全文获取类型
收费全文 | 698篇 |
免费 | 130篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 12篇 |
妇产科学 | 6篇 |
基础医学 | 61篇 |
口腔科学 | 11篇 |
临床医学 | 121篇 |
内科学 | 231篇 |
皮肤病学 | 1篇 |
神经病学 | 44篇 |
特种医学 | 194篇 |
外科学 | 61篇 |
综合类 | 19篇 |
预防医学 | 27篇 |
眼科学 | 4篇 |
药学 | 19篇 |
肿瘤学 | 20篇 |
出版年
2023年 | 11篇 |
2021年 | 8篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 27篇 |
2017年 | 10篇 |
2016年 | 17篇 |
2015年 | 18篇 |
2014年 | 39篇 |
2013年 | 45篇 |
2012年 | 8篇 |
2011年 | 21篇 |
2010年 | 34篇 |
2009年 | 47篇 |
2008年 | 26篇 |
2007年 | 20篇 |
2006年 | 20篇 |
2005年 | 12篇 |
2004年 | 18篇 |
2003年 | 6篇 |
2002年 | 14篇 |
2001年 | 16篇 |
2000年 | 20篇 |
1999年 | 12篇 |
1998年 | 23篇 |
1997年 | 29篇 |
1996年 | 16篇 |
1995年 | 16篇 |
1994年 | 10篇 |
1993年 | 17篇 |
1992年 | 11篇 |
1991年 | 7篇 |
1990年 | 10篇 |
1989年 | 29篇 |
1988年 | 21篇 |
1987年 | 29篇 |
1986年 | 17篇 |
1985年 | 21篇 |
1984年 | 10篇 |
1983年 | 11篇 |
1982年 | 10篇 |
1981年 | 11篇 |
1980年 | 10篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 9篇 |
1976年 | 8篇 |
1975年 | 4篇 |
1973年 | 4篇 |
1944年 | 11篇 |
排序方式: 共有833条查询结果,搜索用时 49 毫秒
51.
52.
ReSllm6 Objectif Nos studes Precedentes out montrd une panne fonCtion de la greffe pulmonaire traitde Prdalablementper perfusion forcde retrograde et un stockage d froid inns ~. L' etude Prdsente a pour but de determiner l' effet de ~ surlefiot mngUin du poumon trait4 Prdalablement per perfusion retrograde forcde et un stockage d froid. met~. 12poumons donneurs canins out ate trait4s per perfusion r4tFograde de solution UW. Chez 6 animaux du grouch A, 250ng furent injectes dans l' artrdre… 相似文献
53.
Antiretroviral therapy in adults: updated recommendations of the International AIDS Society-USA Panel 总被引:22,自引:1,他引:22
Carpenter CC Cooper DA Fischl MA Gatell JM Gazzard BG Hammer SM Hirsch MS Jacobsen DM Katzenstein DA Montaner JS Richman DD Saag MS Schechter M Schooley RT Thompson MA Vella S Yeni PG Volberding PA 《JAMA》2000,283(3):381-390
OBJECTIVE: To update recommendations for antiretroviral therapy for adult human immunodeficiency virus type 1 (HIV-1) infection, based on new information and drugs that are available. PARTICIPANTS: A 17-member international physician panel with antiretroviral research and HIV patient care experience initially convened by the International AIDS Society-USA in December 1995. EVIDENCE: Available clinical and basic science data including phase 3 controlled trials; data on clinical, virologic, and immunologic end points; research conference reports; HIV pathogenesis data; and panel expert opinion. Recommendations were limited to therapies available (US Food and Drug Administration approved) in 1999. CONSENSUS PROCESS: The panel assesses new research reports and interim results and regularly meets to consider how the new data affect therapy recommendations. Recommendations are updated via full-panel consensus. Guidelines are presented as recommendations if the supporting evidence warrants routine use in the particular situation and as considerations if data are preliminary or incomplete but suggestive. CONCLUSIONS: The availability of new antiretroviral drugs has expanded treatment choices. The importance of adherence, emerging long-term complications of therapy, recognition and management of antiretroviral failure, and new monitoring tools are addressed. Optimal care requires individualized management and ongoing attention to relevant scientific and clinical information in the field. 相似文献
54.
STUDY OBJECTIVE: To investigate the serum bactericidal activity (SBA) over time of extended-release clarithromycin against moderately resistant strains of Streptococcus pneumoniae. DESIGN: Prospective, single-dose pharmacodynamic study. SETTING: University-affiliated research center. SUBJECTS: Eleven healthy male volunteers. INTERVENTION: All volunteers received a single dose of extended-release clarithromycin as two 500-mg tablets, and blood samples were obtained at 0, 2, 6, 12, and 24 hours after administration of the dose. MEASUREMENTS AND MAIN RESULTS: For each blood sample, a serum bactericidal titer (SBT) was determined against S. pneumoniae strains with minimum inhibitory concentrations (MICs) of 0.5, 1.0, 2.0, 4.0, and 8.0 microg/ml to clarithromycin. The median SBT was determined for each time period. The extended-release formulation of clarithromycin exhibited SBA for 24 hours against pneumococcal strains with MICs of 0.5, 1.0, and 2.0 microg/ml. No SBA was observed against isolates with MICs of 4.0 or 8.0 microg/ml. CONCLUSION: The extended-release formulation of clarithromycin, taken once/day, will provide SBA for 24 hours against strains of S. pneumoniae with MICs of 2.0 microg/ml or less. 相似文献
55.
Trends in adult cigarette smoking in California compared with the rest of the United States, 1978-1994 总被引:2,自引:0,他引:2 下载免费PDF全文
Siegel M Mowery PD Pechacek TP Strauss WJ Schooley MW Merritt RK Novotny TE Giovino GA Eriksen MP 《American journal of public health》2000,90(3):372-379
OBJECTIVES: This study compared trends in adult cigarette smoking prevalence in California and the remainder of the United States between 1978 and 1994. METHODS: We used data from National Health Interview Surveys and Behavioral Risk Factor Surveillance System surveys to compare trends in smoking prevalence among persons 18 years and older. RESULTS: In both California and the remainder of the United States, the estimated annual rate of decline in adult smoking prevalence accelerated significantly from 1985 to 1990: to -1.22 percentage points per year (95% confidence interval [CI] = -1.51, -0.93) in California and to -0.93 percentage points per year (95% CI = -1.13, -0.73) in the remainder of the nation. The rate of decline slowed significantly from 1990 to 1994: to -0.39 percentage points per year (95% CI = -0.76, -0.03) in California and to -0.05 percentage points per year (95% CI = -0.34, 0.24) in the remainder of the United States. CONCLUSIONS: The presence of an aggressive tobacco control intervention has supported a significant decline in adult smoking prevalence in California from 1985 to 1990 and a slower but still significant decline from 1990 to 1994, a period in which there was no significant decline in the remainder of the nation. To restore nationwide progress in reducing smoking prevalence, other states should consider similar interventions. 相似文献
56.
E G Sandstrom C Andrews R T Schooley R Byington M S Hirsch 《Clinical immunology and immunopathology》1986,40(2):253-258
The ability of cells infected with human T lymphotropic virus type III (HTLV-III) to suppress lymphocyte responses to concanavalin A (ConA) was evaluated. Thirty homosexual men, both HTLV-III seropositive and seronegative, and 11 seronegative laboratory personnel were studied. Peripheral blood lymphocytes from all groups had lower responses to ConA in the presence of HTLV-III-infected H9 cells than in the presence of uninfected H9 cells. Among HTLV-III-seropositive males, responses to ConA in the presence of infected or uninfected H9 cells correlated with the number of T4 cells present. The studies suggest that HTLV-III-infected cells can suppress normal lymphocyte responses. Possible mechanisms of this suppression are discussed. 相似文献
57.
Noncardiogenic pulmonary edema is a recognized but uncommon manifestation of type 2 decompression sickness. It typically occurs within 6 hours of a dive. Because the adult respiratory distress syndrome in this setting is believed to be due to microbubbles in the pulmonary vasculature, recompression in a hyperbaric chamber has been recommended as a form of therapy. A patient developed noncardiogenic pulmonary edema following a seawater dive to 75 feet. There was complete radiologic and clinical resolution within 5 hours of hyperbaric therapy. 相似文献
58.
Isolation and characterization of murine cell surface components. I. Purification of milligram quantities of Thy-1.1 总被引:1,自引:0,他引:1 下载免费PDF全文
The Thy-l.1 molecule was isolated from the BW5147 murine lymphoblastoid cell line. The initial step in purification was the preparation of a crude plasma membrane fraction followed by acetone precipitation. The acetone pellet was solubilized using deoxycholate (DOC) and Thy-1.1 was purified by use of a Lens culinaris lectin affinity column and an AcA-34 gel filtration column. The purified glycoprotein with Thy-1.1 activity had a mol wt of approximately 25,000 daltons. The isolation of this molecule was effected by detecting Thy-I activity utilizing rabbit anti- mouse brain serum tested on rat thymocytes. Congenic anti-Thy-l.1 serum was ineffective in detecting Thy-l.1 after DOC solubilization. An antiserum prepared in rabbits to the purified Thy-1.1 was found to be cytotoxic to mouse and rat thymocytes. The cytotoxic activity of this antisera could be completely absorbed with AKR/Jax brain and thymus but was not absorbed by liver. In addition, AKR/Jax thymocytes totally absorbed all cytotoxic activity of the rabbit anti-purified Thy-1 serum for BW5147 cells suggesting that the cell line shares identical specificities with normal thymocytes. The purified Thy-1.1 molecule was able to totally absorb the cytotoxic activity of mouse congenic anti-Thy-1. These studies serve as a model for the isolation of other murine lymphoid cell surface components in quantities for detailed structural and functional analysis. 相似文献
59.
M. TROSSAËRT V. REGNAULT† M. SIGAUD P. BOISSEAU‡ E. FRESSINAUD T. LECOMPTE† 《Journal of thrombosis and haemostasis》2008,6(3):486-493
Summary. Introduction: In some patients with mild hemophilia A, there are discrepancies between 1-stage (1-st) and 2-stage (2-st) factor VIII (FVIII) clotting assays, and also chromogenic assays for FVIII activity (FVIII:C). We examined whether thrombography could provide a better evaluation of the hemostatic status of these patients. Methods: Two families with such discrepancies and markedly contrasting clinical histories were studied. Family X had no serious bleedings, in contrast to family Y. Sixty-one moderate/mild hemophiliacs without discrepancy and 15 healthy subjects served as controls. Calibrated automated thrombography was performed with platelet-rich plasma after one freeze-thawing cycle and low tissue factor concentration. Results: The chromogenic FVIII:C levels were higher (0.90 ± 0.15 and 0.47 ± 0.13 IU mL−1 ) than the 1-st clotting ones (0.14 ± 0.05 and 0.10 ± 0.05 IU mL−1 ) in family X and Y, respectively ( P < 0.001). Mean endogenous thrombin potential (ETP) was 1579 ± 359 n m min−1 and 1060 ± 450 for healthy controls and hemophilic controls, respectively. For members of family X, the ETP values were 1188, 1317 and 2277 n m min−1 , whereas for those of family Y they ranged from 447 to 1122 n m min−1 . Two novel missense point mutations were evidenced: p.Ile369Thr in family X and p.Phe2127Ser in family Y. In family X, we postulate that the mutation is responsible for a delayed but non-deleterious FVIII activation. Conclusions: Our results suggest that the hemostatic phenotype assessed by thrombography may be clinically relevant in moderate/mild hemophilic patients with discrepant FVIII:C results. 相似文献
60.