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1.
J Korean Med Sci ; 39(21): e166, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38832476

RESUMO

BACKGROUND: The Korea Expert Committee on Immunization Practices (KECIP) is a key advisory body the government to develop guidelines and provide technical advisory activities on immunization policies in Korea. A recent policy study, inspired by global best practices, aims to enhance KECIP's functionality for providing timely and transparent recommendations in the face of evolving vaccine science and emerging infectious diseases like COVID-19. METHODS: This study reviewed the current status of KECIP and collected expert opinions through surveys and consultations. Among the 40 panel members who were surveyed, 19 responded to a questionnaire specifically designed to assess the potential areas of improvement within KECIP. RESULTS: The majority of respondents favored maintaining the current member count and emphasized the need for a subcommittee. Opinions varied on issues such as the length of KECIP's term, the representation of vaccine manufacturers' perspectives, and the chairperson's role. However, there was a consensus on the importance of expertise, transparency, and fair proceedings within the committee. CONCLUSION: This study underscores the pivotal role of KECIP in shaping national immunization policies, emphasizing the necessity for informed guidance amidst evolving vaccine science and emerging infectious diseases. Furthermore, it stressed the importance of enhancing KECIP's capacity to effectively address evolving public health challenges and maintain successful immunization programs in South Korea.


Assuntos
COVID-19 , Consenso , Humanos , República da Coreia , COVID-19/prevenção & controle , Inquéritos e Questionários , Imunização , Comitês Consultivos , SARS-CoV-2 , Política de Saúde , Vacinas contra COVID-19
2.
Sensors (Basel) ; 24(2)2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38257684

RESUMO

This paper provides a comprehensive overview of the security vulnerability known as rowhammer in Dynamic Random-Access Memory (DRAM). While DRAM offers many desirable advantages, including low latency, high density, and cost-effectiveness, rowhammer vulnerability, first identified in 2014, poses a significant threat to computing systems. Rowhammer attacks involve repetitive access to specific DRAM rows, which can cause bit flips in neighboring rows, potentially compromising system credentials, integrity, and availability. The paper discusses the various stages of rowhammer attacks, explores existing attack techniques, and examines defense strategies. It also emphasizes the importance of understanding DRAM organization and the associated security challenges.

3.
J Korean Med Sci ; 38(27): e211, 2023 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-37431541

RESUMO

BACKGROUND: Paxlovid is an oral antiviral drug that received emergency use authorization in South Korea for the treatment of patients with mild-to-moderate coronavirus disease 2019 (COVID-19) on January 14, 2022. Since the onset of the severe acute respiratory syndrome coronavirus 2 pandemic, the virus has continued to evolve. The emergence of new variants has raised concerns about possible reductions in the effectiveness of vaccines and drugs. The effectiveness of Paxlovid in patients infected with the omicron variant and subvariants has not yet been determined. This study assessed the effectiveness of Paxlovid at reducing the risk of severe/critical illness or death and death in patients with mild-to-moderate COVID-19 caused by omicron subvariant BA.5. METHODS: In this nationwide retrospective cohort study, data on 8,902,726 patients were collected from four sources (the Drug Utilization Review database, COVID-19 Patient Information Management System, confirmed patient information, and basic epidemiological investigation data) between July 1 and November 30, 2022. Multivariable logistic regression analysis was conducted, with adjustment for age, sex, severe acute respiratory syndrome coronavirus 2 immunity (vaccination), and comorbidities. RESULTS: A total of 1,936,925 patients with COVID-19 were included in the analysis, including 420,996 patients treated with Paxlovid, and 1,515,959 patients not treated with Paxlovid. Paxlovid treatment in patients aged ≥ 60 years of age was associated with significantly reduced risk of severe/critical illness or death (46.0%), and death rate (32.5%), and its effectiveness was high, regardless of vaccination status. CONCLUSION: Paxlovid is effective at reducing the risk of death due to COVID-19 in patients with omicron BA.5 infection, especially in older patients, regardless of vaccination status. This suggests that older patients with COVID-19-related symptoms should be administered Paxlovid, regardless of their vaccination status, to reduce severity and risk of death.


Assuntos
Antivirais , COVID-19 , Humanos , Idoso , Pessoa de Meia-Idade , Antivirais/uso terapêutico , Estado Terminal , Estudos Retrospectivos , SARS-CoV-2 , República da Coreia/epidemiologia
4.
Arch Orthop Trauma Surg ; 143(6): 3183-3190, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36282315

RESUMO

INTRODUCTION: There have been no previous studies comparing serial radiologic results between primary and revision Bankart repair despite the significance of capsulolabral height and slope restoration. The purpose of this study was (1) to compare serially the height and slope of the repaired labrum in the early postoperative period among primary and revision Bankart repair groups, and (2) to compare clinical outcomes between the two groups. MATERIALS AND METHODS: This study included each 24 patients who underwent arthroscopic primary Bankart repair (Group A) and revision Bankart repair (Group B) matched by age, sex, and glenoid defect ratio. Postoperative serial radiologic assessment of the repaired labral height and slope was proceeded using magnetic resonance imaging (MRI) or computed tomographic arthrography (CTA) at 3 weeks and 6 months. RESULTS: There were no significant differences in labral height and slope at 3 weeks and 6 months postoperatively in Group A. However, significant reductions in labral height and slope were evident between 3 weeks and 6 months postoperatively in Group B (P < 0.05). Group A yielded superior results to Group B with respect to labral height and slope at each time point (P < 0.05) in between-group analyses. The clinical outcomes were not significantly different between the two groups except for the patients' return to their premorbid sports activity level (P = 0.024). CONCLUSIONS: The height and slope of the repaired capsulolabral structures in the early postoperative period after arthroscopic revision Bankart repair group were significantly lower than those of the primary Bankart repair group. Also the reduction of labral height and slope was significant in the revision Bankart repair group over time. Nonetheless, clinical outcomes did not differ significantly except return to premorbid sports activity level at final follow-up.


Assuntos
Instabilidade Articular , Luxação do Ombro , Articulação do Ombro , Humanos , Articulação do Ombro/cirurgia , Articulação do Ombro/diagnóstico por imagem , Análise por Pareamento , Instabilidade Articular/cirurgia , Artrografia , Imageamento por Ressonância Magnética , Artroscopia/métodos , Luxação do Ombro/cirurgia , Recidiva
5.
J Environ Sci (China) ; 132: 43-55, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37336609

RESUMO

The below-cloud aerosol scavenging process by precipitation is one of the most important mechanisms to remove aerosols from the atmosphere. Due to its complexity and dependence on both aerosol and raindrop sizes, wet scavenging process has been poorly treated, especially during the removal of fine particles. This makes the numerical simulation of below-cloud scavenging in large-scale aerosol models unrealistic. To consider the slip effects of submicron particles, a simplified expression for the diffusion scavenging was developed by approximating the Cunningham slip correction factor. The derived analytic solution was parameterized as a simple power function of rain intensity under the assumption of the lognormal size distribution of particles. The resultant approximated expression was compared to the observed data and the results of previous studies including a 3D atmospheric chemical transport model simulation. Compared with the default GEOS-Chem coefficient of 0.00106R0.61 and the observation-based coefficient of 0.0144R0.9268, the coefficient of a and b in Λm = aRb spread in the range of 0.0002- 0.1959 for a and 0.3261- 0.525 for b over a size distribution of GSD of 1.3-2.5 and a geometric mean diameter of 0.01- 2.5 µm. Overall, this study showed that the scavenging coefficient varies widely by orders of magnitude according to the size distribution of particles and rain intensity. This study also demonstrated that the obtained simplified expression could consider the theoretical approach of aerosol polydispersity. Our proposed analytic approach showed that results can be effectively applied for reduced computational burden in atmospheric modeling.


Assuntos
Poluentes Atmosféricos , Poluentes Atmosféricos/análise , Simulação por Computador , Modelos Químicos , Aerossóis/análise , Chuva
6.
J Korean Med Sci ; 37(37): e285, 2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36163479

RESUMO

On 22 June, a man who returned to South Korea from Germany tested positive for the monkeypox virus using real-time polymerase chain reaction. We identified 49 contacts concerning the first monkeypox case and classified them into two groups based on risk exposure levels. Through active monitoring of eight people in the medium-risk group and passive monitoring of 41 people in the low-risk group, we identified that no secondary transmission occurred over 21 days. The prompt active or passive monitoring of the index case of imported monkeypox could prevent community transmission in Korea.


Assuntos
Mpox , Humanos , Masculino , Mpox/diagnóstico , Mpox/epidemiologia , Monkeypox virus/genética , Reação em Cadeia da Polimerase em Tempo Real , República da Coreia , Fatores de Risco
7.
BMC Surg ; 21(1): 159, 2021 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-33752671

RESUMO

BACKGROUND: Sentinel lymph node biopsy (SLNB) is unnecessarily performed too often, owing to the high upstaging rates of ductal carcinoma in situ (DCIS). This study aimed to evaluate the upstaging rates of DCIS to invasive cancer, determine the prevalence of axillary lymph node metastasis, and identify the clinicopathological factors associated with upstaging and lymph node metastasis. We also examined surgical patterns among DCIS patients and determined whether SLNB guidelines were followed. METHODS: We retrospectively analysed 307 consecutive DCIS patients diagnosed by preoperative biopsy in a single centre between 2014 and 2018. Data from clinical records, including imaging studies, axillary and breast surgery types, and pathology results from preoperative and postoperative biopsies, were extracted. Univariate analyses using Chi-square tests and multiple logistic regression analyses were used to analyse the data. RESULTS: The rate of upstaging to invasive cancer was 19.2% (59/307). DCIS diagnosed by core-needle biopsy (odds ratio [OR]: 6.861, 95% confidence interval [CI]: 2.429-19.379), the presence of ultrasonic mass-forming lesions (OR: 2.782, 95% CI: 1.224-6.320), and progesterone receptor-negative status (OR: 3.156, 95% CI: 1.197-8.323) were found to be associated with upstaging. The rate of sentinel lymph node metastasis was only 1.9% (4/202), and all were total mastectomy patients diagnosed by core-needle biopsy. SLNB was performed in 37.2% of 145 breast-conserving surgery patients and 91.4% of 162 total mastectomy patients. Among the 202 patients who underwent SLNB, 145 (71.7%) without invasive cancer on final pathology had redundant SLNB. Two of 59 patients (3.4%) with disease upstaged to invasive cancer had inadequate primary staging of the axilla, as the rate seemed sufficiently small. CONCLUSIONS: In patients with a preoperative diagnosis of DCIS, although an unavoidable possibility of upstaging to invasive cancer exists, axillary metastasis is unlikely. Only 2.7% of patients with DCIS undergoing total mastectomy were found to have sentinel lymph node metastases. SLNB should not be performed in breast-conserving surgery patients and should be reserved only for total mastectomy patients diagnosed by core-needle biopsy.


Assuntos
Neoplasias da Mama , Carcinoma Intraductal não Infiltrante , Biópsia de Linfonodo Sentinela , Adulto , Axila/patologia , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Carcinoma Intraductal não Infiltrante/patologia , Carcinoma Intraductal não Infiltrante/cirurgia , Feminino , Humanos , Mastectomia , Pessoa de Meia-Idade , Estudos Retrospectivos , Procedimentos Desnecessários
8.
Sensors (Basel) ; 21(14)2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34300508

RESUMO

For a reliable and stable sensor system, it is essential to precisely measure various sensor signals, such as electromagnetic field, pressure, and temperature. The measured analog signal is converted into digital bits through the sensor readout system. However, in extreme radiation environments, such as in space, during flights, and in nuclear fusion reactors, the performance of the analog-to-digital converter (ADC) constituting the sensor readout system can be degraded due to soft errors caused by radiation effects, leading to system malfunction. This paper proposes a soft-error-tolerant successive-approximation-register (SAR) ADC using dual-capacitor sample-and-hold (S/H) control, which has robust characteristics against total ionizing dose (TID) and single event effects (SEE). The proposed ADC was fabricated using 65-nm CMOS process, and its soft-error-tolerant performance was measured in radiation environments. Additionally, the proposed circuit techniques were verified by utilizing a radiation simulator CAD tool.

9.
BMC Musculoskelet Disord ; 20(1): 124, 2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30909898

RESUMO

BACKGROUND: Antiplatelet medication has been frequently performed in elderly patients with hip fracture, because of comorbidities. This observational cohort study was to evaluate the effect of continuous perioperative antiplatelet medication on the outcomes after cephalomedullary nailing (CMN) in elderly patients with a proximal femur fracture. METHODS: One hundred and sixty-two consecutive patients aged ≥70 years undergoing CMN for proximal femur fracture between January 2015 and January 2017 were recruited. Of the 162 patients, 47 (study group) taking antiplatelets preoperatively due to comorbidities were compared with 107 (control group) who were not on antiplatelets. 8 patients taking anticoagulant medication were excluded. Postoperative hemoglobin (Hb) and hematocrit (Hct) levels, transfusion amount and estimated blood loss (EBL), occurrence of venous thromboembolism (VTE) and delirium, intensive care unit (ICU) admission, complications, length of hospital stay, readmission, and in-hospital and 1-year mortalities were measured and compared between the two groups. RESULTS: A higher number of patients in the study group had concomitant cardiovascular (p = 0.006) and endocrinologic (p = 0.004) diseases, received perioperative transfusion (p = 0.003), and were admitted to ICU postoperatively (p = 0.014). However, there were no significant differences in postoperative Hb and Hct levels, EBL, length of hospital stay, and the incidences of VTE and delirium between the two groups. In addition, in-hospital and 1-year mortalities as well as postoperative complications showed no significant differences between both groups. CONCLUSIONS: CMN can be performed without delay in elderly patients with proximal femoral fracture receiving antiplatelet therapy prior to admission without discontinuing antiplatelets, and is as safe as in patients who are not on antiplatelet medication. However, more caution is required with respect to transfusions and ICU care after surgery in these patients.


Assuntos
Fraturas do Fêmur/tratamento farmacológico , Fraturas do Quadril/tratamento farmacológico , Assistência Perioperatória/métodos , Inibidores da Agregação Plaquetária/administração & dosagem , Complicações Pós-Operatórias/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Fraturas do Fêmur/cirurgia , Fraturas do Quadril/cirurgia , Humanos , Masculino , Complicações Pós-Operatórias/diagnóstico , Estudos Retrospectivos
10.
Sensors (Basel) ; 20(1)2019 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-31892184

RESUMO

For stable and effective control of the sensor system, analog sensor signals such as temperature, pressure, and electromagnetic fields should be accurately measured and converted to digital bits. However, radiation environments, such as space, flight, nuclear power plants, and nuclear fusion reactors, as well as high-reliability applications, such as automotive semiconductor systems, suffer from radiation effects that degrade the performance of the sensor readout system including analog-to-digital converters (ADCs) and cause system malfunctions. This paper investigates an optimal ADC structure in radiation environments and proposes a successive- approximation-register (SAR) ADC using delay-based double feedback flip-flops to enhance the system tolerance against radiation effects, including total ionizing dose (TID) and single event effects (SEE). The proposed flip-flop was fabricated using 130 nm complementary metal-oxide-semiconductor (CMOS) silicon-on-insulator (SOI) process, and its radiation tolerance was measured in actual radiation test facilities. Also, the proposed radiation-hardened SAR ADC with delay-based dual feedback flip-flops was designed and verified by utilizing compact transistor models, which reflect radiation effects to CMOS parameters, and radiation simulator computer aided design (CAD) tools.

11.
Prep Biochem Biotechnol ; 49(8): 790-799, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31140364

RESUMO

The sweet-tasting protein brazzein is a candidate sugar substitute owing to its sweet, sugar-like taste and good stability. To commercialize brazzein as a sweetener, optimization of fermentation and purification procedure is necessary. Here, we report the expression conditions of brazzein in the yeast Kluyveromices lactis and purification method for maximum yield. Transformed K. lactis was cultured in YPGlu (pH 7.0) at 25 °C and induced by adding glucose:galactose at a weight ratio of 1:2 (%/%) during the stationary phase, which increased brazzein expression 2.5 fold compared to the previous conditions. Cultures were subjected to heat treatment at 80 °C for 1 h, and brazzein containing supernatant was purified using carboxymethyl-sepharose cation exchange chromatography using 50 mM NaCl in 50 mM sodium acetate buffer (pH 4.0) as a wash buffer and 400 mM NaCl (pH 7.0) for elution. The yield of purified brazzein under these conditions was 2.0-fold higher than that from previous purification methods. We also determined that the NanoOrange assay was a suitable method for quantifying tryptophan-deficient brazzein. Thus, it is possible to obtain pure recombinant brazzein with high yield in K. lactis using our optimized expression, purification, and quantification protocols, which has potential applications in the food industry.


Assuntos
Clonagem Molecular/métodos , Microbiologia Industrial/métodos , Kluyveromyces/genética , Proteínas de Plantas/genética , Edulcorantes/metabolismo , Vetores Genéticos/genética , Humanos , Kluyveromyces/metabolismo , Proteínas de Plantas/análise , Proteínas de Plantas/metabolismo , Proteínas Recombinantes/análise , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Edulcorantes/análise , Paladar , Triptofano/análise , Triptofano/genética , Triptofano/metabolismo
12.
Prep Biochem Biotechnol ; 47(10): 1037-1042, 2017 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-29020510

RESUMO

Agarase catalyzes the hydrolysis of agar, which is primarily used as a medium for microbiology, various food additives, and new biomass materials. In this study, we described the expression of the synthetic gene encoding ß-agarase from Agarivorans albus (Aaß-agarase) in Escherichia coli. The synthetic ß-agarase gene was designed based on the biased codons of E. coli to optimize its expression and extracellular secretion in an active, soluble form. The synthesized agarase gene, including its signal sequence, was cloned into the pET-26 expression vector, and the pET-Aaß-agarase plasmid was introduced into E. coli BL21-Star (DE3) cells. The E. coli transformants were cultured for high-yield secretion of recombinant Aaß-agarase in Luria-Bertani broth containing 0.6 mM isopropyl ß-D-1-thiogalactopyranoside for 9 h at 37°C. The expressed recombinant Aaß-agarase was purified by ammonium sulfate precipitation and diethylaminoethyl-sepharose column chromatography, yielding ∼10 mg/L Aaß-agarase. The purified recombinant Aaß-agarase exhibited optimal activity at pH 7 and 40°C, and its activity was strongly inhibited by Cu2+, Mn2+, Zn2+, and Al3+ ions. Furthermore, the KM and kcat values for purified Aaß-agarase were ∼0.02 mM and ∼45/s, respectively. These kinetic values were up to approximately 15-100-fold lower than the KM values reported for other agarases and approximately 7-30-fold higher than the kcat/KM values reported for other agarases, indicating that recombinant Aaß-agarase exhibited good substrate-binding ability and high catalytic efficiency. These results demonstrated that the E. coli expression system was capable of producing recombinant Aaß-agarase in an active form, at a high yield, and with attributes useful in the relevant industries.


Assuntos
Alteromonadaceae/enzimologia , Alteromonadaceae/genética , Escherichia coli/genética , Glicosídeo Hidrolases/genética , Clonagem Molecular , Eletroforese em Gel de Poliacrilamida , Vetores Genéticos/genética , Glicosídeo Hidrolases/isolamento & purificação , Glicosídeo Hidrolases/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Temperatura , Transformação Genética
13.
J Korean Med Sci ; 31(4): 579-84, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27051242

RESUMO

We investigated the association between breastfeeding and cognitive development in infants during their first 3 years. The present study was a part of the Mothers' and Children's Environmental Health (MOCEH) study, which was a multi-center birth cohort project in Korea that began in 2006. A total of 697 infants were tested at age 12, 24, and 36 months using the Korean version of the Bayley Scales of Infant Development II (K-BSID-II). The use and duration of breastfeeding and formula feeding were measured. The relationship between breastfeeding and the mental development index (MDI) score was analyzed by multiple linear regression analysis. The results indicated a positive correlation between breastfeeding duration and MDI score. After adjusting for covariates, infants who were breastfed for ≥ 9 months had significantly better cognitive development than those who had not been breastfed. These results suggest that the longer duration of breastfeeding improves cognitive development in infants.


Assuntos
Aleitamento Materno , Desenvolvimento Infantil/fisiologia , Cognição/fisiologia , Adulto , Pré-Escolar , Demografia , Feminino , Seguimentos , Humanos , Lactente , Entrevistas como Assunto , Modelos Lineares , Masculino , Mães/psicologia , Análise Multivariada , Avaliação de Programas e Projetos de Saúde , Estudos Prospectivos , República da Coreia
14.
BMC Urol ; 15: 55, 2015 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-26104313

RESUMO

BACKGROUND: This study was carried out a network meta-analysis of evidence from randomized controlled trials (RCTs) to evaluate stent-related discomfort in patients with alfuzosin or tamsulosin versus placebo. METHODS: Relevant RCTs were identified from electronic databases. The proceedings of appropriate meetings were also searched. Seven articles on the basis of RCTs were included in our meta-analysis. Using pairwise and network meta-analyses, comparisons were made by qualitative and quantitative syntheses. Evaluation was performed with the Ureteric Stent Symptoms Questionnaire to assess the urinary symptom score (USS) and body pain score (BPS). RESULTS: One of the seven RCTs was at moderate risk of bias for all quality criteria; two studies had a high risk of bias. In the network meta-analysis, both alfuzosin (mean difference [MD];-4.85, 95 % confidence interval [CI];-8.53--1.33) and tamsulosin (MD;-8.84, 95 % CI;-13.08--4.31) showed lower scores compared with placebo; however, the difference in USS for alfuzosin versus tamsulosin was not significant (MD; 3.99, 95 % CI;-1.23-9.04). Alfuzosin (MD;-5.71, 95 % CI;-11.32--0.52) and tamsulosin (MD;-7.77, 95 % CI;-13.68--2.14) showed lower scores for BPS compared with placebo; however, the MD between alfuzosin and tamsulosin was not significant (MD; 2.12, 95 % CI;-4.62-8.72). In the rank-probability test, tamsulosin ranked highest for USS and BPS, and alfuzosin was second. CONCLUSION: The alpha-blockers significantly decreased USS and BPS in comparison with placebo. Tamsulosin might be more effective than alfuzosin.


Assuntos
Antagonistas Adrenérgicos alfa/administração & dosagem , Dor/tratamento farmacológico , Quinazolinas/administração & dosagem , Stents/efeitos adversos , Sulfonamidas/administração & dosagem , Teorema de Bayes , Humanos , Dor/etiologia , Medição da Dor , Ensaios Clínicos Controlados Aleatórios como Assunto , Tansulosina , Resultado do Tratamento , Obstrução Ureteral/diagnóstico , Obstrução Ureteral/terapia
15.
Artigo em Inglês | MEDLINE | ID: mdl-38995703

RESUMO

This paper proposes an envelope-detector-less (EDL) amplitude-shift-keying (ASK) forward telemetry (FT) demodulator for wireless power/data transfer (WPDT) systems. The EDL ASK FT demodulator can substitute bulky and power-hungry components, which are an envelope detector and an analog comparator in the conventional ASK FT demodulator, with a digital controller, reducing both power dissipation and chip area. The proposed demodulator shares the gate control signals of pass transistors, which are used in an ac-dc regulator for wireless power reception, to maintain a constant load voltage while efficiently demodulating the forward telemetry data. Also, a proposed digital cleaner in the EDL demodulator refines this control signal into a wide pulse without suffering from resonant frequency noise, while a synchronizer can align its frequency with the data rate and resonant frequency. The 0.25-µm CMOS prototype chip of the proposed power-path-less EDL ASK FT demodulator, equipped with the ac-dc regulator, demonstrates a significant 38.2% reduction in power dissipation compared to the conventional ASK FT demodulator. Moreover, the EDL ASK FT demodulator occupies only 0.023-mm2 silicon area and achieves a low bit error rate (BER) less than 10-4 while maintaining a regulated voltage of 4.5 V on the load.

16.
Front Neuroanat ; 18: 1385932, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38562955

RESUMO

Transmembrane proteins known as hyperpolarization-activated cyclic nucleotide-gated (HCN) channels control the movement of Na+ and K+ ions across cellular membranes. HCN channels are known to be involved in crucial physiological functions in regulating neuronal excitability and rhythmicity, and pacemaker activity in the heart. Although HCN channels have been relatively well investigated in the brain, their distribution and function in the retina have received less attention, remaining their physiological roles to be comprehensively understood. Also, because recent studies reported HCN channels have been somewhat linked with the dysfunction of photoreceptors which are affected by retinal diseases, investigating HCN channels in the retina may offer valuable insights into disease mechanisms and potentially contribute to identifying novel therapeutic targets for retinal degenerative disorders. This paper endeavors to summarize the existing literature on the distribution and function of HCN channels reported in the vertebrate retinas of various species and discuss the potential implications for the treatment of retinal diseases. Then, we recapitulate current knowledge regarding the function and regulation of HCN channels, as well as their relevance to various neurological disorders.

18.
Sci Total Environ ; 920: 170822, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38365024

RESUMO

Seoul has high PM2.5 concentrations and has not attained the national annual average standard so far. To understand the reasons, we analyzed long-term (2015-2021) hourly observations of aerosols (PM2.5, NO3-, NH4+, SO42-, OC, and EC) and gases (CO, NO2, and SO2) from Seoul and Baekryeong Island, a background site in the upwind region of Seoul. We applied the weather normalization method for meteorological conditions and a 3-dimensional chemical transport model, GEOS-Chem, to identify the effect of policy implementation and aerosol formation mechanisms. The monthly mean PM2.5 ranges between about 20 µg m-3 (warm season) and about 40 µg m-3 (cold season) at both sites, but the annual decreasing rates were larger at Seoul than at Baengnyeong (-0.7 µg m-3 a-1 vs. -1.8 µg m-3 a-1) demonstrating the effectiveness of the local air quality policies including the Special Act on Air Quality in the Seoul Metropolitan Area (SAAQ-SMA) and the seasonal control measures. The weather-normalized monthly mean data shows the highest PM2.5 concentration in March and the lowest concentration in August throughout the 7 years with NO3- accounting for about 40 % of the difference between the two months at both sites. Taking together with the GEOS-Chem model results, which reproduced the elevated NO3- in March, we concluded the elevated atmospheric oxidant level increases in HNO3 (which is not available from the observation) and the still low temperatures in March promote rapid production of NO3-. We used Ox (≡ O3 + NO2) from the observation and OH from the GEOS-Chem as a proxy for the atmospheric oxidant level which can be a source of uncertainty. Thus, direct observations of OH and HNO3 are needed to provide convincing evidence. This study shows that reducing HNO3 levels through atmospheric oxidant level control in the cold season can be effective in PM2.5 mitigation in Seoul.

19.
Hum Vaccin Immunother ; 20(1): 2346966, 2024 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38741240

RESUMO

This research examines the low rate of co-administration of influenza and COVID-19 vaccines among seniors aged 65 and older in Korea, despite recommendations from authorities and academia worldwide. The study aimed to understand the influence of general characteristics and health beliefs on the vaccination choices of seniors, who were categorized into four groups based on their vaccination status: influenza only, COVID-19 only, both, or neither. A total of 400 participants, aged 65 and above, were selected through proportional stratified random sampling from five major Korean regions for a survey conducted between November 24th and December 15th, 2023. The results indicated no significant differences in general characteristics across these groups. However, regarding the health beliefs showed significant differences in perceived susceptibility and self-efficacy between the influenza-only and co-administration groups. Higher levels of perceived susceptibility and self-efficacy were associated with choosing co-administration. Contrary to previous studies focusing on safety concerns as a primary factor in vaccine hesitancy, this study highlights the role of individual health-related beliefs, particularly perceived susceptibility and self-efficacy, as critical in influencing the decision for co-administration among the elderly in Korea.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Vacinas contra Influenza , Influenza Humana , Humanos , Idoso , Vacinas contra Influenza/administração & dosagem , Masculino , Feminino , Influenza Humana/prevenção & controle , República da Coreia , Vacinas contra COVID-19/administração & dosagem , COVID-19/prevenção & controle , Idoso de 80 Anos ou mais , Vacinação/psicologia , Vacinação/estatística & dados numéricos , Hesitação Vacinal/estatística & dados numéricos , Hesitação Vacinal/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Inquéritos e Questionários , Autoeficácia , SARS-CoV-2/imunologia , Tomada de Decisões
20.
Sci Adv ; 10(24): eadl3350, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38875324

RESUMO

We present the fabrication of 4 K-scale electrochemical random-access memory (ECRAM) cross-point arrays for analog neural network training accelerator and an electrical characteristic of an 8 × 8 ECRAM array with a 100% yield, showing excellent switching characteristics, low cycle-to-cycle, and device-to-device variations. Leveraging the advances of the ECRAM array, we showcase its efficacy in neural network training using the Tiki-Taka version 2 algorithm (TTv2) tailored for non-ideal analog memory devices. Through an experimental study using ECRAM devices, we investigate the influence of retention characteristics on the training performance of TTv2, revealing that the relative location of the retention convergence point critically determines the available weight range and, consequently, affects the training accuracy. We propose a retention-aware zero-shifting technique designed to optimize neural network training performance, particularly in scenarios involving cross-point devices with limited retention times. This technique ensures robust and efficient analog neural network training despite the practical constraints posed by analog cross-point devices.

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