• Journal of Semiconductor Engineering
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• v.1 no.1
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• pp.46-56
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• 2020

This article highlights new opportunities of inorganic semiconductor materials for bio-implantable electronics, as a subset of 'transient' technology defined by an ability to physically dissolve, chemically degrade, or disintegrate in a controlled manner. Concepts of foundational materials for this area of technology with historical background start with the dissolution chemistry and reaction kinetics associated with hydrolysis of nanoscale silicon surface as a function of temperature and pH level. The following section covers biocompatibility of silicon, including related other semiconductor materials. Recent transient demonstrations of components and device levels for bioresorbable implantation enable the future direction of the transient electronics, as temporary implanters and other medical devices that provide important diagnosis and precisely personalized therapies. A final section outlines recent bioresorbable applications for sensing various biophysical parameters, monitoring electrophysiological activities, and delivering therapeutic signals in a programmed manner.

• Annals of Clinical Neurophysiology
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• v.13 no.2
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• pp.97-100
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• 2011

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired immune-mediated polyneuropathy. Corticosteroids, intravenous immunoglobulin (IVIG) and plasmapheresis have been reported to be effective treatment. Rarely, CIDP can occur in the patients with HIV infection. The clinical features and electrophysiological findings of CIDP are known to be similar in patients with and without HIV infection. We report a 30-year-old male with HIV infection associated CIDP who improved after the administration of intravenous immunoglobulin and long term oral prednisone.

• Annals of Clinical Neurophysiology
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• v.3 no.2
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• pp.115-121
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• 2001

The occurrence of muscle weakness in patients with sepsis or multiple organ failure managed in the intensive care unit has been recognized with increasing frequency in the last two decades. The difficulty in examining critically ill patients may explain why this complication has been only recently recognized. This weakness is due to an axonal polyneuropathy which is called critical illness polyneuropathy(CIP). It must be differentiated from myopathy or neuromuscular junction disturbance that can also occur in the intensive care setting. Neither the cause nor the exact mechanism of CIP has been elucidated. Electrophysiological studies demonstrated an acute axonal damage of the peripheral nerves. Before the recognition of CIP, these cases were usually misdiagnosed as Guillain-$Barr{\acute{e}}$ syndrome. Clinical recovery from the neuropathy is rapid and nearly complete in those patients who survive. Thus, neuropathy acquired during critical illness, although causing a delayed in weaning from ventilatory support and hospital discharge, does not worsen long-term prognosis.

• Annals of Clinical Neurophysiology
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• v.9 no.2
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• pp.89-92
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• 2007

A 33-year-old women developed weakness in all limbs 3 days prior to admission. Motor examination showed decreased strength in all limbs, but sensory examination was normal. Deep tendon reflexes were areflexia. Electrophysiological examination showed conduction blocks with nearly normal conduction velocities and terminal latencies in motor nerves and normal amplitudes and velocities in sensory nerves. Her serum was positive for IgG antibodies to gangliosides GM1, GD1b, and galactocerebroside. Acute motor conduction block neuropathy may be another variant of Guillain-Barre syndrome.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.39
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• pp.129-142
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• 1996

The early diagnosis has an very important role in curing dementia. But there was not the effective method to diagnose it until now. In this paper we analyzed the EEG of Alzheimer's disease patients and normal groups by nonlinear methods. In the analysis we calculated the correlation dimensions $D_2$ and the largest Lyapunov exponent $L_1$. We found that patients with Alzheimer's disease have significantly lower $D_2$ and TEX>$L_1$ than normal groups. It means that brains injured by Alzheimer's disease have electrophysiological inactive elements and have decreased chaotic behaviour. We propose the nonlinear analysis of the EEG as a useful tool for the early diagnosis of Alzheimer's disease.

• Translational and Clinical Pharmacology
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• v.26 no.4
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• pp.145-149
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• 2018

Cases of drug-induced QT prolongation and sudden cardiac deaths resulted in market withdrawal of many drugs and world-wide regulatory changes through accepting the ICH guidelines E14 and S7B. However, because the guidelines were not comprehensive enough to cover the electrophysiological changes by drug-induced cardiac ion channel blocking, CiPA was initiated by experts in governments and academia in the USA, Europe, and Japan in 2013. Five years have passed since the launch of the CiPA initiative that aimed to improve the current ICH guidelines. This report reviews the current achievements of the CiPA initiative and explores unresolved issues.

• Current Optics and Photonics
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• v.3 no.1
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• pp.1-7
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• 2019

Optical stimulation provides a promising alternative to electrical stimulation to selectively modulate tissue. However, developing noninvasive techniques to directly stimulate excitable tissue without introducing genetic modifications and minimizing cellular stress remains an ongoing challenge. Infrared (IR) light has been used to achieve optical pacing for electrophysiological studies in embryonic quail and mammalian hearts. Here, we demonstrate optical stimulation and pacing of the embryonic chicken heart using a pulsed infrared thulium laser with a wavelength of 1927 nm. By recording stereomicroscope outputs and quantifying heart rates and movements through video processing, we found that heart rate increases instantly following irradiation with a large spot size and high radiant exposure. Targeting the atrium using a smaller spot size and lower radiant exposure achieved pacing, as the heart rate synchronized with the laser to 2 Hz. This study demonstrates the viability of using the 1927 nm thulium laser for cardiac stimulation and optical pacing, expanding the optical parameters and IR lasers that can be used to modulate cardiac dynamics.

• Annals of Clinical Neurophysiology
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• v.21 no.1
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• pp.61-65
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• 2019

$Sj{\ddot{o}}gren^{\prime}s$ syndrome (SS)-associated polyradiculopathy is rarely reported. A 51-year-old woman presented with a history of gradual weakness in all four extremities for several months. Based on electrophysiological studies, spinal magnetic resonance imaging and cerebrospinal fluid examination, inflammatory polyradiculopathy was confirmed. During a search for the aetiology, the patient was ultimately diagnosed with SS. This study introduces SS-associated polyradiculopathy that primarily presented with motor symptoms, thus mimicking motor neuron disease.

• Annals of Clinical Neurophysiology
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• v.21 no.2
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• pp.113-116
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• 2019

Myasthenia gravis (MG) and amyotrophic lateral sclerosis (ALS) are distinct disorders. ALS affects motor neurons that control muscle movement, while MG controls communication between neurons and muscles, which occurs at neuromuscular junctions. However, on rare occasions, ALS develops after MG and vice versa. The coexistence of the two diseases represents a diagnostic challenge and requires thoughtful interpretation of clinical features. We present the case of a 53-year-old Korean male who developed ALS after MG, confirmed by clinical and electrophysiological follow-up.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.05a
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• pp.107-113
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• 2002

We examined the psychophysiological effects of navigation in a virtual reality (VR). Subjects were exposed to the VR, and required to detect specific objects. Ten electrophysiological signals were recorded before, during, and after navigation in the VR. Six questionnaires on the VR experience were acquired from 45 healthy subjects. There were significant changes between the VR period and the pre-VR control period in several psychophysiological measurements. During the VR period, eye blink, skin conductance level, and alpha frequency of EEG were decreased but gamma wave were increased. Physiological changes associated with cybersickness included increased heart rate, eye blink, skin conductance response, and gamma wave and decreased photoplethysmogram and skin temperature. These results suggest an attentional change during VR navigation and activation of the autonomic nervous system for cybersickness. These findings would enhance our understanding for the psychophysiological changes during VR navigation and cybersickness.