DNA G-quadruplexes are not only attractive drug targets for cancer therapeutics, but also have important applications in supramolecular assembly. Here, we report a platinum(II)-based tripod ...(Pt-tripod) specifically binds the biological relevant hybrid-1 human telomeric G-quadruplex (Tel26), and strongly inhibits telomerase activity. Further investigations illustrate Pt-tripod induces the formation of monomeric and multimeric Pt-tripod‒Tel26 complex structures in solution. We solve the 1:1 and the unique dimeric 4:2 Pt-tripod-Tel26 complex structures by NMR. The structures indicate preferential binding of Pt-tripod to the 5'-end of Tel26 at a low Pt-tripod/Tel26 ratio of 0-1.0. After adding more Pt-tripod, the Pt-tripod binds the 3'-end of Tel26, unexpectedly inducing a unique dimeric 4:2 structure interlocked by an A:A non-canonical pair at the 3'-end. Our structures provide a structural basis for understanding the dynamic binding of small molecules with G-quadruplex and DNA damage mechanisms, and insights into the recognition and assembly of higher-order G-quadruplexes.
Fly ash is the fine solid particulate residue driven out of the boiler with the flue gases in coal-fired power plants. Now it can be used for making geopolymer which acts as a cement-like product. ...The geopolymer technology provides an alternative good solution to the utilization of fly ash with little negative impact on environment. This review summarizes and examines the scientific advances in the preparation, properties and applications of fly ash-based geopolymer. The production of fly ash-based geopolymer is mainly based on alkali activated geopolymerization which can occur under mild conditions and is considered as a cleaner process due to much lower CO2 emission than that from the production of cement. The geopolymerization can trap and fix the trace toxic metal elements from fly ash or external sources. The Si/Al ratios, the type and the amount of the alkali solution, the temperature, the curing conditions, and the additives are critical factors in a geopolymerization process. The mechanical performances of the fly ash-based geopolymer, including compressive strength, flexural and splitting tensile strength, and durability such as the resistance to chloride, sulfate, acid, thermal, freeze-thaw and efflorescence, are the primary concerns. These properties of fly ash-based geopolymer are inherently dependent upon the chemical composition and chemical bonding and the porosity. The mechanical properties and durability can be improved by fine tuning Si/Al ratios, alkali solutions, curing conditions, and adding slag, fiber, rice husk-bark ash and red mud. Fly ash-based geopolymer is expected to be used as a kind of novel green cement. Fly ash-based geopolymer can be used as a class of materials to adsorb and immobilize toxic or radioactive metals. The factors affecting the performances of fly ash-based geopolymer concrete, in particular aggregate, are discussed. For future studies on fly ash-based geopolymer, further enhancing mechanical performance, scaling up production and exploring new applications are suggested.
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•Fly ash is activated by alkali to form geopolymer and such a process is cleaner.•Slag, rice husk-bark ash, fiber and red mud are added to improve the performance of fly ash-based geopolymer.•Mechanical properties and durability of fly ash-based geopolymer are main concerns.•Fly ash-based geopolymer is used as cement and as fixation materials for toxic metals.•Improving performance, scaling-up production and finding new applications are proposed for future.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Lignocellulosic biomass is the most abundant and bio-renewable resource with great potential for sustainable production of chemicals and fuels. This critical review provides insights into the ...state-of the-art accomplishments in the chemocatalytic technologies to generate fuels and value-added chemicals from lignocellulosic biomass, with an emphasis on its major component, cellulose. Catalytic hydrolysis, solvolysis, liquefaction, pyrolysis, gasification, hydrogenolysis and hydrogenation are the major processes presently studied. Regarding catalytic hydrolysis, the acid catalysts cover inorganic or organic acids and various solid acids such as sulfonated carbon, zeolites, heteropolyacids and oxides. Liquefaction and fast pyrolysis of cellulose are primarily conducted over catalysts with proper acidity/basicity. Gasification is typically conducted over supported noble metal catalysts. Reaction conditions, solvents and catalysts are the prime factors that affect the yield and composition of the target products. Most of processes yield a complex mixture, leading to problematic upgrading and separation. An emerging technique is to integrate hydrolysis, liquefaction or pyrolysis with hydrogenation over multifunctional solid catalysts to convert lignocellulosic biomass to value-added fine chemicals and bio-hydrocarbon fuels. And the promising catalysts might be supported transition metal catalysts and zeolite-related materials. There still exist technological barriers that need to be overcome (229 references).
Potassium-ion batteries (PIBs) are considered as potential replacements to lithium-ion batteries for large scale energy storage applications due to abundant potassium resources and low cost. However, ...it is a rough road to find suitable materials with high capacity and cycling stability due to the large K ion radius. In this study, a simple method, electrodeposition, is used to anchor SnO2 nanoparticles on three dimensional carbon foam (SnO2@CF) as a freestanding anode for PIBs. The prepared freestanding SnO2@CF electrode features a three dimensional (3D) conductive carbon frame and SnO2 nanoparticles, which can enhance electron transfer, prevent SnO2 from losing electrical contact after large volume changes and facilitate electrolyte infiltration and K ion transfer. As expected, SnO2@CF delivers a high K storage specific capacity, and outstanding cycling stability (231.7 mA h g−1 after 400 cycles at 1 A g−1) and rate performance (371.4, 307.6, 247.3 and 143.5 mA h g−1 at 0.5, 1, 2 and 5 A g−1, respectively). Meanwhile, the phase transition of the SnO2@CF electrode is tracked during the charge and discharge processes in PIBs. This study provides a facile method to prepare freestanding electrode materials and a promising anode material for PIBs.
We have provided a brief review about biomass derived carbon materials and their applications for electrochemical energy storage.
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•Provide a brief review about biomass derived carbon ...materials.•Address the pore formation mechanism on carbon materials.•Hierarchical porous carbon show high capacity and good cycles.•Demonstrate two effective pore formation methods on carbon.
Natural biomass-derived carbons have attracted great attention due to their interesting characteristics of naturally porous or hierarchical structured and heteroatom doping. In this review, the recent progress in the synthesis of naturally-derived carbon and their composite electrodes is summarized in detail. Advantages and disadvantages of different methods (e.g., chemical and physical activations) are discussed. In addition, we further address the pore formation mechanism on biomass-derived carbons. Furthermore, their applications for electrochemical energy storage in lithium ion batteries and sodium ion batteries are briefly reviewed and highlighted associated with their structural merits such as hierarchical porous structure, high conductivity as well as large surface area. Outlook of research trends on next-generation high-performance electrodes based on biomass-derived carbons is provided at the end.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Many studies suggest that naturally-occurring layered clay minerals can be used as a class of biocompatible solid supports for immobilizing enzymes. The corresponding clay mineral enzyme hybrids ...prove to have great potentials in catalysis and biosensing. This article reviews latest advances in using clay minerals as supports for the immobilization of enzymes. The immobilization of enzyme onto clay minerals can be made via non-covalent adsorption and covalent bonding. The non-covalent immobilization involves van der Waals forces, electrostatic interactions, hydrogen bonding, and hydrophobic interactions. For avoiding desorption of enzymes, immobilization can be conducted through direct covalent bonding between enzymes and clay minerals. Organic modification of clay minerals and addition of linking molecules are made to improve the immobilization so as to increase the loading, activity and stability of enzymes. Regarding the applications of enzyme immobilized on clay minerals, recent studies are made mainly in biocatalytic processes and in biosensors. For manufacturing biosensing electrodes, clay minerals with metal nanoparticles, graphene and carbon nanotubes prove to be more effective owing mainly to the enhanced electron transfer. Future work on clay mineral enzyme hybrids could lie in integrating more additional functional materials with clay mineral enzyme hybrids to build hierarchical structured catalysts and electrodes.
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•Advances in using clay minerals for immobilization of enzyme are reviewed.•Immobilization of enzyme on clay minerals is made by adsorption or covalent bonding.•Interactions between enzymes and pristine or modified clay minerals are examined.•Clay mineral enzyme hybrids are now developed for biocatalysis or biosensing.•Functionality and uses of clay mineral enzyme hybrids are still concerns in future.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Whether goal-directed fluid therapy based on dynamic predictors of fluid responsiveness (GDFTdyn) alone improves clinical outcomes in comparison with standard fluid therapy among patients undergoing ...surgery remains unclear.
PubMed, EMBASE, the Cochrane Library and ClinicalTrials.gov were searched for relevant studies. Studies comparing the effects of GDFTdyn with that of standard fluid therapy on clinical outcomes among adult patients undergoing surgery were considered eligible. Two analyses were performed separately: GDFTdyn alone versus standard fluid therapy and GDFTdyn with other optimization goals versus standard fluid therapy. The primary outcomes were short-term mortality and overall morbidity, while the secondary outcomes were serum lactate concentration, organ-specific morbidity, and length of stay in the intensive care unit (ICU) and in hospital.
We included 37 studies with 2910 patients. Although GDFTdyn alone lowered serum lactate concentration (mean difference (MD) - 0.21 mmol/L, 95% confidence interval (CI) (- 0.39, - 0.03), P = 0.02), no significant difference was found between groups in short-term mortality (odds ratio (OR) 0.85, 95% CI (0.32, 2.24), P = 0.74), overall morbidity (OR 1.03, 95% CI (0.31, 3.37), P = 0.97), organ-specific morbidity, or length of stay in the ICU and in hospital. Analysis of trials involving the combination of GDFTdyn and other optimization goals (mainly cardiac output (CO) or cardiac index (CIx)) showed a significant reduction in short-term mortality (OR 0.45, 95% CI (0.24, 0.85), P = 0.01), overall morbidity (OR 0.41, 95% CI (0.28, 0.58), P < 0.00001), serum lactate concentration (MD - 0.60 mmol/L, 95% CI (- 1.04, - 0.15), P = 0.009), cardiopulmonary complications (cardiac arrhythmia (OR 0.58, 95% CI (0.37, 0.92), P = 0.02), myocardial infarction (OR 0.35, 95% CI (0.16, 0.76), P = 0.008), heart failure/cardiovascular dysfunction (OR 0.31, 95% CI (0.14, 0.67), P = 0.003), acute lung injury/acute respiratory distress syndrome (OR 0.13, 95% CI (0.02, 0.74), P = 0.02), pneumonia (OR 0.4, 95% CI (0.24, 0.65), P = 0.0002)), length of stay in the ICU (MD - 0.77 days, 95% CI (- 1.07, - 0.46), P < 0.00001) and in hospital (MD - 1.18 days, 95% CI (- 1.90, - 0.46), P = 0.001).
It was not the optimization of fluid responsiveness by GDFTdyn alone but rather the optimization of tissue and organ perfusion by GDFTdyn and other optimization goals that benefited patients undergoing surgery. Patients managed with the combination of GDFTdyn and CO/CI goals might derive most benefit.
Abstract
We investigate the parameter estimation problems of two-atom system driven by the phase noise lasers (PNLs) environment. And we give a general method of numeric solution to handle the ...problems of atom system under the PNLs environment. The calculation results of this method on Quantum Fisher Information (QFI) are consistent with our former results. Moreover, we consider the dipole–dipole (
d
–
d
) interaction between the atoms under PNLs environment with the collective decay, and the results show that larger
d
–
d
interaction and smaller collective decay rate lead to larger QFI of the two-atom system. So the collective decay will destroy the QFI while the
d
–
d
interaction will preserve the QFI, these results can be used to protect the QFI of two-atom system driven by the PNLs environment.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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•N-CQDs were prepared by a facile hydrothermal of glucose and m-phenylenediamine.•N-CQDs emit stable blue emission under UV irradiation in different conditions.•N-CQDs are excellent ...fluorescent probes of Fe3+ and CrO42−.•The static quenching mechanism is based on inner filter effect.•N-CQDs are superior cell-imaging reagents for Hela cells.
Carbon quantum dots (CQDs), owing to their characteristic luminescent properties, have become a new favorite in the field of luminescence. They have been widely used in light emitting diode, ion detection, cell-imaging, ect. Herein a facile synthesis method of nitrogen-doped carbon quantum dots (N-CQDs) has been developedviaa one-step hydrothermal of glucose and m-phenylenediamine. The chemical composition, surface functional groups, and crystal structure of so prepared N-CQDs were systematically characterized. The characterizations indicate that nitrogen has been chemically doped in the CQDs and the N-CQDs crystallize in a graphene structure. Photoluminescence (PL) measurements show that the N-CQDs emit strong blue emission under the irradiation of ultraviolet. The emission is excitation-dependent, is resistant to photo bleaching and high ionic strength, and slightly decreases with the increase of temperature. The quantum yield of them is about 17.5%. The PL intensity of N-CQDs quenches linearly with the increase of the concentrations of Fe3+(0.5–1.0 mM) and CrO42−(0.3–0.6 mM), which are a kind of excellent fluorescent probe for the detection of Fe3+ and CrO42−. The quenching mechanism of Fe3+ and CrO42−is verified to be a static quenching mechanism based on inner filter effect. The N-CQDs are also found to be a good cell-imaging reagent of Hela cells.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Silicon (Si) is promising for high capacity anodes in lithium‐ion batteries due to its high theoretical capacity, low working potential, and natural abundance. However, there are two main drawbacks ...that impede its further practical applications. One is the huge volume expansion generating during lithiation and delithiation progresses, which leads to severe structural pulverization and subsequently rapid capacity fading of the electrode. The other is the relatively low intrinsic electronic conductivity, therefore, seriously impacting the rate performance. In the past decades, numerous efforts have been devoted for improving the cycling stability and rate capability by rational designs of different nanostructures of Si materials and incorporations with some conductive agents. In this review, the authors summarize the exciting recent research works and focus on not only the synthesis techniques, but also the composition strategies of silicon nanostructures. The advantages and disadvantages of the nanostructures as well as the perspective of this research field are also discussed. We aim to give some reference for engineering application on Si anodes in lithium ion batteries.
The authors summarize the strategies that developed lately for improving the electrochemical performance of Si materials. Special focus in this review is the recent progresses in the rational fabrication of Si nanostructures with multiple morphologies, including nanoparticles, nanowires, thin films, and porous structures. Moreover, further improvement tactics, such as collaborating with carbonaceous materials, conductive polymers, and alloy materials are also discussed.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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