Serial Mass Screening for Tuberculosis Among Incarcerated Persons in Brazil.

BACKGROUND: An active search for tuberculosis cases through mass screening is widely described as a tool to improve case detection in hyperendemic settings. However, its effectiveness in high-risk populations, such as incarcerated people, is debated. METHODS: Between 2017 and 2021, 3 rounds of mass screening were carried out in 3 Brazilian prisons. Social and health questionnaires, chest X-rays, and Xpert MTB/RIF were performed. RESULTS: More than 80% of the prison population was screened. Overall, 684 cases of pulmonary tuberculosis were diagnosed. Prevalence across screening rounds was not statistically different. Among incarcerated persons with symptoms, the overall prevalence of tuberculosis per 100 000 persons was 8497 (95% confidence interval [CI], 7346-9811), 11 115 (95% CI, 9471-13 082), and 7957 (95% CI, 6380-9882) in screening rounds 1, 2, and 3, respectively. Similar to our overall results, there were no statistical differences between screening rounds and within individual prisons. We found no statistical differences in Computer-Aided Detection for TB version 5 scores across screening rounds among people with tuberculosis-the median scores in rounds 1, 2, and 3 were 82 (interquartile range [IQR], 63-97), 77 (IQR, 60-94), and 81 (IQR, 67-92), respectively. CONCLUSIONS: In this environment with hyperendemic rates of tuberculosis, 3 rounds of mass screening did not reduce the overall tuberculosis burden. In prisons, where a substantial number of tuberculosis cases is undiagnosed annually, a range of complementary interventions and more frequent tuberculosis cases screening may be required.

Glass Fiber Reinforced Epoxy-Amine Thermosets and Solvate IL: Towards New Composite Polymer Electrolytes for Lithium Battery Applications.

To effectively use (Li) lithium metal anodes, it is becoming increasingly necessary to create membranes with high lithium conductivity, electrochemical and thermal stabilities, as well as adequate mechanical properties. Composite gel polymer electrolytes (CGPE) have emerged as a promising strategy, offering improved ionic conductivity and structural performance compared to polymer electrolytes. In this study, a simple and scalable approach was developed to fabricate a crosslinked polyethylene oxide (PEO)-based membrane, comprising two different glass fiber reinforcements, in terms of morphology and thickness. The incorporation of a solvated ionic liquid into the developed membrane enhances the ionic conductivity and reduces flammability in the resulting CGPE. Galvanostatic cycling experiments demonstrate favorable performance of the composite membrane in symmetric Li cells. Furthermore, the CGPE demonstrated electrochemical stability, enabling the cell to cycle continuously for more than 700 h at a temperature of 40 °C without short circuits. When applied in a half-cell configuration with lithium iron phosphate (LFP) cathodes, the composite membrane enabled cycling at different current densities, achieving a discharge capacity of 144 mAh·g-1. Overall, the findings obtained in this work highlight the potential of crosslinked PEO-based composite membranes for high-performance Li metal anodes, with enhanced near room temperature conductivity, electrochemical stability, and cycling capability.

Prevalence of chronic pulmonary aspergillosis regarding time of tuberculosis diagnosis in Brazil.

BACKGROUND: Data on the prevalence of chronic pulmonary aspergillosis (CPA) in patients with active or cured tuberculosis (TB) are scarce, mainly due to diagnostic difficulties. The diagnosis of CPA is based on pulmonary symptoms and chest computed tomography (CT) scans and is considered confirmed when there is microbiological or serological evidence of Aspergillus spp. OBJECTIVES: To estimate the prevalence of CPA in patients treated or undergoing treatment for PTB, seen in two referral hospitals in Mato Grosso do Sul, Brazil. PATIENTS AND METHODS: A total of 193 consecutive patients who were treated or previously treated for pulmonary tuberculosis underwent prospective evaluation: (a) clinical evaluation; (b) chest CT scan; (c) sputum examination-culture for fungi and smears for direct mycology; (d) detection of anti-Aspergillus fumigatus antibodies using an enzyme-linked immunosorbent assay Platelia® test; and (e) anti-Aspergillus spp. antibodies were assessed via a DID test. RESULTS: The global prevalence of CPA was 10.9% (95% confidence interval, 7.2%-16.1%), but it increased with the time of TB diagnosis. The variables independently associated with CPA were previous pulmonary tuberculosis over 4 years ago and haemoptysis. Cavities, pleural thickening and the presence of a fungal ball were the most frequent tomographic findings in patients with CPA. CONCLUSIONS: The high prevalence observed and its increase over time suggest the need for continuous surveillance of CPA in patients with active or previous pulmonary tuberculosis and throughout life, with clinical, tomographic and serological evaluations (ELISA) for a timely diagnosis and a better prognosis.

Local and Travel-Associated Transmission of Tuberculosis at Central Western Border of Brazil, 2014-2017.

International migrants are at heightened risk for tuberculosis (TB) disease. Intensified incarceration at international borders may compound population-wide TB risk. However, few studies have investigated the contributions of migration, local transmission, or prisons in driving incident TB at international borders. We conducted prospective population-based genomic surveillance in 3 cities along Brazil's central western border from 2014-2017. Although most isolates (89/132; 67%) fell within genomic transmission clusters, genetically unique isolates disproportionately occurred among participants with recent international travel (17/42; 40.5%), suggesting that both local transmission and migration contribute to incident TB. Isolates from 40 participants with and 76 without an incarceration history clustered together throughout a maximum-likelihood phylogeny, indicating the close interrelatedness of prison and community epidemics. Our findings highlight the need for ongoing surveillance to control continued introductions of TB and reduce the disproportionate burden of TB in prisons at Brazil's international borders.

[Antituberculosis-drug resistance in the border of Brazil with Paraguay and Bolivia]. / Resistência às drogas antituberculose na fronteira do Brasil com Paraguai e Bolívia.

OBJECTIVE: To estimate the rate of drug resistance among pulmonary tuberculosis (PTB) cases in the state of Mato Grosso do Sul, Brazil, and specifically in the border areas with Paraguay and Bolivia, as well as to identify associated risk factors. METHOD: The present cross-sectional, epidemiological study focused on PTB cases recorded between January 2007 and December 2010 in the State Reportable Disease Information System with results of susceptibility tests to rifampicin, isoniazid, ethambutol, and streptomycin. Dependent variables were development of resistance to a single drug or any combination of drugs. Independent variables were being a new or treated case, living in border areas, presence/absence of diabetes, and history of alcoholism. RESULTS: There were 789 TBP cases with susceptibility testing. The following characteristics were associated with resistance: treated case (P = 0.0001), border region (P = 0.0142), alcoholism (P = 0.0451), and diabetes (P = 0.0708). The rates of combined, primary, and acquired resistance for the state were 16.3%, 10.6%, and 39.0%, vs. 22.3%, 19.2%, and 37.5% for the border region. The rates of combined, primary, and acquired multidrug resistance for the state were 1.8%, 0.6%, and 6.3%, vs. 3.1%, 1.2%, and 12.5% for the border region. CONCLUSIONS: In the border region, the state should investigate drug resistance in all patients with respiratory symptoms, determine the pattern of resistance in confirmed cases, adopt directly observed treatment for cases of PTB, and develop health actions together with neighboring countries. Across the state, the levels of acquired resistance should be monitored, with investigation of resistance in all treated cases and implementation of directly observed treatment especially among patients with diabetes or alcoholism.

Incidence and transmission patterns of tuberculosis among indigenous populations in Brazil.

Approximately 10% of the Brazilian indigenous population lives in the state of Mato Grosso do Sul (MS), where a large number of new cases of tuberculosis (TB) are reported. This study was conducted to assess TB occurrence, transmission and the utility of TB diagnosis based on the Ogawa-Kudoh (O-K) culture method in this remote population. The incidence of TB was estimated by a retrospective review of the surveillance data maintained by the Notifiable Diseases Surveillance System for the study region. The TB transmission pattern among indigenous people was assessed by genotyping Mycobacterium tuberculosis isolates using the IS 6110 restriction fragment length polymorphism (RFLP) technique. Of the 3,093 cases identified from 1999-2001, 610 (~20%) were indigenous patients (average incidence: 377/100,000/year). The use of the O-K culture method increased the number of diagnosed cases by 34.1%. Of the genotyped isolates from 52 indigenous patients, 33 (63.5%) belonged to cluster RFLP patterns, indicating recently transmitted TB. These results demonstrate high, on-going TB transmission rates among the indigenous people of MS and indicate that new efforts are needed to disrupt these current transmissions.

Designing Versatile Polymers for Lithium-Ion Battery Applications: A Review.

Solid-state electrolytes are a promising family of materials for the next generation of high-energy rechargeable lithium batteries. Polymer electrolytes (PEs) have been widely investigated due to their main advantages, which include easy processability, high safety, good mechanical flexibility, and low weight. This review presents recent scientific advances in the design of versatile polymer-based electrolytes and composite electrolytes, underlining the current limitations and remaining challenges while highlighting their technical accomplishments. The recent advances in PEs as a promising application in structural batteries are also emphasized.

The role of prisons in disseminating tuberculosis in Brazil: A genomic epidemiology study.

Background: Globally, prisons are high-incidence settings for tuberculosis. Yet the role of prisons as reservoirs of M. tuberculosis, propagating epidemics through spillover to surrounding communities, has been difficult to measure directly. Methods: To quantify the role of prisons in driving wider community M. tuberculosis transmission, we conducted prospective genomic surveillance in Central West Brazil from 2014 to 2019. We whole genome sequenced 1152 M. tuberculosis isolates collected during active and passive surveillance inside and outside prisons and linked genomes to detailed incarceration histories. We applied multiple phylogenetic and genomic clustering approaches and inferred timed transmission trees. Findings: M. tuberculosis sequences from incarcerated and non-incarcerated people were closely related in a maximum likelihood phylogeny. The majority (70.8%; 46/65) of genomic clusters including people with no incarceration history also included individuals with a recent history of incarceration. Among cases in individuals with no incarceration history, 50.6% (162/320) were in clusters that included individuals with recent incarceration history, suggesting that transmission chains often span prisons and communities. We identified a minimum of 18 highly probable spillover events, M. tuberculosis transmission from people with a recent incarceration history to people with no prior history of incarceration, occurring in the state's four largest cities and across sampling years. We additionally found that frequent transfers of people between the state's prisons creates a highly connected prison network that likely disseminates M. tuberculosis across the state. Interpretation: We developed a framework for measuring spillover from high-incidence environments to surrounding communities by integrating genomic and spatial information. Our findings indicate that, in this setting, prisons serve not only as disease reservoirs, but also disseminate M. tuberculosis across highly connected prison networks, both amplifying and propagating M. tuberculosis risk in surrounding communities. Funding: Brazil's National Council for Scientific and Technological Development and US National Institutes of Health.

Assessment of the quality of dna extracted by two techniques from Mycobacterium tuberculosis for fast molecular identification and genotyping.

We report a comparative study of two DNA extraction techniques, thermolysis and chemical lysis (CTAB), for molecular identification and genotyping of M. tuberculosis. Forty DNA samples were subjected to PCR and the results demonstrated that with thermolysis it is possible to obtain useful data that enables fast identification and genotyping.

3D-printed cryomilled poly(ε-caprolactone)/graphene composite scaffolds for bone tissue regeneration.

In this study, composite scaffolds based on poly(caprolactone) (PCL) and non-covalently functionalized few-layer graphene (FLG) were manufactured by an extrusion-based system for the first time. For that, functionalized FLG powder was obtained through the evaporation of a functionalized FLG aqueous suspension prepared from a graphite precursor. Cryomilling was shown to be an efficient mixing method, producing a homogeneous dispersion of FLG particles onto the PCL polymeric matrix. Thereafter, fused deposition modeling (FDM) was used to print 3D scaffolds and their morphology, thermal, biodegradability, mechanical, and cytotoxicity properties were analysed. The presence of functionalized FLG demonstrated to induce slight changes in the microstructure of the scaffold, did not affect the thermal stability and enhanced significantly the compressive modulus. The composite scaffolds presented a porosity of around 40% and a mean pore size in the range of 300 µm. The cell viability and proliferation of SaOs-2 cells were assessed and the results showed good cell viability and long-term proliferation onto produced composite scaffolds. Therefore, these new FLG/PCL scaffolds comprised adequate morphological, thermal, mechanical, and biological properties to be used in bone tissue regeneration.

A Simple Method for Anchoring Silver and Copper Nanoparticles on Single Wall Carbon Nanotubes.

Single walled carbon nanotubes (SWCNT) were functionalized using the 1,3-dipolar cycloaddition reaction of an azomethine ylide under solvent-free conditions, a one-pot procedure that yields pyrrolidine type of groups at the nanotubes surface. The functionalized SWCNT were further decorated with Ag and Cu nanoparticles by reduction of the corresponding metal salts in dimethylformamide. The extensive reduction of silver from its nitrate was observed, as well as the partial reduction of copper from its acetate. X-ray photoelectron spectroscopy (XPS) confirmed the functionalization of SWCNT with pyrrolidine that provided anchoring sites for the metal nanoparticles. Metal nanoparticles (NP) were formed at the surface of the organically functionalized SWCNT in higher yields as compared to the same procedure carried out with pristine SWCNT. This was observed using scanning electron microscopy (SEM) and quantified by XPS. Raman spectroscopy demonstrated that functionalization and metal decoration of the SWCNT did not induce structural damage to the SWCNT.

Performance of diagnostic tests for pulmonary tuberculosis in indigenous populations in Brazil: the contribution of Rapid Molecular Testing.

OBJECTIVE: To evaluate the accuracy of rapid molecular testing as a diagnostic tool and estimate the incidence of smear-positive pulmonary tuberculosis among the indigenous population. METHODS: This is an epidemiological study based on secondary data. We calculated the incidence of smear-positive pulmonary tuberculosis between January 1st, 2011 and December 31, 2016, and the performance of bacilloscopy and rapid molecular testing in diagnosing pulmonary tuberculosis compared to sputum culture (standard test). RESULTS: We included 4,048 cases of indigenous people with respiratory symptoms who provided sputum samples for analysis. Among them, 3.7%, 6.7%, and 3.7% had positive results for bacilloscopy, sputum culture, and rapid molecular testing, respectively. The mean incidence of pulmonary tuberculosis was 269.3/100 thousand inhabitants. Rapid molecular testing had 93.1% sensitivity and 98.2% specificity, compared to sputum culture. Bacilloscopy showed 55.1% sensitivity and 99.6% specificity. CONCLUSIONS: Rapid molecular testing can be useful in remote areas with limited resources and a high incidence of tuberculosis, such as indigenous villages in rural regions of Brazil. In addition, the main advantages of rapid molecular testing are its easy handling, fast results, and the possibility of detecting rifampicin resistance. Together, these attributes enable the early start of treatment, contributing to reduce the transmission in communities recognized as vulnerable to infection and disease.

Surface functionality analysis by Boehm titration of graphene nanoplatelets functionalized via a solvent-free cycloaddition reaction.

In this work, the functionalization of graphene nanoplatelets (GNPs) performed by a solvent-free cycloaddition reaction on GNPs with iminodiacetic acid (IDA) and paraformaldehyde (PFA), and the functionality analysis of the resulting functionalized GNPs (f-GNPs) by Boehm titration are introduced. The f-GNPs synthesized at different temperatures were characterized by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM) for structural and morphological properties. Back titration of the f-GNPs selectively identified 3 types of functional groups on the f-GNP surface, carboxylic, lactonic and phenolic, and suggested that 200 °C gives the highest carboxylic group functionality. With the reaction temperature increasing from 180 to 220 °C, a decrease in the phenolic functionality and an increase in that of lactonic are observed. In the case of 250 °C reactions, it was found that the carboxylic functionality is greatly reduced, while the phenolic functionality showed a significant increase. The f-GNP samples were further characterized by thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS), the results of which showed a good agreement with the titration analysis.

Validation of an online course on postural care for preterm newborns / Validación del curso online sobre cuidados posturales del recién nacido prematuro / Validação de curso on-line sobre cuidados posturais ao recém-nascido prematuro

ABSTRACT Objectives: Validation of an online course content on postural care for newborns in the Neonatal Intensive Care Unit and assessment of participant satisfaction. Method: Methodological study of content validation by 13 judges with expertise in neonatology and online education who responded to the educational content validation instrument, and by 175 course participants who evaluated the course through a satisfaction questionnaire. The criterion for validation was agreement above 80.0%, analyzed through the Content Validity Index (CVI), Content Validation Coefficient (CVC), binomial test, and descriptive statistics for analyzing satisfaction variables. Data collection took place from January to June 2022 for the validation stage, and during June 2023 for the evaluation stage conducted by the course participants. Results: All items obtained agreement above 80.0% with a total CVI and CVC of 83.3% and 91.0%, respectively. The course participants positively evaluated the course regarding content organization, coherence between theory and practice, navigability, quality of materials, and applicability in professional practice. Conclusion: The online course was considered valid regarding its objectives, structure/presentation, and relevance. Therefore, it can be offered as an open educational resource in the training of healthcare and nursing professionals to provide postural care to newborns in critical environments, thereby enhancing the performance of developmental care.

RESUMEN Objetivos: Validar el contenido de un curso online sobre cuidados posturales del recién nacido en la Unidad de Cuidados Intensivos Neonatales y verificar la satisfacción de los participantes del curso. Método: Estudio metodológico de validación de contenido realizado por 13 jueces con experiencia en neonatología y educación en línea que respondieron al instrumento de validación de contenido educativo: y por 175 participantes del curso que evaluaron el curso mediante un cuestionario de satisfacción. El criterio de validación fue una concordancia mayor al 80,0%, analizado mediante el Content Validity Index (CVI), Coeficiente de Validación de Contenido (CVC), prueba binomial y estadística descriptiva para analizar las variables de satisfacción. La recolección de datos se realizó de enero a junio de 2022 para la etapa de validación; y en junio de 2023 para la etapa de evaluación realizada por los participantes del curso. Resultados: Todos los ítems lograron una concordancia superior al 80,0% con un CVI y un CVC total de 83,3% y 91,0%, respectivamente. Los participantes del curso coincidieron en una evaluación positiva en términos de organización de contenidos, coherencia entre teoría y práctica, navegabilidad, calidad de los materiales y posibilidad de aplicación en la práctica profesional. Conclusión: El curso en línea se consideró válido en términos de objetivos, estructura/presentación y relevancia. Por lo tanto, puede ofrecerse como un recurso educativo abierto para el perfeccionamiento de los profesionales de la salud y de enfermería con el fin de brindar cuidados posturales a los recién nacidos en ambientes críticos, y elevar la prestación de los cuidados del desarrollo.

RESUMO Objetivos: Validar o conteúdo de um curso on-line sobre cuidados posturais ao recém-nascido na Unidade de Terapia Intensiva Neonatal e verificar a satisfação dos cursistas. Método: Estudo metodológico de validação de conteúdo por 13 juízes com expertise em neonatologia e educação on-line que responderam ao instrumento de validação de conteúdo educacional: e por 175 cursistas que avaliaram o curso mediante um questionário de satisfação. O critério para validação foi concordância superior a 80,0%, analisado por meio do Content Validity Index (CVI), Coeficiente de Validação de Conteúdo (CVC), teste binomial e estatística descritiva para análise das variáveis de satisfação. A coleta de dados ocorreu de janeiro a junho de 2022 para a etapa da validação; e no período de junho de 2023 para a etapa de avaliação realizada pelos cursistas. Resultados: Todos os itens obtiveram concordância superior a 80,0% com CVI e CVC total de 83,3% e 91,0%, respectivamente. Os cursistas avaliaram positivamente o curso quanto à organização do conteúdo, coerência entre teoria e prática, navegabilidade, qualidade dos materiais e possibilidade de aplicação na prática profissional. Conclusão: O curso on-line foi considerado válido no tocante aos objetivos, estrutura/apresentação e relevância. Portanto, pode ser ofertado como recurso educacional aberto no aperfeiçoamento de profissionais de saúde e enfermagem a fim de prestar o cuidado postural aos recém-nascidos em ambiente crítico, elevando o desempenho dos cuidados desenvolvimentais.

Genetic Diversity and Molecular Epidemiology of Mycobacterium tuberculosis in Roraima State, Brazil.

National border areas are special places for the spread of Mycobacterium tuberculosis (MTB). These regions concentrate vulnerable populations and constant population movements. Understanding the dynamics of the transmission of MTB is fundamental to propose control measures and to monitor drug resistance. We conducted a population-based prospective study of tuberculosis (TB) to evaluate molecular characteristics of MTB isolates circulating in Roraima, a state on the border of Venezuela and Guyana. Eighty isolates were genotyped by IS6110-RFLP (restriction fragment length polymorphism), spoligotyping, and 24-locus mycobacterial interspersed repetitive unit-variable number of repeats tandem (MIRU-VNTR). Drug susceptibility tests were performed by using the proportion method and GeneXpert® MTB/RIF (Cepheid, Sunnyvale, CA). Isolates showing a phenotypic resistance profile were submitted to polymerase chain reaction (PCR) and sequencing. Spoligotyping showed 40 distinct patterns with a high prevalence of Latin-American and Mediterranean (LAM), Haarlem (H), and the "ill-defined" T clades. Mycobacterial interspersed repetitive unit -VNTR and IS6110-RFLP showed clustering rates of 21.3% and 30%, respectively. Drug resistance was detected in 11 (15.1%) isolates, and all were found to have primary resistance; among these, six (8.2%) isolates were streptomycin mono-resistant, four (5.4%) isoniazid mono-resistant, and one (1.3%) multidrug resistant. This is the first study on the molecular epidemiology and drug resistance profile of MTB from Roraima. Herein, we describe high diversity of genetic profiles circulating in this region that may be driven by the introduction of new strain types because of large population flow in this region. In summary, our results showed that analyses of these circulating strains can contribute to a better understanding of TB epidemiology in the northern Brazilian border and be useful to establish public health policies on TB prevention.

Identification of non-tuberculous mycobacteria from the Central Public Health Laboratory from Mato Grosso do Sul and analysis of clinical relevance.

Non-tuberculous mycobacteria isolated at the Central Public Health Laboratory from Mato Grosso do Sul in 2003 and 2004 were identified by conventional phenotypic methods (TI) and by PCR-Restriction Enzyme Analysis (PRA) using the hsp65 gene as target (PRA-hsp65). With 15 of the 32 analysed isolates, results of both methods were concordant, being 8 Mycobacterium avium, 3 M. fortutium, 1 M. kansasii, 1 M. flavescens, 1 M. peregrinum and 1 Nocardia brasiliensis. TI of 12 isolates was inconclusive. Novel PRA-hsp65 patterns were observed with 11 isolates. Medical data were evaluated for inference of clinical relevance of these isolates.

The chemical functionalization of graphene nanoplatelets through solvent-free reaction.

Graphene nanoplatelets (GNPs) were functionalized through 1,3-dipolar cycloaddition of azomethine ylide using a solvent-free approach and under different reaction conditions. The yield and the functionality of the carboxyl-terminated pyrrolidine ring attached on the surface of GNPs could be affected by varying the reaction temperature as well as the reactant to GNP weight ratio. The functionalized GNPs were characterized extensively using a range of spectroscopic and microscopy techniques.

A diagnosis of pulmonary tuberculosis and drug resistance among inmates in Mato Grosso do Sul, Brazil.

INTRODUCTION: High endemic levels of pulmonary tuberculosis in prisons result from overcrowding, limited access to healthcare, delayed diagnosis, sustained transmission owing to poor control measures, and multidrug resistance. This study evaluated locally implemented measures for early pulmonary tuberculosis diagnosis and evaluated resistance to anti-tuberculosis drugs. METHODS: This transversal study employed data from the Mato Grosso do Sul State Tuberculosis Control Program obtained from 35 correctional facilities in 16 counties for 2 periods (2007-2010 and 2011-2014). RESULTS: Statewide prevalence (per 100,000) was 480.0 in 2007 and 972.9 in 2014. The following indicators showed improvement: alcohol-acid-fast bacillus testing (from 82.7% to 92.9%); cultures performed (55.0% to 81.8%); drug susceptibility testing of positive cultures (71.6% to 62.4%); and overall drug susceptibility testing coverage (36.6% to 47.4%). Primary and acquired resistance rates for 2007-2014 were 21.1% and 30.0%, respectively. Primary and acquired multidrug resistance rates were 0.3% and 1.3%, respectively. CONCLUSIONS: Prevalence rates increased, and laboratory indicators improved as a result of capacity building and coordination of technical teams and other individuals providing healthcare to inmates. Resistance rates were high, thereby negatively affecting disease control.

Water Dispersible Few-Layer Graphene Stabilized by a Novel Pyrene Derivative at Micromolar Concentration.

The search for graphene or few-layer graphene production methods that are simple, allow mass production, and yield good quality material continues to provoke intense investigation. The present work contributes to this investigation through the study of the aqueous exfoliation of four types of graphene sources, which are namely graphite and graphite nanoflakes with different morphologies and geographical origins. The exfoliation was achieved in an aqueous solution of a soluble pyrene derivative that was synthesized to achieve maximum interaction with the graphene surface at low concentration (5 × 10-5 M). The yield of bilayer and few-layer graphene obtained was quantified by Raman spectroscopic analysis, and the adsorption of the pyrene derivative on the graphene surface was studied by thermogravimetric analysis and X-ray diffraction. The whole procedure was rationalized with the help of molecular modeling.

Genetic Clustering of Tuberculosis in an Indigenous Community of Brazil.

We conducted a population-based study of tuberculosis (TB) from 2009 to 2015 in an indigenous community of Brazil, the largest in the country, to investigate risk factors associated with recent TB transmission. The clinical isolates of Mycobacterium tuberculosis were genotyped by IS6110-RFLP (restriction fragment length polymorphism) and spoligotyping analysis. Among 67 isolates typed by RFLP, 69% fell into fifteen clusters, and 91% of TB cases with shared IS6110-RFLP pattern were diagnosed within 2 years of another case in the cluster. Individual risk factors associated with genetic clustering were domestic overcrowding (odds ratio [OR]: 6.10; 95% confidence interval [CI]: 1.50-24.88) and low social class (OR: 3.72; 95% CI: 1.00-13.98). Most reported contacts (76%) were identified within the household of the index TB case, but most of the genetic clustering of M. tuberculosis occurred outside of household (79%). Expanded contacts investigation and prophylaxis outside of household should be considered as a priority for TB control programs in this population.