全文获取类型
收费全文 | 1422篇 |
免费 | 124篇 |
出版年
2023年 | 12篇 |
2022年 | 16篇 |
2021年 | 43篇 |
2020年 | 37篇 |
2019年 | 34篇 |
2018年 | 41篇 |
2017年 | 41篇 |
2016年 | 50篇 |
2015年 | 96篇 |
2014年 | 94篇 |
2013年 | 132篇 |
2012年 | 137篇 |
2011年 | 119篇 |
2010年 | 72篇 |
2009年 | 63篇 |
2008年 | 76篇 |
2007年 | 73篇 |
2006年 | 50篇 |
2005年 | 45篇 |
2004年 | 41篇 |
2003年 | 47篇 |
2002年 | 31篇 |
2001年 | 25篇 |
2000年 | 11篇 |
1999年 | 17篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 10篇 |
1991年 | 14篇 |
1990年 | 6篇 |
1989年 | 8篇 |
1988年 | 7篇 |
1987年 | 5篇 |
1986年 | 9篇 |
1985年 | 7篇 |
1984年 | 4篇 |
1983年 | 9篇 |
1982年 | 6篇 |
1980年 | 6篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 6篇 |
1976年 | 2篇 |
1973年 | 2篇 |
1972年 | 3篇 |
1971年 | 2篇 |
1936年 | 1篇 |
排序方式: 共有1546条查询结果,搜索用时 15 毫秒
991.
Lionel Cavin Larbi Boudad Haiyan Tong Emilie L?ng Jér?me Tabouelle Romain Vullo 《PloS one》2015,10(5)
The mid-Cretaceous vertebrate assemblage from south-eastern Morocco is one of the most diversified continental vertebrate assemblages of this time worldwide. The bony fish component (coelacanths, lungfishes and ray-finned fishes) is represented by relatively complete specimens and, mostly, by fragmentary elements scattered along 250 kilometres of outcrops. Here we revisit the bony fish assemblage by studying both isolated remains collected during several fieldtrips and more complete material kept in public collections. The assemblage comprises several lungfish taxa, with the first mention of the occurrence of Arganodus tiguidiensis, and possibly two mawsoniid coelacanths. A large bichir cf. Bawitius, is recorded and corresponds to cranial elements initially referred to ‘Stromerichthys’ from coeval deposits in Egypt. The ginglymodians were diversified with a large ‘Lepidotes’ plus two obaichthyids and a gar. We confirm here that this gar belongs to a genus distinctive from Recent gars, contrary to what was suggested recently. Teleosteans comprise a poorly known ichthyodectiform, a notopterid, a probable osteoglossomorph and a large tselfatiiform, whose cranial anatomy is detailed. The body size and trophic level for each taxon are estimated on the basis of comparison with extant closely related taxa. We plotted the average body size versus average trophic level for the Kem Kem assemblage, together with extant marine and freshwater assemblages. The Kem Kem assemblage is characterized by taxa of proportionally large body size, and by a higher average trophic level than the trophic level of the extant compared freshwater ecosystems, but lower than for the extant marine ecosystems. These results should be regarded with caution because they rest on a reconstructed assemblage known mostly by fragmentary remains. They reinforce, however, the ecological oddities already noticed for this mid-Cretaceous vertebrate ecosystem in North Africa. 相似文献
992.
Tomasz Chroboczek Martin Cour Romain Hernu Thomas Baudry Julien Bohé Vincent Piriou Bernard Allaouchiche Fran?ois Disant Laurent Argaud 《PloS one》2015,10(5)
BackgroundAcute epiglottitis is a potentially life threatening disease, with a growing incidence in the adult population. Its long-term outcome after Intensive Care Unit (ICU) hospitalization has rarely been studied.
Methodology and Principal Findings
Thirty-four adult patients admitted for acute epiglottitis were included in this retrospective multicentric study. The mean age was 44±12 years (sex ratio: 5.8). Sixteen patients (47%) had a history of smoking while 8 (24%) had no previous medical history. The average time of disease progression before ICU was 2.6±3.6 days. The main reasons for hospitalization were continuous monitoring (17 cases, 50%) and acute respiratory distress (10 cases, 29%). Microbiological documentation could be made in 9 cases (26%), with Streptococcus spp. present in 7 cases (21%). Organ failure at ICU admission occurred in 8 cases (24%). Thirteen patients (38%) required respiratory assistance during ICU stay; 9 (26%) required surgery. Two patients (6%) died following hypoxemic cardiac arrest. Five patients (15%) had sequelae at 1 year. Patients requiring respiratory assistance had a longer duration of symptoms and more frequent anti inflammatory use before ICU admission and sequelae at 1 year (p<0.05 versus non-ventilated patients). After logistic regression analysis, only exposure to anti-inflammatory drugs before admission was independently associated with airway intervention (OR, 4.96; 95% CI, 1.06-23.16).Conclusions and Significance
The profile of the cases consisted of young smoking men with little comorbidity. Streptococcus spp. infection represented the main etiology. Outcome was favorable if early respiratory tract protection could be performed in good conditions. Morbidity and sequelae were greater in patients requiring airway intervention. 相似文献993.
Axel Van Der Gucht Mehdi Aoun Sebaiti Emmanuel Itti Jessie Aouizerate Eva Evangelista Julia Chalaye Romain K. Gherardi Nilusha Ragunathan-Thangarajah Anne-Catherine Bachoud-Levi Fran?ois-Jér?me Authier 《PloS one》2015,10(6)
Background
Patients with aluminum hydroxide adjuvant-induced macrophagic myofasciitis (MMF) complain of arthromyalgias, chronic fatigue and cognitive deficits. This study aimed to characterize brain perfusion in these patients.Methods
Brain perfusion SPECT was performed in 76 consecutive patients (aged 49±10 y) followed in the Garches-Necker-Mondor-Hendaye reference center for rare neuromuscular diseases. Images were acquired 30 min after intravenous injection of 925 MBq 99mTc-ethylcysteinate dimer (ECD) at rest. All patients also underwent a comprehensive battery of neuropsychological tests, within 1.3±5.5 mo from SPECT. Statistical parametric maps (SPM12) were obtained for each test using linear regressions between each performance score and brain perfusion, with adjustment for age, sex, socio-cultural level and time delay between brain SPECT and neuropsychological testing.Results
SPM analysis revealed positive correlation between neuropsychological scores (mostly exploring executive functions) and brain perfusion in the posterior associative cortex, including cuneus/precuneus/occipital lingual areas, the periventricular white matter/corpus callosum, and the cerebellum, while negative correlation was found with amygdalo-hippocampal/entorhinal complexes. A positive correlation was also observed between brain perfusion and the posterior associative cortex when the time elapsed since last vaccine injection was investigated.Conclusions
Brain perfusion SPECT showed a pattern of cortical and subcortical changes in accordance with the MMF-associated cognitive disorder previously described. These results provide a neurobiological substrate for brain dysfunction in aluminum hydroxide adjuvant-induced MMF patients. 相似文献994.
Vincent Le Moing Fran?ois Alla Thanh Doco-Lecompte Fran?ois Delahaye Lionel Piroth Catherine Chirouze Pierre Tattevin Jean-Philippe Lavigne Marie-Line Erpelding Bruno Hoen Fran?ois Vandenesch Xavier Duval VIRSTA study group 《PloS one》2015,10(5)
ObjectivesTo update the epidemiology of S. aureus bloodstream infection (SAB) in a high-income country and its link with infective endocarditis (IE).MethodsAll consecutive adult patients with incident SAB (n = 2008) were prospectively enrolled between 2009 and 2011 in 8 university hospitals in France.ResultsSAB was nosocomial in 54%, non-nosocomial healthcare related in 18% and community-acquired in 26%. Methicillin resistance was present in 19% of isolates. SAB Incidence of nosocomial SAB was 0.159/1000 patients-days of hospitalization (95% confidence interval [CI] 0.111-0.219). A deep focus of infection was detected in 37%, the two most frequent were IE (11%) and pneumonia (8%). The higher rates of IE were observed in injecting drug users (IE: 38%) and patients with prosthetic (IE: 33%) or native valve disease (IE: 20%) but 40% of IE occurred in patients without heart disease nor injecting drug use. IE was more frequent in case of community-acquired (IE: 21%, adjusted odds-ratio (aOR) = 2.9, CI = 2.0-4.3) or non-nosocomial healthcare-related SAB (IE: 12%, aOR = 2.3, CI = 1.4-3.5). S. aureus meningitis (IE: 59%), persistent bacteremia at 48 hours (IE: 25%) and C-reactive protein > 190 mg/L (IE: 15%) were also independently associated with IE. Criteria for severe sepsis or septic shock were met in 30% of SAB without IE (overall in hospital mortality rate 24%) and in 51% of IE (overall in hospital mortality rate 35%).ConclusionSAB is still a severe disease, mostly related to healthcare in a high-income country. IE is the most frequent complication and occurs frequently in patients without known predisposing conditions. 相似文献
995.
Sophie Ayciriex Romain Carrire Chlo Bardet J. C. Yves Le Blanc Arnaud Salvador Tanguy Fortin Jrme Lemoine 《Proteomics》2020,20(2)
MS‐based targeted proteomics is a relevant technology for sensitive and robust relative or absolute quantification of proteins biomarker candidates in complex human biofluids or tissue extracts. Performing a multiplex assay imposes time scheduling of peptide monitoring only around their expected retention time that needs to be defined with synthetic peptide. Time‐scheduled monitoring is clearly a constraint that precludes from straightforward assay transfer between biological matrices or distinct experimental setup. Any unexpected retention time (RT) shift challenges assay robustness and its implementation for large‐scale analysis. Recently, Scout‐multiple reaction monitoring that fully releases multiplexed targeted acquisition from RT scheduling by successively monitoring complex transition groups triggered with sentinel molecules called Scout has been introduced. It is herein documented how Peptide Selector database and tool streamlines the building of a multiplexed method thanks to RT indexation relative to Scout peptides. This case study deals with surrogate peptides of biomarker candidates related to drug‐induced liver and vascular injury, running such on‐line built method (eight Scouts triggering the monitoring of a total of 692 transitions) enables 100% recovery of a panel of 93 spiked‐in heavy labeled standards, despite significant RT shifts between serum, plasma, or urine. This result illustrates the simplicity of automatically building and deploying robust proteomics targeted assay. 相似文献
996.
Pennec Flora Gérard Caroline Meterreau Laura Monghiemo Claude Ngawolo Jean-Christophe Bokika Laurent Romain Narat Victor 《International journal of primatology》2020,41(6):775-799
International Journal of Primatology - Understanding the ecological and behavioral variation of primates is central to improving conservation strategies. Studies of chimpanzees (Pan troglodytes)... 相似文献
997.
998.
999.
1000.
Quyên Do Wen Tian Rodrigue Yougnia Thomas Gaslonde Bruno Pfeiffer Alain Pierré Stéphane Léonce Laurence Kraus-Berthier Marie-Hélène David-Cordonnier Sabine Depauw Amélie Lansiaux Romain Mazinghien Michel Koch François Tillequin Sylvie Michel Hanh Dufat 《Bioorganic & medicinal chemistry》2009,17(5):1918-1927
Monocinnamoyl esters at position 2 of (±)-cis-1,2-dihydroxy-6-methoxy-3,3,14-trimethyl-1,2,3,14-tetrahydro-7H-benzo[b]pyrano[3,2-h]acridin-7-one and their acetyl derivatives at position 1 were prepared as stabilized analogues of the anticancer alkylating agent S23906-1. Monocinnamoyl esters at position 2 were slower DNA alkylators than the reference 2-monoacetate. Mixed esters bearing an acetyl ester group at position 1 and a cinnamoyl ester group at position 2 alkylated DNA slower than S23906-1. A strong correlation was observed between cytotoxicity and DNA alkylation kinetics, with slower alkylators displaying more potent antiproliferative activities. The most cytotoxic compounds proved to be significantly active in vivo against murine C-38 adenocarcinoma implanted in mice, but less potent than S23906-1. 相似文献