Mercury(Hg)ions can lead to a serious impact on the environment;therefore,it was necessary to find an effective method for absorbing these toxic Hg ions.Here,the adsorbent(Zn-AHMT)was synthesized from zinc nitrate and...Mercury(Hg)ions can lead to a serious impact on the environment;therefore,it was necessary to find an effective method for absorbing these toxic Hg ions.Here,the adsorbent(Zn-AHMT)was synthesized from zinc nitrate and 4-amino 3-hydrazine-5 mercapto-1,2,4-triazole(AHMT)by one-step method and,characterized the microstruc-ture and absorption performance by fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscopy(FESEM),X-ray diffraction(XRD),Brunauer-Emmett Teller(BET),Thermal Gravimetric Analyzer(TGA)and X-ray photoelectron spectroscopy(XPS).Through a plethora of measurements,we found that the maximum adsorption capacity was 802.8 mg/g when the optimal pH of Zn-AHMT was 3.0.The isothermal and kinetic experiments confirm that the reaction process of Zn-AHMT was chemisorption,while the adsorption process conforms to the Hill model and pseudo second order kinetic model.Thermodynamic experiments showed that the adsorption process was spontaneous and exothermic.Selective experiments were performed in the simulated wastewater containing Mn,Mg,Cr,Al,Co,Ni,Hg ions.Our results showed that the Zn-AHMT has a stronger affinity for Hg ions.The removal rate of Zn-AHMT remained above 98%,indicating that the Zn-AHMT had a good stability validated by three adsorption-desorption repeatable tests.According to the XPS results,the adsorption reaction of Zn-AHMT was mainly attributed to the chelation and ion exchange.This was further explained by both density functional theory(DFT)calculation and frontier molecular orbital theory.We therefore propose the adsorption mechanism of Zn-AHMT.The adsorption reaction facilitates via the synergistic action of S and N atoms.Moreover,the bonding between the adsorbent and the N atom has been proved to be more stable.Our study demonstrated that Zn-AHMT had a promising application prospect in mercury removal.展开更多
A novel adsorbent(MTZ-MOFs)was synthesized by a one-step reaction of zinc nitrate hexahydrate and 1-(2-dimethylaminoethyl)-1H-5-mercaptotetrazole to remove mercury from waste water.The results showed that MTZ-MOFs had...A novel adsorbent(MTZ-MOFs)was synthesized by a one-step reaction of zinc nitrate hexahydrate and 1-(2-dimethylaminoethyl)-1H-5-mercaptotetrazole to remove mercury from waste water.The results showed that MTZ-MOFs had excellent selectivity and repeatability for Hg(Ⅱ),the optimum pH was 3.0,the maximum adsorption capacity was 872.8 mg/g,and the process was a spontaneous exothermic reaction.The adsorption behavior was chemisorption,which conformed to the pseudo-second-order kinetic and Freundlich isothermal model.Moreover,the adsorption mechanism showed that the adsorption process mainly depended on ion exchange and chelation,and the synergistic action of S and N atoms played a key role.So,MTZ-MOFs were an efficient adsorbent for mercury ion removal.展开更多
An efficient regeneration system of Rhynchostylis retusa was established to provide technical reference for the application of tissue culture tube seedlings in production.The mixtures of callus and protocorm from asep...An efficient regeneration system of Rhynchostylis retusa was established to provide technical reference for the application of tissue culture tube seedlings in production.The mixtures of callus and protocorm from aseptic germination were used as explants.The optimal media of each stage was selected for callus proliferation,protocorm occurrence and growth,rejuvenation and rooting via a single,complete combination and orthogonal experiment.The results showed that the optimal medium for callus proliferation,protocorms occurrence and growth was 1/2 Murashige and Skoog(MS)medium adding 50 g·L^(−1) banana puree,0.1 mg·L^(−1)α-naphthaleneacetic acid(NAA),1.5 mg·L^(−1)6-benzylaminopurine(6-BA)and 1.0 mg·L^(−1) kinetin(KT)with 17.33 proliferation coefficient of callus and 19.63 occurrence coefficient of buds after 90 days.Then the buds occurred from protocorm were cultured on 1/2 MS medium including 100 g·L^(−1) banana puree,1.0 mg·L^(−1) NAA,2.0 mg·L^(−1)6-BA and 0.05 mg·L^(−1) KT,in which the proliferation coefficient of callus was 10.32 and occurrence coefficient of buds reached 17.87.In the further subculture,the same medium was simultaneously used for callus proliferation,protocorm occurrence and bud growth.The plantlets developed roots in 1/2 MS medium containing 70 mL·L^(−1) coconut water and 1.5 mg·L^(−1) NAA with 100%rooting rates after 90 days.The survival rate was more than 90%after domestication and transplantation.This regeneration protocol will provide technique foundation for protecting wild resource and developing artificial cultivation.展开更多
Nucleotide variants in cell type-specific gene regulatory elements in the human brain are risk factors for human disease.We measured chromatin accessibility in 1932 aliquots of sorted neurons and non-neurons from 616 ...Nucleotide variants in cell type-specific gene regulatory elements in the human brain are risk factors for human disease.We measured chromatin accessibility in 1932 aliquots of sorted neurons and non-neurons from 616 human postmortem brains and identified 34,539 open chromatin regions with chromatin accessibility quantitative trait loci(caQTLs).Only 10.4%of caQTLs are shared between neurons and non-neurons,which supports cell type-specific genetic regulation of the brain regulome.Incorporating allele-specific chromatin accessibility improves statistical fine-mapping and refines molecular mechanisms that underlie disease risk.Using massively parallel reporter assays in induced excitatory neurons,we screened 19,893 brain QTLs and identified the functional impact of 476 regulatory variants.Combined,this comprehensive resource captures variation in the human brain regulome and provides insights into disease etiology.展开更多
Transcription factors （TFs） are important regulators of gene expression. To better understand TFencoding genes in maize （Zea mays L.）, a genome-wide TF prediction was performed using the updated B73 reference geno...Transcription factors （TFs） are important regulators of gene expression. To better understand TFencoding genes in maize （Zea mays L.）, a genome-wide TF prediction was performed using the updated B73 reference genome. A total of 2 298 TF genes were identified, which can be classified into 56 families. The largest family, known as the MYB superfamily, comprises 322 MYB and MYB-related TF genes. The expression patterns of 2014 （87.64%） TF genes were examined using RNA-seq data, which resulted in the identification of a subset of TFs that are specifically expressed in particular tissues （including root, shoot, leaf, ear, tassel and kernel）. Similarly, 98 kernel-specific TF genes were further analyzed, and it was observed that 29 of the kernel-specific genes were preferentially expressed in the early kernel developmental stage, while 69 of the genes were expressed in the late kernel developmental stage. Identification of these TFs, particularly the tissue-specific ones, provides important information for the understanding of development and transcriptional regulation of maize.展开更多
We propose a simple quasi-continuous monolayer graphene structure and achieve a dynamically tunable triple plasmon-induced transparency(PIT)effect in the proposed structure.Additional analyses indicate that the propos...We propose a simple quasi-continuous monolayer graphene structure and achieve a dynamically tunable triple plasmon-induced transparency(PIT)effect in the proposed structure.Additional analyses indicate that the proposed structure contains a selfconstructed bright-dark-dark mode system.A uniform theoretical model is introduced to investigate the spectral response characteristics and slow light-effects in the proposed system,and the theoretical and the simulated results exhibit high consistency.In addition,the influences of the Fermi level and the carrier mobility of graphene on transmission spectra are discussed.It is found that each PIT window exhibits an independent dynamical adjustability owing to the quasi-continuity of the proposed structure.Finally,the slow-light effects are investigated based on the calculation of the group refractive index and phase shift.It is found that the structure displays excellent slow-light effects near the PIT windows with high-group indices,and the maximum group index of each PIT window exceeds 1000 when the carrier mobility of graphene increases to 3.5 m^2 V^-1s^-1.The proposed structure has potential to be used in multichannel filters,optical switches,modulators,and slow-light devices.Additionally,the established theoretical model lays a theoretical basis for research on multimode coupling effects.展开更多
基金the Hubei Provincial Department of Education Science and Technology Research Program Young Talent Project(Q20201102)the National Natural Science Foundation of China(51864042 and 51804220).
文摘Mercury(Hg)ions can lead to a serious impact on the environment;therefore,it was necessary to find an effective method for absorbing these toxic Hg ions.Here,the adsorbent(Zn-AHMT)was synthesized from zinc nitrate and 4-amino 3-hydrazine-5 mercapto-1,2,4-triazole(AHMT)by one-step method and,characterized the microstruc-ture and absorption performance by fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscopy(FESEM),X-ray diffraction(XRD),Brunauer-Emmett Teller(BET),Thermal Gravimetric Analyzer(TGA)and X-ray photoelectron spectroscopy(XPS).Through a plethora of measurements,we found that the maximum adsorption capacity was 802.8 mg/g when the optimal pH of Zn-AHMT was 3.0.The isothermal and kinetic experiments confirm that the reaction process of Zn-AHMT was chemisorption,while the adsorption process conforms to the Hill model and pseudo second order kinetic model.Thermodynamic experiments showed that the adsorption process was spontaneous and exothermic.Selective experiments were performed in the simulated wastewater containing Mn,Mg,Cr,Al,Co,Ni,Hg ions.Our results showed that the Zn-AHMT has a stronger affinity for Hg ions.The removal rate of Zn-AHMT remained above 98%,indicating that the Zn-AHMT had a good stability validated by three adsorption-desorption repeatable tests.According to the XPS results,the adsorption reaction of Zn-AHMT was mainly attributed to the chelation and ion exchange.This was further explained by both density functional theory(DFT)calculation and frontier molecular orbital theory.We therefore propose the adsorption mechanism of Zn-AHMT.The adsorption reaction facilitates via the synergistic action of S and N atoms.Moreover,the bonding between the adsorbent and the N atom has been proved to be more stable.Our study demonstrated that Zn-AHMT had a promising application prospect in mercury removal.
基金supported by the Hubei Provincial Department of Education Science and Technology Research Program Young Talent Project,China (No. Q20201102)the National Natural Science Foundation of China (Nos. 51864042, 51804220)
文摘A novel adsorbent(MTZ-MOFs)was synthesized by a one-step reaction of zinc nitrate hexahydrate and 1-(2-dimethylaminoethyl)-1H-5-mercaptotetrazole to remove mercury from waste water.The results showed that MTZ-MOFs had excellent selectivity and repeatability for Hg(Ⅱ),the optimum pH was 3.0,the maximum adsorption capacity was 872.8 mg/g,and the process was a spontaneous exothermic reaction.The adsorption behavior was chemisorption,which conformed to the pseudo-second-order kinetic and Freundlich isothermal model.Moreover,the adsorption mechanism showed that the adsorption process mainly depended on ion exchange and chelation,and the synergistic action of S and N atoms played a key role.So,MTZ-MOFs were an efficient adsorbent for mercury ion removal.
基金The research was supported by Yunnan Breeding and Cultivation Research and Development Center of Endangered and Daodi Chinese Medicinal Materials(No.2016DH011).
文摘An efficient regeneration system of Rhynchostylis retusa was established to provide technical reference for the application of tissue culture tube seedlings in production.The mixtures of callus and protocorm from aseptic germination were used as explants.The optimal media of each stage was selected for callus proliferation,protocorm occurrence and growth,rejuvenation and rooting via a single,complete combination and orthogonal experiment.The results showed that the optimal medium for callus proliferation,protocorms occurrence and growth was 1/2 Murashige and Skoog(MS)medium adding 50 g·L^(−1) banana puree,0.1 mg·L^(−1)α-naphthaleneacetic acid(NAA),1.5 mg·L^(−1)6-benzylaminopurine(6-BA)and 1.0 mg·L^(−1) kinetin(KT)with 17.33 proliferation coefficient of callus and 19.63 occurrence coefficient of buds after 90 days.Then the buds occurred from protocorm were cultured on 1/2 MS medium including 100 g·L^(−1) banana puree,1.0 mg·L^(−1) NAA,2.0 mg·L^(−1)6-BA and 0.05 mg·L^(−1) KT,in which the proliferation coefficient of callus was 10.32 and occurrence coefficient of buds reached 17.87.In the further subculture,the same medium was simultaneously used for callus proliferation,protocorm occurrence and bud growth.The plantlets developed roots in 1/2 MS medium containing 70 mL·L^(−1) coconut water and 1.5 mg·L^(−1) NAA with 100%rooting rates after 90 days.The survival rate was more than 90%after domestication and transplantation.This regeneration protocol will provide technique foundation for protecting wild resource and developing artificial cultivation.
文摘Nucleotide variants in cell type-specific gene regulatory elements in the human brain are risk factors for human disease.We measured chromatin accessibility in 1932 aliquots of sorted neurons and non-neurons from 616 human postmortem brains and identified 34,539 open chromatin regions with chromatin accessibility quantitative trait loci(caQTLs).Only 10.4%of caQTLs are shared between neurons and non-neurons,which supports cell type-specific genetic regulation of the brain regulome.Incorporating allele-specific chromatin accessibility improves statistical fine-mapping and refines molecular mechanisms that underlie disease risk.Using massively parallel reporter assays in induced excitatory neurons,we screened 19,893 brain QTLs and identified the functional impact of 476 regulatory variants.Combined,this comprehensive resource captures variation in the human brain regulome and provides insights into disease etiology.
基金supported by the National Basic Research Program of China (973 Program: 2009CB118400)
文摘Transcription factors （TFs） are important regulators of gene expression. To better understand TFencoding genes in maize （Zea mays L.）, a genome-wide TF prediction was performed using the updated B73 reference genome. A total of 2 298 TF genes were identified, which can be classified into 56 families. The largest family, known as the MYB superfamily, comprises 322 MYB and MYB-related TF genes. The expression patterns of 2014 （87.64%） TF genes were examined using RNA-seq data, which resulted in the identification of a subset of TFs that are specifically expressed in particular tissues （including root, shoot, leaf, ear, tassel and kernel）. Similarly, 98 kernel-specific TF genes were further analyzed, and it was observed that 29 of the kernel-specific genes were preferentially expressed in the early kernel developmental stage, while 69 of the genes were expressed in the late kernel developmental stage. Identification of these TFs, particularly the tissue-specific ones, provides important information for the understanding of development and transcriptional regulation of maize.
基金supported by the National Natural Science Foundation of China(Grant No.61275174)the Natural Science Foundation of Hunan Province(Grant No.2019JJ50147)the Fundamental Research Funds for the Central Universities of Central South University(Grant No.2018zzts105)。
文摘We propose a simple quasi-continuous monolayer graphene structure and achieve a dynamically tunable triple plasmon-induced transparency(PIT)effect in the proposed structure.Additional analyses indicate that the proposed structure contains a selfconstructed bright-dark-dark mode system.A uniform theoretical model is introduced to investigate the spectral response characteristics and slow light-effects in the proposed system,and the theoretical and the simulated results exhibit high consistency.In addition,the influences of the Fermi level and the carrier mobility of graphene on transmission spectra are discussed.It is found that each PIT window exhibits an independent dynamical adjustability owing to the quasi-continuity of the proposed structure.Finally,the slow-light effects are investigated based on the calculation of the group refractive index and phase shift.It is found that the structure displays excellent slow-light effects near the PIT windows with high-group indices,and the maximum group index of each PIT window exceeds 1000 when the carrier mobility of graphene increases to 3.5 m^2 V^-1s^-1.The proposed structure has potential to be used in multichannel filters,optical switches,modulators,and slow-light devices.Additionally,the established theoretical model lays a theoretical basis for research on multimode coupling effects.
