Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Prev Med ; 169: 107451, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36796589

RESUMO

Adolescent girls consistently report worse mental health than boys. This study used reports from a 2018 national health promotion survey (n = 11,373) to quantitatively explore why such gender-based differences exist among young Canadians. Using mediation analyses and contemporary social theory, we explored mechanisms that may explain differences in mental health between adolescents who identify as boys versus girls. The potential mediators tested were social supports within family and friends, engagement in addictive social media use, and overt risk-taking. Analyses were performed with the full sample and in specific high-risk groups, such as adolescents who report lower family affluence. Higher levels of addictive social media use and lower perceived levels of family support among girls mediated a significant proportion of the difference between boys and girls for each of the three mental health outcomes (depressive symptoms, frequent health complaints, and diagnosis of mental illness). Observed mediation effects were similar in high-risk subgroups; however, among those with low affluence, effects of family support were somewhat more pronounced. Study findings point to deeper, root causes of gender-based mental health inequalities that emerge during childhood. Interventions designed to reduce girls' addictive social media use or increase their perceived family support, to be more in line with their male peers, could help to reduce differences in mental health between boys and girls. Contemporary focus on social media use and social supports among girls, especially those with low affluence, warrant study as the basis for public health and clinical interventions.


Assuntos
Transtornos Mentais , Adolescente , Feminino , Humanos , Masculino , Canadá , Transtornos Mentais/epidemiologia , Fatores Sexuais , Saúde Mental , Nível de Saúde
2.
SSM Popul Health ; 16: 100946, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34746359

RESUMO

OBJECTIVES: Adolescent mental health is an emergent clinical and public health priority in Canada. Gender-based differences in mental health are well established. The objective of this study was to evaluate a new data mining technique to identify social locations of young Canadians where differences in mental health between adolescent males and females were most pronounced. METHODS: We examined reports from 21,221 young Canadians aged 11-15 years (10,349 males, 10,872 females) who had responded to a 2018 national health and health behaviours survey. Using recursive partitioning for subgroup identification (SIDES), we identified social locations that were associated with the strongest differences between males and females for three reported mental health outcomes: positive psychosomatic health, symptoms of depression, and having a diagnosed mental illness. RESULTS: The SIDES algorithm identified both established and new intersections of social factors that were associated with gender-based differences in mental health experiences, most favouring males. DISCUSSION: This analysis represents a novel proof-of-concept to demonstrate the utility of a subgroup identification algorithm to reveal important differences in mental health experiences between adolescent males and females. The algorithm detected new social locations (i.e., where gender intersected with other characteristics) associated with poor mental health outcomes. These findings set the stage for further intersectional research, involving both quantitative and qualitative analyses, to explore how axes of discrimination may intersect to shape potential gender-based health inequalities that emerge during childhood.

3.
Eur Arch Paediatr Dent ; 19(3): 197-203, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29767382

RESUMO

AIM: This study was to compare the success of resin-modified Portland cement-based material (TheraCal) with MTA in direct pulp capping (DPC) of primary molars. METHODS: Symmetrical bilateral primary molars (92) from 46 healthy subjects aged 5-7 years were included in this split-mouth randomised clinical trial. DPC for small non-contaminated pulp exposures using either TheraCal or MTA were randomly performed in symmetrical molars. Thereafter, teeth were restored with amalgam. Clinical and radiographic evaluations were performed at 6 and 12 month follow-ups. Data were analysed using Chi square test at a significance level of 0.05. RESULTS: At the final follow-up session 74 teeth were available. After 12 months, the overall success rates for MTA and TheraCal were 94.5 and 91.8%, respectively. The difference between outcomes of the two groups was not statistically significant (P > 0.05). CONCLUSION: Within the limitations of the current study, radiographic and clinical findings revealed that TheraCal exhibited a comparable outcome to MTA in DPC of primary molars after 12 months.


Assuntos
Compostos de Alumínio , Compostos de Cálcio , Capeamento da Polpa Dentária/métodos , Óxidos , Agentes de Capeamento da Polpa Dentária e Pulpectomia , Silicatos , Criança , Pré-Escolar , Combinação de Medicamentos , Humanos , Dente Molar , Cimentos de Resina , Cimento de Silicato , Dente Decíduo
4.
Eur Arch Paediatr Dent ; 19(2): 113-116, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29330841

RESUMO

BACKGROUND: Traumatic tooth avulsion requires an urgent intervention to replant the tooth. Prolonged post-injury dry extra-oral conditions worsen the prognosis and increase the risk of root resorption. Fluoride has the potential to delay replacement resorption. Calcium silicate cements (CSC) are used to seal the root canal system and to stimulate periapical regeneration in immature open apex teeth (apexification). This report suggests the application of a novel fast-setting CSC with fluoride for apexification in an attempt to hinder root resorption. CASE REPORT: A delayed replantation of an avulsed open apex permanent central incisor after 75 h of storage in a dry condition in a 6-year-old girl. Standard treatment guidelines for avulsed immature permanent teeth were followed. After tooth replantation a novel fast-setting, CSC containing fluoride was used for apexification. FOLLOW-UP: The radiographic and clinical evaluations over a period of 3 years demonstrated periodontal bone healing without root resorption, mobility, and ankylosis and an acceptable periapical tissue tolerance to the novel CSC. However, a longer follow-up period is needed. CONCLUSIONS: Delayed replantation of the avulsed open apex permanent incisor after 75 h of storage under dry conditions and apexification with a novel fast-setting CSC showed a successful outcome after 3 years. Novel CSC with fluoride demonstrated an acceptable biocompatibility and tissue tolerance.


Assuntos
Apexificação/métodos , Compostos de Cálcio/uso terapêutico , Cimentos Dentários/uso terapêutico , Fluoretos/uso terapêutico , Incisivo/lesões , Silicatos/uso terapêutico , Avulsão Dentária/cirurgia , Reimplante Dentário/métodos , Criança , Feminino , Seguimentos , Humanos
5.
Neuroscience ; 305: 372-83, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26272536

RESUMO

Prenatal morphine exposure throughout pregnancy can induce a series of neurobehavioral and neurochemical disturbances by affecting central nervous system development. This study was designed to investigate the effects of an enriched environment on behavioral deficits and changes in hippocampal brain-derived neurotrophic factor (BDNF) levels induced by prenatal morphine in rats. On pregnancy days 11-18, female Wistar rats were randomly injected twice daily with saline or morphine. Offspring were weaned on postnatal day (PND) 21. They were subjected to a standard rearing environment or an enriched environment on PNDs 22-50. On PNDs 51-57, the behavioral responses including anxiety and depression-like behaviors, and passive avoidance memory as well as hippocampal BDNF levels were investigated. The light/dark (L/D) box and elevated plus maze (EPM) were used for the study of anxiety, forced swimming test (FST) was used to assess depression-like behavior and passive avoidance task was used to evaluate learning and memory. Prenatal morphine exposure caused a reduction in time spent in the EPM open arms and a reduction in time spent in the lit side of the L/D box. It also decreased step-through latency and increased time spent in the dark side of passive avoidance task. Prenatal morphine exposure also reduced immobility time and increased swimming time in FST. Postnatal rearing in an enriched environment counteracted with behavioral deficits in the EPM and passive avoidance task, but not in the L/D box. This suggests that exposure to an enriched environment during adolescence period alters anxiety profile in a task-specific manner. Prenatal morphine exposure reduced hippocampal BDNF levels, but enriched environment significantly increased BDNF levels in both saline- and morphine-exposed groups. Our results demonstrate that exposure to an enriched environment alleviates behavioral deficits induced by prenatal morphine exposure and up-regulates the decreased levels of BDNF. BDNF may contribute to the beneficial effects of an enriched environment on prenatal morphine-exposed to rats.


Assuntos
Analgésicos Opioides/toxicidade , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Meio Ambiente , Hipocampo/metabolismo , Transtornos Mentais , Morfina/toxicidade , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Fatores Etários , Análise de Variância , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto , Transtornos Mentais/metabolismo , Transtornos Mentais/enfermagem , Transtornos Mentais/patologia , Gravidez , Ratos , Ratos Wistar , Natação/psicologia , Fatores de Tempo
6.
Spectrochim Acta A Mol Biomol Spectrosc ; 137: 1004-15, 2015 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-25286113

RESUMO

In the present study, zinc sulfide nanoparticle loaded on activated carbon (ZnS-NP-AC) simply was synthesized in the presence of ultrasound and characterized using different techniques such as SEM and BET analysis. Then, this material was used for brilliant green (BG) removal. To dependency of BG removal percentage toward various parameters including pH, adsorbent dosage, initial dye concentration and contact time were examined and optimized. The mechanism and rate of adsorption was ascertained by analyzing experimental data at various time to conventional kinetic models such as pseudo-first-order and second order, Elovich and intra-particle diffusion models. Comparison according to general criterion such as relative error in adsorption capacity and correlation coefficient confirm the usability of pseudo-second-order kinetic model for explanation of data. The Langmuir models is efficiently can explained the behavior of adsorption system to give full information about interaction of BG with ZnS-NP-AC. A multiple linear regression (MLR) and a hybrid of artificial neural network and partial swarm optimization (ANN-PSO) model were used for prediction of brilliant green adsorption onto ZnS-NP-AC. Comparison of the results obtained using offered models confirm higher ability of ANN model compare to the MLR model for prediction of BG adsorption onto ZnS-NP-AC. Using the optimal ANN-PSO model the coefficient of determination (R(2)) were 0.9610 and 0.9506; mean squared error (MSE) values were 0.0020 and 0.0022 for the training and testing data set, respectively.


Assuntos
Carvão Vegetal/química , Modelos Químicos , Nanopartículas/química , Redes Neurais de Computação , Compostos de Amônio Quaternário/química , Sulfetos/química , Compostos de Zinco/química , Purificação da Água/métodos
7.
Spectrochim Acta A Mol Biomol Spectrosc ; 132: 639-54, 2014 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-24892545

RESUMO

The influence of variables, namely initial dye concentration, adsorbent dosage (g), stirrer speed (rpm) and contact time (min) on the removal of methyl orange (MO) by gold nanoparticles loaded on activated carbon (Au-NP-AC) and Tamarisk were investigated using multiple linear regression (MLR) and artificial neural network (ANN) and the variables were optimized by partial swarm optimization (PSO). Comparison of the results achieved using proposed models, showed the ANN model was better than the MLR model for prediction of methyl orange removal using Au-NP-AC and Tamarisk. Using the optimal ANN model the coefficient of determination (R2) for the test data set were 0.958 and 0.989; mean squared error (MSE) values were 0.00082 and 0.0006 for Au-NP-AC and Tamarisk adsorbent, respectively. In this study a novel and green approach were reported for the synthesis of gold nanoparticle and activated carbon by Tamarisk. This material was characterized using different techniques such as SEM, TEM, XRD and BET. The usability of Au-NP-AC and activated carbon (AC) Tamarisk for the methyl orange from aqueous solutions was investigated. The effect of variables such as pH, initial dye concentration, adsorbent dosage (g) and contact time (min) on methyl orange removal were studied. Fitting the experimental equilibrium data to various isotherm models such as Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich models show the suitability and applicability of the Langmuir model. Kinetic models such as pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion models indicate that the second-order equation and intraparticle diffusion models control the kinetic of the adsorption process. The small amount of proposed Au-NP-AC and activated carbon (0.015 g and 0.75 g) is applicable for successful removal of methyl orange (>98%) in short time (20 min for Au-NP-AC and 45 min for Tamarisk-AC) with high adsorption capacity 161 mg g(-1) for Au-NP-AC and 3.84 mg g(-1) for Tamarisk-AC.


Assuntos
Algoritmos , Compostos Azo/isolamento & purificação , Carvão Vegetal/química , Ouro/química , Nanopartículas Metálicas/química , Redes Neurais de Computação , Tamaricaceae/química , Adsorção , Corantes/isolamento & purificação , Concentração de Íons de Hidrogênio , Cinética , Modelos Lineares , Nanopartículas Metálicas/ultraestrutura , Porosidade , Espectrofotometria Ultravioleta , Temperatura , Fatores de Tempo
8.
Spectrochim Acta A Mol Biomol Spectrosc ; 131: 606-14, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-24858196

RESUMO

In this research, a novel adsorbent gold nanoparticle loaded on activated carbon (Au-NP-AC) was synthesized by ultrasound energy as a low cost routing protocol. Subsequently, this novel material characterization and identification followed by different techniques such as scanning electron microscope(SEM), Brunauer-Emmett-Teller(BET) and transmission electron microscopy (TEM) analysis. Unique properties such as high BET surface area (>1229.55m(2)/g) and low pore size (<22.46Å) and average particle size lower than 48.8Å in addition to high reactive atoms and the presence of various functional groups make it possible for efficient removal of 1,3,4-thiadiazole-2,5-dithiol (TDDT). Generally, the influence of variables, including the amount of adsorbent, initial pollutant concentration, contact time on pollutants removal percentage has great effect on the removal percentage that their influence was optimized. The optimum parameters for adsorption of 1,3,4-thiadiazole-2, 5-dithiol onto gold nanoparticales-activated carbon were 0.02g adsorbent mass, 10mgL(-1) initial 1,3,4-thiadiazole-2,5-dithiol concentration, 30min contact time and pH 7. The Adaptive neuro-fuzzy inference system (ANFIS), and multiple linear regression (MLR) models, have been applied for prediction of removal of 1,3,4-thiadiazole-2,5-dithiol using gold nanoparticales-activated carbon (Au-NP-AC) in a batch study. The input data are included adsorbent dosage (g), contact time (min) and pollutant concentration (mg/l). The coefficient of determination (R(2)) and mean squared error (MSE) for the training data set of optimal ANFIS model were achieved to be 0.9951 and 0.00017, respectively. These results show that ANFIS model is capable of predicting adsorption of 1,3,4-thiadiazole-2,5-dithiol using Au-NP-AC with high accuracy in an easy, rapid and cost effective way.


Assuntos
Carvão Vegetal/química , Poluentes Ambientais/isolamento & purificação , Ouro/química , Nanopartículas Metálicas/química , Tiadiazóis/isolamento & purificação , Tolueno/análogos & derivados , Adsorção , Modelos Lineares , Nanopartículas Metálicas/ultraestrutura , Modelos Químicos , Modelos Moleculares , Tolueno/isolamento & purificação
9.
Ecotoxicol Environ Saf ; 96: 110-7, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23849465

RESUMO

In the present study, activated carbon (AC) simply derived from Pistacia khinjuk and characterized using different techniques such as SEM and BET analysis. This new adsorbent was used for methylene blue (MB) adsorption. Fitting the experimental equilibrium data to various isotherm models shows the suitability and applicability of the Langmuir model. The adsorption mechanism and rate of processes was investigated by analyzing time dependency data to conventional kinetic models and it was found that adsorption follow the pseudo-second-order kinetic model. Principle component analysis (PCA) has been used for preprocessing of input data and genetic algorithm optimization have been used for prediction of adsorption of methylene blue using activated carbon derived from P. khinjuk. In our laboratory various activated carbon as sole adsorbent or loaded with various nanoparticles was used for removal of many pollutants (Ghaedi et al., 2012). These results indicate that the small amount of proposed adsorbent (1.0g) is applicable for successful removal of MB (RE>98%) in short time (45min) with high adsorption capacity (48-185mgg(-1)).


Assuntos
Algoritmos , Carvão Vegetal/química , Azul de Metileno/química , Modelos Genéticos , Pistacia/química , Adsorção , Lógica Fuzzy , Cinética , Análise de Componente Principal
10.
J Clin Pediatr Dent ; 36(2): 127-32, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22524072

RESUMO

AIM: The present study evaluated the effect of listening to a pictorial story about going to the dentist on pain perception, situational anxiety and behavioral feedback during dental treatment in pediatric dental patients. STUDY DESIGN: Eighty, 6-7-year-old children were included The childhood anxiety-related disorders using Screen for Child Anxiety Related Disorders (SCARED) Parent Version scale and intelligence quotient using Raven's Progressive Matrices were evaluated The subjects were randomly assigned to two groups, listening to a pictorial story about going to a dentist (test), or listening to a pictorial story about going to a barbershop (control). A dental treatment was performed on each subject, during which, behavior was assessed using Sound, Eye, and Motor Scale. Pain perception and situational anxiety were then assessed using Wong-Baker Fasces Pain Rating Scale and Faces version of the Modified Child Dental Anxiety Scale, respectively. RESULTS: There was a significant decrease in pain perception (P=0.02) and situational anxiety (P<0.001) in the test group. In addition, the test intervention significantly improved children behavioral feedback during dental treatment (P<0.001). CONCLUSION: Preparation of children with pictorial story can be effective in decreasing pain perception and situational anxiety as well as improving behavior during dental treatment.


Assuntos
Comportamento Infantil , Terapia Cognitivo-Comportamental/métodos , Ansiedade ao Tratamento Odontológico/prevenção & controle , Percepção da Dor , Educação de Pacientes como Assunto/métodos , Leitura , Análise de Variância , Distribuição de Qui-Quadrado , Criança , Método Duplo-Cego , Feminino , Humanos , Inteligência , Masculino , Escala de Ansiedade Manifesta , Medição da Dor
11.
Neuroscience ; 151(4): 1173-83, 2008 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-18207332

RESUMO

The beneficial effects of exercise on learning and memory are well documented but the effects of prenatal exposure to maternal exercise on offspring are not clear yet. Using a two-trial-per-day Morris water maze for five consecutive days, succeeded by a probe trial 2 days later we showed that maternal voluntary exercise (wheel running) by pregnant rats increased the acquisition phase of the pups' learning. Maternal forced swimming by pregnant rats increased both acquisition and retention phases of the pups' learning. Also we found that the rat pups whose mother was submitted to forced-swimming during pregnancy had significantly higher brain, liver, heart and kidney weights compared with their sedentary counterparts. On the other hand we estimated the cell number of different regions of the hippocampus in the rat pups. We found that both exercise models during pregnancy increased the cell number in cornus ammonis subregion 1 (CA1) and dentate gyrus of the hippocampus in rat pups. To determine the role that noradrenergic and serotonergic neurotransmission and N-methyl-D-aspartate (NMDA) receptors hold in mediation of the maternal exercise in offspring, we used N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4), p-chloroamphetamine (PCA) and MK-801 to eliminate or block the above systems, respectively. Blocking the NMDA receptors, significantly abolished learning and memory in rat pups from all three experimental groups. Elimination of noradrenergic or serotonergic input did not significantly attenuate the learning and memory in rat pups whose mothers were sedentary, while it significantly reversed the positive effects of maternal exercise during pregnancy on rat pups' learning and memory. The presented results suggest that noradrenergic and serotonergic systems in offspring brain seem to have a crucial specific role in mediating the effects of maternal physical activity during pregnancy on rat pups' cognitive function in both models of voluntary and forced exercise.


Assuntos
Comportamento Materno/fisiologia , Memória/fisiologia , Norepinefrina/metabolismo , Condicionamento Físico Animal/fisiologia , Serotonina/metabolismo , Percepção Espacial/fisiologia , Análise de Variância , Animais , Animais Recém-Nascidos , Comportamento Animal , Benzilaminas/toxicidade , Corticosterona/sangue , Feminino , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Memória/efeitos dos fármacos , Gravidez , Ratos , Ratos Wistar , Tempo de Reação/fisiologia , Percepção Espacial/efeitos dos fármacos , Natação , p-Cloroanfetamina/toxicidade
12.
Neuroscience ; 149(4): 729-38, 2007 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-17945427

RESUMO

Previous studies indicated that stress levels of glucocorticoid hormones (cortisol in humans, and corticosterone in rodents) induce impairment of long-term memory retrieval, but the underlying mechanisms (genomic or nongenomic) are not clear. To clarify this issue, we investigated the involvement of brain corticosteroid receptors and protein synthesis in the corticosterone-induced impairment of memory retrieval. Young rats were trained in the water maze task with six trials per day for 6 consecutive days. Retention of the spatial training was assessed 24 h after the last training session with a 60-s probe trial. Experiments included intraventricular injections of anisomycin, a specific protein synthesis inhibitor or specific antagonists for both types of corticocosteroid receptors (mineralocorticoid receptor, MR, and glucocorticoids receptor, GR) before corticosterone administration shortly before retention testing. The results showed that administration of anisomycin did not change the corticosterone response. Administration of the MR, but not GR, antagonist blocked the corticosterone-induced response dose dependently. These findings provide evidence for the view that glucocorticoids impair memory retrieval through nongenomic mechanisms involving an interaction with central MRs.


Assuntos
Corticosterona , Transtornos da Memória/metabolismo , Receptores de Mineralocorticoides/fisiologia , Animais , Anisomicina/administração & dosagem , Comportamento Animal , Relação Dose-Resposta a Droga , Vias de Administração de Medicamentos , Interações Medicamentosas , Antagonistas de Hormônios/administração & dosagem , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Transtornos da Memória/induzido quimicamente , Mifepristona/administração & dosagem , Inibidores da Síntese de Proteínas/administração & dosagem , Ratos , Ratos Wistar , Espironolactona/administração & dosagem , Natação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...