全文获取类型
| 收费全文 | 173426篇 |
| 免费 | 33627篇 |
| 国内免费 | 2529篇 |
专业分类
| 耳鼻咽喉 | 5424篇 |
| 儿科学 | 5876篇 |
| 妇产科学 | 2969篇 |
| 基础医学 | 6266篇 |
| 口腔科学 | 2477篇 |
| 临床医学 | 28292篇 |
| 内科学 | 53642篇 |
| 皮肤病学 | 8024篇 |
| 神经病学 | 16563篇 |
| 特种医学 | 6777篇 |
| 外科学 | 44838篇 |
| 综合类 | 401篇 |
| 现状与发展 | 72篇 |
| 一般理论 | 3篇 |
| 预防医学 | 8786篇 |
| 眼科学 | 3742篇 |
| 药学 | 2290篇 |
| 中国医学 | 128篇 |
| 肿瘤学 | 13012篇 |
出版年
| 2024年 | 519篇 |
| 2023年 | 4928篇 |
| 2022年 | 1499篇 |
| 2021年 | 3967篇 |
| 2020年 | 6404篇 |
| 2019年 | 3003篇 |
| 2018年 | 8317篇 |
| 2017年 | 7820篇 |
| 2016年 | 8915篇 |
| 2015年 | 9064篇 |
| 2014年 | 16448篇 |
| 2013年 | 16847篇 |
| 2012年 | 7481篇 |
| 2011年 | 7539篇 |
| 2010年 | 11531篇 |
| 2009年 | 15242篇 |
| 2008年 | 7435篇 |
| 2007年 | 5728篇 |
| 2006年 | 8033篇 |
| 2005年 | 5149篇 |
| 2004年 | 4321篇 |
| 2003年 | 3240篇 |
| 2002年 | 3217篇 |
| 2001年 | 3907篇 |
| 2000年 | 3093篇 |
| 1999年 | 3342篇 |
| 1998年 | 3807篇 |
| 1997年 | 3589篇 |
| 1996年 | 3477篇 |
| 1995年 | 3313篇 |
| 1994年 | 2024篇 |
| 1993年 | 1635篇 |
| 1992年 | 1432篇 |
| 1991年 | 1447篇 |
| 1990年 | 1098篇 |
| 1989年 | 1206篇 |
| 1988年 | 1049篇 |
| 1987年 | 879篇 |
| 1986年 | 903篇 |
| 1985年 | 746篇 |
| 1984年 | 578篇 |
| 1983年 | 557篇 |
| 1982年 | 556篇 |
| 1981年 | 441篇 |
| 1980年 | 401篇 |
| 1979年 | 324篇 |
| 1978年 | 352篇 |
| 1977年 | 420篇 |
| 1975年 | 300篇 |
| 1972年 | 312篇 |
排序方式： 共有10000条查询结果，搜索用时 31 毫秒
41.
A mixed‐method study of effects of a therapeutic play intervention for children on parental anxiety and parents' perceptions of the intervention 
下载免费PDF全文
下载免费PDF全文 42.
43.
44.
Dan Azagury Tara E Mokhtari Luis Garcia Ulysses S Rosas Trit Garg Homero Rivas John Morton 《Surgery》2019,165(3):565-570
Background
Laparoscopic Roux-en-Y gastric bypass, laparoscopic sleeve gastrectomy, and laparoscopic adjustable gastric banding all lead to substantial weight loss in obese patients. Long-term weight loss can be highly variable beyond 1-year postsurgery. This study examines and compares the frequency distribution of weight loss and lack of treatment effect rates after laparoscopic Roux-en-Y gastric bypass, laparoscopic sleeve gastrectomy, and laparoscopic adjustable gastric banding.Methods
A total of 1,331 consecutive patients at a single academic institution were reviewed from a prospectively collected database. Preoperative data collected included demographics, body mass index, and percent excess weight loss. Postoperative BMI and %EWL were collected at 12, 24, and 36 months. Percent excess weight loss was analyzed by the percentiles of excess weight lost, and the distribution of percent excess weight loss was evaluated in 10% increments. Lack of a successful treatment effect was defined as <25% excess weight loss.Results
Of the 1,331 patients, 72.4% (963) underwent laparoscopic Roux-en-Y gastric bypass, 18.3% (243) laparoscopic sleeve gastrectomy, and 9.4%(125) laparoscopic adjustable gastric banding. Mean percent excess weight loss was greatest for laparoscopic Roux-en-Y gastric bypass, followed by laparoscopic sleeve gastrectomy, and then by laparoscopic adjustable gastric banding at every time point: at 2 years mean percent excess weight loss was 77.9± 24.4 for laparoscopic Roux-en-Y gastric bypass, 50.8 ± 25.8 for laparoscopic sleeve gastrectomy, and 40.8± 25.9 for laparoscopic adjustable gastric banding (P < .0001). The rates of a successful treatment effect s for laparoscopic Roux-en-Y gastric bypass, laparoscopic sleeve gastrectomy, and laparoscopic adjustable gastric banding were 0.9%, 5.2%, and 24.3% at 1 year; 0.3%, 11.1%, and 26.0% at 2 years; and 1.0%, 25.3%, and 30.2% at 3 years. At 1 year, the odds ratio of lack of a successful treatment effect of laparoscopic sleeve gastrectomy versus laparoscopic Roux-en-Y gastric bypass was 6.305 (2.125–19.08; P?=?.0004), the odds ratio for laparoscopic adjustable gastric banding versus laparoscopic Roux-en-Y gastric bypass was 36.552 (15.64–95.71; P < .0001), and the odds ratio for laparoscopic adjustable gastric banding versus laparoscopic sleeve gastrectomy was 5.791 (2.519–14.599; P < .0001). At 2 years, the odds ratio for laparoscopic sleeve gastrectomy versus laparoscopic Roux-en-Y gastric bypass increased to 70.7 (9.4–531.7; P < .0001), the odds ratio for laparoscopic adjustable gastric banding versus laparoscopic Roux-en-Y gastric bypass increased to 128.1 (16.8–974.3; P < .0001), and the odds ratio for laparoscopic adjustable gastric banding versus laparoscopic sleeve gastrectomy decreased to 1.8 (0.9–3.6; P?=?.09).Conclusion
This study emphasizes the existing variability in weight loss across bariatric procedures as well as in the lack of a treatment effect for each procedure. Although laparoscopic adjustable gastric banding has the greatest rate of a lack of a successful treatment effect, the rate remained stable over 3 years postoperatively. Laparoscopic sleeve gastrectomy showed a doubling in the rate of a lack of a successful treatment effect every year reaching 25% at year 3. The rates for lack of a successful treatment effect for laparoscopic Roux-en-Y gastric bypass remained stable at about 1% for the first 3 years postoperatively. 相似文献45.
46.
47.
48.
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49.
Maria Gonzalez-Cao Cristina Carrera Juan Francisco Rodriguez Moreno Pedro Rodríguez-Jiménez Mónica Antoñanzas Basa Rosa Feltes Ochoa Teresa Puertolas Eva Muñoz-Couselo José Luis Manzano Ivan Marquez-Rodas Juan Martín-Liberal Ainara Soria Pilar Lopez Criado Almudena Garcia-Castaño Aram Boada Pablo Ayala de Miguel Susana Puig Guillermo Crespo Alfonso Berrocal 《Journal of the American Academy of Dermatology》2021,84(5):1412-1415
50.
Breast Elastography: How to Perform and Integrate Into a “Best-Practice” Patient Treatment Algorithm
Breast elastography has been available for more than 15 years but is not widely incorporated into clinical practice. Many publications report extremely high accuracy for various breast elastographic techniques. However, results in the literature are extremely variable. This variability is most likely due to variations in technique, a relatively steep learning curve, and variability in methods between vendors. This article describes our protocol for performing breast elastography using both strain elastography and shear wave elastography, which produces high sensitivity and specificity. Additionally, we will describe the most commonly known false-positive and false-negative lesions as well as how to detect them. 相似文献