全文获取类型
收费全文 | 16920篇 |
免费 | 1001篇 |
国内免费 | 108篇 |
专业分类
耳鼻咽喉 | 214篇 |
儿科学 | 342篇 |
妇产科学 | 179篇 |
基础医学 | 2435篇 |
口腔科学 | 287篇 |
临床医学 | 1709篇 |
内科学 | 3945篇 |
皮肤病学 | 444篇 |
神经病学 | 1935篇 |
特种医学 | 1098篇 |
外科学 | 2620篇 |
综合类 | 95篇 |
一般理论 | 7篇 |
预防医学 | 680篇 |
眼科学 | 264篇 |
药学 | 813篇 |
中国医学 | 8篇 |
肿瘤学 | 954篇 |
出版年
2023年 | 141篇 |
2022年 | 68篇 |
2021年 | 371篇 |
2020年 | 261篇 |
2019年 | 364篇 |
2018年 | 407篇 |
2017年 | 303篇 |
2016年 | 423篇 |
2015年 | 436篇 |
2014年 | 622篇 |
2013年 | 845篇 |
2012年 | 1311篇 |
2011年 | 1295篇 |
2010年 | 810篇 |
2009年 | 757篇 |
2008年 | 1176篇 |
2007年 | 1154篇 |
2006年 | 1085篇 |
2005年 | 1101篇 |
2004年 | 990篇 |
2003年 | 876篇 |
2002年 | 806篇 |
2001年 | 219篇 |
2000年 | 173篇 |
1999年 | 208篇 |
1998年 | 144篇 |
1997年 | 115篇 |
1996年 | 88篇 |
1995年 | 92篇 |
1994年 | 68篇 |
1993年 | 54篇 |
1992年 | 74篇 |
1991年 | 73篇 |
1990年 | 88篇 |
1989年 | 70篇 |
1988年 | 55篇 |
1987年 | 55篇 |
1986年 | 54篇 |
1985年 | 38篇 |
1984年 | 51篇 |
1983年 | 37篇 |
1982年 | 30篇 |
1979年 | 31篇 |
1978年 | 25篇 |
1977年 | 32篇 |
1975年 | 34篇 |
1974年 | 32篇 |
1973年 | 25篇 |
1971年 | 22篇 |
1969年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Kamolz Lars-Peter Kotzbeck Petra Schintler Michael Spendel Stephan 《European Surgery》2022,54(3):163-169
European Surgery - Large skin defects caused by trauma (e.g., burns) or due to other reasons (e.g., tumor-related skin resections) require sufficient skin replacement. The constant improvement of... 相似文献
2.
Roman Kia Rahimi-Nedjat Andrea Tuettenberg Keyvan Sagheb Carmen Loquai Benedict Rybczynski Stephan Grabbe Christian Walter Bilal Al-Nawas 《Journal of cranio-maxillo-facial surgery》2021,49(4):317-322
To investigate factors that affect and also decrease the duration for recurrences and secondary tumors in cSCC.A retrospective study was conducted for all patients who were treated for a cSCC of the head and neck between 2009 and 2016. Anamnestic as well as epidemiological and histological data were noted and correlated with the occurrence of recurrences and secondary cancers. The duration between surgery and these events was used to determine if histological factors accelerate their occurrence.The highest risk for recurrences was seen in patients with previous skin cancers (RR 3.23). Histological ulceration (p = 0.003) and grading (p = 0.031) of the tumor were found as significant factors accelerating the time to relapse. Surrounding chronic precancerotic lesions (p < 0.001) and poor tumor grading (p = 0.035) were found as significant factors accelerating the time until a secondary cSCC was observed.Known risk factors increase not only the risk for a cSCC but also for recurrences. Specific histologic findings can help to adjust follow-up intervals to identify recurrences and secondary tumors at an early stage as these were shown to decrease the duration for a further event. 相似文献
3.
Fiore Manganelli Silvia Parisi Maria Nolano Francesco Miceli Stefano Tozza Chiara Pisciotta Rosa Iodice Vincenzo Provitera Rita Cicatiello Stephan Zuchner Maurizio Taglialatela Tommaso Russo Lucio Santoro 《Journal of the peripheral nervous system : JPNS》2019,24(4):330-339
The development of patient‐specific induced pluripotent stem cells (iPSCs) offered interesting insights in modeling the pathogenesis of Charcot‐Marie‐Tooth (CMT) disease and thus we decided to explore the phenotypes of iPSCs derived from a single CMT patient carrying a mutant ATP1A1 allele (p.Pro600Ala). iPSCs clones generated from CMT and control fibroblasts, were induced to differentiate into neural precursors and then into post‐mitotic neurons. Control iPSCs differentiated into neuronal precursors and then into post‐mitotic neurons within 6‐8 days. On the contrary, the differentiation of CMT iPSCs was clearly defective. Electrophysiological properties confirmed that post‐mitotic neurons were less mature compared to the normal counterpart. The impairment of in vitro differentiation of CMT iPSCs only concerned with the neuronal pathway, because they were able to differentiate into mesendodermal cells and other ectodermal derivatives. ATP1A1 was undetectable in the few neuronal cells derived from CMT iPSCs. ATP1A1 gene mutation (p.Pro600Ala), responsible for a form of axonal CMT disease, is associated in vitro with a dramatic alteration of the differentiation of patient‐derived iPSCs into post‐mitotic neurons. Thus, the defect in neuronal cell development might lead in vivo to a decreased number of mature neurons in ATP1A1‐CMT disease. 相似文献
4.
Maheen Islam Mridul Mazumder Derek Schwabe-Warf Yannick Stephan Angelina R. Sutin Antonio Terracciano 《Journal of the American Medical Directors Association》2019,20(2):131-137
Objective
To examine changes in personality in individuals with mild cognitive impairment (MCI) or dementia as observed by family members using both new data and a meta-analysis with the published literature.Design
Current and retrospective personality assessments of individuals with dementia by family informants. PubMed was searched for studies with a similar design and a forward citation tracking was conducted using Google Scholar in June 2018. Results from a new sample and from published studies were combined in a random effect meta-analysis.Setting and participants
Family members of older adults with MCI or dementia.Measures
The 5 major dimensions (neuroticism, extraversion, openness, agreeableness, and conscientiousness) and facets of personality were assessed with NEO Personality Inventory questionnaires.Results
The new sample (n = 50) and meta-analysis (18 samples; n = 542) found consistent shifts in personality from the premorbid to current state in patients with cognitive impairment. The largest changes (>1 standard deviation) were declines in conscientiousness (particularly for the facets of self-discipline and competence) and extraversion (decreased energy and assertiveness), as well as increases in neuroticism (increased vulnerability to stress). The new sample suggested that personality changes were larger in individuals taking cognition-enhancing medications (cholinesterase inhibitors or memantine). More recent studies and those that examined individuals with MCI found smaller effects.Conclusions and implications
Consistent with the clinical criteria for the diagnosis of dementia, the new study and meta-analysis found replicable evidence for large changes in personality among individuals with dementia. Future research should examine whether there are different patterns of personality changes across etiologies of dementia to inform differential diagnosis and treatments. Prospective, repeated assessments of personality using both self- and informant-reports are essential to clarify the temporal evolution of personality change across the preclinical, prodromal, and clinical phases of dementia. 相似文献5.
Karyopherin Alpha 2 Is an Adverse Prognostic Factor in Clear-Cell and Papillary Renal-Cell Carcinoma
6.
Distinct genetic alterations and luminal molecular subtype in nested variant of urothelial carcinoma
7.
8.
Stephan Koter Tina U. Cohnert Korbinian B. Hindermayr Jörg Lindenmann Maximilian Brückner Wolfgang K. Oswald Georg Werkgartner Doris Wagner 《Journal of vascular surgery》2019,69(4):1227-1232
Objective
Low psoas muscle area is shown to be an indicator for worse postoperative outcome in patients undergoing vascular surgical. Additionally, it has been associated with longer durations of hospital stay in patients with cancer who undergo surgery and subsequently greater health care costs in Europe and the United States. We sought to evaluate this effect on hospital expenditure for patients undergoing vascular repair in a health care system with universal access.Methods
Skeletal muscle mass was assessed on preoperative abdominal computed tomography scans of patients undergoing open aortic aneurysm repair in a retrospective fashion. The skeletal muscle index (SMI) was used to define low muscle mass. Health care costs were obtained for all patients and the relationship between a low SMI and higher costs was explored using linear regression and cross-sectional analysis.Results
We included 156 patients (81.5% male) with a median age of 72 years undergoing elective surgery for infrarenal abdominal aortic aneurysm in this analysis. The median SMI for patients with low skeletal muscle mass was 53.21 cm2/kg and for patients without, 70.07 cm2/kg. Hospital duration of stay was 2 days longer in patients with low skeletal muscle mass as compared with patients with normal (14 days vs 11 days; P = .001), as was duration of intensive care stay (3 days vs 1 day; P = .01). The median overall hospital costs were €10,460 higher for patients with a low SMI as compared with patients with a normal physical constitution (€53,739 [interquartile range, €45,007-€62,471] vs €43,279 [interquartile range, €39,509-€47,049]; P = .001). After confounder adjustment, a low SMI was associated with a 14.68% cost increase in overall hospital costs, for a cost increase of €6521.Conclusions
Low skeletal muscle mass is independently associated with higher hospital as well as intensive care costs in patients undergoing elective aortic aneurysm repair. Strategies to reduce this risk factor are warranted for these patients. 相似文献9.
10.
Johannes Poms Stephan Sacher Matthias Nixdorf Michael Dekner Sabine Wallner-Mang Ines Janssen 《Pharmaceutical development and technology》2019,24(6):739-750
An undesirable characteristic in lyophilized parenteral products is the potential presence of particulate matter in the final product, which may affect patient safety. In this study, quality risk management tools described in the International Conference on Harmonization Guideline Q9 were used to estimate the risks for a pharmaceutical manufacturing line, based on three critical quality attributes: (1) visible particulate matter; (2) lyo-cake collapse traces; and (3) lyo-cake melt-back traces. Together with a Process Failure Mode Effect Analysis (PFMEA), an input-output analysis of the individual unit operations identified seven major material classes of extrinsic particulate matter. In addition to the process assessment, an experimental investigation of the location of impurities in lyophilized products was performed. To that end, intentionally contaminated vials were examined to locate the particulate matter and its possible migration. The results emphasize the importance of a full transmission mode release testing since the particles may enter the interior of the lyo-cake. A theoretical explanation of the observed impurity locations is provided. 相似文献