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   1985篇
  免费   111篇
  国内免费   8篇
耳鼻咽喉   20篇
儿科学   88篇
妇产科学   74篇
基础医学   205篇
口腔科学   53篇
临床医学   115篇
内科学   428篇
皮肤病学   17篇
神经病学   168篇
特种医学   77篇
外科学   361篇
综合类   64篇
预防医学   62篇
眼科学   28篇
药学   147篇
中国医学   9篇
肿瘤学   188篇
  2023年   17篇
  2022年   8篇
  2021年   46篇
  2020年   26篇
  2019年   44篇
  2018年   55篇
  2017年   36篇
  2016年   42篇
  2015年   42篇
  2014年   58篇
  2013年   79篇
  2012年   122篇
  2011年   147篇
  2010年   61篇
  2009年   67篇
  2008年   104篇
  2007年   120篇
  2006年   101篇
  2005年   87篇
  2004年   89篇
  2003年   67篇
  2002年   86篇
  2001年   64篇
  2000年   60篇
  1999年   47篇
  1998年   17篇
  1997年   14篇
  1996年   14篇
  1995年   13篇
  1992年   19篇
  1991年   16篇
  1990年   21篇
  1989年   24篇
  1988年   21篇
  1987年   31篇
  1986年   22篇
  1985年   29篇
  1984年   14篇
  1983年   13篇
  1982年   10篇
  1981年   10篇
  1980年   8篇
  1979年   23篇
  1978年   9篇
  1977年   8篇
  1976年   11篇
  1974年   11篇
  1973年   12篇
  1970年   7篇
  1968年   12篇
排序方式: 共有2104条查询结果,搜索用时 62 毫秒
91.
92.
BackgroundLeft ventricular hypertrophy (LVH) has been proved as one among the cardiovascular complications and predominant in patients with CKD. In CKD patients, Glycated albumin (GA) express a superior marker of glycemic control than HbA1c. Nevertheless, the precision of GA for the prediction of cardiovascular diseases among the CKD population has been ineffectively reported. The present study looks at the part of GA, HbA1c in CKD to envisage vascular complications.Materials and methodsOne hundred and ninety-four patients were selected in the present study. The study has a control group (Group I, N: 52) and participants were divided into two groups based on vein diseases (Group II, N: 42; two vessels and group III, N: 100; triple vessel disease). Serum glycated albumin, hsCRP and other routine parameters were estimated in all the three groups. 2-dimensional echocardiography (2D Echo) has been done by a cardiologist to all the study patients for assessing ejection fraction and distinguish the sort of vessel diseases.ResultsGroup I compared with group II and III shown there was a significant association among blood glucose, serum creatinine, HbA1c, mean blood glucose, GA, ejection fraction and hsCRP. Additionally, observed that increased levels of HbA1c, GA and creatinine inversely related to the left ventricle ejection fraction. Notwithstanding, GA and hsCRP predict precisely the left ventricle ejection fraction than different parameters.ConclusionGA alongside hsCRP might be appropriate markers for anticipating cardiovascular diseases particularly left ventricle hypertrophy in diabetic CKD population.  相似文献   
93.
The effects of mitragynine on anxiety-related behaviours in the open-field and elevated plus-maze tests were evaluated. Male Sprague–Dawley rats were orally treated with mitragynine (10, 20 and 40 mg/kg) or diazepam (10 mg/kg) 60 min before behavioural testing. Mitragynine doses used in this study were selected on the basis of approximately human equivalent doses with reference to our previous literature reports. Acute administration of mitragynine (10, 20 and 40 mg/kg) or diazepam (10 mg/kg) increased central zone and open arms exploration in the open-field and elevated plus-maze tests respectively. These anxiolytic-like effects of mitragynine were effectively antagonized by intraperitoneal administration of naloxone (2 mg/kg), flumazenil (10 mg/kg), sulpiride (0.5 mg/kg) or SCH 23390 (0.02 mg/kg) 15 min before mitragynine treatments. These findings reveal that the acute administration of mitragynine produces anxiolytic-like effects and this could be possibly attributed to the interactions among opioidergic, GABAergic and dopaminergic systems in brain regions involved in anxiety.  相似文献   
94.

Introduction

Platelets are involved in regeneration at sites of pathology, apart from their role in clotting. A preparation composed mainly of platelets (platelet-rich plasma gel) applied to sites of bony pathology, after surgical treatment of lesions, may hasten bone regeneration.

Materials and methods

An autologous platelet-rich plasma (PRP) gel was prepared using a standardized technique, without using thrombin clot accelerator, and applied to surgical site in six patients of study group. Five patients were enrolled as controls, in whom PRP gel was not used. The differences in the occurrence of radiographic changes between the study and control group at 6, 12, 18 and 24 weeks after surgery were analysed with chi-square test. Intragroup radiographic changes, i.e. within the study and control groups occurring over the 24 weeks of follow-up, were analysed with Friedman test.

Results

A trend towards more rapid healing was observed in the study group at 6, 12, 18 and 24 weeks. However, these differences between the study and control group were not statistically significant. Both the study and control group demonstrated significant healing changes over the 24 weeks of follow-up.

Conclusions

It is possible to prepare platelet-rich plasma gel without using thrombin clot accelerator. PRP, as prepared and applied to surgical sites in this study, was not observed to significantly enhance bone regeneration. All surgical sites, both in the PRP and control group, showed significant healing changes over 6 months.  相似文献   
95.
Abdominal Radiology - To discuss the imaging appearances of various pathologies affecting adult male urethra and to review the role of imaging in the assessment of artificial urinary sphincters and...  相似文献   
96.
97.
98.
As a redox-sensitive coenzyme, nicotinamide adenine dinucleotide (NAD+) plays a central role in cellular energy metabolism and homeostasis. Low NAD+ levels are linked to multiple disease states, including age-related diseases, such as metabolic and neurodegenerative diseases. Consequently, restoring/increasing NAD+ levels in vivo has emerged as an important intervention targeting age-related neurodegenerative diseases. One of the widely studied approaches to increase NAD+ levels in vivo is accomplished by using NAD+ precursors, such as nicotinamide mononucleotide (NMN). Oral administration of NMN has been shown to successfully increase NAD+ levels in a variety of tissues; however, it remains unclear whether NMN can cross the blood–brain barrier to increase brain NAD+ levels. This study evaluated the effects of oral NMN administration on NAD+ levels in C57/B6J mice brain tissues. Our results demonstrate that oral gavage of 400 mg/kg NMN successfully increases brain NAD+ levels in mice after 45 min. These findings provide evidence that NMN may be used as an intervention to increase NAD+ levels in the brain.  相似文献   
99.
As existing vaccines fail to completely prevent COVID-19 infections or community transmission, there is an unmet need for vaccines that can better combat SARS-CoV-2 variants of concern (VOC). We previously developed highly thermo-tolerant monomeric and trimeric receptor-binding domain derivatives that can withstand 100 °C for 90 min and 37 °C for four weeks and help eliminate cold-chain requirements. We show that mice immunised with these vaccine formulations elicit high titres of antibodies that neutralise SARS-CoV-2 variants VIC31 (with Spike: D614G mutation), Delta and Omicron (BA.1.1) VOC. Compared to VIC31, there was an average 14.4-fold reduction in neutralisation against BA.1.1 for the three monomeric antigen-adjuvant combinations and a 16.5-fold reduction for the three trimeric antigen-adjuvant combinations; the corresponding values against Delta were 2.5 and 3.0. Our findings suggest that monomeric formulations are suitable for upcoming Phase I human clinical trials and that there is potential for increasing the efficacy with vaccine matching to improve the responses against emerging variants. These findings are consistent with in silico modelling and AlphaFold predictions, which show that, while oligomeric presentation can be generally beneficial, it can make important epitopes inaccessible and also carries the risk of eliciting unwanted antibodies against the oligomerisation domain.  相似文献   
100.
Interleukin‐8 (IL‐8) is a pro‐angiogenic cytokine associated with aggressive prostate cancer (CaP). We detected high levels of IL‐8 in sera from patients with CaP compared with healthy controls and patients with benign prostatic hypertrophy. This study examines the role of IL‐8 in the pathogenesis of metastatic prostate cancer. We developed a biocompatible, cationic polylactide (CPLA) nanocarrier to complex with and efficiently deliver IL‐8 small interfering RNA (siRNA) to CaP cells in vitro and in vivo. CPLA IL‐8 siRNA nanocomplexes (nanoplexes) protect siRNA from rapid degradation, are non‐toxic, have a prolonged lifetime in circulation, and their net positive charge facilitates penetration of cell membranes and subsequent intracellular trafficking. Administration of CPLA IL‐8 siRNA nanoplexes to immunodeficient mice bearing human CaP tumours produced significant antitumour activities with no adverse effects. Systemic (intravenous) or local intra‐tumour administration of IL‐8 siRNA nanoplexes resulted in significant inhibition of CaP growth. Magnetic resonance imaging and ultrasonography of experimental animals demonstrated reduction of tumour perfusion in vivo following nanoplex treatment. Staining of tumour sections for CD31 confirmed significant damage to tumour neovasculature after nanoplex therapy. These studies demonstrate the efficacy of IL‐8 siRNA nanotherapy for advanced, treatment‐resistant human CaP.  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