Fatty acids,tocopherols, phenolic and antioxidant properties of six citrus fruit species: a comparative study

Citrus fruit is a rich source of bioactive phytochemicals. Information on the fatty acid and tocopherol composition of locally grown citrus fruits in Korea is elusive. This work was aimed to study fatty acid, tocopherols, ascorbic acid, antioxidant potential, and selected phenolics from peel and pulp of six citrus species. The most dominant fatty acid was linoleic acid (15–45%), followed by linolenic, palmitic, and oleic acid. Stearic acid was highly abundant in yuzu peel (14.45%) and pulp (15.88%) compared to the other fruits. Unsaturated fatty acids (54–74%) contributed higher composition than saturated fatty acids (25–46%). Peel exhibited better antioxidant potential and contained higher phytochemicals than pulp. The concentrations of α-tocopherol and γ-tocopherol were ranged from 22.96 (yuzu) to 86.93 (cheonhyeyang) and 38.59 (yuzu) ~83.03 (tangerine) μg/g DW, respectively. J-Redhyeyang peel exhibited highest total flavonoids (4.17?±?0.10 mgQE/g DW) and DPPH radical scavenging activity (6.17?±?0.03 mgTE/g DW). FRAP values were highest (20.05?±?0.64 mgTE/g DW) in yuzu peel, while peel of cheonhyeyang was superior in total phenolic contents. Tangerine (3.02?±?0.05 mg/g DW) and yuzu (7.49?±?0.38 mg/g DW) had higher hesperidin concentrations in pulp and peel, respectively. Naringin was found in an appreciable amount in yuzu pulp (2.04?±?0.09 mg/g DW) and peel (6.30?±?0.19 mg/g DW) but not detected in all other fruit species. Our results indicate that citrus fruit peel is the rich source of antioxidant compounds, which can be used to prepare antioxidant rich food product.     

Cyclic-oxidation behaviours of the powder-metallurgy TiAl–4Nb–3Mn and TiAl–2Nb–2Mo beta-gamma alloys

For this study, cyclic-oxidation tests for the powder-metallurgy TiAl–4Nb–3Mn and TiAl–2Nb–2Mo alloys were carried out in air between room temperature and 900°C, and the oxidation behaviours under cyclic oxidation were compared with those under isothermal oxidation. The morphologies and structures of the oxides are identical to those from isothermal oxidation, except for the Mn-oxide formation on the top surface in the case of the TiAl–4Nb–3Mn alloy. The growth rate of the oxides in the TiAl–2Nb–2Mo alloy is slower and more stable than that of the oxides in the TiAl–4Nb–3Mn alloy, and severe internal oxidation is also evident in the latter alloy; however, the weight gain showed a sudden drop in the TiAl–2Nb–2Mo alloy that is mainly due to the enhanced formation of titanium nitrides at the interface.     

Tocols in caneberry seed oils

The compositional analysis of tocols in oils extracted from Korean caneberry seeds was compared with commercial soybean, corn, olive, canola, perilla, and grape seed oils. The oils from caneberry seeds of six different species were extracted using either a chloroform–methanol–water system or hot hexane. Tocols from all of the oils were analysed using isocratic HPLC. The contents of total tocopherols in the caneberry seed oils were about 75–290 mg/100 g oil, whereas tocotrienols were not detected. γ-Tocopherol was the most abundant tocopherol (31.8–239 mg/100 g oil) in the caneberry seed oils, followed by α-tocopherol (7.6–58.2 mg/100 g oil). The contents of total tocols in soybean, corn, olive, canola, perilla, and grape seed oils were 99.9, 61.1, 28, 27, 45.4, and 52.2 mg/100 g oil, respectively. Total tocol content was higher in most of the caneberry seed oils including the refined ones than in the commercial vegetable oils.     

A stochastic analysis of contaminant transport through a rough-surfaced fracture

A stochastic model for the calculation of flow and contaminant transport in a single fracture with variable apertures was presented. The spatially varying apertures of the fracture were generated using a geostatistical method, based on a given aperture probability density distribution and a specified spatial correlation length. Fluid flowed between two points in the fracture plane. The fluid potential at each node of the discretization mesh was computed and the steady state flow rates between all the nodes were obtained. Then the contaminant transport was calculated using a particle tracking method. The migration plumes of contaminant between the inlet and the outlet were displayed in contour plots and contaminant elution profiles were also plotted. Calculations showed that fluid flow occured predominantly in a few preferred paths. Hence, the large range of apertures in the fracture gives rise to flow channeling. Simulation results were correlated with the basic input parameters: standard deviation of a lognormal aperture distribution function and the spatial correlation length.     

Extraction of antioxidants and flavonoids from yuzu (<Emphasis Type=Italic>Citrus junos</Emphasis> Sieb ex Tanaka) peels: a response surface methodology study

In the present investigation, extraction of antioxidants and flavonoids from the peels of yuzu fruit using a single factor experiment and a response surface methodology (RSM) based on central composite design was studied. Four independent variables were evaluated at five levels with total 29 experimental runs, including ethanol concentration (EtOH), ratio of liquid to material (L/S), extraction temperature (T), and extraction time (t). The total phenolic content (TPC), total flavonoids content (TFC), two indicators of antioxidant capacity (FRAP and DPPH), and three individual major flavonoids in yuzu (hesperidin, naringin, and phloretin) served as the response functions. Quadratic polynomial equations were obtained by multiple regression analysis to predict the optimal extraction conditions. The regression analysis showed that >95?% of variations were explained by the models of different responses considered. The responses were significantly influenced by all studied factors. The Multiresponse optimized conditions targeted at maximizing all the responses were found to be EtOH?=?65.550?%; T?=?43.864?°C; t?=?119.673 min; and L/S?=?37.168 ml/g, with a desirability of 0.950. At the optimized conditions, the experimental values of FRAP (964.9?±?23.1 mgTE/g DW), DPPH (453.0?±?5.2 mgTE/g DW), TPC (1161.2?±?25.2 mgGAE/g DW), (TFC393.4?±?mgQE/g DW), hesperidin (337.2?±?4.0 mg/g DW), naringin (244.9?±?1.1 mg/g DW), and phloretin (43.9 mg/g DW) were in a reasonable agreement with the predicted values. The extraction method was applied successfully to extract antioxidants and flavonoids from yuzu peels. It also allows a fast and cost-saving process for extraction of the studied phytochemicals, in addition to improvement of the quantity of the targeted extract.     

Tubulin-Based Nanotubes as Delivery Platform for Microtubule-Targeting Agents

Tubulin-based nanotubes (TNTs) to deliver microtubule-targeting agents (MTAs) for clinical oncology are reported. Three MTAs, docetaxel (DTX), laulimalide (LMD), and monomethyl auristatin E (MMAE), which attach to different binding sites in a tubulin, are loaded onto TNTs and cause structural changes in them, including shape anisotropy and tubulin layering. This drug-driven carrier transformation leads to changes in the drug-loading efficiency and stability characteristics of the carrier. TNTs coloaded with DTX and LMD efficiently deliver dual drug cargoes to cellular tubulins by the endolysosomal pathway, and results in synergistic anticancer and antiangiogenic action of the drugs in vitro. In in vivo tests, TNTs loaded with a microtubule-destabilizing agent MMAE suppress the growth of tumors with much higher efficacy than free MMAE did. This work suggests a new concept of using a drug's target protein as a carrier. The findings demonstrate that the TNTs developed here can be used universally as a delivery platform for many MTAs.     

Reducing image sticking in AMOLED displays with time‐ratio gray scale by analog calibration

Abstract— Early loss of image uniformity has been a critical drawback of active‐matrix organic light‐emitting‐diode (AMOLED) displays operated in time‐ratio gray‐scale mode. This problem is addressed with an analog calibration technique which measures the voltage across each OLED for a given current and subsequently controls the supply voltage of pixels and the voltage drop across the driving th in‐film transistor (TFT) of each OLED. The uniformity of test cells, which were aged to produce image sticking in a chessboard pattern, were improved. A measure of image sticking, called the extracted image‐sticking value (EISV), was formulated, which is developed and used for the quantitative evaluation of the calibration method. OLED voltages over a range of about 0.35 V were compensated to produce more uniform OLED currents than those before aging. The variation of luminance associated with image sticking was reduced by about 40% for a full‐white image after between 2 and 10 hours of accelerated aging with a constant voltage of 8 V across an OLED.     

Paper‐Like,Thin, Foldable,and Self‐Healable Electronics Based on PVA/CNC Nanocomposite Film

The facile fabrication of thin and foldable self‐healing electronics on a poly(vinyl alcohol)/cellulose nanocrystal (PVA/CNC) composite film is reported. The self‐healing property of the PVA/CNC nanocomposite film can be activated by spraying water on the film surface, via dynamic formation of hydrogen bonding. The self‐healing efficiency of PVA/CNC is influenced by the content of CNC in the film, pH of the spraying solution, and the temperature. Via vacuum filtration and pattern transfer techniques, both a supercapacitor and a temperature sensor are fabricated on the same PVA/CNC film using gold nanosheet (AuNS) and polyaniline/multiwalled nanotube (PANI/MWCNT) electrodes. The fabricated supercapacitor with a gel‐type electrolyte exhibits a high electrochemical performance, and the thermoresistive temperature sensor shows a linear sensitivity with a fast response. Both devices exhibit superior mechanical stability and self‐healing property over 100 repetitive folding and five repetitive healing cycles, respectively, retaining the device performance owing to the percolated network of the conductive materials. This work demonstrates that our paper‐like thin PVA/CNC film‐based self‐healable devices can serve as highly durable and deformable electronics with longevity.     

A Textile-Based Temperature-Tolerant Stretchable Supercapacitor for Wearable Electronics

Among the extensive development of wearable electronics, which can be implanted onto bodies or embedded in clothes, textile-based devices have gained significant attention. For daily basis applications, wearable energy storage devices are required to be stable under harsh environmental conditions and different deformational conditions. In this study, a textile-based stretchable supercapacitor with high electrochemical performance, mechanical stability, and temperature tolerance over a wide temperature range is reported. It exhibits high areal capacitances of 28.0, 30.4, and 30.6 mF cm⁻² at −30, 25, and 80 °C, respectively, while the capacitance remains stable over three repeated cycles of cooling and heating from −30 to 80 °C. The supercapacitor is stable under stretching up to 50% and 1000 repetitive cycles of stretching. A temperature sensor and an liquid-crystal display are simultaneously driven at temperatures between −20 and 80 °C by the supercapacitors. The supercapacitors are woven into a nylon glove power a micro-light-emitting diode stably regardless of the bending of the index finger. Furthermore, the encapsulated supercapacitors retain the capacitance during being immersed in water for a few days. This study demonstrates the potential application of the fabricated supercapacitor as a wearable energy storage device that works under extreme temperature variations, high humidity, and body movements.