全文获取类型
收费全文 | 1705篇 |
免费 | 144篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 81篇 |
妇产科学 | 72篇 |
基础医学 | 175篇 |
口腔科学 | 60篇 |
临床医学 | 148篇 |
内科学 | 437篇 |
皮肤病学 | 26篇 |
神经病学 | 106篇 |
特种医学 | 180篇 |
外科学 | 216篇 |
综合类 | 53篇 |
预防医学 | 114篇 |
眼科学 | 31篇 |
药学 | 75篇 |
中国医学 | 1篇 |
肿瘤学 | 85篇 |
出版年
2023年 | 11篇 |
2022年 | 12篇 |
2021年 | 25篇 |
2020年 | 22篇 |
2019年 | 30篇 |
2018年 | 28篇 |
2017年 | 16篇 |
2016年 | 22篇 |
2015年 | 51篇 |
2014年 | 49篇 |
2013年 | 49篇 |
2012年 | 62篇 |
2011年 | 112篇 |
2010年 | 72篇 |
2009年 | 70篇 |
2008年 | 66篇 |
2007年 | 67篇 |
2006年 | 74篇 |
2005年 | 74篇 |
2004年 | 87篇 |
2003年 | 56篇 |
2002年 | 44篇 |
2001年 | 45篇 |
2000年 | 39篇 |
1999年 | 38篇 |
1998年 | 35篇 |
1997年 | 46篇 |
1996年 | 27篇 |
1995年 | 27篇 |
1994年 | 28篇 |
1993年 | 16篇 |
1992年 | 31篇 |
1991年 | 28篇 |
1990年 | 31篇 |
1989年 | 32篇 |
1988年 | 28篇 |
1987年 | 39篇 |
1986年 | 29篇 |
1985年 | 28篇 |
1984年 | 19篇 |
1983年 | 20篇 |
1982年 | 18篇 |
1981年 | 10篇 |
1980年 | 16篇 |
1979年 | 20篇 |
1977年 | 12篇 |
1976年 | 12篇 |
1975年 | 13篇 |
1973年 | 10篇 |
1966年 | 10篇 |
排序方式: 共有1862条查询结果,搜索用时 0 毫秒
11.
12.
Clough RA Leavitt BJ Morton JR Plume SK Hernandez F Nugent W Lahey SJ Ross CS O'Connor GT 《Archives of surgery (Chicago, Ill. : 1960)》2002,137(4):428-32; discussion 432-3
HYPOTHESIS: Comorbid conditions are associated with the risk of death from coronary artery bypass graft surgery. DESIGN: Prospective cohort study data were collected on patient and disease characteristics and comorbid conditions including hypertension, diabetes, obesity, vascular disease, chronic obstructive pulmonary disease, cancer (excluding nonmelanoma skin cancer), dialysis-dependent renal failure, liver disease, and dementia. Statistical analysis used logistic regression for the calculation of adjusted odds ratios (ORs) and 95% confidence intervals (CIs). SETTING: Regional cardiac surgery database. PATIENTS: A total of 27,239 consecutive patients undergoing isolated coronary artery bypass graft surgery. MAIN OUTCOME MEASURE: In-hospital mortality rate. RESULTS: The prevalence of comorbid conditions was as follows: hypertension, 64.3%; diabetes, 30.1%; obesity, 24.6%; severe obesity, 7.2%; vascular disease, 18.3%; chronic obstructive pulmonary disease, 10.9%; peptic ulcer, 7.5%; cancer, 3.8%; renal failure, 1.5%; liver disease, 0.6%; and dementia, 0.1%. After adjustment for patient and disease characteristics, including age, sex, previous cardiac surgery, priority of surgery, degree of left main coronary stenosis, number of diseased coronary arteries, and left ventricular ejection fraction, the following comorbid conditions were significant predictors of in-hospital mortality: diabetes (OR, 1.19; 95% CI, 1.01-1.40; P =.03), vascular disease (OR, 1.67; 95% CI, 1.41-1.97; P<.001), chronic obstructive pulmonary disease (OR, 1.57; 95% CI, 1.29-1.91; P<.001), peptic ulcer (OR, 1.34; 95% CI, 1.05-1.71; P =.02), and dialysis-dependent renal failure (OR, 3.68; 95% CI, 2.65-5.13; P<.001). There was no significant association between in-hospital mortality and hypertension, obesity or severe obesity, cancer, liver disease, or dementia. CONCLUSION: Even after adjustment for other patient and disease characteristics, comorbid conditions (especially diabetes, vascular disease, chronic obstructive pulmonary disease, peptic ulcer disease, and dialysis-dependent renal failure) are associated with significantly increased risk of death after coronary artery bypass graft surgery. 相似文献
13.
The present study tested the hypothesis that acute posttraumatic hyperarousal would lead to the development of emotional numbing (EN) symptoms in a pediatric injury population. Eighty-two youths aged 8-18 years were recruited from the emergency department of a Midwestern children's hospital. Heart rate was recorded from emergency medical services reports and a 12-hour urine collection was initiated upon admission. Six weeks and 6 months later, depression and PTSD symptoms were assessed. Initial heart rate and urinary cortisol levels predicted 6-week and 6-month EN after controlling for concurrent depression, avoidance, and reexperiencing symptoms and 6-week hyperarousal symptoms. These findings provide empirical support for prior hypotheses concerning the development of PTSD symptoms over time. 相似文献
14.
Cell culture and animal data support the role of endothelial cells and endothelial-based compounds in regulating vascular repair after injury. We describe a long-term study in pigs in which the biological and immunological responses to endothelial cell implants were investigated 3 months after angioplasty, approximately 2 months after the implants have degraded. Confluent porcine or bovine endothelial cells grown in polymer matrices were implanted adjacent to 28 injured porcine carotid arteries. Porcine and bovine endothelial cell implants significantly reduced experimental restenosis compared to control by 56 and 31%, respectively. Host humoral responses were investigated by detection of an increase in serum antibodies that bind to the bovine or porcine cell strains used for implantation. A significant increase in titer of circulating antibodies to the bovine cells was observed after 4 days in all animals implanted with xenogeneic cells. Detected antibodies returned to presurgery levels after Day 40. No significant increase in titer of antibodies to the porcine cells was observed during the time course of the experiment in animals implanted with porcine endothelial cells. No implanted cells, Gelfoam, or focal inflammatory reaction could be detected histologically at any of the implant sites at 90 days. These data suggest that tissue-engineered endothelial cell implants may provide long-term control of vascular repair after injury, rather than simply delaying lesion formation and that allogeneic implants are able to provide a greater benefit than xenogeneic implants. 相似文献
15.
Zielinsky A; Hirsh J; Straumanis G; Carter CJ; Gent M; Sackett DL; Hull R; Kelton JG; Powers P; Turpie AG 《Blood》1982,59(2):346-350
We have evaluated the fibrinogen/fibrin fragment E antigen assay as a diagnostic test in patients with clinically suspected venous thrombosis by comparing the results of this assay with venography in 272 patients. The result of the fragment E antigen assay was elevated in 79 of 80 patients with positive venograms for recent venous thrombosis (sensitivity 99%) and within the normal range in 161 of 192 patients with normal venograms (specificity 84%). The fragment E assay was also evaluated in 130 medical and surgical controls without evidence of venous thrombosis by leg scanning and the test was found to be relatively nonspecific. However, in the patient group under study, a correct clinical diagnosis of no thrombosis, based on a normal fragment E result, was made in 161 of 162 cases (negative predictive value of 99%). Therefore, a normal test result effectively excludes a diagnosis of venous thrombosis in clinically symptomatic patients. The assay, as currently performed, is technically demanding and takes 24 hr to complete. Therefore, it will have to be simplified before it can be applied to clinical practice. 相似文献
16.
A human monoclonal autoantibody recognizes a neoantigen on glycoprotein IIIa expressed on stored and activated platelets 总被引:2,自引:1,他引:2
We prepared a heterohybrid cell line that secretes a human IgM monoclonal autoantibody that recognizes an antigen found on thrombin-activated or stored platelets. The surface expression of the epitope recognized by this autoantibody, 5E5, increases with time as platelets age in vitro, suggesting that it may represent a senescence or activation-specific antigen. 5E5 binds to the purified platelet membrane glycoprotein (GP) IIb-IIIa complex in an enzyme-linked immunosorbent assay (ELISA). In an immunoblot technique, 5E5 binds to a protein with an apparent mol wt of 95,000, which is identical to that of GPIIIa under nonreduced conditions. In crossed immunoelectrophoresis (CIE), the predominant antigen recognized by 5E5 is contained in the GPIIb-IIIa precipitin arc. An additional precipitin arc recognized by 5E5 is often observed only on gels derived from lysates of platelets stored under blood bank conditions for greater than 3 days. These findings illustrate the usefulness of human monoclonal antibodies for the identification of membrane neoantigens expressed as a result of platelet activation or revealed as platelets age in vitro. 相似文献
17.
Lauren Desrosiers Sarah Scollon Rebecca Littlejohn Kimberly Nugent Rebecca Althaus Jessica Corredor Emily Berenson Rachel Wyatt Timothy Griffin Kelly Vallance Jonathan Gill Gail Tomlinson Juan Carlos Bernini Angshumoy Roy George Miles Jacquelyn Reuther Shashikant Kulkarni Christine Eng Sharon Plon 《Molecular genetics and metabolism》2021
18.
Abstract. A case of warm antibody auto-immune hemolytic anemia is described in which the serum antibody, and an eluate from the patient's red cells, both had anti-U specificity. The antibody did not react with Rhnull red cells, and gave weaker reactions with -D- red cells than with other U-positive red cells. Five other anti-U sera were tested in comparative titrations and some of these also reacted more weakly against -D- red cells than against red cells having common Rh phenotypes. 相似文献
19.
Serum lysozyme (muramidase) concentrations were measured in three groups of patients: control, ulcerative colitis and proctitis, and Crohn's disease. The mean +/-SD for each group was: control, 7 +/- 2; ulcerative colitis and proctitis, 7 +/- 2; and Crohn's disease, 10 +/- 4. Although a significant difference was seen between values in patients with Crohn's disease and values observed in those with ulcerative colitis or control patients, an important overlap was found between these groups. Further studies are necessary to explain the disparate results between this study and previous reports. 相似文献
20.
R B Belshe E M Swierkosz E L Anderson F K Newman S L Nugent H F Maassab 《The Journal of infectious diseases》1992,165(4):727-732
Seventeen triply seronegative infants and young children, and 15 infants and young children seropositive to all three influenza virus strains were vaccinated intranasally with 10(5) TCID50 of each of three (H1N1, H3N2, and B) live attenuated, cold-adapted influenza vaccine strains. Seventeen controls were given placebo. Vaccination with trivalent influenza vaccine was not associated with adverse reactions in triply seronegative or seropositive children. Overall, 12 (71%), 13 (76%), and 13 (76%) of seronegative children were infected by H1N1, H3N2, or B vaccine viruses, respectively, as indicated by viral shedding or by hemagglutination inhibition assay or ELISA antibody response. Of the triply seronegative children, 47% shed all three viruses; 7 children had an antibody rise to all three vaccine viruses and 4 shed all three viruses. A dose of 10(4.4) - 10(5.0) TCID50 of each of three intranasally administered vaccine viruses was safe, immunogenic and antigenic; however, strategies to increase the proportion of children infected by each of the vaccine viruses should be studied, including higher doses and multiple doses of live trivalent vaccine. 相似文献