全文获取类型
收费全文 | 64033篇 |
免费 | 4277篇 |
国内免费 | 1787篇 |
专业分类
耳鼻咽喉 | 821篇 |
儿科学 | 2046篇 |
妇产科学 | 1167篇 |
基础医学 | 5866篇 |
口腔科学 | 972篇 |
临床医学 | 7526篇 |
内科学 | 9084篇 |
皮肤病学 | 2101篇 |
神经病学 | 4708篇 |
特种医学 | 1483篇 |
外国民族医学 | 1篇 |
外科学 | 3872篇 |
综合类 | 9537篇 |
现状与发展 | 3篇 |
预防医学 | 7240篇 |
眼科学 | 723篇 |
药学 | 8111篇 |
46篇 | |
中国医学 | 2632篇 |
肿瘤学 | 2158篇 |
出版年
2024年 | 102篇 |
2023年 | 859篇 |
2022年 | 1814篇 |
2021年 | 2556篇 |
2020年 | 2348篇 |
2019年 | 1997篇 |
2018年 | 2092篇 |
2017年 | 2064篇 |
2016年 | 2189篇 |
2015年 | 2245篇 |
2014年 | 4458篇 |
2013年 | 4717篇 |
2012年 | 4229篇 |
2011年 | 4371篇 |
2010年 | 3467篇 |
2009年 | 3164篇 |
2008年 | 3221篇 |
2007年 | 3140篇 |
2006年 | 2638篇 |
2005年 | 2277篇 |
2004年 | 1854篇 |
2003年 | 1598篇 |
2002年 | 1290篇 |
2001年 | 1186篇 |
2000年 | 1028篇 |
1999年 | 960篇 |
1998年 | 792篇 |
1997年 | 739篇 |
1996年 | 645篇 |
1995年 | 629篇 |
1994年 | 562篇 |
1993年 | 453篇 |
1992年 | 484篇 |
1991年 | 449篇 |
1990年 | 365篇 |
1989年 | 377篇 |
1988年 | 363篇 |
1987年 | 331篇 |
1986年 | 257篇 |
1985年 | 298篇 |
1984年 | 228篇 |
1983年 | 183篇 |
1982年 | 215篇 |
1981年 | 158篇 |
1980年 | 147篇 |
1979年 | 118篇 |
1978年 | 96篇 |
1977年 | 77篇 |
1976年 | 64篇 |
1975年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Defining con-founders that affect the reliability of diagnostic tests for coronavirus disease 2019 is vital to breaking the chain of infection. The elderly population is a higher risk group for the emerging virus. However, gender seems to exert a critical role in modifying the infection risk among women owing to hormonal changes. The menopause transition is an exceptional period for older women where the protective and immunomodulatory effects of the estrogen hormone are lost. Accordingly, attention should be given to postmenopausal women since they will have an increased risk compared to their pre-menopausal peers. 相似文献
2.
《Gait & posture》2022
BackgroundOne in two people with multiple sclerosis (PwMS) will fall in a three-month period. Predicting which patients will fall remains a challenge for clinicians. Standardized functional assessments provide insight into balance deficits and fall risk but their use has been limited to supervised visits.Research questionThe study aim was to characterize unsupervised 30-second chair stand test (30CST) performance using accelerometer-derived metrics and assess its ability to classify fall status in PwMS compared to supervised 30CST.MethodsThirty-seven PwMS (21 fallers) performed instrumented supervised and unsupervised 30CSTs with a single wearable sensor on the thigh. In unsupervised conditions, participants performed bi-hourly 30CSTs and rated their balance confidence and fatigue over 48-hours. ROC analysis was used to classify fall status for 30CST performance.ResultsNon-fallers (p = 0.02) but not fallers (p = 0.23) differed in their average unsupervised 30CST performance (repetitions) compared to their supervised performance. The unsupervised maximum number of 30CST repetitions performed optimized ROC classification AUC (0.79), accuracy (78.4%) and specificity (90.0%) for fall status with an optimal cutoff of 17 repetitions.SignificanceBrief durations of instrumented unsupervised monitoring as an adjunct to routine clinical assessments could improve the ability for predicting fall risk and fluctuations in functional mobility in PwMS. 相似文献
3.
《Archivos de bronconeumología》2022,58(5):406-411
IntroductionLung cancer (LC) is usually diagnosed at advanced stages with only a 12% 5-year survival. Trials as NLST and NELSON show a mortality decrease, which justifies implementation of lung cancer screening in risk population. Our objective was to show survival results of the largest LC screening program in Spain with low dosage computed tomography (LDCT).MethodsClinical records from International Early Lung Cancer Detection Program (IELCAP) at Valencia, Spain were analysed. This program recruited volunteers, ever-smokers aged 40-80 years, since 2008. Results are compared to those from other similar sizeable programs.ResultsA total of 8278 participants were screened with at least two-rounds until November 2020. A mean of 6 annual screening rounds were performed. We detected 239 tumours along 12-year follow-up. Adenocarcinoma was the most common histology, being 61.3% at stage I. The lung cancer prevalence and incidence proportion was 1.5% and 1.4%, respectively with an annual detection rate of 0.17. One-year survival and 10-year survival were 90% and 80.1%, respectively. Adherence was 96.84%.ConclusionLargest lung cancer screening in Spain shows that survival is improved when is performed in multidisciplinary team experienced in management of LC, and is comparable to similar screening programs. 相似文献
4.
IntroductionThis study was designed to assess whether a dental caries management protocol combining a single application of 38% silver diamine fluoride (SDF) with comprehensive oral health education will successfully divert high-risk children from dental treatment under dental general anaesthesia (DGA), arrest active caries in primary teeth, and improve parent-reported child oral health–related quality of life (OHRQoL).MethodsChildren aged 2 to 10 years, who attended two public dental agencies in Victoria, Australia, and were unable to tolerate restorative treatments in the clinic setting, elected to participate in either a 38% SDF intervention protocol or, alternatively, referral for DGA. Follow-up examinations were completed at 6 months to assess caries progression, decayed missing filled tooth index, PUFA index (pulpal involvement, ulceration, fistula, abscess), DGA referral rates, and OHRQoL (Early Childhood Oral Health Impact Scale [ECOHIS]).ResultsOf the total sample, 89.5% of children (n = 102) [mean (SD) age, 4.1 (1.0) years] with 401 active carious lesions elected to participate in the 38% SDF protocol; 10.5% (n = 12) of parents opted for referral for treatment under DGA. The proportion of active caries subsequently arrested at follow-up (number of arrested lesions/number of lesions treated) was 0.78 (95% CI, 0.69 to 0.87). There was an 88% reduction in referrals for DGA in eligible children over the 6-month period. The 38% SDF intervention group showed a significant improvement in ECOHIS scores at follow-up (P < .001).DiscussionAdoption of the 38% SDF intervention protocol resulted in a significant reduction in the rate of preventable dental hospitalisations. Most parents opted against referral for DGA. Parent-reported OHRQoL for children improved significantly. 相似文献
5.
Esin Benli Küçük Ercan Kaydok Kürsad Ramazan Zor Gamze Yıldırım Biçer 《Topics in stroke rehabilitation》2020,27(8):630-635
ABSTRACT Objective: Dry eye is reported to be associated with several neurological diseases. The aim of this study is to evaluate the patients with hemiplegia after stroke for dry eye and compare their results with a control group. Materials and methods: Forty-five patients with hemiplegia and 45 individuals as the control group were included in the study. Tear function tests (Schirmer and tear breakup time) and a dry eye questionnaire for dry eye symptoms (ocular surface disease index) were performed and the results of the two groups were compared. Results: Schirmer test results were significantly lower in the post-stroke hemiplegia group compared to the control group (11.3 ± 8.2 mm and 20.6 ± 11.6 mm, respectively, p < .001). Tear breakup time results were significantly lower in the post-stroke hemiplegia group compared to the control group (7.9 ± 3.1 s and 12.1 ± 4.3 s, respectively, p < .001). Ocular surface disease index scores were not significantly different between hemiplegia and control groups (21.6 ± 20.0 and 19.8 ± 13.9, respectively, p = .635). Schirmer scores lower than 10 mm (60% and 30%, p < .001) and tear breakup time results lower than 10 s (65.6% and 28.9%, p < .001) were also higher in the hemiplegia group compared to control group. Conclusion: We found lower Schirmer test and tear breakup time results and similar OSDI scores in hemiplegia patients compared to controls. Hemiplegia patients may have dry eye without typical symptoms. This should be taken into consideration in the follow-up and rehabilitation of post-stroke hemiplegia patients. 相似文献
6.
7.
Omar Abdel-Rahman 《Clinical genitourinary cancer》2019,17(2):e329-e338
Background
The objective of the study was to evaluate the outcomes of clinically localized prostate cancer treated with prostatectomy versus radiation therapy within the context of a prospective prostate cancer screening study.Patients and Methods
Within the PLCO (Prostate, Lung, Colorectal, and Ovary) trial, patients who were diagnosed with clinically localized prostate cancer and subsequently received treatment with prostatectomy or radiation therapy (with or without hormonal treatment) were included. Univariate and multivariate Cox regression analyses were then performed to determine factors affecting overall and prostate cancer-specific survival. Factors with P < .05 in univariate analysis were included in the multivariate analysis.Results
A total of 3953 patients were included in the current analysis. These included 2044 patients treated with prostatectomy and 1909 patients treated with radiation therapy with or without hormonal treatment. In an adjusted multivariate analysis for factors affecting overall survival, prostatectomy was associated with better overall survival compared with radiation therapy (hazard ratio, 0.548; 95% confidence interval [CI], 0.440- 681; P < .001). Likewise, in an adjusted multivariate analysis for factors affecting prostate cancer-specific survival, prostatectomy was associated with better prostate cancer-specific survival compared with radiation therapy (hazard ratio, 0.485; 95% CI, 0.286- 0.822; P = .007). Similar findings were found with propensity score matching and repeating the same analyses on the post-matching cohort.Conclusion
Prostatectomy seems to predict better overall and prostate cancer-specific survival compared with radiation therapy among patients with clinically localized prostate cancer diagnosed within the PLCO trial. 相似文献8.
9.
10.
《Respiratory investigation》2022,60(1):137-145
BackgroundSome chronic obstructive pulmonary disease (COPD) patients develop hypoxemia with disease progression, with some even requiring long-term oxygen therapy (LTOT). Lung function, especially diffusing capacity, and the annual decline in PaO2, are reported to be predictive factors of chronic respiratory failure. However, the association between lung morphometry evaluated using computed tomography (CT) images and LTOT initiation is unknown.MethodsWe retrospectively evaluated the relationship between clinical indices, including pulmonary function, body mass index (BMI), and CT parameters, at baseline and LTOT initiation in two prospective COPD cohorts. In the Nara Medical University cohort (n = 76), the low attenuation area (LAA) and its fractal dimension (fractal D) were adapted as the indices for parenchymal destruction in CT images. The association between these CT measurements and LTOT initiation was replicated in the Kyoto University cohort (n = 130).ResultsIn the Nara Medical University cohort, lower BMI (hazard ratio [HR]:0.70, p = 0.006), lower % diffusing capacity (%DLCO) (HR: 0.92, p = 0.006), lower %DLCO/VA (HR, 0.90, p = 0.008), higher RV/TLC (HR, 1.26, p = 0.012), higher LAA% (HR: 1.18, p = 0.001), and lower fractal D (HR: 3.27 × 10?8, p < 0.001) were associated with LTOT initiation. Multivariate analysis in the Kyoto University cohort confirmed that lower %DLCO and lower fractal D were independently associated with LTOT initiation, whereas LAA% was not.ConclusionFractal D, which is the index for morphometric complexity of LAA in CT analysis, is predictive of LTOT initiation in COPD patients. 相似文献