Following the publication of Xu et al.(2022),an error was identified in Figure 1D.Specifically,the top left panel was inadvertently duplicated during figure preparation.To ensure the accuracy and integrity of our publ...Following the publication of Xu et al.(2022),an error was identified in Figure 1D.Specifically,the top left panel was inadvertently duplicated during figure preparation.To ensure the accuracy and integrity of our published work,we request the publication of a corrigendum with the corrected image.We apologize for this oversight and any confusion it may have caused.The amended figure is provided in the updated Supplementary Materials.展开更多
An efficient synthesis of substituted 1,4-diazepines is developed.The accessible intermediates have been obtained via Pd-catalyzed amination.The subsequent hydrogenation and intramolecular condensation sequences could...An efficient synthesis of substituted 1,4-diazepines is developed.The accessible intermediates have been obtained via Pd-catalyzed amination.The subsequent hydrogenation and intramolecular condensation sequences could be conducted successively in one pot without special operation.The mild and general strategy enables the synthesis of various substituted 1,4-diazepines in high yields.展开更多
Cell division and differentiation after egg fertilization are critical steps in the development of embryos from single cells to multicellular individuals and are regulated by DNA methylation via its effects on gene ex...Cell division and differentiation after egg fertilization are critical steps in the development of embryos from single cells to multicellular individuals and are regulated by DNA methylation via its effects on gene expression.However,the mechanisms by which DNA methylation regulates these processes in insects remain unclear.Here,we studied the impacts of DNA methylation on early embryonic development in Bombyx mori.Genome methylation and transcriptome analysis of early embryos showed that DNA methylation events mainly occurred in the 5'region of protein metabolism-related genes.The transcription factor gene zinc finger protein 615(ZnF615)was methylated by DNA methyltransferase 1(Dnmt1)to be up-regulated and bind to protein metabolism-related genes.Dnmt1 RNA interference(RNAi)revealed that DNA methylation mainly regulated the expression of nonmethylated nutrient metabolism-related genes through ZnF615.The same sites in the ZnF615 gene were methylated in ovaries and embryos.Knockout of ZnF615 using CRISPR/Cas9 gene editing decreased the hatching rate and egg number to levels similar to that of Dnmt1 knockout.Analysis of the ZnF615 methylation rate revealed that the DNA methylation pattern in the parent ovary was maintained and doubled in the offspring embryo.Thus,Dnmt1-mediated intragenic DNA methylation of the transcription factor ZnF615 enhances its expression to ensure ovarian and embryonic development.展开更多
An efficient method for mono-phosphorylation of 2 （KRP203） using cbz-protection, dibenzylphosphoryl chloride and TMSI affording 2-P （KRP203-P） was developed. We applied the present method to the synthesis of KRP20...An efficient method for mono-phosphorylation of 2 （KRP203） using cbz-protection, dibenzylphosphoryl chloride and TMSI affording 2-P （KRP203-P） was developed. We applied the present method to the synthesis of KRP203 phosphate analogs which were difficult to produce through tradition procedures.展开更多
A one pot protocol for the synthesis of dibenzodiazepinones was developed. The substituted ethyl 2- halobenzoates are cross-coupled with o-phenylenediamine utilizing a ligand-free, Cul catalyzed system, which spontane...A one pot protocol for the synthesis of dibenzodiazepinones was developed. The substituted ethyl 2- halobenzoates are cross-coupled with o-phenylenediamine utilizing a ligand-free, Cul catalyzed system, which spontaneously undergo an intramolecular N-acylation in ethylene glycol to give the corresponding products in high yields. This synthetic protocol provides a concise and efficient access to a wide variety of dibenzodiazepinone, including biologically active molecules.展开更多
The distribution of nuclei produced in the^(40)Ar+^(232)Th reaction has been studied at the gas-filled recoil separator(SHANS2)at the China Accelerator Facility for Superheavy Elements(CAFE2).The bombardment was carri...The distribution of nuclei produced in the^(40)Ar+^(232)Th reaction has been studied at the gas-filled recoil separator(SHANS2)at the China Accelerator Facility for Superheavy Elements(CAFE2).The bombardment was carried out at a beam energy of 205 MeV with the detection system installed at the focal plane.Forty-four isotopes heavier than 208Pb were observed.These isotopes were identified as the transfer reaction(or target-like)products,and their relative cross-sections were extracted.Based on the mass distribution of these products,we exclude the possibility that they were produced by fusion-fission reactions;thus,they may originate from quasi-fission of the^(40)Ar+^(232)Th reaction.展开更多
Methyl-CpG(mCpG)binding domain(MBD)proteins especially bind with methylated DNA,and are involved in many important biological processes;however,the binding mechanism between insect MBD2/3 and mCpG remains unclear.In t...Methyl-CpG(mCpG)binding domain(MBD)proteins especially bind with methylated DNA,and are involved in many important biological processes;however,the binding mechanism between insect MBD2/3 and mCpG remains unclear.In this study,we identified 2 isoforms of the MBD2/3 gene in Bombyx mori,MBD2/3-S and MBD2/3-L.Binding analysis of MBD2/3-L,MBD2/3-S,and 7 mutant MBD2/3-L proteins deficient inβ1−β6 orα1 in the MBD showed thatβ2−β3-turns in theβ-sheet of the MBD are necessary for the formation of the MBD2/3–mCpG complex;furthermore,other secondary structures,namely,β4−β6 and anα-helix,play a role in stabilizing theβ-sheet structure to ensure that the MBD is able to bind mCpG.In addition,sequence alignment and binding analyses of different insect MBD2/3s indicated that insect MBD2/3s have an intact and conserved MBD that binds to the mCpG of target genes.Furthermore,MBD2/3 RNA interference results showed that MBD2/3-L plays a role in regulating B.mori embryonic development,similar to that of DNA methylation;however,MBD2/3-S withoutβ4−β6 andα-helix does not alter embryonic development.These results suggest that MBD2/3-L recognizes and binds to mCpG through the intactβ-sheet structure in its MBD,thus ensuring silkworm embryonic development.展开更多
DNA methylation and transcription factors play roles in gene expression and animal development.In insects,DNA methylation modifies gene bodies,but how DNA methylation and transcription factors regulate gene expression...DNA methylation and transcription factors play roles in gene expression and animal development.In insects,DNA methylation modifies gene bodies,but how DNA methylation and transcription factors regulate gene expression is unclear.In this study,we investigated the mechanism that regulates the expression of Bombyx mori Zinc finger pro-tein 615(ZnF 615),which is a downstream gene of DNA methyltransferase 1(Dnmt1),and its effects on the regulation of embryonic development.By progressively truncating the ZnF 615 promoter,it was found that the-223 and-190 nt region,which contains homeobox(Hox)protein cis-regulatory elements(CREs),had the greatest impact on the transcription of ZnF 615.RNA interference(RNAi)-mediated knockdown and overexpres-sion of Hox family genes showed that Hox A1-like can enhance the messenger RNA level of ZnF 615.Further studies showed that Hox A1-like regulates ZnF 615 expression by directly binding to the-223 and-190 nt region of its promoter.Simultaneous RNAi-mediated knockdown or overexpression of Hox A1-like and Dnmtl significantly inhibited or enhanced the regulatory effect of either gene alone on ZnF 615 expression,suggesting that both DNA methylation of gene bodies and binding of transcription factors to pro-moters are essential for gene expression.RNAi-mediated knockdown of Hox A1-like and Dnmtl showed that the embryonic development was retarded and the hatching rate was decreased.Taken together,these data suggest that Hox A1-like and DNA methylation en-hance the expression of ZnF 615,thereby affecting the development of B.mori embryos.展开更多
Purpose We are building an MRTOF-MS(multi-reflection time-of-flight mass spectrometer)for isobaric separation for the Lanzhou Penning Trap.The potentials applied on the electrodes of our MRTOF mass analyzer operating ...Purpose We are building an MRTOF-MS(multi-reflection time-of-flight mass spectrometer)for isobaric separation for the Lanzhou Penning Trap.The potentials applied on the electrodes of our MRTOF mass analyzer operating in in-trap-lift mode have to be optimized to achieve a very high mass resolving power.Methods Our method to design and optimize an MRTOF mass analyzer has been updated to introduce constraints on the potentials,and this method now can be used to optimize the parameters of MRTOF-MS both operating in mirror-switching mode and in in-trap-lift mode.By using this method,the optimal potential parameters of the electrodes have been obtained for our MRTOF mass analyzer operating in the in-trap-lift mode.Results and conclusion With a beam size of 2.8 mm diameter and an initial average ion kinetic energy of 1500 eV,the maximal mass resolving power has been achieved to be 3.2×10^(4) with a total TOF of 7.0 ms for an ion species of ^(40)Ar^(1+).It can reach up to 5.6×10^(4) for a beam size of 0.3 mm diameter.The simulation shows that the inaccuracy of the potentials applied on the outermost mirror electrodes M1–M2 must be less than 50 ppm or preferably 20 ppm.展开更多
文摘Following the publication of Xu et al.(2022),an error was identified in Figure 1D.Specifically,the top left panel was inadvertently duplicated during figure preparation.To ensure the accuracy and integrity of our published work,we request the publication of a corrigendum with the corrected image.We apologize for this oversight and any confusion it may have caused.The amended figure is provided in the updated Supplementary Materials.
基金supported by National Natural Science Foundation of China(No.81102322)
文摘An efficient synthesis of substituted 1,4-diazepines is developed.The accessible intermediates have been obtained via Pd-catalyzed amination.The subsequent hydrogenation and intramolecular condensation sequences could be conducted successively in one pot without special operation.The mild and general strategy enables the synthesis of various substituted 1,4-diazepines in high yields.
基金supported by the National Natural Science Foundation of China(31872286,32100374)。
文摘Cell division and differentiation after egg fertilization are critical steps in the development of embryos from single cells to multicellular individuals and are regulated by DNA methylation via its effects on gene expression.However,the mechanisms by which DNA methylation regulates these processes in insects remain unclear.Here,we studied the impacts of DNA methylation on early embryonic development in Bombyx mori.Genome methylation and transcriptome analysis of early embryos showed that DNA methylation events mainly occurred in the 5'region of protein metabolism-related genes.The transcription factor gene zinc finger protein 615(ZnF615)was methylated by DNA methyltransferase 1(Dnmt1)to be up-regulated and bind to protein metabolism-related genes.Dnmt1 RNA interference(RNAi)revealed that DNA methylation mainly regulated the expression of nonmethylated nutrient metabolism-related genes through ZnF615.The same sites in the ZnF615 gene were methylated in ovaries and embryos.Knockout of ZnF615 using CRISPR/Cas9 gene editing decreased the hatching rate and egg number to levels similar to that of Dnmt1 knockout.Analysis of the ZnF615 methylation rate revealed that the DNA methylation pattern in the parent ovary was maintained and doubled in the offspring embryo.Thus,Dnmt1-mediated intragenic DNA methylation of the transcription factor ZnF615 enhances its expression to ensure ovarian and embryonic development.
基金financially supported by National Natural Science Foundation of China(No.81102322)
文摘An efficient method for mono-phosphorylation of 2 （KRP203） using cbz-protection, dibenzylphosphoryl chloride and TMSI affording 2-P （KRP203-P） was developed. We applied the present method to the synthesis of KRP203 phosphate analogs which were difficult to produce through tradition procedures.
基金National Natural Science Foundation of China(No.81102322)the Global Alliance for TB Drug Development(TB alliance)for their financial supports
文摘A one pot protocol for the synthesis of dibenzodiazepinones was developed. The substituted ethyl 2- halobenzoates are cross-coupled with o-phenylenediamine utilizing a ligand-free, Cul catalyzed system, which spontaneously undergo an intramolecular N-acylation in ethylene glycol to give the corresponding products in high yields. This synthetic protocol provides a concise and efficient access to a wide variety of dibenzodiazepinone, including biologically active molecules.
基金Supported by the Gansu Key Project of Science and Technology(23ZDGA014)the National Key R&D Program of China(2023YFA1606500)+5 种基金the Guangdong Major Project of Basic and Applied Basic Research(2021B0301030006)the CAS Project for Young Scientists in Basic Research(YSBR-002)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2023439,2020409)the National Natural Science Foundation of China(12365016)the National Key Research and Development Program of China(2024YFE0110400,W2412040)the Natural Science Foundation of Guangxi(2023GXNSFAA026016)。
文摘The distribution of nuclei produced in the^(40)Ar+^(232)Th reaction has been studied at the gas-filled recoil separator(SHANS2)at the China Accelerator Facility for Superheavy Elements(CAFE2).The bombardment was carried out at a beam energy of 205 MeV with the detection system installed at the focal plane.Forty-four isotopes heavier than 208Pb were observed.These isotopes were identified as the transfer reaction(or target-like)products,and their relative cross-sections were extracted.Based on the mass distribution of these products,we exclude the possibility that they were produced by fusion-fission reactions;thus,they may originate from quasi-fission of the^(40)Ar+^(232)Th reaction.
基金funded by the National Natural Sci-ence Foundation of China,grant numbers 32100374 and 31872286.
文摘Methyl-CpG(mCpG)binding domain(MBD)proteins especially bind with methylated DNA,and are involved in many important biological processes;however,the binding mechanism between insect MBD2/3 and mCpG remains unclear.In this study,we identified 2 isoforms of the MBD2/3 gene in Bombyx mori,MBD2/3-S and MBD2/3-L.Binding analysis of MBD2/3-L,MBD2/3-S,and 7 mutant MBD2/3-L proteins deficient inβ1−β6 orα1 in the MBD showed thatβ2−β3-turns in theβ-sheet of the MBD are necessary for the formation of the MBD2/3–mCpG complex;furthermore,other secondary structures,namely,β4−β6 and anα-helix,play a role in stabilizing theβ-sheet structure to ensure that the MBD is able to bind mCpG.In addition,sequence alignment and binding analyses of different insect MBD2/3s indicated that insect MBD2/3s have an intact and conserved MBD that binds to the mCpG of target genes.Furthermore,MBD2/3 RNA interference results showed that MBD2/3-L plays a role in regulating B.mori embryonic development,similar to that of DNA methylation;however,MBD2/3-S withoutβ4−β6 andα-helix does not alter embryonic development.These results suggest that MBD2/3-L recognizes and binds to mCpG through the intactβ-sheet structure in its MBD,thus ensuring silkworm embryonic development.
基金funded by the National Natural Science Foundation of China,grant numbers 32100374 and 31872286the China Postdoctoral Science Foundation,grant number 2020M682750.
文摘DNA methylation and transcription factors play roles in gene expression and animal development.In insects,DNA methylation modifies gene bodies,but how DNA methylation and transcription factors regulate gene expression is unclear.In this study,we investigated the mechanism that regulates the expression of Bombyx mori Zinc finger pro-tein 615(ZnF 615),which is a downstream gene of DNA methyltransferase 1(Dnmt1),and its effects on the regulation of embryonic development.By progressively truncating the ZnF 615 promoter,it was found that the-223 and-190 nt region,which contains homeobox(Hox)protein cis-regulatory elements(CREs),had the greatest impact on the transcription of ZnF 615.RNA interference(RNAi)-mediated knockdown and overexpres-sion of Hox family genes showed that Hox A1-like can enhance the messenger RNA level of ZnF 615.Further studies showed that Hox A1-like regulates ZnF 615 expression by directly binding to the-223 and-190 nt region of its promoter.Simultaneous RNAi-mediated knockdown or overexpression of Hox A1-like and Dnmtl significantly inhibited or enhanced the regulatory effect of either gene alone on ZnF 615 expression,suggesting that both DNA methylation of gene bodies and binding of transcription factors to pro-moters are essential for gene expression.RNAi-mediated knockdown of Hox A1-like and Dnmtl showed that the embryonic development was retarded and the hatching rate was decreased.Taken together,these data suggest that Hox A1-like and DNA methylation en-hance the expression of ZnF 615,thereby affecting the development of B.mori embryos.
基金Supported by the National Natural Science Foundation of China(Grant Nos:11675224,11405243,11605268,11735017)the Chinese Academy of Sciences(No.113462KYSB20150026,QYZDJ-SSW-SLH041)the National Basic Research Program of China(973 Program)(No.2013CB834400).
文摘Purpose We are building an MRTOF-MS(multi-reflection time-of-flight mass spectrometer)for isobaric separation for the Lanzhou Penning Trap.The potentials applied on the electrodes of our MRTOF mass analyzer operating in in-trap-lift mode have to be optimized to achieve a very high mass resolving power.Methods Our method to design and optimize an MRTOF mass analyzer has been updated to introduce constraints on the potentials,and this method now can be used to optimize the parameters of MRTOF-MS both operating in mirror-switching mode and in in-trap-lift mode.By using this method,the optimal potential parameters of the electrodes have been obtained for our MRTOF mass analyzer operating in the in-trap-lift mode.Results and conclusion With a beam size of 2.8 mm diameter and an initial average ion kinetic energy of 1500 eV,the maximal mass resolving power has been achieved to be 3.2×10^(4) with a total TOF of 7.0 ms for an ion species of ^(40)Ar^(1+).It can reach up to 5.6×10^(4) for a beam size of 0.3 mm diameter.The simulation shows that the inaccuracy of the potentials applied on the outermost mirror electrodes M1–M2 must be less than 50 ppm or preferably 20 ppm.
