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1.
Nutr J ; 23(1): 43, 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38637805

RESUMEN

BACKGROUND: It has been suggested that Mukbang and Cookbang, a type of eating broadcast originating from Korea and gaining popularity, may contribute to obesity. However, despite suggestions that Mukbang might contribute to obesity, studies investigating the impact of watching Mukbang on obesity is lacking. The goal of this study is to analyze the relationship between watching Mukbang and Cookbang and body mass index (BMI) status in Korean adolescents. All analyses were stratified by gender. METHODS: This study utilized data from the 2022 Korea Youth Risk Behavior Web-based Surveys. The anonymous online survey was conducted with 56,213 students, and 51,850 students (92.2%) who participated in the survey were analyzed. Participants reported the frequency of watching Mukbang and Cookbang per week over the previous 12 months. BMI was categorized into four subgroups based on percentiles: underweight (< 5th percentile), normal (5th - 85th percentiles), overweight (85th - 95th percentiles), and obese (> 95th percentile). This study used multinomial logistic regression for analysis. RESULTS: The likelihood of being obese was significantly higher in Mukbang-watching boys compared to those who never watched Mukbang and Cookbang (adjusted odds ratio [aOR]: 1.22, 95% confidence interval [CI]: 1.12-1.32). A dose-dependent association was found between the frequency of Mukbang and Cookbang watching and the likelihood of obesity among boys (p-for-trend < 0.0001). Subgroups that currently smoke, currently drink alcohol, frequently consume fast food, or drink sweetened beverages showed significantly higher odds of being obese in the "Ever" group than those in the "Never" group. CONCLUSION: This study found a relationship between watching Mukbang and Cookbang and obesity in boys. Appropriate interventions should be considered for boys watching Mukbang and Cookbang.


Asunto(s)
Obesidad , Sobrepeso , Masculino , Adolescente , Humanos , Índice de Masa Corporal , Peso Corporal , Obesidad/epidemiología , República de Corea/epidemiología
2.
Acc Chem Res ; 54(23): 4319-4333, 2021 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-34784182

RESUMEN

Asymmetric cation-binding catalysis in principle enables the use of (alkali) metal salts, otherwise insoluble in organic solvents, as reagents and effectors in enantioselective reactions. However, this concept has been a formidable challenge due to the difficulties associated with creating a highly organized chiral environment for cations and anions simultaneously. Over the last four decades, various chiral crown ethers have been developed as cation-binding phase-transfer catalysts and examined in asymmetric catalysis. However, the limited ability of chiral crown ethers to generate soluble reactive anions in a confined chiral cage offers a restricted reaction scope and unsatisfactory chirality induction. To address the constraints of monofunctional chiral crown ethers as cation-binding catalysts, it is therefore desirable to develop a cooperative cation-binding catalyst possessing secondary binding sites for anions, which enables the generation of a reactive anion within a chiral cage of a catalyst. This account summarizes our design, development, and applications of chiral BINOL-based oligoethylene glycols (oligoEGs) as a new type of bifunctional cation-binding catalyst. We initially found that achiral oligoEGs were efficient promoters in nucleophilic fluorination with potassium fluoride. Thereby, we hypothesized that, by breaking the closed cyclic ether unit of chiral crown ethers, the free terminal -OH groups could activate the electrophiles by hydrogen bonding whereas the ether oxygens could act as the Lewis base to coordinate metal ions, thus generating soluble anions in a confined chiral cage. This hypothesis was realized by synthesizing a series of chiral variants of oligoEGs by connecting two 3,3'-disubstituted-BINOL units with glycol linkers. Readily available BINOL-based chiral oligoEGs enabled numerous asymmetric transformations out of the reach of chiral monofunctional crown ether catalysts. We have demonstrated that this new type of bifunctional cation-binding catalysts can generate a soluble fluoride anion from alkali metal fluorides, which can be a versatile chiral promoter for diverse asymmetric catalytic reactions, kinetic resolution (selectivity factor of up to ∼2300), asymmetric protonation, Mannich reactions, tandem cyclization reactions, and the isomerization of allylic alcohols and hemithioacetals. We have also successfully utilized our chiral oligoEG catalysts along with alkali metal salts of carbon- and heteroatom-based nucleophiles, respectively, for asymmetric Strecker reactions and the asymmetric synthesis of chiral aminals. The power of our cooperative cation-binding catalysis was exemplified by kinetic resolution reactions of secondary alcohols, achieving highly enantioselective catalysis with only <1 ppm loading of an organocatalyst with high TOFs (up to ∼1300 h-1 at 1 ppm catalyst loading). The broadness and generality of our cooperative asymmetric cation-binding catalysis can be ascribed, in a similar fashion, to active-site architectures of enzymes using allosteric interactions, highly confined chiral cages formed by the incorporation of alkali metal salts in the catalyst polyether chain backbone, and the cooperative activation of reacting partners by hydrogen-bonding and ion-ion interactions. Confining reactive components in such a chiral binding pocket leads to enhanced reactivity and efficient transfer of the stereochemical information.

3.
J Synchrotron Radiat ; 27(Pt 1): 17-24, 2020 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-31868731

RESUMEN

With each single X-ray pulse having its own characteristics, understanding the individual property of each X-ray free-electron laser (XFEL) pulse is essential for its applications in probing and manipulating specimens as well as in diagnosing the lasing performance. Intensive research using XFEL radiation over the last several years has introduced techniques to characterize the femtosecond XFEL pulses, but a simple characterization scheme, while not requiring ad hoc assumptions, to address multiple aspects of XFEL radiation via a single data collection process is scant. Here, it is shown that single-particle diffraction patterns collected using single XFEL pulses can provide information about the incident photon flux and coherence property simultaneously, and the X-ray beam profile is inferred. The proposed scheme is highly adaptable to most experimental configurations, and will become an essential approach to understanding single X-ray pulses.

4.
Chemistry ; 24(5): 1020-1025, 2018 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-28833708

RESUMEN

Asymmetric cation-binding catalysis, in principle, can generate "chiral" anionic nucleophiles, where the counter cations are coordinated within chiral environments. Nitrogen nucleophiles are intrinsically basic, therefore, its use as nucleophiles is often challenging and limiting the scope of the reaction. Particularly, a formation of configurationally labile aminal centers with alkyl substituents has been a formidable challenge due to the enamine/imine equilibrium of electrophilic substrates. Herein, we report enantioselective nucleophilic addition reactions of potassium phthalimides to Boc-protected alkyl- and aryl-substituted α-amido sulfones. In situ generated imines smoothly reacted with the nitrogen nucleophiles to corresponding aminals with good to excellent enantioselectivitiy under mild reaction conditions. In addition, transformation of aminal products gave biologically relevant pyrrolidinone-fused hexahydropyrimidine scaffold with excellent stereoselectivity and good yield.

5.
Photodermatol Photoimmunol Photomed ; 31(1): 36-43, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25227960

RESUMEN

BACKGROUND: The Methylaminolevulinate-photodynamic therapy (MAL-PDT) has been reported to be effective in treating actinic keratosis (AK). Fluorescent images taken after topical MAL application have been used to diagnose cancerous lesions. OBJECTIVES: We evaluated therapeutic efficacy of MAL-PDT for multiple AK and defined value of fluorescent images in evaluating treatment response. We also investigated photorejuvenation effects of PDT. METHODS: Ten patients with multiple AK were enrolled. We did histological confirmation of the lesion by biopsy. After 3 h of MAL cream occlusion, red light was illuminated with 37 J/cm(2) on 0, 4, 16, and 20 weeks. At each visit, lesions were counted by inspection and fluorescent images were taken under ultraviolet A light. We repeated skin biopsy in 16 weeks. RESULTS: All patients showed significant improvement after three sessions of PDT. The average remission rate was 85.96%. Overall, patients showed significant improvement in photoaging such as erythema, coarse wrinkles, and skin roughness. Histological examination also showed improvement. There was meaningful agreement between lesion count by fluorescent imaging and inspection (coefficient = 0.9). CONCLUSIONS: PDT was found to be effective, well-tolerated, cosmetically acceptable for AK treatment and photorejuvenation, both clinically and histologically. In addition, fluorescent images taken after MAL application aided in evaluation of treatment response as well as diagnosis.


Asunto(s)
Queratosis Actínica , Imagen Óptica , Fotoquimioterapia , Anciano , Anciano de 80 o más Años , Eritema/diagnóstico , Eritema/tratamiento farmacológico , Eritema/patología , Femenino , Humanos , Queratosis Actínica/diagnóstico , Queratosis Actínica/tratamiento farmacológico , Queratosis Actínica/patología , Masculino , Persona de Mediana Edad , Envejecimiento de la Piel/efectos de los fármacos
6.
Micromachines (Basel) ; 15(1)2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-38258222

RESUMEN

Bottom-gate thin-film transistors (TFTs) with n-type amorphous indium-gallium-zinc oxide (a-IGZO) active channels and indium-tin oxide (ITO) source/drain electrodes were fabricated. Then, an ultraviolet (UV) nanosecond pulsed laser with a wavelength of 355 nm was scanned to locally anneal the active channel at various laser powers. After laser annealing, negative shifts in the threshold voltages and enhanced on-currents were observed at laser powers ranging from 54 to 120 mW. The energy band gap and work function of a-IGZO extracted from the transmittance and ultraviolet photoelectron spectroscopy (UPS) measurement data confirm that different energy band structures for the ITO electrode/a-IGZO channel were established depending on the laser annealing conditions. Based on these observations, the electron injection mechanism from ITO electrodes to a-IGZO channels was analyzed. The results show that the selective laser annealing process can improve the electrical performance of the a-IGZO TFTs without any thermal damage to the substrate.

7.
Org Lett ; 19(19): 5336-5339, 2017 10 06.
Artículo en Inglés | MEDLINE | ID: mdl-28953402

RESUMEN

Biologically relevant chiral 3,3-disubstituted oxindole products containing a ß-fluoroamine unit are obtained in high yields and with excellent stereoselectivity (up to 99% ee, dr >20:1 for syn) through the organocatalytic direct Mannich reaction of 3-fluoro-oxindoles as fluoroenolate precursors and α-amidosulfones as the bench-stable precursors of sensitive imines by using a chiral oligoethylene glycol and KF as a cation-binding catalyst and base, respectively. This protocol can be easily scaled without compromising the asymmetric induction. Furthermore, this protocol was also successfully extended to generate tetrasubstituted C-Cl and C-Br stereogenic centers.

8.
Nat Commun ; 8: 14877, 2017 04 04.
Artículo en Inglés | MEDLINE | ID: mdl-28374736

RESUMEN

Glyoxalase I plays a critical role in the enzymatic defence against glycation by catalysing the isomerization of hemithioacetal, formed spontaneously from cytotoxic α-oxoaldehydes and glutathione, to (S)-α-hydroxyacylglutathione derivatives. Upon the hydrolysis of the thioesters catalysed by glyoxalase II, inert (S)-α-hydroxy acids, that is, lactic acid, are then produced. Herein, we demonstrate highly enantioselective glyoxalase I mimic catalytic isomerization of in-situ-generated hemithioacetals, providing facile access to both enantiomers of α-hydroxy thioesters. Owing to the flexibility of thioesters, a family of optically pure α-hydroxyamides, which are highly important drug candidates in the pharmaceutical industry, were prepared without any coupling reagents. Similar to real enzymes, the enforced proximity of the catalyst and substrates by the chiral cage in situ formed by the incorporation of potassium salt can enhance the reactivity and efficiently transfer the stereochemical information.


Asunto(s)
Aldehídos/metabolismo , Biomimética , Ésteres/metabolismo , Lactoilglutatión Liasa/metabolismo , Catálisis , Estereoisomerismo
9.
Org Lett ; 19(12): 3279-3282, 2017 06 16.
Artículo en Inglés | MEDLINE | ID: mdl-28574270

RESUMEN

The potential of Song's chiral oligoethylene glycols (oligoEGs) as catalysts was explored in the enantioselective protonation of trimethylsilyl enol ethers in combination with alkali metal fluoride (KF and CsF) and in the presence of a proton source. Highly enantioselective protonations of various silyl enol ethers of α-substituted tetralones were achieved, producing chiral α-substituted tetralones in full conversion and with up to 99% ee. The established protocol was successfully extended to the synthesis of biologically relevant chiral α-substituted chromanone and thiochromanone derivatives.

10.
J Dermatol ; 43(11): 1293-1300, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27028221

RESUMEN

There have been many studies on the relationship between androgenetic alopecia (AGA) and cardiovascular risk factors, but the study results were inconsistent and research on AGA in Asians remains insufficient. This study investigated the relationship between Korean AGA and various cardiovascular risk factors, considering life habits, type of hair loss and sex. We investigated subjects who visited a hospital for public or industrial health medical examinations between October 2012 and December 2014. A questionnaire as well as anthropometric measurements and a blood test were performed. Among the 1884 total subjects, 52.6% had AGA. AGA patients displayed a significantly higher prevalence rate of cardiovascular diseases, smoking rate, fasting glucose and triglyceride, and a significantly lower high-density lipoprotein cholesterol level than did the non-AGA group. The results of the subgroup analysis showed higher prevalence rates of hypertension, stroke, metabolic syndrome and smoking in male AGA patients. The more severe the AGA, the higher the incidences of hypertension, diabetes and smoking were observed. According to the analysis results by BASP classification, the F-type AGA patients displayed a higher body mass index, waist circumference and diastolic blood pressure, and had a significantly higher prevalence rate of hypertension. As a result of the large population-based study, modifications in lifestyle and early screening for cardiovascular disease, as well as hypertension and diabetes, are suggested.


Asunto(s)
Alopecia/epidemiología , Enfermedades Cardiovasculares/epidemiología , Femenino , Humanos , Estilo de Vida , Masculino , Persona de Mediana Edad , República de Corea/epidemiología , Factores de Riesgo , Índice de Severidad de la Enfermedad
11.
Nat Commun ; 6: 7512, 2015 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-26085287

RESUMEN

The field of organocatalysis has blossomed over the past few decades, becoming an alternative to transition-metal catalysis or even replacing the realm of transition-metal catalysis. However, a truly powerful organocatalyst with a high turnover number (TON) and turnover frequency (TOF) while retaining high enantioselectivity is yet to be discovered. Similar to metal catalysis, extremely low catalyst loading (p.p.m. or p.p.b. levels) is the ultimate goal of the organocatalysis community. Herein we report a remarkable contribution in this context: 1 p.p.m. loading of a simple 1,1'-bi-2-naphthol-based organocatalyst was enough to achieve highly enantioselective silylation reactions of alcohols. The unprecedented TONs and excellent enantioselectivity are ascribed to the robustness of the catalyst and systematic cooperative hydrogen-bonding organocatalysis in a densely confined chiral space.

14.
Ann Dermatol ; 26(2): 264-6, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24882989
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