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Boosting selectivity and stability on Pt/BN catalysts for propane dehydrogenation via calcination & reduction-mediated strong metal-support interaction

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Journal of Energy Chemistry 2022年第4期31卷 451-457页

作者： Yaoxin Wang Jiandian Wang Ping Zheng Changyong Sun Junyin Luo xiaowei xie Key Laboratory of Clean Chemical Technology of Guangdong Regular Higher Education Institutions School of Chemical Engineering and Light IndustryGuangdong University of TechnologyGuangzhou 510006GuangdongChina

Propane dehydrogenation(PDH) provides an alternative route for producing propylene. Herein, we demonstrates that h-BN is a promising support of Pt-based catalysts for PDH. The Pt catalysts supported on h-BN were prepared by an impregnation method using Pt(NH_(3))_(4)(NO_(3))_(2) as metal precursors. It has been found that the Pt/BN catalyst undergoing calcination and reduction is highly stable in both PDH reaction and coke-burning regeneration, together with low coke deposition and outstanding propylene selectivity(99%). Detailed characterizations reveal that the high coke resistance and high propylene selectivity of the Pt/BN catalyst are derived not only from the absence of acidity on BN support, but also from the calcination-induced and reduction-adjusted strong metal-support interaction(SMSI) between Pt and BN, which causes the partial encapsulation of Pt particles by BO_(x) overlayers. The BO_(x) overlayers can block the low-coordinated Pt sites and constrain Pt particles into smaller ensembles, suppressing side reactions such as cracking and deep dehydrogenation. Moreover, the BO_(x) overlayers can effectively inhibit Pt sintering by the spatial isolation of Pt during periodic reaction-regeneration cycles. In this work, the catalyst support for PDH is expanded to nonoxide BN, and the understanding of SMSI between Pt and BN will provide rational design strategy for BN-based catalysts.

关键词： Pt catalyst BN SMSI Propane dehydrogenation Selectivity Stability Coke Sintering

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A Simple and Efficient Copper（Ⅱ） Complex as a Catalyst for N-Arylation of Imidazoles

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Chinese Journal of Chemistry 2013年第2期31卷 267-270页

作者： Yanli Jiao Nannan Yan Jianwei xie xiaowei Ma Ping Liu Bin Dai School of Chemistry and Chemical Engineering the Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan Shihezi University North 4th Road Shihezi Xinjiang 832003 China

Four inexpensive and air-/moisture-stable pyrrolecarbaldiminato-Cu complexes 1-4 were synthesized and evaluated to be a novel class of catalysts for the N-arylation of imidazoles with aryl halides. A variety of aryl iodides, bromides and activated aryl chlorides underwent the coupling with imidazoles, promoted by the catalyst 4, in moderate to good yields without the protection by an inert gas.

关键词： pyrrolecarbaldiminato-Cu complexes homogeneous catalyst N-arylation imidazoles N-heterocycles

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A comparative study on different regeneration processes of Pt-Sn/γ-Al2O3 catalysts for propane dehydrogenation

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Journal of Energy Chemistry 2018年第1期27卷 311-318页

作者： Changyong Sun Junyin Luo Mingjin Cao Ping Zheng Guocheng Li Jiahao Bu Zhou Cao Shihong Chen xiaowei xie Key Laboratory of Clean Chemical Technology School of Chemical Engineering and Light IndustryGuangdong University of TechnologyGuangzhou 510006GuangdongChina

Three different regeneration processes including hydrogen or nitrogen purging and coke-burning treatment were used to restore the Pt-Sn/γ-AlOcatalysts, through which propane dehydrogenation reaction was performed in a consecutive reaction-regeneration mode. It was found that the catalyst using hydrogen regeneration showed the best stability compared with those regenerated by nitrogen purging and coke-burning treatment, suggesting that hydrogen regeneration is an effective approach for maintaining the performance of Pt-Sn/γ-AlOcatalysts in propane dehydrogenation reaction. The effect of different regeneration atmospheres on the metal active center and the coke deposition was investigated by XRD,TEM, N-physisorption, TPO, TG and Raman technologies, and the results revealed that hydrogen or nitrogen regeneration resulted in little impact on the size and structure of metal active center, retaining the effective Pt Sn phase over the catalyst. Moreover, hydrogen regeneration not only removed the low dense components of the coke, but also altered the property of the residual coke through hydrogenation, leading to a higher mobility of coke, and thus a higher accessibility of the metal active centers. Whereas nitrogen regeneration only removed the low dense components of the coke. Although coke-burning regeneration caused a thorough coke removal, the catalyst subjected to repeated redox exhibited poor stability due to metal agglomeration, phase segregation and the resulting large PtSn particle and core-shell structure with a Sn-rich surface.

关键词： Platinum-tin Pt-Sn/γ -Al2O3 Propane dehydrogenation Regeneration processesCoke

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Single-cell transcriptomes of peripheral blood cells indicate and elucidate severity of COVID-19

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Science China(Life Sciences) 2021年第10期64卷 1634-1644页

作者： xiaowei xie Xuelian Cheng Gaoxiang Wang Biao Zhang Mengyao Liu Liting Chen Hui Cheng Sha Hao Jianfeng Zhou Ping Zhu Tao Cheng State Key Laboratory of Experimental Hematology and National Clinical Research Center for Blood Diseases Institute of Hematology and Blood Diseases HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeTianjin 300020China Department of Hematology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Center for Stem Cell Medicine and Department of Stem Cell&Regenerative Medicine Chinese Academy of Medical Sciences and Peking Union Medical CollegeTianjin 300020China

The blood and immune system of coronavirus disease 2019(COVID-19)infected patients are dysfunctional,and numerous studies have been conducted to resolve their characteristics and pathogenic ***,the variations of immune responses along with disease severity have not been comprehensively ***,we profiled the single-cell transcriptomes of 96,313 peripheral blood mononuclear cells(PBMCs)derived from 12 COVID-19 patients(including four moderate,four severe and four critical cases)and three healthy *** showed that proliferative CD8 effector T cells with declined immune functions and cytotoxicity accumulated in the critical *** contrast,the quantity of natural killer(NK)cells was significantly reduced,while they exhibited enhanced immune ***,a gradually attenuated responseto COVID-19 along with disease severity was observed in monocytes,in terms of cellular composition,transcriptional discrepancy and transcription factor regulatory ***,we identified immune cell-type dependent cytokine signatures distinguishing the severity of COVID-19 *** addition,cell interactions between CD8 effector T/NK cells and monocytes mediated by inflammatory cytokines were enhanced in moderate and severe stages,but weakened in critical ***,our work uncovers the cellular and molecular players underlying the disordered and heterogeneous immune responses associated with COVID-19 severity,which could provide valuable insights for the treatment of critical COVID-19 patients.

关键词： COVID-19 severity PBMCs immune response single-cell RNA-seq

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Lignin-assisted construction of sub-10 nm supramolecular self-assembly for photothermal immunotherapy and potentiating anti-PD-1 therapy against primary and distant breast tumors

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Asian Journal of Pharmaceutical Sciences 2022年第5期17卷 713-727页

作者： Xudong Fan Tianxiang Yue Aidi Liu xiaowei xie Weixiang Fang Yinghui Wei Hangsheng Zheng Hongyue Zheng Meiqi Zhou Jigang Piao Fanzhu Li School of Pharmaceutical Sciences Zhejiang Chinese Medical UniversityHangzhou 310053China Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province School of Pharmaceutical SciencesZhejiang Chinese Medical UniversityHangzhou 310053China Libraries of Zhejiang Chinese Medical University Zhejiang Chinese Medical UniversityHangzhou 310053China Department of Breast Surgery Key Laboratory of Cancer Prevention and InterventionChina National Ministry of EducationSecond Hospital of ZhejiangUniversity College of MedicineHangzhou 310009China Academy of Chinese Medical Sciences Zhejiang Chinese Medical UniversityHangzhou 310053China

Photothermal therapy(PTT)has brought hope for cancer treatments,with hyperthermia-induced immunogenic cell death(ICD),which is a critical part of therapeutically induced antitumor immune *** immune stimulation response in PTT is the primary reason for incomplete tumor ablation,therefore demonstrating urgent requirements for ICD ***,a sub-10 nm supramolecular nanoassembly was formed by coassembly of clinically approved aluminum adjuvant and commonly used indocyanine green(ICG)under the assistance of lignosulfonate(LS,a green and sustainable multifunctional lignin derivative)for localized photothermal-immunotherapy of breast *** overall results revealed that LS-Al-ICG is capable of inducing amplified ICD,efficiently eliciting solid immune responses through dendritic cells(DCs)activation and cytotoxic T-cell responses initiation for tumor ***,anti-PD-1 therapy blocked the PD-1 pathway and led to remarkable anti-tumor efficacy against laser-irradiated primary tumors and distant tumors by potentiating systemic tumor specific T cell *** results of this study demonstrate a handy and extensible approach for engineering green natural lignin nanoparticles for cancer immunotherapy,which shows promise for delivering other therapeutics in biomedical applications.

关键词： Lignin Supramolecular self-assembly Photothermal-immunotherapy Anti-PD-1

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Effective and precise adenine base editing n mouse zygotes

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Protein & Cell 2018年第9期9卷 808-813页

作者： Puping Liang Hongwei Sun Xiya Zhang xiaowei xie Jinran Zhang Yaofu Bai Xueling Ouyang Shengyao Zhi Yuanyan Xiong Wenbin Ma Dan Liu Junjiu Huang Zhou Songyang Key Laboratory of Gene Engineering of the Ministry of Education Guangzhou Key Laboratory of Healthy Aging Research and SYSU-BCM Joint Research Center School of Life Sciences Sun Yat-sen University Guangzhou 510275 China Key Laboratory of Reproductive Medicine of Guangdong Province School of Life Sciences and the First Affiliated Hospital Sun Yatsen University Guangzhou 510275 China State Key Laboratory of Ophthalmology Zhongshan Ophthalmic Center Sun Yat-sen University Guangzhou 510060 China Verna and Marrs Mclean Department of Biochemistry and Molecular Biology Baylor College of Medicine One Baylor Plaza Houston TX 77030 USA

Dear Editor, Many human genetic diseases are caused by pathogenic single nucleotide mutations. Animal models are often used to study these diseases where the pathogenic point mutations are created and/or corrected through gene editing （e.g., the CRISPP-JCas9 system）（Komor et al., 2017; Liang et al., 2017）. CRISPR/Cas9-mediated gene editing depends on DNA double-strand breaks （DSBs）, which can be of low efficiency and lead to indels and off-target cleavage （Kim et al., 2016）. We and others have shown that base editors （BEs） may represent an attractive alternative for disease mouse model generation （Liang et al., 2017; Kim et al., 2017）. Compared to CRISPR/ Cas9, cytidine base editors （CBEs） can generate C·G to T·A mutations in mouse zygotes without activating DSB repair pathways （Liang et al., 2017; Kim et al., 2017; Komor et al., 2016）. In addition, CBEs showed much lower off-targets than CRISPR]Cas9 （Kim et al., 2017）, making the editing process potentially safer and more controllable. Recently, adenine base editors （ABEs） that were developed from the tRNA- specific adenosine deaminase （TADA） of Escherichia coli were also reported （Gaudelli et al., 2017）. As a RNA-guided programmable adenine deaminase, ABE can catalyze the conversion of A to I. Following DNA replication, base I is replaced by G, resulting in A·T to G·C conversion （Gaudelli et al., 2017; Hu et al., 2018）. The development of ABEs has clearly expanded the editing capacity and application of BEs. Here, we tested whether ABEs could effectively generate disease mouse models, and found high efficiency by ABEs in producing edited mouse zygotes and mice with single-nucleotide substitutions.

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Effective gene editing by high-fidelity base editor 2 in mouse zygotes

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Protein & Cell 2017年第8期8卷 601-611页

作者： Puping Liang Hongwei Sun Ying Sun Xiya Zhang xiaowei xie Jinran Zhang zhen Zhang Yuxi Chen Chenhui Ding Yuanyan Xiong Wenbin Ma Dan Liu Junjiu Huang Zhou Songyang Key Laboratory of Gene Engineering of the Ministry of Education Guangzhou Key Laboratory of Healthy Aging Researchand State Key Laboratory of Biocontrol SYSU-BCM Joint Research Center School of Life Sciences Sun Yat-sen UniversityGuangzhou 510275 China State Key Laboratory of Ophthalmology Zhongshan Ophthalmic Center Sun Yat-sen University Guangzhou 510275 China Key Laboratory of Reproductive Medicine of Guangdong Province School of Life Sciences and the First Affiliated HospitalSun Yat-sen University Guangzhou 510275 China Guangzhou Magigen Biotechnology Co.Ltd Guangzhou 510320 China 5 Vernaand Marrs Mclean Department of Biochemistry and Molecular Biology Baylor College of Medicine One Baylor Plaza Houston TX 77030 USA

Targeted point mutagenesis through homologous recombination has been widely used in genetic studies and holds considerable promise for repairing disease- causing mutations in patients. However, problems such as mosaicism and low mutagenesis efficiency continue to pose challenges to clinical applicaUon of such approaches. Recently, a base editor （BE） system built on cytidine （C） deaminase and CRISPR/Cas9 technology was developed as an alternative method for targeted point mutagenesis in plant, yeast, and human cells. Base editors convert C in the deamination window to thymidine （T） efficiently, however, it remains unclear whether targeted base editing in mouse embryos is feasible. In this report, we generated a modified high- fidelity version of base editor 2 （HF2-BE2）, and investigated its base editing efficacy in mouse embryos. We found that HF2-BE2 could convert C to T efficiently, with up to 100% biallelic mutation efficiency in mouse embryos. Unlike BE3, HF2-BE2 could convert C to T on both the target and non-target strand, expanding the editing scope of base editors. Surprisingly, we found HF2-BE2 could also deaminate C that was proximal to the gRNA-binding region. Taken together, our work demonstrates the feasibility of generating point mutations in mouse by base editing, and underscores the need to carefully optimize base editing systems in order to eliminate proximal-site deamination.

关键词： base editor high-fidelity mouse embryos,proximal-site deamination whole-genome sequencing

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钯三角双锥单孪晶的合成

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高等学校化学学报 2017年第12期38卷 2149-2155页

作者：孙长勇林亮标解晓伟广东工业大学轻工化工学院清洁化学技术重点实验室广州510006

采用液相还原法,以Na_2PdCl_4为钯源,PVP为还原剂和分散剂,碘离子作为晶面选择吸附剂和配位剂,硝酸根离子作为氧化蚀刻剂,水为溶剂,在n(Na_2PdCl_4)∶n(PVP)∶n(KI)∶n(NaNO_3)=1∶35∶10∶9和pH=11条件下,合成了形貌规整的纯度大于99%... 详细信息

采用液相还原法,以Na_2PdCl_4为钯源,PVP为还原剂和分散剂,碘离子作为晶面选择吸附剂和配位剂,硝酸根离子作为氧化蚀刻剂,水为溶剂,在n(Na_2PdCl_4)∶n(PVP)∶n(KI)∶n(NaNO_3)=1∶35∶10∶9和pH=11条件下,合成了形貌规整的纯度大于99%的钯三角双锥单孪晶.碘离子在合成体系中主要通过改变钯前驱体还原速率来影响钯晶种的生长转化和产物的形貌,对氧化蚀刻作用的影响在较高pH值下并不明显.钾离子和钠离子比例的变化显著影响了产物的形貌组成,此阳离子效应可归因于反应体系在钠离子存在时较钾离子存在时表现出更快的钯前驱体还原速率.

关键词：三角双锥钯单孪晶氧化蚀刻还原速率阳离子效应

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CRISPR/Cas9-mediated gene editing in human tripronuclear zygotes

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Protein & Cell 2015年第5期6卷 363-372页

作者： Puping Liang Yanwen Xu Xiya Zhang Chenhui Ding Rui Huang Zhen Zhang Jie Lv xiaowei xie Yuxi Chen Yujing Li Ying Sun Yaofu Bai Zhou Songyang Wenbin Ma Canquan Zhou Junjiu Huang Guangdong Province Key Laboratory of Reproductive Medicine the First Affiliated Hospital and Key Laboratory of GeneEngineering of the Ministry of Education School of Life Sciences Sun Yat-sen University Guangzhou 510275 China

Genome editing tools such as the clustered regularly interspaced short palindromic repeat （CRISPR）-associated system （Cas） have been widely used to modify genes in model systems including animal zygotes and human cells, and hold tremendous promise for both basic research and clinical applications. To date, a serious knowledge gap remains in our understanding of DNA repair mechanisms in human early embryos, and in the efficiency and potential off-target effects of using technologies such as CRISPR/Cas9 in human pre-implantation embryos. In this report, we used tripronuclear （3PN） zygotes to further investigate CRISPR/Cas9-mediated gene editing in human cells. We found that CRISPR/Cas9 could effectively cleave the endogenous β-globin gene （HBB）. However, the efficiency of homologous recombination directed repair （HDR） of HBB was low and the edited embryos were mosaic. Off-target cleavage was also apparent in these 3PN zygotes as revealed by the T7E1 assay and whole-exome sequencing. Furthermore, the endogenous delta-globin gene （HBD）, which is homologous to HBB, competed with exogenous donor oligos to act as the repair template, leading to untoward mutations. Our data also indicated that repair of the HBB locus in these embryos occurred preferentially through the non-crossover HDR pathway. Taken together, our work highlights the pressing need to further improve the fidelity and specificity of the CRISPR/Cas9 platform, a prerequisite for any clinical applications of CRSIPR/Cas9-mediated editing.

关键词： CRISPR/Cas9 β-thalassemia humantripronuclear zygotes gene editing homologousrecombination whole-exome sequencing

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Correction of β-thalassemia mutant by base editor in human embryos

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Protein & Cell 2017年第11期8卷 811-822页

作者： Puping Liang Chenhui Ding Hongwei Sun xiaowei xie Yanwen Xu Xiya Zhang Ying Sun Yuanyan Xiong Wenbin Ma Yongxiang Liu Yali Wang Jianpei Fang Dan Liu Zhou Songyang Canquan Zhou Junjiu Huang Key Laboratory of Gene Engineering of the Ministry of Education Guangzhou Key Laboratory of Healthy Aging Research and State Key Laboratory of Biocontrol SYSU-BCM Joint Research Center School of Life Sciences Sun Yat-sen University Guangzhou 510275 China Key Laboratory of Reproductive Medicine of Guangdong Province School of Life Sciences and the First Affiliated Hospital Sun Yat-sen University Guangzhou 510275 China Department of Pediatrics Second Affiliated Hospital Sun Yat-sen University Guangzhou 510120 China Verna and Marrs Mclean Department of Biochemistry and Molecular Biology Baylor College of Medicine One Baylor Plaza Houston. TX 77030. USA

β-Thalassemia is a global health issue, caused by mutations in the HBB gene. Among these mutations, HBB -28 （A〉G） mutations is one of the three most common mutations in China and Southeast Asia patients with β-thalassemia. Correcting this mutation in human embryos may prevent the disease being passed onto future generations and cure anemia. Here we report the first study using base editor （BE） system to correct disease mutant in human embryos. Firstly, we produced a 293T cell line with an exogenous HBB -28 （A〉G） mutant fragment for gRNAs and targeting efficiency evaluation. Then we collected primary skin fibroblast cells from a β-thalassemia patient with HBB -28 （A〉G） homozygous mutation. Data showed that base editor could precisely correct HBB -28 （A〉G） mutation in the patient＇s primary cells. To model homozygous mutation disease embryos, we consb＇ucted nuclear transfer embryos by fusing the lymphocyte or skin fibroblast cells with enucleated in vitro matured （IVM） ***, the gene correction efficiency was over 23.0% in these embryos by base editor. Although these embryos were still mosaic, the percentage of repaired blastomeres was over 20.0%. In addition, we found that base editor variants, with narrowed deamination window, could promote G-to-A conversion at HBB -28 site precisely in human embryos. Collectively, this study demonstrated the feasibility of curing genetic disease in human somatic cells and embryos by base editor system.

关键词： β-thalassemia HBB -28 (A〉G) baseeditor human embryo

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