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   4389篇
  免费   300篇
  国内免费   31篇
耳鼻咽喉   72篇
儿科学   122篇
妇产科学   97篇
基础医学   607篇
口腔科学   77篇
临床医学   400篇
内科学   1007篇
皮肤病学   87篇
神经病学   435篇
特种医学   103篇
外科学   454篇
综合类   23篇
一般理论   2篇
预防医学   373篇
眼科学   110篇
药学   367篇
中国医学   12篇
肿瘤学   372篇
  2024年   9篇
  2023年   82篇
  2022年   142篇
  2021年   247篇
  2020年   138篇
  2019年   156篇
  2018年   202篇
  2017年   116篇
  2016年   149篇
  2015年   149篇
  2014年   216篇
  2013年   255篇
  2012年   389篇
  2011年   371篇
  2010年   207篇
  2009年   177篇
  2008年   281篇
  2007年   290篇
  2006年   229篇
  2005年   220篇
  2004年   172篇
  2003年   142篇
  2002年   122篇
  2001年   29篇
  2000年   24篇
  1999年   22篇
  1998年   18篇
  1997年   13篇
  1996年   6篇
  1995年   4篇
  1994年   7篇
  1993年   12篇
  1992年   16篇
  1991年   11篇
  1990年   6篇
  1989年   4篇
  1988年   7篇
  1987年   5篇
  1986年   10篇
  1985年   6篇
  1983年   2篇
  1980年   2篇
  1979年   13篇
  1978年   5篇
  1977年   7篇
  1976年   5篇
  1975年   2篇
  1974年   7篇
  1973年   8篇
  1971年   3篇
排序方式: 共有4720条查询结果,搜索用时 15 毫秒
71.
72.
A platinum–silver graphene (Pt–Ag/Gr) nanocomposite modified electrode was fabricated for the electrochemical detection of dopamine (DA). Electrochemical studies of the Pt–Ag/Gr nanocomposite towards DA detection were performed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The CV analysis showed that Pt–Ag/Gr/GCE had enhanced electrocatalytic activity towards DA oxidation due to the synergistic effects between the platinum–silver nanoparticles and graphene. The DPV results showed that the modified sensor demonstrated a linear concentration range between 0.1 and 60 μM with a limit of detection of 0.012 μM. The Pt–Ag/Gr/GCE presented satisfactory results for reproducibility, stability and selectivity. The prepared sensor also showed acceptable recoveries for a real sample study.

A platinum–silver graphene nanocomposite was synthesized and characterized. A nanocomposite modified electrode was fabricated in order to investigate the electrochemical detection of dopamine.  相似文献   
73.
The Collaborative Transplant Study (CTS) was initiated in 1982. Over the last 30 years, it has collected information on over half a million kidney, liver, heart, lung, and pancreas transplant procedures. Participation is voluntary and the study has strictly scientific objectives. Analyses of the CTS database serve as an international reference source in the field of solid organ transplantation.  相似文献   
74.
Midodrine is an alpha-agonist that causes peripheral vasoconstriction, resulting in increased blood pressure. It has been reported to be safe and effective in patients with end stage renal disease (ESRD) and is widely used for hemodialysis-associated hypotension. We report a case report of midodrine-induced ischemia in a patient on hemodialysis and review the literature relating to the safety of midodrine in patients with end stage renal disease.  相似文献   
75.
Chronic wounds that fail to heal are a common complication of diabetes mellitus and the most common precipitating reason for nontraumatic lower limb amputation. Unfortunately, the bacterial species that cause these infections are becoming more resistant to antibiotics, making them increasingly difficult to treat. We assessed the feasibility of combating chronic bacterial infections with a topically delivered bacteriophage cocktail in two animal models of diabetes mellitus. Microbiological, planimetric, and histological parameters were compared in debrided infected wounds with or without topical bacteriophage treatment. We determined that bacteriophage treatment effectively decreased bacterial colony counts and improved wound healing, as indicated by smaller epithelial and dermal gaps, in Staphylococcus aureus and Pseudomonas aeruginosa infections but was not as effective against Acinetobacter baumannii. Although the improvements were more significant in the rodent model than in the porcine model, our results suggest that topically administered bacteriophage treatment may be effective in resolving chronic infections, especially when applied in conjunction with wound debridement. These findings have important implications for the feasibility of using topical antimicrobial therapies to safely treat chronic infections in diabetes mellitus patients.  相似文献   
76.

Introduction

Attention to the negative effects of structural barriers on HIV efforts is increasing. Reviewing national legal and policy environments with attention to the international human rights commitments of states is a means of assessing and providing focus for addressing these barriers to effective HIV responses.

Methods

Law and policy data from the 171 countries reporting under the Declaration of Commitment from the 2001 United Nations General Assembly Special Session on HIV/AIDS were analyzed to assess attention to human rights in national legal and policy environments as relevant to the health and rights of key populations such as people who inject drugs, men who have sex with men and sex workers.

Results

Seventy-eight governments and civil society in 106 countries report the existence of laws and policies which present obstacles to accessing HIV services for key populations. Laws and policies which positively affect access to HIV-related services, in and of themselves constituting structural interventions, were also reported. The dissonance between laws and how this impacts the availability and use of HIV-related services deserve greater attention.

Conclusions

Recognition of the harms inherent in laws that constitute structural barriers to effective HIV responses and the potential positive role that a supportive legal environment can play suggests the need for legal reform to ensure an enabling regulatory framework within which HIV services can be effectively delivered and used by the populations who need them. Moving beyond laws and policies, further efforts are required to determine how to capture information on the range of structural barriers. Teasing apart the impact of different barriers, as well as the structural interventions put in place to address them, remains complicated. Capturing the impact of policy and legal interventions can ultimately support governments and civil society to ensure the human rights of key populations are protected in national HIV responses.  相似文献   
77.
78.
We undertook this phase I study to investigate the feasibility of the combination of temozolomide (TMZ) and lapatinib (LP) and to define the maximum tolerated dose (MTD) of LP in patients with relapsed high-grade gliomas. Eligible patients were enrolled in this dose escalation study of LP. TMZ was administered at a fixed dose of 200 mg/m2 d1–d5 every 28 days. Starting dose of LP was set at 1,000 mg daily continuously, escalated by 250 mg in cohorts of minimum three patients. Translational research investigations were also undertaken in available biopsy material. Between January 2009 and December 2010, 16 patients were entered into the study at three LP levels: 1,000 mg sid (11 patients), 1,250 mg sid (4 patients) and 1,500 mg sid (1 patient). A total of 55 cycles had been delivered. Fourteen patients had stopped treatment because of disease progression, and two because of toxicity. Three patients received 10, 11 and 17 cycles of treatment. Dose-limiting hematological toxicity was observed in 2 patients at the second LP dose level of 1,250 mg sid. MTD was defined at LP 1,000 mg sid. Median progression-free survival (PFS) and survival were 2.4 and 5.9 months, respectively. EGFR amplification and EGFRvIII expression were not related to PFS. Combination of TMZ and LP is feasible with manageable toxicity. The activity of this combination in patients with recurrent glioblastoma multiforme is further investigated in a recently initiated phase II trial.  相似文献   
79.
Neurological Sciences - The Fist-Palm Test (FiPaT) is a novel non-verbal task to be used at the patient’s bedside for a cognitive functions screening. The aims of this study are to analyze...  相似文献   
80.
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