A novel copper-based MOFs adsorbent (Cu-BTC-Th) was prepared using an one-step method by introducing a new organic ligand of 4-thioureidobenzoicacid (Th) with active groups for selectively adsorbing ...Pb(II) from aqueous solutions. The chemical composition and structure of the prepared MOFs materials were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS ), Brunner−Emmet−Teller (BET) analysis, and zeta potential measurements. The adsorption capability of the prepared Cu-MOFs was significantly enhanced by introducing the new organic ligand of Th in the materials. The maximum adsorption capacity of the Cu-BTC-Th for Pb(II) attains 732.86 mg/g under the optimal conditions. In addition, the adsorption kinetics and adsorption isotherm analysis showed that the adsorption process followed the pseudo-second-order kinetic model and Langmuir adsorption model, indicating that the adsorption of Pb(II) by Cu-BTC-Th was a monolayer chemisorption. The adsorption mechanism of Cu-BTC-Th for Pb(II) was discussed and revealed. On one hand, the adsorption of Pb(II) is mainly through ion exchange with the Cu(II). On the other hand, the −NH2 and −C=S functional groups introduced in the Cu-BTC-Th materials have stronger coordination ability with the Pb(II) ions to enhance the adsorption capability.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Directly discharging low-concentration rare-earth wastewater not only wastes rare-earth resources but also pollutes the environment. In this study, the biosorption behavior of
Serratia marcescens
for ...Eu(III) was studied with emphasis on the optimization of adsorption conditions, adsorption kinetics, and adsorption isotherm. It was shown that the maximum adsorption capacity of
Serratia marcescens
reached 115.36 mg·g
−1
under an optimal condition, indicating the good adsorption capability of
Serratia marcescens
for Eu(III). The adsorption kinetics and adsorption isotherm analysis showed that the adsorption process conforms to the pseudo-second-order kinetic model and Langmuir adsorption isotherm, indicating that the adsorption of Eu(III) by
Serratia marcescens
is a monolayer chemical adsorption process. In addition, the adsorption mechanism was investigated by using characterizations of zeta potential, scanning electron microscope–energy dispersive spectrometer (SEM-EDS), Fourier transform infrared (FT-IR), and X-ray photoelectron spectroscopy (XPS) analyses. It was revealed that the adsorption of Eu(III) by
S. marcescens
is a combination of electrostatic attraction, ions exchange and coordination. These findings indicate that S. marcescens can be used as a potential biosorbent to recover rare earth elements from rare earth wastewater.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Linear induction motor (LIM) has the advantages of low noise, strong climbing ability and small turning radius. It is widely used in middle-low speed maglev traffic. However, in actual operation, the ...linear motor will weaken the thrust output due to the existence of the end effect which will lead to the reduction of the traction efficiency. At the same time, the fluctuation of normal force will disturb the suspension system and affect its suspension stability. To solve the above problems, this paper first establishes a LIM dynamic model considering the end effect, and proposes constant slip frequency vector control. According to the different requirements of normal force and thrust of the train in constant power and force area, the sectional constant slip control is carried out. Then an improved particle swarm optimization (IPSO) is introduced to optimize slip frequency at two stages to reduce the theoretically solved error of optimal slip frequency. Finally, the proposed algorithm is simulated and hardware-in-the-loop tests are carried out; The experimental results show that the proposed algorithm and improvements can meet the requirements of full speed thrust output and normal force of the train. It provides a certain reference value for traction control of the linear motor in middle-low speed maglev train.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Cerium oxide (CeO2) nanospheres have limited enzymatic activity that hinders further application in catalytic therapy, but they have an "oxidation switch" to enhance their catalytic activity by ...increasing oxygen vacancies. In this study, according to the defect-engineering strategy, we developed PtCuOX/CeO2-X nanozymes as highly efficient SOD/CAT mimics by introducing bimetallic copper (Cu) and platinum (Pt) into CeO2 nanospheres to enhance the oxygen vacancies, in an attempt to combine near-infrared (NIR) irradiation to regulate microenvironment for osteoarthritis (OA) therapy. As expected, the Cu and Pt increased the Ce3+/Ce4+ ratio of CeO2 to significantly enhance the oxygen vacancies, and simultaneously CeO2 (111) facilitated the uniform dispersion of Cu and Pt. The strong metal-carrier interaction synergy endowed the PtCuOX/CeO2-X nanozymes with highly efficient SOD/CAT-like activity by the decreased formation energy of oxygen vacancy, promoted electron transfer, the increased adsorption energy of intermediates, and the decreased reaction activation energy. Besides, the nanozymes have excellent photothermal conversion efficiency (55.41%). Further, the PtCuOX/CeO2-X antioxidant system effectively scavenged intracellular ROS and RNS, protected mitochondrial function, and inhibited the inflammatory factors, thus reducing chondrocyte apoptosis. In vivo, experiments demonstrated the biosafety of PtCuOX/CeO2-X and its potent effect on OA suppression. In particular, NIR radiation further enhanced the effects. Mechanistically, PtCuOX/CeO2-X nanozymes reduced ras-related C3 botulinum toxin substrate 1 (Rac-1) and p-p65 protein expression, as well as ROS levels to remodel the inflammatory microenvironment by inhibiting the ROS/Rac-1/nuclear factor kappa-B (NF-κB) signaling pathway. This study introduces new clinical concepts and perspectives that can be applied to inflammatory diseases.Cerium oxide (CeO2) nanospheres have limited enzymatic activity that hinders further application in catalytic therapy, but they have an "oxidation switch" to enhance their catalytic activity by increasing oxygen vacancies. In this study, according to the defect-engineering strategy, we developed PtCuOX/CeO2-X nanozymes as highly efficient SOD/CAT mimics by introducing bimetallic copper (Cu) and platinum (Pt) into CeO2 nanospheres to enhance the oxygen vacancies, in an attempt to combine near-infrared (NIR) irradiation to regulate microenvironment for osteoarthritis (OA) therapy. As expected, the Cu and Pt increased the Ce3+/Ce4+ ratio of CeO2 to significantly enhance the oxygen vacancies, and simultaneously CeO2 (111) facilitated the uniform dispersion of Cu and Pt. The strong metal-carrier interaction synergy endowed the PtCuOX/CeO2-X nanozymes with highly efficient SOD/CAT-like activity by the decreased formation energy of oxygen vacancy, promoted electron transfer, the increased adsorption energy of intermediates, and the decreased reaction activation energy. Besides, the nanozymes have excellent photothermal conversion efficiency (55.41%). Further, the PtCuOX/CeO2-X antioxidant system effectively scavenged intracellular ROS and RNS, protected mitochondrial function, and inhibited the inflammatory factors, thus reducing chondrocyte apoptosis. In vivo, experiments demonstrated the biosafety of PtCuOX/CeO2-X and its potent effect on OA suppression. In particular, NIR radiation further enhanced the effects. Mechanistically, PtCuOX/CeO2-X nanozymes reduced ras-related C3 botulinum toxin substrate 1 (Rac-1) and p-p65 protein expression, as well as ROS levels to remodel the inflammatory microenvironment by inhibiting the ROS/Rac-1/nuclear factor kappa-B (NF-κB) signaling pathway. This study introduces new clinical concepts and perspectives that can be applied to inflammatory diseases.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
A single-/dual-band metamaterial absorber (MMA) based on cross-circular-loop resonator (CCLR) with shorted stubs is discussed at microwave frequencies in this paper. The single-/dual-band ...characteristics are realized by adjusting the positions of the shorted stubs. We briefly analyze the equivalent circuit model of the MMA unit cell and then numerically and experimentally investigate the near-perfect absorptions in such two conditions (single- and dual-band). The results indicate that the proposed MMA exhibits near-perfect impedance matching with free space and high absorptivity of 99.74 % at 8.65 GHz for single-band condition, and absorptivities of 99.75 % and 97.35 % at 8.525 and 9.1 GHz, respectively, for dual-band condition. It also exhibits a wide range of angles of incidence for both transverse electric (TE) and transverse magnetic (TM) radiation. The two operating frequency bands, in dual-band condition, can be further controlled by adjusting the positions of shorted stubs or adding other shorted stubs. So it opens the way to fabricate controllable MMAs, and so controllable perfectly matched layers and bolometers.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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Pile-fermentation is a common processing step for Phyllanthus emblica L. fruit (PEF) in its producing area. This process enhances its flavor, reduces astringency, and increases its ...health benefits. However, the mechanism behind pile-fermentation and the key factors impacting PEF quality remain unknown, becoming an urgent challenge that limits its further application. To address this issue, 87 volatile compounds were analyzed by HS-SPME/GC-QQQ-MS/MS and identified acetic acid and ethyl acetate as distinguishing markers before and after fermentation. The results found that 2-methoxy-3-isobutylpyrazine contributes to the differences in odor after fermentation based on the odor intensity characteristic spectrum. Illumina Miseq sequencing of ITS1 region and 16SrDNA V4 region was performed to investigate the microbial succession during the pile-fermentation. A total of 4 phyla 34 genera of fungi and 15 phyla 61 genera of bacteria were detected in all samples. The results showed that the dominant bacteria had significant differences due to different habitats before fermentation, and the diversity increased after fermentation, while the fungal diversity exhibited the opposite trend. Aspergillus and the Unclassified_f_Necriaceae genus emerged as dominant genera after fermentation. Additionally, through UPLC-QTOF-MS analysis, we identified 18 differential components before and after fermentation. Among these, 5 compounds, such as 2-O-galloyl-1,4-galactolactone and 1-methyl-2-gallate galactose ester, showed a downward trend, whereas 13 compounds, including corilagin and chebulitic acid, exhibited an upward trend. These changes weakened astringency while improving sourness and aftertaste sweetness. The results of this study hold significant importance in clarifying the fermentation mechanism and improving the quality standards of PEF.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Osteoarthritis (OA) progresses due to the excessive generation of reactive oxygen and nitrogen species (ROS/RNS) and abnormal ATP energy metabolism related to the oxidative phosphorylation pathway in ...the mitochondria. Highly active single-atom nanozymes (SAzymes) can help regulate the redox balance and have shown their potential in the treatment of inflammatory diseases. In this study, we innovatively utilised ligand-mediated strategies to chelate Pt4+ with modified g-C3N4 by π–π interaction to prepare g–C3N4–loaded Pt single-atom (Pt SA/C3N4) nanozymes that serve as superoxide dismutase (SOD)/catalase (CAT) mimics to scavenge ROS/RNS and regulate mitochondrial ATP production, ultimately delaying the progression of OA. Pt SA/C3N4 exhibited a high loading of Pt single atoms (2.45 wt%), with an excellent photothermal conversion efficiency (54.71%), resulting in tunable catalytic activities under near-infrared light (NIR) irradiation. Interestingly, the Pt–N6 active centres in Pt SA/C3N4 formed electron capture sites for electron holes, in which g-C3N4 regulated the d-band centre of Pt, and the N-rich sites transferred electrons to Pt, leading to the enhanced adsorption of free radicals and thus higher SOD- and CAT-like activities compared with pure g-C3N4 and g–C3N4–loaded Pt nanoparticles (Pt NPs/C3N4). Based on the use of H2O2-induced chondrocytes to simulate ROS-injured cartilage invitro and an OA joint model invivo, the results showed that Pt SA/C3N4 could reduce oxidative stress-induced damage, protect mitochondrial function, inhibit inflammation progression, and rebuild the OA microenvironment, thereby delaying the progression of OA. In particular, under NIR light irradiation, Pt SA/C3N4 could help reverse the oxidative stress-induced joint cartilage damage, bringing it closer to the state of the normal cartilage. Mechanistically, Pt SA/C3N4 regulated the expression of mitochondrial respiratory chain complexes, mainly NDUFV2 of complex 1 and MT-ATP6 of ATP synthase, to reduce ROS/RNS and promote ATP production. This study provides novel insights into the design of artificial nanozymes for treating oxidative stress-induced inflammatory diseases.
•Design of a ligand-mediated strategy for nanozyme preparation.•Tunable enzymatic activity under NIR light irradiation to scavenge ROS/RNS.•Density Functional Theory study on the SOD/CAT-like catalytic mechanism of Pt SA/C3N4 nanozymes.•Regulation of the expression of mitochondrial respiratory chain complexes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this letter, a novel design of dual-band negative permittivity metamaterial is presented, which is based on a cross circular loop resonator (CCLR) with shorting stubs. The electromagnetic ...characteristics of this metamaterial are analyzed straightforwardly by an equivalent circuit. Numerical simulations and microwave experiments are further employed to illustrate the theoretical expectations. Moreover, the dependence between both the two frequencies and the positions of shorting stubs are discussed. Our results open a way to design the dual-notched ultrawideband (UWB) antennas and filters and dual-band metamaterial absorbers.
The ECM protein Del-1 is one of several novel ECM proteins that accumulate around angiogenic blood vessels in embryonic and tumor tissue and promote angiogenesis in the absence of exogenous growth ...factors. Del-1 expressed in mouse or rabbit ischemic hind-limb muscle by gene transfer rapidly promotes new blood vessel formation and restores muscle function. This angiogenic ECM protein initiates angiogenesis by binding to integrin alphavbeta5 on resting endothelium, thereby resulting in expression of the transcription factor Hox D3 and integrin alphavbeta3. Hox D3 converts resting endothelium to angiogenic endothelium by inducing expression of proangiogenic molecules such as integrin alphavbeta3. These findings provide evidence for an angiogenic switch that can be initiated in the absence of exogenous growth factors and indicate that the angiogenic matrix protein Del-1 may be a useful tool for the therapy of ischemic disease.
In this study, attapulgite (AT) and graphene oxide (GO) nanosheets were grafted together via a silane coupling agent to synthesize attapulgite–graphene oxide (AT–GO) composites and apply them to ...remove the emulsified oil from the oily wastewater. The structure and morphology of the AT–GO composites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction spectroscopy, zeta potential measurements, and transmission electron microscopy. The amphiphilicity of the AT–GO composites was evaluated by visual observation of their distribution in the oil–water mixture. The results showed that the AT–GO composites have been successively prepared and have good amphiphilic and interfacial activity. The effects of the pH, demulsifier dosage, temperature, and the mass ratio of AT and GO (R A/G) in the composites on the demulsification performance of AT–GO were studied. It was found that the demulsification process could be completed efficiently and quickly at room temperature. Under optimal demulsification conditions, the demulsification efficiency is above 95%. The demulsification mechanism was studied and discussed. It is believed that the interaction behavior between the AT–GO material and the emulsified molecules of asphaltenes is a key for the demulsification. Once the nanoparticles are combined with the emulsified molecules, the external stirring, vibration, and other mechanical actions provide them enough kinetic energy to destroy the protective film at the oil/water interface and then promote the merging of dispersed oil droplets to realize the oil–water separation.
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