全文获取类型
收费全文 | 8996篇 |
免费 | 560篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 36篇 |
儿科学 | 417篇 |
妇产科学 | 339篇 |
基础医学 | 976篇 |
口腔科学 | 87篇 |
临床医学 | 2002篇 |
内科学 | 1389篇 |
皮肤病学 | 123篇 |
神经病学 | 619篇 |
特种医学 | 319篇 |
外科学 | 773篇 |
综合类 | 84篇 |
一般理论 | 28篇 |
预防医学 | 1316篇 |
眼科学 | 155篇 |
药学 | 464篇 |
中国医学 | 9篇 |
肿瘤学 | 443篇 |
出版年
2023年 | 48篇 |
2022年 | 53篇 |
2021年 | 150篇 |
2020年 | 138篇 |
2019年 | 212篇 |
2018年 | 231篇 |
2017年 | 178篇 |
2016年 | 205篇 |
2015年 | 203篇 |
2014年 | 289篇 |
2013年 | 513篇 |
2012年 | 644篇 |
2011年 | 784篇 |
2010年 | 333篇 |
2009年 | 339篇 |
2008年 | 708篇 |
2007年 | 610篇 |
2006年 | 602篇 |
2005年 | 631篇 |
2004年 | 640篇 |
2003年 | 591篇 |
2002年 | 546篇 |
2001年 | 58篇 |
2000年 | 41篇 |
1999年 | 65篇 |
1998年 | 102篇 |
1997年 | 93篇 |
1996年 | 72篇 |
1995年 | 62篇 |
1994年 | 50篇 |
1993年 | 47篇 |
1992年 | 37篇 |
1991年 | 23篇 |
1990年 | 37篇 |
1989年 | 24篇 |
1988年 | 28篇 |
1987年 | 17篇 |
1986年 | 17篇 |
1985年 | 19篇 |
1984年 | 22篇 |
1983年 | 20篇 |
1982年 | 31篇 |
1981年 | 23篇 |
1980年 | 13篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1974年 | 2篇 |
排序方式: 共有9579条查询结果,搜索用时 31 毫秒
91.
Inverse association between prostate cancer and the use of calcium channel blockers. 总被引:3,自引:0,他引:3
Jose D Debes Rosebud O Roberts Debra J Jacobson Cynthia J Girman Michael M Lieber Donald J Tindall Steven J Jacobsen 《Cancer epidemiology, biomarkers & prevention》2004,13(2):255-259
Calcium channel blockers block calcium signal-mediated apoptosis. It is hypothesized that the use of these drugs may be associated with the development of cancer. This study investigated the association between daily use of calcium channel blockers and prostate cancer in a community-based cohort of men who participated in a longitudinal study of lower urinary tract symptoms. Study subjects were men ages 40 to 79 years by January 1, 1990, and were randomly selected from Olmsted County in Minnesota. At baseline, participants underwent an interview to determine all medications taken on a daily basis, including calcium channel blockers and to elicit a family history of prostate cancer. During follow-up, all men with a histological diagnosis of prostate cancer were identified through patient self-report and by a review of the complete medical record. Over 12,668 person years of follow-up, 15 (6.8%) of 220 calcium channel blocker users and 120 (10.5%) of 1142 nonusers developed prostate cancer (P = 0.09; odds ratio, 0.62; 95% confidence interval, 0.36-1.10). With adjustment for age and family history of prostate cancer, the risk (odds ratio, 95% confidence interval) of prostate cancer was 0.55 (0.31-0.97) in calcium channel blocker users compared with nonusers. In analyses stratified by family history of prostate cancer, the risk of prostate cancer was 0.45 (0.23-0.88) in men without a family history and 2.64 (0.82-8.47) in men with a family history of prostate cancer (P = 0.006). These findings suggest an association between prostate cancer and daily use of calcium channel blockers that varies by family history of prostate cancer. 相似文献
92.
Effects of a high-selenium yeast supplement on celecoxib plasma levels: a randomized phase II trial.
Denise H Frank Denise J Roe H-H Sherry Chow Jose M Guillen Karin Choquette Debra Gracie Jennifer Francis Airley Fish David S Alberts 《Cancer epidemiology, biomarkers & prevention》2004,13(2):299-303
A combination of celecoxib and selenium was used in a randomized double-blind Phase II trial as a preliminary study to a multicenter Phase III colorectal cancer chemoprevention trial using these two agents together. The purpose of this trial was to determine whether high-selenium baker's yeast [(Saccharomyces cerevisiae) 200 microg once daily] in combination with celecoxib (400 mg once daily) altered the steady-state plasma concentration of celecoxib or produced clinically significant toxicities. Seventy-three healthy subjects (ages 40-75 years) were recruited to the 6-week study from the general local population and were randomized to either the celecoxib plus selenized baker's yeast group or the celecoxib plus placebo group after a 2-week run in period of celecoxib only. Blood samples were taken at baseline (to document that there was no evidence of celecoxib intake), after the 2-week run-in period on celecoxib to verify steady-state blood levels of this agent, and at end of study (4 weeks postrandomization). Toxicities were monitored at 2 weeks after initiation of celecoxib, at 4 weeks after initiation, and at the end of the study. Blood level concentrations of celecoxib did not differ between the two groups as determined by high-performance liquid chromatography analysis nor were there significant differences in blood chemistry values between the two groups. Subjects' self-report of general physical toxicities was uncommon and limited to National Cancer Institute toxicity grade 2 or less; however, 2 female participants (3%) were removed from the study medications because of grade 2 edema and significant weight gain after 2 and 2.5 weeks of celecoxib administration. In conclusion, high-selenium yeast and celecoxib can be taken at the described doses with minimum short-term negative effects. In future Phase III chemoprevention trials of celecoxib, weight gain should be carefully monitored, and participants should be made aware of this potential side effect before study entry. 相似文献
93.
Wen-Kai Weng Debra Czerwinski John Timmerman Frank J Hsu Ronald Levy 《Journal of clinical oncology》2004,22(23):4717-4724
PURPOSE: The unique immunoglobulin idiotype (Id) expressed by each B-cell lymphoma is a target for immunotherapy. Vaccination with Id induces humoral and/or cellular anti-Id immune responses. However, the clinical impact of these anti-Id immune responses is unknown. We and others have previously reported that immunoglobulin G Fc receptor (FcgammaR) polymorphisms predict the clinical response of lymphoma patients to passive anti-CD20 antibody infusions. In this study, we tested whether anti-Id immune responses or FcgammaR polymorphisms associate with clinical outcome of patients who received Id vaccination. PATIENTS AND METHODS: We analyzed 136 patients with follicular lymphoma who had received Id vaccination. The anti-Id immune responses were measured and FcgammaRIIIa and FcgammaRIIa polymorphisms were determined and correlated with clinical outcome for these patients. RESULTS: Patients who mounted humoral immune responses had a longer progression-free survival (PFS) than those who did not (8.21 v 3.38 years; P = .018). Patients with FcgammaRIIIa 158 valine/valine (V/V) genotype also had a longer PFS than those with valine/phenylalanine (V/F) or phenylalanine/phenylalanine (F/F) genotypes (V/V, 8.21 v V/F, 3.38 years; P = .004; v F/F, 4.47 years; P = .035). Multivariate analysis using the Cox proportional hazards model showed that V/V genotype and humoral immune responses were independent positive predictors for PFS. CONCLUSION: This study is the first to identify the predictive value of FcgammaR polymorphism on clinical outcome in patients who received active immunotherapy with tumor antigen vaccines. Our results imply that the antibodies induced against a tumor antigen are beneficial and that FcgammaR-bearing cells mediate an antitumor effect by killing antibody-coated tumor cells. 相似文献
94.
95.
Neeraj Kaushik MD Debra Brody Neil Christie Kevin McGrath 《Journal of gastrointestinal cancer》2003,34(2-3):95-99
Basaloid squamous cell carcinoma (BSCC) is a rare form of cancer that arises primarily in the upper aerodigestive tract. Esophageal BSCC is extremely rare, accounting for less than 2% of primary esophageal malignancies. It is histopathologically distinct from squamous cell carcinoma and has an aggressive biological behavior with poor survival outcomes. There is no known association of Barrett’s esophagus with esophageal BSCC. Here, we report what we believe is the first such case of esophageal BSCC occurring in the setting of Barrett’s esophagus. 相似文献
96.
Dietary factors and the risk of squamous cell esophageal cancer among black and white men in the United States 总被引:4,自引:0,他引:4
Linda Morris Brown Christine A. Swanson Gloria Gridley G. Marie Swanson Debra T. Silverman Raymond S. Greenberg Richard B. Hayes Janet B. Schoenberg Linda M. Pottern Ann G. Schwartz Jonathan M. Liff Robert Hoover Joseph F. Fraumeni 《Cancer causes & control : CCC》1998,9(5):467-474
Objectives: To investigate dietary factors for squamous cell esophageal cancer and whether these factors may contribute to the five-fold higher incidence of this cancer in the black versus white population of the United States.Methods: Data from a food frequency questionnaire were analyzed for 114 white men and 219 black men with squamous cell esophageal cancer, and 681 white and 557 black male controls from three areas of the United States who participated in a population-based case-control study of esophageal cancer.Results: Protective effects were associated with intake of raw fruits and vegetables (odds ratio for high versus low consumers=0.3 in both white and black men) and use of vitamin supplements (especially vitamin C; odds ratio for high versus low consumers=0.4 in both races), with the frequency of consumption of raw fruits and vegetables and vitamin supplements being greater for white than black controls. In addition, elevated risks were associated with high versus low intake of red meat (OR=2.7 for blacks and 1.5 for whites) and processed meat (OR=1.6 for blacks and 1.7 for whites), with the levels of consumption being greater for black than white controls.Conclusions: In the United States, these dietary factors may contribute in part to the much higher incidence of squamous cell esophageal cancer among black compared to white men. 相似文献
97.
Joseph H Sisson Julie A Stoner Debra J Romberger John R Spurzem Todd A Wyatt Joseph Owens-Ream David M Mannino 《Alcohol》2005,36(1):19-30
Little is known about the effect of moderate alcohol intake on lung function in the general population. Because moderate alcohol intake appears to reduce cardiovascular disease risk, we hypothesized that moderate alcohol intake is associated with better pulmonary function. To test this hypothesis, we examined the association between alcohol intake and pulmonary function, measured by spirometry, in a representative sample of U.S. adults who participated in the Third National Health and Nutrition Examination Survey. A stratified multistage clustered probability design was used to select a population-based sample. Data analyzed included alcohol intake, smoking status, education, body mass, sex, age, race, diabetes status, and CHF status. The Third National Health and Nutrition Examination Survey was conducted from 1988 to 1994 by the National Center for Health Statistics of the Centers for Disease Control and Prevention, Atlanta, GA. We analyzed data from 15,294 study participants who completed extensive questionnaires in the household and a comprehensive physical examination, including pulmonary function testing, either in the household or at a specially equipped mobile examination center. Low-to-moderate alcohol intake was not associated with reduced odds of obstructive lung function. In fact, increased odds for obstructive lung pattern were observed only in former heavy drinkers. In contrast, low-to-moderate alcohol intake was associated with better forced vital capacity and forced exhaled volume in 1s in the absence of obstruction, consistent with reduced odds for lung restriction. Using a logistic regression model, we found that individuals reporting alcohol consumption had a lower risk of lung restriction both before and after adjusting for confounding factors including smoking (P< or =.001). Alcohol intake-related reduced risk for restriction was associated with lower risk of CHF, diabetes, obesity, and lower markers of inflammation (white blood cell, fibrinogen, and C-reactive protein) consistent with less lung congestion, external restriction, and/or lung inflammation. Our analyses indicate that alcohol consumption, even at very modest intake levels, is associated with less lung restriction. 相似文献
98.
Debra J Holden Peter Messeri W Douglas Evans Erik Crankshaw Maureen Ben-Davies 《Health education & behavior》2004,31(5):548-563
This article presents a conceptual framework that was developed to guide a national evaluation of the American Legacy Foundation's (Legacy) Statewide Youth Movement Against Tobacco Use (SYMATU) program. This program was designed to develop youth-led, youth-directed initiatives within local communities. Two evaluation studies were designed and implemented from 2000 through 2003: a cross-site study that collected standard data elements across all 17 programs and a case study of five programs that collected formative data on variables thought to affect program implementation. In developing the youth empowerment (YE) conceptual framework, the authors started by reviewing literature to identify the concepts necessary for these types of initiatives and present a summary of their findings here. This article focuses on the development of the authors'overarching conceptual framework used to guide their evaluation studies. Other articles contained within this special issue present results from each of the SYMATU evaluation studies. 相似文献
99.
Thanks to improvements in treatment regimens, more and more patients are now surviving cancer. However, cancer survivors are faced with the serious long-term effects of the different modalities of cancer treatments. One of these adverse effects is chemotherapy-induced irreversible damage to the ovarian tissues, which leads to premature ovarian failure and its resulting consequences such as hot flashes, osteoporosis, sexual dysfunction and the risk of infertility. Chemotherapy-induced ovarian failure (or chemotherapy-induced premature menopause) affects the quality of life of female cancer survivors. Although there is no clear definition of chemotherapy-induced ovarian failure, irreversible amenorrhoea lasting for several months (>12 months) following chemotherapy and a follicle stimulating hormone level of > or = 30 MIU/mL in the presence of a negative pregnancy test seems to be an appropriate characterisation. Different chemotherapy agents, alkylating cytotoxics in particular, have the potential to cause progressive and irreversible damage to the ovaries. The result of this damage is a state of premature ovarian failure, with progressive declining of estrogen levels, decreasing bone mass and an increased risk of fractures. Historically, hormonal replacement therapy (HRT) has been used to treat menopausal problems in the general population, but concerns about the potential of estrogen to increase the risk of breast cancer in women at high-risk or increase the risk of recurrence in cancer survivors, have forced physicians to utilise alternative treatments. This review discusses some of the newer therapies that are now available to provide appropriate symptom control, avoid complications such as fractures and possibly prevent infertility by making the ovarian epithelium less susceptible to cytotoxic agents. 相似文献
100.
Aman U Buzdar Nuhad K Ibrahim Deborah Francis Daniel J Booser Eva S Thomas Richard L Theriault Lajos Pusztai Marjorie C Green Banu K Arun Sharon H Giordano Massimo Cristofanilli Debra K Frye Terry L Smith Kelly K Hunt Sonja E Singletary Aysegul A Sahin Michael S Ewer Thomas A Buchholz Donald Berry Gabriel N Hortobagyi 《Journal of clinical oncology》2005,23(16):3676-3685
PURPOSE: The objective of this study was to determine whether the addition of trastuzumab to chemotherapy in the neoadjuvant setting could increase pathologic complete response (pCR) rate in patients with human epidermal growth factor receptor 2 (HER2) -positive disease. PATIENTS AND METHODS: Forty-two patients with HER2-positive disease with operable breast cancer were randomly assigned to either four cycles of paclitaxel followed by four cycles of fluorouracil, epirubicin, and cyclophosphamide or to the same chemotherapy with simultaneous weekly trastuzumab for 24 weeks. The primary objective was to demonstrate a 20% improvement in pCR (assumed 21% to 41%) with the addition of trastuzumab to chemotherapy. The planned sample size was 164 patients. RESULTS: Prognostic factors were similar in the two groups. After 34 patients had completed therapy, the trial's Data Monitoring Committee stopped the trial because of superiority of trastuzumab plus chemotherapy. pCR rates were 25% and 66.7% for chemotherapy (n = 16) and trastuzumab plus chemotherapy (n = 18), respectively (P = .02). The decision was based on the calculation that, if study continued to 164 patients, there was a 95% probability that trastuzumab plus chemotherapy would be superior. Of the 42 randomized patients, 26% in the chemotherapy arm achieved pCR compared with 65.2% in the trastuzumab plus chemotherapy arm (P = .016). The safety of this approach is not established, although no clinical congestive heart failure was observed. A more than 10% decrease in the cardiac ejection fraction was observed in five and seven patients in the chemotherapy and trastuzumab plus chemotherapy arms, respectively. CONCLUSION: Despite the small sample size, these data indicate that adding trastuzumab to chemotherapy, as used in this trial, significantly increased pCR without clinical congestive heart failure. 相似文献