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In recent years, caffeic acid and its derivatives have received increasing attention due to their obvious physiological activities and wide distribution in nature. In this paper, to clarify the status of research on plant-derived caffeic acid and its derivatives, nuclear magnetic resonance spectroscopy data and possible biosynthetic pathways of these compounds were collected from scientific databases (SciFinder, PubMed and China Knowledge). According to different types of substituents, 17 caffeic acid and its derivatives can be divided into the following classes: caffeoyl ester derivatives, caffeyltartaric acid, caffeic acid amide derivatives, caffeoyl shikimic acid, caffeoyl quinic acid, caffeoyl danshens and caffeoyl glycoside. Generalization of their 13C-NMR and 1H-NMR data revealed that acylation with caffeic acid to form esters involves acylation shifts, which increase the chemical shift values of the corresponding carbons and decrease the chemical shift values of the corresponding carbons of caffeoyl. Once the hydroxyl group is ester, the hydrogen signal connected to the same carbon shifts to the low field (1.1~1.6). The biosynthetic pathways were summarized, and it was found that caffeic acid and its derivatives are first synthesized in plants through the shikimic acid pathway, in which phenylalanine is deaminated to cinnamic acid and then transformed into caffeic acid and its derivatives. The purpose of this review is to provide a reference for further research on the rapid structural identification and biofabrication of caffeic acid and its derivatives. [ABSTRACT FROM AUTHOR]

The prebiotic mechanism to produce molecular oxygen (O2) in carbon dioxide (CO2)-rich planetary atmospheres is of great importance in understanding astrochemical reactions and is potentially relevant to the origin of life on Earth. Here, we demonstrate that, aside from the direct productions of O2 by photodissociation and dissociative electron attachment, the low-energy ion-molecule reaction between cationic helium in solar winds and molecular CO2 is a noticeable mechanism. Branching ratios of the reaction channels are determined, and their absolute cross-sections are estimated accordingly. The present findings represent a further, indispensable step towards fully understanding the origins of atmospheric O2. The abiotic production of molecular oxygen in carbon dioxide-rich planetary atmospheres is important in understanding astrochemical reactions and potentially the origin of life on Earth. Here, the authors demonstrate that the low-energy reaction between helium ions, as found in solar winds, and carbon dioxide produces molecular oxygen. [ABSTRACT FROM AUTHOR]

We had successfully fabricated CuInSe 2 (CIS) thin film by electro-deposition technique. Electro-deposited ternary selenide precursor was thermally annealed under nitrogen conditions to form CuInSe 2 films. The structure, composition, chemical state and optical characterization of CuInSe 2 films were measured using several techniques, including Scanning electron microscopy (SEM), Atomic force microscopy (AFM), Atomic emission spectroscopy (AES), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Ultraviolet Spectrophotometry (UV) and electrochemical workstation. The results showed that the CuInSe 2 thin films formed using electro-deposition had dense grain structure whose size was various with the increase of the deposited voltage and annealing temperature. The band gap of CuInSe 2 was 1.43 eV when deposition voltage was 1.7 V, and CIS film exhibited the most excellent property. [ABSTRACT FROM AUTHOR]

The work is focused on electroless nickel plating on polyimide film. The Ni salt activation, which neglects the use of palladium, is adopted in pretreatment. The orthogonal experiment and single factor test are used to optimize the experiment, thus the optimum compositions and conditions of electroless nickel plating are obtained. The cleaned, activated and deposited polyimide films are also characterized by their structure, morphology, component and chemical state. The activation process of nickel salt is analyzed on basis of experiment and test. A Ni–P film with fine and dense structure is achieved on the polyimide film which consists of 92.23 wt.% Ni and 7.77 wt.% P. The result of tensile test indicates that the adhesion between the substrate and the coating layer is sufficiently excellent due to dimples by etching. [ABSTRACT FROM AUTHOR]