Flavonoid Glycosides from Ziziphus jujuba var. inermis (Bunge) Rehder Seeds Inhibit α-Melanocyte-Stimulating Hormone-Mediated Melanogenesis.

Ziziphus jujuba extracts possess a broad spectrum of biological activities, such as antioxidant and anticancer activities in melanoma cancers. Nevertheless, the compounds contain high antioxidant capacities and anticancer activities in melanoma cells, shown to be effective in hyperpigmentation disorders, but whether flavonoid glycosides from Z. jujuba regulate anti-melanogenesis remains unclear. In this study, we evaluated the anti-melanogenic activity of five flavonoid glycosides from Z. jujuba var. inermis (Bunge) Rehder seeds, including jujuboside A (JUA), jujuboside B (JUB), epiceanothic acid (EPA), betulin (BTL), and 6'''-feruloylspinosin (FRS), in B16F10 melanoma cells and zebrafish larvae. According to our results, JUB, EPA, and FRS potently inhibited α-melanocyte-stimulating hormone (α-MSH)-induced melanogenesis and prevented hyperpigmentation in zebrafish larvae. In particular, under α-MSH-stimulated conditions, FRS most significantly inhibited α-MSH-induced intracellular and extracellular melanin content in B16F10 melanoma cells. Additionally, JUB, EPS, and FRS remarkably downregulated melanogenesis in α-MSH-treated zebrafish larvae, with no significant change in heart rate. Neither JUA nor BTA were effective in downregulating melanogenesis in B16F10 melanoma cells and zebrafish larvae. Furthermore, JUB, EPA, and FRS directly inhibited in vitro mushroom tyrosinase enzyme activity. JUB, EPA, and FRS also downregulated cyclic adenosine monophosphate (cAMP) levels and the phosphorylation of cAMP-response element-binding protein (CREB), and subsequent microphthalmia transcription factor (MITF) and tyrosinase expression. In conclusion, this study demonstrated that JUB, EPA, and FRS isolated from Z. jujuba var. inermis (Bunge) Rehder seeds exhibit potent anti-melanogenic properties by inhibition of the cAMP-CERB-MITF axis and consequent tyrosinase activity.

Subseasonal relationship between Arctic and Eurasian surface air temperature.

The subseasonal relationship between Arctic and Eurasian surface air temperature (SAT) is re-examined using reanalysis data. Consistent with previous studies, a significant negative correlation is observed in cold season from November to February, but with a local minimum in late December. This relationship is dominated not only by the warm Arctic-cold Eurasia (WACE) pattern, which becomes more frequent during the last two decades, but also by the cold Arctic-warm Eurasia (CAWE) pattern. The budget analyses reveal that both WACE and CAWE patterns are primarily driven by the temperature advection associated with sea level pressure anomaly over the Ural region, partly cancelled by the diabatic heating. It is further found that, although the anticyclonic anomaly of WACE pattern mostly represents the Ural blocking, about 20% of WACE cases are associated with non-blocking high pressure systems. This result indicates that the Ural blocking is not a necessary condition for the WACE pattern, highlighting the importance of transient weather systems in the subseasonal Arctic-Eurasian SAT co-variability.

Physicochemical Property and Oxidative Stability of Whey Protein Concentrate Multiple Nanoemulsion Containing Fish Oil.

The objectives of this research were to produce whey protein concentrate (WPC) multiple nanoemulsion (MNE) and to study how whey protein concentration level and antioxidant type affected the physicochemical properties and oxidative stability of fish oil in MNE. The morphological and physicochemical characteristics of MNE were investigated by using transmission electron microscopy and particle size analyzer, respectively. The oxidative stability of fish oil in MNEs was assessed by measuring peroxide value (PV), p-anisidine value, and volatile compounds. The spherical forms of emulsions with size ranging from 190 to 210 nm were observed indicating the successful production of MNE. Compared with free fish oil, fish oil in MNE exhibited lower PV, p-anisidine value, and formation of maker of oxidation of fish oil indicating the oxidative stability of fish oil in MNE was enhanced. PV, p-anisidine value, and makers of oxidation of fish oil were decreased with increased WPC concentration level. The combined use of Vitamin C and E in MNE resulted in a reduction in PV and p-anisidine value, and development of maker of oxidation. In conclusion, WPC concentration level and antioxidant type are key factors affecting the droplet size of MNE and oxidative stability of fish oil.

New Blue Emitting Material with Asymmetric Limb Structure.

The new assymmetric limb-structured blue light emitting material, composed of anthracene main core, naphthalene units at 9, 10-position of anthracene and xylene units at 2,3-positon of anthracene, was designed and synthesized. The three-dimensional structure from theoretical calculation was characterized to elucidate non-copolar structure with inhibited intermolecular interaction. The limb-structured blue material was thermally stable up to 373 degrees C with T(g) of 143 degrees C. ITO/TAPC/CBP (3% BMPNA)/Bphen/LiF/Al device exhibits the maximum quantum efficiency of 3.42% and maximum current efficiency of 3.07 cd/A with deep blue emission of (0.141, 0.115) CIE coordinates.

Synthesis and characterization of a new poly(octathiophene) based copolymer for organic thin-film transistor.

A new poly(octathiophene) based copolymer was designed and synthesized by the palladium catalyzed Suzuki coupling reaction. The structure of the newly obtained copolymer was confirmed by 1H-NMR and IR. The number-average molecular weight (M(n)) of the polymer was 36,000 with a poly-dispersity index of 1.15. The polymer has good solubility in common solvents such as chloroform, toluene, chlorobenzene, dichlorobenzene and tetrahydrofuran at room temperature. The optical, thermal and electrochemical properties of the polymer were characterized by UV-vis absorption, TGA and DSC and cyclovoltametry, respectively. A thin film transistor using the new polymer as an organic semiconductor was found to exhibit typical p-channel FET characteristics with a hole mobility of 5 x 10(-4) cm2/Vs.

Synthesis and characterization of pentathiophene based copolymer for organic thin film transistor.

The new dialkylated pentathiophene based copolymer was synthesized by Suzuki coupling reaction. The PD5TADF is synthesized and used as an active material for organic thin film transistor (OTFTs). The copolymer has good solubility in common organic solvent such as toluene, tetrahydrofuran (THF), chloroform, chlorobenzene and dichlorobenzene. The number average molecular weight (Mn) was measured to be 148,000. The TGA curve shows that the polymers exhibit good thermal stability with a weight loss of less than 5% upon heating to 419 °C with glass temperature at 184.9 °C. The ultraviolet (UV) maximum of the polymer was found at 494 nm in solution and 498 nm in the film. A thin-film transistor with PD5TADF was found to exhibit typical p-channel FET characteristics with a hole mobility of 2.6 x 10(-4) cm2/Vs and an on/off ratio of 3.04 x 10(4) with a threshold voltage of -4.5 V.

Organic semiconductor based on asymmetric naphthalene-thiophene molecule for organic thin film transistor.

The new asymmetric semiconductor 5-(6-decylnaphthalen-2-yl)-5'-(naphthalene-2-yl)-2,2'-bithiophene (NBTND) was synthesized by Suzuki coupling reaction for an organic thin film transistor (OTFT) material. This asymmetric molecule was characterized by H-NMR, IR, HRMS, UV-visible spectroscopy, cyclovoltammetry, thermogravimetric analysis, differential scanning calorimetry. The thin film transistor using new asymmetric semiconductor exhibited the field effect mobility of 2.68 x 10(-2) cm2 V(-1) s(-1).

Conjugated polymers and an iron complex as electrocatalytic materials for an enzyme-based biofuel cell.

Poly-5,2':5',2''-terthiophen-3'-carboxylic acid (polyTTCA) and poly-Fe(III)-[N,N'-bis[4-(5,2':5',2''-terthien-3'-yl)salicyliden]-1,2-ethanediamine] (polyFeTSED) were synthesized and electrochemically polymerized on an Au surface for use as mediators and catalysts for a biofuel cell. The atomic force microscopy (AFM) images of (a) the TTCA homopolymer (polyTTCA) and (b) the TTCA-FeTSED copolymer (poly(TTCA-FeTSED)) layers show a nanoparticle structure. The enzymes (glucose oxidase (GOx) or horseradish peroxidase (HRP)) were immobilized onto the conducting polymer layer through covalent bond formation, which allowed for direct electron transfer processes of the enzymes. A quartz crystal microbalance (QCM) revealed that the surface coverages of GOx and HRP were 4.21 x 10(-12)M and 9.65 x 10(-12)M, respectively. The anode with immobilized GOx and the cathode with immobilized HRP were used as model enzyme systems in biofuel cells for glucose and H(2)O(2) detection, respectively. The biofuel cell composed of the GOx/polyTTCA/Au and the HRP/poly(TTCA-FeTSED)/Au electrodes was assembled and examined for cell performance. The copolymer of polyFeTSED complex with polyTTCA revealed a catalytic activity for the electrochemical reduction of H(2)O(2) and resulted in approximately a sevenfold increase in the power density of the biofuel cell over that of polyTTCA itself. Moreover, the conjugated polymers extend the biofuel cell lifetime to 4 months through the stabilization of immobilized enzymes. The biofuel cell operated in a solution containing glucose and anode-produced H(2)O(2) generated an open-circuit voltage of approximately 366.0 mV, while the maximum electrical power density extracted from the cell was 5.12 microW cm(-2) at an external optimal load of 25.0 k Omega.

One-step synthesis of gold nanoparticles using azacryptand and their applications in SERS and catalysis.

A new aqueous-phase method for the preparation of stable gold nanoparticles by using 1,4,7,10,13,16,21,24-octaazabicyclo[8.8.8]hexacosane (azacryptand) as both reductant and stabilizer is reported. Reduction of HAuCl(4) with azacryptand at room temperature yields nano-sized particles within a short time. The obtained gold nanoparticles have been characterized by UV-vis spectroscopy, transmission electron microscopy, and X-ray diffraction. Comparison of FT-IR spectra of azacryptand before and after reaction revealed that azacryptand molecules reduce gold ions as the amino moieties in the molecules are oxidized to imino groups. The prepared gold nanoparticles show efficient surface-enhanced Raman scattering properties and can effectively catalyze reduction of 4-nitrophenol by sodium borohydride in aqueous solution.