299 research outputs found
Organic-Inorganic Hybrid Coatings for Corrosion Protection of Metallic Surfaces
A variety of organic-inorganic hybrids have been designed to act as anticorrosive coatings of metallic substrates. Among them, epoxy-silica and poly(methyl methacrylate) (PMMA)- silica hybrids, prepared by the sol-gel process and deposited onto steel or aluminum alloys, have demonstrated high anticorrosive efficiency combined with high thermal and mechanical resistance. Lignin, carbon nanotubes, and graphene oxide have been incorporated into PMMA-silica hybrids as reinforcement agents, and cerium (IV) as corrosion inhibitor. Both hybrids were characterized in terms of their structural and thermal characteristics using different pectroscopies, microscopies and thermogravimetric analysis. Both hybrids present homogeneous nanostructure composed of highly condensed silica nanodomains covalently bonded to the polymeric phase. The transparent coatings with a thickness of 2–7 μm have low surface roughness, high adhesion to metallic substrates, elevated thermal stability, and excellent barrier behavior. Electrochemical impedance spectroscopy showed for coated samples a high corrosion resistance of up to 50 GΩ cm2 and durability >18 months in saline solution. Further improvement of corrosion resistance, thermal and mechanical stability was achieved by incorporation of lignin, carbon nanotubes, and graphene oxide into PMMA-silica matrix, and a self-healing effect was observed after Ce(IV) addition. The results are compared and discussed with those recently reported for a variety of hybrid coatings
Congenital Chagas Disease: Recommendations for Diagnosis, Treatment and Control of Newborns, Siblings and Pregnant Women
SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Physiological responses to basic tastes for sensory evaluation of chocolate using biometric techniques
Facial expressions are in reaction to basic tastes by the response to receptor stimulation. The objective of this study was to assess the autonomic nervous system responses to basic tastes in chocolates and to identify relationships between conscious and unconscious responses from participants. Panelists (n = 45) tasted five chocolates with either salt, citric acid, sugar, or monosodium glutamate, which generated four distinctive basic tastes plus bitter, using dark chocolate. An integrated camera system, coupled with the Bio-Sensory application, was used to capture infrared thermal images, videos, and sensory responses. Outputs were used to assess skin temperature (ST), facial expressions, and heart rate (HR) as physiological responses. Sensory responses and emotions elicited during the chocolate tasting were evaluated using the application. Results showed that the most liked was sweet chocolate (9.01), while the least liked was salty chocolate (3.61). There were significant differences for overall liking (p < 0.05) but none for HR (p = 0.75) and ST (p = 0.27). Sweet chocolate was inversely associated with angry, and salty chocolate positively associated with sad. Positive emotion-terms were associated with sweet samples and liking in self-reported responses. Findings of this study may be used to assess novel tastes of chocolate in the industry based on conscious and emotional responses more objectively
Phylogenetic Analysis of Bolivian Bat Trypanosomes of the Subgenus Schizotrypanum Based on Cytochrome b Sequence and Minicircle Analyses
The aim of this study was to establish the phylogenetic relationships of trypanosomes present in blood samples of Bolivian Carollia bats. Eighteen cloned stocks were isolated from 115 bats belonging to Carollia perspicillata (Phyllostomidae) from three Amazonian areas of the Chapare Province of Bolivia and studied by xenodiagnosis using the vectors Rhodnius robustus and Triatoma infestans (Trypanosoma cruzi marenkellei) or haemoculture (Trypanosoma dionisii). The PCR DNA amplified was analyzed by nucleotide sequences of maxicircles encoding cytochrome b and by means of the molecular size of hyper variable regions of minicircles. Ten samples were classified as Trypanosoma cruzi marinkellei and 8 samples as Trypanosoma dionisii. The two species have a different molecular size profile with respect to the amplified regions of minicircles and also with respect to Trypanosoma cruzi and Trypanosoma rangeli used for comparative purpose. We conclude the presence of two species of bat trypanosomes in these samples, which can clearly be identified by the methods used in this study. The presence of these trypanosomes in Amazonian bats is discussed
β-Lactam Effects on Mixed Cultures of Common Respiratory Isolates as an Approach to Treatment Effects on Nasopharyngeal Bacterial Population Dynamics
BACKGROUND: Streptococcus pneumoniae, Streptococcus pyogenes and Haemophilus influenzae are bacteria present in the nasopharynx as part of normal flora. The ecological equilibrium in the nasopharynx can be disrupted by the presence of antibiotics. METHODOLOGY/PRINCIPAL FINDINGS: A computerized two-compartment pharmacodynamic model was used to explore beta-lactam effects on the evolution over time of a bacterial load containing common pharyngeal isolates by simulating free serum concentrations obtained with amoxicillin (AMX) 875 mg tid, amoxicillin/clavulanic acid (AMC) 875/125 mg tid and cefditoren (CDN) 400 mg bid regimens over 24 h. Strains and MICs (microg/ml) of AMX, AMC and CDN were: S. pyogenes (0.03, 0.03 and 0.015), S. pneumoniae (2, 2 and 0.25), a beta-lactamase positive H. influenzae (BL(+); >16, 2 and 0.06) and a beta-lactamase positive AMC-resistant H. influenzae (BLPACR, >16, 8 and 0.06). Mixture of identical 1:1:1:1 volumes of each bacterial suspension were prepared yielding an inocula of approximately 4 x 10(6) cfu/ml. Antibiotic concentrations were measured both in bacterial and in bacteria-free antibiotic simulations. beta-lactamase production decreased AMX concentrations and fT(>MIC) against S. pneumoniae (from 43.2% to 17.7%) or S. pyogenes (from 99.9% to 24.9%), and eradication was precluded. The presence of clavulanic acid countered this effect of co-pathogenicity, and S. pyogenes (but not BL(+) and S. pneumoniae) was eradicated. Resistance of CDN to TEM beta-lactamase avoided this co-pathogenicity effect, and CDN eradicated S. pyogenes and H. influenzae strains (fT(>MIC) >58%), and reduced in 94% S. pneumoniae counts (fT(>MIC) approximately 25%). CONCLUSIONS/SIGNIFICANCE: Co-pathogenicity seems to be gradual since clavulanic acid countered this effect for strains very susceptible to AMX as S. pyogenes but not for strains with AMX MIC values in the limit of susceptibility as S. pneumoniae. There is a potential therapeutic advantage for beta-lactamase resistant cephalosporins with high activity against streptococci
Maternal Infection with Trypanosoma cruzi and Congenital Chagas Disease Induce a Trend to a Type 1 Polarization of Infant Immune Responses to Vaccines
Vaccines are of crucial importance to prevent morbidity and mortality due to infectious diseases in childhood. A modulation of the fetal/neonatal immune system (considered immature) toward Th1 or Th2 dominance could modify responses to vaccines administered in early life. T. cruzi is the agent of Chagas' disease, in Latin America currently infecting about 2 million women at fertile ages who are susceptible to transmitting the parasite to their fetus. In previous studies we showed that T. cruzi-infected mothers can induce a pro-inflammatory environment in their uninfected neonates (M+B−), whereas congenitally infected newborns (M+B+) are able to develop a pro-Th1 parasite-specific T cell response. In the present study, we analysed the cellular and/or antibody responses to Bacillus Calmette Guerin (BCG), hepatitis B birus (HBV), diphtheria and tetanus vaccines in 6- to 7-month-old infants living in Bolivia. M+B− infants produced more IFN-γ in response to BCG, whereas M+B+ infants developed a stronger IFN-γ response to hepatitis B, diphtheria and tetanus vaccines and enhanced antibody production to HBs antigen. These results show that both maternal infection with T. cruzi and congenital Chagas disease do not interfere with responses to BCG, hepatitis B, diphtheria and tetanus vaccines in the neonatal period and that T. cruzi infection in early life tends to favour type 1 immune responses to vaccinal antigens
Relación clima y virosis en los cultivos de trigo y maíz
PosterNumerosos procesos infecciosos de las enfermedades de las plantas están influenciados por el clima, en particular con variables como la temperatura, la precipitación y el viento. Además del efecto del clima sobre los cultivos, cuando estos son susceptibles a las mismas virosis (Figura 1), algunas variables pueden actuar como fuente de inóculo desde donde se dispersan estos patógenos.Instituto de Patología VegetalFil: Gómez Montenegro, Brenda Emiliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Gómez Montenegro, Brenda Emiliana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Suarez, F. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Estadística y Biometría; ArgentinaFil: Suarez, F. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Giannini Kurina, F. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Estadística y Biometría; ArgentinaFil: Torrico Ramallo, Ada Karina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Torrico Ramallo, Ada Karina. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Gimenez, Maria De La Paz. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Gimenez, Maria De La Paz. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Giolitti, Fabian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Giolitti, Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Balzarini, Monica. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Estadística y Biometría; ArgentinaFil: Balzarini, Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Alemandri, Vanina Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Alemandri, Vanina Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); Argentin
Delamanid-containing regimens and multidrug-resistant tuberculosis: A systematic review and meta-analysis
Introduction: Multidrug-resistant tuberculosis (MDR-TB) is a life-threatening condition needing long poly-chemotherapy regimens. As no systematic reviews/meta-analysis is available to comprehensively evaluate the role of delamanid (DLM), we evaluated its effectiveness and safety. Methods: We reviewed the relevant scientific literature published up to January 20, 2022. The pooled success treatment rate with 95% confidence intervals (CI) was assessed using a random-effect model. We assessed studies for quality and bias, and considered P0.05). The overall pooled treatment success rate in DLM and bedaquiline-containing regimens was 75.2% (95% CI 68.1-81.1) with no evidence of publication bias (Begg's test; P >0.05). In experimental studies the pooled treatment success rate of DLM-containing regimens was 72.5 (95% CI 44.2-89.8, P 0.05). Conclusions: In MDR-TB patients receiving DLM, culture conversion and treatment success rates were high despite extensive resistance with limited adverse events
New chemotherapy regimens and biomarkers for Chagas disease: The rationale and design of the TESEO study, an open-label, randomised, prospective, phase-2 clinical trial in the Plurinational State of Bolivia.
Introduction Chagas disease (CD) affects ∼7 million people worldwide. Benznidazole (BZN) and nifurtimox (NFX) are the only approved drugs for CD chemotherapy. Although both drugs are highly effective in acute and paediatric infections, their efficacy in adults with chronic CD (CCD) is lower and variable. Moreover, the high incidence of adverse events (AEs) with both drugs has hampered their widespread use. Trials in CCD adults showed that quantitative PCR (qPCR) assays remain negative for 12 months after standard-of-care (SoC) BZN treatment in ∼80% patients. BZN pharmacokinetic data and the nonsynchronous nature of the proliferative mammal-dwelling parasite stage suggested that a lower BZN/NFX dosing frequency, combined with standard or extended treatment duration, might have the same or better efficacy than either drug SoC, with fewer AEs. Methods and analysis New ThErapies and Biomarkers for ChagaS infEctiOn (TESEO) is an open-label, randomised, prospective, phase-2 clinical trial, with six treatment arms (75 patients/arm, 450 patients). Primary objectives are to compare the safety and efficacy of two new proposed chemotherapy regimens of BZN and NFX in adults with CCD with the current SoC for BZN and NFX, evaluated by qPCR and biomarkers for 36 months posttreatment and correlated with CD conventional serology. Recruitment of patients was initiated on 18 December 2019 and on 20 May 2021, 450 patients (study goal) were randomised among the six treatment arms. The treatment phase was finalised on 18 August 2021. Secondary objectives include evaluation of population pharmacokinetics of both drugs in all treatment arms, the incidence of AEs, and parasite genotyping. Ethics and dissemination The TESEO study was approved by the National Institutes of Health (NIH), U.S. Food and Drug Administration (FDA), federal regulatory agency of the Plurinational State of Bolivia and the Ethics Committees of the participating institutions. The results will be disseminated via publications in peer-reviewed journals, conferences and reports to the NIH, FDA and participating institutions. Trial registration number NCT03981523.We are very grateful to Marcelo Abril, Fundación Mundo Sano, Buenos Aires, Argentina, and Dr. Sergio Sosa-Estani, DNDi, Rio de Janeiro, Brazil, for their continuous support during the elaboration and implementation of this trial; Dr. Martin Springsklee (Medical Affairs Anti-Infectives), Dr. Ulrich-Dietmar Madeja (Head, Neglected Tropical Disease Programmes), and Dr. Maria-Luisa Rodriguez (Global Project Leader) at Bayer AG, Berlin, Germany, and this company for the kind donation of the nifurtimox to be used in this study; Dr. Pedro Albajar Viñas, WHO, for the support to the study through the kind advancement of nifurtimox from the WHO stockpile; Ernesto Palma (Business Development and External Markets Manager) and Luis Ferrero (former ELEA’s Especial Business Manager), at Laboratorio ELEA Phoenix S.A., Buenos Aires, Argentina, and this company for the generous donation of the benznidazole to be used in the TESEO study. We also thank Dr. Soyoung Jeon (currently at the New Mexico State University) and Dr. Xiaogang Su, Dept. of Mathematical Sciences, Border Biomedical Research Center (BBRC), University of Texas at El Paso, for the statistical analyses performed during the TESEO project evaluation by NIH. We are very thankful to all the medical, supporting (nurses, social workers, and laboratory staff) and administrative personnel of the three Chagas Platforms in Bolivia for their technical assistance and dedication in the recruitment, treatment, and follow-up of the CCD patients in this study. We would also like to thank all the staff (postdoctoral fellows, technicians, and administrative personnel) and graduate and undergraduate students of the participating institutions involved in this clinical trial and part of the TESEO Study Group
Mechanisms of Esophago-Pharyngeal Acid Regurgitation in Human Subjects
Esophago-pharyngeal regurgitation is implicated in various otolaryngologic and respiratory disorders. The pathophysiological mechanisms causing regurgitation are still largely unknown
- …