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   214180篇
  免费   19047篇
  国内免费   4530篇
耳鼻咽喉   3275篇
儿科学   4189篇
妇产科学   3629篇
基础医学   17431篇
口腔科学   7384篇
临床医学   20119篇
内科学   20847篇
皮肤病学   2465篇
神经病学   10825篇
特种医学   5973篇
外国民族医学   11篇
外科学   20686篇
综合类   33855篇
现状与发展   9篇
一般理论   32篇
预防医学   28775篇
眼科学   2050篇
药学   20558篇
  333篇
中国医学   26177篇
肿瘤学   9134篇
  2024年   595篇
  2023年   4178篇
  2022年   6641篇
  2021年   10675篇
  2020年   10258篇
  2019年   11631篇
  2018年   10311篇
  2017年   8889篇
  2016年   7946篇
  2015年   7467篇
  2014年   14572篇
  2013年   15061篇
  2012年   13056篇
  2011年   13956篇
  2010年   11250篇
  2009年   9706篇
  2008年   9059篇
  2007年   9108篇
  2006年   7730篇
  2005年   6532篇
  2004年   5465篇
  2003年   4850篇
  2002年   3730篇
  2001年   3129篇
  2000年   2763篇
  1999年   2257篇
  1998年   1818篇
  1997年   1642篇
  1996年   1334篇
  1995年   1267篇
  1994年   1155篇
  1993年   1003篇
  1992年   934篇
  1991年   848篇
  1990年   744篇
  1989年   723篇
  1988年   673篇
  1987年   599篇
  1986年   554篇
  1985年   1804篇
  1984年   2079篇
  1983年   1307篇
  1982年   1719篇
  1981年   1196篇
  1980年   1023篇
  1979年   912篇
  1978年   746篇
  1977年   556篇
  1976年   704篇
  1975年   480篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Infracture Technique for the zygomatic body and arch reduction   总被引:2,自引:0,他引:2  
In the Orient, prominent malar regions are considered unaesthetic and the majority of women with a prominent malar want to reduce the zygoma. Various operative procedures such as shaving or chiseling the zygomatic body or the zygomatic arch have been used for reducing malar eminence, but the zygomatic arch cannot be reduced sufficiently by these methods. By combining intraoral shaving of the zygomatic body and a new effect arch infracture technique through a temporopreauricular incision, we have obtained very satisfactory results in 19 cases and notable minimal complications over the last three years.  相似文献   
992.
Electrically conducting soluble polyaniline (PANI), containing different amounts of a bulky lipophilic cationic additive, tridodecylmethylammonium chloride (TDMACl), was studied by Raman (λexc=780 nm) and UV–vis spectroscopy. PANI was made simultaneously electrically conducting and soluble with bis[4-(1,1,3,3-tetramethylbutyl)phenyl]phosphoric acid in dichloromethane. The PANI membranes were prepared by drop casting on glassy carbon or ITO substrates. Raman and UV–vis measurements were carried out in a 0.1 M CaCl2 solution at potentials between 400 and ?600 mV (vs. SCE) at pH 6, or alternatively at the open circuit potential at pH 10. The results of Raman, UV–vis and cyclic voltammetric measurements confirm that the incorporation of TDMACl into the PANI membrane facilitates the oxidation and reduction of PANI.  相似文献   
993.
颈椎侧块钢板在脊髓型颈椎病治疗中应用   总被引:2,自引:1,他引:1  
目的 对15例脊髓型颈椎病患者行后入路椎管减压、椎板成型术的同时使用颈椎侧块钢板固定,探讨和分析该手术方法的优点和手术治疗效果。方法 从自2000年3月—2002年12月,对15例脊髓型颈椎病患者(术前颈椎MR显示有三个节段颈椎椎间盘水平病变并有黄韧带增厚突入椎管),行颈椎后入路双开门椎板成型术加双侧颈椎侧块钢板固定。按JOA评分法评定患者手术前后恢复情况。结果 本组患者男10例,女5例,随访5个月—1年2个月,平均9个月,术后2—7天(平均3.5天)可戴颈围坐起,颈围外固定时间12周,融合时间3—5个月,(平均为3.5个月),术后JOA评分明显提高,所有病人无术中血管、神经根损伤,无植骨不愈合,无内固定断裂。结论 行颈椎后入路双开门椎板成型术联合应用颈椎侧块钢板固定,从后方扩大椎管容积,对脊髓进行减压,辅助以侧块钢板对减压后的颈椎行即时的稳定的固定,增加后方所植髂骨的融合成功率,大大地减少颈椎术后后突畸形发生和术后卧床并发症的发生率。  相似文献   
994.
A retrospective study of 103 thymectomies examines the effects of the integration of surgical and medical therapy in patients affected by myasthenia gravis accompanied by thymoma. An extended thymectomy via a median longitudinal sternotomy was used in 102 patients. The operative mortality was 4.85% (5/103 patients), the 10-year survival rate was 78% with a recurrence rate of 3.06% (3/98). Neoplastic infiltration and postoperative radiotherapy did not influence the survival rate. There was no correlation between a preoperative Osserman's class better than III and postoperative outcome. The improvement of medical treatment, and anaesthesiological and intensive care techniques resulted in a decrease of the operative mortality and long-term death rate during the last 10 years of our 20-year series. Extended thymectomy via sternotomy is the best intervention in patients with myasthenia gravis associated with thymoma judged by the low operative mortality and the favorable 10-year survival rates.  相似文献   
995.
An automated measurement of total and free hydroxyproline in serum or urine is presented that uses flow injection analysis. After exclusion of nonspecific substances, hydroxyproline was oxidized by chloramine- T and L-cysteine with Ehrlich's reagent. The linearity obtained was from 3.8μmole/ L to 1.22 mmole/L with good precision (CV <3%). Comparison of the proposed method with HPLC yielded r = 0.939 as the correlation coefficient. Reference intervals of free and total hydroxyproline are 1.4–9.7 μmole/L, 3.8–27.2 μmole/L for serum, and 10.0–72.5 μmole/L, 25.2–303.6 μmole/L for urine, respectively. Serum free and total hydroxyproline levels in renal osteodystrophy patients on maintenance hemodialysis (N = 71) were significantly higher than in controls (P<0.0001). This method is superior to the use of HPLC with regard to stability of the color reaction. The measurement of serum free and total hydroxyproline is a useful marker for therapeutic observation of renal osteodystrophy patients. © 1994 Wiley-Liss, Inc.  相似文献   
996.
Immune L3T4+ and Lyt-2+ lymphocytes play an important role in the acquired resistance of mice to challenge with virulent Candida albicans, and release macrophage-activating cytokines in response to yeast cells in vitro. To determine whether antigen (Ag)-specific cytotoxic T lymphocytes are generated during fungal infection, purified L3T4+ and Lyt-2+ lymphocytes from immunized mice were cultured in the presence of syngeneic accessory cells, Candida Ag, and IL-2. Yeast-infected bone marrow macrophages and peritoneal exudate neutrophils were used as target cells in a standard 51Cr release assay. Ag-specific, MHC-unrestricted lysis of infected macrophages was evident with immune Lyt-2+ cells after 5–10 days in culture. Under the same experimental conditions, the cytotoxic activity of L3T4+ cells was negligible, but its expression could be induced by the addition of anti-CD3 antibody.Culturing immune Lyt-2+ cells for shorter periods of time (1–2 days) resulted in preferential lysis of infected neutrophils. In addition, at limiting effector cell numbers, Ag-specific MHC-restricted lymphocytes with cytotoxic activity to infected macrophages could be identified. We suggest that C. albicans infection stimulates multiple cytotoxic T-cell precursors with varying recognition stringency, wich may have an important role in antifungal resistance in vivo.  相似文献   
997.
经调查河南省七县1988~04~1989~03孕产妇死亡率为136.1/10万,高于全国平均水平(94.7/10万)。从七县中选择了死亡率偏高的三个县(147.9/10万)为样本.进行厂降低农村孕产妇死亡率保健措施的研究。自1990年4月1日~1992年3月31日。在三县采取了以下保健措施:①加强基层妇幼卫生建设,特别是中心乡卫生院的建设,②整顿和完善三级保健网;③建全孕产妇系统管理制度,高危妊娠筛查,转化和转诊制度,④配备必要设备,建立联合小产院,实行定点接生。两年内孕产妇死亡率,由1989年的147.9/10万下降到67.7/10万,下降幅度为54.44%,最高达72.1%。此工作为实现2000年孕产妇死亡率下降一半的规划目标提供了依据。  相似文献   
998.
程乐 《实用医技杂志》2003,10(4):397-398
介入治疗是融合了内科药物治疗、外科手术治疗及医学影像学的一种特殊的治疗体系 ,其疗效受到世人瞩目并成为目前发展最为迅速的学科之一。但是 ,再好的方法也会存在不足之处 ,介入治疗也不例外。随着介入治疗在各家医院的普遍应用 ,并发症的发生也会越来越多 ,迫使人们关注这个问题。所谓介入治疗并发症 ,是指因血管造影及 (或 )血管内治疗所引起、需要一定治疗、使病人的治疗复杂化或延长病人住院时间的不良反应 ,就其全身多系统而言 ,介入治疗引发并发症的原因大致可归纳为两个主要因素即介入器材操作和引入人体内的物质(包括介入治疗所…  相似文献   
999.
Malignant transformation of a benign Warthin's tumour (adenolymphoma) is extremely rare. The light microscopic and ultrastructural features of an adenocarcinoma arising in a Warthin's tumour in the parotid gland are described. Light microscopy demonstrated a transition zone from the benign to the malignant component, and the malignant cells revealed oncocytic features by both light- and electronmicroscopy.  相似文献   
1000.
桡骨头切除对肘关节稳定性影响的生物力学研究   总被引:25,自引:6,他引:19  
目的:探讨桡骨头粉碎性骨折不同治疗方法对肘关节稳定性的影响。方法:将10个尸体标本,分别测定在其它组织无损伤时,肘内侧副韧带切断时,肘内侧副韧带和前臂骨间膜均切断时的力-位移曲线(纵向位移)及肘外翻角。结果:肘内侧副韧带切断时的纵向位移及肘外翻角均大于其它组织无损伤时;肘内侧副韧带和前臂骨间膜均切断时的纵向位移及肘外翻角均大于其它组织无损伤时和肘内侧副韧带切断时,两两间比较均有显著性差异(P<0.001)。结论:在其它组织无损伤时,单纯桡骨头切除是安全的;合并肘内侧副韧带损伤时,可在有效修补韧带的同时作单纯头切除,必要时行假体置换;合并肘内侧副韧带和前臂骨间膜均损伤时,最好作假体置换。  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