Dense optical flow software to quantify cellular contractility.

Cell membrane deformation is an important feature that occurs during many physiological processes, and its study has been put to good use to investigate cardiomyocyte function. Several methods have been developed to extract information on cardiomyocyte contractility. However, no existing computational framework has provided, in a single platform, a straightforward approach to acquire, process, and quantify this type of cellular dynamics. For this reason, we develop CONTRACTIONWAVE, high-performance software written in Python programming language that allows the user to process large data image files and obtain contractility parameters by analyzing optical flow from images obtained with videomicroscopy. The software was validated by using neonatal, adult-, and human-induced pluripotent stem-cell-derived cardiomyocytes, treated or not with drugs known to affect contractility. Results presented indicate that CONTRACTIONWAVE is an excellent tool for examining changes to cardiac cellular contractility in animal models of disease and for pharmacological and toxicology screening during drug discovery.

Emergence and Transmission of Drug-/Multidrug-resistant Mycobacterium leprae in a Former Leprosy Colony in the Brazilian Amazon.

BACKGROUND: Leprosy has been treated with multidrug therapy, which has been distributed for free across the globe and regarded as highly efficient. However, the impossibility of growing Mycobacterium leprae in axenic media has historically impaired assessments of M. leprae resistance, a parameter only recently detectable through molecular methods. METHODS: A systematic, population-based search for M. leprae resistance in suspected leprosy relapse cases and contacts was performed in Prata Village, an isolated, hyperendemic, former leprosy colony located in the Brazilian Amazon. Results led to an extended active search involving the entire Prata population. Confirmed leprosy cases were investigated for bacterial resistance using a combination of in vivo testing and direct sequencing of resistance genes folP1, rpoB, and gyrA. A molecular epidemiology analysis was performed using data from 17 variable number tandem repeats (VNTR). RESULTS: Mycobacterium leprae was obtained from biopsies of 37 leprosy cases (18 relapses and 19 new cases): 16 (43.24%) displayed drug-resistance variants. Multidrug resistance to rifampicin and dapsone was observed in 8 relapses and 4 new cases. Single resistance to rifampicin was detected in 1 new case. Resistance to dapsone was present in 2 relapses and 1 new case. Combined molecular resistance and VNTR data revealed evidence of intra-familial primary transmission of resistant M. leprae. CONCLUSIONS: A comprehensive, population-based systematic approach to investigate M. leprae resistance in a unique population revealed an alarming scenario of the emergence and transmission of resistant strains. These findings may be used for the development of new strategies for surveillance of drug resistance in other populations.

Emergence and transmission of drug-/multidrug-resistant Mycobacterium leprae in a former leprosy colony in the Brazilian Amazon

BACKGROUND: Leprosy has been treated with multidrug therapy (MDT) distributed for free across the globe and regarded as highly efficient. However, the impossibility to grow M. leprae in axenic media has historically impaired assessment of M. leprae resistance, a parameter only recently detectable through molecular methods. METHODS: A systematic, population-based search for M. leprae resistance in suspected leprosy relapse cases and contacts was performed in Prata Village, an isolated, hyper-endemic former leprosy colony located in the Brazilian Amazon. Results led to an extended active search involving the entire Prata population. Confirmed leprosy cases were investigated for bacterial resistance using a combination of in vivo testing and direct sequencing of resistance genes folP1, rpoB and gyrA. Molecular epidemiology analysis was performed using data from 17 variable number tandem repeats (VNTR). RESULTS: M. leprae was obtained from biopsies of 37 leprosy cases (18 relapses and 19 new); 16 (43.24%) displayed drug-resistance variants. Multi-drug resistance to rifampicin and dapsone was observed in 8 relapses and 4 new cases. Single resistance to rifampicin was detected in one new case. Resistance to dapsone was present in two relapses and one new case. Combined molecular resistance and VNTR data revealed evidence of intra-familial primary transmission of resistant M. leprae. CONCLUSIONS: A comprehensive, population-based systematic approach to investigate M. leprae resistance in a unique population revealed an alarming scenario of emergence and transmission of resistant strains. These findings may be used for the development of new strategies for surveillance of drug resistance in other populations.

Volterra Kernels Assessment via Time-Delay Neural Networks for Nonlinear Unsteady Aerodynamic Loading Identification.

Reduced-order modeling using the Volterra series approach has been successfully applied in the past decades to weakly nonlinear aerodynamic and aeroelastic systems. However, aspects regarding the identification of the kernels associated with the convolution integrals of Volterra series can profoundly affect the quality of the resulting reduced-order model (ROM). An alternative method for their identification based on artificial neural networks is evaluated in this work. This relation between the Volterra kernels and the internal parameters of a time-delay neural network is explored for the application in the reduced-order modeling of nonlinear unsteady aerodynamic loads. An impulse-type Volterra-based ROM is also under consideration for comparison. All aerodynamic data used for the construction of the reduced-order models are obtained from computational fluid dynamics (CFD) simulations of the NACA 0012 airfoil using the Euler equations. Prescribed inputs in pitch and in plunge degrees of freedom at different free-stream Mach numbers are used to evaluate the range of applicability of the obtained models. For weakly nonlinear test cases, the modeling performance of the neural network Volterra ROM was comparable to the impulse-type ROM. Additional accuracy and adequate modeling of stronger nonlinearities, however, could only be attained with the inclusion of the neural network kernels of higher-order in the Volterra ROM. A generic expression is derived for the kernel function of p th -order from the internal parameters of a time-delay neural network.

Kinetic estimated glomerular filtration rate in critically ill patients: beyond the acute kidney injury severity classification system.

BACKGROUND: Although significant advances have been achieved in acute kidney injury (AKI) research following its classification, potential pitfalls can be identified in clinical practice. The nonsteady-state (kinetic) estimated glomerular filtration rate (KeGFR) could add clinical and prognostic information in critically ill patients beyond the current AKI classification system. METHODS: This was a retrospective analysis using data from the Multiparameter Intelligent Monitoring in Intensive Care II project. The KeGFR was calculated during the first 7 days of intensive care unit (ICU) stay in 13,284 patients and was correlated with outcomes. RESULTS: In general, there was not a good agreement between AKI severity and the worst achieved KeGFR. The stepwise reduction in the worst achieved KeGFR conferred an incremental risk of death, rising from 7.0% (KeGFR > 70 ml/min/1.73 m2) to 27.8% (KeGFR < 30 ml/min/1.73 m2). This stepwise increment in mortality remained in each AKI severity stage. For example, patients with AKI stage 3 who maintained KeGFR had a mortality rate of 16.5%, close to those patients with KeGFR < 30 ml/min/1.73 m2 but no AKI; otherwise, mortality increased to 40% when both AKI stage 3 and KeGFR < 30 ml/min/1.73 m2 were present. In relation to another outcome-renal replacement therapy (RRT)-patients with the worst achieved KeGFR < 30 ml/min/1.73 m2 and KDIGO stage 1/2 had a rate of RRT of less than 10%. However, this rate was 44% when both AKI stage 3 and a worst KeGFR < 30 ml/min/1.73 m2 were observed. This interaction between AKI and KeGFR was also present when looking at long-term survival. CONCLUSION: Both the AKI classification system and KeGFR are complementary to each other. Assessing both AKI stage and KeGFR can help to identify patients at different risk levels in clinical practice.

Isotopic Effect on the Gel and Glass Formation of a Charged Colloidal Clay: Laponite.

The time evolution of both dynamic and static structure factors of a charged colloidal clay, Laponite, dispersed in both H2O and D2O solvents has been investigated through multiangle dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS) as a function of weight concentration. The aging phenomenology and the formation of arrested states, both gel and glass, are preserved in D2O, while the dynamics is slowed down with respect to water. These findings are important to understand the role played by the solvent in the interparticle interactions and for techniques such as neutron scattering and nuclear magnetic resonance that allow for the extension of the accessible scattering vectors and time scales.

Assessment of carbon storage under rainforests in Humic Hapludox along a climosequence extending from the Atlantic coast to the highlands of northeastern Brazil.

An understanding of the stock of soil organic carbon (SOC) in the umbric epipedon of Oxisols located in the tropical forests surrounded by a semi-arid region is limited but essential because of their importance in the global cycle of carbon (C). The purpose of this study was to assess the effects of climatic (temperature and rainfall), soil organic matter (SOM) composition and litter on the stability of C in surfaces and subsurfaces in five Humic Oxisols along a 475-km climosequence from 143 to 963ma.s.l. in a tropical environment in northeastern Brazil. We assessed vertical changes in SOC; soil total nitrogen (N); C from the microbial biomass; δ(13)C, δ(15)N and the humified composition of SOM; the composition of the humin (HUM) fraction by Fourier Transform Infrared (FTIR); and Thermogravimetry (TG) and Differential Scanning Calorimetry (DSC) at depth. The elemental and isotopic composition of the litter samples were analyzed in all areas studied. The results indicated that the current climate and recalcitrant organic compounds are not preponderant factors in the formation of the umbric epipedon, as suggested by the partial influence of temperature and rainfall on SOM. In addition, SOM was dominated by easily decomposable compounds, as indicated by the predominance of aliphatic C-H groups in the HUM fraction in the FTIR spectra; by the thermal oxidation through DSC-TG, which revealed that approximately 50% of the HUM was composed easily decomposable compounds; and by the high proportion of organic C present in the microbial biomass. Values of δ(13)C showed a predominance of C3 plant-C in SOM whereas δ(15)N patterns indicated that N dynamics differ among the profiles and drive the accumulation of C. These findings can help to characterize the susceptibility of these soils to changes in climate and land use and the implications for the sequestration of soil C.

Association between participation and compliance with Continuing Medical Education and care production by physicians: a cross-sectional study.

OBJECTIVE: Physician participation in Continuing Medical Education programs may be influenced by a number of factors. To evaluate the factors associated with compliance with the Continuing Medical Education requirements at a private hospital, we investigated whether physicians' activity, measured by volumes of admissions and procedures, was associated with obtaining 40 Continuing Medical Education credits (40 hours of activities) in a 12-month cycle. METHODS: In an exclusive and non-mandatory Continuing Medical Education program, we collected physicians' numbers of hospital admissions and numbers of surgical procedures performed. We also analyzed data on physicians' time since graduation, age, and gender. RESULTS: A total of 3,809 credentialed, free-standing, private practice physicians were evaluated. Univariate analysis showed that the Continuing Medical Education requirements were more likely to be achieved by male physicians (odds ratio 1.251; p=0.009) and who had a higher number of hospital admissions (odds ratio 1.022; p<0.001). Multivariate analysis showed that age and number of hospital admissions were associated with achievement of the Continuing Medical Education requirements. Each hospital admission increased the chance of achieving the requirements by 0.4%. Among physicians who performed surgical procedures, multivariate analysis showed that male physicians were 1.3 time more likely to achieve the Continuing Medical Education requirements than female physicians. Each surgical procedure performed increased the chance of achieving the requirements by 1.4%. CONCLUSION: The numbers of admissions and number of surgical procedures performed by physicians at our hospital were associated with the likelihood of meeting the Continuing Medical Education requirements. These findings help to shed new light on our Continuing Medical Education program.

Association between participation and compliance with Continuing Medical Education and care production by physicians: a cross-sectional study / Associação entre participação e cumprimento de um programa de Educação Médica Continuada e produção assistencial dos médicos: estudo transversal

Objective Physician participation in Continuing Medical Education programs may be influenced by a number of factors. To evaluate the factors associated with compliance with the Continuing Medical Education requirements at a private hospital, we investigated whether physicians’ activity, measured by volumes of admissions and procedures, was associated with obtaining 40 Continuing Medical Education credits (40 hours of activities) in a 12-month cycle. Methods In an exclusive and non-mandatory Continuing Medical Education program, we collected physicians’ numbers of hospital admissions and numbers of surgical procedures performed. We also analyzed data on physicians’ time since graduation, age, and gender. Results A total of 3,809 credentialed, free-standing, private practice physicians were evaluated. Univariate analysis showed that the Continuing Medical Education requirements were more likely to be achieved by male physicians (odds ratio 1.251; p=0.009) and who had a higher number of hospital admissions (odds ratio 1.022; p<0.001). Multivariate analysis showed that age and number of hospital admissions were associated with achievement of the Continuing Medical Education requirements. Each hospital admission increased the chance of achieving the requirements by 0.4%. Among physicians who performed surgical procedures, multivariate analysis showed that male physicians were 1.3 time more likely to achieve the Continuing Medical Education requirements than female physicians. Each surgical procedure performed increased the chance of achieving the requirements by 1.4%. Conclusion The numbers of admissions and number of surgical procedures performed by physicians at our hospital were associated with the likelihood of meeting the Continuing Medical Education requirements. These findings help to shed new light on our Continuing Medical Education program. .

Objetivo A participação de médicos em programas de Educação Médica Continuada pode ser influenciada por inúmeros fatores. Para avaliar os fatores associados ao cumprimento dos requisitos para Educação Médica Continuada em um hospital privado, investigamos se a atividade médica, medida por volume de internações e procedimentos, esteve relacionada à obtenção de 40 créditos (40 horas-aula) em um ciclo do programa de 12 meses. Métodos Em um programa exclusivo e não obrigatório de Educação Médica Continuada, coletamos o número de admissões e de procedimentos realizados por médico. Analisamos dados como tempo de formado, idade e sexo. Resultados Foram analisados dados de 3.809 médicos credenciados e autônomos. A análise univariada mostrou que os requisitos de Educação Médica Continuada eram mais preenchidos por médicos do sexo masculino (odds ratio de 1,251; p=0,009) e que eles apresentavam números de internações mais significativos (odds ratio de 1,022; p<0,001). A análise multivariada mostrou que idade e número de admissões estiveram associados ao cumprimento das metas estabelecidas. Cada admissão aumentou a chance de atingir a meta em 0,4%. Entre os que realizaram procedimentos cirúrgicos, a análise multivariada mostrou que médicos do sexo masculino eram 1,3 vez mais propensos a atingir a meta estabelecida que seus pares do sexo feminino. Cada procedimento cirúrgico realizado elevou a chance de atingir a meta em 1,4%. Conclusão O número de admissões e de procedimentos cirúrgicos realizados por médicos em nosso hospital foi associado à probabilidade de alcançar a meta de Educação Médica Continuada. Estes achados lançaram uma nova luz sobre o nosso programa de Educação Médica Continuada. .

Structural and microscopic relaxations in a colloidal glass.

The aging dynamics of a colloidal glass has been studied by multiangle dynamic light scattering, neutron spin echo, X-ray photon correlation spectroscopy and molecular dynamics simulations. The two relaxation processes, microscopic (fast) and structural (slow), have been investigated in an unprecedentedly wide range of time and length scales covering both ergodic and nonergodic regimes. The microscopic relaxation time remains diffusive at all length scales across the glass transition scaling with wavevector Q as Q(-2). The length-scale dependence of structural relaxation time changes from diffusive, characterized by a Q(-2)-dependence in the early stages of aging, to a Q(-1)-dependence in the full aging regime which marks a discontinuous hopping dynamics. Both regimes are associated with a stretched behaviour of the correlation functions. We expect these findings to provide a general description of both relaxations across the glass transition.

Glass-glass transition during aging of a colloidal clay.

Colloidal suspensions are characterized by a variety of microscopic interactions, which generate unconventional phase diagrams encompassing fluid, gel and glassy states and offer the possibility to study new phase and/or state transitions. Among these, glass-glass transitions are rare to be found, especially at ambient conditions. Here, through a combination of dilution experiments, X-ray photon correlation spectroscopy, small angle X-ray scattering, rheological measurements and Monte Carlo simulations, we provide evidence of a spontaneous glass-glass transition in a colloidal clay. Two different glassy states are distinguished with evolving waiting time: a first one, dominated by long-range screened Coulombic repulsion (Wigner glass) and a second one, stabilized by orientational attractions (Disconnected House of Cards glass), occurring after a much longer time. These findings may have implications for heterogeneously charged systems out-of-equilibrium and for applications where a fine control of the local order and/or long term stability of the amorphous materials are required.

RFID technology for hazardous waste management and tracking.

The illegal dumping of hazardous waste is one of the most concerning occurrences related to illegal waste activities. The waste management process is quite vulnerable, especially when it comes to assuring the right destination for the delivery of the hazardous waste. The purpose of this paper is to present a new system design and prototype for applying the RFID technology so as to guarantee the correct destination for the hazardous waste delivery. The aim of this innovative approach, compared with other studies that employ the same technology to the waste disposal process, is to focus on the certification that the hazardous waste will be delivered to the right destination site and that no inappropriate disposal will occur in the transportation stage. These studies were carried out based on data collected during visits to two hazardous waste producer companies in Brazil, where the material transportation and delivery to a company in charge of the waste disposal were closely monitored.

Dual aging behaviour in a clay-polymer dispersion.

Clay-polymer compounds have recently attracted increasing attention due to their intriguing physical properties in colloidal science and their rheological non-trivial behaviour in technological applications. Aqueous solutions of Laponite clay spontaneously age from a liquid up to an arrested state of different nature (gel or glass) depending on the colloidal volume fraction and ionic strength. We have investigated, through dynamic light scattering, how the aging dynamics of Laponite dispersions at fixed clay concentration (Cw = 2.0%) is modified by the addition of various amounts of poly(ethylene oxide) (PEO) (CPEO = (0.05 ÷ 0.50) %) at two different molecular weights (Mw = 100 kg mol(-1) and Mw = 200 kg mol(-1)). A surprising and intriguing phenomenon has been observed: the existence of a critical polymer concentration C that discriminates between two different aging dynamics. With respect to pure Laponite systems the aging will be assisted (faster) or hindered (slower) for PEO concentrations respectively lower (CPEO < C) or higher (CPEO > C) than the critical concentration. In this way a control on the aging dynamics of PEO-Laponite systems is obtained. A possible explanation based on the balance of competitive mechanisms related to the progressive saturation of the clay surface by polymers is proposed. This study shows how a real control on the aging speed of the PEO-Laponite system is at hand and renders possible a real control of the complex interparticle interaction potential.

Ventricular fibrillation during sport activity successfully treated.

Survival after out-of-hospital cardiopulmonary arrest is estimated at less than 5%. We report a case of ventricular fibrillation during sports activity. Cardiopulmonary resuscitation was initiated early by a layperson, and defibrillation was successfully performed within less than three minutes, with an automated external defibrillator. The public access to defibrillation programs has increased the survival after out-of-hospital ventricular fibrillation. We should encourage the training of laypeople in relation to the use of automated external defibrillators and the Basic Life Support program by stimulating their implementation in places where large numbers of people gather or where people are at a high risk of sudden death, as is the case of sports centers.

Fibrilação ventricular durante atividade esportiva tratada com sucesso / Fibrilación ventricular durante actividad deportiva tratada con êxito / Ventricular fibrillation during sport activity successfully treated

A sobrevida após parada cardio-respiratória extra-hospitalar é estimada em menos de 5 por cento. Apresentamos um caso de fibrilação ventricular, durante atividade esportiva. Ressuscitação cardio-pulmonar foi iniciada precocemente por pessoa leiga, e desfibrilação foi realizada em menos de três minutos, com desfibrilador externo automático, com sucesso. O programa de acesso público à desfibrilação tem aumentado a sobrevida após fibrilação ventricular extra-hospitalar. Devemos estimular o treinamento de pessoas leigas com relação ao uso de desfibriladores externos automáticos e o programa Suporte Básico de Vida, incentivando a implementação deste em locais com grande afluxo de pessoas e locais com risco elevado de ocorrer morte súbita, a exemplo de centros esportivos.

Survival after out-of-hospital cardiopulmonary arrest is estimated at less than 5 percent. We report a case of ventricular fibrillation during sports activity. Cardiopulmonary resuscitation was initiated early by a layperson, and defibrillation was successfully performed within less than three minutes, with an automated external defibrillator. The public access to defibrillation programs has increased the survival after out-of-hospital ventricular fibrillation. We should encourage the training of laypeople in relation to the use of automated external defibrillators and the Basic Life Support program by stimulating their implementation in places where large numbers of people gather or where people are at a high risk of sudden death, as is the case of sports centers.

La sobrevida tras una parada cardiorrespiratoria extrahospitalaria se estima en menos del 5 por ciento. Presentamos un caso de fibrilación ventricular durante actividad deportiva La resucitación cardiopulmonar fue iniciada precozmente por personal no técnico, y la desfibrilación se realizó en menos de tres minutos, con desfibrilador externo automático, con éxito. El programa de acceso público a la desfibrilación aumentó la sobrevida después de la fibrilación ventricular extrahospitalaria. Debemos estimular la capacitación de personas no técnicas con relación al uso de desfibriladores externos automáticos y el programa Soporte Básico de Vida, incentivando la implementación del mismo en locales con gran afluencia de personas y locales con riesgo elevado de ocurrencia de muerte súbita, como es el caso de los centros deportivos.

Estudo comparativo: analgesia tópica pós-peeling facial médio com ácido tricloroacético (ATA) a 30 utilizando água destilada e heparina sódica tópica em spray (Alimax®) / Comparative study: topical analgesia after facial peeling with trichloroacetic acid (TCA) 30(per cent) utilizing distilled water and topical sodic heparin in spray(Alimax®)

A dor pós-peeling é um fator limitante ao seu uso universal. Alguns pacientes com indicação para tal tratamento estético acabam se abstendo desta terapia devido ao temor da dor imediatamente após este procedimento. O que poderia tornar um procedimento seguro, simples, barato e de fácil reprodução, mais difundido entre pacientes e profissionais, seria o controle efetivo desta dor, de preferência se fosse por meio de uma terapia tópica. A avaliação da dor após o uso de heparina sódica tópica em spray (ALIMAX®), utilizada para tratamento tópico em queimaduras, e sua comparação à água destilada, utilizada pela mesma via, foi estudada em 12 pacientes após o peeling médio com ácido tricloroacético (ATA) a 30(per cent) em face.

The pain after peeling limits the universalization of this aesthetic procedure. Many patients with indication for such treatment deny the use of this therapy, fearing the pain immediatelyafter the peeling. The effective control of the pain could became the a procedure safe, simple, cheap and easily reproductable more diffused among patients and professionals, especiallyby a topical therapy. The evaluation of the pain after the use of sodium aqueous heparin solution in spray (ALIMAX®), utilized for topical treatment in burns, and its comparison to the distilled water, utilized by the same way, was studied in 12 patients after the medium-depthpeeling with trichloroacetic acid (TCA) 30% on face.

Malignant hypertension with intestinal ischemia secondary to juxtaglomerular cell tumor.

Malignant hypertension is a well-defined condition associated with high blood pressure and acute target-organ damage. Although 95% of cases are secondary to essential hypertension, its etiological profile is broad. Juxtaglomerular cell tumor is a rare condition, with only approximately 65 cases reported to date. We describe a patient with malignant hypertension with acute renal failure and intestinal ischemia secondary to a juxtaglomerular cell tumor. We believe this is the first case of juxtaglomerular cell tumor causing malignant hypertension. The diagnostic approach and treatment are discussed.