Publications by authors named "Masayuki Sawada"

Article Synopsis
  • The study introduces robust design methods for a vertical avalanche photodiode-based CMOS image sensor, focusing on three practical factors: eliminating guard rings for better pixel isolation, ensuring device performance is stable regardless of voltage and temperature changes, and maintaining consistent operation under intense light conditions.
  • The design minimizes trade-offs between electric field concentration and pixel isolation, validated through both simulations and experiments, resulting in effective optimization strategies.
  • A global feedback resistor is used to stabilize device characteristics, while an in-pixel overflow transistor improves resistance to high illumination; the sensor's robustness is confirmed by extensive testing on multiple chips under extreme conditions for over 1000 hours.
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Strong lockdowns to control COVID-19 pandemic have been enforced globally and strongly restricted social activities with consequent negative effects on mental health. Japan has effectively implemented a unique voluntary policy to control COVID-19, but the mental health impact of the policy has not been examined on a large scale. In this study, we examined the effect of the first declaration on the mental health of affected residents.

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Prader-Willi syndrome (PWS) is a neuro-genetic disorder caused by the absence/loss of expression of one or more paternally expressed genes on chromosome 15 (q11-13). In this study, a comparative analysis of intelligence level and autistic traits was conducted between children with PWS (n = 30; 18 males, 12 females; age = 10.6 ± 2.

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Recent developments in near-infrared spectroscopy (NIRS) have enabled non-invasive clarification of brain functions in psychiatric disorders. Functional neuroimaging studies of patients with obsessive-compulsive disorder (OCD) have suggested that the frontal cortex and subcortical structures may play a role in the pathophysiology of the disorder. Twelve treatment-naïve children with OCD and 12 age- and sex-matched healthy control subjects participated in the present study after giving consent.

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Objective: In adults, it is sometimes difficult to discriminate between pervasive developmental disorder (PDD) and schizophrenia (SCH) when positive symptoms are not outstanding. We examined whether the Japanese version of the National Adult Reading Test (JART), is a valid scale for evaluating pre-morbid intelligence quotient (IQ) in patients with SCH, and the Wechsler Adult Intelligence Scale-Revised (WAIS-R) are useful for helping to discriminate between PDD and SCH.

Methods: Sixteen patients with adult PDD and 16 age-, education- and sex-matched patients with SCH participated in the present study.

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Aim: Attention-deficit/hyperactivity disorder (ADHD) is a relatively common central nervous system disorder in school-age children, which may involve a specific disorder in cognition and/or information processing. Event-related potentials (ERP) are commonly used as physiological measures of cognitive function as they are easily measured and non-invasive. Thus, in the present study, we examined the effects of osmotic-release methylphenidate (MPH) (Concerta), a common treatment for childhood attention-deficit/hyperactivity disorder (ADHD), in ADHD children as measured by ERP.

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Article Synopsis
  • Tai Chi exercises may improve sleep quality and reduce depressive symptoms in elderly patients with cerebral vascular disorder (CVD), compared to standard rehabilitation.
  • The study involved 34 CVD patients who participated in either Tai Chi or rehabilitation sessions over 12 weeks, assessing cognitive effects using P300 measurements and health questionnaires.
  • Results indicated that while there were no significant changes in cognitive function measurements, significant improvements were noted in sleep quality and mental health scores for those practicing Tai Chi.
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Recent developments in near-infrared spectroscopy (NIRS) have enabled non-invasive clarification of brain functions in psychiatric disorders with measurement of hemoglobin concentrations as cerebral blood volume. Twenty medication-naïve children with attention-deficit/hyperactivity disorder (ADHD) and 20 age- and sex-matched healthy control subjects participated in the present study after giving consent. The relative concentrations of oxyhemoglobin (oxy-Hb) were measured with frontal probes every 0.

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The present study examined the correlation between the attention deficit hyperactivity disorder (ADHD) Rating Scale-IV Japanese version (ADHD RS-IV-J) score and mismatch negativity (MMN), in 10 pervasive developmental disorder (PDD) children with ADHD-like symptoms, and examined whether MMN become the objective measure to assess the severity of ADHD-like symptoms in PDD children. Consequently, score of ADHD RS-IV-J had a positive correlative tendency with MMN latency and had a significant strong negative correlation with MMN amplitude. Therefore, MMN may become an objective measure to assess the severity of ADHD-like symptoms in PDD children.

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