87 research outputs found
Electrochemically primed functional redox mediator generator from the decomposition of solid state electrolyte.
Recent works into sulfide-type solid electrolyte materials have attracted much attention among the battery community. Specifically, the oxidative decomposition of phosphorus and sulfur based solid state electrolyte has been considered one of the main hurdles towards practical application. Here we demonstrate that this phenomenon can be leveraged when lithium thiophosphate is applied as an electrochemically "switched-on" functional redox mediator-generator for the activation of commercial bulk lithium sulfide at up to 70 wt.% lithium sulfide electrode content. X-ray adsorption near-edge spectroscopy coupled with electrochemical impedance spectroscopy and Raman indicate a catalytic effect of generated redox mediators on the first charge of lithium sulfide. In contrast to pre-solvated redox mediator species, this design decouples the lithium sulfide activation process from the constraints of low electrolyte content cell operation stemming from pre-solvated redox mediators. Reasonable performance is demonstrated at strict testing conditions
Characterization of the 4,6-α-glucanotransferase GTFB enzyme of Lactobacillus reuteri 121 isolated from inclusion bodies
BACKGROUND: The GTFB enzyme of the probiotic bacterium Lactobacillus reuteri 121 is a 4,6-α-glucanotransferase of glycoside hydrolase family 70 (GH70; http://www.cazy.org ). Contrary to the glucansucrases in GH70, GTFB is unable to use sucrose as substrate, but instead converts malto-oligosaccharides and starch into isomalto-/malto- polymers that may find application as prebiotics and dietary fibers. The GTFB enzyme expresses well in Escherichia coli BL21 Star (DE3), but mostly accumulates in inclusion bodies (IBs) which generally contain wrongly folded protein and inactive enzyme. METHODS: Denaturation followed by refolding, as well as ncIB preparation were used for isolation of active GTFB protein from inclusion bodies. Soluble, refolded and ncIB GTFB were compared using activity assays, secondary structure analysis by FT-IR, and product analyses by NMR, HPAEC and SEC. RESULTS: Expression of GTFB in E. coli yielded > 100 mg/l relatively pure and active but mostly insoluble GTFB protein in IBs, regardless of the expression conditions used. Following denaturing, refolding of GTFB protein was most efficient in double distilled H2O. Also, GTFB ncIBs were active, with approx. 10 % of hydrolysis activity compared to the soluble protein. When expressed as units of activity obtained per liter E. coli culture, the total amount of ncIB GTFB expressed possessed around 180 % hydrolysis activity and 100 % transferase activity compared to the amount of soluble GTFB enzyme obtained from one liter culture. The product profiles obtained for the three GTFB enzyme preparations were similar when analyzed by HPAEC and NMR. SEC investigation also showed that these 3 enzyme preparations yielded products with similar size distributions. FT-IR analysis revealed extended β-sheet formation in ncIB GTFB providing an explanation at the molecular level for reduced GTFB activity in ncIBs. The thermostability of ncIB GTFB was relatively high compared to the soluble and refolded GTFB. CONCLUSION: In view of their relatively high yield, activity and high thermostability, both refolded and ncIB GTFB derived from IBs in E. coli may find industrial application in the synthesis of modified starches
CCN1, a Pro-Inflammatory Factor, Aggravates Psoriasis Skin Lesions by Promoting Keratinocyte Activation
Psoriasis is a common chronic skin disease characterized by epidermal hyperplasia and inflammation. The pathogenesis of psoriasis is multifactorial and is not fully understood. Here we demonstrate that CCN1 (also called Cyr61, which is short for cysteine-rich 61), an extracellular matrix protein that is also considered a pro-inflammatory factor, is highly expressed in the lesional skin of psoriasis patients, as well as in that of imiquimod (IMQ)- and IL-23-treated psoriasis-like mice. Then we show that blocking CCN1 function in vivo attenuates epidermal hyperplasia and inflammation in psoriasis-like mice. Further, in primary cultured normal human keratinocytes and HaCaT (human keratinocyte cell line) cells, CCN1 promotes keratinocyte activation, including the proliferation and expression of immune-related molecules. Finally, we observe that integrin α6β1 is the receptor of CCN1 in keratinocytes, and CCN1 stimulation activates the downstream phosphoinositide-3 kinase/Akt/NF-κB signaling pathway. Taken together, our findings reveal that CCN1 has a critical role in psoriasis pathogenesis. Moreover, as CCN1 is a secreted extracellular matrix (ECM) protein, our study also provides evidence that ECM, which is involved in psoriatic pathogenesis, could be a potent target for psoriasis treatment
Land management institution as a key confinement of urbanization in Baotou, ChinaApplication of proposed endogenous urbanization model
A Facile Synthesis of Hollow Palladium/Copper Alloy Nanocubes Supported on N-Doped Graphene for Ethanol Electrooxidation Catalyst
In this paper, a catalyst of hollow PdCu alloy nanocubes supported on nitrogen-doped graphene support (H-PdCu/ppy-NG) is successfully synthesized using a simple one-pot template-free method. Two other catalyst materials such as solid PdCu alloy particles supported on this same nitrogen-doped graphene support (PdCu/ppy-NG) and hollow PdCu alloy nanocubes supported on the reduced graphene oxide support (H-PdCu/RGO) are also prepared using the similar synthesis conditions for comparison. It is found that, among these three catalyst materials, H-PdCu/ppy-NG gives the highest electrochemical active area and both the most uniformity and dispersibility of H-PdCu particles. Electrochemical tests show that the H-PdCu/ppy-NG catalyst can give the best electrocatalytic activity and stability towards the ethanol electrooxidation when compared to other two catalysts. Therefore, H-PdCu/ppy-NG should be a promising catalyst candidate for anodic ethanol oxidation in direct ethanol fuel cells
Influence of space properties of enclosed patio on thermal performance in hot-humid areas of China
Patio plays an important role in climate adaptation and microclimate adjustment of buildings. This study aims to explore enclosed patio design guidelines, which are essential for both architectural design methodology and practical projects for providing better thermally comfortable indoor and outdoor spaces. A combined qualitative and quantitative methodological approach was used to clarify how the passive design strategies of the enclosed patio affect the thermal environment of houses around the patio. The findings reveal the spacial characteristics and thermal adjustment of enclosed patios. The results of simulation indicate that appropriate design parameters of enclosed patio can achieve a better indoor and outdoor thermal comfort environment for its users, which includes similar dimension in width and depth, increased number of windows in a high ratio of width to depth, semi-open auxiliary space, 3-4 floor height, upper-lower double windows of four-sided enclosed patio and south opening direction of three-sided enclosed patio
Doubly iterative multiple-input-multiple-output-bit-interleaved coded modulation receiver with joint channel estimation and randomised sampling detection
Food-derived non-phenolic α-amylase and α-glucosidase inhibitors for controlling starch digestion rate and guiding diabetes-friendly recipes
Progress in cyclodextrins as important molecules regulating catalytic processes of glycoside hydrolases
Cyclodextrins (CDs) are important starch derivatives and commonly comprise α-, β-, and γ-CDs. Their hydrophilic surface and hydrophobic inner cavity enable regulation of enzyme catalysis through direct or indirect interactions. Clarifying interactions between CDs and enzyme is of great value for enzyme screening, mechanism exploration, regulation of catalysis, and applications. We summarize the interactions between CDs and glycoside hydrolases (GHs) according to two aspects: 1) CD as products, substrates, inhibitors and activators of enzymes, directly affecting the reaction process; 2) CDs indirectly affecting the enzymatic reaction by solubilizing substrates, relieving substrate/product inhibition, increasing recombinant enzyme production and storage stability, isolating and purifying enzymes, and serving as ligands in crystal structure to identify functional amino acid residues. Additionally, CD enzyme mimetics are developed and used as catalysts in traditional artificial enzymes as well as nanozymes, making the application of CDs no longer limited to GHs. This review concerns the regulation of GHs catalysis by CDs, and gives insights into research on interactions between enzymes and ligands
PENet: A phenotype encoding network for automatic extraction and representation of morphological discriminative features
Abstract Digitalized natural history collections serve as vital ecological and evolutionary research resources. Specimen retrieval based on morphological features allows for the rapid acquisition of similar specimens from these collections, aiding in maximizing the utilization of their resources and catering to the requirements of related research. However, achieving this objective requires effective feature extraction and representation techniques. We developed a phenotype encoding network (PENet), a deep learning‐based model that combines hashing methods to automatically extract and encode discriminative features into hash codes. We evaluated the performance of PENet on six data sets, including a newly constructed beetle data set (6566 images), which covers over 60% of the genera within the six subfamilies of Scarabaeidae. Phenotype encoding network showed high performance in feature extraction and image retrieval, allowing users to input an image of a specimen and efficiently retrieve all specimens with similar morphology. Two visualization methods, t‐SNE and Grad‐CAM, were used to evaluate the representation ability of the hash codes. Additionally, by using the hash codes generated from PENet, a phenetic distance tree was constructed based on the beetle data set. The result indicated that the hash codes could reveal the phenetic distances and relationships among categories to a certain extent. PENet provides an automatic and efficient method to extract and represent morphological discriminative features. The generated hash code can be used as a low‐dimensional carrier of these features, enabling efficient specimen retrieval. Moreover, the distance information carried by these hash codes suggests their potential in systematics, deserving further exploration
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