The porcine microsatellite SW943 was regionally localized on 12p11-(2/3p13) by the two methods: the Primed in situ (PRINS) labelling on the pachytene bivalents of pigs using the Dig-11-dUTP as the report molecule and ...The porcine microsatellite SW943 was regionally localized on 12p11-(2/3p13) by the two methods: the Primed in situ (PRINS) labelling on the pachytene bivalents of pigs using the Dig-11-dUTP as the report molecule and pig X rodent Somatic Cell Hybrid Panel (SCHP) which contains 27 cell lines through PCR amplification. Advantages and disadvantages of the two methods for physical mapping of microsatellites were also discussed.展开更多
A novel substrate for in situ synthesis of oligonucleotide was prepared by hydrolyzing microporous polyamide-6 membranes in a 0.01mol/L NaOH/(H2O-CH3OH) mixture medium. The formation of amines (NH2) on the surface was...A novel substrate for in situ synthesis of oligonucleotide was prepared by hydrolyzing microporous polyamide-6 membranes in a 0.01mol/L NaOH/(H2O-CH3OH) mixture medium. The formation of amines (NH2) on the surface was proved by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The treated membrane was applied for in situ synthesis of oligonucleotide and a single step coupling efficiency determined by ultraviolet (UV) spectra was above 98 %.展开更多
Fe-based alloy coatings containing TiB2–TiN –(h-BN) were synthesized in situ on Q235 steel substrates by a plasma cladding process using the powders of Fe901 alloy, Ti, and h-BN as raw materials. The effects of Ti...Fe-based alloy coatings containing TiB2–TiN –(h-BN) were synthesized in situ on Q235 steel substrates by a plasma cladding process using the powders of Fe901 alloy, Ti, and h-BN as raw materials. The effects of Ti/h-BN mass ratio on interfacial bonds between the coating and substrate along with the microstructures and microhardnesses of the coatings were investigated. The results show that the Ti/h-BN mass ratio is a vital factor in the formation of the coatings. Free h-BN can be introduced into the coatings by adding an excess amount of h-BN into the precursor. Decreases in the Ti/h-BN mass ratio improve the microstructural uniformity and compactness and enhance the interfacial bonds of the coatings. At a Ti/h-BN mass ratio of 10/20, the coating is free of cracks and micropores, and mainly consists of Fe-Cr, Fe3B, TiB2, TiN, Ti2N, TiB, FeN, FeB, Fe2B, and h-BN phases. Its average microhardness in the zone between 0.1–2.8 mm from the coating surface is about Hv0.2 551.5.展开更多
Gold(Au)nanoclusters supported on various supports have been widely used in the fields of energy and catalysis.However,the poor thermal stability of Au nanoclusters on the support interface usually leads to a reductio...Gold(Au)nanoclusters supported on various supports have been widely used in the fields of energy and catalysis.However,the poor thermal stability of Au nanoclusters on the support interface usually leads to a reduction or even loss of catalytic activity.Herein,we used an in situ reduction method to synthesize Au nanoclusters on ceria(CeO_(2))carriers.In this method,sulfhydryl groups were used to modify CeO_(2) nanospheres first,and then Au clusters with an average diameter of 1.5 nm were grown on the surface of ceria reduced with sodium borohydride.The presence of the Au-S-Ce structure enhances the electron transfer efficiency,making the material exhibit high CO oxidation activity at room temperature.Furthermore,due to the strong binding energy of S and Au,the material exhibits a high stability for long time running process.This strategy provides an idea for designing stable and active supported ultrasmall Au nanoclusters catalytic materials.展开更多
The rational exploitation of non-precious metal catalyst with high activity,strong durability and low cost for the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is of vital importance for metalair ba...The rational exploitation of non-precious metal catalyst with high activity,strong durability and low cost for the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is of vital importance for metalair batteries.Herein,a composite of Co_(3)O_(4)nanoparticles confined in three-dimensional(3 D)N-doped porous carbon(Co-NpCs)was prepared by a simple freeze-drying and in situ pyrolysis method.The effect of different dosages of Co(NO_(3))_(2)on the catalytic performance was discussed.The Co-NpC-12%exhibits the best catalytic performance(E_(1/2)=0.78 V,better stability than 20%Pt/C)in ORR and in OER among all the as-synthesized samples.Furthermore,it also exhibits the best bifunctional activity(ΔE=0.849 V).The excellent properties of Co-NpCs are mainly due to the synergy between Co_(3)O_(4)and carbon.Firstly,a high Co_(3)O_(4)loading amount can boost the defect level of the N-doped hierarchical porous carbon and expose more active sites.Secondly,the unique in situ pyrolysis guarantees a largearea contact between Co_(3)O_(4)and carbon as well as a strong C-O-Co bonding,which promotes charge transfer,avoids the peeling of Co_(3)O_(4)nanoparticles and effectively improves the stability of the material.This work is expected to offer a feasible strategy to produce metal oxide/carbon nanocomposite and push forward the development of bifunctional electrocatalyst with high activity and stability.展开更多
A phase-pure NaTi2(PO4)3/reduced graphene oxide (rGO) nanocomposite was prepared using a microwave-assisted one-pot method and subsequent heat treatment. The well-crystallized NaTi2(PO4)3 nanoparticles (30-40 n...A phase-pure NaTi2(PO4)3/reduced graphene oxide (rGO) nanocomposite was prepared using a microwave-assisted one-pot method and subsequent heat treatment. The well-crystallized NaTi2(PO4)3 nanoparticles (30-40 nm) were uniformly precipitated on rGO templates through Ti-O-C bonds. The chemical interactions between the NaTi2(PO4)3 nanoparticles and rGO could immobilize the NaTi2(PO4)3 nanoparticles on the rGO sheets, which might be responsible for the excellent electrochemical performance of the nanocomposite. The NaTi2(PO4)B/rGO nanocomposite exhibited a specific capacity of 128.6 mA-h.g-1 approaching the theoretical value at a 0.1 C-rate with an excellent rate capability (72.9% capacity retention at 50 C-rate) and cycling performance (only 4.5% capacity loss after 1,000 cycles at a high rate of 10 C). These properties were maintained even when the electrodes were prepared without the use of an additional conducting agent. The excellent sodium storage properties of the NaTi2(PO4)B/rGO nanocomposite could be attributed to the nano-sized NaTi2(PO4)3 particles, which significantly reduced the transport lengths for Na+ ions, and an intimate contact between the NaTi2(PO4)3 particles and rGO due to chemical bonding.展开更多
ZrB2 in MgO-C composite materials obtained by both microwave sintering synthesis and in-situ reaction at lower temperature was investigated. The test result shows that 66.67 % of reactant changed into Zrb2, and the ot...ZrB2 in MgO-C composite materials obtained by both microwave sintering synthesis and in-situ reaction at lower temperature was investigated. The test result shows that 66.67 % of reactant changed into Zrb2, and the other form Al2O3, which could optimize the properties of carbon containing materials. Therefore, the method of in situ synthesizing ZrB2 acting as antioxidant in carbon containing materials is considered as one of best ways to reduce the cost and ZrB2 as refractories is used on a large-scale.展开更多
Cell membrane affinity chromatography has been widely applied in membrane protein(MP)-targeted drug screening and interaction analysis.However,in current methods,the MP sources are derived from cell lines or recombina...Cell membrane affinity chromatography has been widely applied in membrane protein(MP)-targeted drug screening and interaction analysis.However,in current methods,the MP sources are derived from cell lines or recombinant protein expression,which are time-consuming for cell culture or purification,and also difficult to ensure the purity and consistent orientation of MPs in the chromatographic stationary phase.In this study,a novel in situ synthesis membrane protein affinity chromatography(iSMAC)method was developed utilizing cell-free protein expression(CFE)and covalent immobilized affinity chromatography,which achieved efficient in situ synthesis and unidirectional insertion of MPs into liposomes in the stationary phase.The advantages of iSMAC are:1)There is no need to culture cells or prepare recombinant proteins;2)Specific and purified MPs with stable and controllable content can be obtained within 2 h;3)MPs maintain the transmembrane structure and a consistent orientation in the chromatographic stationary phase;4)The flexible and personalized construction of cDNAs makes it possible to analyze drug binding sites.iSMAC was successfully applied to screen PDGFRβinhibitors from Salvia miltiorrhiza and Schisandra chinensis.Micro columns prepared by in-situ synthesis maintain satisfactory analysis activity within 72 h.Two new PDGFRβinhibitors,salvianolic acid B and gomisin D,were screened out with KD values of 13.44 and 7.39μmol/L,respectively.In vitro experiments confirmed that the two compounds decreasedα-SMA and collagen Ⅰ mRNA levels raised by TGF-βin HSC-T6 cells through regulating the phosphorylation of p38,AKT and ERK.In vivo,Sal B could also attenuate CCl_(4)-induced liver fibrosis by downregulating PDGFRβdownstream related protein levels.The iSMAC method can be applied to other general MPs,and provides a practical approach for the rapid preparation of MP-immobilized or other biological solid-phase materials.展开更多
The mononuclear complex, Cu(H2SIP-O)(bpy)(H2O) (H4SIP-O = 4-hydroxyl- 5-sulfoisophthalic acid and bpy = 2,2'-dipyridyl), has been synthesized by the hydrothermal reaction of Cu(OH)2 with NaH2SIP and bpy at ...The mononuclear complex, Cu(H2SIP-O)(bpy)(H2O) (H4SIP-O = 4-hydroxyl- 5-sulfoisophthalic acid and bpy = 2,2'-dipyridyl), has been synthesized by the hydrothermal reaction of Cu(OH)2 with NaH2SIP and bpy at 160 ℃, and characterized by single-crystal X-ray diffraction, elemental analysis and IR spectrum. The new ligand 4-hydroxyl-5-sulfoisophthalic acid derived from 5-sulfoisophthalic acid ligand under an in situ hydrothermal condition. The crystal of the complex crystallizes in a triclinic system, space group P1, with a = 7.757(4), b = 10.663(6), c = 11.727(7)A, α = 94.272(4), β = 104.067(7), γ = 97.400(7)°, V= 927.4(9)A^3, Z = 2, C18H14N2O9SCu, Mr= 497.93, Dc= 1.783 g/cm^3,μ = 1.350 mm^-1, F(000) = 506, the final R = 0.0518 and wR = 0.1513 for 4180 observed reflections with I 〉 2σ(I). The central Cu(II) ion is five-coordinated by two oxygen atoms from the H2SIP-O^2- ligand and two nitrogen atoms of bpy ligand in a distorted square-planar geometry as well as a water oxygen atom in the apical position to complete a distorted square-pyramidal coordination geometry. The mononuclear copper molecules are linked by hydrogen bonds between coordinated water molecules and sulfonate groups to form a one-dimensional double-chain structure. The chains are further held together through extensive π-π stacking interactions between the aromatic rings to form a three- dimensional supramolecular structure.展开更多
A process for in situ synthesis of terbium complex with salicylic acid by a two-step solgel method in silica matrix has been proposed. The luminescence properties of the silica gelscodoped with terbium and salicylic a...A process for in situ synthesis of terbium complex with salicylic acid by a two-step solgel method in silica matrix has been proposed. The luminescence properties of the silica gelscodoped with terbium and salicylic acid have also been discussed with respect to that of the geldoped with terbium and that of pure terbium complex with salicylic acid.展开更多
A novel maskless technique, self-driving micro-fluid porous type printing (SMPTP), was reported to in situ synthesize oligonucleotide arrays on glass slide, which has the merits of low cost, high quality and simple ...A novel maskless technique, self-driving micro-fluid porous type printing (SMPTP), was reported to in situ synthesize oligonucleotide arrays on glass slide, which has the merits of low cost, high quality and simple craft. In SMPTP for fabricating gene- chips, porous fiber tubes with a number of nanometric or micron channels functioned as "active letters" and were assembled in designed patterns, which are identical to the distribution of monomers in each layer of the array, and four patterns were needed for each layer. By means of capillarity, the synthesis solution was automatically taken into porous tubes assembled in a printing plate and reached the surface. An oligonucleotide array of 160 features with four different 15-mer probes was in situ synthesized using this technique. The four specific oligonucleotide probes, including the matched and the mismatched by the fluorescent target sequence, gave obviously different hybridization fluorescent signals.展开更多
Poly(tetrafluoroethylene) (PTFE) was treated with plasma in a mixture of nitrogen and hydrogen (1 : 2 in volume). X-ray photoelectron spectroscopy (XPS) demonstrated the success of amino group grafting. The a...Poly(tetrafluoroethylene) (PTFE) was treated with plasma in a mixture of nitrogen and hydrogen (1 : 2 in volume). X-ray photoelectron spectroscopy (XPS) demonstrated the success of amino group grafting. The as-treated PTFE slices were successively applied to the in situ synthesis of oligonucleotides. With the detection of gold-label-silver-stain, the hybridization signals were recorded with a gel document and analysis system. A target DNA concentration as low as 10 pmol/L could be detected. The complementary and mismatched sequences were distinguished clearly, and the ratio of background-subtracted gray scale values for perfect match : 1 base mismatch : 2 base mismatch : 3 base mismatch was 72 : 44.4 : 22.5 : 11.4. The sensitivity of in situ synthesis system was 1 order of magnitude higher than that of spotting system, and the signal of the former was about 1.5 times stronger than that of the latter under the same target DNA concentration. These plasma modified PTFE slices might open novel prospects for the in situ synthesis of DNA micro-arrays.展开更多
Chemodynamic therapy (CDT) has attracted tremendous interest in cancer therapy because it is independent of oxygen and photoirradiation. However, the therapeutic efficacy of CDT is restricted by insufficient H_(2)O_(2...Chemodynamic therapy (CDT) has attracted tremendous interest in cancer therapy because it is independent of oxygen and photoirradiation. However, the therapeutic efficacy of CDT is restricted by insufficient H_(2)O_(2) levels in tumor cells. Herein, employing endogenous GSH as a template and cationic polymeric chitosan (CS) as crosslinker and stabilizer exhibiting easy cell uptake, red luminescent gold nanoclusters (denoted CS-GSH@AuNCs) were successfully synthesized in HeLa cells. The in situ synthesized CS-GSH@AuNCs exhibited both superoxidase dismutase (SOD) and peroxidase (POD)-like activity, which could promote the production of H_(2)O_(2) from superoxide anion radicals (O_(2)^(·-)) and then ^(·)OH. The combination of GSH elimination and H_(2)O_(2) elevation boosted the generation of ^(·)OH, which could trigger cancer cell apoptosis and death. The enzyme-like activity of CS-GSH@AuNCs could be effectively activated under acidic conditions, and showed a high killing effect on tumor cells but minimal toxicity to normal cells. The developed GSH consumption and ^(·)OH promotion theranostic platform is an innovative route for enhanced CDT by the amplification of oxidative stress.展开更多
One novel 3D 3d-4f coordination polymer, [LaZn(glc)(ox)2(H20)2]n (1, glc = glycinate, ox = oxalate), was obtained by the in situ synthesis of glycinate from the reaction of tetrazole-l-acetic acid, sodium oxal...One novel 3D 3d-4f coordination polymer, [LaZn(glc)(ox)2(H20)2]n (1, glc = glycinate, ox = oxalate), was obtained by the in situ synthesis of glycinate from the reaction of tetrazole-l-acetic acid, sodium oxalate, zinc nitrate and lanthanide oxide in the presence of a trace quantity of nitric acid under hydrothermal conditions. Compound 1 is of monoclinic, space group P21/n with a = 0.99601(9), b = 1.14592(10), c = 1.19107(10) nm and β = 108.7150(10)°. 1 exhibits an unusual 3D heterometallic coordination framework constructed by heterometallic dinuclear LaZn subunits and mixed ox and glc linkers with a uninodal 6-connected vine {33.43.58.6} net.展开更多
Using Al Mg and Al Mg Y alloys as raw materials and nitrogen as gas reactants, AlN powders and composite AlN powders by in situ synthesis method were prepared. AlN lumps prepared by the nitriding of Al Mg and Al ...Using Al Mg and Al Mg Y alloys as raw materials and nitrogen as gas reactants, AlN powders and composite AlN powders by in situ synthesis method were prepared. AlN lumps prepared by the nitriding of Al Mg and Al Mg Y alloys have porous microstructure, which is favorable for pulverization. They have high purity, containing 1.23%(mass fraction) oxygen impurity, and consisted of AlN single phase. The average particle size of AlN powders is 6.78 μm. Composite AlN powders consist of AlN phases and rare earth oxide Y 2O 3 phase. The distribution of particle size of AlN powders shows two peaks. In view of packing factor, AlN powders with such size distribution can easily be sintered to high density.展开更多
Titanium-based composite coatings reinforced by in situ synthesized TiB and TiC particles between titanium and B4C were successfully fabricated on Ti6Al4V by laser cladding. Phase constituents of the coatings were pre...Titanium-based composite coatings reinforced by in situ synthesized TiB and TiC particles between titanium and B4C were successfully fabricated on Ti6Al4V by laser cladding. Phase constituents of the coatings were predicted by thermodynamic calculations in the Ti-BnC-Al and Ti-B-C-Al systems, respectively, and were validated well by X-ray diffraction (XRD) analysis results. Microstructural and metallographic analyses were made by scanning electron microscopy (SEM) and electron probe micro-analysis (EPMA). The results show that the coatings are mainly composed of α-Ti cellular dendrites and the eutecticum in which a large number of needle-shaped TiB and a few equiaxial TiC particles are embedded. C is enriched in α-Ti cellular dendrites and far exceeds the theoretical maximum dissolubility, owing to the extension of saturation during laser cladding. The coatings have a good metallurgical bond with the substrate due to the existence of the dilution zone, in which a great amount of lamella β-Ti grains consisting of a thin needle-shaped martensitic microstructure are present and grow parallel to the heat flux direction; a few TiB and TiC reinforcements are observed at the boundaries of initial β-Ti grains.展开更多
A titanium-based composite coating reinforced by in situ synthesized TiB and TiC particles was fabricated on Ti6A14V by laser cladding. The microstructure and mechanical properties were investigated. The coating was m...A titanium-based composite coating reinforced by in situ synthesized TiB and TiC particles was fabricated on Ti6A14V by laser cladding. The microstructure and mechanical properties were investigated. The coating was mainly composed of a-Ti cellular dendrites and an eutectic in which a large number of rod/ needle-shaped TiB and a few equiaxial TiC particles were homogeneously embedded. The microstructural evolution could be divided into four stages: precipitation and growth of primary fl-Ti phase, formation of the binary eutectic fl-Ti+TiB, formation of the ternary eutectic fl-Ti+TiB+TiC, and solid transformation from fl-Ti to a-Ti. Microhardness of the coating showed a gradient variation from the surface (about HV0.2 876) to the bottom (about HV0.2 660) and was prominently improved in comparison with that of the substrate. Fracture toughness of the coating also exhibited a gradient variation from the surface (6.3 MPa-m1/2) to the interface (11.9 MPa-mV2). Wear resistance of the coating was significantly superior to that of Ti6A14V.展开更多
The in situ synthesized NbC particles reinforced Ni-based alloy composite coating was produced by laser cladding a precursor mixture of Ni-based alloy powder, graphite and niobium powders on a steel substrate. The mic...The in situ synthesized NbC particles reinforced Ni-based alloy composite coating was produced by laser cladding a precursor mixture of Ni-based alloy powder, graphite and niobium powders on a steel substrate. The microstructure, phase composition and wear property of the composite coating were investigated by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and dry sliding wear test. The experiment results show that the composite coating is homogeneous and free from cracks, and about 0.8 mm thick. The microstructure of the composite coating is mainly composed of NbC particles, CrB type chromium borides, 7-Ni primary dendrites, and interdendritic eutectics. CrB phases often nucleate and grow on the surface of NbC particles or in their close vicinity. NbC particles are formed via in situ reaction between niobium and graphite in the molten pool during the laser cladding process and they are commonly precipitated in three kinds of morphologies, such as quadrangle, cluster, and flower-like shape. Compared with the pure Ni- based alloy coating, the microhardness of the composite coating is increased about 38%, giving a high average hardness of HV0.21000, and the wear rate of the composite coating is decreased by about 32%, respectively. These are attributed to the presence of in situ synthesized NbC particles and their well distribution in the coating.展开更多
Nickel-based composite coatings reinforced by in situ synthesized TiB2 and WC particles were deposited on stainless steel by laser cladding, and their microstmcture and mechanical properties were investigated. The res...Nickel-based composite coatings reinforced by in situ synthesized TiB2 and WC particles were deposited on stainless steel by laser cladding, and their microstmcture and mechanical properties were investigated. The results show that the coatings are mainly composed of 7-Ni cellular dendrites and dispersed spherical/strip/network shaped TiB2 and equiaxial WC particles. The initial WC particles are dissolved to become fine and mostly dispersed within Y-Ni cellular dendrites. The coating prepared at a special laser energy of 0.225 kJ@mm^-2 is uniform, continuous, and free of pores and cracks. With the decrease in special energy density, TiB2 phase changes from fine spherical particles which cluster together to strip shape with different morphologies and further crystallizes to form network structure, and the dispersion zone also gradually changes from intragranular to intergranular phase. The coating possesses a higher microhardness compared with the substrate, and it has a good metallurgical bond with the substrate and excellent cracking resistance.展开更多
基金supported by the National Key Projects of Basic Research and Development Plan(G2000016103)the National Natural Science Foundation of China(39970541)+1 种基金the National Outstanding Youth Science Foundation(3992507)the Doctorate Foundation of the Minister of Education of China(1999004004).
文摘The porcine microsatellite SW943 was regionally localized on 12p11-(2/3p13) by the two methods: the Primed in situ (PRINS) labelling on the pachytene bivalents of pigs using the Dig-11-dUTP as the report molecule and pig X rodent Somatic Cell Hybrid Panel (SCHP) which contains 27 cell lines through PCR amplification. Advantages and disadvantages of the two methods for physical mapping of microsatellites were also discussed.
文摘A novel substrate for in situ synthesis of oligonucleotide was prepared by hydrolyzing microporous polyamide-6 membranes in a 0.01mol/L NaOH/(H2O-CH3OH) mixture medium. The formation of amines (NH2) on the surface was proved by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The treated membrane was applied for in situ synthesis of oligonucleotide and a single step coupling efficiency determined by ultraviolet (UV) spectra was above 98 %.
基金financially supported by the Natural Science Foundation of Jiangsu Province, China (No.BK2011250)the Jiangsu Province Postdoctoral Science Foundation (No. 1101017C)+1 种基金the China Postdoctoral Science Foundation (No. 20100481079)the China Scholarship Council and Outstanding Innovative Talents Support Plan of Hohai University
文摘Fe-based alloy coatings containing TiB2–TiN –(h-BN) were synthesized in situ on Q235 steel substrates by a plasma cladding process using the powders of Fe901 alloy, Ti, and h-BN as raw materials. The effects of Ti/h-BN mass ratio on interfacial bonds between the coating and substrate along with the microstructures and microhardnesses of the coatings were investigated. The results show that the Ti/h-BN mass ratio is a vital factor in the formation of the coatings. Free h-BN can be introduced into the coatings by adding an excess amount of h-BN into the precursor. Decreases in the Ti/h-BN mass ratio improve the microstructural uniformity and compactness and enhance the interfacial bonds of the coatings. At a Ti/h-BN mass ratio of 10/20, the coating is free of cracks and micropores, and mainly consists of Fe-Cr, Fe3B, TiB2, TiN, Ti2N, TiB, FeN, FeB, Fe2B, and h-BN phases. Its average microhardness in the zone between 0.1–2.8 mm from the coating surface is about Hv0.2 551.5.
基金supported by the National Science and Technology Major Project of China(No.2021YFB3500700)the National Natural Science Foundation of China(Nos.22020102003,22025506)+1 种基金the Key Research Program of the Chinese Academy of Sciences(No.ZDRW-CN-2021-3-3)the K.C.Wong Education Foundation,China(No.GJTD-2018-09).
文摘Gold(Au)nanoclusters supported on various supports have been widely used in the fields of energy and catalysis.However,the poor thermal stability of Au nanoclusters on the support interface usually leads to a reduction or even loss of catalytic activity.Herein,we used an in situ reduction method to synthesize Au nanoclusters on ceria(CeO_(2))carriers.In this method,sulfhydryl groups were used to modify CeO_(2) nanospheres first,and then Au clusters with an average diameter of 1.5 nm were grown on the surface of ceria reduced with sodium borohydride.The presence of the Au-S-Ce structure enhances the electron transfer efficiency,making the material exhibit high CO oxidation activity at room temperature.Furthermore,due to the strong binding energy of S and Au,the material exhibits a high stability for long time running process.This strategy provides an idea for designing stable and active supported ultrasmall Au nanoclusters catalytic materials.
基金the National Natural Science Foundation of China(Nos.51871046,51902046,51874079,51571054,51771046 and 51674068)the Natural Science Foundation of Liaoning Province(No.201602257)+1 种基金the Natural Science Foundation of Hebei Province(Nos.E2019501097,E2018501091 and E2020501004)the Fundamental Research Funds for the Central Universities(Nos.N182304017,N182304015,N172302001 and N172304044)。
文摘The rational exploitation of non-precious metal catalyst with high activity,strong durability and low cost for the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is of vital importance for metalair batteries.Herein,a composite of Co_(3)O_(4)nanoparticles confined in three-dimensional(3 D)N-doped porous carbon(Co-NpCs)was prepared by a simple freeze-drying and in situ pyrolysis method.The effect of different dosages of Co(NO_(3))_(2)on the catalytic performance was discussed.The Co-NpC-12%exhibits the best catalytic performance(E_(1/2)=0.78 V,better stability than 20%Pt/C)in ORR and in OER among all the as-synthesized samples.Furthermore,it also exhibits the best bifunctional activity(ΔE=0.849 V).The excellent properties of Co-NpCs are mainly due to the synergy between Co_(3)O_(4)and carbon.Firstly,a high Co_(3)O_(4)loading amount can boost the defect level of the N-doped hierarchical porous carbon and expose more active sites.Secondly,the unique in situ pyrolysis guarantees a largearea contact between Co_(3)O_(4)and carbon as well as a strong C-O-Co bonding,which promotes charge transfer,avoids the peeling of Co_(3)O_(4)nanoparticles and effectively improves the stability of the material.This work is expected to offer a feasible strategy to produce metal oxide/carbon nanocomposite and push forward the development of bifunctional electrocatalyst with high activity and stability.
文摘A phase-pure NaTi2(PO4)3/reduced graphene oxide (rGO) nanocomposite was prepared using a microwave-assisted one-pot method and subsequent heat treatment. The well-crystallized NaTi2(PO4)3 nanoparticles (30-40 nm) were uniformly precipitated on rGO templates through Ti-O-C bonds. The chemical interactions between the NaTi2(PO4)3 nanoparticles and rGO could immobilize the NaTi2(PO4)3 nanoparticles on the rGO sheets, which might be responsible for the excellent electrochemical performance of the nanocomposite. The NaTi2(PO4)B/rGO nanocomposite exhibited a specific capacity of 128.6 mA-h.g-1 approaching the theoretical value at a 0.1 C-rate with an excellent rate capability (72.9% capacity retention at 50 C-rate) and cycling performance (only 4.5% capacity loss after 1,000 cycles at a high rate of 10 C). These properties were maintained even when the electrodes were prepared without the use of an additional conducting agent. The excellent sodium storage properties of the NaTi2(PO4)B/rGO nanocomposite could be attributed to the nano-sized NaTi2(PO4)3 particles, which significantly reduced the transport lengths for Na+ ions, and an intimate contact between the NaTi2(PO4)3 particles and rGO due to chemical bonding.
基金ItemSponsored by National"863"Plan (2002AA335060) National Natural Science Foundation of China (50332010)
文摘ZrB2 in MgO-C composite materials obtained by both microwave sintering synthesis and in-situ reaction at lower temperature was investigated. The test result shows that 66.67 % of reactant changed into Zrb2, and the other form Al2O3, which could optimize the properties of carbon containing materials. Therefore, the method of in situ synthesizing ZrB2 acting as antioxidant in carbon containing materials is considered as one of best ways to reduce the cost and ZrB2 as refractories is used on a large-scale.
基金supported by the National Natural Science Foundation of China (Grant Nos. 82073814, 81973275, 82003909, 81973291, 82122066, 81803815)Rising-Star Program of Shanghai Science and Technology Committee (19QA1411500)
文摘Cell membrane affinity chromatography has been widely applied in membrane protein(MP)-targeted drug screening and interaction analysis.However,in current methods,the MP sources are derived from cell lines or recombinant protein expression,which are time-consuming for cell culture or purification,and also difficult to ensure the purity and consistent orientation of MPs in the chromatographic stationary phase.In this study,a novel in situ synthesis membrane protein affinity chromatography(iSMAC)method was developed utilizing cell-free protein expression(CFE)and covalent immobilized affinity chromatography,which achieved efficient in situ synthesis and unidirectional insertion of MPs into liposomes in the stationary phase.The advantages of iSMAC are:1)There is no need to culture cells or prepare recombinant proteins;2)Specific and purified MPs with stable and controllable content can be obtained within 2 h;3)MPs maintain the transmembrane structure and a consistent orientation in the chromatographic stationary phase;4)The flexible and personalized construction of cDNAs makes it possible to analyze drug binding sites.iSMAC was successfully applied to screen PDGFRβinhibitors from Salvia miltiorrhiza and Schisandra chinensis.Micro columns prepared by in-situ synthesis maintain satisfactory analysis activity within 72 h.Two new PDGFRβinhibitors,salvianolic acid B and gomisin D,were screened out with KD values of 13.44 and 7.39μmol/L,respectively.In vitro experiments confirmed that the two compounds decreasedα-SMA and collagen Ⅰ mRNA levels raised by TGF-βin HSC-T6 cells through regulating the phosphorylation of p38,AKT and ERK.In vivo,Sal B could also attenuate CCl_(4)-induced liver fibrosis by downregulating PDGFRβdownstream related protein levels.The iSMAC method can be applied to other general MPs,and provides a practical approach for the rapid preparation of MP-immobilized or other biological solid-phase materials.
基金Supported by the Education Department of Jiangxi Province (No 2007-125)the Initial Fund for Doctors from Jiangxi Normal University
文摘The mononuclear complex, Cu(H2SIP-O)(bpy)(H2O) (H4SIP-O = 4-hydroxyl- 5-sulfoisophthalic acid and bpy = 2,2'-dipyridyl), has been synthesized by the hydrothermal reaction of Cu(OH)2 with NaH2SIP and bpy at 160 ℃, and characterized by single-crystal X-ray diffraction, elemental analysis and IR spectrum. The new ligand 4-hydroxyl-5-sulfoisophthalic acid derived from 5-sulfoisophthalic acid ligand under an in situ hydrothermal condition. The crystal of the complex crystallizes in a triclinic system, space group P1, with a = 7.757(4), b = 10.663(6), c = 11.727(7)A, α = 94.272(4), β = 104.067(7), γ = 97.400(7)°, V= 927.4(9)A^3, Z = 2, C18H14N2O9SCu, Mr= 497.93, Dc= 1.783 g/cm^3,μ = 1.350 mm^-1, F(000) = 506, the final R = 0.0518 and wR = 0.1513 for 4180 observed reflections with I 〉 2σ(I). The central Cu(II) ion is five-coordinated by two oxygen atoms from the H2SIP-O^2- ligand and two nitrogen atoms of bpy ligand in a distorted square-planar geometry as well as a water oxygen atom in the apical position to complete a distorted square-pyramidal coordination geometry. The mononuclear copper molecules are linked by hydrogen bonds between coordinated water molecules and sulfonate groups to form a one-dimensional double-chain structure. The chains are further held together through extensive π-π stacking interactions between the aromatic rings to form a three- dimensional supramolecular structure.
文摘A process for in situ synthesis of terbium complex with salicylic acid by a two-step solgel method in silica matrix has been proposed. The luminescence properties of the silica gelscodoped with terbium and salicylic acid have also been discussed with respect to that of the geldoped with terbium and that of pure terbium complex with salicylic acid.
文摘A novel maskless technique, self-driving micro-fluid porous type printing (SMPTP), was reported to in situ synthesize oligonucleotide arrays on glass slide, which has the merits of low cost, high quality and simple craft. In SMPTP for fabricating gene- chips, porous fiber tubes with a number of nanometric or micron channels functioned as "active letters" and were assembled in designed patterns, which are identical to the distribution of monomers in each layer of the array, and four patterns were needed for each layer. By means of capillarity, the synthesis solution was automatically taken into porous tubes assembled in a printing plate and reached the surface. An oligonucleotide array of 160 features with four different 15-mer probes was in situ synthesized using this technique. The four specific oligonucleotide probes, including the matched and the mismatched by the fluorescent target sequence, gave obviously different hybridization fluorescent signals.
基金Project supported by Hunan Province Natural Science Foundation (No. 04jj40023), the Trans-century Training Program Foundation for the Talents by the Ministry of Education of China, and the Post-doctoral Science Foundation of China.
文摘Poly(tetrafluoroethylene) (PTFE) was treated with plasma in a mixture of nitrogen and hydrogen (1 : 2 in volume). X-ray photoelectron spectroscopy (XPS) demonstrated the success of amino group grafting. The as-treated PTFE slices were successively applied to the in situ synthesis of oligonucleotides. With the detection of gold-label-silver-stain, the hybridization signals were recorded with a gel document and analysis system. A target DNA concentration as low as 10 pmol/L could be detected. The complementary and mismatched sequences were distinguished clearly, and the ratio of background-subtracted gray scale values for perfect match : 1 base mismatch : 2 base mismatch : 3 base mismatch was 72 : 44.4 : 22.5 : 11.4. The sensitivity of in situ synthesis system was 1 order of magnitude higher than that of spotting system, and the signal of the former was about 1.5 times stronger than that of the latter under the same target DNA concentration. These plasma modified PTFE slices might open novel prospects for the in situ synthesis of DNA micro-arrays.
基金supported by the National Natural Science Foundation of China (No. 22074007)。
文摘Chemodynamic therapy (CDT) has attracted tremendous interest in cancer therapy because it is independent of oxygen and photoirradiation. However, the therapeutic efficacy of CDT is restricted by insufficient H_(2)O_(2) levels in tumor cells. Herein, employing endogenous GSH as a template and cationic polymeric chitosan (CS) as crosslinker and stabilizer exhibiting easy cell uptake, red luminescent gold nanoclusters (denoted CS-GSH@AuNCs) were successfully synthesized in HeLa cells. The in situ synthesized CS-GSH@AuNCs exhibited both superoxidase dismutase (SOD) and peroxidase (POD)-like activity, which could promote the production of H_(2)O_(2) from superoxide anion radicals (O_(2)^(·-)) and then ^(·)OH. The combination of GSH elimination and H_(2)O_(2) elevation boosted the generation of ^(·)OH, which could trigger cancer cell apoptosis and death. The enzyme-like activity of CS-GSH@AuNCs could be effectively activated under acidic conditions, and showed a high killing effect on tumor cells but minimal toxicity to normal cells. The developed GSH consumption and ^(·)OH promotion theranostic platform is an innovative route for enhanced CDT by the amplification of oxidative stress.
基金Supported by Public science and technology research funds projects of ocean (No. 2000905021)the Guangdong Oceanic Fisheries Technology Promotion Project (No. A2009003-018(c))+1 种基金the Guangdong Chinese Academy of Sciences comprehensive strategic cooperation project (No. 2009B091300121)the Guangdong Province key project in the field of social development (No. A2009011-007(c))
文摘One novel 3D 3d-4f coordination polymer, [LaZn(glc)(ox)2(H20)2]n (1, glc = glycinate, ox = oxalate), was obtained by the in situ synthesis of glycinate from the reaction of tetrazole-l-acetic acid, sodium oxalate, zinc nitrate and lanthanide oxide in the presence of a trace quantity of nitric acid under hydrothermal conditions. Compound 1 is of monoclinic, space group P21/n with a = 0.99601(9), b = 1.14592(10), c = 1.19107(10) nm and β = 108.7150(10)°. 1 exhibits an unusual 3D heterometallic coordination framework constructed by heterometallic dinuclear LaZn subunits and mixed ox and glc linkers with a uninodal 6-connected vine {33.43.58.6} net.
文摘Using Al Mg and Al Mg Y alloys as raw materials and nitrogen as gas reactants, AlN powders and composite AlN powders by in situ synthesis method were prepared. AlN lumps prepared by the nitriding of Al Mg and Al Mg Y alloys have porous microstructure, which is favorable for pulverization. They have high purity, containing 1.23%(mass fraction) oxygen impurity, and consisted of AlN single phase. The average particle size of AlN powders is 6.78 μm. Composite AlN powders consist of AlN phases and rare earth oxide Y 2O 3 phase. The distribution of particle size of AlN powders shows two peaks. In view of packing factor, AlN powders with such size distribution can easily be sintered to high density.
基金supported by Shanghai Science and Technology Development Foundation(No.08QA14035)the Special Foundation of Shanghai Education Commission for Nano-Materials Research(No.0852nm01400)the Crucial Project of Shanghai Science and Technology Commission(No.08520513400),China
文摘Titanium-based composite coatings reinforced by in situ synthesized TiB and TiC particles between titanium and B4C were successfully fabricated on Ti6Al4V by laser cladding. Phase constituents of the coatings were predicted by thermodynamic calculations in the Ti-BnC-Al and Ti-B-C-Al systems, respectively, and were validated well by X-ray diffraction (XRD) analysis results. Microstructural and metallographic analyses were made by scanning electron microscopy (SEM) and electron probe micro-analysis (EPMA). The results show that the coatings are mainly composed of α-Ti cellular dendrites and the eutecticum in which a large number of needle-shaped TiB and a few equiaxial TiC particles are embedded. C is enriched in α-Ti cellular dendrites and far exceeds the theoretical maximum dissolubility, owing to the extension of saturation during laser cladding. The coatings have a good metallurgical bond with the substrate due to the existence of the dilution zone, in which a great amount of lamella β-Ti grains consisting of a thin needle-shaped martensitic microstructure are present and grow parallel to the heat flux direction; a few TiB and TiC reinforcements are observed at the boundaries of initial β-Ti grains.
基金the National Natural Science Foundation of China (No. 51002093)the Shanghai Science and Technology Development Foundation, China (No. 08QA14035)the Shanghai Leading Academic Discipline Project, China (No. J51402)
文摘A titanium-based composite coating reinforced by in situ synthesized TiB and TiC particles was fabricated on Ti6A14V by laser cladding. The microstructure and mechanical properties were investigated. The coating was mainly composed of a-Ti cellular dendrites and an eutectic in which a large number of rod/ needle-shaped TiB and a few equiaxial TiC particles were homogeneously embedded. The microstructural evolution could be divided into four stages: precipitation and growth of primary fl-Ti phase, formation of the binary eutectic fl-Ti+TiB, formation of the ternary eutectic fl-Ti+TiB+TiC, and solid transformation from fl-Ti to a-Ti. Microhardness of the coating showed a gradient variation from the surface (about HV0.2 876) to the bottom (about HV0.2 660) and was prominently improved in comparison with that of the substrate. Fracture toughness of the coating also exhibited a gradient variation from the surface (6.3 MPa-m1/2) to the interface (11.9 MPa-mV2). Wear resistance of the coating was significantly superior to that of Ti6A14V.
基金Funded by the National Natural Science Foundation of China (No.50675136 and No.50375096)
文摘The in situ synthesized NbC particles reinforced Ni-based alloy composite coating was produced by laser cladding a precursor mixture of Ni-based alloy powder, graphite and niobium powders on a steel substrate. The microstructure, phase composition and wear property of the composite coating were investigated by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and dry sliding wear test. The experiment results show that the composite coating is homogeneous and free from cracks, and about 0.8 mm thick. The microstructure of the composite coating is mainly composed of NbC particles, CrB type chromium borides, 7-Ni primary dendrites, and interdendritic eutectics. CrB phases often nucleate and grow on the surface of NbC particles or in their close vicinity. NbC particles are formed via in situ reaction between niobium and graphite in the molten pool during the laser cladding process and they are commonly precipitated in three kinds of morphologies, such as quadrangle, cluster, and flower-like shape. Compared with the pure Ni- based alloy coating, the microhardness of the composite coating is increased about 38%, giving a high average hardness of HV0.21000, and the wear rate of the composite coating is decreased by about 32%, respectively. These are attributed to the presence of in situ synthesized NbC particles and their well distribution in the coating.
基金the Special Foundation of the Shanghai Education Commission for Out-standing Young Teachers in Universities, China (No. 05XPYQ16) the Leading Academic Discipline Project of the Shanghai Education Commission, China (No. XK0706)
文摘Nickel-based composite coatings reinforced by in situ synthesized TiB2 and WC particles were deposited on stainless steel by laser cladding, and their microstmcture and mechanical properties were investigated. The results show that the coatings are mainly composed of 7-Ni cellular dendrites and dispersed spherical/strip/network shaped TiB2 and equiaxial WC particles. The initial WC particles are dissolved to become fine and mostly dispersed within Y-Ni cellular dendrites. The coating prepared at a special laser energy of 0.225 kJ@mm^-2 is uniform, continuous, and free of pores and cracks. With the decrease in special energy density, TiB2 phase changes from fine spherical particles which cluster together to strip shape with different morphologies and further crystallizes to form network structure, and the dispersion zone also gradually changes from intragranular to intergranular phase. The coating possesses a higher microhardness compared with the substrate, and it has a good metallurgical bond with the substrate and excellent cracking resistance.