全文获取类型
收费全文 | 3852篇 |
免费 | 270篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 145篇 |
妇产科学 | 92篇 |
基础医学 | 552篇 |
口腔科学 | 73篇 |
临床医学 | 447篇 |
内科学 | 847篇 |
皮肤病学 | 77篇 |
神经病学 | 352篇 |
特种医学 | 107篇 |
外科学 | 381篇 |
综合类 | 15篇 |
一般理论 | 3篇 |
预防医学 | 297篇 |
眼科学 | 53篇 |
药学 | 367篇 |
中国医学 | 8篇 |
肿瘤学 | 299篇 |
出版年
2023年 | 41篇 |
2022年 | 60篇 |
2021年 | 130篇 |
2020年 | 81篇 |
2019年 | 99篇 |
2018年 | 98篇 |
2017年 | 69篇 |
2016年 | 110篇 |
2015年 | 109篇 |
2014年 | 124篇 |
2013年 | 185篇 |
2012年 | 251篇 |
2011年 | 262篇 |
2010年 | 143篇 |
2009年 | 108篇 |
2008年 | 210篇 |
2007年 | 223篇 |
2006年 | 213篇 |
2005年 | 204篇 |
2004年 | 186篇 |
2003年 | 172篇 |
2002年 | 171篇 |
2001年 | 86篇 |
2000年 | 72篇 |
1999年 | 73篇 |
1998年 | 45篇 |
1997年 | 30篇 |
1996年 | 18篇 |
1995年 | 16篇 |
1994年 | 24篇 |
1992年 | 38篇 |
1991年 | 33篇 |
1990年 | 30篇 |
1989年 | 26篇 |
1988年 | 29篇 |
1987年 | 19篇 |
1986年 | 24篇 |
1985年 | 19篇 |
1984年 | 21篇 |
1983年 | 20篇 |
1982年 | 15篇 |
1981年 | 10篇 |
1979年 | 18篇 |
1978年 | 13篇 |
1977年 | 11篇 |
1976年 | 10篇 |
1973年 | 10篇 |
1972年 | 11篇 |
1969年 | 9篇 |
1966年 | 10篇 |
排序方式: 共有4141条查询结果,搜索用时 15 毫秒
991.
Joseph Zenga Jeffrey D. Sharon Paul Santiago Brian Nussenbaum Bruce H. Haughey Ida K. Fox Terence M. Myckatyn Jason A. Diaz Michael R. Chicoine 《Skull base》2015,76(5):397-408
Objectives To review the indications, techniques, and outcomes for a series of patients in whom the lower trapezius flaps was used for repair of complex posterior scalp and neck defects after posterior occipital-cervical surgeries.
Design Retrospective case series.
Setting Tertiary academic hospital.
Participants A retrospective review of cases that required complex occipital-cervical repair was performed to identify patients who underwent reconstruction using the lower trapezius flap. Data collected included demographics, clinical presentations, surgical anatomy, operative techniques, and outcomes with review of the pertinent literature.
Outcomes Nine patients who underwent reconstruction using the lower trapezius flap were identified. Prior surgical interventions included five complex tumor resections, two patients with multiple instrumented cervical spine surgeries, one patient with a craniotomy for attempted extracranial to intracranial arterial bypass for a basilar aneurysm repair, and a posterior occipital-cervical decompression after trauma. During the median follow-up period of 7 months, all nine single-stage reconstructions resulted in successful healing without major surgical complications.
Conclusion Lower trapezius island flaps provide a reliable option for the reconstruction of complex scalp and neck defects that develop after complex occipital-cervical surgeries. 相似文献
992.
The Effect of Induction of CYP3A4 by St John's Wort on Ambrisentan Plasma Pharmacokinetics in Volunteers of known CYP2C19 Genotype
下载免费PDF全文
![点击此处可从《Basic & clinical pharmacology & toxicology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Christoph Markert Ida Maria Kastner Regina Hellwig Peter Kalafut Yvonne Schweizer Michael Marcus Hoffmann Jürgen Burhenne Johanna Weiss Gerd Mikus Walter Emil Haefeli 《Basic & clinical pharmacology & toxicology》2015,116(5):423-428
To evaluate the impact of CYP2C19 polymorphisms on ambrisentan exposure and to assess its modification by St. John's wort (SJW), 20 healthy volunteers (10 CYP2C19 extensive, four poor and six ultrarapid metabolizers) received therapeutic doses of ambrisentan (5 mg qd po) for 20 days and concomitantly SJW (300 mg tid po) for the last 10 days. To quantify changes of CYP3A4 activity, midazolam (3 mg po) as a probe drug was used. Ambrisentan pharmacokinetics was assessed on days 1, 10 and 20, and midazolam pharmacokinetics before and on days 1, 10, 17 and 20. At steady state, ambrisentan exposure was similar in extensive and ultrarapid metabolizers but 43% larger in poor metabolizers (p < 0.01). In all volunteers, SJW reduced ambrisentan exposure and the relative change (17–26%) was similar in all genotype groups. The extent of this interaction did not correlate with the changes in CYP3A activity (midazolam clearance) (rs = 0.23, p = 0.34). Ambrisentan had no effect on midazolam pharmacokinetics. In conclusion, SJW significantly reduced exposure with ambrisentan irrespective of the CYP2C19 genotype. The extent of this interaction was small and thus likely without clinical relevance. 相似文献
993.
994.
Tripodi Domenico Cannistra’ Claudio Gagliardi Federica Casella Giovanni Lauro Augusto De Luca Alessandro Amabile Maria Ida Palumbo Piergaspare Pironi Daniele Mascagni Domenico D’Andrea Vito Vergine Massimo Sorrenti Salvatore 《Digestive diseases and sciences》2022,67(2):437-444
Digestive Diseases and Sciences - Multiple primary malignant neoplasms (MPMN) represent the occurrence of a second malignancy in the same patient within 6 months after the detection of... 相似文献
995.
Extraintestinal manifestation of inflammatory bowel disease in Asian patients: A multinational study
Soo-Kyung Park Zhiqin Wong Sang Hyoung Park Khien Van Vu Ki Bae Bang Panida Piyachaturawat Thein Myint Ida Hilmi Dong-Il Park 《Digestive and liver disease》2021,53(2):196-201
Background/aimAlthough inflammatory bowel disease (IBD) incidence has increased over the past two decades in Asia, data on extraintestinal manifestations (EIMs) of IBD in Asian patients are limited. We aimed to evaluate the prevalence and clinical characteristics of EIMs in Asian IBD patients.MethodsIn total, 1,764 patients (1,130 with ulcerative colitis [UC] and 634 with Crohn's disease [CD]) were recruited from 10 tertiary centers in Asia. The medical records of IBD patients were retrospectively reviewed for the presence, clinical characteristics, chronological order, and therapeutic management of EIMs.ResultsEIMs were reported in 199 (11.3%) patients, of which 17 (1.0%) patients had multiple EIMs. EIMs were more prevalent in CD patients (P = 0.02). Multiple logistic regression analysis revealed that female sex (odds ratio [OR] 2.02, 95% confidence interval [CI] 1.15–3.55), stricture (OR 2.49, 95% CI 1.41–4.39) and female sex (OR 2.57, 95% CI 1.52–4.34), extensive colitis (OR 2.63, 95% CI 1.57–4.41) were associated with EIMs in CD and UC patients respectively. EIMs appeared in 8% of patients before IBD diagnosis; 95% of cases with EIM could be managed via first-line therapy.ConclusionEIM prevalence is lower among Asian IBD patients than among patients from Western countries; however, the risk factors for EIM were similar between both populations. 相似文献
996.
Abu Tholib Aman Tri Wibawa Herman Kosasih Rizka Humardewayanti Asdie Ida Safitri Umi Solekhah Intansari Yuli Mawarti Pratiwi Sudarmono Mansyur Arif Dwiyanti Puspitasari Bachti Alisjahbana Ketut Tuti Merati Parwati Muhammad Hussein Gasem Dewi Lokida Nurhayati Lukman Teguh Sarry Hartono Yan Mardian C Jason Liang Sophia Siddiqui Muhammad Karyana Chuen‐Yen Lau 《Influenza and other respiratory viruses》2021,15(1):34-44
997.
Daniela Pietrogiacomi Maria Cristina Campa Ida Pettiti Simonetta Tuti Giulia Luccisano Leandro Ardemani Igor Luisetto Delia Gazzoli 《Materials》2021,14(10)
Ni/ZrO2 catalysts, active and selective for the catalytic partial oxidation of methane to syngas (CH4-CPO), were prepared by the dry impregnation of zirconium oxyhydroxide (Zhy) or monoclinic ZrO2 (Zm), calcination at 1173 K and activation by different procedures: oxidation-reduction (ox-red) or direct reduction (red). The characterization included XRD, FESEM, in situ FTIR and Raman spectroscopies, TPR, and specific surface area measurements. Catalytic activity experiments were carried out in a flow apparatus with a mixture of CH4:O2 = 2:1 in a short contact time. Compared to Zm, Zhy favoured the formation of smaller NiO particles, implying a higher number of Ni sites strongly interacting with the support. In all the activated Ni/ZrO2 catalysts, the Ni–ZrO2 interaction was strong enough to limit Ni aggregation during the catalytic runs. The catalytic activity depended on the activation procedures; the ox-red treatment yielded very active and stable catalysts, whereas the red treatment yielded catalysts with oscillating activity, ascribed to the formation of Niδ+ carbide-like species. The results suggested that Ni dispersion was not the main factor affecting the activity, and that active sites for CH4-CPO could be Ni species at the boundary of the metal particles in a specific configuration and nuclearity. 相似文献
998.
999.
Ida Perrotta Francesca Maria Moraca Alfonso Sciangula Saveria Aquila Sergio Mazzulla 《Ultrastructural pathology》2015,39(3):198-206
Calcific aortic stenosis (CAS) is the most common valvular disease in Western countries. Histological findings in patients with CAS extremely resemble those of atherosclerosis and include accumulation and modification of lipoproteins, inflammation, extracellular matrix remodeling, and calcification. Angiogenesis is another prominent feature of CAS; however, there is only a limited amount of data available regarding the mechanisms behind the pathological neovascularization of a structure that is originally avascular. The present study aims to identify the molecular basis that regulates blood vessel growth in stenotic aortic valves, focusing on the role of HIF-1α and VEGF pathway. A total of 19 native degenerating aortic valves obtained at valve replacement surgery have been processed for Western blot, immunohistochemical, morphometric, and ultrastructural analyses. First, we have demonstrated the adverse ECM remodeling and the significant thickening of the leaflet also showing that HIF-1α and VEGF are significantly upregulated in the stenotic valves, are locally produced and colocalize with angiogenesis and areas of calcification. Next, we have characterized, for the first time to the best of our knowledge, the morphological features of the neovasculature evidencing the presence of intact blood vessels in close proximity to the mineralized zones. These results suggest that the complex structural remodeling of the matrix might reduce oxygen availability in the valve cusp contributing to the stabilization of HIF-1α that in turn induces a metabolic adaptation through the upregulation of VEGF and the formation of new blood vessels not only to overcome the hypoxic state but also to sustain the calcification process. 相似文献
1000.
Competence in advanced older people nursing: development of ‘Nursing older people – Competence evaluation tool’
下载免费PDF全文
![点击此处可从《International journal of older people nursing》网站下载免费的PDF全文](/ch/ext_images/free.gif)