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   7602篇
  免费   559篇
  国内免费   148篇
耳鼻咽喉   410篇
儿科学   82篇
妇产科学   94篇
基础医学   953篇
口腔科学   164篇
临床医学   659篇
内科学   576篇
皮肤病学   54篇
神经病学   1675篇
特种医学   432篇
外科学   631篇
综合类   722篇
预防医学   429篇
眼科学   289篇
药学   680篇
  2篇
中国医学   241篇
肿瘤学   216篇
  2024年   13篇
  2023年   118篇
  2022年   217篇
  2021年   388篇
  2020年   285篇
  2019年   242篇
  2018年   256篇
  2017年   284篇
  2016年   260篇
  2015年   260篇
  2014年   453篇
  2013年   497篇
  2012年   378篇
  2011年   405篇
  2010年   350篇
  2009年   347篇
  2008年   389篇
  2007年   377篇
  2006年   325篇
  2005年   248篇
  2004年   206篇
  2003年   186篇
  2002年   166篇
  2001年   117篇
  2000年   138篇
  1999年   130篇
  1998年   132篇
  1997年   118篇
  1996年   117篇
  1995年   83篇
  1994年   91篇
  1993年   66篇
  1992年   66篇
  1991年   61篇
  1990年   47篇
  1989年   50篇
  1988年   39篇
  1987年   41篇
  1986年   42篇
  1985年   46篇
  1984年   43篇
  1983年   28篇
  1982年   38篇
  1981年   33篇
  1980年   19篇
  1979年   36篇
  1978年   11篇
  1977年   12篇
  1976年   16篇
  1972年   10篇
排序方式: 共有8309条查询结果,搜索用时 15 毫秒
1.
2.
ObjectiveImprovement in the quality of life is reflected in the narrowing of the gap between health-adjusted life expectancy (HALE) and life expectancy (LE). The effect of megacity expansion on narrowing the gap is rarely reported. This study aimed to disclose this potential relationship.MethodsAnnual life tables were constructed from identified death records and population counts from multiple administrative sources in Guangzhou, China, from 2010 to 2020. Joinpoint regression was used to evaluate the temporal trend. Generalized principal component analysis and multilevel models were applied to examine the county-level association between the gap and social determinants.ResultsAlthough LE and HALE in megacities are increasing steadily, their gap is widening. Socio-economic and health services are guaranteed to narrow this gap. Increasing personal wealth, a growing number of newborns and healthy immigrants, high urbanization, and healthy aging have helped in narrowing this gap.ConclusionIn megacities, parallel LE and HALE growth should be highly considered to narrow their gap. Multiple social determinants need to be integrated as a whole to formulate public health plans.  相似文献   
3.
目的:探讨2型糖尿病(T2DM)患者不同脂质参数与糖尿病肾病(DKD)发生的相关性。方法:检测226例T2DM患者血清TC、TG、LDL-C、HDL-C水平及相关生化指标,计算血浆致动脉硬化指数(AIP)以及脂质三角相关指标(TC/HDL-C、TG/HDL-C、LDL-C/HDL-C)。根据DKD临床诊断标准和Mogensen分期标准分为:Ⅰ~Ⅱ期组136例,Ⅲ期组55例,Ⅳ~Ⅴ期组35例。应用多因素logistic回归分析不同脂质参数与DKD发生的关系。结果:与Ⅰ~Ⅱ期组相比,随着DKD分期加重,TC、TG、LDL-C、LDL-C/HDL-C、AIP水平明显增高(P<0.01)。LDL-C/HDL-C和AIP与24 h尿蛋白水平呈正相关(r=0.724;r=0.769,均P<0.05)。LDL-C/HDL-C和AIP是T2DM合并DKD患者的独立预测因子(P=0.002;P=0.004)。结论:LDL-C/HDL-C和AIP对T2DM合并DKD病情进展有较高的预测价值,可为临床诊治提供参考。  相似文献   
4.
BACKGROUND Degree of portal hypertension(PH) is the most important prognostic factor for the decompensation of liver cirrhosis and death, therefore adequate care for patients with liver cirrhosis requires timely detection and evaluation of the presence of clinically significant PH(CSPH) and severe PH(SPH). As the most accurate method for the assessment of PH is an invasive direct measurement of hepatic venous pressure gradient(HVPG), the search for non-invasive methods to diagnose these conditions is actively ongoing.AIM To evaluate the feasibility of parameters of endogenously induced displacements and strain of liver to assess degree of PH.METHODS Of 36 patients with liver cirrhosis and measured HVPG were included in the casecontrol study. Endogenous motion of the liver was characterized by derived parameters of region average tissue displacement signal(dantero, dretro, d RMS) and results of endogenous tissue strain imaging using specific radiofrequency signal processing algorithm. Average endogenous strain μ and standard deviation σ of strain were assessed in the regions of interest(ROI)(1 cm × 1 cm and 2 cm × 2 cm in size) and different frequency subbands of endogenous motion(0-10 Hz and 10-20 Hz).RESULTS Four parameters showed statistically significant(P 0.05) correlation with HVPG measurement. The strongest correlation was obtained for the standard deviation of strain(estimated at 0-10 Hz and 2 cm × 2 cm ROI size). Three parameters showed statistically significant differences between patient groups with CSPH, but only dretro showed significant results in SPH analysis. According to ROC analysis area under the curve(AUC) of the σROI[0…10 Hz, 2 cm × 2 cm] parameter reached 0.71(P = 0.036) for the diagnosis of CSPH; with a cut-off value of 1.28 μm/cm providing 73% sensitivity and 70% specificity. AUC for the diagnosis of CSPH for μROI[0…10 Hz, 1 cm × 1 cm] was 0.78(P = 0.0024); with a cut-off value of 3.92 μm/cm providing 73% sensitivity and 80% specificity. Dretro parameter had an AUC of 0.86(P = 0.0001) for the diagnosis of CSPH and 0.84(P = 0.0001) for the diagnosis of SPH. A cut-off value of-132.34 μm yielded 100% sensitivity for both conditions, whereas specificity was 80% and 72% for CSPH and SPH respectively.CONCLUSION The parameters of endogenously induced displacements and strain of the liver correlated with HVPG and might be used for non-invasive diagnosis of PH.  相似文献   
5.
6.
The Russian writer Dostoevsky (1821–1881) suffered from a rare form of temporal lobe epilepsy termed “ec-static epilepsy.” Dostoevsky used his epileptic experiences to create Prince Myshkin, the protagonist of The Idiot. The recent case of a patient who experienced ecstatic epilepsy as a result of a temporal lobe brain tumor is presented and compared with that of Prince Myshkin. Reading Dostoevsky can give the contemporary physician an insight into the inner life of an epileptic patient — an example of how art can directly benefit medical practice.  相似文献   
7.
108例支气管哮喘患者舌脉象特征分析   总被引:1,自引:0,他引:1  
目的:探讨对支气管哮喘临床辨证有意义的舌脉象客观指标,以辅助临床诊断。方法:应用TP—I型中医舌脉象数字化分析仪检测108例患者舌脉象参数,分析支气管哮喘发作期与缓解期的舌脉象特征。结果:108例支气管哮喘患者的舌象中,舌色以淡红舌、淡紫舌多见,舌苔以白苔、黄苔、薄苔为多见;脉象以弦脉、滑脉、弦滑脉为多见;舌脉象参数中舌色指数、苔色指数、厚苔指数、胖瘦指数在哮喘发作期各证型中有显著性差异(P〈0.05);RPSR1、RPSR3、RPSR4、RBF、RLMS2、PLMP2、RLMS3、RLMP3在哮喘发作期与缓解期有显著性差异(P〈0.05)。结论:支气管哮喘患者的脉象参数、舌色指数、苔色指数、厚苔指数、胖瘦指数、RPSR1、RPSR3、RPSR4、RBF、RLMS2、PLMP2、RLMS3、RLMP3对其辨证分型有重要参考价值。  相似文献   
8.
目的观察针灸治疗血管性痴呆(VD)的临床疗效。方法将54例血管性痴呆患者随机分为针灸组及药物组,治疗21d,观察治疗前后智力测定量表(MMSE)、日常生活能力表(ADL)评分值变化。结果两组各临床疗效指标均有改善,尤以针灸组显著。结论在针灸治疗的基础上,配合药物治疗VD患者,是一种行之有效的方法。  相似文献   
9.
目的探讨颞筋膜瓣或颞肌筋膜瓣与自体全厚皮片移植,在下睑凹陷性瘢痕畸形修复中的应用效果。方法设计以颞浅动脉为蒂的颞筋膜瓣,对伴眶下壁骨缺损者同时行以颞浅、深动脉为蒂的颞肌筋膜瓣,并取耳后全厚皮片移植联合矫正下睑凹陷性畸形。结果8例患者,术后组织瓣及皮片成活良好,凹陷处填充效果满意。随访6个月至1年,睑外翻矫正,瘢痕不显,颞部供区毛发生长良好。结论应用颞筋膜瓣或颞肌筋膜瓣与全厚皮片移植,联合矫正下睑凹陷性畸形的方法,具有操作简便,且无明显的供区损害的特点,是修复下睑凹陷性瘢痕畸形较理想的方法。  相似文献   
10.
An investigation was made into the directional sensitivity of cells in the macaque anterior superior temporal polysensory region (STPa) to the motion of objects. The cells studied were sensitive to the presence of motion but showed little or no selectivity for the form of the stimulus. Directional tuning was not continuously distributed about all possible directions. The majority of cells were most responsive to motion in a direction within 15° of one of the three cartesian axes (up/down, left/right, towards/away). Tuning to direction varied in sharpness. For most (34/37) cells the angular change in direction required to reduce response to half maximal was between 45 and 70° (for 3/37 cells it was > 90°). The estimates of the directionality (median I d = 0.97) of STPa cells was similar to that reported for posterior motion processing areas (the middle temporal area, MT, and the medial superior temporal area, MST). The tuning for direction (sharpness, distribution and discrimination) of the motion-sensitive STPa cells were found to be similar to the tuning for perspective view of STPa cells selective for static form of the head and body. On average the STPa responses showed a 100- to 300-ms transient burst of activity followed by a tonic discharge maintained at approximately 20% of the peak firing rate for the duration of stimulation. The responses of motion-sensitive STPa cells occurred at an earlier latency (mean 91 ms) than responses of cells selective for static form (mean 119 ms), but the time course of responses of the two classes of cell were similar in many other respects. The early response latency and directional selectivity indicate that motion sensitivity in STPa cells derives from the dorsal visual pathway via MT/MST. The similarity of tuning for direction and perspective view within STPa may facilitate the integration of motion and form processing within this high-level brain area.  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