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   16974篇
  免费   1462篇
  国内免费   928篇
耳鼻咽喉   156篇
儿科学   208篇
妇产科学   332篇
基础医学   2080篇
口腔科学   346篇
临床医学   2252篇
内科学   2669篇
皮肤病学   242篇
神经病学   881篇
特种医学   468篇
外国民族医学   7篇
外科学   1845篇
综合类   2465篇
现状与发展   1篇
一般理论   12篇
预防医学   956篇
眼科学   425篇
药学   1741篇
  8篇
中国医学   708篇
肿瘤学   1562篇
  2024年   90篇
  2023年   281篇
  2022年   628篇
  2021年   747篇
  2020年   567篇
  2019年   546篇
  2018年   596篇
  2017年   493篇
  2016年   456篇
  2015年   727篇
  2014年   906篇
  2013年   916篇
  2012年   1309篇
  2011年   1434篇
  2010年   900篇
  2009年   710篇
  2008年   889篇
  2007年   911篇
  2006年   865篇
  2005年   828篇
  2004年   584篇
  2003年   554篇
  2002年   401篇
  2001年   374篇
  2000年   377篇
  1999年   437篇
  1998年   264篇
  1997年   260篇
  1996年   177篇
  1995年   165篇
  1994年   132篇
  1993年   96篇
  1992年   111篇
  1991年   85篇
  1990年   75篇
  1989年   59篇
  1988年   87篇
  1987年   77篇
  1986年   45篇
  1985年   43篇
  1984年   22篇
  1983年   20篇
  1982年   14篇
  1981年   11篇
  1980年   7篇
  1979年   28篇
  1978年   9篇
  1975年   8篇
  1974年   8篇
  1972年   7篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
目的:建立口腔愈疡颗粒的质量标准。方法:采用高效液相色谱法对成品中芍药苷进行含量测定。结果:芍药香浓度线性范围为:0.104—0.520μg/ml,γ=0.9993。样品平均回收率为98.85%,RSD为1.27%(n=5)。结论:该方法适用于口腔愈疡颗粒的质量控制。  相似文献   
42.
Liao WM  Chiu KY  Li FB  Qiu JS  Han SY  Chow SP 《Orthopedics》2000,23(11):1175-1178
Nm23 protein expression was analyzed by immunohistochemical staining using formalin-fixed, paraffin-embedded sections from 39 cases with osteosarcomas and compared with the histologic findings and early metastasis for the purpose of detecting nm23 expression in osteosarcoma and elucidating the clinical significance of its expression. Immunoreactivity of nm23 protein was detected in 48.7% of the total cases. There was no statistical difference between nm23 expression and early metastasis, but there was a trend for cases with nm23 expression to progress to early metastasis within 1 year after operation. The role of nm23 as a tumor metastasis suppressor in osteosarcomas appeared less prominent.  相似文献   
43.
目的:为解决颅底恶性肿瘤的广泛切除或根治性切除术后所致的颅底骨与软组织缺损,预防此缺损所致的颅内感染,脑脊液漏等并发症。方法:在术中应用了斜方肌下部岛状肌皮瓣,胸大肌下部岛状肌皮瓣,颞肌复合组织瓣等各种修复方法分别对18例患者进行了一期修复。结果:修复成功率73.2%(13例),术后并发症27.8%(5例).结论:根据组织缺损的不同大小、范围、程度、部位和不同的手术入路来选择不同的修复方法,关系到手术成败。  相似文献   
44.
李锐  廖雪贞 《中成药》1998,20(11):33-37
采用水迷宫法、穿梭箱法、避暗法、跳台法观察了生命1号对小鼠学习、记忆、巩固的影响。灌胃给生命1号可改善东莨菪碱、樟柳碱致小鼠记忆获得障碍。生命1号能明显提高单核细胞吞噬功能,显著增加小鼠血清溶血素的含量,促进T淋巴细胞的转化。除此之外,还能明显地增加阳虚大鼠股骨的重量、长度、直径及皮质厚度;提高血清钙、磷水平;降低血清碱性磷酸酶的含量,具有促进骨骼生长的作用。  相似文献   
45.
SV129 or C57BL/6 mice were exposed to hyperbaric oxygenation (HBO, 5 days, 1 h every day, 100% O(2) at 3 atm absolute). One day after the 5th HBO session focal cerebral ischemia was induced. In SV129 mice, HBO induced tolerance against permanent focal cerebral ischemia (n=42, mean infarct volume reduction 27%, P=0.001), but not against transient (30 or 60 min) focal cerebral ischemia. In the C57BL/6 strain of mice, HBO did not induce tolerance against focal cerebral ischemia, even when the duration of ischemia or the HBO protocol were modified. For the first time we demonstrate that HBO can induce tolerance to focal cerebral ischemia, but this effect is strain dependent.  相似文献   
46.
PURPOSE: We describe the establishment and preliminary characterization of a cell line designated SCRC-1, which was derived from a primary renal small cell carcinoma. MATERIALS AND METHODS: Continuous cultures of a primary stage IVa renal small cell carcinoma and a xenograft in nude mice derived therefrom were characterized by immunohistology, electron microscopy, immunofluorescence/flow cytometry, cytogenetic analysis, and an in vitro drug resistance assay. RESULTS: SCRC-1 cells were reactive with antibodies to NSE, chromogranin-A, bombesin, Bcl-2, CD44s, CD44v6, CD44v7 to 8, vimentin and S100 protein (predominantly beta-subunit), and were unreactive with antibodies to EMA, CD54, EGFR(R1), URO-5, URO-7, URO-8 and URO-10. A similar immunoprofile was also found in both the primary tumor and the xenograft. Cytogenetic analysis revealed the following common clonal aberrations in all 50 metaphases analyzed: 45, XX, t (X;10;18) (p11;p11;q11), -der(18)t(X;10;18), indicating the clonal nature of this neoplasm. SCRC-1 cells showed low drug resistance to cyclophosphamide, doxorubicin, gemcitabine and fluorouracil, intermediate resistance to carmustine and mitomycin-C, and extreme resistance to cisplatin. CONCLUSION: We have documented the initial characterization of SCRC-1, which may be the first cell line reported to be derived from a primary small cell carcinoma of the kidney. This cell line can be used for further studies uncovering the biology and histogenesis of this rare cancer and delineating differences among small cell carcinomas of the kidney and other histological types.  相似文献   
47.
目的研究抗单核细胞抗体与冠心病的关系。方法以健康成人外周血单核细胞(MOC)为靶抗原,用微量间接酶免疫组织化学技术检测了35例冠心病(CHD)患者,27例献血员血清中抗单核细胞抗体(AMA)。结果冠心病组和献血员组血清中抗单核细胞抗体阳性率分别为54.3%、14.8%,平均滴度分别为1∶6.05、1∶2.63。病例组与对照组比较阳性率和平均滴度都明显增加(P<0.01),CHD患者血清稀释4倍AMA阳性率为48.6%,其四种临床类型AMA阳性率有差异,但不具显著性(P>0.05)。结论抗单核细胞抗体与冠心病有一定的关系。  相似文献   
48.
BACKGROUND: Insomnia causes severe distress in patients with breast cancer who receive chemotherapy. Few studies have focused on using objective methods to assess sleep. This study explored the quality of sleep and related factors in patients with breast cancer during chemotherapy. METHODS: The participants were 16 women with stage I or II breast cancer receiving their third cycle of chemotherapy with cyclophosphamide, epirubicin and fluorouracil, or cyclophosphamide, methotrexate and fluorouracil. The effects of chemotherapy on sleep were assessed on the 8th and 9th days of the third cycle, i.e. the active phase in terms of side effects, and the last 2 days before the start of the fourth cycle for comparison. Instruments used to assess sleep quality and related factors included actigraphy, the Hospital Anxiety and Depression Scale (HADS), the Symptom Distress Scale (SDS), the Fatigue Visual Analogue Scale (FVAS), the Epworth Sleepiness Scale (ESS), and sleep logs. RESULTS: During the active phase, patients showed an anxiety tendency with an average HADS score of 7.8 +/- 3.8. The average FVAS score was 4 +/- 2, indicative of mild fatigue, and SDS score (1.8 +/- 0.3) also indicated mild symptom distress. The number of awakenings each night was 2.2 +/- 1.6 by sleep logs, and the total time spent awake during these episodes was 47.8 +/- 26.1 minutes by Actiwatch. Sleep efficiency measured by Actiwatch in the active phase was 82.1 +/- 9.4% below the normal limit. Daytime sleepiness assessed by ESS showed mild sleepiness (6.0 +/- 3.5) in the active phase. CONCLUSION: The study showed poor sleep quality and daytime sleepiness in patients with breast cancer during the active phase of chemotherapy. Chemotherapy may bring symptom distress to patients and adversely influence sleep quality.  相似文献   
49.
PURPOSE: Tumor necrosis treatment (TNT) uses degenerating tumor cells and necrotic regions of tumors as targets for radioimmunotherapy. Previous studies in animal tumor models and clinical trials have demonstrated that when linked to the therapeutic radionuclide iodine-131, recombinant chimeric TNT antibody ((131)I-chTNT) can deliver therapeutic doses to tumors regardless of the location or type of malignancy. Therapeutic efficacy and toxicity of (131)I-chTNT in advanced lung cancer patients were studied in this pivotal registration trial. PATIENTS AND METHODS: Patients with advanced lung cancer were treated with systemic or intratumoral injection of (131)I-chTNT in eight oncology centers in China. The objective response rate (ORR) was assessed as the primary end point. RESULTS: All 107 patients who were entered onto the study and completed therapy had experienced treatment failure after prior radiotherapy or chemotherapy a mean of three times. The results showed an ORR of 34.6% (complete response, 3.7%; partial response, 30.8%; no change, 55.1%; and progressive disease, 10.3%) in all patients and 33% in 97 non-small-cell lung cancer patients. A biodistribution study demonstrated excellent localization of the radioactivity in tumors in both systemically and intratumorally injected patients. The most obvious adverse side effect was mild and reversible bone marrow suppression. CONCLUSION: Radioimmunotherapy with (131)I-chTNT was well tolerated and can be used systemically or locally to treat refractory tumors of the lung.  相似文献   
50.
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