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   1585篇
  免费   120篇
  国内免费   111篇
耳鼻咽喉   9篇
儿科学   31篇
妇产科学   24篇
基础医学   230篇
口腔科学   20篇
临床医学   199篇
内科学   511篇
皮肤病学   20篇
神经病学   96篇
特种医学   83篇
外科学   174篇
综合类   41篇
预防医学   33篇
眼科学   56篇
药学   168篇
中国医学   9篇
肿瘤学   112篇
  2023年   12篇
  2022年   33篇
  2021年   83篇
  2020年   39篇
  2019年   48篇
  2018年   44篇
  2017年   39篇
  2016年   63篇
  2015年   71篇
  2014年   114篇
  2013年   94篇
  2012年   141篇
  2011年   133篇
  2010年   84篇
  2009年   62篇
  2008年   92篇
  2007年   139篇
  2006年   85篇
  2005年   84篇
  2004年   58篇
  2003年   30篇
  2002年   34篇
  2001年   12篇
  2000年   9篇
  1999年   9篇
  1998年   28篇
  1997年   16篇
  1996年   23篇
  1995年   14篇
  1994年   13篇
  1993年   13篇
  1992年   11篇
  1991年   9篇
  1990年   13篇
  1989年   10篇
  1988年   11篇
  1987年   2篇
  1986年   4篇
  1985年   5篇
  1984年   5篇
  1983年   3篇
  1982年   2篇
  1980年   2篇
  1979年   5篇
  1978年   3篇
  1977年   2篇
  1973年   1篇
  1972年   2篇
  1969年   2篇
  1968年   1篇
排序方式: 共有1816条查询结果,搜索用时 31 毫秒
1.
2.

Background

In Leriche syndrome, postoperative graft thrombosis remains one of the most significant clinical challenges.

Methods

We reviewed 51 patients who underwent surgery for aortoiliac occlusive disease at our hospital from January 2007 to December 2014. The factors associated with graft patency were determined using the Cox proportional hazard model.

Results

The 2-year prosthetic graft patency rate was 72.5%. Younger age (p = 0.017, Odd ratio (OR) = 1.112), postoperative uncontrolled hypertension (p = 0.044, OR = 3.797), and associated Trans Atlantic Inter-Society Consensus for the Management of Peripheral Arterial Disease II (TASC II) D femoropopliteal lesion (p = 0.008, OR = 11.139) were significantly related factors for prosthetic graft patency after surgical repair. The existing comorbidities of the patients that indicated the need for axillo-bifemoral bypass seemed to be related to lower graft patency or other complications.

Conclusions

For better graft patency after an open surgical repair of Leriche syndrome, strict postoperative hypertension control and distal run-off resolution are necessary.  相似文献   
3.
PINK1 mutations in sporadic early-onset Parkinson's disease.   总被引:5,自引:0,他引:5  
Pathogenic PINK1 mutations have been described in PARK6-linked Parkinson's disease (PD) patients of Asian origin. However, data on the frequency of PINK1 mutations in sporadic early-onset Parkinson's disease (EOPD) Asian patients are lacking. The objectives of this study were to report the frequency of PINK1 mutations of sporadic EOPD in an Asian cohort comprising of ethnic Chinese, Malays, and Indians, and to highlight a PINK1-positive patient who presented with restless legs symptoms. Eighty consecutive sporadic EOPD patients from the movement disorder clinics of two major tertiary institutions in the country were included. We performed sequence analysis of all the coding and exon-intron junctions of the PINK1 using specific primer sets. In addition, we genotyped polymorphisms detected from the analysis in a group of sporadic PD patients and controls. Three different mutations (two homozygous nonsense and one heterozygous missense) in the putative kinase domain were found in three patients, giving a 3.7% frequency of PINK1 mutations in our EOPD cohort. All the mutations were absent in 200 healthy controls. One patient with a novel homozygous nonsense PINK1 mutation presented unusually with restless legs symptoms. Separately, analysis of the frequency of four PINK1 polymorphisms in a group of sporadic PD and controls did not reveal any significant differences. We highlight a 3.7% frequency of PINK1 mutations in an Asian cohort (ethnic Chinese, Malay, and Indian) of EOPD. The phenotypic spectrum associated with PINK1-positive patients may be wider than previously reported. Polymorphisms of PINK1 do not appear to modulate risk of PD in our population.  相似文献   
4.
5.
Two triazaspirodienes, having similar phenoxy propyloxy side chain, were identified as potent mammalian dihydrofolate reductase inhibitors; one having a 6,5‐spiro bicyclic ring system (IC50 = 2.3 nm ) and the other a 6,6‐spiro bicyclic system (IC50 = 6.9 nm ). They also showed more than 50% antiproliferative activity against the MCF‐7 breast cancer cells at 20 μm . This study demonstrated the potential lead of the diamino‐triazaspirodienes in anticancer chemotherapeutical agents’ discovery.  相似文献   
6.
7.
1. Fifty-five intact and six baroreceptor denervated and vagotomized cats of either sex were anaesthetized intraperito-neally with urethane (400 mg/kg) and a-chloralose (40 mg/kg). Responses of the systemic arterial pressure (SAP), mean SAP (MSAP) and sympathetic vertebral nerve (VNA) and renal nerve activities (RNA) were recorded. 2. In intact animals, monosodium L-glutamate (Glu, 0.1 mol/L, 50 nL) was microinjected into pressor areas of the locus coeruleus (LC), gigantocellular tegmental field (GTF), rostral ventrolateral medulla (RVLM) and dorsomedial medulla (DM), and the depressor areas of caudal ventrolateral medulla (CVLM). The induced actions were compared before and after microinjection of either glutamate antagonists, glutamate diethylester (GDEE, 0.5 mol/L, 50–100nL), a competitive AMPA receptor blocker, or 2-amino-5-phosphonovaleric acid (D-AP5, 0.025 mol/L, 50–100 nL), a competitive N-methyl-D-aspartate (NMDA) receptor blocker. GDEE completely blocked the increases of SAP and VNA elicited from all pressor areas. D-AP5 only partially blocked the pressor but slightly blocked VNA and RNA responses from LC, GTF and DM, particularly those from RVLM. Neither GDEE nor D-AP5 blocked the depressor responses of SAP and two nerve activities elicited from CVLM. 3. In baroreceptor denervated animals, NMDA (2 mmol/L, 50–100 nL) and AMPA (0.2 mmol/L, 50–100 nL) were micro-injected into the same pressor areas of GTF, RVLM and DM and the depressor area of CVLM responsive to Glu activation (0.1 mol/L, 30 nL). In RVLM, DM and CVLM, the results of either NMDA or AMPA were similar to those induced by Glu. However, in GTF, microinjection of either NMDA or AMPA did not induce similar responses to Glu. This suggests that the nature of GTF may differ from RVLM and DM. 4. The above results suggest that the Glu-induced pressor responses from LC, GTF, DM and especially RVLM, are primarily mediated through AMPA receptors. The Glu-induced depressor responses from CVLM may not be predominantly mediated by either AMPA or NMDA receptors. 5. In both baroreceptor-intact and -denervated cats stimulation of the pressor areas often produced an increase of VNA and a decrease of RNA, while in the depressor CVLM decreased both VNA and RNA. The VNA, but not RNA were positively correlated with the pressor responses, while both VNA and RNA were positively correlated with the depressor responses. This may suggest that neurons of the sympathetic vertebral and renal nerves are topographically organized in the brain.  相似文献   
8.
Thirty-five patients hospitalized for recent angiographically documented arterial occlusion in the legs (27 femoropopliteal arteries and eight grafts) benefited from local fibrinolytic therapy delivered at the site of the occlusion with a 4- or 5-F catheter. This therapy combined a continuous urokinase (UK) infusion of 1,000 U/kg/hour and a lysyl plasminogen (LYS-PLG) infusion of 15 microkatals every 30 minutes. Angiographically confirmed lysis was obtained in 85% of the cases. Only 3% of the patients had major and 6% had minor groin hematomas. Only two patients had concentrations of fibrinogen as low as 100 mg/dl. Intravascular infusion of UK-LYS-PLG is as effective as streptokinase. Its excellent tolerance makes it a good alternative in the treatment of acute ischemia in the lower limbs.  相似文献   
9.
BACKGROUND/AIMS: Carcinogenesis is characterized by the abnormal regulation of cell cycle. The abnormal expression of the regulators of cell cycle may be related to the prognosis. Since the clinical significance of the expression of the three proteins in colorectal carcinomas is still controversial, we evaluated the prognostic value of the expression of cyclin E, p27 and mutant p53 in stage II colorectal cancer. METHODS: The expression levels of cyclin E, p27 and mutant p53 proteins in 41 patients with stage II colorectal carcinomas were analyzed by immunohistochemistry. RESULTS: In the univariate analysis, the level of CEA at diagnosis was associated with disease relapse. In the multivariate analysis, the clinicopathological variables such as age, gender, site of primary tumor, tumor size, state of tumor differentiation and preoperative plasma CEA level were not associated with disease relapse. When Kaplan-Meier survival curves were constructed to determine the prognosis, cyclin E, p27 and mutant p53 expressions did not predict poor prognosis. CONCLUSIONS: Our results suggested that the expression of cyclin E, p27 and mutant p53 proteins did not predict the clinical outcome in the stage II colorectal carcinomas.  相似文献   
10.
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