全文获取类型
收费全文 | 5084篇 |
免费 | 415篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 52篇 |
儿科学 | 162篇 |
妇产科学 | 75篇 |
基础医学 | 852篇 |
口腔科学 | 181篇 |
临床医学 | 528篇 |
内科学 | 988篇 |
皮肤病学 | 89篇 |
神经病学 | 580篇 |
特种医学 | 101篇 |
外科学 | 597篇 |
综合类 | 37篇 |
一般理论 | 6篇 |
预防医学 | 507篇 |
眼科学 | 80篇 |
药学 | 342篇 |
中国医学 | 13篇 |
肿瘤学 | 335篇 |
出版年
2023年 | 46篇 |
2022年 | 60篇 |
2021年 | 117篇 |
2020年 | 65篇 |
2019年 | 111篇 |
2018年 | 124篇 |
2017年 | 82篇 |
2016年 | 102篇 |
2015年 | 131篇 |
2014年 | 170篇 |
2013年 | 226篇 |
2012年 | 354篇 |
2011年 | 376篇 |
2010年 | 196篇 |
2009年 | 190篇 |
2008年 | 325篇 |
2007年 | 316篇 |
2006年 | 315篇 |
2005年 | 320篇 |
2004年 | 298篇 |
2003年 | 308篇 |
2002年 | 256篇 |
2001年 | 65篇 |
2000年 | 58篇 |
1999年 | 71篇 |
1998年 | 50篇 |
1997年 | 63篇 |
1996年 | 36篇 |
1995年 | 27篇 |
1994年 | 39篇 |
1993年 | 42篇 |
1992年 | 37篇 |
1991年 | 45篇 |
1990年 | 38篇 |
1989年 | 45篇 |
1988年 | 38篇 |
1987年 | 33篇 |
1986年 | 46篇 |
1985年 | 21篇 |
1984年 | 28篇 |
1983年 | 20篇 |
1981年 | 14篇 |
1980年 | 12篇 |
1979年 | 22篇 |
1978年 | 19篇 |
1977年 | 13篇 |
1974年 | 12篇 |
1969年 | 15篇 |
1966年 | 12篇 |
1965年 | 12篇 |
排序方式: 共有5525条查询结果,搜索用时 25 毫秒
71.
72.
Alexander Buerle Anna-Lena Frewer Vanessa Rentrop Lynik Chantal Schüren Marco Niedergethmann Julia Lortz Eva-Maria Skoda Martin Teufel 《Nutrients》2022,14(9)
Overweight and obesity carry a tremendous burden in terms of physiological and psychological comorbidities. There is a great variety of weight management applications to support weight reduction, but a systematical analysis of individuals’ needs and requirements to adopt sustaining lifestyle changes is missing so far. This study aimed to assess the acceptance of such applications and its underlying predictors in individuals with overweight/obesity. A cross-sectional study was conducted, including 439 overweight/obese individuals. Health-related internet use and acceptance of weight management applications were examined using a modified questionnaire based on the Unified Theory of Acceptance and Use of Technology (UTAUT). The general acceptance of weight management applications was high, with significant age differences. Compared to older individuals, younger ones showed a higher acceptance. BMI was not significantly associated with acceptance. Besides psychometric data and eHealth-related data, performance expectancy, effort expectancy, and social influence proved to be significant predictors for acceptance. The total variance explanation provided by the extended UTAUT model was 61.2%. The knowledge of the influencing factors on acceptance might be useful in developing, optimizing, and establishing weight management applications. For determining acceptance and its predictors of weight management applications, the UTAUT model is a valid approach. 相似文献
73.
Specific knock‐down of tissue non‐specific alkaline phosphatase mRNA levels inhibits intracellular lipid accumulation in 3T3‐L1 and HepG2 cells
下载免费PDF全文
![点击此处可从《International journal of experimental pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
George Chirambo Chantal van Niekerk Nigel J. Crowther 《International journal of experimental pathology》2017,98(5):260-268
The use of non‐specific inhibitors of tissue non‐specific alkaline phosphatase (TNSALP) in pre‐adipocytes blocks intracellular lipid accumulation. TNSALP is also expressed in hepatocytes, which are known to accumulate lipid in a similar manner to pre‐adipocytes. The purpose of this study was to use specific silencing of TNSALP mRNA, using short interfering (si) RNA, to investigate the role of TNSALP in intracellular lipid accumulation in 3T3‐L1 and HepG2 cells. Cellular activity of TNSALP was measured using an automated colorimetric assay, and intracellular lipid accumulation was determined using the lipid‐specific dye, Oil Red O. Cells were transfected with siRNA directed against TNSALP mRNA, and expression of the TNSALP gene was determined at selected time points postinduction of lipid droplet formation. Expression of the TNSALP gene was inhibited by a maximum of 88 ± 1.9% (P < 0.005 vs. control) 11 days after initiation of lipid droplet formation in the 3T3‐L1 cells and 80 ± 8.9% (P < 0.05 vs. control) after 4 days in the HepG2 cells. This led to significant inhibition of both TNSALP activity and intracellular lipid accumulation in both cell lines. These data demonstrates that TNSALP plays an important role in the control of lipid droplet formation in both pre‐adipocyte and hepatocyte cell lines. 相似文献
74.
75.
C. Nagant B. Pitts K. Nazmi M. Vandenbranden J. G. Bolscher P. S. Stewart J.-P. Dehaye 《Antimicrobial agents and chemotherapy》2012,56(11):5698-5708
Persistent Pseudomonas aeruginosa infections are a major cause of morbidity and mortality in cystic fibrosis (CF) patients and are linked to the formation of a biofilm. The development of new biofilm inhibition strategies is thus a major challenge. LL-37 is the only human antimicrobial peptide derived from cathelicidin. The effects on the P. aeruginosa PAO1 strain of synthetic truncated fragments of this peptide were compared with the effects of the original peptide. Fragments of LL-37 composed of 19 residues (LL-19, LL13-31, and LL7-25) inhibited biofilm formation. The strongest antibiofilm activity was observed with the peptides LL7-37 and LL-31, which decreased the percentage of biomass formation at a very low concentration. Some peptides were also active on the bacteria within an established biofilm. LL7-31, LL-31, and LL7-37 increased the uptake of propidium iodide (PI) by sessile bacteria. The peptide LL7-37 decreased the height of the biofilm and partly disrupted it. The peptides active within the biofilm had an infrared spectrum compatible with an α-helix. LL-37, but not the peptides LL7-31 and LL7-37, showed cellular toxicity by permeabilizing the eukaryotic plasma membrane (uptake of ethidium bromide and release of lactate dehydrogenase [LDH]). None of the tested peptides affected mitochondrial activity in eukaryotic cells. In conclusion, a 25-amino-acid peptide (LL7-31) displayed both strong antimicrobial and antibiofilm activities. The peptide was even active on cells within a preformed biofilm and had reduced toxicity toward eukaryotic cells. Our results also suggest the contribution of secondary structures (α-helix) to the activity of the peptides on biofilms. 相似文献
76.
Wenfeng Feng Antigona Martinez Michael Pitts Yue-Jia Luo Steven A. Hillyard 《Neuropsychologia》2012,50(14):3461-3468
It is widely reported that inverting a face dramatically affects its recognition. Previous studies have shown that face inversion increases the amplitude and delays the latency of the face-specific N170 component of the event-related potential (ERP) and also enhances the amplitude of the occipital P1 component (latency 100–132 ms). The present study investigates whether these effects of face inversion can be modulated by visual spatial attention. Participants viewed two streams of visual stimuli, one to the left and one to the right of fixation. One stream consisted of a sequence of alphanumeric characters at 6.67 Hz, and the other stream consisted of a series of upright and inverted images of faces and houses presented in randomized order. The participants’ task was to attend selectively to one or the other of the streams (during different blocks) in order to detect infrequent target stimuli. ERPs elicited by inverted faces showed larger P1 amplitudes compared to upright faces, but only when the faces were attended. In contrast, the N170 amplitude was larger to inverted than to upright faces only when the faces were not attended. The N170 peak latency was delayed to inverted faces regardless of attention condition. These inversion effects were face specific, as similar effects were absent for houses. These results suggest that early stages of face-specific processing can be enhanced by attention, but when faces are not attended the onset of face-specific processing is delayed until the latency range of the N170. 相似文献
77.
78.
79.
Michael P. Keith Chantal Moratz Ryan Egan Athina Zacharia Eric L. Greidinger Robert W. Hoffman 《Autoimmunity》2013,46(3):208-216
Natural Abs and autoantibodies bind antigens displayed by ischemia-conditioned tissues, followed by complement activation and enhanced tissue injury during reperfusion. Anti-ribonucleoprotein (RNP) Ab is associated with lung disease in patients with autoimmune disease but it is not known whether these abs contribute to lung injury. Mesenteric I/R in mice leads to local and remote lung injury. Accordingly, we used this model to investigate whether anti-RNP Abs would reconstitute I/R damage with prominent lung damage in injury-resistant Rag1? / ? animals. Rag1? / ? mice injected with anti-RNP Ab containing serum and subjected to mesenteric I/R suffered greater intestinal injury than control-treated and sham-operated animals. The magnitude of the reconstituted damage was anti-RNP Ab titer-dependent. Anti-RNP Ab-treated animals demonstrated a dose-dependent increase in lung histologic injury scores compared to control and sham animals. Anti-RNP mediated injury was shown to be complement dependent. These experiments reveal a novel mechanism whereby anti-RNP Abs contributes to the development of pulmonary pathology in patients with autoimmune diseases following exposure of remote organs to I/R injury. 相似文献
80.
Diagnosis of invasive pulmonary aspergillosis (IPA) is a challenging process in immunocompromised patients. Galactomannan (GM) antigen detection in bronchoalveolar lavage (BAL) fluid is a method to detect IPA with improved sensitivity over conventional studies. We sought to determine the diagnostic yield of BAL GM assay in a diverse population of immunocompromised patients. A retrospective review of 150 fiberoptic bronchoscopy (FOB) with BAL for newly diagnosed pulmonary infiltrate in immunocompromised patients was performed. Patient information, procedural details and laboratory studies were collected. BAL and serum samples were evaluated for GM using enzyme‐linked immunoassay. Of 150 separate FOB with BAL, BAL GM was obtained in 143 samples. There were 31 positive BAL GM assays. In those 31 positive tests, 13 were confirmed as IPA, giving a positive predictive value of 41.9%. There was one false negative BAL GM. Of the 18 false positive BAL GM, 4 were receiving piperacillin–tazobactam and 11 were receiving an alternative beta‐lactam antibiotic. BAL GM assay shows excellent sensitivity for diagnosing IPA. There was a significant number of false positive BAL GM assays and several of those patients were receiving beta‐lactam antibiotics at the time of bronchoscopy. 相似文献