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•A highly efficient CTL sensor for acetone vapor coupled with UIO-66 as the preconcentrator was established.•A simple and low-cost home-made adsorption apparatus with UIO-66 was ...fabricated.•The proposed CTL sensing platform demonstrated advantages of high sensitivity, selectivity, and speediness.
Metal-organic frameworks (MOFs) showed a significant sorption potential in the gas capture and preconcentration during recent years because of its super porosity. Herein, we fabricated a simple and inexpensive home-made adsorption apparatus based on UIO-66 as the preconcentrator, which was firstly coupled with a rapid cataluminescence (CTL) sensor to determine acetone vapor. The CTL emission was enhanced by 25 times after the preconcentration of UIO-66, indicating the UIO-66 preconcentrator could efficiently ameliorate sensitivity. As for the adsorption mechanism of UIO-66 for acetone molecules, we deduced that acetone molecules were preferentially located on the Zr clusters with high hydrophilicity. The proposed CTL sensor in combine with UIO-66 adsorption granted a detection limit of acetone down to 2.79 ppm, and demonstrated good selectivity, simplicity, rapidity, and recyclability. This study provides appealing perspectives of UIO-66 as the preconcentrator for the improvement of analytical performance, and the prospect of a miniaturized portable acetone sensor.
Plants have evolved diverse molecular mechanisms that enable them to respond to a wide range of pathogens. It has become clear that microRNAs, a class of short single-stranded RNA molecules that ...regulate gene expression at the transcriptional or post-translational level, play a crucial role in coordinating plant-pathogen interactions. Specifically, miRNAs have been shown to be involved in the regulation of phytohormone signals, reactive oxygen species, and
gene expression, thereby modulating the arms race between hosts and pathogens. Adding another level of complexity, it has recently been shown that specific lncRNAs (ceRNAs) can act as decoys that interact with and modulate the activity of miRNAs. Here we review recent findings regarding the roles of miRNA in plant defense, with a focus on the regulatory modes of miRNAs and their possible applications in breeding pathogen-resistance plants including crops and trees. Special emphasis is placed on discussing the role of miRNA in the arms race between hosts and pathogens, and the interaction between disease-related miRNAs and lncRNAs.
This mini‐review describes the recent developments in quantum dots‐based nanoprobes in liquid‐phase chemiluminescence (CL) analysis. In the referenced reports, multiple quantum dots (QDs) were ...adopted as final emission species either after direct oxidation reactions (direct CL) or after chemiluminescence resonance energy transfer (indirect CL). This review does not include papers in which QDs have been used as enhancers, catalysts, carriers or quenchers in chemiluminescence systems. A brief overview on the CL mechanisms of various QDs‐based nanoprobes and their analytical applications over the last decade is given, followed by comments on the future challenges and prospects in this field.
Carbon nanodots (C-Dots) as a new form of carbonaceous nanomaterials have aroused much interest and intensive research due to their inspiring properties. Compared to traditional semiconductor quantum ...dots, these newly emergent nanodots possess a number of advantageous characteristics, among which low-toxicity is particularly fascinating. More and more research into C-Dots have focused on synthesis methods and biology-related applications. Microwave-assisted approaches have attracted attention because microwave treatment can provide intensive and efficient energy, and as a consequence shorten the reaction time. In this article, we designed a "green", rapid, eco-friendly and waste-reused approach to synthesize fluorescent and water-soluble C-Dots from eggshell membrane (ESM) ashes according to a microwave-assisted process. ESM selected as the carbon source was a common protein-rich waste in daily life and can be obtained easily and cheaply. The C-Dots from our method showed the maximal fluorescence emission peak at 450 nm and the fluorescence quantum yield was about 14%. We further designed a sensitive probe for glutathione based on the fluorescence turn off and on of the C-Dots-Cu
2+
system, which showed a linear range of 0.5-80 μmol L
−1
and detection limit of 0.48 μmol L
−1
. In general, the C-Dots prepared briefly and inexpensively from ESM revealed excellent fluorescent property with promising potential for applications such as sample detection and biotechnology.
Fluorescent probe for turn-on sensing of glutathione based on a carbon nanodots and copper system.
In this work, rice husk biomass was utilized as an abundant source to controllably prepare high-quality graphene quantum dots (GQDs) with a yield of ca. 15 wt %. The size, morphology, and structure ...of the rice-husk-derived GQDs were determined by high-resolution transmission electron microscopy, atomic force microscopy, and Raman spectroscopy. The as-fabricated GQDs can be stably dispersed in water, exhibiting bright and tunable photoluminescence. A cell viability test further confirmed that the GQDs possess excellent biocompatibility, and they can be easily adopted for cell imaging via a facile translocation into the cytoplasm. It is worth noting that mesoporous silica nanoparticles were also synthesized as a byproduct during the fabrication of GQDs. As such, our strategy achieves a comprehensive utilization of rice husks, exhibiting tremendous benefits on both the economy and environment.
Because of its simplicity and high efficiency, logistic regression algorithm has been widely applied in the field of data mining. However, logistic regression classifiers always show poor performance ...when the categories are imbalanced. In this paper, a new algorithm named
KLR (
times k-means logistic regression) is proposed to deal with the imbalanced classification problem. Compared to other traditional methods, the effectiveness of the proposed algorithm is verified through experiments based on simulated data and real data.
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► SiO2/graphene composite prepared by a facile chemical route was considered as a novel adsorbent for Pb(II) ion. ► SiO2/graphene composite indicated high selectivity and efficiency ...for the removal of Pb(II) ion. ► The Pb(II) ion adsorption rate of the composite is rapid. ► Potential to be used in the water treatment as an adsorbent for Pb(II) ion.
SiO2/graphene composite was prepared through a simple two-step reaction, including the preparation of SiO2/graphene oxide and the reduction of graphene oxide (GO). The composite was characterized by UV–Vis spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscope, and X-ray photoelectron spectroscopy, and what is more, the adsorption behavior of as-synthesized SiO2/graphene composite was investigated. It was interestingly found that the composite shows high efficiency and high selectivity toward Pb(II) ion. The maximum adsorption capacity of SiO2/graphene composite for Pb(II) ion was found to be 113.6mgg−1, which was much higher than that of bare SiO2 nanoparticles. The results indicated that SiO2/graphene composite with high adsorption efficiency and fast adsorption equilibrium can be used as a practical adsorbent for Pb(II) ion.
Inorganic nanomaterials that mimic enzymes are fascinating as they potentially have improved properties relative to native enzymes, such as greater resistance to extremes of pH and temperature and ...lower sensitivity to proteases. Although many artificial enzymes have been investigated, searching for highly-efficient and stable catalysts is still of great interest. In this paper, we first demonstrated that bovine serum albumin (BSA)-stabilized MnO(2) nanoparticles (NPs) exhibited highly peroxidase-, oxidase-, and catalase-like activities. The activities of the BSA-MnO(2) NPs were evaluated using the typical horseradish peroxidase (HRP) substrates o-phenylenediamine (OPD) and 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of either hydrogen peroxide or dissolved oxygen. These small-sized BSA-MnO(2) NPs with good dispersion, solubility and biocompatibility exhibited typical Michaelis-Menten kinetics and high affinity for H(2)O(2), OPD and TMB, indicating that BSA-MnO(2) NPs can be used as satisfactory enzyme mimics. Based on these findings, BSA-MnO(2) NPs were used as colorimetric immunoassay tags for the detection of goat anti-human IgG in place of HRP. The colorimetric immunoassay using BSA-MnO(2) NPs has the advantages of being fast, robust, inexpensive, easily prepared and with no HRP and H(2)O(2) being needed. These water-soluble BSA-MnO(2) NPs may have promising potential applications in biotechnology, bioassays, and biomedicine.
On the basis of the state parameter of de Sitter space-time satisfying the first law of thermodynamics, we can derive some effective thermodynamic quantities. When the temperature of the black hole ...horizon is equal to that of the cosmological horizon, we think that the effective temperature of the space-time should have the same value. Using this condition, we obtain a differential equation of the entropy of the de Sitter black hole in the higher-dimensional de Rham, Gabadadze and Tolley (dRGT) massive gravity. Solving the differential equation, we obtain the corrected entropy and effective thermodynamic quantities of the de Sitter black hole. The results show that for multi-parameter black holes, the entropy satisfied differential equation is invariable with different independent state parameters. Therefore, the entropy of higher-dimensional dS black holes in dRGT massive gravity is only a function of the position of the black hole horizon, and is independent of other state parameters. It is consistent with the corresponding entropy of the black hole horizon and the cosmological horizon. The thermodynamic quantities of self-consistent de Sitter space-time are given theoretically, and the equivalent thermodynamic quantities have the second-order phase transformation similar to AdS black hole, but unlike AdS black hole, the equivalent temperature of de Sitter space-time has a maximum value. By satisfying the requirement of thermodynamic equilibrium and stability of space-time, the conditions for the existence of dS black holes in the universe are obtained.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Despite the tremendous progress in the research of luminescent probes for reactive oxygen species (ROS), designing luminescent ROS probes with high sensitivity for the individual ROS is still ...retarded because of their high reactivity and the rapid and complex interconversion reactions among them. Herein, organosiloxane and polyhedral oligomeric silsesquioxanes (POSS) compounds are designed as a novel class of luminescent molecular probes to produce extraordinary chemiluminescence (CL) based on the specific electrophilic attack of •OH. No CL signal can be obtained by the other ROS and strong oxidants. AEAP-POSS formed by hydrolytical condensation of 3-(2-aminoethylamino)propyltrimethoxysilane (AEAPTMS) is constructed to covalently link a dye molecular, perylene diimide derivative (PDI), and an intramolecular chemiluminescence resonance energy transfer (CRET) system is obtained to realize the red shift of CL wavelength and enhanced CL intensity. This probe based on CRET is applied to monitor inherent •OH in ambient particular matter (PM2.5 and PM10). Density functional theory (DFT), ion chromatograph, X-ray photoelectron spectroscopy (XPS), particle size analysis, and fluorescence spectrum (FL) are applied to study the CL mechanism. These studies discover that electronically carbonyl CH3CO• is the CL emitter, and the silicon–oxygen skeleton in the organosiloxane and POSS compounds plays the key role in undergoing chemiluminescence (CL) reaction.
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