全文获取类型
收费全文 | 7124篇 |
免费 | 386篇 |
国内免费 | 62篇 |
专业分类
耳鼻咽喉 | 75篇 |
儿科学 | 178篇 |
妇产科学 | 253篇 |
基础医学 | 954篇 |
口腔科学 | 200篇 |
临床医学 | 961篇 |
内科学 | 1213篇 |
皮肤病学 | 161篇 |
神经病学 | 490篇 |
特种医学 | 288篇 |
外科学 | 901篇 |
综合类 | 139篇 |
一般理论 | 2篇 |
预防医学 | 682篇 |
眼科学 | 122篇 |
药学 | 568篇 |
中国医学 | 65篇 |
肿瘤学 | 320篇 |
出版年
2023年 | 43篇 |
2022年 | 89篇 |
2021年 | 189篇 |
2020年 | 99篇 |
2019年 | 171篇 |
2018年 | 214篇 |
2017年 | 146篇 |
2016年 | 134篇 |
2015年 | 200篇 |
2014年 | 225篇 |
2013年 | 308篇 |
2012年 | 473篇 |
2011年 | 495篇 |
2010年 | 272篇 |
2009年 | 216篇 |
2008年 | 357篇 |
2007年 | 373篇 |
2006年 | 327篇 |
2005年 | 296篇 |
2004年 | 325篇 |
2003年 | 248篇 |
2002年 | 264篇 |
2001年 | 211篇 |
2000年 | 236篇 |
1999年 | 189篇 |
1998年 | 137篇 |
1997年 | 117篇 |
1996年 | 109篇 |
1995年 | 88篇 |
1994年 | 68篇 |
1993年 | 80篇 |
1992年 | 90篇 |
1991年 | 79篇 |
1990年 | 86篇 |
1989年 | 81篇 |
1988年 | 78篇 |
1987年 | 53篇 |
1986年 | 53篇 |
1985年 | 45篇 |
1984年 | 33篇 |
1983年 | 32篇 |
1982年 | 24篇 |
1981年 | 18篇 |
1979年 | 20篇 |
1978年 | 22篇 |
1977年 | 15篇 |
1976年 | 17篇 |
1974年 | 18篇 |
1972年 | 13篇 |
1971年 | 13篇 |
排序方式: 共有7572条查询结果,搜索用时 0 毫秒
21.
Bladder cancer is one of the malignancies encountered frequently in urological practice. Since the three main treatment modalities
(surgery, chemotherapy and radiotherapy) may be used alone or together, there are many treatment options. In this paper the
current approaches in the treatment of bladder tumours are reviewed and the policy in Marmara University Hospital is described. 相似文献
22.
Association of HLA-DQA1*03011-DQB1*0301 haplotype with the development of respiratory scleroma. 总被引:1,自引:0,他引:1
Luis Alberto Sánchez-Marín Daniel Bross-Soriano José Arrieta Simón Kawa-Karasik Víctor Martínez-Vilchis Rocío Jiménez-Lucio Angélica Olivo-Díaz 《Otolaryngology--head and neck surgery》2007,136(3):481-483
OBJECTIVE: Respiratory scleroma (RS) is a progressive, chronic, granulomatous disease caused by Klebsiella rhinoscleromatis. There is only one report of RS association with HLA-DQ3. In this study, molecular association of HLA class II and RS was determined. STUDY DESIGN AND SETTING: Nine RS patients and 163 healthy controls were compared. DQA1, DQB1, and DRB1 loci were typed. RESULTS: Statistical analysis demonstrated association between DQB1*0301 and susceptibility to RS (P(c) = 0.004). Haplotype analysis showed an association of DQA1*03011-DQB1*0301 (P = 1.21E-19) and DRB1*0407-DQA1*03011-DQB1*0301 (P = 0.0002). CONCLUSIONS: Results established that DQA1*03011-DQB1*0301 haplotype is a strong risk factor for development of RS. 相似文献
23.
24.
In 260 asbestos-exposed individuals evaluated by means of computed tomography (CT), 43 unsuspected pulmonary masses were found in 27 individuals. The masses included fissural pleural plaques (n = 10), dense fibrotic bands (n = 3), round atelectasis (n = 11), carcinomas (n = 3), and other presumed benign masses (n = 16). The most helpful features in the diagnosis of rounded atelectasis with CT were (a) contiguity to areas of diffuse pleural thickening, (b) a lentiform or wedge-shaped outline, (c) evidence of volume loss in the adjacent lung, and (d) a characteristic "comet tail" of vessels and bronchi sweeping into the margins of the mass. Less advanced areas of focal atelectasis had fewer classic features. Intrafissural pleural plaques were readily identified with high-resolution CT. In asbestos-related masses, the demonstration of stability over time is necessary. Careful interpretation of CT and high-resolution CT features and close surveillance can obviate the need for biopsy in the majority of instances. 相似文献
25.
Angiotensin-(1–7) stimulates water transport in rat inner medullary collecting duct: evidence for involvement of vasopressin V2 receptors 总被引:1,自引:0,他引:1
Magaldi AJ Cesar KR de Araújo M Simões e Silva AC Santos RA 《Pflügers Archiv : European journal of physiology》2003,447(2):223-230
The peptide angiotensin-(1–7) [Ang-(1–7)] is known to enhance water transport in rat inner medullary collecting duct (IMCD). The aim of this study was to determine the mechanism of the Ang-(1–7) effect on osmotic water permeability (P
f). P
f was measured in the normal rat IMCD perfused in vitro in presence of agonists [Ang-(1–7), arginine vasopressin (AVP) and Ang-(3–8)], and antagonists of the angiotensin and the vasopressin cascade. Ang-(1–7), but not Ang-(3–8), increased P
f significantly. The effect of Ang-(1–7) on P
f was abolished by its selective antagonist, A-779, added before or after Ang-(1–7). Prostaglandin E2 and the protein kinase A inhibitor H8 also blocked the Ang-(1–7) effect. Blockade of vasopressin V1 receptors by antagonists did not change the Ang-(1–7) effect, but pre-treatment with a V2 antagonist abolished the effect of Ang-(1–7) on P
f. Similarly, pre-treatment with A-779 inhibited AVPs effect on P
f. Forskolin-stimulated P
f was blocked both by A-779 and by the V2 antagonist. Finally, Ang-(1–7) increased cAMP levels in fresh IMCD cell suspensions whilst the forskolin-stimulated cAMP synthesis was decreased by A-779 and the V2 antagonist. These data provide evidence that Ang-(1–7) interacts via its receptor with the AVP V2 system through a mechanism involving adenylate-cyclase activation. 相似文献
26.
Michelle K Williamson Jane Pirkis Jon J Pfaff Orla Tyson Moira Sim Ngaire Kerse Nicola T Lautenschlager Nigel P Stocks Osvaldo P Almeida 《BMC medical research methodology》2007,7(1):42
Background
Recruiting and retaining GPs for research can prove difficult, and may result in sub-optimal patient participation where GPs are required to recruit patients. Low participation rates may affect the validity of research. 相似文献27.
The presence of blocking factors in Brugia malayi microfilaraemic patients 总被引:1,自引:0,他引:1 下载免费PDF全文
Serum from microfilaraemic patients have been shown to be unable to promote the antibody-dependent, cell-mediated adherence reaction to infective larvae of Brugia malayi in vitro. In this study, it was found that peripheral leucocytes from microfilaraemic patients were also incapable of promoting the adherence reaction even when incubated with serum of tropical pulmonary eosinophilia (TPE) patients. The TPE sera would normally promote the most intense adherence reaction. It was further shown that preincubation of normal human peripheral leucocytes with sera of microfilaraemic patients would similarly render them incapable of adherence. Such preliminary studies suggest that blocking factors may be present in microfilaraemic patients. 相似文献
28.
Enrique Hilario Emilia Rodeño Josu Simón Francisco J. Alvarez Salvador F. Aliño 《Virchows Archiv : an international journal of pathology》1992,421(6):485-490
Summary The growth and vascularization patterns of B16 melanoma colonies in the liver and lungs were measured and compared by histological techniques and dye diffusion patterns after injection of the fluorochrome Hoechst 33342. In the liver, the fluorescent pattern of dye diffusion revealed that uninodular tumours measuring up to 146 n in diameter were not functionally vascularized. However, when the nodules fused to give rise to multinodular tumours measuring between 256 and 366 n in diameter, a reticular dye diffusion pattern revealed functional tumour vascularization. In the lungs, subpleural, parenchymal and peritubular (i.e. surrounding blood vessels and airways) tumours were observed. The two former classes were vascularized down to thicknesses and diameters of 49 and 24 m respectively. In contrast, dye diffusion was never seen in peritubular tumour cuffs up to 609 m in thickness. The results indicate differences in vascularization patterns in B16 tumours in the liver and lungs, and differences between tumours growing in different sites within the lungs. If these results are applicable to metastases in these two organs, they indicate potential diffusion-mediated resistance to chemotherapy, and potential hypoxia-mediated resistance to radiotherapy of both metastases and micrometastases. 相似文献
29.
New studies on the Macushi Indians of northern Brazil 总被引:2,自引:0,他引:2
F M Salzano H Mohrenweiser H Gershowitz J V Neel M A Mestriner A L Sim?es J Constans M J De Melo e Freitas 《Annals of human biology》1984,11(4):337-350
Demographic data and genetic information concerning 40 genetic systems are reported for three populations of Macushi Indians, and have been compared to those already obtained for three other communities of this tribe. These are young populations (mean age, 19 years), with a low sex ratio (90), low percentages of non-Indian ancestry (1-2%) and of marriages between locally born persons (34). Intertribal unions (14%) are less frequent than among their neighbours, the Wapishana. Fertility is high (average of 8.2 children per woman who completed reproduction), but the variance in family size and the frequency of premature deaths relatively low for populations at this cultural level. This conditions the lowest Index of Opportunity for Selection (0.45) calculated thus far among South American Indians. No variation was observed in 20 genetic systems, limited variation in 3, and larger variability in the remaining 17. In 13 of the 29 comparisons (45%), the Macushi gene frequencies present values in the middle third of the range observed among South American Indians. The previously reported private genetic polymorphism of esterase A was encountered in one of the three villages. A comparison of the genetic distances between villages with and without this polymorphism, and a similar comparison for the villages of the neighbouring Wapishana, yields no clue as to the tribe in which this polymorphism originated. 相似文献
30.
The t(X;1)(p11.2;q21.2) translocation in papillary renal cell carcinoma fuses a novel gene PRCC to the TFE3 transcription factor gene 总被引:4,自引:2,他引:4