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91.
Wegard Skistad Shewangizaw Teketel Francesca Lønstad Bleken Pablo Beato Silvia Bordiga Merete Hellner Nilsen Unni Olsbye Stian Svelle Karl Petter Lillerud 《Topics in Catalysis》2014,57(1-4):143-158
Product flexibility is key to meeting fluctuating chemicals demands in the future. In this contribution, the methanol to hydrocarbons (MTH) reaction was investigated over two Ge-containing H-ITQ-13 samples, one with needle-like (H-ITQ-13(N), with (Si+Ge)/Al) = 42) and another with plate-like (H-ITQ-13(P), with (Si+Ge)/Al > 100) morphology. The samples were characterised using XRD, BET, SEM/EDS and FTIR spectroscopy, and their MTH performance was compared with the performance of H-ZSM-5 and H-ZSM-22. Similar specific surface areas (413 and 455 m2 g?1 for H-ITQ-13(N) and (P), respectively) and similar acid strength (Δν ~ ?327(?310) cm?1) was observed for the two H-ITQ-13 samples. Testing of H-ITQ-13(N) at weight hourly space velocity (WHSV) = 2–8 h?1 at 350–450 °C revealed that C5+ alkenes were the main products (35–45 % selectivity at 400 °C), followed by propene and butene. A low but significant selectivity for aromatic products was observed (6–8 % selectivity at 400 °C). Product selectivity was found to be independent of deactivation. The methanol conversion capacity of H-ITQ-13(N) was 120–150 g methanol g?1 catalyst at 400 °C. Testing H-ITQ-13 at high (30 atm) and ambient pressure, respectively, at 350 °C showed that a high pressure led to enhanced C5+ selectivity, but close to a tenfold decrease in methanol conversion capacity. H-ITQ-13(P) was tested at 400 °C and 2 h?1. It gave lower conversion than H-ITQ-13(N). Furthermore, when compared at the same conversion level, H-ITQ-13(P) gave higher C5+ alkene selectivity, lower aromatics selectivity, and a higher propene to ethene ratio than H-ITQ-13(N). The H-ITQ-13 samples yielded a product spectrum intermediate of H-ZSM-22 and H-ZSM-5. The effluent product cut-off of H-ITQ-13 was similar to that of H-ZSM-5 with tetramethylbenzene as the largest significant product, while H-ZSM-22 produced mainly linear and branched alkenes. The lifetime of H-ITQ-13(N) was clearly enhanced compared to H-ZSM-22, but inferior to H-ZSM-5. 相似文献
92.
Davide Giglio Riccardo Minciardi Simona Sacone Silvia Siri 《Discrete Event Dynamic Systems》2014,24(3):339-352
A class of production systems are considered in this paper with the aim of determining closed-loop strategies providing the production effort as functions of the system state. The key feature of the considered class of systems is that the demand and the way it is satisfied are asynchronous sequences of part requests and instantaneous withdrawals, respectively, generated by discrete-event processes, whereas the production process has continuous-time dynamics. The optimization problem, whose objective is to minimize inventory and lateness costs, is restated as an optimal control problem by exploiting some structural properties of the optimal solution. Then, optimal closed-loop strategies are found with dynamic programming techniques. 相似文献
93.
Roberta Bongiovanni Andrea Medici Alberto Zompatori Silvia Garavaglia Claudio Tonelli 《Polymer International》2012,61(1):65-73
Perfluoropolyether (PFPE) structures can be functionalized with acrylic groups using appropriate hydrogenated acrylic monomers: the macromers obtained are highly reactive under UV irradiation, and fluorinated polymers can be obtained. In the first part of this work is described the synthesis of new PFPE (meth)acrylic oligomers by extending OH‐terminated fluorinated chains with urethane groups and reactive acrylic functions. The photopolymerization reaction of each product is then reported followed by the characterisation of the main thermal, mechanical and surface properties of UV‐cured coatings. The polymers have good thermal resistance and fair mechanical and chemical resistance. More interestingly they show very low refractive index and low surface tension. For these latter properties the products can be advantageously used in highly demanding applications such as photonic devices and nano‐patterning. Copyright © 2011 Society of Chemical Industry 相似文献
94.
Ana Laura CIMADOR Emeli Luciana GALANTE Lucila Ibel MUÑOZ Patricia Silvia ROMANO Antonella Denisse LOSINNO María Cristina VANRELL 《Biocell》2019,43(1):13-20
Trypanosoma rangeli and T. cruzi are both parasitic unicellular species that infect humans. Unlike T. cruzi,
the causative agent of Chagas disease, T. rangeli is an infective and non-pathogenic parasite for humans, but pathogenic
for vectors from the Rhodnius genus. Because both species can coexist in different hosts and overlap their infective
cycles but very little is known about the infection of T. rangeli in mammalian cells, we decided to characterize both the
development of this parasite in cell culture and the effect of therapeutic agents with potential trypanocidal action on
it. We found that T. rangeli exhibits a cycle of infection in Vero cells similar to that for T. cruzi and that the repurposed
drug, 17-AAG, and the natural extract Artemisia sp. essential oil produce a toxic effect on epimastigotes showing
a trypanocidal action from the fifth day of culture. Both treatments also affected the infection of trypomastigotes
and reduced the capacity of replication of amastigotes of T. rangeli. Since T. cruzi / T. rangeli coinfection cases have
been reported, the finding of drugs with potential activity against both species could be significant in the future.
Furthermore, studies of susceptibility of both species to drugs could also help to know the different mechanisms of
pathogenicity in humans displayed by T. cruzi that are absent in T. rangeli 相似文献
95.
96.
Dr. Francesca Ferlenghi Dr. Michele Mari Prof. Gabriella Gobbi Dr. Gian Marco Elisi Prof. Marco Mor Prof. Silvia Rivara Prof. Federica Vacondio Dr. Silvia Bartolucci Prof. Annalida Bedini Dr. Fabiola Fanini Prof. Gilberto Spadoni 《ChemMedChem》2021,16(19):3071-3082
The MT2-selective melatonin receptor ligand UCM765 (N-(2-((3-methoxyphenyl)(phenyl)amino)ethyl)acetamide), showed interesting sleep inducing, analgesic and anxiolytic properties in rodents, but suffers from low water solubility and modest metabolic stability. To overcome these limitations, different strategies were investigated, including modification of metabolically liable sites, introduction of hydrophilic substituents and design of more basic derivatives. Thermodynamic solubility, microsomal stability and lipophilicity of new compounds were experimentally evaluated, together with their MT1 and MT2 binding affinities. Introduction of a m-hydroxymethyl substituent on the phenyl ring of UCM765 and replacement of the replacement of the N,N-diphenyl-amino scaffold with a N-methyl-N-phenyl-amino one led to highly soluble compounds with good microsomal stability and receptor binding affinity. Docking studies into the receptor crystal structure provided a rationale for their binding affinity. Pharmacokinetic characterization in rats highlighted higher plasma concentrations for the N-methyl-N-phenyl-amino derivative, consistent with its improved microsomal stability and makes this compound worthy of consideration for further pharmacological investigation. 相似文献
97.
Silvia Bierlich Timmy Reimann Frauke Gellersen Arne F. Jacob Jörg Töpfer 《Journal of the European Ceramic Society》2019,39(10):3077-3081
Sc3+ substituted M-type ferrites are effective microwave magnetic materials with a ferromagnetic resonance frequency in the range of 20 GHz–50 GHz. We report on the fabrication of oriented ferrite thick films as microwave components for application in the Ka-band at 30 GHz. Films of BaFe11.5.Sc0.5O19 were prepared by screen-printing on alumina substrates, drying in an external magnetic field, and sintering at 900 °C. Low-temperature sintering is achieved through use of a mixed BBSZ/CuO sintering aid. A strong anisotropy of the sintered ferrite films is revealed by XRD analysis. Microwave properties of the films were determined in a coplanar waveguide setup. The ferromagnetic resonance frequency of the films is at 30 GHz and the textured films possess good nonreciprocal properties which scale with film thickness. The films were tested in a Y-junction circulator, and represent promising materials for self-biased microwave components fabricated in thick film technology. 相似文献
98.
Silvia Vega-Rubín-de-Celis Lisa Kinch Samuel Pea-Llopis 《International journal of molecular sciences》2020,21(23)
Beclin 1 is a major regulator of autophagy, and it is a core component of the class III PI3K complexes. Beclin 1 is a highly conserved protein and its function is regulated in a number of ways, including post-translational modifications. Several studies indicate that receptor and non-receptor tyrosine kinases regulate autophagy activity in cancer, and some suggest the importance of Beclin 1 tyrosine phosphorylation in this process. Here we summarize the current knowledge of the mechanism whereby some oncogenic tyrosine kinases regulate autophagy through Beclin 1. 相似文献
99.
Iliescu Florina Silvia Teo Jeremy Choon Meng Vrtacnik Danilo Taylor Hayden Iliescu Ciprian 《Microsystem Technologies》2018,24(7):2905-2912
Microsystem Technologies - Cell transplantation traditionally employs needles to inject donor cells into tissues to treat certain diseases. However, it is difficult for the current method to... 相似文献
100.