It is still a great challenge to mimic the structure and function of natural rubber by introducing polar components into synthetic polyisoprene.In order to explore the function of phosphate groups on the mechanical pr...It is still a great challenge to mimic the structure and function of natural rubber by introducing polar components into synthetic polyisoprene.In order to explore the function of phosphate groups on the mechanical properties of polyisoprene rubber,a terminally functionalized compound(PIP-P)containing phosphate groups was synthesized and further vulcanized to prepare the model compound V-PIP-P.Through analyzing the test results,it was found that these phosphate groups formed polar aggregates in non-polar polyisoprene rubber matrix,serving as an additional dynamic cross-linking sites,which increases the cross-linking density and improves mechanical properties.The influence of the phosphate groups on the strain-induced crystallization(SIC)was further investigated via synchrotron wide-angle X-ray diffraction(WAXD)experiment.These phosphate group aggregates not only reduced the onset strain of SIC,but also slowed down the molecular chain mobility,which hinder the crystal lateral growth.The above results help us to gain a deeper understanding for the function of phosphate groups in the formation of"naturally occurring network"and guide the molecular design of next generation polyisoprene rubber.展开更多
Because of the influence of OH groups in phosphate glasses on the radiation of rare-earth ions, the laser performance is degraded. The laser efficiency and the small signal gain experiment of several phosphate glass s...Because of the influence of OH groups in phosphate glasses on the radiation of rare-earth ions, the laser performance is degraded. The laser efficiency and the small signal gain experiment of several phosphate glass samples have been done, the concentration of OH groups in glasses was calculated from the measured absorption coefficient at 3.47 μm. It is shown that the concentration of OH groups in phosphate glasses can seriously influence the laser output characteristics, and the OH groups have worse influence on the laser amplifier than laser oscillator.展开更多
Guanosine triphosphate(GTP),a purine nucleotide central to cellular function,has long been celebrated as both an energy currency and a dynamic regulator of life's most fundamental processes'.Its canonical role...Guanosine triphosphate(GTP),a purine nucleotide central to cellular function,has long been celebrated as both an energy currency and a dynamic regulator of life's most fundamental processes'.Its canonical role as an energy carrier-donating phosphate groups to drive reactions ranging from protein synthesis to microtubule polymerization-has been extensively characterized,paralleling the functions of its more abundant counterpart,adenosine triphosphate(ATP).展开更多
TiO2 has been tested to be toxic to DNA under the photo-irradiation of ultraviolet A （UVA）. However, in the dark conditions, after several days of treatment with TiO2 in aqueous solution, the interaction between TiO...TiO2 has been tested to be toxic to DNA under the photo-irradiation of ultraviolet A （UVA）. However, in the dark conditions, after several days of treatment with TiO2 in aqueous solution, the interaction between TiO2 and two types of DNA was detected and the mechanisms were studied by the methods of gel-electrophoresis, IR spectroscopy and TEM. The results showed that the DNA would be bound to TiO2; the ratio of binding was related to the concentration and the treating time; the mechanism of binding is related to phosphate groups of DNA. Besides, DNA with different structure showed different degree of binding. These findings showed a new possible way through which the TiO2 nanoparticles interact with DNA.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51973126,51333003).The authors gratefully acknowledge the Shanghai Synchrotron Radiation Facility(SSRF).
文摘It is still a great challenge to mimic the structure and function of natural rubber by introducing polar components into synthetic polyisoprene.In order to explore the function of phosphate groups on the mechanical properties of polyisoprene rubber,a terminally functionalized compound(PIP-P)containing phosphate groups was synthesized and further vulcanized to prepare the model compound V-PIP-P.Through analyzing the test results,it was found that these phosphate groups formed polar aggregates in non-polar polyisoprene rubber matrix,serving as an additional dynamic cross-linking sites,which increases the cross-linking density and improves mechanical properties.The influence of the phosphate groups on the strain-induced crystallization(SIC)was further investigated via synchrotron wide-angle X-ray diffraction(WAXD)experiment.These phosphate group aggregates not only reduced the onset strain of SIC,but also slowed down the molecular chain mobility,which hinder the crystal lateral growth.The above results help us to gain a deeper understanding for the function of phosphate groups in the formation of"naturally occurring network"and guide the molecular design of next generation polyisoprene rubber.
文摘Because of the influence of OH groups in phosphate glasses on the radiation of rare-earth ions, the laser performance is degraded. The laser efficiency and the small signal gain experiment of several phosphate glass samples have been done, the concentration of OH groups in glasses was calculated from the measured absorption coefficient at 3.47 μm. It is shown that the concentration of OH groups in phosphate glasses can seriously influence the laser output characteristics, and the OH groups have worse influence on the laser amplifier than laser oscillator.
基金supported by the grants from the Ministry of Science and Technology of China(No.2021YFA0804700)National Natural Science Foundation of China(Grant Nos.32370744 and 32350710195)UK Medical Research Council(Grant Nos.MC_UU_12021/3 and MC_U137788471)。
文摘Guanosine triphosphate(GTP),a purine nucleotide central to cellular function,has long been celebrated as both an energy currency and a dynamic regulator of life's most fundamental processes'.Its canonical role as an energy carrier-donating phosphate groups to drive reactions ranging from protein synthesis to microtubule polymerization-has been extensively characterized,paralleling the functions of its more abundant counterpart,adenosine triphosphate(ATP).
文摘TiO2 has been tested to be toxic to DNA under the photo-irradiation of ultraviolet A （UVA）. However, in the dark conditions, after several days of treatment with TiO2 in aqueous solution, the interaction between TiO2 and two types of DNA was detected and the mechanisms were studied by the methods of gel-electrophoresis, IR spectroscopy and TEM. The results showed that the DNA would be bound to TiO2; the ratio of binding was related to the concentration and the treating time; the mechanism of binding is related to phosphate groups of DNA. Besides, DNA with different structure showed different degree of binding. These findings showed a new possible way through which the TiO2 nanoparticles interact with DNA.
