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   208310篇
  免费   15282篇
  国内免费   5090篇
耳鼻咽喉   1644篇
儿科学   2840篇
妇产科学   3311篇
基础医学   25036篇
口腔科学   4062篇
临床医学   15150篇
内科学   29169篇
皮肤病学   2380篇
神经病学   12664篇
特种医学   7709篇
外国民族医学   4篇
外科学   23034篇
综合类   28788篇
现状与发展   25篇
一般理论   8篇
预防医学   15805篇
眼科学   2406篇
药学   27321篇
  102篇
中国医学   13140篇
肿瘤学   14084篇
  2024年   343篇
  2023年   2847篇
  2022年   4991篇
  2021年   9110篇
  2020年   7636篇
  2019年   7375篇
  2018年   7366篇
  2017年   7895篇
  2016年   8134篇
  2015年   7651篇
  2014年   9610篇
  2013年   13361篇
  2012年   11045篇
  2011年   13046篇
  2010年   8503篇
  2009年   8406篇
  2008年   9702篇
  2007年   10629篇
  2006年   9918篇
  2005年   9060篇
  2004年   7750篇
  2003年   6834篇
  2002年   5419篇
  2001年   4809篇
  2000年   4042篇
  1999年   3422篇
  1998年   2688篇
  1997年   2762篇
  1996年   2529篇
  1995年   2199篇
  1994年   2136篇
  1993年   1772篇
  1992年   1639篇
  1991年   1535篇
  1990年   1320篇
  1989年   1078篇
  1988年   1047篇
  1987年   942篇
  1986年   869篇
  1985年   1251篇
  1984年   995篇
  1983年   752篇
  1982年   781篇
  1981年   635篇
  1980年   607篇
  1979年   488篇
  1978年   311篇
  1977年   267篇
  1976年   246篇
  1975年   189篇
排序方式: 共有10000条查询结果,搜索用时 812 毫秒
961.
目的探讨鼻内镜下等离子低温射频治疗常年性变应性鼻炎(PAR)的疗效及其优越性。方法在鼻内镜下用等离子低温射频治疗PAR48例,按照海口会议修订的“过敏性鼻炎诊断和疗效评定标准”,用计分法分别评定其疗效。结果该组48例术后随访半年进行评价,其中显效27.1%(13/48),有效58.3%(28/48),无效14.6%(7/48),总有效率为85.4%。疗效评分显示治疗前平均总分为(9.58±1.69)分,治疗后为(5.63±1.15)分(P<0.05)。结论鼻内镜下等离子低温射频烧灼筛前神经终末区域治疗PAR,具有简便、安全等优点,短期效果显著,特别适用于临床上应用抗组胺类药物及鼻内应用糖皮质激素治疗效果不甚理想及由于各种原因不能长期接受抗组胺类药物及鼻内应用糖皮质激素治疗的患者;但长期疗效有待进一步研究。  相似文献   
962.
血清纤维结合蛋白的酶免疫检测法   总被引:2,自引:0,他引:2  
张超 《贵州医药》2006,30(5):414-416
目的建立血清纤维结合蛋白(Fn)含量的酶免疫分析(EIA)检测方法。方法利用现有Fn检测试剂盒建立Fn的EIA测定法,并对所建立的方法从灵敏度、精密度、特异性、重复性等方面进行方法学评价。结果该法灵敏度为11.69ml/L,线性范围为50~300mg/L,批内变异系数为 3.82%,批间变异系数为5.10%,回收率97.7%。肺结核组及正常对照组血清Fn含量分别为 (188.82±5.51)mg/L和(275.25±18.11)mg/L,两组间差异有显著性意义(P<0.01);肺结核稳定期患者血清Fn显著高于进展期及好转期(P<0.05)。结论该方法线性范围适宜,准确度、精密度较好,符合临床检验工作要求。  相似文献   
963.
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   
964.
Whereas water loss in land living animals occurs continuously, water intake takes place discontinuously. At the normal operating set point of plasma osmolality, urine is more concentrated than plasma due to secretion of vasopressin. Thus animals operate around a state of mild dehydration. As water loss occurs, the severity of dehydration and thirst increase in intensity and at some point water intake occurs. Sufficient water is consumed to return plasma osmolality to the normal operating set point. Food intake and water balance are interdependent as food provides the osmoles which determine obligatory renal solute excretion. When dry food with the same osmotic content was substituted for canned food (water content 74%), dogs increased water intake from 24.2 +/- 4.3 to 62.2 +/- 8.8 ml/kg. Urine output and urine osmolality were unchanged, as under conditions of normal hydration, near maximal urine concentration is achieved. Changing water intake is the only available variable to maintain water balance. During water deprivation, the major renal mechanism appears to be natriuresis. In rehydration, satiety mechanisms ensure appropriate water intake and renal sodium conservation restores sodium balance.  相似文献   
965.
Simultaneous recording of adult subjects sipping small amounts of fluid from a cup have been obtained by videofluoroscopy together with feeding respiratory patterns and swallow sounds from the Exeter Dysphagia Assessment Technique (EDAT). These allowed visual representations of respiration and swallow sounds to be superimposed on a videofluoroscopy recording using a split-screen technique. Sequentially numbered, 1/50 sec, half-frame photographic prints were examined and schematic drawings of the relevant radiographs were made. These were superimposed on to the actual EDAT printed chart of the same swallow event, theri exact time relationship with respiration and cervical swallow sounds being preserved. The results allow events in the barium videofluoroscopy to be related to events in the feeding respiratory pattern and swallow sounds recorded by EDAT.  相似文献   
966.
在心脏手术中应用多普勒彩色超声心动仪直接探测和观察19例患者,其中风湿性心瓣膜病11例、先天性心脏病7例、左心房粘液瘤1例。风心病及左房粘液瘤患者手术前、中检查的结果基本一致;先心病术前诊断符合率为84.2%(5/7),术中诊断符合率为100%。本文对检查结果作了分析讨论,并提出符合我国情况的有关检查设想。  相似文献   
967.
Ten patients with subhepatic fluid collections complicating laparoscopic Cholecystectomy were successfully treated by interventional radiological procedures. The series included five abscesses, three hematomas, one biloma, and one serous collection. Abdominal pain or fever developed from 3 to 21 days after the laparoscopic intervention. All patients were asymptomatic 72 h after percutaneous drainage and there were no complications related to the procedure. Subhepatic fluid accumulations are common findings after laparoscopic cholecystectomies and have been considered an unreliable indicator of infection or other postoperative complications. However, the significance of these collections should not be underestimated in symptomatic patients. In such cases we propose diagnostic aspiration and drainage, when necessary, to safely and promptly establish the precise diagnosis and treatment. More serious complications can be avoided by early percutaneous intervention.  相似文献   
968.
医疗纠纷的非诉讼解决方式-医疗纠纷ADR   总被引:18,自引:0,他引:18  
由于在纠纷解决方面所表现出来的简便,经济,快捷,专业性及保密性强等优点,非诉讼纠纷解决方式(又可译为代替性纠纷解决方式)ADR(Alternative Dispute Resolution)逐渐成为许多国家和地区解决民事纠纷的一大趋势,我国现行医疗纠纷解决机制存在着较多的问题,有待于进一步的改善与完善,根据我国所面临的现实情况,将ADR引入医疗纠纷领域是一条快速,有效地解决医疗纠纷的途径,医疗纠纷的非诉讼纠纷解决方式主要包括仲裁,调解与和解,这3种纠纷解决方式各具特点,适用于不同情况下医疗纠纷的解决。  相似文献   
969.
Electrocatalytic dehalogenation of organohalides was studied using a nickel(II) tetraazamacrocyclic complex-modified graphite felt electrode. The nickel(II) tetraazamacrocyclic complex-modified graphite felt electrode was prepared by attaching nickel(II) (6-(2′-hydroxyethyl)-1,4,8,11-tetraazacyclotetradecane)perchlorate chemically to the carboxyl groups of a thin poly(acrylic acid) layer coated on the graphite felt. The modified electrode gave a reversible electron transfer for the nickel(II)/nickel(I) redox couple in cyclic voltammetry at ?0.95 V versus Ag/AgCl. A preparative electrocatalytic dehalogenation of organohalides was successfully achieved on the modified electrode with an adequate current efficiency (55.6–94.8%), conversion (34.2–100%) and turnover number of the Ni catalyst (667–3333).  相似文献   
970.
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   
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