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   6898篇
  免费   488篇
  国内免费   122篇
耳鼻咽喉   73篇
儿科学   131篇
妇产科学   190篇
基础医学   903篇
口腔科学   141篇
临床医学   929篇
内科学   940篇
皮肤病学   116篇
神经病学   411篇
特种医学   206篇
外国民族医学   6篇
外科学   449篇
综合类   755篇
一般理论   1篇
预防医学   585篇
眼科学   157篇
药学   594篇
  15篇
中国医学   244篇
肿瘤学   662篇
  2024年   19篇
  2023年   135篇
  2022年   338篇
  2021年   474篇
  2020年   349篇
  2019年   260篇
  2018年   265篇
  2017年   264篇
  2016年   207篇
  2015年   357篇
  2014年   424篇
  2013年   415篇
  2012年   574篇
  2011年   602篇
  2010年   328篇
  2009年   289篇
  2008年   396篇
  2007年   369篇
  2006年   286篇
  2005年   252篇
  2004年   199篇
  2003年   188篇
  2002年   139篇
  2001年   61篇
  2000年   50篇
  1999年   53篇
  1998年   35篇
  1997年   34篇
  1996年   15篇
  1995年   13篇
  1994年   20篇
  1993年   15篇
  1992年   15篇
  1991年   9篇
  1990年   8篇
  1989年   14篇
  1988年   4篇
  1987年   4篇
  1986年   3篇
  1985年   2篇
  1984年   2篇
  1983年   2篇
  1982年   2篇
  1981年   2篇
  1980年   3篇
  1979年   2篇
  1976年   2篇
  1973年   2篇
  1971年   2篇
  1905年   2篇
排序方式: 共有7508条查询结果,搜索用时 15 毫秒
91.
92.
93.
94.
儿童Lowe综合征OCRL基因突变2例报告   总被引:1,自引:0,他引:1  
目的探讨儿童Lowe综合征的临床特点和基因特征。方法分析2例Lowe综合征患儿的临床资料和OCRL基因检测结果,并复习相关文献。结果 2例患儿均为男性,均存在小分子蛋白尿、高钙尿症、佝偻病和肾结石。例2患儿还有轻度代谢性酸中毒、糖尿和隐睾症。例1患儿生后不久发现有视力异常和先天性白内障,并行手术治疗,同时存在精神运动发育落后,头颅磁共振成像(MRI)示胼胝体发育不良。例2患儿就诊时肾外症状不明显,但眼科检查发现有先天性白内障,头颅MRI示脑发育低下、脑白质髓鞘化延迟,且随访过程中逐渐出现智力发育落后。OCRL基因检测发现2个突变,例1为剪切位点突变NG 008638.1:g.46846-46848del TAA/ins C,例2为缺失移码突变NM000276.3:c.321del C,两种突变以前文献均未报道。结论 Lowe综合征的诊断主要通过临床表现和OCRL基因检测,对于有先天性白内障、肾小管病变的患儿需要与Lowe综合征鉴别。本研究发现2个OCRL基因的新突变。  相似文献   
95.
目的探讨脾动脉头端真性动脉瘤的切除方法以及血管重建方法,总结临床治疗经验。方法回顾性总结2000年1月—2013年6月作者收治的11例资料,均经彩色超声、CT和血管造影检查证实脾动脉头端真性动脉瘤。肝动脉脾脏动脉远端自体静脉移植1例;肾下主动脉—脾动脉人工血管转流7例;动脉瘤、脾脏切除2例,多发动脉瘤切除、脾动脉结扎、脾切除1例。结果手术后10~14天治愈出院,随访1~14年,9例存活,2例死亡,其中1例主脾转流后2年死于急性心肌梗死,1例动脉瘤切除、脾切除后5年死于急性脑出血。7例主脾转流中,1例术后2年吻合口逐渐狭窄,术后6年完全闭塞,但一直无脾脏梗死,脾脏供血由胃短血管及其侧枝提供;余6例主脾转流和1例自体血管移植者未见吻合口狭窄或假性动脉瘤。结论脾动脉头端真性动脉瘤切除、脾动脉血管重建是一种较好的治疗方案。  相似文献   
96.
Objective: To explored the effects of puerarin on cognitive deficits and tissue oxidative stress and the underlying mechanisms. Methods: 6 to 8 week old male Wistar rats were adopted as experimental animals. Morris water maze (MWM) test was adopted to test the learning and memory function of rats. MDA, glutathione peroxidase and total thiol assessment was done to reflect the oxidative stress in the brain tissue. Cell Counting Kit-8 (CCK8) and flow cytometry (FCM) were performed to examine the cell viability and apoptosis rate. Reactive oxygen species (ROS) generation was determined by the 2’, 7’-dichlorofluorescein diacetate (DCFH-DA) assay. qPCR and Western blot (WB) were adopted to test the molecular function mechanisms of puerarin. Results: Our results indicated a protective effect of puerarin on vascular dementia. Administration of puerarin could improve the impaired learning and memory function. The levels of MDA were partially decreased by puerarin. The levels of glutathione peroxidase and total thiol were partially restored. Cell viability was improved in a dose-dependent pattern (P < 0.05). Cell apoptosis rate was reduced in a dose-dependent pattern (P < 0.05). Puerarin could scavenge ROS generation induced by pre-treatment of hydrogen peroxide. The results showed up-regulated levels of Nrf2, FoxO1, FoxO3 and FoxO4 (P < 0.05). Conclusion: Puerarin is protective on the vascular dementia by reducing oxidative stress and improving learning and memory functions. On the molecular level, Nrf2, FoxO1, FoxO3 and FoxO4 were up regulated by puerarin.  相似文献   
97.
The aim of this study was to investigate the association of vitamin D receptor (VDR) gene polymorphism and hypertension in a Chinese Han population. The authors genotyped 3 tagSNPs (rs11574129, rs2228570, and rs739837) of the VDR gene using TaqMan assays in a case‐control study including 2409 patients with hypertension and 3063 controls. The results showed that rs2228570 presented statistical correlations with decreased risk of male hypertension after adjustment for confounding factors, odds ratios (ORs) and 95% confidence intervals (CIs) of additive, dominant, and recessive models were 0.828 (0.74–0.927), 0.75 (0.631–0.89), and 0.816 (0.67–0.995), and P values were .001, .001, and .044, respectively. Significant associations were found in the smoking population and ORs (95% CIs) of additive and dominant models were 0.81 (0.69–0.952) and 0.71 (0.552–0.913) (P values .011 and .008), respectively, after adjustment for covariates. Quantitative trait analysis indicated that the untreated cases with TT genotype of rs2228570 showed higher systolic blood pressure compared with the TC/CC genotype (P=.015). Our findings suggest that VDR genetic polymorphism rs2228570 is significantly associated with the decreased risk of hypertension in Chinese men and smokers.  相似文献   
98.
High frequency oscillations (HFOs) are emerging as biomarkers of epileptogenicity. They have been shown to originate from small brain regions. Surprisingly, spontaneous HFOs can be recorded from the scalp. To understand how is it possible to observe these small events on the scalp, one avenue is the analysis of the cortical correlates at the time of scalp HFOs. Using simultaneous scalp and intracranial recordings of 11 patients, we studied the spatial distribution of scalp events on the cortical surface. For typical interictal epileptiform discharges the subdural distributions were, as expected, spatially extended. On the contrary, for scalp HFOs the subdural maps corresponded to focal sources, consisting of one or a few small spatial extent activations. These topographies suggest that small cortical areas generated the HFOs seen on the scalp. Similar scalp distributions corresponded to distinct distributions on a standard 1 cm subdural grid and averaging similar scalp HFOs resulted in focal subdural maps. The assumption that a subdural grid “sees” everything that contributes to the potential of nearby scalp contacts was not valid for HFOs. The results suggest that these small extent events are spatially undersampled with standard scalp and grid inter-electrode distances. High-density scalp electrode distributions seem necessary to obtain a solid sampling of HFOs on the scalp. A better understanding of the influence of spatial sampling on the observation of high frequency brain activity on the scalp is important for their clinical use as biomarkers of epilepsy.  相似文献   
99.
With the advantages and development of MRI nano-contrast agents (CAs), increasing number of MRI-based theranostic nanoparticles have emerged. Liposome, as a biosafe nanocarrier has been used phase III trial for cancer treatment. In this study, liposome was employed as a nanocarrier to co-encapsulate MRI nano-contrast agent poly(ethylene glycol)-grafted manganese oxide (PEG-MnO) and anticancer drug paclitaxel (PTX) for the fabrication of a novel theranostic nanocomplex. After being further modified with AS1411 aptamer, the obtained nanoprobe AS1411-liposome-PEG-MnO-PTX displayed the potential of simultaneous MRI diagnosis and therapy of renal carcinoma in vitro and in vivo. It was found that compared with PEG-MnO nano-CA, liposome-PEG-MnO and AS1411-liposome-PEG-MnO presented a stronger MR contrast enhancement effect in the tumor and longer retention time in the tumor region. More importantly, the introduction of AS1411 aptamer further enhanced the MRI effect and the tumor growth inhibition effect, showing its potential use as a theranostic nanoprobe for renal carcinoma.

AS1411 aptamer modified theranostic liposomes co-encapsulating manganese oxide nano-contrast agent and paclitaxel for MRI and therapy of cancer was realized.  相似文献   
100.
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