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   8242篇
  免费   625篇
  国内免费   26篇
耳鼻咽喉   23篇
儿科学   195篇
妇产科学   170篇
基础医学   1450篇
口腔科学   101篇
临床医学   850篇
内科学   1624篇
皮肤病学   230篇
神经病学   950篇
特种医学   220篇
外科学   645篇
综合类   36篇
一般理论   3篇
预防医学   707篇
眼科学   110篇
药学   763篇
中国医学   13篇
肿瘤学   803篇
  2023年   85篇
  2022年   141篇
  2021年   267篇
  2020年   143篇
  2019年   227篇
  2018年   244篇
  2017年   153篇
  2016年   221篇
  2015年   238篇
  2014年   328篇
  2013年   418篇
  2012年   683篇
  2011年   626篇
  2010年   358篇
  2009年   289篇
  2008年   536篇
  2007年   599篇
  2006年   511篇
  2005年   498篇
  2004年   492篇
  2003年   435篇
  2002年   383篇
  2001年   60篇
  2000年   42篇
  1999年   84篇
  1998年   89篇
  1997年   66篇
  1996年   57篇
  1995年   44篇
  1994年   31篇
  1993年   31篇
  1992年   31篇
  1991年   19篇
  1990年   30篇
  1989年   25篇
  1988年   23篇
  1987年   22篇
  1986年   11篇
  1985年   27篇
  1984年   16篇
  1983年   10篇
  1982年   22篇
  1981年   17篇
  1980年   11篇
  1979年   21篇
  1978年   14篇
  1977年   9篇
  1976年   12篇
  1970年   10篇
  1969年   11篇
排序方式: 共有8893条查询结果,搜索用时 15 毫秒
81.
It has been established that up to 8.3% of the biallelic coding SNPs present in dbSNP are actually artefactual polymorphism‐like errors, previously termed single nucleotide differences, or SNDs. In this study, a previous analysis of SNPs in dbSNP was extended and updated to examine how the incidence of SNDs has changed over an intervening five year period. The incidence of SNDs was found to be lower than in the previous analysis at 2.2% of all biallelic SNPs. There was only a modest reduction in the percentage of SNDs in the original set of biallelic coding SNPs tested. This suggests that the overall reduction in the incidence of SNDs over the intervening 5‐year period is related to an improvement in SNP detection methods and more rigorous curation, rather than efforts to ameliorate the presence of SNDs. We note that SNDs contaminating the dbSNP may lead to erroneous conclusions on human conditions.  相似文献   
82.

Background

A new generation of ear thermometers with preheated tips and several measurements points should allow a more precise temperature measurement. The aim of the study was to evaluate if the ear temperature measured by this ear thermometer can be used to screen for fever and whether the thermometer is in agreement with the rectal temperature and if age, use of hearing devices or time after admission influences the temperature measurements.

Methods

Open cross-sectional clinical single site study patients, >?18?years old, who were acutely admitted to the short stay unit at the ED. A sample size of 99 patient per subgroup was recruited as random convenience series. As ear thermometer Braun Thermoscan Pro 4000® and as rectal thermometer Omron Flex Temp Smart ® was used. For different cut off of temperature the AUC was calculated and Bland-Altman analysis for calculation of 95% limits of agreement with rectal temperature, with subgroup analysis concerning age, time span from admission time and use of hearing aid.

Results

Among 599 patients the sensitivity to detect fever with an ear thermometer varied between 68 and 70% with AUC from 0.88–0.97. If the ear temperature was ≥37.5 oC, the sensitivity to detect patients with ≥38.0 oC rectally was 95% which raised to 100% for a rectal temperature of ≥38.3 oC. For the ear thermometer’s ability to determine the exact temperature the 95% limits of agreement were +/??0.8 oC. with no influence from age, duration of hospital stay or hearing aids.

Conclusion

The examined ear thermometer is able to detect fever, defined as ≥38 oC rectally in an adult ED population by using an ear cut-point of 37.5 oC, but not to measure the exact temperature. Used in this way around a fifth of the patients will still be in need of a rectal temperature measurement, but less than 5% with fever ≥38.0 oC will remain undetected and none with fever ≥38.3 oC. Age, admission time and use of hearing aid did not influence the temperature measurements.

Trial registration

Clinical Trials: ID NCT02977481, date 11/18/2016.
  相似文献   
83.

Background

Venous thromboembolism (VTE) is a relatively rare condition in childhood with treatment mainly based on extrapolation from studies in adults. Therefore, clinical trials of anticoagulation in children require novel approaches to deal with numerous challenges. The EINSTEIN-Jr program identified pediatric rivaroxaban regimens commencing with in vitro dose finding studies followed by evaluation of children of different ages through phase I and II studies using extensive modeling to determine bodyweight-related doses. Use of this approach resulted in drug exposure similar to that observed in young adults treated with rivaroxaban 20?mg once-daily.

Methods

EINSTEIN-Jr phase III is a randomized, open-label, study comparing the efficacy and safety of rivaroxaban 20?mg-equivalent dose regimens with those of standard anticoagulation for the treatment of any types of acute VTE in children aged 0–18?years.A total of approximately 500 children are expected to be included during the 4-year study window. Flexibility of treatment duration is allowed with study treatment to be given for 3?months with the option to continue treatment in 3-month increments, up to a total of 12?months. However, based on most common current practice, children younger than 2?years with catheter-related thrombosis will have a main treatment period of 1?month with the option to prolong treatment in 1-month increments, up to a total of 3?months.

Conclusions

EINSTEIN-Jr will compare previously established 20?mg-equivalent rivaroxaban dosing regimens with standard anticoagulation for the treatment of VTE in children. Demonstration of similarity of disease, as well as equivalent rivaroxaban exposure and exposure-response will enable extrapolation of efficacy from adult trials, which is critical given the challenges of enrollment in pediatric anticoagulation trials.

Trial registration

Clinicaltrials.gov NCT02234843, registered on 9 September 2014.
  相似文献   
84.

Background

The EINSTEIN-Jr program will evaluate rivaroxaban for the treatment of venous thromboembolism (VTE) in children, targeting exposures similar to the 20 mg once-daily dose for adults.

Methods

This was a multinational, single-dose, open-label, phase I study to describe the pharmacodynamics (PD), pharmacokinetics (PK) and safety of a single bodyweight-adjusted rivaroxaban dose in children aged 0.5–18 years. Children who had completed treatment for a venous thromboembolic event were enrolled into four age groups (0.5–2 years, 2–6 years, 6–12 years and 12–18 years) receiving rivaroxaban doses equivalent to 10 mg or 20 mg (either as a tablet or oral suspension). Blood samples for PK and PD analyses were collected within specified time windows.

Results

Fifty-nine children were evaluated. In all age groups, PD parameters (prothrombin time, activated partial thromboplastin time and anti-Factor Xa activity) showed a linear relationship versus rivaroxaban plasma concentrations and were in line with previously acquired adult data, as well as in vitro spiking experiments. The rivaroxaban pediatric physiologically based pharmacokinetic model, used to predict the doses for the individual body weight groups, was confirmed. No episodes of bleeding were reported, and treatment-emergent adverse events occurred in four children and all resolved during the study.

Conclusions

Bodyweight-adjusted, single-dose rivaroxaban had predictable PK/PD profiles in children across all age groups from 0.5 to 18 years. The PD assessments based on prothrombin time and activated partial thromboplastin time demonstrated that the anticoagulant effect of rivaroxaban was not affected by developmental hemostasis in children.

Trial registration

ClinicalTrials.gov number, NCT01145859.
  相似文献   
85.
A novel poly(epsilon-caprolactone) (PCL) supramolecular network exhibiting shape-memory behavior was successfully constructed with pendant UPy units that are highly able to dimerize. The dynamic network was obtained by a simple and versatile strategy consisting of chain-extension reaction between α,ω-dihydroxyoligoPCL and hydroxylated UPy units in the presence of hexamethylene diisocyanate as a coupling agent and further intermolecular dimerization of the UPy along the polyurethane backbone. 1H NMR analyses confirmed the dynamic features of the system, and DMTA in tensile mode was investigated to assess the SMP properties. Recyclability was also assessed by taking advantage of these supramolecular networks. Further addition of cellulose nanocrystals into the polymer network enabled adjustment of the extent of the net-points and therefore the SMP features. As confirmed by dispersion tests in solution and SEM observations, these bio-based nanofillers were homogeneously distributed in the network via supramolecular interaction between the hydroxyl groups present on their surface and UPy moieties along the polyurethane backbone. Thus, the here developed nanomaterials might reveal applicability in areas where a combination of SMP and biocompatibility is needed.

Novel melt-recyclable poly(ε-caprolactone)/cellulose nanocrystals supramolecular nanocomposite networks with shape-memory behavior have been successfully constructed by playing with UPy chemistry.  相似文献   
86.
AimsOral therapies, including hormone‐based or targeted therapies, have recently taken an increasing place in cancer treatment. In this context, a state of the art of the available studies dealing with the adherence of adult patients to oral anticancer treatment is warranted. The purpose of this review is to address (i) the association between assessment methods and measured adherence, (ii) the putative factors related to adherence and (iii) new ways of improving adherence to oral cancer therapies.MethodsWe conducted a literature‐based narrative review of studies obtained from Pubmed using medical subject heading terms and free‐text terms combining concepts related to oral anticancer medication and adherence.ResultsThe analysis is based on 48 studies published since 1990, mostly assessing hormone‐based therapy in breast cancer and targeted therapies in chronic myeloid leukaemia. Various methods of adherence were reported including self‐report, medication measurement or combinations of methods. Adherence rates were found to vary from 14% to 100%. Beside patient related‐factors, adherence rate discrepancies were found to be dependent on the method used. Furthermore, there was no consensual definition of adherence even regarding the same methods, some of them tolerating a period of interruption during the treatment period. Finally, several studies addressing persistence found a progressive decrease in adherence with time.ConclusionAdherence to novel oral therapies is a major issue and further research is warranted to standardize adherence assessment in clinical studies better and to define better the most appropriate approaches to improve long term adherence in oncology practice.  相似文献   
87.
88.
Diabetes mellitus is a growing epidemic with a prevalence among patients with heart failure (HF) approaching 30%. Diabetes worsens the prognosis of HF, and the pathophysiology is complex and multifactorial. Early detection of subtle alterations in cardiac function by modern tools, such as Doppler echocardiography or brain natriuretic peptide dosage, is thus important in these patients. All drugs known to be effective in HF with systolic dysfunction are also effective in patients with diabetes. Angiotensin-converting enzyme inhibitors and angiotensin II receptor antagonists also seem particularly useful. Overall, however, little is known about the treatment of diabetic patients with HF, especially in case of preserved systolic function. Ongoing and future trials should help to determine the best treatment for these patients with or without associated diabetes. This review assesses the relationships between diabetes mellitus and HF and discusses the various medical strategies.  相似文献   
89.
90.
Mycobacterium thermoresistibile is a rapidly growing environmental nontuberculous mycobacterium, seldom reported in human infections. Here, we describe a rare case of tibial-nail-related osteomyelitis due to Mycobacterium thermoresistibile. We also review the literature about the infections caused by this pathogen.  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