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   102449篇
  免费   43646篇
  国内免费   1886篇
耳鼻咽喉   1664篇
儿科学   4868篇
妇产科学   874篇
基础医学   17608篇
口腔科学   5433篇
临床医学   16269篇
内科学   25749篇
皮肤病学   7768篇
神经病学   14175篇
特种医学   2996篇
外国民族医学   7篇
外科学   15228篇
综合类   6091篇
现状与发展   6篇
一般理论   25篇
预防医学   6837篇
眼科学   2038篇
药学   8811篇
  40篇
中国医学   2850篇
肿瘤学   8644篇
  2024年   81篇
  2023年   391篇
  2022年   902篇
  2021年   2383篇
  2020年   5974篇
  2019年   11456篇
  2018年   10779篇
  2017年   12184篇
  2016年   12722篇
  2015年   12985篇
  2014年   13286篇
  2013年   13709篇
  2012年   6302篇
  2011年   6417篇
  2010年   10673篇
  2009年   6773篇
  2008年   3721篇
  2007年   2589篇
  2006年   2559篇
  2005年   2019篇
  2004年   1726篇
  2003年   1717篇
  2002年   1590篇
  2001年   1523篇
  2000年   1262篇
  1999年   691篇
  1998年   274篇
  1997年   259篇
  1996年   179篇
  1995年   141篇
  1994年   133篇
  1993年   72篇
  1992年   93篇
  1991年   53篇
  1990年   44篇
  1989年   52篇
  1988年   33篇
  1987年   38篇
  1986年   33篇
  1985年   28篇
  1984年   12篇
  1983年   7篇
  1982年   8篇
  1981年   17篇
  1980年   10篇
  1979年   15篇
  1978年   9篇
  1975年   9篇
  1974年   9篇
  1973年   11篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
肝硬化病人施行胆道手术35例分析   总被引:2,自引:0,他引:2  
本文对我院近10年来收治的肝硬化病人施行胆道手术35例进行分析,术前漏诊肝硬化12例,占3O%以上,死亡5例,有3例死于胆囊床大出血与术前漏诊有关。作者就术前漏诊原因、术前准备和手术处理体会进行讨论。  相似文献   
102.
Background: It has been suggested that oral cobalamin (vitamin B12) therapy may be an effective therapy for treating cobalamin deficiencies related to food‐cobalamin malabsorption. However, the duration of this treatment was not determined. Patients and method: In an open‐label, nonplacebo study, we studied 30 patients with established cobalamin deficiency related to food‐cobalamin malabsorption, who received between 250 and 1000 μg of oral crystalline cyanocobalamin per day for at least 1 month. Endpoints: Blood counts, serum cobalamin and homocysteine levels were determined at baseline and during the first month of treatment. Results: During the first month of treatment, 87% of the patients normalized their serum cobalamin levels; 100% increased their serum cobalamin levels (mean increase, +167 pg/dl; P < 0.001 compared with baseline); 100% had evidence of medullary regeneration; 100% corrected their initial macrocytosis; and 54% corrected their anemia. All patients had increased hemoglobin levels (mean increase, +0.6 g/dl) and reticulocyte counts (mean increase, +35 × 106/l) and decreased erythrocyte cell volume (mean decrease, 3 fl; all P < 0.05). Conclusion: Our findings suggest that crystalline cyanocobalamin, 250–1000 μg /day, given orally for 1 month, may be an effective treatment for cobalamin deficiencies not related to pernicious anemia.  相似文献   
103.
The objective of this study was to compare the clinical and laboratory consequences of left and right displacement of the abomasum (LDA and RDA), short‐ and long‐term survival after surgery and the findings in cows, that could not be cured by omentopexy. Data from 564 cases of displaced abomasum (466 LDA, 98 RDA) were analysed retrospectively. Clinical and laboratory findings were compared between the two manifestations of DA. Survival was assessed after 10 days and after 15 months. Necropsy was carried out on cows that died or were killed. On arrival at the clinic, left displacement of the abomasum (LDA) cows had been recognized as diseased for longer. LDA occurred earlier in lactation, and more cows with right displacement of the abomasum (RDA) were pregnant. Overall clinical symptoms were more severe in RDA than in LDA cows. Heart rate was higher, body temperature was lower, inanition, abnormal faeces and ruminal stasis were more frequent in RDA cows. Leucocyte counts were higher, and potassium and chloride levels were lower in RDA cows. Acetonuria was more frequent in LDA cows. More LDA than RDA cows were released from the clinic as cured (82.0% versus 74.5%). However, survival after the early post‐surgical period was similar for RDA and LDA cows. At necropsy, diseases of the gastrointestinal system were the predominant finding in RDA cows, while in LDA cows, diseases of the liver and other concurrent diseases were more important.  相似文献   
104.
To evaluate changes in matrix molecules of the joint capsule, the right knees of 24 skeletally mature female NZW rabbits were immobilized while the contralateral limb served as an unoperated control. The immobilization was discontinued at 8 weeks and the rabbits were divided among four groups (n = 6) based on the number of weeks the right knees were remobilized: 0, 8, 16, or 32. Three rabbits (six knees) that did not have operations provided normal control joint capsules. The mRNA levels for collagen types I, II, and III, and MMP-1 and -13 were significantly increased in the joint capsules of the contracture knees in all groups when compared to normal and contralateral limb joint capsules. In contrast, the mRNA levels for TIMP-1, -2, and -3 were decreased in the joint capsules of the contracture knees in all groups when compared to normal and contralateral limb joint capsules. The mRNA levels for lumican and decorin were increased in the joint capsules of the contracture knees in all groups when compared to normal capsules. Many of the changes observed in this animal model are similar to those observed in human joint capsules from posttraumatic elbow contractures, supporting the value of this rabbit model.  相似文献   
105.
106.
医源性子宫内膜异位症是指由于医学检查或治疗的影响而使子宫内膜异位种植,存活或已有的内膜异位灶进一步发展,近年发病率逐渐上升,原因主要与各种妇产科操作的增多有关,现就医源性子宫内膜异位症的治疗进展作一综述。  相似文献   
107.
体外培养的小鼠骨髓基质细胞对血细胞集落形成的支持   总被引:2,自引:0,他引:2  
为探讨骨髓基质细胞在液体条件下支持造血的能力,对小鼠骨髓有核细胞体外培养,在液体培养基中形成基质细胞贴壁层,更换培养液,再种植骨髓有核细胞。结果在贴壁的基质细胞上形成了细胞集落。按细胞形态特征分为两类:一类为基质细胞集落,仅为偶见。另一类为造血细胞集落,数量较多,并且集落通过一定的结构与贴壁的基质细胞连接。结果提示,造血细胞集落的形成,需要有与骨髓基质细胞接触的微环境,并可对基质细胞的生长发育有一定的反作用。本文提出了造血细胞集落的液体培养法。  相似文献   
108.
109.
Objective: To determine the effects of a total laryngectomy on the swallow and subsequent quality of life in head and neck cancer patients. Design: Cross‐sectional single centre cohort study. Setting: Head and Neck Oncology Unit, Tertiary Referral Unit. Patients: Sixty‐two patients who underwent total laryngectomy at our centre participated in the study. Methods: Subjects were stratified by age, sex, tumour stage, other procedures such as myotomy and nerve re‐implantation. Pharyngectomy, glossectomy, flap reconstruction, neck dissection and previous radio‐ and chemotherapy were also assessed to see if they affected swallow and subsequent quality of life. Main outcome was measured using the MD Anderson Dysphagia Inventory questionnaire. Results: Responses were received from 46 males and 16 females (response rate of 80.5%) with a mean age of 64.7 years (SD 9.4). Median follow‐up in patients was 90 months (range 1–276). The mean MD Anderson Dysphagia Inventory total score in our series of patients was 77.7 (SD 16.6). MD Anderson Dysphagia Inventory global score was 79.4 (SD 22.6), Emotional score was 77.7 (SD 17.8), Functional score 81.3 (SD 15.9) and Physical score was 74.1(SD 18). Statistically significant differences were seen between the emotional scores of glossectomised and non‐glossectomised patients (Mann Whitney, P = 0.04). No significant correlation was seen between the subscale scores and the remaining treatment variables such as age, gender, site, tumour stage, myotomy, nerve implantation, radiotherapy, reconstruction and major complications. Conclusion: This questionnaire study is the largest of its type to assess the swallow of patients who have undergone laryngectomy at a single centre. The overall result confirmed that most patients had a subjectively good swallow. Only glossectomy and the method of PE segment closure were shown to significantly affect swallowing outcomes following surgery. We recommend further work especially prospective studies pre and post surgery using this or similarly validated instruments to fully assess swallow in the laryngectomy population.  相似文献   
110.
HQJ-500多功能净水装置装舰试用评价   总被引:1,自引:1,他引:0  
目的:改善舰船官兵的饮用水水质,提高舰员的生活质量。方法:将研制的HQJ-500多功能净水装置装舰试用,征求试用意见并进行水质分析。结果:经实船试用证实,该多功能净水器能经受住各种海况下颠簸,摇晃的考验。运行正常。处理后的水质有明显改善。结论:该装置净化,消毒效果肯定,适合舰船使用,可推广应用。  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