全文获取类型
收费全文 | 75332篇 |
免费 | 7774篇 |
国内免费 | 2030篇 |
专业分类
耳鼻咽喉 | 787篇 |
儿科学 | 1289篇 |
妇产科学 | 1319篇 |
基础医学 | 4476篇 |
口腔科学 | 1695篇 |
临床医学 | 12917篇 |
内科学 | 8904篇 |
皮肤病学 | 2015篇 |
神经病学 | 3199篇 |
特种医学 | 1722篇 |
外国民族医学 | 6篇 |
外科学 | 5597篇 |
综合类 | 9311篇 |
现状与发展 | 1篇 |
一般理论 | 9篇 |
预防医学 | 12080篇 |
眼科学 | 1424篇 |
药学 | 8763篇 |
228篇 | |
中国医学 | 5791篇 |
肿瘤学 | 3603篇 |
出版年
2024年 | 353篇 |
2023年 | 1859篇 |
2022年 | 2847篇 |
2021年 | 4069篇 |
2020年 | 4292篇 |
2019年 | 3508篇 |
2018年 | 3188篇 |
2017年 | 3461篇 |
2016年 | 3347篇 |
2015年 | 3236篇 |
2014年 | 5635篇 |
2013年 | 6119篇 |
2012年 | 4841篇 |
2011年 | 4849篇 |
2010年 | 3747篇 |
2009年 | 3573篇 |
2008年 | 3559篇 |
2007年 | 3392篇 |
2006年 | 3017篇 |
2005年 | 2431篇 |
2004年 | 2080篇 |
2003年 | 1747篇 |
2002年 | 1380篇 |
2001年 | 1159篇 |
2000年 | 950篇 |
1999年 | 813篇 |
1998年 | 632篇 |
1997年 | 610篇 |
1996年 | 515篇 |
1995年 | 506篇 |
1994年 | 420篇 |
1993年 | 345篇 |
1992年 | 348篇 |
1991年 | 235篇 |
1990年 | 196篇 |
1989年 | 218篇 |
1988年 | 162篇 |
1987年 | 136篇 |
1986年 | 81篇 |
1985年 | 163篇 |
1984年 | 175篇 |
1983年 | 97篇 |
1982年 | 85篇 |
1981年 | 79篇 |
1980年 | 91篇 |
1979年 | 56篇 |
1978年 | 42篇 |
1976年 | 42篇 |
1975年 | 31篇 |
1938年 | 30篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Journal of the Academy of Nutrition and Dietetics》2022,122(11):2060-2071
BackgroundVoices for Food was a longitudinal community, food pantry–based intervention informed by the social ecological model, and designed to improve food security, dietary intake, and quality among clients, which was carried out in 24 rural food pantries across 6 Midwestern states.ObjectiveOur objective was to evaluate changes in adult food security, dietary intake, and quality from baseline (2014) to follow-up (2016), and to assess the role of adult food security on dietary outcomes.DesignA multistate, longitudinal, quasi-experimental intervention with matched treatment and comparison design was used to evaluate treatment vs comparison group changes over time and changes in both groups over time.Participants/settingAdult food pantry clients (n = 617) completed a demographic food security survey, and up to three 24-hour dietary recalls at baseline (n = 590) and follow-up (n = 160).InterventionCommunity coaching served as the experimental component, which only “treatment” communities received, and a food council guide and food pantry toolkit were provided to both “treatment” and matched “comparison” communities.Main outcome measuresChange in adult food security status, mean usual intakes of nutrients and food groups, and Healthy Eating Index-2010 scores were the main outcome measures.Statistical analyses performedLinear mixed models estimated changes in outcomes by intervention group and by adult food security status over time.ResultsImprovements in adult food security score (–0.7 ± 0.3; P = .01), Healthy Eating Index-2010 total score (4.2 ± 1.1; P < .0001), and empty calories component score (3.4 ± 0.5; P <.0001) from baseline to follow-up were observed in treatment and comparison groups, but no statistically significant changes were found for adult food security status, dietary quality, and usual intakes of nutrients and food groups between the 2 groups over time. The intervention effect on dietary quality and usual intake changes over time by adult food security status were also not observed.ConclusionsFood pantry clients in treatment and comparison groups had higher food security and dietary quality at the follow-up evaluation of the Voices for Food intervention trial compared with baseline, despite the lack of difference among the groups as a result of the experimental coaching component. 相似文献
2.
3.
Karl Johnson Katherine W. Saylor Isabella Guynn Karen Hicklin Jonathan S. Berg Kristen Hassmiller Lich 《Genetics in medicine》2022,24(2):262-288
PurposeUnderstanding the value of genetic screening and testing for monogenic disorders requires high-quality, methodologically robust economic evaluations. This systematic review sought to assess the methodological quality among such studies and examined opportunities for improvement.MethodsWe searched PubMed, Cochrane, Embase, and Web of Science for economic evaluations of genetic screening/testing (2013-2019). Methodological rigor and adherence to best practices were systematically assessed using the British Medical Journal checklist.ResultsAcross the 47 identified studies, there were substantial variations in modeling approaches, reporting detail, and sophistication. Models ranged from simple decision trees to individual-level microsimulations that compared between 2 and >20 alternative interventions. Many studies failed to report sufficient detail to enable replication or did not justify modeling assumptions, especially for costing methods and utility values. Meta-analyses, systematic reviews, or calibration were rarely used to derive parameter estimates. Nearly all studies conducted some sensitivity analysis, and more sophisticated studies implemented probabilistic sensitivity/uncertainty analysis, threshold analysis, and value of information analysis.ConclusionWe describe a heterogeneous body of work and present recommendations and exemplar studies across the methodological domains of (1) perspective, scope, and parameter selection; (2) use of uncertainty/sensitivity analyses; and (3) reporting transparency for improvement in the economic evaluation of genetic screening/testing. 相似文献
4.
5.
6.
7.
8.
Syed M. Gilani Muhammad Khan Andrea Barbieri Manju L. Prasad 《Diagnostic Histopathology》2021,27(6):263-271
Anaplastic thyroid carcinoma (ATC) is an aggressive thyroid malignancy with high mortality rate. This malignancy arises in thyroid follicular cells either denovo or with an associated differentiated thyroid carcinoma component. Clinically, it usually presents as a rapidly enlarging mass, pain and locally compressive symptoms. Histopathologic variability and heterogeneity often pose diagnostic challenges, especially in scant and paucicellular specimens. This article describes the clinical, histopathologic and molecular features of ATC and also addresses the associated diagnostic limitations and challenges. 相似文献
9.
《Journal of vascular and interventional radiology : JVIR》2021,32(10):1449-1456
PurposeTo investigate the safety and efficacy of thyroid artery embolization (TAE) in the treatment of nodular goiter (NG).MethodsDuring a 5.5-year period, 56 consecutive patients with a NG underwent TAE. In Group A, there were 20 patients with a solitary/dominant 5–11-cm nodule, and in Group B, there were 36 patients with numerous nodules. Of the 56 patients, 47 (84%) had a retrosternal goiter and 25 had hyperthyroidism. In all patients, clinical and radiological evaluations were made at baseline and 6 months after TAE, and these parameters were statistically compared.ResultsIn 56 patients, 145 of the 146 thyroid arteries were successfully embolized. The 30-day mortality rate was 1.8%. Minor and major complications occurred in 25 and 2 patients, respectively. Six months after the TAE, the mean nodule volume was reduced from 80.2 mL to 25.0 mL, the mean thyroid volume was reduced from 147.0 mL to 62.6 mL, and the mean intrathoracic extension was reduced from 31.7 mm to 15.9 mm (P < .001). Of the 22 patients with non–Graves hyperthyroidism, 19 (86%) became euthyroid. The mean thyroid-related patient-reported outcome scores improved from 155.4 to 70.4 (P < .001). Of the 51 patients, 50 (98%) declared that they would recommend TAE to other patients with NG.ConclusionsTAE is safe and effective for the treatment of NG, with a significant volume reduction of the nodule(s) and thyroid gland. 相似文献
10.
《Journal of vascular and interventional radiology : JVIR》2022,33(4):359-367.e8
PurposeTo review and to compare indirectly the outcomes of minimally invasive therapies for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia.Materials and MethodsA literature search via Medline and Cochrane Central databases was completed for randomized control studies published between January 2000 to April 2020 for the following therapies: Rezum, Urolift, Aquablation, and prostatic artery embolization (PAE). Data on the following variables were included: International prostate symptom score (IPSS), maximum urinary flow rate, quality of life, and postvoid residual (PVR). Standard mean differences between treatments were compared through a meta-analysis using transurethral resection of the prostate (TURP) to assess differences in treatment effect.ResultsThere was no significant difference in outcomes between therapies for IPSS at the 3, 6, and 12-month follow ups. Although outcomes for Rezum were only available out to 3 months, there were no consistently significant differences in outcomes when comparing Aquablation versus PAE versus Rezum. TURP PVR was significantly better than Urolift at 3, 6, and 12 months. No significant differences in minor or major adverse events were noted.ConclusionAlthough significant differences in outcomes were limited, Aquablation and PAE were the most durable at 12 months. PAE has been well studied on multiple randomized control trials with minimal adverse events while Aquablation has limited high quality data and has been associated with bleeding-related complications. 相似文献