The Li metal battery with ultrahigh-nickel cathode(LiNi_(x)M_(1-x)O_(2),M=Mn,Co,and x≥0.9)under high-voltage is regarded as one of the most promising approaches to fulfill the ambitious target of 400 Wh/kg.However,th...The Li metal battery with ultrahigh-nickel cathode(LiNi_(x)M_(1-x)O_(2),M=Mn,Co,and x≥0.9)under high-voltage is regarded as one of the most promising approaches to fulfill the ambitious target of 400 Wh/kg.However,the practical application is impeded by the instability of electrode/electrolyte interface and Ni-rich cathode itself.Herein we proposed an electron-defect electrolyte additive trimethyl borate(TMB)which is paired with the commercial carbonate electrolyte to construct highly conductive fluorine-and boron-rich cathode electrolyte interface(CEI)on LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)(NCM90)surface and solid electrolyte interphase(SEI)on lithium metal surface.The modified CEI effectively mitigates the structural transformation from layered to disordered rock-salt phase,and consequently alleviate the dissolution of transition metal ions(TMs)and its“cross-talk”effect,while the enhanced SEI enables stable lithium plating/striping and thus demonstrated good compatibility between electrolyte and lithium metal anode.As a result,the common electrolyte with 1 wt%TMB enables 4.7 V NCM90/Li cell cycle stably over 100 cycles with 70%capacity retention.This work highlights the significance of the electron-defect boron compounds for designing desirable interfacial chemistries to achieve high performance NCM90/Li battery under high voltage operation.展开更多
LHP1 mediates recruitment of the PRC2 histone methyltransferase complex to chromatin and thereby facilitates maintenance of H3K27me3 on FLC, a key flowering repressor gene. Here, we report that the PWWP domain protei...LHP1 mediates recruitment of the PRC2 histone methyltransferase complex to chromatin and thereby facilitates maintenance of H3K27me3 on FLC, a key flowering repressor gene. Here, we report that the PWWP domain proteins （PDPs） interact with FVE and MSI5 to suppress FLC expression and thereby promote flowering. We demonstrated that FVE, MSI5, and PDP3 were co-purified with LHP1. The H3K27me3 level on FLC was decreased in the pdp mutants as welt as in the fve/ msi5 double mutant. This study suggests that PDPs function together with FVE and MSI5 to regulate the function of the PRC2 complex on FLC.展开更多
The effects of epigenetic modification on the differentiation of islet cells and the expression of associated genes（Pdx-1,Pax4,MafA,and Nkx6.1,etc） were investigated.The promoter methylation status of islet differen...The effects of epigenetic modification on the differentiation of islet cells and the expression of associated genes（Pdx-1,Pax4,MafA,and Nkx6.1,etc） were investigated.The promoter methylation status of islet differentiation-associated genes（Pdx-1,Pax4,MafA and Nkx6.1）,Oct4 and MLH1 genes of mouse embryonic stem cells,NIH3T3 cells and NIT-1 cells were profiled by methylated DNA immunoprecipitation,real-time quantitative PCR（MeDIP-qPCR） techniques.The histone modification status of these genes promoter region in different cell types was also measured by using chromatin immunoprecipitation real-time quantitative PCR methods.The expression of these genes in these cells was detected by using real-time quantitative PCR.The relationship between the epigenetic modification（DNA methylation,H3 acetylation,H3K4m3 and H3K9m3） of these genes and their expression was analyzed.The results showed that：（1） the transcription-initiation-sites of Pdx-1,MafA and Nkx6.1 were highly methylated in NIH3T3 cells; （2） NIH3T3 cells showed a significantly higher level of DNA methylation modification in the transcription-initiation-site of Pdx-1,Pax4,MafA and Nkx6.1 genes than that in mES cells and NIT-1 cells（P〈0.05）; （3） NIT-1 cells had a significantly higher level of H3K4m3 modification in the transcription-initiation-site of Pdx-1,Pax4,MafA and Nkx6.1 genes than that in mES cells and NIH3T3 cells（P〈0.05）,with significantly increased level of gene expression; （4） NIH3T3 cell had a significantly higher level of H3K9m3 modification in the transcription-initiation-site of Pdx-1,Pax4,MafA and Nkx6.1 genes than that in mES cells and with NIT-1 cell（P〈0.05）,with no detectable mRNA expression of these genes.It was concluded that histone modification（H3K4m3 and H3K9m3） and DNA methylation might have an intimate communication between each other in the differentiation process from embryonic stem cells into islet cells.展开更多
Objective To investigate whether α-hemoglobin stabilizing protein (AHSP), the α-globin-specific molecular chaperone, is regulated by erythroid transcription factor NF-E2. Methods We established the stable cell line ...Objective To investigate whether α-hemoglobin stabilizing protein (AHSP), the α-globin-specific molecular chaperone, is regulated by erythroid transcription factor NF-E2. Methods We established the stable cell line with NF-E2p45 (the larger subunit of NF-E2) short hairpin RNA to silence its expression. Western blot, real-time polymerase chain reaction, and chromatin immunoprecipitation (ChIP) analysis were performed to detect the expression of AHSP, the histone modifications at AHSP gene locus, and the binding of GATA-1 at the AHSP promoter with NF-E2p45 deficiency. ChIP was also carried out in dimethyl sulfoxide (DMSO)-induced DS19 cells and estrogen-induced G1E-ER4 cells to examine NF-E2 binding to the AHSP gene locus and its changes during cell erythroid differentiation. Finally, luciferase assay was applied in HeLa cells transfected with AHSP promoter fragments to examine AHSP promoter activity in the presence of exogenous NF-E2p45. Results We found that AHSP expression was highly dependent on NF-E2p45. NF-E2 bound to the regions across AHSP gene locus in vivo, and the transcription of AHSP was transactivated by exogenous NF-E2p45. In addition, we observed the decrease of H3K4 trimethylation and GATA-1 occupancy at the AHSP gene locus in NF-E2p45-deficient cells. Restoration of GATA-1 in G1E-ER4 cells in turn led to increased DNA binding of NF-E2p45. Conclusion NF-E2 may play an important role in AHSP gene regulation, providing new insights into the molecular mechanisms underlying the erythroid-specific expression of AHSP as well as new possibilities for β-thalassemia treatment.展开更多
The mammalian protein kinase C-interacting cousin of thioredoxin(PICOT;also termed glutaredoxin 3)is a multi-domain monothiol glutaredoxin that is involved in a wide variety of signaling pathways and biological proces...The mammalian protein kinase C-interacting cousin of thioredoxin(PICOT;also termed glutaredoxin 3)is a multi-domain monothiol glutaredoxin that is involved in a wide variety of signaling pathways and biological processes.PICOT is required for normal and transformed cell growth and is critical for embryonic development.Recent studies in T lymphocytes demonstrated that PICOT can translocate to the nucleus and interact with embryonic ectoderm development,a polycomb group protein and a core component of the polycomb repressive complex 2,which contributes to the maintenance of transcriptional repression and chromatin remodeling.Furthermore,PICOT was found to interact with chromatin-bound embryonic ectoderm development and alter the extent of histone 3 lysine 27 trimethylation at the promoter region of selected polycomb repressive complex 2 target genes.PICOT knockdown in Jurkat T cells led to increased histone 3 lysine 27 trimethylation at the promoter region of CCND2,a cell cycle-regulating gene which encodes the cyclin D2 protein.As a result,the expression levels of CCND2 mRNA and protein levels were reduced,concomitantly with inhibition of the cell growth rate.Analysis of multiple data sets from the Cancer Genome Atlas revealed that a high expression of PICOT correlated with a low expression of CCND2 in a large number of human cancers.In addition,this parameter correlated with poor patient survival,suggesting that the ratio between PICOT/CCND2 mRNA levels might serve as a predictor of patient survival in selected types of human cancer.展开更多
For efficient mucosal vaccine delivery, nanoparticulate antigens are better taken by microfold cells in the nasal associated lymphoid tissue and also dendritic cells. Nanoparticles based on polymers such as chitosan(C...For efficient mucosal vaccine delivery, nanoparticulate antigens are better taken by microfold cells in the nasal associated lymphoid tissue and also dendritic cells. Nanoparticles based on polymers such as chitosan(CHT) and its water soluble derivative, trimethylchitosan(TMC), could be successfully used as carrier/adjuvant for this purpose. Sodium alginate, a negatively charged biopolymer, could modify the immunostimulatory properties of CHT and TMC NPs and increase their stability. Sodium alginate(ALG)-coated chitosan(CHT)and trimethylchitosan(TMC) nanoparticles(NPs) loaded with inactivated PR8 influenza virus were successfully prepared by direct coating of the virus with CHT or TMC polymers to evaluate their immunoadjuvant potential after nasal immunization. After nasal immunizations in BALB/c mice, PR8-CHT formulation elicited higher IgG2 a and Ig G1 antibody titers compared with PR8-TMC. ALG coating of this formulation(PR8-CHT-ALG) significantly decreased the antibody titers and a less immune response was induced than PR8-TMC-ALG formulation. PR8-TMC-ALG formulation showed significantly higher Ig G2 a/Ig G1 ratio, as criteria for Th1-type immune response, compared with PR8-CHT-ALG and PR8 virus alone. Altogether, the PR8-TMC-ALG formulation could be considered as an efficient intranasal antigen delivery system for nasal vaccines.展开更多
Zn2GeO4 nanorods were prepared by a surfactant-assisted solution phase route.The as-prepared products were characterized by X-ray powder diffraction(XRD),scanning electron microscopy(SEM),high-resolution transmission ...Zn2GeO4 nanorods were prepared by a surfactant-assisted solution phase route.The as-prepared products were characterized by X-ray powder diffraction(XRD),scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM),inductively coupled plasma atomic emission spectrometer(ICP-AES),UV-vis diffuse reflection spectroscopy and photoluminescence(PL) spectroscopy.The possible formation mechanism of Zn2GeO4 nanorods was discussed.It was supposed that the CTA+ cations preferentially adsorb on the planes of Zn2GeO4 nanorods,leading to preferential growth along the c-axis to form the Zn2GeO4 rods with larger aspect ratio and higher surface area,which showed the improved photocatalytic activity for photoreduction of CO2.The photoluminescence(PL) property of Zn2GeO4 nanorods was investigated through the emission spectra.展开更多
Because of the superior features of boron-10 isotope in absorbing hot neutrons, boric-10 acid(H310BO3)has been used widely in nuclear industry. Boric-10 acid is obtained from boron-10 trifluoride(10BF3) by esterificat...Because of the superior features of boron-10 isotope in absorbing hot neutrons, boric-10 acid(H310BO3)has been used widely in nuclear industry. Boric-10 acid is obtained from boron-10 trifluoride(10BF3) by esterification and hydrolyzation. In this study, trimethyl borate-10 [(CH3O)310B] was prepared from boron-10 trifluoride(10BF3)through chemical exchange rectification. In addition, the hydrolyzation of trimethyl borate-10 was investigated with different p H values, temperatures and molar ratios of water to trimethyl borate-10. Under the optimum process conditions, high yield of boric-10 acid with nuclear industrial purity grade was realized.展开更多
Mesoporous cerium-zirconium mixed oxides were prepared by hydrothermal method using cetyl trimethyl ammonium bromide (CTAB) as template. The effects of amount of template, pH value of solution and hydrothermal tempera...Mesoporous cerium-zirconium mixed oxides were prepared by hydrothermal method using cetyl trimethyl ammonium bromide (CTAB) as template. The effects of amount of template, pH value of solution and hydrothermal temperature on mesostructure of samples were systematically investigated. The final products were characterized by XRD, TEM, FT-IR, and BET. The results indicate that all the cerium-zirconium mixed oxides present a meso-structure. At molar ratio of n(CTAB)/n((Ce)+(Zr))= 0.15, pH value of 9, and hydrothermal temperature of 120 ℃, the samples obtained possess a specific surface area of 207.9 m2/g with pore diameter of 3.70 nm and pore volume of 0.19 cm3/g.展开更多
The liquid membrane oscillation of a novel water （aqueous tetradecyl trimethyl ammoniumbromide, TTAB and alcohol solution）/oil （picric acid in chloroform solution）/water （aqueous glucose solution） system was inv...The liquid membrane oscillation of a novel water （aqueous tetradecyl trimethyl ammoniumbromide, TTAB and alcohol solution）/oil （picric acid in chloroform solution）/water （aqueous glucose solution） system was investigated. By using homemade device, the curves of various liquid membranes oscillation with different concentration of TTAB and picric acid, types of alcohol and other organic solvents at different temperature were measured. The results show that the water （aqueous 7 mmol/L of TTAB and 0.5 mol/L of n-propanol solution）/oil （0.5 mmol/L of picric acid in chloroform solution）/water （aqueous glucose solution） system performed sustained and stable oscillation at 30 ℃. And the novel system can recognise added amino acid.展开更多
Bipolar membrane electrodialysis(BMED) has already been described for the preparation of quaternary ammonium hydroxide. However, compared to quaternary ammonium hydroxide, di-quaternary ammonium hydroxide has raised g...Bipolar membrane electrodialysis(BMED) has already been described for the preparation of quaternary ammonium hydroxide. However, compared to quaternary ammonium hydroxide, di-quaternary ammonium hydroxide has raised great interest due to its high thermal stability and good oriented performance.In order to synthesize N,N-hexamethylenebis(trimethyl ammonium hydroxide)(HM(OH)_2) by EDBM,experiments designed by response surface methodology were carried out on the basis of single-factor experiments. The factors include current density, feed concentration and flow ratio of each compartment(feed compartment: base compartment: acid compartment: buffer compartment). The relationship between current efficiency and the above-mentioned three factors was quantitatively described by a multivariate regression model. According to the results, the feed concentration was the most significant factor and the optimum conditions were as follows: the current efficiency was up to 76.2%(the hydroxide conversion was over 98.6%), with a current density of 13.15 m A·cm^(-2), a feed concentration of 0.27 mol·L^(-1) and a flow ratio of 20 L·h^(-1):26 L·h^(-1):20 L·h^(-1):20 L·h^(-1) for feed compartment, base compartment, acid compartment, and intermediate compartment, respectively. This study demonstrates the optimized parameters of manufacturing HM(OH)_2 by direct splitting its halide for industrial application.展开更多
Objective To study the regulatory mechanism of SATB1 repression in cells other than T cells or erythroid cells, which have high expression level of SATB1. Methods HeLa epithelial cells were treated with either histone...Objective To study the regulatory mechanism of SATB1 repression in cells other than T cells or erythroid cells, which have high expression level of SATB1. Methods HeLa epithelial cells were treated with either histone deacetylase inhibitor (HDACi) trichostatin A (TSA) or DNA methylation inhibitor 5-Aza-C before detecting SATB1 expression. Luciferase reporter system was applied to measure effects of EZH2 on SATB1 promoter activity. Over-expression or knockdown of EZH2 and subsequent quantitative reverse transcription-polymerase chain reaction were performed to determine the effect of this Polycomb group protein on SATB1 transcription. Chromatin immunoprecipitation (ChIP) assay was applied to measure enrichment of EZH2 and trimethylated H3K27 (H3K27me3) at SATB1 promoter in HeLa cells. K562 cells and Jurkat cells, both having high-level expression of SATB1, were used in the ChIP experiment as controls. Results Both TSA and 5-Aza-C increased SATB1 expression in HeLa cells. Over-expression of EZH2 reduced promoter activity as well as the mRNA level of SATB1, while knockdown of EZH2 apparently enhanced SATB1 expression in HeLa cells but not in K562 cells and Jurkat cells. ChIP assay results suggested that epigenetic silencing of SATB1 by EZH2 in HeLa cells was mediated by trimethylation modification of H3K27. In contrast, enrichment of EZH2 and H3K27me3 was not detected within proximal promoter region of SATB1 in either K562 or Jurkat cells. Conclusion SATB1 is a bona fide EZH2 target gene in HeLa cells and the repression of SATB1 by EZH2 may be mediated by trimethylation modification on H3K27.展开更多
An eco-friendly synthesis of cyclododecanone (CDON) from cyclododecatriene (CDT) is described. Selec- tive epoxidation of CDT with hydrogen peroxide using hexadecyl trimethyl ammonium heteropolyphospha- totungstate [(...An eco-friendly synthesis of cyclododecanone (CDON) from cyclododecatriene (CDT) is described. Selec- tive epoxidation of CDT with hydrogen peroxide using hexadecyl trimethyl ammonium heteropolyphospha- totungstate [(n-C16H33NMe3)3PW4O16, HAHPT] as catalyst and water as solvent followed by the hydrogena- tion on Raney nickel catalyst gave cyclododecanol (CDOL). The latter was oxidized with hydrogen peroxide using HAHPT as catalyst and a mixture of water and t-butanol as solvent to afford CDON. The total yield was 53.4% under the optimum reaction conditions.展开更多
A new kind of silicon-based biological lubricating base oil with good viscosity-temperature behavior,viscosity index,thermostability,oxidation stability and wear resistance performance was synthesized as a derivative ...A new kind of silicon-based biological lubricating base oil with good viscosity-temperature behavior,viscosity index,thermostability,oxidation stability and wear resistance performance was synthesized as a derivative of methyl oleate.Trimethylsilylation reaction was introduced to further improve methyl oleate oxidation stability and lubricity after epoxidation and open-ring reactions.The order of effectiveness of acid binding agent was N,N-diisopropylethylamine(DIEA) > pyridine > diethylamine > triethylamine,and the effects of various parameters on the trimethylsilylation reaction as well as on the silicon-oxygen bond stability and reaction yield were studied.A maximum yield of 34.54%was achieved at hydroxyl/trimethyl chlorosilane/DIEA molar ratio of1:1.25:1,reaction temperature 40℃,reaction time 1.5 h.展开更多
The novel high-performance nanocomposites of polyaniline (PANI) and graphene oxide sheets (GOs) was synthesized via in situ polymerization in the presence of Hexadecyl trimethyl ammonium Bromide intercalated graphite ...The novel high-performance nanocomposites of polyaniline (PANI) and graphene oxide sheets (GOs) was synthesized via in situ polymerization in the presence of Hexadecyl trimethyl ammonium Bromide intercalated graphite oxide (CGO), basing on PANI and GOs as a matrix respectively. The result showed that ANI monomer was intercalated into the spacing of CGO, and the CGO was well exfoliated into nanosheets while polymerization. Owing to π–π electron stacking effect between the PANI and the GOs, the electrical conductivity of GOs/PANI nanocomposites (0.47 S/cm), which basing on PANI as a matrix, improved in comparison with pure PANI nanowires (0.02 S/cm) and GO (2.5×10-5 S/cm), while the electrical conductivity of PANI/GOs nanocomposites, which basing on GOs as a matrix, was only 6.2×10-3 S/cm. And it also indicated that the mole ratio of APS, the concentration of HCl, other with the polymerization time, are also important influencing factors of the conductivity of nanocomposites.展开更多
OBJECTIVE To elucidate the structural-pharmacokinetic relationship and identify resveratrol analogs with favorable pharmacokinetic profiles for potential medicinal application. METHODS The pharmacokinetic data of resv...OBJECTIVE To elucidate the structural-pharmacokinetic relationship and identify resveratrol analogs with favorable pharmacokinetic profiles for potential medicinal application. METHODS The pharmacokinetic data of resveratrol(trans-3,5,4-trihydroxystilbene),pterostilbene(trans-3,5-dimethoxy-4-hydroxystilbene),resveratrol trimethyl ether(trans-3,5,4-trimethoxystilbene)and some other herbal resveratrol analogs were extracted from the authors′recent publications and compared.RESULTS Aqueous solubility,to different extent,has been identified as a barrier to oral absorption of resveratrol and its analogs.In addition,the para hydroxyl group(s)on the aromatic ring was less liable to metabolism compared to the meta-hydroxyl group(s).Pterostilbene and resveratrol trimethyl ether displayed more superior pharmacokinetic properties than resveratrol,i.e.much slower clearance and abundant plasma exposure.CONCLUSION Pterostilbene appears to be a favorable candidate for further development.Resveratrol analogs with meta-hydroxyl group(s)might have poor metabolic stability and suffer from rapid clearance and low oral bioavailability.展开更多
The liquid membrane oscillation of a novel water（aqueous tetradecyl trimethyl ammoniumbromide,TTAB and alcohol solution）/oil（picric acid in chloroform solution）/water（aqueous glucose solution） system was investi...The liquid membrane oscillation of a novel water（aqueous tetradecyl trimethyl ammoniumbromide,TTAB and alcohol solution）/oil（picric acid in chloroform solution）/water（aqueous glucose solution） system was investigated by means of a homemade device.The results show that the water（aqueous 7 mmol/L TTAB and 0.5 mol/L n-propanol solution）/oil（0.5 mmol/L icric acid in chloroform solution）/water（0.1 mol/L glucose solution） system performed sustained and stable oscillation at 30℃.The oscillation curve under optimized conditions is considered to be referent.Several oscillation curves were accumulated with the addition of different amino acids.The results showed that the novel system can recognize the added amino acids such as L-tryptophan,L-tyrosine,and D,L-tyrosine.And there is corresponding relationship between the change of curve shape and the quantity of amino acid added.展开更多
Densities of methanol＋trimethyl phosphate binary mixtures were measured over a temperature range of （293.15 to 333.15）K at atmospheric pressure. From these data, excess molar volume（VE） was calculated. Viscositie...Densities of methanol＋trimethyl phosphate binary mixtures were measured over a temperature range of （293.15 to 333.15）K at atmospheric pressure. From these data, excess molar volume（VE） was calculated. Viscosities of trimethyl phosphate were also measured over a temperature range of （283.15 to 373.15）K and the data were fitted to the Andrade equation. The density data were fitted to a second-order polynomial. The excess molar volumes were fitted to the Redlich-Kister equation using a nonlinear regression method. Results show that the density and viscosity gradually decreases with the increase of temperature.展开更多
基金financially supported by the National Key Research and Development Program of China(2022YFE0206300)the National Natural Science Foundation of China(U21A2081,22075074,22209047)+1 种基金the Natural Science Foundation of Hunan Province(2022JJ40140)the Hunan Provincial Department of Education Outstanding Youth Project(22B0864,23B0037)。
文摘The Li metal battery with ultrahigh-nickel cathode(LiNi_(x)M_(1-x)O_(2),M=Mn,Co,and x≥0.9)under high-voltage is regarded as one of the most promising approaches to fulfill the ambitious target of 400 Wh/kg.However,the practical application is impeded by the instability of electrode/electrolyte interface and Ni-rich cathode itself.Herein we proposed an electron-defect electrolyte additive trimethyl borate(TMB)which is paired with the commercial carbonate electrolyte to construct highly conductive fluorine-and boron-rich cathode electrolyte interface(CEI)on LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)(NCM90)surface and solid electrolyte interphase(SEI)on lithium metal surface.The modified CEI effectively mitigates the structural transformation from layered to disordered rock-salt phase,and consequently alleviate the dissolution of transition metal ions(TMs)and its“cross-talk”effect,while the enhanced SEI enables stable lithium plating/striping and thus demonstrated good compatibility between electrolyte and lithium metal anode.As a result,the common electrolyte with 1 wt%TMB enables 4.7 V NCM90/Li cell cycle stably over 100 cycles with 70%capacity retention.This work highlights the significance of the electron-defect boron compounds for designing desirable interfacial chemistries to achieve high performance NCM90/Li battery under high voltage operation.
基金supported by the National Key Research and Development Program of China (2016YFA0500801)the 973 Program (2011CB812600) from the Chinese Ministry of Science and Technology (to X.J.H.)the National Natural Science Foundation of China (31370317 and 31571584 to B.W.)
文摘LHP1 mediates recruitment of the PRC2 histone methyltransferase complex to chromatin and thereby facilitates maintenance of H3K27me3 on FLC, a key flowering repressor gene. Here, we report that the PWWP domain proteins （PDPs） interact with FVE and MSI5 to suppress FLC expression and thereby promote flowering. We demonstrated that FVE, MSI5, and PDP3 were co-purified with LHP1. The H3K27me3 level on FLC was decreased in the pdp mutants as welt as in the fve/ msi5 double mutant. This study suggests that PDPs function together with FVE and MSI5 to regulate the function of the PRC2 complex on FLC.
文摘The effects of epigenetic modification on the differentiation of islet cells and the expression of associated genes（Pdx-1,Pax4,MafA,and Nkx6.1,etc） were investigated.The promoter methylation status of islet differentiation-associated genes（Pdx-1,Pax4,MafA and Nkx6.1）,Oct4 and MLH1 genes of mouse embryonic stem cells,NIH3T3 cells and NIT-1 cells were profiled by methylated DNA immunoprecipitation,real-time quantitative PCR（MeDIP-qPCR） techniques.The histone modification status of these genes promoter region in different cell types was also measured by using chromatin immunoprecipitation real-time quantitative PCR methods.The expression of these genes in these cells was detected by using real-time quantitative PCR.The relationship between the epigenetic modification（DNA methylation,H3 acetylation,H3K4m3 and H3K9m3） of these genes and their expression was analyzed.The results showed that：（1） the transcription-initiation-sites of Pdx-1,MafA and Nkx6.1 were highly methylated in NIH3T3 cells; （2） NIH3T3 cells showed a significantly higher level of DNA methylation modification in the transcription-initiation-site of Pdx-1,Pax4,MafA and Nkx6.1 genes than that in mES cells and NIT-1 cells（P〈0.05）; （3） NIT-1 cells had a significantly higher level of H3K4m3 modification in the transcription-initiation-site of Pdx-1,Pax4,MafA and Nkx6.1 genes than that in mES cells and NIH3T3 cells（P〈0.05）,with significantly increased level of gene expression; （4） NIH3T3 cell had a significantly higher level of H3K9m3 modification in the transcription-initiation-site of Pdx-1,Pax4,MafA and Nkx6.1 genes than that in mES cells and with NIT-1 cell（P〈0.05）,with no detectable mRNA expression of these genes.It was concluded that histone modification（H3K4m3 and H3K9m3） and DNA methylation might have an intimate communication between each other in the differentiation process from embryonic stem cells into islet cells.
基金Supported by National Natural Science Foundation of China (30130026, U0632005, 30721063)National Basic Research Program of China (973 Program) (2011CB964803)+1 种基金National Laboratory of Medical Molecular Biology grant (2060204)Beijing municipal government grant (YB20081002301)
文摘Objective To investigate whether α-hemoglobin stabilizing protein (AHSP), the α-globin-specific molecular chaperone, is regulated by erythroid transcription factor NF-E2. Methods We established the stable cell line with NF-E2p45 (the larger subunit of NF-E2) short hairpin RNA to silence its expression. Western blot, real-time polymerase chain reaction, and chromatin immunoprecipitation (ChIP) analysis were performed to detect the expression of AHSP, the histone modifications at AHSP gene locus, and the binding of GATA-1 at the AHSP promoter with NF-E2p45 deficiency. ChIP was also carried out in dimethyl sulfoxide (DMSO)-induced DS19 cells and estrogen-induced G1E-ER4 cells to examine NF-E2 binding to the AHSP gene locus and its changes during cell erythroid differentiation. Finally, luciferase assay was applied in HeLa cells transfected with AHSP promoter fragments to examine AHSP promoter activity in the presence of exogenous NF-E2p45. Results We found that AHSP expression was highly dependent on NF-E2p45. NF-E2 bound to the regions across AHSP gene locus in vivo, and the transcription of AHSP was transactivated by exogenous NF-E2p45. In addition, we observed the decrease of H3K4 trimethylation and GATA-1 occupancy at the AHSP gene locus in NF-E2p45-deficient cells. Restoration of GATA-1 in G1E-ER4 cells in turn led to increased DNA binding of NF-E2p45. Conclusion NF-E2 may play an important role in AHSP gene regulation, providing new insights into the molecular mechanisms underlying the erythroid-specific expression of AHSP as well as new possibilities for β-thalassemia treatment.
基金Supported by the USA-Israel Binational Science Foundation,No.2013034the Israel Science Foundation administered by the Israel Academy of Science,No.1235/17+1 种基金the Jacki and Bruce Barron Cancer Research Scholars’ProgramCity of Hope and the Israel Cancer Research Fund,No.87735611.
文摘The mammalian protein kinase C-interacting cousin of thioredoxin(PICOT;also termed glutaredoxin 3)is a multi-domain monothiol glutaredoxin that is involved in a wide variety of signaling pathways and biological processes.PICOT is required for normal and transformed cell growth and is critical for embryonic development.Recent studies in T lymphocytes demonstrated that PICOT can translocate to the nucleus and interact with embryonic ectoderm development,a polycomb group protein and a core component of the polycomb repressive complex 2,which contributes to the maintenance of transcriptional repression and chromatin remodeling.Furthermore,PICOT was found to interact with chromatin-bound embryonic ectoderm development and alter the extent of histone 3 lysine 27 trimethylation at the promoter region of selected polycomb repressive complex 2 target genes.PICOT knockdown in Jurkat T cells led to increased histone 3 lysine 27 trimethylation at the promoter region of CCND2,a cell cycle-regulating gene which encodes the cyclin D2 protein.As a result,the expression levels of CCND2 mRNA and protein levels were reduced,concomitantly with inhibition of the cell growth rate.Analysis of multiple data sets from the Cancer Genome Atlas revealed that a high expression of PICOT correlated with a low expression of CCND2 in a large number of human cancers.In addition,this parameter correlated with poor patient survival,suggesting that the ratio between PICOT/CCND2 mRNA levels might serve as a predictor of patient survival in selected types of human cancer.
基金part of Amir-Hossein Sabbaghi Pharm.D.thesis(Grant number:911042)supported by Vice Chancellor for Research,Mashhad University of Medical Sciences
文摘For efficient mucosal vaccine delivery, nanoparticulate antigens are better taken by microfold cells in the nasal associated lymphoid tissue and also dendritic cells. Nanoparticles based on polymers such as chitosan(CHT) and its water soluble derivative, trimethylchitosan(TMC), could be successfully used as carrier/adjuvant for this purpose. Sodium alginate, a negatively charged biopolymer, could modify the immunostimulatory properties of CHT and TMC NPs and increase their stability. Sodium alginate(ALG)-coated chitosan(CHT)and trimethylchitosan(TMC) nanoparticles(NPs) loaded with inactivated PR8 influenza virus were successfully prepared by direct coating of the virus with CHT or TMC polymers to evaluate their immunoadjuvant potential after nasal immunization. After nasal immunizations in BALB/c mice, PR8-CHT formulation elicited higher IgG2 a and Ig G1 antibody titers compared with PR8-TMC. ALG coating of this formulation(PR8-CHT-ALG) significantly decreased the antibody titers and a less immune response was induced than PR8-TMC-ALG formulation. PR8-TMC-ALG formulation showed significantly higher Ig G2 a/Ig G1 ratio, as criteria for Th1-type immune response, compared with PR8-CHT-ALG and PR8 virus alone. Altogether, the PR8-TMC-ALG formulation could be considered as an efficient intranasal antigen delivery system for nasal vaccines.
基金Project(51208102)supported by the National Natural Science Foundation of China
文摘Zn2GeO4 nanorods were prepared by a surfactant-assisted solution phase route.The as-prepared products were characterized by X-ray powder diffraction(XRD),scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM),inductively coupled plasma atomic emission spectrometer(ICP-AES),UV-vis diffuse reflection spectroscopy and photoluminescence(PL) spectroscopy.The possible formation mechanism of Zn2GeO4 nanorods was discussed.It was supposed that the CTA+ cations preferentially adsorb on the planes of Zn2GeO4 nanorods,leading to preferential growth along the c-axis to form the Zn2GeO4 rods with larger aspect ratio and higher surface area,which showed the improved photocatalytic activity for photoreduction of CO2.The photoluminescence(PL) property of Zn2GeO4 nanorods was investigated through the emission spectra.
基金Supported by the Independent Innovation Fund of Tianjin University(No.1307)
文摘Because of the superior features of boron-10 isotope in absorbing hot neutrons, boric-10 acid(H310BO3)has been used widely in nuclear industry. Boric-10 acid is obtained from boron-10 trifluoride(10BF3) by esterification and hydrolyzation. In this study, trimethyl borate-10 [(CH3O)310B] was prepared from boron-10 trifluoride(10BF3)through chemical exchange rectification. In addition, the hydrolyzation of trimethyl borate-10 was investigated with different p H values, temperatures and molar ratios of water to trimethyl borate-10. Under the optimum process conditions, high yield of boric-10 acid with nuclear industrial purity grade was realized.
基金Project(CHCL0501) supported by Hubei Provincial Open Fund of Key Laboratory of Catalytic Material Science and Technology
文摘Mesoporous cerium-zirconium mixed oxides were prepared by hydrothermal method using cetyl trimethyl ammonium bromide (CTAB) as template. The effects of amount of template, pH value of solution and hydrothermal temperature on mesostructure of samples were systematically investigated. The final products were characterized by XRD, TEM, FT-IR, and BET. The results indicate that all the cerium-zirconium mixed oxides present a meso-structure. At molar ratio of n(CTAB)/n((Ce)+(Zr))= 0.15, pH value of 9, and hydrothermal temperature of 120 ℃, the samples obtained possess a specific surface area of 207.9 m2/g with pore diameter of 3.70 nm and pore volume of 0.19 cm3/g.
文摘The liquid membrane oscillation of a novel water （aqueous tetradecyl trimethyl ammoniumbromide, TTAB and alcohol solution）/oil （picric acid in chloroform solution）/water （aqueous glucose solution） system was investigated. By using homemade device, the curves of various liquid membranes oscillation with different concentration of TTAB and picric acid, types of alcohol and other organic solvents at different temperature were measured. The results show that the water （aqueous 7 mmol/L of TTAB and 0.5 mol/L of n-propanol solution）/oil （0.5 mmol/L of picric acid in chloroform solution）/water （aqueous glucose solution） system performed sustained and stable oscillation at 30 ℃. And the novel system can recognise added amino acid.
文摘Bipolar membrane electrodialysis(BMED) has already been described for the preparation of quaternary ammonium hydroxide. However, compared to quaternary ammonium hydroxide, di-quaternary ammonium hydroxide has raised great interest due to its high thermal stability and good oriented performance.In order to synthesize N,N-hexamethylenebis(trimethyl ammonium hydroxide)(HM(OH)_2) by EDBM,experiments designed by response surface methodology were carried out on the basis of single-factor experiments. The factors include current density, feed concentration and flow ratio of each compartment(feed compartment: base compartment: acid compartment: buffer compartment). The relationship between current efficiency and the above-mentioned three factors was quantitatively described by a multivariate regression model. According to the results, the feed concentration was the most significant factor and the optimum conditions were as follows: the current efficiency was up to 76.2%(the hydroxide conversion was over 98.6%), with a current density of 13.15 m A·cm^(-2), a feed concentration of 0.27 mol·L^(-1) and a flow ratio of 20 L·h^(-1):26 L·h^(-1):20 L·h^(-1):20 L·h^(-1) for feed compartment, base compartment, acid compartment, and intermediate compartment, respectively. This study demonstrates the optimized parameters of manufacturing HM(OH)_2 by direct splitting its halide for industrial application.
基金Supported by National Natural Science Foundation of China (30721063)National Basic Research Program of China (973 Program) (2005CB522402, 2006CB910403)+1 种基金National Laboratory of Medical Molecular Biology grant (2060204)Beijing municipal government grant (YB20081002301)
文摘Objective To study the regulatory mechanism of SATB1 repression in cells other than T cells or erythroid cells, which have high expression level of SATB1. Methods HeLa epithelial cells were treated with either histone deacetylase inhibitor (HDACi) trichostatin A (TSA) or DNA methylation inhibitor 5-Aza-C before detecting SATB1 expression. Luciferase reporter system was applied to measure effects of EZH2 on SATB1 promoter activity. Over-expression or knockdown of EZH2 and subsequent quantitative reverse transcription-polymerase chain reaction were performed to determine the effect of this Polycomb group protein on SATB1 transcription. Chromatin immunoprecipitation (ChIP) assay was applied to measure enrichment of EZH2 and trimethylated H3K27 (H3K27me3) at SATB1 promoter in HeLa cells. K562 cells and Jurkat cells, both having high-level expression of SATB1, were used in the ChIP experiment as controls. Results Both TSA and 5-Aza-C increased SATB1 expression in HeLa cells. Over-expression of EZH2 reduced promoter activity as well as the mRNA level of SATB1, while knockdown of EZH2 apparently enhanced SATB1 expression in HeLa cells but not in K562 cells and Jurkat cells. ChIP assay results suggested that epigenetic silencing of SATB1 by EZH2 in HeLa cells was mediated by trimethylation modification of H3K27. In contrast, enrichment of EZH2 and H3K27me3 was not detected within proximal promoter region of SATB1 in either K562 or Jurkat cells. Conclusion SATB1 is a bona fide EZH2 target gene in HeLa cells and the repression of SATB1 by EZH2 may be mediated by trimethylation modification on H3K27.
文摘An eco-friendly synthesis of cyclododecanone (CDON) from cyclododecatriene (CDT) is described. Selec- tive epoxidation of CDT with hydrogen peroxide using hexadecyl trimethyl ammonium heteropolyphospha- totungstate [(n-C16H33NMe3)3PW4O16, HAHPT] as catalyst and water as solvent followed by the hydrogena- tion on Raney nickel catalyst gave cyclododecanol (CDOL). The latter was oxidized with hydrogen peroxide using HAHPT as catalyst and a mixture of water and t-butanol as solvent to afford CDON. The total yield was 53.4% under the optimum reaction conditions.
基金Supported by the National Natural Science Foundation of China(21306088)National Key Technologies R&D Program of China(2015BAD15B07)+1 种基金State Key Laboratory of Chemical Engineering(SKL-Ch E-13A01,Tsinghua University,China)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD,China)
文摘A new kind of silicon-based biological lubricating base oil with good viscosity-temperature behavior,viscosity index,thermostability,oxidation stability and wear resistance performance was synthesized as a derivative of methyl oleate.Trimethylsilylation reaction was introduced to further improve methyl oleate oxidation stability and lubricity after epoxidation and open-ring reactions.The order of effectiveness of acid binding agent was N,N-diisopropylethylamine(DIEA) > pyridine > diethylamine > triethylamine,and the effects of various parameters on the trimethylsilylation reaction as well as on the silicon-oxygen bond stability and reaction yield were studied.A maximum yield of 34.54%was achieved at hydroxyl/trimethyl chlorosilane/DIEA molar ratio of1:1.25:1,reaction temperature 40℃,reaction time 1.5 h.
文摘The novel high-performance nanocomposites of polyaniline (PANI) and graphene oxide sheets (GOs) was synthesized via in situ polymerization in the presence of Hexadecyl trimethyl ammonium Bromide intercalated graphite oxide (CGO), basing on PANI and GOs as a matrix respectively. The result showed that ANI monomer was intercalated into the spacing of CGO, and the CGO was well exfoliated into nanosheets while polymerization. Owing to π–π electron stacking effect between the PANI and the GOs, the electrical conductivity of GOs/PANI nanocomposites (0.47 S/cm), which basing on PANI as a matrix, improved in comparison with pure PANI nanowires (0.02 S/cm) and GO (2.5×10-5 S/cm), while the electrical conductivity of PANI/GOs nanocomposites, which basing on GOs as a matrix, was only 6.2×10-3 S/cm. And it also indicated that the mole ratio of APS, the concentration of HCl, other with the polymerization time, are also important influencing factors of the conductivity of nanocomposites.
基金The project supported by a start-up grant from the National University of Singapore(R148000174133)
文摘OBJECTIVE To elucidate the structural-pharmacokinetic relationship and identify resveratrol analogs with favorable pharmacokinetic profiles for potential medicinal application. METHODS The pharmacokinetic data of resveratrol(trans-3,5,4-trihydroxystilbene),pterostilbene(trans-3,5-dimethoxy-4-hydroxystilbene),resveratrol trimethyl ether(trans-3,5,4-trimethoxystilbene)and some other herbal resveratrol analogs were extracted from the authors′recent publications and compared.RESULTS Aqueous solubility,to different extent,has been identified as a barrier to oral absorption of resveratrol and its analogs.In addition,the para hydroxyl group(s)on the aromatic ring was less liable to metabolism compared to the meta-hydroxyl group(s).Pterostilbene and resveratrol trimethyl ether displayed more superior pharmacokinetic properties than resveratrol,i.e.much slower clearance and abundant plasma exposure.CONCLUSION Pterostilbene appears to be a favorable candidate for further development.Resveratrol analogs with meta-hydroxyl group(s)might have poor metabolic stability and suffer from rapid clearance and low oral bioavailability.
基金Supported by the Open Research Fund of Shenzhen Key Laboratory of Functional Polymer,China
文摘The liquid membrane oscillation of a novel water（aqueous tetradecyl trimethyl ammoniumbromide,TTAB and alcohol solution）/oil（picric acid in chloroform solution）/water（aqueous glucose solution） system was investigated by means of a homemade device.The results show that the water（aqueous 7 mmol/L TTAB and 0.5 mol/L n-propanol solution）/oil（0.5 mmol/L icric acid in chloroform solution）/water（0.1 mol/L glucose solution） system performed sustained and stable oscillation at 30℃.The oscillation curve under optimized conditions is considered to be referent.Several oscillation curves were accumulated with the addition of different amino acids.The results showed that the novel system can recognize the added amino acids such as L-tryptophan,L-tyrosine,and D,L-tyrosine.And there is corresponding relationship between the change of curve shape and the quantity of amino acid added.
文摘Densities of methanol＋trimethyl phosphate binary mixtures were measured over a temperature range of （293.15 to 333.15）K at atmospheric pressure. From these data, excess molar volume（VE） was calculated. Viscosities of trimethyl phosphate were also measured over a temperature range of （283.15 to 373.15）K and the data were fitted to the Andrade equation. The density data were fitted to a second-order polynomial. The excess molar volumes were fitted to the Redlich-Kister equation using a nonlinear regression method. Results show that the density and viscosity gradually decreases with the increase of temperature.
