Effect of a DC Electric field on the melting temperature, nucleation and ice growth rate of the TIP4P/ICE water model

Understanding the effect of electric fields on the thermal stability and phase transitions of water could have potential applications in the food industry, cryopreservation, and environmental science. In this work, we investigate the effect of a static electric field on the melting temperature (Tm), ice nucleation and ice growth rate of two phases of ice, hexagonal ice (Ih) and ferroelectric cubic ice (Icf), for the TIP4P/ICE water model. By means of direct coexistence simulations, we establish that Tm of Ice Ih is shifted toward lower values, whereas Tm of Ice Icf grows, becoming the most stable ice phase for sufficiently largevalues of the applied electric field. We also investigate ice nucleation for both ice phases under an external electric field and find that, for a given supercooling with respect to Tm, while the field slows down the nucleation rate of ice Ih significantly, it barely affects that of ice Icf, due to the enhanced ability of water molecules to orient favorably along the direction of the field in the latter phase. In terms of absolute temperature, overall ice formation is promoted by the electric field because it increases the melting point of ice Icf. Finally, we show how the electric field slows down the crystal growth of Ice Ih and increases that of Ice Icf by a factor of about two

Response letter: Serological evidence confirms the presumed diagnosis of Zika virus congenital infection in infants with microcephaly and ocular findings

FAV, Recife, PE, BrazilHosp Olhos HOPE, Recife, PE, BrazilUniv Fed Sao Paulo UNIFESP, EPM, Dept Ophthalmol & Visual Sci, Sao Paulo, SP, BrazilInst Visiao, Sao Paulo, SP, BrazilHosp Barao de Lucena, Recife, PE, BrazilHUOC, Recife, PE, BrazilUniv Fed Sao Paulo UNIFESP, EPM, Dept Ophthalmol & Visual Sci, Sao Paulo, SP, BrazilWeb of Scienc

Histological Study of Fresh Versus Frozen Semitendinous Muscle Tendon Allografts

OBJECTIVE: The purpose of this study was to histologically analyze allografts from cadaveric semitendinous muscle after cryopreservation at -80°C in comparison to a control group kept at only -4°C to test the hypothesis that the histological characteristics of the tissue are maintained when the tendons are kept at lower temperatures. METHODS: In a tissue bank, 10 semitendinous tendons from 10 cadavers were frozen at -80ºC as a storage method for tissue preservation. They were kept frozen for 40 days, and then a histological study was carried out. Another 10 tendon samples were analyzed while still "fresh". RESULTS: There was no histological difference between the fresh and frozen samples in relation to seven variables. CONCLUSIONS: Semitendinous muscle tendon allografts can be submitted to cryopreservation at -80ºC without suffering histological modifications

Flexible Optical-Comb-Based Multi-Wavelength Conversion for Optical Switching and Multicast

Experimental results on multi-wavelength conversion based on optical comb generation for optical switching and multicast applications are presented. All the newly generated channels showed good performance with clear and open eye diagrams.The work of R. Vilar is supported by the Spanish Government through an FPU grant. This work was partially supported by the BONE NoE (FP7-ICT-2007-1-216863) and by the European Project FIVER (FP7-ICT-2009-4-249142).Vilar Mateo, R.; Marques, C.; Nogueira, RI.; Teixeira, A.; Llorente Sáez, R.; Ramos Pascual, F. (2011). Flexible Optical-Comb-Based Multi-Wavelength Conversion for Optical Switching and Multicast. En Proceedings of the 2011 16th European Conference on Networks and Optical Communications (NOC 2011). Institute of Electrical and Electronics Engineers (IEEE). 196-199. http://hdl.handle.net/10251/61358S19619

DIBMA nanodiscs keep α-synuclein folded

α-Synuclein (αsyn) is a cytosolic intrinsically disordered protein (IDP) known to fold into an α-helical structure when binding to membrane lipids, decreasing protein aggregation. Model membrane enable elucidation of factors critically affecting protein folding/aggregation, mostly using either small unilamellar vesicles (SUVs) or nanodiscs surrounded by membrane scaffold proteins (MSPs). Yet SUVs are mechanically strained, while MSP nanodiscs are expensive. To test the impact of lipid particle size on α-syn structuring, while overcoming the limitations associated with the lipid particles used so far, we compared the effects of large unilamellar vesicles (LUVs) and lipid-bilayer nanodiscs encapsulated by diisobutylene/maleic acid copolymer (DIBMA) on αsyn secondary-structure formation, using human-, elephant- and whale -αsyn. Our results confirm that negatively charged lipids induce αsyn folding in h-αsyn and e-αsyn but not in w-αsyn. When a mixture of zwitterionic and negatively charged lipids was used, no increase in the secondary structure was detected at 45 °C. Further, our results show that DIBMA/lipid particles (DIBMALPs) are highly suitable nanoscale membrane mimics for studying αsyn secondary-structure formation and aggregation, as folding was essentially independent of the lipid/protein ratio, in contrast with what we observed for LUVs having the same lipid compositions. This study reveals a new and promising application of polymer-encapsulated lipid-bilayer nanodiscs, due to their excellent efficiency in structuring disordered proteins such as αsyn into nontoxic α-helical structures. This will contribute to the unravelling and modelling aspects concerning protein-lipid interactions and α-helix formation by αsyn, paramount to the proposal of new methods to avoid protein aggregation and disease.info:eu-repo/semantics/publishedVersio

Bayesian spatio-temporal models for mapping TB mortality risk and its relationship with social inequities in a region from Brazilian Legal Amazon

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Asymptotic Behavior of the Solution to a Nonisentropic Hydrodynamic Model of Semiconductors

AbstractWe study the asymptotic behavior of the solution for a hydrodynamic model of semiconductors where the energy equation is included. We study the case where the flow is subsonic and the doping profile is close to a negative constant, depending on the spacial variablex. We shall show that a given steady state solution is asymptotically stable or unstable depending on whether or not the density of the initial data satisfiesP=0, wherePis defined in (3.5)