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   11325篇
  免费   1054篇
  国内免费   302篇
耳鼻咽喉   161篇
儿科学   166篇
妇产科学   41篇
基础医学   851篇
口腔科学   326篇
临床医学   1858篇
内科学   1309篇
皮肤病学   57篇
神经病学   489篇
特种医学   399篇
外科学   1414篇
综合类   1779篇
现状与发展   1篇
预防医学   840篇
眼科学   183篇
药学   905篇
  19篇
中国医学   1524篇
肿瘤学   359篇
  2024年   46篇
  2023年   193篇
  2022年   416篇
  2021年   608篇
  2020年   552篇
  2019年   484篇
  2018年   448篇
  2017年   503篇
  2016年   502篇
  2015年   448篇
  2014年   926篇
  2013年   841篇
  2012年   746篇
  2011年   777篇
  2010年   640篇
  2009年   530篇
  2008年   467篇
  2007年   435篇
  2006年   429篇
  2005年   355篇
  2004年   297篇
  2003年   264篇
  2002年   250篇
  2001年   218篇
  2000年   170篇
  1999年   133篇
  1998年   119篇
  1997年   113篇
  1996年   114篇
  1995年   114篇
  1994年   79篇
  1993年   65篇
  1992年   60篇
  1991年   52篇
  1990年   44篇
  1989年   27篇
  1988年   32篇
  1987年   27篇
  1986年   20篇
  1985年   32篇
  1984年   21篇
  1983年   19篇
  1982年   12篇
  1981年   12篇
  1980年   14篇
  1979年   5篇
  1978年   7篇
  1977年   4篇
  1976年   6篇
  1974年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Summary;To investigate the distribution of possible novel mutations from parkin gene in variant sub-set of patients with Parkinson’s disease(PD)in China and explore whether parkin gene plays an im-portant role in the pathogenesis of PD,70 patients were divided into early-onset group and late-onsetgroup; 70 healthy subjects were included as controls.Genomic DNA from 70 normal controls andfrom those of PD patients were extracted from peripheral blood leukocytes by using standard proce-dures.Mutations of parkin gene(exon 1—12)in all the subjects were screened by PCR-single strandconformation polymorphism(SSCP),and further sequencing was performed in tue samples with ab-normal SSCP results,in order to confirm the mutation and its location.A new missense mutationGly284Arg in a patient and 3 abnormal bands in SSCP electrophoresis from samples of another 3 pa-tients were found.All the DNA variants were sourced from the samples of the patients with early-on-set PD.It was concluded that Parkin point mutation a  相似文献   
12.
The HACCP (hazard analysis critical control point) concept is now widely applied in the food industry and provides a structured and critical approach to the identification and control of hazards that may affect food safety. It has shifted the emphasis for control from retrospective end-product testing to the effective control of raw materials and key processing operations.
This paper discusses how the HACCP approach can be applied to enteral feeding. This involves each unit assembling a multidisciplinary team of personnel involved in enteral feeding. This team will then carry out a detailed analysis of the process from selection of ingredients and feeding systems through to consumption of the feed by the patient by constructing a flow chart that relates specifically to each unit. They can then identify and assess the hazards associated with the handling of the product at each stage in the process. This will enable them to identify the points where control over an identified hazard can be achieved (critical control points, CCP) such as quality of ingredients, design of administration systems, preparation and distribution of the feeds and the procedures involved in the assembly and manipulation of the systems. Control and monitoring procedures can then be specified and implemented at relevant stages in the process. The major strengths of the HACCP procedure are that it entails a team effort from key personnel involved in the full range of activities associated with the product and each detailed analysis is specific to each unit's practices and resources and can be continually reviewed and modified in response to changing circumstances.  相似文献   
13.
Summary To investigate the distribution of possible novel mutations from parkin gene in variant subset of patients with Parkinson’s disease (PD) in China and explore whether parkin gene plays an important role in the pathogenesis of PD, 70 patients were divided into early-onset group and late-onset group; 70 healthy subjects were included as controls. Genomic DNA from 70 normal controls and from those of PD patients were extracted from peripheral blood leukocytes by using standard procedures. Mutations of parkin gene (exon 1–12) in all the subjects were screened by PCR-single strand conformation polymorphism (SSCP), and further sequencing was performed in the samples with abnormal SSCP results, in order to confirm the mutation and its location. A new missense mutation Gly284Arg in a patient and 3 abnormal bands in SSCP electrophoresis from samples of another 3 patients were found. All the DNA variants were sourced from the samples of the patients with early-onset PD. It was concluded that Parkin point mutation also partially contributes to the development of early-onset Parkinson’s disease in Chinese. WANG Tao, male, born in 1961, Associate Professor This work was supported by grants from the key program of the special scientific project of Scientific & Technologic Agency of Hubei Province (Serial No. 2001AA308B01) and the Hygienic Research Project of Hygienic Agency of Hubei province (Serial No. WJ 01529).  相似文献   
14.
应用视觉近点测定评价纺织厂不同作业工人的视疲劳。检查了32名修布工人和38名验布工人。同一工厂的33名保育员作对照组。结果表明:视觉近点的测定指标比调查受试者主诉的眼视觉症状更为敏感。修布和验布组在工作后,作业者的视觉近点比上班前明显变远,但时照蛆工作前后无明显变化。三组视觉近点比较,发现修布和验布组视觉近点的变化。提示由修布和验布作业引起的视觉疲劳,可以通过测定视觉近点来进行评价。  相似文献   
15.
上消化道出血798例分析   总被引:33,自引:0,他引:33  
目的 探讨上消化道出血的病因和相关因素。方法 回顾性分析我院 8年来 798例上消化道出血病人的临床资料。结果 男性并发上消化道出血占 80 .2 0 %、女性占 19.80 % ,男性明显高于女性 (χ2 =6 .5 6 ,P <0 .0 5 ) ;青年人、中年人及老年人各占 2 7.82 %、5 7.6 1%和 14 .5 7% (P <0 .0 1) ,老年人合并重度上消化道出血多见 ;不同性别、年龄者出血的原因不尽相同。结论 上消化道出血的病人以消化性溃疡、胃癌、急性胃粘膜损害、食道胃底静脉曲张为最常见的病因 ,性别、年龄等均为上消化道出血的相关因素  相似文献   
16.
ELFP方案治疗晚期鼻咽癌及上消化道癌疗效分析   总被引:3,自引:1,他引:2  
目的探索ELFP方案治疗转移复发的晚期鼻咽癌、食管癌、胃癌的临床疗效和毒性.方法选择病理证实的64例晚期鼻咽癌、食管癌、胃癌采用Vp-16 0.1 g静滴,d1-3;CF 0.1 g静滴,d1-3 5-FU 0.5 g静滴,d1-3;DDP 50 mg静滴,d1-2;21 d为1周期.治疗2~6个周期.结果鼻咽癌,食管癌、胃癌有效率(CR PR)分别为75%、70%、43.8%,其中胃癌与鼻咽癌及食管癌分别比较有差异;单病灶与多病灶之间疗效无差异.全组病例总生存期为3~41月,中位生存期分别为11.5、10、7.5个月.主要毒性为骨髓抑制,其中Ⅲ、Ⅳ度白细胞下降占21.9%;Ⅲ、Ⅳ度血红蛋白下降占15.6%;Ⅲ、Ⅳ度血小板下降占3.1%.Ⅲ、Ⅳ度恶心、呕吐发生率为7.8%.结论ELFP对晚期鼻咽癌及食管癌有较好的疗效,其毒性可以耐受,是临床治疗鼻咽癌,食管癌切实可行的方案.  相似文献   
17.
The purpose of this study was to evaluate the outcome of tension-free vaginal tape (TVT) procedure in women with urodynamic stress incontinence diagnosed as having intrinsic sphincteric deficiency (ISD). The combination of a maximal urethral closure pressure <20 cm H2O and a Valsalva leak point pressure <60 cm H2O was considered as diagnostic of ISD. Subjects with detrusor overactivity on preoperative urodynamics were excluded. A total of 35 patients with both low closure pressure and leak point pressure were enrolled. Bladder perforation occurred in three (8.6%) cases. Postoperative urinary voiding difficulties occurred in nine (25.7%) women. Two patients underwent surgical detension of the tape, with complete resolution of urinary retention and no relapse of incontinence. Women with postoperative voiding dysfunction had a significantly lower detrusorial pressure at the peak flow on preoperative urodynamics compared to those who voided efficiently after TVT. The mean (range) follow-up time was 12.5 months (3–36). The objective cure rate for stress incontinence was 91.4%. Two of the three (66%) patients in whom the TVT procedure failed had a fixed urethra. De novo urge incontinence was found in five (14.3%) patients.  相似文献   
18.
Some recent works suggest that extranodal atrial fibers may form part of the reenlry circuit in the atrioventricular (AV) nodal reentrant tachycardia (AVNRT). This hypothesis is based on the fact that the perinodal dissection successfully abolished AVNRT while preserving intact AV conduction. Apart from the surgical success, the electrophysiological evidence supporting this hypothesis has not been demonstrated, especially in the uncommon (fast-slow) form of AVNRT. We present some electrophysiological evidence suggesting atrial participation in eight patients with the fast-slow form of AVNRT. During the tachycardia, rapid pacing or extrastimulation was done from the orifice of the coronary sinus (CS) and the right atrium (RA), while recording the electrograms of the CS and the low septal RA. In seven patients, right and left atrial dissociation was demonstrated during pacing from the RA, while in the remaining one this was demonstrated from the CS. The interatrial dissociation will be unlikely if the intranodal reentry circuit connects with the atria via a single upper common pathway. This suggests that the upper turnaround of the reentry circuit involves atrial tissue and that the extranodal accessory pathway with long conduction times may form the ascending limb of the circuit (atrionodal reentry). Alternatively, the reentry circuit is entirely intranodal and two or more connecting pathways are present between the atria and the circuit.  相似文献   
19.
试尖对根管充填质量影响的研究   总被引:4,自引:0,他引:4  
目的:了解试尖对侧向加压法根管充填质量的影响因素。方法:随机提取我院1998年10月至2004年12月所完成的根管充填病例的X线片1000例,按试尖与未试尖,分别对前牙、前磨牙和磨牙根管充填质量进行分析。结果:在482例未试尖根管充填病例中,前牙、前磨牙和磨牙的适充比例分别为46%、37%和23%,欠充为20%、29%和47%。超充为34%、33%和29%:在518例试尖病例中,前牙、前磨牙和磨牙的适充比例分别为68%、62%和51%,欠充为6%、12%和13%,超充为25%、24%和36%。结论:在侧向加压法根管充填中,试尖可明显改善充填质量。  相似文献   
20.
目的探讨鱼腥草治疗上呼吸道感染所致发热病人的疗效。方法将确诊的病例随机分为2组,治疗组和对照组各30例。治疗组给予鱼腥草、青霉素钠静滴,对照组用病毒唑、青霉素钠静滴。结果治疗组退热时间多在2d以内,对照组多在2d后。治疗组症状消失时间多在5d以内,对照组多在5d以后。差异有统计学意义。结论用鱼腥草和青霉素静滴可缩短发热时间,且症状消失快。  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