF infusion to lateral ventricle. 相似文献
52.
53.
Mapping the Von Hippel -- Lindau disease tumour suppressor gene: identification of germline deletions by pulsed field gel electrophoresis 总被引:3,自引:0,他引:3
Richards Frances M.; Phipps Maude E.; Latlf Farida; Yao Masahlro; Crossey Paul A.; Foster Kelth; Llnehan W. Marston; Affara Nabeel A.; Lerman Michael I.; Zbar Berton; Ferguson-Smith Malcolm A.; Maher Eamonn R. 《Human molecular genetics》1993,2(7):879-882
Von HlppelLindau (VHL) disease is a dominantly Inheritedfamillal cancer syndrome In which affected individuals havea greatly increased predisposition to the development of haemangloblastomasof the central nervous system and retina, renal cell carcinomaand phaeochromocytoma. The VHL gene has been mapped to chromosome3p25 -p26 by genetic linkage studies and we have previouslydemonstrated that the VHL gene is tightly linked to the D3S601locus (Zmax = 18.86 at 相似文献
54.
Phillip A. Reece Heather S. Hill R. Malcolm Green Raymond G. Morris Barry M. Dale Dusan Kotasek Robert E. Sage 《Cancer chemotherapy and pharmacology》1988,22(4):348-352
Summary The renal clearance of melphalan and the fraction unbound in plasma were determined after intravenous infusion of 5 mg/m2 over 5 min in nine patients with cancer to obtain information regarding the mechanism of renal handling of melphalan. Four of the patients underwent bone marrow transplantation and also received an IV dose of 220 mg/m2. Total melphalan clearance after the 5 mg/m2 dose ranged from 66.0 to 272 ml/min per m2; the percentage of the dose excreted unchanged in urine, from 2.5% to 92.8%; renal clearance, from 4.1 to 188 ml/min per m2; the fraction unbound in plasma, from 0.0598 to 0.460; and t1/2, from 39.4 to 84.3 min. Unbound melphalan clearance and renal clearance calculated from the unbound fraction in plasma for each patient ranged from 441 to 3356 ml/min per m2 and 15 to 961 ml/min per m2 respectively and were not related to serum albumin, serum creatinine or creatinine clearance. The percentage of the dose exctreted and melphalan renal clearance were not related to urine flow. There was evidence of active secretion of melphalan in the kidney an possible reabsorption. There were no significant paired differences in melphalan disposition between the high- and low-dose studies. Highly variable renal clearance involving active secretion may contribute in part to large interpatient differences in the total plasma clearance of melphalan in patients with cancer.This study was supported by a grant from The Queen Elizabeth Hospital Research Foundation 相似文献
55.
Joint custody: historical, legal, and clinical perspectives with emphasis on the situation in Canada
The search for ways to mitigate the effects of family breakdown on parents and children includes legislative and clinical efforts which to some extent influence each other. In the past year much public interest has been aroused in Canada, and particularly in Ontario, in the issue of legislative changes which would make joint custody the usual or "preferred" legal disposition of custody cases. This paper provides a discussion of the legislated preference, or "rebutable presumption" of joint custody from a historical, legal and clinical point of view. Definition and elaboration of what joint custody is from the legal and practical perspectives is provided with an emphasis on Canadian laws and practice. The legal rights of the non-custodial parent are explained, and relevant case law is highlighted. The relationship between joint custody, support orders and relitigation rates are elaborated. Following this is a critical overview of the empirical research on joint custody as it relates to the adjustment of children and parent satisfaction is included. It is concluded that while there is little question that shared parenting can be beneficial to children, the enthusiasm of legislators for joint custody has not been supported by empirical data. It is necessary to examine under what circumstances and for which kinds of parents and children joint custody might be beneficial since it is unlikely that one solution will fit the needs of all families and all stages of family life. 相似文献
56.
The role of genetics in the development of asthma and atopy 总被引:8,自引:0,他引:8
Blumenthal MN 《Current opinion in allergy and clinical immunology》2005,5(2):141-145
PURPOSE OF REVIEW: The mapping of complex traits such as asthma and atopy is one of the most important and central areas of human genetics. This article will present an overview of the current status of genetic studies of asthma and atopy using genome screens and association studies that have occurred in the literature since January 2003. RECENT FINDINGS: Many regions of the genome have been found to have linkage with the phenotypes of asthma and atopy. Over 70 variants in candidate genes have been reported to be associated with these phenotypes. The main regions these variants have been found are on chromosomes 2q, 5q, 6p, 11q, 12q, 16q and 17q. Five potential asthma susceptibility genes or complexes have been identified using a positional approach. These are ADAM33, DPP10, PHF11 and SETDB2, GPRA and SPINK5. It is evident that environmental factors will influence the expression of genes and the ultimate clinical phenotype of asthma and atopy. SUMMARY: The development of asthma and atopy involves many genes and environmental factors. An understanding of their genetic basis has great implications for their management. 相似文献
57.
This study examined the acquisition and transfer of a fine motor skill, namely the rotary pursuit, in 99 patients with Alzheimer's disease (AD) and 100 normal controls (NCs). To identify optimal learning strategies, the authors had participants practice the rotary pursuit under constant, blocked, random, or no training conditions. Transfer was assessed using speeds that were different from those practiced during acquisition. AD patients and NCs receiving constant practice outperformed their peers in the blocked and random conditions during acquisition. Whereas all 3 types of practice facilitated transfer in the NCs, AD patients only benefited from constant practice. The inability of the AD patients to benefit from variable practice suggests that these individuals may have difficulty accessing and/or forming motor schemas. 相似文献
58.
59.
60.
Hamvas RM Johnson M Vlieger AM Ling C Sherriff A Wade A Klein NJ Turner MW Webster AD 《Infection and immunity》2005,73(8):5238-5240
Polymorphisms in exon 1 of the MBL-2 gene, resulting in reduced plasma levels of mannose binding lectin, were significantly overrepresented in 23 patients with primary antibody deficiency and culture-proven mycoplasma infections (P = 0.0038). This association persisted with the inclusion of a further nine suspected (doxycycline-responsive) cases (P = 0.0087). The lectin was shown to bind to three strains of mycoplasma. 相似文献