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   72028篇
  免费   7747篇
  国内免费   2705篇
耳鼻咽喉   182篇
儿科学   620篇
妇产科学   274篇
基础医学   3185篇
口腔科学   1320篇
临床医学   6186篇
内科学   7329篇
皮肤病学   1081篇
神经病学   2395篇
特种医学   1038篇
外国民族医学   7篇
外科学   2492篇
综合类   9774篇
现状与发展   5篇
一般理论   6篇
预防医学   5551篇
眼科学   718篇
药学   31858篇
  45篇
中国医学   4666篇
肿瘤学   3748篇
  2024年   69篇
  2023年   1178篇
  2022年   1434篇
  2021年   2473篇
  2020年   2681篇
  2019年   2674篇
  2018年   2719篇
  2017年   2994篇
  2016年   2838篇
  2015年   2862篇
  2014年   4858篇
  2013年   7993篇
  2012年   4982篇
  2011年   5122篇
  2010年   4027篇
  2009年   3646篇
  2008年   3521篇
  2007年   3506篇
  2006年   3126篇
  2005年   2801篇
  2004年   2298篇
  2003年   2070篇
  2002年   1626篇
  2001年   1549篇
  2000年   1179篇
  1999年   981篇
  1998年   816篇
  1997年   773篇
  1996年   640篇
  1995年   602篇
  1994年   533篇
  1993年   458篇
  1992年   509篇
  1991年   414篇
  1990年   331篇
  1989年   274篇
  1988年   279篇
  1987年   265篇
  1986年   205篇
  1985年   218篇
  1984年   179篇
  1983年   134篇
  1982年   117篇
  1981年   95篇
  1980年   70篇
  1979年   62篇
  1978年   72篇
  1977年   53篇
  1976年   52篇
  1975年   50篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
BackgroundAdverse drug reactions (ADRs) and adverse drug events (ADEs) in older people contribute to a significant proportion of hospital admissions and are common following discharge. Effective interventions are therefore required to combat the growing burden of preventable ADRs. The Prediction of Hospitalisation due to Adverse Drug Reactions in Elderly Community Dwelling Patients (PADR-EC) score is a validated risk score developed to assess the risk of ADRs in people aged 65 years and older and has the potential to be utilised as part of an intervention to reduce ADRs.ObjectivesThis trial was designed to investigate the effectiveness of an intervention to reduce ADR incidence in older people and to obtain further information about ADRs and ADEs in the 12–24 months following hospital discharge.MethodsThe study is an open-label randomised-controlled trial to be conducted at the Royal Hobart Hospital, a 500-bed public hospital in Tasmania, Australia. Community-dwelling patients aged 65 years and older with an unplanned overnight admission to a general medical ward will be recruited. Following admission, the PADR-EC ADR score will be calculated by a research pharmacist, with the risk communicated to clinicians and discussed with participants. Following discharge, nominated general practitioners and community pharmacists will receive the risk score and related medication management advice to guide their ongoing care of the patient. Follow-up with participants will occur at 3 and 12 and 18 and 24 months to identify ADRs and ADEs. The primary outcome is moderate-severe ADRs at 12 months post-discharge, and will be analysed using the cumulative incidence proportion, survival analysis and Poisson regression.SummaryIt is hypothesised that the trial will reduce ADRs and ADEs in the intervention population. The study will also provide valuable data on post-discharge ADRs and ADEs up to 24 months post-discharge.  相似文献   
4.
美国食品药品管理局(FDA)于2022年7月发布了"治疗等效性评价供企业用指导原则"(草案)。该指导原则阐明了FDA治疗等效性的标准以及治疗等效性编码系统,目的是准确评价仿制药与参比制剂的治疗等效性并通过治疗等效性代码,在"橙皮书"中迅速检索到治疗等效的仿制药。而中国目前尚无类似的指导原则,详细介绍FDA该指导原则主要内容,期望对中国加强仿制药的治疗等效性评价和加速完善和实施符合国情的治疗等效性编码系统有所帮助。  相似文献   
5.
6.
7.
8.
  1. Download : Download high-res image (204KB)
  2. Download : Download full-size image
  相似文献   
9.
ObjectivesPreclinical and clinical studies indicate a role for MLC901 (NeuroAiD II) in Alzheimer's disease (AD). The primary aim was to investigate its safety as add-on therapy to standard treatment and the secondary aims its effect on cognition and slowing disease progression.DesignRandomized double-blind placebo-controlled delayed-start study.Setting and ParticipantPatients with mild to moderate probable AD by NINCDS-ADRDA criteria, stable on acetylcholinesterase inhibitors or memantine (n = 125), were randomized to receive MLC901 (early starters) or placebo (delayed starters) for 6 months, followed by a further 6 months when all patients received MLC901, in a delayed-start design (clinical trial registration: ClinicalTrials.gov, NCT03038035).MethodsThe primary outcome measure was occurrence of serious adverse events (SAEs) at 6 months. Secondary outcomes included the Alzheimer's Disease Assessment Scale–Cognitive subscale (ADAS-Cog) and other assessment scales.ResultsThere was no significant difference in the risk of SAEs between early and delayed starters at month (M) 6 (22.6% vs 27.0%, risk difference ?4.4%, 90% CI –16.9% to 8.3%). Similarly, there was no significant difference in the risk of adverse events and the occurrence of stroke or vascular events between early and delayed starters throughout the 12-month study period. Early starters did not differ significantly on ADAS-Cog from delayed starters at M6 [mean difference (MD) ?1.0, 95% CI –3.3 to 1.3] and M12 (MD –2.35, 95% CI –5.45 to 0.74) on intention-to-treat analysis. Other cognitive assessment scales did not show significant differences.Conclusions and ImplicationsThis study of 125 persons with dementia found no evidence of a significant increase in adverse events between MLC901 and placebo, thus providing support for further studies on both efficacy and safety. Analyses suggest the potential of MLC901 in slowing down AD progression, but this requires further confirmation in larger and longer studies using biomarkers for AD.  相似文献   
10.
BackgroundHydrogel systems are increasingly gaining visibility involving biomedicine, tissue engineering, environmental treatments, and drug delivery systems. These systems have a three-dimensional network composition and high-water absorption capacity, are biocompatible, allowing them to become an option as photosensitizer carriers (PS) for applications in Photodynamic Therapy (PDT) protocols.MethodsA nanohydrogel system (NAHI), encapsulated with chloroaluminium phthalocyanine (ClAlPc) was synthesized for drug delivery.. NAHI was synthesized using gelatin as based polymer by the chemical cross-linking technique. The drug was encapsulated by immersing the hydrogel in a 1.0 mg.mL−1 ClAlPc solution. The external morphology of NAHI was examined by scanning electron microscopy (SEM). The degree of swelling of the synthesized system was evaluated to determine the water absorption potential. The produced nanohydrogel system was characterized by photochemical, photophysical and photobiologial studies.ResultsThe images from the SEM analysis showed the presence of three-dimensional networks in the formulation. The swelling test demonstrated that the nanohydrogel freeze-drying process increases its water holding capacity. All spectroscopic results showed excellent photophysical parameters of the drug studied when served in the NAHI system. The incorporation efficiency was 70%. The results of trypan blue exclusion test have shown significant reduction (p < 0.05) in the cell viability for all groups treated with PDT, in all concentrations tested. In HeLa cells, PDT mediated by 0,5 mg.mL−1 ClAlPc encapsulated in NAHI showed a decrease in survival close to 95%. In the internalization cell study was possible to observe the internalization of phthalocyanine after one hour of incubation, at 37 °C, with the the accumulation of PS in the cytoplasm and inside the nucleus at both concentrations tested.ConclusionsGiven the peculiar performance of the selected system, the resulting nanohydrogel is a versatile platform and display potential applications as controlled delivery systems of photosensitizer for photodynamic therapy application.  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