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A pioneering aggregation-induced emission (AIE) fluorescent compound, PCBO, has been engineered initially, combining oxalyl di-hydrazide and a phenylcarbazole derivative. When tested ...in a THF/H2O solution with a fraction of water (fw) at 70 %, the compound reveals superior selectivity, interference-resilience, and expansive pH range. Additionally, it manifests as a recyclable 'turn-off' fluorescent sensor for Cu2+ in an aqueous medium, with a detection limit (LOD) standing impressively low at 1.6 × 10−7 M. The coordination ratio that emerges between PCBO and Cu2+ is maintained at 2:1, alongside a binding constant of approximately 3.18 × 1011 M−2. The testing paper generated demonstrates commendable performance in the measurement of Cu2+ in water samples. The working principle of the fluorescence mechanism is theorized and established through sophisticated simulation calculations.
In this paper, a new flexible stab-resistant composite material was prepared by growing ZnO nanowires on aramid plain fabric by the hydrothermal method. Through SEM, FTIR, and XRD characterization, ...it is proved that ZnO nanowires have been grown on aramid fabric and the surfaces of aramid filaments become much rougher. Moreover, the inter-filament friction and breaking strength of aramid fabric with nanowires are increased significantly, especially the inter-filament friction, which has been increased by more than 4 times after ZnO nanowires growth. Stab tests were conducted on the bare aramid fabric sample and aramid fabric sample with ZnO nanowires based on the test standard of GA 68–2019. Both of the two samples are 43 layers and are subject to 5 stabs of D1 knife, 3 stabs of D2 knife and 3 stabs of D3 knife. The stab resistance of aramid fabric grown with nanowires is significantly enhanced, and the average penetration depth under the D1 knife impact is decreased by 49.7%. The reason may be that the inter-filament friction increases dramatically with the nanowires and thus the friction energy consumption increases. The flexibility test results show that the softness characteristics of the single aramid fabric and the 43-layer fabric with the nanowires are still maintained. In addition, although the growth of nanowires will lead to smaller voids and a decrease of air permeability of the fabric, the moisture permeability has been slightly improved because ZnO nanowires have the ability to bind with water.
A macroporous amphoteric ion exchange membrane was prepared by blending chitosan (CS) and carboxymethylcellulose (CMC) in aqueous solution, with glutaraldehyde as a crosslinking agent and silica ...particles as porogens. The good compatibility between CS and CMC was confirmed by attenuated total reflectance Fourier-transform infrared spectroscopy (FTIR-ATR). A scanning electron microscope was used to observe the morphology of CS/CMC blend membranes, in which a three-dimensional opening structure was formed, and no phase separation was discovered. Tobacco extract was used as a separation model to get tobacco protein. And the effects of the pH value, adsorption time, CS/CMC content, initial protein concentration, and CS/CMC composition on tobacco protein adsorption were investigated by coomassie blue staining during the adsorption process. The results showed that the maximum adsorption capacity of 271.78 mg/g can be achieved under the condition of pH 6.15, adsorption time of 8 h, initial protein concentration of 1.52 mg/mL, and CS/CMC weight of 0.05 g with a mass ratio of 80 : 20. Tobacco proteins were successfully separated from tobacco extract by adjusting the pH of the feed and the desorption solutions to change their electrostatic force. It was found that the high desorption capacity and protein desorption efficiency can be achieved at pH 9.40. The blend membranes also demonstrated good reusability after 3 adsorption-desorption cycles.
Porous carbons (PCs), widely deployed sorbents in diverse areas, are usually synthesized by thermochemically carbonizing carbonaceous precursors and thermally regenerated at great energy-cost. To ...seek alternative solutions to such energy penalty and based on the exceptional localized Eddy current heating (LECH) capacity of metal objects upon their exposure to an alternating magnetic field, LECH-driven synthesis of PCs is explored and exemplified by using nickel foam (NF)-delivered LECH to drive carbonization of phenolic resin (PR) infilled within the voids of NF, producing varied PC-incorporated NFs (NF@PCs). Compared with the PCs prepared by using conventional tubular furnace heating, LECH-driven carbonization of PR is able to produce PCs at lower temperature and with greatly enhanced porosity, surface area and graphitization degree, which are mainly resulting from the localized heating nature of LECH. Driven by the same NF-delivered LECH, the moisture adsorbed in the LiCl-loaded NF@PC can be rapidly and completely released at moderate temperature, demonstrating the highly efficient LECH-driven regeneration of PCs. Given that the LECH is delivered by cost-effective and widely available NFs, occurs within the matrix of PR and PC bulk solid, and remotely triggered by an external magnetic field with greatly mitigated energy loss, LECH-driven carbonization of PR and water desorption from PCs thus demonstrated a new, energy-efficient and low-cost strategy to effectively synthesize and regenerate PCs.
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Based on the typical Suzuki coupling reaction and Schiff base reaction, a novel fluorescent molecular PCBW is synthesized and applied as a fluorescence and colorimetric sensor to detect Cu
in aqueous ...solution. The PCBW sensor presents the aggregation-caused quenching (ACQ) effect and at 1 × 10
mol L
it emits the strongest turquoise fluorescence in the DMSO-H
O system (
= 40%). The sensor exhibits a 'turn-off' fluorescent characteristic by adding Cu
, and its fluorescent intensity shows a reliable linear relationship with the Cu
concentration in the range of 0-6 × 10
mol L
, with a detection limit of 1.19 × 10
mol L
. Meanwhile, the PCBW sensor also exhibits the colorimetric sensing from colorless to light yellow. The sensor has good selectivity and anti-interference and its pH application range can be extended from 5 to 10. The intramolecular charge transfer (ICT) is speculated as the main fluorescence mechanism of PCBW. In addition, the sensor presents good reusability and is practicable to detect Cu
in diverse aqueous samples.
Graphene (GR)-wrapped WO3 nanosphere composite was synthesized by using a facile sol–gel method. The morphology and structural properties of the GR-WO3 nanocomposites were characterized by ...field-emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and Raman spectroscopy. The GR-wrapped WO3 nanospheres composite exhibits p-type gas sensing behavior and the response of GR-WO3 sensor toward NO2 shows a linear increase with an increase in the concentration from 7 to 56ppm at room temperature. Upon exposure to 56ppm NO2, its response value becomes 40.8%, but there is no responsiveness for the sensors based on pure WO3 and graphene sensors. The effective charge transfer through chemically bonded interfacial contact between graphene and WO3 nanospheres is proposed to be responsible for the room temperature sensing performance. This work may provide a new insight into the structural design of GR-base nanocomposites and has a potential prospect in the environment monitoring or disease detection of NO2 at room temperature.
Molecular docking has been widely applied in the discovery of new sweeteners, yet the interpretation of computational results sometimes remains difficult. Here, the interaction between the T1R2-T1R3 ...sweet taste receptor and 66 tasting compounds, including 26 sweet, 19 bitter, and 21 sour substances was investigated by batch molecular docking processes. Statistical analysis of the docking results generated two novel methods of interpreting taste properties. Quantitative correlation between relative sweetness (RS) and docking results created a multiparameter model to predict sweetness intensity, whose correlation coefficient
= 0.74 is much higher than
= 0.17 for the linear correlation model between sweetness and binding energy. The improved correlation indicated that docking results besides binding energy contain undiscovered information about the ligand-protein interaction. Qualitative discriminant analysis of different tasting molecules generated an uncorrelated linear discriminant analysis (UDLA) model, which achieved an overall 93.1% accuracy in discriminating the taste of molecules, with specific accuracy for verifying sweet, bitter, and sour compounds reaching 88.0%, 92.1%, and 100%. These unprecedented models provide a unique perspective for interpreting computational results and may inspire future research on sweetener discovery.
Background
Hydrogen sulfide (H2S) is the most important compound causing oral malodor, and its concentration is thought to be closely correlated with oral microorganism activity. Therefore, ...clarifying the correlation between oral microbes and metabolites is important.
Methods
This study tested with 16S rRNA gene amplicon and shotgun metagenomic sequencing of oral microorganisms and oral malodor tests.
Results
There were different of the microbial taxa between the low and high H2S groups. And in the high H2S group, most of the enriched taxa were genera which abundance was correlated with H2S concentration. Fusobacterium periodonticum and Prevotella nanceiensis were significantly different in coverage breadth and depth and in LPS biosynthesis contributions between the two groups. The contribution of F. periodonticum to sulfur metabolism was significantly different between the two groups, and the relative F. periodonticum abundance was higher in the high H2S group.
Conclusions
The H2S content is significantly associated with the oral cavity microorganism composition and abundance. Most microorganisms enriched in people with high H2S levels are associated with oral diseases such as caries and periodontal diseases.
Based on the typical Suzuki coupling reaction and Schiff base reaction, a novel fluorescent molecular
PCBW
is synthesized and applied as a fluorescence and colorimetric sensor to detect Cu
2+
in ...aqueous solution. The
PCBW
sensor presents the aggregation-caused quenching (ACQ) effect and at 1 × 10
−5
mol L
−1
it emits the strongest turquoise fluorescence in the DMSO-H
2
O system (
f
w
= 40%). The sensor exhibits a 'turn-off' fluorescent characteristic by adding Cu
2+
, and its fluorescent intensity shows a reliable linear relationship with the Cu
2+
concentration in the range of 0-6 × 10
−6
mol L
−1
, with a detection limit of 1.19 × 10
−8
mol L
−1
. Meanwhile, the
PCBW
sensor also exhibits the colorimetric sensing from colorless to light yellow. The sensor has good selectivity and anti-interference and its pH application range can be extended from 5 to 10. The intramolecular charge transfer (ICT) is speculated as the main fluorescence mechanism of
PCBW
. In addition, the sensor presents good reusability and is practicable to detect Cu
2+
in diverse aqueous samples.
A novel carbazole-based
PCBW
molecule presents excellent fluorometric and colorimetric sensing capacity towards Cu
2+
in a DMSO-H
2
O system (
f
w
= 40%).
Based on the typical Suzuki coupling reaction and Schiff base reaction, a novel fluorescent molecular PCBW is synthesized and applied as a fluorescence and colorimetric sensor to detect Cu2+ in ...aqueous solution. The PCBW sensor presents the aggregation-caused quenching (ACQ) effect and at 1 × 10−5 mol L−1 it emits the strongest turquoise fluorescence in the DMSO–H2O system (fw = 40%). The sensor exhibits a ‘turn-off’ fluorescent characteristic by adding Cu2+, and its fluorescent intensity shows a reliable linear relationship with the Cu2+ concentration in the range of 0–6 × 10−6 mol L−1, with a detection limit of 1.19 × 10−8 mol L−1. Meanwhile, the PCBW sensor also exhibits the colorimetric sensing from colorless to light yellow. The sensor has good selectivity and anti-interference and its pH application range can be extended from 5 to 10. The intramolecular charge transfer (ICT) is speculated as the main fluorescence mechanism of PCBW. In addition, the sensor presents good reusability and is practicable to detect Cu2+ in diverse aqueous samples.
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