The growing industrial demand for flexible optoelectric devices has led to intensive researches on highly flexible transparent electrode materials such as graphene, reduced graphene‐oxide (r‐GO), Ag‐nanowire, and 2D metal oxides. However, except Ag‐nanowire, transparent electrode materials having optoelectric properties comparable to that of indium–tin–oxide (ITO) have not yet been developed. In this study, an ultrathin ruthenium film with a ruthenium oxide (RuO2) subsurface layer has been introduced as a flexible transparent electrode. The metallic Ru thin film is fabricated from a RuO2 nanosheet using a layer‐by‐layer coating technique, followed by thermal reduction. The thin film (≈6 nm) reveals comparable sheet resistance and transmittance as that of conventional ITO electrodes. The high transmittance (≈79%) of the metal thin film in the visible range is attributed to the presence of an oxide subsurface layer which acts as antireflection. The Ru film (with oxide subsurface layer) with figure‐of‐merit ≈3.4 × 10−4 Ω−1 shows the best performance among the thin films fabricated using a wet‐chemistry process with 2D nanosheets including graphene, r‐GO, and other metal oxides. In addition, the high mechanical flexibility of Ru thin film makes it next‐generation flexible transparent conducting electrodes, beyond graphene, r‐GO, and 2D metal oxides.

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Rosa canina L. is health functional food materials that can help to temporarily relieve symptoms of arthritis. This study has been conducted to develop and validate analytical methods for hyperoside of Rosa canina L.. Methods based on HPLC with ultraviolet detection (UVD) were established through instrumental analytical conditions, and the examination of data, such as domestic and foreign reliable methods and journals. HPLC UVD analysis using Capcell Pak C 18 MG II column at 353 nm was determined on test through the column, mobile phase. The validation has been performed on the method to determine linearity, accuracy, limits of quantification (LOQ) and repeatability for hyperoside. The method showed high linearity in the calibration curve at a coefficient of correlation (R 2 ) of 0.999, and the LOQ was 0.393 µg/mL. Relative standard deviation (RSD) values of data from repeatability precision was between 0.6 and 2.6%. Recovery rate test at hyperoside scored between 98 and 99%. These results indicate that the established HPLC method is very useful for the determination of hyperoside in Rosa canina L. to develop a health functional material.