全文获取类型
收费全文 | 341895篇 |
免费 | 30631篇 |
国内免费 | 12116篇 |
专业分类
耳鼻咽喉 | 2646篇 |
儿科学 | 5160篇 |
妇产科学 | 4390篇 |
基础医学 | 57039篇 |
口腔科学 | 6742篇 |
临床医学 | 23854篇 |
内科学 | 55644篇 |
皮肤病学 | 5271篇 |
神经病学 | 31534篇 |
特种医学 | 8930篇 |
外国民族医学 | 93篇 |
外科学 | 24362篇 |
综合类 | 44063篇 |
现状与发展 | 40篇 |
一般理论 | 6篇 |
预防医学 | 14373篇 |
眼科学 | 3432篇 |
药学 | 53733篇 |
78篇 | |
中国医学 | 12780篇 |
肿瘤学 | 30472篇 |
出版年
2023年 | 5411篇 |
2022年 | 7205篇 |
2021年 | 14003篇 |
2020年 | 12328篇 |
2019年 | 11736篇 |
2018年 | 11348篇 |
2017年 | 11258篇 |
2016年 | 11234篇 |
2015年 | 13041篇 |
2014年 | 19948篇 |
2013年 | 22823篇 |
2012年 | 19418篇 |
2011年 | 22643篇 |
2010年 | 18746篇 |
2009年 | 19149篇 |
2008年 | 18995篇 |
2007年 | 17314篇 |
2006年 | 15319篇 |
2005年 | 13306篇 |
2004年 | 11578篇 |
2003年 | 10638篇 |
2002年 | 8542篇 |
2001年 | 7284篇 |
2000年 | 6074篇 |
1999年 | 5302篇 |
1998年 | 4459篇 |
1997年 | 4328篇 |
1996年 | 3736篇 |
1995年 | 3707篇 |
1994年 | 3421篇 |
1993年 | 2986篇 |
1992年 | 2443篇 |
1991年 | 2250篇 |
1990年 | 1852篇 |
1989年 | 1594篇 |
1988年 | 1449篇 |
1987年 | 1282篇 |
1986年 | 1312篇 |
1985年 | 2257篇 |
1984年 | 2318篇 |
1983年 | 1665篇 |
1982年 | 1753篇 |
1981年 | 1502篇 |
1980年 | 1239篇 |
1979年 | 1033篇 |
1978年 | 701篇 |
1977年 | 557篇 |
1976年 | 571篇 |
1975年 | 432篇 |
1974年 | 318篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
Prasanth Ganesan Manikandan Dhanushkodi Trivadi S. Ganesan Venkatraman Radhakrishnan Krishnarathinam Kannan Shirley Sundersingh Tenali Gnana Sagar 《Clinical Lymphoma, Myeloma & Leukemia》2019,19(2):116-122
Background
The International Prognostic Scoring System (IPSS) consisting of 7 parameters (IPS7) has been the standard prognostic model used in advanced Hodgkin lymphoma (aHL). However, recent studies have questioned its discriminatory power. For retrospective analyses, its utility might be limited by missing parameters. A recent study has shown that the IPSS consisting of only 3 high-risk features (IPS3; stage IV, age 45 years or older, and hemoglobin <105 g/L) is a simple predictor of survival in aHL. However, there are limited data validating the IPS3.Patients and Methods
Outcomes of adults with aHL treated between 2001 and 2015 at a single center were retrospectively analyzed with data from medical records. The prognostic validity of various baseline parameters was assessed individually as well as in combination (IPS7 and IPS3 scores). The Kaplan–Meier method was used to describe the event-free survival (EFS) and overall survival (OS) and univariate (log rank) and multivariate (Cox regression) tests were performed to identify prognostic factors.Results
We identified 314 patients (median age, 32 [range, 18-60] years; male sex [n = 215; 68%]) treated during this period. IPS7 was available in 231 of 314 (73%) and IPS3 in all (100%) patients. Most (71%) were treated with 6 to 8 cycles of ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) and others received hybrid or cyclophosphamide, vincristine, procarbazine, prednisolone regimens, and 72 (23%) underwent interim positron emission tomography imaging with escalation to bleomycin, etoposide, adriamycin, cyclophosphamide, vincristine, procarbazine, prednisolone in 8 patients. After a median follow-up of 57 months (range, 1.3-167), the 5-year EFS and OS were 72% and 82%, respectively. IPS3 produced a wider separation of survival curves than IPS7 in univariate analysis. In multivariate analysis for EFS, IPS3 (scores of 2 or 3 vs. scores of 0 and 1; hazard ratio, 2.1; P = .004) was the only significant predictor. For OS, no factor emerged as significant.Conclusion
The IPS3 is a simple 3-point system that is very useful for prediction of outcomes in aHL and might be particularly suited for retrospective data analysis where all components of the IPS7 might not be available. 相似文献994.
995.
996.
The purpose of this study was to design a toolkit that interacts with the Monaco (Elekta AB, Stockholm, Sweden) treatment planning system (TPS) for optimization of intensity-modulated radiation therapy and volumetric-modulated arc therapy without the need for a dedicated application programming interface. Successful inverse planning of radiotherapeutic treatment depends on the tweaking of many parameters; a tool was thus needed to explore these parameters more exhaustively without significantly increasing planning time. The software that we used was based on an open-source library that mimics human interaction with Microsoft Windows applications. We developed a simple Autoflow software routine that analyzes and optimizes calculated plans by considering the relative impact of different cost functions and modifying constraints accordingly. It was also designed to change segmentation parameters to fit more complex treatments. The toolkit is publicly available for download at https://bitbucket.org/hgugmradiofisica/pymonaco/src/master/. A study of prostate cancer cases was conducted to compare automatically created plans with previously treated cases. The toolkit fully automated the radiotherapy planning procedure, allowing the TPS to calculate or optimize plans during nonworking hours. In the prostate study, the use of this tool reduced the dose to organs at risk with a negligible decrease in target coverage. This tool enables the efficient use of the TPS, allowing research and clinical applications to coexist without conflict. It provides consistency and efficiency throughout the treatment planning process, which may be of great value to clinics with few resources. The impact of this tool on clinical workflow is important, as it not only provides better efficiency, but also increases treatment quality. 相似文献
997.
目的探讨改良内固定融合术治疗成人Ⅱ型痛性足副舟骨(painful accessory navicular,PAN)的疗效。方法2016 年 1 月—2017 年 12 月,采用改良内固定融合术治疗 29 例(37 足)Ⅱ型 PAN。其中男 12 例,女 17 例;年龄 18~50 岁,平均 41.4 岁。扭伤 24 例,无明显诱因 5 例。患者均行 6 个月以上保守治疗,症状无明显改善。术前及末次随访时采用美国矫形足踝协会(AOFAS)中足评分评估临床疗效;X 线片测量跟骨倾斜角、距骨第 1 跖骨角、距舟关节包容角、距骨第 2 跖骨角。结果术后 1 例出现切口浅表感染,经加强换药后愈合;其余患者切口均Ⅰ期愈合,无深部感染或骨髓炎发生。29 例均获随访,随访时间 12~33 个月,平均 25.1 个月。X 线片示关节面均于术后 2~5 个月愈合,平均 3.4 个月。随访期间未见内固定物松动或断裂。末次随访时,AOFAS 疼痛、功能、力线评分及总分以及距舟关节包容角、距骨第 1 跖骨角和距骨第 2 跖骨角均较术前显著改善,差异有统计学意义(P<0.05);跟骨倾斜角手术前后差异无统计学意义(t=1.097,P=0.276)。 结论采用改良内固定融合术治疗成人Ⅱ型 PAN 可有效缓解症状,患足功能恢复良好,并发症少。 相似文献
998.
Osric A. Forrest Daniel M. Chopyk Yael Gernez Milton R. Brown Carol K. Conrad Richard B. Moss Vin Tangpricha Limin Peng Rabindra Tirouvanziam 《Journal of cystic fibrosis》2019,18(1):64-70
Background
Resistin is an immunometabolic mediator that is elevated in several inflammatory disorders. A ligand for Toll-like receptor 4, resistin modulates the recruitment and activation of myeloid cells, notably neutrophils. Neutrophils are major drivers of cystic fibrosis (CF) lung disease, in part due to the release of human neutrophil elastase- and myeloperoxidase-rich primary granules, leading to tissue damage. Here we assessed the relationship of resistin to CF lung disease.Methods
Resistin levels were measured in plasma and sputum from three retrospective CF cohorts spanning a wide range of disease. We also assessed the ability of neutrophils to secrete resistin upon activation in vitro. Finally, we constructed a multivariate model assessing the relationship between resistin levels and lung function.Results
Plasma resistin levels were only marginally higher in CF than in healthy control subjects. By contrast, sputum resistin levels were very high in CF, reaching 50–100 fold higher levels than in plasma. Among CF patients, higher plasma resistin levels were associated with allergic bronchopulmonary aspergillosis, and higher sputum resistin levels were associated with CF-related diabetes. Mechanistically, in vitro release of neutrophil primary granules was concomitant with resistin secretion. Overall, sputum resistin levels were negatively correlated with CF lung function, independently of other variables (age, sex, and genotype).Conclusions
Our data establish relationships between resistin levels in the plasma and sputum of CF patients that correlate with disease status, and identify resistin as a novel mechanistic link between neutrophilic inflammation and lung disease in CF. 相似文献999.
Khaled Adil Marija Popovic Fabio L. Cury Sergio L. Faria Marie Duclos Luis Souhami 《Practical radiation oncology》2019,9(1):24-28
Purpose
This study aimed to investigate 3 planning target volume (PTV) margin expansions and determine the most appropriate volume to be used in bladder preservation therapy when using daily cone beam computed tomography (CBCT). We aimed to establish whether a smaller PTV expansion is feasible without risking geographical miss.Methods and materials
The study included patients with bladder cancer who were treated with a hypofractionated course of radiation therapy delivered with intensity modulated radiation therapy. The clinical target volume (CTV) was the whole empty bladder, and the PTV consisted of a 1.5-cm margin around the bladder (PTV1.5 cm). Patients underwent daily CBCT imaging before treatment to assess the bladder volume and ensure accurate positioning. We investigated 2 additional smaller PTV margin expansions to determine the most appropriate volume to be used with CBCT as a daily image guided radiation therapy modality. These margins were created retrospectively on every CBCT. The first additional volume was a uniform PTV margin of the surrounding 1 cm (PTV1 cm). When considering that the majority of the internal bladder movement was due to the variation in filling that occurs in the superior and anterior directions, a second volume of an anisotropic PTV margin with a 1.5-cm superior/anterior and 1 cm in other directions (PTV1/1.5 cm) was created. We recorded the frequency and measured the volume of bladder falling out of each PTV based on the daily CBCT.Results
For the purpose of this study, we considered an arbitrary 5 cm3 of CTV falling out of the designated PTV as a clinically significant volumetric miss. The frequency of such a miss when applying the uniform PTV1 cm was 1%. However, when applying the uniform PTV1.5 cm and anisotropic PTV1/1.5 cm margins, the frequency was 0.5% and 0.5%, respectively.Conclusions
The anisotropic PTV expansion of 1.5 cm superiorly and anteriorly and 1 cm in all other directions around the bladder (CTV) provides a safe PTV approach when daily CBCT imaging is used to localize an empty bladder. 相似文献1000.