全文获取类型
收费全文 | 3118篇 |
免费 | 194篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 119篇 |
妇产科学 | 38篇 |
基础医学 | 505篇 |
口腔科学 | 32篇 |
临床医学 | 258篇 |
内科学 | 518篇 |
皮肤病学 | 163篇 |
神经病学 | 364篇 |
特种医学 | 129篇 |
外科学 | 280篇 |
综合类 | 8篇 |
一般理论 | 1篇 |
预防医学 | 216篇 |
眼科学 | 91篇 |
药学 | 291篇 |
中国医学 | 6篇 |
肿瘤学 | 296篇 |
出版年
2024年 | 4篇 |
2023年 | 26篇 |
2022年 | 43篇 |
2021年 | 63篇 |
2020年 | 48篇 |
2019年 | 64篇 |
2018年 | 77篇 |
2017年 | 62篇 |
2016年 | 89篇 |
2015年 | 91篇 |
2014年 | 111篇 |
2013年 | 144篇 |
2012年 | 227篇 |
2011年 | 256篇 |
2010年 | 151篇 |
2009年 | 132篇 |
2008年 | 241篇 |
2007年 | 217篇 |
2006年 | 216篇 |
2005年 | 229篇 |
2004年 | 197篇 |
2003年 | 176篇 |
2002年 | 140篇 |
2001年 | 30篇 |
2000年 | 12篇 |
1999年 | 13篇 |
1998年 | 34篇 |
1997年 | 32篇 |
1996年 | 24篇 |
1995年 | 12篇 |
1994年 | 18篇 |
1993年 | 18篇 |
1992年 | 6篇 |
1991年 | 5篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 9篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 5篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1972年 | 5篇 |
1971年 | 4篇 |
排序方式: 共有3324条查询结果,搜索用时 0 毫秒
81.
S2k Guidelines for the diagnosis and treatment of chronic pruritus – update – short version 下载免费PDF全文
Sonja Ständer Claudia Zeidler Matthias Augustin Gudrun Bayer Andreas E. Kremer Franz J. Legat Peter Maisel Thomas Mettang Martin Metz Alexander Nast Volker Niemeier Ulrike Raap Gudrun Schneider Hartmut F. Ständer Petra Staubach Markus Streit Elke Weisshaar 《Journal der Deutschen Dermatologischen Gesellschaft》2017,15(8):860-872
Associated with a host of different diseases, pruritus is a cardinal symptom that poses an interdisciplinary diagnostic and therapeutic challenge. Over time, that symptom may progress independently of the initial cause, thus losing its function as a warning sign and turning into a clinically relevant disease of its own. In Germany, approximately 13.5 % of the general population are affected by chronic pruritus, with an incidence of 7 %. All forms of chronic pruritus require targeted treatment consisting of (a) diagnosis and management of the underlying disease, (b) dermatological treatment of primary or secondary (for example, dry skin, scratch lesions) symptoms, (c) symptomatic antipruritic treatment, and (d) psychological/psychotherapeutic treatment in case of an underlying or associated psychological or psychosomatic condition. Medical care of patients with chronic pruritus should therefore include an interdisciplinary approach, in particular with respect to diagnosis and therapy of the underlying disease as well as in terms of the management of treatment and adverse events. The objective of the present interdisciplinary guidelines is to define and standardize diagnostic and therapeutic procedures in patients with chronic pruritus. This is a short version of the current S2 guidelines on chronic pruritus. The long version may be found at www.awmf.org . 相似文献
82.
Elke Weisshaar Magdalena Radulescu Michael Bock Ursel Albrecht Elisabeth Zimmermann Thomas L. Diepgen 《Journal der Deutschen Dermatologischen Gesellschaft》2005,3(1):33-38
Background: Healthcare workers have an increased risk of occupational dermatoses. In January 2002, the Department of Social Medicine, Occupational and Environmental Dermatology of the University of Heidelberg started organizing special prevention courses for this group of employees in cooperation with the Accident Prevention & Insurance Association for Health Care Workers (BGW). The major aims are to improve individual skin protection and skin care habits, as well as to optimize diagnostic procedures and therapy. Patients and Methods: The two‐day course has up to 14 participants. Teaching units mainly focus on skin structure and function, general aspects of occupational skin diseases, general information concerning skin protection and practical exercises emphasizing the correct use of skin cleansing and skin protection products. Additionally, every participant undergoes a dermatological examination including a detailed history and skin inspection. Individual skin protection strategies are developed, and the participants are provided with the opportunity to ask the dermatologist questions in confidence. Results: Most of the 355 participants have been female (87,3 %) with a mean age of 36,9 years. 95 % had hand eczema, predominantly dyshidrotic morphology. In many cases, there was a mixture of atopic, irritant and allergic contact dermatitis but irritant contact dermatitis was most common (43 %). Atopy was present in 68 % of the patients. The participants rated the course as good to excellent. Other benefits are the exchange of experience between patients working in the same or similar occupations and transfer of the new knowledge to colleagues, family and friends. Conclusions: Examinations and advisory services in occupational dermatology are still fragmentary. Skin barrier creams and moisturizers are not sufficiently utilized in daily practice. In the future, similar courses should be offered for employees in other professions with an increased risk of occupational skin diseases. 相似文献
83.
We have used the techniques of DNA fingerprinting and polymerase chain reaction (PCR) with probes specific for hypervariable repetitive DNA sequences (mini- and microsatellite DNAs) to analyze 36 yeast strains belonging to 10 species and 2 genera. Using (GTG)5, (GACA)4, phage M13 DNA and the M13 sequence GAGGGTGGCGGTTCT as probes and primers, respectively, we obtained DNA polymorphisms which allowed us to discriminate 23 biotechnologically important strains of the yeast Saccaromyces cerevisiae and to distinguish them from strains of S. pastorianus, S. bayanus and S. willianus. Our results demonstrate that both DNA and PCR fingerprinting are suitable tools for an easy, fast and reliable molecular typing of yeasts. The DNA fingerprinting method seems to be more sensitive than PCR fingerprinting with respect to the individualization of strains. Nevertheless, using the PCR fingerprinting technique we were able to unambigously dicriminate between yeast genotypes of different species. Therefore, PCR fingerprinting might become a useful tool in the classification of yeasts on the basis of phylogenetic relatedness. 相似文献
84.
CTLA-4 up-regulation of lymphocyte function-associated antigen 1 adhesion and clustering as an alternate basis for coreceptor function 下载免费PDF全文
Schneider H Valk E da Rocha Dias S Wei B Rudd CE 《Proceedings of the National Academy of Sciences of the United States of America》2005,102(36):12861-12866
Although cytotoxic T lymphocyte antigen-4 (CTLA-4) negatively regulates T cell activation, the full range of functions mediated by this coreceptor has yet to be established. In this study, we report the surprising finding that CTLA-4 engagement by soluble antibody or CD80 potently up-regulates lymphocyte function-associated antigen 1 (LFA-1) adhesion to intercellular adhesion molecule-1 (ICAM-1) and receptor clustering concurrent with IL-2 inhibition. This effect was also observed with CTLA-4 ligation and not with other coreceptors. T cell antigen receptor (TcR)-induced lymphocyte function-associated antigen 1 function was also dependent on CTLA-4 expression as observed with reduced adhesion/clustering on CTLA-4(-/-) primary T cells. CTLA-4 up-regulated adhesion was mediated by regulator for cell adhesion and polarization type 1 (Rap-1) as shown by anti-CTLA-4-induced Rap-1 activation as well as Rap-1-N17 blockade and Rap-1-V12 mimicry of adhesion/clustering. Our findings identify a potent role for CTLA-4 in directing integrin adhesion and provide an alternate mechanism to account for aspects of CTLA-4 function in T cell immunity. 相似文献
85.
In Vitro Expression of Adhesion Receptors and Diapedesis by Polymorphonuclear Neutrophils during Experimentally Induced Streptococcus uberis Mastitis 下载免费PDF全文
Elke Smits Christian Burvenich Albert J. Guidry Eddy Roets 《Infection and immunity》1998,66(6):2529-2534
The expression of adhesion receptors and diapedesis by polymorphonuclear neutrophils (PMN) were studied before and during experimentally induced Streptococcus uberis mastitis. Both quarters of the left half of the udders of five midlactation cows were inoculated with a suspension containing approximately 500 CFU of S. uberis 0140J. Clinical signs of an inflammatory reaction and leukocyte influx were observed 24 h after challenge. The expression of CD11b/CD18 adhesion receptors, determined by flow cytometry, was upregulated 24 h after challenge. A confluent monolayer of bovine secretory mammary epithelial cells on collagen-coated inserts was used to study PMN diapedesis. Bovine C5a was used as the chemoattractant. An 80% decrease in PMN diapedesis was observed 24 h after challenge. The decrease in diapedesis continued for 3 weeks after challenge. 相似文献
86.
87.
Brix G Nissen-Meyer S Lechel U Nissen-Meyer J Griebel J Nekolla EA Becker C Reiser M 《European journal of radiology》2009,72(2):342-347
X-ray procedures have a substantial impact not only on patient care but also on man-made radiation exposure. Since a reliable risk-benefit analysis of medical X-rays can only be performed for diagnosis-related groups of patients, we determined specific exposure data for patients with the ten most common types of cancer. For all patients with the considered cancers undergoing medical X-ray procedures in a maximum-care hospital between 2000 and 2005, patient- and examination-specific data were retrieved from the hospital/radiology information system. From this data, the cumulative 5-year effective dose was estimated for each patient as well as the mean annual effective dose per patient and the mean patient observation time for each cancer site. In total, 151,439 radiographic, fluoroscopic, and CT procedures, carried out in 15,866 cancer patients (age, 62 ± 13 years), were evaluated. The mean 5-year cumulative dose varied between 8.6 mSv (prostate cancer) and 68.8 mSv (pancreas cancer). Due to an increasing use of CT scans, the mean annual effective dose per patient increased from 13.6 to 18.2 mSv during the 6-year period. Combining the results obtained in this study for a particular hospital with cancer incidence data for Germany, we estimated that cancer patients having X-ray studies constitute at least 1% of the population but receive more than 10% of the total effective dose related to all medical X-ray procedures performed nationwide per year. A large fraction of this dose is radiobiologically ineffective due to the reduced life expectancy of cancer patients. 相似文献
88.
Jennifer S. Kullmann Jan‐Sebastian Grigoleit Philipp Lichte Philipp Kobbe Christina Rosenberger Christina Banner Oliver T. Wolf Harald Engler Reiner Oberbeck Sigrid Elsenbruch Ulrike Bingel Michael Forsting Elke R. Gizewski Manfred Schedlowski 《Human brain mapping》2013,34(9):2217-2227
Increases in peripheral cytokines during acute inflammation may affect various neuropsychological functions. The aim of this functional magnetic resonance imaging (fMRI) study was to investigate the effects of acute endotoxemia on mood and the neural response to emotionally aversive visual stimuli in healthy human subjects. In a double‐blind, randomized crossover study, 18 healthy males received a bolus injection of bacterial lipopolysaccharide (LPS; 0.4 ng/kg) or saline. Plasma levels of pro‐ and anti‐inflammatory cytokines and cortisol as well as mood ratings were analyzed together with the blood‐oxygen‐level dependent (BOLD) response during the presentation of aversive versus neutral pictures. Endotoxin administration induced pronounced transient increases in plasma levels of TNF‐α, IL‐1ra, IL‐6, IL‐10, and cortisol. Positive mood was decreased and state anxiety increased. In addition, activation of right inferior orbitofrontal cortex (OFC) in response to emotional visual stimuli was significantly increased in the LPS condition. Increased prefrontal activation during the presentation of emotional material may reflect enhanced cognitive regulation of emotions as an adaptive response during an acute inflammation. These findings may have implications for the putative role of inflammatory processes in the pathophysiology of depression. Hum Brain Mapp 34:2217–2227, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
89.
Gökce Orhan MD Merle Bock MSc Dorien Schepers MSc Elena I. Ilina MSc Stephanie Nadine Reichel BSc Heidi Löffler Nicole Jezutkovic Sarah Weckhuysen MD Simone Mandelstam MB ChB Arvid Suls PhD Timm Danker PhD Elke Guenther PhD Ingrid E. Scheffer MBBS PhD Peter De Jonghe MD PhD Holger Lerche MD Snezana Maljevic PhD 《Annals of neurology》2014,75(3):382-394
90.
PURPOSE: To explore acute effects of pregabalin (PGB) on human motor cortex excitability with transcranial magnetic stimulation (TMS). METHODS: PGB, 600 mg/day, was orally administered in 19 healthy subjects twice daily in a randomized, double-blind, placebo-controlled crossover design. Several measures of motor cortex excitability were tested with single- and paired-pulse TMS. RESULTS: Mean short-interval intracortical inhibition (SICI) was reduced after PGB (74 +/- 7% of unconditioned response) compared with placebo (60 +/- 6% of unconditioned response). In contrast, mean long-interval intracortical inhibition (LICI) was increased by PGB (26 +/- 4% of unconditioned response) compared with placebo (45 +/- 8% of unconditioned response), and mean cortical silent period (CSP) showed an increase from 139 +/- 8 ms or 145 +/- 8 ms after placebo to 162 +/- 7 ms or 161 +/- 10 ms after PGB. Motor thresholds, intracortical facilitation, and corticospinal excitability were unaffected. CONCLUSIONS: The observed excitability changes with oppositional effects on SICI and LICI or CSP suggest gamma-aminobutyric acid (GABA)B-receptor activation. They are markedly distinct from those induced by gabapentin, although both PGB and gabapentin are thought to mediate their function by binding to the alpha2-delta subunit of voltage-gated calcium channels. Conversely, the TMS profile of PGB shows striking similarities with the pattern evoked by the GABA-reuptake inhibitor tiagabine. 相似文献