Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic struct...Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic structure light pressure electric generator(Basic-LPEG),which utilized a layered configuration of Ag/Pb(Zr,Ti)O_(3)(PZT)/Pt/GaAs to generate electricity based on light-induced pressure on the PZT.In this study,we sought to enhance the performance of this Basic-LPEG by introducing Ag nanoparticles/graphene oxide(AgNPs/GO)composite units(NP-LPEG),creating upgraded harvesting device.Specifically,by depositing the AgNPs/GO units twice onto the Basic-LPEG,we observed an increase in output voltage and current from 241 mV and 3.1μA to 310 mV and 9.3μA,respectively,under a solar simulator.The increase in electrical output directly correlated with the intensity of the light pressure impacting the PZT,as well as matched the Raman measurements,finite-difference time-domain simulations,and COMSOL Multiphysics Simulation.Experimental data revealed that the enhancement in electrical output was proportional to the number of hot spots generated between Ag nanoparticles,where the electric field experienced substantial amplification.These results underline the effectiveness of AgNPs/GO units in boosting the light-induced electric generation capacity,thereby providing a promising pathway for high-efficiency energy harvesting devices.展开更多
Mesenchymal stromal cell transplantation is an effective and promising approach for treating various systemic and diffuse diseases.However,the biological characteristics of transplanted mesenchymal stromal cells in hu...Mesenchymal stromal cell transplantation is an effective and promising approach for treating various systemic and diffuse diseases.However,the biological characteristics of transplanted mesenchymal stromal cells in humans remain unclear,including cell viability,distribution,migration,and fate.Conventional cell tracing methods cannot be used in the clinic.The use of superparamagnetic iron oxide nanoparticles as contrast agents allows for the observation of transplanted cells using magnetic resonance imaging.In 2016,the National Medical Products Administration of China approved a new superparamagnetic iron oxide nanoparticle,Ruicun,for use as a contrast agent in clinical trials.In the present study,an acute hemi-transection spinal cord injury model was established in beagle dogs.The injury was then treated by transplantation of Ruicun-labeled mesenchymal stromal cells.The results indicated that Ruicunlabeled mesenchymal stromal cells repaired damaged spinal cord fibers and partially restored neurological function in animals with acute spinal cord injury.T2*-weighted imaging revealed low signal areas on both sides of the injured spinal cord.The results of quantitative susceptibility mapping with ultrashort echo time sequences indicated that Ruicun-labeled mesenchymal stromal cells persisted stably within the injured spinal cord for over 4 weeks.These findings suggest that magnetic resonance imaging has the potential to effectively track the migration of Ruicun-labeled mesenchymal stromal cells and assess their ability to repair spinal cord injury.展开更多
Enhanced UV-B radiation represents a major environmental factor impacting global cereal production.Researchers have explored various approaches to reduce the detrimental impact of UV-B radiation on crops.Recently,engi...Enhanced UV-B radiation represents a major environmental factor impacting global cereal production.Researchers have explored various approaches to reduce the detrimental impact of UV-B radiation on crops.Recently,engineered nanoparticles,particularly cerium oxide nanoparticles(CeO_(2)-NPs),have attracted widespread interest for their ability to boost plant tolerance to a range of abiotic stresses.This study investigates how CeO_(2)-NPs application affects the morphology,physiology,biochemistry,and transcriptomics profiles of wheat seedling roots subjected to enhanced UV-B stress.The findings demonstrate that CeO_(2)-NPs notably promoted root length,fresh and dry weights,and root activity(p<0.05)under enhanced UV-B stress.CeO_(2)-NP treatment reduced the content of hydrogen peroxide<(H_(2)O_(2))and malondialdehyde(MDA)in wheat,alleviating oxidative damage in seedling roots and partially restoring the root phenotype.Under non-UV-B stress conditions,CeO_(2)-NP treatment triggered the difference of 237 transcripts in plants relative to the control group.Under enhanced UV-B stress,CeO_(2)-NP treatment exhibited differentially expressed genes(DEGs)linked to the antioxidant defense mechanism responsible for reactive oxygen species(ROS)scavenging,compared to the non-nanoparticle control.This suggests that ROS scavenging may be a key mechanism by which CeO_(2)-NPs enhance wheat resistance to enhanced UV-B radiation.This study elucidates a potential molecular mechanism through which CeO_(2)nanoparticles may enhance wheat tolerance to UV-B stress.展开更多
Synthesis of zinc oxide nanoparticles(ZnO-NPs)via green method is an outstanding alternative to conventional/regular methods;however,the safety or toxicity of the biosynthesized ZnO-NPs in vivo is not fully explored.T...Synthesis of zinc oxide nanoparticles(ZnO-NPs)via green method is an outstanding alternative to conventional/regular methods;however,the safety or toxicity of the biosynthesized ZnO-NPs in vivo is not fully explored.This study was conducted to evaluate the protective efficiency of cinnamaldehyde-loaded chitosan nanoparticles(Cin@CSNPs)against oxidative damage and genotoxicity of ZnO-NPs in mice.ZnO-NPs were biosynthesized using the extract of fresh leaves of Mentha pulegium L.Cin was extracted from cinnamon essential oil,and was loaded into chitosan nanoparticle(Cin@CSNPs).Both ZnO-NPs,Cin@CSNPs and CSNPs were characterized.The in vitro release of Cin@CSNPs was determined.In the biological study,6 groups of male BALB/c mice were treated by gavage for 3 weeks as follows,control group,the group received ZnO-NPs(25 mg/kg b.w),the groups received Cin@CSNPs at low dose(50 mg/kg b.w)or high dose(100 mg/kg b.w),and the groups received ZnO-NPs plus Cin@CSNPs at the 2 tested doses.Blood and tissue samples were collected for different biochemical,genetical and histological studies.The particle size of ZnO-NPs,CSNPs,and Cin@CSNPs were(20.78±2.60),(170.0±3.7),and(218.23±2.90)nm,andξ-potential were(32.7±4.6),(8.32±0.27)and(4.80±0.21)mV,respectively.ZnO-NPs disturbed the biochemical and oxidative stress indices,AFP,CEA,TNF-α,chromosomal aberrations in somatic and germ cells,and sperm abnormality along with severe pathological changes in the hepatic,renal,and testicular tissues.Cin@CSNPs improved significantly all the parameters tested and the histological picture in a dose-dependent.Therefore,the biosynthesized ZnO-NPs exhibit oxidative damage and genotoxicity,and Cin@CSNPs have potential protective effects against the risks of ZnO-NPs and may be a promising tool to overcome the challenges of using Cin in food and pharmaceuticals applications.展开更多
Objective:Cyclophosphamide(CP)is an anticancer drug that induces oxidative stress,leading to gonadal toxicity.This study aimed to evaluate the effectiveness of co-treatment with zinc oxide nanoparticles(nZno)and melat...Objective:Cyclophosphamide(CP)is an anticancer drug that induces oxidative stress,leading to gonadal toxicity.This study aimed to evaluate the effectiveness of co-treatment with zinc oxide nanoparticles(nZno)and melatonin(Mel)on lipid peroxidation and antioxidant enzyme levels against CP-induced testicular damage.Methods:In this study,42 adult male rats were divided into six groups.The control group received intraperitoneal(i.p.)saline solution.The CP group was administered CP at 60 mg/kg/week.The Mel+CP and nZno+CP groups received CP along with 10 mg/kg Mel and 5 mg/kg nZno,respectively.The Mel+nZno+CP group received CP plus 10 mg/kg Mel and 5 mg/kg nZno,simultaneously.The Mel+nZno group received 10 mg/kg Mel and 5 mg/kg nZno simultaneously.Eight weeks after the treatment,hormonal assays,total antioxidant capacity(TAC),histological studies,lipid peroxidation levels,and antioxidant enzyme status were assessed.Results:Biochemical results showed that CP decreased spermatogenic lineage cells,TAC,levels of antioxidant enzymes catalase(CAT),glutathione(GSH),and glutathione peroxidase(GSH-Px),and reproductive hormone levels luteinizing hormone(LH),follicle-stimulating hormone(FSH)and testosterone,and increased malondialdehyde(MDA)content.In contrast,co-treatment with Mel and nZno in the Mel+nZno+CP group resulted in a significant improvement in all examined parameters(P<0.05).Conclusion:The results indicate that the simultaneous administration of Mel and nZno could be used as a potential protective agent against CP-induced reproductive toxicity.展开更多
Ultrasmall superparamagnetic iron oxide nanoparticles(usSPIONs)are promising alternatives to gadolinium‐based contrast agents for positive contrast enhancement in magnetic resonance imaging(MRI).Unlike larger SPIONs ...Ultrasmall superparamagnetic iron oxide nanoparticles(usSPIONs)are promising alternatives to gadolinium‐based contrast agents for positive contrast enhancement in magnetic resonance imaging(MRI).Unlike larger SPIONs that primarily function as T2/T2*negative contrast agents,usSPIONs with core diameters below 5 nm can effectively shorten T1 relaxation times,producing bright signals in T1‐weighted images.This distinct behavior stems from their unique magnetic properties,including single‐domain configurations,surface spin canting,and rapid Néel relaxation dynamics,which are particularly enhanced at low magnetic field strengths.The biocompatibility of iron oxide,efficient renal clearance pathways,and versatility for surface functionalization offer potential advantages over gadolinium‐based agents,especially regarding safety concerns related to nephrogenic systemic fibrosis and gadolinium deposition.These nanoparticles show particular promise for applications in lowfield MRI,vascular imaging,targeted molecular imaging,and theranostic platforms.Although challenges remain in optimizing synthesis methods for consistent production of monodisperse usSPIONs with tailored surface chemistry,ongoing research continues to advance their potential for clinical translation.This review explores the mechanisms,synthesis approaches,applications,and future perspectives of usSPIONs as positive contrast agents in MRI.展开更多
This study systematically explored the oxidation behavior of a Ni-10Cr alloy without and with surface spraying hexagonal closed pack(hcp)-structuredα-Al_(2)O_(3)orα-Fe_(2)O_(3)nanoparticles.Despite the distinct equi...This study systematically explored the oxidation behavior of a Ni-10Cr alloy without and with surface spraying hexagonal closed pack(hcp)-structuredα-Al_(2)O_(3)orα-Fe_(2)O_(3)nanoparticles.Despite the distinct equilibrium dissociation oxygen partial pressure of the two kinds of oxide nanoparticles,they both contributed to the selective oxidation of Ni-10Cr alloy,achieving the transition from internal Cr oxidation to external Cr_(2)O_(3)scale formation.Nano-scaled characterization indicates that a coherent interface was developed between the newly grown Cr_(2)O_(3)grains and the hcp-structured oxide nanoparticles,whereby promoting epitaxial Cr_(2)O_(3)nucleation surrounding the nanoparticles and kinetically accelerating the formation of a continuous Cr_(2)O_(3)scale at the transient oxidation stage.The findings provide new insights into the selective oxidation mechanism of alloys with low Cr contents.展开更多
Objective:To examine the protective effects of green-synthesized zinc oxide nanoparticles with Berberis vulgaris L.fruit aqueous extract(BVZnONPs)on cyclophosphamide(CP)-induced nephrotoxicity in Wistar rats.Methods:3...Objective:To examine the protective effects of green-synthesized zinc oxide nanoparticles with Berberis vulgaris L.fruit aqueous extract(BVZnONPs)on cyclophosphamide(CP)-induced nephrotoxicity in Wistar rats.Methods:35 Adult male Wistar rats were divided into 5 groups:normal,BVZnONPs(20 mg/kg),CP(100 mg/kg),and 2 co-treatment groups receiving CP with BVZnONPs(10 and 20 mg/kg).All treatments were administered intraperitoneally for 28 days.Serum levels of antioxidant enzymes(catalase,superoxide dismutase,glutathione peroxidase,nitric oxide)and kidney function parameters(creatinine,total protein,blood urea nitrogen)were measured.The expressions of p53 and Bcl-2 proteins were assessed via immunohistochemical assay while kidney volume and substructures were estimated stereologically.Results:CP induced nephrotoxicity with significant increases(P<0.05)in nitric oxide,creatinine,and blood urea nitrogen levels,and decreases(P<0.05)in catalase,superoxide dismutase,and glutathione peroxidase levels.It also increased p53 protein expression and decreased Bcl-2 protein expression.Treatment with BVZnONPs significantly increased(P<0.05)antioxidant enzyme levels and decreased nitric oxide levels in the 20 mg/kg group compared to CP.Blood urea nitrogen and creatinine levels were significantly reduced in the BVZnONPs-treated groups,with greater effects at 20 mg/kg.However,total protein serum levels were not significant(P>0.05)in the BVZnONPs-treated groups compared to CP.Conclusions:These findings suggest that BVZnONPs can mitigate CP-induced nephrotoxicity,likely due to their antioxidant and anti-apoptotic properties,though longer treatment duration may be necessary for tissue-level improvements.展开更多
Magnetic iron oxide nanoparticles(Fe_(x)O_(y) NPs,mainly Fe3O4 andγ-Fe2O_(3))are nanomaterials ubiquitously present in aquatic,terrestrial,and atmospheric environments,with a high prevalence and complex sources.Over ...Magnetic iron oxide nanoparticles(Fe_(x)O_(y) NPs,mainly Fe3O4 andγ-Fe2O_(3))are nanomaterials ubiquitously present in aquatic,terrestrial,and atmospheric environments,with a high prevalence and complex sources.Over the past decade,numerous reports have emerged on the presence of exogenous particles in human body,facilitated by the rapid development of separation and detection methods.The health risk associated with magnetic Fe_(x)O_(y) NP have garnered escalating attention due to their presence in human blood and brain tissues,especially for their potential association with neurodegenerative diseases like Alzheimer’s disease.In this paper,we provide a comprehensive overview of sources,analysis methods,environmental impacts,and health risks of magnetic Fe_(x)O_(y) NP.Currently,most researches are primarily based on engineered Fe_(x)O_(y) NP,while reports aboutmagnetic Fe_(x)O_(y) NP existing in real-world environments are still limited,especially for their occurrence levels in various environmental matrices,environmental transformation behavior,and biotoxic effects.Our study reviews this emerging pollutant,providing insights to address current research deficiencies and chart the course for future studies.展开更多
Graphene oxide(GO)is a two-dimensional carbon material with a graphene-like structure and many oxygen-containing functional groups,and in recent years from research into the unique optical properties of GO,GO-based co...Graphene oxide(GO)is a two-dimensional carbon material with a graphene-like structure and many oxygen-containing functional groups,and in recent years from research into the unique optical properties of GO,GO-based composite materials formed by combining with other materials have shown improved overall performance.Reported here is an investigation of how doping with Ni,Fe,and Ag nanoparticles affects the linear and nonlinear optical properties of GO films.The morphology and structure of films of GO,GO with Ni nanoparticles,GO with Fe nanoparticles,and GO with Ag nanoparticles were studied by laser scanning confocal microscopy,SEM,energy dispersive spectroscopy,XRD,and Raman spectroscopy.UV-visible absorption spectra were used to study the optical absorption properties,and the optical band gaps of GO and the composites were calculated from those spectra via Tauc plots.The results show that the band gaps of GO films can be effectively regulated by metal nanoparticles,and so the properties of GO composites can be manipulated.The nonlinear optical properties of GO and GO-metal-nanoparticle composite films were studied by femtosecond laser Z-scanning.The results show that the femtosecond laser power can be tuned to the optical limiting behavior of GO.The strong synergistic coupling effect between metal nanoparticles and GO enhances the nonlinear absorption and nonlinear refraction of composite thin films.The nonlinear absorption coefficient of the composite thin films is improved significantly,and the optical limiting properties are excellent.GO-metal-nanoparticle composite materials have potential applications and advantages in improving optical absorption,band-gap control,and optical limiting.They can promote the expansion of GO composite materials in various practical applications and are candidates for good optical materials,opening the way to GO photonics.展开更多
A Fe-12Cr-2W-0.2Zr-0.1Ti-0.35Y_(2)O_(3)ODS ferritic alloy was prepared by ball milling,hot isostatic pressing(HIP)and thermomechanical processing herein.The evolution of oxide nanoparticles(ONPs)with differ-ent interm...A Fe-12Cr-2W-0.2Zr-0.1Ti-0.35Y_(2)O_(3)ODS ferritic alloy was prepared by ball milling,hot isostatic pressing(HIP)and thermomechanical processing herein.The evolution of oxide nanoparticles(ONPs)with differ-ent intermediate annealing temperatures of thermomechanical processing and its effect on microstructure and mechanical properties of the ODS alloy were investigated.The result shows that the intermediate annealing temperatures played a decisive role in the size,morphology and structure of nanoparticles in the final alloy since this was attributed to the fact that fine particles were dissolved through dislocation shearing during cold deformation and then re-precipitated during subsequent heat treatment.The high intermediate annealing temperature promotes the growth of the near-spherical ONPs,while the ellip-soidal nanoparticles are developed at relatively low temperature.Meanwhile,the structural change of the ONPs was also facilitated by the dissolution-reprecipitation behavior.The predominant Y_(2)(Zr_(y)Ti_(1−y))_(2)O_(7)with cubic pyrochlore phase in as-HIPed alloy can be transformed into Y_(4)Zr_(3)O_(12)particles with rhom-bohedral structure during the thermomechanical treatment.However,compared with the change in size of ONPs,the change in morphology and structure of ONPs has no obvious influence on the mechanical strength.Different intermediate annealing temperatures play a different role in the coarsening of ONPs during thermomechanical treatment,which makes the alloy annealed at low temperature exhibiting more uniform distribution of ONPs and better mechanical properties.展开更多
Pt-based methanol oxidation reaction(MOR)electrocatalysts with high activity,stability,and carbon monoxide(CO)tolerance are critical for advancing direct methanol fuel cells(DMFC).Herein,a low-Pt-content electrocataly...Pt-based methanol oxidation reaction(MOR)electrocatalysts with high activity,stability,and carbon monoxide(CO)tolerance are critical for advancing direct methanol fuel cells(DMFC).Herein,a low-Pt-content electrocatalyst(Pt/CeO_(2)-carbon nanofiber(CNF))is developed through electrospinning,high-temperature calcination,and sodium borohydride(NaBH4)reduction,featuring highly dispersed Pt nanoparticles anchored on oxygen vacancy(Ov)-rich CeO_(2) embedded within CNF.The strong metal–support interaction(SMSI)induces Pt–O–Ce interfacial bonding,facilitating electron transfer and enhancing MOR performance.Pt/CeO_(2)-CNF achieves a mass activity of 5.29 A·mgPt^(-1),3.5 times higher than commercial Pt/C,alongside exceptional stability(92%retention after 1000 cycles)and CO tolerance.When deployed as a DMFC anode,it delivers a peak power density of 34.72 mW·cm^(-2),outperforming Pt/C by 31%.Characterization results indicate that SMSI induces charge redistribution between Pt and CeO_(2),which synergistically enhances the reaction kinetics of MOR with the hydroxyl groups produced by CeO_(2) hydrolysis.In addition,the uniform dispersion of in-situ grown CeO_(2) is ensured on CNF,and Ov acts as an anchoring point to stabilize Pt nanoparticles,improving the stability of the catalyst.This work establishes a design framework for synthesizing high-performance Pt-based DMFC electrocatalysts through controlled structural and electronic modulation strategies.展开更多
Herein,a modified screen printed carbon electrode(SPCE)based on a composite material,graphene oxide-gold nanoparticles(GO-AuNPs),and poly(3-aminobenzoic acid)(P3ABA)for the detection of paraquat(PQ)is introduced.The m...Herein,a modified screen printed carbon electrode(SPCE)based on a composite material,graphene oxide-gold nanoparticles(GO-AuNPs),and poly(3-aminobenzoic acid)(P3ABA)for the detection of paraquat(PQ)is introduced.The modified electrode was fabricated by drop casting of the GO-AuNPs,followed by electropolymerization of 3-aminobenzoic acid to achieve SPCE/GO-AuNPs/P3ABA.The morphology and microstructural characteristics of the modified electrodes were revealed by scanning electron microscopy(SEM)for each step of modification.The composite GO-AuNPs can provide high surface area and enhance electroconductivity of the electrode.In addition,the presence of negatively charged P3ABA notably improved PQ adsorption and electron transfer rate,which stimulate redox reaction on the modified electrode,thus improving the sensitivity of PQ analysis.The SPCE/GOAuNPs/P3ABA offered a wide linear range of PQ determination(10^(−9)-10^(−4) mol/L)and low limit of detection(LOD)of 0.45×10^(−9) mol/L or 0.116μg/L,which is far below international safety regulations.The modified electrode showed minimum interference effect with percent recovery ranging from 96.5%to 116.1%after addition of other herbicides,pesticides,metal ions,and additives.The stability of the SPCE/GO-AuNPs/P3ABA was evaluated,and the results indicated negligible changes in the detection signal over 9 weeks.Moreover,this modified electrode was successfully implemented for PQ analysis in both natural and tapped water with high accuracy.展开更多
Objective: Application of magnetic nanoparticles as gene carrier in gene therapy has developed quickly. This study was designed to investigate the preparation of superparamagnetic dextran-coated iron oxide nanoparticl...Objective: Application of magnetic nanoparticles as gene carrier in gene therapy has developed quickly. This study was designed to investigate the preparation of superparamagnetic dextran-coated iron oxide nanoparticles (SDION) and the feasibility of SDION used as a novel gene carrier for plasmid DNA in vitro. Methods: SDION were prepared by chemical coprecipitation and separated by gel filtration on Sephacryl S-300HR, characterized by TEM, laser scattering system and Vibrating Sample Magnetometer Signal Processor. The green fluorescent protein (pGFP-C2) plasmid DNA was used as target gene. SDION-pGFP-C2 conjugate compounds were produced by means of oxidoreduction reaction. The connection ratio of SDION and pGFP-C2 DNA was analyzed and evaluated by agarose electrophoresis and the concentration of pGFP-C2 in supernatant was measured. Using liposome as control, the transfection efficiency of SDION and liposome was respectively evaluated under fluorescence microscope in vitro. Results: The diameter of SDION ranges from 3 nm to 8 nm, the effective diameter was 59.2 nm and the saturation magnetization was 0.23 emu/g. After SDION were reasonably oxidized, SDION could connect with pGFP-C2 to a high degree. The transfection efficiency of SDION as gene carrier was higher than that of liposome. Conclusion: The successes in connecting SDION with pGFP-C2 plasmid by means of oxidoreduction reaction and in transferring pGFP-C2 gene into human bladder cancer BIU-87 cells in vitro provided the experimental evidence for the feasibility of SDION used as a novel gene carrier.展开更多
Titanium dioxide nanoparticles(TiO_2 NPs) are one of the most widely used nanomaterials in the consumer products, agriculture, and energy sectors. Their large demand and widespread applications will inevitably cause d...Titanium dioxide nanoparticles(TiO_2 NPs) are one of the most widely used nanomaterials in the consumer products, agriculture, and energy sectors. Their large demand and widespread applications will inevitably cause damage to organisms and ecosystems. A better understanding of TiO_2 NP toxicity in living organisms may promote risk assessment and safe use practices of these nanomaterials. This review summarizes the toxic effects of TiO_2 NPs on multiple taxa of microorganisms, algae, plants, invertebrates, and vertebrates. The mechanism of TiO_2 NP toxicity to organisms can be outlined in three aspects: The Reactive Oxygen Species(ROS)produced by TiO_2 NPs following the induction of electron–hole pairs; cell wall damage and lipid peroxidation of the cell membrane caused by NP-cell attachment by electrostatic force owing to the large surface area of TiO_2 NPs; and TiO_2 NP attachment to intracellular organelles and biological macromolecules following damage to the cell membranes.展开更多
Nanostructured cerium oxide （CeO2） commonly known as nanoceria is a rare earth metal oxide, which plays a technologically important role due to its versatile applications as antomobile exhaust catalysts, oxide ion c...Nanostructured cerium oxide （CeO2） commonly known as nanoceria is a rare earth metal oxide, which plays a technologically important role due to its versatile applications as antomobile exhaust catalysts, oxide ion conductors in solid oxide fuel cells, electrode materials for gas sensors, ultraviolet absorbents and glass-polishing materials. However, nanoceria has little or weak luminescence, and therefore its uses in high-performance luminescent devices and biomedical areas are limited. In this review, we present the recent advances of nanoceria in the aspects of synthesis, luminescence and biomedical studies. The CeO2 nanoparticles can bc synthesized by solution-based methods including co-precipitation, hydrothemlal, microemulsion process, sol-gel techniques, combustion reaction and so on. Achieving controlled morphologies and enhanced luminescence efficiency of nanoceria particles arc quite essential for its potential energyand environment-related applications. Additionally, a new fiontier for nanoccria particles in biomedical research has also been opened, which involves low toxicity, retinopathy, biosensors and cancer therapy aspects. Finally, the summary and outlook on the challenges and perspectives of the nanoceria particles are proposed.展开更多
The ultrafine Ce-based oxide nanoparticles with different element dopings （Zr, Y） were synthesized by the method of mi- cropores-diffused coprecipitation （MDC） using ammonia solution as the precipitation agent. Th...The ultrafine Ce-based oxide nanoparticles with different element dopings （Zr, Y） were synthesized by the method of mi- cropores-diffused coprecipitation （MDC） using ammonia solution as the precipitation agent. The activities of the catalysts for soot oxidation were evaluated by the temperature-programmed oxidation （TPO） reaction. Ce-based oxides prepared in this study exhibited high catalytic activity for soot oxidation under tile condition of loose contact between soot particles and catalysts, and the catalytic ac- tivity ofultrafine Ce0.gZr0 iO2 nanoparticle for soot combustion was the highest, whose/＂10, Ts0 and Sco2m was 364, 442 ~C and 98.3%, respectively. All catalysts were systematically characterized by means of X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, Brumauer-Emett-Teller （BET）, Fourier transform infrared spectroscopy （FT-IR） and UV-Vis diffuse reflectance spectroscopy （UV-Vis DRS）. It was indicated that the MDC method could prepare the ultrafine Ce-bascd oxide nanoparticles whose the crystal lattice were perfect, and the BET surface area and average crystal size of the ultrafine nanoparticles changed with the different element dopings （Zr, Y）. The H2-TPR measurements showed that the ultrafine Ce-based ox- ide nanoparticles with the doping-Zr cation could be favorable for improving the redox property of the catalysts.展开更多
Here,a preparation of stable,non-toxic,transparent,high performance zinc oxide thin-film semiconductor via thermal processing of composite system of zinc source solution filled zinc oxide nanoparticles layer was repor...Here,a preparation of stable,non-toxic,transparent,high performance zinc oxide thin-film semiconductor via thermal processing of composite system of zinc source solution filled zinc oxide nanoparticles layer was reported.The zinc oxide nanocrystals synthesized through the thermolysis of Zn-oleate complex in organic solvent medium were first deposited on the ATO/ITO/glass substrate and treated by annealing,then the zinc source solution was deposited on the zinc oxide nanoparticle layer to form precursor thin film by spin-coating process.The thin film transistor with well-controlled and densely packed nanocrystals in zinc oxide semiconductor layer was obtained by thermal annealing the system of precursor film coated ATO/ITO/glass substrate.By optimizing the fabrication conditions,the fabricated thin film transistors exhibited superior field-effect property and carrier mobility property,their saturation mobility reached 2.17 cm^(2)·V^(-1)·s^(-1),which was more than twice as high compared to the transistor devices coated only by zinc oxide nanoparticles.Our method of fabricating zinc oxide thin film transistors was simple,high efficiency,and feasible for the batch production with low cost.展开更多
In recent years, zinc oxide nanoparticles(ZnO NPs) have gained tremendous attention attributed to their unique properties. Notably, evidence has shown that zinc is an important nutrient in living organisms. As such, b...In recent years, zinc oxide nanoparticles(ZnO NPs) have gained tremendous attention attributed to their unique properties. Notably, evidence has shown that zinc is an important nutrient in living organisms. As such, both prokaryotes and eukaryotes including bacteria, fungi and yeast are exploited for the synthesis of ZnO NPs by using microbial cells or enzyme, protein and other biomolecules compounds in either an intracellular or extracellular route. ZnO NPs exhibit antimicrobial properties, however, the properties of nanoparticles(NPs) are depended upon on their size and shape, which make them specific for various applications. Nevertheless, the desired size and shape of NPs can be obtained through the optimization process of microbes mediated synthesis by manipulating their reaction conditions. It should be noted that ZnO NPs are synthesized by various chemical and physical methods.Nonetheless, these methods are expensive and not environmentally friendly. On that account, the microbes mediated synthesis of ZnO NPs have rapidly evolved recently where the microbes are cleaner, eco-friendly, nontoxic and biocompatible as the alternatives to chemical and physical practices. Moreover, zinc in the form of NPs is more effective than their bulk counterparts and thus, they have been explored for many potential applications including in animals industry. Notably, with the advent of multi-drug resistant strains, ZnO NPs have emerged as the potential antimicrobial agents. This is mainly due to their superior properties in combating a broad spectrum of pathogens. Moreover, zinc is known as an essential trace element for most of the biological function in the animal’s body. As such, the applications of ZnO NPs have been reported to significantly enhance the health and production of the farm animals. Thus, this paper reviews the biological synthesis of ZnO NPs by the microbes, the mechanisms of the biological synthesis, parameters for the optimization process and their potential application as an antimicrobial agent and feed supplement in the animal industry as well as their toxicological hazards on animals.展开更多
Cytotoxicity of selected metal oxide nanoparticles（MNPs）（ZnO,CuO,Co 3 O 4 and TiO 2）was investigated in Escherichia coli both under light and dark conditions.Cytotoxicity experiments were conducted with spread pla...Cytotoxicity of selected metal oxide nanoparticles（MNPs）（ZnO,CuO,Co 3 O 4 and TiO 2）was investigated in Escherichia coli both under light and dark conditions.Cytotoxicity experiments were conducted with spread plate counting and the LC 50 values were calculated.We determined the mechanism of toxicity via measurements of oxidative stress,reduced glutathione,lipid peroxidation,and metal ions.The overall ranking of the LC 50 values was in the order of ZnO 〈 CuO 〈 Co 3 O 4 〈 TiO 2 under dark condition and ZnO 〈 CuO 〈 TiO 2 〈 Co 3 O 4 under light condition.ZnO MNPs were the most toxic among the tested nanoparticles.Our results indicate depletion of reduced glutathione level and elevation of malondialdehyde level correlated with the increase in oxidative stress.Released metal ions were found to have partial effect on the toxicity of MNPs to E.coli.In summary,the dynamic interactions of multiple mechanisms lead to the toxicity of the tested MNPs to E.coli.展开更多
基金supported by Korea Evaluation Institute of Industrial Technology(KEIT)grant funded by the Korea Government(MOTIE)(RS-2022-00154720,Technology Innovation Program Development of next-generation power semiconductor based on Si-on-SiC structure)the National Research Foundation of Korea(NRF)by the Korea government(RS-2023-NR076826)Global-Learning&Academic Research Institution for Master's·PhD students,and Postdocs(LAMP)Program of the National Research Foundation of Korea(NRF)by the Ministry of Education(No.RS-2024-00443714).
文摘Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic structure light pressure electric generator(Basic-LPEG),which utilized a layered configuration of Ag/Pb(Zr,Ti)O_(3)(PZT)/Pt/GaAs to generate electricity based on light-induced pressure on the PZT.In this study,we sought to enhance the performance of this Basic-LPEG by introducing Ag nanoparticles/graphene oxide(AgNPs/GO)composite units(NP-LPEG),creating upgraded harvesting device.Specifically,by depositing the AgNPs/GO units twice onto the Basic-LPEG,we observed an increase in output voltage and current from 241 mV and 3.1μA to 310 mV and 9.3μA,respectively,under a solar simulator.The increase in electrical output directly correlated with the intensity of the light pressure impacting the PZT,as well as matched the Raman measurements,finite-difference time-domain simulations,and COMSOL Multiphysics Simulation.Experimental data revealed that the enhancement in electrical output was proportional to the number of hot spots generated between Ag nanoparticles,where the electric field experienced substantial amplification.These results underline the effectiveness of AgNPs/GO units in boosting the light-induced electric generation capacity,thereby providing a promising pathway for high-efficiency energy harvesting devices.
基金supported by the National Key R&D Program of China,Nos.2017YFA0104302(to NG and XM)and 2017YFA0104304(to BW and ZZ)
文摘Mesenchymal stromal cell transplantation is an effective and promising approach for treating various systemic and diffuse diseases.However,the biological characteristics of transplanted mesenchymal stromal cells in humans remain unclear,including cell viability,distribution,migration,and fate.Conventional cell tracing methods cannot be used in the clinic.The use of superparamagnetic iron oxide nanoparticles as contrast agents allows for the observation of transplanted cells using magnetic resonance imaging.In 2016,the National Medical Products Administration of China approved a new superparamagnetic iron oxide nanoparticle,Ruicun,for use as a contrast agent in clinical trials.In the present study,an acute hemi-transection spinal cord injury model was established in beagle dogs.The injury was then treated by transplantation of Ruicun-labeled mesenchymal stromal cells.The results indicated that Ruicunlabeled mesenchymal stromal cells repaired damaged spinal cord fibers and partially restored neurological function in animals with acute spinal cord injury.T2*-weighted imaging revealed low signal areas on both sides of the injured spinal cord.The results of quantitative susceptibility mapping with ultrashort echo time sequences indicated that Ruicun-labeled mesenchymal stromal cells persisted stably within the injured spinal cord for over 4 weeks.These findings suggest that magnetic resonance imaging has the potential to effectively track the migration of Ruicun-labeled mesenchymal stromal cells and assess their ability to repair spinal cord injury.
基金supported by Graduate Innovation Project of Shanxi Normal University(Grant No.2021Y443).
文摘Enhanced UV-B radiation represents a major environmental factor impacting global cereal production.Researchers have explored various approaches to reduce the detrimental impact of UV-B radiation on crops.Recently,engineered nanoparticles,particularly cerium oxide nanoparticles(CeO_(2)-NPs),have attracted widespread interest for their ability to boost plant tolerance to a range of abiotic stresses.This study investigates how CeO_(2)-NPs application affects the morphology,physiology,biochemistry,and transcriptomics profiles of wheat seedling roots subjected to enhanced UV-B stress.The findings demonstrate that CeO_(2)-NPs notably promoted root length,fresh and dry weights,and root activity(p<0.05)under enhanced UV-B stress.CeO_(2)-NP treatment reduced the content of hydrogen peroxide<(H_(2)O_(2))and malondialdehyde(MDA)in wheat,alleviating oxidative damage in seedling roots and partially restoring the root phenotype.Under non-UV-B stress conditions,CeO_(2)-NP treatment triggered the difference of 237 transcripts in plants relative to the control group.Under enhanced UV-B stress,CeO_(2)-NP treatment exhibited differentially expressed genes(DEGs)linked to the antioxidant defense mechanism responsible for reactive oxygen species(ROS)scavenging,compared to the non-nanoparticle control.This suggests that ROS scavenging may be a key mechanism by which CeO_(2)-NPs enhance wheat resistance to enhanced UV-B radiation.This study elucidates a potential molecular mechanism through which CeO_(2)nanoparticles may enhance wheat tolerance to UV-B stress.
基金supported by the National Research Centre,Dokki,Cairo,Egypt project#13050302.
文摘Synthesis of zinc oxide nanoparticles(ZnO-NPs)via green method is an outstanding alternative to conventional/regular methods;however,the safety or toxicity of the biosynthesized ZnO-NPs in vivo is not fully explored.This study was conducted to evaluate the protective efficiency of cinnamaldehyde-loaded chitosan nanoparticles(Cin@CSNPs)against oxidative damage and genotoxicity of ZnO-NPs in mice.ZnO-NPs were biosynthesized using the extract of fresh leaves of Mentha pulegium L.Cin was extracted from cinnamon essential oil,and was loaded into chitosan nanoparticle(Cin@CSNPs).Both ZnO-NPs,Cin@CSNPs and CSNPs were characterized.The in vitro release of Cin@CSNPs was determined.In the biological study,6 groups of male BALB/c mice were treated by gavage for 3 weeks as follows,control group,the group received ZnO-NPs(25 mg/kg b.w),the groups received Cin@CSNPs at low dose(50 mg/kg b.w)or high dose(100 mg/kg b.w),and the groups received ZnO-NPs plus Cin@CSNPs at the 2 tested doses.Blood and tissue samples were collected for different biochemical,genetical and histological studies.The particle size of ZnO-NPs,CSNPs,and Cin@CSNPs were(20.78±2.60),(170.0±3.7),and(218.23±2.90)nm,andξ-potential were(32.7±4.6),(8.32±0.27)and(4.80±0.21)mV,respectively.ZnO-NPs disturbed the biochemical and oxidative stress indices,AFP,CEA,TNF-α,chromosomal aberrations in somatic and germ cells,and sperm abnormality along with severe pathological changes in the hepatic,renal,and testicular tissues.Cin@CSNPs improved significantly all the parameters tested and the histological picture in a dose-dependent.Therefore,the biosynthesized ZnO-NPs exhibit oxidative damage and genotoxicity,and Cin@CSNPs have potential protective effects against the risks of ZnO-NPs and may be a promising tool to overcome the challenges of using Cin in food and pharmaceuticals applications.
基金Immunogenetic Research Center(IRC)of Sari Medical Faculty and Chancellor for Research and Technology of Mazandaran University of Medical Sciences(93-1997)。
文摘Objective:Cyclophosphamide(CP)is an anticancer drug that induces oxidative stress,leading to gonadal toxicity.This study aimed to evaluate the effectiveness of co-treatment with zinc oxide nanoparticles(nZno)and melatonin(Mel)on lipid peroxidation and antioxidant enzyme levels against CP-induced testicular damage.Methods:In this study,42 adult male rats were divided into six groups.The control group received intraperitoneal(i.p.)saline solution.The CP group was administered CP at 60 mg/kg/week.The Mel+CP and nZno+CP groups received CP along with 10 mg/kg Mel and 5 mg/kg nZno,respectively.The Mel+nZno+CP group received CP plus 10 mg/kg Mel and 5 mg/kg nZno,simultaneously.The Mel+nZno group received 10 mg/kg Mel and 5 mg/kg nZno simultaneously.Eight weeks after the treatment,hormonal assays,total antioxidant capacity(TAC),histological studies,lipid peroxidation levels,and antioxidant enzyme status were assessed.Results:Biochemical results showed that CP decreased spermatogenic lineage cells,TAC,levels of antioxidant enzymes catalase(CAT),glutathione(GSH),and glutathione peroxidase(GSH-Px),and reproductive hormone levels luteinizing hormone(LH),follicle-stimulating hormone(FSH)and testosterone,and increased malondialdehyde(MDA)content.In contrast,co-treatment with Mel and nZno in the Mel+nZno+CP group resulted in a significant improvement in all examined parameters(P<0.05).Conclusion:The results indicate that the simultaneous administration of Mel and nZno could be used as a potential protective agent against CP-induced reproductive toxicity.
文摘Ultrasmall superparamagnetic iron oxide nanoparticles(usSPIONs)are promising alternatives to gadolinium‐based contrast agents for positive contrast enhancement in magnetic resonance imaging(MRI).Unlike larger SPIONs that primarily function as T2/T2*negative contrast agents,usSPIONs with core diameters below 5 nm can effectively shorten T1 relaxation times,producing bright signals in T1‐weighted images.This distinct behavior stems from their unique magnetic properties,including single‐domain configurations,surface spin canting,and rapid Néel relaxation dynamics,which are particularly enhanced at low magnetic field strengths.The biocompatibility of iron oxide,efficient renal clearance pathways,and versatility for surface functionalization offer potential advantages over gadolinium‐based agents,especially regarding safety concerns related to nephrogenic systemic fibrosis and gadolinium deposition.These nanoparticles show particular promise for applications in lowfield MRI,vascular imaging,targeted molecular imaging,and theranostic platforms.Although challenges remain in optimizing synthesis methods for consistent production of monodisperse usSPIONs with tailored surface chemistry,ongoing research continues to advance their potential for clinical translation.This review explores the mechanisms,synthesis approaches,applications,and future perspectives of usSPIONs as positive contrast agents in MRI.
基金supported by the National Natural Science Foundation of China(No.52301089)the Jiangxi Provincial Key Research and Development Program(No.20232BBE50007).
文摘This study systematically explored the oxidation behavior of a Ni-10Cr alloy without and with surface spraying hexagonal closed pack(hcp)-structuredα-Al_(2)O_(3)orα-Fe_(2)O_(3)nanoparticles.Despite the distinct equilibrium dissociation oxygen partial pressure of the two kinds of oxide nanoparticles,they both contributed to the selective oxidation of Ni-10Cr alloy,achieving the transition from internal Cr oxidation to external Cr_(2)O_(3)scale formation.Nano-scaled characterization indicates that a coherent interface was developed between the newly grown Cr_(2)O_(3)grains and the hcp-structured oxide nanoparticles,whereby promoting epitaxial Cr_(2)O_(3)nucleation surrounding the nanoparticles and kinetically accelerating the formation of a continuous Cr_(2)O_(3)scale at the transient oxidation stage.The findings provide new insights into the selective oxidation mechanism of alloys with low Cr contents.
文摘Objective:To examine the protective effects of green-synthesized zinc oxide nanoparticles with Berberis vulgaris L.fruit aqueous extract(BVZnONPs)on cyclophosphamide(CP)-induced nephrotoxicity in Wistar rats.Methods:35 Adult male Wistar rats were divided into 5 groups:normal,BVZnONPs(20 mg/kg),CP(100 mg/kg),and 2 co-treatment groups receiving CP with BVZnONPs(10 and 20 mg/kg).All treatments were administered intraperitoneally for 28 days.Serum levels of antioxidant enzymes(catalase,superoxide dismutase,glutathione peroxidase,nitric oxide)and kidney function parameters(creatinine,total protein,blood urea nitrogen)were measured.The expressions of p53 and Bcl-2 proteins were assessed via immunohistochemical assay while kidney volume and substructures were estimated stereologically.Results:CP induced nephrotoxicity with significant increases(P<0.05)in nitric oxide,creatinine,and blood urea nitrogen levels,and decreases(P<0.05)in catalase,superoxide dismutase,and glutathione peroxidase levels.It also increased p53 protein expression and decreased Bcl-2 protein expression.Treatment with BVZnONPs significantly increased(P<0.05)antioxidant enzyme levels and decreased nitric oxide levels in the 20 mg/kg group compared to CP.Blood urea nitrogen and creatinine levels were significantly reduced in the BVZnONPs-treated groups,with greater effects at 20 mg/kg.However,total protein serum levels were not significant(P>0.05)in the BVZnONPs-treated groups compared to CP.Conclusions:These findings suggest that BVZnONPs can mitigate CP-induced nephrotoxicity,likely due to their antioxidant and anti-apoptotic properties,though longer treatment duration may be necessary for tissue-level improvements.
基金supported by the National Key R&D Program of China(No.2023YFC3708302)the National Natural Science Foundation of China(Nos.22188102 and 22306041)+1 种基金the Chinese Academy of Sciences Project for Young Scientists in Basic Research(No.YSBR-086)China Postdoctoral Science Foundation(No.2023M733679).
文摘Magnetic iron oxide nanoparticles(Fe_(x)O_(y) NPs,mainly Fe3O4 andγ-Fe2O_(3))are nanomaterials ubiquitously present in aquatic,terrestrial,and atmospheric environments,with a high prevalence and complex sources.Over the past decade,numerous reports have emerged on the presence of exogenous particles in human body,facilitated by the rapid development of separation and detection methods.The health risk associated with magnetic Fe_(x)O_(y) NP have garnered escalating attention due to their presence in human blood and brain tissues,especially for their potential association with neurodegenerative diseases like Alzheimer’s disease.In this paper,we provide a comprehensive overview of sources,analysis methods,environmental impacts,and health risks of magnetic Fe_(x)O_(y) NP.Currently,most researches are primarily based on engineered Fe_(x)O_(y) NP,while reports aboutmagnetic Fe_(x)O_(y) NP existing in real-world environments are still limited,especially for their occurrence levels in various environmental matrices,environmental transformation behavior,and biotoxic effects.Our study reviews this emerging pollutant,providing insights to address current research deficiencies and chart the course for future studies.
基金funded by the Henan Key Laboratory of Intelligent Manufacturing Equipment Integration for Superhard Materials(Grant No.JDKJ2022-01)the Key Lab of Modern Optical Technologies of Education Ministry of China,Soochow University。
文摘Graphene oxide(GO)is a two-dimensional carbon material with a graphene-like structure and many oxygen-containing functional groups,and in recent years from research into the unique optical properties of GO,GO-based composite materials formed by combining with other materials have shown improved overall performance.Reported here is an investigation of how doping with Ni,Fe,and Ag nanoparticles affects the linear and nonlinear optical properties of GO films.The morphology and structure of films of GO,GO with Ni nanoparticles,GO with Fe nanoparticles,and GO with Ag nanoparticles were studied by laser scanning confocal microscopy,SEM,energy dispersive spectroscopy,XRD,and Raman spectroscopy.UV-visible absorption spectra were used to study the optical absorption properties,and the optical band gaps of GO and the composites were calculated from those spectra via Tauc plots.The results show that the band gaps of GO films can be effectively regulated by metal nanoparticles,and so the properties of GO composites can be manipulated.The nonlinear optical properties of GO and GO-metal-nanoparticle composite films were studied by femtosecond laser Z-scanning.The results show that the femtosecond laser power can be tuned to the optical limiting behavior of GO.The strong synergistic coupling effect between metal nanoparticles and GO enhances the nonlinear absorption and nonlinear refraction of composite thin films.The nonlinear absorption coefficient of the composite thin films is improved significantly,and the optical limiting properties are excellent.GO-metal-nanoparticle composite materials have potential applications and advantages in improving optical absorption,band-gap control,and optical limiting.They can promote the expansion of GO composite materials in various practical applications and are candidates for good optical materials,opening the way to GO photonics.
基金financially supported by the Research Fund of Nuclear Materials of China Atomic Energy Authority(No.ICNM-2023-YZ-03).
文摘A Fe-12Cr-2W-0.2Zr-0.1Ti-0.35Y_(2)O_(3)ODS ferritic alloy was prepared by ball milling,hot isostatic pressing(HIP)and thermomechanical processing herein.The evolution of oxide nanoparticles(ONPs)with differ-ent intermediate annealing temperatures of thermomechanical processing and its effect on microstructure and mechanical properties of the ODS alloy were investigated.The result shows that the intermediate annealing temperatures played a decisive role in the size,morphology and structure of nanoparticles in the final alloy since this was attributed to the fact that fine particles were dissolved through dislocation shearing during cold deformation and then re-precipitated during subsequent heat treatment.The high intermediate annealing temperature promotes the growth of the near-spherical ONPs,while the ellip-soidal nanoparticles are developed at relatively low temperature.Meanwhile,the structural change of the ONPs was also facilitated by the dissolution-reprecipitation behavior.The predominant Y_(2)(Zr_(y)Ti_(1−y))_(2)O_(7)with cubic pyrochlore phase in as-HIPed alloy can be transformed into Y_(4)Zr_(3)O_(12)particles with rhom-bohedral structure during the thermomechanical treatment.However,compared with the change in size of ONPs,the change in morphology and structure of ONPs has no obvious influence on the mechanical strength.Different intermediate annealing temperatures play a different role in the coarsening of ONPs during thermomechanical treatment,which makes the alloy annealed at low temperature exhibiting more uniform distribution of ONPs and better mechanical properties.
基金supported by the Natural Science Foundation of Beijing Municipal(No.2252043)the National Natural Science Foundation of China(No.52170019),the Fundamental Research Funds for the Central Universities(No.06500100)the“Ten Thousand Plan”-National High-level personnel of special support program.
文摘Pt-based methanol oxidation reaction(MOR)electrocatalysts with high activity,stability,and carbon monoxide(CO)tolerance are critical for advancing direct methanol fuel cells(DMFC).Herein,a low-Pt-content electrocatalyst(Pt/CeO_(2)-carbon nanofiber(CNF))is developed through electrospinning,high-temperature calcination,and sodium borohydride(NaBH4)reduction,featuring highly dispersed Pt nanoparticles anchored on oxygen vacancy(Ov)-rich CeO_(2) embedded within CNF.The strong metal–support interaction(SMSI)induces Pt–O–Ce interfacial bonding,facilitating electron transfer and enhancing MOR performance.Pt/CeO_(2)-CNF achieves a mass activity of 5.29 A·mgPt^(-1),3.5 times higher than commercial Pt/C,alongside exceptional stability(92%retention after 1000 cycles)and CO tolerance.When deployed as a DMFC anode,it delivers a peak power density of 34.72 mW·cm^(-2),outperforming Pt/C by 31%.Characterization results indicate that SMSI induces charge redistribution between Pt and CeO_(2),which synergistically enhances the reaction kinetics of MOR with the hydroxyl groups produced by CeO_(2) hydrolysis.In addition,the uniform dispersion of in-situ grown CeO_(2) is ensured on CNF,and Ov acts as an anchoring point to stabilize Pt nanoparticles,improving the stability of the catalyst.This work establishes a design framework for synthesizing high-performance Pt-based DMFC electrocatalysts through controlled structural and electronic modulation strategies.
基金supported by the ProgramManagement Unit on Area Based Development (PMUA),Thailand (No.4594393)the National Science and Technology Development Agency (NSTDA),Thailand (No.P2250367).
文摘Herein,a modified screen printed carbon electrode(SPCE)based on a composite material,graphene oxide-gold nanoparticles(GO-AuNPs),and poly(3-aminobenzoic acid)(P3ABA)for the detection of paraquat(PQ)is introduced.The modified electrode was fabricated by drop casting of the GO-AuNPs,followed by electropolymerization of 3-aminobenzoic acid to achieve SPCE/GO-AuNPs/P3ABA.The morphology and microstructural characteristics of the modified electrodes were revealed by scanning electron microscopy(SEM)for each step of modification.The composite GO-AuNPs can provide high surface area and enhance electroconductivity of the electrode.In addition,the presence of negatively charged P3ABA notably improved PQ adsorption and electron transfer rate,which stimulate redox reaction on the modified electrode,thus improving the sensitivity of PQ analysis.The SPCE/GOAuNPs/P3ABA offered a wide linear range of PQ determination(10^(−9)-10^(−4) mol/L)and low limit of detection(LOD)of 0.45×10^(−9) mol/L or 0.116μg/L,which is far below international safety regulations.The modified electrode showed minimum interference effect with percent recovery ranging from 96.5%to 116.1%after addition of other herbicides,pesticides,metal ions,and additives.The stability of the SPCE/GO-AuNPs/P3ABA was evaluated,and the results indicated negligible changes in the detection signal over 9 weeks.Moreover,this modified electrode was successfully implemented for PQ analysis in both natural and tapped water with high accuracy.
基金This project was supported by a grant from the National Natural Science Foundation of China (No. 30271300).
文摘Objective: Application of magnetic nanoparticles as gene carrier in gene therapy has developed quickly. This study was designed to investigate the preparation of superparamagnetic dextran-coated iron oxide nanoparticles (SDION) and the feasibility of SDION used as a novel gene carrier for plasmid DNA in vitro. Methods: SDION were prepared by chemical coprecipitation and separated by gel filtration on Sephacryl S-300HR, characterized by TEM, laser scattering system and Vibrating Sample Magnetometer Signal Processor. The green fluorescent protein (pGFP-C2) plasmid DNA was used as target gene. SDION-pGFP-C2 conjugate compounds were produced by means of oxidoreduction reaction. The connection ratio of SDION and pGFP-C2 DNA was analyzed and evaluated by agarose electrophoresis and the concentration of pGFP-C2 in supernatant was measured. Using liposome as control, the transfection efficiency of SDION and liposome was respectively evaluated under fluorescence microscope in vitro. Results: The diameter of SDION ranges from 3 nm to 8 nm, the effective diameter was 59.2 nm and the saturation magnetization was 0.23 emu/g. After SDION were reasonably oxidized, SDION could connect with pGFP-C2 to a high degree. The transfection efficiency of SDION as gene carrier was higher than that of liposome. Conclusion: The successes in connecting SDION with pGFP-C2 plasmid by means of oxidoreduction reaction and in transferring pGFP-C2 gene into human bladder cancer BIU-87 cells in vitro provided the experimental evidence for the feasibility of SDION used as a novel gene carrier.
基金supported by the National Natural Science Foundation of China (Nos.21607043,21577032)the Youth Innovation Promotion Association,Chinese Academy of Sciences (No.2018054)+1 种基金the Fundamental Research Funds for the Central Universities (Nos.2016ZZD06,2018ZD11)the Open Project of Key Laboratory of Environmental Biotechnology,CAS (No.kf2016009)
文摘Titanium dioxide nanoparticles(TiO_2 NPs) are one of the most widely used nanomaterials in the consumer products, agriculture, and energy sectors. Their large demand and widespread applications will inevitably cause damage to organisms and ecosystems. A better understanding of TiO_2 NP toxicity in living organisms may promote risk assessment and safe use practices of these nanomaterials. This review summarizes the toxic effects of TiO_2 NPs on multiple taxa of microorganisms, algae, plants, invertebrates, and vertebrates. The mechanism of TiO_2 NP toxicity to organisms can be outlined in three aspects: The Reactive Oxygen Species(ROS)produced by TiO_2 NPs following the induction of electron–hole pairs; cell wall damage and lipid peroxidation of the cell membrane caused by NP-cell attachment by electrostatic force owing to the large surface area of TiO_2 NPs; and TiO_2 NP attachment to intracellular organelles and biological macromolecules following damage to the cell membranes.
基金supported by Natural Science Foundation of Hebei Province(E2015205159)High Level Talents Foundation in Hebei Province(C201400327)Natural Science Foundation of Hebei Education Department(ZD2014045)
文摘Nanostructured cerium oxide （CeO2） commonly known as nanoceria is a rare earth metal oxide, which plays a technologically important role due to its versatile applications as antomobile exhaust catalysts, oxide ion conductors in solid oxide fuel cells, electrode materials for gas sensors, ultraviolet absorbents and glass-polishing materials. However, nanoceria has little or weak luminescence, and therefore its uses in high-performance luminescent devices and biomedical areas are limited. In this review, we present the recent advances of nanoceria in the aspects of synthesis, luminescence and biomedical studies. The CeO2 nanoparticles can bc synthesized by solution-based methods including co-precipitation, hydrothemlal, microemulsion process, sol-gel techniques, combustion reaction and so on. Achieving controlled morphologies and enhanced luminescence efficiency of nanoceria particles arc quite essential for its potential energyand environment-related applications. Additionally, a new fiontier for nanoccria particles in biomedical research has also been opened, which involves low toxicity, retinopathy, biosensors and cancer therapy aspects. Finally, the summary and outlook on the challenges and perspectives of the nanoceria particles are proposed.
基金supported by National Natural Science Foundation of China(21177160,21173270 and 21303263)
文摘The ultrafine Ce-based oxide nanoparticles with different element dopings （Zr, Y） were synthesized by the method of mi- cropores-diffused coprecipitation （MDC） using ammonia solution as the precipitation agent. The activities of the catalysts for soot oxidation were evaluated by the temperature-programmed oxidation （TPO） reaction. Ce-based oxides prepared in this study exhibited high catalytic activity for soot oxidation under tile condition of loose contact between soot particles and catalysts, and the catalytic ac- tivity ofultrafine Ce0.gZr0 iO2 nanoparticle for soot combustion was the highest, whose/＂10, Ts0 and Sco2m was 364, 442 ~C and 98.3%, respectively. All catalysts were systematically characterized by means of X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, Brumauer-Emett-Teller （BET）, Fourier transform infrared spectroscopy （FT-IR） and UV-Vis diffuse reflectance spectroscopy （UV-Vis DRS）. It was indicated that the MDC method could prepare the ultrafine Ce-bascd oxide nanoparticles whose the crystal lattice were perfect, and the BET surface area and average crystal size of the ultrafine nanoparticles changed with the different element dopings （Zr, Y）. The H2-TPR measurements showed that the ultrafine Ce-based ox- ide nanoparticles with the doping-Zr cation could be favorable for improving the redox property of the catalysts.
文摘Here,a preparation of stable,non-toxic,transparent,high performance zinc oxide thin-film semiconductor via thermal processing of composite system of zinc source solution filled zinc oxide nanoparticles layer was reported.The zinc oxide nanocrystals synthesized through the thermolysis of Zn-oleate complex in organic solvent medium were first deposited on the ATO/ITO/glass substrate and treated by annealing,then the zinc source solution was deposited on the zinc oxide nanoparticle layer to form precursor thin film by spin-coating process.The thin film transistor with well-controlled and densely packed nanocrystals in zinc oxide semiconductor layer was obtained by thermal annealing the system of precursor film coated ATO/ITO/glass substrate.By optimizing the fabrication conditions,the fabricated thin film transistors exhibited superior field-effect property and carrier mobility property,their saturation mobility reached 2.17 cm^(2)·V^(-1)·s^(-1),which was more than twice as high compared to the transistor devices coated only by zinc oxide nanoparticles.Our method of fabricating zinc oxide thin film transistors was simple,high efficiency,and feasible for the batch production with low cost.
基金Universiti Putra Malaysia(UPM)for financing this work through Putra Graduate Initiative(IPS)
文摘In recent years, zinc oxide nanoparticles(ZnO NPs) have gained tremendous attention attributed to their unique properties. Notably, evidence has shown that zinc is an important nutrient in living organisms. As such, both prokaryotes and eukaryotes including bacteria, fungi and yeast are exploited for the synthesis of ZnO NPs by using microbial cells or enzyme, protein and other biomolecules compounds in either an intracellular or extracellular route. ZnO NPs exhibit antimicrobial properties, however, the properties of nanoparticles(NPs) are depended upon on their size and shape, which make them specific for various applications. Nevertheless, the desired size and shape of NPs can be obtained through the optimization process of microbes mediated synthesis by manipulating their reaction conditions. It should be noted that ZnO NPs are synthesized by various chemical and physical methods.Nonetheless, these methods are expensive and not environmentally friendly. On that account, the microbes mediated synthesis of ZnO NPs have rapidly evolved recently where the microbes are cleaner, eco-friendly, nontoxic and biocompatible as the alternatives to chemical and physical practices. Moreover, zinc in the form of NPs is more effective than their bulk counterparts and thus, they have been explored for many potential applications including in animals industry. Notably, with the advent of multi-drug resistant strains, ZnO NPs have emerged as the potential antimicrobial agents. This is mainly due to their superior properties in combating a broad spectrum of pathogens. Moreover, zinc is known as an essential trace element for most of the biological function in the animal’s body. As such, the applications of ZnO NPs have been reported to significantly enhance the health and production of the farm animals. Thus, this paper reviews the biological synthesis of ZnO NPs by the microbes, the mechanisms of the biological synthesis, parameters for the optimization process and their potential application as an antimicrobial agent and feed supplement in the animal industry as well as their toxicological hazards on animals.
基金NSF-SBIR grant # IIP-0823040NSF-CREST program with grant # HRD-0833178Strengthening the Environmental Science Ph.D program in instruction,grant # P031B090210-11
文摘Cytotoxicity of selected metal oxide nanoparticles（MNPs）（ZnO,CuO,Co 3 O 4 and TiO 2）was investigated in Escherichia coli both under light and dark conditions.Cytotoxicity experiments were conducted with spread plate counting and the LC 50 values were calculated.We determined the mechanism of toxicity via measurements of oxidative stress,reduced glutathione,lipid peroxidation,and metal ions.The overall ranking of the LC 50 values was in the order of ZnO 〈 CuO 〈 Co 3 O 4 〈 TiO 2 under dark condition and ZnO 〈 CuO 〈 TiO 2 〈 Co 3 O 4 under light condition.ZnO MNPs were the most toxic among the tested nanoparticles.Our results indicate depletion of reduced glutathione level and elevation of malondialdehyde level correlated with the increase in oxidative stress.Released metal ions were found to have partial effect on the toxicity of MNPs to E.coli.In summary,the dynamic interactions of multiple mechanisms lead to the toxicity of the tested MNPs to E.coli.
