全文获取类型
收费全文 | 1362726篇 |
免费 | 96131篇 |
国内免费 | 1900篇 |
专业分类
耳鼻咽喉 | 18985篇 |
儿科学 | 39130篇 |
妇产科学 | 34989篇 |
基础医学 | 203812篇 |
口腔科学 | 40693篇 |
临床医学 | 118461篇 |
内科学 | 260451篇 |
皮肤病学 | 29763篇 |
神经病学 | 102289篇 |
特种医学 | 52313篇 |
外国民族医学 | 142篇 |
外科学 | 216740篇 |
综合类 | 25600篇 |
现状与发展 | 1篇 |
一般理论 | 345篇 |
预防医学 | 95650篇 |
眼科学 | 31954篇 |
药学 | 106441篇 |
3篇 | |
中国医学 | 3028篇 |
肿瘤学 | 79967篇 |
出版年
2018年 | 13114篇 |
2016年 | 11129篇 |
2015年 | 12601篇 |
2014年 | 17065篇 |
2013年 | 25630篇 |
2012年 | 34878篇 |
2011年 | 37165篇 |
2010年 | 21879篇 |
2009年 | 20876篇 |
2008年 | 36186篇 |
2007年 | 38213篇 |
2006年 | 39114篇 |
2005年 | 37644篇 |
2004年 | 36411篇 |
2003年 | 35010篇 |
2002年 | 34410篇 |
2001年 | 73557篇 |
2000年 | 76138篇 |
1999年 | 63203篇 |
1998年 | 15234篇 |
1997年 | 13363篇 |
1996年 | 13740篇 |
1995年 | 12792篇 |
1994年 | 11865篇 |
1993年 | 11021篇 |
1992年 | 48156篇 |
1991年 | 47029篇 |
1990年 | 46040篇 |
1989年 | 44718篇 |
1988年 | 40957篇 |
1987年 | 40104篇 |
1986年 | 37500篇 |
1985年 | 35958篇 |
1984年 | 25881篇 |
1983年 | 22076篇 |
1982年 | 11713篇 |
1981年 | 10430篇 |
1979年 | 23858篇 |
1978年 | 16483篇 |
1977年 | 14075篇 |
1976年 | 12803篇 |
1975年 | 14290篇 |
1974年 | 17238篇 |
1973年 | 16198篇 |
1972年 | 15559篇 |
1971年 | 14829篇 |
1970年 | 13966篇 |
1969年 | 13191篇 |
1968年 | 12140篇 |
1967年 | 11002篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
A study of the relationship between the fever caused by bacterial pyrogens and the fever accompanying acute infections 总被引:8,自引:8,他引:0
BENNETT IL 《The Journal of experimental medicine》1948,88(3):267-278
The relationship between the fever of acute infection and that following injection of bacterial pyrogen was studied by administering pyrogens to animals convalescent from acute infections. Rabbits surviving dermal pneumococcal infections or peritonitis due to Escherichia coli were given intravenous injections of typhoid or E. coli vaccine. They showed no evidence of tolerance to the fever-promoting effect of these pyrogenic materials. Tolerance did develop in infected animals given daily pyrogen injections during the course of the infection. Certain previous observations upon the ability of rabbits to develop tolerance to pyrogens, the broad nature of the tolerance, and its duration were confirmed. It is concluded that the pyrogen produced by certain bacteria plays little or no r?le in the production of the fever of infection. These findings are compatible with the hypothesis that there is a common factor, perhaps a product of cell injury, underlying the fever accompanying diseases of various types. 相似文献
992.
993.
994.
995.
Background
Cerebral arterial gas embolism is a potentially life-threatening event. Intraarterial air can occlude blood flow directly or cause thrombosis. Sclerotherapy is an extremely rare cause of cerebral arterial gas embolism. 相似文献996.
997.
C. Oprea P.J. Szalanski M.V. Gustova I.A. Oprea V. Buzguta 《Applied radiation and isotopes》2009,67(12):2142-2145
R-mode factor analysis was applied to characterize the chemical composition of human teeth investigated by particle induced X-ray emission (PIXE), Rutherford backscattering spectrometry (RBS) and X-ray fluorescence (XRF) techniques. The approach developed in this study enabled the separation between essential mineral teeth components and the pollutants deposited in teeth tissues during the human life. The three independent sources of metals incorporated in human teeth were found. The first source, representing about 43% of the variance of the concentration data, was characterized by pollutant elements of power industry emissions. The second factor was loaded with toxic elements of general urban pollution. The third factor represented the tooth source as it contained mainly large fractions of the mineral components of the tooth tissue as Ca and K. 相似文献
998.
999.
L.J. Mackintosh† M.N.C. de Koning‡ W.G.V. Quint‡ J. ter Schegget‡ I.M. Morgan R.M. Herd† M.S. Campo 《The British journal of dermatology》2009,161(1):56-62
Background Nonmelanoma skin cancer (NMSC) has been linked to cutaneous human papillomaviruses of the genus beta (betaPV).
Objectives We sought to assess the presence of betaPV in NMSC biopsies from a group of Scottish skin cancer patients, both immunocompetent (IC) patients and immunosuppressed (IS) organ transplant recipients.
Methods One hundred and twenty-one paraffin-embedded skin tumours (27 actinic keratosis, 41 intraepidermal carcinoma, 53 squamous cell carcinoma) and 11 normal skin samples were analysed for the presence of betaPV by a polymerase chain reaction–reverse hybridization assay designed to detect the presence of the 25 known betaPV genotypes.
Results In IC patients, betaPV was detected in 30 of 59 (51%) tumours and two of 11 (18%) normal skin samples ( P = 0·046). In IS patients, betaPV was found in 27 of 62 (44%) tumours; no normal skin samples were available for comparison. The most frequently found genotypes were HPV-24, HPV-15 and HPV-38. Of those tumours infected with betaPV, 28 of 57 (49%) were infected with more than one genotype (range 2–8). Tumours from IS patients were from a younger age group (mean age 57·4 years) than IC patients (mean age 73·8 years). Multiple infections were more common in tumours from IC patients (21 of 30; 70%) compared with those from IS patients (seven of 27; 26%) ( P < 0·001). In the IC group, age did not appear to influence the distribution of single and multiple infections whereas in IS patients the proportion of multiple infections to single infections increased with age. There were no multiple infections in normal skin.
Conclusions A wide spectrum of betaPV types was detected in our samples. Further characterization of betaPV in vivo is needed in order to determine the mechanisms by which the virus contributes to cutaneous carcinogenesis. 相似文献
Objectives We sought to assess the presence of betaPV in NMSC biopsies from a group of Scottish skin cancer patients, both immunocompetent (IC) patients and immunosuppressed (IS) organ transplant recipients.
Methods One hundred and twenty-one paraffin-embedded skin tumours (27 actinic keratosis, 41 intraepidermal carcinoma, 53 squamous cell carcinoma) and 11 normal skin samples were analysed for the presence of betaPV by a polymerase chain reaction–reverse hybridization assay designed to detect the presence of the 25 known betaPV genotypes.
Results In IC patients, betaPV was detected in 30 of 59 (51%) tumours and two of 11 (18%) normal skin samples ( P = 0·046). In IS patients, betaPV was found in 27 of 62 (44%) tumours; no normal skin samples were available for comparison. The most frequently found genotypes were HPV-24, HPV-15 and HPV-38. Of those tumours infected with betaPV, 28 of 57 (49%) were infected with more than one genotype (range 2–8). Tumours from IS patients were from a younger age group (mean age 57·4 years) than IC patients (mean age 73·8 years). Multiple infections were more common in tumours from IC patients (21 of 30; 70%) compared with those from IS patients (seven of 27; 26%) ( P < 0·001). In the IC group, age did not appear to influence the distribution of single and multiple infections whereas in IS patients the proportion of multiple infections to single infections increased with age. There were no multiple infections in normal skin.
Conclusions A wide spectrum of betaPV types was detected in our samples. Further characterization of betaPV in vivo is needed in order to determine the mechanisms by which the virus contributes to cutaneous carcinogenesis. 相似文献
1000.
Capello E. Vuolo L. Gualandi F. Van Lint M. T. Roccatagliata L. Bonzano L. Pardini M. Uccelli A. Mancardi Gianluigi 《Neurological sciences》2009,30(2):175-175
Autologous haematopoietic stem-cell transplantation has been evaluated over the last years as a possible new therapeutic strategy in severe forms of multiple sclerosis unresponsive to the approved therapies. Up to now, more than 400 patients have been treated and numerous are the phase I and phase II studies which addressed the feasibility of this treatment, the efficacy, side effects and transplant-related mortality. The clinical response is strongly related to the intensity of the conditioning regimen utilized as well as to the phase of the disease course in which the therapy is carried out. Rapidly evolving multiple sclerosis with a relapsing–remitting clinical course and MRI signs of activity are the cases that can take more advantage. The risk of mortality, which dropped in the last years to 2–3%, is still the main problem of this powerful therapy. 相似文献