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   225554篇
  免费   30232篇
  国内免费   7389篇
耳鼻咽喉   1912篇
儿科学   1877篇
妇产科学   5491篇
基础医学   15910篇
口腔科学   10711篇
临床医学   17762篇
内科学   21290篇
皮肤病学   1827篇
神经病学   1018篇
特种医学   6114篇
外国民族医学   253篇
外科学   29576篇
综合类   27631篇
现状与发展   40篇
一般理论   3篇
预防医学   11199篇
眼科学   172篇
药学   17491篇
  165篇
中国医学   6032篇
肿瘤学   86701篇
  2024年   751篇
  2023年   4881篇
  2022年   9241篇
  2021年   12154篇
  2020年   11564篇
  2019年   10480篇
  2018年   10065篇
  2017年   10392篇
  2016年   11078篇
  2015年   12725篇
  2014年   18147篇
  2013年   18392篇
  2012年   14489篇
  2011年   14724篇
  2010年   10698篇
  2009年   10862篇
  2008年   11108篇
  2007年   10392篇
  2006年   9184篇
  2005年   7620篇
  2004年   6341篇
  2003年   5315篇
  2002年   4535篇
  2001年   4158篇
  2000年   3454篇
  1999年   2916篇
  1998年   2460篇
  1997年   2245篇
  1996年   1792篇
  1995年   1668篇
  1994年   1398篇
  1993年   1079篇
  1992年   972篇
  1991年   859篇
  1990年   669篇
  1989年   639篇
  1988年   515篇
  1987年   462篇
  1986年   366篇
  1985年   437篇
  1984年   364篇
  1983年   254篇
  1982年   264篇
  1981年   249篇
  1980年   212篇
  1979年   145篇
  1978年   104篇
  1977年   114篇
  1976年   91篇
  1975年   64篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
AIM: The clinical significance of the urinary white blood cell (U-WBC) count and serum C-reactive protein (CRP) level was evaluated in an effort to improve the efficiency of prostate biopsies. METHODS: We enrolled 228 consecutive patients with serum prostate-specific antigen (PSA) ranging from 3.0 to 20.0 ng/mL, normal digital rectal examination findings, and who underwent prostate biopsies between January 2001 and August 2004. Of these, 157 patients had histologically confirmed benign prostatic disease and the remaining 71 patients had prostate cancer. Patients with a pretreatment U-WBC count < or =3 or >3/high power field were defined as non-pyuria and pyuria, respectively. The patients were also separated into two groups based on the serum CRP level prior to biopsy. Several clinical factors were compared among these subgroups. RESULTS: Inflammation was histologically detected at rates of 58.1% and 34.1% in the pyuria and non-pyuria groups, respectively (P = 0.0014). The rates of cancer detection were significantly lower in the pyuria, than in the non-pyuria group (P = 0.0384). The cancer detection rates did not significantly differ according to serum CRP levels prior to biopsy. CONCLUSION: The U-WBC count appears to be a reliable indicator of minute prostatic inflammation. The serum PSA level was elevated in patients with asymptomatic prostatitis. Counting U-WBC is a simple, convenient and non-invasive method that should be valuable part of routine urological examinations.  相似文献   
32.
We report a rare case of granulomatous balanoposthitis after intravesical Bacillus-Calmette-Guerin (BCG) instillation therapy in a 58-year-old man, which followed transurethral resection (TUR) for recurrent bladder cancer, when his anterior urethra was slightly narrow and his foreskin was with phimosis. Intravesical BCG instillation therapy was started for prophylaxis of recurrent bladder cancer after TUR. Multiple painless firm papules on glans penis, edema in the foreskin and low-grade fever appeared after the seventh instillation, for which the single antituberculous agent isoniazid (300 mg/day) was administered. Biopsy of the papules on glans penis and foreskin revealed granulomatous balanoposthitis. Low-grade fever normalized and the papules disappeared within 1 week. The patient continued chemotherapy with isoniazid for the next 12 months. There was no recurrence of bladder cancer or balanoposthitis for 15 months and to date.  相似文献   
33.
The incidence of uterine cervical cancer has increased slightly in Western countries, with an increase in relatively young women. Overexpression of matrix metalloproteinases (MMPs)-2 and -9 has turned out as a prognostic factor in many cancers. We compared the expression of the proteins MMP-2 and MMP-9 in cervical primary tumors with clinical outcome and risk factors of cervical cancer. One hundred sixty-one patients with cervical cancer treated in Ume? University Hospital or Sahlgrenska University Hospital, Sweden, between 1991 and 1995 were included in the study. Paraffin-embedded tissue samples obtained prior to treatment were examined immunohistochemically by specific antibodies for MMP-2 and MMP-9. Forty-two percent of the tumors were intensively positive for MMP-2 and 31% for MMP-9. Nineteen percent of the samples were intensively positive for both proteinases and 47% negative or weak for both. Overexpression of MMP-2 seemed to predict unfavorable survival under Kaplan-Meier analysis and in the multivariate analysis. Early sexual activity and low parity seemed to correlate to overexpression of MMP-2. MMP-9 was not associated with survival or sexual behavior. Intensive MMP-9 was noted in grade 1 tumors. We conclude that MMP-2 and MMP-9 have different roles in uterine cervical cancer. MMP-2 could be associated with aggressive behavior, but MMP-9 expression diminishes in high-grade tumors.  相似文献   
34.
35.
BACKGROUND: Oral hairy leukoplakia (OHL) may be an indicator of the progression of Human Immunodeficiency Virus (HIV)-induced immuno-depression, and the evaluation of risk factors leading to OHL is important in the management of these HIV-infected patients. However, there are few studies that analyze risk factors leading to OHL in the Brazilian population. The aim of this case-control study is to present data about prevalence rates and risk factors leading to OHL in a sample of HIV-infected adults in Brazil. METHODS: This case-control study included 111 HIV-infected patients treated at a clinic for sexually transmitted diseases and HIV. In the initial examinations with dentists, variables were collected from all patients. Diagnosis of OHL was performed in accordance with the International Classification System and cytological features. The Fisher and the chi-squared tests were used for statistical analysis. The proportional prevalence and odds ratio were estimated. RESULTS: Outcome presented a positive, statistically significant association among the presence of OHL and viral load of 3000 copies/mul or greater (P = 0.0001; odds ratio (OR) = 5.8), presence of oral candidiasis (P = 0.0000; OR = 11.1), previous use of fluconazole (P = 0.0000; OR = 24.6), and use of systemic acyclovir (P = 0.032; OR = 4.3). Antiretroviral medication presented a negative, statistically significant association with the presence of OHL (P = 0.002; OR = 8.4). CONCLUSIONS: Prevalence of OHL was 28.8%. Viral load, oral candidiasis, previous use of fluconazole, and systemic acyclovir were determined to be risk factors for OHL. Antiretroviral medication proved to be protective against the development of OHL.  相似文献   
36.
Background.Computers that collect data from patients and provide both patients and practitioners with printed feedback on a range of health risks are a tool for assisting general practitioners with preventive care. This study assessed the impact of computer-generated printed feedback on cervical screening among women who were underscreened for cervical cancer.Method.Female attenders at two Australian general practices were randomly allocated to Experimental or Control groups. Women in both groups completed a health risk survey on a touch screen computer prior to their consultation. Those in the Experimental group received printed pages summarizing their results, including their eligibility for cervical screening and last Pap test, for themselves and their doctor. The number and proportion of underscreened women who had a Pap test in the 6 months after completing the computer survey, as determined by pathology records, were examined.Results.Of the 679 participants, 139 were classified as underscreened on the basis of self-report (74 Experimental, 65 Control) and 272 on the basis of their pathology records (148 Experimental, 124 Control). Overall about one-third of women had a test in the 6-month period, and the differences between the groups were not significant for women overall (18–70 years) or for women 18–49 years. Among women 50–70 who were underscreened based on self-report, those receiving the printout were more likely to have a Pap test in the next 6 months (P< 0.05). This pattern was also evident, but did not reach statistical significance, for older women who were underscreened based on pathology records.Conclusions.We are unable to draw conclusions regarding the effectiveness of the computer system due to the modest proportions of women screened, the small numbers, and the fact that the computer survey may have created an intervention effect in the Control group. As the study suggests the computer system is acceptable to women and may be effective for encouraging screening among older women, further exploration of the system is desirable.  相似文献   
37.
The direct causal relationship between dermatomyositis-polymyositis (PM) and malignancy remains controversial. We describe herein the case of a patient who underwent surgical treatment for colon cancer, which had preceded the onset of PM with tumor relapse. The PM markedly improved following the initiation of steroid therapy, and has remained under control, probably as a result of chemotherapy. The current concepts of variable clinical courses and the possible mechanism for the association of PM with malignancy are discussed following this case report.  相似文献   
38.
目的 建立人端粒酶RNA表达的检测方法。方法 制备人端粒酶RNA,(human telomeraseRNA,hTR)的cDNA探针,分别应用RNA斑点杂交与端粒重复序列扩增法(TRAP)分析检测不同胃粘膜的端粒酶RNA的表达与端粒酶活性。结果 人端粒酶RNA的cDNA探针制备成功。18例活检胃癌组织及45例手术胃癌组织RNA斑点杂交检测的阳性率均为l00%,相应TRAP分析的阳性率分别为88.89%、86.67%,低于RNA斑点杂交(P<0.05)。同时RNA斑点杂交结果提示在非癌胃组织中随着肠化程度增高人端粒酶RNA表达也增强。结论 RNA斑点杂交检测人端粒酶RNA,具有高度的敏感性和特异性,弥补了TRAP分析敏感性不足的缺点。  相似文献   
39.
Background: The study reviews the anticancer properties of naturalisoflavones which occur in especially high concentration in soybeans. Itconsiders the suitability of soybean products for clinical trials aiming toreduce the progression of breast cancer.Methods: Evidence is reviewed that plant isoflavones such asgenistein show cytostatic activity against human mammary cancer cell linesin vitro and can also suppress carcinogen-induced mammary cancer inyoung and mature rats.Results: Plant isoflavones are converted in the bowel to compoundswith potential antioestrogenic and antioxidative properties. These compoundsshow cytostatic activity for both oestrogen receptor-positive and negativehuman mammary cancer cell lines, and also inhibit growth and progress of therat mammary cancer model. The high content of soybean products in the diet ofAsian women has been postulated as one reason for their relatively low breastcancer incidence.Conclusion: Preclinical studies suggest that soybean products begiven priority for clinical trials in breast cancer protection. A pilot studycould test soy protein supplements as long-term adjuvant dietary treatmentafter primary surgery for early breast cancer, looking for a decrease in therisk of recurrence or of second primary tumours.  相似文献   
40.
Cancer causes significatlt emotional distress to a considerable majority of patients. Many of these patients typically receive little formal psychological intervention. Support groups, however, have provided one forum from which patients can attempt to gain help and can use to overcome some psychological trauma that accompanies the cancer hagnosis, subsequent treatment and relapse. This article reviews past studies of professionally run cancer support groups as opposed to psychological intervention groups. These studies are considered in light of the proposed benefits and the methodological limitations frequently inherent in such studies.  相似文献   
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