16 research outputs found

    Bias-free solar hydrogen production at 19.8???mA???cm???2 using perovskite photocathode and lignocellulosic biomass

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    Solar hydrogen production is one of the ultimate technologies needed to realize a carbon-neutral, sustainable society. However, an energy-intensive water oxidation half-reaction together with the poor performance of conventional inorganic photocatalysts have been big hurdles for practical solar hydrogen production. Here we present a photoelectrochemical cell with a record high photocurrent density of 19.8???mA???cm???2 for hydrogen production by utilizing a high-performance organic???inorganic halide perovskite as a panchromatic absorber and lignocellulosic biomass as an alternative source of electrons working at lower potentials. In addition, value-added chemicals such as vanillin and acetovanillone are produced via the selective depolymerization of lignin in lignocellulosic biomass while cellulose remains close to intact for further utilization. This study paves the way to improve solar hydrogen productivity and simultaneously realize the effective use of lignocellulosic biomass

    Lignin as a multifunctional photocatalyst for solar-powered biocatalytic oxyfunctionalization of C???H bonds

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    Each year, the pulp and paper industry produces approximately 50???million metric tons of lignin as waste, 95% of which is combusted or abandoned. Here, we report the use of lignin as a photocatalyst that forms H2O2 by O2 reduction and H2O oxidation under visible light. We investigated the photophysical and electronic properties of two lignin models, lignosulfonate and kraft lignin, by spectroscopic and photoelectrochemical analyses, and demonstrated the photoredox chemistry of lignin using these and other lignin models (for example, native-like cellulolytic enzyme lignin, artificial lignin dehydrogenation polymer and phenolic ??-aryl ether-type lignin dimer). Furthermore, the integration of lignin and H2O2-dependent unspecific peroxygenases (UPOs) enabled the highly enantioselective oxyfunctionalization of various C???H bonds. The use of lignin photocatalysts solves a number of the challenges relating to the sustainable activation of UPOs, notably, eliminating the need for artificial electron donors and suppressing the HO??-mediated inactivation of UPOs. Thus, the lignin???UPO hybrid catalyst achieved a total turnover number of UPO of 81,000 for solar-powered biocatalytic oxyfunctionalization in photochemical platforms

    Anticoagulant Activity of Low-Molecular Weight Compounds from Heterometrus laoticus Scorpion Venom

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    Scorpion venoms are complex polypeptide mixtures, the ion channel blockers and antimicrobial peptides being the best studied components. The coagulopathic properties of scorpion venoms are poorly studied and the data about substances exhibiting these properties are very limited. During research on the Heterometrus laoticus scorpion venom, we have isolated low-molecular compounds with anticoagulant activity. Determination of their structure has shown that one of them is adenosine, and two others are dipeptides LeuTrp and IleTrp. The anticoagulant properties of adenosine, an inhibitor of platelet aggregation, are well known, but its presence in scorpion venom is shown for the first time. The dipeptides did not influence the coagulation time in standard plasma coagulation tests. However, similarly to adenosine, both peptides strongly prolonged the bleeding time from mouse tail and in vitro clot formation in whole blood. The dipeptides inhibited the secondary phase in platelet aggregation induced by ADP, and IleTrp decreased an initial rate of platelet aggregation induced by collagen. This suggests that their anticoagulant effects may be realized through the deterioration of platelet function. The ability of short peptides from venom to slow down blood coagulation and their presence in scorpion venom are established for the first time. Further studies are needed to elucidate the precise molecular mechanism of dipeptide anticoagulant activity

    Phosphomolybdic Acid as a Catalyst for Oxidative Valorization of Biomass and Its Application as an Alternative Electron Source

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    Power- and solar-to-chemical energy conversion has been spotlighted as a promising technology for the efficient use of renewable energy resources. In principle, various chemicals can be sustainably produced through (photo)electrochemical reduction using water as a cheap and clean electron source. However, oxidation of water is a challenging task that results in low energy efficiency and reliability issues for the practical application of power- and solar-to-chemical energy conversion. Here, we show that various biomasses including lignin can be used as alternative electron sources. Electrons can be readily extracted from biomass using phosphomolybdic acid as a catalyst for oxidative depolymerization of biomass and an electron mediator at a much lower potential (0.95 V vs. reversible hydrogen electrode) than water using the best-performing but expensive catalysts (1.5-1.6 V). In particular, value-added chemicals such as CO and vanillin are produced as byproducts upon oxidative depolymerization of lignin. As a result, this approach allows efficient (photo)electrochemical production of hydrogen with a Faradaic efficiency close to unity at acidic pHs and brings additional economic benefits from byproducts

    Recombinant lignin peroxidase with superior thermal stability and melanin decolorization efficiency in a typical human skin-mimicking environment

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    Recently, the desire for a safe and effective method for skin whitening has been growing in the cosmetics industry. Commonly used tyrosinase-inhibiting chemical reagents exhibit side effects. Thus, recent studies have focused on performing melanin decolorization with enzymes as an alternative due to the low toxicity of enzymes and their ability to decolorize melanin selectively. Herein, 10 different isozymes were expressed as recombinant lignin peroxidases (LiPs) from Phanerochaete chrysosporium (PcLiPs), and PcLiP isozyme 4 (PcLiP04) was selected due to its high stability and activity at pH 5.5 and 37 ??C, which is close to human skin conditions. In vitro melanin decolorization results indicated that PcLiP04 exhibited at least 2.9-fold higher efficiency than that of well-known lignin peroxidase (PcLiP01) in a typical human skin-mimicking environment. The interaction force between melanin films measured by a surface forces apparatus (SFA) revealed that the decolorization of melanin by PcLiP04 harbors a disrupted structure, possibly interrupting ??????? stacking and/or hydrogen bonds. In addition, a 3D reconstructed human pigmented epidermis skin model showed a decrease in melanin area to 59.8% using PcLiP04, which suggests that PcLiP04 exhibits a strong potential for skin whitening

    Impact of interventions on the quality of life of cancer patients: a systematic review and meta-analysis of longitudinal research

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    Abstract The impact of cancer interventions has been conducted in several research due to the significant burden of this non-communicable disease. The interventions that played an important role in the improvement of the patient’s quality of life (QoL) and health-related quality of life (HRQL) can be classified into two main groups: pharmaceutical and non-pharmacological methods. However, studies so far often analyze a specific group of interventions for specific types of cancer. Thus, in this systematic review and meta-analysis, we synthesized the overall impact of cancer interventions on patients’ quality of life in several cancers. In this research, we followed the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) to search the longitudinal original research on the Web of Science (WOS) database. After that, the Newcastle-Ottawa Scale (NOS) and Jadad Scale were used to assess the quality of non-randomized control trials and randomized control trials, respectively. Then, the characteristics of the included studies were described in the six main fields table and the random effect model with robust estimation was applied to analyze the impact of interventions on the health utility of patients. From the database, 122 longitudinal original research were included in the meta-regression, with most of them having high or fair quality. The European Organization for the research and treatment of cancer scale for quality of life (EORTC-QLQ) was the most used health utility measurement at 65.15%. In the adjusted effect models, the Visual Analogue Scale (VAS) had significant statistics in all models when we compared it with the EQ-5D Scale (p < 0.05) and several types of cancer such as breast, lung, and prostate cancer had significant statistics when comparing with hematological cancer in the model types of cancer (p < 0.01). Moreover, radiotherapy, screening, and a combination of chemotherapy and best supportive care also had significant statistics (p < 0.01) in the model of interventions when compared with radiotherapy applied only. Our research can suggest a vital combination of both pharmaceutical and non-pharmacological interventions to improve the quality of life of some common types of cancer patients
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