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1.
Braz. j. biol ; 84: e254628, 2024. ilus
Artigo em Inglês | VETINDEX | ID: biblio-1364516

RESUMO

Insects' ethology is an important factor when it is desired to carry out pest management. This knowledge makes it possible to manipulate behavioral activities, repel, or attract insects according to needs and interests. The maize weevil Sitophilus zeamais (Mots., 1855) (Coleoptera: Curculionidae), one of the main stored grain pests, has been the target of studies of behavioral changes studies through natural substances due to its resistance to different insecticidal classes. Thus, this study aimed to evaluate the effect of sublethal concentrations of neem extract and copaiba oil on the locomotor behavior of S. zeamais. The behavioral characteristic considered were walking activity, the frequency of contact of insects with the treated grain mass, and the time spent for this behavior. The walking activity of the S. zeamais increased with exposure to Neem extract and Copaiba oil. In general, the Neem extract and Copaiba oil-induced more contact with grain mass than the control, suggesting an attractive effect on the insect, however more significant for the Neem oil. The insect's behavior was altered, presenting a specific path due to Copaiba oil and Neem extract stimuli. These results indicate that Copaiba oil and Neem extract can be a potential alternative for controlling S. zeamais on stored products since changes in this pests' behavior can reduce qualitative and quantitative grain damage. Thus, the development of products based on Copaiba oil and Neem extract may be helpful for storage pest management.


A etologia dos insetos é um fator importante quando se deseja relizar manejo de pragas. Através deste conhecimento, é possível manipular atividades comportamentais, repelir, ou atrair os insetos de acordo com as necessidades e interesses. O gorgulho do milho Sitophilus zeamais (Mots., 1855) (Coleoptera: Curculionidae), uma das principais pragas de grãos armazenados tem sido alvo de estudos de alterações comportamentais através de substâncias naturais devido à sua resistência a diferentes classes de insecticidas. Assim, este estudo teve como objetivo avaliar o efeito de concentrações subletais de extrato de neem e do óleo de copaíba sobre o comportamento de movimentação de S. zeamais. As características comportamentais consideradas foram: a atividade de caminhamento, a frequência do contato dos insetos com a massa de grãos tratada, e o tempo gasto para realização destes comportamentos. A atividade de caminhamento do S. zeamais aumentou quando os insetos foram expostos ao extrato de Neem e ao óleo de copaíba. Em geral, o extrato de Neem e o óleo de Copaíba induziram mais contato com a massa de grãos do que o controle, sugerindo um efeito atrativo sobre o inseto, contudo este efeito foi mais significativo para o óleo de Neem. O comportamento do inseto foi alterado, apresentando um caminhamento específico devido aos estímulos do óleo de copaíba e do extrato de Neem. Estes resultados indicam que o óleo de copaíba e o extrato de Neem podem ser alternativas potenciais para o controle do S. zeamais em produtos armazenados, uma vez que alterações no comportamento desta praga podem reduzir os danos qualitativos e quantitativos nos grãos. Assim, o desenvolvimento de produtos baseados no óleo de copaíba e no extrato de Neem pode ser útil para o manejo de pragas de armazenamento.


Assuntos
Óleos , Controle de Pragas , Zea mays
3.
Braz. j. biol ; 842024.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1469376

RESUMO

Abstract Insects' ethology is an important factor when it is desired to carry out pest management. This knowledge makes it possible to manipulate behavioral activities, repel, or attract insects according to needs and interests. The maize weevil Sitophilus zeamais (Mots., 1855) (Coleoptera: Curculionidae), one of the main stored grain pests, has been the target of studies of behavioral changes studies through natural substances due to its resistance to different insecticidal classes. Thus, this study aimed to evaluate the effect of sublethal concentrations of neem extract and copaiba oil on the locomotor behavior of S. zeamais. The behavioral characteristic considered were walking activity, the frequency of contact of insects with the treated grain mass, and the time spent for this behavior. The walking activity of the S. zeamais increased with exposure to Neem extract and Copaiba oil. In general, the Neem extract and Copaiba oil-induced more contact with grain mass than the control, suggesting an attractive effect on the insect, however more significant for the Neem oil. The insect's behavior was altered, presenting a specific path due to Copaiba oil and Neem extract stimuli. These results indicate that Copaiba oil and Neem extract can be a potential alternative for controlling S. zeamais on stored products since changes in this pests' behavior can reduce qualitative and quantitative grain damage. Thus, the development of products based on Copaiba oil and Neem extract may be helpful for storage pest management.


Resumo A etologia dos insetos é um fator importante quando se deseja relizar manejo de pragas. Através deste conhecimento, é possível manipular atividades comportamentais, repelir, ou atrair os insetos de acordo com as necessidades e interesses. O gorgulho do milho Sitophilus zeamais (Mots., 1855) (Coleoptera: Curculionidae), uma das principais pragas de grãos armazenados tem sido alvo de estudos de alterações comportamentais através de substâncias naturais devido à sua resistência a diferentes classes de insecticidas. Assim, este estudo teve como objetivo avaliar o efeito de concentrações subletais de extrato de neem e do óleo de copaíba sobre o comportamento de movimentação de S. zeamais. As características comportamentais consideradas foram: a atividade de caminhamento, a frequência do contato dos insetos com a massa de grãos tratada, e o tempo gasto para realização destes comportamentos. A atividade de caminhamento do S. zeamais aumentou quando os insetos foram expostos ao extrato de Neem e ao óleo de copaíba. Em geral, o extrato de Neem e o óleo de Copaíba induziram mais contato com a massa de grãos do que o controle, sugerindo um efeito atrativo sobre o inseto, contudo este efeito foi mais significativo para o óleo de Neem. O comportamento do inseto foi alterado, apresentando um caminhamento específico devido aos estímulos do óleo de copaíba e do extrato de Neem. Estes resultados indicam que o óleo de copaíba e o extrato de Neem podem ser alternativas potenciais para o controle do S. zeamais em produtos armazenados, uma vez que alterações no comportamento desta praga podem reduzir os danos qualitativos e quantitativos nos grãos. Assim, o desenvolvimento de produtos baseados no óleo de copaíba e no extrato de Neem pode ser útil para o manejo de pragas de armazenamento.

5.
Braz J Biol ; 83: e274149, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37820207

RESUMO

Pseudomonas aeruginosa is a non-lactose fermenting Gram-negative bacteria responsible for causing numerous nosocomial infections. The present research aimed to analyze the anti-Pseudomonas aeruginosa potential of 2-Chloro-N-(4-fluoro-3-nitrophenyl)acetamide (A8). The antibacterial potential of A8 was evaluated from the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Association using the checkerboard method. MIC and MBC values were 512 µg/mL for all P. aeruginosa strains evaluated, demonstrating predominantly bactericidal activity. Furthermore, when A8 was associated with the drug ceftriaxone, pharmacological additivity and indifference were evidenced. In this sense, the synthetic amide was interesting, since it demonstrates the potential to become a possible candidate for an antimicrobial drug.


Assuntos
Anti-Infecciosos , Ceftriaxona , Ceftriaxona/farmacologia , Pseudomonas aeruginosa , Amidas , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana
6.
Front Neurosci ; 17: 1131214, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36937673

RESUMO

With the increasing prevalence of Alzheimer's disease (AD) and difficulties in finding effective treatments, it is essential to discover alternative therapies through new approaches. In this regard, non-pharmacological therapies, such as physical exercise, have been proposed and explored for the treatment of AD. Recent studies have suggested that resistance exercise (RE) is an effective strategy for promoting benefits in memory and cognitive function, producing neuroprotective and anti-inflammatory effects, and reducing amyloid load and plaques, thereby reducing the risk, and alleviating the neurodegeneration process of AD and other types of dementia in the elderly. In addition, RE is the exercise recommended by the World Health Organization for the elderly due to its benefits in improving muscle strength and balance, and increasing autonomy and functional capacity, favoring improvements in the quality of life of the elderly population, who is more likely to develop AD and other types of dementia. In this mini-review, we discuss the impact of RE on humans affected by MCI and AD, and animal models of AD, and summarize the main findings regarding the effects of RE program on memory and cognitive functions, neurotrophic factors, Aß deposition and plaque formation, as well as on neuroinflammation. Overall, the present review provides clinical and preclinical evidence that RE plays a role in alleviating AD symptoms and may help to understand the therapeutic potential of RE, thereby continuing the advances in AD therapies.

7.
Front Immunol ; 14: 1256526, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38283335

RESUMO

Introduction: The combination of patterns is a frequent and challenging situation in the daily laboratory routine of autoantibodies testing using HEp-2 cells indirect immunofluorescence assay (HEp-2-IFA). Recently, the Brazilian Consensus on Autoantibodies (BCA) named these combinations as complex patterns (CPs) and organized them into 3 subtypes: multiple, mixed, and composite. This study aimed to describe the most frequent combinations of HEp-2-IIF patterns according to this new nomenclature. Methods: Routine HEp-2-IFA results reported in January and June 2017 were reviewed using the new BCA classification. Visual pattern recognition was performed by experts on HEp-2-IFA readings, using the International Consensus on Antinuclear Antibodies (ANA) Patterns (ICAP) and BCA recommendations. Results: 54,990 serum samples from different patients were tested for ANA-HEp-2, and 11,478 (20.9%) were positive at a titer ≥ 1/80. Among these positive samples, 1,111 (9.7%) displayed CPs, divided into 95 different combinations. A higher proportion of CPs was observed in the pediatric age group. Multiple, mixed, and composite patterns were present in 85.3, 5.4, and 9.5% of the samples, respectively. In the multiple/mixed pattern group (n=1,005), double, triple, and quadruple combinations (ICAP/BCA codes) were observed in 97.7%, 2.2%, and 0.1%, respectively. The double nuclear pattern was the most prevalent combination observed (67.6%). The most common CPs registered were AC-4 (nuclear fine speckled) + AC-6,7 (nuclear discrete dots) (n=264); AC-2 (nuclear dense fine speckled) + AC-6,7 (n=201); AC-4+AC-8,9,10 (nucleolar) (n=129); and AC-3 (centromere)+AC-4 (n=124). All of these combinations were in the multiple subgroup. Conclusion: Almost 10% of positive results in the HEp-2 procedure displayed CPs. Among the 3 subtypes of CPs proposed, the multiple pattern was the most prevalent, especially in the pediatric population. The AC-4, AC-2, and AC-6,7 were the most prevalent single patterns observed in the combinations described in this study. There was a significant association between age and the prevalence of most combined patterns. The AC-4+AC-6,7 combination was the most prevalent complex pattern detected regardless of the age group. The AC-2+AC-6,7 was more prevalent in younger individuals. The concepts involved in the CPs definition should add value to the reading and interpretation of the HEp-2-IIF assay.


Assuntos
Anticorpos Antinucleares , Autoanticorpos , Humanos , Criança , Técnica Indireta de Fluorescência para Anticorpo/métodos , Consenso , Brasil
8.
Braz. j. biol ; 83: e274149, 2023. tab
Artigo em Inglês | LILACS-Express | VETINDEX | ID: biblio-1513859

RESUMO

Abstract Pseudomonas aeruginosa is a non-lactose fermenting Gram-negative bacteria responsible for causing numerous nosocomial infections. The present research aimed to analyze the anti-Pseudomonas aeruginosa potential of 2-Chloro-N-(4-fluoro-3-nitrophenyl)acetamide (A8). The antibacterial potential of A8 was evaluated from the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Association using the checkerboard method. MIC and MBC values were 512 µg/mL for all P. aeruginosa strains evaluated, demonstrating predominantly bactericidal activity. Furthermore, when A8 was associated with the drug ceftriaxone, pharmacological additivity and indifference were evidenced. In this sense, the synthetic amide was interesting, since it demonstrates the potential to become a possible candidate for an antimicrobial drug.


Resumo Pseudomonas aeruginosa é uma bactéria Gram-negativa não fermentadora de lactose, responsável por causar inúmeras infecções nosocomiais. A presente pesquisa teve como objetivo analisar o potencial anti-Pseudomonas aeruginosa da molécula 2-Cloro-N-(4-fluoro-3-nitrofenil)acetamida (A8). O potencial antibacteriano do A8 foi avaliado a partir da Concentração Inibitória Mínima (CIM), Concentração Bactericida Mínima (CBM) e Associação pelo método de checkboard. Os valores de CIM e CBM foram de 512 µg/mL para todas as cepas de P. aeruginosa avaliadas, demonstrando atividade predominantemente bactericida. Além disso, quando o A8 foi associado ao fármaco ceftriaxona, evidenciou-se aditividade e indiferença farmacológica. Nesse sentido, a amida sintética se mostrou interessante, pois demonstra potencial para se tornar um possível candidato a fármaco antimicrobiano.

9.
Eur J Clin Nutr ; 76(12): 1705-1712, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35906333

RESUMO

Intrauterine environment can influence the offspring's body adiposity whose distribution affect the cardiometabolic risk. Underlying mechanisms may involve the gut microbiome. We investigated associations of gestational weight gain with the adult offspring's gut microbiota, body adiposity and related parameters in participants of the Nutritionists' Health Study. METHODS: This cross-sectional analysis included 114 women who had early life and clinical data, body composition, and biological samples collected. The structure of fecal microbiota was analyzed targeting the V4 region of the 16 S rRNA gene. Beta diversity was calculated by PCoA and PERMANOVA used to test the impact of categorical variables into the diversity. Bacterial clusters were identified based on the Jensen-Shannon divergence matrix and Calinski-Harabasz index. Correlations were tested by Spearman coefficient. RESULTS: Median age was 28 (IQR 24-31) years and BMI 24.5 (IQR 21.4-28.0) kg/m2. Fifty-eight participants were assigned to a profile driven by Prevotella and 56 to another driven by Blautia. Visceral adipose tissue was correlated to abundance of Acidaminococcus genus considering the entire sample (r = 0.37; p < 0.001) and the profiles (Blautia: r = 0.35, p = 0.009, and Prevotella: r = 0.38, p = 0.006). In Blautia-driven profile, the same genus was also correlated to maternal gestational weight gain (r = 0.38, p = 0.006). CONCLUSIONS: Association of Acidaminococcus with gestational weight gain could reinforce the relevance with mothers' nutritional status for gut colonization at the beginning of life. Whether Acidaminococcus abundance could be a marker for central distribution of adiposity in young women requires further investigation.


Assuntos
Ganho de Peso na Gestação , Adulto , Humanos , Feminino , Adiposidade , Acidaminococcus , Índice de Massa Corporal , Estudos Transversais , Filhos Adultos , Obesidade Abdominal , Obesidade
10.
Rev. med. Chile ; 150(6): 727-735, jun. 2022. ilus, tab
Artigo em Espanhol | LILACS | ID: biblio-1424125

RESUMO

BACKGROUND: Mammograms are one of the most effective preventive means for the early detection of breast cancer. OBJECTIVE: To describe the features of patients and results of mammograms performed at a public breast imaging service of the Santiago Metropolitan Area. MATERIAL AND METHODS: We reviewed the reports of mammograms performed on 174,017 women and 18 men, between 2008 and 2018 in an Imaging Center. The BI-RADS classification was used in the reports. RESULTS: Forty-six percent of mammograms (75,781) were reported as BI-RADS 2. The high proportion of BI-RADS 4 reports (674 reports) was seen in patients aged 40 to 49 years, corresponding to 30% of reports in this age range. Among patients aged 50 to 59 years, there were 779 BI-RADS 4 reports (35%). BI-RADS 5 reports were more common among patients aged 50 to 59 years (50 reports, 30%) and among patients aged 70 years or older (83 reports, 28%). CONCLUSIONS: The presence of a significant number of women between 40 and 49 years of age with a BI-RADS 4 mammography result stands out; being an opportunity to develop new clinical research and public health strategies within the framework of the Universal Health Care policy for breast cancer in Chile.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/diagnóstico por imagem , Mamografia/métodos , Chile/epidemiologia
11.
Med Oral Patol Oral Cir Bucal ; 27(4): e392-e396, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35368007

RESUMO

BACKGROUND: Oral and oropharyngeal cancer (OPC) is an important cause of morbidity and mortality worldwide. Populations in situations of social vulnerability tend to have higher incidences of cancer, a higher proportion of late diagnosis, greater difficulties in accessing health services, and, consequently, worse prognosis. The aim of this study was to evaluate the relationship between race/skin color and OPC prognosis in Brazil. MATERIAL AND METHODS: This is a cross-sectional epidemiological study using OPC data from the National Cancer Institute between the years 2000 and 2019. The selected variables were: gender, race/skin color, age, education, smoking and alcohol consumption, stage of the disease and disease status at the end of the 1st treatment. RESULTS: 154,214 cases were recorded. Black men, in the 6th decade of life, were the most affected population. Blacks had a lower level of education when compared to non-blacks (p<0.001). Blacks were more exposed to smoking and alcohol consumption (p<0.001). At the time of diagnosis, the black population was at the most advanced stage when compared to non-blacks (p<0.001). At the end of the 1st treatment, more black patients had disease in progression, as well as more black patients died (p<0.001). CONCLUSIONS: Blacks had a worse prognosis for OPC in Brazil. Despite the limitations, these results are important to elucidate the scenario of health disparities in relation to the race/skin color of the Brazilian population.


Assuntos
Neoplasias Bucais , Neoplasias Orofaríngeas , Brasil/epidemiologia , Estudos Transversais , Humanos , Masculino , Neoplasias Bucais/epidemiologia , Neoplasias Orofaríngeas/epidemiologia , Prognóstico , População Branca
12.
Braz J Biol ; 84: e254628, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35239787

RESUMO

Insects' ethology is an important factor when it is desired to carry out pest management. This knowledge makes it possible to manipulate behavioral activities, repel, or attract insects according to needs and interests. The maize weevil Sitophilus zeamais (Mots., 1855) (Coleoptera: Curculionidae), one of the main stored grain pests, has been the target of studies of behavioral changes studies through natural substances due to its resistance to different insecticidal classes. Thus, this study aimed to evaluate the effect of sublethal concentrations of neem extract and copaiba oil on the locomotor behavior of S. zeamais. The behavioral characteristic considered were walking activity, the frequency of contact of insects with the treated grain mass, and the time spent for this behavior. The walking activity of the S. zeamais increased with exposure to Neem extract and Copaiba oil. In general, the Neem extract and Copaiba oil-induced more contact with grain mass than the control, suggesting an attractive effect on the insect, however more significant for the Neem oil. The insect's behavior was altered, presenting a specific path due to Copaiba oil and Neem extract stimuli. These results indicate that Copaiba oil and Neem extract can be a potential alternative for controlling S. zeamais on stored products since changes in this pests' behavior can reduce qualitative and quantitative grain damage. Thus, the development of products based on Copaiba oil and Neem extract may be helpful for storage pest management.


Assuntos
Controle de Insetos , Inseticidas , Óleos Voláteis , Extratos Vegetais , Gorgulhos , Animais , Controle Comportamental , Inseticidas/farmacologia , Melia/química , Óleos Voláteis/farmacologia , Extratos Vegetais/farmacologia
13.
Rev Med Chil ; 150(6): 727-735, 2022 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-37906907

RESUMO

BACKGROUND: Mammograms are one of the most effective preventive means for the early detection of breast cancer. OBJECTIVE: To describe the features of patients and results of mammograms performed at a public breast imaging service of the Santiago Metropolitan Area. MATERIAL AND METHODS: We reviewed the reports of mammograms performed on 174,017 women and 18 men, between 2008 and 2018 in an Imaging Center. The BI-RADS classification was used in the reports. RESULTS: Forty-six percent of mammograms (75,781) were reported as BI-RADS 2. The high proportion of BI-RADS 4 reports (674 reports) was seen in patients aged 40 to 49 years, corresponding to 30% of reports in this age range. Among patients aged 50 to 59 years, there were 779 BI-RADS 4 reports (35%). BI-RADS 5 reports were more common among patients aged 50 to 59 years (50 reports, 30%) and among patients aged 70 years or older (83 reports, 28%). CONCLUSIONS: The presence of a significant number of women between 40 and 49 years of age with a BI-RADS 4 mammography result stands out; being an opportunity to develop new clinical research and public health strategies within the framework of the Universal Health Care policy for breast cancer in Chile.


Assuntos
Neoplasias da Mama , Mamografia , Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Chile/epidemiologia , Mamografia/métodos , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/epidemiologia
15.
Phys Chem Chem Phys ; 23(34): 18694-18706, 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34612407

RESUMO

The electronic properties of BaTiO3 perovskite oxides are not completely understood, despite their excellent electro-optical performance and potential for light generation. Particularly, when there is multiple peak formation in the photoluminescence spectra, their origins are not discussed. Their luminescence spectra reveal an unexpected thermodynamic relationship between the core excitonic states and the surface of the BaTiO3. These results give a broad insight into the origins of the emission properties of perovskite oxides. The self-trapped excitons contribution to the broadbands highlights their extrinsic origin. Through spectroscopy techniques and parallel factor analysis (PARAFAC) modeling, we demonstrate that additional broadbands are sensitive to extrinsic defects, type ν-CH3, a product of decomposition of 2-propanol. The presence of C-H bonds shows the dependence with the calcination temperature and the increase of the lattice expansion coefficient until 4.7 × 10-6 K-1 resulting in the contribution to the change of band gap with the temperature ((dEg/dT)P). In this work, we correlated the electronic properties of BaTiO3 with intrinsic and extrinsic defects and elucidated the presence of additional broadbands. This approach differentiates the contributions of excitonic states and surfaces, which is necessary to understand the electronic properties of perovskite oxides.

16.
Med Oral Patol Oral Cir Bucal ; 26(6): e778-e785, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34023843

RESUMO

BACKGROUND: Oral Potentially Malignant Disorders (OPMDs) are defined as lesions with a greater likelihood of progressing to cancer. Population-based studies that evaluate the prevalence of OPMDs are scarce in Brazil. The aim of the present study was to determine the prevalence of OPMDs and associated risk factors in a semi-urban Brazilian population. MATERIAL AND METHODS: This is a cross-sectional study, whose universe included individuals aged 40 years or older residing in a medium-sized city of northeastern Brazil. Data collection was divided into two steps: interview and oral examination. The outcome variable was the presence of OPMDs. The predictor variables were sociodemographic characteristics and risk habits. The bivariate analysis was performed through chi-square test. The crude prevalence ratios (PR) and its respective 95% confidence intervals (CI) were calculated. Poisson regression analysis with robust variance was used to calculate adjusted PRs and 95% CI. RESULTS: Three hundred fourteen individuals were included in the study. When asked about risk habits, 58.9% reported being current smokers or ex-smokers and 62.2% reported being current drinkers or ex-drinkers. The prevalence of OPMDs was 7.6% and was significantly higher among individuals with black skin color (p < 0.001), alcohol users (p = 0.017), and individuals with both tobacco and alcohol habits (p = 0.012). CONCLUSIONS: Therefore, the population in the present study had a high frequency of risk habits associated with PMDs of the oral cavity.


Assuntos
Neoplasias Bucais , Brasil/epidemiologia , Estudos Transversais , Humanos , Neoplasias Bucais/epidemiologia , Prevalência , Fatores de Risco
19.
Phys Chem Chem Phys ; 22(26): 15022-15034, 2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32597431

RESUMO

Photonic and electronic properties exist inherently in ferroelectric barium titanate (BaTiO3); severe luminescence quenching also exists due to the insufficient confinement of excitons. In this sense, high optical emission can only be achieved by its chemical and structural modification. Thin BaTiO3 and Er:BaTiO3 films were grown by the spin coating method on a glass substrate at room temperature. Self-trapping of excitons in the thin BaTiO3 film and its structural modification due to the doping with Er3+ ions (Er:BaTiO3) are verified using scanning confocal fluorescence microscopy (SCFM), where self-trapping excitons never occured in its pure state. By thermal treatment and doping (BaTiO3 and Er:BaTiO3) we obtained localization of the excitons, which would further induce lattice strain around the surface defects, to accommodate the self-trapped excitons. With such a self-trapped state, the structure of BaTiO3 generates broadband emission of several overlapping bands between 1.95 and 2.65 eV at room temperature, while the structure Er:BaTiO3 showed defined emission bands at 2.24 and 2.35 eV, with very weak contributions of the emission due to the self-trapping state. The influence of the variation of the excitation wavelength using 1PE and 2PE on the emission bands of BaTiO3 and Er:BaTiO3 is also investigated. The results of enhanced emission bands suggest a clear dependence of the emission intensity on the excitation energy, where a ∼3 fold enhancement in emission has been demonstrated under Er3+ (1.55 eV) excitation, which can be attributed to effective energy transfer between the Er3+ ions. As a result, it is concluded that the developed BaTiO3 and Er:BaTiO3 can pave the way for future photonic devices.

20.
Braz J Med Biol Res ; 53(5): e9255, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32348427

RESUMO

The neurochemical mechanisms underlying neuropathic pain (NP) are related to peripheral and central sensitization caused by the release of inflammatory mediators in the peripheral damaged tissue and ectopic discharges from the injured nerve, leading to a hyperexcitable state of spinal dorsal horn neurons. The aim of this work was to clarify the role played by cyclooxygenase (COX) in the lesioned peripheral nerve in the development and maintenance of NP by evaluating at which moment the non-steroidal anti-inflammatory drug indomethacin, a non-selective COX inhibitor, attenuated mechanical allodynia after placing one loose ligature around the nervus ischiadicus, an adaptation of Bennett and Xie's model in rodents. NP was induced in male Wistar rats by subjecting them to chronic constriction injury (CCI) of the nervus ischiadicus, placing one loose ligature around the peripheral nerve, and a sham surgery (without CCI) was used as control. Indomethacin (2 mg/kg) or vehicle was intraperitoneally and acutely administered in each group of rats and at different time windows (1, 2, 4, 7, 14, 21, and 28 days) after the CCI or sham surgical procedures, followed by von Frey's test for 30 min. The data showed that indomethacin decreased the mechanical allodynia threshold of rats on the first, second, and fourth days after CCI (P<0.05). These findings suggested that inflammatory mechanisms are involved in the induction of NP and that COX-1 and COX-2 are involved in the induction but not in the maintenance of NP.


Assuntos
Indometacina/administração & dosagem , Neuralgia/tratamento farmacológico , Medição da Dor , Nervo Isquiático/lesões , Animais , Constrição , Modelos Animais de Doenças , Masculino , Neuralgia/etiologia , Limiar da Dor , Ratos , Ratos Sprague-Dawley , Ratos Wistar
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