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   5444篇
  免费   549篇
  国内免费   490篇
耳鼻咽喉   34篇
儿科学   107篇
妇产科学   42篇
基础医学   614篇
口腔科学   78篇
临床医学   687篇
内科学   904篇
皮肤病学   76篇
神经病学   362篇
特种医学   265篇
外国民族医学   10篇
外科学   504篇
综合类   1059篇
现状与发展   2篇
预防医学   317篇
眼科学   135篇
药学   617篇
  2篇
中国医学   299篇
肿瘤学   369篇
  2024年   17篇
  2023年   77篇
  2022年   210篇
  2021年   294篇
  2020年   189篇
  2019年   189篇
  2018年   191篇
  2017年   162篇
  2016年   160篇
  2015年   248篇
  2014年   317篇
  2013年   237篇
  2012年   427篇
  2011年   414篇
  2010年   264篇
  2009年   203篇
  2008年   281篇
  2007年   272篇
  2006年   300篇
  2005年   261篇
  2004年   212篇
  2003年   235篇
  2002年   195篇
  2001年   167篇
  2000年   145篇
  1999年   133篇
  1998年   96篇
  1997年   89篇
  1996年   77篇
  1995年   66篇
  1994年   57篇
  1993年   38篇
  1992年   48篇
  1991年   45篇
  1990年   30篇
  1989年   25篇
  1988年   32篇
  1987年   20篇
  1986年   21篇
  1985年   14篇
  1984年   3篇
  1983年   7篇
  1982年   2篇
  1981年   6篇
  1978年   1篇
  1977年   1篇
  1976年   1篇
  1975年   3篇
  1974年   1篇
排序方式: 共有6483条查询结果,搜索用时 11 毫秒
11.
Over a follow-up period of 6 years, 4 out of 31 live related renal allograft recipients (12.9%) developed azathioprine induced bone marrow suppression. Presentation in 3 patients was with fever and 2 patients also had associated graft dysfunction. All patients had leucopenia, 2 patients in addition had anaemia and one patient had pancytopenia. Bone marrow suppression developed 9.6 months (3.5-16.0 months) following transplantation and recovery followed over a period of 30 (18-49 days) days after withdrawal of the drug. One patient succumbed during the phase of bicytopenia.KEY WORDS: Azathioprine, Bone marrow suppression, Kidney transplantation  相似文献   
12.
The genes coding for separate isoforms of both the human glutathioneS-transferase class mu and class theta enzymes (GSTM1and GSTT1) arepolymorphic with a variable ethnic distribution. These enzymes detoxifyreactive epoxides, including carcinogens produced by tobacco smoke. Becauseof this, the null polymorphism in the GSTM1 gene (coding for the glutathioneS-transferase class mu enzyme) has been studied widely as a possible sourceof inherited susceptibility to smoking-related lung cancer. The more recentlydescribed null polymorphism in the GSTT1 gene also could contribute to anincreased risk of smoking-related lung cancer. As the incidence of lungcancer is known to differ by ethnicity, we have conducted a case-controlstudy in the United States of 108 African-Americans (Blacks) and 60Mexican-Americans (Hispanics) with lung cancer and 132 African-American(Black) and 146 Mexican-American (Hispanic) controls to investigate theassociation of the GSTT1 and GSTM1 polymorphi sms with lung cancer inminority populations. In the unadjusted data, there was a borderlinesignificant association of the GSTM1 null polymorphism with lung cancer inMexican-Americans (odds ratio [OR] = 1.8, 95 percent confidence interval [CI]= 1.0-3.3 ) that was not observed in African-Americans. The GSTT1 nullpolymorphism also had a higher prevalence in cases than controls in bothracial/ethnic groups, but this increase was not statistically significant.When the data were analyzed using logistic regression controlling for age,gender, race, and smoking, no significant association of either trait withlung cancer was observed, with ORs for both traits of approximately 1.3.However, when the prevalence of individuals who were null for bothpolymorphisms was compared by case status, a significant interaction wasobserved. Logistic regression models showed the OR for the association oflung cancer and the presence of both null polymorphisms compared with one(either GSTT1 or GSTM1) or no null genotype to be 2.9 (P < 0.04). Theseresults suggest that there may be carcinogenic intermediates in cigarettesmoke that are substrates for both the GSTT1 and GSTM1 enzymes, and that lungcancer risk is increased more than additively for individuals who have bothGSTT1 and GSTM1 null polymorphisms.  相似文献   
13.
放疗联合肝动脉化疗栓塞治疗肝癌的研究进展   总被引:3,自引:1,他引:3  
对于不能手术的原发性肝癌患者,放射治疗配合肝动脉栓塞化疗(TACE)的疗效明显好于单纯放疗或单纯化疗,治疗并发症的发生率和程度可以接受,大多数患者可以耐受。放疗配合动脉栓塞化疗是治疗不能手术的原发性肝癌患者的非常有发展前途的治疗方法。现综述这二种治疗方法的技术特点、疗效和协同作用研究的现状及最新进展。  相似文献   
14.
2-吡啶甲醇及2-吡啶甲醛的合成   总被引:2,自引:0,他引:2  
以 2 -甲基吡啶为原料、过氧化氢为氧化剂制备 2 -吡啶甲醇和 2 -吡啶甲醛,工艺方法经济、安全  相似文献   
15.
16.
目的探讨经CD34^+纯化的自体外周造血干细胞移植治疗小儿皮肌炎的疗效。方法1例3岁皮肌炎患儿接受经CD34^+纯化的自体外周造血干细胞移植。采用环磷酰胺(CTX)+粒细胞集落刺激因子(G-CSF)方案动员外周血干细胞后,通过CliniMACS细胞分选仪分选CD34+细胞,预处理选用CTX、兔抗人T淋巴免疫球蛋白(ATG)和马法兰(MeL)。0天回输CD34^+细胞数9.45×10^6/kg。观察症状体征变化、造血重建及免疫恢复情况。结果动员获得单核细胞数为1.04×10^7/kg,经纯化获得CD34^+细胞占94%,CD34^+细胞回收率达67%,去除3个对数级CD3^+。+9d粒系植入,+14d巨核系植入。+19d皮损恢复正常,四肢肌力由移植前Ⅱ级或Ⅲ级转为Ⅳ级。+180d免疫恢复,+210d肌力恢复Ⅴ级。结论对常规治疗无效的小儿皮肌炎,可选择CD34^+纯化自体外周造血干细胞移植。  相似文献   
17.
Background: The role of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children with high-risk (HR) T-cell acute lymphoblastic leukemia (T-ALL) in first complete remission (CR1) is still under evaluation. Moreover, relapse is the main factor affecting survival. This study aimed to explore the effect of allo-HSCT (especially haploidentical HSCT [haplo-HSCT]) on improving survival and reducing relapse for HR childhood T-ALL in CR1 and the prognostic factors of childhood T-ALL in...  相似文献   
18.
19.
This study aims to analyze the characteristics of idiopathic membranous nephropathy (iMN) with nondiabetic urine glucose during the follow-up. We retrospectively analyzed the data of 1313 patients who were diagnosed iMN. The prevalence of nondiabetic urine glucose during follow-up was 10.89%. There were significant differences between the patients with nondiabetic urine glucose and those without urine glucose in gender, hypertension ratio, proteinuria, N-acetyl-β-glucosaminidase, retinol binding protein, serum albumin, serum creatinine (Scr), cholesterol, triglyceride and positive anti-phospholipase A2 receptor antibody ratio, glomerular sclerosis ratio, acute and chronic tubular injury lesion at baseline. To exclude the influence of the baseline proteinuria and Scr, case control sampling of urine glucose negative patients was applied according to gender, baseline proteinuria and Scr. The proteinuria nonremission (NR) ratio was 45.83 versus 12.50% of the urine glucose positive group and case control group. Partial remission (PR) ratio of the two groups was 36.46 versus 23.96% and complete remission (CR) ratio was 19.79% versus 63.54%, respectively. Patients with urine glucose had higher risk of 50% estimated glomerular filtration rate (eGFR) reduction. Cox regression showed that urine glucose and baseline Scr were risk factors of 50% reduction of eGFR. Urine glucose remission ratio of the patients with proteinuria NR, PR, and CR was 13.33, 56.25, and 94.73% (p < 0.005). Patients who got urine glucose remission also had better renal survival. In conclusion, non-diabetic urine glucose was closely related to proteinuria. It could be applied as a tubular injury marker to predict renal function.  相似文献   
20.
The objective was to determine the potential associations of the angiotensin II receptor type 1 (AGTR1) gene polymorphism, methylation, and lipid metabolism in Chinese farmers with hypertension.A case-control study was conducted in Wuzhi county of Henan province in China in 2013 to 2014. A total of 1034 local residents (35–74 years, 386 hypertensive cases, and 648 normotensive subjects) were enrolled in this study. Triglyceride (TG), total cholesterol (TC), high-density lipoprotein, and low-density lipoprotein were measured using automatic chemistry analyzer. The AGTR1 gene promoter methylation level was measured using quantitative methylation-specific polymerase chain reaction method. The single nucleotide polymorphism rs275653 was genotyped with TaqMan probe assay at an applied biosystems platform.The gender, body mass index (BMI), TG, TC, and family history of hypertension in the hypertension group were significantly higher than those in control group (P < .05). No significant difference was observed in the distribution of AGTR1 rs275653 polymorphism in the hypertension and controls (P > .05). The AGTR1 gene methylation in subjects carrying different genotypes was not significantly observed (P > .05). The logistic regression analysis found the AGTR1 gene methylation level was negative correlation with hypertension in the present study (odds ratio, 0.946, 95% confidence interval, 0.896–0.999) through adjusting for age, gender, BMI, education, smoking, alcohol drinking, fruit and vegetable intake, pickles intake, and family history of hypertension.The association of AGTR1 gene hypomethylation and essential hypertension was observed in Chinese farmers; no significant difference was observed in the distribution of AGTR1 rs275653 polymorphism.  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