An analytical methodology based on an O-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine(MQD)-silica hybrid monolithic column was developed for the enantioseparation of 9-fluorenylmethoxycarbonyl(FMOC)deriv...An analytical methodology based on an O-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine(MQD)-silica hybrid monolithic column was developed for the enantioseparation of 9-fluorenylmethoxycarbonyl(FMOC)derivatized amino acids by nano-liquid chromatography.The mobile phase was optimized including the apparent pH,content of ACN,and concentration of the buffer to obtain a satisfactory enantioresolution performance.27 FMOC derivatized amino acids including 19 protein and 8 non-protein amino acids were tested,and 19 out of them were enantiomerically discriminated obtaining baseline separation for 11 of them.Analytical characteristics of the method were evaluated for norvaline and tryptophan in terms of linearity,precision,accuracy,limits of detection(LOD)and quantitation(LOQ)showing good performance to be applied to the enantiomeric determination of these amino acids in dietary supplements.LOD and LOQ values were 9.3 and 31 mM for norvaline enantiomers and 7.5 and 25 mM for tryptophan enantiomers,respectively.The contents of D-norvaline and D-tryptophan were below their respective LODs in all the analyzed samples.Quantitation of L-tryptophan and L-norvaline showed good agreement with the labeled contents except for one sample which did not show presence of L-norvaline,contrary to the label indication.展开更多
Xiao-Xu-Ming decoction has been widely used to treat stroke and sequelae of stroke. We have previously shown that the active fractions of Xiao-Xu-Ming decoction attenuate cerebral ischemic injury. However, the global ...Xiao-Xu-Ming decoction has been widely used to treat stroke and sequelae of stroke. We have previously shown that the active fractions of Xiao-Xu-Ming decoction attenuate cerebral ischemic injury. However, the global protein profile and signaling conduction pathways regulated by Xiao-Xu-Ming decoction are still unclear. This study established a two-vessel occlusion rat model by bilateral common carotid artery occlusion. Rats were intragastrically administered 50 or 150 mg/kg Xiao-Xu-Ming decoction for 4 consecutive weeks. Learning and memory abilities were measured with Morris water maze. Motor ability was detected with prehensile test. Coordination ability was examined using the inclined screen test. Neuronal plasticity was observed by immunofluorescent staining. Differentially expressed proteins of rat hippocampus were analyzed by label-free quantitative proteomics. Real time-polymerase chain reaction and western blot assay were used to identify the changes in proteins. Results showed that Xiao-Xu-Ming decoction dramatically alleviated learning and memory deficits, and motor and coordination dysfunction, and increased the expression of microtubule-associated protein 2. Xiao-Xu-Ming decoction extract remarkably decreased 13 upregulated proteins and increased 39 downregulated proteins. The regulated proteins were mainly involved in oxidation reduction process, intracellular signaling cascade process, and protein catabolic process. The signaling pathways were mainly involved in ubiquitin mediated proteolysis and the phosphatidylinositol signaling system. Furthermore, there was an interaction among Rab2 a, Ptpn1, Ppm1 e, Cdk18, Gorasp2, Eps15, Capza2, Syngap1 and Mt-nd1. Protein analyses confirmed the changes in expression of MTND1. The current findings provide new insights into the molecular mechanisms of Xiao-Xu-Ming decoction extract's effects on chronic cerebral hypoperfusion.展开更多
The complexity and diversity of peptide mixture from protein hydrolysates make their characterization difficult. In this study, a method combining nano LC-MS/MS with molecular docking was applied to identifying and ch...The complexity and diversity of peptide mixture from protein hydrolysates make their characterization difficult. In this study, a method combining nano LC-MS/MS with molecular docking was applied to identifying and characterizing a peptide with angiotensin-? converting enzyme(ACE-I) inhibiting activity from Venerupis philippinarum hydrolysate. Firstly, ethanol supernatant of V. philippinarum hydrolysate was separated into active fractions with chromatographic methods such as ion-exchange chromatography and high performance liquid chromatography in combination. Then seven peptides from active fraction were identified according to the searching result of the MS/MS spectra against protein databases. Peptides were synthesized and subjected to ACE-Iinhibition assay. The peptide NTLTLIDTGIGMTK showed the highest potency with an IC_(50) of 5.75 μmol L^(-1). The molecular docking analysis showed that the ACE-I inhibiting peptide NTLTLIDTGIGMTK bond with residues Glu123, Glu403, Arg522, Glu376, Gln281 and Asn285 of ACE-I. Therefore, active peptides could be identified with the present method rather than the traditional purification and identification strategies. It may also be feasible to identify other food-derived peptides which target other enzymes and receptors with the method developed in this study.展开更多
The homogeneously dispersed, less agglomerated (Nd0.01Y0.99)3Al5O12 nano-sized powders were synthesized by the low temperature combustion (LCS), using Nd2O3, Y2O3, Al(NO3)3·9H2O, ammonia water and citric acid as ...The homogeneously dispersed, less agglomerated (Nd0.01Y0.99)3Al5O12 nano-sized powders were synthesized by the low temperature combustion (LCS), using Nd2O3, Y2O3, Al(NO3)3·9H2O, ammonia water and citric acid as starting materials. This method effectively solves the problems caused by solid-state reaction at high temperature and hard agglomerates brought by the chemical precipitation method. The powders were characterized by TG-DTA, XRD, FT-IR, TEM respectively and the photoluminescence (PL) spectra of (Nd0.01Y0.99)3Al5O12 green and sintered ceramic disks were measured. The results show that the forming temperature of YAG crystal phase is 850 ℃ and YAP crystal phase appearing during the calcinations transforms to pure YAG at 1050 ℃. The particle size of the powders synthesized by the LCS is in a range of 20～50 nm depending on the thermal treatment temperatures. The effectively induced cross section (σin) with the value 4.03×10-19 cm2 of (Nd0.01Y0.99)3Al5O12 ceramics is about 44% higher than that of single crystal.展开更多
substitutes tion, high loosely dis Neodymium doped-yttrium aluminum garnet （Nd ： YAG） transparent polycrystalline ceramics already become of single crystals because they are provided with easy fabrication, low cost...substitutes tion, high loosely dis Neodymium doped-yttrium aluminum garnet （Nd ： YAG） transparent polycrystalline ceramics already become of single crystals because they are provided with easy fabrication, low cost, large size, highly doped concentraheat conductivity, mass fabrication, multi-layers and multi-filnctions. The Nd：YAG precursor powders with persed , slightly agglomerated, super fine and YAG cubic crystal phase were synthesized at 1100 ℃ by the homogeneous precipitation method, using Nd2O3, Y2O3, Al（NO3）3·9H2O and urea as raw materials, （NH4）2SO4 as electrical stabilizer, TEOS as sintering additive. The Nd：YAG transparent ceramics were prepared after being vacuum sintered at 1700 ℃ for 5 h. The Nd：YAG ceramic materials were characterized by the TG-DTA, XRD, FT-IR, TEM, FEG-ESEM and FT-PL. The results show that the crystallization temperature of YAG is 850 ℃ and the intermediate crystal phase YAP forming during the heat treatment transforms to YAG cubic crystal phase at 1050 ℃. The lasing wavelength of （Nd0.01 Y0.99）3Al5O12 transparent ceramics is 1.065 μm and there exists a slight red-shift compared to the single crystal with the same chemical composition. The optical transmittance is 45 % in the visible light and 58 % in the near infrared light and the optical transmittance descends with the decreasing the wavelength.展开更多
（Nd0.01Y0.99）3Al5O12 nano-sized powders were synthesized by low temperature combustion （LCS）, using Nd2O3, Y2O3, Al（NO3）3.9H2O, ammonia water and citric acid as starting materials. The powders were characterized...（Nd0.01Y0.99）3Al5O12 nano-sized powders were synthesized by low temperature combustion （LCS）, using Nd2O3, Y2O3, Al（NO3）3.9H2O, ammonia water and citric acid as starting materials. The powders were characterized by TG-DTA, XRD, FT-IR, ICP and TEM, respectively. The grain sizes were calculated by the Scherrer＇s formula using the full width at half maximum （FWHM） of YAG （420） crystal plane diffraction lines. The study focused on crystallization of ceramics at different heat treatment temperatures. The experimental results show that crystallizing temperature of YAG is 850 ℃, and the intermediate crystal phase YAP, appearing during heat treatment, transforms to YAG cubic crystal phase at the temperature of 1 050℃. The particle size of the powders synthesized by LCS is nano-sized. With the temperature increasing, the mean grain sizes raise, the stand deviations keep almost at the value of 2.0 and the lattice parameters decrease. The grains mainly grow by grain boundary diffusion. The lattice parameter expansion is caused by an increase of the repulsive dipolar interactions on surfaces of crystallites,展开更多
新型冠状病毒肺炎(COVID-19)疫情的爆发给世界公共卫生安全带来前所未有的挑战。随着新型冠状病毒(SARS-CoV-2)相关研究的不断深入,众多分析检测技术相继被应用,推动了病毒检测、疫苗和创新疗法的研发,从而使疫情早日得到控制。分离技...新型冠状病毒肺炎(COVID-19)疫情的爆发给世界公共卫生安全带来前所未有的挑战。随着新型冠状病毒(SARS-CoV-2)相关研究的不断深入,众多分析检测技术相继被应用,推动了病毒检测、疫苗和创新疗法的研发,从而使疫情早日得到控制。分离技术作为生命科学、医学、药学领域的关键技术,操作简单,分离效率高,选择性强,在新型冠状病毒的分离、检测、诊疗及防疫中起到不可替代的作用。该文以SARS-CoV-2或COVID-19为关键词在ISI Web of Science中进行主题检索,归纳了2020年度新型冠状病毒相关的研究论文,简要介绍主要的研究方向,并对国际顶级学术期刊Nature,Science,Cell的论文发表情况进行了统计。通过检索影响因子较高的期刊,综述了新型冠状病毒研究中主要应用的分离技术,并从亲和色谱和尺寸排阻色谱、液相色谱、磁珠分离、离心、微纳分离以及电泳6个方面进行说明。综述统计了亲和色谱和尺寸排阻色谱纯化的病毒相关蛋白,并介绍了其在新型冠状病毒传播、感染机制以及药物筛选中的应用;介绍了液相色谱对病毒候选药物评估以及复杂基质中单一成分的鉴定;介绍了磁珠分离在细胞分离、核酸提取和免疫学检测中的应用;介绍了离心对病毒颗粒、细胞以及血清的分离;介绍了微纳分离结合其他技术以实现病毒蛋白的高灵敏检测;简要介绍了电泳在聚合酶链式反应(PCR)产物分析中的应用。该文综述了2020年度新型冠状病毒研究和防疫检测中分离技术的应用情况,分析了分离技术在新型冠状病毒检测中发挥的作用,旨在为从事分离研究的科研工作者提供一些参考。展开更多
文摘An analytical methodology based on an O-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine(MQD)-silica hybrid monolithic column was developed for the enantioseparation of 9-fluorenylmethoxycarbonyl(FMOC)derivatized amino acids by nano-liquid chromatography.The mobile phase was optimized including the apparent pH,content of ACN,and concentration of the buffer to obtain a satisfactory enantioresolution performance.27 FMOC derivatized amino acids including 19 protein and 8 non-protein amino acids were tested,and 19 out of them were enantiomerically discriminated obtaining baseline separation for 11 of them.Analytical characteristics of the method were evaluated for norvaline and tryptophan in terms of linearity,precision,accuracy,limits of detection(LOD)and quantitation(LOQ)showing good performance to be applied to the enantiomeric determination of these amino acids in dietary supplements.LOD and LOQ values were 9.3 and 31 mM for norvaline enantiomers and 7.5 and 25 mM for tryptophan enantiomers,respectively.The contents of D-norvaline and D-tryptophan were below their respective LODs in all the analyzed samples.Quantitation of L-tryptophan and L-norvaline showed good agreement with the labeled contents except for one sample which did not show presence of L-norvaline,contrary to the label indication.
基金supported in part by the National Natural Science Foundation of China,No.81473383(to YHW)the Significant New-Drugs Creation of Science and Technology Major Projects in China,No.2018ZX09711001-003-019(to YHW)the Innovation Fund for Graduate of Beijing Union Medical College of China,No.2017-1007-02(to XC)
文摘Xiao-Xu-Ming decoction has been widely used to treat stroke and sequelae of stroke. We have previously shown that the active fractions of Xiao-Xu-Ming decoction attenuate cerebral ischemic injury. However, the global protein profile and signaling conduction pathways regulated by Xiao-Xu-Ming decoction are still unclear. This study established a two-vessel occlusion rat model by bilateral common carotid artery occlusion. Rats were intragastrically administered 50 or 150 mg/kg Xiao-Xu-Ming decoction for 4 consecutive weeks. Learning and memory abilities were measured with Morris water maze. Motor ability was detected with prehensile test. Coordination ability was examined using the inclined screen test. Neuronal plasticity was observed by immunofluorescent staining. Differentially expressed proteins of rat hippocampus were analyzed by label-free quantitative proteomics. Real time-polymerase chain reaction and western blot assay were used to identify the changes in proteins. Results showed that Xiao-Xu-Ming decoction dramatically alleviated learning and memory deficits, and motor and coordination dysfunction, and increased the expression of microtubule-associated protein 2. Xiao-Xu-Ming decoction extract remarkably decreased 13 upregulated proteins and increased 39 downregulated proteins. The regulated proteins were mainly involved in oxidation reduction process, intracellular signaling cascade process, and protein catabolic process. The signaling pathways were mainly involved in ubiquitin mediated proteolysis and the phosphatidylinositol signaling system. Furthermore, there was an interaction among Rab2 a, Ptpn1, Ppm1 e, Cdk18, Gorasp2, Eps15, Capza2, Syngap1 and Mt-nd1. Protein analyses confirmed the changes in expression of MTND1. The current findings provide new insights into the molecular mechanisms of Xiao-Xu-Ming decoction extract's effects on chronic cerebral hypoperfusion.
基金supported by the Public Science and Technology Research Funds (Projects of Ocean)State Ocean Administration of P. R. China (Nos. 201305007 and 201405017)+3 种基金National High Technology Research and Development Program of China (No. 2013AA093003)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)Jiangsu Qinglan ProjectJiangsu 333 Project
文摘The complexity and diversity of peptide mixture from protein hydrolysates make their characterization difficult. In this study, a method combining nano LC-MS/MS with molecular docking was applied to identifying and characterizing a peptide with angiotensin-? converting enzyme(ACE-I) inhibiting activity from Venerupis philippinarum hydrolysate. Firstly, ethanol supernatant of V. philippinarum hydrolysate was separated into active fractions with chromatographic methods such as ion-exchange chromatography and high performance liquid chromatography in combination. Then seven peptides from active fraction were identified according to the searching result of the MS/MS spectra against protein databases. Peptides were synthesized and subjected to ACE-Iinhibition assay. The peptide NTLTLIDTGIGMTK showed the highest potency with an IC_(50) of 5.75 μmol L^(-1). The molecular docking analysis showed that the ACE-I inhibiting peptide NTLTLIDTGIGMTK bond with residues Glu123, Glu403, Arg522, Glu376, Gln281 and Asn285 of ACE-I. Therefore, active peptides could be identified with the present method rather than the traditional purification and identification strategies. It may also be feasible to identify other food-derived peptides which target other enzymes and receptors with the method developed in this study.
文摘The homogeneously dispersed, less agglomerated (Nd0.01Y0.99)3Al5O12 nano-sized powders were synthesized by the low temperature combustion (LCS), using Nd2O3, Y2O3, Al(NO3)3·9H2O, ammonia water and citric acid as starting materials. This method effectively solves the problems caused by solid-state reaction at high temperature and hard agglomerates brought by the chemical precipitation method. The powders were characterized by TG-DTA, XRD, FT-IR, TEM respectively and the photoluminescence (PL) spectra of (Nd0.01Y0.99)3Al5O12 green and sintered ceramic disks were measured. The results show that the forming temperature of YAG crystal phase is 850 ℃ and YAP crystal phase appearing during the calcinations transforms to pure YAG at 1050 ℃. The particle size of the powders synthesized by the LCS is in a range of 20～50 nm depending on the thermal treatment temperatures. The effectively induced cross section (σin) with the value 4.03×10-19 cm2 of (Nd0.01Y0.99)3Al5O12 ceramics is about 44% higher than that of single crystal.
文摘substitutes tion, high loosely dis Neodymium doped-yttrium aluminum garnet （Nd ： YAG） transparent polycrystalline ceramics already become of single crystals because they are provided with easy fabrication, low cost, large size, highly doped concentraheat conductivity, mass fabrication, multi-layers and multi-filnctions. The Nd：YAG precursor powders with persed , slightly agglomerated, super fine and YAG cubic crystal phase were synthesized at 1100 ℃ by the homogeneous precipitation method, using Nd2O3, Y2O3, Al（NO3）3·9H2O and urea as raw materials, （NH4）2SO4 as electrical stabilizer, TEOS as sintering additive. The Nd：YAG transparent ceramics were prepared after being vacuum sintered at 1700 ℃ for 5 h. The Nd：YAG ceramic materials were characterized by the TG-DTA, XRD, FT-IR, TEM, FEG-ESEM and FT-PL. The results show that the crystallization temperature of YAG is 850 ℃ and the intermediate crystal phase YAP forming during the heat treatment transforms to YAG cubic crystal phase at 1050 ℃. The lasing wavelength of （Nd0.01 Y0.99）3Al5O12 transparent ceramics is 1.065 μm and there exists a slight red-shift compared to the single crystal with the same chemical composition. The optical transmittance is 45 % in the visible light and 58 % in the near infrared light and the optical transmittance descends with the decreasing the wavelength.
基金the Chinese Education Ministry Excellent Teacher Foundation(KB20026)
文摘（Nd0.01Y0.99）3Al5O12 nano-sized powders were synthesized by low temperature combustion （LCS）, using Nd2O3, Y2O3, Al（NO3）3.9H2O, ammonia water and citric acid as starting materials. The powders were characterized by TG-DTA, XRD, FT-IR, ICP and TEM, respectively. The grain sizes were calculated by the Scherrer＇s formula using the full width at half maximum （FWHM） of YAG （420） crystal plane diffraction lines. The study focused on crystallization of ceramics at different heat treatment temperatures. The experimental results show that crystallizing temperature of YAG is 850 ℃, and the intermediate crystal phase YAP, appearing during heat treatment, transforms to YAG cubic crystal phase at the temperature of 1 050℃. The particle size of the powders synthesized by LCS is nano-sized. With the temperature increasing, the mean grain sizes raise, the stand deviations keep almost at the value of 2.0 and the lattice parameters decrease. The grains mainly grow by grain boundary diffusion. The lattice parameter expansion is caused by an increase of the repulsive dipolar interactions on surfaces of crystallites,
文摘新型冠状病毒肺炎(COVID-19)疫情的爆发给世界公共卫生安全带来前所未有的挑战。随着新型冠状病毒(SARS-CoV-2)相关研究的不断深入,众多分析检测技术相继被应用,推动了病毒检测、疫苗和创新疗法的研发,从而使疫情早日得到控制。分离技术作为生命科学、医学、药学领域的关键技术,操作简单,分离效率高,选择性强,在新型冠状病毒的分离、检测、诊疗及防疫中起到不可替代的作用。该文以SARS-CoV-2或COVID-19为关键词在ISI Web of Science中进行主题检索,归纳了2020年度新型冠状病毒相关的研究论文,简要介绍主要的研究方向,并对国际顶级学术期刊Nature,Science,Cell的论文发表情况进行了统计。通过检索影响因子较高的期刊,综述了新型冠状病毒研究中主要应用的分离技术,并从亲和色谱和尺寸排阻色谱、液相色谱、磁珠分离、离心、微纳分离以及电泳6个方面进行说明。综述统计了亲和色谱和尺寸排阻色谱纯化的病毒相关蛋白,并介绍了其在新型冠状病毒传播、感染机制以及药物筛选中的应用;介绍了液相色谱对病毒候选药物评估以及复杂基质中单一成分的鉴定;介绍了磁珠分离在细胞分离、核酸提取和免疫学检测中的应用;介绍了离心对病毒颗粒、细胞以及血清的分离;介绍了微纳分离结合其他技术以实现病毒蛋白的高灵敏检测;简要介绍了电泳在聚合酶链式反应(PCR)产物分析中的应用。该文综述了2020年度新型冠状病毒研究和防疫检测中分离技术的应用情况,分析了分离技术在新型冠状病毒检测中发挥的作用,旨在为从事分离研究的科研工作者提供一些参考。
