Propriedade fotoluminescente da ZrO2: Tb+3, Eu+3, Tm+3 obtida pelo método de polimerização de complexos

Recent studies are investigating a new class of inorganic materials which arise as a promising option for high performance applications in the field of photoluminescence. Highlight for rare earth (TR +3 ) doped, which have a high luminous efficiency, long decay time and being able to emit radiation in the visible range, specific to each element. In this study, we synthesized ZrO2: Tb +3 , Eu +3 , Tm +3 nanoparticles complex polymerization method (CPM). We investigated the influences caused by the heat treatment temperature and the content of dopants in zirconia photoluminescent behavior. The particles were calcined at temperature of 400, 500 and 600 ° C for two hours and ranged in concentration of dopants 1, 2, 4 and 8 mol% TR +3 . The samples were characterized by thermal analysis, X-ray diffraction, photoluminescence of measurements and uv-visible of spectroscopies. The results of X-ray diffraction confirmed the formation of the tetragonal and cubic phases in accordance with the content of dopants. The photoluminescence spectra show emission in the region corresponding simultaneous to blue (450 nm), green (550 nm) and red (615 nm). According to the results, ZrO2 particles co-doped with rare earth ions is a promising material white emission with a potential application in the field of photoluminescence

Propriedade fotoluminescente da ZrO2: Tb+3, Eu+3, Tm+3 obtida pelo método de polimerização de complexos

Recent studies are investigating a new class of inorganic materials which arise as a promising option for high performance applications in the field of photoluminescence. Highlight for rare earth (TR +3 ) doped, which have a high luminous efficiency, long decay time and being able to emit radiation in the visible range, specific to each element. In this study, we synthesized ZrO2: Tb +3 , Eu +3 , Tm +3 nanoparticles complex polymerization method (CPM). We investigated the influences caused by the heat treatment temperature and the content of dopants in zirconia photoluminescent behavior. The particles were calcined at temperature of 400, 500 and 600 ° C for two hours and ranged in concentration of dopants 1, 2, 4 and 8 mol% TR +3 . The samples were characterized by thermal analysis, X-ray diffraction, photoluminescence of measurements and uv-visible of spectroscopies. The results of X-ray diffraction confirmed the formation of the tetragonal and cubic phases in accordance with the content of dopants. The photoluminescence spectra show emission in the region corresponding simultaneous to blue (450 nm), green (550 nm) and red (615 nm). According to the results, ZrO2 particles co-doped with rare earth ions is a promising material white emission with a potential application in the field of photoluminescence

Avaliação de efeitos de um extrato de "três bailarinas" em modelos experimentais em diferentes níveis de organização biológica

Drogas naturais ou sintéticas podem ser capazes de alterar a sobrevivência de culturas bacterianas, interferir na marcação de estruturas sanguíneas com tecnécio- 99m (99mTc) e alterar a morfologia das hemácias. De acordo com as instruções do fabricante, a formula denominada de Três Bailarinas (TB) é sugerida para ser usada, como bebida, por pessoas que desejam ajustar o peso sem dieta. Os ingredientes dessa fórmula são a Cassia angustifolia e a Malva verticellate. Informações cientificas sobre TB não foram encontradas no indexador PubMed, e esse fato tem estimulado nossas investigações sobre seus efeitos biológicos. O objetivo deste estudo foi avaliar, em diferentes modelos experimentais, o efeito de um extrato aquoso de Três Bailarinas: (i) na sobrevivência de culturas de E. coli AB1157, ii) efeito do SnCl2 em culturas bacterianas, iii) na marcação das hemácias e proteínas plasmáticas e celulares com 99mTc e iv) na morfologia de hemácias de sangue de ratos Wistar. Os resultados encontrados demonstram que o extrato de TB não alterou a sobrevivência de cultura de E. coli AB1157 e aboliu o efeito letal do SnCl2 na sobrevivência dessa cultura bacteriana. Na marcação de estruturas sangüíneas com 99mTc o extrato de TB reduziu a percentagem de atividade (%ATI) referente ao 99mTc no compartimento celular e nas proteínas plasmáticas, mas não alterou a %ATI nas proteínas celulares. O extrato de TB não foi capaz de alterar a morfologia das hemácias. Os modelos experimentais realizados mostram a importância dos mesmos na avaliação de efeitos biológicos de agentes químicos, e contribui para um melhor entendimento das propriedades do extrato de Três Bailarinas. Esse trabalho abrange varias áreas do conhecimento, tais como: radiobiologia, botânica, fitoterapia e hematologia

Obtenção de sistemas multiparticulados de isoniazida revestidos com polímero de liberação entérica

Known for thousands of years, tuberculosis (TB) is the leading cause of mortality by a single infectious disease due to lack of patient adherence to available treatment regimens, the rising of multidrug resistant strains of TB (MDR-TB) and co-infection with HIV virus. Isoniazid and rifampicin are the most powerful bactericidal agents against M. tuberculosis. Because of that, this couple of drugs becomes unanimity in anti-TB treatment around the world. However, the rifampicin in acidic conditions in the stomach can be degraded rapidly, especially in the presence of isoniazid, which reduces the amount of available drug for absorption, as well as its bioavailability, contributing to the growing resistance to tuberculostatic drugs. Rifampicin is well absorbed in the stomach because of its high solubility between pH 1 and 2 and the gastric absorption of isoniazid is considered poor, therefore it is mostly intestinal. This work has as objective the development of gastro-resistant multiple-systems (granules and pellets) of isoniazid aiming to prevent the contact with rifampicin, with consequent degradation in acid stomach and modulate the release of isoniazid in the intestine. Granules of isoniazid were obtained by wet method using both alcoholic and aqueous solutions of PVP K-30 as aggregating and binder agent, at proportions of 5, 8 and 10%. The influence of the excipients (starch, cellulose or filler default) on the physical and technological properties of the granules was investigated. The pellets were produced by extrusionesferonization technique using isoniazid and microcrystalline cellulose MC 101 (at the proportion of 85:15) and aqueous solution of 1% Methocel as platelet. The pellets presented advantages over granular, such as: higher apparent density, smaller difference between apparent and compaction densities, smoother surface and, especially, smaller friability, and then were coated with an organic solution of Acrycoat L 100 ® in a fluidized bed. Different percentages of coating (15, 25 and 50%) were applied to the pellets which had their behavior evaluated in vitro by dissolution in acidic and basic medium. Rifampicin dissolution in the presence of uncoated and coated isoniazid pellets was evaluated too. The results indicate that the gastro resistance was only achieved with the greatest amount of coating and isoniazid is released successfully in basic step. The amount of rifampicin in the dissolution medium when the isoniazid pellets were not coated was lower than in the presence of enteric release pellets. Therefore, the polymer Acrycoat L 100 ® was efficient for coating with gastro-resistant function and can solve the problem of low bioavailability of rifampicin and help to reduce its dosage

A organização do dots em um distrito sanitário de Natal/RN, 2009

Tuberculosis is an ancient disease that remains a serious problem of Public Health, requiring a pressing attention. Advances in the knowledge and technology available to control it has not been sufficient to significantly impact on morbidity and mortality, especially in developing countries. To enable patient compliance with TB treatment, preventing the abandonment of this to ensure the correct use of medicines has been suggested the DOTS (Directly Observed Treatment - Short course) or directly Observable Short Course Treatment. This study focuses on the incorporation of two technical components of the DOTS strategy at the Family Health, namely, active search for respiratoy symptoms and Supervisioned Treatment (ST). The West Sanitary District was considered best suited to be the focus of study because it is assumed that those sites that were better structured would provide better information about the situation of the strategy in the municipality. Its purpose is to analyze the organization of DOTS as the active search for respiratory symptoms and Directly Observed Therapy in Health Teams Family belonging to a Health District in the city of Natal, Brazil. An exploratory descriptive study with a quantitative approach which involved health professionals from 11 units of Family Health, West Sanitary District, Natal, Rio Grande do Norte. We interviewed 62 professionals on the professional category, their involvement in the DOTS strategy, managers' contributions to the sustainability of the strategy, actions Search for symptomatic diagnosis and supervised treatment of TB cases and difficulties and facilities for the sustainability of the DOTS strategy. It is concluded that the actions taken by the professionals of the FHS West Health District are organized in more supervised treatment, a fact noted in their perceptions about DOTS

A busca de sintomáticos respiratórios de tuberculose na prática e perspectiva do agente comunitário de saúde nos distritos sanitários de Natal

The objective of this work - which is characterized analyze the search for symptomatic tuberculosis in practice and perspective of the Community Health Agent (ACS) in the districts of Natal. Methods: This is a cross-sectional study. The study population was 646 professionals, and conducted a probabilistic random sampling, stratified by districts. The data were collected from one instrument to collect data based on Primary Care Assesment Toll (PCAT) and analyzed by descriptive statistics. The sample consisted of ACS was 87% female. Among the study participants 58% completed high school and 120 months of exercise training (95% CI 111.9 to 129.5) on average. 90% were USF. The average follow-up of cases found were 2 cases of TB since the beginning of the career of the ACS and the last three years the average is presented in a case accompanied. The ACS received satisfactory ratings on the bond of trust with the user, so as access to homes in the community. The ACS reported for denying the fear of being positive result was the biggest reason for not performing the sputum. All units have a professional that responds to the Tuberculosis Control Program. Regarding the structural capacity of primary care settings for the diagnosis of TB, we observed satisfactory levels in different districts of pots for sputum collection, however, a point that deserves attention from managers is lack of materials for packaging sputum. Fear of positive result was one of the reasons for the refusal of sputum collection, followed by alcoholism. With regard to TB suspects, all responded that ACS always suspect when the user has TB coughs, but in all districts were noticed at low delivery of requests for applications for smear. BSR in TB control, is characterized in practice as a complex action goes beyond technical expertise and contact with the family that breaks with the Cartesian. The BSR is part of the ACS can perform them from the daily visits. We conclude that the ACS is difficult to achieve. This practice should not be the privilege of this actor, but the entire team of primary care. We must rethink the practices of TB care, seeing the health surveillance while aegis of the working process of primary care teams for early diagnosis and thereby reduce TB in communities

Desempenho dos serviços de atenção primária do município de Natal/RN para o diagnóstico e controle da tuberculose

Tuberculosis (TB) is one of the most important health problems being faced worldwide. In Brazil, the responsibility for the actions of to diagnosis and control of this disease was transferred to the municipalities within the Primary Health Care (PHC), aiming at improvement in epidemiological indicators, requiring reorientation of the practice of family health teams and requiring methodologies to analyze the extent to which components of the PHC are being achieved. Thus, this study aims to analyze the performance of primary care services in the city of Natal-RN for the diagnosis and control of TB, from the perspective of health professionals (doctors and nurses). The study is descriptive, cross-sectional and quantitative. Data collection was conducted from March to July 2011 and involved 121 health professionals working in 52 health units (family health unit, basic health unit and mixed units). The instrument is structured based on the Primary Care Assessment Tool (PCAT), validated and adapted to assess attention to TB in Brazil, and includes questions regarding the Structure and Process components of health services. For quantitative analysis, it was constructed indicators, whose response patterns are followed according to the Likert scale between one and five, which meant the degree of preference relation (or agreement) of the claims. Values between 1 and 3 were considered unsatisfactory for the indicator, between 3 and less than 4, regular, and between 4 and 5, satisfactory. With regard to inputs and equipment, the units had satisfactory condition for form (  = 4.26), consultation (  = 4.02) and basic basket (  = 4.24); regular condition to pot (  = 3.56) and unsatisfactory conditions for transportation tickets (  = 1.50) and sputum smear microscopy (  = 2.42) and X-rays (  = 1.07). In relation to actions, there was satisfactory development for those focused on the individual patient. Actions aimed at the collective level, as the search for respiratory symptoms (RS), monitoring of contacts and guidelines for the community ranged from regular to unsatisfactory (  = 3.16 -  = 1.34). With regard to training, 94,2% received training to identify RS. As regards the time for diagnosis, the median time elapsed between the identification of RS and the beginning of treatment it was 22 days. In relation to the difficulties faced by professionals in the diagnosis of TB, 56,2% reported that they are related only to health services, especially for the failure in the rearguard laboratory and in the specialized services reference, the lack of human and material resources and low performing an active search. The professionals perceive the performance of diagnosis and control of TB, permeated with limitations and barriers to organizational and operational character of various sizes, emerging the need for effective coordination of various sectors and key stakeholders of TB care, to adoption of a new intersectoral strategies that aim to increase the responsiveness of the PHC, providing the best performance in service delivery to the user, family and community, and ensuring effective action and resolving the needs of this population group.

As ações de controle da tuberculose na atenção primária à saúde: a visão do doente

Tuberculosis is a disease of great impact on the world context today. In Brazil, the disease management was directed to the Primary Health Care, due to the determination of the Ministry of Health to decentralize health actions for primary care. Thus, since the actions of diagnosis, treatment and control of the disease should happen in this context, however, there are still many barriers that may hinder the realization of these determinations. This study aims to analyze the development of tuberculosis control activities conducted in the services of primary health care from the patient's vision. This is a descriptive, cross-sectional and quantitative study. The population consists of 517 tuberculosis patients treated in units of Primary Health Care in the city of Natal-RN; the sample consists of 93 TB patients. The collect instrument is structured, based in The Primary Care Assessment Tool (PCAT), validated in Brazil and adapted to assess attention to TB in Brazil, with modifications. This instrument was divided into blocks: the first one describes the socio-demographic information of patients with TB and the second one describes the health services working in control, diagnosis and treatment of TB, and includes issues related to the dimensions of primary care: access, bond, services, coordination of care, guidance to the community and family focus. For quantitative analysis, were built indicators for each item of the instrument. The response patterns are followed according to the Likert scale, which was assigned a value between one and five meant that the degree of preference relation (or agreement) of the statements. Values between 1 and 3 were considered unsatisfactory for the indicator, between 3 and less than 4, regular, and between 4 and 5, satisfactory. The results indicate that 62.37% of patients are male, 27.96% aged 41 to 50 years old, and 34.41% unemployed, with low education and low family income. It was found that the reference hospital services are the front door to the patient (59.14%), and are also the local diagnosis of the disease (72.04%). On access, the conditions satisfactory found are: the number of times the patients need to pick up the health care issue, the marking and the facility to get a consultancy in the HS, assistance provided without harm to the individual's attendance labor and facilities related to the proximity between the residence and services; were considered unsatisfactory conditions related to travel to the HS, and on hours and days of operation of services. As for the cast of services were satisfactory and regular actions related to the request for examination to become viable in the first HS, the availability of pot to perform smear and medicines for the treatment, as well as consultations control and receiving information about the disease and the treatment performed; it is considered unsatisfactory the performance of the home care for patients with TB by the HS that acts as a front door, for implementation of the Directly Observed Treatment (DOT), home visits during treatment, the provision of transportation allowance to the patient and the existence of groups for TB patients. Regarding the coordination of care, resulted in regular the action of referring the patient to other HS to obtain examinations, and as unsatisfactory referral to obtain medications. The relationship bond between patient and health team were considered satisfactory in the majority or regular. As for the family and community focus, is satisfactory only the indicator relating to questions from professionals to the patient about the existence of respiratory symptoms in the family. It is considered that there is need for greater commitment from government entities to the incentives required to TB control, as well as the availability of necessary inputs and training of human resources working in the PHC in the ongoing quest to strengthen primary care, as a place of broader host needs to contact the user with the actions and health professionals. It is recommended the adoption of management mechanisms possible to expand the capacity of the health PHC, promoting the service delivery to the user and ensuring attention to population health.

O conhecimento e as atitudes das famílias de pacientes em tratamento em tuberculose na atenção primária à saúde

This study thus sought to examine knowledge about TB and attitudes of patients families in disease treatment in Primary Health Care in Natal- RN. To this end, a cross-sectional study was undertaken through a questionnaire with families of patients diagnosed with TB and follow up by APS from Natal. The study subjects were recruited from a non-probabilistic way, by convenience, contemplating a sample of 50 families. Among the criteria considered for inclusion of subjects, older than 18 years were considered, as well as residing with the TB patient and in Natal and availability to participate in the research. Data collection was performed by own researcher and an assistant, through a questionnaire with families of patients diagnosed with TB following the double independent digitalization of data. In the analytical phase, was initially conducted an exploratory phase and univariate data, with description of the position measurements (mean, median, mode) and dispersion (confidence interval and standard deviation). In bivariate analysis, it was conducted an intersection of dependent variables of knowledge e and changes of attitude dichotomous, with each of the independent variables, using contingency tables and calculating the chi-square test and, when appropriate, the Fisher exact test. In 2x2 tables, calculated the odds ratio (OR) with confidence intervals of 95% (95% CI). From the selected sample, 43 (86%) subjects were female, average age and median respectively of 46.64 and 46.50 years, 25 (50%) had elementary school. The knowledge expressed by family members about TB was considered satisfactory. However, the lack of interest of the family (54%) in seeking information about tuberculosis; the wrong way of reply in relation to the organism causing the disease (64%); the water content (62%) and contaminated food (54% ) as a means of spreading TB was a weakness identified in the investigation. Regarding the time of transmission, 90% of respondents indicated not know or answered wrong. From investigated independent variables, only two were associated with lack of knowledge of TB, and they did not have religion (OR: 0.146, 95% CI: 0.027 to 0.800) and income below 1, 7 minimum wages (OR: 0.155, 95% CI: 0.029 to 0.813). Thus they seem to exercise a protective effect on this outcome. As for the changes in attitude, most of the found variables had no association with statistical significance, except no internet access (OR: 0.212, 95% CI: 0,048-0, 935). Most attitudes were positive in relation to TB patient. Results have demonstrated weaknesses in TB care, which has taken on a more individual and welfare character. Data not only express health outcomes produced by health services, but also the political and social situation of the families that are affected by TB

Estudo do Cultivo de dois clones de Escherichia coli recombinantes (eIF, LACK) para a Expressão de Antígenos da Leishmania chagasi

With advent of the technology of the recombinant DNA, the recombinant protein expression becomes an important tool in the studies of the structure, function and identification of new proteins, mainly with therapeutical purposes. The Escherichia coli has been procarioto predominant in the studies of genetic engineering due to wealth of information regarding its metabolism. Despite the expressivo advance of the studies of molecular biology and the immunology of the infections, it does not exist, currently, no prophylactic drug capable to prevent calazar. Of this form, it exists a great necessity of specific antigen identification for the vaccine development and kits for disgnostic against the visceral Leishmaniose. In this context, this work objectified to study the recombinant antigen expression of the Leishmania chagasi during the culture of Escherichia coli in shaker. A first set of assays was carried through with the objective of if knowing the kinetic behavior of the growth of two clones recombinant proteins (eIF, LACK) in two different compositions of culture medium (2xTY, TB) supplemented by antibiotics, without IPTG addition. In the second stage of the assays, the procedure of induction for IPTG was carried through, in order to verify the influence of the composition of the ways tested in the expression them recombinant proteins. On the basis of the gotten results, can be observed that the high complexity of culture medium favored the kinetic one of growth of clones recombinant (eIF, LACK), however, to if to deal with the assays submitted to the procedure of induction for IPTG, the raised complexity of culture medium did not favor the expression of recombinant proteins. On the other hand, they had been gotten resulted positive for all clones recombinant (eIF, LACK) tested, confirmed through the eletroforético profile

Avaliação de dois clones de Escherichia coli recombinante quanto ao crescimento e expressão de antígenos de Leishmania chagasi (kmp11 e P36)

Visceral leishmaniosis caused by Leishmania chagasi, also known as calazar, presented, in the period from 1990 to 2005, tax of incidence in Brazil varying between 1 and 3 cases for 100 000 inhabitants. The Northeast region that up to the year of 2000 contributed with almost 90% of the registered cases is reducing his participation in the current decade, reaching 56% in 2005. Conventional leishmaniasis treatment is costly and it shows high toxicity, demanding more research for alternative treatments, with special interest in development of vaccines and diagnosis kits which include production of recombinant antigens by host cells. Escherichia coli has been the microorganism most studied and used as a host for recombinant protein production. Therefore, the aim of this work was to study the influence of induction on cellular growth and to verify the type of Leishmania chagasi antigens expression (intra or extracellular) during two recombinant E. coli clones (kmp11 and P36) cultivation in rotary incubator (shaker) using three different media (2xTY, TB, FASS+EL). For that, tests were carried out using conditions established in the literature for E. coli (37°C and 200 rpm) and media supplemented with antibiotics to guarantee that only competent cells grows. First, tests were carried out without induction in order to verify the two microorganisms kinetic behavior (growth and substrate consumption) in different media. Next, the induction was carried out through the addition of IPTG (1mM as final concentration), at the first hour of cultivation. It was observed that protein expression were intracellular for all clones and media tested, however the highest level of expression was clearly observed by the electrophoresis band density (intensity) for 2xTY medium and kmp11 protein. Although it contains the lowest substrate concentration, consequently, a reduced cellular concentration when compared to other media, it appeared that this medium and clone combination is the most indicated for recombinant protein production. Therefore, the objective of this work was achieved, since the interested proteins were produced. Consequently, this result motivates new studies for production optimization using different cultivation strategies

Influência das condições de cultivo na produção de antígenos recombinantes de Leishmania i. chagasi utilizando Escherichia coli M15 cultivada em incubador rotativo e biorreator

Escherichia coli has been one of the most widely used hosts in recombinant protein production, in both laboratory and industrial scale since the advent of recombinant DNA technology. Despite the substantial progress of studies on the molecular biology and immunology of infections, there is currently no medication-based prophylaxis capable of preventing leishmaniasis. As such, there is a great need to identify specific antigens for the development of vaccines and diagnostic kits against visceral leishmaniasis. Thus, the primary goal of the present study is to assess the influence of cultivation conditions on the production of Leishmania chagasi antigens, carried out in a rotating incubator and bioreactor. To that end, several assays were conducted to evaluate the kinetic behavior of antigens (648, 503) of Leishmania. i. chagasi in two different compositions of media (2xTY, TB), with and without an inducer. In order to improve expression, assays were performed in a benchtop bioreactor using the best conditions obtained in a rotating incubator, in addition to assessing the influence of stirring speed. Results show that high complexity of the cultivation medium favored kinetic growth of clones (648, 503). However, in assays submitted to induction by IPTG, this elevated complexity did not promote the expression of recombinant proteins. Expression of antigens 648 and 503 exhibited behavior associated with growth and, in terms of location, proteins 648 and 503 are intracellularly stored. Lactose may be the most adequate inducer in protein expression, when considering factors, cost, toxicity and stability. Elevated stirring may increase cell growth in clone 53, although it may not result in high concentrations for the protein of interest. On the other hand, positive results were obtained for all recombinant clones (648, 503) tested, confirmed by the electrophoretic profile

Efeito in vitro da terapia fotodinâmica sobre bactérias orais em suspensão e na formação de biofilme : ensaio com azul de metileno e toluidina ativados por luz halógena

Photodynamic therapy (PDT) has been proposed as an alternative method for the treatment of biofilm-dependent oral diseases like dental caries. This therapy consists of simultaneous action of a visible light (L) and a photosensitizer (FS) in the presence of oxygen, which leads to production of different reactive oxygen species that can interact with the bacterial cell components, and promote cell death. This study aims to evaluate the antimicrobial action of PDT on oral bacteria in suspension, as well as the formation of mono and multi-species biofilms, in vitro, from a standard strain of Streptococcus mutans (ATCC 25175) and saliva samples, respectively. The dye methylene blue (MB) and toluidine blue (TB) were used at a concentration of 100 mg/ L and activated by halogen light (600 to 750 nm) from a modified hand held photopolymerizer (Ultralux ®, Dabi Atlante, Ribeirão Preto , São Paulo, Brazil.). Planktonic cultures were prepared and submitted to different experimental conditions: 1. PDT using TB 2. PDT using MB, 3. L+ FS- , 4. TB + L - ; 5. MB+ L-; 6. L- FS- (negative control) and 7. administration of 0.12% chlorhexidine digluconate (positive control) (Periogard ®, Colgate-Palmolive Company, New York, USA). The immediate and mediated action of PDT on bacterial suspensions, as well as its effect on biofilm formation were observed from the number of colony-forming units per milliliter (CFU/mL) and measures optical density (OD). The data were statistically analyzed using the Kruskal-Wallis and Mann-Whitney test for the significance level of 5%. According to the results, the PDT showed no antibacterial action on suspensions of S. mutans, regardless of the dye used. PDT with MB activated by halogen light was able to reduce 86.6% CFU/mL multi-species planktonic cultures, however, this reduction was not significant (p > 0.05). PDT showed antibacterial effect, mediate on multi-species planktonic cultures with TB (p < 0.001) and MB (p < 0.001), activated by halogen light. PDT was able to prevent the formation of multispecies biofilm, through the activation of TB by halogen light (p = 0.01). We conclude that activation of the dye toluidine blue and methylene blue, by halogen light (PDT) showed antimicrobial activity, compared to multi-species planktonic cultures prepared from saliva samples

Confecção e caracterização físico-química de filmes compósitos autossustentáveis NaAlg-TiO2-WO3

A new self-sustainable film was prepared through the sol-gel modified method, previously employed in our research group; sodium alginate was used as the polymer matrix, along with plasticizer glycerol, doped with titanium dioxide (TiO2) and tungsten trioxide (WO3). By varying WO3 concentration (0,8, 1,6, 2,4 and 3,2 μmol) and keeping TiO2 concentration constant (059 mmol), it was possible to study the contribution of these oxides on the obtained films morphological and electrical properties. Self-sustainable films have analyzed by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XDR), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and Electrochemical Impedance Spectroscopy (EIS). By the IR specters, it was possible identify the TiO2, and posteriorly WO3, addition has provided dislocation of alginate characteristics bands to smaller vibrations frequencies indicating an electrostatic interaction between the oxides and the polymer matrix. Diffractograms show predominance of the amorphous phase in the films. SEM, along with EDX, analysis revealed self-sustainable films showed surface with no cracks and relative dispersion of the oxides throughout the polymer matrix. From Impedance analysis, it was observe increasing WO3 concentration to 2,4 μmol provided a reduction of films resistive properties and consequent improvement of conductive properties