Why is HSO5- so effective against bacteria? Insights into the mechanisms of Escherichia coli disinfection by unactivated peroxymonosulfate.

This study examined the antimicrobial efficacy of peroxymonosulfate (PMS) against bacteria, using Escherichia coli (E. coli) as a model organism. Our investigation delineates the complex mechanisms exerted by unactivated PMS. Thus, an initial redox reaction between PMS and the target biomolecules of bacteria generates SO4•- as the pivotal reactive species for bacterial inactivation; to a lesser extent, •OH, 1O2, or O2•- may also participate. Damage generated during oxidation was identified using an array of biochemical techniques. Specifically, redox processes are promoted by PMS and SO4•- targets and disrupt various components of bacterial cells, predominantly causing extracellular damage as well as intracellular lesions. Among these, external events are the key to cell death. Finally, by employing gene knockout mutants, we uncovered the role of specific gene responses in the intracellular damage induced by radical pathways. The findings of this study not only expand the understanding of PMS-mediated bacterial inactivation but also explain the ten-fold higher effectiveness of PMS than that reported for H2O2. Hence, we provide clear evidence that unactivated PMS solutions generate SO4•- in the presence of bacteria, and consequently, should be considered an effective disinfection method.

Synthesis of Bis(amino acids) Containing the Styryl-cyclobutane Core by Photosensitized [2+2]-Cross-cycloaddition of Allylidene-5(4H)-oxazolones.

The irradiation of 2-aryl-4-(E-3'-aryl-allylidene)-5(4H)-oxazolones 1 with blue light (456 nm) in the presence of [Ru(bpy)3](BF4)2 (bpy = 2,2'-bipyridine, 5% mol) gives the unstable cyclobutane-bis(oxazolones) 2 by [2+2]-photocycloaddition of two oxazolones 1. Each oxazolone contributes to the formation of 2 with a different C=C bond, one of them reacting through the exocyclic C=C bond, while the other does so through the styryl group. Treatment of unstable cyclobutanes 2 with NaOMe/MeOH produces the oxazolone ring opening reaction, affording stable styryl-cyclobutane bis(amino acids) 3. The reaction starts with formation of the T1 excited state of the photosensitizer 3[Ru*(bpy)3]2+, which reacts with S0 of oxazolones 1 through energy transfer to give the oxazolone T1 state 3(oxa*)-1, which is the reactive species and was characterized by transient absorption spectroscopy. Measurement of the half-life of 3(oxa*)-1 for 1a, 1b and 1d shows large values for 1a and 1b (10-12 µs), while that of 1d is shorter (726 ns). Density functional theory (DFT) modeling displays strong structural differences in the T1 states of the three oxazolones. Moreover, study of the spin density of T1 state 3(oxa*)-1 provides clues to understanding the different reactivity of 4-allylidene-oxazolones described here with respect to the previously reported 4-arylidene-oxazolones.

Stereoselective, Ruthenium-Photocatalyzed Synthesis of 1,2-Diaminotruxinic Bis-amino Acids from 4-Arylidene-5(4H)-oxazolones.

The irradiation of (Z)-2-phenyl-4-aryliden-5(4H)-oxazolones 1 in deoxygenated CH2Cl2 at 25 °C with blue light (465 nm) in the presence of [Ru(bpy)3](BF4)2 (5% mole ratio) as a triplet photocatalyst promotes the [2+2] photocycloaddition of the C═C bonds of the 4-arylidene moiety, thus allowing the completely regio- and stereoselective formation of cyclobutane-bis(oxazolone)s 2 as single stereoisomers. Cyclobutanes 2 have been unambiguously characterized as the µ-isomers and contain two E-oxazolones coupled in an anti-head-to-head form. The use of continuous-flow techniques in microreactors allows the synthesis of cyclobutanes 2 in only 60 min, compared with the 24-48 h required in batch mode. Ring opening of the oxazolone heterocycle in 2 with a base affords the corresponding 1,2-diaminotruxinic bis-amino esters 3, which are also obtained selectively as µ-isomers. The ruthenium complex behaves as a triplet photocatalyst, generating the reactive excited state of the oxazolone via an energy-transfer process. This reactive excited state has been characterized as a triplet diradical 3(E/Z)-1* by laser flash photolysis (transient absorption spectroscopy). This technique also shows that this excited state is the same when starting from either (Z)- or (E)-oxazolones. Density functional theory calculations show that the first step of the [2+2] cycloaddition between 3(E/Z)-1* and (Z)-1 is formation of the C(H)-C(H) bond and that (Z) to (E) isomerization takes place at the 1,4-diradical thus formed.

[Occupational health administrative coordination a propos of a case: brake linings with asbestos in a company]. / La coordinación administrativa en salud laboral a propósito de un caso: Zapatas de freno con amianto en una empresa.

The current structure of the Spanish State of Autonomies is characterized by institutional pluralism and the autonomy of the different public administrations. In this context, the principle of coordination is fundamental for the cohesion of the system, but experience shows that its implementation is difficult. This paper examines the set of actions carried out by the administrations in relation to an occupational and public health problem raised in March 2016. The Public Health General Direction of Aragon's Government was informed of a possible use of brake linings with asbestos to manufacture axles for agricultural machinery by a Company from Zaragoza; the collaboration from Aragon's Institute of Occupational Safety and Health, the Industry Department and the Labour and Social Security Inspectorate were asked; the joint action of these administrations detected the use of several models of brake linings with a content of 2-5% of Chrysotile. The brake linings came from a Chinese company. The axles nated are sold in several Spanish Autonomous Communities. A national alert was activated by the SIRIPQ (System of Rapid Exchange of Information on Chemical Products) which is coordinated by the Ministry of Health, Social Services and Equality. Several measures were taken including: ceasing the work with the brake linings, the replacement of brake linings with asbestos, the immobilization of brake linings in the company by application of the REACH Reglament, etc. This case shows that the cooperation and co-responsibility of public administrations from different territorial, sectoral and competence areas allows improving the occupational risks prevention and the public health.

La actual estructura del Estado de las Autonomías se caracteriza por el pluralismo institucional y la autonomía de las diferentes administraciones públicas. En este contexto el principio de coordinación es fundamental para la cohesión del Estado, pero la experiencia muestra que es difícil su puesta en práctica. En este trabajo se examinó el conjunto de actuaciones realizado por las administraciones en relación a un problema de salud laboral y de salud pública planteado en marzo de 2016. La Dirección General de Salud Pública del Gobierno de Aragón tuvo conocimiento de la posible utilización por una empresa de Zaragoza de zapatas de freno con amianto para fabricar ejes de maquinaria agrícola. Se recabó la colaboración del Instituto Aragonés de Seguridad y Salud Laboral (ISSLA), del Departamento de Industria y de la Inspección de Trabajo y Seguridad Social, dichas administraciones detectaron la utilización de varios modelos de zapatas con un contenido de crisotilo del 2-5%. Las zapatas procedían de una empresa china. Los ejes eran comercializados en varias Comunidades Autónomas. Se activó una alerta nacional a través del SIRIPQ (Sistema de Intercambio Rápido de Información de Productos Químicos) coordinado por el Ministerio de Sanidad, Servicios Sociales e Igualdad. Se tomaron medidas tales como el cese del trabajo con las zapatas, la sustitución de las ya instaladas mediante la aplicación de un Plan Único de Trabajo, la inmovilización de las zapatas presentes en la empresa, etc. Este caso muestra que la cooperación y la corresponsabilidad de administraciones públicas de diferentes ámbitos territoriales, sectoriales y competenciales permite mejorar la prevención de riesgos laborales.

La coordinación administrativa en salud laboral a propósito de un caso: zapatas de freno con amianto en una empresa / Occupational health administrative coordination a propos of a case: brake linings with asbestos in a company

La actual estructura del Estado de las Autonomías se caracteriza por el pluralismo institucional y la autonomía de las diferentes administraciones públicas. En este contexto el principio de coordinación es fundamental para la cohesión del Estado, pero la experiencia muestra que es difícil su puesta en práctica. En este trabajo se examinó el conjunto de actuaciones realizado por las administraciones en relación a un problema de salud laboral y de salud pública planteado en marzo de 2016. La Dirección General de Salud Pública del Gobierno de Aragón tuvo conocimiento de la posible utilización por una empresa de Zaragoza de zapatas de freno con amianto para fabricar ejes de maquinaria agrícola. Se recabó la colaboración del Instituto Aragonés de Seguridad y Salud Laboral (ISSLA), del Departamento de Industria y de la Inspección de Trabajo y Seguridad Social, dichas administraciones detectaron la utilización de varios modelos de zapatas con un contenido de crisotilo del 2-5%. Las zapatas procedían de una empresa china. Los ejes eran comercializados en varias Comunidades Autónomas. Se activó una alerta nacional a través del SIRIPQ (Sistema de Intercambio Rápido de Información de Productos Químicos) coordinado por el Ministerio de Sanidad, Servicios Sociales e Igualdad. Se tomaron medidas tales como el cese del trabajo con las zapatas, la sustitución de las ya instaladas mediante la aplicación de un Plan Único de Trabajo, la inmovilización de las zapatas presentes en la empresa, etc. Este caso muestra que la cooperación y la corresponsabilidad de administraciones públicas de diferentes ámbitos territoriales, sectoriales y competenciales permite mejorar la prevención de riesgos laborales

The current structure of the Spanish State of Autonomies is characterized by institutional pluralism and the autonomy of the different public administrations. In this context, the principle of coordination is fundamental for the cohesion of the system, but experience shows that its implementation is difficult. This paper examines the set of actions carried out by the administrations in relation to an occupational and public health problem raised in March 2016. The Public Health General Direction of Aragon’s Government was informed of a possible use of brake linings with asbestos to manufacture axles for agricultural machinery by a Company from Zaragoza; the ollaboration from Aragon’s Institute of Occupational Safety and Health, the Industry Department and the Labour and Social Security Inspectorate were asked; the joint action of these administrations detected the use of several models of brake linings with a content of 2-5% of Chrysotile. The brake linings came from a Chinese company. The axles nated are sold in several Spanish Autonomous Communities. A national alert was activated by the SIRIPQ (System of Rapid Exchange of Information on Chemical Products) which is coordinated by the Ministry of Health, Social Services and Equality. Several measures were taken including: ceasing the work with the brake linings, the replacement of brake linings with asbestos, the immobilization of brake linings in the company by application of the REACH Reglament, etc. This case shows that the cooperation and coresponsibility of public administrations from different territorial, sectoral and competence areas allows improving the occupational risks prevention and the public health

Recent advances in microencapsulation of natural sources of antimicrobial compounds used in food - A review.

Food safety and microbiological quality are major priorities in the food industry. In recent years, there has been an increasing interest in the use of natural antimicrobials in food products. An ongoing challenge with natural antimicrobials is their degradation during food storage and/or processing, which reduces their antimicrobial activity. This creates the necessity for treatments that maintain their stability and/or activity when applied to food. Microencapsulation of natural antimicrobial compounds is a promising alternative once this technique consists of producing microparticles, which protect the encapsulated active substances. In other words, the material to be protected is embedded inside another material or system known as wall material. There are few reports in the literature about microencapsulation of antimicrobial compounds. These published articles report evidence of increased antimicrobial stability and activity when the antimicrobials are microencapsulated when compared to unprotected ones during storage. This review focuses mainly on natural sources of antimicrobial compounds and the methodological approach for encapsulating these natural compounds. Current data on the microencapsulation of antimicrobial compounds and their incorporation into food suggests that 1) encapsulation increases compound stability during storage and 2) encapsulation of antimicrobial compounds reduces their interaction with food components, preventing their inactivation.