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1.
J Hazard Mater ; 451: 131150, 2023 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-36893597

RESUMEN

With the fact that there are Novichoks in the list of toxic chemicals by the Chemical Weapons Convention parties, it is necessary to develop methods of effective neutralization of the agents as well as for other organophosphorus toxic substances. However, experimental studies on their persistence in the environment and effective decontamination measures remain scarce. Therefore, here, we investigated the persistence behavior and decontamination methods of A-234 (ethyl N-[1-(diethylamino)ethylidene]phosphoramidofluoridate), a Novichok series, A-type nerve agent to assess its potential risk to the environment. Different analytical methods were implemented, including 31P solid-state magic angle spinning nuclear magnetic resonance (NMR), liquid 31P NMR, gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry, and vapor-emission screening using a microchamber/thermal extractor with GC-MS. Our results showed that A-234 is extremely stable in sand and poses a long-lasting risk to the environment even when released in trace quantities. Moreover, the agent is not easily decomposed by water, dichloroisocyanuric acid sodium salt, sodium persulfate, and chlorine-based water-soluble decontaminants. However, it is efficiently decontaminated by Oxone® monopersulfate, calcium hypochlorite, KOH, NaOH, and HCl within 30 min. Our findings provide valuable insights for eliminating the highly dangerous Novichok agents from the environment.

2.
Front Hum Neurosci ; 16: 943478, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35992945

RESUMEN

Background: Attention deficit hyperactivity disorder (ADHD) is clinically diagnosed; however, quantitative analysis to statistically analyze the symptom severity of children with ADHD via the measurement of head movement is still in progress. Studies focusing on the cues that may influence the attention of children with ADHD in classroom settings, where children spend a considerable amount of time, are relatively scarce. Virtual reality allows real-life simulation of classroom environments and thus provides an opportunity to test a range of theories in a naturalistic and controlled manner. The objective of this study was to investigate the correlation between participants' head movements and their reports of inattention and hyperactivity, and to investigate how their head movements are affected by different social cues of different sensory modalities. Methods: Thirty-seven children and adolescents with (n = 20) and without (n = 17) ADHD were recruited for this study. All participants were assessed for diagnoses, clinical symptoms, and self-reported symptoms. A virtual reality-continuous performance test (VR-CPT) was conducted under four conditions: (1) control, (2) no-cue, (3) visual cue, and (4) visual/audio cue. A quantitativecomparison of the participants' head movements was conducted in three dimensions (pitch [head nods], yaw [head turns], and roll [lateral head inclinations]) using a head-mounted display (HMD) in a VR classroom environment. Task-irrelevant head movements were analyzed separately, considering the dimension of movement needed to perform the VR-CPT. Results: The magnitude of head movement, especially task-irrelevant head movement, significantly correlated with the current standard of clinical assessment in the ADHD group. Regarding the four conditions, head movement showed changes according to the complexity of social cues in both the ADHD and healthy control (HC) groups. Conclusion: Children and adolescents with ADHD showed decreasing task-irrelevant movements in the presence of social stimuli toward the intended orientation. As a proof-of-concept study, this study preliminarily identifies the potential of VR as a tool to understand and investigate the classroom behavior of children with ADHD in a controlled, systematic manner.

3.
ACS Appl Mater Interfaces ; 14(28): 32522-32532, 2022 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-35793246

RESUMEN

With the growing interest in chemical and biological warfare agents (CWAs/BWAs), the focus has shifted toward aerosol protection using protective clothing. However, compared to air-permeable membranes, those with water vapor permeability have been investigated more extensively. Filtering membranes without air permeability have limited practical usage in personal protective suits and masks. In this study, polyacrylonitrile membranes with tightly attached activated carbon and doped copper(II) oxide were prepared via electrospinning. The nanofibers with uniformly controlled diameters and smooth morphologies enable water/air breathability and protection against aerosol (100 nm polystyrene nanobeads similar to SARS-CoV-2) penetration. The uniformly distributed and tightly attached activated carbon and doped copper(II) oxide particles enhance the sorptive performance of the membranes by blocking gaseous CWAs, including soman, nerve chemical agents, and BWAs. Such dual-purpose membranes can be implemented in protective equipment owing to their high performance and easy processing.


Asunto(s)
COVID-19 , Carbón Orgánico , Aerosoles , COVID-19/prevención & control , Cobre , Humanos , Permeabilidad , SARS-CoV-2
4.
Adv Sci (Weinh) ; 9(8): e2105420, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35001517

RESUMEN

The kinetic body motions have guided the core-shell fabrics of wearable bioelectronics to be elastoplastic. However, the polymeric electrodes follow the trade-off relationship between toughness and stretchability. To this end, the stress dissipation encoded silk fibroin electrode is proposed as the core electrode of wearable bioelectronics. Significantly, the high degree of intrinsic stress dissipation is realized via an amino acid crosslink. The canonical phenolic amino acid (i.e., tyrosine) of silk fibroin is engineered to bridge the secondary structures. A sufficient crosslink network is constructed when tyrosine is exposed near the amorphous strand. The stress dissipative tyrosine crosslink affords 12.5-fold increments of toughness (4.72 to 58.9 MJ m-3 ) and implements the elastoplastic silk fibroin. The harmony of elastoplastic core electrodes with shell fabrics enables the wearable bioelectronics to employ mechanical performance (elastoplasticity of 750 MJ m-3 ) and stable electrical response. The proposed wearable is capable of assisting the effective workouts via triboelectricity. In principle, active mobility with suggested wearables potentially relieves muscular fatigues and severe injuries during daily fitness.


Asunto(s)
Fibroínas , Atletas , Electrodos , Fibroínas/química , Humanos , Polímeros , Seda
5.
Adv Healthc Mater ; 11(6): e2102095, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34826360

RESUMEN

The delivery of nitric oxide (NO)-an intrinsic cellular signaling molecule-is promising for disease treatment, in particular to vascular diseases, due to its endothelial-derived inherent nature. The limited diffusion distance of labile NO prompts researchers to develop various carriers and targeting methods for specific sites. In contrast to the apoptotic effect of NO, such as anticancer, delivering low NO concentration at the desired targeting area is still intricate in a physiological environment. In this study, the layer-by-layer assembled nanocoating is leveraged to develop a direct NO delivery platform to individual endothelial cells (ECs). NO can be localized to individual ECs via S-nitrosothiol-bound polyacrylic acid which is a polymer directly providing an endothelial-like constant level of NO. To increase angiogenic activation along with NO, VEGF is additionally applied to specific receptors on the cell surface. Notably, the survival and proliferation of ECs are significantly increased by a synergistic effect of NO and VEGF co-localized via nanocoating. Furthermore, the nanocoating remarkably promoted cell migration and tubule formation-prerequisites of angiogenesis. The proposed unique technology based on nanocoating demonstrates great potential for conferring desired angiogenic functions to individual ECs through efficient NO delivery.


Asunto(s)
Células Endoteliales/fisiología , Neovascularización Fisiológica , Óxido Nítrico/fisiología , Factor A de Crecimiento Endotelial Vascular/fisiología , Movimiento Celular , Células Endoteliales/citología , Humanos , Óxido Nítrico/metabolismo
6.
J Hazard Mater ; 427: 127884, 2022 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-34863570

RESUMEN

Chemical warfare agents (CWAs) are toxic materials that cause death by contact with the skin or by respiration. Although studies on detoxification of CWAs have been intensively conducted, studies that block CWAs permeation are rare. In this study, for blocking CWAs, a multilayer thin film composed of linear polyethylenimine (LPEI) and graphene oxide (GO) is simply prepared through a spray-assisted Layer-by-Layer (LbL) assembly process. LPEI could change its morphology dependent on pH, which is known as a representative hydrogen donor and acceptor. By controlling the shape of the polymer chain, a heterogenous film could have a loose or dense inner structure. CWAs mainly move through diffusion and have hydrogen bonding sites. Therefore, the heterogeneous film can limit CWAs movement based on controlling pathways and hydrogen bonds within the film. The protective effect of this membrane is investigated using dimethyl methylphosphonate (DMMP), a nerve gas simulant. DMMP vapor transmittance rate (DVTR) and N2 permeance of LPEI/GO are 67.91 g/m2 day and 34,293.04 GPU. It means that the protection efficiency is 72.65%. Although this membrane has a thin thickness (100 nm), it shows a high protective effect with good breathability. And water/DMMP selectivity of the membrane is 66.63. Since this multilayer membrane shows efficient protection performance with a simple preparation method, it has a high potential for applications such as protective suits and masks.


Asunto(s)
Sustancias para la Guerra Química , Grafito , Enlace de Hidrógeno , Polímeros
7.
ACS Appl Mater Interfaces ; 13(45): 54363-54374, 2021 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-34730330

RESUMEN

Zwitterions have been attracting emerging attention as an anti-fouling polymer. However, the relationship between structured solvation shells and controlled drug release induced by deceleration of water molecule's translational and vibrational motions of zwitterions is an uncharted territory. Herein, sulfobetaine zwitterion nanoparticles (ZWNPs) were designed as a stable nitric oxide (NO)-delivering carrier. The condensed water structure of the solvation shell at its isoelectric point (PI) and the loose structure of water under different pH conditions were investigated through rheological and thermodynamical analyses. The ZWNPs showed a sustained-release profile at the PI, which presented a structured solvation barrier. On the other hand, NO-loaded ZWNPs showed different release profiles with the burst release at pH 5.5. Notably, an increased cell proliferation rate and a decreased antibacterial effect were observed at the same concentration depending on solvation shell's characteristics.


Asunto(s)
Antibacterianos/química , Betaína/análogos & derivados , Nanopartículas/química , Óxido Nítrico/química , Antibacterianos/farmacología , Betaína/química , Incrustaciones Biológicas/prevención & control , Proliferación Celular/efectos de los fármacos , Portadores de Fármacos/química , Liberación de Fármacos , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Humanos , Concentración de Iones de Hidrógeno , Pruebas de Sensibilidad Microbiana , Óxido Nítrico/farmacología , Solubilidad , Staphylococcus aureus/efectos de los fármacos , Termodinámica
8.
Chem Eng J ; 426: 130763, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34131388

RESUMEN

Infectious pollutants bioaerosols can threaten human public health. In particular, the indoor environment provides a unique exposure situation to induce infection through airborne transmission like SARS-CoV-2. To prevent the infection from spreading, personal protective equipment or indoor air purification is necessary. However, it has been discovered that the conventional filter can become contaminated by pathogen-containing aerosols, meaning that advanced filtering and self-sterilization systems are required. Here, we fabricate a multilayered nanocoating around the fabric using laponite (LAP) with Cu2+ ions (LAP-Cu2+ nanocoating) two contradictory functions in one system: trapping proteinaceous pathogens and antibacterial effect. Due to the strong LAP-protein interaction, albumin and spike protein (S-protein) are trapped into the fabric when proteins are sprayed using a nebulizer. The protein-blocking performance of the nanocoated fabric is 9.55-fold higher than bare fabric. These trapping capacities are retained after rinsing and repeated adsorption cycles, showing reproducibility for air filtration. Even though the protein-binding occurred, the LAP-Cu2+ fabric indicates antibacterial effect. LAP-Cu2+ fabric has an equivalent air and water transmittance rate to that of bare fabric with a stability under physiological environment. Therefore, given its excellent "Spear-and-shield" functions, the proposed LAP-Cu2+ fabric shows great potential for use in filter and masks during the viral pandemic.

9.
ACS Appl Mater Interfaces ; 13(27): 32193-32204, 2021 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-34185496

RESUMEN

Cultured meat is artificial meat produced via the mass culture of cells without slaughtering livestock. In the production process of cultured meat, the mass proliferation for preparing abundant cells is a strenuous and time-consuming procedure requiring expensive and excess serum. Herein, C-phycocyanin (C-PC) extracted from blue algae was selected as a substitute for animal-derived serum and a polysaccharide film-based platform was developed to effectively deliver C-PC to myoblast while reducing the cost of cell medium. The polysaccharide platform has a sophisticated structure in which an agarose layer is capped on a porous multilayer film formed by molecular reassembly between chitosan and carboxymethylcellulose (CMC). The porous multilayer film provides an inner structure in which C-PC can be incorporated, and the agarose layer protects and stabilizes the C-PC. The completed platform was easily applied to a cell culture plate to efficiently release C-PC, thereby improving myoblast proliferation in a serum-reduced environment during long-term culture. We developed a cell sheet-based meat model using this polysaccharide platform to evaluate the improved cost-efficiency by the platform method in the mass proliferation of cells. This strategy and innovative technology can simplify the production system and secure price competitiveness to commercialize cultured meat.


Asunto(s)
Técnicas de Cultivo de Célula/economía , Celulosa/química , Quitosano/química , Carne , Nanoestructuras/química , Ficocianina/química , Ficocianina/farmacología , Diferenciación Celular/efectos de los fármacos , Celulasa/química , Análisis Costo-Beneficio , Mioblastos/citología , Mioblastos/efectos de los fármacos , Porosidad , Factores de Tiempo
10.
Langmuir ; 37(15): 4587-4598, 2021 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-33822629

RESUMEN

Cell surface coating using the layer-by-layer assembly (LbL) method has many advantages for biomedical applications. Because the cell surface is a dynamic and highly complex structure, it is hypothesized that LbL multilayer films on cells have characteristics different from those observed in traditional film characterization results. Here, to demonstrate the mechanism of LbL-film formation on cells, LbL films are prepared on HeLa cells using collagen (Col) and hyaluronic acid (HA). The growth behavior of the film and the main driving forces inducing the formation of an LbL film on the cells are investigated. Col self-assembles via electrostatic and hydrophobic interactions; therefore, the Col-based film on the cells grows laterally rather than volumetrically. For the film construction conditions, the ionic density and chain conformation of the polymers change, resulting in mainly hydrophobic interactions. Additional interactions, such as hydrophobic interactions and biological recognition between the substrate and building blocks, also exist and tightly stabilize the films on the cells. The Col/HA film shows an even distribution on the cell surface as the extracellular matrix, and it activates proliferation and the cytoprotective signaling pathway under harsh conditions, resulting in the focal adhesion kinase signaling pathway and low lactate dehydrogenase release. Therefore, information for film construction on cells is beneficial to understand the effectiveness of an LbL film for cells.


Asunto(s)
Colágeno Tipo I , Colágeno , Membrana Celular , Matriz Extracelular , Células HeLa , Humanos
11.
ACS Nano ; 15(4): 6811-6828, 2021 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-33769787

RESUMEN

Zwitterionic polymers have extraordinary properties, that is, significant hydration and the so-called antipolyelectrolyte effect, which make them suitable for biomedical applications. The hydration induces an antifouling effect, and this has been investigated significantly. The antipolyelectrolyte effect refers to the extraordinary ion-responsive behavior of particular polymers that swell and hydrate considerably in physiological solutions. This actuation begins to attract attention to achieve in vivo antifouling that is challenging for general polyelectrolytes. In this study, we established the sophisticated cornerstone of the antipolyelectrolyte effect in detail, including (i) the essential parameters, (ii) experimental verifications, and (iii) effect of improving antifouling performance. First, we find that both osmotic force and charge screening are essential factors. Second, we identify the antipolyelectrolyte effect by visualizing the swelling and hydration dynamics. Finally, we verify that the antifouling performance can be enhanced by exploiting the antipolyelectrolyte effect and report reduction of 85% and 80% in ex and in vivo biofilm formation, respectively.


Asunto(s)
Polímeros , Polielectrolitos
12.
J Hazard Mater ; 414: 125472, 2021 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-33640729

RESUMEN

The potential health hazards of particulates, such as micro/nano-sized plastics and carbon materials have recently received extensive attention. However, their toxicological properties in association with stem cell differentiation is still relatively unexplored. In this study, we elucidated the cytotoxic effects of 2D graphene oxide (GO), in relation to differentiation of human induced pluripotent stem cells (hiPSCs). Supplementation of GO to hiPSCs demonstrated uptake of GO through the plasma membrane and intracellular accumulation was observed. Increasing the concentration of GO led to reduced viability and increased likelihood of hiPSC colony detachment. Moreover, treatment of GO resulted in significant loss in pluripotency markers, OCT-4 and NANOG. In particular, when hiPSCs were cultured with GO in cardiomyocyte induction medium, upregulation of cardiomyocyte marker, NKX2.5, along with observation of early triggering of differentiation were observed. Taken together, our results highlight the risk in the uptake and accumulation of GO on the stem cell development by unwanted loss in pluripotency and accelerated initiation of differentiation.


Asunto(s)
Grafito , Células Madre Pluripotentes Inducidas , Células Madre Pluripotentes , Diferenciación Celular , Grafito/toxicidad , Humanos
13.
Mater Sci Eng C Mater Biol Appl ; 118: 111440, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33255033

RESUMEN

Functionalized scaffolds hold promise for stem cell therapy by controlling stem cell fate and differentiation potential. Here, we have examined the potential of a 2-dimensional (2D) scaffold to stimulate bone regeneration. Solubilized extracellular matrix (ECM) from human bone tissue contains native extracellular cues for human skeletal cells that facilitate osteogenic differentiation. However, human bone ECM displays limited mechanical strength and degradation stability under physiological conditions, necessitating modification of the physical properties of ECM before it can be considered for tissue engineering applications. To increase the mechanical stability of ECM, we explored the potential of synthetic Laponite® (LAP) clay as a counter material to prepare a 2D scaffold using Layer-by-Layer (LbL) self-assembly. The LAP and ECM multilayer nanofilms (ECM/LAP film) were successfully generated through electrostatic and protein-clay interactions. Furthermore, to enhance the mechanical properties of the ECM/LAP film, application of a NaCl solution wash step, instead of deionized water following LAP deposition resulted in the generation of stable, multi-stacked LAP layers which displayed enhanced mechanical properties able to sustain human skeletal progenitor cell growth. The ECM/LAP films were not cytotoxic and, critically, showed enhanced osteogenic differentiation potential as a consequence of the synergistic effects of ECM and LAP. In summary, we demonstrate the fabrication of a novel ECM/LAP nanofilm layer material with potential application in hard tissue engineering.


Asunto(s)
Matriz Extracelular , Osteogénesis , Huesos , Diferenciación Celular , Humanos , Silicatos , Células Madre , Andamios del Tejido
14.
Biomacromolecules ; 21(10): 4336-4344, 2020 10 12.
Artículo en Inglés | MEDLINE | ID: mdl-32955862

RESUMEN

Vesicles made from functionally folded, globular proteins that perform specific biological activities, such as catalysis, sensing, or therapeutics, show potential applications as artificial cells, microbioreactors, or protein drug delivery vehicles. The mechanical properties of vesicle membranes, including the elastic modulus and hardness, play a critical role in dictating the stability and shape transformation of the vesicles under external stimuli triggers. Herein, we have developed a strategy to tune the mechanical properties and integrity of globular protein vesicle (GPV) membranes of which building molecules are recombinant fusion protein complexes: a mCherry fused with an acidic leucine zipper (mCherry-ZE) and a basic leucine zipper fused with an elastin-like polypeptide (ZR-ELP). To control the mechanical properties of GPVs, we introduced a nonstandard amino acid (para-azidophenylalanine (pAzF)) into the ELP domains (ELP-X), which enabled the creation of crosslinked vesicles under ultraviolet (UV) irradiation. Crosslinked GPVs made from mCherry-ZE/ZR-ELP-X complexes presented higher stability than noncrosslinked GPVs under hypotonic osmotic stress. The degree of swelling of GPVs increased as less crosslinking was achieved in the vesicle membranes, which resulted in the disassembly of GPVs into membraneless coacervates. Nanoindentation by atomic force microscopy (AFM) confirmed that the stiffness and Young's elastic modulus of GPVs increase as the blending molar ratio of ZR-ELP-X to ZR-ELP increases to make vesicles. The results obtained in this study suggest a rational design to make GPVs with tunable mechanical properties for target applications by simply varying the blending ratio of ZR-ELP and ZR-ELP-X in the vesicle self-assembly.


Asunto(s)
Elastina , Péptidos , Sistemas de Liberación de Medicamentos , Módulo de Elasticidad , Proteínas Recombinantes de Fusión
15.
Cyberpsychol Behav Soc Netw ; 23(10): 715-720, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32678684

RESUMEN

Test anxiety has been a growing problem in school-aged children, especially for students in East-Asian countries where the pressure for academic achievement is high. These students are more vulnerable to academic stress, which could further lead to anxiety disorders. For this reason, this study examined the feasibility of virtual reality (VR) test anxiety program in managing anxiety in students. A total of 22 typically developing children with varying levels of test anxiety and no history of psychiatric illnesses participated in the study (mean age = 11.6 and standard deviation [SD] = 1.84). A self-reported questionnaire measuring test anxiety, state-trait anxiety, and depression was administered. Heart rate (HR) variability and subjective anxiety were also measured to examine the changes during each of the anxiety-inducing (Exam 1 and Exam 2) and meditation (Med 1 and Med 2) sessions in the program. There was a significant difference in self-perceived anxiety during the program (p < 0.001), as well as a significant main effect of time on the standard deviation of R-R interval (p = 0.002). In addition, a significant relationship between changes in HR and perceived anxiety during Exam 1 (p = 0.003), Med 1 (p < 0.001), and Med 2 (p = 0.011) was found. In conclusion, this work demonstrates the feasibility of the virtual environment to induce different levels of anxiety and explores the potential use of VR program as a viable method to manage the negative emotion in students. This work shows the potential of technology-enhanced tools in addressing psychological problems in school-aged children. Further study is needed to validate the use of the program in clinical practice.


Asunto(s)
Meditación/métodos , Estudiantes/psicología , Ansiedad ante los Exámenes/terapia , Realidad Virtual , Adolescente , Niño , Estudios de Factibilidad , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Meditación/psicología , Aplicaciones Móviles , Proyectos Piloto , Ansiedad ante los Exámenes/fisiopatología , Ansiedad ante los Exámenes/psicología
16.
Cancers (Basel) ; 12(3)2020 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-32150885

RESUMEN

This study demonstrates the possibility of developing a rapidly degradable chitosan-based multilayer film for controlled drug release. The chitosan (CHI)-based multilayer nanofilms were prepared with three different types of anions, hyaluronic acid (HA), alginic acid (ALG) and tannic acid (TA). Taking advantage of the Layer-by-Layer (LBL) assembly, each multilayer film has different morphology, porosity and thickness depending on their ionic density, molecular structure and the polymer functionality of the building blocks. We loaded drug models such as doxorubicin hydrochloride (DOX), fluorescein isothiocyanate (FITC) and ovalbumin (Ova) into multilayer films and analyzed the drug loading and release profiles in phosphate-buffered saline (PBS) buffer with the same osmolarity and temperature as the human body. Despite the rapid degradation of the multilayer film in a high pH and salt solution, the drug release profile can be controlled by increasing the functional group density, which results in interaction with the drug. In particular, the abundant carboxylate groups in the CHI/HA film increased the loading amount of DOX and decreased rapid drug release. The TA interaction with DOX via electrostatic interaction, hydrogen bonding and hydrophobic interaction showed a sustained drug release profile. These results serve as principles for fabricating a tailored multilayer film for drug delivery application.

17.
Psychiatry Investig ; 16(4): 292-299, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31042691

RESUMEN

OBJECTIVE: Previous studies have suggested that a virtual classroom is immersive and ecologically valid neuropsychological assessment, but those studies have limited components for social attentions. Therefore, the objective in the current study is the development of a joint attention virtual reality (JA-VR) classroom to incorporate social attentions between a participant and a virtual avatar teacher. METHODS: Fifty-eight participants were recruited for current study (25 for pilot and 33 for main studies; 32.8% female, n=19; age: M=24.5, SD=4.0). We suggested a JA-VR classroom, and compared it with previous methods including a VR classroom without JA components. We conducted attention experiments with AX-version of continuous performance tasks. RESULTS: Our results suggest that the new JA-VR classroom had convergent validity with previous methods, and that the JA-VR classroom promoted attentional processing among participants better than both old VR and non-VR measures. CONCLUSION: We add an important social attention concept to the virtual classroom, and believe that this work is an methodological foundation for the study of social attention in school life. We hope it ultimately help people with mental handicaps in social attention.

18.
Biofabrication ; 11(2): 025016, 2019 03 28.
Artículo en Inglés | MEDLINE | ID: mdl-30808012

RESUMEN

We report a novel approach for generating nanosized DNA hollow spheres (HSs) using enzymatically produced DNA microsponges in a self-templating manner. In previous studies, preparation of DNA nanostructures with specified functions required multiple complicated steps. In this study, however, a simple treatment with the nucleophilic agent 4-dimethylaminopyridine (DMAP) enabled a gradual disentanglement of DNA in microsponges by electrostatic interactions between DMAP and DNA, and the DNA underwent a reassembly process to generate hollow shell structures without denaturation/annealing by thermal cycling. In addition, this synthetic process was conducted in a water-based system without organic solvents, enabling the synthesis of biologically and environmentally friendly products. Based on the benefits of hollow shell structures, which include their high surface-to-volume ratio and ability to encapsulate small molecules, we envision that this simple approach for synthesizing DNA HSs will provide a new platform for maximizing their potential use in drug delivery and bio-imaging.


Asunto(s)
ADN/química , Nanosferas/química , 4-Aminopiridina/análogos & derivados , 4-Aminopiridina/química , Oro/química , Simulación de Dinámica Molecular , Nanosferas/ultraestructura
19.
Sci Rep ; 9(1): 2754, 2019 02 26.
Artículo en Inglés | MEDLINE | ID: mdl-30808924

RESUMEN

The oxygen barrier properties are essential for the food packaging systems that preserve perishable food. In this research, the facile surface modification method for oxygen barrier properties is introduced by using spray assisted layer-by-layer (LbL) self-assembly. The nano-sized graphene oxide (GO-) multilayer films were developed and characterized. Positively charged amine-functionalized GO+ was synthesized using the negatively charged GO- dispersion, ethylenediamine, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide methiodide (EDC). Alternating layers of GO- and GO+ were deposited onto the flexible polyethylene (PE) substrate which has no intrinsic gas barrier properties. This method is able to modify surfaces which are challenging for the conventional dipping LbL method. The oxygen transmittance rate of coated PE film (3511.5 cc/m2·day) decreased significantly to 1091 cc/m2·day after a GO film with a thickness of only 60 nm was deposited. The light transmittance in the visible light range was not significantly decreased after coating of GO films, thus ensuring transparency for PE packaging applications.

20.
Cyberpsychol Behav Soc Netw ; 22(3): 198-204, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30672714

RESUMEN

Virtual reality (VR) neuropsychological assessments have the potential for the ecological measurement of attention. We analyzed the newly developed VR continuous performance test (VR-CPT) for Korean children with attention-deficit/hyperactivity disorder (ADHD) and typically developing children (TDC). To identify specific features of a virtual environment that influence the attention performance of children, we investigated whether the presence of a virtual teacher and social cues in the VR environment affects their attention performance. A total of 38 participants (18 TDC and 20 ADHD children and adolescents) were recruited for VR-CPT testing. Bivariate correlational analysis was conducted to examine the associations between the results of the VR-CPT and ADHD questionnaires to determine the capacity of VR-CPT to mirror real-life attention behaviors. Mixed-design analysis of variables was conducted to compare the effects of the social aspects of the VR-CPT on attention performance in groups. There were significant associations between ADHD rating scores and the omission error, commission error, reaction time (RT), reaction time variability (RTV), and total accuracy of the VR-CPT in the ADHD group. In addition, the ADHD group exhibited comparable performance with the TDC group for all measures of the VR-CPT. Also there seemed to be a trend of decreasing RTV when a virtual teacher with social cues was present compared with the equipment control condition in the ADHD group. Performance in the VR-CPT program was associated with behavioral measures of ADHD symptoms. Adding social aspects to a VR environment commonly encountered by children and adolescents has the potential to make a difference in the attention performance of youths with ADHD.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad , Señales (Psicología) , Pruebas Neuropsicológicas , Realidad Virtual , Adolescente , Trastorno por Déficit de Atención con Hiperactividad/clasificación , Trastorno por Déficit de Atención con Hiperactividad/diagnóstico , Trastorno por Déficit de Atención con Hiperactividad/psicología , Niño , Humanos , República de Corea , Encuestas y Cuestionarios
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