High‐Performance Piezo‐Electrocatalytic Sensing of Ascorbic Acid with Nanostructured Wurtzite Zinc Oxide

2021 ◽  
pp. 2105697
Author(s):  
Nianzu Liu ◽  
Ruoxing Wang ◽  
Shengjie Gao ◽  
Ruifang Zhang ◽  
Fengru Fan ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Zinc Oxide ◽  
High Performance

Core-shell nanostructured Zn-Co-O@CoS arrays for high-performance hybrid supercapacitors

2021 ◽  
Author(s):  
Yi He ◽  
Lei Xie ◽  
Shixiang Ding ◽  
Yujia Long ◽  
Xinyi Zhou ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Energy Storage ◽  
Active Sites ◽  
High Performance ◽  
Electronic Conductivity ◽  
Wide Distribution ◽  
Energy Storage Materials ◽  
Core Shell ◽  
Storage Materials ◽  
Hybrid Supercapacitors

Although the zinc oxide (ZnO) with wide distribution is one of the most attractive energy storage materials, the low electronic conductivity and insufficient active sites of bulk ZnO increase the...

scholarly journals (−)-Epicatechin—An Important Contributor to the Antioxidant Activity of Japanese Knotweed Rhizome Bark Extract as Determined by Antioxidant Activity-Guided Fractionation

Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 133
Author(s):  
Urška Jug ◽  
Katerina Naumoska ◽  
Irena Vovk
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
High Performance ◽  
Radical Scavenging ◽  
Size Exclusion ◽  
Solvent Mixtures ◽  
Japanese Knotweed ◽  
Compound Identification ◽  
Rp Hplc ◽  
Ic50 Value

The antioxidant activities of Japanese knotweed rhizome bark extracts, prepared with eight different solvents or solvent mixtures (water, methanol, 80% methanol(aq), acetone, 70% acetone(aq), ethanol, 70% ethanol(aq), and 90% ethyl acetate(aq)), were determined using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging assay. Low half maximal inhibitory concentration (IC50) values (2.632–3.720 µg mL−1) for all the extracts were in the range of the IC50 value of the known antioxidant ascorbic acid at t0 (3.115 µg mL−1). Due to the highest extraction yield (~44%), 70% ethanol(aq) was selected for the preparation of the extract for further investigations. The IC50 value calculated for its antioxidant activity remained stable for at least 14 days, while the IC50 of ascorbic acid increased over time. The stability study showed that the container material was of great importance for the light-protected storage of the ascorbic acid(aq) solution in a refrigerator. Size exclusion–high-performance liquid chromatography (SEC-HPLC)–UV and reversed phase (RP)-HPLC-UV coupled with multistage mass spectrometry (MSn) were developed for fractionation of the 70% ethanol(aq) extract and for further compound identification, respectively. In the most potent antioxidant SEC fraction, determined using an on-line post-column SEC-HPLC-DPPH assay, epicatechin, resveratrol malonyl hexoside, and its in-source fragments (resveratrol and resveratrol acetyl hexoside) were tentatively identified by RP-HPLC-MSn. Moreover, epicatechin was additionally confirmed by two orthogonal methods, SEC-HPLC-UV and high-performance thin-layer chromatography (HPTLC) coupled with densitometry. Finally, the latter technique enabled the identification of (−)-epicatechin. (−)-Epicatechin demonstrated potent and stable time-dependent antioxidant activity (IC50 value ~1.5 µg mL−1) for at least 14 days.

scholarly journals Effects of Natural Antioxidants on Phospholipid and Ceramide Profiles of 3D-Cultured Skin Fibroblasts Exposed to UVA or UVB Radiation

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 578
Author(s):  
Agnieszka Gęgotek ◽  
Wojciech Łuczaj ◽  
Elżbieta Skrzydlewska
Keyword(s):  
Ascorbic Acid ◽  
High Performance ◽  
Three Dimensional ◽  
Natural Antioxidants ◽  
Phospholipid Metabolism ◽  
Culture Conditions ◽  
Membrane Properties ◽  
Dimensional System ◽  
Uvb Radiation ◽  
Liquid Chromatograph

Ultraviolet (UV) radiation is one of the primary factors responsible for disturbances in human skin cells phospholipid metabolism. Natural compounds that are commonly used to protect skin, due to their lipophilic or hydrophilic nature, show only a narrow range of cytoprotective activity, which prompts research on their combined application. Therefore, the aim of this study was to examine the effect of ascorbic acid and rutin on the phospholipid and ceramide profiles in UV-irradiated fibroblasts cultured in a three-dimensional system that approximates the culture conditions to the dermis. An ultra-high-performance liquid chromatograph coupled with a quadrupole time-of-flight mass spectrometer was used for phospholipid and ceramide profiling. As a result of UVA and UVB cells irradiation, upregulation of phosphatidylcholines, ceramides, and downregulation of sphingomyelins were observed, while treatment with ascorbic acid and rutin of UVA/UVB-irradiated fibroblast promoted these changes to provide cells a stronger response to stress. Moreover, an upregulation of phosphatidylserines in cells exposed to UVB and treated with both antioxidants suggests the stimulation of UV-damaged cells apoptosis. Our findings provide new insight into action of rutin and ascorbic acid on regulation of phospholipid metabolism, which improves dermis fibroblast membrane properties.

Modification of a polymer gate insulator by zirconium oxide doping for low temperature, high performance indium zinc oxide transistors

RSC Advances ◽  
2014 ◽  
Vol 4 (86) ◽  
pp. 45742-45748 ◽  
Author(s):  
Byeong-Geun Son ◽  
So Yeon Je ◽  
Hyo Jin Kim ◽  
Jae Kyeong Jeong
Keyword(s):  
Zinc Oxide ◽  
Low Temperature ◽  
Zirconium Oxide ◽  
High Performance ◽  
Gate Insulator ◽  
Indium Zinc Oxide

Determination of ascorbic acid in the retina during chicken embryo development using high performance liquid chromatography and UV detection

2016 ◽  
Vol 8 (27) ◽  
pp. 5441-5447 ◽  
Author(s):  
Débora R. S. Lima ◽  
Marcelo Cossenza ◽  
Carlos Gustavo Garcia ◽  
Camila C. Portugal ◽  
Flávia F. de C. Marques ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Embryo Development ◽  
Chicken Embryo ◽  
High Performance ◽  
Uv Detection

A HPLC-UV method has been developed and validated for the determination of ascorbic acid in chicken embryo retina.

scholarly journals The Characteristics of Aluminum-Gallium-Zinc-Oxide Ultraviolet Phototransistors by Co-Sputtering Method

Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 631
Author(s):  
Wei-Lun Huang ◽  
Sheng-Po Chang ◽  
Cheng-Hao Li ◽  
Shoou-Jinn Chang
Keyword(s):  
Zinc Oxide ◽  
Thin Film Transistors ◽  
High Performance ◽  
Wide Bandgap ◽  
Visible Light Region ◽  
Current Ratio ◽  
Rejection Ratio ◽  
Light Region ◽  
Sputtering Power ◽  
Solar Blind

In this thesis, Aluminum-Gallium-Zinc oxide (AGZO) photo thin film transistors (PTFTs) fabricated by the co-sputtered method are investigated. The transmittance and absorption show that AGZO is highly transparent across the visible light region, and the bandgap of AGZO can be tuned by varying the co-sputtering power. The AGZO TFT demonstrates high performance with a threshold voltage (VT) of 0.96 V, on/off current ratio of 1.01 × 107, and subthreshold swing (SS) of 0.33 V/dec. Besides, AGZO has potential for solar-blind applications because of its wide bandgap. The AGZO PTFT of this research can achieve a rejection ratio of 4.31 × 104 with proper sputtering power and a rising and falling time of 35.5 s and 51.5 s.

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