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新型冠状病毒复制子人工合成和应用研究进展

合成生物学 2024年第1期5卷 174-190页

作者：万里川王学军王升启军事医学研究院生物信息中心北京100850

从2019年12月初首次报道到2023年9月,新型冠状病毒在全世界已造成约7.7亿人感染和696万人死亡。由于该病毒具有极强的传染性,理论上相关的研究工作都必须在生物安全三级或以上的实验室中进行。为了克服这一局限性,研究人员应用反向遗传... 详细信息

从2019年12月初首次报道到2023年9月,新型冠状病毒在全世界已造成约7.7亿人感染和696万人死亡。由于该病毒具有极强的传染性,理论上相关的研究工作都必须在生物安全三级或以上的实验室中进行。为了克服这一局限性,研究人员应用反向遗传学技术构建了众多复制子,使得在生物安全二级实验室中就可以进行相关的研究工作。科学家们通常会在复制子中插入绿色荧光蛋白或荧光素酶等报告基因以及遗传霉素等抗性基因,方便检测病毒和建立稳定的细胞株。另外,新冠病毒复制子还可通过与共转染的病毒糖蛋白的反式互补作用形成只能单次侵染的病毒粒子,使之能侵染无新冠病毒受体的细胞。因此,本文总结了合成新冠病毒复制子的主要方法,如通过Ⅱ型或ⅡS型限制性内切酶进行体外连接、基于细菌人工染色体的构建、利用酵母转化相关重组进行克隆和应用环形聚合酶延伸反应构建,同时综述了新冠病毒的单周期和稳定表达复制子系统。总之,多种复制子系统的构建和应用为研究新冠病毒基因功能、病毒与宿主互作机制和抗病毒药物的高通量筛选奠定了坚实的基础,为阻止病毒的蔓延和保卫人类的健康做出了重大贡献。

关键词：新冠病毒复制子反向遗传系统 BAC tar

Formation Mechanism of Biomass Aromatic Hydrocarbon tar on Quantum Chemistry

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Journal of Renewable Materials 2022年第12期10卷 3491-3504页

作者： Bo Chen Bo Liu Yong Chao Chao Zhong School of Mechanical Engineering Hunan Institute of EngineeringXiangtan411104China School of Electrical and Information Engineering Hunan Institute of EngineeingXiangtan411104China Hunan Shuanghuan Fiber Forming Equipment Co ItdXiangtan411100China

The formation process of aromatic hydrocarbon tar during the pyrolysis process of biomass components of cel-lulose and lignin was carried out by quantum chemical calculation based on density functional theory method B3LYP/6-31G++(d,p).5 Hydroxymethylfurfural was chosen as the model compound of cellulose and hemicel-lulose,and syringa ldehyde was chosen as the model compound of lignin.The calculation results show that the formation process of cellulose monocyclic aromatic hydrocarbon tar is the conversion process of benzene ring from furan ring,and the highest reaction energy barrier appears in the process of decarbonylation,which is 370.8 kJ/mol.The formation of lignin monocyclic aromatic hydrocarbon tar is mainly the process of side chains removal and the formation of phenol,The highest reaction energy barrier appears in the process of decarbonyla-tion,which is 374.9 kJ/mol.The reaction mechanism of phenanthrene formation from naphthalene was selected as the formation of cellulose and lignin polycydic aromatic hydrocarbon tar.The calculation results show that he total barrier of the pathway that naphthalene dehydrogenates to form naphthalene free radicals and then reacts with ethylene twice by addition action,finally occurs cydization reactions and isomerizes to produce phenan-threne is lowest,that is 38.6 kJ/mol.So it is proved that the evolution of tar is the process of deoxygenation and cyclization with the increase of the temperature from a theoretical point of view.

关键词： Cellulose lignin tar aromatic hydrocarbon quantum chemistry

Decomposition of biomass gasification tar model compounds over waste tire pyrolysis char

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Waste Disposal and Sustainable Energy 2022年第2期4卷 75-89页

作者： Amal S.Al-Rahbi Paul T.Williams Present address:Applied Sciences Department Higher College of TechnologyUniversity of Technology and Applied SciencesMuscatSultanate of Oman School of Chemical and Process Engineering University of LeedsLeedsLS29JTUK

Gasification of biomass produces a syngas containing trace amounts of viscous hydrocarbon tar,which causes serious problems in downstream pipelines,valves and processing equipment.This study focuses on the use of tire-derived pyrolysis char for tar conversion using biomass tar model compounds representative of tar.The catalytic decomposition of tar model compounds,including methylnaphthalene,furfural,phenol,and toluene,over tire char was investigated using a fixed bed reactor at a bed temperature of 700℃and 60 min time on stream.The influence of temperature,reaction time,porous texture,and acidity of the tire char was investigated with the use of methylnaphthalene as the tar model compound.Oxygenated tar model compounds were found to have higher conversion than those containing a single or multi-aromatic ring.The reactivity of tar compounds followed the order of furfural>phenol>toluene>methylnaphthalene.The conversion of the model compounds in the presence of the tire char was much higher than tar thermal cracking.Gas production increased dramatically with the introduction of tire char.The H_(2)potential for the studied tar model compounds was found to be in the range of 40%–50%.The activity of tire char for naphthalene removal was compared with two commercial activated carbons possessing a very well-developed porous texture.The results suggest that the influence of Brunauer-Emmett-Teller surface area of the carbon on tar cracking is negligible compared with the mineral content in the carbon samples.

关键词： Biomass Gasification Syngas tar Tire Char

Fe-doped olivine and char for in-bed elimination of gasification tars in an air-blown fluidised bed reactor coupled with oxidative hot gas filtration

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Carbon Resources Conversion 2022年第4期5卷 271-288页

作者： Miguel Ruiz Adam Schnitzer Claire Courson Guillain Mauviel LRGP CNRSUniversity of LorraineENSIC1 Rue GrandvilleNancyFrance University of Lorraine LERMaBENSTIB27 Rue Philippe S´eguinPO Box 1041F-88051 EpinalFrance Institut of Chemistry and Processes for Energy Environment and HealthICPEES–UMR 7515University of Strasbourg25 Rue Becquerel67087 StrasbourgFrance

Gasification experiments were carried out in a pilot scale fluid bed reactor operated under allothermal mode and low fluidisation regime with iron-doped olivine and char as catalyst for in-situ tar abatement.The catalyst combination resulted in a reduction of 50%in the overall tar yield with respect to the reference values.Furthermore,the integration of an oxidative Hot Gas Filtration unit downstream the gasification reactor led to a further reduction in overall tar yield and relatively clean gas was obtained(approx.1 g/Nm3,benzene-free).The tar dew point of the resulting producer gas was estimated to 80℃,only 40℃ above the threshold value recommended for its valorisation in standard internal combustion engines.Moreover,catalyst elutriation and char hold-up took place to a large extent inside the reactor.The analysis of catalyst samples at different Time-On-Stream(TOS)revealed:(i)a considerable loss of iron oxides during the first hour of test because of the interparticle mechanical attrition(mostly surface abrasion)and partial reduction of hematite to magnetite and wustite but,stable composition at higher TOS,(ii)the loss of the iron oxide coverage of Fe/olivine particles and the formation of agglomerates with increasing TOS and,(iii)the amount of carbon deposited in the surface of the Fe/olivine particles increased with TOS,but in any case,these carbon deposits can be completely oxidized above 650℃.

关键词： Gasification tar Oxidative hot gas filtration Char Iron-doped olivine

Population-based prevalence study of common congenital malformations of the alimentary tract and abdominal wall in Thailand:a study using data from the National Health Security Office

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World Journal of Pediatric Surgery 2023年第3期6卷 129-135页

作者： Kulpreeya Sirichamratsakul Wison Laochareonsuk Komwit Surachat Surasak Sangkhathat Department of Surgery Faculty of MedicinePrince of Songkla UniversityHat YaiThailand Translational Medicine Research CenterFaculty of MedicinePrince of Songkla UniversityHat YaiThailand Department of Biomedical Sciences and Biomedical EngineeringPrince of Songkla UniversityHat YaiThailand

Background The study aimed to estimate the prevalence of major congenital anomalies of the alimentary system and the abdominal wall in Thailand using a nationwide hospital discharge database from the National Health Security Office(2017–2020).Methods The study extracted data from records with International Classification of Diseases-10(ICD-10)codes related to esophageal malformation(ESO),congenital duodenal obstruction(CDO),jejunoileal atresia(INTES),Hirschsprung’s disease(HSCR),anorectal malformation(ARM),abdominal wall defects(omphalocele(OMP)and gastroschisis(GAS)),and diaphragmatic hernia from the database with patient age selection set to less than 1year.Results A total of 2539 matched ICD-10 records were found in 2376 individuals over the 4-year study period.Concerning foregut anomalies,the prevalence of ESO was 0.88/10000 births,while that of CDO was 0.54/10000 births.The prevalence figures of INTES,HSCR,and ARM were 0.44,4.69,and 2.57 cases per 10000 births,respectively.For abdominal wall defects,the prevalences of OMP and GAS were 0.25 and 0.61 cases/10000 births,respectively.The mortality in our cases was 7.1%,and survival analysis found that associated cardiac defects had a statistically significant influence on survival in most anomalies studied.In HSCR,both Down syndrome(DS)(hazard ratio(HR)=7.57,95%confidence interval(CI)=4.12 to 13.91,p<0.001)and cardiac defects(HR=5.82,95%CI=2.85 to 11.92,p<0.001)were significantly associated with poorer survival outcomes.However,only DS(adjusted HR=5.55,95%CI=2.63 to 11.75,p<0.001)independently predicted worse outcomes by multivariable analysis.Conclusions Our analysis of the hospital discharge database found that the prevalence of gastrointestinal anomalies in Thailand was lower than that reported in other countries,except for HSCR and anorectal malformations.Associated Down syndrome and cardiac defects influence the survival outcomes of these anomalies.

关键词： database Office tar

Latent HIV-1 tar Regulates 7SK-responsive P-TEFb target Genes and targets Cellular Immune Responses in the Absence of Tat

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Genomics, Proteomics & Bioinformatics 2017年第5期15卷 313-323页

作者： Sebastian Eilebrecht Bernd-Joachim Benecke Arndt G. Benecke CNRS UMR8246 Université Pierre et Marie Curie Paris 75005 France ACSIOMA GmbH Technologiezentrum Ruhr Bochum 44799 Germany Center for Innate Immunity and Immune Disease University of Washington School of Medicine Seattle WA 98195 USA

The transactivating response element （tar） structure of the nascent HIV-1 transcript is critically involved in the recruitment of inactive positive transcription elongation factor b （P-TEFb） to the promoter proximal paused RNA polymerase II. The viral transactivator Tat is responsible for subsequent P-TEFb activation in order to start efficient viral transcription elongation. In the absence of the viral transactivator of transcription （Tat）, e.g., during latency or in early stages of HIV tran- scription, tar mediates an interaction of P-TEFb with its inhibitor hexamethylene bis-aeetamide- inducible protein 1 （HEXIM1）, keeping P-TEFb in its inactive form. In this study, we address the function of HIV-1 tar in the absence of Tat by analyzing consequences of HIV-1 tar overexpres- sion on host cellular gene expression. An RNA chimera consisting of Epstein-Barr virus-expressed RNA 2 （EBER2） and HIV-1 tar was developed to assure robust overexpression of tar in HEK293 cells. The overexpression results in differential expression of more than 800 human genes. A significant proportion of these genes is involved in the suppression of cellular immune responses, including a significant set of 7SK-responsive P-TEFb target genes. Our findings identify a novel role for HIV-1 tar in the absence of Tat, involving the interference with host cellular immune responses by targeting 7SK RNA-mediated gene expression and P-TEFb inactivation.

关键词： HIV-1 Latency tar 7SK RNA Cellular immunity

Performance of Co/MgO catalyst for CO_2 reforming of toluene as a model compound of tar derived from biomass gasification

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Journal of Energy Chemistry 2014年第6期23卷 795-800页

作者： Xiuxiu Bao Meng Kong Wen Lu Jinhua Fei Xiaoming Zheng Institute of Catalysis Key Lab of Applied Chemistry of Zhejiang Province Zhejiang University

Catalytic performances of the CO2 reforming of toluene on Co/MgO catalysts with different cobalt loadings were evaluated in a fluidized-bed reactor. The results showed that the conversion of toluene and the stability of Co/MgO increased, but the apparent reaction rate decreased at the initial stage with increasing the amount of metallic Co formed from the reduction of Co/MgO catalysts at 700 ~C. The deactivation of Co/MgO catalysts was mainly resulted from that a part of the metallic Co was oxidized by CO2 and could not be re-reduced by H2 at reaction temperature. Therefore, the excess metallic Co on the higher Co loading catalysts was beneficial to the catalyst stability.

关键词： cobalt catalyst magnesia carbon dioxide reforming toluene biomass tar

Preparation and characterization of high softening point and homogeneous isotropic pitches produced from distilled ethylene tar by a novel bromination method

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新型炭材料 2018年第1期33卷 97-100页

作者： Chuan-zhang Ge Zhen-long Sun Hai-xiao Yang Dong-hui Long Wen-ming Qiao Li-cheng Ling State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China Shanghai Key Laboratory of Multiphase Materials Chemical Engineering East China University of Science and TechnologyShanghai 200237China

摘要: 以乙烯渣油减压蒸馏重组分（ET-HR）为原料，采用溴化/脱溴聚合两步法制备了新型高软化点各向同性沥青，研究了溴化温度和溴引入量对所得产品性质参数的影响。GCMS与LDI TOF/MS测试结果表明，ET-HR主要由富含饱和脂肪侧链的3-6环... 详细信息

摘要: 以乙烯渣油减压蒸馏重组分（ET-HR）为原料，采用溴化/脱溴聚合两步法制备了新型高软化点各向同性沥青，研究了溴化温度和溴引入量对所得产品性质参数的影响。GCMS与LDI TOF/MS测试结果表明，ET-HR主要由富含饱和脂肪侧链的3-6环芳香烃组成。ET-HR分别经30℃和200℃溴化后直接经350℃热处理发生脱溴化氢缩合反应。与简单热缩聚相比，该两步法显著提高了所得沥青的软化点（241~264℃）、产品得率（62 wt.%~67 wt.%）以及氮气下的残碳率（57 wt.%~77 wt.%）。对所得脱溴聚合沥青的组成和结构通过元素分析、 1H NMR、FT-IR和LDI-TOF/MS等技术手段进行了表征，结果表明脱溴聚合显著增强了前驱体的芳构化和缩聚反应程度。800℃炭化结果表明，溴化/脱溴聚合两步法所得各向同性沥青能够完全转变为各向异性织构，从而可广泛应用于高级炭材料领域。

关键词： high softening point and homogeneous isotropic pitches produced from distilled ethylene tar romination method

Influence of temperature and Ca(OH)2 on releasing tar and coal gas during lignite coal pyrolysis and char gasification

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Chinese Journal of Chemical Engineering 2019年第11期27卷 2788-2798页

作者： Sunel Kumar Zhihua Wang Zhang Kang Jun Xia Ronald Whiddon Yong He Jaffri Gul-e-Rana Zain Ali Saleh Bairq Kefa Cen State Key Laboratory of Clean Energy Utilization Zhejiang UniversityHangzhou 310027China Department of Mechanical Aerospace and Civil EngineeringBrunel University LondonUxbridge UB83PHUK Fuel Research Centre PCSIRKarachi 75280Pakistan College of Chemistry and Chemical Engineering Hunan UniversityChangsha 410082China

The yield of tar and syngas has been investigated by catalytic pyrolysis of Pingzhuang lignite(PZL)over Ca(OH)2 catalyst in temperature range of 600℃-1000℃in a tube furnace.The results show that the yield of volatile pyrolysis increases and char decreases with rising temperature for both raw and catalyzed Pingzhuang lignite.The hydrogen fraction(H2)increased from 20%to 40%for the PZL sample;but,for the PZL-Ca(OH)2 sample,H2 fraction fluctuated randomly between 35%to 42%,with the maximum H2 fraction found at 1000℃.The Gaschromatography mass-spectroscopic(GC-MS)analysis revealed that the maximum tar yield at 800℃and 700℃was obtained for PZL and PZL-Ca(OH)2,respectively.The surface morphology of PZL and PZL-Ca(OH)2 chars underwent different transformation in the presence of catalyst as illustrated by SEM/EDX,FTIR,and BET analysis.Furthermore,char sample was investigated for the carbon conversion and reactivity index using TGA analysis under N2 and CO atmosphere.

关键词： Catalyzed coal pyrolysis Release volatiles of tar and coal gas Surface area Pore volume