全文获取类型
收费全文 | 2526篇 |
免费 | 249篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 103篇 |
妇产科学 | 67篇 |
基础医学 | 342篇 |
口腔科学 | 25篇 |
临床医学 | 333篇 |
内科学 | 372篇 |
皮肤病学 | 35篇 |
神经病学 | 292篇 |
特种医学 | 77篇 |
外科学 | 277篇 |
综合类 | 57篇 |
一般理论 | 5篇 |
预防医学 | 285篇 |
眼科学 | 44篇 |
药学 | 196篇 |
中国医学 | 4篇 |
肿瘤学 | 253篇 |
出版年
2023年 | 18篇 |
2022年 | 27篇 |
2021年 | 83篇 |
2020年 | 46篇 |
2019年 | 62篇 |
2018年 | 66篇 |
2017年 | 49篇 |
2016年 | 72篇 |
2015年 | 76篇 |
2014年 | 85篇 |
2013年 | 117篇 |
2012年 | 196篇 |
2011年 | 149篇 |
2010年 | 91篇 |
2009年 | 89篇 |
2008年 | 125篇 |
2007年 | 117篇 |
2006年 | 116篇 |
2005年 | 108篇 |
2004年 | 122篇 |
2003年 | 107篇 |
2002年 | 105篇 |
2001年 | 51篇 |
2000年 | 32篇 |
1999年 | 52篇 |
1998年 | 36篇 |
1997年 | 22篇 |
1996年 | 26篇 |
1995年 | 16篇 |
1994年 | 21篇 |
1993年 | 11篇 |
1992年 | 31篇 |
1991年 | 29篇 |
1990年 | 39篇 |
1989年 | 32篇 |
1988年 | 19篇 |
1986年 | 19篇 |
1985年 | 23篇 |
1984年 | 11篇 |
1983年 | 12篇 |
1982年 | 18篇 |
1981年 | 14篇 |
1979年 | 20篇 |
1978年 | 19篇 |
1977年 | 14篇 |
1976年 | 11篇 |
1974年 | 16篇 |
1973年 | 9篇 |
1972年 | 12篇 |
1967年 | 9篇 |
排序方式: 共有2780条查询结果,搜索用时 15 毫秒
81.
82.
Hildi J. Hagedorn Allison M. Gustavson Princess E. Ackland Ann Bangerter Mark Bounthavong Barbara Clothier Alex H. S. Harris Marie E. Kenny Siamak Noorbaloochi Hope A. Salameh Adam J. Gordon 《Journal of general internal medicine》2022,37(14):3594
BackgroundIdentifying effective strategies to improve access to medication treatments for opioid use disorder (MOUD) is imperative. Within the Veterans Health Administration (VHA), provision of MOUD varies significantly, requiring development and testing of implementation strategies that target facilities with low provision of MOUD.ObjectiveDetermine the effectiveness of external facilitation in increasing the provision of MOUD among VHA facilities with low baseline provision of MOUD compared to matched controls.DesignPre-post, block randomized study designed to compare facility-level outcomes in a stratified sample of eligible facilities. Four blocks (two intervention facilities in each) were defined by median splits of both the ratio of patients with OUD receiving MOUD and number of patients with OUD not currently receiving MOUD (i.e., number of actionable patients). Intervention facilities participated in a 12-month implementation intervention.ParticipantsVHA facilities in the lowest quartile of MOUD provision (35 facilities), eight of which were randomly assigned to participate in the intervention (two per block) with twenty-seven serving as matched controls by block.InterventionExternal facilitation included assessment of local barriers/facilitators, formation of a local implementation team, a site visit for action planning and training/education, cross-facility quarterly calls, monthly coaching calls, and consultation.Main MeasuresPre- to post-change in the facility-level ratio of patients with an OUD diagnosis receiving MOUD compared to control facilities.Key ResultsIntervention facilities significantly increased the ratio of patients with OUD receiving MOUD from an average of 18% at baseline to 30% 1 year later, with an absolute difference of 12% (95% confidence interval [CI]: 6.6%, 17.0%). The difference in differences between intervention and control facilities was 3.0% (95% CI: − 0.2%. 6.7%). The impact of the intervention varied by block, with smaller, less complex facilities more likely to outperform matched controls.ConclusionsIntensive external facilitation improved the adoption of MOUD in most low-performing facilities and may enhance adoption beyond other interventions less tailored to individual facility contexts. 相似文献
83.
Gwen Musial Suman Adhikari Hanieh Mirhajianmoghadam Hope M. Queener Alexander W. Schill Nimesh B. Patel Jason Porter 《Investigative ophthalmology & visual science》2022,63(1)
PurposeThere is conflicting evidence regarding whether a loss of radial peripapillary capillaries (RPCs) precedes neuronal loss in glaucoma. We examined the time course of in vivo changes in RPCs, optic nerve head (ONH) structure, and retinal nerve fiber layer thickness (RNFLT) in experimental glaucoma (EG).MethodsSpectral domain optical coherence tomography images were acquired before and approximately every two weeks after inducing unilateral EG in nine rhesus monkeys to quantify mean anterior lamina cribrosa surface depth (ALCSD), minimum rim width (MRW), and RNFLT. Perfused RPC density was measured from adaptive optics scanning laser ophthalmoscope images acquired on the temporal half of the ONH. The time of first significant change was quantified as when values fell and remained outside of the 95% confidence interval established from control eyes.ResultsMean ALCSD and/or MRW were the first parameters to change in eight EG eyes. RPC density changed first in the ninth. At their first points of change, mean ALCSD posteriorly deformed by 100.2 ± 101.2 µm, MRW thinned by 82.3 ± 65.9 µm, RNFLT decreased by 25 ± 14 µm, and RPC density decreased by 4.5 ± 2.1%. RPC density decreased before RNFL thinning in 5 EG eyes. RNFLT decreased before RPC density decreased in two EG eyes, whereas two EG eyes had simultaneous changes.ConclusionsIn most EG eyes, RPC density decreased before (or simultaneous with) a change in RNFLT, suggesting that vascular factors may play a role in axonal loss in some eyes in early glaucoma. 相似文献
84.
Katrina Hueniken MPH Catriona M. Douglas BSc MBChB MD Ashok R. Jethwa MD Maryam Mirshams MSc Lawson Eng MD Andrew Hope MD Douglas B. Chepeha MD David P. Goldstein MD MSc Jolie Ringash MD MSc Aaron Hansen BSc MBBS Rosemary Martino PhD Madeline Li MD PhD Geoffrey Liu MD Wei Xu MD John R. de Almeida MD MSc 《Cancer》2020,126(17):4042-4050
85.
Sarina A. Piha-Paul Do-Youn Oh Makoto Ueno David Malka Hyun Cheol Chung Adnan Nagrial Robin K. Kelley Willeke Ros Antoine Italiano Kazuhiko Nakagawa Hope S. Rugo Filippo de Braud Andrea Iolanda Varga Aaron Hansen Hui Wang Suba Krishnan Kevin G. Norwood Toshihiko Doi 《International journal of cancer. Journal international du cancer》2020,147(8):2190-2198
We present data from patients with advanced biliary tract cancer (BTC) receiving pembrolizumab in the KEYNOTE-158 (NCT02628067; phase 2) and KEYNOTE-028 (NCT02054806; phase 1b) studies. Eligible patients aged ≥18 years from both studies had histologically/cytologically confirmed incurable BTC that progressed after standard treatment regimen(s), measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, Eastern Cooperative Oncology Group performance status 0/1, and no prior immunotherapy. Programmed death ligand 1 (PD-L1)-positive tumors were required for eligibility in KEYNOTE-028 only. Patients received pembrolizumab 200 mg every three weeks (KEYNOTE-158) or 10 mg/kg every two weeks (KEYNOTE-028) for ≤2 years. Primary efficacy endpoint was objective response rate (ORR) by RECIST v1.1. Response assessed by independent central review is reported. KEYNOTE-158 enrolled 104 patients and KEYNOTE-028 enrolled 24 patients. Median (range) follow-up was 7.5 months (0.6-34.3) in KEYNOTE-158 and 5.7 months (0.6-55.4) in KEYNOTE-028. In KEYNOTE-158, ORR was 5.8% (6/104; 95% CI, 2.1%-12.1%); median duration of response (DOR) was not reached (NR) (range, 6.2-26.6+ months). Median (95% CI) OS and PFS were 7.4 (5.5-9.6) and 2.0 (1.9-2.1) months. Among PD-L1-expressers (n = 61) and PD-L1-nonexpressers (n = 34), respectively, ORR was 6.6% (4/61) and 2.9% (1/34). In KEYNOTE-028, ORR was 13.0% (3/23; 95% CI, 2.8%-33.6%); median DOR was NR (range, 21.5-53.2+ months). Median (95% CI) OS and PFS were 5.7 (3.1-9.8) and 1.8 (1.4-3.1) months. Grade 3 to 5 treatment-related adverse events occurred in 13.5% of patients in KEYNOTE-158 (no grade 4; grade 5 renal failure, n = 1) and 16.7% in KEYNOTE-028 (no grade 4/5). In summary, pembrolizumab provides durable antitumor activity in 6% to 13% of patients with advanced BTC, regardless of PD-L1 expression, and has manageable toxicity. 相似文献
86.
John McAteer Stephanie Jernigan Chad Mao Mark D. Gonzalez Renee J. Watson Rochelle Liverman Melissa Tobin‐D Angelo Hope Dishman M. Andi Shane Inci Yildirim 《Pediatric transplantation》2020,24(1)
We report a cluster of pediatric cryptosporidiosis infections among solid organ transplant recipients at a summer camp in Georgia, USA. A retrospective cohort study was conducted to investigate the risk factors for infection. A total of 118 campers attended the camp during July 23‐28, 2017. The overall attack rate among campers during the outbreak was 11% (13/118). Sanger‐based amplicon sequencing of stool specimens from 7 (80%) campers identified Cryptosporidium hominis as the suspected etiologic agent. All infected campers were heart or kidney transplant recipients receiving immunosuppressive therapy. The median reported symptom duration was 12 days (range 6‐18 days) and 9 (69.2%) were hospitalized for at least one night (median length of stay 5 days, range 2‐16 days). There were no deaths or acute rejection events attributed to infection. The results of the epidemiologic and environmental investigation suggest a recreational pool as the presumed source, although there was no direct evidence to support this. Many long‐term interventions were implemented, and there have been no further outbreaks at the camp in the following two years. This outbreak demonstrates that cryptosporidiosis may be associated with notable burden in pediatric transplant recipients, and illustrates the challenges associated with source identification and containment. 相似文献
87.
88.
89.
Norihiko Kamioka Vasilis Babaliaros Michael Andrew Morse Tiberio Frisoli Stamatios Lerakis Jose Miguel Iturbe Jose Binongo Frank Corrigan Altayyeb Yousef Patrick Gleason John A. Wells Hope Caughron Andy Dong Evelio Rodriguez Bradley Leshnower William O’Neill Gaetano Paone Marvin Eng Adam Greenbaum 《JACC: Cardiovascular Interventions》2018,11(12):1131-1138
Objectives
There are minimal data regarding clinical outcomes and echocardiographic findings after transcatheter mitral valve-in-valve replacement (TMVR) compared with redo surgical mitral valve replacement (SMVR).Background
TMVR therapy has emerged as therapy for a degenerated bioprosthetic valve failure.Methods
The authors retrospectively identified patients with degenerated mitral bioprostheses who underwent redo SMVR or TMVR at 3 U.S. institutions. The authors compared clinical and echocardiographic outcomes of patients who had TMVR with those of patients who underwent redo SMVR.Results
Sixty-two patients underwent TMVR and 59 patients underwent SMVR during the study period. Mean age and the Society of Thoracic Surgeons Predicted Risk of Mortality (STS PROM) scores were significantly higher in patients with TMVR than in those with SMVR (age 74.9 ± 9.4 years vs. 63.7 ± 14.9 years; p < 0.001; STS PROM 12.7 ± 8.0% vs. 8.7 ± 10.1%; p < 0.0001). Total procedure time, intensive care unit hours, and post-procedure length of stay were all significantly shorter in the TMVR group. There was no difference in mortality at 1 year between the 2 groups (TMVR 11.3% vs. SMVR 11.9%; p = 0.92). Mean mitral valve pressure gradient and the grade of mitral regurgitation (MR) were similar between the TMVR group and the SMVR group (mitral valve pressure gradient 7.1 ± 2.5 mm Hg vs. 6.5 ± 2.5 mm Hg; p = 0.42; MR [≥moderate] 3.8% vs. 5.6%; p = 1.00) at 30 days. At 1 year, the mitral valve pressure gradient was higher in the TMVR group (TMVR 7.2 ± 2.7 vs. SMVR 5.5 ± 1.8; p = 0.01), although there was no difference in the grade of MR.Conclusions
Despite the higher STS PROM in TMVR patients, there was no difference in 1-year mortality between the TMVR and SMVR groups. Echocardiographic findings after TMVR were similar to SMVR at 30 days. There was a statistically significant difference in mitral gradient at 1 year, though this is likely not clinically important. TMVR may be an alternative to SMVR in patients with previous mitral bioprosthetic valves. 相似文献90.
Herault O Hope KJ Deneault E Mayotte N Chagraoui J Wilhelm BT Cellot S Sauvageau M Andrade-Navarro MA Hébert J Sauvageau G 《The Journal of experimental medicine》2012,209(5):895-901
The determinants of normal and leukemic stem cell self-renewal remain poorly characterized. We report that expression of the reactive oxygen species (ROS) scavenger glutathione peroxidase 3 (GPx3) positively correlates with the frequency of leukemia stem cells (LSCs) in Hoxa9+Meis1-induced leukemias. Compared with a leukemia with a low frequency of LSCs, a leukemia with a high frequency of LSCs showed hypomethylation of the Gpx3 promoter region, and expressed high levels of Gpx3 and low levels of ROS. LSCs and normal hematopoietic stem cells (HSCs) engineered to express Gpx3 short hairpin RNA (shRNA) were much less competitive in vivo than control cells. However, progenitor cell proliferation and differentiation was not affected by Gpx3 shRNA. Consistent with this, HSCs overexpressing Gpx3 were significantly more competitive than control cells in long-term repopulation experiments, and overexpression of the self-renewal genes Prdm16 or Hoxb4 boosted Gpx3 expression. In human primary acute myeloid leukemia samples, GPX3 expression level directly correlated with adverse prognostic outcome, revealing a potential novel target for the eradication of LSCs. 相似文献