This work deals with the behavior of fermions in the background of kinklike structures in the twodimensional spacetime. The kinklike structures appear from bosonic scalar field models that engender distinct profiles a...This work deals with the behavior of fermions in the background of kinklike structures in the twodimensional spacetime. The kinklike structures appear from bosonic scalar field models that engender distinct profiles and interact with the fermion fields via the standard Yukawa coupling. We first consider two models that engender parity symmetry, one leading to the exclusion of fermion bound states, and the other to the inclusion of bound states, when the parameter that controls the bosonic structure varies from zero to unity. We then investigate a third model where the kinklike solution explicitly breaks parity symmetry, leading to fermion bound states that are spatially asymmetric.展开更多
The present study aimed to purify and characterize one polygalacturonase from L. gongylophorus (PGaseLg), the symbiotic fungus of Atta sexdens. The enzyme was isolated by salting out of crude extract followed by two c...The present study aimed to purify and characterize one polygalacturonase from L. gongylophorus (PGaseLg), the symbiotic fungus of Atta sexdens. The enzyme was isolated by salting out of crude extract followed by two chromatographic steps. PGaseLG was identified with MS analysis and molecular exclusion chromatography revealed the monomeric nature of a protein with an estimated molecular weight of about 39 kDa. PGaseLg has an optimum temperature of 60°C and optimum pH activity at 5.0. Using polygalacturonate as a substrate, the calculations of K<sub>M</sub>, V<sub>max</sub> and k<sub>cat</sub> were 0.65 mg·mL<sup>-1</sup>, 1800 μmol·min<sup>-1</sup>·mg<sup>-1</sup> and 35.97 s<sup>-1</sup>, respectively. The enzyme was stable for more than 3 h at 50°C at pH 5.0;otherwise, at lower or higher pH values, the PGaseLg was less stable. The influence of several metals, EDTA and β-mercaptoethanol on enzyme activity was also determined. Thin layer chromatography (TLC) analyses indicated that PGaseLg is an exopolygalacturonase.展开更多
<span style="font-family:Verdana;">Chimaeras</span><span style="font-family:;" "=""><span style="font-family:Verdana;">, fish in the order Chimaerif...<span style="font-family:Verdana;">Chimaeras</span><span style="font-family:;" "=""><span style="font-family:Verdana;">, fish in the order Chimaeriformes, are among the rarest and least studied fish in the class Chondrichthyes (cartilaginous fish). Previous records have indicated that a species of chimaera known as the elephantfish, or cockfish, </span><i><span style="font-family:Verdana;">Callorhinchus callorynchus</span></i><span style="font-family:Verdana;">, may be found in marine waters off southeastern Brazil, as far north as the state of S<span style="font-size:10.0pt;font-family:"">ã</span>o Paulo. Here we report that </span><i><span style="font-family:Verdana;">C. callorynchus</span></i><span style="font-family:Verdana;">, caught with bottom gillnet, was found in an urban fish market in the city of Rio de Janeiro (~23<span style="white-space:nowrap;">˚</span>S). This and other records from a variety of places call into question the distribution limits of the American elephantfish in the southwestern Atlantic Ocean and whether, at least seasonally, this species may often be found as far north as the state of Rio de Janeiro. Because of scientific and conservation interests in the poorly known Chimaeriformes, we recommend long-term monitoring of the fish catch in ports along the southern Brazilian coast, to better understand the natural history of the intriguing chimeras.</span></span>展开更多
Temperature dependence of the dielectric constant of oleic acid with different degrees of puritywas measured in the 233-313 K range.It was observed that the presence of impurities(palmiticand linolenic acids)strongly ...Temperature dependence of the dielectric constant of oleic acid with different degrees of puritywas measured in the 233-313 K range.It was observed that the presence of impurities(palmiticand linolenic acids)strongly influences the dielectric constant,melting point and dipole moment of the oleic acid.The values of apparent dipole moment and the Kirkwood correlation parameterswere evaluated using the Kirkwood's model and were estimated to be about 1.20,1.61 and 2.27 D,respectively for 60,90 and 97 wt%oleic acid.展开更多
基金the Brazilian agencies CAPES and CNPq for financial supportUniversidade Federal de Pernambuco for Qualis A funding
文摘This work deals with the behavior of fermions in the background of kinklike structures in the twodimensional spacetime. The kinklike structures appear from bosonic scalar field models that engender distinct profiles and interact with the fermion fields via the standard Yukawa coupling. We first consider two models that engender parity symmetry, one leading to the exclusion of fermion bound states, and the other to the inclusion of bound states, when the parameter that controls the bosonic structure varies from zero to unity. We then investigate a third model where the kinklike solution explicitly breaks parity symmetry, leading to fermion bound states that are spatially asymmetric.
文摘The present study aimed to purify and characterize one polygalacturonase from L. gongylophorus (PGaseLg), the symbiotic fungus of Atta sexdens. The enzyme was isolated by salting out of crude extract followed by two chromatographic steps. PGaseLG was identified with MS analysis and molecular exclusion chromatography revealed the monomeric nature of a protein with an estimated molecular weight of about 39 kDa. PGaseLg has an optimum temperature of 60°C and optimum pH activity at 5.0. Using polygalacturonate as a substrate, the calculations of K<sub>M</sub>, V<sub>max</sub> and k<sub>cat</sub> were 0.65 mg·mL<sup>-1</sup>, 1800 μmol·min<sup>-1</sup>·mg<sup>-1</sup> and 35.97 s<sup>-1</sup>, respectively. The enzyme was stable for more than 3 h at 50°C at pH 5.0;otherwise, at lower or higher pH values, the PGaseLg was less stable. The influence of several metals, EDTA and β-mercaptoethanol on enzyme activity was also determined. Thin layer chromatography (TLC) analyses indicated that PGaseLg is an exopolygalacturonase.
文摘<span style="font-family:Verdana;">Chimaeras</span><span style="font-family:;" "=""><span style="font-family:Verdana;">, fish in the order Chimaeriformes, are among the rarest and least studied fish in the class Chondrichthyes (cartilaginous fish). Previous records have indicated that a species of chimaera known as the elephantfish, or cockfish, </span><i><span style="font-family:Verdana;">Callorhinchus callorynchus</span></i><span style="font-family:Verdana;">, may be found in marine waters off southeastern Brazil, as far north as the state of S<span style="font-size:10.0pt;font-family:"">ã</span>o Paulo. Here we report that </span><i><span style="font-family:Verdana;">C. callorynchus</span></i><span style="font-family:Verdana;">, caught with bottom gillnet, was found in an urban fish market in the city of Rio de Janeiro (~23<span style="white-space:nowrap;">˚</span>S). This and other records from a variety of places call into question the distribution limits of the American elephantfish in the southwestern Atlantic Ocean and whether, at least seasonally, this species may often be found as far north as the state of Rio de Janeiro. Because of scientific and conservation interests in the poorly known Chimaeriformes, we recommend long-term monitoring of the fish catch in ports along the southern Brazilian coast, to better understand the natural history of the intriguing chimeras.</span></span>
基金FFS acknowledges the support from MCT/CNPqEdital 14/2011(process.482495/2011-1)and theauthors thank the Brazilian institutions CAPES,FUNCAP,FAPESPA and CNPq for financial sup-port.Authors also acknowledge Dr.Jeanlex Sousafor a critical reading of the manuscript.
文摘Temperature dependence of the dielectric constant of oleic acid with different degrees of puritywas measured in the 233-313 K range.It was observed that the presence of impurities(palmiticand linolenic acids)strongly influences the dielectric constant,melting point and dipole moment of the oleic acid.The values of apparent dipole moment and the Kirkwood correlation parameterswere evaluated using the Kirkwood's model and were estimated to be about 1.20,1.61 and 2.27 D,respectively for 60,90 and 97 wt%oleic acid.
