ABSTRACT
Objective Aiming at the problem that mechanical properties for the continuum of muscle tissues cannot be considered in active and passive behaviors of different structurally coupled muscles, a method of passive and active coupling in the same constitutive equation was proposed to construct ahyperelastic active and passive constitutive model of skeletal muscle continuum. Methods In order to calibrate parameters of the passive constitutive model, the uniaxial tensile experiment method and conditions were given, and through theoretical derivation, the specific method of using experimental data to solve the passive model parameters was introduced. In order to verify effectiveness of the active model, the model was verified with an example. Results The curves predicted by the model were in good agreement with the experimental output stress-stretch ratio curves. At the same strain, the maximum error of passive stress and total stress were only 20 kPa and 40 kPa. Conclusions The continuum hyperelastic constitutive model can better simulate active and passive behavior of skeletal muscles, which is beneficial for modeling and simulation of human muscles in further study.
ABSTRACT
Since noise-induced hearing loss (NIHL) is one of prevalent issues in the occupational settings, hearing protection device (HPD) has been widely used to reduce noise exposure levels and to prevent developing NIHL. This review study aimed to introduce several types of the HPD in terms of current trends, its variety and functions, and application. Including a brief history of the HPD, we explain its two types, i.e., passive and active functions, in the first part of main body. The passive HPD has a flat attenuation across the overall frequency range, whereas the active HPD effectively preserves communication components such as meaningful speech with low intensity stimuli while filtering out the high levels of noise. In the second part of the main body, we discuss some negative issues of hearing functions when users are wearing the HPD. In detail, the active HPD does not much degrade the hearing performance for speech detection/recognition and sound source localization compared to the passive HPD. Rather, reduced sound (or music) quality is improved with active one in general. In the final part, we mention that although various applications in the special fields such as factory, mining, army, airplane, and music have been demonstrated, the usage and awareness of HPD in occupational aspect may not follow its fast technological development. Furthermore, most people do not know about either importance or use method of HPD in the non-occupational setting. For these reasons, we conclude that hearing professionals have to access the latest trends of the HPD and to increase their knowledge on it, and thus they should provide the best HPD prescription for the public as well as employees who have to protect their ears from hazard noise impacts.
Subject(s)
Aircraft , Ear , Hearing Loss, Noise-Induced , Hearing , Methods , Mining , Music , Noise , Prescriptions , Public HealthABSTRACT
This study used topographic near-infrared spectroscopy (NIRS) to characterize frontal lobe activation while individuals actively or passively listened to exciting or calm music. Participants were 22 healthy female volunteers (mean age, 21± 4.1 years). Initial analysis showed that oxy-Hb significantly decreased in many channels when subjects listened to calm music. In contrast, oxy-Hb significantly increased when subjects listened to lively music. In addition, after listening to calm music, cortisol, α-amylase, and immunoglobulin A significantly decreased. A subsequent analysis showed that oxy-Hb signif-icantly increased when subjects listened to music while clapping to its rhythm compared with when subjects listened to music only. Our study suggests that calm music reduces levels of human stress and enables effective relaxation. In addition, our data suggests that clapping to the rhythm of music increases brain activation. Therefore, active music therapy may be more effective than passive music therapy with respect to brain activation. Such active therapy (i.e., playing rather than listening to music) may improve functional and psychological status, and cooperative abilities.
ABSTRACT
Mother-to-child transmission (MTCT)is an important way of hepatitis B virus (HBV)transmission.Blocking the HBV MTCT has a great significance for the prevention and treatment of hepatitis B.This article reviews the current blocking strategies implemented in the antepar-tum,peripartum,and postpartum stages,and summarizes the controversies existing in the blocking strategies in different stages.The significance of HBV occult infection and germ cell transmission in the HBV MTCT is analyzed.The results indicate that the current strategies for the prevention of hepatitis B MTCT need further improvement.Attentions should be focused on HBV occult infection and germ cell transmission.
ABSTRACT
Drug addiction is one of the most important health problems in the world. This psychiatry disease results in the death of about 500 000 individuals annually in the world. Despite this scenario, the development of effective drug therapies against this disease has been slow and not very successful. In recent years, new alternative pharmacological strategies against drug addiction have been designed and validated. Among them are vaccines against drugs like nicotine, morphine or cocaine and their subsequent use in immunotherapeutic pharmacological procedures for the treatment of addictive behaviors of drug consumption, both in animal models and in humans. These strategies are based on the experimental design and synthesis of various structural formulations of therapeutic vaccines against drugs of abuse. When dosed in active immunization schedules, they induce the production of specific antibodies, which recognize and bind these substances in the intravascular space and prevent the drug permeability through the blood brain barrier, resulting in decreased effects of drugs into the brain. In 2006, our research group at the National Institute of Psychiatry Ramón de la Fuente Muñiz (INPRFM) achieved and consolidated the design, synthesis, application and validation of immunoprotective therapeutic effects against relapse to morphine/heroin addiction in a rodent animal model, a model vaccine for potential human use against addiction to morphine/heroin. This model shows immunogenic capacities (high and sustained titers of highly specific antibodies) and immunoprotection (attenuates the effect up to 15mg/kg sc morphine) that the structural vaccine models competing have not been matched, which makes it the leading vaccine model against the addictive effects of heroin and morphine.
La adicción a una droga de abuso representa uno de los problemas sanitarios más importantes ya que esta patología genera la muerte de cerca de 500 000 sujetos anualmente en el mundo. A pesar de este panorama, el desarrollo de terapias farmacológicas efectivas contra esta enfermedad es lento y poco exitoso. En los últimos años se han diseñado y validado nuevas estrategias farmacológicas alternativas contra la adicción a drogas de abuso, como las vacunas y su uso en procedimientos farmacológicos inmunoterapéuticos para el tratamiento de esas conductas tanto en modelos de animales como en el humano. Estas nuevas estrategias experimentales están basadas en el diseño y síntesis de diversas formulaciones estructurales de vacunas terapéuticas contra las sustancias de abuso las cuales, al ser dosificadas en esquemas de inmunización activa, inducen la producción de anticuerpos séricos específicos que reconocen y se unen a estas sustancias en el espacio intravascular sistémico e impiden que crucen la barrera hematoencefálica, con lo cual disminuyen sus efectos en el cerebro. En el año 2006 nuestro grupo de trabajo en el Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz (INPRFM) logró y consolidó el diseño, síntesis, aplicación y validación de efectos terapéuticos inmunoprotectores contra recaídas al consumo adictivo de morfina/heroína, en un modelo animal con roedores y su escalamiento potencial para uso humano contra la adicción a esas sustancias. Este modelo muestra capacidades inmunogénicas (títulos altos y sostenidos de anticuerpos altamente específicos) y de inmunoprotección (atenúa el efecto de hasta 15mg/Kg sc de morfina) que los modelos estructurales de vacuna desarrollados por otros grupos de investigadores no han podido igualar. Esto lo convierte en un modelo líder de vacuna contra los efectos adictivos de la heroína y morfina.