Search results for: Y. M. L. Cordeiro
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 15

Search results for: Y. M. L. Cordeiro

15 Thermal Characterization of Graphene Oxide-Epoxy Nanocomposites Produced by Aqueous Emulsion

Authors: H. A. Brandão Cordeiro, M. G. Bocardo, N. C. Penteado, V. T. de Moraes, S. M. Giampietri Lebrão, G. W. Lebrão

Abstract:

The present study desired to obtain a nanocomposite of epoxy resin reinforced with graphene oxide (OG), for aerospace application, produced by aqueous emulsion. It was obtained proof bodies with 0.00 wt%, 0.10 wt%, 0.25 wt% and 0.50 wt% in weight of nanoparticles, to check the influence of it in the final quality of the obtained product. The validation of the results was done by the application thermal characterization by differential scanning calorimetry (DSC). It was seen that the nanocomposite reinforced with 0.10 wt% of OG showed the best results, the average glass transition temperature, at 2 °C, compared to the pure resin.

Keywords: aqueous emulsion, graphene, nanocomposites, thermal characterization

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14 Machine Learning for Aiding Meningitis Diagnosis in Pediatric Patients

Authors: Karina Zaccari, Ernesto Cordeiro Marujo

Abstract:

This paper presents a Machine Learning (ML) approach to support Meningitis diagnosis in patients at a children’s hospital in Sao Paulo, Brazil. The aim is to use ML techniques to reduce the use of invasive procedures, such as cerebrospinal fluid (CSF) collection, as much as possible. In this study, we focus on predicting the probability of Meningitis given the results of a blood and urine laboratory tests, together with the analysis of pain or other complaints from the patient. We tested a number of different ML algorithms, including: Adaptative Boosting (AdaBoost), Decision Tree, Gradient Boosting, K-Nearest Neighbors (KNN), Logistic Regression, Random Forest and Support Vector Machines (SVM). Decision Tree algorithm performed best, with 94.56% and 96.18% accuracy for training and testing data, respectively. These results represent a significant aid to doctors in diagnosing Meningitis as early as possible and in preventing expensive and painful procedures on some children.

Keywords: machine learning, medical diagnosis, meningitis detection, pediatric research

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13 Disaggregating and Forecasting the Total Energy Consumption of a Building: A Case Study of a High Cooling Demand Facility

Authors: Juliana Barcelos Cordeiro, Khashayar Mahani, Farbod Farzan, Mohsen A. Jafari

Abstract:

Energy disaggregation has been focused by many energy companies since energy efficiency can be achieved when the breakdown of energy consumption is known. Companies have been investing in technologies to come up with software and/or hardware solutions that can provide this type of information to the consumer. On the other hand, not all people can afford to have these technologies. Therefore, in this paper, we present a methodology for breaking down the aggregate consumption and identifying the highdemanding end-uses profiles. These energy profiles will be used to build the forecast model for optimal control purpose. A facility with high cooling load is used as an illustrative case study to demonstrate the results of proposed methodology. We apply a high level energy disaggregation through a pattern recognition approach in order to extract the consumption profile of its rooftop packaged units (RTUs) and present a forecast model for the energy consumption.  

Keywords: energy consumption forecasting, energy efficiency, load disaggregation, pattern recognition approach

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12 Current Account on Teaching Psychology and Career Psychology in Portuguese Higher Education

Authors: Sivia Amado Cordeiro, Bruna Rodrigues, Maria Do Ceu Taveira, Catia Marques, Iris Oliveira, Ana Daniela Silva, Cristina Costa-Lobo

Abstract:

This work intends to analyse the teaching of Psychology in Portugal and, particularly, the teaching of Career Psychology, reflecting about the changes that have occurred to date. Were analysed the educational offerings of 31 Portuguese higher education institutions, 12 public and 19 private, who teach the course of Psychology. The three degrees of study were considered, namely, bachelors, masters and doctoral. The analysis of the data focused on the curricular plans of the different degrees of studies in Psychology made available online by higher education institutions. Through them, we identified the curricular units with themes related to the teaching of Career Psychology. The results show the existence of 89 higher psychology courses in Portugal, distributed throughout the three degrees of studies. Concerning to the teaching of Career Psychology there were registered 49 curricular units with themes dedicated to this area of knowledge. There were identified 16 curricular units in the bachelor’s degree, 31 in master’s degree, and two in doctoral degree. It was observed a reduction in the number of degrees in Psychology in the last nine years in Portugal. We discuss the current situation of Psychology teaching, particularly the teaching of Career Psychology. The aim is to stimulate reflection about future perspectives of Psychology teaching, and specifically, specialized training in Psychology of Career, in Portugal.

Keywords: career psychology, higher education, psychology, Portugal

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11 Evaluation of Football Forecasting Models: 2021 Brazilian Championship Case Study

Authors: Flavio Cordeiro Fontanella, Asla Medeiros e Sá, Moacyr Alvim Horta Barbosa da Silva

Abstract:

In the present work, we analyse the performance of football results forecasting models. In order to do so, we have performed the data collection from eight different forecasting models during the 2021 Brazilian football season. First, we guide the analysis through visual representations of the data, designed to highlight the most prominent features and enhance the interpretation of differences and similarities between the models. We propose using a 2-simplex triangle to investigate visual patterns from the results forecasting models. Next, we compute the expected points for every team playing in the championship and compare them to the final league standings, revealing interesting contrasts between actual to expected performances. Then, we evaluate forecasts’ accuracy using the Ranked Probability Score (RPS); models comparison accounts for tiny scale differences that may become consistent in time. Finally, we observe that the Wisdom of Crowds principle can be appropriately applied in the context, driving into a discussion of results forecasts usage in practice. This paper’s primary goal is to encourage football forecasts’ performance discussion. We hope to accomplish it by presenting appropriate criteria and easy-to-understand visual representations that can point out the relevant factors of the subject.

Keywords: accuracy evaluation, Brazilian championship, football results forecasts, forecasting models, visual analysis

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10 Preliminary Conceptions of 3D Prototyping Model to Experimental Investigation in Hypersonic Shock Tunnels

Authors: Thiago Victor Cordeiro Marcos, Joao Felipe de Araujo Martos, Ronaldo de Lima Cardoso, David Romanelli Pinto, Paulo Gilberto de Paula Toro, Israel da Silveira Rego, Antonio Carlos de Oliveira

Abstract:

Currently, the use of 3D rapid prototyping, also known as 3D printing, has been investigated by some universities around the world as an innovative technique, fast, flexible and cheap for a direct plastic models manufacturing that are lighter and with complex geometries to be tested for hypersonic shock tunnel. Initially, the purpose is integrated prototyped parts with metal models that actually are manufactured through of the conventional machining and hereafter replace them with completely prototyped models. The mechanical design models to be tested in hypersonic shock tunnel are based on conventional manufacturing processes, therefore are limited forms and standard geometries. The use of 3D rapid prototyping offers a range of options that enables geometries innovation and ways to be used for the design new models. The conception and project of a prototyped model for hypersonic shock tunnel should be rethought and adapted when comparing the conventional manufacturing processes, in order to fully exploit the creativity and flexibility that are allowed by the 3D prototyping process. The objective of this paper is to compare the conception and project of a 3D rapid prototyping model and a conventional machining model, while showing the advantages and disadvantages of each process and the benefits that 3D prototyping can bring to the manufacture of models to be tested in hypersonic shock tunnel.

Keywords: 3D printing, 3D prototyping, experimental research, hypersonic shock tunnel

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9 A Corpus-Based Approach to Understanding Market Access in Fisheries and Aquaculture: A Systematic Literature Review

Authors: Cheryl Marie Cordeiro

Abstract:

Although fisheries and aquaculture studies might seem marginal to international business (IB) studies in general, fisheries and aquaculture IB (FAIB) management is currently facing increasing pressure to meet global demand and consumption for fish in the next coming decades. In part address to this challenge, the purpose of this systematic review of literature (SLR) study is to investigate the use of the term ‘market access’ in its context of use in the generic literature and business sector discourse, in comparison to the more specific literature and discourse in fisheries, aquaculture and seafood. This SLR aims to uncover the knowledge/interest gaps between the academic subject discourses and business sector practices. Corpus driven in methodology and using a triangulation method of three different text analysis software including AntConc, VOSviewer and Web of Science (WoS) analytics, the SLR results indicate a gap in conceptual knowledge and business practices in how ‘market access’ is conceived and used in the context of the pharmaceutical healthcare industry and FAIB research and practice. While it is acknowledged that the product orientation of different business sectors might differ, this SLR study works with the assumption that both business sectors are global in orientation. These business sectors are complex in their operations from product to market. This SLR suggests a conceptual model in understanding the challenges, the potential barriers as well as avenues for solutions to developing market access for FAIB.

Keywords: market access, fisheries and aquaculture, international business, systematic literature review

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8 Social Support and Depressive Symptoms in Participants of a University of the Third Age: Evidences From a Cross-Sectional Study in Brazil

Authors: Ana Luiza Blanco, Juliana Cordeiro Carvalho, Tábatta Renata Pereira Brito, Ariene Angelini dos Santos Orlandi, Ligiana Pires Corona, Daniella Pires Nunes

Abstract:

Depressive symptoms are recurrent in older adults and affect the quality of life and well-being of individuals. One of the strategies to reduce depression is social support, but studies are still needed to determine which types of social support are most effective in moderating this effect in certain populations. The objective was to identify the relationship between social support and depressive symptoms in participants of a University of the Third Age. This is a cross-sectional study. Participants were 82 individuals (≥ 50 years) who responded to the Geriatric Depression Scale - GDS and the Medical Outcomes Study - MOS. Data collection was carried out from November 2020 to May 2021. The Chi-Square and Mann Whitney tests were used, at a significance level of 5% for data analysis. Among the participants, 83.4% were female, 57.3% were age between 60 to 69 years, 83.1% studied 12 year or more and 48.1% receive from 4 to 10 minimum wages. The prevalence of depressive symptoms was 12.2%. The type of support with the highest median score was affective (100 points) and the lowest, or emotional (87.5 points). The results showed that participants without depressive symptoms had higher median scores for informational support when compared to those with depressive symptoms (p=0.029). The other types of social support were not statistically significant. The findings suggested that informational support is related to depressive symptoms in older adults. Promote informational support and educational actions in Universities of the Third Age may be an important strategy for preventing depressive symptoms and improve the quality of life of this population.

Keywords: aged, depressive symptoms, social support, university of the third age

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7 Mercury (Hg) Concentration in Fish Marketed in the São Luís Fish Market (MA) and Potential Exposure of Consumers

Authors: Luiz Drude de Lacerda, Kevin Luiz Cordeiro Ferrer do Carmo, Victor Lacerda Moura, Rayone Wesley Santos de Oliveira, Moisés Fernandes Bezerra

Abstract:

Fish is a food source well recognized for its health benefits. However, the consumption of fish, especially carnivorous species, is the main path of human exposure to Hg, a widely distributed pollutant on the planet and that accumulates along food chains. Studies on the impacts on public health by fish intake show existing toxic risks even when at low concentrations. This study quantifies, for the first time, the concentrations of Hg in muscle tissue of the nine most commercialized fish species in the fish market of São Luís (MA) in north Brazil and estimates the consequent human exposure through consumption. Concentrations varied according to trophic level, with the highest found in the larger carnivorous species; the Yellow hake (Cynoscion acoupa) (296.4 ± 241.2 ng/g w.w) and the Atlantic croaker (Micropogonias undulatus) (262.8 ± 89.1 ng/g w.w.), whereas the lowest concentrations were recorded in iliophagous Mullets (Mugil curema) (20.5 ± 9.6 ng/g w.w.). Significant correlations were observed between Hg concentrations and individual length in only two species: the Flaming catfish (Bagre marinus) and the Atlantic bumper (Chloroscombrus crysurus). Given the relatively uniform size of individuals of the other species and/or the small number of samples, this relationship was not found for the other species. The estimated risk coefficients, despite the relatively low concentrations of Hg, suggest that yellow hake and Whitemouth croaker (Micropogonias furnieri), fish most consumed by the local population, present some risk to human health (> 1) HQ and THQ, depending on the frequency of their consumption.

Keywords: contamination, fish, human exposure, risk assessment

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6 The Event of Extreme Precipitation Occurred in the Metropolitan Mesoregion of the Capital of Para

Authors: Natasha Correa Vitória Bandeira, Lais Cordeiro Soares, Claudineia Brazil, Luciane Teresa Salvi

Abstract:

The intense rain event that occurred between February 16 and 18, 2018, in the city of Barcarena in Pará, located in the North region of Brazil, demonstrates the importance of analyzing this type of event. The metropolitan mesoregion of Belem was severely punished by rains much above the averages normally expected for that time of year; this phenomenon affected, in addition to the capital, the municipalities of Barcarena, Murucupi and Muruçambá. Resulting in a great flood in the rivers of the region, whose basins were affected with great intensity of precipitation, causing concern for the local population because in this region, there are located companies that accumulate ore tailings, and in this specific case, the dam of any of these companies, leaching the ore to the water bodies of the Murucupi River Basin. This article aims to characterize this phenomenon through a special analysis of the distribution of rainfall, using data from atmospheric soundings, satellite images, radar images and data from the GPCP (Global Precipitation Climatology Project), in addition to rainfall stations located in the study region. The results of the work demonstrated a dissociation between the data measured in the meteorological stations and the other forms of analysis of this extreme event. Monitoring carried out solely on the basis of data from pluviometric stations is not sufficient for monitoring and/or diagnosing extreme weather events, and investment by the competent bodies is important to install a larger network of pluviometric stations sufficient to meet the demand in a given region.

Keywords: extreme precipitation, great flood, GPCP, ore dam

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5 Profile of Serological Response of Equids Naturally Infected with Burkholderia mallei

Authors: Iahtasham Khan, Vania Lucia De Assis Santana, Marcilia Maria Alves De Souza, Mabel Hanna Vance Harrop, Fernando Leandro Dos Santos, Cecília Maria Souza Leão E. Silva, Pedro Paulo Silveira, Marcelo Brasil, Marcus Vinícius, Hélio Cordeiro Manso Filho, Muhammad Younus, Aman Ullah Khan

Abstract:

Glanders ranks high on clinical lists in some regions of Brazil as a cause of respiratory and lymphatic disease in equids. Glanders is caused by Burkolderia mallei (B. mallei) Gram-negative bacterium. B. mallei was first biological agent used in World War I in 20th century. The complement fixation test (CFT) is a serodiagnostic tool prescribed by the World Organization for Animal Health (OIE)for the diagnosis of glanders in the international trade of equids. The aim of the present study was to monitor the serological responses in equines naturally infected with B. mallei using the CFT. A total of 574 equids were tested with CFT, 30 days apart in a total of 12 samplings. One hundred thirty-four sera tested negative in all samplings; 192 sera tested positive in one sampling and 125 sera tested positive in two or more samplings. Remaining 123 samples showed uncertain results. Thus, CFT results can vary over a period of time. These variations could be the consequence of the effects of the natural immune response in each animal. The findings of the present study demonstrate difficulties regarding the simultaneous implementation of CFT and test and slaughter policies to eradicate glanders. Another constraint to control this disease is the presence of carrier/transitory CFT-negative animals, which are a potential source of disease in glanders-free areas. Serodiagnostic tests of higher sensitivity and specificity like immunobloat should be implemented to achieve success in the eradication of glanders.

Keywords: glanders, equids, horses, immunological, mules

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4 Subjective Well-Being, Emotional Regulation and Motivational Orientation of Competition Athletes

Authors: Cristina Costa-Lobo, Priscila Martins, Silvia Amado Cordeiro, Ana Campina

Abstract:

Behavior directed toward high levels of sports performance and excellence implies task-focused processes, processes of cognitive and emotional regulation. This research aims to understand if subjective well-being, emotional regulation, and motivational orientation influence the performance of competitive athletes. The sample of this study is a non-probabilistic convenience sample, consisting of 50 male athletes, aged 14 to 15 years, who belong to training teams integrated in the pedagogical department of a sports club in the North of Portugal. In terms of performance, the distinction between team A and team B is due to the championships in which the respective athletes participate. Team A participates in national championships where the levels of demand and challenge are more pronounced and the team B only participates in championships at the district level. Was verified the internal consistency of the subjective happiness scale, the emotional regulation scale, and the motivational orientation questionnaire. SPSS, version 22.0, was used in the data treatment. When comparing the dimensions of emotional regulation with performance, it can be seen that athletes with lower sports scores have higher levels of emotional control and emotional self-awareness. As far as situational responsiveness is concerned, only the emotional self-control dimension and the emotional self-awareness dimension show an influence on the income, although, contrary to what would be expected, they appear to be associated with lower incomes. When comparing the motivational orientation with the athletic performance, it is verified that the athletes with the highest performance present an ego-oriented motivation, evidencing the athletes with a lower performance athletic tendency towards the task orientation. Only the ego-oriented dimension seems to be associated with high sport performance. The motivational orientation for the ego and the dimensions emotional control and emotional self-awareness are presented in this study as having influence on sports performance. Following these studies that have shown concern with the characterization of the best athletes and the promotion of higher sports performances, this work contributes to the signaling of psychological variables associated with high sports income.

Keywords: subjective well-being, emotional regulation, motivational orientation, sports performance

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3 Analysing Time Series for a Forecasting Model to the Dynamics of Aedes Aegypti Population Size

Authors: Flavia Cordeiro, Fabio Silva, Alvaro Eiras, Jose Luiz Acebal

Abstract:

Aedes aegypti is present in the tropical and subtropical regions of the world and is a vector of several diseases such as dengue fever, yellow fever, chikungunya, zika etc. The growth in the number of arboviruses cases in the last decades became a matter of great concern worldwide. Meteorological factors like mean temperature and precipitation are known to influence the infestation by the species through effects on physiology and ecology, altering the fecundity, mortality, lifespan, dispersion behaviour and abundance of the vector. Models able to describe the dynamics of the vector population size should then take into account the meteorological variables. The relationship between meteorological factors and the population dynamics of Ae. aegypti adult females are studied to provide a good set of predictors to model the dynamics of the mosquito population size. The time-series data of capture of adult females of a public health surveillance program from the city of Lavras, MG, Brazil had its association with precipitation, humidity and temperature analysed through a set of statistical methods for time series analysis commonly adopted in Signal Processing, Information Theory and Neuroscience. Cross-correlation, multicollinearity test and whitened cross-correlation were applied to determine in which time lags would occur the influence of meteorological variables on the dynamics of the mosquito abundance. Among the findings, the studied case indicated strong collinearity between humidity and precipitation, and precipitation was selected to form a pair of descriptors together with temperature. In the techniques used, there were observed significant associations between infestation indicators and both temperature and precipitation in short, mid and long terms, evincing that those variables should be considered in entomological models and as public health indicators. A descriptive model used to test the results exhibits a strong correlation to data.

Keywords: Aedes aegypti, cross-correlation, multicollinearity, meteorological variables

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2 Depressive-Like Behavior in a Murine Model of Colorectal Cancer Associated with Altered Cytokine Levels in Stress-Related Brain Regions

Authors: D. O. Miranda, L. R. Azevedo, J. F. C. Cordeiro, A. H. Dos Santos, S. F. Lisboa, F. S. Guimarães, G. S. Bisson

Abstract:

Background: The Colorectal cancer (CRC) is one of the most common cancers and the fourth leading cause of cancer death in the world. The prevalence of psychiatric-disorders among CRC patients, mainly depression, is high, resulting in impaired quality of life and side effects of primary treatment. High levels of proinflammatory cytokines at tumor microenvironment is a feature of CRC and the literature suggests that those mediators could contribute to the development of psychiatric disorders. Nevertheless, the ability of tumor-associated biological processes to affect the central nervous system (CNS) has only recently been explored in the context of symptoms of depression and is still not well understood. Therefore, the aim of the present study was to test the hypothesis that depressive-like behavior in an experimental model of CCR induced by N-methyl-N-nitro-N-nitrosoguanidine (MNNG) was correlated to proinflammatory profile in the periphery and in the brain. Methods: Colorectal carcinogenesis was induced in adult C57BL/6 mice (n=12) by administration of MNNG (5mg/kg, 0.1ml/intrarectal instillation) 2 times a week, for 2 week. Control group (n=12) received saline (0.1ml/intrarectal instillation). Eight weeks after beginning of MNNG administration animals were submitted to the forced swim test (FST) and the sucrose preference test for evaluation, respectively, of depressive- and anhedonia-like behaviors. After behavioral evaluation, the colon was collected and brain regions dissected (cortex-C, striatum-ST and hippocampus-HIP) for posterior evaluation of cytokine levels (IL-1β, IL-10, IL-17, and CX3CL1) by ELISA. Results: MNNG induced depressive-like behavior, represented by increased immobility time in the FST (Student t test, p < 0.05) and lower sucrose preference (Student t test, p < 0.05). Moreover, there were increased levels of IL-1β, IL-17 and CX3CL1 in the colonic tissue (Student t test, p < 0.05) and in the brain (IL-1 β in the ST and HIP, Student t test, p < 0.05; IL-17 and CX3CL1 in the C and HIP, p < 0.05). IL-10 levels, in contrast, were decreased in both the colon (p < 0.05) and the brain (C and HIP, p < 0.05). Conclusions: The results obtained in the present work support the notion that tumor growth induces neuroinflammation in stress-related brain regions and depressive-like behavior, which could be related to the high incidence of depression in colorectal carcinogenesis. This work have important clinical and research implications, taken into account that cytokine levels may be a marker promissory for the developing depression in CRC patients. New therapeutic strategies to assist in alleviating mental suffering in cancer patients might result from a better understanding of the role of cytokines in the pathophysiology of depression in these subjects.

Keywords: cytokines, brain, depression, colorectal cancer

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1 Green Production of Chitosan Nanoparticles and their Potential as Antimicrobial Agents

Authors: L. P. Gomes, G. F. Araújo, Y. M. L. Cordeiro, C. T. Andrade, E. M. Del Aguila, V. M. F. Paschoalin

Abstract:

The application of nanoscale materials and nanostructures is an emerging area, these since materials may provide solutions to technological and environmental challenges in order to preserve the environment and natural resources. To reach this goal, the increasing demand must be accompanied by 'green' synthesis methods. Chitosan is a natural, nontoxic, biopolymer derived by the deacetylation of chitin and has great potential for a wide range of applications in the biological and biomedical areas, due to its biodegradability, biocompatibility, non-toxicity and versatile chemical and physical properties. Chitosan also presents high antimicrobial activities against a wide variety of pathogenic and spoilage microorganisms. Ultrasonication is a common tool for the preparation and processing of polymer nanoparticles. It is particularly effective in breaking up aggregates and in reducing the size and polydispersity of nanoparticles. High-intensity ultrasonication has the potential to modify chitosan molecular weight and, thus, alter or improve chitosan functional properties. The aim of this study was to evaluate the influence of sonication intensity and time on the changes of commercial chitosan characteristics, such as molecular weight and its potential antibacterial activity against Gram-negative bacteria. The nanoparticles (NPs) were produced from two commercial chitosans, of medium molecular weight (CS-MMW) and low molecular weight (CS-LMW) from Sigma-Aldrich®. These samples (2%) were solubilized in 100 mM sodium acetate pH 4.0, placed on ice and irradiated with an ultrasound SONIC ultrasonic probe (model 750 W), equipped with a 1/2" microtip during 30 min at 4°C. It was used on constant duty cycle and 40% amplitude with 1/1s intervals. The ultrasonic degradation of CS-MMW and CS-LMW were followed up by means of ζ-potential (Brookhaven Instruments, model 90Plus) and dynamic light scattering (DLS) measurements. After sonication, the concentrated samples were diluted 100 times and placed in fluorescence quartz cuvettes (Hellma 111-QS, 10 mm light path). The distributions of the colloidal particles were calculated from the DLS and ζ-potential are measurements taken for the CS-MMW and CS-LMW solutions before and after (CS-MMW30 and CS-LMW30) sonication for 30 min. Regarding the results for the chitosan sample, the major bands can be distinguished centered at Radius hydrodynamic (Rh), showed different distributions for CS-MMW (Rh=690.0 nm, ζ=26.52±2.4), CS-LMW (Rh=607.4 and 2805.4 nm, ζ=24.51±1.29), CS-MMW30 (Rh=201.5 and 1064.1 nm, ζ=24.78±2.4) and CS-LMW30 (Rh=492.5, ζ=26.12±0.85). The minimal inhibitory concentration (MIC) was determined using different chitosan samples concentrations. MIC values were determined against to E. coli (106 cells) harvested from an LB medium (Luria-Bertani BD™) after 18h growth at 37 ºC. Subsequently, the cell suspension was serially diluted in saline solution (0.8% NaCl) and plated on solid LB at 37°C for 18 h. Colony-forming units were counted. The samples showed different MICs against E. coli for CS-LMW (1.5mg), CS-MMW30 (1.5 mg/mL) and CS-LMW30 (1.0 mg/mL). The results demonstrate that the production of nanoparticles by modification of their molecular weight by ultrasonication is simple to be performed and dispense acid solvent addition. Molecular weight modifications are enough to provoke changes in the antimicrobial potential of the nanoparticles produced in this way.

Keywords: antimicrobial agent, chitosan, green production, nanoparticles

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