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1.
Artículo en Inglés | MEDLINE | ID: mdl-37015407

RESUMEN

This paper presents an 8-channel electrocardiogram (ECG) monitoring integrated circuit (IC) controlled by time-division multiplexing (TDM). The proposed TDM compensates the electrode DC offsets by forming an individual discrete-time feedback loop per channel while sharing an analog frontend. This enables a chopping-free open-loop amplification, achieving a high input impedance suitable for a noncontact ECG monitoring. In addition, a common-mode interference (CMI) cancellation scheme is also introduced in the proposed TDM schedule for the realization of a pseudo-driven-right leg (DRL) in a multichannel environment. The designed system is implemented in 180 nm CMOS. The chip dissipates 18.6 µW/channel including the power consumption by ADC. It shows the total-CMRR of 100 dB against CMI voltage swing up to 20 VPP. The chip is verified in noncontact 8-channel ECG using conventional passive electrodes.

2.
PeerJ Comput Sci ; 7: e718, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34616894

RESUMEN

In multi-agent reinforcement learning, the cooperative learning behavior of agents is very important. In the field of heterogeneous multi-agent reinforcement learning, cooperative behavior among different types of agents in a group is pursued. Learning a joint-action set during centralized training is an attractive way to obtain such cooperative behavior; however, this method brings limited learning performance with heterogeneous agents. To improve the learning performance of heterogeneous agents during centralized training, two-stage heterogeneous centralized training which allows the training of multiple roles of heterogeneous agents is proposed. During training, two training processes are conducted in a series. One of the two stages is to attempt training each agent according to its role, aiming at the maximization of individual role rewards. The other is for training the agents as a whole to make them learn cooperative behaviors while attempting to maximize shared collective rewards, e.g., team rewards. Because these two training processes are conducted in a series in every time step, agents can learn how to maximize role rewards and team rewards simultaneously. The proposed method is applied to 5 versus 5 AI robot soccer for validation. The experiments are performed in a robot soccer environment using Webots robot simulation software. Simulation results show that the proposed method can train the robots of the robot soccer team effectively, achieving higher role rewards and higher team rewards as compared to other three approaches that can be used to solve problems of training cooperative multi-agent. Quantitatively, a team trained by the proposed method improves the score concede rate by 5% to 30% when compared to teams trained with the other approaches in matches against evaluation teams.

3.
J Craniofac Surg ; 30(3): e270-e272, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31048625

RESUMEN

The absence of an adequate recipient vessel for free flap pedicle anastomosis near local defect sites discourages surgeons from performing free flap transfers over the scalp because of the challenging neck dissection and the thrombogenic potential of vein grafts for pedicle elongation. We present a case in which a large scalp defect was successfully reconstructed using the wrist as a "free flap carrier," which is an alternative method. A 78-year-old patient with a totally occluded common carotid artery presented to our clinic with a large scalp defect. Reconstruction of the scalp defect was performed in a 2-stage procedure. In the first stage, a free latissimus dorsi (LD) muscle flap was transferred to the defect site, and the pedicle anastomosis was held at the ipsilateral wrist to provide inflow and outflow of blood through the radial artery and vena comitante and cephalic vein that were anastomosed to the flap pedicle. After subsequent split-thickness skin graft, the elevated position of the arm was achieved using a splint and sutures for 3 weeks. In the second stage, the flap was divided, and an additional skin graft over the flap division site and radial artery repair with vein graft was performed. Successful coverage of the scalp defect was confirmed on postoperative day 14 of the second procedure with no complications.


Asunto(s)
Colgajos Tisulares Libres/irrigación sanguínea , Cuero Cabelludo/cirugía , Trasplante de Piel , Articulación de la Muñeca/irrigación sanguínea , Anciano , Arteria Carótida Común , Estenosis Carotídea/complicaciones , Humanos , Masculino , Cuero Cabelludo/lesiones
4.
Neurosci Lett ; 643: 59-64, 2017 03 16.
Artículo en Inglés | MEDLINE | ID: mdl-28189746

RESUMEN

2-Hydroxy-4-trifluoromethylbenzoic acid (HTB) is a metabolite of triflusal (TF), and has been reported to exert anti-inflammatory effect. In this study, the authors investigated whether HTB has a neuroprotective effect against ischemic brain injuries. We showed that intravenous administration of HTB (5mg/kg) 30min before or 1, 3, or 6h after middle cerebral artery occlusion (MCAO) reduced brain infarct to 10.4±3.3%, 16.9±2.3%, 22.2±1.5% and 40.7±7.5%, respectively, of that of treatment-naive MCAO controls, and the therapeutic time window extended to 9h after MCAO (40.7±7.5%). Furthermore, HTB suppressed infarct formation, protected motor activities, and ameliorated neurological deficits more effectively than by TF or salicylic acid (SA). HTB markedly suppressed microglial activation and proinflammatory cytokines expressions in the postischemic brain and in BV2 cells and suppressed LPS-induced nitrite production by inhibiting IkB degradation. In addition, HTB suppressed NMDA-induced neuronal cell death more effectively than TF or SA in primary cortical neuron cultures. Together, these results indicate that HTB has multi-modal protective effects against ischemic brain damage that encompass anti-inflammatory, anti-excitotoxicity, and anti-Zn2+-toxicity effects.


Asunto(s)
Isquemia Encefálica/tratamiento farmacológico , Encéfalo/efectos de los fármacos , Salicilatos/farmacología , Animales , Antiinflamatorios/farmacología , Aspirina/farmacología , Encéfalo/metabolismo , Isquemia Encefálica/metabolismo , Citocinas/metabolismo , Infarto de la Arteria Cerebral Media/metabolismo , Masculino , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Fármacos Neuroprotectores/farmacología , Ratas Sprague-Dawley
5.
Uisahak ; 25(1): 41-75, 2016 Apr.
Artículo en Coreano | MEDLINE | ID: mdl-27301855

RESUMEN

Fujita Tsuguakira was a man who established Jahyeuiwon, a governmental medical facility, during the Residency-General Period and took over the presidency of a committee in the Japanese Government-General of Chosun after Chosun was annexed to Japanese. In addition, he is a man well qualified to be placed on the top of the list when discussing the Japanese colonial medicine in Chosun, considering his personal history of getting evolved in the colonial rule of Taiwan for seven years as an army surgeon. He led the colonial medicine in Chosun for nine years before and after the Japanese annexation of Korea. He was engaged in almost all the areas related to the colonial medicine such as anti-cholera projects, Hansung Sanitation Union, Deahan Hospital, Chosun Chongdokbu Hospital, Jahyeuiwon, medical schools affiliated to the Japanese Government-General of Chosun. In all respects, his life was in sync with the expansionist strategies of Imperial Japan. Especially, his deeds in Chosun was an "active aid to the instructions" from Army Minister Terauchi Masatake " as Sato Kozo testifies. Fujita was chosen by the military, and so he faithfully served the role given from it. The rewards that he received form the military attest to this fact. He took the position of Surgeon General in Army Medical Service on September, 1912, the top place that an army surgeon could hold. The position was first given to the officer who worked outside Japan proper, and he was the only army surgeon with no doctorial degree to receive such title except for Ishiguro Tadanori who was the first army surgeon in Japan. To sum up, Fujita was not a "doctor" but a "military officer". His walk of life mainly lay in the role of an aider adjusted to the ups and downs and the speeds of the plans of Imperial Japan to invade the continent. Therefore, the Japanese colonial medicine controlled by such man as Fujita in Chosun was inevitably studded with the military things. As a chief in the army medicine, what was important to him was the hospitals for managing the armed troops and projects for preventing infectious disease that could threaten the military sanitation. As a result, the medical service for those under the colonial rule was naturally put on the back burner. This study was conducted mainly based on Fujita's memoirs called Army Surgeon General Fujita Tsuguakira (1943), and accordingly it would be not without limitations. However, as he is a man who cannot be put aside when discussing the Japanese colonial medicine in Chosun, the records by this study of his life and past activities are expected to give no small amount of contribution to these discussions.


Asunto(s)
Colonialismo , Medicina Militar/historia , Cirujanos/historia , Historia del Siglo XX , Japón , Corea (Geográfico)
6.
ACS Nano ; 9(8): 8312-20, 2015 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-26169189

RESUMEN

Molybdenum disulfide (MoS2) nanosheet, one of two-dimensional (2D) semiconductors, has recently been regarded as a promising material to break through the limit of present semiconductors. With an apparent energy band gap, it certainly provides a high carrier mobility, superior subthreshold swing, and ON/OFF ratio in field-effect transistors (FETs). However, its potential in carrier mobility has still been depreciated since the field-effect mobilities have only been measured from metal-insulator-semiconductor (MIS) FETs, where the transport behavior of conducting carriers located at the insulator/MoS2 interface is unavoidably interfered by the interface traps and gate voltage. Moreover, thin MoS2 MISFETs have always shown large hysteresis with unpredictable negative threshold voltages. Here, we for the first time report MoS2-based metal semiconductor field-effect transistors (MESFETs) using NiOx Schottky electrode which makes van der Waals interface with MoS2. We thus expect that the maximum mobilities or carrier transport behavior of the Schottky devices may hardly be interfered by interface traps or an on-state gate field. Our MESFETs with a few and ∼10 layer MoS2 demonstrate intrinsic-like high mobilities of 500-1200 cm(2)/(V s) at a certain low threshold voltage between -1 and -2 V without much hysteresis. Moreover, they work as a high speed and highly sensitive phototransistor with 2 ms switching and ∼5000 A/W, respectively, supporting their high intrinsic mobility results.

7.
ACS Appl Mater Interfaces ; 6(20): 17599-605, 2014 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-25247447

RESUMEN

We report on the energy band gap and optical transition of a series of divalent metal ion (Cu(2+), Ni(2+), Zn(2+), and Co(2+)) modified DNA (M-DNA) double crossover (DX) lattices fabricated on fused silica by the substrate-assisted growth (SAG) method. We demonstrate how the degree of coverage of the DX lattices is influenced by the DX monomer concentration and also analyze the band gaps of the M-DNA lattices. The energy band gap of the M-DNA, between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO), ranges from 4.67 to 4.98 eV as judged by optical transitions. Relative to the band gap of a pristine DNA molecule (4.69 eV), the band gap of the M-DNA lattices increases with metal ion doping up to a critical concentration and then decreases with further doping. Interestingly, except for the case of Ni(2+), the onset of the second absorption band shifts to a lower energy until a critical concentration and then shifts to a higher energy with further increasing the metal ion concentration, which is consistent with the evolution of electrical transport characteristics. Our results show that controllable metal ion doping is an effective method to tune the band gap energy of DNA-based nanostructures.


Asunto(s)
ADN/química , Metales/química , Conformación de Ácido Nucleico , Fenómenos Ópticos , Cristalización , Iones , Microscopía de Fuerza Atómica , Termodinámica
8.
J Org Chem ; 79(19): 9231-45, 2014 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-25188915

RESUMEN

A straightforward and high-yielding synthesis of 1,4-diaryl-1H-imidazoles is reported. 1,4-Diaryl-1H-imidazoles have been difficult to access in ambient conditions, but our method utilizes two different facets of isocyanide reactivity to achieve it. The reaction is believed to involve (1) NHC-copper-catalyzed isocyanide insertion into alcohol to form an N-arylformimidate intermediate and (2) subsequent base-promoted cycloaddition with benzyl isocyanide derivatives. There is cooperation between these two processes through the deprotonation of benzyl isocyanide by KOtBu. The deprotonation gives tert-butyl alcohol and the benzyl isocyanide anion, which are used for the first and second steps of the reaction, respectively. Various control and kinetic experiments were carried out to gain an in-depth understanding of the reaction mechanism and isocyanide reactivity. The reaction mechanism determined by density functional theory calculations was consistent with the experimental data and provided detailed explanations for the reactivity trends.

9.
BMC Med Res Methodol ; 13: 130, 2013 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-24156760

RESUMEN

BACKGROUND: International clinical trials are now rapidly expanding into Asia. However, the proportion of global trials is higher in South Korea compared to Japan despite implementation of similar governmental support in both countries. The difference in clinical trial environment might influence the respective physicians' attitudes and experience towards clinical trials. Therefore, we designed a questionnaire to explore how physicians conceive the issues surrounding clinical trials in both countries. METHODS: A questionnaire survey was conducted at Kyoto University Hospital (KUHP) and Seoul National University Hospital (SNUH) in 2008. The questionnaire consisted of 15 questions and 2 open-ended questions on broad key issues relating to clinical trials. RESULTS: The number of responders was 301 at KUHP and 398 at SNUH. Doctors with trial experience were 196 at KUHP and 150 at SNUH. Among them, 12% (24/196) at KUHP and 41% (61/150) at SUNH had global trial experience. Most respondents at both institutions viewed clinical trials favorably and thought that conducting clinical trials contributed to medical advances, which would ultimately lead to new and better treatments. The main reason raised as a hindrance to conducting clinical trials was the lack of personnel support and time. Doctors at both university hospitals thought that more clinical research coordinators were required to conduct clinical trials more efficiently. KUHP doctors were driven mainly by pure academic interest or for their desire to find new treatments, while obtaining credits for board certification and co-authorship on manuscripts also served as motivation factors for doctors at SNUH. CONCLUSIONS: Our results revealed that there might be two different approaches to increase clinical trial activity. One is a social level approach to establish clinical trial infrastructure providing sufficient clinical research professionals. The other is an individual level approach that would provide incentives to encourage doctors to participate in and conduct clinical trials.


Asunto(s)
Actitud del Personal de Salud , Ensayos Clínicos como Asunto , Médicos , Adulto , Femenino , Hospitales Universitarios , Humanos , Consentimiento Informado , Japón , Masculino , Persona de Mediana Edad , República de Corea , Encuestas y Cuestionarios
10.
Plast Reconstr Surg ; 114(7): 1783-9, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15577349

RESUMEN

Diabetic foot ulcers often pose a difficult problem for health care professionals because of the defects associated with fibroblast functioning. Although there has been much interest recently in the use of topical growth factors for the treatment of diabetic foot ulcers, the effects are generally not very dramatic. Cryopreserved fibroblast implants, which are able to adjust to a wound's environment and provide the desired growth factors and other substances that may be lacking in a chronic wound, represent an exciting development and a major advance. These products may well provide growth factors in the right concentration and in the right sequence, something that has proved difficult to achieve with the topical application of recombinant growth factors. However, cell activities are impaired by cryopreservation. The purpose of this study was to assess the effects of fresh human allogeneic fibroblast grafting for the treatment of diabetic foot ulcers. Eight patients with diabetic foot ulcers ranging from 6 to 17 weeks in duration were treated. The size of the wounds ranged from 2.0 to 6.0 cm2, with three patients exhibiting exposed bones. A history of diabetic foot ulcers was present in five patients. Human dermal fibroblasts from healthy teenagers were cultured in Dulbecco's modified Eagle medium/Ham's F-12 supplemented with 10% autologous serum. The cultured cells were applied over the wounds immediately after debridement; fibrin was used as a cell carrier. A dressing was then applied with Tegaderm and kept moist until healing was complete. The progress and time for complete wound closure and patient satisfaction were assessed, with follow-up time ranging from 6 to 18 months. Complete wound healing occurred in all patients. Eleven to 21 days were needed for complete reepithelization of the wound, and no clinical or laboratory abnormalities were noted. Patient satisfaction was also very positive. In this study, the use of fresh human fibroblast allografts was found to be a safe and effective treatment for diabetic foot ulcers.


Asunto(s)
Pie Diabético/cirugía , Fibroblastos/trasplante , Trasplante de Piel/métodos , Cicatriz/etiología , Desbridamiento , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Satisfacción del Paciente , Proyectos Piloto , Trasplante de Piel/efectos adversos , Cicatrización de Heridas
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