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   42838篇
  免费   4569篇
  国内免费   858篇
耳鼻咽喉   303篇
儿科学   885篇
妇产科学   549篇
基础医学   3191篇
口腔科学   1496篇
临床医学   4212篇
内科学   5499篇
皮肤病学   468篇
神经病学   3305篇
特种医学   1275篇
外国民族医学   3篇
外科学   3411篇
综合类   4861篇
现状与发展   5篇
一般理论   2篇
预防医学   7351篇
眼科学   576篇
药学   3348篇
  25篇
中国医学   4459篇
肿瘤学   3041篇
  2024年   132篇
  2023年   940篇
  2022年   1251篇
  2021年   1782篇
  2020年   1754篇
  2019年   1710篇
  2018年   1696篇
  2017年   1618篇
  2016年   1492篇
  2015年   1322篇
  2014年   3128篇
  2013年   3158篇
  2012年   2530篇
  2011年   2702篇
  2010年   2074篇
  2009年   1974篇
  2008年   2221篇
  2007年   2292篇
  2006年   2044篇
  2005年   1716篇
  2004年   1413篇
  2003年   1350篇
  2002年   1037篇
  2001年   958篇
  2000年   769篇
  1999年   664篇
  1998年   485篇
  1997年   518篇
  1996年   400篇
  1995年   414篇
  1994年   357篇
  1993年   297篇
  1992年   299篇
  1991年   261篇
  1990年   220篇
  1989年   203篇
  1988年   194篇
  1987年   154篇
  1986年   122篇
  1985年   114篇
  1984年   100篇
  1983年   67篇
  1982年   65篇
  1981年   61篇
  1980年   57篇
  1979年   32篇
  1978年   29篇
  1977年   26篇
  1976年   18篇
  1975年   18篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
宣威昆明两地肺癌ras基因表达及突变的比较研究   总被引:1,自引:0,他引:1  
目的 :比较ras基因在宣威、昆明两地肺癌中遗传变异的差异性 .方法 :采用免疫组化染色和PCR -SSCP -DNA直接测序技术 ,对 4 5例宣威地区肺癌和 4 5例昆明地区肺癌石蜡包埋组织标本中ras蛋白的表达及k -ras基因 12密码子突变进行检测 .结果 :5 5例 (5 5 / 90 )ras蛋白表达阳性 ,其中宣威肺癌组 31例 ,昆明肺癌组 2 4例 ,2 8例 (2 8/ 90 )检测到k -ras基因 12密码子突变 .对ras基因在两组肺癌中的表达及突变进行比较分析表明 :ras蛋白表达及k -ras基因 12密码子突变在宣威肺癌组中高于昆明肺癌组 ,但差异无统计学意义 (P >0 0 5 ) ,ras蛋白在Ⅰ期肺癌病例以及腺癌病例中的表达 ,宣威肺癌组均高于昆明肺癌组 ,差异有统计学意义 (P =0 0 4 5 ,χ2 =4 5 72 ,P =0 0 32 ) .结论 :ras基因的激活是肺癌发生过程中常见的分子生物学事件 ;宣威地区肺癌与昆明地区肺癌相比 ,ras蛋白在Ⅰ期病例以及腺癌病例中的表达存在着差异 .k -ras基因 12密码子在宣威地区肺癌中的突变与昆明地区肺癌相比无明显特异性  相似文献   
102.
关于中医证候研究的几点想法   总被引:21,自引:5,他引:16  
中医证候学研究是目前中医药研究工作的前沿领域.近年来,虽从不同的角度取得了一些进展,但就本质而言,依旧没有明显的突破.虽然证候的传统定义是基本清楚的,但证候的宏观(定性)标准不十分规范,证候宏观(定性)标准量化研究方法有待统一.这在很大程度上阻碍了整个中医药现代化的进程,因此,证候的现代研究思路值得进一步探讨.在证候研究过程中,建议:(1)以现代疾病为切入点,从基本证候(单证)着手,逐步向复证研究过渡;(2)以人为研究对象,取得相当成果后再进行动物实验才有意义;(3)不仅要与生命科学接轨,更要与整个的自然科学接轨.  相似文献   
103.
104.
Review of the literature reveals little to no data regarding the use of the CO2 laser as a surgical modality in the local treatment of breast cancer. This study was undertaken to determine if the CO2 laser is a surgical improvement over the scalpel, influencing patient care during the surgical and postsurgical period. In the author's series, a total of 209 procedures were performed. Within this group, 105 cases were performed with CO2 laser and 104 cases performed with the scalpel. Biopsies were always performed as a separate procedure prior to definitive surgery. This study was not designed to compare cure rates, the medical follow-up period being 1 year. The results of this study demonstrate a significant improvement in patients' postoperative care, surgical technique, and hospital cost-effectiveness.  相似文献   
105.
妇科恶性肿瘤术后骨质疏松症的防治   总被引:1,自引:0,他引:1  
王焱  金健  刘晓红 《中医正骨》2005,17(11):10-11
为探讨妇科恶性肿瘤术后骨质疏松症的预防措施,采用补充紫竹爱维和乐力胶囊来预防骨质疏松的发生,分别与未服药的妇科恶性肿瘤及良性肿瘤术后作对照,并对其对骨代谢指标血清骨性碱性磷酸酶(BALP)及血清抗酒石酸酸性磷酸酶(TRAP)的影响进行了临床观察.结果发现恶性肿瘤术后较良性肿瘤术后患者的BALP降低,TRAP增高,服用紫竹爱维与乐力胶囊的患者TRAP均低于未服药的恶性肿瘤术后患者,P<0.05,均有显著性差异.表明妇科恶性肿瘤术后患者较良性肿瘤更易患骨质疏松症,服用紫竹爱维与乐力胶囊均能有效防治骨质疏松症,前者效果更佳,但应掌握性激素补充治疗(HRT)的应用指征.  相似文献   
106.
六神丸及其加味抗急性白血病的实验研究   总被引:4,自引:0,他引:4  
本研究从血象、骨髓、病理、骨髓细胞增殖动力学的角度证明:六神丸具有明显的抑制和杀伤实验白血病小鼠(L7212)白血病细胞的作用(主要机理类似细胞毒剂),具有缓解、减轻白血病细胞对肝脾浸润,明显延长白血病小鼠生存期的作用;六神丸加味(加用清热解毒方、活血化淤方、益气养阴方、补气养血方、补肾方)和六神丸具有明显的协同作用。  相似文献   
107.
BACKGROUND: Adipokines are involved in the regulation of many inflammatory processes and are present at very high concentrations in cord blood of term infants. OBJECTIVE: We analysed data of a large prospective birth cohort study to examine whether adiponectin and leptin concentration in cord blood are determinants of wheezing disorders in children within the first 2 years of life. METHODS: Seven hundred and forty mothers and their newborns were included in this analysis. Adiponectin and leptin concentrations were measured in cord blood. The cumulative incidence of physician-reported asthma or obstructive bronchitis was recorded during a 2-year follow-up. RESULTS: During the first 2 years of life, asthma or obstructive bronchitis was reported by the caring paediatricians for 157 (19.6%) of the children. We found a strong interaction of cord blood adiponectin and history of atopic disease in the mother with respect to the risk of physician-reported asthma or obstructive bronchitis (P=0.006). Compared with children with cord blood levels in the middle quintile (reference category), the odds ratios for physician-reported asthma or obstructive bronchitis in the bottom quintile and top quintile were 0.14 [95% confidence interval (CI) 0.02-0.90] and 2.12 (95% CI 0.67-6.66), respectively (P for trend=0.0003), among children of mothers with a history of atopy. This association was independent of other established risk factors. Leptin levels in cord blood were not associated with risk of asthma or obstructive bronchitis. CONCLUSIONS: In children of mothers with a history of atopy, concentrations of adiponectin in cord blood could play an important role in determining risk of wheezing disorders in early childhood.  相似文献   
108.
Summary A randomized prospective study was performed to compare the results of filtering surgery using a Limbusbased versus a Fornix-based conjunctival flap. The wound closure of the Fornix-based flap was performed using a running 10/0 nylon suture at the limbus. No statistical significant difference of IOP regulation was found between the two groups. There was a tendency of reduced occurrence of shallow anterior chamber and of less vascularized filtering blebs in the Fornix-based technique.  相似文献   
109.
110.
Valid classification of stroke is essential to initiate effective acute management and early secondary prevention strategies. To accurately evaluate stroke subtype a number of diagnostic procedures have to be performed. This study sought to investigate variations in use of diagnostic procedures across selected European hospitals. First-ever stroke patients were sampled over a 1-year period through 11 hospital-based registers across 10 European countries. We defined a diagnostic standard for valid aetiological classification of ischemic stroke including brain imaging, vascular imaging and echocardiography. The impact of socio-demographic, clinical and structural characteristics on performance of the diagnostic standard was assessed using multivariate logistic regression analyses. A total of 1721 patients were included in the study. 83.1% received brain imaging, ranging from 32.8% to 100%. The diagnostic standard was performed in 40.4% of stroke patients, ranging from 0% to 77.2%. Patients with increasing age ( P  < 0.001) and with more severe strokes ( P  = 0.001) were less probably to receive the diagnostic standard. Patients treated in stroke units and neurological departments were more frequently investigated with the diagnostic standard ( P  < 0.001). Less than half of hospitalized stroke patients across Europe underwent diagnostic procedures to allow for aetiological classification of stroke, which may hamper the initiation of effective early management and secondary prevention.  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