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1.
Nano Lett ; 24(4): 1223-1230, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38232153

RESUMEN

Hybridizing a microwave mode with a quantum state requires precise frequency matching of a superconducting microwave resonator and the corresponding quantum object. However, fabrication always brings imperfections in geometry and material properties, causing deviations from the desired operating frequencies. An effective and universal strategy for their resonant coupling is to tune the frequency of a resonator, as quantum states like phonons are hardly tunable. Here, we demonstrate gate-tunable, titanium-nitride (TiN)-based superconducting resonators by implementing a nanowire inductor whose kinetic inductance is tuned via the gate-controlled supercurrent (GCS) effect. We investigate their responses for different gate biases and observe 4% (∼150 MHz) frequency tuning with decreasing internal quality factors. We also perform temperature-controlled experiments to support phonon-related mechanisms in the GCS effect and the resonance tuning. The GCS effect-based method proposed in this study provides an effective route for locally tunable resonators that can be employed in various hybrid quantum devices.

2.
Curr Issues Mol Biol ; 46(4): 3081-3091, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38666923

RESUMEN

Oxidative stress, a driver of liver pathology, remains a challenge in clinical management, necessitating innovative approaches. In this research, we delved into the therapeutic potential of polyphenols for oxidative liver injury using a multiscale network analysis framework. From the Phenol-Explorer database, we curated a list of polyphenols along with their corresponding PubChem IDs. Verified target information was then collated from multiple databases. We subsequently measured the propagative effects of these compounds and prioritized a ranking based on their correlation scores for oxidative liver injury. This result underwent evaluation to discern its effectiveness in differentiating between known and unknown polyphenols, demonstrating superior performance over chance level in distinguishing these compounds. We found that lariciresinol and isopimpinellin yielded high correlation scores in relation to oxidative liver injury without reported evidence. By analyzing the impact on a multiscale network, we found that lariciresinol and isopimpinellin were predicted to offer beneficial effects on the disease by directly acting on targets such as CASP3, NR1I2, and CYP3A4 or by modulating biological functions related to the apoptotic process and oxidative stress. This study not only corroborates the efficacy of identified polyphenols in liver health but also opens avenues for future investigations into their mechanistic actions.

3.
Int J Equity Health ; 23(1): 82, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38664773

RESUMEN

BACKGROUND: In South Korea, Korean Chinese workers experience ethnic discrimination although they share physical similarities and ethnic heritage with native-born Koreans. This study aimed to examine whether perceived ethnic discrimination is associated with poor self-rated health and whether the association differs by gender among Korean Chinese waged workers in South Korea. METHODS: We conducted a pooled cross-sectional analysis using data of 13,443 Korean Chinese waged workers from the Survey on Immigrants' Living Conditions and Labor Force conducted in 2018, 2020, and 2022. Based on perceived ethnic discrimination, asking for fair treatment, and subsequent situational improvement, respondents were classified into the following four groups: "Not experienced," "Experienced, not asked for fair treatment," "Experienced, asked for fair treatment, not improved," and "Experienced, asked for fair treatment, improved." Poor self-rated health was assessed using a single question "How is your current overall health?" We applied logistic regression to examine the association between perceived ethnic discrimination and poor self-rated health, with gender-stratified analyses. RESULTS: We found an association between ethnic discrimination and poor self-rated health among Korean Chinese waged workers. In the gender-stratified analysis, the "Experienced, not asked for fair treatment" group was more likely to report poor self-rated health compared to the "Not experienced" group, regardless of gender. However, gender differences were observed in the group stratified by situational improvements. For male workers, no statistically significant association was found in the "Experienced, asked for fair treatment, improved" group with poor self-rated health (odd ratios: 0.87, 95% confidence intervals: 0.30-2.53). Conversely, among female workers, a statistically significant association was observed (odd ratios: 2.63, 95% confidence intervals: 1.29-5.38). CONCLUSIONS: This study is the first to find an association between perceived ethnic discrimination and poor self-rated health, along with gender differences in the association between situational improvements after asking for fair treatment and poor self-rated health among Korean Chinese waged workers in South Korea.


Asunto(s)
Autoevaluación Diagnóstica , Estado de Salud , Discriminación Percibida , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , China/etnología , Estudios Transversales , Pueblos del Este de Asia , Racismo , República de Corea , Factores Sexuales , Encuestas y Cuestionarios
4.
Int Arch Occup Environ Health ; 97(2): 199-206, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38172373

RESUMEN

PURPOSE: Workers' health can be influenced by risk factors from their family environments as well as their work environments. This paper sought to examine how the association between long working hours and depressive symptoms differs based on the level of FWC after being stratified by worker's gender. METHODS: We used the dataset of 20,384 full-time wage workers from the sixth Korean Working Conditions Survey (2020). Long working hours were defined as working 52 h or more per week. FWC was measured using a 2-item questionnaire, and depressive symptoms were measured using the WHO-5 well-being index. Applying modified Poisson regression, we evaluated how the association between long working hours and depressive symptoms differs by the level of FWC male and female workers separately. RESULTS: In the analysis of the female workers, long working hours were associated with depressive symptoms in the high FWC group (PR 1.35, 95% CI 1.17, 1.55) after adjusting for potential confounders whereas no association was observed in the low FWC group. Among the male workers, a statistically significant association was observed in both high FWC (PR 1.22, 95% CI 1.07, 1.38) and low FWC (PR 1.28, 95% CI 1.12, 1.47) groups. CONCLUSION: FWC may act as a workplace stressor that potentially amplifies the health impact of long working hours among female workers.


Asunto(s)
Depresión , Conflicto Familiar , Humanos , Masculino , Femenino , Depresión/epidemiología , Encuestas y Cuestionarios , Empleo , Lugar de Trabajo
5.
Sensors (Basel) ; 23(8)2023 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-37112402

RESUMEN

In digital identity authentication, credentials are typically stored in a digital wallet and authenticated through a single key-based signature and public key verification. However, ensuring compatibility between systems and credentials can be challenging and the existing architecture can create a single point of failure, which can hinder system stability and prevent data interchange. To address this problem, we propose a multiparty distributed signature structure using FROST, a Schnorr signature-based threshold signature algorithm, applied to the WACI protocol framework for credential interaction. This approach eliminates a single point of failure and secures the signer's anonymity. Additionally, by following standard interoperability protocol procedures, we can ensure interoperability during the exchange of digital wallets and credentials. This paper presents a method that combines a multiparty distributed signature algorithm and an interoperability protocol, and discusses the implementation results.

6.
J Environ Manage ; 332: 117313, 2023 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-36716541

RESUMEN

Phytoremediation has emerged as an ecofriendly technique to reduce hazardous particulate matter (PM) in the air. Although previous studies have conducted statistical analyses to reveal PM removal capabilities of various plant species according to their leaf characteristics, the underlying physical mechanism of PM adsorption of plants remains unclear. Conventional methodologies for measuring PM accumulation usually require long-term field tests and provide limited understanding on PM removal effects of individual leaf traits of various plants. In this study, we propose a novel methodology which can compare the electrostatic interactions between PMs and plant leaves according to their trichome structures by using digital in-line holographic microscopy (DIHM). Surface characteristics of Perilla frutescens and Capsicum annuum leaves are measured to examine electrostatic effects according to the morphological features of trichomes. 3D settling motions of PMs near the microstructures of trichomes of the two plant species are compared in detail. To validate the PM removal effect of the hairy microstructures, a polydimethylsiloxane (PDMS) replica model of a P. frutescens leaf is fabricated to demonstrate accelerated settling velocities of PMs near trichome-like microstructures. The size and electric charge distributions of PMs with irregular shapes are analyzed using DIHM. Numerical simulation of the PM deposition near a trichome-like structure is conducted to verify the empirical results. As a result, the settling velocities of PMs on P. frutescens leaves and a PDMS replica sample are 12.11 ± 1.88% and 34.06 ± 4.19% faster than those on C. annuum leaves and a flat PDMS sample, respectively. These findings indicate that the curved microstructures of hairy trichomes of plant leaves increase the ability to capture PMs by enhancing the electric field intensity just near trichomes. Compared with conventional methods, the proposed methodology can quantitatively evaluate the settling velocity of PMs on various plant leaves according to the morphological structure and density of trichomes within a short period of time. The present research findings would be widely utilized in the selection of suitable air-purifying plants for sustainable removal of harmful air pollutants in urban and indoor environments.


Asunto(s)
Contaminantes Atmosféricos , Material Particulado , Material Particulado/análisis , Monitoreo del Ambiente/métodos , Contaminantes Atmosféricos/análisis , Plantas , Hojas de la Planta/química
7.
Opt Express ; 30(2): 2487-2502, 2022 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-35209387

RESUMEN

The geometric-phase lens (GPLs) with small form factor compared to traditional refractive lenses has been identified as a compelling solution in augmented-/virtual-/mixed-reality (AR/VR/MR) headsets. Formed either with liquid crystals (LCs) or metasurfaces, the GPL is a type of emerging leading technology that implements the arbitrary aspheric phase to realize low loss and minimal ghosting. However, the inherent chromatic abberation (CA) of GPLs can significantly degrade the image quality. A possible solution is the independent spectral phase implementation for RGB. In this work, we propose the design of three types of multi-twist LC based color-selective GPLs (CS-GPLs), exhibiting highly chromatic efficiency spectra with diameter 30 mm, focal length around 41.2~mm, and F -number 1.37. Through theoretical and experimental validation, each type of CS-GPL manifests high diffraction efficiency (>91%) on respective primary color of orthogonal polarization and high transmission on the complementary color of input polarization. The triplet composed by RGB CS-GPLs demonstrates relative contrast ratio and minimal ghosting. The strong color and polarization dependency of CS-GPLs not only provide a novel technique to mitigate CA but also offer more design freedom in the AR/VR/MR polarization and imaging system.

8.
Nano Lett ; 21(4): 1800-1806, 2021 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-33555879

RESUMEN

Nanoscale electromechanical coupling provides a unique route toward control of mechanical motions and microwave fields in superconducting cavity electromechanical devices. However, conventional devices composed of aluminum have presented severe constraints on their operating conditions due to the low superconducting critical temperature (1.2 K) and magnetic field (0.01 T) of aluminum. To enhance their potential in device applications, we fabricate a superconducting electromechanical device employing niobium and demonstrate a set of cavity electromechanical dynamics, including back-action cooling and amplification, and electromechanically induced reflection at 4.2 K and in strong magnetic fields up to 0.8 T. Niobium-based electromechanical transducers operating at this temperature could potentially be employed to realize compact, nonreciprocal microwave devices in place of conventional isolators and cryogenic amplifiers. Moreover, with their resilience to magnetic fields, niobium devices utilizing the electromechanical back-action effects could be used to study spin-phonon interactions for nanomechanical spin-sensing.

9.
J Prosthet Dent ; 2022 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-35305834

RESUMEN

STATEMENT OF PROBLEM: Digital light processing (DLP) and milling (MIL) are computer-aided design and computer-aided manufacturing (CAD-CAM) systems that have become popular for fabricating definitive complete dentures. However, few studies have compared the accuracy of the ridge laps of diagnostic tooth arrangements fabricated with these systems and their adaptation with the denture base sockets. PURPOSE: The purpose of this in vitro study was to comparatively analyze the accuracy of the ridge laps of the diagnostic tooth arrangements fabricated by using MIL and different layer thicknesses in DLP. MATERIAL AND METHODS: A virtual definitive complete denture was designed with a CAD software program on a scanned virtual digital cast, divided into diagnostic tooth arrangement and a denture base that accommodated the arrangement, and saved as a standard tessellation language (STL) file. From this file, 27 diagnostic tooth arrangements were fabricated by DLP (50 µm and 100 µm) and MIL. The ridge laps were scanned and overlapped on the file (reference data) to analyze the accuracy (trueness and precision). The ridge laps of all groups were overlapped on the reference denture base data to analyze their adaptation with the sockets. The measurements of the trueness, precision, and adaptation were analyzed statistically by using the nonparametric Kruskal-Wallis test and post hoc Mann-Whitney U test with Bonferroni correction. RESULTS: The diagnostic tooth arrangements showed significant differences among the groups (P<.001). The values were the lowest in the MIL group and highest in the DLP group for the following parameters: trueness root-mean-square (RMS) value, 173 ±7 µm versus 286 ±15 µm; precision RMS value, 22 ±3 µm versus 57 ±20 µm; and adaptation RMS value, 41 ±5 µm versus 112 ±13 µm. CONCLUSIONS: Of the 2 diagnostic tooth arrangements fabricated with the CAD-CAM systems, the one fabricated with MIL was clinically more appropriate.

10.
J Prosthet Dent ; 127(1): 108-114, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33239193

RESUMEN

STATEMENT OF PROBLEM: Computer-aided design and computer-aided manufacturing (CAD-CAM) systems are increasingly used to fabricate removable complete dentures. However, comparisons and analyses of the trueness and adaptation of the socketed surface of denture bases produced by milling (MIL) and digital light processing (DLP) are lacking. PURPOSE: The purpose of this in vitro study was to evaluate and compare the trueness and socketed surface adaptation of denture bases fabricated by using additive and subtractive manufacturing. MATERIAL AND METHODS: Based on a denture base standard tessellation language (STL) file, a total of 15 denture bases were produced by using DLP (horizontal and vertical direction) and MIL. The intaglio and cameo surfaces of the fabricated denture bases were scanned with a dental scanner. The scanned intaglio and cameo surfaces were overlapped with the corresponding reference denture base STL file for trueness evaluation. In addition, the ridge lap STL file of the diagnostic tooth arrangement, in which reverse normal was performed, was superimposed on the socketed surface of the denture base of all groups to evaluate adaptation. RESULTS: The root mean square (RMS) values of trueness and adaptation showed statistically significant differences (P<.05). For the trueness RMS value of the intaglio surface of the denture base, the MIL-denture base (MDB) group had the lowest value of 150 ±6 µm, whereas the vertical denture base (VDB) of the DLP group was the largest with 328 ±4 µm. For the trueness RMS value of the cameo surface, the MDB group was the lowest with 50 ±1 µm, whereas the VDB group was the largest with 334 ±24 µm. For the adaptation RMS value of the socketed surface of the denture base, the MDB group was the lowest with 44 µm, whereas the VDB group was the largest with 117 ±2 µm. CONCLUSIONS: Within the limits of this in vitro study, the MDB group showed better trueness and socketed surface adaptation than the DLP groups (HDB and VDB).


Asunto(s)
Bases para Dentadura , Diseño de Dentadura , Diseño Asistido por Computadora , Dentadura Completa , Proyectos de Investigación
11.
J Prosthet Dent ; 127(2): 276-281, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33243469

RESUMEN

STATEMENT OF PROBLEM: A staircase effect is noted in the fabrication of metal frameworks for removable partial dentures (RPDs) when using stereolithography apparatus (SLA). It affects the adaptation of the definitive metal framework depending on the layer thickness setting. However, studies on the effect of the layer thickness setting on the adaptation of metal frameworks are lacking. PURPOSE: The purpose of this in vitro study was to determine the optimal layer thickness through comparative analysis of the adaptation of SLA-fabricated metal frameworks with different layer thickness settings. MATERIAL AND METHODS: A total of 15 metal RPD frameworks were SLA-fabricated by using 3 different layer thickness settings (16 µm, 50 µm, and 100 µm). The adaptation of the frameworks was measured by using the silicone replica technique, sectioned at the canine, first molar, and second molar regions by using a guide. The thickness of the light-body silicone was measured with a digital microscope at 3 points in each of the 3 areas. The measurements of the adaptation were statistically analyzed using the nonparametric Kruskal-Wallis test and post hoc Mann-Whitney U test with Bonferroni correction. RESULTS: The gaps measured in each area showed statistically significant differences in all 3 groups (P<.05). In the anterior, middle, and posterior areas, the 16-µm metal framework group showed the narrowest gaps (207 ±46 µm, 195 ±49 µm, and 188 ±40 µm, respectively). The 3 groups showed statistically significant differences in total gaps in the RPD frameworks relative to the layer thickness settings (P<.05); the total gap was lowest (197 ±42 µm) for the 16-µm group. CONCLUSIONS: For SLA, 50 µm is the recommended layer thickness considering the effect of layer thickness settings on the adaptation of the RPD framework and the fabrication time.


Asunto(s)
Dentadura Parcial Removible , Estereolitografía , Diseño Asistido por Computadora
12.
BMC Psychiatry ; 21(1): 162, 2021 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-33757483

RESUMEN

BACKGROUND: We sought to examine the association between childhood experience of parental death (CEPD) and adulthood suicidal ideation, and the mediating role of adulthood SES in the association. METHODS: We analyzed a nationally representative dataset of 8609 adults from the Korea Welfare Panel Study, which is a longitudinal cohort dataset in South Korea. CEPD was measured using a question: "During your childhood (0-17 years old), have you experienced the death of parents?" We classified responses of CEPD during 2006-2011 into 'yes,' and the others into 'no.' Suicidal ideation over the past year was assessed annually during 2012-2019. As a potential mediator, adulthood educational attainment and household income in 2011 were included in the analysis. Logistic regression was applied to examine the association of CEPD with adulthood suicidal ideation across age groups (early adulthood, 19-39 years old; middle adulthood, 40-59 years old; late adulthood, ≥60 years old), after excluding people who reported lifetime suicidal ideation in 2011. Causal mediation analysis using a parametric regression model was applied to examine the mediating role of adulthood SES in the association between CEPD and adulthood suicidal ideation. RESULTS: After adjusting for potential confounders including childhood SES, CEPD was significantly associated with adulthood suicidal ideation among the late adulthood group (OR: 1.43; 95% CI: 1.13-1.81), while the association was not statistically significant among the early; and middle adulthood groups. In mediation analysis of adulthood household income, both indirect association (ORNIE: 1.05; 95% CI: 1.02-1.09) and direct association (ORNDE: 1.37; 95% CI: 1.09-1.73) were statistically significant among the late adulthood group. In the mediation analysis of adulthood education attainment among the late adulthood, only a direct association was statistically significant (ORNDE: 1.43; 95% CI: 1.14-1.80). CONCLUSIONS: These results suggest that CEPD could be a risk factor for adulthood suicidal ideation. Furthermore, the findings imply that income security policy might be necessary to reduce suicide among the late adulthood group.


Asunto(s)
Muerte Parental , Suicidio , Adolescente , Adulto , Niño , Preescolar , Humanos , Lactante , Recién Nacido , Análisis de Mediación , Persona de Mediana Edad , República de Corea/epidemiología , Factores de Riesgo , Ideación Suicida , Adulto Joven
13.
Int Arch Occup Environ Health ; 94(6): 1405-1413, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33813675

RESUMEN

OBJECTIVES: This study sought to examine whether the experience of occupational injuries was associated with depressive symptoms and whether the rejection of workers' compensation claims was associated with depressive symptoms among Korean firefighters. METHODS: We conducted a nationwide survey of 6793 Korean firefighters in 2015. Based on the experience of occupational injuries and workers' compensation claims over the past year, respondents were classified into four groups: "Not injured", "Injured, not applied", "Injured, applied, but rejected" and "Injured, applied, and accepted." Depressive symptoms over the preceding week were assessed using the 11-item version of the Centers for Epidemiologic Studies Depression Scale. RESULTS: Compared to firefighters who did not get injured, injured firefighters had a higher prevalence of depressive symptoms (PR 2.01, 95% CI 1.83, 2.22) after controlling for confounders including job assignment. Also, when we restricted the analysis to injured firefighters, a higher prevalence of depressive symptoms was observed among "Injured, applied, but rejected" (PR 1.70, 95% CI 1.11, 2.59) group, compared to "Injured, applied, and accepted" group. CONCLUSIONS: This finding suggests that rejection of workers' compensation claims, as well as the experience of occupational injuries, may increase the risk of depressive symptoms among Korean firefighters.


Asunto(s)
Depresión/epidemiología , Bomberos/psicología , Traumatismos Ocupacionales/psicología , Indemnización para Trabajadores/estadística & datos numéricos , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Traumatismos Ocupacionales/economía , Traumatismos Ocupacionales/epidemiología , República de Corea/epidemiología
14.
J Prosthet Dent ; 125(1): 139-145, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32089361

RESUMEN

STATEMENT OF PROBLEM: Layer thickness in additive manufacturing has stair-step effects that greatly affect the accuracy of the definitive prosthesis. Although the layer thickness can be set, insufficient data comparing and analyzing the accuracy of the fabricated prosthesis after adjusting the layer thickness are available. PURPOSE: The purpose of this in vitro study was to evaluate and compare the accuracy of trial dentures fabricated with different layer thicknesses by using stereolithography (SLA) apparatus. MATERIAL AND METHODS: A maxillary complete edentulous cast was duplicated with silicone material to make a master gypsum cast which was scanned by using a laboratory scanner and saved as a standard tessellation language (STL) file. This was exported into a computer-aided design software program to produce and store the trial denture. Twenty dentures were fabricated according to the set layer thicknesses (50 µm and 100 µm) by using the SLA. The trueness was measured by scanning the intaglio and cameo surfaces to find the best overlap with the reference model to obtain the root mean square value. The precision was evaluated based on the RMS value gained by superimposing the identical scan data from each group and using the combination formula. The Mann-Whitney U-test was used to confirm significant differences among the groups (α=.05). RESULTS: The trueness of the 50-µm-SLA trial denture and the 100-µm-SLA trial denture was significantly different for the intaglio and cameo surfaces (P<.05). However, the intaglio surface did not show a statistically significant difference (P=.987) for precision, but the cameo surface did (P<.05). CONCLUSIONS: It is clinically more appropriate to set the layer thickness to 100 µm rather than 50 µm for the fabrication of accurate trial dentures by using SLA.


Asunto(s)
Diseño Asistido por Computadora , Maxilar , Dentaduras , Estereolitografía
15.
J Prosthet Dent ; 125(3): 479-485, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32276824

RESUMEN

STATEMENT OF PROBLEM: Conventional fabrication of complete denture metal bases is being replaced by the computer-aided design and computer-aided manufacturing (CAD-CAM) systems. However, a comparative analysis of subtractive and additive CAD-CAM manufacturing techniques is lacking. PURPOSE: The purpose of this in vitro study was to compare the adaptation of complete denture metal bases fabricated by milling (subtractive manufacturing) and stereolithography apparatus (SLA) and digital light processing (DLP) (additive manufacturing). MATERIAL AND METHODS: Thirty metal bases were manufactured by using the milling (MIL group), SLA (SLA group), and DLP (DLP group) techniques. The silicone replica technique was used to evaluate the adaptation of the complete denture metal bases, and 30 silicone blocks were fabricated. The silicone block was cut equally in the canine, first molar, and second molar areas. The gap between the model and the metal base was measured by using a digital microscope at the 3 locations, and the measured data were statistically analyzed by using a statistical software program (α=.05). RESULTS: The gaps measured at the 3 areas showed significant differences in all 3 groups (P<.05). At the anterior, middle, and posterior areas, the SLA group showed the narrowest gap (302 ±31 µm, 241 ±39 µm, 201 ±43 µm, respectively). The SLA group also had the narrowest total gap of the metal bases (218 ±33 µm). CONCLUSIONS: The adaptation of the fabricated metal bases varied significantly across the techniques used but fell within a clinically allowable range. The SLA group was the most precise in the fabrication of complete denture metal bases. Further studies are required to analyze the effects of the layer thickness setting, wax elimination, and casting temperature on the adaptation of metal bases manufactured by using SLA.


Asunto(s)
Diseño Asistido por Computadora , Dentadura Completa , Adaptación Marginal Dental , Diseño de Prótesis Dental , Bases para Dentadura , Estereolitografía
16.
Opt Express ; 28(16): 23569-23583, 2020 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-32752351

RESUMEN

Plenty of issues on quantal features in chaotic systems have been raised since chaos was accepted as one of the intrinsic properties of nature. Through intensive studies, it was revealed that resonance spectra in chaotic systems exhibit complicated structures, which is deeply concerned with sophisticated resonance dynamics. Motivated by these phenomena, we investigate light absorption characteristics of chaotic nanowires in an array. According to our results, a chaotic cross-section of a nanowire induces a remarkable augmentation of absorption channels, that is, an increasing number of absorption modes leads to substantial light absorption enhancement, as the deformation of cross-section increases. We experimentally demonstrate the light absorption enhancement with free-standing Si-nanowire polydimethylsiloxane (PDMS) composites. Our results are applicable not only to transparent solar cells but also to complementary metal-oxide-semiconductor (CMOS) image sensors to maximize absorption efficiency.

18.
J Prosthet Dent ; 123(1): 135-142, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31027960

RESUMEN

STATEMENT OF PROBLEM: Three-dimensional (3D)-printed casts are used successfully as diagnostic casts in orthodontics. However, whether 3D-printed casts are sufficiently accurate to be used as definitive casts for fixed dental prostheses (FDPs) is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the fit of 3-unit FDPs fabricated on 3D-printed casts made by digital light processing and to investigate the clinical applicability of 3D printing. MATERIAL AND METHODS: A master model was fabricated from epoxy resin. Stone casts were made from dual viscosity impressions (conventional stone cast [CS] group, n=10). The 3D-printed casts were fabricated using a 3D printer after obtaining digital virtual casts by digital scans (3D-printed cast [3DP] group, n=10). All FDPs were fabricated with a 5-axis milling machine. The master model and intaglio surface of the milled FDPs was superimposed using 3D analysis software to measure the accuracy. Two-way ANOVA was performed to identify a significant difference between the groups (3DP and CS) and sides (pontic side, nonpontic side) and their interactive effects (α=.05). The Tukey honestly significant difference test was used for post hoc analysis. RESULTS: Two-way ANOVA showed significant differences between the 2 groups (3DP and CS) in the marginal and internal root mean square (RMS) values (P<.001). However, no significant difference was found in the marginal RMS values (P=.762) between the pontic and nonpontic sides. The 3DP showed significantly higher RMS values than the CS (P<.001). CONCLUSIONS: The fit of FDPs produced from 3D-printed casts was inferior to that of conventional stone casts; however, all FDPs showed clinically acceptable accuracy. These results suggest that 3D-printed casts have clinical applicability but that further improvement of the 3D printer is necessary for their application in prosthodontics.


Asunto(s)
Técnica de Impresión Dental , Modelos Dentales , Diseño Asistido por Computadora , Diseño de Prótesis Dental , Dentadura Parcial Fija , Impresión Tridimensional
19.
BMC Oral Health ; 20(1): 157, 2020 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-32487153

RESUMEN

BACKGROUND: Three-dimensional (3D) printing is widely used in the fabrication of dental prostheses; however, the influence of dental materials used for 3D printing on temporary restoration of fibroblasts in tissues is unclear. Thus, the influence of different dental materials on fibroblasts were investigated. METHODS: Digital light processing (DLP) type 3D printing was used. Specimens in the control group were fabricated by mixing liquid and powder self-curing resin restoration materials. The temporary resin materials used were Model, Castable, Clear-SG, Tray, and Temporary, and the self-curing resin materials used were Lang dental, Alike, Milky blue, TOKVSO CUREFAST, and UniFast III. Fibroblast cells were cultured on each specimen and subsequently post-treated for analysis. Morphology of the adhered cells were observed using a confocal laser scanning microscope (CLSM) and a scanning electron microscope (SEM). RESULTS: CLSM and SEM cell imaging revealed that the 3D printed material group presented better cell adhesion with well-distributed filopodia compared to that in the conventional resin material group. Cell proliferation was significantly higher in the 3D printing materials. CONCLUSION: Superior cytocompatibility of the specimens fabricated through 3D printing and polishing process was demonstrated with the proof of better cell adhesion and higher cell proliferation.


Asunto(s)
Resinas Compuestas , Materiales Dentales , Impresión Tridimensional , Fibroblastos , Humanos , Ensayo de Materiales , Propiedades de Superficie
20.
Am J Ind Med ; 62(1): 74-79, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30507041

RESUMEN

BACKGROUND: Emergency medical service (EMS) providers may face sexual harassment (SH) from citizens. No studies have assessed SH prevalence and its association with depressive symptoms among EMS providers in South Korea. METHODS: We conducted a nationwide cross-sectional survey of 1346 EMS providers in South Korea. SH experience was assessed by asking, "During the past 12 months, have you ever experienced sexual harassment on duty by civil citizens?" Depressive symptoms during the preceding week were assessed using the Centers for Epidemiologic Studies Depression Scale. Modified Poisson regression was applied to examine association between SH and depressive symptoms. RESULTS: Among EMS providers, 28.1% of females and 5.6% of males reported sexual harassment. In the gender-stratified analysis, EMS providers those who experienced SH were more likely to have depressive symptoms among females (PR: 2.97, 95% CI: 1.99, 4.44) and males (PR: 2.01, 95% CI: 1.41, 2.86). CONCLUSIONS: Female EMS providers were about five times more likely to experience SH than males.


Asunto(s)
Depresión/epidemiología , Depresión/psicología , Auxiliares de Urgencia/psicología , Acoso Sexual/psicología , Acoso Sexual/estadística & datos numéricos , Adulto , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis de Regresión , República de Corea/epidemiología , Distribución por Sexo , Adulto Joven
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