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Sensing of cytoplasmic chromatin by cGAS activates innate immune response in SARS-CoV-2 infection

Signal Transduction and Targeted Therapy 2021年第12期6卷 3653-3665页

作者： Zhuo Zhou Xinyi Zhang Xiaobo Lei Xia Xiao Tao Jiao Ruiyi Ma Xiaojing Dong Qi Jiang Wenjing Wang Yujin Shi Tian Zheng Jian Rao Zichun Xiang Lili Ren Tao Deng Zhengfan Jiang Zhixun Dou Wensheng Wei Jianwei Wang Biomedical Pioneering Innovation Center Beijing Advanced Innovation Center for GenomicsPeking-Tsinghua Center for Life SciencesPeking University Genome Editing Research CenterState Key Laboratory of Protein and Plant Gene ResearchSchool of Life SciencesPeking UniversityBeijingChina NHC Key Laboratory of Systems Biology of Pathogens Institute of Pathogen BiologyChinese Academy of Medical Sciences and Peking Union Medical College100730 BeijingP.R.China Key Laboratory of Respiratory Disease Pathogenomics Chinese Academy of Medical Sciences and Peking Union Medical College100730 BeijingP.R.China Christophe Merieux Laboratory Institute of Pathogen BiologyChinese Academy of Medical Sciences and Peking Union Medical College100730 BeijingP.R.China CAS Key Laboratory of Pathogenic Microbiology and Immunology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education School of Life SciencesPseking UniversityBeijing 100871China Peking-Tsinghua Center for Life Sciences Peking UniversityBeijing 100871China Center for Regenerative Medicine Massachusetts General HospitalBostonMAUSA Harvard Stem Cell Institute Harvard UniversityCambridgeMAUSA Department of Medicine Massachusetts General HospitalHarvard Medical SchoolBostonMAUSA

The global coronavirus disease 2019(COVID-19)pandemic is caused by severe acute respiratory syndrome coronavirus 2(SARSCoV-2),a positive-sense RNA virus.How the host immune system senses and responds to SARS-CoV-2 infection remain largely unresolved.Here,we report that SARS-CoV-2 infection activates the innate immune response through the cytosolic DNA sensing cGAS-STING pathway.SARS-CoV-2 infection induces the cellular level of 2′3′-cGAMP associated with STING activation.cGAS recognizes chromatin DNA shuttled from the nucleus as a result of cell-to-cell fusion upon SARS-CoV-2 infection.We further demonstrate that the expression of spike protein from SARS-CoV-2 and ACE2 from host cells is sufficient to trigger cytoplasmic chromatin upon cell fusion.Furthermore,cytoplasmic chromatin-cGAS-STING pathway,but not MAVS-mediated viral RNA sensing pathway,contributes to interferon and pro-inflammatory gene expression upon cell fusion.Finally,we show that cGAS is required for host antiviral responses against SARS-CoV-2,and a STING-activating compound potently inhibits viral replication.Together,our study reported a previously unappreciated mechanism by which the host innate immune system responds to SARS-CoV-2 infection,mediated by cytoplasmic chromatin from the infected cells.Targeting the cytoplasmic chromatin-cGAS-STING pathway may offer novel therapeutic opportunities in treating COVID-19.In addition,these findings extend our knowledge in host defense against viral infection by showing that host cells’self-nucleic acids can be employed as a“danger signal”to alarm the immune system.

关键词： infection Together cGAS

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Nitrogen reduction reaction on small iron clusters supported by N-doped graphene:A theoretical study of the atomically precise active-site mechanism

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Nano Research 2020年第8期13卷 2280-2288页

作者： Chaonan Cui Hongchao Zhang zhixun Luo Beijing National Laboratory for Molecular Sciences(BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesInstitute of ChemistryChinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China

Nonprecious metal catalysts are known of significance for electrochemical N2 reduction reaction(NRR)of which the mechanism has been illustrated by ongoing investigations of single atom catalysis.However,it remains challenging to fully understand the size-dependent synergistic effect of active sites inherited in substantial nanocatalysts.In this work,four types of small iron clusters Fen(n=1–4)supported on nitrogen-doped graphene sheets are constructed to figure out the size dependence and synergistic effect of active sites for NRR catalytic activities.It is revealed that Fe3 and Fe4 clusters on N4G supports exhibit higher NRR activity than single-iron atom and iron dimer clusters,showing lowered limiting potential and restricted hydrogen evolution reaction(HER)which is a competitive reaction channel.In particular,the Fe4-N4G displays outstanding NRR performance for“side-on”adsorption of N2 with a small limiting potential(−0.45 V).Besides the specific structure and strong interface interaction within the Fe4-N4G itself,the high NRR activity is associated with the unique bonding/antibonding orbital interactions of N-N and N-Fe for the adsorptive N2 and NNH intermediates,as well as relatively large charge transfer between N2 and the cluster Fe4-N4G.

关键词： N2 reduction reaction(NRR) iron clusters cluster catalysis active-site mechanism density functional theory(DFT)

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Transient flameout process of boron-magnesium agglomerates during combustion in oxygen-rich atmospheres

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Particuology 2024年第5期88卷 290-301页

作者： Lian Duan zhixun Xia Yunchao Feng Binbin Chen Likun Ma Jianxin Hu College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China School of Mechanical Engineering and Mechanics Xiangtan UniversityXiangtan 411105China

In this study,boron–magnesium agglomerates with varying mass ratios were prepared by drying a micron-sized boron–magnesium mixed suspension,and the combustion process of these agglomerates under different oxygen-rich concentrations were investigated using a laser ignition system.The test results showed that when the mass fraction of magnesium powder in boron-magnesium agglomerates exceeded a certain threshold(between 2%and 5%),flame extinction and reignition occurred after a significant reduction in the agglomerate volume during combustion.This process is referred to as the transient flameout process,which is affected by the magnesium content of the agglomerate and the oxygen concentration in the ambient atmosphere.An increase in the magnesium content or oxygen concentration makes this phenomenon more pronounced.During weakening of the flame intensity,a dark film gradually covered the particle surfaces.X-ray diffraction and elemental analyses of the cross-section and outer surface of the condensed combustion product suggested that the dark film is primarily composed of Mg-B-O ternary oxides.This film prevents direct contact between boron and oxygen,thereby inhibiting surface and gas-phase reactions and leading to the occurrence of the transient flameout phenomenon.

关键词： Agglomerated particle Boron–magnesium fuel Boron combustion Transient flameout process Solid fuel ramjet

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反思民事诉讼中对立案证据的要求

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法学 2024年第1期 141-157页

作者：曹志勋北京大学法学院

虽然历经改革努力与修法,立案审查问题及“立案难”现象仍然存在。我国现行法和司法实践通常要求原告在起诉时提供相关证据,但是其具体标准并不明确。包括“预立案”现象在内的司法实践对立案证据的重视有多重理由。对立案证据的要求与... 详细信息

虽然历经改革努力与修法,立案审查问题及“立案难”现象仍然存在。我国现行法和司法实践通常要求原告在起诉时提供相关证据,但是其具体标准并不明确。包括“预立案”现象在内的司法实践对立案证据的重视有多重理由。对立案证据的要求与我国现行法和立案登记制改革的大方向存在张力,无法在立案阶段完成要件化的改造,两大法系的共通经验也不包括这一要求。对立案证据的要求也不符合民事诉讼中立案前后阶段的分工,法院更应当在立案且送达后收集证据并据此审查诉讼要件。证据调查在庭审结构中的位置与证据调查的直接原则也反对对立案证据的要求。不过,在涉及纯粹程序性事项和与公益相关的特别规则时,应当例外地承认立案证据要求。

关键词：立案审查立案登记诉讼要件被告答辩证据调查

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The reactivity of O_(2) with copper cluster anions Cu_(n)^(-)(n = 7-20):Leveling effect of spin accommodation

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Chinese Chemical Letters 2022年第2期33卷 995-1000页

作者： Qiuying Du Baoqi Yin Si Zhou zhixun Luo Jijun Zhao Key laboratory of Material Modiﬁcation by Laser Ion and Electron Beams(Dalian University of Technology)Ministry of EducationDalian 116024China Beijing National Laboratory for Molecular Sciences(BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China

The activation of molecular oxygen is an important step in metal-catalyzed oxidation reactions and a hot subject for the research of gas-phase metal clusters.It is known that the Ag and Au clusters readily re-act with O_(2)when they have open shell electronic structures.Distinct from this,here we observed Cu_(n)^(-)(n=7−20)clusters of both open and closed shells possess high reactivity with O_(2)with few exceptions.In a combination with ab initio calculations,we demonstrate that the activation of O_(2)on the even-and odd-sized Cu_(n)^(-)clusters follows the single and double electron transfer models,respectively.Such phe-nomenon of metal clusters with different basicity to activate oxygen is enabled by the leveling effect of spin accommodation.The activity of Cu_(n)^(-)clusters is correlated to the HOMO level,and for the close-shell clusters is also governed by the vertical spin excitation energy(VSE).In encountering the attack of dioxygen,the activity of the copper cluster anions not only depends on their basicity to donate electrons,but also closely associated with the cluster sizes.Small copper clusters Cu_(n)^(-)(n=7−13)can dissociate O_(2)spontaneously,while large clusters require extra energies and display close relationship between the reaction rates and electronic vertical detachment energies(VDE).Our work illuminates a novel reaction mechanism between Cu_(n)^(-)clusters and O_(2),which sheds light in manipulating the activity and stability of coinage clusters by controlling the spin and charge states.

关键词： Copper cluster Mass spectrometry Ab initio O_(2)adsorption O_(2)dissociation Leveling effect Spin accommodation

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Ligand accommodation causes altered reactivity of silver clusters with iodomethane:superatomic stability of Ag_(9)I_(2)^(+)in mimicking XeF_(2)

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Science China Chemistry 2022年第8期65卷 1594-1600页

作者： Haiming Wu Mengzhou Yang Benben Huang Wen Gan zhixun Luo Beijing National Laboratory for Molecular Sciences(BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Exploring metal cluster reactivity with alkyl halides enables to understand the related chemical mechanism of metal surfaces in terms of active sites.Here we report a study of Ag_(n)^(+)(n=1-27)clusters reacting with iodomethane by a flow tube apparatus in tandem with a customized triple quadrupole mass spectrometer.Strong even/odd alternation of the Ag_(n)^(+)is observed in their reactions with CH_(3)I,where silver clusters with even-number,Ag_(2n)^(+),find favorable products of Ag_(2n)I_(1,3)^(+)series,while the Ag_(2n−1)^(+)clusters form Ag_(2n−1)I_(2,4)^(+)products.Interestingly,Ag_(9)^(+)shows up with prominent mass abundance but allows for the formation of Ag_(9)I_(2)^(+),which finds an echo with the formation of Ag_(10)I_(3)^(+).We illustrate the enhanced stability of Ag_(9)I_(2)^(+)and Ag_(10)I_(3)^(+)by showing their significantly enlarged highest occupied molecular orbital(HOMO)-lowest unoccupied molecular orbital(LUMO)gaps and balanced charge distribution compared with the bare metal clusters,respectively.Also elucidated,is the superatomic nature of these bare and iodinated silver clusters,especially Ag_(9)I_(2)^(+)which mimics the rare-gas compound XeF_(2).This study expands a vivid example of special and general superatoms,and enriches the general knowledge on how a ligand stabilizes a metal cluster.

关键词： metal cluster superatom halide superatomic complex gas-phase reaction

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Plasma-Assisted Dinitrogen Activation via Dual Platinum Cluster Catalysis:A Strategy for Ammonia Synthesis under Mild Conditions

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CCS Chemistry 2023年第3期5卷 682-694页

作者： Chaonan Cui Yuhan Jia Hanyu Zhang Lijun Geng zhixun Luo Beijing National Laboratory for Molecular Sciences(BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesInstitute of ChemistryChinese Academy of SciencesBeijing 100190 University of Chinese Academy of Sciences Beijing 100049

The activation and reduction of N_(2)to produce ammonia under mild conditions is of great interest,but challenges remain.Here,we report a breakthrough in efficient dinitrogen cleavage by employing small Ptn+(n=1–4)clusters and convenient plasma assistance.The reactivity of Pt3+is found to be substantially higher than that of other clusters,and the formed Pt3N7+shows prominent mass abundance among the odd-nitrogen products.We illustrate that a chain reaction path within dual cluster cooperation,especially via a“3+2”mode,is beneficial to N≡N triple bond dissociation,embodying efficient synergistic catalysis.A key intermediate containing a bridged N_(2)of binding with two Pt clusters facilitates N_(2)activation with significantly enhanced interactions between the d orbitals of Pt and the antibondingπ*-orbitals of N_(2).Furthermore,by reacting the Pt_(n)N_(m)+clusters with H_(2),we observed hydrogenation products of both evenand odd-hydrogen species,indicative of ammonia release.The in situ synthesized platinum nitride clusters,typically Pt_(3)N_(7)+,induce a highly active N site for hydrogen anchoring,enabling a cost-effective hydrotreating process for ammonia synthesis.

关键词： dual-metal cluster nitrogen activation ammonia synthesis platinum nitride clusters plasma-assistance

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论民事给付之诉及其执行的明确性要求

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华东政法大学学报 2023年第2期26卷 134-151页

作者：曹志勋北京大学法学院

无论给付的内容是金钱、特定物还是行为,给付之诉内容的确定与相应的判决与执行在民事诉讼中都具有重要意义。现行法要求起诉状中的给付诉讼请求和给付判决主文都应当具有明确性,这也体现了强制执行程序立法中的争议问题。该诉讼要件不... 详细信息

无论给付的内容是金钱、特定物还是行为,给付之诉内容的确定与相应的判决与执行在民事诉讼中都具有重要意义。现行法要求起诉状中的给付诉讼请求和给付判决主文都应当具有明确性,这也体现了强制执行程序立法中的争议问题。该诉讼要件不同于案件的实体胜诉要件,不适用补正裁定和补充判决,也体现出处分权主义下诉讼请求与判决主文之间的紧密关联。由于两者所处的诉讼阶段不同并考虑民事诉讼处于动态推进中的基本特征,对判决主文的明确性要求更为关键,其应高于对立案请求的要求。在判断请求与主文明确性时,在指向作为行为的诉讼中满足客观唯一性标准即满足明确性要求,但是双方无争议的主观标准也可以被接受。而在停止侵害之诉中,我国法院也可能例外地将以“近似”为代表的不确定法律概念评价为明确;如果参考德国法经验补强相关裁判技术,也能形成与前述指向作为行为的诉讼相似的、客观标准辅以主观标准的审查标准;中外经验共同指向比例原则在强制执行法中的细化应用。在审判程序中,法院有权通过解释明确诉讼请求的内容,但是当请求不够明确时,法院不应排除当事人就其在实体法上本可以被支持的请求另诉的机会。在执行程序中,执行法官同样有解释判决主文的职权,其也可以准许当事人提起确认之诉或者利用当事人达成的新合意,实现就判决主文明确性要求的额外补救。

关键词：给付之诉具体的诉讼请求停止侵害之诉不确定法律概念立审执相协调

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A comparative study on the reactivity of cationic niobium clusters with nitrogen and oxygen

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Chinese Chemical Letters 2022年第2期33卷 1058-1064页

作者： Benben Huang Mengzhou Yang Xin Lei Wen Gan zhixun Luo Beijing National Laboratory for Molecular Sciences(BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

We have prepared well-resolved Nb^(+)_(n)(n=1-10)clusters and report here an in-depth study on the es-sentially different reactivity with N_(2)and O_(2),by utilizing a multiple-ion laminar flow tube reactor in tandem with a customized triple quadrupole mass spectrometer(MIFT-TQMS).As results,the Nb^(+)_(n)clus-ters are found to readily react with N_(2)and form adsorption products Nb_(n)N^(+)_(2m);in contrast,the reactions with O_(2)give rise to Nb_(n)O^(+)_(1−4)products,and the odd-oxygen products indicate O-O bond dissociation,as well as increased mass abundance of NbO^(+)pertaining to oxygen-etching reactions.We illustrate how N_(2) prefers a physical adsorption on Nb^(+)_(n)clusters with an end-on orientation for all the products,and allow for size-selective Nb^(+)_(n)clusters to act as electron donor or acceptor in forming Nb_(n)N^(+)_(2m).In contrast to these nitrides,the dioxides Nb_(n)O+2display much larger binding energies,with O_(2)always as an electron acceptor,corresponding to superoxide or peroxide states in the initial reactions.Density-of-states and orbital anal-yses show that the interactions between Nb^(+)_(n)and O_(2)are dominated by strongπ-backdonation indicative of incidental electron transfer;whereas weakπ-backdonation and simultaneousσdonation interactions exist in Nb_(n)N^(+)_(2).Further,reaction dynamics analysis illustrates the different interactions for N_(2)and O_(2) in approaching the Nb^(+)_(n)clusters,showing the energy diagrams for N_(2)adsorption and O-O bond dissoci-ation in producing odd-oxygen products.Fragment analyses with orbital correlation and donor-acceptor charge transfer are also performed,giving rise to full insights into the reactivities and interactions of such transition metal clusters with typical diatomic molecules.

关键词： Gas phase reaction Nb cluster Chemical adsorption Orbital analysis Energy decomposition analysis

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A special column highlighting young scientists at Institute of Chemistry, Chinese Academy of Sciences (ICCAS)

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Chinese Chemical Letters 2018年第3期29卷 343-344页

作者： zhixun,Luo Zhenzhong Yang chinese academy of sciences state key laboratory for structural chemistry of unstable and stable species institute of chemistrychinese academy of sciences Beijing 100190 China

Just seeing off the BOth anniversary of the Institute of Chemistry, Chinese Academy of Sciences （ICCAS）, we are here with pleasure to conduct A Special Column for Young Scientists at ICCAS published in Chinese Chemistry Letters （CCL） endeavoring to disseminate positive energy of several enthusiastic chemists and spread their recent research to the global scientific community.

关键词： ICCAS A special column highlighting young scientists at Institute of Chemistry Chinese Academy of Sciences

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