全文获取类型
收费全文 | 184845篇 |
免费 | 1833篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 1193篇 |
儿科学 | 6948篇 |
妇产科学 | 3246篇 |
基础医学 | 18072篇 |
口腔科学 | 1615篇 |
临床医学 | 13428篇 |
内科学 | 32820篇 |
皮肤病学 | 904篇 |
神经病学 | 17507篇 |
特种医学 | 9139篇 |
外国民族医学 | 2篇 |
外科学 | 29873篇 |
综合类 | 2346篇 |
现状与发展 | 1篇 |
一般理论 | 6篇 |
预防医学 | 18816篇 |
眼科学 | 2926篇 |
药学 | 9983篇 |
中国医学 | 634篇 |
肿瘤学 | 17265篇 |
出版年
2024年 | 25篇 |
2023年 | 147篇 |
2022年 | 251篇 |
2021年 | 516篇 |
2020年 | 328篇 |
2019年 | 494篇 |
2018年 | 22296篇 |
2017年 | 17659篇 |
2016年 | 19814篇 |
2015年 | 1270篇 |
2014年 | 1306篇 |
2013年 | 1325篇 |
2012年 | 7840篇 |
2011年 | 21843篇 |
2010年 | 19242篇 |
2009年 | 11818篇 |
2008年 | 20069篇 |
2007年 | 22250篇 |
2006年 | 1061篇 |
2005年 | 2723篇 |
2004年 | 3810篇 |
2003年 | 4734篇 |
2002年 | 2829篇 |
2001年 | 313篇 |
2000年 | 434篇 |
1999年 | 204篇 |
1998年 | 283篇 |
1997年 | 264篇 |
1996年 | 119篇 |
1995年 | 128篇 |
1994年 | 116篇 |
1993年 | 79篇 |
1992年 | 44篇 |
1991年 | 90篇 |
1990年 | 133篇 |
1989年 | 79篇 |
1988年 | 57篇 |
1987年 | 46篇 |
1986年 | 30篇 |
1985年 | 38篇 |
1984年 | 26篇 |
1983年 | 25篇 |
1982年 | 28篇 |
1980年 | 43篇 |
1938年 | 60篇 |
1937年 | 25篇 |
1935年 | 23篇 |
1934年 | 32篇 |
1932年 | 58篇 |
1930年 | 47篇 |
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
951.
952.
Pulse oximeters rely on the technique of photoplethysmography (PPG) to estimate arterial oxygen saturation (SpO\(_2\)). In conditions of poor peripheral perfusion such as hypotension, hypothermia, and vasoconstriction, the PPG signals detected are often weak and noisy, or in some cases unobtainable. Hence, pulse oximeters produce erroneous SpO\(_2\) readings in these circumstances. The problem arises as most commercial pulse oximeter probes are designed to be attached to peripheral sites such as the finger or toe, which are easily affected by vasoconstriction. In order to overcome this problem, the ear canal was investigated as an alternative site for measuring reliable SpO\(_2\) on the hypothesis that blood flow to this central site is preferentially preserved. A novel miniature ear canal PPG sensor was developed along with a state of the art PPG processing unit to investigate PPG measurements from the bottom surface of the ear canal. An in vivo study was carried out in 15 healthy volunteers to validate the developed technology. In this comparative study, red and infrared PPGs were acquired from the ear canal and the finger of the volunteers, whilst they were undergoing artificially induced hypothermia by means of cold exposure (10 \(^\circ\)C). Normalised Pulse Amplitude (NPA) and SpO\(_2\) was calculated from the PPG signals acquired from the ear canal and the finger. Good quality baseline PPG signals with high signal-to-noise ratio were obtained from both the PPG sensors. During cold exposure, significant differences were observed in the NPA of the finger PPGs. The mean NPA of the red and infrared PPGs from the finger have dropped by >80%. Contrary to the finger, the mean NPA of red and infrared ear canal PPGs had dropped only by 0.2 and 13% respectively. The SpO\(_2\)s estimated from the finger sensor have dropped below 90% in five volunteers (failure) by the end of the cold exposure. The ear canal sensor, on the other hand, had only failed in one volunteer. These results strongly suggest that the ear canal may be used as a suitable alternative site for monitoring PPGs and arterial blood oxygen saturation at times were peripheral perfusion is compromised. 相似文献
953.
954.
955.
Roselien Pas Mira Meeus Anneleen Malfliet Isabel Baert Sophie Van Oosterwijck Laurence Leysen Jo Nijs Kelly Ickmans 《Revista brasileira de fisioterapia (S?o Carlos (S?o Paulo, Brazil))》2018,22(3):248-253
Background
Current treatment for adults with chronic pain often includes Pain Neuroscience Education (PNE) to make people understand the nature underlying their pain and thus provides a clear rational for a biopsychosocial approach. Despite recommendations to use Pain Neuroscience Education as well in children with chronic pain, a specific program, tailored to children aged 6–12 years is lacking.Objectives
The aim of this study was to develop a Pain Neuroscience Education program for children with chronic pain and test its feasibility.Methods
First the internet and scientific literature was searched for sources (e.g., books, videos, etc.) that might be supportive in teaching children about the neurophysiology of pain. Based on this content, we developed a Pain Neuroscience Education program for children, ‘PNE4Kids’, which was tested for feasibility in three groups of healthy children (n = 18; 9 girls and 9 boys) aged between 6 and 12 years old.Results and conclusions
This paper provides both scientists and clinicians with a specific program to explain the neurophysiology of pain to children with chronic pain, since it is past high time to use a modern neuroscience approach in this vulnerable population. Further research should examine the effectiveness of this developed PNE4Kids program on pain-related outcomes in children with chronic pain.Registration number: NCT02880332 (https://clinicaltrials.gov/ct2/show/NCT02880332). 相似文献956.
Background
Emergency medicine is characterized by a high patient flow where timely decisions are essential. Clinical decision support systems have the potential to assist in such decisions but will be dependent on the data quality in electronic health records which often is inadequate. This study explores the effect of automated documentation of vital signs on data quality and workload.Methods
An observational study of 200 vital sign measurements was performed to evaluate the effects of manual vs automatic documentation on data quality. Data collection using questionnaires was performed to compare the workload on wards using manual or automatic documentation.Results
In the automated documentation time to documentation was reduced by 6.1?min (0.6?min vs 7.7?min, p?<? 0.05) and completeness increased (98% vs 95%, p?<? 0.05). Regarding workflow temporal demands were lower in the automatic documentation workflow compared to the manual group (50 vs 23, p?<? 0.05). The same was true for frustration level (64 vs 33, p?<? 0.05). The experienced reduction in temporal demands was in line with the anticipated, whereas the experienced reduction in frustration was lower than the anticipated (27 vs 54, p?<?0.05).Discussion
The study shows that automatic documentation will improve the currency and the completeness of vital sign data in the Electronic Health Record while reducing workload regarding temporal demands and experienced frustration. The study also shows that these findings are in line with staff anticipations but indicates that the anticipations on the reduction of frustration may be exaggerated among the staff. The open-ended answers indicate that frustration focus will change from double documentation of vital signs to technical aspects of the automatic documentation system.957.
Christian Backer Mogensen Malene Bue Vilhelmsen Johanne Jepsen Lilian Keene Boye Maiken Hjuler Persson Florence Skyum 《BMC emergency medicine》2018,18(1):51
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 11/18/2016.958.
Anthonie W. A. Lensing Christoph Male Guy Young Dagmar Kubitza Gili Kenet M. Patricia Massicotte Anthony Chan Angelo C. Molinari Ulrike Nowak-Goettl Ákos F. Pap Ivet Adalbo William T. Smith Amy Mason Kirstin Thelen Scott D. Berkowitz Mark Crowther Stephan Schmidt Victoria Price Martin H. Prins Paul Monagle 《Thrombosis journal》2018,16(1):34
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 2014.959.
Dagmar Kubitza Stefan Willmann Michael Becka Kirstin Thelen Guy Young Leonardo R. Brandão Paul Monagle Christoph Male Anthony Chan Gili Kennet Ida Martinelli Paola Saracco Anthonie W. A. Lensing 《Thrombosis journal》2018,16(1):31
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, NCT01145859.960.
Elizabeth Sarah Mayne Malcolm Tait Barry Frank Jacobson Evashin Pillay Susan J. Louw 《Thrombosis journal》2018,16(1):30