Gold nanoparticles with different morphologies, such as spindle, octahedron, and decahedron were obtained by using different molar ratios of HAuCl4/HEPES in the presence and absence of surfactants at room temperature....Gold nanoparticles with different morphologies, such as spindle, octahedron, and decahedron were obtained by using different molar ratios of HAuCl4/HEPES in the presence and absence of surfactants at room temperature.These nanoparticles were characterized by X-ray diffraction（XRD）, transmission electron microscopy（TEM）, high-resolution transmission electron microscopy（HRTEM）, scanning electron microcopy（SEM）, energy-dispersive X-rays analysis（EDX）, and selected area electron diffraction（SAED）.The kinetics of the formation of gold nanoparticles in HEPES buffer was studied by UV-visible spectrophotometer.The formation of gold nanoparticles was strongly dependent on the concentration of HEPES and pH value.The surfactants play a crucial role in the size and shape controlled synthesis of gold nanoparticles.展开更多
EPES has proved to stabilize M intermediate of Bacteriorhodopsin. Absorp-tion and Raman spectra showed that there was a more stable form of M intermedi-ate in BR-HEPES solution. It was found by SPS that there were two...EPES has proved to stabilize M intermediate of Bacteriorhodopsin. Absorp-tion and Raman spectra showed that there was a more stable form of M intermedi-ate in BR-HEPES solution. It was found by SPS that there were two main interme-diates . M and O , existing in BR-HEPES solution.展开更多
Objective: This study was conducted to determine whether N-hydroxyethylpiperazine-N-ethanesulfonate (HEPES)-buff-ered medium used for the microinjection of sperm into oocytes may be detrimental for the embryo. Design:...Objective: This study was conducted to determine whether N-hydroxyethylpiperazine-N-ethanesulfonate (HEPES)-buff-ered medium used for the microinjection of sperm into oocytes may be detrimental for the embryo. Design: Controlled randomized study. Setting: Private IVF center. Patient(s): Women (n = 708) undergoing ICSI. Intervention(s): The women were randomized into two study groups: 2,204 oocytes from 357 women were treated using a medium buffered with bicarbonate without HEPES during the ICSI procedure, and 2,168 oocytes from 351 women were treated using a medium buffered with HEPES during the ICSI procedure. Main OutcomeMeasure(s): Fertilization rate, degeneration rate, triploid rate, cleavage rate, embryo quality, pregnancy rate, implantation rate, and abortion rate. Result(s): Oocytes treated with a HEPES-buffered medium showed a statistically significant higher rate of triploid and degenerated oocytes after fertilization with ICSI compared with oocytes treated with a medium without HEPES. The embryos obtained from oocytes microinjected with a HEPES buffered medium showed a statistically significant higher rate of highly fragmented embryos compared with the controls. Pregnancy rate and implantation rate were statistically significantly lower in the patient group with oocytes treated with the HEPES buffered medium. The other parameters evaluated did not show any statistically significant differences. Concluxion(s): Our study showed that the use of media buffered with HEPES, during the microinjection of sperm into the oocytes, is detrimental for IVF outcome and should be avoided.展开更多
Terbium （Tb） has been extensively used as a fluorescence probe for the identification of calcium-binding sites in proteins and for fluorometric analysis of organic ligands. In the current study, we reported that HEP...Terbium （Tb） has been extensively used as a fluorescence probe for the identification of calcium-binding sites in proteins and for fluorometric analysis of organic ligands. In the current study, we reported that HEPES, a commonly used pH buffer reagent, significantly enhanced the characteristic emission of Tb at 585 nm. The maximum emission of Tb at 490 nm and 549 um were also enhanced by HEPES to a less extent. Thus, cautions should be taken when quantitative analysis is performed based on the fluorescence emission of Tb at 549 nm, since the emission may vary due to the buffer reagents. Additionally, the fluorescence intensity at 585 um was proportional to the concentration of both HEPES and terbium ions, which might be utilized to develop new fluorometric analytical methods.展开更多
A highly sensitive fluorescent“turn-on”probe NapP-deap based on naphthalimide derivative was developed that bound Hg^2+ ions rapidly in the N-2-hydroxyethylpiperazine-N-ethane-sulphonic acid(HEPES)buffer solution vi...A highly sensitive fluorescent“turn-on”probe NapP-deap based on naphthalimide derivative was developed that bound Hg^2+ ions rapidly in the N-2-hydroxyethylpiperazine-N-ethane-sulphonic acid(HEPES)buffer solution via photo-induced electron transfer(PET)being inhibited mechanism.The titration experiment displayed that the emission intensity of NapP-deap at 540 nm was almost linearly increased by about 3-fold.The Job’s plot showed a stoichiometry factor of 1:1 of the ligand-to-metal ratio.The detection limit of fluorescent probe was calculated to be 6.2×10^?9 mol/L.^1H NMR studies could confirm that one Hg^2+ ion was bound by the N atoms(a,b)of piperazine or the N atom(c)of pyridine.The fluorescent probe could be used for the detection of Hg^2+ ions in living cells.展开更多
基金supports from the Program for Excellent Talents of the Department of Education of Hubei Province, China (No. Q20081504)the Area of Excellence Scheme administered by the University Grant Committee and the University of Hong Kong (No.AoE/ P-10/ 01)
文摘Gold nanoparticles with different morphologies, such as spindle, octahedron, and decahedron were obtained by using different molar ratios of HAuCl4/HEPES in the presence and absence of surfactants at room temperature.These nanoparticles were characterized by X-ray diffraction（XRD）, transmission electron microscopy（TEM）, high-resolution transmission electron microscopy（HRTEM）, scanning electron microcopy（SEM）, energy-dispersive X-rays analysis（EDX）, and selected area electron diffraction（SAED）.The kinetics of the formation of gold nanoparticles in HEPES buffer was studied by UV-visible spectrophotometer.The formation of gold nanoparticles was strongly dependent on the concentration of HEPES and pH value.The surfactants play a crucial role in the size and shape controlled synthesis of gold nanoparticles.
文摘EPES has proved to stabilize M intermediate of Bacteriorhodopsin. Absorp-tion and Raman spectra showed that there was a more stable form of M intermedi-ate in BR-HEPES solution. It was found by SPS that there were two main interme-diates . M and O , existing in BR-HEPES solution.
文摘Objective: This study was conducted to determine whether N-hydroxyethylpiperazine-N-ethanesulfonate (HEPES)-buff-ered medium used for the microinjection of sperm into oocytes may be detrimental for the embryo. Design: Controlled randomized study. Setting: Private IVF center. Patient(s): Women (n = 708) undergoing ICSI. Intervention(s): The women were randomized into two study groups: 2,204 oocytes from 357 women were treated using a medium buffered with bicarbonate without HEPES during the ICSI procedure, and 2,168 oocytes from 351 women were treated using a medium buffered with HEPES during the ICSI procedure. Main OutcomeMeasure(s): Fertilization rate, degeneration rate, triploid rate, cleavage rate, embryo quality, pregnancy rate, implantation rate, and abortion rate. Result(s): Oocytes treated with a HEPES-buffered medium showed a statistically significant higher rate of triploid and degenerated oocytes after fertilization with ICSI compared with oocytes treated with a medium without HEPES. The embryos obtained from oocytes microinjected with a HEPES buffered medium showed a statistically significant higher rate of highly fragmented embryos compared with the controls. Pregnancy rate and implantation rate were statistically significantly lower in the patient group with oocytes treated with the HEPES buffered medium. The other parameters evaluated did not show any statistically significant differences. Concluxion(s): Our study showed that the use of media buffered with HEPES, during the microinjection of sperm into the oocytes, is detrimental for IVF outcome and should be avoided.
基金National Natural Science Foundation of China(Grant No.20637010 and 20871008).
文摘Terbium （Tb） has been extensively used as a fluorescence probe for the identification of calcium-binding sites in proteins and for fluorometric analysis of organic ligands. In the current study, we reported that HEPES, a commonly used pH buffer reagent, significantly enhanced the characteristic emission of Tb at 585 nm. The maximum emission of Tb at 490 nm and 549 um were also enhanced by HEPES to a less extent. Thus, cautions should be taken when quantitative analysis is performed based on the fluorescence emission of Tb at 549 nm, since the emission may vary due to the buffer reagents. Additionally, the fluorescence intensity at 585 um was proportional to the concentration of both HEPES and terbium ions, which might be utilized to develop new fluorometric analytical methods.
基金Supported by the National Key Research and Development Program of China(No.2016YFF0203704)the Innovation Fund for Graduate Students of Shanghai University of Engineering Science,China(Nos.l 8KY0416,16KY0410)the National Natural Science Foundation of China(No.21404068).
文摘A highly sensitive fluorescent“turn-on”probe NapP-deap based on naphthalimide derivative was developed that bound Hg^2+ ions rapidly in the N-2-hydroxyethylpiperazine-N-ethane-sulphonic acid(HEPES)buffer solution via photo-induced electron transfer(PET)being inhibited mechanism.The titration experiment displayed that the emission intensity of NapP-deap at 540 nm was almost linearly increased by about 3-fold.The Job’s plot showed a stoichiometry factor of 1:1 of the ligand-to-metal ratio.The detection limit of fluorescent probe was calculated to be 6.2×10^?9 mol/L.^1H NMR studies could confirm that one Hg^2+ ion was bound by the N atoms(a,b)of piperazine or the N atom(c)of pyridine.The fluorescent probe could be used for the detection of Hg^2+ ions in living cells.
