Cerium/Ascorbic Acid/Iodine Active Species for Redox Flow Energy Storage Battery.

In this study, we developed a novel cerium/ascorbic acid/iodine active species to design a redox flow battery (RFB), in which the cerium nitrate hexahydrate [Ce(NO3)3·6H2O] was used as a positive Ce3+/Ce4+ ion pair, and the potassium iodate (KIO3) containing ascorbic acid was used as a negative I2/I- ion pair. In order to improve the electrochemical activity and to avoid cross-contamination of the redox pair ions, the electroless plating and sol-gel method were applied to modify the carbon paper electrode and the Nafion 117 membrane. The electrocatalytic and electrochemical properties of the composite electrode using methanesulfonic acid as a supporting electrolyte were assessed using the cyclic voltammetry (CV) test. The results showed that the Ce (III)/Ce (IV) active species presented a symmetric oxidation/reduction current ratio (1.09) on the C-TiO2-PdO composite electrode. Adding a constant amount of ascorbic acid to the iodine solution led to a good reversible oxidation/reduction reaction. Therefore, a novel Ce/ascorbic acid/I RFB was developed with C-TiO2-PdO composite electrodes and modified Nafion 117-SiO2-SO3H membrane using the staggered-type flow channel, of which the energy efficiency (EE%) can reach about 72%. The Ce/ascorbic acid/I active species can greatly reduce the electrolyte cost compared to the all-vanadium redox flow battery system, and it therefore has greater development potential.

Evaluating the Antioxidants, Whitening and Antiaging Properties of Rice Protein Hydrolysates.

Plant-derived protein hydrolysates have potential applications in nutrition. Rice protein hydrolysates (RPHs), an excellent source of proteins, have attracted attention for the development of cosmeceuticals. However, few studies have reported the potential application of RPH in analysis, and this study examined their antioxidant activities and the inhibitory activities of skin aging enzymes. The results indicated that the total phenolic and flavonoid concentrations were 2.06 ± 0.13 mg gallic acid equivalent/g RPHs and 25.96 ± 0.52 µg quercetin equivalent/g RPHs, respectively. RPHs demonstrated dose-dependent activity for scavenging free radicals from 1,1-diphenyl-2-picrylhydrazyl [half-maximal inhibitory concentration (IC50) = 42.58 ± 2.1 mg/g RPHs] and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (IC50 = 2.11 ± 0.88 mg/g RPHs), dose-dependent reduction capacity (6.95 ± 1.40 mg vitamin C equivalent/g RPHs) and oxygen radical absorbance capacity (473 µmol Trolox equivalent/g RPHs). The concentrations of the RPH solution required to achieve 50% inhibition of hyaluronidase and tyrosinase activities were determined to be 8.91 and 107.6 mg/mL, respectively. This study demonstrated that RPHs have antioxidant, antihyaluronidase, and antityrosinase activities for future cosmetic applications.

Light Energy Conversion Surface with Gold Dendritic Nanoforests/Si Chip for Plasmonic Polymerase Chain Reaction.

Surfaces with gold dendritic nanoforests (Au DNFs) on Si chips demonstrate broadband-light absorption. This study is the first to utilize localized surface plasmons of Au DNFs/Si chips for polymerase chain reaction (PCR) applications. A convenient halogen lamp was used as the heating source to illuminate the Au DNFs/Si chip for PCR. A detection target of Salmonella spp. DNA fragments was reproduced in this plasmonic PCR chip system. By semi-quantitation in gel electrophoresis analysis, the plasmonic PCR with 30 cycles and a largely reduced processing time provided results comparable with those of a commercial PCR thermal cycler with 40 cycles in more than 1 h. In the presence of an Au DNFs/Si chip, the plasmonic PCR provides superior results in a short processing time.

Effects of Storage Time and Temperature on Antioxidants in Juice from Momordica charantia L. and Momordica charantia L. var. abbreviata Ser.

This study determined the antioxidant activities of juice from Momordica charantia L. (MC) and MC var. abbreviata Ser. (MCVAS) by analyzing 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging ability, ferric reducing power (FRP), and total phenolic content (TPC). The effects of storage time and storage temperature on these antioxidant activities were investigated. Liquid chromatography-mass spectrometry was conducted to identify the major components of MC and MCVAS. The results revealed that the antioxidant activity of MCVAS was better than that of MC, possibly because of richer components of MCVAS. For MC and MCVAS, the scavenging concentrations of 50% DPPH were 3.33 and 1.19 mg/mL, respectively; moreover, the FRP values were 68.93 and 118.14 mg ascorbic acid equivalent/g dry weight, respectively; and the TPC values were 8.15 and 11.47 mg gallic acid equivalent/g dry weight, respectively. The antioxidant activities of MC and MCVAS decreased with storage time. High storage temperature decreased antioxidant activity more quickly than a low temperature. In addition, MC had exhibited a faster decline in DPPH scavenging ability and FRP than MCVAS during 24-day storage, but no difference was observed in TPC.

Green biosynthesis of gold nanoparticles using Chenopodium formosanum shell extract and analysis of the particles' antibacterial properties.

BACKGROUND: Various physical and chemical methods for synthesis of metal nanoparticles have had some drawbacks. Therefore, green synthesis of gold nanoparticles (Au NPs) has became one of the most crucial emerging areas of nanobiotechnology. In the present study, plant-mediated synthesis of Au NPs was performed using Djulis (Chenopodium formosanum) shell extract as a reducing and stabilizing agent. RESULTS: Reaction parameters were manipulated to optimize the Au NPs using a UV-visible spectrophotometer. Optimized Au NPs with a surface plasmon resonance band at 533 nm were prepared using a 744 µg mL-1 extract and a solution of pH 2.62 chloroauric acid (HAuCl4 ·3H2 O) at 40 °C. High-resolution transmission electron microscopy (HR-TEM) results indicated that most of the resultant Au NPs were spherical in shape and exhibited a mean size of 8 ± 6 nm. Energy-dispersive X-ray spectroscopy (EDS), and selected area electron diffraction (SAED), and X-ray diffraction (XRD) confirmed the elemental gold and crystalline nature of the resultant NPs. FTIR spectrum analysis indicated the critical role of phenolic groups in the reduction of Au3+ ions and stabilization of the formed Au NPs. Moreover, the synthesized Au NPs possessed antibacterial activity for Escherichia coli and Staphylococcus aureus. CONCLUSION: In this study, Au NPs were synthesized with high efficiency and stability using Djulis shell extract, and related antibacterial applications were demonstrated. © 2019 Society of Chemical Industry.

Antioxidation and Melanogenesis Inhibition of Various Dendrobium tosaense Extracts.

This study investigated the polyphenol content, antioxidant activity, and inhibition ability of mushroom tyrosinase and melanogenesis of Dendrobium tosaense (DT) extract. Ground DT was extracted using deionized water (W) or 50% ethanol (50E) at room temperature (RT) or 50 °C (50T) for 20 min. The 50T + 50E extract exhibited the highest total phenol content 47.0 ± 4.0 mg gallic acid equivalent/g DT extract, the highest level of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) free-radical scavenging 66.0 ± 3.0 mg Trolox equivalent/g DT extract, and the highest reducing power 12.00 ± 0.50 mg vitamin C equivalent/g DT extract. The RT + W extract had the highest total flavonoid content 110.0 ± 3.0 mg quercetin equivalent/g DT extract. The RT + 50E extract had the lowest half maximal inhibitory concentration 1.30 ± 0.00 mg/mL for 2,2-diphenyl-1-picrylhydrazyl free-radical scavenging, and the lowest half maximal inhibitory concentration 6.40 ± 0.30 mg/mL for mushroom tyrosinase inhibition activity. DT extracts, especially RT + W and 50T + W, exhibited potent inhibitory effects on melanogenesis of B16/F10 cells. These results demonstrated the application potential of DT extract for skincare.

Recent Advances in Antimicrobial Polymers: A Mini-Review.

Human safety and well-being is threatened by microbes causing numerous infectious diseases resulting in a large number of deaths every year. Despite substantial progress in antimicrobial drugs, many infectious diseases remain difficult to treat. Antimicrobial polymers offer a promising antimicrobial strategy for fighting pathogens and have received considerable attention in both academic and industrial research. This mini-review presents the advances made in antimicrobial polymers since 2013. Antimicrobial mechanisms exhibiting either passive or active action and polymer material types containing bound or leaching antimicrobials are introduced. This article also addresses the applications of these antimicrobial polymers in the medical, food, and textile industries.

Synthesis of uniform core-shell gelatin-alginate microparticles as intestine-released oral delivery drug carrier.

A core-shell gelatin-alginate composite used for intestine-released oral delivery drug carrier was synthesized through microfluidic technique. At the fixed continuous phase flow rate, the size of the core-shell gelatin-alginate microparticles increases with the dispersed phase flow rate, and monodispersity can be retained (the variation coefficient for the diameter distribution can be kept less than 10%). The fabricated microparticles could remain intact in gastric juice for at least 3 h, indicating that the gelatin core could be well protected by alginate shell in acid environment. However, the alginate shell of the microparticles would swell or collapse in alkali environment in half an hour, assuring the controlled drug release in intestinal juice. The fabricated uniform core-shell gelatin-alginate microparticles were potential as pH-responsive drug carriers.

Synthesis of uniform poly(d,l-lactide) and poly(d,l-lactide-co-glycolide) microspheres using a microfluidic chip for comparison.

Applications of poly(l-lactide) (PLA) and poly(d,l-lactide-co-glycolide) (PLGA) microspheres are widely used in the biomedical and pharmaceutical fields. The effects of PLA/PLGA on microsphere properties when using conventional particulate preparation methods are not easily defined due to the uncontrollable particle size and size distribution. This study was aimed to synthesize uniform PLA and PLGA microspheres using a phenol formaldehyde resin-based microfluidic chip, which has the advantage of being solvent-resistant, flexible, and is readily disassembled for cleaning. The proposed chip can rapidly fabricate reproducible PLA and PLGA microspheres. Uniform emulsion droplets can be achieved by hydrodynamic flow focusing. After solvent evaporation, the free-flowing PLA and PLGA microspheres have a high level of morphological uniformity and size, allowing for a clear comparison of material effects. The results indicate that the sizes of the PLA and PLGA microspheres for the various flow rates of dispersed/continuous phases are very similar. The PLA/PLGA materials do not have a significant effect on particle size, but the particle surface indicates a different morphology. The result of the cytotoxicity evaluation shows no difference between PLA and PLGA and ensures the biocompatibility of both prepared PLA and PLGA microspheres for biomedical and pharmaceutical applications in the future.

A novel evaporation detection system using an impedance sensing chip.

This paper presents a novel real-time impedance sensing chip for the evaporation detection of small volume solutions. Time sharing detection is performed for multiple sample measurements by a relay switching technique. In contrast to a conventional weight loss approach, the advantage of this proposed impedance sensing system is that it not only merely requires as little as 0.5 mL of test samples, but also provides high sensitivity and fast detection. More importantly, this proposed impedance sensing chip has advantages of a small chip size and easy decomposition for cleaning and reuse.

Effects of water quality on dissolution of yerba mate extract powders.

Yerba mate tea is known as one of the most popular nonalcoholic beverages favoured by South Americans due to its nutrition facts and medicinal properties. The processing of yerba mate tea is found to affect the properties of its final forms. This study presents an investigation into the effects of water sources on the dissolution of yerba mate extract powders. Comparisons were conducted between yerba mate teas prepared by dissolving yerba mate extract powders into tap water and deionized water. Topics to be explored in this work are the major compositions and antioxidant activities, including total phenol content, reducing power, DPPH scavenging activity, and ABTS(+)• scavenging capacity. It is indicated that there is little difference for antioxidant activities and major constituents of yerba mate teas between both water sources. However, a deeper color is seen in the tap water case, resulting from the reaction between tannic acid and ions. This research finding can be treated as a way to benefit the yerba mate tea processing for applications.

Fermented broth in tyrosinase- and melanogenesis inhibition.

Fermented broth has a long history of applications in the food, pharmaceutical and cosmetic industries. Recently, the use of fermented broth in skin care products is in ascendance. This review investigates the efficacy of fermented broth in inhibiting tyrosinase and melanogenesis. Possible active ingredients and hypopigmentation mechanisms of fermented broth are discussed, and potential applications of fermented broth in the cosmetic industry are also addressed.

Fluorescence photobleaching and recovery of fluorescein sodium in carbomer film.

This study investigated fluorescence photobleaching and the recovery of fluorescein sodium (FS)-loaded carbomer films. To mitigate errors caused by the self-quenching effect, the experiments were conducted at FS concentrations of 0.1, 0.5, and 1 wt%. The results revealed a nonlinear relationship between fluorescence intensity and FS concentration (0.1-1 wt%). Moreover, the degree and rate of photobleaching increased with FS concentration. The recovery level and recovery rate exhibited contrasting relationships with FS concentration. Higher FS concentrations were associated with a longer recovery time, which can be attributed to the prolonged irradiation, resulting in a bleached region that was larger than the initially irradiated area.

A High Copper Concentration Copper-Quadrol Complex Electroless Solution for Chip Bonding Applications.

This article presents a novel bonding method for chip packaging applications in the semiconductor industry, with a focus on downsizing high-density and 3D-stacked interconnections to improve efficiency and performance. Microfluidic electroless interconnections have been identified as a potential solution for bonding pillar joints at low temperatures and pressures. However, the complex and time-consuming nature of their production process hinders their suitability for mass production. To overcome these challenges, we propose a tailored plating solution using an enhanced copper concentration and plating rate. By eliminating the need for fluid motion and reducing the process time, this method can be used for mass production. The Taguchi approach is first used to optimize the copper-quadrol complex solution with the plating rate and decomposition time. This solution exhibits a copper concentration that is over five times higher than that of conventional solutions, a plating rate of 22.2 µm/h, and a decomposition time of 8 min on a Cu layer substrate. This technique enables Cu pillars to be successfully bonded within 7 min at 35 °C. Planarizing the pillar surface yields a high bonding percentage of 99%. Mechanical shear testing shows a significant fracture strength of 76 MPa.

Microfluidic synthesis of tail-shaped alginate microparticles using slow sedimentation.

This study reports the synthesis of tail-shaped alginate particles using a microfluidic platform combined with a sedimentation strategy. By utilizing microfluidic emulsification in the cross-junction channel, the formation of regular droplets was achieved. Following a facile and convenient sedimentation process and an ionic crosslinking process, sodium-alginate droplets became tail-shaped and then gradually developed into calcium-alginate microparticles. The effects of the concentration of the CaCl(2) crosslinker and the viscosity of the alginate solution on the shape and/or size of the particles were further investigated. The proposed synthesis methodology has the advantages of actively controlling the tail-shape formation, having a narrow size distribution, as well as being a facile and convenient process with a high throughput. This approach can be applied to many applications in the pharmaceutical and biomedical arena.

A real-time impedance-sensing chip for the detection of emulsion phase separation.

This paper describes a novel real-time impedance chip for the detection of squalene-water emulsion phase separation. Each impedance chip contains eight pairs of indium tin oxide microelectrode arrays for detecting eight samples, and six chips can be connected with the switch relay to measure 48 samples in the system simultaneously. The proposed impedance chip has the advantages of needing only a small sample volume (0.5 mL), and provides parallel, continuous, and real-time detection. The effects of the surfactant concentration on the stability of a squalene/water emulsion were studied by means of a visual inspection, a conductance probe, and by impedance chip. Three different concentrations of Tween 20 surfactant (9, 17, and 29 wt%) were employed for the examinations. The results indicated that the phase separation rate was faster in the lower surfactant concentration. However, the emulsion of 29 wt% Tween 20 was fairly stable for more than 2 days since there were no signal changes according to the three detection methods. The reaction time (TR) for completing the measured phase separation process differed for each of the three methods (measuring aqueous phase height, conductance, and impedance, respectively). For the 9 wt% Tween 20, the reaction times were 24 h, 20 min, and 5 min in the tests using visual inspection, conductance probe, and impedance chip, respectively. For the 17 wt% Tween 20, the TR was also shorter when using the impedance chip method compared to the other two methods. Therefore the proposed impedance chip has a quick reaction response and provides an alternative and effective method to detect emulsion stability.

Effects of water solutions on extracting green tea leaves.

This study investigates the effects of water solutions on the antioxidant content of green tea leaf extracts. Green teas prepared with tap water and distilled water were compared with respect to four antioxidant assays: total phenol content, reducing power, DMPD assay, and trolox equivalent antioxidant capacity assay. The results indicate that green tea prepared with distilled water exhibits higher antioxidant activity than that made with tap water. The high performance liquid chromatography showed that major constituents of green tea were found in higher concentrations in tea made with distilled water than in that made with tap water. This could be due to less calcium fixation in leaves and small water clusters. Water solutions composed of less mineralisation are more effective in promoting the quality of green tea leaf extracts.

A facile fabrication of alginate microbubbles using a gas foaming reaction.

Microbubble particles have been extensively utilized as temporal templates for various biomedical applications. This study proposes a facile strategy to obtain microbubble-containing alginate particles (i.e., microbubbles inside alginate gel particles, called alginate microbubbles). The chemical reaction of sodium bicarbonate and hydrogen peroxide to produce gaseous carbon dioxide and oxygen was utilized to form microbubbles within alginate particles. Uniform alginate particles were obtained by a stable needle-based droplet formation process. Kinetic reaction of gas formation was monitored for 2% alginate particles. The gas formation increased with the concentrations of sodium bicarbonate (1-5 wt%) and hydrogen peroxide (0-36.5 wt%).

A microfluidic chip using phenol formaldehyde resin for uniform-sized polycaprolactone and chitosan microparticle generation.

This study develops a new solvent-compatible microfluidic chip based on phenol formaldehyde resin (PFR). In addition to its solvent-resistant characteristics, this microfluidic platform also features easy fabrication, organization, decomposition for cleaning, and reusability compared with conventional chips. Both solvent-dependent (e.g., polycaprolactone) and nonsolvent-dependent (e.g., chitosan) microparticles were successfully prepared. The size of emulsion droplets could be easily adjusted by tuning the flow rates of the dispersed/continuous phases. After evaporation, polycaprolactone microparticles ranging from 29.3 to 62.7 µm and chitosan microparticles ranging from 215.5 to 566.3 µm were obtained with a 10% relative standard deviation in size. The proposed PFR microfluidic platform has the advantages of active control of the particle size with a narrow size distribution as well as a simple and low cost process with a high throughput.

Applications of Lactobacillus rhamnosus spent culture supernatant in cosmetic antioxidation, whitening and moisture retention applications.

This study was aimed at investigating the antioxidant, whitening, and moisture-retention properties of Lactobacillus rhamnosus spent culture supernatant (Lr-SCS) in cosmetic applications. Results reveal that Lr-SCS effectively and gradually scavenges 1,1-diphenyl-2-picrylhydrazyl as well as 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cations, and increases reducing power in a dose-dependent manner. Additionally, Lr-SCS can also suppress tyrosinase activity in vitro and effectively promote moisture retention. Heat treatment at 100 °C for 30 min does not influence the functions of Lr-SCS. We conclude that Lr-SCS can be used effectively in skin care cosmetics.