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1.
Small ; : e2402425, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-39007453

RESUMEN

A low-cost and indium-tin-oxide (ITO)-free electrode-based flexible perovskite solar cell (PSC) that can be fabricated by roll-to-roll processing shall be developed for successful commercialization. High processing temperatures present a challenge for the PSC fabrication on flexible substrates. The most efficient planar n-i-p PSC structures, which utilize a metal oxide as an electron transport layer (ETL), necessitate high annealing temperatures. In addition, the device performance deteriorates owing to the migration of halogen ions, which causes the oxidation of the metal electrodes. These drawbacks conflict with the development of highly efficient flexible PSCs fabricated on ITO-free transparent electrodes. Herein, an efficient ETL material that enables low-temperature processing is presented. Tin dioxide (SnO2) is modified by (sulfobetaine-N,N-dimethylamino)propyl naphthalene diimide (NDI-B) and used as an ETL. The NDI-B effectively reduces the interfacial nonradiative recombination between the ETL and perovskite and suppresses the ion migration by passivating oxygen-vacancy defects in SnO2 and strongly interacting with halogen ions, respectively. Based on the NDI-B-blended SnO2 ETL, a record PCE of 17.48% is achieved in the ITO-free flexible PSC fabricated at low temperature.

2.
Opt Express ; 32(5): 8146-8159, 2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38439479

RESUMEN

Flat optics or metasurfaces have opened new frontiers in wavefront shaping and its applications. Polarization optics is one prominent area which has greatly benefited from the shape-birefringence of metasurfaces. However, flat optics comprising a single layer of meta-atoms can only perform a subset of polarization transformations, constrained by a symmetric Jones matrix. This limitation can be tackled using metasurfaces composed of bilayer meta-atoms but exhausting all possible combinations of geometries to build a bilayer metasurface library is a very daunting task. Consequently, bilayer metasurfaces have been widely treated as a cascade (product) of two decoupled single-layer metasurfaces. Here, we test the validity of this assumption for dielectric metasurfaces by considering a metasurface made of titanium dioxide on fused silica substrate at a design wavelength of 532 nm. We explore regions in the design space where the coupling between the top and bottom layers can be neglected, i.e., producing a far-field response which approximates that of two decoupled single-layer metasurfaces. We complement this picture with the near-field analysis to explore the underlying physics in regions where both layers are strongly coupled. We also show the generality of our analysis by applying it to silicon metasurfaces at telecom wavelengths. Our unified approach allows the designer to efficiently build a multi-layer dielectric metasurface, either in transmission or reflection, by only running one full-wave simulation for a single-layer metasurface.

3.
Allergy ; 79(8): 2173-2185, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38995241

RESUMEN

BACKGROUND: There is evidence that global anthropogenic climate change may be impacting floral phenology and the temporal and spatial characteristics of aero-allergenic pollen. Given the extent of current and future climate uncertainty, there is a need to strengthen predictive pollen forecasts. METHODS: The study aims to use CatBoost (CB) and deep learning (DL) models for predicting the daily total pollen concentration up to 14 days in advance for 23 cities, covering all five continents. The model includes the projected environmental parameters, recent concentrations (1, 2 and 4 weeks), and the past environmental explanatory variables, and their future values. RESULTS: The best pollen forecasts include Mexico City (R2(DL_7) ≈ .7), and Santiago (R2(DL_7) ≈ .8) for the 7th forecast day, respectively; while the weakest pollen forecasts are made for Brisbane (R2(DL_7) ≈ .4) and Seoul (R2(DL_7) ≈ .1) for the 7th forecast day. The global order of the five most important environmental variables in determining the daily total pollen concentrations is, in decreasing order: the past daily total pollen concentration, future 2 m temperature, past 2 m temperature, past soil temperature in 28-100 cm depth, and past soil temperature in 0-7 cm depth. City-related clusters of the most similar distribution of feature importance values of the environmental variables only slightly change on consecutive forecast days for Caxias do Sul, Cape Town, Brisbane, and Mexico City, while they often change for Sydney, Santiago, and Busan. CONCLUSIONS: This new knowledge of the ecological relationships of the most remarkable variables importance for pollen forecast models according to clusters, cities and forecast days is important for developing and improving the accuracy of airborne pollen forecasts.


Asunto(s)
Alérgenos , Predicción , Polen , Polen/inmunología , Predicción/métodos , Humanos , Cambio Climático , Modelos Teóricos , Monitoreo del Ambiente/métodos
4.
Transpl Int ; 37: 11878, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38644935

RESUMEN

The effect of changes in immunosuppressive therapy during the acute phase post-heart transplantation (HTx) on clinical outcomes remains unclear. This study aimed to investigate the effects of changes in immunosuppressive therapy by corticosteroid (CS) weaning and everolimus (EVR) initiation during the first year post-HTx on clinical outcomes. We analyzed 622 recipients registered in the Korean Organ Transplant Registry (KOTRY) between January 2014 and December 2021. The median age at HTx was 56 years (interquartile range [IQR], 45-62), and the median follow-up time was 3.9 years (IQR 2.0-5.1). The early EVR initiation within the first year post-HTx and maintenance during the follow-up is associated with reduced the risk of primary composite outcome (all-cause mortality or re-transplantation) (HR, 0.24; 95% CI 0.09-0.68; p < 0.001) and cardiac allograft vasculopathy (CAV) (HR, 0.39; 95% CI 0.19-0.79; p = 0.009) compared with EVR-free or EVR intermittent treatment regimen, regardless of CS weaning. However, the early EVR initiation tends to increase the risk of acute allograft rejection compared with EVR-free or EVR intermittent treatment.


Asunto(s)
Corticoesteroides , Everolimus , Rechazo de Injerto , Trasplante de Corazón , Inmunosupresores , Sistema de Registros , Humanos , Everolimus/administración & dosificación , Everolimus/uso terapéutico , Trasplante de Corazón/efectos adversos , Persona de Mediana Edad , Masculino , Femenino , Inmunosupresores/uso terapéutico , Inmunosupresores/administración & dosificación , República de Corea/epidemiología , Rechazo de Injerto/prevención & control , Corticoesteroides/administración & dosificación , Corticoesteroides/uso terapéutico , Resultado del Tratamiento , Supervivencia de Injerto , Estudios Retrospectivos
5.
J Korean Med Sci ; 39(19): e163, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38769922

RESUMEN

BACKGROUND: Transthyretin amyloidosis cardiomyopathy (ATTR-CM) is an under-recognized cause of heart failure (HF) with clinical phenotypes that vary across regions and genotypes. We sought to characterize the clinical characteristics of ATTR-CM in Asia. METHODS: Data from a nationwide cohort of patients with ATTR-CM from six major tertiary centres in South Korea were analysed between 2010 and 2021. All patients underwent clinical evaluation, biochemical laboratory tests, echocardiography, and transthyretin (TTR) genotyping at the time of diagnosis. The study population comprised 105 Asian ATTR-CM patients (mean age: 69 years; male: 65.7%, wild-type ATTR-CM: 41.9%). RESULTS: Among our cohort, 18% of the patients had a mean left ventricular (LV) wall thickness < 12 mm. The diagnosis of ATTR-CM increased notably during the study period (8 [7.6%] during 2010-2013 vs. 22 [21.0%] during 2014-2017 vs. 75 [71.4%] during 2018-2021). Although the duration between symptom onset and diagnosis did not differ, the proportion of patients with HF presenting mild symptoms increased during the study period (25% NYHA class I/II between 2010-2013 to 77% between 2018-2021). In contrast to other international registry data, male predominance was less prominent in wild-type ATTR-CM (68.2%). The distribution of TTR variants was also different from Western countries and from Japan. Asp38Ala was the most common mutation. CONCLUSION: A nationwide cohort of ATTR-CM exhibited less male predominance, a proportion of patients without increased LV wall thickness, and distinct characteristics of genetic mutations, compared to cohorts in other parts of the world. Our results highlight the ethnic variation in ATTR-CM and may contribute to improving the screening process for ATTR-CM in the Asian population.


Asunto(s)
Neuropatías Amiloides Familiares , Cardiomiopatías , Ecocardiografía , Prealbúmina , Humanos , Masculino , Femenino , Anciano , República de Corea , Neuropatías Amiloides Familiares/genética , Neuropatías Amiloides Familiares/diagnóstico , Neuropatías Amiloides Familiares/patología , Cardiomiopatías/genética , Cardiomiopatías/diagnóstico , Prealbúmina/genética , Persona de Mediana Edad , Estudios de Cohortes , Pueblo Asiatico/genética , Genotipo , Mutación , Insuficiencia Cardíaca/diagnóstico , Anciano de 80 o más Años
6.
Nano Lett ; 23(15): 7086-7091, 2023 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-37471630

RESUMEN

Metallic nanogaps have emerged as a versatile platform for realizing ultrastrong coupling in terahertz frequencies. Increasing the coupling strength generally involved reducing the gap width to minimize the mode volume, which presents challenges in fabrication and efficient material coupling. Here, we propose employing terahertz nanoslots, which can efficiently squeeze the mode volume in an extra dimension alongside the gap width. Our experiments using 500 nm wide nanoslots integrated with an organic-inorganic hybrid perovskite demonstrate ultrastrong phonon-photon coupling with a record-high Rabi splitting of 48% of the original resonance (Ω = 0.48ω0), despite having a gap width 5 times larger than previously reported structures with Ω = 0.45ω0. Mechanisms underlying this effective light--matter coupling are investigated with simulations using coupled mode theory. Moreover, bulk polariton analyses reveal that our results account for 68% of the theoretical maximum Rabi splitting, with the potential to reach 82% through further optimization of the nanoslots.

7.
Sensors (Basel) ; 23(23)2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-38067845

RESUMEN

This research article focuses on developing a baseline digital twin model for a wave power generator structure located in Yongsu-ri, Jeju-do, South Korea. First, this study performs a cause analysis on the discrepancy of the dynamic properties from the real structure and an existing simulation model and finds the necessity of modeling the non-structural masses and the environmental factors. The large amounts of the ballast are modeled in the finite element model to enhance the accuracy of the digital twin. Considering the influence of environmental factors such as tide level and wave direction, the added mass effect of structural members, one of the hydrodynamic effects, depending on the change of the ocean environments is calculated based on the rule of Det Norske Veritas and applied. The results indicate that non-structural mass components significantly impact the dynamic characteristics of the structure. Additionally, environmental factors have a greater effect on the dynamic behavior of the box-type structure compared to lightweight offshore structures.

8.
BMC Med ; 20(1): 309, 2022 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-36068525

RESUMEN

BACKGROUND: Recent studies have reported improved diastolic function in patients administered sodium-glucose cotransporter 2 inhibitors (SGLT2i). We aimed to investigate the effect of dapagliflozin on left ventricular (LV) diastolic function in a diabetic animal model and to determine the molecular and cellular mechanisms underlying its function. METHODS: A total of 30 male New Zealand white rabbits were randomized into control, diabetes, or diabetes+dapagliflozin groups (n = 10/per each group). Diabetes was induced by intravenous alloxan. Cardiac function was evaluated using echocardiography. Myocardial samples were obtained for histologic and molecular evaluation. For cellular evaluation, fibrosis-induced cardiomyoblast (H9C2) cells were obtained, and transfection was performed for mechanism analysis (serum and glucocorticoid-regulated kinase 1 (SGK1) signaling analysis). RESULTS: The diabetes+dapagliflozin group showed attenuation of diastolic dysfunction compared with the diabetes group. Dapagliflozin inhibited myocardial fibrosis via inhibition of SGK1 and epithelial sodium channel (ENaC) protein, which was observed both in myocardial tissue and H9C2 cells. In addition, dapagliflozin showed an anti-inflammatory effect and ameliorated mitochondrial disruption. Inhibition of SGK1 expression by siRNA decreased and ENaC and Na+/H+ exchanger isoform 1 (NHE1) expression was confirmed as significantly reduced as siSGK1 in the diabetes+dapagliflozin group. CONCLUSIONS: Dapagliflozin attenuated left ventricular diastolic dysfunction and cardiac fibrosis via regulation of SGK1 signaling. Dapagliflozin also reduced macrophages and inflammatory proteins and ameliorated mitochondrial disruption.


Asunto(s)
Diabetes Mellitus , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Animales , Masculino , Conejos , Compuestos de Bencidrilo/farmacología , Compuestos de Bencidrilo/uso terapéutico , Fibrosis , Glucósidos/farmacología , Glucósidos/uso terapéutico , Inhibidores del Cotransportador de Sodio-Glucosa 2/farmacología , Inhibidores del Cotransportador de Sodio-Glucosa 2/uso terapéutico
9.
Clin Exp Allergy ; 52(8): 965-973, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35906963

RESUMEN

BACKGROUND: The Coronavirus disease 2019 (COVID-19) pandemic is currently in its third year. This follow-up survey was commissioned by the Asia Pacific Association of Allergy Asthma and Clinical Immunology (APAAACI) Task Force on COVID-19 to compare and contrast changes in the epidemiology, clinical profile, therapeutics and public health measures of the pandemic in the Asia Pacific region. METHODS: A questionnaire-based survey comprising 32 questions was electronically sent out to all 15 member countries of APAAACI using Survey Monkey® from 1 December 2021 to 28 February 2022. RESULTS: Seventeen responses were received from 14/15 (93.4%) member countries and 3 individual members. Mild-to-moderate COVID-19 predominated over severe infection, largely contributed by COVID-19 vaccination programmes in the region. The incidence of vaccine adverse reactions in particular anaphylaxis from messenger ribonucleic acid (mRNA) vaccines was no longer as high as initially anticipated, although perimyocarditis remains a concern in younger males. Novel therapeutics for mild-to-moderate disease including neutralizing antibodies casirivimab/imdevimab (REGEN-COV®) and sotrovimab (Xevudy®), anti-virals Paxlovid® (nirmatrelvir and ritonavir) and Molnupiravir pre-exposure prophylaxis for high-risk persons with Tixagevimab and Cilgavimab (Evusheld) are now also available to complement established therapeutics (e.g., remdesivir, dexamethasone and baricitinib) for severe disease. In the transition to endemicity, public health measures are also evolving away from containment/elimination strategies. CONCLUSIONS: With access to internationally recommended standards of care including public health preventive measures, therapeutics and vaccines among most APAAACI member countries, much progress has been made over the 2-year period in minimizing the morbidity and mortality from COVID-19 disease.


Asunto(s)
COVID-19 , Pandemias , Anticuerpos Monoclonales , Anticuerpos Monoclonales Humanizados , Anticuerpos Neutralizantes , COVID-19/epidemiología , Vacunas contra la COVID-19/administración & dosificación , Combinación de Medicamentos , Estudios de Seguimiento , Humanos , Masculino , Pandemias/prevención & control , Encuestas y Cuestionarios
10.
Cardiovasc Diabetol ; 21(1): 291, 2022 12 27.
Artículo en Inglés | MEDLINE | ID: mdl-36575485

RESUMEN

BACKGROUND: High glycemic variability (GV) is a poor prognostic marker in cardiovascular diseases. We aimed to investigate the association of GV with all-cause mortality in patients with acute heart failure (HF). METHODS: The Korean Acute Heart Failure registry enrolled patients hospitalized for acute HF from 2011 to 2014. Blood glucose levels were measured at the time of admission, during hospitalization, and at discharge. We included those who had 3 or more blood glucose measurements in this study. Patients were divided into two groups based on the coefficient of variation (CoV) as an indicator of GV. Among survivors of the index hospitalization, we investigated all-cause mortality at 1 year after discharge. RESULTS: The study analyzed 2,617 patients (median age, 72 years; median left-ventricular ejection fraction, 36%; 53% male). During the median follow-up period of 11 months, 583 patients died. Kaplan-Meier curve analysis revealed that high GV (CoV > 21%) was associated with lower cumulative survival (log-rank P < 0.001). Multivariate Cox proportional analysis showed that high GV was associated with an increased risk of 1-year (HR 1.56, 95% CI 1.26-1.92) mortality. High GV significantly increased the risk of 1-year mortality in non-diabetic patients (HR 1.93, 95% CI 1.47-2.54) but not in diabetic patients (HR 1.19, 95% CI 0.86-1.65, P for interaction = 0.021). CONCLUSIONS: High in-hospital GV before discharge was associated with all-cause mortality within 1 year, especially in non-diabetic patients with acute HF.


Asunto(s)
Insuficiencia Cardíaca , Hiperglucemia , Humanos , Masculino , Anciano , Femenino , Glucemia , Volumen Sistólico , Pronóstico , Función Ventricular Izquierda , Hospitalización , Hospitales
11.
Allergy Asthma Proc ; 43(5): e25-e30, 2022 09 25.
Artículo en Inglés | MEDLINE | ID: mdl-35879023

RESUMEN

Background: In Korea, the number of households with indoor pets is rapidly increasing in parallel with changes in cultural lifestyles. The sensitization rate of pet allergens is also increasing in Korea. Objective: We evaluated the effectiveness of washing machines to remove dog and cat hair and their allergens. In addition, this study aimed to investigate whether only a mechanical dryer without mechanical washing could be used for pet allergen removal. Method: We brushed cats and dogs, and thereafter collected their hair and used a residential vacuum cleaner to obtain dust and other particulate matter from a household. The contents of the vacuum bag were sifted through a 300-µm sieve filter. Some of the contents were placed in phosphate-buffered saline solution with 0.5% Tween 20 to make a liquid extract. Hair, dust, and liquid extract-contaminated fabric samples after mechanical washing or after drying without mechanical washing were analyzed for pet allergens (Fel d l [cat], Can f 1 [dog]) by using a two-site enzyme-linked immunosorbent assay. We assessed the remaining allergens in the contaminated fabrics after mechanical drying and washing. Results: The mean Fel d l and mean Can f 1 removal ratios after mechanical washing with detergent were > 99.99% for the dust, hair, and liquid extract. The removal ratios after mechanical washing without a detergent were lower for both Fel d 1 and Can f 1, for hair, dust, and their respective liquid extracts (p < 0.05). Mechanical drying was just as effective as mechanical washing with detergent for removing Can f 1 but was less effective for Fel d 1 (p < 0.05). Conclusion: Mechanical washing with detergent is important to remove pet allergens from contaminated fabrics. If washing is difficult, then using just a dryer without washing can be an alternative method to remove allergens from contaminated bedding or clothing.


Asunto(s)
Enfermedades de los Gatos , Enfermedades de los Perros , Alérgenos , Animales , Gatos , Detergentes , Perros , Polvo , Glicoproteínas , Humanos
12.
Sensors (Basel) ; 22(2)2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-35062624

RESUMEN

The key to coping with global warming is reconstructing energy governance from carbon-based to sustainable resources. Offshore energy sources, such as offshore wind turbines, are promising alternatives. However, the abnormal climate is a potential threat to the safety of offshore structures because construction guidelines cannot embrace climate outliers. A cosine similarity-based maintenance strategy may be a possible solution for managing and mitigating these risks. However, a study reporting its application to an actual field structure has not yet been reported. Thus, as an initial study, this study investigated whether the technique is applicable or whether it has limitations in the real field using an actual example, the Gageocho Ocean Research Station. Consequently, it was found that damage can only be detected correctly if the damage states are very similar to the comparison target database. Therefore, the high accuracy of natural frequencies, including environmental effects, should be ensured. Specifically, damage scenarios must be carefully designed, and an alternative is to devise more efficient techniques that can compensate for the present procedure.


Asunto(s)
Clima , Fuentes Generadoras de Energía
13.
Int J Mol Sci ; 23(9)2022 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-35563621

RESUMEN

Non-alcoholic steatohepatitis (NASH) has pathological characteristics similar to those of alcoholic hepatitis, despite the absence of a drinking history. The greatest threat associated with NASH is its progression to cirrhosis and hepatocellular carcinoma. The pathophysiology of NASH is not fully understood to date. In this study, we investigated the pathophysiology of NASH from the perspective of glycolysis and the Warburg effect, with a particular focus on microRNA regulation in liver-specific macrophages, also known as Kupffer cells. We established NASH rat and mouse models and evaluated various parameters including the liver-to-body weight ratio, blood indexes, and histopathology. A quantitative phosphoproteomic analysis of the NASH rat model livers revealed the activation of glycolysis. Western blotting and immunohistochemistry results indicated that the expression of pyruvate kinase muscle 2 (PKM2), a rate-limiting enzyme of glycolysis, was upregulated in the liver tissues of both NASH models. Moreover, increases in PKM2 and p-PKM2 were observed in the early phase of NASH. These observations were partially induced by the downregulation of microRNA122-5p (miR-122-5p) and occurred particularly in the Kupffer cells. Our results suggest that the activation of glycolysis in Kupffer cells during NASH was partially induced by the upregulation of PKM2 via miR-122-5p suppression.


Asunto(s)
Neoplasias Hepáticas , MicroARNs , Enfermedad del Hígado Graso no Alcohólico , Piruvato Quinasa/metabolismo , Animales , Modelos Animales de Enfermedad , Regulación hacia Abajo , Glucólisis , Macrófagos del Hígado/metabolismo , Neoplasias Hepáticas/metabolismo , Ratones , MicroARNs/genética , MicroARNs/metabolismo , Músculos/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Piruvato Quinasa/genética , Ratas
14.
Circ Res ; 125(12): 1141-1145, 2019 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-31804914

RESUMEN

Cardiovascular diseases have shown a continuous increase in Korea over the past decade and became the second most common cause of mortality in Korea. Although the number and the amount of total grants for cardiovascular research have increased in Korea, the proportion of the number of grants and total amount allocated for the cardiac/cardiovascular field to all health and medical research fields has not changed much over this period. In addition, the publications related to clinical research have substantially increased in Korea along with the number of nation-wide registries for cardiovascular diseases, but basic and translational research did not show significant growth, requiring new measures to promote basic and translational cardiovascular research in Korea.


Asunto(s)
Investigación Biomédica/tendencias , Enfermedades Cardiovasculares/epidemiología , Publicaciones Periódicas como Asunto/tendencias , Sistema de Registros , Sociedades Médicas/tendencias , Investigación Biomédica/métodos , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/terapia , Humanos , República de Corea/epidemiología
15.
Pediatr Allergy Immunol ; 32(5): 872-879, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33583098

RESUMEN

INTRODUCTION: Children with allergies are at greater risk of becoming sensitized to allergenic pollens in response to environmental changes. This study investigated the relationship between changes in pollination associated with meteorologic changes and the sensitization rates of children to tree pollen allergens in the metropolitan area of Seoul, Korea. METHODS: The study population consisted of 8,295 children who visited the pediatric allergy clinics at Hanyang University Seoul and Guri Hospital for allergy symptoms between January 1, 1998, and December 31, 2019. Pollen was collected at the two hospitals during the study using a Burkard 7-day sampler. Meteorologic data were obtained from the National Weather Service. RESULTS: Among the major tree pollens, the largest increase in allergic sensitization was to oak, hazel, and alder pollens (0.28% annually). The pollen-sensitization rates increased annually within younger age groups. The duration of the pollen season was 98 days in 1998 and 140 days in 2019. Positive correlations were determined between the duration of the pollen season and the rates of sensitization to tree pollens, as well as between the pollen-sensitization rates and increasing temperature. CONCLUSIONS: This study demonstrated the correlation between weather changes and the resulting changes in the pollen season with sensitization rates to allergenic pollens in children living in the Seoul metropolitan area. An annual increase in sensitization rates in younger children was determined. This pattern is expected to continue due to continuing climate change.


Asunto(s)
Hipersensibilidad , Árboles , Adolescente , Alérgenos , Niño , Humanos , Hipersensibilidad/epidemiología , Polen , República de Corea/epidemiología , Estaciones del Año , Seúl/epidemiología
16.
Sensors (Basel) ; 21(4)2021 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-33672172

RESUMEN

The driving performance of an off-road vehicle is closely related to soil strength. A bevameter is used to measure the soil strength, and it usually consists of two independent devices: a pressure-sinkage test device and a shear test device. However, its development and measurement processes have not been standardized; thus, researchers apply it in various fields according to their own discretion. In this study, a new bevameter was developed, and experiments were conducted to clarify the factors that affect the measurement performance of the bevameter. The pressure-sinkage test device was tested with circular plates of different sizes, and the results confirmed that the pressure-sinkage parameters decreased with the plate size. For the shear-test device, normal pressure was applied using a dead load to prevent normal-pressure variation due to displacement and speed. In addition, a spline was installed on top of the shaft connected to the shear ring to measure slip sinkage during the shear test. The results showed that the slip sinkage increased in proportion to the normal pressure and slip displacement, but the increase gradually decreased and converged to a certain point.

17.
Sensors (Basel) ; 21(2)2021 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-33440684

RESUMEN

In order to utilize wave energy, various wave power systems are being actively researched and developed and interest in them is increasing. To maximize the operational efficiency, it is very important to monitor and maintain the fault of components of the system. In recent years, interest in the management cost, high reliability and facility utilization of such systems has increased. In this regard, fault diagnosis technology including fault factor analysis and fault reproduction is drawing attention as an important main technology. Therefore, in this study, to reproduce and monitor the faults of a wave power system, firstly, the failure mode of the system was analyzed using FMEA analysis. Secondly, according to the derived failure mode and effect, the thrust bearing was selected as a target for fault reproduction and a test equipment bench was constructed. Finally, with the vibration data obtained by conducting the tests, the vibration spectrum was analyzed to extract the features of the data for each operating status; the data was classified by applying the three machine learning algorithms: naïve Bayes (NB), k-nearest neighbor (k-NN), and multi-layer perceptron (MLP). The criteria for determining the fault were derived. It is estimated that a more efficient fault diagnosis is possible by using the standard and fault monitoring method of this study.

18.
J Mol Cell Cardiol ; 138: 244-255, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31866378

RESUMEN

BACKGROUND: Survivin has an anti-apoptotic effect against anthracycline-induced cardiotoxicity. Clinically, statin use is associated with a lower risk for heart failure in breast cancer patients with anthracycline chemotherapy. So, the purpose of our study was to investigate whether survivin mediates the protective effect of statin against anthracycline-induced cardiotoxicity. METHODS: Mice were treated once a week with 5 mg/kg doxorubicin for 4 weeks with or without atorvastatin 20 mg/kg every day then heart tissues were analyzed. Molecular and cellular biology analyses were performed with H9c2 cell lysates. RESULTS: Doxorubicin suppressed survivin expression via activation of FOXO1 in H9c2 cardiomyocytes. Whereas, atorvastatin inhibited FOXO1 by increasing phosphorylation and inhibiting nuclear localization. Doxorubicin induced FOXO1 binding to STAT3 and prevented STAT3 from interacting with Sp1. However, atorvastatin inhibited these interactions and stabilized STAT3/Sp1 transcription complex. Chromatin immunoprecipitation analysis demonstrated that doxorubicin decreased STAT3/Sp1 complex binding to survivin promoter, whereas atorvastatin stabilized this binding. In mouse model, atorvastatin rescued doxorubicin-induced reduction of survivin expression and of heart function measured by cardiac magnetic resonance imaging. CONCLUSIONS: Our study suggested a new pathophysiologic mechanism that survivin mediated protective effect of atorvastatin against doxorubicin-induced cardiotoxicity via FOXO1/STAT3/Sp1 transcriptional network.


Asunto(s)
Atorvastatina/farmacología , Cardiotónicos/farmacología , Citoprotección , Doxorrubicina/toxicidad , Proteína Forkhead Box O1/antagonistas & inhibidores , Miocitos Cardíacos/metabolismo , Survivin/metabolismo , Animales , Línea Celular , Núcleo Celular/efectos de los fármacos , Núcleo Celular/metabolismo , Citoprotección/efectos de los fármacos , Modelos Animales de Enfermedad , Proteína Forkhead Box O1/metabolismo , Masculino , Ratones Endogámicos C57BL , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Fosfatidilinositol 3-Quinasas/metabolismo , Transporte de Proteínas/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Transducción de Señal/efectos de los fármacos , Factor de Transcripción Sp1/metabolismo , Transcripción Genética/efectos de los fármacos , Activación Transcripcional/efectos de los fármacos
19.
Int Arch Allergy Immunol ; 181(9): 675-679, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32615568

RESUMEN

PURPOSE: Pollen may spread indoors through clothes contaminated during outdoor activities. This study aimed to evaluate the pollen removal efficacy of a mechanical dryer. METHODS: Cotton clothes served as laundry, and fabrics measuring 2 × 5 cm served as test samples. Pollen was spread evenly on the test fabrics. The fabrics were then fixed on the cloth and left for 8 h to imitate real-life conditions. This experiment was conducted under 2 conditions, wet (after washing clothes) and dry (without washing). After drying, we counted pollen on the test fabrics to evaluate the pollen removal rate. We measured the remaining allergens in extracts from the contaminated fabrics after mechanical drying. The concentrations of allergens (Amb a 1, Bet v 1, Crp j 1, and Phl p 1) in each extracted solution were measured using 2-site ELISA. RESULTS: For ragweed, Japanese cedar, birch, and timothy grass, the mean pollen removal ratios for the dry samples were 99.88 ± 0.09%, 99.96 ± 0.03%, 99.89 ± 0.02%, and 99.82 ± 0.11%, respectively, and those for the wet samples were 98.83 ± 0.87%, 97.91 ± 1.81%, 97.29 ± 1.19%, and 96.3 ± 0.92%, respectively. Further, for the pollen allergens Amb a 1 [ragweed], Crp j 1 [Japanese cedar], Bet v 1 [birch], and Phl p 1 [timothy grass], the mean pollen allergen removal ratios for the dry samples were 99.81 ± 0.06%, 99.94 ± 0.23%, 99.90 ± 0.11%, and 99.84 ± 0.17%, respectively, and those for the wet samples were 98.11 ± 0.14%, 96.04 ± 1.52%, 97.21 ± 0.83%, and 95.23 ± 0.92%, respectively. There was no statistically significant difference for each species. CONCLUSIONS: Mechanical drying effectively removed pollen and allergens from dry and wet fabrics. We expect that further studies on the removal of other indoor allergens would contribute to improved environmental control for allergy patients.


Asunto(s)
Alérgenos/metabolismo , Anafilaxia/prevención & control , Antígenos de Plantas/metabolismo , Polen/metabolismo , Rinitis Alérgica Estacional/inmunología , Anafilaxia/etiología , Vestuario , Exposición a Riesgos Ambientales/efectos adversos , Humanos , Inmunoglobulina E/metabolismo , Fenómenos Mecánicos , Rinitis Alérgica Estacional/complicaciones
20.
J Allergy Clin Immunol ; 144(6): 1542-1550.e1, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31536730

RESUMEN

BACKGROUND: Although the different age groups had differences in sensitivity of asthma exacerbations (AEs) to environmental factors, no comprehensive study has examined the age-stratified effects of environmental factors on AEs. OBJECTIVE: We sought to examine the short-term effects in age-stratified groups (infants, preschool children, school-aged children, adults, and the elderly) of outdoor environmental factors (air pollutants, weather conditions, aeroallergens, and respiratory viral epidemics) on AEs. METHODS: We performed an age-stratified analysis of the short-term effects of 4 groups of outdoor environmental factors on AEs in Seoul Metropolitan City (Korea) from 2008 and 2012. The statistical analysis used a Poisson generalized linear regression model, with a distributed lag nonlinear model for identification of lagged and nonlinear effects and convergent cross-mapping for identification of causal associations. RESULTS: Analysis of the total population (n = 10,233,519) indicated there were 28,824 AE events requiring admission to an emergency department during the study period. Diurnal temperature range had significant effects in pediatric (infants, preschool children, and school-aged children) and elderly (relative risk [RR], 1.056-1.078 and 1.016, respectively) subjects. Tree and weed pollen, human rhinovirus, and influenza virus had significant effects in school-aged children (RR, 1.014, 1.040, 1.042, and 1.038, respectively). Tree pollen and influenza virus had significant effects in adults (RR, 1.026 and 1.044, respectively). Outdoor air pollutants (particulate matter of ≤10 µm in diameter, nitrogen dioxide, ozone, carbon monoxide, and sulfur dioxide) had significant short-term effects in all age groups (except for carbon monoxide and sulfur dioxide in infants). CONCLUSION: These findings provide a need for the development of tailored strategies to prevent AE events in different age groups.


Asunto(s)
Contaminantes Atmosféricos/efectos adversos , Asma , Exposición a Riesgos Ambientales/efectos adversos , Modelos Biológicos , Sistema de Registros , Adolescente , Adulto , Factores de Edad , Asma/epidemiología , Asma/etiología , Niño , Femenino , Humanos , Masculino , República de Corea/epidemiología , Factores de Riesgo
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