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1.
Small ; : e2312120, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38558528

RESUMEN

The tunable properties of 2D transition-metal dichalcogenide (TMDs) materials are extensively investigated for high-performance and wavelength-tunable optoelectronic applications. However, the precise modification of large-scale systems for practical optoelectronic applications remains a challenge. In this study, a wafer-scale atomic assembly process to produce 2D multinary (binary, ternary, and quaternary) TMDs for broadband photodetection is demonstrated. The large-area growth of homogeneous MoS2, Ni0.06Mo0.26S0.68, and Ni0.1Mo0.9S1.79Se0.21 is carried out using a succinct coating of the single-source precursor and subsequent thermal decomposition combined with thermal evaporation of the chalcogen powder. The optoelectrical properties of the multinary TMDs are dependent on the combination of heteroatoms. The maximum photoresponsivity of the MoS2-, Ni0.06Mo0.26S0.68-, and Ni0.1Mo0.9S1.79Se0.21-based photodetectors is 3.51 × 10-4, 1.48, and 0.9 A W-1 for 532 nm and 0.063, 0.42, and 1.4 A W-1 for 1064 nm, respectively. The devices exhibited excellent photoelectrical properties, which is highly beneficial for visible and near-infrared (NIR) photodetection.

2.
J Pharmacol Exp Ther ; 378(1): 10-19, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33846234

RESUMEN

The secretion of platelet-derived growth factors (PDGFs) into vascular smooth muscle cells (VSMCs) induced by specific stimuli, such as oxidized low-density lipoprotein (LDL) cholesterol, initially increases the proliferation and migration of VSMCs, and continuous stimulation leads to VSMC apoptosis, resulting in the formation of atheroma. Autophagy suppresses VSMC apoptosis, and statins can activate autophagy. Thus, this study aimed to investigate the mechanism of the autophagy-mediated vasoprotective activity of rosuvastatin, one of the most potent statins, in VSMCs continuously stimulated with PDGF-BB, a PDGF isoform, at a high concentration (100 ng/ml) to induce phenotypic switching of VSMC. Rosuvastatin inhibited apoptosis in a concentration-dependent manner by reducing cleaved caspase-3 and interleukin-1ß (IL-1ß) levels and reduced intracellular reactive oxygen species (ROS) levels in PDGF-stimulated VSMCs. It also inhibited PDGF-induced p38 phosphorylation and increased the expression of microtubule-associated protein light chain 3 (LC3) and the conversion of LC3-I to LC3-II in PDGF-stimulated VSMCs. The ability of rosuvastatin to inhibit apoptosis and p38 phosphorylation was suppressed by treatment with 3-methyladenine (an autophagy inhibitor) but promoted by rapamycin (an autophagy activator) treatment. SB203580, a p38 inhibitor, reduced the PDGF-induced increase in intracellular ROS levels and inhibited the formation of cleaved caspase-3, indicating the suppression of apoptosis. In carotid ligation model mice, rosuvastatin decreased the thickness and area of the intima and increased the area of the lumen. In conclusion, our observations suggest that rosuvastatin inhibits p38 phosphorylation through autophagy and subsequently reduces intracellular ROS levels, leading to its vasoprotective activity. SIGNIFICANCE STATEMENT: This study shows the mechanism responsible for the vasoprotective activity of rosuvastatin in vascular smooth muscle cells under prolonged platelet-derived growth factor stimulation. Rosuvastatin inhibits p38 activation through autophagy, thereby suppressing intracellular reactive oxygen species levels, leading to the inhibition of apoptosis and reductions in the intima thickness and area. Overall, these results suggest that rosuvastatin can be used as a novel treatment to manage chronic vascular diseases such as atherosclerosis.


Asunto(s)
Autofagia/efectos de los fármacos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Músculo Liso Vascular/efectos de los fármacos , Factor de Crecimiento Derivado de Plaquetas/toxicidad , Rosuvastatina Cálcica/farmacología , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidores , Animales , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Autofagia/fisiología , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Células Cultivadas , Relación Dosis-Respuesta a Droga , Masculino , Ratones , Ratones Endogámicos C57BL , Músculo Liso Vascular/metabolismo , Ratas , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
3.
Acta Pharmacol Sin ; 42(8): 1311-1323, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32973326

RESUMEN

Propionate is a short-chain fatty acid (SCFA) mainly produced from carbohydrates by gut microbiota. Sodium propionate (SP) has shown to suppress the invasion in G protein-coupled receptor 41 (GPR41) and GPR43-overexpressing breast cancer cells. In this study we investigated the effects of SP on the proliferation, apoptosis, autophagy, and antioxidant production of breast cancer cells. We showed that SP (5-20 mM) dose-dependently inhibited proliferation and induced apoptosis in breast cancer cell lines JIMT-1 (ER-negative and HER2-expressing) and MCF7 (ER-positive type), and this effect was not affected by PTX, thus not mediated by the GPR41 or GPR43 SCFA receptors. Meanwhile, we demonstrated that SP treatment increased autophagic and antioxidant activity in JIMT-1 and MCF7 breast cancer cells, which might be a compensatory mechanism to overcome SP-induced apoptosis, but were not sufficient to overcome SP-mediated suppression of proliferation and induction of apoptosis. We revealed that the anticancer effect of SP was mediated by inhibiting JAK2/STAT3 signaling which led to cell-cycle arrest at G0/G1 phase, and increasing levels of ROS and phosphorylation of p38 MAPK which induced apoptosis. In nude mice bearing JIMT-1 and MCF7 cells xenograft, administration of SP (20 mg/mL in drinking water) significantly suppressed tumor growth by regulating STAT3 and p38 in tumor tissues. These results suggest that SP suppresses proliferation and induces apoptosis in breast cancer cells by inhibiting STAT3, increasing the ROS level and activating p38. Therefore, SP is a candidate therapeutic agent for breast cancer.


Asunto(s)
Antineoplásicos/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Propionatos/uso terapéutico , Animales , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Femenino , Puntos de Control de la Fase G1 del Ciclo Celular/efectos de los fármacos , Humanos , Ratones Desnudos , Propionatos/farmacología , Especies Reactivas de Oxígeno/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto
5.
BMC Ophthalmol ; 19(1): 131, 2019 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-31208393

RESUMEN

BACKGROUND: This study is aim to compare the clinical effectiveness between the two most prominent dry eye disease (DED)-specific eye drops, 0.05% cyclosporine (CN) and 3% diquafosol (DQ). METHODS: This is a multi-centered, randomized, masked, prospective clinical study. A total of 153 DED patients were randomly allocated to use CN twice per day or DQ six times daily. Cornea and conjunctival staining scores (NEI scale), tear break-up time (TBUT), Schirmer test scores, and ocular surface disease index (OSDI) score were measured at baseline, 4 and 12 weeks after treatment. RESULTS: At 12 weeks after treatment, NEI scaled scores were significantly reduced from the baseline by - 6.60 for CN and - 6.63 for DQ group (all P < 0.0001, P = 0.9739 between groups). TBUT and Schirmer values for CN were significantly improved from the baseline at 4 and 12 weeks (P = 0.0034, P < 0.0001 for TBUT, P = 0.0418, P = 0.0031 for Schirmer test). However, for DQ, TBUT showed significant improvement at 12 weeks only (P = 0.0281). Mean OSDI score differences from the baseline to 12 weeks were improved by - 13.03 ± 19.63 for CN and - 16.11 ± 20.87 for DQ, respectively (all P < 0.0001, P = 0.854 between groups). Regarding drug compliance, the mean instillation frequency of CN was less than that of DQ (P < 0.001). There were no statistically significant intergroup differences in safety evaluation. CONCLUSIONS: The level of improvement regarding NEI, TBUT, and OSDI scores were not significantly different between the two treatment groups. However, with regards to the early improvement of TBUT and patient compliance, patients using CN improved faster and with greater adherence to drug usage than did those treated with DQ. TRIAL REGISTRATION: KCT0002180 , retrospectively registered on 23 December 2016.


Asunto(s)
Ciclosporina/uso terapéutico , Síndromes de Ojo Seco/tratamiento farmacológico , Inmunosupresores/uso terapéutico , Soluciones Oftálmicas/uso terapéutico , Polifosfatos/uso terapéutico , Nucleótidos de Uracilo/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Conjuntiva/patología , Femenino , Humanos , Gotas Lubricantes para Ojos/uso terapéutico , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Lágrimas/fisiología , Adulto Joven
6.
BMC Complement Altern Med ; 19(1): 55, 2019 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-30841887

RESUMEN

BACKGROUND: Mulberry is a Korean medicinal herb that shows effective prevention and treatment of obesity and diabetes. Bioconversion is the process of producing active ingredients from natural products using microorganisms or enzymes. METHODS: In this study, we prepared bioconverted mulberry leaf extract (BMLE) with Viscozyme L, which we tested in insulin-sensitive cells (i.e., skeletal muscle cells and adipocytes) and insulin-secreting pancreatic ß-cells, as well as obese diabetic mice induced by co-administration of streptozotocin (100 mg/kg, IP) and nicotinamide (240 mg/kg, IP) and feeding high-fat diet, as compared to unaltered mulberry leaf extract (MLE). RESULTS: BMLE increased the glucose uptake in C2C12 myotubes and 3 T3-L1 adipocytes and increased glucose-stimulated insulin secretion in HIT-T15 pancreatic ß-cells. The fasting blood glucose levels in diabetic mice treated with BMLE or MLE (300 and 600 mg/kg, PO, 7 weeks) were significantly lower than those of the vehicle-treated group. At the same concentration, BMLE-treated mice showed better glucose tolerance than MLE-treated mice. Moreover, the blood concentration of glycated hemoglobin (HbA1C) in mice treated with BMLE was lower than that in the MLE group at the same concentration. Plasma insulin levels in mice treated with BMLE or MLE tended to increase compared to the vehicle-treated group. Treatment with BMLE yielded significant improvements in insulin resistance and insulin sensitivity. CONCLUSION: These results indicate that in the management of diabetic condition, BMLE is superior to unaltered MLE due to at least, in part, high concentrations of maker compounds (trans-caffeic acid and syringaldehyde) in BMLE.


Asunto(s)
Glucemia/efectos de los fármacos , Hipoglucemiantes/farmacología , Morus/química , Extractos Vegetales/farmacología , Animales , Peso Corporal/efectos de los fármacos , Diabetes Mellitus Experimental/sangre , Diabetes Mellitus Experimental/metabolismo , Dieta Alta en Grasa , Hipoglucemiantes/metabolismo , Resistencia a la Insulina/fisiología , Ratones , Ratones Endogámicos C57BL , Extractos Vegetales/metabolismo , Hojas de la Planta/química
7.
Korean J Physiol Pharmacol ; 22(3): 349-360, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29719457

RESUMEN

Autophagy has been studied as a therapeutic strategy for cardiovascular diseases. However, insufficient studies have been reported concerning the influence of vascular smooth muscle cells (VSMCs) through autophagy regulation. The aim of the present study was to determine the effects of VSMCs on the regulation of autophagy under in vitro conditions similar to vascular status of the equipped microtubule target agent-eluting stent and increased release of platelet-derived growth factor-BB (PDGF-BB). Cell viability and proliferation were measured using MTT and cell counting assays. Immunofluorescence using an anti-α-tubulin antibody was performed to determine microtubule dynamic formation. Cell apoptosis was measured by cleavage of caspase-3 using western blot analysis, and by nuclear fragmentation using a fluorescence assay. Autophagy activity was assessed by microtubule-associated protein light chain 3-II (LC-II) using western blot analysis. Levels of intracellular reactive oxygen species (ROS) were measured using H2DCFDA. The proliferation and viability of VSMCs were inhibited by microtubule regulation. Additionally, microtubule-regulated and PDGF-BB-stimulated VSMCs increased the cleavage of caspase-3 more than only the microtubule-regulated condition, similar to that of LC3-II, implying autophagy. Inhibitory autophagy of microtubule-regulated and PDGF-BB-stimulated VSMCs resulted in low viability. However, enhancement of autophagy maintained survival through the reduction of ROS. These results suggest that the apoptosis of conditioned VSMCs is decreased by the blocking generation of ROS via the promotion of autophagy, and proliferation is also inhibited. Thus, promoting autophagy as a therapeutic target for vascular restenosis and atherosclerosis may be a good strategy.

8.
J Nat Prod ; 80(7): 2018-2025, 2017 07 28.
Artículo en Inglés | MEDLINE | ID: mdl-28621938

RESUMEN

The cucurbitaceous plant Momordica charantia L., named "bitter melon", inhabits Asia, Africa, and South America and has been used as a traditional medicine. The atypical proliferation of vascular smooth muscle cells (VSMCs) plays an important role in triggering the pathogenesis of cardiovascular diseases. Platelet-derived growth factor (PDGF) is regarded as the most powerful growth factor in promoting the intimal accumulation of VSMCs. The current study features the identification of six new cucurbitane-type triterpenoids (1-6) from the fruits of M.  charantia, utilizing diverse chromatographic and spectroscopic techniques. In particular, the 2D structure of 1 was confirmed utilizing the long-range HSQMBC NMR pulse, capable of measuring heteronuclear long-range correlations (4-6JCH). The cucurbitanes were also assessed for their inhibitory activity against PDGF-induced VSMC proliferation. This current study may constitute a basis for developing those chemotypes into sensible pharmacophores alleviating cardiovascular disorders.


Asunto(s)
Glicósidos/farmacología , Momordica charantia/química , Músculo Liso Vascular , Factor de Crecimiento Derivado de Plaquetas/farmacología , Triterpenos/farmacología , Animales , Frutas/química , Glicósidos/química , Humanos , Estructura Molecular , Músculo Liso Vascular/efectos de los fármacos , Músculo Liso Vascular/metabolismo , Resonancia Magnética Nuclear Biomolecular , Ratas , Ratas Sprague-Dawley , República de Corea , Triterpenos/química
9.
BMC Cancer ; 16: 60, 2016 02 04.
Artículo en Inglés | MEDLINE | ID: mdl-26846663

RESUMEN

BACKGROUND: Aberrant TGF-ß1 signaling is suggested to be involved in gastric carcinogenesis. However, the role of TGF-ß1 in intestinal-type [i-GC] and diffuse-type [d-GC] gastric cancer remains largely unknown. In this study, we evaluated the expression of TGF-ß1 signaling molecules and compared the clinicopathological features of i-GC and d-GC. METHODS: Patients (n=365, consecutive) who underwent curative gastrectomy for gastric adenocarcinoma in 2005 were enrolled. We performed immunohistochemical staining of TGF-ß1, TGF-ß1 receptor-2 (TßR2), Smad4, p-ERK1/2, TGF-activated kinase (TAK)1, and p-Akt in 68 paraffin-embedded tumor blocks (33 i-GC and 35 d-GC), scored the expression according to the extent of staining, and evaluated differences between the histologic subtypes. RESULTS: Patients with d-GC differed from those with i-GC as follows: younger and more likely to be female; more aggressive stage; higher recurrence rate. The expression of TGF-ß1 and TßR2 was higher in i-GC (P = 0.05 and P <0.001, respectively). The expression of Smad4, a representative molecule of the Smad-dependent pathway, was decreased in both subtypes. TAK1 and p-Akt, two major molecules involved in the Smad-independent pathway, were over-expressed (69 ~87% of cases stained), without a statistically significant difference between i-GC and d-GC. Of note, the expression of p-ERK1/2, a Smad-independent pathway, was significantly increased in i-GC (P = 0.008). CONCLUSIONS: The clinicopathological characteristics vary in different histologic gastric cancer subtypes. Although TGF-ß1 signaling in gastric cancer cells appears hyper-activated in i-GC compared to d-GC, the Smad-dependent pathway seems down-regulated while the Smad-independent pathway seems up-regulated in both histologic subtypes.


Asunto(s)
Carcinogénesis/genética , Proteínas de Neoplasias/biosíntesis , Neoplasias Gástricas/genética , Factor de Crecimiento Transformador beta1/biosíntesis , Anciano , Proteínas Reguladoras de la Apoptosis , Supervivencia sin Enfermedad , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Péptidos y Proteínas de Señalización Intracelular/biosíntesis , Péptidos y Proteínas de Señalización Intracelular/genética , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Proteínas Mitocondriales/biosíntesis , Proteínas Mitocondriales/genética , Transducción de Señal , Neoplasias Gástricas/patología , Neoplasias Gástricas/cirugía , Factor de Crecimiento Transformador beta1/genética
10.
Angew Chem Int Ed Engl ; 53(27): 6925-8, 2014 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-24828751

RESUMEN

An artificial light-harvesting multiporphyrin dendrimer (8P(Zn)P(FB)) composed of a focal freebase porphyrin (P(FB)) with eight zinc(II) porphyrin (P(Zn)) wings exhibited unique photophysical property switching in response to specific guest molecule binding. UV/Vis titration studies indicated stable 1:2 host-guest complex formation between 8P(Zn)P(FB) and meso-tetrakis(4-pyridyl)-porphyrin (TPyP) for which the first and second association constants were estimated to be >10(8) M(-1) and 3.0×10(7) M(-1), respectively. 8P(Zn)P(FB) originally shows 94% energy transfer efficiency from P(Zn) to the focal P(FB). By the formation of the host-guest complex (8P(Zn)P(FB)⋅2TPyP) the emission intensity of 8P(Zn)P(FB) is significantly decreased, and an ultrafast charge separation state is generated. The energy transfer process from P(Zn) wings to the P(FB) core in 8P(Zn)P(FB) is almost entirely switched to an electron transfer process by the formation of 8P(Zn)P(FB)⋅2TPyP.


Asunto(s)
Materiales Biocompatibles/química , Dendrímeros/química , Transporte de Electrón , Transferencia de Energía , Luz , Complejos de Proteína Captadores de Luz/química , Espectroscopía de Resonancia Magnética , Porfirinas/química
11.
Biomed Pharmacother ; 175: 116735, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38744220

RESUMEN

G-protein-coupled receptors are a diverse class of cell surface receptors that orchestrate numerous physiological functions. The G-protein-coupled receptors, GPR41 and GPR43, sense short-chain fatty acids (SCFAs), which are metabolites of dietary fermentation by the host's intestinal bacteria. These receptors have gained attention as potential therapeutic targets against various diseases because of their SCFA-mediated beneficial effects on the host's intestinal health. Mounting evidence has associated the activity of these receptors with chronic metabolic diseases, including obesity, diabetes, inflammation, and cardiovascular disease. However, despite intensive research using various strategies, including gene knockout (KO) mouse models, evidence about the precise roles of GPR41 and GPR43 in disease treatment remains inconsistent. Here, we comprehensively review the latest findings from functional studies of the signaling mechanisms that underlie the activities of GPR41 and GPR43, as well as highlight their multifaceted roles in health and disease. We anticipate that this knowledge will guide future research priorities and the development of effective therapeutic interventions.


Asunto(s)
Receptores Acoplados a Proteínas G , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Animales , Humanos , Transducción de Señal , Enfermedades Metabólicas/metabolismo , Ácidos Grasos Volátiles/metabolismo
12.
Clin Orthop Surg ; 16(1): 86-94, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38304217

RESUMEN

Background: The lumbosacral (LS) junction has a higher nonunion rate than other lumbar segments, especially in long-level fusion. Nonunion at L5-S1 would result in low back pain, spinal imbalance, and poor surgical outcomes. Although anterior column support at L5-S1 has been recommended to prevent nonunion in long-level LS fusion, fusion length requiring additional spinopelvic fixation (SPF) in LS fusion with anterior column support at L5-S1 has not been evaluated thoroughly. This study aimed to determine the number of fused levels requiring SPF in LS fusion with anterior column support at L5-S1 by assessing the interbody fusion status using computed tomography (CT) depending on the fusion length. Methods: Patients who underwent instrumented LS fusion with L5-S1 interbody fusion without additional augmentation and CT > 1 year postoperatively were included. The fusion rates were assessed based on the number of fused segments. Patients were divided into two groups depending on the L5-S1 interbody fusion status: those with union vs. those with nonunion. Binary logistic regression analyses were performed to identify risk factors for LS junctional nonunion. Results: Fusion rates of L5-S1 interbody fusion were 94.9%, 90.3%, 80.0%, 50.0%, 52.6%, and 43.5% for fusion of 1, 2, 3, 4, 5, and ≥ 6 levels, respectively. The number of spinal levels fused ≥ 4 (p < 0.001), low preoperative bone mineral density (BMD; adjusted odds ratio [aOR], 0.667; p = 0.035), and postoperative pelvic incidence (PI) - lumbar lordosis (LL) mismatch (aOR, 1.034; p = 0.040) were identified as significant risk factors for nonunion of L5-S1 interbody fusion according to the multivariate logistic regression analysis. Conclusions: Exhibiting ≥ 4 fused spinal levels, low preoperative BMD, and large postoperative PI-LL mismatch were identified as independent risk factors for nonunion of anterior column support at L5-S1 in LS fusion without additional fixation. Therefore, SPF should be considered in LS fusion extending to or above L2 to prevent LS junctional nonunion.


Asunto(s)
Lordosis , Fusión Vertebral , Humanos , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Estudios Retrospectivos , Tomografía Computarizada por Rayos X , Fusión Vertebral/métodos , Resultado del Tratamiento
13.
Adv Sci (Weinh) ; 11(23): e2308976, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38582529

RESUMEN

Portable and personalized artificial intelligence (AI)-driven sensors mimicking human olfactory and gustatory systems have immense potential for the large-scale deployment and autonomous monitoring systems of Internet of Things (IoT) devices. In this study, an artificial Q-grader comprising surface-engineered zinc oxide (ZnO) thin films is developed as the artificial nose, tongue, and AI-based statistical data analysis as the artificial brain for identifying both aroma and flavor chemicals in coffee beans. A poly(vinylidene fluoride-co-hexafluoropropylene)/ZnO thin film transistor (TFT)-based liquid sensor is the artificial tongue, and an Au, Ag, or Pd nanoparticles/ZnO nanohybrid gas sensor is the artificial nose. In order to classify the flavor of coffee beans (acetic acid (sourness), ethyl butyrate and 2-furanmethanol (sweetness), caffeine (bitterness)) and the origin of coffee beans (Papua New Guinea, Brazil, Ethiopia, and Colombia-decaffeine), rational combination of TFT transfer and dynamic response curves capture the liquids and gases-dependent electrical transport behavior and principal component analysis (PCA)-assisted machine learning (ML) is implemented. A PCA-assisted ML model distinguished the four target flavors with >92% prediction accuracy. ML-based regression model predicts the flavor chemical concentrations with >99% accuracy. Also, the classification model successfully distinguished four different types of coffee-bean with 100% accuracy.


Asunto(s)
Nariz Electrónica , Aprendizaje Automático , Humanos , Inteligencia Artificial , Gusto/fisiología , Café/química , Odorantes/análisis , Olfato/fisiología , Lengua/fisiología , Óxido de Zinc/química , Análisis de Componente Principal
14.
ACS Appl Mater Interfaces ; 16(23): 30264-30273, 2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38832451

RESUMEN

Despite the advancement of the Internet of Things (IoT) and portable devices, the development of zero-biased sensing systems for the dual detection of light and gases remains a challenge. As an emerging technology, direct energy conversion driven by intriguing physical properties of two-dimensional (2D) materials can be realized in nanodevices or a zero-biased integrated system. In this study, we unprecedentedly attempted to exploit the photostimulated pyrothermoelectric coupling of two-dimensional SnSe for use in zero-biased multimodal transducers for the dual detection of light and gases. We synthesized homogeneous, large-area 6 in SnSe multilayers via a rational synthetic route based on the thermal decomposition of a solution-processed single-source precursor. Zero-biased SnSe transducers for the dual monitoring of light and gases were realized by exploiting the synergistic coupling of the photostimulated pyroelectric and thermoelectric effects of SnSe. The extracted photoresponsivity at 532 nm and NO2 gas responsivity of the SnSe-based transducers corresponded to 1.07 × 10-6 A/W and 13263.6% at 0 V, respectively. To bring universal applicability of the zero-biased SnSe transducers, the wide operation bandwidth photoelectrical properties (visible to NIR) and dynamic current responses toward two NO2/NH3 gases were systematically evaluated.

15.
Obesity (Silver Spring) ; 31(7): 1871-1883, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37309717

RESUMEN

OBJECTIVE: This study aimed to investigate the possible mechanisms by which orphan G protein-coupled receptor GPR41 activation enhances glucose uptake into C2C12 myotubes using a GPR41-selective agonist, AR420626, and to examine the ability of this agent to improve insulin sensitivity and glucose homeostasis in vivo. METHODS: Basal and insulin-stimulated glucose uptake and glucose transporter 4 translocations were measured in C2C12 myotubes. Ca2+ influx into cells was measured and GPR41-mediated signaling by AR420626 was examined. An oral glucose tolerance test was performed, and plasma insulin levels were measured in streptozotocin-treated or high-fat diet-fed diabetic mice. The glycogen content was measured in skeletal muscle tissue. RESULTS: AR420626 increased basal and insulin-stimulated glucose uptake, which was reduced by pertussis toxin, an inhibitor of Gαi -mediated signaling, and treatment with small interfering RNA for GPR41 (siGPR41). AR420626 increased intracellular Ca2+ influx and phosphorylated Ca2+ /calmodulin-dependent protein kinase type II, cyclic AMP-responsive element-binding protein, and mitogen-activated protein kinase (p38) in C2C12 myotubes, which were inhibited by treating with pertussis toxin, amlodipine (Ca2+ channel blocker), and siGPR41. AR420626 increased plasma insulin levels and skeletal muscle glycogen content and improved glucose tolerance in streptozotocin- and high-fat diet-induced diabetic mouse models. CONCLUSIONS: GPR41 activation with AR420626 increased glucose uptake mediated by Ca2+ signaling via GPR41, improving diabetes mellitus.


Asunto(s)
Diabetes Mellitus Experimental , Glucosa , Animales , Ratones , Diabetes Mellitus Experimental/metabolismo , Glucosa/metabolismo , Glucógeno , Insulina/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/metabolismo , Toxina del Pertussis , Estreptozocina
16.
Sci Rep ; 13(1): 18070, 2023 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-37872268

RESUMEN

Cast-in-place anchors are being increasingly used in many applications including building construction, bridge, and power plants. The anchorage to concrete systems are subjected to tensile, shear and combined loads from a variety of loading circumstances including static, dynamic, and shock loading. Despite extensive studies on these systems, reliable numerical models for predicting the behavior of these anchors are still limited. Therefore, this paper investigated the tensile behavior of cast-in-place anchorage to concrete systems, to propose an effective model for reproducing anchorage behavior using finite element (FE) methods. Experiments and code-based models for the anchorage system in tension were used to evaluate the numerical models for cast-in-place anchors in concrete, and the most suitable model, with advantages in accuracy and saving analysis time, was chosen. Finally, the FE model was used to study the tensile capacity and related dynamic increase factor for various strain rates, anchor diameters, and embedment depths.

17.
J Cataract Refract Surg ; 49(10): 1036-1042, 2023 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-37440456

RESUMEN

PURPOSE: To compare patient experiences and cooperation and the clinical outcomes illuminated chopper vs conventional chopper during cataract surgery. SETTING: 4 tertiary institutions in Korea. DESIGN: Prospective, randomized, paired-eye, controlled pilot study. METHODS: 152 eyes of 76 patients who underwent bilateral cataract surgeries were enrolled in this study. The surgical method was randomly assigned to each patient's eye (1 eye using the illuminated chopper with a light source and the other using the conventional chopper under the microscope light). Patient suffering scores (the degree of strong light perception, glare, inability to fixate, anxiety, discomfort, and fear) from 0 to 10 (10 being the most severe level); cooperation score from 0 to 3 (3 being the best cooperation); operating time; and corneal endothelial cell density (ECD) preoperatively and postoperatively were compared between the 2 groups. RESULTS: The mean patient suffering score of all 6 parameters in the iChopper group was significantly smaller than those in the control group (all P < .05). The mean patient cooperation score of the iChopper group (2.3 ± 0.8) was significantly greater than that of the control (1.6 ± 0.9; P < .001). There was no significant difference in the mean operating time and corneal ECD at each visit between the groups, albeit the mean corneal ECD was significantly decreased from baseline to 1 month after cataract surgery in both groups. CONCLUSIONS: Phacoemulsification using the illuminated chopper provides less glare and anxiety and better cooperation during cataract surgery without increasing the operating time and damaging corneal endothelium compared with the conventional chopper.


Asunto(s)
Catarata , Facoemulsificación , Humanos , Implantación de Lentes Intraoculares , Estudios Prospectivos , Agudeza Visual , Facoemulsificación/métodos , Endotelio Corneal , Evaluación del Resultado de la Atención al Paciente , Recuento de Células
18.
Materials (Basel) ; 15(19)2022 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-36234352

RESUMEN

In this study, a modified version of electrospun nylon 66 nanofibers by silica particles were blended into ordinary Portland cement to investigate the microstructure and some mechanical properties of cementitious material. The addition of silica into the nanofibers improved the tensile and compressive properties of the hardened cement pastes. The observations from the mechanical strength tests showed an increase of 41%, 33% and 65% in tensile strength, compressive strength, and toughness, respectively, when modifying the cement pastes with the proposed nanofibers. The observations from scanning electron microscopy and transmission electron microscopy showed the morphology and microstructure of the fibers as well as their behaviors inside the cement matrix. Additionally, X-ray diffraction and thermal gravimetric analysis clarified the occurrence of the extra pozzolanic reaction, as well as the calcium hydroxide consumption by the attached silica inside the cement matrix. Finally, the observations from this study showed the successful fabrication of the modified nanofibers and the feasibility of improving the tensile and compressive behaviors of cement pastes using the proposed electrospun nanofibers.

19.
Materials (Basel) ; 15(21)2022 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-36363046

RESUMEN

The hybrid retrofit system using FRP and concrete overlay applied on the top of slabs has proven effective in strengthening and overcoming logistical constraints, compared with conventional strengthening techniques using externally bonded composite materials to the underside of the slabs. Nevertheless, the performance of retrofitted slabs is governed by debonding failure due to the low bond strength between CFRP and concrete overlay. Thus, this study investigates the behavior of flexural strengthened slabs with FRP retrofit systems and the effect of bond-slip laws on debonding failure. Firstly, two full-scale RC slabs with and without a retrofit system were tested in a four-point bending setup as the control specimens. Then, the same retrofitted slab was simulated by utilizing the commercial program ABAQUS. A sensitivity analysis was conducted to consider the influence of bond-slip laws to predict the failure mechanism of the retrofitted slabs based on load-deflection relationships. The results showed that the strengthened slab enhanced the load-carrying capacity by 59%, stiffness by 111%, and toughness by 29%. The initial stiffness of 0.1K0 and maximum shear stress of 0.13τmax, compared with the corresponding values of Neubauer's and Rostasy's bond-slip law, can be used to simulate the global response of the retrofitted slab validated by experiment results.

20.
J Cataract Refract Surg ; 48(6): 710-716, 2022 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-34629379

RESUMEN

PURPOSE: To compare the efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) and steroidal eyedrops for inflammation management after cataract surgery using slitlamp indicators. SETTING: 11 eye centers in South Korea. DESIGN: Randomized prospective multicenter study with a blinded evaluator. METHOD: In 125 (250 eyes) patients who underwent cataract surgery, bromfenac sodium hydrate 0.1% (NSAID group) was applied twice a day in 1 eye, whereas the other eye was treated with fluorometholone 0.1% (steroid group), 4 times a day for 4 weeks postoperatively. The primary efficacy outcome was the presence of anterior chamber cells and flare at 1 week postoperatively. Anterior chamber cells and flare at 4 to 8 weeks, corrected distance visual acuity, central corneal thickness, conjunctival hyperemia, dry eye parameters, foveal thickness, and ocular and visual discomfort were evaluated as secondary outcomes. RESULTS: At week 1, residual anterior chamber inflammation was not statistically significantly different between the groups (-1.03 ± 1.27 vs -0.95 ± 1.24, P = .4850). However, the NSAID group recovered from conjunctival hyperemia more rapidly than the steroid group (0.30 ± 0.52 vs 0.44 ± 0.81, P = .0144 at week 1). The increase in central corneal thickness in the NSAID group was less than that in the steroid group 1 week postoperatively (7.87 ± 22.46 vs 29.47 ± 46.60 µm, P < .0001). The change in foveal thickness in the NSAID group was significantly less than that in the steroid group (18.11 ± 68.19 vs 22.25 ± 42.37 µm, P = .0002). Lower levels of postoperative ocular and visual discomfort were reported in the NSAID group than in the steroid group under treatment. CONCLUSIONS: Preservative-free bromfenac was as effective as preservative-free fluorometholone eyedrops in anterior chamber inflammation control and showed better signs and symptoms after cataract surgery.


Asunto(s)
Extracción de Catarata , Catarata , Hiperemia , Facoemulsificación , Corticoesteroides/uso terapéutico , Antiinflamatorios no Esteroideos/uso terapéutico , Fluorometolona/uso terapéutico , Humanos , Hiperemia/tratamiento farmacológico , Inflamación/tratamiento farmacológico , Soluciones Oftálmicas , Complicaciones Posoperatorias/tratamiento farmacológico , Conservadores Farmacéuticos/uso terapéutico , Estudios Prospectivos , Resultado del Tratamiento
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