NO/H2S "crosstalk" Reactions. The Role of Thionitrites (SNO-) and Perthionitrites (SSNO-)

The redox chemistry of H2S with NO and other oxidants containing the NO group is discussed on a mechanistic basis because of the expanding interest in their biological relevance, with an eye open to the chemical differences of H2S and thiols RSH. We focus on the properties of two "crosstalk" intermediates, SNO- (thionitrite) and SSNO- (perthionitrite, nitrosodisulfide) based in the largely controversial status on their identity and chemistry in aqueous/nonaqueous media, en route to the final products N2O, NO2 -, NH2OH/NH3, and S8. Thionitrous acid, generated either in the direct reaction of NO + H2S or through the transnitrosation of RSNO's (nitrosothiols) with H2S at pH 7.4, is best described as a mixture of rapidly interconverting isomers, {(H)SNO}. It is reactive in different competitive modes, with a half-life of a few seconds at pH 7.4 for homolytic cleavage of the N-S bond, and could be deprotonated at pH values of up to ca. 10, giving SNO-, a less reactive species than {(H)SNO}. The latter mixture can also react with HS-, giving HNO and HS2 - (hydrogen disulfide), a S0(sulfane)-transfer reagent toward {(H)SNO}, leading to SSNO-, a moderately stable species that slowly decomposes in aqueous sulfide-containing solutions in the minute-hour time scale, depending on [O2]. The previous characterization of HSNO/SNO- and SSNO- is critically discussed based on the available chemical and spectroscopic evidence (mass spectrometry, UV-vis, 15N NMR, Fourier transform infrared), together with computational studies including quantum mechanics/molecular mechanics molecular dynamics simulations that provide a structural and UV-vis description of the solvatochromic properties of cis-SSNO- acting as an electron donor in water, alcohols, and aprotic acceptor solvents. In this way, SSNO- is confirmed as the elusive "yellow intermediate" (I412) emerging in the aqueous crosstalk reactions, in contrast with its assignment to polysulfides, HSn -. The analysis extends to the coordination abilities of {(H)SNO}, SNO-, and SSNO- into heme and nonheme iron centers, providing a basis for best unraveling their putative specific signaling roles.Fil: Marcolongo, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Venâncio, Mateus F.. Universidade Federal de Minas Gerais; BrasilFil: Rocha, Willian R.. Universidade Federal de Minas Gerais; BrasilFil: Doctorovich, Fabio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Olabe Iparraguirre, Jose Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentin

PPARα-targeted mitochondrial bioenergetics mediate repair of intestinal barriers at the host-microbe intersection during SIV infection.

Chronic gut inflammatory diseases are associated with disruption of intestinal epithelial barriers and impaired mucosal immunity. HIV-1 (HIV) causes depletion of mucosal CD4+ T cells early in infection and disruption of gut epithelium, resulting in chronic inflammation and immunodeficiency. Although antiretroviral therapy (ART) is effective in suppressing viral replication, it is incapable of restoring the "leaky gut," which poses an impediment for HIV cure efforts. Strategies are needed for rapid repair of the epithelium to protect intestinal microenvironments and immunity in inflamed gut. Using an in vivo nonhuman primate intestinal loop model of HIV/AIDS, we identified the pathogenic mechanism underlying sustained disruption of gut epithelium and explored rapid repair of gut epithelium at the intersection of microbial metabolism. Molecular, immunological, and metabolomic analyses revealed marked loss of peroxisomal proliferator-activated receptor-α (PPARα) signaling, predominant impairment of mitochondrial function, and epithelial disruption both in vivo and in vitro. To elucidate pathways regulating intestinal epithelial integrity, we introduced probiotic Lactobacillus plantarum into Simian immunodeficiency virus (SIV)-inflamed intestinal lumen. Rapid recovery of the epithelium occurred within 5 h of L. plantarum administration, independent of mucosal CD4+ T cell recovery, and in the absence of ART. This intestinal barrier repair was driven by L. plantarum-induced PPARα activation and restoration of mitochondrial structure and fatty acid β-oxidation. Our data highlight the critical role of PPARα at the intersection between microbial metabolism and epithelial repair in virally inflamed gut and as a potential mitochondrial target for restoring gut barriers in other infectious or gut inflammatory diseases

Enhance democracy: resilience and meritocracy

This paper presents an exploratory study that meant to contribute to the comprehension of the process of formation of Portuguese political elites groups, especially to enlightening if the individual elite status is due to exceptional abilities, assessed by its resilience’s categories and professional and academical backgrounds or by “inheritance”, due to favorable factors as family and social relationships – that may have induced to a state power type formation that may have led, as one of the major factors, to inequality and mischaracterization of the concept of Democracy itself and to its disbelief, reinforced by the growing corruption and therefore facilitator of populist, dictatorial and xenophobes models that it’s urgent to reverse. Concomitantly, it is fundamental to promote resilience-related aspects and merit, to restore society’s trust in the system, as WHO (2017) recently explained the importance of trust, measured by the absence of corruption in business and government, to happiness and therefore well-being

Phylogeography of the reef fish Cephalopholis argus (Epinephelidae) indicates Pleistocene isolation across the indo-pacific barrier with contemporary overlap in the coral triangle

Background: \ud The Coral Triangle (CT), bounded by the Philippines, the Malay Peninsula, and New Guinea, is the epicenter of marine biodiversity. Hypotheses that explain the source of this rich biodiversity include 1) the center of origin, 2) the center of accumulation, and 3) the region of overlap. Here we contribute to the debate with a phylogeographic survey of a widely distributed reef fish, the Peacock Grouper (Cephalopholis argus; Epinephelidae) at 21 locations (N = 550) using DNA sequence data from mtDNA cytochrome b and two nuclear introns (gonadotropin-releasing hormone and S7 ribosomal protein).\ud \ud Results: \ud Population structure was significant (ΦST = 0.297, P < 0.001; FST = 0.078, P < 0.001; FST = 0.099, P < 0.001 for the three loci, respectively) among five regions: French Polynesia, the central-west Pacific (Line Islands to northeastern Australia), Indo-Pacific boundary (Bali and Rowley Shoals), eastern Indian Ocean (Cocos/Keeling and Christmas Island), and western Indian Ocean (Diego Garcia, Oman, and Seychelles). A strong signal of isolation by distance was detected in both mtDNA (r = 0.749, P = 0.001) and the combined nuclear loci (r = 0.715, P < 0.001). We detected evidence of population expansion with migration toward the CT. Two clusters of haplotypes were detected in the mtDNA data (d = 0.008), corresponding to the Pacific and Indian Oceans, with a low level of introgression observed outside a mixing zone at the Pacific-Indian boundary.\ud \ud Conclusions: \ud We conclude that the Indo-Pacific Barrier, operating during low sea level associated with glaciation, defines the primary phylogeographic pattern in this species. These data support a scenario of isolation on the scale of 105 year glacial cycles, followed by population expansion toward the CT, and overlap of divergent lineages at the Pacific-Indian boundary. This pattern of isolation, divergence, and subsequent overlap likely contributes to species richness at the adjacent CT and is consistent with the region of overlap hypothesis

Apparatus to Measure Optical Scatter of Coatings Versus Annealing Temperature

Light scattered by amorphous thin-film optical coatings limits the sensitivity of interferometric gravitational-wave detectors. We describe an imaging scatterometer to assess the role that crystal growth during annealing plays in this scatter

Engineering single-atom Fe-N active sites on hollow carbon spheres for oxygen reduction reaction

Seeking alternatives to noble metals-based electrocatalysts for oxygen reduction reaction (ORR), hollow carbon spheres (CSs) were finely tuned with stable single-atom Fe-N species through a synthesis methodology requiring only earth-abundant metal precursors. CSs with different sizes were synthesized by sol-gel polycondensation of resorcinol with formaldehyde over silica nanoparticles, followed by thermal annealing and silica etching. A catalyst screening revealed the positive impact of both the hollow core and structural defects of the CSs for ORR. Single-atom Fe-N active sites were introduced on the best performing CSs through simultaneous incorporation of iron and nitrogen precursors, and glucose. A significant enhancement in ORR activity was observed despite the small iron load introduced (0.12 wt%). ORR performance indicators, advanced characterization, and molecular simulation studies revealed nitrogen's crucial role in anchoring individual iron atoms and modulating the charge density nearby the active sites (increase of 80 mV in the half-wave potential). Adding glucose as a chelating agent enhances the metal-heteroatom coordination and subsequent dispersion of iron, accounting for an increase of 20 mV in the half-wave potential, an average of electrons transferred as high as 3.9 (at 0.4 V vs. RHE), and higher stability (99%) than that of a platinum-based (20 wt%) electrocatalyst (92%).11 página

Current limitations of SNP data from the public domain for studies of complex disorders: a test for ten candidate genes for obesity and osteoporosis

BACKGROUND: Public SNP databases are frequently used to choose SNPs for candidate genes in the association and linkage studies of complex disorders. However, their utility for such studies of diseases with ethnic-dependent background has never been evaluated. RESULTS: To estimate the accuracy and completeness of SNP public databases, we analyzed the allele frequencies of 41 SNPs in 10 candidate genes for obesity and/or osteoporosis in a large American-Caucasian sample (1,873 individuals from 405 nuclear families) by PCR-invader assay. We compared our results with those from the databases and other published studies. Of the 41 SNPs, 8 were monomorphic in our sample. Twelve were reported for the first time for Caucasians and the other 29 SNPs in our sample essentially confirmed the respective allele frequencies for Caucasians in the databases and previous studies. The comparison of our data with other ethnic groups showed significant differentiation between the three major world ethnic groups at some SNPs (Caucasians and Africans differed at 3 of the 18 shared SNPs, and Caucasians and Asians differed at 13 of the 22 shared SNPs). This genetic differentiation may have an important implication for studying the well-known ethnic differences in the prevalence of obesity and osteoporosis, and complex disorders in general. CONCLUSION: A comparative analysis of the SNP data of the candidate genes obtained in the present study, as well as those retrieved from the public domain, suggests that the databases may currently have serious limitations for studying complex disorders with an ethnic-dependent background due to the incomplete and uneven representation of the candidate SNPs in the databases for the major ethnic groups. This conclusion attests to the imperative necessity of large-scale and accurate characterization of these SNPs in different ethnic groups

Fluid Intake and Decreased Risk for Hospitalization for Dengue Fever, Nicaragua

In a hospital and health center-based study in Nicaragua, fluid intake during the 24 hours before being seen by a clinician was statistically associated with decreased risk for hospitalization of dengue fever patients. Similar results were obtained for children <15 years of age and older adolescents and adults in independent analyses

Medios de comunicación y derecho a la información en Jalisco, 2015

El octavo informe Q ITESO: Análisis Crítico de Medios revisa el funcionamiento del sistema de comunicación política durante el proceso electoral de 2015, así como diversos aspectos relevantes de unas elecciones que culminaron con un cambio radical en el panorama político en Jalisco. En el universo de los medios de comunicación, se analizan los cambios experimentados por estos en el marco de la coyuntura electoral local, la equidad y profundidad en la cobertura por parte de los periódicos y la difusión que hicieron de las encuestas, así como el discurso e impacto de la propaganda difundida a través de la televisión y la Internet, a lo que se suma los debates registrados en redes sociales como Twitter, y la percepción sobre las campañas por parte de la audiencia tapatía. El examen político se enfoca en la campaña realizada por los candidatos independientes, el planteamiento socioeconómico de los contendientes por la capital del estado y el impacto electoral de un personaje incómodo como el papá del gobernador, para culminar este informe con una reflexión general y un balance de quiénes perdieron y quiénes ganaron al término de las elecciones de 2015.ITESO, A.C