全文获取类型
收费全文 | 702篇 |
免费 | 64篇 |
出版年
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 21篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 19篇 |
2017年 | 7篇 |
2016年 | 17篇 |
2015年 | 28篇 |
2014年 | 33篇 |
2013年 | 48篇 |
2012年 | 82篇 |
2011年 | 51篇 |
2010年 | 44篇 |
2009年 | 41篇 |
2008年 | 52篇 |
2007年 | 42篇 |
2006年 | 32篇 |
2005年 | 43篇 |
2004年 | 40篇 |
2003年 | 53篇 |
2002年 | 50篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 8篇 |
1998年 | 4篇 |
1997年 | 6篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
排序方式: 共有766条查询结果,搜索用时 15 毫秒
141.
The possibility to observe microsecond dynamics at the sub-micron scale, opened by recent technological advances in fast camera sensors, will affect many biophysical studies based on particle tracking in optical microscopy. A main limiting factor for further development of fast video microscopy remains the illumination of the sample, which must deliver sufficient light to the camera to allow microsecond exposure times. Here we systematically compare the main illumination systems employed in holographic tracking microscopy, and we show that a superluminescent diode and a modulated laser diode perform the best in terms of image quality and acquisition speed, respectively. In particular, we show that the simple and inexpensive laser illumination enables less than s camera exposure time at high magnification on a large field of view without coherence image artifacts, together with a good hologram quality that allows nm-tracking of microscopic beads to be performed. This comparison of sources can guide in choosing the most efficient illumination system with respect to the specific application. 相似文献
142.
143.
Stephane Régnier William Malcolm Felicity Allen Jonathan Wright Vladimir Bezlyak 《PloS one》2014,9(7)
Objective
Compare the efficacy of ranibizumab, aflibercept, laser, and sham in the first-line treatment of diabetic macular edema (DME) to inform technology assessments such as those conducted by the UK National Institute for Health and Care Excellence (NICE).Data sources
MEDLINE, Embase, Cochrane Library, congress abstracts, ClinicalTrials.gov registry and Novartis data on file.Inclusion criteria
Studies reporting 6- or 12-month results of randomized controlled trials (RCTs) evaluating at least two of ranibizumab 0.5 mg pro re nata, aflibercept 2.0 mg bi-monthly, laser photocoagulation or sham. Study quality was assessed based on likelihood of bias in selection, attrition, detection and performance.Outcome measure
Improvement in best-corrected visual acuity (BCVA) measured as the proportion of patients gaining ≥10 letters on the Early Treatment Diabetic Retinopathy Study scale. The outcome was chosen following acceptance by NICE of a Markov model with 10-letter health states in the assessment of ranibizumab for DME.Meta-analysis
Bayesian network meta-analyses with fixed and random effects adjusted for differences in baseline BCVA or central retinal thickness.Results
The analysis included 1,978 patients from eight RCTs. The random effects model adjusting for baseline BCVA was the best model based on total residual. The efficacy of ranibizumab was numerically, but not statistically, superior to aflibercept (odds ratio [OR] 1.59; 95% credible interval [CrI], 0.61–5.37). Ranibizumab and aflibercept were statistically superior to laser monotherapy with ORs of 5.50 (2.73–13.16) and 3.45 (1.62–6.84) respectively. The probability that ranibizumab is the most efficacious treatment was 73% compared with 14% for aflibercept, 12% for ranibizumab plus laser, and 0% for laser.Limitations
Three of the eight RCTs included are not yet published. The models did not adjust for all potential effect modifiers.Conclusion
Ranibizumab was non-significantly superior to aflibercept and both anti-VEGF therapies had statistically superior efficacy to laser. 相似文献144.
145.
Stephane Hausmann Christian P Vivarès Stewart Shuman 《The Journal of biological chemistry》2002,277(1):96-103
A scheme of eukaryotic phylogeny has been suggested based on the structure and physical linkage of the enzymes that catalyze mRNA cap formation. Here we show that the intracellular parasite Encephalitozoon cuniculi encodes a complete mRNA capping apparatus consisting of separate triphosphatase (EcCet1), guanylyltransferase (EcCeg1), and methyltransferase (Ecm1) enzymes, which we characterize biochemically and genetically. The triphosphatase EcCet1 belongs to a metal-dependent phosphohydrolase family that includes the triphosphatase components of the capping apparatus of fungi, DNA viruses, and the malaria parasite Plasmodium falciparum. These enzymes are structurally and mechanistically unrelated to the metal-independent cysteine phosphatase-type RNA triphosphatases found in metazoans and plants. Our findings support the proposed evolutionary connection between microsporidia and fungi, and they place fungi and protozoa in a common lineage distinct from that of metazoans and plants. RNA triphosphatase presents an attractive target for antiprotozoal/antifungal drug development. 相似文献
146.
Jerry Asalma Nboyine Stephane Boyer David J. Saville Stephen David Wratten 《Insect Science》2018,25(3):475-486
The efficacy of different combinations of undervine and inter‐row treatments for managing a soil‐dwelling orthopteran pest, weta (Hemiandrus sp.), in vineyards was investigated over 2 seasons. This insect damages vine buds, thus reducing subsequent grape yield. The undervine treatments comprised pea straw mulch, mussel shells, tick beans [Vicia faba Linn. var minor (Fab)], plastic sleeves on vine trunks (treated control) and control (no intervention), while inter‐rows contained either the existing vegetation or tick beans. Treatments were arranged in a randomized complete block design with 10 replicates. Data were collected on weta densities, damage to beans and components of yield. The latter were numbers of bud laid down per vine, shoots per bud, clusters per shoot, grape bunches per vine, bunch weight and yield. The undervine treatments significantly affected all variables except the number of shoots per bud. In contrast, none of the variables was significantly affected by the inter‐row treatments or their interaction with undervine treatments, apart from weta density. At the end of the experiment, weta density in the shell treatment was about 58% lower than in the control. As a result, there was about 39% significant yield increase in that treatment compared to the control. Although the undervine beans and sleeves treatments increased yield, there were no reductions in weta density. With undervine beans, the insect fed on the bean plants instead of vine buds. Thus, yield in that treatment was approximately 28% higher than in the control. These results demonstrate that simple agroecological management approaches can reduce above‐ground damage by soil‐dwelling insects. 相似文献
147.
Thierry Allario Aude Tixier Hosam Awad Cedric Lemaire Nicole Brunel Eric Badel Têtè S. Barigah Jean‐Louis Julien Pierre Peyret Ewa J. Mellerowicz Herve Cochard Stephane Herbette 《Physiologia plantarum》2018,163(4):502-515
While the xylem hydraulic properties, such as vulnerability to cavitation (VC), are of paramount importance in drought resistance, their genetic determinants remain unexplored. There is evidence that pectins and their methylation pattern are involved, but the detail of their involvement and the corresponding genes need to be clarified. We analyzed the hydraulic properties of the 35S::PME1 transgenic aspen that ectopically under‐ or over‐express a xylem‐abundant pectin methyl esterase, PtxtPME1. We also produced and analyzed 4CL1::PGII transgenic poplars expressing a fungal polygalacturonase, AnPGII, under the control of the Ptxa4CL1 promoter that is active in the developing xylem after xylem cell expansion. Both the 35S::PME1 under‐ and over‐expressing aspen lines developed xylem with lower‐specific hydraulic conductivity and lower VC, while the 4CL1::PGII plants developed xylem with a higher VC. These xylem hydraulic changes were associated with modifications in xylem structure or in intervessel pit structure that can result in changes in mechanical behavior of the pit membrane. This study shows that homogalacturonans and their methylation pattern influence xylem hydraulic properties, through its effect on xylem cell expansion and on intervessel pit properties and it show a role for PtxtPME1 in the xylem hydraulic properties. 相似文献
148.
Yu-Ru Su Chongzhi Di Stephanie Bien Licai Huang Xinyuan Dong Goncalo Abecasis Sonja Berndt Stephane Bezieau Hermann Brenner Bette Caan Graham Casey Jenny Chang-Claude Stephen Chanock Sai Chen Charles Connolly Keith Curtis Jane Figueiredo Manish Gala Li Hsu 《American journal of human genetics》2018,102(5):904-919
149.
Vishnu Chaturvedi Jean-Philippe Bouchara Ferry Hagen Ana Alastruey-Izquierdo Hamid Badali Anamelia Lorenzetti Bocca Jose F. Cano-Lira Cunwei Cao Sudha Chaturvedi Sanjay H. Chotirmall Anne D. van Diepeningen Jean-Pierre Gangneux Jesus Guinea Sybren de Hoog Macit Ilkit Rui Kano Weida Liu Nilce M. Martinez-Rossi Marcia de Souza Carvalho Melhem Mario Augusto Ono Yuping Ran Stephane Ranque Celia Maria de Almeida Soares Takashi Sugita Philip A. Thomas Anna Vecchiarelli Nancy L. Wengenack Patrick C. Y. Woo Jianping Xu Rosely M. Zancope-Oliveira 《Mycopathologia》2018,183(6):859-877
Mycopathologia was founded in 1938 to ‘diffuse the understanding of fungal diseases in man and animals among mycologists.’ This was an important mission considering that pathogenic fungi for humans and animals represent a tiny minority of the estimated 1.5–5 million fungal inhabitants on Earth. These pathogens have diverged from the usual saprotrophic lifestyles of most fungi to colonize and infect humans and animals. Medical and veterinary mycology is the subdiscipline of microbiology that dwells into the mysteries of parasitic, fungal lifestyles. Among the oldest continuing scientific publications on the subject, Mycopathologia had its share of ‘classic papers’ since the first issue was published in 1938. An analysis of the eight decades of notable contributions reveals many facets of host–pathogen interactions among 183 volumes comprising about 6885 articles. We have analyzed the impact and relevance of this body of work using a combination of citation tools (Google Scholar and Scopus) since no single citation metric gives an inclusive perspective. Among the highly cited Mycopathologia publications, those on experimental mycology accounted for the major part of the articles (36%), followed by diagnostic mycology (16%), ecology and epidemiology (15%), clinical mycology (14%), taxonomy and classification (10%), and veterinary mycology (9%). The first classic publication, collecting nearly 200 citations, appeared in 1957, while two articles published in 2010 received nearly 150 citations each, which is notable for a journal covering a highly specialized field of study. An empirical analysis of the publication trends suggests continuing interests in novel diagnostics, fungal pathogenesis, review of clinical diseases especially with relevance to the laboratory scientists, taxonomy and classification of fungal pathogens, fungal infections and carriage in pets and wildlife, and changing ecology and epidemiology of fungal diseases around the globe. We anticipate that emerging and re-emerging fungal pathogens will continue to cause significant health burden in the coming decades. It remains vital that scientists and physicians continue to collaborate by learning each other’s language for the study of fungal diseases, and Mycopathologia will strive to be their partner in this increasingly important endeavor to its 100th anniversary in 2038 and beyond. 相似文献
150.