Effect of resveratrol on pancreatic oxygen free radicals in rats with severe acute pancreatitis

AIM： To investigate the therapeutic effects of resveratrol （RESV） as a free radical scavenger on experimental severe acute pancreatitis （SAP）. METHODS： Seventy-two male Sprague-Dawley rats were divided randomly into sham operation group, SAP group, and resveratrol-treated group. Pancreatitis was induced by intraductal administration of 0.1 mL/kg 4% sodium taurocholate. RESV was given intravenously at a dose of 20 mg/kg body weight. All animals were killed at 3, 6, 12 h after induction of the model. Serum amylase, pancreatic superoxide dismutase （SOD）, malondialdehyde （MDA）, and myeloperoxidase （MPO） were determined. Pathologic changes of the pancreas were observed under optical microscope. RESULTS： The serum amylase, pancreatic MPO and the score of pathologic damage increased after the induction of pancreatitis, early （3, 6 h） SAP samples were characterized by decreased pancreatic SOD and increased pancreatic MDA. Resveratrol exhibited a protective effect against lipid peroxidation in cell membrane caused by oxygen free radicals in the early stage of SAP. This attenuation of the redox state impairment reduced cellular oxidative damage, as reflected by lower serum amylase, less severe pancreatic lesions, normal pancreatic MDA levels, as well as diminished neutrophil infiltration in pancreas. CONCLUSION： RESV may exert its therapeutic effect on SAP by lowering pancreatic oxidative free radicals and reducing pancreatic tissue infiltration of neutrophils.

Synthesis of Well-Dispersed CeO_2-CuO_x composite Hollow Spheres with Superior Catalyticactivity for Cooxidation

<正>Well-dispersed CeO_2-CuO_x composite hollow spheres have been successfully synthesized through a facilereflux method using carbon spheres as sacrificial templates.The shells of the hollow spheres,~40 nm inthickness,consist of self-assembled 10~15nm sized nanoparticles.Scanning electron microsco-

Grain size refinement of additive manufactured Ce-TZP ceramics by coupled two-step pre-sintering and HIP

Ceria-stabilized tetragonal zirconia polycrystal(Ce-TZP)has exceptional fracture toughness and flaw tolerance due to facile t‒m phase transformation toughening.However,its wider-range applications are limited by its relatively low strength due to its large grain size and low transformation stress,which results in yield-like failure.Here,we combined additive manufacturing(AM),pressureless two-step sintering,and hot isostatic pressing(HIP),and addressed the challenging grain size refinement problem in Ce-TZPs.We successfully produced dense ultrafine-grained Ce-TZP ceramics with an average grain size below 500 nm,a three-point bending strength above 800 MPa,and a single-edge-notch-beam fracture toughness in the range of 11‒12 MPa·m^(1/2).The critical roles of processing design,mixed Ce valences,and under-vs.over-stabilization of tetragonal polymorphs were noted.Our work offers insights and strategies for the future development of stronger and tougher Ce-TZP ceramics that can compete with tetragonal yttria-stabilized zirconia in various applications,including additive manufacturing.

Intermediate phase assisted sequential deposition of reverse-graded quasi-2D alternating cation perovskites for MA-free perovskite solar cells

One-step deposition approaches have been widely applied and developed in the fabrication of quasi-2D perovskites.However,the regulation of quantum wells(QWs)and crystalline orientation is difficult and complicated when using this methodology.Sequential deposition is another widespread synthetic approach for preparing perovskite films and perovskite dimension engineering.In this article,δ-CsPbI_(3)intermediate phase assisted sequential(IPAS)deposition is successfully carried out to fabricate MA-free quasi-2D ACI perovskites.The amount of theδ-CsPbI_(3)intermediate phase in the PbI2 layer and the concentration of GAI molecule in the IPA solution both play important roles in the production of MA-free quasi-2D ACI perovskite films.The n value of the MA-free quasi-2D ACI perovskites can be adjusted,which affects the photovoltaic performance and device stability.Compared with one-step deposition,the MA-free quasi-2D ACI perovskites prepared via IPAS deposition have opposite reverse-graded QW distribution and improved vertical orientation,leading to a remarkable PEC of up to 18.86%and allowing the preparation of unpackaged devices with prominent working stability(80%,400 h).The underlying mechanism and crystallization pathway of IPAS deposition confirm that sequential deposition has unique superiority in regulating the QW distribution and crystalline orientation of quasi-2D perovskites.

Enhanced catalytic activity and thermal stability by highly dispersed Pd-based nanocatalysts embedded in ZrO_(2)hollow spheres

Sintering resistant noble metal nanoparticles are critical to the development of advanced catalysts with high activity and stability.Herein,we reported the construction of highly dispersed Pd nanoparticles loaded at the inner wall of ZrO_(2)hollow spheres(Pd@HS-ZrO_(2)),which shows improved activity and thermal stability over references in the Pd-ZrO_(2)(catalyst-support)system.Even after 800℃ high temperature calcination,the Pd nanoparticles and ZrO_(2)hollow spheres did not undergo morphological changes.The Pd@HS-ZrO_(2)manifests batter catalytic activity and thermal stability than the counterpart Pd/ZrO_(2)catalysts.In comparison to Pd/ZrO_(2)-800,Pd@ZrO_(2)-800 exhibits a 25℃ reduction in the temperature required for complete conversion of CO.The enhanced catalytic activity and thermal stability of Pd@HS-ZrO_(2)can be attributed to the nanoconfinement effect offered by the 10 nm wall thickness of the ZrO_(2)hollow spheres,which suppresses the coarsening of the Pd nanoparticles(active center for catalysis).

In situ polymerization of 1,3-dioxolane infiltrating 3D garnet framework with high ionic conductivity and excellent interfacial stability for integrated solid-state Li metal battery

The polymer-ceramic composite electrolyte is considered as one of promising electrolytes for solid-state battery.However,in previous research,ceramic particles are usually dispersed in polymer matrix and could not form continuous Li+conductive channels.The agglomeration of ceramic particles could also lead to low ionic conductivity and poor interfacial electrode/electrolyte contact.In this paper,self-supported porous Li_(6.4)La_(3) Zr_(1.4)Ta_(0.6)O_(12)(LLZTO) electrolyte is synthesized by gelcasting process,which possesses three-dimensional(3D) interconnected pore channels and relatively high strength.The 1,3-dioxolane(DOL) could penetrate into the porous LLZTO framework for its excellent fluidity.The subsequent in situ polymerization process by thermal treatment could completely fill the internal pores and improve the interfacial contact with electrode.The resulting 3D composite electrolyte with dual continuous Li+transport channels in ceramic and polymer components exhibits high ionic conductivity of 2.8 × 10^(-4) S·cm^(-1) at room temperature and low Li/electrolyte interfacial resistance of 94 Ω·cm^(2) at 40 ℃.The corresponding Li/Li symmetric cell delivers stable voltage profiles for over 600 h under 0.1 and 0.2 mA·cm^(-2).The solid-state Li/LiFePO_(4) battery shows superior rate and cycling performance under 0.1 C and 0.2 C.This work guides the preparation of composite electrolyte with dual continuous Li+conductive paths as well as high ceramic ratio and interface modification strategy for solid-state Li metal battery.

Microstructure and properties of porous Si_(3)N_(4)ceramics by gelcasting-self-propagating high-temperature synthesis(SHS)

Porous silicon nitride ceramics have attracted a considerable attention due to their excellent overall performance,but poor porosity homogeneity and structural shrinkage induced by prolonged high temperature sintering limit its further application.Herein,as a three-in-one solution for the above issues,for the first time we develop a novel approach that integrates the merits of gelcasting-SHS(self-propagating high-temperature synthesis)to prepare porous Si_(3)N_(4)ceramics to simultaneously achieve high porosity,high strength,high toughness,and low thermal conductivity across a wide temperature range.By regulating the solid content,porous Si_(3)N_(4)ceramics with homogeneous pore structure are obtained,where the pore size falls inbetween 1.61 and 4.41 pm,and the elongated grains are interlaced and interlocked to form micron-sized coherent interconnected pores.At the same time,porous Si_(3)N_(4)ceramics with porosity of 67.83%to 78.03%are obtained,where the compressive strength reaches 11.79 to 47.75 MPa and fracture toughness reaches 1.20 to 6.71 MPa-m1/2.

Electrochemical performance of La_(2)NiO_(4+δ)-Ce_(0.55)La_(0.45)O_(2−δ)as a promising bifunctional oxygen electrode for reversible solid oxide cells

In this work,La_(2)NiO_(4+δ)-Ce_(0.55)La_(0.45)O_(2−δ)(denoted as LNO-xLDC)with various LDC contents(x=0,10,20,30,and 40 wt%)were prepared and evaluated as bifunctional oxygen electrodes for reversible solid oxide cells(RSOCs).Compared with the pure LNO,the optimum composition of LNO-30LDC exhibited the lowest polarization resistance(Rp)of 0.53 and 0.12Ω·cm^(2)in air at 650 and 750℃,respectively.The enhanced electrochemical performance of LNO-30LDC oxygen electrode was mainly attributed to the extended triple phase boundary and more oxygen ionic transfer channels.The hydrogen electrode supported single cell with LNO-30LDC oxygen electrode displayed peak power densities of 276,401,and 521 mW·cm^(−2)at 700,750,and 800℃,respectively.Moreover,the electrolysis current density of the single cell demonstrated 526.39 mA·cm^(−2) under 1.5 V at 800℃,and the corresponding hydrogen production rate was 220.03 mL·cm^(−2)·h^(−1).The encouraging results indicated that LNO-30LDC was a promising bifunctional oxygen electrode material for RSOCs.

A self-standing,UV-cured semi-interpenetrating polymer network reinforced composite gel electrolytes for dendrite-suppressing lithium ion batteries

A self-standing,flexible and lithium dendrite growth-suppressing composite gel polymer electrolyte membrane was designed for the use of room-temperature lithium ion batteries.The multi-functional composite semi-interpenetrating polymer network(referred to as“Cs-IPN”)electrolyte membrane was fabricated by combining a UV-cured ethoxylated trimethylolpropane triacrylate(ETPTA)macromer with alumina nanoparticles in the presence of liquid electrolyte and thermoplastic linear poly(ethylene oxide)(PEO).The polymer electrolyte membrane exhibits a semi-interpenetrating polymer network structure and a higher room temperature ionic conductivity,which impart the electrolyte with a significant cycling(120 mAh g^(-1)after 200 cycles)and a remarkable rate(137 mAh g^(-1)at 0.1℃,130 mAh g^(-1)at 0.5℃,119 mAh g^(-1)at 1℃ and 100 mAh g^(-1)at 2℃)performance in Li/LiFePO4 battery.More importantly,the polymer electrolyte possesses superior ability to inhibit the growth of lithium dendrites,which makes it promising for next generation lithium ion batteries.

Thermal shock behavior of ZrB2-SiC ceramics with different quenching media

The thermal shock behavior of ZrB2-SiC ceramics was studied with water, air and methyl silicone oil as quenching media, respectively. The temperature of all coolants was room temperature （25℃） and the residual strength of the ceramics after quenching was tested. The strength of the ceramics after water quenching had an obvious drop when the temperature difference, AT, was about 275℃, while the residual strength of the specimens quenched by air and silicone oil only varied a little and even increased slightly when the temperature difference was higher than 800℃. The different thermal conductive coefficient of the coolants and surface heat transfer coefficient resulted in the differences in the thermal shock behavior. The formation of oxidation layer was beneficial for improving the residual strength of the ceramics after quenching.

Hierarchically porous CMC/rGo/CNFs aerogels for leakage-proof mirabilite phase change materials with superior energy thermal storage

As a kind of essential hydrated salt phase change energy storage materials,mirabilite with high energy storage density and mild phase-transition temperature has excellent application potential in the problems of solar time and space mismatch.However,there are some disadvantages such as supercooling,substantial phase stratification and leakage problem,limiting its further applications.In this work,for the preparation of shaped mirabilite phase change materials(MPcMs),graphene(GO),sodium carboxymethyl cellulose(CMC),and carbon nanofibers(CNFs)were used as starting materials to prepare lightweight CMC/rGO/CNFs carbon aerogel(CGCA)as support with stable shape,high specific surface area,and well-arranged hierarchically porous structure.The results show that CGCA has regular layered plentiful pores and stable foam structure,and the pore and sheet interspersed structure in CGCA stabilizes PcMs via capillary force and surface tension.The hydrophilic aerogels supported MPCMs decrease mirabilite leaking and reduce supercooling to around 0.7-1C.The latent heats of melting and crystallization of CGCA-supported mirabilite phase change materials(CGCA-PCMs)are 157.1 and 114.8 J-g-1,respectively.Furthermore,after 1500 solid-liquid cycles,there is no leakage,and the retention rate of crystallization latent heat is 45.32%,exhibiting remarkable thermal cycling stability.

Facile synthesis of tremella-like MnO2 and its application as supercapacitor electrodes

In this work, three kinds of ultrathin tremella-like MnO2 have been simply synthesized by decomposing KMnO4 under mild hydrothermal conditions. When applied as electrode materials, they all exhibited excellent electrochemical performance. The as- prepared MnO2 samples were characterized by means of XRD, SEM, TEM and XPS. Additionally, the relationship of the crystalline nature with the electrochemical performance was investigated. Among the three samples, the product with the poorest crystallinity had the highest capacitance of 220 Fig at a current density of 0.1 A/g. It is thought that the ultrathin MnO2 nanostructures can serve as promising electrode materials for supercapacitors.

SrTiO3/TiO2 heterostructure nanowires with enhanced electron-hole separation for efficient photocatalytic activity

Heterostructure is an effective strategy to facilitate the charge carrier separation and promote the photocatalytic performance.In this paper,uniform SrTiO3 nanocubes were in-situ grown on TiO2 nanowires to construct heterojunctions.The composites were prepared by a facile alkaline hydrothermal method and an in-situ deposition method.The obtained SrTiO3/TiO2 exhibits much better photocatalytic activity than those of pure TiO2 nanowires and commercial TiO2(P25)evaluated by photocatalytic water splitting and decomposition of Rhodamine B(RB).The hydrogen generation rate of SrTiO3/TiO2 nanowires could reach 111.26 mmol·g^−1·h^−1 at room temperature,much better than those of pure TiO2 nanowires(44.18 mmol·g^−1·h^−1)and P25(35.77 mmol·g^−1·h^−1).The RB decomposition rate of SrTiO3/TiO2 is 7.2 times of P25 and 2.4 times of pure TiO2 nanowires.The photocatalytic activity increases initially and then decreases with the rising content of SrTiO3,suggesting an optimum SrTiO3/TiO2 ratio that can further enhance the catalytic activity.The improved photocatalytic activity of SrTiO3/TiO2 is principally attributed to the enhanced charge separation deriving from the SrTiO3/TiO2 heterojunction.

Preparation and characterization of monodispersed spherical Fe_2O_3@SiO_2 reddish pigments with core-shell structure

The α-Fe_2 O_3@SiO_2 reddish pigments with core-shell structure were successfully prepared by hydrothermal and Stober methods. The structure, morphology, and chromaticity of the synthesized pigments were characterized by XRD, SEM, TEM, FTIR, XPS, and colorimetry. The results indicated that the as-prepared pigments have the characteristics of narrow particle size distribution, high dispersion,and good sphericity. The α-Fe_2 O_3@SiO_2 reddish pigments were uniform and well dispersed in solution. In addition, the pigments with different shell thickness were also prepared, and the effect of shell thickness on the color performance of the pigments was discussed.

Exploring the Formation Mechanism of Deformation Twins in CrMnFeCoNi High Entropy Alloy

The deformation twins initiated in CrMnFeCoNi high entropy alloy at cryogenic temperature are experimentally studied. Under the external loading, a three-dimensional shear stress concentration originating from dislocation tangling at both the grain boundaries and twin boundaries could be formed, which promotes emission of partial dislocations from the planar defects and is thus considered to be the key factor for twin formation. A sympathetic nucleation mechanism is proposed to describe the nucleation behaviors of twins.

One-step synthesis of hierarchically porous hybrid TiO2 hollow spheres with high photocatalytic activity

Hierarchically porous hybrid TiO2 hollow spheres were solvothermally synthesized successfully by using tetrabutyl titanate as titanium precursor and hydrated metal sulfates as soft templates. The as-prepared TiO2 spheres with hierarchically pore structures and high specific surface area and pore volume consisted of highly crystallized anatase TiO2 nanocrystals hybridized with a small amount of metal oxide from the hydrated sulfate. The proposed hydrated-sulfate assisted solvothermal （HAS） synthesis strategy was demonstrated to be widely applicable to various systems. Evaluation of the hybrid TiO2 hollow spheres for the photo-decomposition of methyl orange （MO） under visible-light irradiation revealed that they exhibited excellent photocatalytic activity and durability.

Tailored lithium metal/polymer electrolyte interface with LiTa_(2)PO_(8) fillers in PEO-based composite electrolyte

The unstable Li/PEO-based electrolyte interface in allsolid-state lithium metal batteries usually leads to high interfacial resistance,low Coulombie efficiency and fast lithium dendrites growth even under a low current density.The interface composition directly determines the interfacial integrity,dynamic Li^(+)/e^(-)transport processes and the subsequent Li+plating/stripping behavior;thus,it is of significance to regulate the interphase to have better safety and higher energy density for all-solid-state lithium metal batteries.Here,by incorporation of Li^+conducting LiTa_(2) PO_(8) fillers in PEO-based polymer electrolyte.

Facile fabrication of cordierite-based porous ceramics with magnetic properties

In this paper,cordierite-based porous ceramics with magnetic properties have been firstly in-situ synthesized by using MgO,Al_(2)O_(3),and SiO_(2) powders as raw materials and Fe_(3)O_(4) as a functional additive.Combining with the foam freeze casting method,near net size fabrication(total linear shrinkage<2.86%)of the magnetic porous materials was realized by adjusting the amount of Fe_(3)O_(4).The porosity,compressive strength,and saturation magnetization of the prepared materials were 83.9%-87.8%,1.51-2.65 MPa,and 1.2-5.8 emu/g,respectively.The phase composition and microstructure evolutions during sintering were investigated briefly.The results showed that the synthesis temperature of cordierite was lowered about 100℃ due to the addition of Fe_(3)O_(4).Except for the main phase-cordierite,Mg-Al-Fe spinel and α-Fe_(2)O_(3) also existed in the final materials.The lattice parameters of the Mg-Al-Fe spinel and the amount of α-Fe_(2)O_(3) changed obviously with the change in the sintering temperature and Fe_(3)O_(4) amount,which mainly influenced the magnetic properties of the prepared materials.Thus,a facile fabrication method of the cordierite-based porous ceramics with the magnetic properties has been put forward in this paper.

Numerical calculations Of effective thermal conductivity of porous ceramics by image-based finite element method

The effective thermal conductivity of heterogeneous or composite materials is an essential physical parameter of materials selection and design for specific functions in science and engineering. The effective thermal conductivity is heavily relied on the fraction and spatial distribution of each phase. In this work, image- based finite element method （FEM） was used to calculate the effective thermal conductivity of porous ceramics with different pore structures. Compared with former theoretical models such as effective media theory （EMT） equation and parallel model, image-based FEM can be applied to a large variety of material systems with a relatively steady deviation. The deviation of image-based FEM computation mainly comes from the difference between the two dimensional （2D） image and the three dimensional （3D） structure of the real system, and an experiment was carried out to confirm this assumption. Factors influencing 2D and 3D effective thermal conductivities were studied by FEM to illustrate the accuracy and application conditions of image-based FEM.