首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   3062篇
  免费   360篇
  国内免费   4篇
耳鼻咽喉   11篇
儿科学   44篇
妇产科学   61篇
基础医学   423篇
口腔科学   94篇
临床医学   350篇
内科学   702篇
皮肤病学   23篇
神经病学   351篇
特种医学   165篇
外科学   339篇
综合类   87篇
一般理论   4篇
预防医学   370篇
眼科学   23篇
药学   217篇
中国医学   3篇
肿瘤学   159篇
  2021年   57篇
  2020年   37篇
  2019年   47篇
  2018年   60篇
  2017年   33篇
  2016年   41篇
  2015年   58篇
  2014年   58篇
  2013年   97篇
  2012年   120篇
  2011年   154篇
  2010年   95篇
  2009年   75篇
  2008年   129篇
  2007年   137篇
  2006年   137篇
  2005年   137篇
  2004年   124篇
  2003年   107篇
  2002年   80篇
  2001年   91篇
  2000年   87篇
  1999年   81篇
  1998年   64篇
  1997年   41篇
  1996年   36篇
  1995年   33篇
  1994年   40篇
  1993年   32篇
  1992年   74篇
  1991年   55篇
  1990年   53篇
  1989年   68篇
  1988年   59篇
  1987年   39篇
  1986年   50篇
  1985年   49篇
  1984年   48篇
  1983年   31篇
  1982年   33篇
  1981年   30篇
  1979年   35篇
  1978年   33篇
  1976年   30篇
  1975年   28篇
  1973年   29篇
  1972年   30篇
  1969年   28篇
  1968年   34篇
  1966年   34篇
排序方式: 共有3426条查询结果,搜索用时 31 毫秒
1.
2.
Despite significant improvements in the prognosis of acute promyelocytic leukemia brought about by therapeutic advances, understanding of the epidemiology of acute promyelocytic leukemia remains limited. Earlier reports have suggested that Hispanics may have an increased incidence of acute promyelocytic leukemia, but no systematic analysis of national data has yet been reported. We performed a retrospective cohort study, using data from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute from 1992-2001 in order to compare leukemia incidence rates as a function of race and ethnicity. We identified 709 cases of acute promyelocytic leukemia and analyzed incidence rates by race and sex. Hispanics were not found to have greater lifetime incidence rates than whites, with an incidence relative rate (IRR) of 0.86 that of whites (P=0.17). The age distribution among Hispanics was significantly different from non-Hispanic whites, with greater incidence rates for children ages 1-19 years (IRR=1.9, P=0.02) and adult ages 20-44 years (IRR=1.6, P=0.004). Blacks had lower lifetime incidence rates than non-Hispanic whites (IRR=0.75, P=0.04), Hispanics (IRR=0.64, P=0.007), and Asians (IRR=0.67, P=0.03). Asians did not differ from non-Hispanic whites in lifetime or age-specific incidence rates. These results indicate that while US Hispanics do not have greater lifetime incidence rates of acute promyelocytic leukemia, blacks have lower incidence rates of acute promyelocytic leukemia than Hispanics, non-Hispanic whites, and Asians.  相似文献   
3.
Background/aim  Theoretical considerations support the combination of cryosurgery and topical imiquimod to treat basal cell carcinomas (BCC). The aim of the present study was to test the feasibility and efficacy of 'cryosurgery during continued imiquimod application' ('immunocryosurgery') to treat 'high-risk-for-recurrence' BCCs.
Methods  Thirteen patients with 21 biopsy-proven tumours (4 of 21 relapses after prior surgery) were included. After 2–5 weeks (median, 3) of daily 5% imiquimod cream application, the tumours were treated by liquid N2 cryosurgery (spray, two cycles, 10–20 s) and imiquimod was continued for additional 2–12 weeks (median, 4). The outcome after at least 18 months of follow-up (18–24 months) is currently reported.
Results  Nineteen of 21 tumours responded promptly to immunocryosurgery; two tumours required additional treatment cycles to clear. Thus, the clinical clearance rate was 100%. Only 1 of 21(5%) tumour relapsed after at least 18 months of follow-up (cumulative efficacy: 95%).
Conclusions  'Immunocryosurgery' is a promising non-surgical combination modality to treat 'high-risk-for-recurrence BCCs'. Initial evidence is suggestive of an at least additive effect of the two combined modalities. Further studies comparing immunocryosurgery directly with cryosurgery and imiquimod monotherapies will confirm the reported results.  相似文献   
4.
Two different regimens of cephalosporin antibiotic prophylaxis were compared with antiseptic lubricating jelly to try to prevent infection and complications in 196 men after prostatic surgery. Pre-operative urine was cultured and prostatic chips (170 cases) were also cultured to define the source of any infection. The use of antibiotics was associated with a reduced risk of postoperative bacteriuria. No serious complications occurred, although 1 patient in the antiseptic treated group developed rigors; 79 of 170 patients (46%) had positive prostatic chip cultures, of whom 74 had sterile pre-operative urine. There was no association between the result of chip culture and the presence of a pre-operative catheter. Culture positive patients had an increased risk of post-operative urine infection, although the same organism was found in the prostate and urine in only 36% of cases of post-operative bacteriuria and in 43 (54%) the organism cultured from the prostate was Staphylococcus albus. This study provides further evidence of the benefit of true prophylactic antibiotic therapy for transurethral prostatic surgery and the prostatic chip data suggest that some of the risk is due to pre-operative contamination of the prostate in the absence of per-operative urinary infection or catheterisation.  相似文献   
5.
A range of 18 derivatives of flavone-8-acetic acid (FAA) with substituents on the 2-phenyl group have been prepared and their anti-tumour activity evaluated in vitro against a panel of human and murine tumour cell lines and in vivo against MAC 15A. There was no clear-cut relationship between in vitro and in vivo activity but the activity in each situation was found to be very sensitive to the precise substitution pattern with closely related isomers giving widely different activities. Some of the compounds, notably 10b,cj , and r , were active in vivo and these require further studies in order to evaluate their potential for development.  相似文献   
6.
7.
One thousand two hundred and fifty-four adolescents in Hamilton, New Zealand, ranging in age from 10 to 16, were questioned on their awareness of, and attitudes towards, cigarette advertising, and on their image of the young smoker. Most of the respondents felt that tobacco companies advertise to encourage people to buy their brands. Smokers were less likely than non-smokers to feel that cigarette companies advertise to encourage young people to take up smoking. They were also more likely to agree that cigarette companies are generous, public spirited people. Non-smokers were more likely to feel that cigarette advertising was effective in encouraging young people to smoke. Winfield, the most popular brand among smokers, was also the most well known. Smokers had a more positive image than non-smokers of the young person who smokes.  相似文献   
8.
We have used a vaginal speculum to insert a testicular prosthesis through the inguinal approach over the past four years. We have found this technique to be easily performed and reproducible in allowing the testicular prosthesis to be placed in the normal dependent position in the scrotum.  相似文献   
9.
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号