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   17521篇
  免费   1470篇
  国内免费   949篇
耳鼻咽喉   153篇
儿科学   227篇
妇产科学   340篇
基础医学   2141篇
口腔科学   357篇
临床医学   2297篇
内科学   2746篇
皮肤病学   257篇
神经病学   879篇
特种医学   623篇
外国民族医学   7篇
外科学   1875篇
综合类   2555篇
现状与发展   1篇
一般理论   11篇
预防医学   975篇
眼科学   421篇
药学   1788篇
  9篇
中国医学   697篇
肿瘤学   1581篇
  2024年   62篇
  2023年   279篇
  2022年   628篇
  2021年   743篇
  2020年   555篇
  2019年   543篇
  2018年   597篇
  2017年   492篇
  2016年   451篇
  2015年   727篇
  2014年   914篇
  2013年   935篇
  2012年   1324篇
  2011年   1439篇
  2010年   922篇
  2009年   739篇
  2008年   910篇
  2007年   942篇
  2006年   881篇
  2005年   841篇
  2004年   597篇
  2003年   563篇
  2002年   411篇
  2001年   383篇
  2000年   386篇
  1999年   449篇
  1998年   304篇
  1997年   296篇
  1996年   216篇
  1995年   188篇
  1994年   153篇
  1993年   117篇
  1992年   120篇
  1991年   92篇
  1990年   82篇
  1989年   81篇
  1988年   106篇
  1987年   92篇
  1986年   66篇
  1985年   61篇
  1984年   27篇
  1983年   25篇
  1982年   31篇
  1981年   20篇
  1980年   19篇
  1979年   30篇
  1978年   15篇
  1977年   15篇
  1976年   11篇
  1975年   15篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Q. Bin  J. Li  C. Liao  Y. Cao  F. Gao 《Colorectal disease》2011,13(8):837-845
Aim The aim of this study was to evaluate systematically the efficacy and safety of oral uracil‐tegafur (UFT) plus leucovorin (LV) compared with infusional fluorouracil (5‐FU) plus LV for advanced colorectal cancer. Method Eligible studies were identified from Medline, Embase and the Cochrane Library. The end‐points included overall survival and overall tumour response rate, and toxicity including leucopenia, febrile neutropenia, stomatitis/mucositis and diarrhoea. Results Five randomized controlled trials were identified. Pooled data demonstrated no difference in overall survival between the oral UFT plus LV regimen and the 5‐FU bolus plus LV regimen [hazard ratio 1.013; 95% confidence interval (CI) 0.911–1.127].The fixed‐effect pooled estimate for overall tumour response rate showed no significant difference between the two regimens (relative risk 0.893; 0.672–1.187). Grade 3–4 leucopenia [odds ratio (OR) 0.126; 955 CI 0.048–0.326], grade 1–4 leucopenia (OR 0.089; 95% CI 0.067–0.119) and grade1–4 febrile neutropenia (OR 0.020; 95% CI 0.004–0.102) were significantly less prominent in the oral UFT regimens. For nonhaematological toxicities, grade 3–4 stomatitis/mucositis (OR 0.075; 95% CI 0.039–0.146), grade 3–4 infection (OR 0.484; 95% CI 0.310–0.758), grade 1–4 infection (OR 0.672; 95% CI 0.547–0.826, P < 0.001), grade 1–4 diarrhoea (OR 0.743; 95% CI 0.626–0.881) were also less likely to happen in patients in the oral UFT plus LV regimen, while there was no significant difference between the two treatment regimens with respect to grade 1–4 stomatitis/mucositis (OR 0.278; 95% CI 0.053–1.456) and grade 3–4 (OR 1.174; 95% CI 0.983–1.403) diarrhoea. Conclusion Oral UFT or 5‐FU bolus combined with LV results in similar overall survival and tumour response rates for advanced colorectal cancer. The former treatment regimen is greatly superior in terms of toxicity, especially haematological toxicity.  相似文献   
102.
林鹏焘  廖大清  刘进 《四川医学》2006,27(8):780-781
目的 建立急性分离果蝇成虫中枢神经细胞技术,并记录分析其钾电流。方法 取S、R或H品系果蝇成虫3—5只,分离出果蝇脑组织。胶原酶消化处理后,加入10%的胎牛血清果蝇培养基终止酶反应。巴氏吸管吹打,细胞悬液静置1h后用于电生理实验。全细胞电压钳记录并分析其外向钾电流。结果 酶消化法成功急性分离出果蝇成虫中枢神经细胞。85%以上为Ⅱ型神经细胞,少部分为Ⅰ型和Ⅲ型神经细胞。记录到快失活与持续复合型、慢失活型、快失活和持续型四种全细胞钾电流。结论 本技术可成功急性分离三品系果蝇成虫中枢神经细胞,并记录到四种钾电流。  相似文献   
103.
104.
骨质疏松与类风湿关节炎   总被引:3,自引:0,他引:3       下载免费PDF全文
类风湿关节炎和骨质疏松在我国都属于常见病和多发病,而二者之间又有着非常重要的联系。但是目前临床上还没有一个广泛应用的药物可以同时对两者都产生很好的治疗效果。为了进一步了解骨质疏松和类风湿关节炎的关系,将来能够找到更好的治疗药物,笔者从流行病学、发病机制以及治疗方法等方面分别进行了论述。  相似文献   
105.
106.
目的 探讨华南地区某眼科医院感染性角膜炎的病原菌谱及其特点。方法 回顾性系列病例研究。选择2013年7月1日至2017年12月31日在中山大学中山眼科中心进行角膜取材和微生物检测的角膜感染患者3 914例。表面麻醉后刮取病灶边缘的病灶组织,进行细菌、真菌培养及鉴定。培养结果阳性的细菌采用生化比色或质谱进行种属鉴定;真菌依据形态学进行种属鉴定。各季节菌谱阳性率差异比较采用卡方检验。结果 感染性角膜炎患者中,男2 468例(63.1%),女1 446例(36.9%),年龄(49.5±16.8)岁。病原菌培养阳性的患者共1 673例(42.7%),其中单纯细菌749例(44.8%),单纯真菌849例(50.7%),混合感染75例(4.5%)。最常见的细菌是葡萄球菌属(20.1%),其次是假单胞菌属(7.5%);最常见的真菌是镰刀菌属(25.5%),其次是曲霉菌属(10.3%)。细菌的阳性率在5-8月明显高于1-2月和9-12月(P<0.05),真菌的阳性率在5-6月明显低于1-2月和9-12月(P<0.05)。结论 在华南地区一所三甲眼科医院的感染性角膜炎中,真菌感染略高于细菌感染,且细菌和真菌感染存在季节性差异。  相似文献   
107.

Purpose:

To identify and characterize sickle cell disease (SCD)‐related changes in the composition of mandibular bone marrow using qMRI relaxometry histograms.

Materials and Methods:

Thirteen SCD patients and 17 controls underwent brain MR imaging with the mixed turbo spin‐echo (TSE) pulse sequence at 1.5T. The mandible was manually segmented and divided into body, angle, ramus, and condyle. T1 and T2 histograms of each mandible were modeled with Gaussian functions. The relaxation time histogram peaks were calculated, and the number of monomodal versus bimodal curves was compared.

Results:

SCD patients exhibited monomodal distributions on both T1 and T2 histograms, consistent with a composition of predominantly red hematopoietic marrow. Eighty‐eight percent of mandibles in control subjects exhibited a bimodal distribution in T1 and all showed a bimodal distribution in T2, indicating mixed but predominantly yellow marrow composition. The second peak in control subjects was shorter in T1 and longer in T2, consistent with yellow marrow composition.

Conclusion:

Instead of physiological fatty replacement, SCD patients exhibit red marrow persistence in the mandible, likely due to the increased demand for hematopoiesis. This phenomenon can be manifested by a monomodal curve in both T1 and T2 relaxometric histograms. J. Magn. Reson. Imaging 2013;37:1182–1188. © 2012 Wiley Periodicals, Inc.  相似文献   
108.
ObjectiveStudies have shown that some specific body measures are associated with the occurrence of cancers. Few studies have demonstrated the relationship with more comprehensive approaches. This study aims to explore body measures and the combinations associated with internal organ cancers.MethodsThree-dimensional anthropometric body surface scanning data collected 10,215 participants from the health examination department in a medical center of Taiwan during 2000–2010. Follow-up was conducted for an average of 8 years, and 244 internal organ cancer cases were identified.ResultsAn increased risk of internal organ cancers was observed among the subjects with larger waist circumference/smaller thigh circumference, in which waist-to-thigh ratio (WTR) was constructed. Comparing the subjects in the fourth quartile for WTR to the subjects in the first quartile with multiple Cox regression analysis yielded a hazard ratio of 1.842 (95% confidence interval, 1.131~2.999). The association between WTR quartile and internal organ cancers was stronger among male participants, older participants, and participants with chronic conditions.ConclusionsThe study has revealed that WTR is the most significant predictor for the occurrence of cancer in Asian populations. Because it is easy to measure and open to modification, WTR may be more useful in clinical and preventive medicine in the future.  相似文献   
109.
110.
摘 要 目的:考察影响水杨酸滴丸制备的因素,确立其最佳成型工艺。方法: 考察环境因素、加热温度、基质配比与试验步骤对滴丸制备工艺的影响。以丸重差异、溶出时限及外观质量为综合评价指标,通过正交试验进一步优化滴丸的制备工艺。结果: 基质单独加热熔化后再与药液在避光密封的条件下进行混合,可防止药液迅速氧化变红。滴丸的最佳制备工艺为:聚乙二醇400与聚乙二醇6000的比例为1∶5,药液温度为50℃,滴距为8 cm,滴制速度为70滴·min-1。结论:该工艺简单可行,制得滴丸的丸重差异、溶出时限及外观质量均符合质量要求。  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