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   219649篇
  免费   20566篇
  国内免费   15419篇
耳鼻咽喉   1901篇
儿科学   2190篇
妇产科学   2980篇
基础医学   26531篇
口腔科学   3685篇
临床医学   30814篇
内科学   32952篇
皮肤病学   2229篇
神经病学   12386篇
特种医学   8226篇
外国民族医学   138篇
外科学   21723篇
综合类   35424篇
现状与发展   55篇
一般理论   19篇
预防医学   13162篇
眼科学   6695篇
药学   22723篇
  194篇
中国医学   12355篇
肿瘤学   19252篇
  2024年   692篇
  2023年   3552篇
  2022年   9180篇
  2021年   11499篇
  2020年   8600篇
  2019年   7541篇
  2018年   8038篇
  2017年   7087篇
  2016年   6658篇
  2015年   10253篇
  2014年   12555篇
  2013年   10700篇
  2012年   16011篇
  2011年   17950篇
  2010年   10524篇
  2009年   8187篇
  2008年   11117篇
  2007年   11094篇
  2006年   11233篇
  2005年   11325篇
  2004年   7004篇
  2003年   6615篇
  2002年   5506篇
  2001年   4939篇
  2000年   5355篇
  1999年   5696篇
  1998年   3528篇
  1997年   3497篇
  1996年   2813篇
  1995年   2606篇
  1994年   2143篇
  1993年   1376篇
  1992年   1891篇
  1991年   1595篇
  1990年   1290篇
  1989年   1091篇
  1988年   1014篇
  1987年   890篇
  1986年   726篇
  1985年   525篇
  1984年   336篇
  1983年   243篇
  1982年   149篇
  1981年   145篇
  1980年   111篇
  1979年   142篇
  1978年   49篇
  1977年   53篇
  1975年   57篇
  1974年   56篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
OBJECTIVE: To investigate the characteristics of the early stage treponema pallidum infected tissue in ear, nose, oropharynx and larynx and to raise relevance ratio of syphilis in nose and oropharynx and enhance doctor's self-protection awareness. METHODS: The histopathologic characteristics were studied by using HE staining, Warthin-Starry (W-S) staining was adopted to examine the treponema pallidum(TP) in lesion issue and its exudates smear for 12 cases biopsy tissues of suspicious syphilis. The diagnosis was confirmed by venereal disease research laboratory (VDRL), rapid plasma reagin circle test(RPR), treponema pallidum hemagglutination test(TPHA) and fluorescent treponemal antibody-absorption test (FTA-ABS). Treat with curing syphilis methods which published by nation. RESULTS: In the 12 cases mucous membrane specimen, the squamous epithelium proliferated, neutrophilic granulocyte infiltrated, within inherent membrane generous plasmacyte and lymphocyte infiltrated. W-S staining: plenty of treponema pallidum were found inside mucous membrane epithelium and exudate smear. Serology examination: 11 cases VDRL(++++), 7 cases RPR (+), 11 cases TPHA(+), 1 case FTA-ABS(+). After systemic treatment, 11 cases are clinically recovered. All patients serology become negative. CONCLUSION: W-S staining method can directly demonstrate histopathologic characteristics in early syphilis, in intrinsic membrane numerous plasmacyte infiltration. Combining with specific syphilis serology examination could increase diagnosis rate of syphilis in nose and oropharynx.  相似文献   
142.
鼻内窥镜下鼻中隔矫正术   总被引:5,自引:1,他引:4  
目的 :研究鼻内窥镜下鼻中隔矫正术的优点。方法 :鼻内窥镜下鼻中隔矫正术 5 0例 ,同期施行传统的鼻中隔矫正术 5 0例作为对照 ,分析两者手术时间、术中出血量及疼痛情况。结果 :鼻内窥镜组治愈率为96% ,手术时间 ( 35 .5 0± 5 .2 0 ) min,术中出血量 ( 2 3.2 2± 4.2 5 ) ml,疼痛发生率为 1 6% ;传统手术组治愈率为 90 % ,手术时间 ( 4 5 .64± 6.34) min,术中出血量 ( 31 .34± 5 .64) ml,疼痛发生率为 38%。经统计学分析两组治愈率差异无显著性 ( P>0 .0 5 ) ,鼻内窥镜组手术时间明显缩短 ( P<0 .0 1 ) ,术中出血量明显减少 ( P<0 .0 5 ) ,术中疼痛发生率明显降低 ( P<0 .0 5 )。结论 :鼻内窥镜下鼻中隔矫正术照明好 ,术野清晰 ,直视下手术 ,易剥离粘连处和及时发现粘膜损伤 ,手术时间短 ,术中出血量少 ,疼痛轻 ,术后并发症少 ,特别是鼻中隔矫正同期完成功能性鼻内窥镜手术及歪鼻矫正手术时更显示其优越性  相似文献   
143.
眼针治疗阵发性室上性心动过速120例的即时疗效观察   总被引:2,自引:0,他引:2  
目的:观察眼针对阵发性室上性心动过速的即时疗效。方法:选择符合诊断标准的门诊患者120例,针其眼针穴区:心区和上焦区。针后30分钟描记心电图,计算心率,观察眼针对阵发性室上性心动过速的影响。结果:显效103例,占85.83%;有效9例,占7.5%;无效8例,占6.66%;总有效率93.33%.结论:眼针对阵发性室上性心动过速有较好的即时疗效。  相似文献   
144.
刘昌国教授,曾任新疆医科大学附属中医医院肛肠科主任,从事肛肠疾患临床研究逾四十余年,第二批名老中医学术继承专家,对于肛肠科疑难病治疗颇具心得,疗效卓越。今撷取其一加以整理记录,以飨同道。高位复杂性肛瘘是肛肠科的一种疑难病,指瘘道越过外括约肌深部以上,有两个以上外口,手术操作复杂,术中容易损伤肛门括约肌,造成肛门功能障碍,同时,术后也容易复发。自2004年2月至今,从师刘昌国老师,共诊治高位复杂性肛瘘患者12例,现分析如下:  相似文献   
145.
A new micelle system formed from methoxy (polyethylene glycol)-b-poly (5-benzyloxy-trimethylene carbonate; MePEG-b-PBTMC 5000-b-4800) was investigated as a delivery system for the hydrophobic anti-cancer agent, ellipticine. The ellipticine was loaded into the MePEG-b-PBTMC micelles with a loading efficiency of 95% using a high-pressure extrusion technique. The ellipticine-loaded micelles have a spherical morphology and an average diameter of 96 nm. The anti-cancer activity of ellipticine was confirmed to be retained following formulation in the MePEG-b-PBTMC micelles. The extent of protein adsorption to the MePEG-b-PBTMC micelles was investigated by transmission electron microscopy, dynamic light scattering and gel filtration chromatography. Overall, the amount of protein both loosely and tightly associated with the micelles was found to be minimal and insignificant. The partitioning properties of ellipticine between an aqueous medium containing protein and the MePEG-b-PBTMC micelles were examined over a range of protein concentrations. Under physiologically relevant conditions, it was found that 61% of the drug remained within the micelle fraction while 39% was in the protein-containing aqueous phase. In addition, the in vitro drug release profile of ellipticine from the micelles was fit using a modified Higuchi model and found to be accelerated in the presence of protein. These studies demonstrate that although there are no significant interactions between micelle and protein, the properties of the micelle as a delivery vehicle may be strongly influenced by protein-drug interactions.  相似文献   
146.
本文报告用间接免疫荧光法检测特异性IgG抗体对流行性出血热的诊断意义。53例不同病期的出血热患者的血清,其间接荧光抗体的阳性率为49/53(占92.45%)。有77.36%的患者血清,检出IgG抗体的时间是在发病后的1~2周。血清中IgG的滴度与疾病的严重性无密切相关。另25例非EHF患者,其血清特异性IgG抗体均为阴性。可见检测特异性IgG抗体对EHF的诊断颇为有用。  相似文献   
147.
目的:探讨腰椎形态结构变化对峡部裂性滑脱及小关节退变的作用和意义。方法:采用改良的“非种子区域分割方法”及非平行“最佳切割平面”等一系列新型计算机辅助设计(CAD)方法精确建立包括椎间盘高度、腰椎小关节角、椎间盘前凸角改变的L4~L5活动节段有限元模型;在2700N轴向压缩载荷条件下,分别对各有限元模型的峡部、小关节应力、小关节接触力以及椎间盘负载进行测试。结果:压缩载荷下,腰椎活动节段峡部、小关节等效应力及小关节接触力随椎间盘高度的减小而减小,随小关节角的增大而增加,随椎间盘前凸角的增加而减小。结论:椎间盘高度、腰椎小关节角、椎间盘前凸角等形态结构变化对腰椎节段有限元模型的峡部、小关节应力及小关节接触力有明显的影响。提示腰椎峡部应力性骨折及小关节退变的发生与椎间盘高度、腰椎小关节角、椎间盘前凸角等解剖形态因素有关。  相似文献   
148.
利用电化学方法研究医用钛合金在0.9%NaCl生理盐水,模拟人工唾液,模拟人工体液中的腐蚀情况,分析腐蚀电位和腐蚀电流密度,扫面电镜观察腐蚀表面形貌,CA-A型接触角测试仪测试钛合金表面被腐蚀后接触角的变化。实验表明:钛合金在三种生理电解液中的腐蚀情况依次是:模拟人工唾液〉模拟人工体液〉0.9%NaCl生理盐水。扫面电镜观察表明,医用钛合金在0.9% NaCl生理盐水腐蚀后,表面出现了许多腐蚀孔,经模拟人体体液腐蚀后,表面变得粗糙不平整,腐蚀孔数目变化不大,钛合金经人工唾液腐蚀后,腐蚀孔数目增多,部分腐蚀孔孔径明显增大。经三种生理电解液腐蚀后,钛合金表面接触角都减小。结论:医用钛合金在人工唾液中的腐蚀最严重,在临床应用中应给予相应的防范措施。  相似文献   
149.
Abstract:  The risks of developing malignant melanoma (MM) include ultraviolet irradiation and genetic factors. To examine the contribution of rare and common variation within known MM genes in sporadic US MM patients, coding regions of known MM susceptibility genes [cyclin-dependent kinase inhibitor 2A ( CDKN2A ), cyclin-dependent kinase 4, melanocortin 1 receptor ( MC1R ) and tyrosinase ( TYR )] were resequenced in 109–135 MM cases. The significance of variants was examined by comparing their frequencies in 390 cancer-free controls. Potential deleterious mutations in CDKN2A were found in two patients and two others had variants of unknown significance. Cases were more likely than controls to harbour the MC1R 'R' variants known or predicted to alter its function ( P  = 0.002), particularly the R160W variant ( P  = 0.0035). The associated TYR R402Q variant (rs1126809*A) was found in 29% of cases, similar to what has been described previously. One MM patient with a family history of MM, who had developed other skin cancers, was homozygous for a novel TYR variant (P406L) of unknown significance. Hence, rare variants in TYR may be important risk factors for skin cancer.  相似文献   
150.
Ganoderma sinensis has been used widely in Oriental countries for the prevention and treatment of various diseases including cancer. Previous studies have shown that the lipid extract from Ganoderma exhibits direct cytotoxicity against tumor cells. Here, it is reported that the lipid extract from germinating G. sinensis spores, at lower concentrations that have no direct tumoricidal activity, induce potent antitumor immune responses in human monocytes/macrophages. Upon stimulation with the lipid extract, monocytes/macrophages exhibited markedly increased production of proinflammatory cytokines and surface expression of costimulatory molecules. Conditioned medium from stimulated cells effectively suppressed the growth of tumor cells. Apparently, the lipid extract triggered macrophage activation via a mechanism different from that associated with LPS. Moreover, it was observed that the lipid extract could partially re‐establish the antitumor activity of the immunosuppressive tumor‐associated macrophages. These results indicated that in addition to its direct tumoricidal activity, the lipid extract from G. sinensis spores could exert antitumor activity by stimulating the activation of human monocytes/macrophages. Copyright © 2008 John Wiley & Sons, Ltd.  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