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1.
BMC Emerg Med ; 24(1): 55, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38584265

RESUMEN

BACKGROUND: Early identification of patients at risk of potential death and timely transfer to appropriate healthcare facilities are critical for reducing the number of preventable trauma deaths. This study aimed to establish a cutoff value to predict in-hospital mortality using the reverse shock index multiplied by the Glasgow Coma Scale (rSIG). METHODS: This multicenter retrospective cohort study used data from 23 emergency departments in South Korea between January 2011 and December 2020. The outcome variable was the in-hospital mortality. The relationship between rSIG and in-hospital mortality was plotted using the shape-restricted regression spline method. To set a cutoff for rSIG, we found the point on the curve where mortality started to increase and the point where the slope of the mortality curve changed the most. We also calculated the cutoff value for rSIG using Youden's index. RESULTS: A total of 318,506 adult patients with trauma were included. The shape-restricted regression spline curve showed that in-hospital mortality began to increase when the rSIG value was less than 18.86, and the slope of the graph increased the most at 12.57. The cutoff of 16.5, calculated using Youden's index, was closest to the target under-triage and over-triage rates, as suggested by the American College of Surgeons, when applied to patients with an rSIG of 20 or less. In addition, in patients with traumatic brain injury, when the rSIG value was over 25, in-hospital mortality tended to increase as the rSIG value increased. CONCLUSIONS: We propose an rSIG cutoff value of 16.5 as a predictor of in-hospital mortality in adult patients with trauma. However, in patients with traumatic brain injury, a high rSIG is also associated with in-hospital mortality. Appropriate cutoffs should be established for this group in the future.


Asunto(s)
Lesiones Traumáticas del Encéfalo , Heridas y Lesiones , Adulto , Humanos , Escala de Coma de Glasgow , Estudios Retrospectivos , Mortalidad Hospitalaria , Servicio de Urgencia en Hospital
2.
J Fish Biol ; 101(3): 676-685, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35730537

RESUMEN

Bitterlings are freshwater fish that have developed morphological adaptations to improve the survival of their embryos in host mussels. The most well-known adaptation is the development of minute tubercles, which develop in the early embryonic stage when the embryos have poor swimming ability, and disappear when the embryos reach the free-swimming stage and leave the host mussels. In this study, the embryonic developmental stages of Acheilognathus signifer were analysed to elucidate the relationship between the changes in the height of the minute tubercles and their movement. The height changes in the minute tubercles in the embryos can be divided into five stages, i.e., formation, growth, peak, reduction and disappearance. The authors found that the embryos lived in the gill demibranch of the host mussel until day 6 after hatching. The movement of embryos to the suprabranchial cavity in the gill demibranch was firstly observed on day 7. At this point, the embryos showed a heartbeat and movement. From day 13, the minute tubercles had almost disappeared, and the hatchlings started swimming outside the host mussels from day 16. These observations highlight the different adaptations of minute tubercles among bitterling groups without wing-like projections.


Asunto(s)
Bivalvos , Cyprinidae , Animales , Agua Dulce , Branquias , República de Corea
3.
Sci Rep ; 12(1): 3366, 2022 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-35233019

RESUMEN

In this study, the chemical decomposition of a polyimide-film (i.e., a PI-film)-surface into a soft-film-surface containing negatively charged pyromellitic dianhydride (PMDA) and neutral 4,4'-oxydianiline (ODA) was successfully performed. The chemical decomposition was conducted by designing the slurry containing 350 nm colloidal silica abrasive and small molecules with amine functional groups (i.e., ethylenediamine: EDA) for chemical-mechanical planarization (CMP). This chemical decomposition was performed through two types of hydrolysis reactions, that is, a hydrolysis reaction between OH- ions or R-NH3+ (i.e., EDA with a positively charged amine groups) and oxygen atoms covalently bonded with pyromellitimide on the PI-film-surface. In particular, the degree of slurry adsorption of the PI-film-surface was determined by the EDA concentration in the slurry because of the presence of R-NH3+, that is, a higher EDA concentration resulted in a higher degree of slurry adsorption. In addition, during CMP, the chemical decomposition degree of the PI-film-surface was principally determined by the EDA concentration; that is, the degree of chemical composition was increased noticeably and linearly with the EDA concentration. Thus, the polishing-rate of the PI-film-surface increased notably with the EDA concentration in the CMP slurry.

4.
Enzyme Microb Technol ; 153: 109939, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34798448

RESUMEN

Rubusoside, which is used as a natural sweetener or a solubilizing agent for water-insoluble functional materials, is currently expensive to produce owing to the high cost of the membrane-based technologies needed for its extraction and purification from the sweet tea plant (Rubus suavissimus S. Lee). Therefore, this study was carried out to screen for lactic acid bacteria that possess enzymes capable of bio-transforming stevioside into rubusoside. Subsequently, one such rubusoside-producing enzyme was isolated from Lactobacillus plantarum GS100. Located on the bacterial cell surface, this enzyme was stable at pH 4.5-6.5 and 30-40 °C, and it produced rubusoside as a major product through its stevioside-hydrolyzing activity. Importantly, the enzyme showed higher ß-glucosidase activity toward the ß-linked glucosidic bond of stevioside than toward other ß-linked glucobioses. Under optimal conditions, 70 U/L of the rubusoside-producing enzyme could produce 69.03 mM rubusoside from 190 mM stevioside. The ß-glucosidase activity on the cell surface was high at 35 h of culture. This is the first report detailing the production of rubusoside from stevioside by an enzyme derived from a food-grade lactic acid bacterium. The application of this ß-glucosidase could greatly reduce the cost of rubusoside production, hence benefiting all industries that use this natural product.


Asunto(s)
Diterpenos de Tipo Kaurano , Glucósidos , Lactobacillus plantarum/enzimología , beta-Glucosidasa , Diterpenos de Tipo Kaurano/metabolismo , Glucósidos/metabolismo , Ácido Láctico
5.
Front Mol Biosci ; 7: 577284, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33344501

RESUMEN

7,3',4'-Trihydroxyisoflavone (7,3',4'-THIF) is a metabolite of daidzein which is a representative isoflavone found in soybean. Recent studies suggested that 7,3',4'-THIF exerts a hypopigmentary effect in B16F10 cells, however, its underlying molecular mechanisms and specific target protein remain unknown. Here, we found that 7,3',4'-THIF, but not daidzein, inhibited α-melanocyte-stimulating hormone (MSH)-induced intracellular and extracellular melanin production in B16F10 cells by directly targeting melanocortin 1 receptor (MC1R). Western blot data showed that 7,3',4'-THIF inhibited α-MSH-induced tyrosinase, tyrosinase-related protein-1 (TYRP-1), and tyrosinase-related protein-2 (TYRP-2) expressions through the inhibition of Microphthalmia-associated transcription factor (MITF) expression and cAMP response element-binding (CREB) phosphorylation. 7,3',4'-THIF also inhibited α-MSH-induced dephosphorylation of AKT and phosphorylation of p38 and cAMP-dependent protein kinase (PKA). cAMP and Pull-down assays indicated that 7,3',4'-THIF strongly inhibited forskolin-induced intracellular cAMP production and bound MC1R directly by competing with α-MSH. Moreover, 7,3',4'-THIF inhibited α-MSH-induced intracellular melanin production in human epidermal melanocytes (HEMs). Collectively, these results demonstrate that 7,3',4'-THIF targets MC1R, resulting in the suppression of melanin production, suggesting a protective role for 7,3',4'-THIF against melanogenesis.

6.
Nanotechnology ; 31(12): 12LT01, 2020 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-31739301

RESUMEN

We proposed a dislocation sink technology for achieving Si1-x Ge x multi-bridge-channel field-effect-transistor beyond 5 nm transistor design-rule that essentially needs an almost crystalline-defect-free Si1-x Ge x channel. A generation of a dislocation sink via H+ implantations in a strain-relaxed Si0.7Ge0.3 layer grown on a Si substrate and a following annealing almost annihilate completely misfit and threading dislocations located near the interface between a relaxed Si0.7Ge0.3 layer and a Si substrate. A real-time (continuous heating from room temperature to 600 °C) in situ high-resolution-transmission-electron-microscopy and inverse-fast-Fourier-transform image observation at 1.25 MV acceleration voltage obviously demonstrated the annihilation process between dislocation sinks and remaining misfit and threading dislocations during a thermal annealing, called the [SiI or GeI + V Si or V Ge â†’ Si1-x Ge x ] annihilation process, where SiI, GeI, V Si, and V Ge are interstitial Si, interstitial Ge, Si vacancy, and Ge vacancy, respectively. In particular, the annihilation process efficiency greatly depended on the dose of H+ implantation and annealing temperature; i.e. a maximum annihilation process efficiency achieved at 5 × 1015 atoms cm-2 and 800 °C.

7.
Biofouling ; 34(8): 912-924, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30369244

RESUMEN

In this study, the seasonality of the biofouling behavior of pilot-scale membrane bioreactors (MBRs) run in parallel with vacant sheets and quorum quenching (QQ) sheets using real municipal wastewater was investigated. QQ media delayed fouling, but low temperatures caused severe biofouling. The greater amount of extracellular polymeric substances (EPSs) produced in cold weather was responsible for the faster biofouling of a membrane, even with QQ media. There were significant negative relationships between EPS levels and water temperature. Cold weather was detrimental to the degradation of quorum sensing signal molecules by QQ sheets, whose activity was restored with a higher dose of QQ bacteria. The QQ bacteria in the sheets experienced a slight loss in activity during the early stage of the field test, but survived in the pilot-scale MBR fed with real wastewater. There were no significant discrepancies in treatment efficiency among conventional, vacant, and QQ MBRs.


Asunto(s)
Incrustaciones Biológicas , Reactores Biológicos/microbiología , Frío , Membranas Artificiales , Percepción de Quorum , Bacterias/metabolismo , Proyectos Piloto , Aguas Residuales/microbiología
8.
Food Res Int ; 106: 842-852, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29579995

RESUMEN

The soybean plant (Glycine max) is widely used as an ingredient in various foods, nutraceuticals and cosmetics, due to their diverse bioactive compounds. Their metabolic compositions are likely affected by environmental conditions during growth. To investigate the influence of different environmental conditions on the metabolite composition of soybean leaves, we cultivated soybean (G. max Sinhwa) in the southernmost island and volcanic region of Korea, and in the central section and limestone region of the Korean peninsula. Comprehensive metabolite variations of their leaves were analyzed through 1H NMR-based metabolomics approach. With marked differences in soil compositions and climatic conditions between the two growing areas, differences in accumulations of pinitol and diverse flavonoids were noted between the soybean leaves, reflecting the distinct metabolism of soybean plants for physiological adaptation toward different environmental conditions. Therefore, the current study highlights the geographical dependences of diverse soybean leaf metabolites for developing biofunction-enhanced soybean products.


Asunto(s)
Glycine max/química , Metaboloma , Metabolómica , Hojas de la Planta/química , Adaptación Fisiológica , Aminoácidos/análisis , Antioxidantes/análisis , Membrana Celular/química , Flavonoides/análisis , Geografía , Espectroscopía de Resonancia Magnética , Fenoles/análisis , República de Corea , Suelo/química
9.
J Agric Food Chem ; 66(8): 1889-1897, 2018 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-29409322

RESUMEN

With the increase of tea (Camellia sinensis) consumption, its chemical or metabolite compositions play a crucial role in the determination of tea quality. In general, metabolite compositions of fresh tea leaves including shoots depend on plucking seasons and tea cultivators. Therefore, choosing a specific plucking time of tea leaves can provide use-specified tea products. Artificial control of tea growing, typically shade treatments, can lead to significant changes of the tea metabolite compositions. However, metabolic characteristics of tea grown under various shade treatment conditions remain unclear. Therefore, the objective of the current study was to explore effects of various shade conditions on metabolite compositions of tea through a 1H NMR-based metabolomics approach. It was noteworthy that the levels of catechins and their derivatives were only influenced at the initial time of shade treatments while most amino acids were upregulated as amounts of shade and periods were increased: that is, the levels of alanine, asparagine, aspartate, isoleucine, threonine, leucine, and valine in fresh tea leaves were conspicuously elevated when shade levels were raised from 90% to 100% and when period of shade treatments was increased by 20 days. Such increased synthesis of amino acids along with large reductions of glucose level reflected carbon starvation under the dark conditions, indicating remarkable proteolysis in the chloroplast of tea leaves. This study provides important information about making amino acid-enhanced tea products based on global characteristics of diverse tea leaf metabolites induced by various shade treatment conditions.


Asunto(s)
Camellia sinensis/metabolismo , Hojas de la Planta/química , Aminoácidos/química , Aminoácidos/metabolismo , Camellia sinensis/química , Camellia sinensis/crecimiento & desarrollo , Metabolómica , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Estaciones del Año
10.
Genome Announc ; 6(2)2018 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-29326213

RESUMEN

The complete genome sequence of Chryseobacterium camelliae Dolsongi-HT1 is reported here. C. camelliae Dolsongi-HT1, having keratinolytic activity, was isolated from green tea leaves in the Dolsongi tea garden in Jeju, South Korea. The strain Dolsongi-HT1 has 28 candidate protease genes, which may be utilized in further studies and industrial applications of keratinase.

11.
Exp Dermatol ; 27(5): 449-452, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-28453925

RESUMEN

The soy isoflavone daidzein is bioconverted to 7,8,4'-trihydroxyisoflavone (7,8,4'-THIF) by microorganisms. Here, we investigated the matrix metalloproteinase (MMP)-1 inhibitory properties of 7,8,4'-THIF that arise through the suppression of UVB-induced MMP-1 expression. 7,8,4'-THIF reduced UVB-induced MMP-1 expression at the transcriptional level in primary human dermal fibroblasts and inhibited UVB-induced transcriptional activity of AP-1, a major activator of MMP-1 expression. Additionally, it was observed that the mitogen-activated protein kinase (MAPK) pathway, a crucial signalling cascade for MMP-1 expression, was suppressed by 7,8,4'-THIF. Protein kinase C iota (PKCι) was suspected to be a direct target of 7,8,4'-THIF. The direct interaction between 7,8,4'-THIF and PKCι was confirmed using pull-down assays and immobilized metal ion affinity-based fluorescence polarization assays. Finally, we observed that 7,8,4'-THIF inhibited UVB-induced MMP-1 expression in a human skin equivalent model. Taken together, these results suggest that 7,8,4'-THIF, a bioconversion product of daidzein, suppresses UVB-induced MMP-1 expression.


Asunto(s)
Isoenzimas/antagonistas & inhibidores , Isoflavonas/farmacología , Metaloproteinasa 1 de la Matriz/metabolismo , Proteína Quinasa C/antagonistas & inhibidores , Evaluación Preclínica de Medicamentos , Humanos , Envejecimiento de la Piel/efectos de los fármacos , Rayos Ultravioleta
12.
Biotechnol Lett ; 40(1): 197-204, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29064007

RESUMEN

OBJECTIVE: To purify and characterize a specific enzyme from a commercial pectinase for the production of steviol from stevioside (Ste) without adding organic solvent and to improve steviol production. RESULTS: Commercial Sumizyme PX converted Ste to steviol with a yield of 98%. ß-Glucosidase from Sumizyme PX (ßglyPX) was purified in three steps with 12.5-fold purification and 51% yield. The specific activity of the purified ßglyPX was 141 U/mg. The molecular weight of ßglyPX was ~ 116 kDa on SDS-PAGE. Its optimum activity was at pH 3.5 and 65 °C. It was stable for 12 h up to 55 °C and for 24 h at pH 2-9.5. K m values of ßglyPX for pNPGal, oNPGlc, lactose, and Ste were 2.4, 0.7, 18, and 7.8 mM, respectively. The optimum conditions for steviol production were 55 °C, 900 U/ml, 80 mg Ste/ml, 12 h. CONCLUSION: ßglyPX contains great potential for industrial steviol production from Ste.


Asunto(s)
Diterpenos de Tipo Kaurano/aislamiento & purificación , Diterpenos de Tipo Kaurano/metabolismo , Glucósidos/metabolismo , Poligalacturonasa/metabolismo , beta-Glucosidasa/aislamiento & purificación , beta-Glucosidasa/metabolismo , Electroforesis en Gel de Poliacrilamida , Estabilidad de Enzimas , Concentración de Iones de Hidrógeno , Cinética , Peso Molecular , Temperatura , beta-Glucosidasa/química
13.
J Sci Food Agric ; 98(6): 2138-2146, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28960323

RESUMEN

BACKGROUND: Proanthocyanidins are oligomeric or polymeric end products of flavonoid metabolic pathways starting with the central phenylpropanoid pathway. Although soybean (Glycine spp.) seeds represent a major source of nutrients for the human diet, as well as components for the cosmetics industry as a result of their high levels of flavonoid metabolites, including isoflavonoids, anthocyanins and proanthocyanidins, the genetic regulatory mechanisms underlying proanthocyanidin biosynthesis in soybean remain unclear. RESULTS: We evaluated interspecific and intraspecific variability in flavonoid components in soybean using 43 cultivars, landraces and wild soybean accessions. We performed transcriptomic profiling of genes encoding enzymes involved in flavonoid biosynthesis using three soybean genotypes, Hwangkeum (elite cultivar), IT109098 (landrace) and IT182932 (wild accession), in seeds. We identified a Glycine max landrace, IT109098, with a proanthocyanidin content as high as that of wild soybean. Different homologous genes for anthocyanidin reductase, which is involved in proanthocyanidin biosynthesis, were detected as differentially expressed genes between IT109098 and IT182932 compared to Hwangkeum. CONCLUSION: We detected major differences in the transcriptional levels of genes involved in the biosynthesis of proanthocyanidin and anthocyanin among genotypes beginning at the early stage of seed development. The results of the present study provide insights into the underlying genetic variation in proanthocyanidin biosynthesis among soybean genotypes. © 2017 Society of Chemical Industry.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Glycine max/genética , Proteínas de Plantas/genética , Proantocianidinas/biosíntesis , Vías Biosintéticas , Glicina/metabolismo , Proteínas de Plantas/metabolismo , Semillas/genética , Semillas/metabolismo , Glycine max/metabolismo , Transcriptoma
14.
Data Brief ; 14: 607-611, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28879218

RESUMEN

This article includes experimental data on the identification of epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG3''Me) by 2-dimensional (2D) proton (1H) NMR analysis and on the information of amino acid and catechin compound profiles by HPLC analysis in leaf extracts of various tea cultivars. These data are related to the research article "Metabolic phenotyping of various tea (Camellia sinensis L.) cultivars and understanding of their intrinsic metabolism" (Ji et al., 2017) [1]. The assignment for EGCG3x''Me by 1H NMR analysis was also confirmed with spiking experiment of its pure chemical.

15.
Food Chem ; 233: 321-330, 2017 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-28530581

RESUMEN

Recently, we selected three tea (Camellia sinensis) cultivars that are rich in taste, epigallocatechin-3-O-gallate (EGCG) and epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG3″Me) and then cultivated them through asexual propagation by cutting in the same region. In the present study, proton nuclear magnetic resonance (1H NMR)-based metabolomics was applied to characterize the metabotype and to understand the metabolic mechanism of these tea cultivars including wild type tea. Of the tea leaf metabolite variations, reverse associations of amino acid metabolism with catechin compound metabolism were found in the rich-taste, and EGCG- and EGCG3″Me-rich tea cultivars. Indeed, the metabolism of individual catechin compounds in the EGCG3″Me-rich cultivar differed from those of other tea cultivars. The current study highlights the distinct metabolism of various tea cultivars newly selected for cultivation and the important role of metabolomics in understanding the metabolic mechanism. Thus, comprehensive metabotyping is a useful method to assess and then develop a new plant cultivar.


Asunto(s)
Camellia sinensis , Catequina , Extractos Vegetales ,
16.
Enzyme Microb Technol ; 103: 59-67, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28554386

RESUMEN

Astragalin (kaempferol-3-O-ß-d-glucopyranoside, Ast) is a kind of flavonoid known to have anti-oxidant, anti-HIV, anti-allergic, and anti-inflammatory effects. It has low solubility in water. In this study, novel astragalin galactosides (Ast-Gals) were synthesized using ß-galactosidase from Bacillus circulans and reaction conditions were optimized to increase the conversion yield of astragallin. Purified Ast-Gal1 (11.6% of Ast used, w/w) and Ast-Gal2 (6.7% of Ast used, w/w) were obtained by medium pressure chromatography (MPLC) with silica C18 column and open column packed with Sephadex LH-20. The structures of Ast-Gal1 and Ast-Gal2 were identified by nuclear magnetic resonance (NMR) to be kaempferol-3-O-ß-d-glucopyranosyl-(1→6)-ß-d-galactopyranoside and kaempferol-3-O-ß-d-glucopyranosyl-(1→6)-ß-d-galactopyranosyl-(1→4)-ß-d-galactopyranoside, respectively. The water solubility of Ast, Ast-Gal1, and Ast-Gal2 were 28.2±1.2mg/L, 38,300±3.5mg/L, and 38,800±2.8mg/L, respectively. The SC50 value (the concentration required to scavenge 50% of the ABTS+) of Ast, Ast-Gal1, and Ast-Gal2 were 5.1±1.6µM, 6.5±0.4µM, and 4.9±1.1µM, respectively. The IC50 values (the half maximal inhibitory concentration) of Ast, Ast-Gal1, and Ast-Gal2 against angiotensin converting enzyme (ACE) were 171.0±1.2µM, 186.0µM, and 139.0±0.2µM, respectively.


Asunto(s)
Bacillus/enzimología , Proteínas Bacterianas/metabolismo , Quempferoles/biosíntesis , beta-Galactosidasa/metabolismo , Inhibidores de la Enzima Convertidora de Angiotensina/química , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Supervivencia Celular/efectos de los fármacos , Depuradores de Radicales Libres/química , Depuradores de Radicales Libres/farmacología , Galactósidos/biosíntesis , Galactósidos/química , Galactósidos/farmacología , Células HEK293 , Humanos , Microbiología Industrial , Quempferoles/química , Quempferoles/farmacología , Espectroscopía de Resonancia Magnética , Estructura Molecular , Solubilidad
17.
J Prosthet Dent ; 118(3): 372-378, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28222875

RESUMEN

STATEMENT OF PROBLEM: Post space size and cement thickness can differ because of variations in root canal morphology, such as an oval shape, and because the entire canal space cannot be included in the post space preparation. As a result, increased cement thickness around the post may affect the bond strength between the post and the dentin. PURPOSE: The purpose of this in vitro study was to evaluate the push-out bond strength of fiber-reinforced composite resin posts to root dentin with cement layers of varying thickness. MATERIAL AND METHODS: Thirty human premolars were endodontically treated and restored with fiber-reinforced composite resin posts. Post space was prepared using a drill with a 1.5-mm diameter and diameters of 1.25 mm (small [S] group), 1.375 mm (medium [M] group), and 1.5 mm (large [L] group) were cemented. The specimens were sectioned horizontally into 1-mm-thick slices, and the push-out bond strengths of the apical and coronal fragments were evaluated. Bond strength was compared using analysis of variance and 2-sample t tests (α=.05). RESULTS: No significant differences were found in the debonding force and push-out bond strength among fiber-reinforced composite posts of different sizes (P>.05). The mean debonding force and standard deviation of the posts were 25.05 ±9.52 N for the S group, 28.17 ±11.38 N for the M group, and 33.78 ±12.47 N for the L group. The corresponding push-out bond strength values were 3.11 ±1.54 MPa, 3.39 ±1.4 MPa, and 4.15 ±1.75 MPa. The differences in debonding force between the apical (26.43 ±10.72 N) and coronal (31.57 ±12.03 N) areas were not significant (P>.05). However, the differences in push-out bond strength between the apical (4.27 ±1.73 MPa) and coronal areas (2.83 ±1.08 MPa) were significant (P<.05). CONCLUSIONS: The widening of post spaces and, consequently, the increased cement thickness do not significantly affect the bond strength of fiber-reinforced composite resin posts to root dentin.


Asunto(s)
Resinas Compuestas/química , Técnica de Perno Muñón , Cementos de Resina/química , Análisis del Estrés Dental , Humanos , Tratamiento del Conducto Radicular
18.
Crit Rev Food Sci Nutr ; 57(8): 1631-1637, 2017 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-26114360

RESUMEN

Whereas green tea has historically been consumed in high quantities in Northeast Asia, its popularity is also increasing in many Western countries. Green tea is an abundant source of plant polyphenols exhibiting numerous effects that are potentially beneficial for human health. Accumulating evidence suggests that green tea polyphenols confer protective effects on the skin against ultraviolet (UV) irradiation-induced acceleration of skin aging, involving antimelanogenic, antiwrinkle, antioxidant, and anti-inflammatory effects as well as prevention of immunosuppression. Melanin pigmentation in the skin is a major defense mechanism against UV irradiation, but pigmentation abnormalities such as melasma, freckles, senile lentigines, and other forms of melanin hyperpigmentation can also cause serious health and aesthetic issues. Furthermore, UV irradiation initiates the degradation of fibrillar collagen and elastic fibers, promoting the process of skin aging through deep wrinkle formation and loss of tissue elasticity. UV irradiation-induced formation of free radicals also contributes to accelerated photoaging. Additionally, immunosuppression caused by UV irradiation plays an important role in photoaging and skin carcinogenesis. In this review, we summarize the current literature regarding the antimelanogenic, antiwrinkle, antioxidant, and immunosuppression preventive mechanisms of green tea polyphenols that have been demonstrated to protect against UV irradiation-stimulated skin photoaging, and gauge the quality of evidence supporting the need for clinical studies using green tea polyphenols as anti-photoaging agents in novel cosmeceuticals.


Asunto(s)
Antioxidantes/farmacología , Polifenoles/farmacología , Envejecimiento de la Piel/efectos de los fármacos , Té/química , Humanos , Tolerancia Inmunológica , Envejecimiento de la Piel/efectos de la radiación , Rayos Ultravioleta/efectos adversos
19.
Biotechnol Lett ; 39(3): 415-421, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27885509

RESUMEN

OBJECTIVES: To determine the inhibitory activities of flavonoids against NS2B-NS3 protease of ZIKA virus (ZIKV NS2B-NS3pro) expressed in Escherichia coli BL21 (DE3) and their structure activity relationship. RESULTS: ZIKV NS2B-NS3pro was expressed in E. coli BL21(DE3) as a 35 kDa protein. It had a K m of 26 µM with the fluorogenic peptide Dabcyl-KTSAVLQSGFRKME-Edan. The purified ZIKV NS2B-NS3pro was used for inhibition and kinetic assays to determine the activities of 22 polyphenol compounds. These polyphenol compounds at 100 µM inhibited the activity of ZIKV NS2B-NS3pro by 6.2-88%. Seven polyphenol compounds had IC50 ranging from 22 ± 0.2 to 112 ± 5.5 µM. Myricetin showed a mixed type inhibitory pattern against ZIKV NS2B-NS3pro protease. Its IC50 value was 22 ± 0.2 µM with a K i value of 8.9 ± 1.9 µM. CONCLUSION: The chemical structure of a polyphenol compound and its inhibitory activity against ZIKV NS2B-NS3pro can be explored to develop highly selective inhibitors against ZIKV NS2B-NS3pro.


Asunto(s)
Flavonoides/química , Flavonoides/farmacología , Inhibidores de Proteasas/química , Inhibidores de Proteasas/farmacología , Proteínas no Estructurales Virales/antagonistas & inhibidores , Virus Zika/enzimología , Electroforesis en Gel de Poliacrilamida , Polifenoles/química , Polifenoles/farmacología , Relación Estructura-Actividad , Proteínas no Estructurales Virales/metabolismo
20.
J Agric Food Chem ; 64(48): 9203-9213, 2016 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-27933996

RESUMEN

Epigallocatechin gallate (EGCG) is the most abundant catechin found in the leaves of green tea, Camellia sinensis. In this study, novel epigallocatechin gallate-glucocides (EGCG-Gs) were synthesized by using dextransucrase from Leuconostoc mesenteroides B-1299CB4. Response surface methodology was adopted to optimize the conversion of EGCG to EGCG-Gs, resulting in a 91.43% conversion rate of EGCG. Each EGCG-G was purified using a C18 column. Of nine EGCG-Gs identified by nuclear magnetic resonance analysis, five EGCG-Gs (2 and 4-7) were novel compounds with yields of 2.2-22.6%. The water solubility of the five novel compounds ranged from 229.7 to 1878.5 mM. The 5'-OH group of EGCG-Gs expressed higher antioxidant activities than the 4'-OH group of EGCG-Gs. Furthermore, glucosylation at 7-OH group of EGCG-Gs was found to be responsible for maintaining tyrosinase inhibitory activity and increasing browning-resistant activities.


Asunto(s)
Antioxidantes/química , Catequina/análogos & derivados , Glucósidos/biosíntesis , Glucosiltransferasas/metabolismo , Camellia sinensis/química , Catequina/biosíntesis , Inhibidores de Glicósido Hidrolasas/química , Humanos , Leuconostoc mesenteroides/enzimología , Estructura Molecular , Monofenol Monooxigenasa/antagonistas & inhibidores , alfa-Glucosidasas/química
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