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This article introduces a novel model of asymmetric neural networks combined with fractional difference memristors, which has both theoretical and practical implications in the rapidly evolving field of computational intelligence. The proposed model includes two types of fractional difference memristor elements: one with hyperbolic tangent memductance and the other with periodic memductance and memristor state described by sine functions. The authenticity of the constructed memristor is confirmed through fingerprint verification. The research extensively investigates the dynamics of a coupled neural network model, analyzing its stability at equilibrium states, studying bifurcation diagrams, and calculating the largest Lyapunov exponents. The results suggest that when incorporating sine memristors, the model demonstrates coexisting state variables depending on the initial conditions, revealing the emergence of multi-layer attractors. The article further demonstrates how the memristor state shifts through numerical simulations with varying memductance values. Notably, the study emphasizes the crucial role of memductance (synaptic weight) in determining the complex dynamical characteristics of neural network systems. To support the analytical results and demonstrate the chaotic response of state variables, the article includes appropriate numerical simulations. These simulations effectively validate the presented findings and provide concrete evidence of the system's chaotic behavior.
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Redes Neurais de ComputaçãoRESUMO
Chemical reactions form the basis of life and understanding the different patterns and unpredictable changes in the reactions are noteworthy in real life situations. The article aims at constructing a mathematical model of two step reversible chemical reactions with a Caputo fractional difference operator. The reversible reaction involves the breakdown of an ester compound in the presence of water followed by the formation of fatty acid salts from the reaction of a free fatty acid with alkali hydroxide, such as NaOH. Using bifurcation diagrams, the chaotic response exhibited by the system is illustrated for state variables with identical fractional order and variables with non-identical fractional orders. The changes in periodic states of the system are investigated for each state variables with time varying plots and maximum Lyapunov exponents using the Jacobian matrix method are presented in support of the bifurcation diagrams. The synchronization of the subsystems of the proposed system is achieved with nonlinear control functions. Numerical simulations are presented to provide comparison of commensurate and incommensurate order models. Understanding the nature of these processes has significant applications in the production of bio-fuels from vegetable oils and animal fats by a transesterification reaction.
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Our review focused on nanomaterials-based toxicity evaluation and its exposure to the human and aquatic animals when it was leached and contaminated in the environment. Ecotoxicological assessment and its mechanism mainly affect the skin covering layers and its preventive barriers that protect the foreign particles' skin. Nanoscale materials are essential in the medical field, especially in biomedical and commercial applications such as nanomedicine and drug delivery, mainly in therapeutic treatments. However, various commercial formulations of pharmaceutical drugs are manufactured through a series of clinical trials. The role of such drugs and their metabolites has not met the requirement of an individual's need at the early stage of the treatments except few drugs and medicines with minimal or no side effects. Therefore, biology and medicines are taken up the advantages of nano scaled drugs and formulations for the treatment of various diseases. The present study identifies and analyses the different nanoparticles and their chemical components on the skin and their effects due to penetration. There are advantageous factors available to facilitate positive and negative contact between dermal layers. It creates a new agenda for an established application that is mainly based on skin diseases.
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Background & objectives: Uncorrected refractive error and cataract are the two most common causes of impairment of vision among elderly persons, and both are treatable. Treatment-seeking in patients is driven by symptom (decreased vision) rather than any anatomical or physiological measurement. The objective of this study was to evaluate the treatment-seeking behavior and barriers to treatment-seeking among elderly persons with impairment of vision in an urban resettlement colony of New Delhi, India. Methods: This community-based, cross-sectional study was conducted among 604 persons aged ≥60 yr selected by the simple random sampling. House-to-house visit was done, and a self-developed pretested semi-structured interview schedule was used to collect socio-demographic information, treatment-seeking behaviour and barriers to treatment-seeking. Results: Majority of participants reported impairment of vision (84%); 16.5 per cent of them did not visit any healthcare facility for their vision problem. Lack of felt need (48.1%) was the most common barrier to visiting healthcare facility. Of the 401 participants who gave a history of being prescribed spectacles, 277 (69%) used spectacles. Discomfort, lack of improvement in vision and lack of felt need were the most common reasons cited for non-usage. Among 300 participants who gave a history of cataract, 61 (20.3%) had not undergone cataract surgery. Lack of felt need was the most common barrier to cataract surgery. Interpretation & conclusions: A substantial proportion of elderly persons in the urban community have impairment of vision. Lack of felt need was the main reason for not visiting healthcare facility. As quality of spectacles was an important reported deterrent to use of spectacles, provision of appropriate refraction services and low-cost, good quality spectacles would be important.
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Catarata , Erros de Refração , Idoso , Estudos Transversais , Óculos , Humanos , Índia/epidemiologia , Prevalência , Erros de Refração/diagnóstico , Erros de Refração/epidemiologia , Erros de Refração/terapiaRESUMO
Surface enhanced Raman spectroscopy (SERS) measurements are conventionally performed using assemblies of metal nanostructures on a macro- to micro-sized substrate or by dispersing colloidal metal nanoparticles directly onto the sample of interest. Despite intense use, these methods allow neither the removal of the nanoparticles after a measurement nor a defined confinement of the SERS measurement position. So far, tip enhanced Raman spectroscopy is still the key technique in this regard but not adequate for various samples mainly due to diminished signal enhancement compared to other techniques, poor device fabrication reproducibility, and cumbersome experimental setup requirements. Here, we demonstrate that a rational combination of only four gold nanoparticles (AuNPs) on a DNA origami template, and single silicon nanowires (SiNWs) yield functional optical amplifier nanoprobes for SERS. These nanoscale SERS devices offer a spatial resolution below the diffraction limit of light and still a high electric field intensity enhancement factor ( EF) of about 105 despite of miniaturization.
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DNA/química , Ouro/química , Nanopartículas Metálicas/química , Nanofios/química , Silício/química , Análise Espectral Raman/métodos , Azul de Metileno/análise , Modelos Moleculares , Propriedades de SuperfícieAssuntos
Tuberculose Pulmonar , Tuberculose , Suplementos Nutricionais , Progressão da Doença , Humanos , Vitamina ARESUMO
AIM: The aim of this study is to assess the knowledge, attitude, and impact of pictorial warnings present on tobacco packets among patients attending outpatient department of a dental college of Bangalore city. MATERIALS AND METHODS: A cross-sectional study was conducted among 419 patients through convenience sampling, using a structured close-ended questionnaire containing 35 questions. The participants were approached and invited to participate voluntarily. The data obtained were analyzed using descriptive statistics, Chi-square test and ANOVA. RESULTS: Mean age of the participants was 28.1 ± 7.06 years. Out of total 419 participants, 62.8% were tobacco users. About 40.6% of the participants had average knowledge and only 22.9% had positive attitude regarding the pictorial warnings. Nearly 77.9% of tobacco users had previously attempted decreased frequency of tobacco use and 63.7% had tried quitting the habit. The difference was statistically significant (P < 0.05 Chi-square test and ANOVA). CONCLUSION: The present study revealed that most of study participants have noticed the warnings on tobacco products, and most of them believe that they could understand warning labels. This study also showed that most of study participants believed that pictorial health warnings create awareness about probable health hazards of tobacco use and that these pictorial presentations on tobacco packs positively assist in reducing or quitting tobacco smoking.