全文获取类型
收费全文 | 1297篇 |
免费 | 106篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 26篇 |
妇产科学 | 29篇 |
基础医学 | 222篇 |
口腔科学 | 8篇 |
临床医学 | 179篇 |
内科学 | 355篇 |
皮肤病学 | 4篇 |
神经病学 | 131篇 |
特种医学 | 35篇 |
外科学 | 101篇 |
综合类 | 8篇 |
预防医学 | 99篇 |
眼科学 | 8篇 |
药学 | 115篇 |
中国医学 | 3篇 |
肿瘤学 | 78篇 |
出版年
2023年 | 26篇 |
2022年 | 46篇 |
2021年 | 107篇 |
2020年 | 33篇 |
2019年 | 44篇 |
2018年 | 33篇 |
2017年 | 30篇 |
2016年 | 47篇 |
2015年 | 48篇 |
2014年 | 49篇 |
2013年 | 50篇 |
2012年 | 89篇 |
2011年 | 104篇 |
2010年 | 60篇 |
2009年 | 58篇 |
2008年 | 85篇 |
2007年 | 72篇 |
2006年 | 81篇 |
2005年 | 67篇 |
2004年 | 62篇 |
2003年 | 37篇 |
2002年 | 51篇 |
2001年 | 13篇 |
2000年 | 7篇 |
1999年 | 4篇 |
1998年 | 3篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 8篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 2篇 |
1979年 | 7篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1973年 | 2篇 |
1970年 | 2篇 |
1967年 | 2篇 |
1966年 | 2篇 |
1964年 | 3篇 |
1959年 | 1篇 |
排序方式: 共有1407条查询结果,搜索用时 546 毫秒
31.
Digital technology allows people to connect and share similar interests across geographical and temporal borders. Two behavioural disorders related to Internet use have been officially recognised as mental health disorders: Gambling Disorder by the American Psychiatric Association and Gaming Disorder by the World Health Organization. The prevalence estimates and risk indicators of developing problems associated with excessive technology use differ considerably across countries. Individual, structural and situational factors need to be taken into consideration when evaluating existing study outcomes. Based on the current evidence base regarding prevention of problematic technology use including gaming and online gambling and reducing harm, whilst paying attention not to overpathologise everyday behaviours, we recommend a multi-stakeholder approach, engaging researchers, clinicians, regulators and government bodies, community organisations and the industry. Implications for clinical practice include engaging in dialogue across experts and using evidence-based treatment approaches to support those in need of professional help. 相似文献
32.
33.
Natalya Maltseva Elena Borzova Daria Fomina Mojca Bizjak Dorothea Terhorst-Molawi Mitja Košnik Kanokvalai Kulthanan Raisa Meshkova Simon Francis Thomsen Marcus Maurer the COLD-CE Steering Committee 《Allergy》2021,76(4):1077-1094
Cold urticaria (ColdU) is a common form of chronic inducible urticaria characterized by the development of wheals, angioedema or both in response to cold exposure. Recent research and guideline updates have advanced our understanding and management of ColdU. Today, its pathophysiology is thought to involve the cold-induced formation of autoallergens and IgE to these autoallergens, which provoke a release of proinflammatory mediators from skin mast cells. The classification of ColdU includes typical and atypical subtypes. We know that cold-induced wheals usually develop on rewarming and resolve within an hour and that anaphylaxis can occur. The diagnosis relies on the patient's history and cold stimulation testing. Additional diagnostic work-up, including a search for underlying infections, should only be done if indicated by the patient's history. The management of ColdU includes cold avoidance, the regular use of nonsedating antihistamines and the off-label use of omalizumab. However, many questions regarding ColdU remain unanswered. Here, we review what is known about ColdU, and we present important unanswered questions on the epidemiology, underlying pathomechanisms, clinical heterogeneity and treatment outcomes. Our aim is to guide future efforts that will close these knowledge gaps and advance the management of ColdU. 相似文献
34.
35.
Adna Ai Jasminka Prguda-Muji Lana Salihefendi Larisa Bei Daria Ler Ivana eko Almira Hadovi-Duvo Sead Jai Rijad Konjhodi Damir Marjanovi 《Archives of Medical Science》2021,17(3):823
IntroductionSerological detection of SARS-CoV-2-specific immunoglobulins G (IgG) and M (IgM) antibodies is becoming increasingly important in the management of the COVID-19 pandemic.MethodsWe report the first results of COVID-19 serological testing in Bosnia and Herzegovina on 2841 samples collected and analysed in 2 medical institutions in Sarajevo. Antibody detection was performed using commercially available kits.ResultsIn the first cohort, 43 IgM-positive/IgG-negative and 16 IgM-positive/IgG-positive individuals were detected, corresponding to 3.41% of participants having developed antibodies. In the second cohort, 4.28% participants were found to be IgM-negative/IgG-positive.ConclusionsOur results suggest the need for population-wide serological surveying in Bosnia and Herzegovina. 相似文献
36.
Vini Gautam Jack Drury Julian M. C. Choy Christian Stricker Hans-A. Bachor Vincent R. Daria 《Biomedical optics express》2015,6(10):4027-4036
We optimize two-photon imaging of living neurons in brain tissue by temporally gating an incident laser to reduce the photon flux while optimizing the maximum fluorescence signal from the acquired images. Temporal gating produces a bunch of ~10 femtosecond pulses and the fluorescence signal is improved by increasing the bunch-pulse energy. Gating is achieved using an acousto-optic modulator with a variable gating frequency determined as integral multiples of the imaging sampling frequency. We hypothesize that reducing the photon flux minimizes the photo-damage to the cells. Our results, however, show that despite producing a high fluorescence signal, cell viability is compromised when the gating and sampling frequencies are equal (or effectively one bunch-pulse per pixel). We found an optimum gating frequency range that maintains the viability of the cells while preserving a pre-set fluorescence signal of the acquired two-photon images. The neurons are imaged while under whole-cell patch, and the cell viability is monitored as a change in the membrane’s input resistance.OCIS codes: (170.3880) Medical and biological imaging, (170.3660) Light propagation in tissues, (140.0140) Lasers and laser optics, (170.2520) Fluorescence microscopy, (170.6930) Tissue, (110.0110) Imaging systems 相似文献
37.
Daria Soroka Inès Li de la Sierra-Gallay Vincent Dubée Sébastien Triboulet Herman van Tilbeurgh Fabrice Compain Lluis Ballell David Barros Jean-Luc Mainardi Jean-Emmanuel Hugonnet Michel Arthur 《Antimicrobial agents and chemotherapy》2015,59(9):5714-5720
Combinations of β-lactams with clavulanate are currently being investigated for tuberculosis treatment. Since Mycobacterium tuberculosis produces a broad spectrum β-lactamase, BlaC, the success of this approach could be compromised by the emergence of clavulanate-resistant variants, as observed for inhibitor-resistant TEM variants in enterobacteria. Previous analyses based on site-directed mutagenesis of BlaC have led to the conclusion that this risk was limited. Here, we used a different approach based on determination of the crystal structure of β-lactamase BlaMAb of Mycobacterium abscessus, which efficiently hydrolyzes clavulanate. Comparison of BlaMAb and BlaC allowed for structure-assisted site-directed mutagenesis of BlaC and identification of the G132N substitution that was sufficient to switch the interaction of BlaC with clavulanate from irreversible inactivation to efficient hydrolysis. The substitution, which restored the canonical SDN motif (SDG→SDN), allowed for efficient hydrolysis of clavulanate, with a more than 104-fold increase in kcat (0.41 s−1), without affecting the hydrolysis of other β-lactams. Mass spectrometry revealed that acylation of BlaC and of its G132N variant by clavulanate follows similar paths, involving sequential formation of two acylenzymes. Decarboxylation of the first acylenzyme results in a stable secondary acylenzyme in BlaC, whereas hydrolysis occurs in the G132N variant. The SDN/SDG polymorphism defines two mycobacterial lineages comprising rapidly and slowly growing species, respectively. Together, these results suggest that the efficacy of β-lactam–clavulanate combinations may be limited by the emergence of resistance. β-Lactams active without clavulanate, such as faropenem, should be prioritized for the development of new therapies. 相似文献
38.
39.
40.
Anna Szumera‐Ciekiewicz Grzegorz Rymkiewicz Kamil Sok Ewa Paszkiewicz‐Kozik Anita Borysiuk Jan Poleszczuk Katarzyna Bachnio Zbigniew Bystydzienski Renata Woroniecka Beata Grygalewicz Martyna Kotarska Monika Staczak Daria Owczarek Beata Pytlak Monika Prochorec‐Sobieszek Jan Walewski 《International journal of laboratory hematology》2020,42(4):453-463