Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Psychiatry Investig ; 21(10): 1065-1075, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39255965

RESUMO

OBJECTIVE: Semantic verbal fluency (SVF) engages cognitive functions such as executive function, mental flexibility, and semantic memory. Left frontal and temporal lobes, particularly the left inferior frontal gyrus (IFG), are crucial for SVF. This study investigates SVF and associated neural processing in older adults with mild SVF impairment and the relationship between structural abnormalities in the left IFG and functional activation during SVF in those individuals. METHODS: Fifty-four elderly individuals with modest level of mild cognitive impairment whose global cognition were preserved to normal but exhibited mild SVF impairment were participated. Prefrontal oxyhemoglobin (HbO2) activation and frontal cortical thickness were collected from the participants using functional near-infrared spectroscopy (fNIRS) and brain MRI, respectively. We calculated the ß coefficient of HbO2 activation induced by tasks, and performed correlation analysis between SVF induced HbO2 activation and cortical thickness in frontal areas. RESULTS: We observed increased prefrontal activation during SVF task compared to the resting and control task. The activation distinct to SVF was identified in the midline superior and left superior prefrontal regions (p<0.05). Correlation analysis revealed an inverse relationship between SVF-specific activation and cortical thickness in the left IFG, particularly in pars triangularis (r(54)=-0.304, p=0.025). CONCLUSION: The study contributes to understanding the relationship between reduced cortical thickness in left IFG and increased functional activity in cognitively normal individuals with mild SVF impairment, providing implications on potential compensatory mechanisms for cognitive preservation.

2.
Nanotechnology ; 35(27)2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38522102

RESUMO

To obtain high-quality SiNxfilms applicable to an extensive range of processes, such as gate spacers in fin field-effect transistors (FinFETs), the self-aligned quadruple patterning process, etc, a study of plasma with higher plasma density and lower plasma damage is crucial in addition to study on novel precursors for SiNxplasma-enhanced atomic layer deposition (PEALD) processes. In this study, a novel magnetized PEALD process was developed for depositing high-quality SiNxfilms using di(isopropylamino)silane (DIPAS) and magnetized N2plasma at a low substrate temperature of 200 °C. The properties of the deposited SiNxfilms were analyzed and compared with those obtained by the PEALD process using a non-magnetized N2plasma source under the same conditions. The PEALD SiNxfilm, produced using an external magnetic field (ranging from 0 to 100 G) during the plasma exposure step, exhibited a higher growth rate (∼1 Å/cycle) due to the increased plasma density. Additionally, it showed lower surface roughness, higher film density, and enhanced wet etch resistance compared to films deposited using the PEALD process with non-magnetized plasmas. This improvement can be attributed to the higher ion flux and lower ion energy of the magnetized plasma. The electrical characteristics, such as interface trap density and breakdown voltage, were also enhanced when the magnetized plasma was used for the PEALD process. Furthermore, when SiNxfilms were deposited on high-aspect-ratio (30:1) trench patterns using the magnetized PEALD process, an improved step coverage of over 98% was achieved, in contrast to the conformality of SiNxdeposited using non-magnetized plasma. This enhancement is possibly a result of deeper radical penetration enabled by the magnetized plasma.

3.
Nanomaterials (Basel) ; 13(17)2023 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-37686940

RESUMO

Yttrium oxide (Y2O3) resistive random-access memory (RRAM) devices were fabricated using the sol-gel process on indium tin oxide/glass substrates. These devices exhibited conventional bipolar RRAM characteristics without requiring a high-voltage forming process. The effect of current compliance on the Y2O3 RRAM devices was investigated, and the results revealed that the resistance values gradually decreased with increasing set current compliance values. By regulating these values, the formation of pure Ag conductive filament could be restricted. The dominant oxygen ion diffusion and migration within Y2O3 leads to the formation of oxygen vacancies and Ag metal-mixed conductive filaments between the two electrodes. The filament composition changes from pure Ag metal to Ag metal mixed with oxygen vacancies, which is crucial for realizing multilevel cell (MLC) switching. Consequently, intermediate resistance values were obtained, which were suitable for MLC switching. The fabricated Y2O3 RRAM devices could function as a MLC with a capacity of two bits in one cell, utilizing three low-resistance states and one common high-resistance state. The potential of the Y2O3 RRAM devices for neural networks was further explored through numerical simulations. Hardware neural networks based on the Y2O3 RRAM devices demonstrated effective digit image classification with a high accuracy rate of approximately 88%, comparable to the ideal software-based classification (~92%). This indicates that the proposed RRAM can be utilized as a memory component in practical neuromorphic systems.

4.
Nanomaterials (Basel) ; 13(17)2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37686969

RESUMO

Herein, sol-gel-processed Y2O3-Al2O3 mixed oxide-based resistive random-access-memory (RRAM) devices with different proportions of the involved Y2O3 and Al2O3 precursors were fabricated on indium tin oxide/glass substrates. The corresponding structural, chemical, and electrical properties were investigated. The fabricated devices exhibited conventional bipolar RRAM characteristics without requiring a high-voltage forming process. With an increase in the percentage of Al2O3 precursor above 50 mol%, the crystallinity reduced, with the amorphous phase increasing owing to internal stress. Moreover, with increasing Al2O3 percentage, the lattice oxygen percentage increased and the oxygen vacancy percentage decreased. A 50% Y2O3-50% Al2O3 mixed oxide-based RRAM device exhibited the maximum high-resistance-state/low-resistance-state (HRS/LRS) ratio, as required for a large readout margin and array size. Additionally, this device demonstrated good endurance characteristics, maintaining stability for approximately 100 cycles with a high HRS/LRS ratio (>104). The HRS and LRS resistances were also retained up to 104 s without considerable degradation.

5.
Artigo em Inglês | MEDLINE | ID: mdl-37372684

RESUMO

This study aimed to evaluate sarcopenia and locomotive syndrome in Korean elderly patients, analyze the closely related factors, and determine the threshold for distinguishing participants with sarcopenia, locomotive syndrome, and non-disease. To this end, we enrolled 210 subjects aged 65 years or more and classified them into the sarcopenia (n = 36) and locomotive syndrome (n = 164) groups; a control group was also included (n = 10). We evaluated the characteristics of these patients using the Timed Up and Go (TUG) test and Berg Balance Scale (BBS) and performed statistical analysis. Our findings showed statistically significant differences between the groups, leading to the derivation of a significant threshold value. The threshold value of the TUG test between the control and locomotive syndrome groups was 9.47 s; the threshold value of the BBS was 54 points, respectively. The threshold value of the TUG test between the locomotive syndrome and sarcopenia groups was 10.27 s, and the threshold value of the BBS was 50 points, respectively. These findings suggest that sarcopenia is closely related to locomotive syndrome, and that sarcopenia and locomotive syndrome can be identified using a physical therapy diagnostic evaluation tool.


Assuntos
Sarcopenia , Idoso , Humanos , Sarcopenia/diagnóstico , Programas de Rastreamento , Modalidades de Fisioterapia , Equilíbrio Postural
6.
ACS Appl Mater Interfaces ; 15(23): 28763-28771, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37269552

RESUMO

Plasma enhanced atomic layer deposition (PEALD) of silicon nitride (SiNx) using very high frequency (VHF, 162 MHz) plasma source was investigated at the process temperatures of 100, 200, and 300 °C. Two aminosilane precursors having different numbers of amino ligands, bis(tert-butylamino)silane (BTBAS) and di(sec-butylamino)silane (DSBAS), were used as Si precursors. A comparative study was also conducted to verify the effect of the number of amino ligands on the properties of SiNx film. At all process temperatures, DSBAS, having one amino ligand, performed better than BTBAS in various aspects. SiNx films deposited using DSBAS had lower surface roughness, higher film density, lower wet etch rate, improved electrical characteristics, and higher growth rate than those deposited using BTBAS. With the combination of a VHF plasma source and DSBAS with one amino ligand, the SiNx films grown at 300 °C exhibited low wet etch rates (≤2 nm/min) in a dilute HF solution (100:1 of deionized water:HF) as well as low C content below the XPS detection limit. Also, excellent step coverage close to 100% on high aspect ratio (30:1) trench structures was obtained by using VHF plasma, which could provide sufficient flux of plasma species inside the trenches in conjunction with DSBAS having fewer amino ligands than BTBAS.

7.
Psychiatry Investig ; 20(6): 515-523, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37248689

RESUMO

OBJECTIVE: This study employs machine learning and population-based data to examine major factors of antidepressant medication including nitrogen dioxides (NO2) seasonality. METHODS: Retrospective cohort data came from Korea National Health Insurance Service claims data for 43,251 participants with the age of 15-79 years, residence in the same districts of Seoul and no history of antidepressant medication during 2002-2012. The dependent variable was antidepressant-free months during 2013-2015 and the 103 independent variables for 2012 or 2015 were considered, e.g., particulate matter less than 2.5 micrometer in diameter (PM2.5), PM10, NO2, ozone (O3), sulphur dioxide (SO2) and carbon monoxide (CO) in each of 12 months in 2015. RESULTS: It was found that the Cox hazard ratios of NO2 were statistically significant and registered values larger than 10 for every three months: March, June-July, October, and December. Based on random forest variable importance and Cox hazard ratios in brackets, indeed, the top 20 factors of antidepressant medication included age (0.0041 [1.69-2.25]), migraine and sleep disorder (0.0029 [1.82]), liver disease (0.0017 [1.33-1.34]), exercise (0.0014), thyroid disease (0.0013), cardiovascular disease (0.0013 [1.20]), asthma (0.0008 [1.19-1.20]), September NO2 (0.0008 [0.01]), alcohol consumption (0.0008 [1.31-1.32]), gender - woman (0.0007 [1.80-1.81]), July NO2 (0.0007 [14.93]), July PM10 (0.0007), the proportion of the married (0.0005), January PM2.5 (0.0004), September PM2.5 (0.0004), chronic obstructive pulmonary disease (0.0004), economic satisfaction (0.0004), January PM10 (0.0003), residents in welfare facilities per 1,000 (0.0003 [0.97]), and October NO2 (0.0003). CONCLUSION: Antidepressant medication has strong associations with neighborhood conditions including NO2 seasonality and welfare support.

8.
Diagnostics (Basel) ; 12(12)2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36552977

RESUMO

This study presents the most comprehensive machine-learning analysis for the predictors of blood transfusion, all-cause mortality, and hospitalization period in COVID-19 patients. Data came from Korea National Health Insurance claims data with 7943 COVID-19 patients diagnosed during November 2019−May 2020. The dependent variables were all-cause mortality and the hospitalization period, and their 28 independent variables were considered. Random forest variable importance (GINI) was introduced for identifying the main factors of the dependent variables and evaluating their associations with these predictors, including blood transfusion. Based on the results of this study, blood transfusion had a positive association with all-cause mortality. The proportions of red blood cell, platelet, fresh frozen plasma, and cryoprecipitate transfusions were significantly higher in those with death than in those without death (p-values < 0.01). Likewise, the top ten factors of all-cause mortality based on random forest variable importance were the Charlson Comorbidity Index (53.54), age (45.68), socioeconomic status (45.65), red blood cell transfusion (27.08), dementia (19.27), antiplatelet (16.81), gender (14.60), diabetes mellitus (13.00), liver disease (11.19) and platelet transfusion (10.11). The top ten predictors of the hospitalization period were the Charlson Comorbidity Index, socioeconomic status, dementia, age, gender, hemiplegia, antiplatelet, diabetes mellitus, liver disease, and cardiovascular disease. In conclusion, comorbidity, red blood cell transfusion, and platelet transfusion were the major factors of all-cause mortality based on machine learning analysis. The effective management of these predictors is needed in COVID-19 patients.

9.
BMB Rep ; 55(12): 639-644, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36330710

RESUMO

Serine-arginine-rich splicing factors (SRSFs) are members of RNA processing proteins in the serine-arginine-rich (SR) family that could regulate the alternative splicing of the human immunodeficiency virus-1 (HIV-1). Whether SRSF9 has any effect on HIV-1 regulation requires elucidation. Here, we report for the first time the effects and mechanisms of SRSF9 on HIV-1 regulation. The overexpression of SRSF9 inhibits viral production and infectivity in both HEK293T and MT-4 cells. Deletion analysis of SRSF9 determined that the RNA regulation motif domain of SRSF9 is important for anti-HIV-1 effects. Furthermore, overexpression of SRSF9 increases multiple spliced forms of viral mRNA, such as Vpr mRNA. These data suggest that SRSF9 overexpression inhibits HIV-1 production by inducing the imbalanced HIV-1 mRNA splicing that could be exploited further for a novel HIV-1 therapeutic molecule. [BMB Reports 2022; 55(12): 639-644].


Assuntos
HIV-1 , Fatores de Processamento de Serina-Arginina , Humanos , Processamento Alternativo/genética , Células HEK293 , HIV-1/metabolismo , Splicing de RNA/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo
10.
Int J Mol Sci ; 23(20)2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36293198

RESUMO

The positive transcription elongation factor b (P-TEFb) is an essential factor that induces transcription elongation and is also negatively regulated by the cellular factor HEXIM1. Previously, the chimeric protein HEXIM1-Tat (HT) was demonstrated to inhibit human immunodeficiency virus-1 (HIV)-1 transcription. In this study, we attempted to develop an improved antiviral protein that specifically binds viral RNA (vRNA) by fusing HT to HIV-1 nucleocapsid (NC). Thus, we synthesized NC-HEXIM1-Tat (NHT) and HEXIM1-Tat-NC (HTN). NHT and HTN inhibited virus proliferation more effectively than HT, and they did not attenuate the function of HT. Notably, NHT and HTN inhibited the infectivity of the progeny virus, whereas HT had no such effect. NHT and HTN selectively and effectively interacted with vRNA and inhibited the proper packaging of the HIV-1 genome. Taken together, our results illustrated that the novel NC-fused chimeric proteins NHT and HTN display novel mechanisms of anti-HIV effects by inhibiting both HIV-1 transcription and packaging.


Assuntos
HIV-1 , Fator B de Elongação Transcricional Positiva , Humanos , Fator B de Elongação Transcricional Positiva/metabolismo , HIV-1/genética , HIV-1/metabolismo , Produtos do Gene tat do Vírus da Imunodeficiência Humana/metabolismo , RNA Viral/metabolismo , Proteínas do Nucleocapsídeo/genética , Proteínas do Nucleocapsídeo/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Replicação Viral , Nucleocapsídeo/metabolismo , Antivirais/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/farmacologia , Proteínas Recombinantes de Fusão/metabolismo , Fatores de Transcrição/metabolismo
11.
Materials (Basel) ; 15(19)2022 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-36234198

RESUMO

In this study, we fabricated sol-gel-processed Y2O3-based resistive random-access memory (RRAM) devices. The fabricated Y2O3 RRAM devices exhibited conventional bipolar RRAM device characteristics and did not require the forming process. The long-term stability of the RRAM devices was investigated. The Y2O3 RRAM devices with a 20 nm thick Ag top electrode showed an increase in the low resistance state (LRS) and high resistance state (HRS) and a decrease in the HRS/LRS ratio after 30 days owing to oxidation and corrosion of the Ag electrodes. However, Y2O3 RRAM devices with inert Au-passivated Ag electrodes showed a constant RRAM device performance after 30 days. The 150 nm-thick Au passivation layer successfully suppressed the oxidation and corrosion of the Ag electrode by minimizing the chance of contact between water or oxygen molecules and Ag electrodes. The Au/Ag/Y2O3/ITO RRAM devices exhibited more than 300 switching cycles with a decent resistive window (>103). They maintained constant LRS and HRS resistances for up to 104 s, without significant degradation of nonvolatile memory properties for 30 days while stored in air.

12.
J Exerc Rehabil ; 18(4): 256-263, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36110258

RESUMO

This study was conducted to analyze the relationship between locomotive syndrome and sarcopenia in the old people using a functional evaluation tool. In this study, 237 Korean old people selected from the Miraeseum Seongnam Senior Complex and the Misa Riverside Welfare Center were diagnosed with the two diseases and the Berg balance scale was performed to confirm the deterioration of dynamic balance sensory. Through the diagnostic evaluation of the two diseases, the locomotive group (n=180) and the sarcopenia group (n=34) were classified and statistically analyzed. As a result of the study, a significant difference in dynamic balance sensory between the two diseases was confirmed, and a significant negative correlation was confirmed with 25-question geriatric locomotive function scale and grip strength among the diagnostic evaluation items of the two diseases. These results suggest that gradual deterioration of locomotive syndrome and sarcopenia occurs in the deterioration of physical performance in the old people, suggesting that the evaluation of locomotive syndrome can be used as a screening test for sarcopenia.

13.
Obstet Gynecol Sci ; 65(6): 487-501, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35916014

RESUMO

OBJECTIVE: This study systematically analyzed coronavirus disease 2019 (COVID-19) and vaccination details during pregnancy by using the national health insurance claims data. METHODS: Population-based retrospective cohort data of 12,399,065 women aged 15-49 years were obtained from the Korea National Health Insurance Service claims database between 2019 and 2021. Univariate analysis was performed to compare the obstetric outcomes of pregnant women (ICD-10 O00-O94) and their newborns (ICD-10 P00-P96) with and without COVID-19. Univariate analysis was also performed to compare the age and obstetric outcomes of pregnant women receiving different types of vaccines. RESULTS: The percentage of pregnant women with COVID-19 during pregnancy was 0.11%. Some obstetric outcomes of pregnant women with COVID-19, including the rates of preterm birth or cesarean delivery, were significantly better than those of pregnant women without COVID-19. The rate of miscarriage was higher in pregnant women with COVID-19 than without COVID-19. However, the outcomes of newborns of women with and without COVID-19 were not significantly different. Regarding vaccination type, obstetric outcomes of pregnant women appeared to be worse with the viral vector vaccine than with the mRNA vaccine. CONCLUSION: To the best of our knowledge, this is the first study to systematically analyze COVID-19 and vaccination details during pregnancy using the national health insurance claims data in Korea. The obstetric outcomes in pregnant women with and without COVID-19 and their newborns were similar.

14.
Artigo em Inglês | MEDLINE | ID: mdl-35270746

RESUMO

This study employs machine learning and population data for testing the associations of preterm birth with inflammatory bowel disease (IBD), salivary gland disease, socioeconomic status and medication history, including proton pump inhibitors. The source of population-based retrospective cohort data was the Korea National Health Insurance Service claims data for all women aged 25-40 years and who experience their first childbirths as singleton pregnancy during 2015 to 2017 (402,092 women). These participants were divided into the Ulcerative Colitis (UC) Group (1782 women), the Crohn Group (1954 women) and the Non-IBD Group (398,219 women). For each group, the dependent variable was preterm birth during 2015-2017, and 51 independent variables were included. Random forest variable importance was employed for investigating the main factors of preterm birth and testing its associations with salivary gland disease, socioeconomic status and medication history for each group. The proportion of preterm birth was higher for the UC Group and the Non-IBD Group than for the Crohn Group: 7.86%, 7.17% vs. 6.76%. Based on random forest variable importance, salivary gland disease was a top 10 determinant for the prediction of preterm birth for the UC Group, but this was not the case for the Crohn Group or the Non-IBD Group. The top 5 variables of preterm birth for the UC Group during 2015-2017 were socioeconomic status (8.58), age (8.00), proton pump inhibitors (2.35), progesterone (2.13) and salivary gland disease in 2014 (1.72). In conclusion, preterm birth has strong associations with ulcerative colitis, salivary gland disease, socioeconomic status and medication history including proton pump inhibitors.


Assuntos
Colite Ulcerativa , Doença de Crohn , Doenças Inflamatórias Intestinais , Nascimento Prematuro , Doenças das Glândulas Salivares , Colite Ulcerativa/epidemiologia , Doença de Crohn/epidemiologia , Feminino , Humanos , Recém-Nascido , Doenças Inflamatórias Intestinais/epidemiologia , Aprendizado de Máquina , Programas Nacionais de Saúde , Gravidez , Nascimento Prematuro/epidemiologia , Inibidores da Bomba de Prótons , Estudos Retrospectivos , Doenças das Glândulas Salivares/complicações
15.
Arch Gynecol Obstet ; 305(5): 1369-1376, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35038042

RESUMO

PURPOSE: To use machine learning and population data for testing the associations of preterm birth with socioeconomic status, gastroesophageal reflux disease (GERD) and medication history including proton pump inhibitors, sleeping pills and antidepressants. METHODS: Population-based retrospective cohort data came from Korea National Health Insurance Service claims data for all women who aged 25-40 years and gave births for the first time as singleton pregnancy during 2015-2017 (405,586 women). The dependent variable was preterm birth during 2015-2017 and 65 independent variables were included (demographic/socioeconomic determinants, disease information, medication history, obstetric information). Random forest variable importance (outcome measure) was used for identifying major determinants of preterm birth and testing its associations with socioeconomic status, GERD and medication history including proton pump inhibitors, sleeping pills and antidepressants. RESULTS: Based on random forest variable importance, major determinants of preterm birth during 2015-2017 were socioeconomic status (645.34), age (556.86), proton pump inhibitors (107.61), GERD for the years 2014, 2012 and 2013 (106.78, 105.87 and 104.96), sleeping pills (97.23), GERD for the years 2010, 2011 and 2009 (95.56, 94.84 and 93.81), and antidepressants (90.13). CONCLUSION: Preterm birth has strong associations with low socioeconomic status, GERD and medication history such as proton pump inhibitors, sleeping pills and antidepressants. For preventing preterm birth, appropriate medication would be needed alongside preventive measures for GERD and the promotion of socioeconomic status for pregnant women.


Assuntos
Refluxo Gastroesofágico , Nascimento Prematuro , Medicamentos Indutores do Sono , Antidepressivos/uso terapêutico , Feminino , Refluxo Gastroesofágico/epidemiologia , Humanos , Recém-Nascido , Aprendizado de Máquina , Masculino , Programas Nacionais de Saúde , Gravidez , Nascimento Prematuro/epidemiologia , Inibidores da Bomba de Prótons/uso terapêutico , Estudos Retrospectivos
16.
Sensors (Basel) ; 21(19)2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34640900

RESUMO

This paper presents a metamaterial (MTM)-integrated high-gain rectenna for RF sensing and energy harvesting applications that operates at 2.45 GHz, an industry, science, medicine (ISM) band. The novel MTM superstrate approach with a three-layered integration method is firstly introduced for rectenna applications. The integrated rectenna consists of three layers, where the first layer is an MTM superstrate consisting of four-by-four MTM unit cell arrays, the second layer a patch antenna, and the third layer a rectifier circuit. By integrating the MTM superstrate on top of the patch antenna, the gain of the antenna is enhanced, owing to its beam focusing capability of the MTM superstrate. This induces the increase of the captured RF power at the rectifier input, resulting in high-output DC power and high entire end-to-end efficiency. A parametric analysis is performed in order to optimize the near-zero property of the MTM unit cell. In addition, the effects of the number of MTM unit cells on the performance of the integrated rectenna are studied. A prototype MTM-integrated rectenna, which is designed on an RO5880 substrate, is fabricated and characterized. The measured gain of the MTM-integrated rectenna is 11.87 dB. It shows a gain improvement of 6.12 dB compared to a counterpart patch antenna without an MTM superstrate and a maximum RF-DC conversion efficiency of 78.9% at an input RF power of 9 dBm. This results in the improvement of the RF-DC efficiency from 39.2% to 78.9% and the increase of the output DC power from 0.7 mW to 6.27 mW (a factor of 8.96 improvements). The demonstrated MTM-integrated rectenna has shown outstanding performance compared to other previously reported work. We emphasize that the demonstrated MTM-integrated rectenna has a low design complexity compared with other work, as the MTM superstrate layer is integrated on top of the simple patch antenna and rectifier circuit. In addition, the number of MTM units can be determined depending on applications. It is highly envisioned that the demonstrated MTM-integrated rectenna will provide new possibilities for practical energy harvesting applications with improved antenna gain and efficiency in various IoT environments.


Assuntos
Desenho de Equipamento , Impedância Elétrica , Fenômenos Físicos
17.
BMB Rep ; 54(11): 551-556, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34353428

RESUMO

In this study, we investigated how Staufen1 influences the HIV-1 production. The overexpression of Staufen1 increased virus production without any negative affect on the viral infectivity. This increase was not caused by transcriptional activation; but by influencing post-transcriptional steps. Using multiple Gag protein derivatives, we confirmed that the zinc-finger domains of the HIV-1 nucleocapsid (NC) are important for its interaction with Staufen1. We also found that Staufen1 colocalized in stress granules with the mature form of the HIV-1 NC protein. [BMB Reports 2021; 54(11): 551-556].


Assuntos
Proteínas do Citoesqueleto/metabolismo , Produtos do Gene gag/metabolismo , Infecções por HIV/virologia , HIV-1/fisiologia , Nucleocapsídeo/metabolismo , Proteínas de Ligação a RNA/metabolismo , Grânulos de Estresse/metabolismo , Replicação Viral , Proteínas do Citoesqueleto/genética , Produtos do Gene gag/genética , Células HeLa , Humanos , Nucleocapsídeo/genética , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteínas de Ligação a RNA/genética
18.
Diagnostics (Basel) ; 11(3)2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33808913

RESUMO

This study uses machine learning and population data to analyze major determinants of preterm birth including depression and particulate matter. Retrospective cohort data came from Korea National Health Insurance Service claims data for 405,586 women who were aged 25-40 years and gave births for the first time after a singleton pregnancy during 2015-2017. The dependent variable was preterm birth during 2015-2017 and 90 independent variables were included (demographic/socioeconomic information, particulate matter, disease information, medication history, obstetric information). Random forest variable importance was used to identify major determinants of preterm birth including depression and particulate matter. Based on random forest variable importance, the top 40 determinants of preterm birth during 2015-2017 included socioeconomic status, age, proton pump inhibitor, benzodiazepine, tricyclic antidepressant, sleeping pills, progesterone, gastroesophageal reflux disease (GERD) for the years 2002-2014, particulate matter for the months January-December 2014, region, myoma uteri, diabetes for the years 2013-2014 and depression for the years 2011-2014. In conclusion, preterm birth has strong associations with depression and particulate matter. What is really needed for effective prenatal care is strong intervention for particulate matters together with active counseling and medication for common depressive symptoms (neglected by pregnant women).

19.
Talanta ; 190: 391-396, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30172524

RESUMO

Dengue virus (DENV) is one of the life-threatening viruses to the human. In this study, we have designed specific novel primers for rapid discriminative detection of DENV-1, DENV-2, and DENV-4 by real-time reverse transcription loop-mediated isothermal amplification (RT-LAMP) reaction. The effect of parameters such as reaction temperature and magnesium sulfate was investigated on the RT-LAMP reaction for detection of DENV RNA. Under the optimal conditions, this method is able to differentiate and to detect DENV within 25 min, exhibiting detection limit of 3.5 copies/µL. Importantly, the novel specific primers-based RT-LAMP assay did not react with other viruses, suggesting the selectivity of the method towards DENV RNA. The RT-LAMP reaction products are easily visualized with naked-eye when irradiated them under UV light at 365 nm. Amplification products could be visualized directly for color changes. This method provides a facile, and accurate molecular amplication technique for the rapid discriminative detection of dengue viruses. The RT-LAMP platform can be used as a promissing diagnostic tool for discriminative detection of DENV without aid of complicated protocols or sophisticated equipment.


Assuntos
Vírus da Dengue/genética , Vírus da Dengue/isolamento & purificação , Técnicas de Amplificação de Ácido Nucleico/métodos , RNA Viral/genética , Limite de Detecção , Transcrição Reversa , Fatores de Tempo
20.
Biomol Ther (Seoul) ; 26(4): 335-342, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29949843

RESUMO

The incidence and mortality of various cancers are associated with sex-specific disparities. Sex differences in cancer epidemiology are one of the most significant findings. Men are more prone to die from cancer, particularly hematological malignancies. Sex difference in cancer incidence is attributed to regulation at the genetic/molecular level and sex hormones such as estrogen. At the genetic/molecular level, gene polymorphism and altered enzymes involving drug metabolism generate differences in cancer incidence between men and women. Sex hormones modulate gene expression in various cancers. Genetic or hormonal differences between men and women determine the effect of chemotherapy. Until today, animal studies and clinical trials investigating chemotherapy showed sex imbalance. Chemotherapy has been used without consideration of sex differences, resulting in disparity of efficacy and toxicity between sexes. Based on accumulating evidence supporting sex differences in chemotherapy, all clinical trials in cancer must incorporate sex differences for a better understanding of biological differences between men and women. In the present review, we summarized the sex differences in (1) incidence and mortality of cancer, (2) genetic and molecular basis of cancer, (3) sex hormones in cancer incidence, and (4) efficacy and toxicity of chemotherapy. This review provides useful information for sex-based chemotherapy and development of personalized therapeutic strategies against cancer.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA