全文获取类型
收费全文 | 27538篇 |
免费 | 1483篇 |
国内免费 | 60篇 |
专业分类
耳鼻咽喉 | 441篇 |
儿科学 | 1128篇 |
妇产科学 | 876篇 |
基础医学 | 4423篇 |
口腔科学 | 590篇 |
临床医学 | 2293篇 |
内科学 | 5545篇 |
皮肤病学 | 610篇 |
神经病学 | 2692篇 |
特种医学 | 1125篇 |
外国民族医学 | 15篇 |
外科学 | 3977篇 |
综合类 | 130篇 |
一般理论 | 3篇 |
预防医学 | 1415篇 |
眼科学 | 516篇 |
药学 | 1416篇 |
中国医学 | 20篇 |
肿瘤学 | 1866篇 |
出版年
2023年 | 149篇 |
2022年 | 243篇 |
2021年 | 401篇 |
2020年 | 267篇 |
2019年 | 371篇 |
2018年 | 462篇 |
2017年 | 379篇 |
2016年 | 529篇 |
2015年 | 522篇 |
2014年 | 738篇 |
2013年 | 899篇 |
2012年 | 1276篇 |
2011年 | 1343篇 |
2010年 | 674篇 |
2009年 | 718篇 |
2008年 | 1232篇 |
2007年 | 1313篇 |
2006年 | 1218篇 |
2005年 | 1242篇 |
2004年 | 1030篇 |
2003年 | 1013篇 |
2002年 | 939篇 |
2001年 | 926篇 |
2000年 | 955篇 |
1999年 | 807篇 |
1998年 | 352篇 |
1997年 | 277篇 |
1996年 | 227篇 |
1995年 | 209篇 |
1994年 | 183篇 |
1993年 | 180篇 |
1992年 | 491篇 |
1991年 | 514篇 |
1990年 | 496篇 |
1989年 | 413篇 |
1988年 | 388篇 |
1987年 | 409篇 |
1986年 | 398篇 |
1985年 | 400篇 |
1984年 | 282篇 |
1983年 | 218篇 |
1981年 | 145篇 |
1979年 | 262篇 |
1978年 | 184篇 |
1977年 | 156篇 |
1976年 | 158篇 |
1975年 | 166篇 |
1974年 | 192篇 |
1973年 | 169篇 |
1972年 | 155篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
P. von Dadelszen Gynaecology Registrar M. D. G. Gillmer Consultant Gynaecologist M. D. Gray Consultant Gynaecologist H. P. McEwan Consultant Gynaecologist R. J. D. Pyper Consultant Gynaecologist T. P. Rollason Consultant Pathologist A. Wright Gynaecology Registrar 《BJOG : an international journal of obstetrics and gynaecology》1994,101(2):158-161
42.
Christian Rüegg Martin Hersberger Barbara Wusk Katharina Rentsch Gerd A Kullak-Ublick Arnold von Eckardstein Friedrich E Maly 《Clinical chemistry and laboratory medicine》2004,42(5):494-498
Crohn's disease is a complex disorder, with multiple genetic traits. A frameshift mutation (Leu1007fsinsC) and two missense mutations (Gly908Arg and Arg702Trp) in the NOD2/CARD15 gene are strongly associated with susceptibility to Crohn's disease. The presence of one of these risk alleles confers a 2- to 4-fold increase in the risk of developing Crohn's disease, and the presence of two mutant alleles increases the risk over 20-fold. To facilitate the analysis of these polymorphisms, we developed three LightCycler assays to detect the missense mutations Arg702Trp and Gly908Arg and the frameshift mutation Leu100fsinsC in the NOD2/ CARD15 gene. All three assays can be run simultaneously on one LightCycler using identical cycling parameters. Analysis of 53 DNAs from Crohn's patients helped to identify carriers at allele frequencies similar to other Caucasian populations. The sequencing of such DNAs confirmed the accuracy of the assays. In conclusion, we present three rapid and robust assays to detect the Arg702Trp, the Gly908Arg and the Leu1007fsinsC ins mutations in the NOD2/CARD15 gene [corrected] 相似文献
43.
44.
Dr. Heinrich Dickel Otto Blome Karl-Heinz Hagemann Hans Joachim Schwanitz Oliver Kuss Swen Malte John 《Trauma und Berufskrankheit》2003,5(1):109-118
The dermatologist's procedure was introduced in 1972 by employers' liability insurance funds in the industrial, agricultural and public sectors of Germany's statutory occupational accident insurance as a "procedure for early detection of occupational skin diseases". So far, it is still the most relevant tool for secondary prevention in occupational dermatology in Germany. According to the intention of this procedure, insured persons with a skin disease in which an occupational aetiology is suspected must be offered preventive measures and, if necessary, given appropriate treatment to avoid their losing their jobs. On the initiative of the Central Federation of Industrial Professional Associations (HVBG), a study group was set up in 1999 from among its membership in cooperation with the Working Committee of Occupational and Environmental Dermatology (ABD) and the Professional Organisation of German Dermatologists (BVDD) to improve on the efficiency of the "classic" dermatologist's procedure. The proposed "optimised" dermatologist's procedure is based on the assumption that early detection followed by competent and intensified skin protection and skin care will be successful in retarding or stopping the progression of occupational dermatoses, while later treatment is likely to be less effective. In October 2002, a pilot study started in Northwest Germany to establish by scientific evaluation whether the implementation of secondary protective measures is definitively better when the provisional "optimised" dermatologist's procedure is followed. The study results should allow detailed suggestions for an improved dermatologist's procedure before it is introduced nationwide. 相似文献
45.
Antigenic structure of the hexacosapeptide melittin: evidence for three determinants, one with a helical conformation. 总被引:2,自引:0,他引:2 下载免费PDF全文
ELISA-based epitope analysis was performed using rabbit polyclonal antisera against melittin. Antigenic sites were found at the C-terminus, in the middle section and within the N-terminal helix. Antibodies against the helical segment could discriminate between two faces of the amphiphilic helix. The antigenic sites include the bulk of the melittin hexacosapeptide, which is synonymous with a very high epitope density. 相似文献
46.
Invasive pulmonary aspergillosis is characterized by radiological signs allowing a correct diagnosis, including differentiation from pulmonary candidiasis, when they are associated with appropriate clinical symptoms (neutropenia and fever persisting despite broad-spectrum antibiotics). In particular the formation of a pulmonary mycetoma in a previously normal lung is one of these signs. Unlike a simple fungus ball (the saprophytic form of aspergillosis), the rounded density of invasive pulmonary aspergillosis consists of sequestrum of devitalized lung tissue owing to blood vessel invasion by Aspergillus hyphae. This morphologic phenomenon is demonstrated in the present case report and is discussed together with the other roentgenological signs of the invasive aspergillosis. 相似文献
47.
Prenatal nicotine exposure selectively affects perinatal forebrain aromatase activity and fetal adrenal function in male rats. 总被引:2,自引:0,他引:2
N I von Ziegler M Schlumpf W Lichtensteiger 《Brain research. Developmental brain research》1991,62(1):23-31
Previous studies have revealed effects of prenatal nicotine treatment on fetal plasma testosterone and perinatal sexual brain differentiation in the rat. In an attempt to further elucidate the processes underlying this action of nicotine, we studied the effect of the drug on brain steroid aromatase which converts androgens to estrogens and is known to be important in sexual brain differentiation. Aromatase activity (AA) was measured by the conversion of [1 beta-3H]-androstenedione to estrone in a brain region comprising preoptic, hypothalamic and amygdaloid areas. In untreated animals, the development of AA between gestational day (GD) 18 and postnatal day (PN) 15 was similar in both sexes, except for a significant drop of AA in female brain at PN6, i.e., during the later part of the critical period for sexual brain differentiation. When time-pregnant rats were treated with nicotine delivered by an osmotic minipump for either one week (2 mg/kg/d or 6 mg/kg/d from GD12) or two weeks (6 mg/kg/d from GD8), their male offspring showed a decrease of AA to female levels at PN6, the sex difference existing at this stage thus being abolished. AA of offspring from dams bearing tartaric acid-containing minipumps or sham-operated at GD8 or GD12 was identical to that of untreated controls. No drug effect was seen in female fetuses and offspring. Sex differences in the developmental effect of nicotine may thus involve brain aromatase. An additional sex-dependent effect of nicotine was observed in the male fetal adrenal axis at GD18. Whether the drug effects on the two steroid hormone systems are interrelated, remains to be elucidated. 相似文献
48.
J. J. E. Vos J. G. Huisman P. W. Modderman A. E. G. Kr. von dem Borne 《British journal of haematology》1987,65(4):447-450
A radioimmunoassay (RIA) for the detection of platelets and platelet fragments was developed. A sandwich of two monoclonal antibodies directed against the platelet-specific glycoprotein complex IIb-IIIa (GP IIb-IIIa) was used in this assay. A discontinuous 7.5-20% (v/v) albumin gradient was applied to separate platelets and their fragments of various sizes. In platelet suspensions fractionated in this way, we observed that particles smaller than normal platelets still carried the GP IIb-IIIa antigens. This procedure enabled us to detect platelet-derived particles in platelet-rich plasma from thrombocytopenic patients. 相似文献
49.
E M Grischke H Anton W Stolz D von Fournier G Bastert 《Acta obstetricia et gynecologica Scandinavica》1991,70(3):225-229
We compared urodynamic findings and results of lateral urethrocystography in 84 case. The aim of the study was to establish a possible correlation between anatomic findings and functional results. Clinically, a significantly greater increase in the normal axis of urethral inclination was noted in patients with a urodynamic diagnosis of stress incontinence than in patients with urge incontinence or for normal urodynamic findings. Lateral urethrocystography vis-à-vis urodynamic assessment proved to be a method having high sensitivity (91%) but low specificity. These two methods supply different but complementary data. Together with the patients' medical history, the assessment of their complaints, clinical vaginal examination, and clinical stress test, they offer valuable information for an efficient therapeutic concept. 相似文献
50.
Sonja A Kotz Stefan Frisch D Yves von Cramon Angela D Friederici 《Journal of the International Neuropsychological Society》2003,9(7):1053-1060
The role of the basal ganglia in syntactic language processing was investigated with event-related brain potentials in fourteen neurologically impaired patients. Seven of these patients had basal ganglia lesions while 7 other patients primarily had lesions of the left temporo-parietal region excluding the basal ganglia. All patients listened to sentences that were either correct or included a verb argument structure violation. In previous experiments this type of violation elicited a biphasic pattern of an N400-P600 complex in young healthy participants. While the N400 may result from incorrect semantic-thematic role assignment, the P600 reflects the fact that verb information does not license the syntactic structure at present. Results of the patient experiment revealed a double dissociation: patients with left temporo-parietal lesions only show a P600, whereas patients with lesions of the basal ganglia showed no P600, but a negativity with extended duration that resembled an N400. The latter pattern not only confirms previous reports that the basal ganglia modulate the P600 but extends these results by showing that the N400 as a late semantic-thematic integration process appears partially modulated by the basal ganglia. 相似文献