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We describe the epidemiology of a coronavirus disease (COVID-19) outbreak in a call center in South Korea. We obtained information on demographic characteristics by using standardized epidemiologic investigation forms. We performed descriptive analyses and reported the results as frequencies and proportions for categoric variables. Of 1,143 persons who were tested for COVID-19, a total of 97 (8.5%, 95% CI 7.0%-10.3%) had confirmed cases. Of these, 94 were working in an 11th-floor call center with 216 employees, translating to an attack rate of 43.5% (95% CI 36.9%-50.4%). The household secondary attack rate among symptomatic case-patients was 16.2% (95% CI 11.6%- 22.0%). Of the 97 persons with confirmed COVID-19, only 4 (1.9%) remained asymptomatic within 14 days of quarantine, and none of their household contacts acquired secondary infections. Extensive contact tracing, testing all contacts, and early quarantine blocked further transmission and might be effective for containing rapid outbreaks in crowded work settings.
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Betacoronavirus/patogenicidad , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/transmisión , Brotes de Enfermedades , Neumonía Viral/epidemiología , Neumonía Viral/transmisión , Betacoronavirus/genética , COVID-19 , Prueba de COVID-19 , Centrales de Llamados , Técnicas de Laboratorio Clínico/métodos , Trazado de Contacto/estadística & datos numéricos , Infecciones por Coronavirus/diagnóstico , Composición Familiar , Femenino , Humanos , Incidencia , Masculino , Pandemias , Neumonía Viral/diagnóstico , Cuarentena/métodos , República de Corea/epidemiología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , SARS-CoV-2 , Índice de Severidad de la EnfermedadRESUMEN
Plants are constantly challenged by various environmental stresses, including high salinity and drought, and they have evolved defense mechanisms to counteract the deleterious effects of these stresses. The plant hormone ABA regulates plant growth and developmental processes and mediates abiotic stress responses. Here, we report the identification and characterization of a novel CaWDP1 (Capsicum annuum) protein. The expression of CaWDP1 in pepper leaves was induced by ABA, drought and NaCl treatments, suggesting its role in the abiotic stress response. CaWDP1 proteins show conserved sequence homology with other known WDP1 proteins, and they are localized in the nucleus and cytoplasm. We generated CaWDP1-silenced peppers via virus-induced gene silencing (VIGS). We evaluated the responses of these CaWDP1-silenced pepper plants and CaWDP1-overexpressing (OX) transgenic Arabidopsis plants to ABA and drought. CaWDP1-silenced pepper plants displayed enhanced tolerance to drought stress, and this was characterized by low levels of leaf water loss in the drought-treated leaves. In contrast to CaWDP1-silenced plants, CaWDP1-OX plants exhibited an ABA-hyposensitive and drought-susceptible phenotype, which was accompanied by high levels of leaf water loss, low leaf temperatures, increased stomatal pore size and low expression levels of stress-responsive genes. Our results indicate that CaWDP1, a novel pepper negative regulator of ABA, regulates the ABA-mediated defense response to drought stress.
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Ácido Abscísico/metabolismo , Capsicum/fisiología , Sequías , Proteínas de Plantas/metabolismo , Ácido Abscísico/farmacología , Arabidopsis/genética , Capsicum/efectos de los fármacos , Capsicum/genética , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Germinación/efectos de los fármacos , Germinación/fisiología , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Salinidad , Plantones/efectos de los fármacos , Plantones/fisiología , Transducción de Señal , Estrés FisiológicoRESUMEN
We developed a new chemical strategy to enhance the stability of lead selenide nanocrystals (PbSe NCs) against oxidation through the surface passivation by P-O- moieties. In the synthesis of PbSe NCs, tris(diethylamino)phosphine (TDP) selenide (Se) was used as a Se precursor, and the resulting PbSe NCs withstood long-term air exposure while showing nearly no sign of oxidation. Nuclear magnetic resonance (NMR) spectroscopy reveals that TDP derivatives passivate the surface of PbSe NC. Through a series of ligand cleavage reactions, we found that the TDP derivatives are bound on NC surface through the P-O- moiety. Based on such understanding, it turned out that direct addition of various PAs during the synthesis of PbSe NCs also results in the NCs whose absorption spectrum remains nearly intact after air exposure for weeks. The P-O- moieties render the NCs stable in the operation of field effect transistors, suggesting that our findings can enable the use of air stable PbSe NCs in wider array of optoelectronic applications.
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Wet chemical synthesis of covalent III-V colloidal quantum dots (CQDs) has been challenging because of uncontrolled surfaces and a poor understanding of surface-ligand interactions. We report a simple acid-free approach to synthesize highly crystalline indium phosphide CQDs in the unique tetrahedral shape by using tris(dimethylamino) phosphine and indium trichloride as the phosphorus and indium precursors, dissolved in oleylamine. Our chemical analyses indicate that both the oleylamine and chloride ligands participate in the stabilization of tetrahedral-shaped InP CQDs covered with cation-rich (111) facets. Based on density functional theory calculations, we propose that fractional dangling electrons of the In-rich (111) surface could be completely passivated by three halide and one primary amine ligands per the (2×2) surface unit, satisfying the 8-electron rule. This halide-amine co-passivation strategy will benefit the synthesis of stable III-V CQDs with controlled surfaces.
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We developed a novel and easy encapsulation method for quantum dots (QDs) using a partially oxidized semi-crystalline polymeric material which forms a micron-sized granule with a multi-lamellar structure from a dilute solution. The QDs were highly dispersed in the granule in such a way that they were adsorbed on the lamella with â¼12 nm spacing followed by lamellar stacking. The QDs were heavily loaded into the granule to 16.7 wt% without aggregation, a process which took only a few minutes. We found that the quantum yield of the QDs was not degraded after the encapsulation. The encapsulated QD-silicone composite exhibited excellent long-term photo- and thermal stability with its initial photoluminescence intensity maintained after blue LED light radiation for 67 days and storage at 85 °C and 85% relative humidity for 119 days.
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The homologue of human YTHDF2, Ydr374c (Pho92), is the only protein that has a YTH (YT521-B homology) domain in Saccharomyces cerevisiae. Based on microarray analysis, genes involved in the phosphate signal transduction (PHO) pathway were up-regulated in the Δpho92 strain, as were genes regulated by Pho4, which is an important transcription factor in the PHO pathway. To identify the exact mechanism of Pho92 action with respect to phosphate metabolism, we investigated the effect of Pho92 on PHO4 expression. The half-life of PHO4 mRNA was increased in the Δpho92 strain; this phenotype was also observed in the deletion mutants UPF1 and POP2, which are components of the NMD (nonsense-mediated decay) pathway and the Pop2-Ccr4-Not deadenylase complex respectively. Pho92 interacts physically with Pop2 of the Pop2-Ccr4-Not deadenylase complex. Furthermore, Pho92 binding to the 3'-UTR of PHO4 was dependent on the phosphate concentration. Deletion of the PHO4 3'-UTR resulted in PHO4 mRNA resistance to Pho92-dependent degradation. The results of the present study indicate that Pho92 regulates Pho4 expression at the post-transcriptional level via the regulation of mRNA stability. Taken together, Pho92 participates in cellular phosphate metabolism, specifically via the regulation of PHO4 mRNA stability by binding to the 3'-UTR in a phosphate-dependent manner.
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Proteínas de Unión al ADN/metabolismo , Regulación Bacteriana de la Expresión Génica , Proteínas de Transporte de Fosfato/metabolismo , Fosfatos/metabolismo , ARN Bacteriano/metabolismo , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Regiones no Traducidas 3' , Secuencia de Aminoácidos , Sitios de Unión , Secuencia Conservada , Proteínas de Unión al ADN/química , Proteínas de Unión al ADN/genética , Humanos , Mutación , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/metabolismo , Degradación de ARNm Mediada por Codón sin Sentido , Proteínas de Transporte de Fosfato/química , Proteínas de Transporte de Fosfato/genética , Factores de Empalme de ARN , Estabilidad del ARN , ARN Bacteriano/química , ARN Mensajero/química , Proteínas de Unión al ARN/química , Proteínas de Unión al ARN/genética , Ribonucleasas/química , Ribonucleasas/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Homología de Secuencia de Aminoácido , Factores de Escisión y Poliadenilación de ARNm/química , Factores de Escisión y Poliadenilación de ARNm/metabolismoRESUMEN
The fast degradation of lead selenide (PbSe) nanocrystal quantum dots (NQDs) in ambient conditions impedes widespread deployment of the highly excitonic, thus versatile, colloidal NQDs. Here we report a simple in situ post-synthetic halide salt treatment that results in size-independent air stability of PbSe NQDs without significantly altering their optoelectronic characteristics. From TEM, NMR, and XPS results and DFT calculations, we propose that the unprecedented size-independent air stability of the PbSe NQDs can be attributed to the successful passivation of under-coordinated PbSe(100) facets with atomically thin PbX2 (X = Cl, Br, I) adlayers. Conductive films made of halide-treated ultrastable PbSe NQDs exhibit markedly improved air stability and behave as an n-type channel in a field-effect transistor. Our simple in situ wet-chemical passivation scheme will enable broader utilization of PbSe NQDs in ambient conditions in many optoelectronic applications.
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This manuscript presents a comprehensive study on the sustainable optimization of asphalt mixtures tailored for regions prone to flooding. The research addresses the challenges associated with water damage to asphalt pavements by incorporating innovative additives. The study centers on incorporating recycled Low-Density Polyethylene (LDPE) and a tailored Carnauba-Soybean Oil Additive, advancing asphalt mixtures with a Control mix, LDPE (5%) + Control, and LDPE (5%) + 3% Oil + Control. A critical aspect of the research involves subjecting these mixtures to 30 wetting and drying cycles, simulating the conditions prevalent in tropical flood-prone areas. The incorporation of innovative additives in asphalt mixtures has demonstrated significant improvements across various performance parameters. Tensile Strength Ratio (TSR) tests revealed enhanced tensile strength, with the LDPE (5%) + 3% Oil-modified mixture exhibiting an impressive TSR of 85.7%. Dynamic Modulus tests highlighted improved rutting resistance, showcasing a remarkable increase to 214 MPa in the LDPE (5%) with a 3% Oil-modified mixture. The Semi-Circular Bending (SCB) test demonstrated increased fracture resistance and energy absorption, particularly in the LDPE (5%) with 3% Oil-modified mixture. Hamburg Wheel-Tracking (HWT) tests indicated enhanced moisture resistance and superior rutting resistance at 20,000 cycles for the same mixture. Cantabro tests underscored improved aggregate shatter resistance, with the LDPE (5%) + 3% Oil-modified mixture exhibiting the lowest weight loss rate at 9.820%. Field tests provided real-world insights, with the LDPE (5%) + 3% Oil mixture displaying superior stability, a 61% reduction in deflection, and a 256% improvement in surface modulus over the control mixture. This research lays the groundwork for advancing the development of sustainable, high-performance road pavement materials, marking a significant stride towards resilient infrastructure in flood-prone areas.
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Amid the growing demand for sustainable pavement solutions and the need to incorporate recycled materials into construction practices, this study explored the viability of using crushed thermal power plant bottom ash as a filler in polymer-modified asphalt concrete mixtures. Conventional lime filler was replaced with bottom ash at varying levels (0%, 25%, 50%, and 75%), and the resulting mixtures were evaluated using several performance tests. The optimal replacement level was determined to be 25%, based on the results of the indirect tensile strength (ITS) test. Comparisons between the control mixture and the 25% bottom ash-modified mixture were conducted using the dynamic modulus test, Cantabro test, Hamburg wheel tracking (HWT) test, and tensile strength ratio (TSR) test. The findings indicate that the 25% bottom ash-modified mixture demonstrated improved performance across multiple parameters. The HWT test showed enhanced rut durability, with a recorded depth of 7.56 mm compared to 8.9 mm for the control mixture. The Cantabro test results revealed lower weight loss percentages for the modified mixture, indicating better abrasion resistance. The dynamic modulus test indicated higher resilience and stiffness in both high- and low-frequency stages. The TSR test highlighted improved moisture resistance, with higher TSR values after 10 wet-drying cycles. These improvements are attributed to the fine particle size and beneficial chemical composition of bottom ash, which enhance the asphalt mixture's density, binder-aggregate adhesion, and overall durability. The results suggest that incorporating 25% crushed bottom ash as a filler in polymer-modified asphalt concrete mixtures is a viable and sustainable approach to improving pavement performance and longevity.
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PURPOSE: This study aimed to examine the interrupting effect of social distancing (SD) on emergency department (ED) patients with ischemic heart disease (IHD), stroke, asthma, and suicide attempts by PM2.5 exposure in eight Korean megacities from 2017 to 2020. MATERIALS AND METHODS: The study used National Emergency Department Information System and AirKorea data. A total of 469014 patients visited EDs from 2017 to 2020. Interrupted time series analysis was employed to examine changes in the level and slope of the time series, relative risk, and confidence intervals (CIs) by PM2.5 exposure. The SD level was added to the sensitivity analysis. RESULTS: The interrupted time series analysis demonstrated a significant increase in the ratio of relative risk (RRR) of IHD patients in Seoul (RRR=1.004, 95% CI: 1.001, 1.006) and Busan (RRR=1.007, 95% CI: 1.002, 1.012) post-SD. Regarding stroke, only patients in Seoul exhibited a significant decrease post-SD (RRR=0.995, 95% CI: 0.991, 0.999). No significant changes were observed for asthma in any of the cities. In the case of suicide attempts, Ulsan demonstrated substantial pre-SD (RR=0.827, 95% CI: 0.732, 0.935) and post-SD (RRR=1.200, 95% CI: 1.057, 1.362) differences. CONCLUSION: While the interrupting effect of SD was not as pronounced as anticipated, this study did validate the effectiveness of SD in modifying health behaviors and minimizing avoidable visits to EDs in addition to curtailing the occurrence of infectious diseases.
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Asma , Servicio de Urgencia en Hospital , Isquemia Miocárdica , Material Particulado , Accidente Cerebrovascular , Intento de Suicidio , Humanos , Asma/prevención & control , Asma/epidemiología , Material Particulado/efectos adversos , Intento de Suicidio/estadística & datos numéricos , Isquemia Miocárdica/prevención & control , Isquemia Miocárdica/epidemiología , Accidente Cerebrovascular/prevención & control , Accidente Cerebrovascular/epidemiología , Servicio de Urgencia en Hospital/estadística & datos numéricos , República de Corea/epidemiología , Masculino , Femenino , Distanciamiento Físico , Análisis de Series de Tiempo Interrumpido , Persona de Mediana Edad , Exposición a Riesgos Ambientales/efectos adversosRESUMEN
Objective: Social anxiety disorder (SAD) is characterized by heightened sensitivity to social interactions or settings, which disrupts daily activities and social relationships. This study aimed to explore the feasibility of utilizing digital phenotypes for predicting the severity of these symptoms and to elucidate how the main predictive digital phenotypes differed depending on the symptom severity. Method: We collected 511 behavioral and physiological data over 7 to 13 weeks from 27 SAD and 31 healthy individuals using smartphones and smartbands, from which we extracted 76 digital phenotype features. To reduce data dimensionality, we employed an autoencoder, an unsupervised machine learning model that transformed these features into low-dimensional latent representations. Symptom severity was assessed with three social anxiety-specific and nine additional psychological scales. For each symptom, we developed individual classifiers to predict the severity and applied integrated gradients to identify critical predictive features. Results: Classifiers targeting social anxiety symptoms outperformed baseline accuracy, achieving mean accuracy and F1 scores of 87% (with both metrics in the range 84-90%). For secondary psychological symptoms, classifiers demonstrated mean accuracy and F1 scores of 85%. Application of integrated gradients revealed key digital phenotypes with substantial influence on the predictive models, differentiated by symptom types and levels of severity. Conclusions: Leveraging digital phenotypes through feature representation learning could effectively classify symptom severities in SAD. It identifies distinct digital phenotypes associated with the cognitive, emotional, and behavioral dimensions of SAD, thereby advancing the understanding of SAD. These findings underscore the potential utility of digital phenotypes in informing clinical management.
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BACKGROUND/PURPOSE: Distal radius fractures (DRFs) account for approximately 18% of fractures in patients 65 years and older. While plain radiographs are standard, the value of high-resolution computed tomography (CT) for detailed imaging crucial for diagnosis, prognosis, and intervention planning, and increasingly recognized. High-definition 3D reconstructions from CT scans are vital for applications like 3D printing in orthopedics and for the utility of mobile C-arm CT in orthopedic diagnostics. However, concerns over radiation exposure and suboptimal image resolution from some devices necessitate the exploration of advanced computational techniques for refining CT imaging without compromising safety. Therefore, this study aims to utilize conditional Generative Adversarial Networks (cGAN) to improve the resolution of 3 mm CT images (CT enhancement). METHODS: Following institutional review board approval, 3 mm-1 mm paired CT data from 11 patients with DRFs were collected. cGAN was used to improve the resolution of 3 mm CT images to match that of 1 mm images (CT enhancement). Two distinct methods were employed for training and generating CT images. In Method 1, a 3 mm CT raw image was used as input with the aim of generating a 1 mm CT raw image. Method 2 was designed to emphasize the difference value between the 3 mm and 1 mm images; using a 3 mm CT raw image as input, it produced the difference in image values between the 3 mm and 1 mm CT scans. Both quantitative metrics, such as peak signal-to-noise ratio (PSNR), mean squared error (MSE), and structural similarity index (SSIM), and qualitative assessments by two orthopedic surgeons were used to evaluate image quality by assessing the grade (1~4, which low number means high quality of resolution). RESULTS: Quantitative evaluations showed that our proposed techniques, particularly emphasizing the difference value in Method 2, consistently outperformed traditional approaches in achieving higher image resolution. In qualitative evaluation by two clinicians, images from method 2 showed better quality of images (grade: method 1, 2.7; method 2, 2.2). And more choice was found in method 2 for similar image with 1 mm slice image (15 vs 7, p = 201). CONCLUSION: In our study utilizing cGAN for enhancing CT imaging resolution, the authors found that the method, which focuses on the difference value between 3 mm and 1 mm images (Method 2), consistently outperformed.
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Fracturas del Radio , Tomografía Computarizada por Rayos X , Fracturas de la Muñeca , Humanos , Redes Neurales de la Computación , Fracturas del Radio/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Fracturas de la Muñeca/diagnóstico por imagenRESUMEN
Autophagy in eukaryotes functions to maintain homeostasis by degradation and recycling of long-lived and unwanted cellular materials. Autophagy plays important roles in pathogenicity of various fungal pathogens, suggesting that autophagy is a novel target for development of antifungal compounds. Here, we describe bioluminescence resonance energy transfer (BRET)-based high-throughput screening (HTS) strategy to identify compounds that inhibit fungal ATG4 cysteine protease-mediated cleavage of ATG8 that is critical for autophagosome formation. We identified ebselen (EB) and its analogs ebselen oxide (EO) and 2-(4-methylphenyl)-1,2-benzisothiazol-3(2H)-one (PT) as inhibitors of fungal pathogens Botrytis cinerea and Magnaporthe oryzae ATG4-mediated ATG8 processing. The EB and its analogs inhibit spore germination, hyphal development, and appressorium formation in Ascomycota pathogens, B. cinerea, M. oryzae, Sclerotinia sclerotiorum and Monilinia fructicola. Treatment with EB and its analogs significantly reduced fungal pathogenicity. Our findings provide molecular insights to develop the next generation of antifungal compounds by targeting autophagy in important fungal pathogens.
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Ascomicetos , Magnaporthe , Oryza , Antifúngicos/farmacología , Antifúngicos/metabolismo , Virulencia , Autofagia , Proteínas Relacionadas con la Autofagia/metabolismo , Enfermedades de las Plantas/prevención & control , Enfermedades de las Plantas/microbiología , Proteínas Fúngicas/metabolismo , Esporas FúngicasRESUMEN
Background/Aims: : Appropriate tissue tension and clear visibility of the dissection area using traction are essential for effective and safe endoscopic submucosal dissection (ESD). In this study, we developed a retractable robot-assisted traction device and evaluated its performance in colorectal ESD. Methods: : An experienced endoscopist performed ESD 18 times on an ex vivo porcine colon using the robot and 18 times using the conventional method. The outcome measures were procedure time, dissection speed, procedure-related adverse events, and blind dissection rate. Results: : Thirty-six colonic lesions were resected from ex vivo porcine colon samples. The total procedure time was significantly shorter in robot-assisted ESD (RESD) than in conventional ESD (CESD) (20.1±4.1 minutes vs 34.3±8.3 minutes, p<0.05). The submucosal dissection speed was significantly faster in the RESD group than in the CESD group (36.8±9.2 mm2/min vs 18.1±4.7 mm2/min, p<0.05). The blind dissection rate was also significantly lower in the RESD group (12.8%±3.4% vs 35.1%±3.9%, p<0.05). In an in vivo porcine feasibility study, the robotic device was attached to a colonoscope and successfully inserted into the proximal colon without damaging the colonic wall, and ESD was successfully performed. Conclusions: : The dissection speed and safety profile improved significantly with the retractable RESD. Thus, our robotic device has the potential to provide simple, effective, and safe multidirectional traction during colonic ESD.
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Colon , Resección Endoscópica de la Mucosa , Tempo Operativo , Procedimientos Quirúrgicos Robotizados , Animales , Resección Endoscópica de la Mucosa/instrumentación , Resección Endoscópica de la Mucosa/métodos , Porcinos , Procedimientos Quirúrgicos Robotizados/instrumentación , Procedimientos Quirúrgicos Robotizados/métodos , Colon/cirugía , Estudios de Factibilidad , Colonoscopía/instrumentación , Colonoscopía/métodos , Neoplasias Colorrectales/cirugía , Disección/instrumentación , Disección/métodos , Diseño de EquipoRESUMEN
A synthetic approach for fabricating compositionally graded multishell nanocrystal quantum dots (NQDs) from cubic CdSe is presented. The structural shapes with each shell formation were examined using scanning transmission electron microscopy (STEM) coupled with energy dispersive x-ray spectroscopy and electron energy loss spectroscopy (EELS). The optical properties probed via time-resolved spectroscopy further revealed detailed carrier behavior at the core/graded shell interface. A highly luminescing stable optical device was built using our graded multishell NQDs.
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The purpose of this study was to investigate the differences in muscle activation patterns of the biceps brachii (BB) and flexor carpi radialis (FCR) muscles, while measuring the resultant force (RF) at different shoulder flexion angles. [Subjects] Thirteen healthy males (age 24.85±3.4â years, weight; 77.8±7.9â kg; height, 1.7±0.05 m) were enrolled in this study. [Methods] The resultant force was measured by a force transducer . The elbow angle remained constant and the flexion shoulder angle was changed (30°, 45°, 60°, 75° and 90°). [Results] The results of the surface EMG show the largest muscle activities occurred at a shoulder flexion of 75° for BB and 90° for FCR. The largest resultant force was measured at a shoulder flexion angle of 75°. We conclude, that when performing the biceps curl exercise using an arm curl machine, the shoulder should be flexed at 75° to maximize the focus of the exercise for the BB. [Conclusion] These results are useful from the perspective of design as they highlight the differences in the muscle activation of BB and FCR with postural change. Ultimately this knowledge can be used in the design of rehabilitation training for the shoulder as they show that posture can affect muscle activation.
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This study addresses the challenges of overlaying old concrete pavement with asphalt by introducing a new trackless tack coat material containing polymer. The aim is to enhance the durability of asphalt concrete overlay pavement on old cement concrete pavement. It contributes to the development of improved construction techniques for pavement rehabilitation and highlights the need for reliable adhesion performance evaluation based on different spray amounts and surface conditions. Additionally, to evaluate the effect of the adhesion performance based on the spraying amount, a tensile adhesion test was conducted by applying spray amounts of 0.30, 0.45, and 0.60 l/m2 on different surface conditions. The basic and adhesion performances of the polymer-modified tack coat material are evaluated through direct tensile and shear bond strength tests. The test outcomes demonstrated that the newly developed polymer-modified tack coat material had considerably greater adhesion strength compared to the traditional rapid-setting products. Its adhesive strength was 1.68 times higher on concrete and 1.78 times higher on asphalt. The new trackless tack coat material exhibited an adhesion performance of 1.05 MPa in direct tensile strength at 0.45 l/m2, which was 1.21 times higher than the rapid-setting tack coat. Results also confirmed that the new tack coat material exhibits values 1.90 times greater than the conventional rapid-setting tack coat material in shear bond strength, respectively. By simulating the process of separation and re-adhesion of pavement layers caused, the new tack coat material shows a tensile adhesion strength of 63% of the original state, which is advantageous for securing the durability of the pavement. Overall, the newly developed polymer-modified trackless tack coat has been shown to effectively enhance the adhesion performance between pavement layers without process delay, highlighting the potential of the new tack coat material to enhance the durability of asphalt concrete overlay pavement on old cement concrete pavement.
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The quality of pavements in tropical climates is negatively affected by the frequent wet and dry cycles during the rainy season, as well as by issues related to overloading from heavy trucks and traffic congestion. Contributing to this deterioration are factors such as acid rainwater, heavy traffic oils, and municipal debris. In light of these challenges, this study aims to assess the viability of a polymer-modified asphalt concrete mixture. This study investigates the feasibility of a polymer-modified asphalt concrete mixture with the addition of 6% crumb rubber powder from waste car tires and 3% epoxy resin to counter the harsh conditions of tropical climate weather. The study involved subjecting test specimens to five to 10 cycles of contaminated water (100% rainwater + 10% used oil from trucks), curing for 12 h, and air drying in a chamber of 50 °C for 12 h to simulate critical curing conditions. The specimens underwent fundamental laboratory performance tests such as the indirect tensile strength test, dynamic modulus test, four points bending test, and Cantabro test, as well as the double load condition in the Hamburg wheel tracking test to determine the effectiveness of the proposed polymer-modified material in actual conditions. The test results confirmed that the simulated curing cycles had a critical impact on the durability of the specimens, with the greater curing cycles leading to a significant drop in the strength of the material. For example, the TSR ratio of the control mixture dropped from 90% to 83% and 76% after five and 10 curing cycles, respectively. Meanwhile, the modified mixture showed a decrease from 93% to 88% and 85% under the same conditions. The test results revealed that the effectiveness of the modified mixture outperformed the conventional condition in all tests, with a more prominent impact observed under overload conditions. Under double conditions in the Hamburg wheel tracking test and a curing condition of 10 cycles, the maximum deformation of the control mixture sharply increased from 6.91 to 22.7 mm, whereas the modified mixture increased from 5.21 to 12.4 mm. Overall, the test results confirm the durability of the polymer-modified asphalt concrete mixture under harsh tropical climate conditions, promoting its application for sustainable pavements, especially in Southeast Asian countries.
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Rising traffic volume, heavy loads, and construction activities have raised concerns about expansion joint device damage. This study focuses on developing an innovative expansion joint using polymer-modified rubber asphalt as the filling material to enhance its service life. Styrene-butadiene-styrene (SBS) emerged as a suitable modifier for rubber-modified asphalt, significantly improving elasticity and adhesion. Through the strategic combination of 3- and 2-block linear SBS, the elasticity and adhesion properties were significantly improved, resulting in the formulation of a well-suited polymer-modified rubber asphalt binder. The developed asphalt binder exhibits impressive elastic recovery (61.1% to 66.1%), surpassing commercial products, with enhanced constructability and workability (15% to 21% viscosity reduction). The carefully engineered mastic asphalt mixture showcases self-leveling characteristics at a moderate 210 °C, addressing historical constructability challenges. Settlement is 40% less than traditional hot mix asphalt for surface layers, with improved moisture and stripping resistance, enhancing existing asphalt plug joint durability and workability. Collectively, this novel mixture, comprising polymer-modified rubber and mastic asphalt, showcases the potential to enhance the durability of existing asphalt plug joints while ensuring superior constructability and workability.
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Emerging evidence reveals a close association between gut microbiota and human neurological disorders. The present study aimed to assess whether the composition of gut microbiota in participants with episodic migraine (EM) and chronic migraine (CM) was altered in comparison to that of the controls. This study was a cross-sectional, case-control study. The gut microbiota were evaluated by the partial, targeted sequencing of the 16S rRNA V3-V4 region. This study enrolled 42 and 45 participants with EM and CM, respectively, and 43 controls. Alpha and beta diversities revealed no significant difference among the three groups; however, the microbiota composition at the class, order, family, and genus levels differed significantly between EM and the control, CM and the control, and the EM and CM groups. Moreover, higher composition of PAC000195_g was significantly associated with a lower headache frequency among the five genera that exhibited significantly different microbiota composition in EM and CM. Agathobacter revealed a significant negative association with severe headache intensity. The findings of the present study provide evidence of altered gut microbiota in EM and CM. These findings will help in understanding the course and treatment of migraine.