全文获取类型
收费全文 | 248477篇 |
免费 | 13005篇 |
国内免费 | 6905篇 |
专业分类
耳鼻咽喉 | 2998篇 |
儿科学 | 8415篇 |
妇产科学 | 3062篇 |
基础医学 | 18573篇 |
口腔科学 | 5226篇 |
临床医学 | 29258篇 |
内科学 | 40409篇 |
皮肤病学 | 3070篇 |
神经病学 | 11519篇 |
特种医学 | 13548篇 |
外国民族医学 | 23篇 |
外科学 | 43847篇 |
综合类 | 24943篇 |
现状与发展 | 25篇 |
预防医学 | 15655篇 |
眼科学 | 4842篇 |
药学 | 25492篇 |
120篇 | |
中国医学 | 5891篇 |
肿瘤学 | 11471篇 |
出版年
2023年 | 2224篇 |
2022年 | 5343篇 |
2021年 | 10992篇 |
2020年 | 6066篇 |
2019年 | 11744篇 |
2018年 | 6195篇 |
2017年 | 5661篇 |
2016年 | 7723篇 |
2015年 | 10570篇 |
2014年 | 19664篇 |
2013年 | 17240篇 |
2012年 | 20623篇 |
2011年 | 17660篇 |
2010年 | 16087篇 |
2009年 | 15565篇 |
2008年 | 14005篇 |
2007年 | 14052篇 |
2006年 | 12003篇 |
2005年 | 8264篇 |
2004年 | 4588篇 |
2003年 | 3831篇 |
2002年 | 3037篇 |
2001年 | 2495篇 |
2000年 | 2141篇 |
1999年 | 1432篇 |
1998年 | 1774篇 |
1997年 | 1623篇 |
1996年 | 1339篇 |
1995年 | 1335篇 |
1994年 | 1265篇 |
1993年 | 987篇 |
1992年 | 1185篇 |
1991年 | 1050篇 |
1990年 | 1094篇 |
1989年 | 1055篇 |
1988年 | 986篇 |
1987年 | 870篇 |
1986年 | 717篇 |
1985年 | 1646篇 |
1984年 | 1771篇 |
1983年 | 1293篇 |
1982年 | 1384篇 |
1981年 | 1358篇 |
1980年 | 1172篇 |
1979年 | 1009篇 |
1978年 | 775篇 |
1977年 | 777篇 |
1976年 | 670篇 |
1975年 | 437篇 |
1974年 | 460篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
991.
温州医学院胃癌研究课题组 《温州医学院学报》1992,22(3):132-135
报道温州地区胃癌高发区瑞安塘下的致癌危险因素的调查情况,结果表明它是由多种致癌危险因素的综合影响。作者应用内镜活检在18000例慢性胃病患者中查出癌前病变(高危人群)1132例,经3月~14年活检随访,表明胃癌前病变有一定的可逆转性;癌变率较高的是胃溃疡(GU)+不典型增生(ATP)组、GU+慢性萎缩性胃炎(CAG)组及CAG+ATP组均为4.1%;总癌变率为3.1%。早癌检出率占胃癌总数的48.6%,为门诊早癌检出率的6.8倍。此方法简单、经济实用。 相似文献
992.
Hubert A. Shaffer Jr. M.D. Donald A. Eckard Eduard E. de Lange M. R. Ramakrishnan 《Abdominal imaging》1988,13(1):221-223
Hypersensitivity reactions occurring during barium studies of the gastrointestinal tract are rare. A case is presented with radiographically demonstrated angioedema in the stomach and small bowel accompanied by allergic rhinitis, which was apparently an allergic response to the barium sulfate suspension. The reaction was documented twice during separate challenges to the barium suspension performed several months apart. 相似文献
993.
We evaluated retrospectively the varying radiographic appearances of 15 solitary lucent epiphyseal lesions occurring in children. Imaging modalities used included plain films, conventional tomography, nuclear scintigraphy, and computed tomography. Forty percent of the lesions (6) were due to osteomyelitis. The remaining lesions included tuberculosis (1), foreign body granuloma (1), chondroblastoma (2), chondromyxoid fibroma (1), enchondroma (1), osteoid osteoma (2), and eosinophilic granuloma (1). Although the radiographic appearances of such lesions may be particularly characteristic, pathologic correlation is frequently necessary. The high incidence of osteomyelitis in our cases emphasizes its importance as a cause for a lucent epiphyseal lesion. 相似文献
994.
Prediction of phenotype for acetylation and for debrisoquine hydroxylation by DNA-tests in healthy human volunteers 总被引:5,自引:0,他引:5
T. Graf F. Broly F. Hoffmann M. Probst U. A. Meyer PD Dr. H. Howald 《European journal of clinical pharmacology》1992,43(4):399-403
Summary The debrisoquine/sparteine-type polymorphism of drug oxidation and the polymorphism for acetylation are two common inherited variations in human drug metabolism. The phenotypes for hydroxylation and acetylation can be predicted be newly developed methods based on mutation-specific amplification of DNA by the polymerase chain reaction (PCR), which also allow for identification of heterozygous carriers of one mutant allele.In the present study, the results of genotyping of 81 healthy European volunteers were compared with the phenotype obtained by the classical biochemical approach using debrisoquine and caffeine as probe drugs.Genotyping correctly predicted all 73 extensive metabolisers (EMs) and 6 out of 8 poor metabolisers (PMs) of debrisoquine. All 48 rapid acetylators and 33 of 35 slow acetylators were predicted.Overall, the DNA analysis result matched the in vivo phenotype in 97.5 % of individuals. 相似文献
995.
P. M. Bourgouin D. Tampieri W. Johnston J. Steward D. Melançon R. Ethier 《Neuroradiology》1992,34(2):110-111
Summary We report a patient with multiple angiographically occult vascular malformations in the brain and spine. Magnetic resonance imaging showed multiple lesions in brain and spine with hypointense areas on both T1 and T2-weighted images. These hypointense areas are usually secondary to hemosiderin deposits consistent with remote bleeding in the lesions. We conclude that when magnetic resonance reveals an intraspinal lesion with signal intensity characteristics consistent with a vascular malformation, an examination of the brain should be performed to rule out associated intracranial lesions. The finding of multiple lesions in the brain with identical signal intensity characteristics reinforces the diagnosis of vascular malformation. 相似文献
996.
A model was developed which estimates the costs of osteoporosis risk evaluation and treatment, and the resulting savings in terms of reduced fracture frequency, for the adult female population of the United States. In the absence of treatment, the model predicts 1.44 million fractures will occur annually from non-violent causes. Treatment of all women beginning at age 50 with an agent that slows bone loss by 50% would reduce the number of these fractures by 0.59 million. Selective treatment of the 47% of women at the greatest fracture risk would reduce the number of fractures by 0.45 million, but would only cost 47% as much as treating all women. Additional data are required before the model can be used to evaluate specific treatment regimens. However, it appears that selective treatment of those at highest risk would yield the greatest benefit to cost ratio, if only benefits related to reduced fracture frequency are considered. 相似文献
997.
In human cortex and hippocampus area, [3H]5-HT (5 nM) labels 5-HT1A, 5-HT1D and 5-HT1E sites. After masking 5-HT1A receptors by 0.1 μM 8-OH-DPAT, the binding displaced by 0.1 μM 5-CT presumably represented 5-HT1D sites and the remaining binding 5-HT1E sites. In frontal cortex, 5-HT1A receptors represented the main binding in layers II and VI and a lower fraction on other layers. 5-HT1D and 5-HT1E sites, were more homogeneously distributed in layers II to VI (21–34% of specific [3H]5-HT binding). 5-HT1E sites were of similar affinities (KD close to 6–8 nM) in the cortical layers II to VI. In CA1 field of hippocampus, (pyramidal layer, stratum radiatum, molecular layer), CA2 and dentate gyrus, 5-HT1A receptors represented the major fraction, 5-HT1D sites a significant fraction and 5-HT1E a minor fraction of the specific [3H]5-HT binding. In CA3–CA4 fields, 5-HT1A receptors were less densely present, 5-HT1D sites were predominant and 5-HT1E sites represented a significant fraction (27%). The highest densities of 5-HT1E sites have been measured in subiculum, where 5-HT1A, 5-HT1D, and 5-HT1E binding sites were equally represented and in entorhinal cortex where 5-HT1E sites represented the major binding in layer III. They were also present in layers II and IV (29 and 24%) and, to a lesser extent, in layers V and VI. 5-HT1A sites were predominant in layer VI, II and V and were less abundant in other layers. 5-HT1D were homogeneously present in layers II, III, IV and were present in low amounts in other layers. No 5-HT1E were detected in choroid plexus, where [3H]5-HT was dramatically reduced by mesulergine (5-HT2C receptors). No significant displacement of [3H]5-HT by mesulergine was measured in other structures. 相似文献
998.
A review is presented about fagaronine, a benzophenanthridine alkaloid responsible for antitumoural activity. Plant source, extraction, biosynthesis, medicinal properties, especially antileukaemic activity, are described. 相似文献
999.
Monitoring of skin response to sodium lauryl sulphate: clinical scores versus bioengineering methods
The present trial was designed to evaluate clinical scores (single observer) of sodium lauryl sulphate (SLS)-induced skin irritation in a group of subjects (n = 10) over a 10-day period along with various skin function parameters. In order to avoid significant variations due to secondary phenomena, the following parameters were recorded with non-invasive instruments in this order: skin capacitance (C1; arbitrary units; CM420 Corneometer), transepidermal water loss (TEWL; g/m2.h; Evaporimeter) and laser Doppler flowmetry (CBFV: cutaneous blood flow values; Periflux). All examinations were performed during winter on reclined relaxed subjects present for at least 10 min in a test room with controlled temperature and relative humidity (t degrees: 19.5-20.7 degrees C and RH: 47.3-60.3%). The analysis of differential data (delta = value at tx-value before test; 2-way ANOVA) was made on single parameters as a function of site (volar forearm versus neck) and time (from 24 h after 48-h occlusion with 5% SLS up to 10 days later). The profile of erythema scores over time differed between neck and forearm, but the delta CBFV readings with the laser Doppler instrument did not detect significant site-time interactions. Roughness (blind evaluation with palpating finger) and capacitance readings (delta C1) showed significant differences between sites, but the profile over time was similar in both locations. delta TEWL did not differ according to anatomical location. The reason for different erythema scores on neck and forearm might be related to inherent regional variation of optical properties of the skin or to a substantial contribution of SLS-induced roughness to the readings of erythema.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
1000.
交锁髓内钉在股骨、胫骨干骺端骨折中的应用 总被引:6,自引:0,他引:6
目的 探讨交锁髓内钉在股骨,胫骨干骺端骨折中的应用。方法 回顾性分析1999年5月-2001年7月行股骨,胫骨干骺端骨折交锁髓内钉固定术的患者18例,8例股骨骨折中,骨折线位于小转子以上2例,股骨髁面4-6cm以内6例,其中累及膝关节2例。交通伤15例,坠落伤2例,摔伤1例。根据临床疗效综合评价该手术方式的可能性。结果 术后无一例发生伤口感染,骨不连,关节功能障碍等并发症,随访6-24个月,平均18个月,股骨近,远端骨折,胫骨远端骨折平均愈合时间分别为12周,13周,14周,16周,所有骨折均愈合,术后6个月均弃拐行走,评价按Johner-Wruch标准;优良17例,1例畸形愈合,优良率为94%。结论 在股骨,胫骨干骺端骨折使用交锁髓内钉疗效满意,扩大了交锁髓内钉的适应证。 相似文献