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   16543篇
  免费   1374篇
  国内免费   427篇
耳鼻咽喉   336篇
儿科学   173篇
妇产科学   406篇
基础医学   1689篇
口腔科学   262篇
临床医学   1285篇
内科学   1787篇
皮肤病学   329篇
神经病学   120篇
特种医学   723篇
外国民族医学   14篇
外科学   4031篇
综合类   1868篇
现状与发展   2篇
预防医学   285篇
眼科学   28篇
药学   636篇
  7篇
中国医学   99篇
肿瘤学   4264篇
  2024年   27篇
  2023年   268篇
  2022年   484篇
  2021年   686篇
  2020年   651篇
  2019年   630篇
  2018年   610篇
  2017年   554篇
  2016年   592篇
  2015年   586篇
  2014年   1021篇
  2013年   930篇
  2012年   872篇
  2011年   1004篇
  2010年   781篇
  2009年   825篇
  2008年   899篇
  2007年   942篇
  2006年   782篇
  2005年   705篇
  2004年   632篇
  2003年   531篇
  2002年   462篇
  2001年   359篇
  2000年   315篇
  1999年   268篇
  1998年   237篇
  1997年   178篇
  1996年   143篇
  1995年   131篇
  1994年   148篇
  1993年   107篇
  1992年   100篇
  1991年   119篇
  1990年   82篇
  1989年   71篇
  1988年   72篇
  1987年   81篇
  1986年   71篇
  1985年   65篇
  1984年   56篇
  1983年   40篇
  1982年   51篇
  1981年   34篇
  1980年   32篇
  1979年   30篇
  1978年   24篇
  1977年   27篇
  1976年   16篇
  1975年   5篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
The aim of the study was to evaluate whether complication rate, costs, operation times, and hospitalization times differed in two different patient groups: in group 1, frozen section analysis of the sentinel lymph node and lymph node dissection were carried out in the same operation. In group 2, normal investigation of the sentinel lymph node and lymph node dissection were done in a second operation. One hundred thirty-five patients with cutaneous melanoma were included. Hospitalization times, costs, complication rates, and operation times of two-stage and one-stage lymph node dissection of the draining area after detection of metastases in the sentinel lymph node were retrospectively compared. Lymph node metastasis in the sentinel lymph node was found in 23 patients. In 11 patients, removal of the sentinel lymph node and dissection of the lymph node basin was performed in the same operation. In 12 patients, a two-stage procedure was the treatment of choice. Operation times were not different in the two groups (p=0.87) while two-stage operation patients were hospitalized significantly longer (14.2 ± 9.7 vs 23.9 ± 24 days; p=0.01) and costs were significantly higher (7,836.90 ± 2,397.95 Swiss francs vs 5,279.40 ± 1,994.90 Swiss francs). In addition, more complications were found in the two-stage group.  相似文献   
72.
保留神经腹膜后淋巴结清除术治疗睾丸肿瘤   总被引:1,自引:0,他引:1  
目的探讨保留神经腹膜后淋巴结清除术(RPLND)在低期睾丸肿瘤治疗中的作用和效果。方法1999年6月至2003年7月收治睾丸肿瘤患者13例,年龄24~41岁,平均29岁。肿瘤位于左侧9例,右侧4例,大小2cm×3cm×2cm~9cm×6cm×5cm。临床分期:Ⅰ期11例,均为非精原细胞瘤;ⅡA期1例,为畸胎瘤(CT示腹膜后转移灶1cm×2cm);ⅡC期1例,为精原细胞瘤(CT示腹膜后转移灶10cm×9cm)。12例非精原细胞瘤者根治性睾丸切除术后1~4周行保留神经RPLND,1例精原细胞瘤者根治性睾丸切除术后行3疗程BEP方案化疗后行保留神经RPLND。结果术后病理分期:Ⅰ期11例,ⅡA期2例,其中ⅡC期精原细胞瘤患者化疗后分期降为Ⅰ期。13例术后均无肠梗阻、淋巴瘘和体位性低血压。术后2周复查时血AFP和βHCG均降至正常范围。术后8~12周均恢复射精功能。随访18~64个月,平均39个月,无肿瘤复发或转移。结论对于青壮年患者,保留神经RPLND是治疗低期非精原细胞瘤和化疗后降期的精原细胞瘤的首选方法。  相似文献   
73.
作者对结节性甲状腺肿及其非典型结节与甲状腺癌细胞核直径、面积及 DNA 含量检测,发现核直径与面积的(?)和 S 为甲状腺癌组>非典型结节组>对照组(P<0.01);随着细胞增生异型程度的加重,核直径、面积及离散程度随之增加、DNA 含量也显著增加,显示Ⅲ级 DNA 含量细胞出现频率越高恶性的可能性就越大;同时发现各组细胞核不同 DNA 含量的核直径、面积均明显增加,与对照组相比差异生非常显著(P<0.01)。  相似文献   
74.
Recent advances in molecular lymphology and lymphatic phenotyping techniques in small animals offer new opportunities to delineate mutant mouse models. Chy-3 mutant mice were originally named for their chylous ascites, but the underlying lymphatic disorder was not defined. We now re-examined these mice and applied advanced genotyping and lymphatic phenotyping techniques to pinpoint the specific lymphatic defect in this mouse model. We demonstrated that Chy-3 mice carry a large chromosomal deletion that includes Vegfc and narrowed this region by monitoring the heterozygosity of genetic markers. We found that Chy-3 mice not only exhibited chylous ascites but also lymphedema of the hind paws and, in approximately half of the males, lymphedema of the penis. Visual lymphangiography and immunofluorescence staining showed a hypoplastic dermal lymphatic network, whereas the blood vasculature appeared unaffected. This hypoplastic lymphatic network was functional, and all adult Chy-3 mice exhibited a lateral lymphatic pathway directly connecting the inguinal to the axillary lymph node. The dermal superficial to deep lymphatic connections in upper limbs and in all cervical regions were intact and functionally drained the upper body. Lymphatic tracer was not transported from the dermal to the deep truncal lymphatic system in the lower limbs, even though the deep lymphatic vessels and nodes were present and patent. These findings further delineate the lymphatic phenotype of Chy-3 mice, identify a collateral lymph drainage pathway previously undescribed in other genetic models of lymphedema, and demonstrate a predilection for lymphatic abnormalities of the lower limbs.  相似文献   
75.
高频彩超对颈部淋巴结囊性病变的诊断价值   总被引:2,自引:2,他引:0  
①目的探讨高频彩超对颈部淋巴结囊性病变的诊断价值。②方法回顾性分析25例颈部淋巴结囊性病变的高频彩超表现。③结果颈部淋巴结囊性病变见于颈淋巴结囊性转移瘤、化脓性淋巴结炎及淋巴结结核。其中13例为颈部淋巴结囊性转移瘤,其特征性超声表现为颈部淋巴结囊性肿大,伴囊壁实性结节;较大囊壁结节内常可探及动脉血流信号,部分囊壁结节可见微钙化。7例为颈部急性化脓性淋巴结炎,其主要超声表现为上颈部淋巴结呈单发、圆形囊性肿大;囊壁略厚,且较均匀;囊液呈细密点状回声。5例为颈部淋巴结干酪脓肿型结核,其主要超声表现为单侧或双侧中下颈部淋巴结呈多发、椭圆形囊性肿大,部分可融合成团;内壁毛糙,囊液内散在分布点状高回声。④结论高频彩超检查对颈部淋巴结囊性病变的诊断和鉴别诊断具有重要价值。  相似文献   
76.
目的 探讨前哨淋巴结活检术(SLNB)应用于外阴癌的可行性.方法 选择2004年10月-2008年4月间于中国医学科学院肿瘤医院接受手术治疗、术中采用SLNB的外阴癌患者21例,其中处于研究前期(即2005年5月前)的11例患者采用染料法识别前哨淋巴结(SLN)、处于研究后期的10例患者采用核素-染料联合法识别SLN,术后行常规病理检查.以病理检查结果为金标准,观察SLNB的检测效果;并观察与SLNB相关的并发症的发生情况.结果 21例患者中,20例(95%)检出SLN,其中8例为单侧腹股沟、12例为双侧腹股沟.20例SLN阳性患者共检出83枚SLN,每例患者平均检出4.2枚(1~9枚),每侧腹股沟平均2.6枚(1~6枚).其中,染料法每例患者平均检出4.4枚、每侧腹股沟平均2.5枚,核素-染料联合法每例患者平均检出3.9枚、每侧腹股沟平均2.7枚,分别比较,差异均无统计学意义(t=0.459,P=0.652;t=-0.421,P=0.717).20例SLN阳性患者腹股沟浅组淋巴结中均检出SLN,其中1例双侧腹股沟深组淋巴结中也检出SLN.20例SLN阳性的患者中,8例(10侧腹股沟)术后病理检查显示腹股沟淋巴结转移,其中7例患者(9侧腹股沟)的转移淋巴结中均包括有SLN、1例(1侧腹股沟)出现假阴性.以SLN识别预测同侧腹股沟淋巴结转移的假阴性率为10%(1/10),阴性预测值为96%(22/23).未发现与SLNB相关的损伤及不良反应.结论 SLNB应用于外阴癌安全、可行,以SLN预测同侧腹股沟淋巴结转移具有较高准确性.  相似文献   
77.
Sinoatrial node electrogram (SNE) was recorded successfully in recent years, using transvenous electrode catheter. Via SNE and intratrialelectrogram (IEG), one could measure sinoatrial conduction time(SACT) directly, observe sinoatrial node (SN) potential changes in cadiac cycles, diagnose some sinus arrhythmias which couldn't be confirmed by surface ECG. All these could offer accurate evidence for differential diagnosis of sick sinus syndrome (SSS). The authors recommend a modified method for the location of the electrode catheter, by which one can increase success rate of obtaining stable SNE. Using this method, the authors recorded SNE in 10 cases with SSS successfully.  相似文献   
78.
Background: Preoperative lymphoscintigraphy (LS) with99mTc antimony sulphide colloid is now part of the routine management of patients with intermediate thickness melanoma at the Sydney Melanoma Unit. Over a 13-year period, 1375 patients have been examined using LS, and we have observed many unusual lymphatic drainage pathways, including direct drainage through the body wall to retroperitoneal and paravertebral lymph nodes from the skin of the back. The aim of this study was to determine the incidence of such drainage in the 542 patients who had primary melanoma sites on the posterior trunk. Methods: The lymphoscintigrams performed on these patients were examined for the presence of direct lymphatic drainage through the posterior body wall to sentinel nodes in the retroperitoneal and paravertebral regions. Results: Lymphatic drainage directly through the body wall to such lymph nodes occurred in 14 of these 542 patients. Conclusions: Preoperative knowledge of the presence of this lymph drainage pattern may influence surgical management, and follow-up investigations in these patients can be tailored to ensure that the relevant areas are examined with anatomic imaging or F18-FDG PET scans.  相似文献   
79.
A new technique for catheter ablation of atrioventricular (AV)conduction, using temperature-controlled radiofrequency energyand a bipolar asymmetrical electrode configuration, was appliedto 12 patients (mean age, 48 ± 15 years; range, 18–69years) with medically refractory atrioventricular nodal reentranttachycardia (AVNRT) or rapid atrial rhythms. The energy sourcewas a 500 kHz generator with automatic power regulation to apreselected temperature of 80 °C. A specially designed 7F bipolar asymmetric thermo-catheter was used for ablation inall cases. The endpoints of the procedure were: first-degreeAV block in patients with AVN R T and third-degree block inpatients with atrial fibrillation or flutter. Energy was appliedover a range of 1–14 times per patient. After a mean follow-upof 8±4 months, third- or first degree AV block persistedin eight patients. In comparison to constant-power radiofrequencyablation, where impedance rises are commonly observed, no impedancerise or coating of the electrode occurred during any of the97 energy applications in this study. Variable wall contactof the electrode was identified in 20 of 97 applications bya slow temperature rise or a drop in temperature and frequentpower adjustments. Thus, monitoring temperature and automaticpower regulation may help to reduce the total delivered energy.Temperature control during radiofrequency energy avoids coagulumformation and consequently the associated potential hazardsof constant-power application.  相似文献   
80.
应用食道心房调博缩测定健康小儿窦房结功能,以了解西宁地区正常数值与平原地区进行对比。选择27例健康小儿,将F6二级电极导管从鼻腔送入,定位地食道心电图最大正负双相P波处,采用苏州东方电子仪器厂生产的DF-3A型心脏电生理治疗仪进行检查,从而作出诊断。  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