2,052 research outputs found

    Influence of nanostructured ceria support on platinum nanoparticles for methanol electrooxidation in alkaline media

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    The catalytic activity of platinum (Pt) nanoparticles (NPs) towards methanol electrooxidation in alkaline media was demonstrated to be dependent on their interactions with their nanostructured ceria support. Ceria nanorods (NRs) with diameters of 5 to 10 nm and lengths of 15 to 50 nm as well as ceria NPs with diameters of 2 to 6 nm were applied as supports for similarly sized Pt NPs with diameters of 2 to 5 nm. Cyclic voltammetry data showed that Pt NPs supported on ceria NPs exhibited a 2-to-5-fold higher catalytic current density versus ceria NRs. X-ray photoelectron spectroscopic data indicated that Pt NPs deposited onto ceria NRs were disproportionally composed of oxidized species (Pt2+, Pt4+ and Pt–O–M) rather than Pt0 while Pt NPs on ceria NPs mainly consisted of Pt0. Stronger metal-support interactions between Pt NPs and ceria NRs are postulated to induce preferential oxidation of Pt NPs and consequently decrease the catalytic sites and overall activity

    Characterization of Mycobacterium chelonae-like strains by comparative genomics

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    Isolates of the Mycobacterium chelonae-M. abscessus complex are subdivided into four clusters (CHI to CHIV) in the INNO-LiPA (R) Mycobacterium spp DNA strip assay. A considerable phenotypic variability was observed among isolates of the CHII cluster. In this study, we examined the diversity of 26 CHII cluster isolates by phenotypic analysis, drug susceptibility testing, whole genome sequencing and single-gene analysis. Pairwise genome comparisons were performed using several approaches, including average nucleotide identity (ANI) and genome-to-genome distance (GGD) among others. Based on ANI and GGD the isolates were identified as M. chelonae (14 isolates), M. franklinii (2 isolates) and M. salmoniphium (1 isolate). The remaining 9 isolates were subdivided into three novel putative genomospecies. Phenotypic analyses including drug susceptibility testing, as well as whole genome comparison by TETRA and delta differences, were not helpful in separating the groups revealed by ANI and GGD. The analysis of standard four conserved genomic regions showed that rpoB alone and the concatenated sequences clearly distinguished the taxonomic groups delimited by whole genome analyses. In conclusion, the CHII INNO-LiPa is not a homogeneous cluster; on the contrary, it is composed of closely related different species belonging to the M. chelonae-M. abscessus complex and also several unidentified isolates. The detection of these isolates, putatively novel species, indicates a wider inner variability than the presently known in this complex

    Discovery of the first dual GSK3 beta inhibitor/Nrf2 inducer. A new multitarget therapeutic strategy for Alzheimer's disease

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    The formation of neurofibrillary tangles (NFTs), oxidative stress and neuroinflammation have emerged as key targets for the treatment of Alzheimer’s disease (AD), the most prevalent neurodegenerative disorder. These pathological hallmarks are closely related to the over-activity of the enzyme GSK3β and the downregulation of the defense pathway Nrf2-EpRE observed in AD patients. Herein, we report the synthesis and pharmacological evaluation of a new family of multitarget 2,4-dihydropyrano[2,3-c]pyrazoles as dual GSK3β inhibitors and Nrf2 inducers. These compounds are able to inhibit GSK3β and induce the Nrf2 phase II antioxidant and anti-inflammatory pathway at micromolar concentrations, showing interesting structure-activity relationships. The association of both activities has resulted in a remarkable anti-inflammatory ability with an interesting neuroprotective profile on in vitro models of neuronal death induced by oxidative stress and energy depletion and AD. Furthermore, none of the compounds exhibited in vitro neurotoxicity or hepatotoxicity and hence they had improved safety profiles compared to the known electrophilic Nrf2 inducers. In conclusion, the combination of both activities in this family of multitarget compounds confers them a notable interest for the development of lead compounds for the treatment of AD

    Асинхронный электропривод агломерационной машины

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    В выпускной работе предложено заменить морально устаревший и выработавший ресурс электропривод постоянного тока на асинхронный частотно-регулируемый электропривод. По результатам расчета требуемой мощности двигателя выбран электродвигатель фирмы SIEMENS серии 1LG4313-8AB, а также преобразователь частоты типа MICROMACTER 440. В процессе выполнения работы была определена область работы, рассчитаны параметры схемы замещения двигателя и его характеристики. Выполнена оптимизация контуров регулирования электропривода. В ходе имитационных исследований установлено, что обеспечивается требуемый диапазон регулирования 1:10, необходимая точность поддержания скорости не менее 3%, что соответствует техническому заданию.In the final work, it was proposed to replace the obsolete and exhausted resource of a DC electric drive with an asynchronous frequency-controlled electric drive. Based on the results of calculating the required engine power, a SIEMENS electric motor of the 1LG4313-8AB series and a frequency converter of the MICROMACTER 440 type were chosen. During the work, the work area was determined, the parameters of the motor replacement circuit and its characteristics were calculated. Optimization of the control circuits of the electric drive is performed. During simulations it was found that the required control range of 1:10 is provided, the necessary accuracy of maintaining the speed is not less than 3%, which corresponds to the technical specification

    Enfermedad de Hirschsprung, a propósito de un caso

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    Introduction: Hirschsprung's disease (HD) is within theclinical context one of Pediatric diseases that lowerIncidencehas, representing barely 2.7% of all of them, according todata from the American College of Pediatrics (ACP). However, its pathophysiologyand clinical behavior governed by the age of the patient are the main variablesthat complicate the diagnosis and give errors of up to 35%(ACP). The mortality of patients can amount up to 65% whenthe EH is complicated with a picture of Necrotizingenterocolitis, in a patient who has notbeen theeliminationof meconium within the first 12 hours of life must suspecteh, always takinginto account the patient's age and recallingthat preterm the same delay can be considered normal, while in the case oflarger aged patients the incidence of thedisease is lower, however the diagnostic probability should not be disregarded. Sepsis in abdominal origin andnecrotising enterocolitis are two of the major complicationsof which the physician should be prevented, even when, asreported in the present case, even patients who are opposedto the main factors of risk described in literature, such asage, can develop a HD box and a latent risk of complicationlikethe rest of patients that if shared these risk factors. Objective: To describe a case of Hirschsprung's disease. Material and methods: a descriptive, retrospective studyabout Hirschsprung's disease clinical case presenta-tion. Results: Describes a case of Hirschsprung's disease inpediatric patient with complications and resolution satisfactory quirurgica. Conclusions: The proper implementation of the clinicalmethod allows an accurate diagnosis and timely treatmentof Hirschsprung's disease.Introducción: La Enfermedad deHirschsprung (EH) es dentro del contexto clínico-quirúrgico una de las patologías pediátricas que menor incidencia posee, representando a penas el 2,7% de todas ellas según datos del Colegio Americano de Pediatría (ACP). Sin embargo, su fisiopatología y su comportamiento clínico regido por la edad del paciente son las principales variables que complican el diagnóstico y dan errores de hasta un 35% (ACP). La mortalidad de los pacientes puede ascender hasta un 65% cuando la EHse complica con un cuadro de enterocolitis necrotizante, en un paciente que no se ha conseguido la eliminación de meconio dentro de las 12 primeras horas de vida deberá sospecharse de EH, siempre tomando en cuenta la edad del pacientey recordando que en pretérminos el retraso del mismopuede considerarse normal, mientras que en el caso de pacientes más grandes de edadla incidencia de la patología es menor, sin embargo la probabilidad diagnóstica no debe de ser menospreciada. La sepsis de origen abdominal y enterocolitis necrotizante son dos de las grandes complicaciones de las cuales el médico debe estar prevenido, más aún, cuando, como se relata en el presente caso clínico, incluso pacientes que se contraponen a los principales factores de riesgo descritos por la literatura, como la edad, pueden desarrollar un cuadro de EH y tener un riesgo latente de complicación al igual que el resto de pacientes que si comparten dichos factores de riesgos. Objetivo: Describir un caso clínico de Enfermedad de Hirschsprung. Material y métodos: Se realizó un estudio descriptivo, retrospectivo, presentación de caso clínico sobre Enfermedad de Hirschsprung. Resultados: Se describe un caso de Enfermedad de Hirschsprung en paciente pediátrico con complicaciones y resolución quirpurgica satisfactoria. Conclusiones: La adecuada aplicación del método clínico permite un diagnóstico preciso y tratamiento oportuno de la Enfermedad de Hirschsprung

    Enfermedad de Hirschsprung, a propósito de un caso

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    Introduction: Hirschsprung's disease (HD) is within theclinical context one of Pediatric diseases that lowerIncidencehas, representing barely 2.7% of all of them, according todata from the American College of Pediatrics (ACP). However, its pathophysiologyand clinical behavior governed by the age of the patient are the main variablesthat complicate the diagnosis and give errors of up to 35%(ACP). The mortality of patients can amount up to 65% whenthe EH is complicated with a picture of Necrotizingenterocolitis, in a patient who has notbeen theeliminationof meconium within the first 12 hours of life must suspecteh, always takinginto account the patient's age and recallingthat preterm the same delay can be considered normal, while in the case oflarger aged patients the incidence of thedisease is lower, however the diagnostic probability should not be disregarded. Sepsis in abdominal origin andnecrotising enterocolitis are two of the major complicationsof which the physician should be prevented, even when, asreported in the present case, even patients who are opposedto the main factors of risk described in literature, such asage, can develop a HD box and a latent risk of complicationlikethe rest of patients that if shared these risk factors. Objective: To describe a case of Hirschsprung's disease. Material and methods: a descriptive, retrospective studyabout Hirschsprung's disease clinical case presenta-tion. Results: Describes a case of Hirschsprung's disease inpediatric patient with complications and resolution satisfactory quirurgica. Conclusions: The proper implementation of the clinicalmethod allows an accurate diagnosis and timely treatmentof Hirschsprung's disease.Introducción: La Enfermedad deHirschsprung (EH) es dentro del contexto clínico-quirúrgico una de las patologías pediátricas que menor incidencia posee, representando a penas el 2,7% de todas ellas según datos del Colegio Americano de Pediatría (ACP). Sin embargo, su fisiopatología y su comportamiento clínico regido por la edad del paciente son las principales variables que complican el diagnóstico y dan errores de hasta un 35% (ACP). La mortalidad de los pacientes puede ascender hasta un 65% cuando la EHse complica con un cuadro de enterocolitis necrotizante, en un paciente que no se ha conseguido la eliminación de meconio dentro de las 12 primeras horas de vida deberá sospecharse de EH, siempre tomando en cuenta la edad del pacientey recordando que en pretérminos el retraso del mismopuede considerarse normal, mientras que en el caso de pacientes más grandes de edadla incidencia de la patología es menor, sin embargo la probabilidad diagnóstica no debe de ser menospreciada. La sepsis de origen abdominal y enterocolitis necrotizante son dos de las grandes complicaciones de las cuales el médico debe estar prevenido, más aún, cuando, como se relata en el presente caso clínico, incluso pacientes que se contraponen a los principales factores de riesgo descritos por la literatura, como la edad, pueden desarrollar un cuadro de EH y tener un riesgo latente de complicación al igual que el resto de pacientes que si comparten dichos factores de riesgos. Objetivo: Describir un caso clínico de Enfermedad de Hirschsprung. Material y métodos: Se realizó un estudio descriptivo, retrospectivo, presentación de caso clínico sobre Enfermedad de Hirschsprung. Resultados: Se describe un caso de Enfermedad de Hirschsprung en paciente pediátrico con complicaciones y resolución quirpurgica satisfactoria. Conclusiones: La adecuada aplicación del método clínico permite un diagnóstico preciso y tratamiento oportuno de la Enfermedad de Hirschsprung

    Paediatric referrals in rural Tanzania: the Kilombero District Study – a case series

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    BACKGROUND: Referral is a critical part of appropriate primary care and of the Integrated Management of Childhood Illness (IMCI) strategy. We set out to study referrals from the aspect both of primary level facilities and the referral hospital in Kilombero District, southern Tanzania. Through record review and a separate prospective study we estimate referral rates, report on delays in reaching referral care and summarise the appropriateness of pediatric referral cases in terms of admission to the pediatric ward at a district hospital METHODS: A sample of patient records from primary level government health facilities throughout 1993 were summarised by age, diagnosis, whether a new case or a reattendance, and whether or not they were referred. From August 1994 to July 1995, mothers or carers of all sick children less than five years old attending the Maternal and Child Health (MCH) clinic or outpatient department (OPD) of SFDDH were interviewed using a standard questionnaire recording age, sex, diagnosis, place of residence, whether the child was admitted to the paediatric ward, and whether the child was referred. RESULTS: From record review, only 0.6% of children from primary level government facilities were referred to a higher level of care. At the referral hospital, 7.8 cases per thousand under five catchment population had been referred annually. The hospital MCH clinic and OPD were generally used by children who lived nearby: 91% (n = 7,166) of sick children and 75% (n = 607) of admissions came from within 10 km. Of 235 referred children, the majority (62%) had come from dispensaries. Almost half of the referrals (48%) took 2 or more days to arrive at the hospital. Severe malaria and anaemia were the leading diagnoses in referred children, together accounting for a total of 70% of all the referrals. Most referred children (167/235, 71%) were admitted to the hospital paediatric ward. CONCLUSIONS: The high admission rate among referrals suggests that the decision to refer is generally appropriate, but the low referral rate suggests that too few children are referred. Our findings suggest that the IMCI strategy may need to be adapted in sparsely-populated areas with limited transport, so that more children may be managed at peripheral level and fewer children need referral

    Inflammatory response in mixed viral-bacterial community-acquired pneumonia

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    BACKGROUND: The role of mixed pneumonia (virus + bacteria) in community-acquired pneumonia (CAP) has been described in recent years. However, it is not known whether the systemic inflammatory profile is different compared to monomicrobial CAP. We wanted to investigate this profile of mixed viral-bacterial infection and to compare it to monomicrobial bacterial or viral CAP. METHODS: We measured baseline serum procalcitonin (PCT), C reactive protein (CRP), and white blood cell (WBC) count in 171 patients with CAP with definite etiology admitted to a tertiary hospital: 59 (34.5%) bacterial, 66 (39.%) viral and 46 (27%) mixed (viral-bacterial). RESULTS: Serum PCT levels were higher in mixed and bacterial CAP compared to viral CAP. CRP levels were higher in mixed CAP compared to the other groups. CRP was independently associated with mixed CAP. CRP levels below 26 mg/dL were indicative of an etiology other than mixed in 83% of cases, but the positive predictive value was 45%. PCT levels over 2.10 ng/mL had a positive predictive value for bacterial-involved CAP versus viral CAP of 78%, but the negative predictive value was 48%. CONCLUSIONS: Mixed CAP has a different inflammatory pattern compared to bacterial or viral CAP. High CRP levels may be useful for clinicians to suspect mixed CAP

    NG2 antigen is involved in leukemia invasiveness and central nervous system infiltration in MLL-rearranged infant B-ALL

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    Mixed-lineage leukemia (MLL)-rearranged (MLLr) infant B-cell acute lymphoblastic leukemia (iMLLr-B-ALL) has a dismal prognosis and is associated with a pro-B/mixed phenotype, therapy refractoriness and frequent central nervous system (CNS) disease/relapse. Neuron-glial antigen 2 (NG2) is specifically expressed in MLLr leukemias and is used in leukemia immunophenotyping because of its predictive value for MLLr acute leukemias. NG2 is involved in melanoma metastasis and brain development; however, its role in MLL-mediated leukemogenesis remains elusive. Here we evaluated whether NG2 distinguishes leukemia-initiating/propagating cells (L-ICs) and/or CNS-infiltrating cells (CNS-ICs) in iMLLr-B-ALL. Clinical data from the Interfant cohort of iMLLr-B-ALL demonstrated that high NG2 expression associates with lower event-free survival, higher number of circulating blasts and more frequent CNS disease/relapse. Serial xenotransplantation of primary MLL-AF4 + leukemias indicated that NG2 is a malleable marker that does not enrich for L-IC or CNS-IC in iMLLr-B-All. However, NG2 expression was highly upregulated in blasts infiltrating extramedullar hematopoietic sites and CNS, and specific blockage of NG2 resulted in almost complete loss of engraftment. Indeed, gene expression profiling of primary blasts and primografts revealed a migratory signature of NG2 + blasts. This study provides new insights on the biology of NG2 in iMLLr-B-ALL and suggests NG2 as a potential therapeutic target to reduce the risk of CNS disease/relapse and to provide safer CNS-directed therapies for iMLLr-B-ALL

    Study protocol of a randomized controlled trial to assess safety of teleconsultation compared with face-to-face consultation: the ECASeT study

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    BackgroundThe use of remote consultation modalities has exponentially grown in the past few years, particularly since the onset of the COVID-19 pandemic. Although a huge body of the literature has described the use of phone (tele) and video consultations, very few of the studies correspond to randomized controlled trials, and none of them has assessed the safety of these consultation modalities as the primary objective. The primary objective of this trial was to assess the safety of remote consultations (both video and teleconsultation) in the follow-up of patients in the hospital setting.MethodsMulticenter, randomized controlled trial being conducted in four centers of an administrative healthcare area in Catalonia (North-East Spain). Participants will be screened from all individuals, irrespective of age and sex, who require follow-up in outpatient consultations of any of the departments involved in the study. Eligibility criteria have been established based on the local guidelines for screening patients for remote consultation. Participants will be randomly allocated into one of the two study arms: conventional face-to-face consultation (control) and remote consultation, either teleconsultation or video consultation (intervention). Routine follow-up visits will be scheduled at a frequency determined by the physician based on the diagnostic and therapy of the baseline disease (the one triggering enrollment). The primary outcome will be the number of adverse reactions and complications related to the baseline disease. Secondary outcomes will include non-scheduled visits and hospitalizations, as well as usability features of remote consultations. All data will either be recorded in an electronic clinical report form or retrieved from local electronic health records. Based on the complications and adverse reaction rates reported in the literature, we established a target sample size of 1068 participants per arm. Recruitment started in May 2022 and is expected to end in May 2024.DiscussionThe scarcity of precedents on the assessment of remote consultation modalities using randomized controlled designs challenges making design decisions, including recruitment, selection criteria, and outcome definition, which are discussed in the manuscript.Trial registrationNCT05094180. The items of the WHO checklist for trial registration are available in Additional file 1. Registered on 24 November 2021
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