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排序方式: 共有552条查询结果,搜索用时 15 毫秒
21.
Clarisse Roblin Steve Chiumento Cdric Jacqueline Eric Pinloche Cendrine Nicoletti Hamza Olleik Elise Courvoisier-Dezord Agns Amouric Christian Basset Louis Dru Marie Ollivier Aurlie Bogey-Lambert Nicolas Vidal Mohamed Atta Marc Maresca Estelle Devillard Victor Duarte Josette Perrier Mickael Lafond 《International journal of molecular sciences》2021,22(6)
The world is on the verge of a major antibiotic crisis as the emergence of resistant bacteria is increasing, and very few novel molecules have been discovered since the 1960s. In this context, scientists have been exploring alternatives to conventional antibiotics, such as ribosomally synthesized and post-translationally modified peptides (RiPPs). Interestingly, the highly potent in vitro antibacterial activity and safety of ruminococcin C1, a recently discovered RiPP belonging to the sactipeptide subclass, has been demonstrated. The present results show that ruminococcin C1 is efficient at curing infection and at protecting challenged mice from Clostridium perfringens with a lower dose than the conventional antibiotic vancomycin. Moreover, antimicrobial peptide (AMP) is also effective against this pathogen in the complex microbial community of the gut environment, with a selective impact on a few bacterial genera, while maintaining a global homeostasis of the microbiome. In addition, ruminococcin C1 exhibits other biological activities that could be beneficial for human health, as well as other fields of applications. Overall, this study, by using an in vivo infection approach, confirms the antimicrobial clinical potential and highlights the multiple functional properties of ruminococcin C1, thus extending its therapeutic interest. 相似文献
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23.
Marc Gravel Laszlo Kiss Jean-Marc Martel Wilson L. Price 《International Transactions in Operational Research》1994,1(3):363-373
This paper presents a decision support system designed to aid the production planner in choosing the values of the principle parameters governing just-in-time manufacturing. The DSS uses a knowledge base composed of data from simulations of the production of the entire product line under systematically varied conditions. The planners may add data from actual production experience as it is obtained. The stochastic dominance outranking method of Martel and Zaras allows the identification of clusters of parameters that respect the preferences of the decision maker. When launching an order for a product, the decision maker may judge certain sets of parameters to be equivalent. A visual interactive simulation model will then allow their comparison according to three performance criteria. 相似文献
24.
Jean-Pierre Martins Louis Doceul Sbastien Marol Elise Delchi Jean-Jacques Cordier Bruno Levesy Alessandro Tesini Emanuela Ciattaglia Richard Tivey Ren Gillier Christophe Abbes 《Fusion Engineering and Design》2009,84(7-11):1268-1275
In the field of the ITER port plug engineering and integration task, CEA has contributed to define proposals concerning the port plugs vacuum sealing interface with the vessel flange and the equatorial plug handling.The 2001 baseline vacuum flange sealing consisted of TIG welding of a 316L strip plate on to U shapes. This arrangement presented some issues like welding access, implementation of tools, lip consumption, complex local leak test, continuous leak checking. Therefore, an alternate sealing solution based on the use of metallic gaskets is proposed. The different technical aspects are discussed to explain how this design can simplify the maintenance and deal with safety and vacuum requirements.The design of the mechanical attachment and vacuum sealing of the plug has constantly evolved, but the associated remote handling equipment was not systematically reviewed. An update of the cask and maintenance procedure was studied in order to design it in accordance with the last generic plug flange design. This includes a concept of a gripping system that uses the plug flange bolting area and, to help the remote handling process, a cantilever assisting system is suggested to increase the reliability of the transfer operation between vacuum vessel and cask. 相似文献
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Daniel Fozer Nora Valentinyi Laszlo Racz Peter Mizsey 《Clean Technologies and Environmental Policy》2017,19(2):501-515
Microalgae-based biorefineries for the production of renewable biofuels like biodiesel, upgraded bio-oil, biochar, biogas and other high-value chemicals have received great attention in recent decades as potential major sources of energy for the future. Microalgae are a suitable species to produce biodiesel and other high energy density by-products; however, it is questionable whether a net energy gain can be realized or not considering the whole processing chain. In the present study, the energy balances of different algae-based biofuel and bioenergy production technologies are investigated in detail and compared to each other corresponding to a cradle-to-grave overall energetic analysis. The study includes cultivation, harvesting, cell pretreatments (cell disruption, drying, grinding), lipid extraction, transesterification, gasification and hydrothermal liquefaction with bio-oil stabilization and hydroprocessing. The energy consumption and energy gain are estimated for each operational step to determine the net energy ratio (NER, energy output over energy input) for the overall technologies studied. Our detailed investigation enables to detect the most energy consuming unit operation, that is, the bottleneck point(s) of the microalgae-based technologies which should be still improved in the future for the sake of more efficient algae-based biorefineries. The investigation makes also possible to evaluate and compare the different large scale alternatives for biomass transformation. Positive energy balances with a NER value of 1.109 and 1.137 are found in two already existing processes: open raceway ponds and closed photobioreactors, respectively. Our work gives also a detailed algorithm that can be followed at the evaluation of other microalgae-based biorefineries. 相似文献
27.
Subrata Panda Jean-Jacques Fundenberger Yajun Zhao Jianxin Zou Laszlo S. Toth Thierry Grosdidier 《International Journal of Hydrogen Energy》2017,42(35):22438-22448
While severe plastic deformation (SPD) on bulk samples has been widely applied for modifying the H-sorption properties, there has been little attention towards the use of SPD on powder materials. In this context, the aim of the present work was to compare the H-storage properties of high-pressure torsion (HPT) consolidated products obtained from two distinct Mg powder precursors: atomized micro-sized and condensed ultrafine powder particles. The results showed that the nature of the initial powder precursor had a pronounced effect on the H-sorption behavior. The HPT product obtained from the condensed ultrafine powder showed faster absorption kinetics than the consolidated product obtained from the atomized powder. However, the HPT product obtained from atomized powder could absorb more hydrogen and showed faster desorption kinetics corresponding to a lower activation energy. These results are discussed by taking into account the effectiveness of the HPT process to refine the grain sizes and differences in the dispersion of fine MgO oxide particles. 相似文献
28.
Laszlo Takacs 《Journal of Materials Science》2018,53(19):13324-13330
Some form of mechanochemical experience has existed from fine grinding of materials since prehistoric times, yet the first systematic investigations on the chemical effects of mechanical action were carried out only at the end of the nineteenth century. Walthére Spring studied the consolidation and reactions of powdered materials due to high pressure at the University of Liège, in order to understand the formation of minerals in the earth’s crust and M. Carey Lea carried out experiments on the decomposition of compounds by grinding in a mortar. In some of his experiments mechanical action produced distinctly different result from the effect of heat. The first part of this paper compares the circumstances and results of Spring and Lea. The other important period in the history of mechanochemistry was the 1960s, the time when the first dedicated conferences were organized and a broader community of mechanochemists formed. This happened in the Soviet Union and Eastern Europe where several groups were working on subjects related to mechanochemistry. In 1968, the first dedicated conference was organized as a special session of the yearly meeting of Soviet colloid chemists. An attempt is made to reconstruct the circumstances leading to that event and the roles played by Rebinder and Thiessen in bringing it together. The next conference on mechanochemistry was already a separate event and it started a yearly series. Extensions have led to the INCOME conferences, including this one in Ko?ice in 2017. 相似文献
29.
Quantum Information Processing - Historically, the information efficiency of the secret key in quantum key distribution (QKD) schemes based on binary signal formats was limited to 1 bit/particle.... 相似文献
30.
Sherman Jeffrey W.; Kruschke John K.; Sherman Steven J.; Percy Elise J.; Petrocelli John V.; Conrey Frederica R. 《Canadian Metallurgical Quarterly》2009,96(2):305
Stereotype formation may be based on the exaggeration of real group differences (category accentuation) or the misperception of group differences that do not exist (illusory correlation). This research sought to account for both phenomena with J. K. Kruschke's (1996, 2001, 2003) attention theory of category learning. According to the model, the features of majority groups are learned earlier than the features of minority groups. In turn, the features that become associated with a minority are those that most distinguish it from the majority. This second process is driven by an attention-shifting mechanism that directs attention toward group-attribute pairings that facilitate differentiation of the two groups and may lead to the formation of stronger minority stereotypes. Five experiments supported this model as a common account for category accentuation and distinctiveness-based illusory correlation. Implications for the natures of stereotype formation, illusory correlation, and impression formation are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献