全文获取类型
收费全文 | 30380篇 |
免费 | 1621篇 |
国内免费 | 70篇 |
专业分类
耳鼻咽喉 | 82篇 |
儿科学 | 1005篇 |
妇产科学 | 867篇 |
基础医学 | 1692篇 |
口腔科学 | 703篇 |
临床医学 | 3618篇 |
内科学 | 4669篇 |
皮肤病学 | 248篇 |
神经病学 | 2310篇 |
特种医学 | 759篇 |
外科学 | 2259篇 |
综合类 | 1874篇 |
一般理论 | 6篇 |
预防医学 | 7480篇 |
眼科学 | 230篇 |
药学 | 2113篇 |
13篇 | |
中国医学 | 655篇 |
肿瘤学 | 1488篇 |
出版年
2024年 | 36篇 |
2023年 | 1295篇 |
2022年 | 2276篇 |
2021年 | 2376篇 |
2020年 | 2623篇 |
2019年 | 1574篇 |
2018年 | 1330篇 |
2017年 | 1538篇 |
2016年 | 1504篇 |
2015年 | 1420篇 |
2014年 | 2759篇 |
2013年 | 2285篇 |
2012年 | 1667篇 |
2011年 | 1285篇 |
2010年 | 1434篇 |
2009年 | 1309篇 |
2008年 | 665篇 |
2007年 | 679篇 |
2006年 | 482篇 |
2005年 | 392篇 |
2004年 | 294篇 |
2003年 | 332篇 |
2002年 | 296篇 |
2001年 | 272篇 |
2000年 | 197篇 |
1999年 | 236篇 |
1998年 | 191篇 |
1997年 | 144篇 |
1996年 | 174篇 |
1995年 | 155篇 |
1994年 | 122篇 |
1993年 | 74篇 |
1992年 | 74篇 |
1991年 | 71篇 |
1990年 | 64篇 |
1989年 | 49篇 |
1988年 | 45篇 |
1987年 | 23篇 |
1986年 | 28篇 |
1985年 | 32篇 |
1984年 | 33篇 |
1983年 | 26篇 |
1982年 | 27篇 |
1981年 | 18篇 |
1979年 | 19篇 |
1978年 | 15篇 |
1977年 | 18篇 |
1976年 | 18篇 |
1974年 | 17篇 |
1973年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
71.
《Archives of physical medicine and rehabilitation》2022,103(4):711-721
ObjectiveTo examine the association between body mass index (BMI [calculated as weight in kilograms divided by height in meters squared]) and mortality after the first year post spinal cord injury (SCI) overall and across demographic and injury characteristics.DesignCohort study.SettingSixteen Spinal Cord Injury Model Systems (SCIMS) centers.ParticipantsSCIMS Database participants age 20 years or older and having a BMI assessment during the 2007-2011 wave of data collection.InterventionsNot applicable.Main Outcome MeasuresAll-cause mortality rate. Life table method and log-rank test were used to estimate and compare mortality rates across BMI groups and other factors. Cox proportional hazard regression model was conducted to estimate hazard ratio (HR) and 95% confidence interval (CI).ResultsA total of 2346 participants (N=2346) with SCI were classified into 1 of the 8 BMI groups: <18.5 (6.9%), 18.5-19.9 (7.3%), 20.0-22.49 (15.0%), 22.5-24.9 (18.8%), 25.0-27.49 (17.5%), 27.5-29.9 (13.2%), 30.0-34.9 (13.5%), and ≥35.0 (7.8%). Compared with people with BMI of 22.5-29.9, a higher mortality risk was observed among people with BMI<18.5 (HR, 1.76; 95% CI, 1.25-2.49), 18.5-19.9 (HR, 1.51; 95% CI, 1.06-2.15), and ≥35.0 (HR, 1.51; 95% CI, 1.11-2.07) after adjusting for confounding factors (sex, age at the time of BMI assessment, marital status, neurologic status). The U-shape BMI-mortality relationship varied by age, sex, neurologic status, and years since injury.ConclusionsTo improve life expectancy after SCI, health care professionals could focus on weight management among patients with relatively low and extremely high BMI, defined by demographic and injury-related characteristics. Future studies should explore factors that contribute to such a higher mortality after SCI, including pre-existing conditions, poor diet and/or nutrition, and cardiorespiratory fitness. 相似文献
72.
73.
ObjectiveTo develop a trail running injury screening instrument (TRISI) for utilisation as clinical decision aid in determining if a trail runner is at an increased risk for injury.DesignMultiple methods approach.MethodsThe study utilised five phases 1) identification of injury risk factors 2) determining the relevance of each identified risk factor in a trail running context, 3) creating the content of the Likert scale points from 0 to 4, 4) rescaling the Likert scale points to determine numerical values for the content of each Likert scale point, and 5) determining a weighted score for each injury risk factor that contributes to the overall combined composite score.ResultsOf the 77 identified injury risk factors, 26 were deemed relevant in trail running. The weighted score for each injury risk factor ranged from 2.21 to 5.53 with the highest calculated score being 5.53. The final TRISI includes risk categories of training, running equipment, demographics, previous injury, behavioural, psychological, nutrition, chronic disease, physiological, and biomechanical factors.ConclusionThe developed TRISI aims to assist the clinician during pre-race injury screening or during a training season to identify meaningful areas to target in designing injury risk management strategies and/or continuous health education. 相似文献
74.
《Patient education and counseling》2022,105(5):1224-1228
ObjectiveVaccine hesitancy is a persistent barrier to vaccination uptake, and health professionals report interactions with such parents to be difficult. Using discourse analytic techniques, we examine the foundation of a therapeutic relationship: the display of empathy and attempts to build rapport, in consultations between immunisation specialists and vaccine reluctant parents.MethodsConsultations between consenting clinicians and parents in two Specialist Immunisation Clinics in Australia were recorded. Twelve conversations between the clinicians and parents were analysed using interactional sociolinguistic (IS) discourse analytic methods.ResultsThis paper takes a case study approach by citing two interactions that exemplify the interactional work of the consultants as they strive to engender mutual understanding and goodwill, noting examples of discursive choices that demonstrate empathy and the building of rapport.ConclusionAwareness of discourse strategies that interweave relational and clinical goals enable a more nuanced understanding of communication skills that support a guiding partnership in vaccine related decisions with parents.Practical implicationsThrough highlighting the strategic interactional work that displays empathy and builds rapport, we can inform educational approaches and build a repertoire of communication choices that strengthen the communication skills of health professionals. 相似文献
75.
Yinong Young-Xu Julia Thornton Snider Robertus van Aalst Salaheddin M. Mahmud Edward W. Thommes Jason K.H. Lee David P. Greenberg Ayman Chit 《Vaccine》2019,37(11):1484-1490
Background
Observational studies of the relative effectiveness of influenza vaccines are essential for public health decision making. Their estimates, however, are subject to bias due to unmeasured confounders. Instrumental variable (IV) methods can control for observed and unobserved confounders.Methods
We used linked electronic medical record databases in the Veterans Health Administration (VHA) as well as Medicare administrative files to examine the relative vaccine effectiveness (rVE) of high-dose influenza vaccine (HD) versus standard-dose influenza vaccines (SD) in preventing hospitalizations among VHA-enrolled Veterans ≥65?years of age during 5 influenza seasons (2010–2011 through 2014–2015). Using multivariable IV Poisson regression modeling to address unmeasured confounding and bias, we analyzed the data by each season and through longitudinal analysis of all five seasons.Findings
We included 3,638,924 person–influenza seasons of observation where 158,636 (4%) were among HD vaccine recipients and 3,480,288 (96%) were among SD vaccine recipients. Of the 1,728,562 Veterans, 1,702,824 (98.5%) were male and 1,299,412 (75%) were non-Hispanic white. Based on the longitudinal analysis of all five seasons, the IV-adjusted rVE estimate of HD vs. SD was 10% (95% CI, 8–12%) against all-cause hospitalization; 18% (95% CI, 15–21%) against cardiorespiratory-associated hospitalization; and 14% (95% CI, 6–22%) against influenza/pneumonia-associated hospitalization. The findings by season were similar.Interpretation
Our analysis of VHA clinical data collected from approximately 1.7 million Veterans 65?years and older during five seasons demonstrates that high-dose influenza vaccine is more effective than standard-dose influenza vaccines in preventing influenza- or pneumonia-associated hospitalizations, cardiorespiratory hospitalizations, and all-cause hospitalizations. 相似文献76.
《Vaccine》2019,37(41):6054-6059
ObjectiveTo evaluate predictors of vaccination among women who received tetanus, diphtheria, and acellular pertussis vaccination (Tdap), influenza vaccination, and Tdap and influenza vaccinations.Study DesignIn a retrospective cohort study of all full-term (≥37 weeks gestation) deliveries between July 1, 2016 and June 30, 2018 at a single, safety-net institution, we used multinomial logistic regression models to compare predictors of vaccination among women who received Tdap only, influenza only, and both Tdap and influenza vaccines.ResultsAmong 3132 full-term deliveries, women were primarily non-Hispanic black (67.5%), between the ages of 21–34 (65.3%), and multiparous (76.0%). The rates of only influenza or Tdap vaccination were 10.3% and 21.6%, respectively; 43.3% of women received both vaccines, and 24.9% of women did not receive either vaccine. In the adjusted models, Hispanic ethnicity was positively associated with receipt of all types of vaccination and non-Spanish language interpreter use was positively associated with receipt of Tdap vaccination and Tdap and influenza vaccination. A parity of greater than three and inadequate and unknown prenatal care adequacy were negative predictors of all types of vaccination. Pre-existing hypertension was negatively associated with Tdap vaccination, and HIV-positive status was negatively associated with influenza vaccination and Tdap and influenza vaccination.ConclusionCompared to the national rate of both Tdap and influenza vaccination (32.8%), a higher proportion of women received both vaccines in our study population. Vaccine uptake may be affected by race/ethnicity, use of interpreter services, parity, pre-existing comorbidities, and prenatal care adequacy. The lower rate of influenza vaccination compared to Tdap vaccination suggests that other factors, such as vaccine hesitancy and mistrust, may be differentially impacting influenza vaccination uptake in our predominantly minority population. Future provider and public health approaches to vaccine promotion should incorporate culturally appropriate strategies that address vaccine-related beliefs and misconceptions. 相似文献
77.
BackgroundCarbetocin has been found to be superior to oxytocin in terms of need for additional uterotonics and prevention of postpartum haemorrhage at caesarean delivery. However, this is based on combined data from labouring and non-labouring parturients and it remains unclear how effective carbetocin is in the purely elective setting. The aim of this review was to compare carbetocin to oxytocin in elective caesarean delivery.MethodsMedline, Embase, CINAHL, Web of Science, and the Cochrane databases were searched for randomised controlled trials in any language. The primary outcome was need for additional uterotonics. Secondary outcomes were mean blood loss, need for blood transfusion and incidence of postpartum haemorrhage >1000 mL.ResultsNine studies with a total of 1962 patients were included. Trial sequential analysis confirmed that the information size (n=1692) had surpassed that required (n=1166) in order to demonstrate a statistically significant reduction in the use of additional uterotonics. Need for additional uterotonics was reduced by 53% with carbetocin compared to oxytocin (OR 0.47, 95% CI 0.34 to 0.64; P <0.001, I2=63.5). The number needed-to-treat was 11. The risk of bias, data heterogeneity and inconsistency in reporting bleeding outcomes made it difficult to reach definite conclusions about prevention of PPH.ConclusionsCarbetocin is associated with a reduced need for additional uterotonics when compared with oxytocin at elective caesarean delivery. Standardisation of bleeding-related outcomes in studies is necessary to facilitate synthesis of data in future analyses. 相似文献
78.
79.
It is hypothesized that persons who use drugs (PWUD) in Vietnam who are also HIV-positive may face additional challenges in psychosocial outcomes, and these challenges may extend to their family members. In this study, we examined depressive symptoms, stigma, social support, and caregiver burden of HIV-positive PWUD and their family members, compared to the outcomes of HIV-negative PWUD and their family members. Baseline, 3-month, and 6-month assessment data were gathered from 83 PWUD and 83 family members recruited from four communes in Phú Th? Province, Vietnam. For PWUD, although we observed a general decline in overall stigma over time for both groups, HIV-positive PWUD consistently reported significantly higher overall stigma for all three periods. Depressive symptoms among family members in both groups declined over time; however, family members of HIV-positive PWUD reported higher depressive symptoms across all three periods. In addition, family members of HIV-positive PWUD reported lower levels of tangible support across all three periods. Caregiver burden among family members of HIV-positive PWUD increased significantly over time, whereas the reported burden among family members of HIV-negative PWUD remained relatively unchanged. The findings highlight the need for future interventions for PWUD and family members, with targeted and culturally specific strategies to focus on the importance of addressing additional stigma experienced by PWUD who are HIV-positive. Such challenges may have direct negative impact on their family members' depressive symptoms, tangible support, and caregiver burden. 相似文献
80.
ObjectiveThe aim of this study was to determine the frequency of association of major congenital malformations in pregnancy in women exposed to antiepileptic drugs (AEDs) in an inner city population.BackgroundApproximately 0.3–0.5% of all pregnancies involve women with epilepsy. The risk of congenital malformations associated with AED therapy has been well documented, ranging from 2 to 10% as compared to a rate of 3% in the general population. However, the risk of these occurring in a higher risk population, such as an inner city tertiary care center, with multiple comorbidities is not as well known.Design/methodsUsing the Boston Medical Center Database between the years 2003 and 2010, a list of all infants born with major congenital malformations (MCMs) to mothers on AEDs was compiled. Major congenital malformations were defined as cleft lip and/or palate, ventricular or atrial septal defect, other cardiac malformations, and urogenital defects. During pregnancy, AED exposure including serum levels, other medication exposures, breakthrough seizure frequency, positive toxicology tests, and other maternal comorbidities were also analyzed.ResultsOf 17,246 live births between 2003 and 2010, 330 of those births demonstrated a MCM (malformation rate of 1.91%). Of those births, 64 mothers had epilepsy and were exposed to AED therapy during pregnancy, accounting for 0.37% of all births during this time period. Overall, three pregnancies in women with epilepsy resulted in a baby with a MCM, accounting for a 4.7% malformation rate in this patient population. In mothers on AEDs for other indications, the MCM rate was slightly higher, 5.0%, and in women on benzodiazepine monotherapy during pregnancy, the rate was quite high, 10.6%. 相似文献