The palladium complex of the molecular complex of poly(4 vinylpyridine) with acetic acid(PVP/ HAc Pd) was prepared. Its catalytic activity for the hydrogenation of nitrobenzene was found much higher than that of the c...The palladium complex of the molecular complex of poly(4 vinylpyridine) with acetic acid(PVP/ HAc Pd) was prepared. Its catalytic activity for the hydrogenation of nitrobenzene was found much higher than that of the corresponding palladium complex of poly(4 vinylpyridine). In the presence of a strong inorganic alkali, especially potassium hydroxide, the catalytic activity is greatly improved. The suitable hydrogenation condition for PVP/HAc Pd is to use 0 1 mol/L ethanol solution of potassium hydroxide as the hydrogenation medium and the hydrogenation is carried out at 45 ℃.展开更多
Poly（4-vinylpyridine）（P4-VP） nanofiber and fluoresent poly（4-vinylpyridine）/porphyrin（P4-VP/TPPA） nanofiber were respectively prepared by electrospinning. The effect of the concentration of P4-VP/dimethylforma...Poly（4-vinylpyridine）（P4-VP） nanofiber and fluoresent poly（4-vinylpyridine）/porphyrin（P4-VP/TPPA） nanofiber were respectively prepared by electrospinning. The effect of the concentration of P4-VP/dimethylformamide （DMF） electrospinning solutions on the morphology of P4-VP nanofiber was investigated and it was found that the average diameter of the nanofiber of P4-VP/DMF increased with the increase of the concentration of the spinning solution. After the addition of TPPA to the P4-VP/DMF spinning solution, the diameter of P4-VP/TPPA nanofiber became even due to the increase of the conductivity of the P4-VP/DMF-TPPA solution. The photoluminescent（PL） spectral analysis indicates that the emission peak position of P4-VP/TPPA nanofiber is almost the same as that of pure TPPA at about 650 nm without peak shift, and when it was stored for 20 days, the emission peak of P4-VP/TPPA nanofiber is also at 650 nm, indicating that the fluorescent property of P4-VP/TPPA nanofiber is stable. Fourier-transform iufrared（FTIR） spectrum confirms the chemical composition of the resulting P4-VP/TPPA composite nanofiber.展开更多
Poly(styrene-co-4-vinylpyridine)-neodymium complexes(NdCl_3·PS4VPY)with variouscontents of the functional group and neodymium have been prepared and characterized.Theinfrared and X-ray photoelectron spectra indic...Poly(styrene-co-4-vinylpyridine)-neodymium complexes(NdCl_3·PS4VPY)with variouscontents of the functional group and neodymium have been prepared and characterized.Theinfrared and X-ray photoelectron spectra indicate that uncoordinated 4-vinylpyridine(4VPY)unitsremain in the NdCl_3·PS4VPY complexes.The catalytic behaviour of NdCl_3·PS4VPY was described briefly.展开更多
Well-defined P4VP-b-PBLG diblock polymer composed of poly (4-vinylpyridine) (P4VP) and poly (γ-benzyl-L-glutamate) (PBLG) was synthesized by click reaction with alkyne- and azide-functionalized homopolymers. Besides,...Well-defined P4VP-b-PBLG diblock polymer composed of poly (4-vinylpyridine) (P4VP) and poly (γ-benzyl-L-glutamate) (PBLG) was synthesized by click reaction with alkyne- and azide-functionalized homopolymers. Besides, P4VP blocks were synthesized by copper-mediated atom transfer radical polymerization (ATRP) with a chlorine-containing alkyne bifunctional initiator, and the azido-terminated PBLG homopolymers were synthesized by ring-opening polymerization (ROP) of γ-benzyl-L-glutamate with an amine-containing azide initiator. In addition, the synthesized P4VP-b-PBLG with different block ratios has been characterized by proton nuclear magnetic resonance (1H NMR), Gel permeation chromatograph (GPC) and fourier transform infrated spectroscopy (FT-IR). Then, the self-assembly behaviors of P4VP-b-PBLG have been studied by changing parameters like dripping speed and block ratio. The morphologies of self-assembly of spherical, disk-like and ellipsoid-like shape particles have been observed and analyzed by scanning electron microscopy (SEM). These results have provided guidelines for the design of macromolecular self-assembly.展开更多
Objective:To conduct a comparative analysis of the VP4 gene sequences of Indian wild type (06361,0613158,061060 and 0715880) and cell culture adapted(06361-CA,0613158-CA.061060- CA and 0715880-CA) G1P[8]rotavirus stra...Objective:To conduct a comparative analysis of the VP4 gene sequences of Indian wild type (06361,0613158,061060 and 0715880) and cell culture adapted(06361-CA,0613158-CA.061060- CA and 0715880-CA) G1P[8]rotavirus strains.Methods:Full-length VP4 genes of each of the four wild type G1P[8]rotavirus strains and their cell culture adapted counterparts displaying consistent cytopathic effect were subjected to RT-PCR amplification and nucleotide sequencing. Results:All four cell culture adapted G1P[8]rotavirus strains showed nucleotide and amino acid substitutions in the VP4 gene as compared to their wild type strains.The number of substitutions however,varied from 1-64 and 1-13 respectively.The substitutions were distributed in both VP5* and VP8* subunits of VP4 gene respectively of permeabilizalion and hemagglutinaling activity. The presence of unique amino acid substitutions was identified in two of the four wild type(V377G. S387N in 061060 and 1644L in 0715880) and all four cell culture adapted(A46V in 0613158-CA. T60R in 06361-CA,L237V.G389V and Q480H in 061060-CA and S615G and T625P in 0715880-CA) strains for the first time in the VP4 gene of P[8]specificity.Amino acid substitutions generated increase in the hydrophilicity in the cell culture adapted rotavirus strains as compared to their corresponding wild type strains.Conclusions:Amino acid substitutions detected in the VP4 genes of G1P[8]rotavirus strains from this study together with those from other studies highlight occurrence of only strain and/or host specific substitutions during cell culture adaptation. Further evaluation of such substitutions for their role in attenuation,immunogenicity and conformation is needed for the development of newer rolavirus vaccines.展开更多
Paclitaxel （PTX）, one of the most effective cytotoxins for the treatment of breast and lung cancer, is limited by its severe side effects and low tumor selectivity. In this work hollow-poly（4-vinylpyridine） （holl...Paclitaxel （PTX）, one of the most effective cytotoxins for the treatment of breast and lung cancer, is limited by its severe side effects and low tumor selectivity. In this work hollow-poly（4-vinylpyridine） （hollow-p4VP） nanoparticles （NPs） have been used for the first time to generate PTX@p4VP NPs, employing a novel technique in which a gold core in the center of the NP is further oxidized to produce the hollow structure into which PTX molecules can be incorporated. The hollow-p4VP NPs exhibit good physicochemical properties and displayed excellent biocompatibility when tested on blood （no hemolysis） and cell cultures （no cytotoxicity）. Interestingly, PTX@p4VP NPs significantly increased PTX cytotoxicity in human lung （A-549） and breast （MCF-7） cancer cells with a significant reduction of PTX ICs0 （from 5.9 to 3.6 nM in A-549 and from 13.75 to 4.71 nM in MCF-7）. In addition, PTX@p4VP caused a decrease in volume of A-549 and MCF-7 multicellular tumor spheroids （MTS）, an in vitro system that mimics in vivo tumors, in comparison to free PTX. This increased antitumoral activity is accompanied by efficient cell internalization and increased apoptosis, especially in lung cancer MTS. Our results offer the first evidence that hollow- p4VP NPs can improve the antitumoral activity of PTX. This system can be used as a new nanoplatform to overcome the limitations of current breast and lung cancer treatments.展开更多
基金Supported by the Outstanding Youngs Science Foudation of Henan Province(1999)
文摘The palladium complex of the molecular complex of poly(4 vinylpyridine) with acetic acid(PVP/ HAc Pd) was prepared. Its catalytic activity for the hydrogenation of nitrobenzene was found much higher than that of the corresponding palladium complex of poly(4 vinylpyridine). In the presence of a strong inorganic alkali, especially potassium hydroxide, the catalytic activity is greatly improved. The suitable hydrogenation condition for PVP/HAc Pd is to use 0 1 mol/L ethanol solution of potassium hydroxide as the hydrogenation medium and the hydrogenation is carried out at 45 ℃.
基金Supported by the National Natural Science Foundation of China(No.20674023)
文摘Poly（4-vinylpyridine）（P4-VP） nanofiber and fluoresent poly（4-vinylpyridine）/porphyrin（P4-VP/TPPA） nanofiber were respectively prepared by electrospinning. The effect of the concentration of P4-VP/dimethylformamide （DMF） electrospinning solutions on the morphology of P4-VP nanofiber was investigated and it was found that the average diameter of the nanofiber of P4-VP/DMF increased with the increase of the concentration of the spinning solution. After the addition of TPPA to the P4-VP/DMF spinning solution, the diameter of P4-VP/TPPA nanofiber became even due to the increase of the conductivity of the P4-VP/DMF-TPPA solution. The photoluminescent（PL） spectral analysis indicates that the emission peak position of P4-VP/TPPA nanofiber is almost the same as that of pure TPPA at about 650 nm without peak shift, and when it was stored for 20 days, the emission peak of P4-VP/TPPA nanofiber is also at 650 nm, indicating that the fluorescent property of P4-VP/TPPA nanofiber is stable. Fourier-transform iufrared（FTIR） spectrum confirms the chemical composition of the resulting P4-VP/TPPA composite nanofiber.
基金The project was supported by the National Natural Science Foundation of China
文摘Poly(styrene-co-4-vinylpyridine)-neodymium complexes(NdCl_3·PS4VPY)with variouscontents of the functional group and neodymium have been prepared and characterized.Theinfrared and X-ray photoelectron spectra indicate that uncoordinated 4-vinylpyridine(4VPY)unitsremain in the NdCl_3·PS4VPY complexes.The catalytic behaviour of NdCl_3·PS4VPY was described briefly.
文摘Well-defined P4VP-b-PBLG diblock polymer composed of poly (4-vinylpyridine) (P4VP) and poly (γ-benzyl-L-glutamate) (PBLG) was synthesized by click reaction with alkyne- and azide-functionalized homopolymers. Besides, P4VP blocks were synthesized by copper-mediated atom transfer radical polymerization (ATRP) with a chlorine-containing alkyne bifunctional initiator, and the azido-terminated PBLG homopolymers were synthesized by ring-opening polymerization (ROP) of γ-benzyl-L-glutamate with an amine-containing azide initiator. In addition, the synthesized P4VP-b-PBLG with different block ratios has been characterized by proton nuclear magnetic resonance (1H NMR), Gel permeation chromatograph (GPC) and fourier transform infrated spectroscopy (FT-IR). Then, the self-assembly behaviors of P4VP-b-PBLG have been studied by changing parameters like dripping speed and block ratio. The morphologies of self-assembly of spherical, disk-like and ellipsoid-like shape particles have been observed and analyzed by scanning electron microscopy (SEM). These results have provided guidelines for the design of macromolecular self-assembly.
基金supported by National Institute of Virology(NIV,Indian Council of Medical Research, Govt.of India),Pune
文摘Objective:To conduct a comparative analysis of the VP4 gene sequences of Indian wild type (06361,0613158,061060 and 0715880) and cell culture adapted(06361-CA,0613158-CA.061060- CA and 0715880-CA) G1P[8]rotavirus strains.Methods:Full-length VP4 genes of each of the four wild type G1P[8]rotavirus strains and their cell culture adapted counterparts displaying consistent cytopathic effect were subjected to RT-PCR amplification and nucleotide sequencing. Results:All four cell culture adapted G1P[8]rotavirus strains showed nucleotide and amino acid substitutions in the VP4 gene as compared to their wild type strains.The number of substitutions however,varied from 1-64 and 1-13 respectively.The substitutions were distributed in both VP5* and VP8* subunits of VP4 gene respectively of permeabilizalion and hemagglutinaling activity. The presence of unique amino acid substitutions was identified in two of the four wild type(V377G. S387N in 061060 and 1644L in 0715880) and all four cell culture adapted(A46V in 0613158-CA. T60R in 06361-CA,L237V.G389V and Q480H in 061060-CA and S615G and T625P in 0715880-CA) strains for the first time in the VP4 gene of P[8]specificity.Amino acid substitutions generated increase in the hydrophilicity in the cell culture adapted rotavirus strains as compared to their corresponding wild type strains.Conclusions:Amino acid substitutions detected in the VP4 genes of G1P[8]rotavirus strains from this study together with those from other studies highlight occurrence of only strain and/or host specific substitutions during cell culture adaptation. Further evaluation of such substitutions for their role in attenuation,immunogenicity and conformation is needed for the development of newer rolavirus vaccines.
文摘Paclitaxel （PTX）, one of the most effective cytotoxins for the treatment of breast and lung cancer, is limited by its severe side effects and low tumor selectivity. In this work hollow-poly（4-vinylpyridine） （hollow-p4VP） nanoparticles （NPs） have been used for the first time to generate PTX@p4VP NPs, employing a novel technique in which a gold core in the center of the NP is further oxidized to produce the hollow structure into which PTX molecules can be incorporated. The hollow-p4VP NPs exhibit good physicochemical properties and displayed excellent biocompatibility when tested on blood （no hemolysis） and cell cultures （no cytotoxicity）. Interestingly, PTX@p4VP NPs significantly increased PTX cytotoxicity in human lung （A-549） and breast （MCF-7） cancer cells with a significant reduction of PTX ICs0 （from 5.9 to 3.6 nM in A-549 and from 13.75 to 4.71 nM in MCF-7）. In addition, PTX@p4VP caused a decrease in volume of A-549 and MCF-7 multicellular tumor spheroids （MTS）, an in vitro system that mimics in vivo tumors, in comparison to free PTX. This increased antitumoral activity is accompanied by efficient cell internalization and increased apoptosis, especially in lung cancer MTS. Our results offer the first evidence that hollow- p4VP NPs can improve the antitumoral activity of PTX. This system can be used as a new nanoplatform to overcome the limitations of current breast and lung cancer treatments.
