Excess secondary sludge reuse by H2O2 thermal dehydration.

The excess of activated sludge generated in municipal wastewater treatment plants constitutes one of the challenging problems facing modern society. The high-water content of this waste makes difficult the transport, disposal, and management of these solids. In this work, activated sludge excess from a secondary clarifier has been dehydrated by means of a combination of temperature and hydrogen peroxide treatment. Three main operating variables have been considered to affect sludge dewaterability and filterability. Temperature (120-180 °C), hydrogen peroxide dose (0.01-0.03 M), and treatment time (20-60 min) influence have been assessed by completing a 15-run Box Behnken experimental design. Different output variables (water content, resistance to filtration, sedimentation volumetric index, extracellular polymeric substances, etc.) have been monitored. Generally, temperature seems to be the most influencing parameter to obtain a dehydrated sludge with acceptable management/disposal characteristics (sludge volume reduction and filterability). In line with the concept of circular economy, an attempt has been conducted to obtain a sustainable biosorbent from the dehydrated sludge generated in the previous stage. Optimum conditions of carbonization and activation revealed that the solid obtained at 400 °C by using ammonium nitrate as activation agent was the most efficient absorbent to eliminate some model compounds from water (namely, phenol, ofloxacin, and diuron); however, a clear improvement margin in the synthesis is foreseen.

Sulphur retention and in-situ preparation of metal sulphide catalysts during activation of petroleum coke.

Petroleum coke (petcoke) containing sulphur has limited direct applications, but stockpiling the material creates an environmental issue. Although chemical activation can be used to valorise the petcoke to activated carbon, sulphur is released creating alternative environmental problems. In this study, a new activation method for high sulphur content (∼6.5 wt%) petcoke was developed to retain sulphur and prepare transition metal sulphide catalysts simultaneously. Petcoke was mixed with tungsten and nickel precursors and then activated by KOH at 600 °C in the presence of steam. After washing, the activated petcoke had a sulphur content of 5.1 wt%, which was much higher than that in the absence of steam during activation (0.4 wt%). Sulphur was also retained (>4 wt% of sulphur) when other transition metals including molybdenum and cobalt were used. Characterization by XRD, XPS, and SEM-EDS suggested that sulphur was retained on the activated petcoke in the form of metal sulphides. Further thermodynamic analysis of the system revealed that in the presence of steam an H2S/H2 mixture was generated, and this mixture promoted the formation of the metal sulphide species when metal precursors were introduced. The prepared metal sulphide catalysts were active for several reactions including the photoreduction of CO2. Overall, this study provided an effective method to prepare metal sulphide catalysts from sulphur containing carbonaceous waste.

Hematologic parameters and biomarkers predictors of severity in Multisystem Inflammatory Syndrome in children associated with SARS-CoV-2. / Parámetros hematológicos y biomarcadores predictores de gravedad en Síndrome Inflamatorio Pediátrico Multisistémico asociado a SARS-CoV-2.

INTRODUCTION: The multisystem inflammatory syndrome in children associated with SARS-CoV-2 (MIS-C) is cha racterized by a hyperinflammatory state resulting from a cytokine storm, evidenced by alterations in laboratory blood testing and acute-phase proteins. OBJECTIVE: to describe the clinical and labora tory characteristics of patients hospitalized due to MIS-C and identify predictive markers of severity. PATIENTS AND METHOD: Retrospective study of 32 patients. The group was divided into critical and non-critical according to clinical presentation and therapy used. Clinical and laboratory aspects were studied, including complete blood count, coagulation tests, and biomarkers. RESULTS: 18/32 were males, with a median age of 6.8 years. The most frequent manifestations were cardiovascular (84.3%), digestive (84%), and mucocutaneous (59%). The group of critical patients included 15 patients, 12 were males with a median age of 8.9 years, and the non-critical group included 17 patients, 6 were males with a median age of 5.4 years. The laboratory parameters at the admission in the global group showed increased C-reactive protein, D-dimer, leukocytes, neutrophils, ferritin, and fibrinogen. In contrast, albumin and blood sodium levels were decreased. At admission, the critical group was cha racterized by presenting thrombocytopenia, hypoalbuminemia, prolonged prothrombin time, and elevated ferritin. At the time of deterioration, there was an intensification of thrombocytopenia, in creased C-reactive protein together with increased neutrophils level. CONCLUSION: The blood count, C-reactive protein, and albuminemia at admission proved to be significantly important in the identi fication of patients at risk of clinical deterioration.

Estrategias para minimizar el riesgo de infección posterior a una reconstrucción de ligamento cruzado anterior / Strategies for reduce the infection rate after ACL reconstruction

La artritis séptica es una complicación poco común después de una reconstrucción del ligamento cruzado anterior (LCA), por lo que las estrategias de prevención no han sido estudiadas extensamente. Esta revisión se enfocará en la recopilación de diferentes estrategias publicadas para la prevención de infección del LCA postoperatoria. Hay estudios que muestran aumento del riesgo de infección en consumidores de tabaco. El uso de antibióticos intravenosos preoperatorios profilácticos debería ser parte del manejo habitual de todos los pacientes que se sometan a una artroscopía de rodilla. No existe evidencia de los beneficios del uso de drenajes intraarticulares, por lo que deben evitarse. La literatura sugiere que el autoinjerto del tendón patelar tiene menor riesgo de infección que los otros injertos, por lo tanto, se recomienda su uso si se quiere minimizar la tasa de infección después una reconstrucción del LCA. La implementación de un protocolo clínico mejora significativamente la calidad del cuidado de los pacientes que se someten a una reconstrucción del LCA, disminuyendo las tasas de infección. La irrigación de gentamicina en solución podría tener un efecto protector para el desarrollo de artritis séptica después de la reconstrucción artroscópica del LCA, pero se necesitan más estudios para confirmar su efectividad. La inmersión previa de los injertos con vancomicina ha demostrado reducir drásticamente la tasa de infección después de una reconstrucción del LCA y especialmente cuando se realiza una reconstrucción del LCA con autoinjerto de tendones de los isquiotibiales

As septic arthritis after anterior cruciate ligament (ACL) reconstruction is an uncommon complication, information on prevention strategies has not been extensively studied before. This review will focus on collecting different published strategies for prevention of post-operative ACL infection. Regarding tobacco use, there is evidence that it increases the risk of infection; therefore, its use should be strongly discouraged. Preoperative intravenous antibiotics should be the standard of care of any patient undergoing an arthroscopic procedure in the knee. Intra-articular drains have no positive evidence for its use and therefore should be avoided. The literature suggests that patellar tendon autograft has the lowest risk of infection of any graft, recommending its use if the infection rate after ACL reconstruction wants to be minimized. Implementing a clinical pathway significantly improves the quality and consistency of care for patients undergoing ACL reconstruction and decreases the infection rates. Gentamicin irrigation solution may have a protective effect against septic arthritis development following arthroscopic ACL reconstruction, but more studies are needed to confirm its usefulness. Vancomycin presoaking of the grafts has shown to dramatically reduce the infection rate after ACL reconstruction and its use is strongly recommended especially when performing hamstrings autograft ACL reconstruction

Compromiso cardiovascular en pacientes con síndrome inflamatorio pediátrico multisistémico, asociado a infección por SARS-CoV-2 / Cardiovascular involvement in pediatric patients with SARS-CoV-2 associated to multisystemic inflammatory syndrome

INTRODUCCION: El Síndrome Inflamatorio Pediátrico Multisistémico (PIMS) ha emergido como una nueva enfermedad en niños, secundaria a infección por SARSCoV-2. Se caracteriza por presentar compromiso multiorgánico con parámetros inflamatorios elevados y manifestaciones clínicas graves, siendo el corazón el órgano más severamente comprometido. OBJETIVO: Describir las características clínicas y de laboratorio de 23 pacientes con diagnóstico de PIMS con compromiso cardiovascular hospitalizados en un centro único. MÉTODO: Se efectuó un estudio retrospectivo analizando los hallazgos clínicos y de laboratorio junto a las manifestaciones cardiovasculares que presentaron estos pacientes. RESULTADOS: 23/29 pacientes con PIMS (78%) presentaron manifestaciones digestivas y mucocutáneas. Las manifestaciones cardiovasculares fueron: Síndrome Kawasaki y "Kawasaki like" sin compromiso coronario en 15/23 (65%) y con compromiso coronario en 3 (13%). Shock en 9 pacientes (39%), injuria miocárdica- miocarditis en 8 (35%) y derrame pericárdico en 13 (56%). Trastornos del ritmo cardíaco se observaron en 6 pacientes (26%). La terapia más utilizada fue inmunoglobulina y corticoides. 18 /23 requirieron manejo en unidades de intermedio y/o intensivo. Un 70% de los pacientes se recuperó del compromiso cardiovascular antes del alta. CONCLUSIÓN: El compromiso cardiovascular en PIMS es la complicación más frecuente de esta enfermedad, que se acompaña de manifestaciones inmunológicas y hematológicas graves lo que hace necesario un tratamiento multidisciplinario para un mejor manejo de estos pacientes.

INTRODUCTION: Pediatric Multisystemic Inflammatory Syndrome (PIMS) has emerged as a new disease in children, secondary to SARSCoV-2 infection. It is characterized by multi-organ involvement with elevated inflammatory parameters and severe clinical manifestations, the heart being the organ most severely involved. OBJETIVE: to describe the clinical and laboratory characteristics of 23 patients diagnosed with PIMS with cardiovascular involvement hospitalized in a single center. METHOD: We conducted a retrospective study in which we analyzed the clinical and laboratory findings along with the cardiovascular manifestations presented by these patients. Results: 23/29 patients with PIMS and cardiovascular involvement were selected, 78% had digestive and mucocutaneous manifestations. Cardiovascular manifestations consisted of KawasakiKawasaki like syndrome without coronary involvement in 15/23 (65%) and coronary involvement in 3 (13%). Nine patients developed shock (39%), 8 (35%) myocardial injury in and 13 (56%) pericardial effusion.. Heart rhythm disorders were observed in 6 patients (26%). The main therapy was immunoglobulin and corticosteroids. 18 /23 required management in intermediate and/or intensive care unit. 70% of patients recovered from cardiovascular involvement before discharge. CONCLUSION: Cardiovascular involvement in PIMS is the most frequent complication of this disease, but it is associated with severe immunological and hematological manifestations, which makes necessary a multidisciplinary treatment for a better management

Hydrogen Production through Glycerol Photoreforming on TiO2/Mesoporous Carbon: Influence of the Synthetic Method.

This article explores the effect of the synthetic method of titanium dioxide (TiO2)/C composites (physical mixture and the water-assisted/unassisted sol-gel method) on their photocatalytic activity for hydrogen production through glycerol photoreforming. The article demonstrates that, apart from a high surface area of carbon and the previous activation of its surface to favor titania incorporation, the appropriate control of titania formation is crucial. In this sense, even though the amount of incorporated titania was limited by the saturation of carbon surface groups (in our case, ca. 10 wt.% TiO2), the sol-gel process without water addition seemed to be the best method, ensuring the formation of small homogeneously-distributed anatase crystals on mesoporous carbon. In this way, a ca. 110-fold increase in catalyst activity compared to Evonik P25 (expressed as hydrogen micromole per grams of titania) was achieved.

Influence of Boron, Tungsten and Molybdenum Modifiers on Zirconia Based Pt Catalyst for Glycerol Valorization.

The influence of boron, tungsten and molybdenum modifiers on zirconia-based Pt catalyst was studied for glycerol valorization. Zirconia modified supports were prepared by impregnation of ZrO2 with either boric, silicontungstic or phosphomolybdic acids to obtain supports with enhanced Brönsted acidic properties. The modified supports were subsequently impregnated with chloroplatinic acid to obtain Pt-based catalysts. Pt incorporation resulted in the increase in Lewis acidity of the solids, being more significant for the Pt//W/ZrO2 catalyst. Reduced Pt catalysts were tested for the liquid-phase glycerol hydrogenolysis, observing a synergistic effect between catalyst acid sites and metal function that proved to be crucial in glycerol hydrogenolysis. The Pt//W/ZrO2 catalyst was the most active catalyst in this reaction, being the only leading to 1,3-PDO (45% sel., 160 °C) while Pt//Mo/ZrO2 is the best option for 1,2-PDO (49% sel., 180 °C). Reusability studies carried out for Pt//W/ZrO2 showed that catalytic activity dropped after the first use, remaining constant for the second and subsequent ones. Selectivity to reaction products also changes during reuses. Therefore, the selectivity to 1,2 PDO increases in the first reuse in detriment to the selectivity to n-propanol whereas the selectivity to 1,3-PDO remains constant along the uses. This behavior could be associated to the lixiviation of W species and/or catalyst fouling during reaction runs.

Anticonvulsant effect of ethanolic extract of Cyperus articulatus L. leaves on pentylenetetrazol induced seizure in mice.

Cyperus articulatus (CA) rhizomes have demonstrated different properties on nervous system. However, the leaves still have not studied to treat epilepsy. The aim of this study was to determine the effect of CA ethanolic extract on pentylenetetrazol (PTZ) induced seizures in mice as well as measuring its antioxidant activity in vivo and in vitro. Mice were divided into five groups: (1) control (PTZ 80 mg/kg; i.p.), (2) PTZ-Diazepam (1 mg/kg; i.p.), (3-5) PTZ-CA 50, PTZ-CA 150 and PTZ-CA 300 (50, 150 and 300 mg/kg of CA extract, 30 min prior to each PTZ injection). The PTZ-CA 150 group showed lower seizure scores (P < 0.01), latency (P < 0.01), frequency (P < 0.01) and duration (P < 0.01) than control group. The antioxidant activity of CA extract scavenged DPPH radical showed IC 50 = 16.9 ± 0.1 µg/mL and TEAC = 2.28 ± 0.08, mmol trolox/g of extract, the content of gamma amino butyric acid (GABA) and malondialdehyde (MDA) were significantly high (P < 0.01) at dose of 150 mg/kg (82 ± 1.2 ng/g tissue; 1.0 ± 2.2 mol/g tissue, respectively). The present research demonstrated that CA extract possesses a potential effect to prevent PTZ induced seizures, antioxidant activity in addition to increase GABA levels.

Microemulsion and Sol-Gel Synthesized ZrO2-MgO Catalysts for the Liquid-Phase Dehydration of Xylose to Furfural.

Two series of catalysts were prepared by sol-gel and microemulsion synthetic procedure (SG and ME, respectively). Each series includes both pure Mg and Zr solids as well as Mg-Zr mixed solids with 25%, 50% and 75% nominal Zr content. The whole set of catalysts was characterized from thermal, structural and surface chemical points of view and subsequently applied to the liquid-phase xylose dehydration to furfural. Reactions were carried out in either a high-pressure autoclave or in an atmospheric pressure multi-reactor under a biphasic (organic/water) reaction mixture. Butan-2-ol and toluene were essayed as organic solvents. Catalysts prepared by microemulsion retained part of the surfactant used in the synthetic procedure, mainly associated with the Zr part of the solid. The MgZr-SG solid presented the highest surface acidity while the Mg3Zr-SG one exhibited the highest surface basicity among mixed systems. Xylose dehydration in the high-pressure system and with toluene/water solvent mixture led to the highest furfural yield. Moreover, the yield of furfural increases with the Zr content of the catalyst. Therefore, the catalysts constituted of pure ZrO2 (especially Zr-SG) are the most suitable to carry out the process under study although MgZr mixed solids could be also suitable for overall processes with additional reaction steps.

Principales causas de abandono del tratamiento contra la tuberculosis pulmonar / Main causes for abandoning treatment in pulmonary tuberculosis

Se estudiaron 100 pacientes con tuberculosis pulmonar en el medio rural y 74 en el medio urbano, con el objetivo de estudiar las principales causas de abandono del tratamiento. La incidencia del abandono global fue del 42 por ciento (73/174): los factores con mayor fuerza de asociación para abandono, independientemente de la asociación con otros factores, fueron el vivir en un medio rural (RM=10.4; p < 0.001), el no tener escolaridad alguna (analfabeta) (RM=4.5; p < 0.001) y el tomar más de una hora en trasladarse a la unidad de atención médica (RM=2.5; p=0.07). No se encontró asociación con las variables socioeconómicas interrogadas, ni con el conocimiento de la enfermedad por el paciente. Identificar los factores que condicionan el abandono del tratamiento contra la tuberculosis es de primordial importancia, sobre todo si se considera que la mayoría de los abandonos ocurren en los primeros días del tramiento, donde estrategias como el tratamiento acortado de menor número de dosis tienen poca influencia. El mejorar el control del tratamiento seguramente contribuirá a lograr el control deseado de esta enfermedad