全文获取类型
收费全文 | 8053篇 |
免费 | 482篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 135篇 |
儿科学 | 270篇 |
妇产科学 | 173篇 |
基础医学 | 1061篇 |
口腔科学 | 248篇 |
临床医学 | 620篇 |
内科学 | 2154篇 |
皮肤病学 | 104篇 |
神经病学 | 928篇 |
特种医学 | 327篇 |
外科学 | 1054篇 |
综合类 | 33篇 |
一般理论 | 8篇 |
预防医学 | 449篇 |
眼科学 | 150篇 |
药学 | 407篇 |
中国医学 | 14篇 |
肿瘤学 | 440篇 |
出版年
2024年 | 11篇 |
2023年 | 72篇 |
2022年 | 220篇 |
2021年 | 368篇 |
2020年 | 212篇 |
2019年 | 285篇 |
2018年 | 335篇 |
2017年 | 236篇 |
2016年 | 232篇 |
2015年 | 288篇 |
2014年 | 362篇 |
2013年 | 418篇 |
2012年 | 661篇 |
2011年 | 670篇 |
2010年 | 359篇 |
2009年 | 296篇 |
2008年 | 531篇 |
2007年 | 471篇 |
2006年 | 398篇 |
2005年 | 441篇 |
2004年 | 395篇 |
2003年 | 295篇 |
2002年 | 264篇 |
2001年 | 75篇 |
2000年 | 80篇 |
1999年 | 70篇 |
1998年 | 56篇 |
1997年 | 50篇 |
1996年 | 34篇 |
1995年 | 31篇 |
1994年 | 30篇 |
1993年 | 25篇 |
1992年 | 32篇 |
1991年 | 34篇 |
1990年 | 21篇 |
1989年 | 29篇 |
1988年 | 30篇 |
1987年 | 23篇 |
1986年 | 22篇 |
1985年 | 21篇 |
1984年 | 8篇 |
1983年 | 11篇 |
1982年 | 10篇 |
1981年 | 11篇 |
1980年 | 6篇 |
1978年 | 4篇 |
1971年 | 5篇 |
1969年 | 5篇 |
1968年 | 4篇 |
1967年 | 3篇 |
排序方式: 共有8575条查询结果,搜索用时 0 毫秒
21.
Low serum haemolytic function of the fourth complement component (C4) in insulin dependent diabetes. 下载免费PDF全文
G Senaldi B A Millward M J Hussain D A Pyke R D Leslie D Vergani 《Journal of clinical pathology》1988,41(10):1114-1116
Low serum concentrations of the fourth component of complement (C4) are found in insulin dependent diabetes, and may be important in the aetiology of the disease. To ascertain whether function of C4 is also impaired both its haemolytic activity and its concentration were measured in 34 insulin dependent diabetics, 15 non-insulin dependent diabetics, 20 healthy subjects, and 12 pairs of monozygotic twins discordant for insulin dependent diabetes. C4 function was measured by a radial immune haemolytic assay, and C4 concentration by laser nephelometry. Both measurements were significantly lower in insulin dependent diabetics (C4 function: median 47%, range 4-100%; C4 concentration: 0.22 g/l, 0.10-0.38 g/l) than in non-insulin dependent diabetics (67%, 33-138%, p less than 0.01; 0.27 g/l, 0.16-0.50 g/l, p less than 0.02) and controls (74%, 33-138%, p less than 0.01; 0.27 g/l, 0.18-0.40 g/l, p less than 0.03). C4 function and concentration were lower in both diabetic (48%, 12-100%; 0.17 g/l, 0.08-0.31 g/l) and non-diabetic twins (47%, 12-100%; 0.17 g/l, 0.07-0.36 g/l) than controls (p less than 0.01; p less than 0.01). Thirteen (38%) of the insulin dependent diabetics had a reduction in either C4 function or concentration, but in only five were both features reduced. Values of function and concentration were strongly correlated in both diabetic and non-diabetic twins (r = 0.95, p less than 0.001; r = 0.92, p less than 0.001). These results show defects in C4 function and concentration in insulin dependent diabetes, which--being present in the non-diabetic co-twin of diabetics--may represent a genetic predisposition to the disease. 相似文献
22.
23.
24.
Cortés-Gutiérrez EI Cerda-Flores RM González-Ramírez D Zúñiga-Charles MA Lazcano-Martínez S Sampayo-Reyes A Leal-Garza CH 《Mutagenesis》2004,19(3):203-205
The aims of this study were to evaluate the mutagenic and cytotoxic activity of mercurous chloride by the micronucleus technique in vivo on the bone marrow of golden Syrian hamsters after a single i.p. drug administration. Forty male golden Syrian hamsters were classified into eight groups: negative control, positive control and six groups treated with different doses of mercurous chloride (1.25, 2.5, 5, 10, 20 and 40 mg/kg). The negative control was injected with physiological saline i.p. and the positive control with cyclophosphamide at a dose of 80 mg/kg i.p. With respect to mutagenic effect, the average number of micronucleated polychromatic erythrocytes (MPE) in hamsters treated with different doses of mercurous chloride was not significant compared with the negative control. With respect to cytotoxic effect, the average polychromatic erythrocyte/red blood cell ratio showed a significant decrease when the doses were higher than the 2.5 mg/kg dose compared with the negative control. In conclusion, this preliminary study shows a cytotoxic effect but not a mutagenic effect of calomel in vivo at one time point (24 h). 相似文献
25.
Functional characterization of peripheral blood lymphocytes in chronic HBsAg carriers 总被引:3,自引:3,他引:3
G J Alexander M Mondelli N V Naumov K T Nouriaria D Vergani D Lowe A L Eddleston R Williams 《Clinical and experimental immunology》1986,63(3):498-507
Increased proportions of suppressor/cytotoxic T cells have been identified in the peripheral blood of chronic HBsAg carriers and to investigate a possible relationship to T cell cytotoxicity against autologous hepatocytes, suppressor cell activity, viral replication and the histological type of disease, 42 consecutive HBsAg carriers undergoing a liver biopsy have been investigated. The proportion of suppressor/cytotoxic lymphocytes directly correlated with T cell cytotoxicity to autologous hepatocytes and both were higher in those with HBeAg in serum than in those with anti-HBe or those on corticosteroid therapy. There was no relationship to underlying histological classification. In contrast, suppressor cell regulation of IgG producing cells was unrelated to the proportion of suppressor/cytotoxic lymphocytes in peripheral blood or HBeAg status, but impaired function was associated with chronic hepatitis, particularly chronic active hepatitis. These data suggest that the increased proportion of suppressor/cytotoxic lymphocytes in the peripheral blood of HBsAg carriers represents an increase in the cytotoxic and not the suppressor cell subset and that this is a consequence of active viral replication and not of the severity of hepatic inflammation. Defective suppressor cell function may be one factor in the development of chronic active hepatitis, but is not reflected by alterations in the T4:T8 ratio. 相似文献
26.
Maria-Cristina Cuturi Rgis Josien Diego Cantarovich Laurence Bugeon Ignacio Anegon Sverine Menoret Helga Smit Patrice Douillard Jean-Paul Soulillou 《European journal of immunology》1994,24(7):1627-1631
Permanent tolerance to allografts can be induced in adult rats by donor-specific transfusions (DST) prior to transplantation. We have previously reported, in a model of heart allograft, the presence of a heavy leukocyte infiltrate, in the allograft which displayed a strong allospecific cytotoxicity when tested in vitro against donor cells, and a strong accumulation of mRNA for granzyme A and perforin in vivo. In contrast, there was a major decrease in the accumulation of mRNA for interleukin-2 and interferon-γ. These results suggested that the DST-induced tolerance was associated with a decrease in type-1 T helper (Th1) cell function. The major role of preformed antibodies in xeno and allorejection is clearly established. Nevertheless, the consequences of alloantibody production in acute rejection and tolerance induction remains to be elucidated. We here analyze the alloantibody response in rejecting and DST-treated recipients. We show that, after transplantation, tolerant recipients, in contrast to rejecting ones, mount a low IgM alloresponse that switches to low IgG production. Detailed analysis of IgG alloantibodies in DST-treated recipients revealed that their production decrease was not equally distributed. Whereas rejecting animals mounted a strong anti-class I and II IgG alloantibody response, DST-treated recipients produced anti-class II and low titers of anti-class I IgG alloantibodies. Furthermore, among IgG subclasses, tolerant recipients predominantly produced IgG2a, a profile which, in the rat, is compatible with a Th2-controlled response. Finally, the passive transfer of immune serum from rejecting animals to DST-treated recipients could abrogate the tolerance. We suggest that the absence of anti-class I alloantibodies combined with preserved and/or increased anti-class II production plays a major role in graft tolerance in this model. These results reinforced the role of alloantibodies in rejection and in induction of tolerance. 相似文献
27.
Immune changes associated with insulin dependent diabetes may remit without causing the disease: a study in identical twins 总被引:3,自引:0,他引:3
B A Millward L Alviggi P J Hoskins C Johnston D Heaton G F Bottazzo D Vergani R D Leslie D A Pyke 《British medical journal (Clinical research ed.)》1986,292(6523):793-796
Activation of T lymphocytes and islet cell antibodies were studied in two groups of insulin dependent diabetics and their non-diabetic identical cotwins. Group 1 comprised 12 "short term" twin pairs (diabetic twin diagnosed less than five years previously) in whom only a third of the cotwins were likely to develop diabetes; 10 of the 12 non-diabetic cotwins showed increased values of activated T lymphocytes, islet cell antibodies, or both. Group 2 comprised 10 "long term" twin pairs (diabetic twin diagnosed more than 11 years previously) in whom none of the non-diabetic cotwins was likely to develop diabetes; these pairs were selected because all the non-diabetic cotwins had shown islet cell antibodies at some time in the past, but only two still did so (one with an increased value of activated T cells). There was relative glucose intolerance in the cotwins of the short term group but not in those of the long term group. Non-diabetic cotwins of diabetics may show the immune changes associated with insulin dependent diabetes and relative glucose intolerance, but these changes may remit without leading to diabetes. 相似文献
28.
Kundu Abhishake Feijoo Felipe Martinez Diego A. Hermosilla Manuel Matis Timothy 《Health care management science》2022,25(1):89-99
Health Care Management Science - Proactive and objective regulatory risk management of ongoing clinical trials is limited, especially when it involves the safety of the trial. We seek to... 相似文献
30.
Costa Davidson Ribeiro Pessoa Diego Rodrigues Seefeldt Vanessa Borelli Costa David Ribeiro Maia Daniel Tineu Leite dos Santos Maciel Thiago Mota Brenda Barros Magalhães Delpasso Carolina Alves Ribeiro Camila Alves Delpasso Nicolau Renata Amadei 《Lasers in medical science》2021,36(8):1681-1689
Lasers in Medical Science - This study compared the effects of LED therapy associated with occlusal splint (OS) on the signs and symptoms of temporomandibular disorder (TMD). In this randomized,... 相似文献