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OBJECTIVES: To systematically evaluate the effects of telehealth interventions on the caregiver burden and mental health of caregivers for people with dementia (PWD). METHOD: Relevant randomized controlled trials (RCTs) of telehealth interventions on caregivers were extracted from nine electronic databases (PubMed, The Cochrane Library, Web of Science, Embase, CINAHL, SinoMed, CNKI, WanFang, and VIP). The retrieval time was from inception to 26 July 2023. RESULTS: Twenty-two articles with 2132 subjects were included in the final analysis. The meta-analysis demonstrated that telehealth interventions exerted a significant effect in reducing caregiver burden (SMD: -0.14, 95â¯% CI: -0.25, -0.02, p = 0.02), depression (SMD = -0.17; 95%CI: -0.27, -0.07, p < 0.001) and stress (SMD = -0.20, 95%CI: -0.37, -0.04, p = 0.01). However, no statistically significant effect was observed on anxiety (SMD = -0.12, 95%CI: -0.27, 0.03, p = 0.12). Moreover, subgroup analysis showed that tailored interventions were associated with more evident reductions in depression (SMD = -0.26; 95%CI: -0.40, -0.13, p < 0.001) than standardized interventions (SMD = -0.08; 95%CI: -0.22, 0.06, p = 0.25). In addition, telehealth was effective in relieving depression in Internet-based (SMD = -0.17, 95%CI: -0.30, -0.03, p = 0.01) and Telephone-based group (SMD = -0.18, 95%CI: -0.34, -0.02, p = 0.03), while there was no significant difference in the Internet and Telephone-based group (SMD = -0.18, 95%CI: -0.54, 0.18, p = 0.32). CONCLUSION: Telehealth could effectively reduce the burden and relieve the depression and stress of caregivers of PWD, while its effect on anxiety requires further research. Overall, telehealth has potential benefits in dementia care.
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Designing highly active oxygen reduction reaction (ORR) catalysts is crucial to boost the fuel cell economy. Previous research has mainly focused on Pt-based alloy catalysts in which surface Pt is the solely active site and the activity improvement was challenged by the discovered scaling relationship. Herein we report a new concept of utilizing dual active sites for the ORR and demonstrate its effectiveness by synthesizing a SnO x/Pt-Cu-Ni heterojunctioned catalyst. A maximum of 40% enhancement in the apparent specific activity, which corresponds to 10-fold enhancement on interface sites, is measured compared with pure Pt-Cu-Ni. Detailed investigations suggest an altered dual-site cascade mechanism wherein the first two steps occur on SnO x sites and the remaining steps occur on adjacent Pt sites, allowing a significant decrease in the energy barrier. This study with the suggested dual-site cascade mechanism shows the potential to overcome the ORR energy barrier bottleneck to develop highly active catalysts.
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Perovskite oxides (ABO3) have been studied extensively to promote the kinetics of the oxygen evolution reaction (OER) in alkaline electrolytes. However, developing highly active catalysts for OER at near-neutral pH is desirable for many photoelectrochemical/electrochemical devices. In this paper, we systematically studied the activity and stability of well-known perovskite oxides for OER at pH 7. Previous activity descriptors established for perovskite oxides at pH 13, such as having an eg occupancy close to unity or having an O p-band center close to Fermi level, were shown to scale with OER activity at pH 7. Stability was a greater challenge at pH 7 than at pH 13, where two different modes of instability were identified from combined transmission electron microscopy and density functional theory analyses. Perovskites with O p-band close to Fermi level showed leaching of A-site atoms and surface amorphization under all overpotentials examined at pH 7, while those with O p-band far from Fermi level were stable under low OER current/potential but became unstable at high current/potential accompanied by leaching of B-site atoms. Therefore, efforts are needed to enhance the activity and stability of perovskites against A-site or B-site loss if used at neutral pH.
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Many real-life stains have origins from biological matters including proteins, lipids, and carbohydrates that act as gluing agents binding along with other particulates or microbes to exposed surfaces of automobiles, furniture, and fabrics. Mimicking naturally occurring self-defensive processes, we demonstrate in this work that a solid surface carrying partially exposed enzyme granules protected the surface in situ from contamination by biological stains and fingerprints. Attributed to the activities of enzymes which can be made compatible with a wide range of materials, such anti-contamination and self-cleaning functionalities are highly selective and efficient toward sticky chemicals. This observation promises a new mechanism in developing smart materials with desired anti-microbial, self-reporting, self-cleaning, or self-healing functions.
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Materiales Biocompatibles/química , Enzimas/química , Tensoactivos/química , Estabilidad de Enzimas , Enzimas/metabolismo , Contaminación de Equipos/prevención & control , Propiedades de Superficie , TemperaturaRESUMEN
In our developing world, carbon dioxide has become one of the most abundant greenhouse gases in the atmosphere. It is a stable, inert, small molecule that continues to present significant challenges toward its chemical activation as a useful carbon end product. This tutorial review describes one approach to the reduction of carbon dioxide to carbon fuels, using cobalt and nickel molecular catalysts, with particular focus on studying the thermodynamics and kinetics of CO(2) binding to metal catalytic sites.
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Dióxido de Carbono/química , Monóxido de Carbono/química , Cobalto/química , Níquel/química , Compuestos Organometálicos/química , Termodinámica , Catálisis , Enlace de Hidrógeno , Cinética , Oxidación-ReducciónRESUMEN
A citywide traffic crash risk map is of great significance for preventing future traffic crashes. However, the fine-grained geographic traffic crash risk inference is still a challenging task, mainly due to the complex road network structure, human behavior and high data requirements. In this work, we propose a deep-learning framework PL-TARMI, which leverages easily accessible data to achieve accurate fine-grained traffic crash risk map inference. Specifically, we integrate the satellite image and road network image, combine with other accessible data (e.g., point of interest distribution, human mobility data, traffic data, etc.) as input, and finally obtain the pixel-level traffic crash risk map, which could provide more reasonable traffic crash prevention guidance with a lower cost. Extensive experiments on real-world datasets demonstrate the effectiveness of PL-TARMI.
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Accidentes de Tránsito , Aprendizaje Profundo , Humanos , Accidentes de Tránsito/prevención & controlRESUMEN
It has become an inevitable trend for medical personnel to analyze and diagnose Alzheimer's disease (AD) in different stages by combining functional magnetic resonance imaging (fMRI) and artificial intelligence technologies such as deep learning in the future. In this paper, a classification method was proposed for AD based on two different transformation images of fMRI and improved the 3DPCANet model and canonical correlation analysis (CCA). The main ideas include that, firstly, fMRI images were preprocessed, and subsequently, mean regional homogeneity (mReHo) and mean amplitude of low-frequency amplitude (mALFF) transformation were performed for the preprocessed images. Then, mReHo and mALFF images were extracted features using the improved 3DPCANet, and these two kinds of the extracted features were fused by CCA. Finally, the support vector machine (SVM) was used to classify AD patients with different stages. Experimental results showed that the proposed approach was robust and effective. Classification accuracy for significant memory concern (SMC) vs. mild cognitive impairment (MCI), normal control (NC) vs. AD, and NC vs. SMC, respectively, reached 95.00%, 92.00%, and 91.30%, which adequately proved the feasibility and effectiveness of the proposed method.
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Enfermedad de Alzheimer/clasificación , Enfermedad de Alzheimer/diagnóstico por imagen , Disfunción Cognitiva/diagnóstico por imagen , Algoritmos , Inteligencia Artificial , Encéfalo/diagnóstico por imagen , Análisis de Correlación Canónica , Disfunción Cognitiva/clasificación , Biología Computacional , Neuroimagen Funcional/estadística & datos numéricos , Humanos , Interpretación de Imagen Asistida por Computador/estadística & datos numéricos , Imagen por Resonancia Magnética/estadística & datos numéricos , Máquina de Vectores de SoporteRESUMEN
The traditional full-scan method is commonly used for identifying critical links in road networks. This method simulates each link to be closed iteratively and measures its impact on the efficiency of the whole network. It can accurately identify critical links. However, in this method, traffic assignments are conducted under all scenarios of link disruption, making this process prohibitively time-consuming for large-scale road networks. This paper proposes an approach considering the traffic flow betweenness index (TFBI) to identify critical links, which can significantly reduce the computational burden compared with the traditional full-scan method. The TFBI consists of two parts: traffic flow betweenness and endpoint origin-destination (OD) demand (rerouted travel demand). There is a weight coefficient between these two parts. Traffic flow betweenness is established by considering the shortest travel-time path betweenness, link traffic flow and total OD demand. The proposed approach consists of the following main steps. First, a sample road network is selected to calibrate the weight coefficient between traffic flow betweenness and endpoint OD demand in the TFBI using the network robustness index. This index calculates changes in the whole-system travel time due to each link's closure under the traditional full-scan method. Then, candidate critical links are pre-selected according to the TFBI value of each link. Finally, a given number of real critical links are identified from the candidate critical links using the traditional full-scan method. The applicability and computational efficiency of the TFBI-based approach are demonstrated for the road network in Changchun, China.
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Planificación de Ciudades , Modelos Teóricos , Vehículos a Motor/estadística & datos numéricos , Viaje/estadística & datos numéricos , Algoritmos , China , Ciudades/estadística & datos numéricos , Simulación por Computador , Factores de TiempoRESUMEN
Mesoporous carbon (MPC) nanomaterials, with large specific surface area, excellent conductivity and stability, and effective mass transfer are beneficial for use as catalyst support in electrochemical oxygen reduction reaction (ORR) for fuel cell applications. However, MPC utilization was limited by difficulties in loading catalyst nanoparticles within the MPC pores while simultaneously controlling critical particle parameters such as size and distribution. In this study we report a new vacuum impregnation method combined with solid-state chemistry synthesis for preparing highly active ORR catalyst nanoparticles on MPC supports. We confirm the effectiveness of this method by synthesizing octahedral Pt2CuNi nanoparticles on hydrophilic MPC with an even particle distribution in the MPC pores. We also demonstrate the capability of this method in controlling the particle size and morphology by adjusting the synthesis parameters. The synthesized catalysts exhibited excellent ORR activity and promising durability, which proves the goodness of using MPC support in ORR electrocatalysis. The findings offer a new methodology for synthesizing nanoparticles in MPC pores with parameter control and provide an intriguing strategy to develop new ORR catalysts using MPC support structure.
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Carbon nanotubes (CNTs) have been used for various bioelectrochemical applications, presumably for substantial improvement in performance. However, often only moderate results observed, with many governing factors have been considered and suggested yet without much systematic evaluation and verification. In this study, CNT-supported glucose oxidase (CNT-GOx) was examined in the presence of 1,4-benzoquinone (BQ). The intrinsic Michaelis parameters of the reaction catalyzed by CNT-GOx were found very close to those of native GOx. However, the Nafion entrapment of CNT-GOx for an electrode resulted in a much lower activity due to the limited availability of the embedded enzyme. Interestingly, kinetic studies revealed that the biofuel cell employing such an enzyme electrode only generated a power density equivalent to <40% of the reaction capability of the enzyme on electrode. It appeared to us that factors such as electron and proton transfer resistances can be more overwhelming than the heterogeneous reaction kinetics in limiting the power generation of such biofuel cells.
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Fuentes de Energía Bioeléctrica , Electrodos , Glucosa Oxidasa/metabolismo , Nanotubos de Carbono , Benzoquinonas/metabolismo , Electricidad , CinéticaRESUMEN
The vehicle trajectory data is a feasible way for us to understand and reveal urban traffic conditions and human mobility. Therefore, it is extremely valuable to have a fine-grained picture of large-scale vehicle trajectory data, particularly in two different modes, taxis and buses, over the same period at an urban scale. This paper integrates the trajectory data of approximately 7,000 taxis and 1,500 buses in Changchun City, China and accesses the temporal geographically-explicit network of public transport via sequential snapshots of vehicle trajectory data every 30 seconds of the first week in March 2018. In order to reveal urban traffic conditions and human mobility, we construct two-layer urban traffic network (UTN) between these two different transport modes, take crossings as nodes and roads as edges weighted by the volume or average speed of vehicles in each hour. We released this temporal geographically-explicit network of public transport and the dynamics, weighted and directed UTN in simple formats for easy access.
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The efficiency of sunlight-driven reduction of carbon dioxide (CO2), a process mimicking the photosynthesis in nature that integrates the light harvester and electrolysis cell to convert CO2 into valuable chemicals, is greatly limited by the sluggish kinetics of oxygen evolution in pH-neutral conditions. Current non-noble metal oxide catalysts developed to drive oxygen evolution in alkaline solution have poor performance in neutral solutions. Here we report a highly active and stable oxygen evolution catalyst in neutral pH, Brownmillerite Sr2GaCoO5, with the specific activity about one order of magnitude higher than that of widely used iridium oxide catalyst. Using Sr2GaCoO5 to catalyze oxygen evolution, the integrated CO2 reduction achieves the average solar-to-CO efficiency of 13.9% with no appreciable performance degradation in 19 h of operation. Our results not only set a record for the efficiency in sunlight-driven CO2 reduction, but open new opportunities towards the realization of practical CO2 reduction systems.
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Lactate-based chemicals and polymers including poly(lactic acid) (PLA) are highly valuable materials for biomedical, food and general-purpose applications. Chemical synthesis, albeit the high reaction velocities achieved with it, often leaves chemical residues that are subject to health and safety concerns. Alternative biosynthesis is preferred in order to overcome these problems. Herein we report a novel enzymatic synthesis for the preparation of beta-d-galactosyl-l-lactic acid ethyl ester (GLAEE). Such a product, which may find applications in food and personal care products, is generally difficult to synthesize via traditional chemical routes because the reactions have to be highly selective due to the multiple hydroxyl groups of sugars. We further explore the enzymatic polymerization of GLAEE to form a unique biopolymer, poly(beta-d-galactoside-co-l-lactic acid) (PGLA). Novozyme 435 was found efficient in catalyzing the polymerization reaction in acetone with a conversion yield of 60% within 100 h. The molecular weight of the polymer product ranged from about 800-2000 as analyzed by using ESI-MS. It is expected that a variety of sugar-hydroxyl acids copolymers can be prepared through the same approach and a new class of biomaterials can thus be developed.
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Materiales Biocompatibles/metabolismo , Galactósidos/metabolismo , Lactatos/metabolismo , Lipasa/metabolismo , Polímeros/metabolismo , Isótopos de Carbono , Enzimas Inmovilizadas , Ésteres , Proteínas Fúngicas , Galactósidos/química , Glicosilación , Lactatos/química , Ácido Láctico/química , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Poliésteres , Polímeros/química , Factores de TiempoRESUMEN
Enzyme-based biofuel cells are attracting attention rapidly partially due to the promising advances reported recently. However, there are issues to be addressed before biofuel cells become competitive in practical applications. Two critical issues are short lifetime and poor power density, both of which are related to enzyme stability, electron transfer rate, and enzyme loading. Recent progress in nanobiocatalysis opens the possibility to improve in these aspects. Many nano-structured materials, such as mesoporous media, nanoparticles, nanofibers, and nanotubes, have been demonstrated as efficient hosts of enzyme immobilization. It is evident that, when nanostructure of conductive materials are used, the large surface area of these nanomaterials can increase the enzyme loading and facilitate reaction kinetics, and thus improving the power density of biofuel cells. In addition, research efforts have also been made to improve the activity and stability of immobilized enzymes by using nanostructures. It appears to be reasonable to us to expect that progress in nanostuctured biocatalysts will play a critical role in overcoming the major obstacles in the development of powerful biofuel cells.
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Fuentes de Energía Bioeléctrica , Enzimas/metabolismo , Fuentes de Energía Bioeléctrica/tendencias , Catálisis , Transferencia de Energía , Estabilidad de Enzimas , Enzimas/química , Nanoestructuras/químicaRESUMEN
Hierarchically ordered mesocellular mesoporous silica materials (HMMS) were synthesized using a single structure-directing agent. The mesocellular pores are synthesized without adding any pore expander; the pore walls are composed of SBA-15 type mesopores. Small-angle X-ray scattering revealed the presence of uniform pore structures with two different sizes. Using HMMS as a nanoscopic template, hierarchically ordered mesocellular mesoporous carbon (HMMC) and polymer (HMMP) materials were synthesized. HMMS was used as a host for enzyme immobilization. To improve the retention of enzymes in HMMS, we adsorbed enzymes, and then employed crosslinking using glutaraldehyde (GA). The resulting crosslinked enzyme aggregates (CLEAs) show an impressive stability with extremely high enzyme loadings. For example, 0.5 g alpha-chymotrypsin (CT) could be loaded in 1 g of silica with no activity decrease observed with rigorous shaking over one month. In contrast, adsorbed CT without GA treatment resulted in a lower loading, which further decreased due to continuous leaching of adsorbed CT under shaking. The activity of crosslinked CT aggregates in HMMS was approximately 10 times higher than that of the adsorbed CT, which represents a 74-fold increase in activity per unit weight of HMMS due to higher CT loading.
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Reactivos de Enlaces Cruzados/farmacología , Microquímica/métodos , Dióxido de Silicio/química , Adsorción , Carbono/química , Quimotripsina/química , Enzimas/química , Enzimas Inmovilizadas , Glutaral/química , Cinética , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Nitrógeno/química , Polímeros/química , Dispersión de RadiaciónRESUMEN
Brownmillerite Ca2MnAlO5 has an exceptional capability to robustly adsorb half-molecules of oxygen and form Ca2MnAlO5.5. To utilize this unique property to regulate oxygen-involved reactions, it is crucial to match the oxygen release-intake equilibrium with targeted reaction conditions. Here we perform a comprehensive investigation of the strategy of tuning the oxygen storage property of Ca2MnAlO5 through chemical doping. For undoped Ca2MnAlO5+δ, our first-principles calculation predicts that the equilibrium temperature at a pressure of 1 atm of O2 is 848 K, which is in excellent agreement with experimental results. Furthermore, the doping of alkaline earth ions at the Ca site, trivalent ions at the Al site, and 3d transition metal ions at the Mn site is analyzed. By the doping of 12.5% of Ga, V, and Ti, the equilibrium temperature shifts to high values by approximately 110-270 K, while by the doping of 12.5% of Fe, Sr, and Ba, the equilibrium temperature is lowered by approximately 20-210 K. The doping of these elements is thermodynamically stable, and doping other elements including Mg, Sc, Y, Cr, Co, and Ni generates metastable compounds. The doping of a higher content of Fe, however, lowers the oxygen storage capacity. Finally, on the basis of our calculated data, we prove that the formation energetics of nondilute interacting oxygen vacancy in doped Ca2MnAlO5.5 scale linearly with a simple descriptor, the oxygen p-band position relative to the Fermi level. The higher-oxygen p-band position leads to a lower vacancy formation energy and thus a lower oxygen release temperature. Understanding such a relationship between fundamental quantum chemical properties and macroscopic properties paves the road to the design and optimization of novel functional oxides.
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Electrochemical reduction of CO2 to CO on polycrystalline silver (Ag) was greatly improved by a simple anodization treatment. A CO faradaic efficiency of 92.8% was achieved at an overpotential of 0.50 V in an aqueous electrolyte. This study suggests that the enhanced performance is due to a preferred (220) orientation and a thin silver oxide layer formed by anodization.
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Improvement of catalytic efficiency of immobilized enzymes via materials engineering was demonstrated through the preparation of bioactive nanofibers. Bioactive polystyrene (PS) nanofibers with a typical diameter of 120 nm were prepared and examined for catalytic efficiency for biotransformations. The nanofibers were produced by electrospinning functionalized PS, followed by the chemical attachment of a model enzyme, alpha-chymotrypsin. The observed enzyme loading as determined by active site titration was up to 1.4% (wt/wt), corresponding to over 27.4% monolayer coverage of the external surface of nanofibers. The apparent hydrolytic activity of the nanofibrous enzyme in aqueous solutions was over 65% of that of the native enzyme, indicating a high catalytic efficiency as compared to other forms of immobilized enzymes. Furthermore, nanofibrous alpha-chymotrypsin exhibited a much-improved nonaqueous activity that was over 3 orders of magnitude higher than that of its native counterpart suspended in organic solvents including hexane and isooctane. It appeared that the covalent binding also improved the enzyme's stability against structural denaturation, such that the half-life of the nanofibrous enzyme in methanol was 18-fold longer than that of the native enzyme.
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Materiales Biocompatibles/síntesis química , Quimotripsina/química , Enzimas Inmovilizadas/química , Membranas Artificiales , Nanotecnología , Poliestirenos , Animales , Catálisis , Bovinos , Quimotripsina/metabolismo , Campos Electromagnéticos , Activación Enzimática , Estabilidad de Enzimas , Enzimas Inmovilizadas/metabolismo , Hexanos/química , Hidrólisis , Metanol/química , Octanos/química , Páncreas/enzimología , Electricidad Estática , Textiles , Agua/químicaRESUMEN
GOALS: The aim of this study was to evaluate the combination of endoscopic ultrasonography (EUS) and computed tomography (CT) in predicting the maneuvers for therapeutic endoscopy for gastrointestinal submucosal tumors (SMTs). METHODS: Patients with SMTs, who were scheduled for endoscopic resection, were randomized to preoperative performance of both EUS and CT (group A) or EUS only (group B). The following data were collected: therapeutic maneuvers, duration of procedure, dose of propofol, resected lesion size, and complications. RESULTS: A total of 36 patients were included in group A and 36 patients were included in group B. Endoscopic submucosal excavation was performed in 43 patients, endoscopic full-thickness resection in 18 patients, and submucosal tunneling endoscopic resection in 11 patients. No significant differences were observed between the two groups (P>0.05). The coincidence rate between the preoperative program and the actual endoscopic procedures in group A was higher than that in group B (83.3 vs. 61.1%, P<0.05). The procedural time in group A was less than that in group B (39.36±17.83 vs. 48.06±12.03 min, P<0.05), and the dose of propofol in group A was less than that in group B (249.18±125.12 vs. 304.16±102.61 mg, P<0.05). The mean resected lesion size was 2.32±1.46 cm in group A and 2.12±0.75 cm in group B, without differences (P>0.05). A total of 14 cardiopulmonary complications and seven endoscopic complications occurred, without significant differences between the two groups (P>0.05). CONCLUSION: EUS combined with CT can better evaluate SMTs compared with EUS only in predicting the maneuvers for therapeutic endoscopy.
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Neoplasias Gastrointestinales/diagnóstico , Neoplasias Gastrointestinales/cirugía , Adulto , Anciano , Anestésicos Intravenosos/administración & dosificación , Esquema de Medicación , Endosonografía/efectos adversos , Endosonografía/métodos , Femenino , Neoplasias Gastrointestinales/patología , Gastroscopía/efectos adversos , Gastroscopía/métodos , Humanos , Masculino , Persona de Mediana Edad , Imagen Multimodal/métodos , Cuidados Preoperatorios/métodos , Propofol/administración & dosificación , Tomografía Computarizada por Rayos X/efectos adversos , Tomografía Computarizada por Rayos X/métodosRESUMEN
Enzyme-based smart materials constitute a rapidly growing group of functional materials. Often the natively evolved enzymes are not compatible with hydrophobic synthetic materials, thus significantly limiting the performance of enzymes. This work investigates the use of a polyethylene glycol (PEG)-conjugated detergent enzyme for self-cleaning coatings. As a result, PEG conjugated α-amylase demonstrated a much more homogeneous distribution in polyurethane coatings than the parent native enzyme as detected by both fluorescent microscopy and scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (SEM-EDX). Additionally, the conjugated enzyme showed enhanced retention in the coating and much improved thermal stability with a halflife of 20 days detected at 80 °C and over 350 days under room temperature. Such coating-incorporated enzyme afforded interesting self-cleaning functionality against starch-based stains as examined through a slipping drop test.