Suppression of photoreactivation of E. coli by excimer far-UV light (222 nm) via damage to multiple targets.

Low-pressure mercury lamps emitting at 254 nm (UV254) are used widely for disinfection. However, subsequent exposure to visible light results in photoreactivation of treated bacteria. This study employed a krypton chloride excimer lamp emitting at 222 nm (UV222) to inactivate E. coli. UV222 and UV254 treatment had similar E. coli-inactivation kinetics. Upon subsequent irradiation with visible light, E. coli inactivated by UV254 was reactivated from 2.71-log to 4.75-log, whereas E. coli inactivated by UV222 showed negligible photoreactivation. UV222 treatment irreversibly broke DNA strands in the bacterium, whereas UV254 treatment primarily formed nucleobase dimers. Additionally, UV222 treatment caused cell membrane damage, resulting in wizened, pitted cells and permeability changes. The damage to the cell membrane was mainly due to the photolysis of proteins and lipids by UV222. Furthermore, the photolysis of proteins by UV222 destroyed enzymes, which blocked photoreactivation and dark repair. The multiple damages can be further evidenced by 4.0-61.1 times higher quantum yield in the photolysis of nucleobases and amino acids for UV222 than UV254. This study demonstrates that UV222 treatment damages multiple sites in bacteria, leading to their inactivation. Employing UV222 treatment as an alternative to UV254 could be viable for inhibiting microorganism photoreactivation in water and wastewater.

A Neural Network Approach to Estimate the Frequency of a Cantilever Beam with Random Multiple Damages.

Natural frequency is an important parameter in the structural health monitoring (SHM) system. Any changes in this parameter indicate structural alteration due to damage. This study provides a neural network (NN) solution as an alternative to the finite element (FE) method to measure the natural frequencies of a cantilever beam with random multiple damage. It is based on a statistical dataset of a free vibration test obtained from the APDL (Ansys parametric design language) simulation using a MATLAB (matrix laboratory) script. The script can generate an unlimited number of possible damage combinations for any given parameters with the help of the Monte Carlo (MC) technique. MC helps to generate a random number of damages in random locations at each simulation. Damage conditions are controlled by three parameters including damage severity and damage size (in terms of the mean and standard deviation of damage). Moreover, the method proposes a curve-fitting equation to validate the predicted natural frequency for the first three modes obtained from the neural network model. Both methods are in good agreement with each other, having minimal errors in the range of 0.2-3% for each mode. The frequency result shows that the beam frequency is 8.6486 Hz if the area reduction is 10%, whereas it comes down to 7.2338 Hz if there is a 30% area reduction. A two-level factorial test shows that damage severity is the most impactful factor compared to the damage sizes on the frequency shift event. This indicates that damage alters the composition of the beam and has an impact on its frequency change with the assumed damage parameters. Therefore, the proposed NN model can estimate the frequency shift for various damage scenarios. It can be utilized in the vibration-based damage identification process to predict the frequency changes of the damaged beam without any computational burden.

Dianas de la respuesta inflamatoria sistémica desde nuevas perspectivas / Targets of the systemic inflammatory response from new perspectives

Introducción: Existen enfermedades que tienen en su sustento, la respuesta inflamatoria,¿es posible identificar la diana que enmarca el efecto deletéreo de la respuesta inflamatoria? Objetivo: Analizar las expresiones de la respuesta inflamatoria sistémica y sus consecuencias en la morbilidad y mortalidad. Métodos: Se realizó una búsqueda, fundamentalmente en SciELO, con las palabras clave: respuesta inflamatoria sistémica, daño múltiple de órganos, respuesta inflamatoria y sus combinaciones; en idioma español. Se presenta una revisión narrativa a partir del análisis de los documentos obtenidos. Desarrollo: Los mecanismos defensivos de manera no controlada, producen autoagresión del endotelio vascular. La respuesta se acompaña de fallo inmunológico sistémico y disreactividad en la respuesta inflamatoria. La lesión del endotelio vascular, el incremento del consumo de oxígeno, citocinas elevadas en la circulación, activación de la cascada de coagulación y mediadores vasoactivos tienen influencia en esta respuesta. La isquemia intestinal, secundaria al síndrome compartimental abdominal, es causante directa de la translocación bacteriana. La inflamación persistente, asociada a un intenso proceso catabólico conduce a la caquexia y la inmunosupresión. Conclusión: Son múltiples las dianas que se activan en la respuesta inflamatoria sistémica, que explican su disbalance: la disfunción del endotelio vascular y la microcirculación, la disfunción mitocondrial y el estrés oxidativo, la citoprotección celular. Puede haber un punto de convergencia en la necesidad del diagnóstico temprano de esta respuesta disreactiva y en su intento de modulación oportuna(AU)

Introduction: There are diseases that have in their basics, the inflammatory response, is it possible to identify the target that frames the deleterious effect of the inflammatory response? Objective: To analyze the manifestations of the systemic inflammatory response and its consequences in morbidity and mortality. Methods: A search was performed, mainly in SciElo, with the key words: systemic inflammatory response, multiple organ damage, inflammatory response and their combinations; in Spanish language. A narrative review is presented based on the analysis of the documents obtained. Body: The defensive mechanisms in an uncontrolled way, produce self-aggression of the vascular endothelium. The response is accompanied by systemic immune failure and reactivity problems in the inflammatory response. Vascular endothelial injury, increased oxygen consumption, elevated cytokines in the circulation, activation of the coagulation cascade and vasoactive mediators have an influence on this response. Intestinal ischemia, secondary to abdominal compartment syndrome, is a direct cause of bacterial translocation. Persistent inflammation, associated with an intense catabolic process, leads to cachexia and immunosuppression. Conclusion: There are multiple targets that are activated in the systemic inflammatory response, which explain their imbalance: vascular endothelial dysfunction and microcirculation, mitochondrial dysfunction and oxidative stress, cell cytoprotection. There may be a point of convergence in the need for early diagnosis of this dis-reactive response and in its attempt at timely modulation(AU)

Anisotropic constitutive model incorporating multiple damage mechanisms for multiscale simulation of dental enamel.

An anisotropic constitutive model is proposed in the framework of finite deformation to capture several damage mechanisms occurring in the microstructure of dental enamel, a hierarchical bio-composite. It provides the basis for a homogenization approach for an efficient multiscale (in this case: multiple hierarchy levels) investigation of the deformation and damage behavior. The influence of tension-compression asymmetry and fiber-matrix interaction on the nonlinear deformation behavior of dental enamel is studied by 3D micromechanical simulations under different loading conditions and fiber lengths. The complex deformation behavior and the characteristics and interaction of three damage mechanisms in the damage process of enamel are well captured. The proposed constitutive model incorporating anisotropic damage is applied to the first hierarchical level of dental enamel and validated by experimental results. The effect of the fiber orientation on the damage behavior and compressive strength is studied by comparing micro-pillar experiments of dental enamel at the first hierarchical level in multiple directions of fiber orientation. A very good agreement between computational and experimental results is found for the damage evolution process of dental enamel.

Morfología de las autopsias con traumatismos / Morphology of the autopsies with traumata

Introducción: el traumatismo constituye un problema de salud. En el Hospital Militar Central (HMC) "Dr. Luis Díaz Soto" se estudia la expresión morfológica del traumatismo, el daño múltiple de órganos (DMO). Objetivos: caracterizar la morfología del traumatismo en las autopsias realizadas en el HMC en el periodo de 49 años. Métodos: se revisó la Base de Datos de autopsias entre 1962-2010. Se estudiaron 624 casos con trauma y se analizaron dos periodos: con actividad médico legal (1962-1995) y con poca o sin actividad legal (1996-2010). Se compararon las variables: sexo, grupos de edad, especialidad de egreso, sepsis, cáncer, DMO y causas de muerte. Se realizó el análisis porcentual y de tendencia. Resultados: en el primer periodo se estudiaron 493 autopsias, mujeres con media de 53 años y hombres con media de 39 años, con una relación M/F de 1,52. Las especialidades de egreso más frecuentes fueron: quemado, cuerpo de guardia y terapia, y las principales causas: quemaduras y politraumatismo. En el segundo periodo se estudiaron 131 autopsias, mujeres con media de 80 años y hombres con media de 74 años, con relación M/F de 0,54. Las especialidades de egreso fueron: cuidados intermedios y medicina, y las causas: fracturas de caderas y aterosclerosis. La sepsis y el cáncer estuvieron más elevados en este. El DMO estuvo alto en ambos periodos. Conclusiones: las autopsias estudiadas expresan alteraciones morfológicas distintivas como el DMO, con similitud en ambos periodos por la elevada presencia de este, lo cual permite realizar estudios paralelos con los traumatismos

Introduction: the trauma is a health problem. At the "Dr. Luis Díaz Soto" Central Military Hospital (CMH) authors study the morphologic expression of trauma, organ multiple damage (OMD). Objective: to characterize the trauma morphology in the necropsies performed in the CMH over 49 years. Methods: the database of necropsies between 1962-2010 was reviewed. Two hundred twenty four cases presenting with trauma were studied and two periods were analyzed: with legal medical activity (1962-1995) and with a few legal activity (1996-2010). The following variables were compared: sex, age group, discharge specialty, sepsis, cancer, OMD and causes of death. A percentage and of trend analysis was carried out. Results: during the first period 493 necropsies, women mean aged 53 and men mean aged 39, with a relation M:W of 1.52. The more frequent discharge specialties were; Burn service, emergency room and therapy and the major causes were: burns and multiple trauma. During the second period 131 necropsies were studies, women mean aged 80 and men mean aged 74, with a relation M:W of 0.54. The discharge specialties were: intermediate cares and medicine and the causes were: hip fractures and atherosclerosis. Sepsis and cancer were highest in this group. The OMD was high during both periods. Conclusions: the study necropsies express particular morphologic alterations like OMD, with similarity in both periods due to the high presence of this phenomenon; allowing parallel studies with traumata

Preguntas y respuestas sobre el Daño Múltiple de Órganos: Reflexiones acerca de la temática / Questions and answers on the organ multiple damage: Reflections about this subject matter

El daño múltiple de órganos es la expresión morfológica de la respuesta inflamatoria sistémica, que se desencadena por diversos factores causales, y que clínicamente se expresa con el síndrome de disfunción múltiple de órganos. El daño múltiple de órganos se puede diagnosticar tras el estudio detallado de la autopsia. Aunque ambos términos están bien caracterizados clínica y morfológicamente, se mantienen confusiones en el empleo de ambas denominaciones y en otros aspectos relacionados con el tema, que involucran a patólogos, intensivistas, internistas, cirujanos y otros especialistas, por lo que el propósito del presente trabajo consistió en esclarecer aspectos controversiales en relación con el daño múltiple de órganos a través de preguntas y respuestas y brindar las posibilidad de reflexionar al respecto. Se debatieron diferentes aspectos del tema, esclareciendo las bases que sustentan el diagnóstico del daño múltiple de órganos, el cual requiere la realización de una autopsia con máxima calidad, desde el estudio macroscópico hasta el microscópico, la recolección de todas las alteraciones morfológicas encontradas y su valoración en cada paciente estudiado, integrándolos y cuantificando los cambios encontrados para calcular el sistema de puntuación y finalmente valorar el lugar que ocupa este en el cronopatograma del fallecido(AU)

The organ multiple damage is the morphological expression of systemic inflammatory response triggered by many causal factors and the clinically it is expressed with the multiple organ dysfunction syndrome, which could be diagnosed after a detailed necropsy study. Although both terms are well clinically and morphologically characterized there are confusions related to the use of both naming and in other features related to this subject, in which are involved pathologists, intensive care professionals, surgeons and other specialists. The aim of present paper was to clarify the controversial features related to organ multiple damage using questions and answers and to reflect in this respect. Different features on thus subject were discussed clearing up the basis supporting the organ multiple damage diagnosis being necessary a necropsy with high quality, from a macroscopic study up to a microscopic one, collection of all the morphologic alterations founded and its assessment in each study patient and quantifying the changes noted to estimate the mark system and finally to value its place in the chronopathognomy of the deceased(AU)

Preguntas y respuestas sobre el Daño Múltiple de Órganos: Reflexiones acerca de la temática / Questions and answers on the organ multiple damage: Reflections about this subject matter

El daño múltiple de órganos es la expresión morfológica de la respuesta inflamatoria sistémica, que se desencadena por diversos factores causales, y que clínicamente se expresa con el síndrome de disfunción múltiple de órganos. El daño múltiple de órganos se puede diagnosticar tras el estudio detallado de la autopsia. Aunque ambos términos están bien caracterizados clínica y morfológicamente, se mantienen confusiones en el empleo de ambas denominaciones y en otros aspectos relacionados con el tema, que involucran a patólogos, intensivistas, internistas, cirujanos y otros especialistas, por lo que el propósito del presente trabajo consistió en esclarecer aspectos controversiales en relación con el daño múltiple de órganos a través de preguntas y respuestas y brindar las posibilidad de reflexionar al respecto. Se debatieron diferentes aspectos del tema, esclareciendo las bases que sustentan el diagnóstico del daño múltiple de órganos, el cual requiere la realización de una autopsia con máxima calidad, desde el estudio macroscópico hasta el microscópico, la recolección de todas las alteraciones morfológicas encontradas y su valoración en cada paciente estudiado, integrándolos y cuantificando los cambios encontrados para calcular el sistema de puntuación y finalmente valorar el lugar que ocupa este en el cronopatograma del fallecido

The organ multiple damage is the morphological expression of systemic inflammatory response triggered by many causal factors and the clinically it is expressed with the multiple organ dysfunction syndrome, which could be diagnosed after a detailed necropsy study. Although both terms are well clinically and morphologically characterized there are confusions related to the use of both naming and in other features related to this subject, in which are involved pathologists, intensive care professionals, surgeons and other specialists. The aim of present paper was to clarify the controversial features related to organ multiple damage using questions and answers and to reflect in this respect. Different features on thus subject were discussed clearing up the basis supporting the organ multiple damage diagnosis being necessary a necropsy with high quality, from a macroscopic study up to a microscopic one, collection of all the morphologic alterations founded and its assessment in each study patient and quantifying the changes noted to estimate the mark system and finally to value its place in the chronopathognomy of the deceased