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   29565篇
  免费   2577篇
  国内免费   1727篇
耳鼻咽喉   276篇
儿科学   311篇
妇产科学   345篇
基础医学   3670篇
口腔科学   489篇
临床医学   3820篇
内科学   4755篇
皮肤病学   227篇
神经病学   1869篇
特种医学   1141篇
外国民族医学   24篇
外科学   3132篇
综合类   4195篇
现状与发展   5篇
一般理论   16篇
预防医学   2048篇
眼科学   682篇
药学   2945篇
  13篇
中国医学   1357篇
肿瘤学   2549篇
  2024年   80篇
  2023年   387篇
  2022年   989篇
  2021年   1311篇
  2020年   967篇
  2019年   874篇
  2018年   993篇
  2017年   868篇
  2016年   892篇
  2015年   1319篇
  2014年   1505篇
  2013年   1359篇
  2012年   2211篇
  2011年   2318篇
  2010年   1483篇
  2009年   1181篇
  2008年   1646篇
  2007年   1710篇
  2006年   1698篇
  2005年   1576篇
  2004年   1312篇
  2003年   1314篇
  2002年   1164篇
  2001年   624篇
  2000年   563篇
  1999年   566篇
  1998年   349篇
  1997年   370篇
  1996年   302篇
  1995年   283篇
  1994年   248篇
  1993年   172篇
  1992年   212篇
  1991年   173篇
  1990年   150篇
  1989年   93篇
  1988年   90篇
  1987年   80篇
  1986年   61篇
  1985年   62篇
  1984年   58篇
  1983年   22篇
  1982年   26篇
  1981年   23篇
  1980年   16篇
  1979年   14篇
  1978年   11篇
  1977年   9篇
  1974年   9篇
  1973年   8篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Cancer chemotherapy in the elderly: a series of 51 patients aged>70 years   总被引:1,自引:0,他引:1  
Summary A total of 2,238 new cancer patients were treated in our institution in 1988; among the 423 (18.9%) who were>70 years old, 51 underwent chemotherapy. The median age was 75.8 years, and the Karnofsky performance status (KPS) was 70% for 40 patients. Malignancies were hematopoietic in 24 cases (47%) and digestive in 15 patients (29%), and 12 subjects (24%) had other types of cancers. The first chemotherapy course was given at the full dose to 23/51 (45.1%) patients. The drug dose was reduced for 28/51 (54.9%) patients, due in 25 cases to the subjects being>70 years old. Neither age, KPS, pretreatment assessment, nor cancer extent was correlated with the modifications made to the first cycle. An overall toxicity of grade 3+4 (WHO grading scale) was noted in 10 subjects (19.6%). Although these elderly patients were probably selected, analysis of their charts did not evidence an increase in chemotherapy toxicity, regardless of the dose they received.Presented at the EORTC Pharmacokinetics and Metabolism Group Meeting, Bordeaux, November 1990  相似文献   
62.
The diagnosis of extensive intramural hematoma of the esophagus due to a bicycle trauma was considerably delayed because symptoms did not develop until 6 h after the accident. This report underscores the importance of a barium meal and computed tomographic (CT) scan in cases of unexplained chest pain, even after minor trauma.  相似文献   
63.
注射用鹿茸生长素对肾阳虚型骨质疏松症的临床研究   总被引:8,自引:0,他引:8  
目的:探讨鹿茸生长素肾阳虚型骨质疏松的治疗作用。方法:将阳虚型骨质疏松症随机分为两组分别用鹿茸生长素与蛙降钙素治疗,测量治疗前后骨密度、骨代谢生化指标分析,以及观察临床症状和体征结果:经注射用鹿茸生长素治疗后,治疗组临床症状明显改善,骨密度较治疗前提高。  相似文献   
64.
1314例育龄妇女缺铁性贫血发病现状调查   总被引:2,自引:0,他引:2  
目的 :研究育龄妇女缺铁性贫血 (IDA)的发病现状及营养状况与IDA的关系。方法 :检测青岛市城市及农村 1314例妊娠期和非妊娠期育龄妇女的外周血红蛋白浓度 (Hb)、平均红细胞体积 (MCV)、平均红细胞血红蛋白量 (MCH)、血清铁蛋白 (SF) ,并进行个人问卷调查 ,应用营养计算软件评价膳食营养。结果 :1314例育龄妇女IDA发病率为 2 0 .4 0 % ,其中非孕妇的发病率高于孕妇。农村育龄妇女的发病率明显高于城市。孕妇中孕≥ 2 8周组发病率最高 (4 0 % ) ,与其他孕周组相比差异有高度显著性 (P <0 .0 1)。营养评价结果显示非孕妇组热量、维生素A、E、B1、B2 、PP、C的缺乏率高于孕妇组(P <0 .0 0 1)。结论 :农村育龄妇女及孕 2 8周以上的孕妇为IDA高发人群。应加强对农村育龄妇女的膳食营养宣教及指导 ,对孕晚期的孕妇及时采取有针对性的干预措施。  相似文献   
65.
Regular physical activity promotes cardiorespiratory fitness and has been considered a cornerstone for non-pharmacological treatment of more than 17 million Americans with diabetes mellitus. Physical exercise has been shown to positively affect certain cardiovascular risk factors such as insulin resistance, glucose metabolism, blood pressure and body fat composition, which are closely associated with diabetes and heart disease. With the increasingly sedentary life style in our society, routine daily exercise of moderate intensity is highly recommended to reduce cardiovascular risk, the leading cause of death in diabetic patients. Exercise produces many beneficial effects to the heart function such as reduced incidence of coronary heart disease, attenuated severity of diabetic cardiomyopathy, improved cardiac performance, cardiac reserve and autonomic regulation. Nevertheless, many diabetic patients do not appear to gain much benefit from exercise or may even be at risk of performing physical exercise. This review summarizes the benefit and risk of exercise on diabetic heart function, with a special emphasis on myocardial and autonomic function.  相似文献   
66.
PURPOSE: To evaluate safety and preliminary efficacy of the humanized anti-epidermal growth factor receptor monoclonal antibody h-R3 in combination with radiotherapy (RT) in unresectable head and neck cancer patients. Secondary end points were the measurement of h-R3 serum levels and the assessment of the potential mechanisms of antitumor effect on patient biopsies. Anti-idiotypic response to h-R3 was assessed. To predict pharmacologic effect, a mathematical model for antibodies recognizing antigens expressed in tumors and normal tissues was built. PATIENTS AND METHODS: Twenty-four patients with advanced carcinomas of the head and neck received six once-weekly infusions of h-R3 at four dose levels in combination with RT. Pretreatment tumor biopsies were obtained to evaluate epidermal growth factor receptor expression as an enrollment criterion. Second biopsies were taken to evaluate the proliferative activity and angiogenesis in comparison with the pretreatment samples. Patient serum samples were collected to measure h-R3 levels and anti-idiotypic response. RESULTS: The combination of h-R3 and RT was well tolerated. Antibody-related adverse events consisted in infusion reactions. No skin or allergic toxicity appeared. Overall survival significantly increased after the use of the higher antibody doses. Immunohistochemistry studies of tumor specimens before and after treatment revealed that antitumor response correlated with antiproliferative and antiangiogenic effect. One patient developed antibodies to h-R3. The mathematical model predicted that the maximum difference between the area under the curve in tumors and normal tissues is reached when the antibody has intermediate affinity. CONCLUSION: h-R3 is a well-tolerated drug that may enhance radiocurability of unresectable head and neck neoplasms.  相似文献   
67.
68.
目的 观察单纯疱疹病毒胸苷激酶基因(HSV-tk)-环丙氧苷(GCV)系统在胶质瘤基因治疗过程中,GCV能否诱导转导有HSV-tk基因的胶质瘤细胞凋亡。方法 采用光镜、电镜和荧光显微镜观察转导有HSV-tk基因的大鼠C6/tk胶质瘤细胞形态学的改变,以末转导HSV-tk基因的C6细胞作为对照,并以流式细胞术,DNA凝胶电流分析进一步验证细胞凋亡的发生。结果 在5μg/ml GCV作用72h后,C6  相似文献   
69.
喉癌组织恶性度与颈淋巴结转移关系   总被引:2,自引:0,他引:2  
采用五因素评点法对40例喉鳞癌进行组织学和临床方面的研究。结果表明,组织恶性度与T分期无相关性,浸润方式弥散及恶性度高(评分≥11)的肿瘤发生颈淋巴结转移率显著高于有完整肿瘤边界者及恶性度低(评分≤10)者。提示喉癌组织恶性度在预测颈淋巴结转移上有实用价值,可临导临床治疗方案的选择。  相似文献   
70.
直流电脉冲刺激豚鼠耳蜗基底膜振动研究   总被引:3,自引:0,他引:3  
为了在活体上研究哺乳类动物耳蜗基底膜的电-机械特性、将一对铂-铱电极分别置于30只豚鼠耳蜗底回的前庭阶和鼓阶。用矩形直流脉冲电刺激蜗管,用激光多普勒汛速仪测定电刺激诱发的耳蜗基底膜振动的幅度和速度。结果表明,在听敏度正常豚鼠的耳蜗,电刺激可诱发基底膜向正电极方向位移,其位移波形类似于电脉冲的矩形波。在矩形脉冲的起始沿和结束沿,由于外毛细胞的瞬态反应,可诱发与该部位特征频率一致的共振运动。据分析,这  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