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1.
Int J Eat Disord ; 55(1): 108-119, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34761436

RESUMEN

OBJECTIVE: To characterize helpful parent feeding strategies using reflections on childhood eating experiences of adults with symptoms of Avoidant/Restrictive Food Intake Disorder (ARFID). METHOD: We explored a unique text-based dataset gathered from a population of N = 19,239 self-identified adult "picky eaters." The sample included adults with symptoms of ARFID as evidenced by marked interference in psychosocial functioning, weight loss/sustained low weight, and/or nutritional deficiency (likely ARFID), and non-ARFID participants. We leveraged state-of-the-art natural language processing (NLP) methods to classify feeding strategies that were perceived as helpful or not helpful. The best classifiers that distinguished helpful approaches were further analyzed using qualitative coding according to a grounded theory approach. RESULTS: NLP reliably and accurately classified the perceived helpfulness of caregivers' feeding strategies (82%) and provided information about features of helpful parent strategies using recollections of adults with varying degrees of food avoidance. Strategies perceived as forceful were regarded as not helpful. Positive and encouraging strategies were perceived as helpful in improving attitudes toward food and minimizing social discomfort around eating. Although food variety improved, adults still struggled with a degree of avoidance/restriction. DISCUSSION: Adults perceived that positive parent feeding strategies were helpful even though they continued to experience some degree of food avoidance. Creating a positive emotional context surrounding food and eating with others may help to eliminate psychosocial impairment and increase food approach in those with severe food avoidance. Nevertheless, additional tools to optimize parent strategies and improve individuals' capacity to incorporate avoided foods and cope with challenging eating situations are needed.


Asunto(s)
Trastorno de la Ingesta Alimentaria Evitativa/Restrictiva , Trastornos de Alimentación y de la Ingestión de Alimentos , Adulto , Niño , Ingestión de Alimentos , Alimentos , Humanos , Padres , Estudios Retrospectivos
2.
J Cell Physiol ; 236(1): 480-488, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32537777

RESUMEN

Tooth root development occurs through the interaction of multiple growth factors and transcription factors expressed in Hertwig's epithelial root sheath (HERS) and dental mesenchyme. Previously, we demonstrated that bobby sox homolog (Bbx) regulates odontoblast differentiation of human dental pulp stem cells. Here, we generated Bbx knockout (Bbx-/- ) mice to address the functional role of Bbx in tooth formation. During tooth development, Bbx was expressed in both dental epithelium and mesenchyme. However, molar and incisor morphology in Bbx-/- mice at postnatal Day 0 (P0) exhibited no prominent abnormalities compared with their wild-type (Bbx+/+ ) littermates. Until P28, the crown morphology in Bbx-/- mice was not distinctively different from Bbx+/+ littermates. Meanwhile, the length of the mandibular base in Bbx-/- mice was notably less at P28. Compared with Bbx+/+ mice, the mesial and distal root lengths of the first molar were reduced by 21.33% and 16.28% at P14 and 16.28% and 16.24% at P28, respectively, in Bbx-/- mice. The second molar of Bbx-/- mice also showed 10.16% and 6.4% reductions at P28 in the mesial and distal lengths, compared with Bbx+/+ mice, respectively. The gene expression analysis during early tooth root formation (P13) showed that the expression of dentin sialophosphoprotein (Dspp) was significantly decreased in Bbx-/- mice. Collectively, our data suggest that Bbx participates in tooth root formation and might be associated with the regulation of Dspp expression.


Asunto(s)
Dentina/metabolismo , Proteínas de la Matriz Extracelular/metabolismo , Diente Molar/metabolismo , Odontogénesis/fisiología , Fosfoproteínas/metabolismo , Sialoglicoproteínas/metabolismo , Raíz del Diente/crecimiento & desarrollo , Raíz del Diente/metabolismo , Animales , Diferenciación Celular/fisiología , Proliferación Celular/fisiología , Epitelio/metabolismo , Femenino , Masculino , Mesodermo/metabolismo , Ratones , Ratones Transgénicos , Diente Molar/crecimiento & desarrollo , Odontoblastos/metabolismo , Factores de Transcripción/metabolismo
3.
Biochem J ; 475(10): 1687-1699, 2018 05 18.
Artículo en Inglés | MEDLINE | ID: mdl-29669911

RESUMEN

Mitochondrial pyruvate carrier (MPC), which is essential for mitochondrial pyruvate usage, mediates the transport of cytosolic pyruvate into mitochondria. Low MPC expression is associated with various cancers, and functionally associated with glycolytic metabolism and stemness. However, the mechanism by which MPC expression is regulated is largely unknown. In this study, we showed that MPC1 is down-regulated in human renal cell carcinoma (RCC) due to strong suppression of peroxisome proliferator-activated receptor-gamma co-activator (PGC)-1 alpha (PGC-1α). We also demonstrated that overexpression of PGC-1α stimulates MPC1 transcription, while depletion of PGC-1α by siRNA suppresses MPC expression. We found that PGC-1α interacts with estrogen-related receptor-alpha (ERR-α) and recruits it to the ERR-α response element motif located in the proximal MPC1 promoter, resulting in efficient activation of MPC1 expression. Furthermore, the MPC inhibitor, UK5099, blocked PGC-1α-induced pyruvate-dependent mitochondrial oxygen consumption. Taken together, our results suggest that MPC1 is a novel target gene of PGC-1α. In addition, low expression of PGC-1α in human RCC might contribute to the reduced expression of MPC, resulting in impaired mitochondrial respiratory capacity in RCC by limiting the transport of pyruvate into the mitochondrial matrix.


Asunto(s)
Carcinoma de Células Renales/metabolismo , Regulación Neoplásica de la Expresión Génica , Mitocondrias/fisiología , Proteínas de Transporte de Membrana Mitocondrial/genética , Consumo de Oxígeno , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/metabolismo , Carcinoma de Células Renales/genética , Carcinoma de Células Renales/patología , Metabolismo Energético , Humanos , Neoplasias Renales/genética , Neoplasias Renales/metabolismo , Neoplasias Renales/patología , Proteínas de Transporte de Membrana Mitocondrial/metabolismo , Transportadores de Ácidos Monocarboxílicos , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/genética , Regiones Promotoras Genéticas , Ácido Pirúvico/metabolismo , Elementos de Respuesta , Factores de Transcripción , Células Tumorales Cultivadas
4.
Strahlenther Onkol ; 191(4): 321-9, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25339310

RESUMEN

PURPOSE: We retrospectively compared the treatment outcomes of localized prostate cancer between radical prostatectomy (RP) and external beam radiotherapy (EBRT). MATERIALS AND METHODS: We retrospectively analyzed 738 patients with localized prostate cancer who underwent either RP (n = 549) or EBRT (n = 189) with curative intent at our institution between March 2001 and December 2011. Biochemical failure was defined as a prostate-specific antigen (PSA) level of ≥ 0.2 ng/ml in the RP group and the nadir of + ≥ 2 ng/ml in the EBRT group. RESULTS: The median (range) follow-up duration was 48.8 months (0.7-133.2 months) and 48.7 months (1.0-134.8 months) and the median age was 66 years (45-89 years) and 71 years (51-84 years; p < 0.001) in the RP and EBRT groups, respectively. Overall, 21, 42, and 36 % of patients in the RP group, and 15, 27, and 58 % of patients in the EBRT group were classified as low, intermediate, and high risk, respectively (p < 0.001). Androgen-deprivation therapy was more common in the EBRT group (59 vs. 27 %, respectively; p < 0.001). The 8-year biochemical failure-free survival rates were 44 and 72 % (p < 0.001) and the disease-specific survival rates were 98 % and 97 % (p = 0.543) in the RP and EBRT groups, respectively. CONCLUSIONS: Although the EBRT group included more high-risk patients than did the RP group, the outcomes of EBRT were not inferior to those of RP. Our data suggest that EBRT is a viable alternative to RP for treating localized prostate cancer.


Asunto(s)
Recurrencia Local de Neoplasia/prevención & control , Prostatectomía/métodos , Neoplasias de la Próstata/diagnóstico , Neoplasias de la Próstata/terapia , Radioterapia Conformacional/métodos , Anciano , Anciano de 80 o más Años , Supervivencia sin Enfermedad , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/diagnóstico , Estudios Retrospectivos , Resultado del Tratamiento
5.
J Nanosci Nanotechnol ; 15(7): 4851-4, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26373046

RESUMEN

Self-assembled monolayers of thiols (RSH), which are key elements in nanoscience and nanotechnology, have been used to link a range of materials to planar gold surfaces or gold nanoparticles. In this study, the adhesive performance of mercapto silane systems to dental noble metal alloys was evaluated in vitro and compared with that of commercial dental primers. Dental gold-palladium-platinum (Au-Pd-Pt), gold-palladium-silver (Au-Pd-Ag), and palladium-silver (Pd-Ag) alloys were used as the bonding substrates after air-abrasion (sandblasting). One of the following primers was applied to each alloy: (1) no primer treatment (control), (2) three commer- cial primers: V-Primer, Metal Primer II, and M.L. Primer, and (3) two experimental silane primer systems: 2-step application with 3-mercaptopropyltrimethoxysilane (SPS) (1.0 wt%) and then 3-methacryloxypropyltrimethoxysilane (MPS) (1.0 wt%), and a silane blend consisting of SPS and MPS (both 1.0 wt%). Composite resin cylinders with a diameter of 2.38 mm were bonded to the surfaces and irradiated for 40 sec using a curing light. After storage in water at 37 °C for 24 h, all the bonded specimens were thermocycled 5000 times before the shear bond strength test. Regardless of the alloy type, the mercapto silane systems (both the 2-step and blend systems) consistently showed superior bonding performance than the commercial primers. Contact angle analysis of the primed surfaces indicated that higher resin bond strengths were produced on more hydrophilic alloy surfaces. These novel mercapto silane systems are a promising alternative for improving resin bonding to dental noble metal alloys.


Asunto(s)
Aleaciones Dentales/química , Resinas Sintéticas/química , Silanos/química , Compuestos de Sulfhidrilo/química , Oro/química , Paladio/química , Platino (Metal)/química
6.
Eur J Orthod ; 37(5): 550-5, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25548147

RESUMEN

OBJECTIVE: To test the null hypothesis that neither the flexural properties of orthodontic adhesive resins nor the enamel pre-treatment methods would affect metal bracket debonding behaviours, including enamel fracture. MATERIALS AND METHODS: A dimethacrylate-based resin (Transbond XT, TX) and two methyl methacrylate (MMA)-based resins (Super-Bond C&B, SB; an experimental light-cured resin, EXP) were tested. Flexural strength and flexural modulus for each resin were measured by a three-point-bending test. Metal brackets were bonded to human enamel pretreated with total-etch (TE) or self-etch adhesive using one of the three resins (a total of six groups, n = 15). After 24 hours of storage in water at 37°C, a shear bond strength (SBS) test was performed using the wire loop method. After debonding, remaining resin on the enamel surfaces and occurrence of enamel fracture were assessed. Statistical significance was set at P < 0.05. RESULTS: The two MMA resins exhibited substantially lower flexural strength and modulus values than the TX resin. The mean SBS values of all groups (10.15-11.09MPa) were statistically equivalent to one another (P > 0.05), except for the TE-TX group (13.51MPa, P < 0.05). The two EXP groups showed less resin remnant. Only in the two TX groups were enamel fractures observed (three cases for each group). LIMITATIONS: The results were drawn only from ex vivo experiments. CONCLUSIONS: The hypothesis is rejected. This study suggests that a more flexible MMA resin is favourable for avoiding enamel fracture during metal bracket debonding.


Asunto(s)
Desconsolidación Dental/efectos adversos , Esmalte Dental/lesiones , Soportes Ortodóncicos , Cementos de Resina/química , Fracturas de los Dientes/etiología , Grabado Ácido Dental/métodos , Compuestos de Boro/química , Resinas Compuestas/química , Aleaciones Dentales/química , Análisis del Estrés Dental , Módulo de Elasticidad , Humanos , Ensayo de Materiales , Metacrilatos/química , Metilmetacrilatos/química , Docilidad , Polimetil Metacrilato/química , Distribución Aleatoria , Resistencia al Corte , Estrés Mecánico , Propiedades de Superficie , Temperatura , Factores de Tiempo , Agua/química
7.
Acta Odontol Scand ; 72(8): 954-62, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24922092

RESUMEN

OBJECTIVE: This study investigated the effect of different drying methods of dentin surface on the bonding efficacy of self-adhesive resin cements (SRCs). MATERIALS AND METHODS: Three SRCs (RelyX U200, RU; Maxcem Elite, ME; and BisCem, BC) and one resin-modified glass ionomer cement (RelyX Luting 2, RL) were used. The characteristics of the materials were evaluated using thermogravimetric analysis and surface roughness and contact angle measurements. Human dentin surfaces were finished with 600-grit silicon carbide paper and assigned to three groups according to these drying methods: ethanol dehydration, drying by waiting for 10 s after blot-drying and blot-drying. The four cements were used for luting composite overlays to the dried dentin. After 24 h storage at 37°C and 100% relative humidity, stick-shaped specimens with a cross-sectional area of 0.8 mm(2) were prepared and stressed to failure in tension at a crosshead speed of 0.5 mm/min (n = 27). Failure modes of fractured specimens were assessed by optical and scanning electron microscopy. RESULTS: RL was the most hydrophilic, followed by BC and ME and then RU. All the luting cements luted to ethanol-dehydrated dentin showed zero bond strengths. For the three SRCs, drying by waiting produced higher microtensile bond strengths than blot-drying. RU showed the best bonding performance in the above two dentin conditions. RL showed significantly higher bond strength in blot-drying condition than in drying-by-waiting (p < 0.001). CONCLUSIONS: This study suggests that dentin surface moisture has a crucial effect on the bond strength of SRCs.


Asunto(s)
Recubrimiento Dental Adhesivo , Dentina/ultraestructura , Cementos de Resina/química , Resinas Compuestas/química , Materiales Dentales/química , Análisis del Estrés Dental/instrumentación , Recubrimientos Dentinarios/química , Desecación , Etanol/química , Cementos de Ionómero Vítreo/química , Humanos , Humedad , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Solventes/química , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Estrés Mecánico , Propiedades de Superficie , Temperatura , Resistencia a la Tracción , Factores de Tiempo , Humectabilidad
8.
J Adv Prosthodont ; 16(2): 105-114, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38694193

RESUMEN

PURPOSE: This study aimed to evaluate the effect of pretreatment of three different universal adhesives (Single Bond Universal [SBU], All-Bond Universal [ABU], and Prime&Bond universal [PBU]) on the bonding durability of an adhesive (Panavia F 2.0, PF) and a conventional (Duo-Link, DL) resin cements to air-abraded zirconia. MATERIALS AND METHODS: Rectangular-shaped zirconia specimens were prepared. The chemical composition and surface energy parameters of the materials were studied by Fourier transform infrared spectroscopy and contact angle measurement, respectively. To evaluate resin bonding to the zirconia, all the bonding specimens were immersed in water for 24 h and the specimens to be aged were additionally thermocycled 10000 times before the shear bond strength (SBS) test. RESULTS: The materials showed different surface energy parameters, including the degree of hydrophilicity/hydrophobicity. While the DL/CON (no pretreatment) showed the lowest SBS and a significant decrease in the value after thermocycling (P < .001), the PF/CON obtained a higher SBS value than the DL/CON (P < .001) and no decrease even after thermocycling (P = .839). When the universal adhesives were used with DL, their SBS values were higher than the CON (P < .05), but the trend was adhesive-specific. In conjunction with PF, the PF/SBU produced the highest SBS followed by the PF/ABU (P = .002), showing no significant decrease after thermocycling (P > .05). The initial SBS of the PF/PBU was similar to the PF/CON (P = .999), but the value decreased after thermocycling (P < .001). CONCLUSION: The universal adhesive pretreatment did not necessarily show a synergistic effect on the bonding performance of an adhesive resin cement, whereas the pretreatment was beneficial to bond strength and durability of a conventional resin cement.

9.
J Adhes Dent ; 15(5): 453-9, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23560261

RESUMEN

PURPOSE: To investigate the chemical polymerization kinetics of commercial dual-curing adhesive systems when used solely or in conjunction with chemically-curing resin cement. MATERIALS AND METHODS: Four adhesive systems comprising simplified-step adhesives and activators (Prime&Bond NT with Self Cure Activator, Excite DSC, AQ Bond Plus, All-Bond SE) were used. The pH values of the adhesives and adhesive/activator blends were measured. Differential scanning calorimetry (DSC) was used to investigate the extent of the chemical polymerization of the adhesives when used alone or directly intermixed with a chemically-cured resin cement (C&B Cement) for 60 min (n = 5). The data derived from the DSC analysis were statistically compared using one-way ANOVA and the Games-Howell post-hoc test (α = 0.05). RESULTS: All the adhesives were highly acidic; when they were blended with the respective activators, their pH values increased. Neither the adhesive/activator blends nor the adhesive alone/cement mixtures showed any detectable heat generation. The Prime&Bond NT/activator showed delayed heat generation only when intermixed with the catalyst/base paste. The other three adhesive systems produced similar exotherms when intermixed with the catalyst paste alone or with the catalyst/base paste (p > 0.05), but at significantly different maximum rates of polymerization (p < 0.05). Significantly shorter induction periods resulted when AQ Bond Plus and All- Bond SE were intermixed with the catalyst/base paste rather than with the catalyst paste alone (p = 0.004). CONCLUSION: The chemical polymerization occurring at the adhesive system/resin cement interface appears highly dependent on the adhesive system used and may be considerably delayed.


Asunto(s)
Cementos de Resina/química , Auto-Curación de Resinas Dentales/métodos , Rastreo Diferencial de Calorimetría , Resinas Compuestas/química , Recubrimientos Dentinarios/química , Humanos , Concentración de Iones de Hidrógeno , Cinética , Ensayo de Materiales , Metacrilatos/química , Polimerizacion , Ácidos Polimetacrílicos/química , Temperatura , Factores de Tiempo
10.
Biosci Biotechnol Biochem ; 76(3): 581-4, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22451404

RESUMEN

Based on the broad-spectrum antiviral effect of green tea catechins, we established an experimental skin contact model for influenza virus transmission and evaluated the use of a green tea solution as a first-hand disinfectant. The infectivity of the virus on the skin cell layer became obsolete when washed with the green tea solution. The skin contact model could be applied to develop non-pharmaceutical intervention measures for reducing human transmission of the influenza virus.


Asunto(s)
Antivirales/farmacología , Camellia sinensis/química , Desinfección de las Manos/métodos , Extractos Vegetales/farmacología , Animales , Línea Celular , Transmisión de Enfermedad Infecciosa/prevención & control , Perros , Humanos , Subtipo H1N1 del Virus de la Influenza A/efectos de los fármacos , Subtipo H3N2 del Virus de la Influenza A/efectos de los fármacos , Subtipo H5N2 del Virus de la Influenza A/efectos de los fármacos , Piel/virología , Soluciones
11.
ACS Nano ; 16(1): 1208-1219, 2022 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-35020369

RESUMEN

When we touch an object, thermosensation allows us to perceive not only the temperature but also wetness and types of materials with different thermophysical properties (i.e., thermal conductivity and heat capacity) of objects. Emulation of such sensory abilities is important in robots, wearables, and haptic interfaces, but it is challenging because they are not directly perceptible sensations but rather learned abilities via sensory experiences. Emulating the thermosensation of human skin, we introduce an artificial thermosensation based on an intelligent thermo-/calorimeter (TCM) that can objectively differentiate types of contact materials and solvents with different thermophysical properties. We demonstrate a TCM based on pyroresistive composites with ultrahigh sensitivity (11.2% °C-1) and high accuracy (<0.1 °C) by precisely controlling the melt-induced volume expansion of a semicrystalline polymer, as well as the negative temperature coefficient of reduced graphene oxide. In addition, the ultrathin TCM with coplanar electrode design shows deformation-insensitive temperature sensing, facilitating wearable skin temperature monitoring with accuracy higher than a commercial thermometer. Moreover, the TCM with a high pyroresistivity can objectively differentiate types of contact materials and solvents with different thermophysical properties. In a proof-of-principle application, our intelligent TCM, coupled with a machine-learning algorithm, enables objective evaluation of the thermal attributes (coolness and wetness) of skincare products.


Asunto(s)
Grafito , Humanos , Grafito/química , Solventes , Temperatura Cutánea , Tacto , Piel
12.
J Nanosci Nanotechnol ; 21(7): 4046-4050, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-33715742

RESUMEN

Self-assembled nano-layering resulting from interaction of the phosphate functional group of adhesive monomers with zirconia ceramic surface has been proposed. The purpose of this study was to investigate the bond strengths of two adhesive resin cements (Panavia F 2.0 and BisCem) containing phosphate monomers added with various concentrations (0.0, 1.0, 3.0, and 5.0 wt%) of triethylene glycol dimethacrylate (TEGDMA) to air-abraded zirconia ceramic. The polished/air-abraded zirconia plates (KaVo Everest® ZS-Ronde) were imaged using atomic force microscopy and the average surface roughness (Ra) values were calculated (n = 5). The surface energy parameters of the zirconia plates and the resin cements were calculated based on the extended Fowkes theory. All resin-bonded (diameter: 2.38 mm) zirconia specimens were stored in water at 37 °C for 24 h and then half of them additionally thermocycled 10,000 times before the shear bond strength (SBS) test (n = 10). Air-abrasion of zirconia surface significantly increased the γhS (hydrogen bonding component) value (p < 0.001), as well as greatly increasing the surface area (p < 0.001). For both resin cements, the γhS (dipole-dipole component) gradually increased with increasing incorporated TEGDMA concentrations, whereas the γhS gradually decreased. Overall, the addition of 3.0 wt% of TEGDMA consistently resulted in higher SBS values even after thermocycling. Under the tested condition, reducing the concentration of the adhesive monomers with phosphate functional group by adding the dimethacrylate monomer (up to 3.0 wt%) increased the bond strength between the resin cements and zirconia ceramic.


Asunto(s)
Recubrimiento Dental Adhesivo , Cementos de Resina , Adhesivos , Cerámica , Ensayo de Materiales , Resistencia al Corte , Propiedades de Superficie , Circonio
13.
J Nanosci Nanotechnol ; 21(9): 4959-4963, 2021 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-33691899

RESUMEN

Self-assembled nano-layering resulting from combined ionic and hydrogen-bonding interactions of phosphate functional monomers with zirconia have been proposed. The purpose of this study was to investigate the bond strengths of two phosphate monomer-containing adhesive resin cements (Panavia F 2.0 and RelyX U200) to a conventional tetragonal zirconia (Lava Plus, LP) and a new cubic zirconia (Lava Esthetic, LE), with three different shade zones, after air-abrasion. The structures of the zirconia surfaces were examined with scanning electron microscopy (SEM) and X-ray diffractometry (XRD). Vickers hardness and fracture toughness of the surfaces were also evaluated using a hardness tester. After air-abrasion (with 50 µm Al2O3 at a pressure of 0.25 MPa), the surface roughness was measured using confocal laser scanning microscopy (CLSM) and the resin cements were bonded (diameter: 2.38 mm) to the surfaces. All bonded specimens were stored in water at 37 °C for 24 h before performing the shear bond strength (SBS) test (n = 15). In the SEM images, the LP group showed a finer grain size than the LE groups. The XRD patterns confirmed that LP and LE had tetragonal and cubic phases, respectively. Although there were no significant differences in Vickers hardness among the four groups (p = 0.117), the three LE groups revealed inferior fracture toughness to the LP group (p < 0.001). However, neither the surface roughness of the air-abraded zirconia surfaces nor SBS values of each resin cement bonded to them were significantly different (p > 0.05). In conclusion, no significant difference in SBS value was detected between the tetragonal and cubic zirconia within each resin cement used, probably due to the similar surface roughness of the air-abraded zirconia ceramics.


Asunto(s)
Abrasión Dental por Aire , Recubrimiento Dental Adhesivo , Cerámica , Ensayo de Materiales , Resistencia al Corte , Propiedades de Superficie , Circonio
14.
Oper Dent ; 35(2): 203-10, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20420064

RESUMEN

There are few studies available on the post-light activation or post-mix polymerization of dental resin cements as a function of time. This in vitro study evaluated the successive changes in the degree of conversion (DC) and microhardness during polymerization of six commercial resin cements (light-cured [Choice 2, RelyX Veneer], chemical-cured [Multilink, C&B Cement] and dual-cured [Calibra, RelyX ARC]) within the first 24 hours and up to seven days. Resin specimens were prepared for Fourier transform infrared (FTIR) spectroscopy and microhardness testing to determine the DC and Vickers hardness (VH), respectively. The light-cured materials or mixed pastes of the dual-cured materials were irradiated with a light-curing unit (Elipar TriLight) through a precured composite overlay for 40 seconds. The FTIR spectra and microhardness readings were taken at specified times: 1, 2, 5, 10, 15, 30 and 60 minutes; 24 hours and after two days and seven days. According to the FTIR study, most of the curing reaction of Choice 2 and RelyX Veneer occurred within 10 and 30 minutes, respectively. Multilink, C&B Cement and Calibra exhibited gradual increases in the DC up to 24 hours, with no further statistically significant increase (p > 0.05). RelyX ARC attained a DC value within five minutes, similar to that at seven days (p > 0.05). Choice 2 and RelyXARC showed gradual increases in the VH, up to 15 minutes, with no further significant change over the remaining observation time (p > 0.05). For RelyX Veneer, Multilink, C&B Cement and Calibra, there were no significant increases in the VH value after 24 hours (p > 0.05). The light-cured materials produced significantly higher DC values than the chemical-cured materials (p < 0.05). The DC values of the two dual-cured resin cements were significantly different from each other (p < 0.001). The results suggest that the significant polymerization reaction was finished within 24 hours post-mix or post-light activation for all resin cements tested.


Asunto(s)
Curación por Luz de Adhesivos Dentales , Cementos de Resina/química , Auto-Curación de Resinas Dentales , Resinas Compuestas , Restauración Dental Permanente , Análisis del Estrés Dental , Dureza , Ensayo de Materiales , Transición de Fase , Cementos de Resina/efectos de la radiación , Espectroscopía Infrarroja por Transformada de Fourier , Factores de Tiempo
15.
Materials (Basel) ; 13(2)2020 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-31936423

RESUMEN

The purpose of this study was to evaluate whether the incorporation of an acidic monomer into the pulp-capping material TheraCal LC, which has a weak dentin bonding, increases the shear bond strength (SBS) to dentin. Di-2-hydroxyethyl methacryl hydrogenphosphate was incorporated into the material at 0.0 (TL0, control), 5.0 (TL5), and 10.0 (TL10) wt%. The water contact angle (CA) and mechanical properties for each material were also studied (n = 6). Debonding was performed at two different times (immediate and after 24 h) (n = 12). Hydroxyl and calcium ion releases in water at 37 °C were monitored up to 28 days (n = 6). The addition of the acidic monomer decreased the CAs (p < 0.001) and increased the flexural moduli (p < 0.001). The debonding time did not significantly affect the SBS values (p = 0.600). The TL10 group exhibited the highest SBS values, followed by the TL5 group. The TL10 group released significantly more calcium ions than the other two groups from 3 days (p < 0.05). The incorporation of the acidic monomer at 10.0 wt% into TheraCal LC enhanced bonding to dentin, while not negatively affecting the mechanical properties and ion-leaching capacity of the material.

16.
Materials (Basel) ; 13(24)2020 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-33321769

RESUMEN

The influence of residual stress induced by sandblasting the zirconia ceramic surface on the resin bonding to the ceramic is still unclear. The effect of four different sandblasting conditions (with 50 and 110 µm alumina at pressures of 0.2 and 0.4 MPa) on the bonding of adhesive resin cement (Panavia F 2.0) to zirconia (Cercon® ht) was investigated in terms of residual stress. The surface roughness and water contact angle of the zirconia surfaces were measured. The tetragonal-to-monoclinic (t-m) phase transformation and residual stresses (sin2ψ method) were studied by X-ray diffraction. The resin-bonded zirconia specimens were subjected to shear bond strength (SBS) tests before and after thermocycling (10,000 and 30,000 cycles) (n = 10). As the particle size and pressure increased, the roughness gradually and significantly increased (p = 0.023). However, there were no significant differences in roughness-corrected contact angle among all the sandblasted groups (p > 0.05). As the particle size and pressure increased, the m-phase/(t-phase + m-phase) ratios and compressive residual stresses gradually increased. After thermocycling, there were no significant differences in SBS among the sandblasted zirconia groups (p > 0.05). In conclusion, increased surface roughness and residual stress do not directly affect the resin bonding durability.

17.
J Nanosci Nanotechnol ; 20(9): 5575-5578, 2020 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-32331137

RESUMEN

The adhesion property of zirconia powder-incorporated primers was investigated in vitro with the aim of enhancing the resin bond strength to zirconia ceramic. A commercial zirconia primer was modified through the addition of 0 (control), 5, 10, 25, and 50 wt% of a zirconia powder (codes: ZP0, ZP5, ZP10, ZP25, and ZP50, respectively). Prior to primer modification, the powder was characterized via differential scanning calorimetry (DSC) and Fourier-transform infrared (FTIR) spectrophotometry. The surfaces of dental zirconia ceramic discs were air-abraded and treated with one of the five primers. One resin composite cylinder (diameter: 2.38 mm) was bonded on one specimen surface (n = 12/group). The bonded specimens were all stored for 24 h in distilled water at 37 °C and subjected to 5000 thermal cycles prior to shear bond strength (SBS) testing. The DSC and FTIR analyses confirmed that the zirconia powder contained an organic binder. The SBS test results showed that the groups could be arranged as follows, ZP25 > ZP10 > ZP5 > ZP0, i.e., in descending order of the mean value. The lowest SBS value was obtained for the ZP50 group. The results suggest that the incorporation of a zirconia powder into a primer represents a promising modification method for improving the resin bond strength to zirconia ceramic.

18.
Sci Rep ; 9(1): 14809, 2019 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-31616020

RESUMEN

Bacterial communities in wastewater treatment plants (WWTPs) affect plant functionality through their role in the removal of pollutants from wastewater. Bacterial communities vary extensively based on plant operating conditions and influent characteristics. The capacity of WWTPs can also affect the bacterial community via variations in the organic or nutrient composition of the influent. Despite the importance considering capacity, the characteristics that control bacterial community assembly are largely unknown. In this study, we discovered that bacterial communities in WWTPs in Korea and Vietnam, which differ remarkably in capacity, exhibit unique structures and interactions that are governed mainly by the capacity of WWTPs. Bacterial communities were analysed using 16S rRNA gene sequencing and exhibited clear differences between the two regions, with these differences being most pronounced in activated sludge. We found that capacity contributed the most to bacterial interactions and community structure, whereas other factors had less impact. Co-occurrence network analysis showed that microorganisms from high-capacity WWTPs are more interrelated than those from low-capacity WWTPs, which corresponds to the tighter clustering of bacterial communities in Korea. These results will contribute to the understanding of bacterial community assembly in activated sludge processing.


Asunto(s)
Microbiota/genética , Aguas del Alcantarillado/microbiología , Aguas Residuales/microbiología , Purificación del Agua/estadística & datos numéricos , ADN Bacteriano/aislamiento & purificación , ARN Ribosómico 16S/genética , República de Corea , Vietnam , Purificación del Agua/métodos
19.
Basic Clin Pharmacol Toxicol ; 124(2): 228-234, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30171804

RESUMEN

This study aimed to describe the occurrence and to evaluate the predictive factors of thrombocytopenia caused by parenteral linezolid in hospitalised patients without haemato-oncologic diseases. Using electronic medical records, a retrospective safety evaluation was performed among all hospitalised adult patients who received parenteral linezolid therapy between January 2005 and June 2016. Of all identified 264 patients with an average age of 63.4 (SD 15.8) years, thrombocytopenia occurred at a rate of 29.2% after an average of 11.2 (SD 7.4) days of the initiation of linezolid therapy. Significant predictive factors for thrombocytopenia included the duration of linezolid therapy longer than or equal to 7 days (adjusted odds ratios [ORs] 7.25, 19.51 and 28.80; 95% confidence intervals [CIs] 1.92-27.38, 4.76-79.95 and 6.48-127.92 for 7-13 days, 14-20 days and ≥21 days, respectively; P < 0.01 for all values), baseline platelet count <150 × 103 /mm3 (adjusted OR, 5.08; 95% CI, 2.06-12.55; P < 0.001), creatinine clearance <30 mL/min (adjusted OR, 4.19; 95% CI, 1.59-11.06; P = 0.004) and concurrent low-dose aspirin therapy (adjusted OR, 2.99; 95% CI, 1.26-7.08; P = 0.013). Baseline platelet count less than 150 × 103 /mm3 was an independent predictor of early-onset (≤6 days) thrombocytopenia (adjusted OR, 5.07; 95% CI, 1.46-17.58; P = 0.011). Closer monitoring of platelet count is required in patients who receive parenteral linezolid therapy for 7 days or more, and have low baseline platelet counts or impaired renal function.


Asunto(s)
Linezolid/efectos adversos , Trombocitopenia/inducido químicamente , Adulto , Anciano , Antibacterianos/administración & dosificación , Antibacterianos/efectos adversos , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Recuento de Plaquetas , Insuficiencia Renal/fisiopatología , Estudios Retrospectivos , Factores de Riesgo , Trombocitopenia/sangre , Adulto Joven
20.
Materials (Basel) ; 11(8)2018 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-30044435

RESUMEN

Root canal sealers should have good wetting and adhesion with intraradicular dentin. This study evaluated the wetting and adhesion properties of three bioceramic root canal sealers on dentin using contact angle (CA) measurements and calculations based on the Owens⁻Wendt⁻Rabel⁻Kälble (OWRK) model and compared the properties with those of a resin sealer. Three bioceramic sealers (EndoSequence BC Sealer (BC); Endoseal MTA (EM); and MTA Fillapex (MF)) were tested, together with one epoxy resin-based sealer (AH Plus (AP)). Disc-shaped sealer specimens and human premolar teeth with flat and polished intraradicular dentin surfaces were prepared (n = 12). The CAs of two liquids (water and methylene iodide) were measured on the surfaces using the sessile drop method. The wetting and adhesion properties of the four sealers were calculated using the wetting envelope and isogram diagram, respectively. Group BC showed the best wettability among the four sealer groups. The best adhesion was achieved for group EM, followed by group BC, with a significant difference being present between the two groups (p < 0.05). The OWRK-based calculation indicated that the bioceramic BC and EM sealers showed superior wetting and adhesion properties to the AP sealers.

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