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   4992篇
  免费   350篇
  国内免费   5篇
耳鼻咽喉   35篇
儿科学   132篇
妇产科学   151篇
基础医学   584篇
口腔科学   95篇
临床医学   882篇
内科学   769篇
皮肤病学   53篇
神经病学   424篇
特种医学   124篇
外国民族医学   1篇
外科学   531篇
综合类   59篇
一般理论   3篇
预防医学   626篇
眼科学   89篇
药学   298篇
中国医学   5篇
肿瘤学   486篇
  2023年   28篇
  2022年   43篇
  2021年   98篇
  2020年   80篇
  2019年   98篇
  2018年   130篇
  2017年   99篇
  2016年   129篇
  2015年   113篇
  2014年   152篇
  2013年   254篇
  2012年   338篇
  2011年   375篇
  2010年   210篇
  2009年   175篇
  2008年   367篇
  2007年   330篇
  2006年   349篇
  2005年   300篇
  2004年   312篇
  2003年   275篇
  2002年   257篇
  2001年   66篇
  2000年   39篇
  1999年   51篇
  1998年   57篇
  1997年   31篇
  1996年   30篇
  1995年   33篇
  1994年   30篇
  1993年   26篇
  1992年   34篇
  1991年   40篇
  1990年   33篇
  1989年   34篇
  1988年   29篇
  1987年   17篇
  1986年   16篇
  1985年   23篇
  1984年   29篇
  1983年   27篇
  1982年   18篇
  1981年   19篇
  1980年   20篇
  1979年   8篇
  1978年   21篇
  1975年   11篇
  1974年   8篇
  1971年   8篇
  1969年   7篇
排序方式: 共有5347条查询结果,搜索用时 15 毫秒
91.
The impact of the Borrelia burgdorferi surface-localized immunogenic lipoprotein BBA66 on vector and host infection was evaluated by inactivating the encoding gene, bba66, and characterizing the mutant phenotype throughout the natural mouse-tick-mouse cycle. The BBA66-deficient mutant isolate, BbΔA66, remained infectious in mice by needle inoculation of cultured organisms, but differences in spirochete burden and pathology in the tibiotarsal joint were observed relative to the parental wild-type (WT) strain. Ixodes scapularis larvae successfully acquired BbΔA66 following feeding on infected mice, and the organisms persisted in these ticks through the molt to nymphs. A series of tick transmission experiments (n = 7) demonstrated that the ability of BbΔA66-infected nymphs to infect laboratory mice was significantly impaired compared to that of mice fed upon by WT-infected ticks. trans-complementation of BbΔA66 with an intact copy of bba66 restored the WT infectious phenotype in mice via tick transmission. These results suggest a role for BBA66 in facilitating B. burgdorferi dissemination and transmission from the tick vector to the mammalian host as part of the disease process for Lyme borreliosis.  相似文献   
92.
93.

This study aimed to describe the impact that autistic characteristics (core features of autism and co-occurring conditions) have on interactions with police. Twelve autistic adults and 19 parent/carers were interviewed about interactions with police in the past 5 years. Using content analysis, it was found that in most (92.3%) interactions, autistic characteristics were described as having a role in the police interaction, either as a causal factor or more commonly by affecting the conduct of the interaction. In the latter case, the impact was associated with negative perceptions of the interaction. By sampling a more representative group across age, gender, functional abilities and context, this study provides insight into factors that underlie many autistic individual’s reported dissatisfaction with police interactions.

  相似文献   
94.
95.
96.
While the samples and data from the Pima Indians of the Gila River Indian Community have been included in many international HLA workshops and conferences and have been the focus of numerous population reports and the source of novel alleles at the classical HLA loci, they have not been studied for the non-classical loci. In order to expand our HLA-disease association studies, we typed over 300 whole genome sequences from full Pima heritage members, controlled for first degree relationship, and employed recently developed computer algorithms to resolve HLA alleles. Both classical—HLA-A, -B, and -C— and non-classical— HLA-E, -F, -G, -J, -L, -W, -Y, -DPA2, -DPB2, -DMA, -DMB, -DOA, -DRB2, -DRB9, TAP1— loci were typed at the 4-field level of resolution. We present allele and selected haplotype frequencies, test the genotype distributions for population structure, discuss the issues that are created for tests of Hardy-Weinberg equilibrium over the four sample spaces of high resolution HLA typing, and address the implications for the evolution of non-classical pseudogenes that are no longer expressed in a phenotype subject to natural selection.  相似文献   
97.
98.
99.
BackgroundPressure injuries have a major impact on patients and healthcare organisations. The complications of pressure injuries increase morbidity and mortality rates and are costly to individuals and healthcare systems. The total prevalence rate of pressure injuries within acute care hospitals in Australia and New Zealand is unknown, and despite a focus on prevention, pressure injuries still occur within these hospital settings.AimTo report the prevalence of pressure injuries within acute care settings in Australian and New Zealand hospitals and to identify the stage and location of pressure injuries and analyse the methods used to conduct pressure injury point prevalence studies.MethodsA systematic review of studies published in CINAHL, MEDLINE and Cochrane databases and a two-part grey literature search, including a customised Google search and a targeted website search, was undertaken up to July 2019. The systematic review was prospectively registered with PROSPERO (CRD42018105566).FindingsThe overall prevalence of pressure injuries in acute-care hospitals in Australia and New Zealand is 12.9% (95% CI, 9.5%–16.8%) and the hospital-acquired pressure injury prevalence is 7.9% (95% CI, 5.7%–10.3%). Stage I and stage II are the most common pressure injuries. The most frequent locations for pressure injuries are the sacrum/buttock/coccyx area (41%) and the heels (31%). The reporting of details about methodology varies considerably between studies.DiscussionPressure injuries remain a significant problem within acute-care hospital settings. Total prevalence rates are decreasing over time with the numbers of stage I and II pressure injuries decreasing faster than other pressure injuries.ConclusionThe findings from this study can be used to set performance benchmarks within acute-care hospitals in Australia and New Zealand. Pressure injuries are preventable and pressure injury prevalence studies can be used to monitor the effectiveness of nursing care processes to improve patient outcomes.  相似文献   
100.
The profile of patients on chronic dialysis has shifted. There is a growing group of older patients with comorbid dementia and ESKD, who are at risk of overuse, underuse, and misuse of dialysis. Policy is lacking to help guide treatment decisions in this group. This paper explores clinical considerations specific to patients with comorbid ESKD and dementia. These include: the impact of comorbid dementia on dialysis effectiveness and feasibility; burden of care issues that are specific to patients with dementia; and capacity, autonomy, and consent. A better understanding of these issues may help guide discussions and decision making about treatment. For some older patients with multiple comorbidities including dementia, dialysis does not provide survival or quality of life benefit compared to medical management. These patients also experience additional treatment burden due to a ‘dementia unfriendly’ environment. However, exceptions may include patients who are younger, more independent, and have fewer comorbidities. Patients with dementia are often inappropriately assumed to lack capacity to participate in treatment decision making, and are at risk of having their preferences overlooked. Many patients with mild‐to‐moderate dementia remain capable of reporting their preferences and quality of life, and should always be involved in treatment discussions where possible.  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