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   3371363篇
  免费   250622篇
  国内免费   8832篇
耳鼻咽喉   45643篇
儿科学   110141篇
妇产科学   91805篇
基础医学   473984篇
口腔科学   94353篇
临床医学   309287篇
内科学   662943篇
皮肤病学   77233篇
神经病学   278089篇
特种医学   130999篇
外国民族医学   952篇
外科学   503631篇
综合类   72826篇
现状与发展   5篇
一般理论   1290篇
预防医学   265987篇
眼科学   74912篇
药学   247121篇
  74篇
中国医学   6635篇
肿瘤学   182907篇
  2019年   26128篇
  2018年   36872篇
  2017年   28285篇
  2016年   32588篇
  2015年   36744篇
  2014年   50888篇
  2013年   76838篇
  2012年   101651篇
  2011年   107848篇
  2010年   64973篇
  2009年   62220篇
  2008年   100576篇
  2007年   107062篇
  2006年   108878篇
  2005年   104695篇
  2004年   100920篇
  2003年   97301篇
  2002年   93718篇
  2001年   161993篇
  2000年   166417篇
  1999年   140002篇
  1998年   40408篇
  1997年   35947篇
  1996年   36406篇
  1995年   35382篇
  1994年   32647篇
  1993年   30536篇
  1992年   110367篇
  1991年   106563篇
  1990年   103228篇
  1989年   99368篇
  1988年   91295篇
  1987年   89705篇
  1986年   84393篇
  1985年   80646篇
  1984年   60413篇
  1983年   51125篇
  1982年   30393篇
  1981年   27226篇
  1979年   53897篇
  1978年   38297篇
  1977年   32330篇
  1976年   30019篇
  1975年   32040篇
  1974年   38015篇
  1973年   36263篇
  1972年   33871篇
  1971年   31439篇
  1970年   28912篇
  1969年   27509篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
IntroductionShared decision-making incorporates patients’ values and preferences to achieve high-quality decisions. The objective of this study was to develop an acceptable patient decision aid to facilitate shared decision-making for the management of small renal masses (SRMs).MethodsThe International Patient Decision Aids Standards were used to guide an evidence-based development process. Management options included active surveillance, thermal ablation, partial nephrectomy, and radical nephrectomy. A literature review was performed to provide incidence rates for outcomes of each option. Once a prototype was complete, alpha-testing was performed using a 10-question survey to assess acceptability with patients, patient advocates, urologists, and methodological experts. The primary outcome was acceptability of the decision aid.ResultsA novel patient decision aid was created to facilitate shared decision-making for the management of SRMs. Acceptability testing was performed with 20 patients, 10 urologists, two patient advocates, and one methodological expert. Responders indicated the decision aid was appropriate in length (82%, 27/33), well-balanced (82%, 27/33), and had language that was easy to follow (94%, 31/33). All patient responders felt the decision aid would have been helpful during their consultation and would recommend the decision aid for future patients (100%, 20/20). Most urologists reported they intend to use the decision aid (90%, 9/10).ConclusionsA novel patient decision aid was created to facilitate shared decision-making for management of SRMs. This clinical tool was acceptable with patients, patient advocates, and urologists and is freely available at: https://decisionaid.ohri.ca/decaids.html.  相似文献   
72.
ABSTRACT

Background

Post-stroke dysphagia is characterized by reduced corticolingual excitability and lingual pressure; however, it remains unknown if transcranial magnetic stimulation (TMS) directly facilitates lingual pressure generation.  相似文献   
73.
Abstract

Background: Substance use disorder (SUD) treatment centers serve a population of clients who have diverse needs, and may desire or require access to varied treatments while seeking care for their SUDs. While pharmacotherapies have increased in popularity for the treatment of SUDs, adoption rates do remain quite low. But a wider array of pharmacotherapies has become available in recent years which may shift the trend. This article helps shed light on how variations in SUD treatment centers develop and persist with regard to the adoption and delivery of off-label medications. Methods: We use a nationally representative and longitudinal sample of SUD treatment centers in the US (N?=?196). We use a logistic regression to analyze the relationship between organizational characteristics and offering any medications, off-label. We also use a negative binomial regression to analyze the relationship between organizational characteristics and the number of medications that were used off-label. Results: Our findings reveal that older centers, accredited centers, and centers that offer mental health screenings are all positively associated with the provision of off-label medication in SUD treatment. We also find a positive relationship between private funding and offering a greater number of off-label medications. Conclusions: Our results suggest that SUD clients who seek treatment from centers that offer medications off-label, may have access to a greater number of medication-assisted treatment options.  相似文献   
74.
ABSTRACT

We narrate our personal journey through the political minefield that is postpartum crisis by examining our communicative strategies across friendship, research partnership and as mothers on social media platforms. In a country with the highest postpartum maternal death rate in the industrialized world, we argue sharing narratives is a radical feminist act and one that must continue to draw attention to marginalized bodies. We hope to elevate the study of communication challenges mothers may experience for personal and political reasons.  相似文献   
75.
  • Over 21 years, 26 coronary artery fistulae were treated percutaneously, and 21 (81%) were successful.
  • There is still much to be learned about the physiology of coronary fistulae.
  • Transcatheter methods have improved over the years and permit a high success rate, but some cases still require a surgical approach.
  相似文献   
76.

Background

Spontaneous decolonization of antibiotic-resistant bacteria (ARB) takes time: approximately 25% after 30 days for carbapenem-producing Enterobacteriaceae or extended-spectrum beta-lactamase-producing Enterobacteriaceae. Faecal microbiota transplantation (FMT) has been proposed as a new strategy to promote decolonization in order to reduce the risk of superinfection due to these ARB. This paper discusses the literature on the use of FMT for this indication, and the improvement levers available to promote its efficacy.

Methods

Literature available to date concerning the use of FMT to eradicate ARB was reviewed, and the different factors that may have influenced the efficacy of decolonization were evaluated.

Results

Four axes that could have played major roles in the efficacy of FMT were identified: bowel preparation before FMT; donor; dose; and thermal conditioning of faeces. The positive or negative impact of each on the outcome of FMT is discussed.

Conclusion

Although FMT is very efficient for the eradication of Clostridium difficile, the same ‘recipe’ cannot be used for the eradication of ARB. Working together with expert centres may help to improve the efficacy of FMT for this indication, and enable the reduction of in-hospital isolation precautions.  相似文献   
77.

Objectives

Triazole resistance in Aspergillus spp. is emerging and complicates prophylaxis and treatment of invasive aspergillosis (IA) worldwide. New polymerase chain reaction (PCR) tests on broncho-alveolar lavage (BAL) fluid allow for detection of triazole resistance at a genetic level, which has opened up new possibilities for targeted therapy. In the absence of clinical trials, a modelling study delivers estimates of the added value of resistance detection with PCR, and which empiric therapy would be optimal when local resistance rates are known.

Design

A decision-analytic modelling study was performed based on epidemiological data of IA, extended with estimated dynamics of resistance rates and treatment effectiveness. Six clinical strategies were compared that differ in use of PCR diagnostics (used vs not used) and in empiric therapeutic choice in case of unknown triazole susceptibility: voriconazole, liposomal amphotericin B (LAmB) or both. Outcome measures were proportion of correct treatment, survival and serious adverse events.

Results

Implementing aspergillus PCR tests was projected to result in residual treatment-susceptibility mismatches of <5% for a triazole resistance rate up to 20% (using voriconazole). Empiric LAmB outperformed voriconazole at resistance rates >5–20%, depending on PCR use and estimated survival benefits of voriconazole over LAmB. Combination therapy of voriconazole and LAmB performed best at all resistance rates, but the advantage over the other strategies should be weighed against the expected increased number of drug-related serious adverse events. The advantage of combination therapy over LAmB monotherapy became smaller at higher triazole resistance rates.

Conclusions

Introduction of current aspergillus PCR tests on BAL fluid is an effective way to increase the proportion of patients that receive targeted therapy for IA. The results indicate that close monitoring of background resistance rates and adverse drug events are important to attain the potential benefits of LAmB. The choice of strategy ultimately depends on the probability of triazole resistance, the availability of PCR and individual patient characteristics.  相似文献   
78.
Vitamin D can be synthesized in the skin via sunlight exposure as well as ingested through diet. Vitamin D deficiency is currently a major global public health issue, with increasing prevalence in both low and high latitude locations. This cross-sectional analysis aimed to compare the intensity of individual Ultraviolet B radiation levels between women of the same ethnicity living in England and Brazil, respectively; and to investigate the association with circulating 25(OH)D concentrations. We analysed data from 135 Brazilian women (England, n = 56, 51° N; Brazil, n = 79, 16° S) recruited for the D-SOL study (Interaction between Vitamin D Supplementation and Sunlight Exposure in Women Living in Opposite Latitudes). Serum 25(OH)D concentrations were analysed by high performance liquid chromatography tandem mass spectrometry (HPLC-MS), individual UVB radiation via UVB dosimeter badges and dietary intake via 4-day diet diaries. Anthropometric, skin phototype, sociodemographic and lifestyle patterns were also assessed. Mean serum 25(OH)D concentration of England residents was significantly lower than Brazil residents. Daily individual UVB radiation level showed a strong significant positive correlation with serum 25(OH)D concentrations. The required UVB radiation to achieve 75 nmol/L was 2.2 SED and 38.8% of the total variance in 25(OH)D concentrations was explained uniquely by daily individual UVB radiation, after controlling for the influence of age and body mass index. Thus, these results highlight the strong positive association between serum 25(OH)D concentrations and individual UVB radiation and the influence of different individual characteristics and behaviours. Collectively, these factors contribute to meaningful, country-specific, public health strategies and policies for the efficient prevention and treatment of vitamin D inadequacy.  相似文献   
79.
ABSTRACT

We report a patient with autism-like deficits in emotional connectedness, executive dysfunction, and ataxia beginning at age 39. He had compound heterozygous variants in SPG7 (A510V and 1552+1 G>T substitutions), mutation of which is classically associated with spastic paraparesis. Diffusion MRI demonstrated abnormalities in the cerebellar outflow tracts. Transcranial magnetic stimulation showed a prolonged cortical silent period representing exaggerated cortical inhibition, as previously described with pure cerebellar degeneration. The acquired cerebellar cognitive affective syndrome in association with specific anatomic and neurophysiological abnormalities in the cerebellum expand the spectrum of SPG7-related neurodegeneration and support a role for cerebellar output in socio-emotional behavior.  相似文献   
80.
During the ongoing public health crisis, many agencies are reporting COVID-19 health outcome information based on the overall population. This practice can lead to misleading results and underestimation of high risk areas. To gain a better understanding of spatial and temporal distribution of COVID-19 deaths; the long term care facility (LTCF) and household population (HP) deaths must be used. This approach allows us to better discern high risk areas and provides policy makers with reliable information for community engagement and mitigation strategies. By focusing on high-risk LTCFs and residential areas, protective measures can be implemented to minimize COVID-19 spread and subsequent mortality.  These areas should be a high priority target when COVID-19 vaccines become available

During the current public health crisis, many agencies and media outlets are reporting COVID-19 health outcome information based on the overall population of Cook County. As we have demonstrated, overall COVID-19 case counts and mortality can be misleading (details in >Story Map 1). Moreover, they offer little guidance for delivering public health interventions to high risk populations, a critical need during this second and potentially more devastating wave of the pandemic. The University of Illinois Chicago School of Public Health’s Public Health Geographic Information System Program (UIC-SPH-PHGIS) and Purdue research team has been examining spatial and temporal patterns of COVID-19 mortality with a focus on the significant loss of life from COVID-19 among Long-Term Care Facility (LTCF) residents in contrast to mortality in the community among residents of private households (non-LTCF; referred to as household population, HP). The goals of the study are:
  • Improve the accuracy of commonly quoted COVID-19 mortality indicators;
  • Gain a better understanding of spatial and temporal distribution of COVID-19 deaths;
  • Examine the role of race, ethnicity, and socioeconomic status in COVID-19 mortality;
  • Identify population and organizational parameters that can inform strategies for public health interventions.
Prioritizing the allocation of resources based on reliable information is a prerequisite of a successful mitigation strategy and immunization plan. Findings from our research have significant practical implications. The state and federal government face a series of policy decisions both due to the recent surge in positive cases and, when the time comes, the need to rationalize distribution of vaccines to high priority groups beyond healthcare workers and nursing home residents in critical areas. The research team seeks to modify prevailing practices in order to derive reliable information that guides policy decisions. At this stage of the study, we identified high-risk LTCFs and residential areas (HP) of Cook County from readily available, real-time mortality data.  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