• JSTS:Journal of Semiconductor Technology and Science
• /
• 제16권3호
• /
• pp.319-329
• /
• 2016

High-level design aids are mandatory for design of a continuous-time delta-sigma modulator (CTDSM). This paper proposes a top-down methodology design to generate a noise transfer function (NTF) which is compensated for excess loop delay (ELD). This method is applicable to low pass loop-filter topologies. Non-ideal effects including ELD, integrator scaling issue, finite op-amp performance, clock jitter and DAC inaccuracies are explicitly represented in a behavioral simulation of a CTDSM. Mathematical modeling using MATLAB is supplemented with circuit-level simulation using Verilog-A blocks. Behavioral simulation and circuit-level simulation using Verilog-A blocks are used to validate our approach.

• 한국산학기술학회논문지
• /
• 제16권1호
• /
• pp.462-470
• /
• 2015

본 연구는 사회경제적 차이가 아동의 뇌기능과 문제행동증후에 미치는 영향에 대해서 살펴보았다. 장애, 질병 또는 인지기능에 문제가 없는 저소득층(LIC) 아동 30명, 중산층(MC)아동 30명을 대상으로 2013년 1월부터 4월까지 뇌기능 분석과 K-CBCL을 이용한 아동문제행증후의 데이터를 측정 분석하였다. 연구 결과는 첫째, LIC아동은 MC아동보다 세타파(${\Theta}$), SMR파의 비율과 델타파(${\delta}$), 고베타파(${\beta}h$), 알파파(${\alpha}$):저베타(${\beta}l$)의 비율이 유의미하게 높게 나타났고, MC아동은 LIC아동보다 자기조절지수 주의지수 정서지수 항스트레스지수 브레인 지수의 값에서 더 유의미하게 높다는 것을 보여주었다. 둘째, 아동문제행동증후는신체증상, 우울/불안, 사회적 미성숙, 사고의 문제, 주의집중문제, 공격성, 내재화, 외현화, 총 문제행동, 정서불안정에 있어서 LIC아동이 MC아동에 비해서 더 유의미하게 높았고, MC아동은 사회성, 학업수행능력, 총 사회능력에서 LIC아동보다 유의미하게 높았다. 결론적으로, LIC아동과 MC아동의 사회경제적 차이가 상기 뇌기능과 문제행동증후에 영향을 미치는 것으로 밝혀졌다.

• 정신신체의학
• /
• 제24권2호
• /
• pp.200-207
• /
• 2016

연구목적 알츠하이머병은 대표적인 증상인 인지 기능의 저하 외에도 다양한 행동심리증상(Behavioral Psychological Symptoms of Dementia, BPSD)을 흔히 동반하며, 이는 간병인들로 하여금 부양 부담을 야기한다. 본 연구에서는 한국의 치매 환자들과 그들의 간병인들을 대상으로 행동심리증상의 각 항목들과 간병인의 부양 부담에 대한 상관관계를 알아보고자 한다. 방 법 80명의 치매 환자들을 대상으로 행동심리증상을 한국형 신경정신행동검사(Korean neuropsychiatric inventory, K-NPI)를 통해서 평가하였고, 부양자들의 부양부담은 한국판 Zarit Burden Interview(ZBI)를 이용하여 평가하였다. 결 과 K-NPI의 망상, 환각, 초조/공격성, 우울/낙담, 불안, 탈억제, 과민/불안정 빈도와 간병인 부양부담의 평가척도인 ZBI 사이에 통계적으로 유의한 상관이 있었으며, K-NPI의 환각, 초조/공격성, 불안, 탈억제, 이상운동증상, 수면/야간행동의 심각도와 ZBI 척도 간에 유의한 상관이 있었다. K-NPI의 빈도${\times}$심각도 영역에서는 망상, 환각, 초조/공격성, 우울/낙담, 불안, 탈억제, 이상운동증상, 수면/야간행동과 ZBI가 유의한 상관관계를 보였다. 또한 인지기능척도(MMSE-KC, CDR, GDS)와 ZBI 척도 사이에 유의한 상관이 있었으며, 일상생활수행능력(Barthel-ADL, K-ADL)과 ZBI 척도 사이에도 유의한 상관관계를 보였다. 결 론 알츠하이머병 환자의 BPSD와 간병인의 부양부담과 상관관계가 있었다. 또한 간병인의 부양부담은 인지기능 및 일상생활수행능력과도 상관이 있었다. BPSD를 조기에 발견하고 적절하게 치료함으로써 치매 환자의 삶뿐만 아니라 보호자의 삶의 질도 개선시킬 수 있을 것이다.

• Clinical and Experimental Pediatrics
• /
• 제63권6호
• /
• pp.219-225
• /
• 2020

Background: There is increasing concern that moderate preterm (32-33 weeks' gestation) and late preterm (34-36 weeks' gestation) birth may be associated with minor neurodevelopmental problems affecting poor school performance. Purpose: We explored the cognitive function, cognitive visual function, executive function, and behavioral problems at school age in moderate to late preterm infants. Methods: Children aged 7-10 years who were born at 32⁺⁰ to 36⁺⁶ weeks of gestation and admitted to the neonatal intensive care unit from August 2006 to July 2011 at the National Health Insurance Service Ilsan Hospital were included. We excluded children with severe neurologic impairments, congenital malformations, or chromosomal abnormalities. Neuropsychological assessments consisted of 5 neuropsychological tests and 3 questionnaires. Results: A total of 37 children (mean age, 9.1±1.2 years) participated. The mean gestational age at birth was 34.6±7.5 weeks, while the mean birth weight was 2,229.2±472.8 g. The mean full-scale intelligence quotient was 92.89±11.90; 24.3% scored between 70 and 85 (borderline intelligence functioning). An abnormal score was noted for at least one of the variables on the attention deficit hyperactivity disorder diagnostic system for 65% of the children. Scores below borderline function for executive quotient and memory quotient were 32.4% and 24.3%, respectively. Borderline or clinically relevant internalizing problems were noted in 13.5% on the Child Behavior Check List. There were no significant associations between perinatal factors or socioeconomic status and cognitive, visual perception, executive function, or behavior outcomes. Conclusion: Moderate to late preterm infants are at risk of developing borderline intelligence functioning and attention problems at early school age. Cognitive and executive functions that are important for academic performance must be carefully monitored and continuously followed up in moderate to late preterm infants.

• 근관절건강학회지
• /
• 제27권2호
• /
• pp.199-209
• /
• 2020

Purpose: This study examined the prevalence of depressive symptoms and psycho-behavioral factors affecting depressive symptoms in patients with osteoarthritis. Methods: This cross-sectional study enrolled a convenience sample of 157 patients with osteoarthritis in a university hospital between March and December 2018. Depressive symptoms, osteoarthritis function, therapeutic self-efficacy, and health-related quality of life (QoL) were measured using structured questionnaires. Logistic regression analysis was used to investigate factors affecting depressive symptoms. Results: The mean age of participants was 73.3 years with 76.4% of them being women. The prevalence of depressive symptoms was 38.5%. Patients with depressive symptoms were more likely to be currently smoking and had an occupation and worse flexibility function associated with osteoarthritis. Whereas they were less likely to engage in regular physical activity and had a low level of therapeutic self-efficacy and perceived health-related QoL. Conclusion: Therapeutic self-efficacy to regular physical activity, including flexibility function may be primary factors influencing depressive symptoms in patients with osteoarthritis. With the management of osteoarthritis, psycho-behavioral factors should be considered in developing interventions to prevent depressive symptoms in patients with osteoarthritis.

• Biomolecules & Therapeutics
• /
• 제31권2호
• /
• pp.148-160
• /
• 2023

Depression is a neuropsychiatric disorder associated with persistent stress and disruption of neuronal function. Persistent stress causes neuronal atrophy, including loss of synapses and reduced size of the hippocampus and prefrontal cortex. These alterations are associated with neural dysfunction, including mood disturbances, cognitive impairment, and behavioral changes. Synaptic plasticity is the fundamental function of neural networks in response to various stimuli and acts by reorganizing neuronal structure, function, and connections from the molecular to the behavioral level. In this review, we describe the alterations in synaptic plasticity as underlying pathological mechanisms for depression in animal models and humans. We further elaborate on the significance of phytochemicals as bioactive agents that can positively modulate stress-induced, aberrant synaptic activity. Bioactive agents, including flavonoids, terpenes, saponins, and lignans, have been reported to upregulate brain-derived neurotrophic factor expression and release, suppress neuronal loss, and activate the relevant signaling pathways, including TrkB, ERK, Akt, and mTOR pathways, resulting in increased spine maturation and synaptic numbers in the neuronal cells and in the brains of stressed animals. In clinical trials, phytochemical usage is regarded as safe and well-tolerated for suppressing stress-related parameters in patients with depression. Thus, intake of phytochemicals with safe and active effects on synaptic plasticity may be a strategy for preventing neuronal damage and alleviating depression in a stressful life.

• Journal of Korean Biological Nursing Science
• /
• 제17권3호
• /
• pp.219-227
• /
• 2015

Purpose: This study was conducted to review physiological mechanisms of internet addiction and to construct a theoretical framework for cognitive behavioral therapy for internet addicts. Methods: We searched for relevant literature in the PubMed and RISS databases using the terms "internet addiction", "internet game addiction", "internet abuser", and "online game". Only English, full-text articles published from 2000 to 2015 were included in this review of physiological indicators of internet addiction. Finally, 12 articles were selected for review. Results: The theoretical framework developed based on the review proposes that excessive internet use itself may induce physiological stress responses with an increase of stress-related hormones and neurotransmitters. Prolonged abnormal responses of these physiological features produce negative structural and functional changes in the prefrontal cortex, which is mainly involved in cognitive and executive functions. These changes may result in decreased cognitive function. As a stressor, excessive internet use leads to transforming voluntary use into involuntary, habitual use and thus promotes the development of internet addiction. Conclusion: The proposed theoretical framework encompasses cognitive processes that may contribute to the effects of internet use-induced physiological stress on internet addiction. We believe that this framework has important implications for developing cognitive behavioral strategies for internet addicts.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• 제26권2호
• /
• pp.86-93
• /
• 2015

Autism spectrum disorder (ASD) is a neurodevelopmental disorder marked by impaired social communication and repetitive, restricted behaviors and activities. The prevalence of ASD has been increasing for the past 2 decades, but evidence-based therapeutic approaches are lacking for patients with ASD. To date, there is no cure for the core symptoms of ASD, and the existing treatments focus on improving the patient's function and adaptation by using behavioral intervention methods. Behavioral interventions have been proven to show the greatest effect when applied before the age of 2 years, for at least 40-60 hours per week. Many clinicians and ASD families are unfamiliar with the treatment methods, and consequently, may seek unproven and potentially hazardous methods. The purpose of this article was to present an extensive and updated review on evidence-based ASD behavioral interventions that are commonly used in clinical settings.

• Biomolecules & Therapeutics
• /
• 제30권4호
• /
• pp.320-327
• /
• 2022

Neurodevelopmental disorders are complex conditions that pose difficulty in the modulation of proper motor, sensory and cognitive function due to dysregulated neuronal development. Previous studies have reported that an imbalance in the excitation/inhibition (E/I) in the brain regulated by glutamatergic and/or GABAergic neurotransmission can cause neurodevelopmental and neuropsychiatric behavioral deficits such as autism spectrum disorder (ASD). NMDA acts as an agonist at the NMDA receptor and imitates the action of the glutamate on that receptor. NMDA however, unlike glutamate, only binds to and regulates the NMDA receptor subtypes and not the other glutamate receptors. This study seeks to determine whether NMDA administration in mice i.e., over-activation of the NMDA system would result in long-lasting behavioral deficits in the adolescent mice. Both gender mice were treated with NMDA or saline at early postnatal developmental period with significant synaptogenesis and synaptic maturation. On postnatal day 28, various behavioral experiments were conducted to assess and identify behavioral characteristics. NMDA-treated mice show social deficits, and repetitive behavior in both gender mice at adolescent periods. However, only the male mice but not female mice showed increased locomotor activity. This study implies that neonatal exposure to NMDA may illicit behavioral features similar to ASD. This study also confirms the validity of the E/I imbalance theory of ASD and that NMDA injection can be used as a pharmacologic model for ASD. Future studies may explore the mechanism behind the gender difference in locomotor activity as well as the human relevance and therapeutic significance of the present findings.

• Research in Vestibular Science
• /
• 제17권4호
• /
• pp.134-141
• /
• 2018

Objectives: We aimed to study the role of vestibular input on spatial memory performance in mice that had undergone bilateral surgical labyrinthectomy, semicircular canal (SCC) occlusion and 4G hypergravity exposure. Methods: Twelve to 16 weeks old ICR mice (n=30) were used for the experiment. The experimental group divided into 3 groups. One group had undergone bilateral chemical labyrinthectomy, and the other group had performed SCC occlusion surgery, and the last group was exposed to 4G hypergravity for 2 weeks. The movement of mice was recorded using camera in Y maze which had 3 radial arms (35 cm long, 7 cm high, 10 cm wide). We counted the number of visiting arms and analyzed the information of arm selection using program we developed before and after procedure. Results: The bilateral labyrinthectomy group which semicircular canal and otolithic function was impaired showed low behavioral performance and spacial memory. The semicircular canal occlusion with $CO_2$ laser group which only semicircular canal function was impaired showed no difference in performance activity and spatial memory. However the hypergravity exposure group in which only otolithic function impaired showed spatial memory function was affected but the behavioral performance was spared. The impairment of spatial memory recovered after a few days after exposure in hypergravity group. Conclusions: This spatial memory function was affected by bilateral vestibular loss. Space-related information processing seems to be determined by otolithic organ information rather than semicircular canals. Due to otolithic function impairment, spatial learning was impaired after exposure to gravity changes in animals and this impaired performance was compensated after normal gravity exposure.