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   22362篇
  免费   2339篇
  国内免费   726篇
耳鼻咽喉   168篇
儿科学   256篇
妇产科学   206篇
基础医学   919篇
口腔科学   544篇
临床医学   3704篇
内科学   1681篇
皮肤病学   160篇
神经病学   792篇
特种医学   573篇
外国民族医学   7篇
外科学   1338篇
综合类   3339篇
现状与发展   1篇
一般理论   1篇
预防医学   5554篇
眼科学   108篇
药学   3303篇
  77篇
中国医学   2111篇
肿瘤学   585篇
  2024年   107篇
  2023年   551篇
  2022年   821篇
  2021年   1096篇
  2020年   1169篇
  2019年   915篇
  2018年   867篇
  2017年   913篇
  2016年   981篇
  2015年   937篇
  2014年   1747篇
  2013年   1910篇
  2012年   1577篇
  2011年   1613篇
  2010年   1231篇
  2009年   1158篇
  2008年   1070篇
  2007年   1031篇
  2006年   909篇
  2005年   710篇
  2004年   616篇
  2003年   524篇
  2002年   396篇
  2001年   362篇
  2000年   301篇
  1999年   293篇
  1998年   238篇
  1997年   181篇
  1996年   166篇
  1995年   133篇
  1994年   134篇
  1993年   98篇
  1992年   103篇
  1991年   81篇
  1990年   68篇
  1989年   58篇
  1988年   54篇
  1987年   36篇
  1986年   45篇
  1985年   49篇
  1984年   42篇
  1983年   18篇
  1982年   19篇
  1981年   18篇
  1980年   27篇
  1979年   8篇
  1978年   16篇
  1977年   11篇
  1975年   8篇
  1974年   4篇
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
41.
产科危重患者多器官功能障碍综合征的临床分析   总被引:4,自引:0,他引:4  
目的 :分析产科危重患者多器官功能障碍综合征 (MODS)的发病特点及诱因 ,以及与急性生理与慢性健康状况评分II(APACHEII)的关系。方法 :回顾分析 2 0 0 0年1月至 2 0 0 4年 4月转入GICU产科危重患者中发生MODS 6 6例的临床资料 ,并计算其A PACHEII评分。结果 :产科MODS患者诱因主要是产科因素 ,共 4 8例 (72 .73% ) ,死亡 7例 (14 .5 8% ) ,以重度子痫前期或子痫及产后出血为主 ;诱因 18例妊娠合并内外科疾病 ,死亡 11例 ,死亡率为 6 1.11% ,以妊娠合并心脏病和妊娠合并重症肝炎为主。产科MODS患者死亡率随着器官损害数的增多而上升 ,差异有显著性 (P <0 .0 5 ) ;随着器官损害数的增多 ,APACHEII评分逐渐升高 ,差异有显著性 (P <0 .0 5 ) ;APACHEII评分用于预测MODS死亡阳性率 ,2 ,3,4 ,5个器官受损害 ,其阳性率分别为 33.4 5 % ,5 7.12 % ,97.0 9% ,10 0 %。结论 :产科多器官功能障碍 /衰竭的产科主要诱因是重度子痫前期 /子痫 ,产后出血 ;产科MODS患者死亡率也随着器官损害数的增多而上升 ;APACHEII评分可在一定程度上作为评定产科MODS患者病情危重程度和预测预后的指标。  相似文献   
42.
The results of most reported studies show differences between the muscular activity of low back pain patients and healthy subjects, but the focus has usually been on trunk muscles only, and they have not involved work-related tests or exercises. The reintegration of chronic low back pain patients to job market is a common problem. Therefore assessment systems like the functional capacity evaluation (FCE) according to Isernhagen [S.J. Isernhagen, Work Injury: Management and Prevention, Aspen Publishers Inc., Gaithersburg, MD, 1988] are often used tools to determine the physical abilities and deficits of long-time incapacitated persons. The aim of the present study was to compare the healthy persons and chronic low back pain patients in performing a FCE-test and to analyse their muscular activation and motion patterns. The results indicate differences in the activation patterns of the groups in the test task “floor to waist lift” common in many occupations.  相似文献   
43.
Background  Coccygodynia can cause severe pain and disability in patients. There are contradictions in the literature regarding the final results of coccygectomy for coccygodynia. We evaluated the long-term effects of coccygectomy on the intensity, characteristics, and manifestation of pain caused by coccygodynia to determine the adequacy of operation among treatment modalities. Materials and methods  Thirty-four patients with coccygodynia were treated by coccygectomy. In 22 cases, trauma, and in one case childbirth was the cause. 11 cases were regarded as idiopathic. The intensity, characteristics of pain, and the most painful activities were evaluated at an average of 7.6 (3–18) years of follow-up time. Results  Before the operation, all 34 patients had pain while sitting, moreover, 26 of them had pain during standing, walking, at night or a combination of these. 21 patients had intolerable or very intensive, mainly acute, sharp or burning pain. 11 patients had dyschesia, 2 had dysuria and 6 had dyspareunia. At follow-up, 7 patients were completely free of pain, 15 others had moderate, 11 medium, and only one patient had severe, but none had intolerable pain. Only seven patients had acute, sharp or burning pain postoperatively. The decrease of average pain score from 8.0 to 3.2 was significant (P < 10−12). The number of the patients with dyschesia and dyspareunia decreased from 11 to 7 and from 6 to 3, respectively. Two patients had dysuria, but their complaints did not change after the operation. One of the two patients who needed reoperation had an excellent final result, while the other remained unchanged. 12 and 16 patients (together 82%) regarded the final result of the operation excellent and good, respectively. The condition of five others did not change, while one became worse. The patients with younger age, smaller body mass index, and less co-morbidities had better final result. There were no serious complications. Conclusion  Coccygectomy for coccygodynia is a safe method to decrease the intensity of pain and other complaints of the patients. The operation can be the choice of treatment if conservative measures fail.  相似文献   
44.
目的评价早期胃癌不同扩大手术的实际意义,以选择合理的胃切除和淋巴结清除范围。方法以临床病理资料完整、施行规范D2及扩大手术的217例早期胃癌患者为研究对象。分析施行不同扩大手术的原因、淋巴结清除的必要性及第Ⅱ站淋巴结转移与临床病理因素的相关性。结果胃上部癌行全胃切除术6例,No.5、6淋巴结均未见转移;联合脾、脾动脉切除2例,No.10、11p、11d淋巴结均未见转移;胃下部癌联合横结肠系膜切除3例,No.15淋巴结未见转移。以上病例术中多数误认为进展期胃癌而扩大了胃切除或淋巴结清除范围,手术时间长,术中失血较多。胃下部癌清除的第Ⅱ站淋巴结中No.11p、12a、14v均未见转移;黏膜下癌(sm癌)中,No.7、8a淋巴结转移率明显高于黏膜内癌(m癌)(P〈0.05);淋巴管癌栓阳性者No.7淋巴结转移较阴性者明显增多(P〈0.001),No.1、13淋巴结转移仅出现在淋巴结转移高危病例(sm、癌灶大于3.0cm、凹陷型,淋巴管癌栓阳性)。结论早期胃癌不需施行淋巴结扩大清除术和联合脏器切除。早期胃上部癌不需施行全胃切除术。早期胃下部癌中No.11p、12a、14v淋巴结不需清除.但对胃下部癌淋巴结转移高危病例,应行标准D2淋巴结清除术。  相似文献   
45.
Evaluation of students undertaking fieldwork education placements is a critical process in the health professions. As training programs and practice evolve, systems for assessing students need to be reviewed and updated constantly. In 1995, staff of the occupational therapy training program at the University of Queensland, Australia decided to develop a new tool for assessing student fieldwork performance. Using an action research methodology, a team developed the Student Placement Evaluation Form, a flexible and comprehensive criterion-referenced evaluation tool. The present paper examines action research as an appropriate methodology for considering real-life organisational problems in a systematic and participatory manner. The action research cycles undertaken, including preliminary information gathering, tool development, trial stages and current use of the tool, are detailed in the report. Current and future development of the tool is also described.  相似文献   
46.
市售三厂家18种复方氨基酸注射液的质量评价   总被引:3,自引:0,他引:3  
目的对市售3厂家(A、B和E)共9批18种复方氨基酸注射液进行质量比较。方法参考国内外同类产品质量标准,从澄明度、透光率、性状、pH值、不溶性微粒、抗氧剂量、细菌内毒素和含量等方面进行比较。结果外观均为无色澄明液体,430nm波长处透光率均大于99%,pH在5.42~6.61间;A、B、E3厂不溶性微粒≥10、≥25μm的粒子数分别为1.41、0.32,0.83、0.21和1.55、0.56个/ml;抗氧剂的量分别为<33、近330和>500mg/L;细菌内毒素检查与含量测定符合中国药典及国家标准要求。结论不同厂家的产品质量确实存在一定的差异。  相似文献   
47.
重楼是一味传统民族药,其基源为重楼属多种植物的根茎,该属植物全世界共有26种,我国分布有20种.以横断山脉南段为核心的川、滇两省是重楼属植物在欧亚大陆的地理分布中心,也是重楼药材的传统产区.本课题对该地区重楼属的种质资源、开发利用情况、濒危状态开展了实地调查,并依据2005年版<中国药典>重楼药材的质控标准对该地区50份不同产地的重楼药材进行了质量评价,结果 可为重楼药材质量的系统评价和资源保护利用提供参考.  相似文献   
48.
注射用丹参分子排阻色谱及指纹图谱差减分析   总被引:1,自引:0,他引:1  
目的 探讨注射用丹参质量差异的分析方法.方法 取临床不良反应有差异的不同批号的样品进行平行比对试验,分别应用凝胶分子排阻色谱、碳十八反相液相色谱进行指纹图谱分析,通过综合差减分析揭示非小分子酚酸类成分信息.结果 注射用丹参的凝胶分子排阻色谱有显著的批间差异,非小分子酚酸类成分批间差异显著,与豚鼠急性毒性反应程度相对应.结论 非小分子酚酸类成分应作为丹参系列注射剂质量控制的重点.提出谱毒学研究是中药注射剂安全性研究的重要方向之一.  相似文献   
49.
We report the case of a 25-year-old male patient who presented with complaints of redness, photophobia, and decreased vision in the right eye of a week's duration. Slit-lamp biomicroscopic examination revealed a cream-colored, irregular elevated inferior iris mass, extending on to the anterior lens surface. Differential diagnoses of a fungal granuloma, a medulloepithelioma, and an amelanotic melanoma were considered. An excisional biopsy of the mass was performed through a superior clear corneal incision. Polymerase chain reaction analysis of the aqueous humor showed a positive pan fungal genome. Histopathology of the biopsied mass showed a giant cell granuloma with surrounding numerous branching, septate hyphae. Culture growth revealed Aspergillus fumigatus We report this case because of the rarity of Aspergillus iris granuloma as a primary presentation of endogenous Aspergillosis and review the relevant literature. Absence of a significant systemic history compounded the diagnostic dilemma in our patient. Definitive differentiation of this rare entity from a foreign body, amelanotic melanoma, and other inflammatory conditions such as sarcoidosis and tuberculosis, may be possible only on microbiological and histo-pathological evaluation.  相似文献   
50.
预防医学考试试卷分析与评价   总被引:5,自引:3,他引:2  
目的分析并评价郧阳医学院 2 0 0 0级本科临床医学专业预防医学期末考试试卷。方法随机选择 2 0 0 0级本科临床医学专业 3 5 1名学生的期末考试试卷进行统计分析。结果考试成绩呈负偏态分布 ,平均成绩为 72 3分 ,标准差为9 77分 ,试卷信度为 0 99。结论本试卷能较全面地考核学生对课程的掌握程度 ,但是也反映出学生综合应用试题得分较低、某些试题难易不当等问题 ,为改进教学质量提供了参考依据  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