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Insertion sequence transposition activates antimycobacteriophage immunity through an Isr2-silenced lipid metabolism gene island

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mLife 2024年第1期3卷 87-100页

作者： Yakun Li Yuyun Wei Xiao Guo xiaohui Li Lining Lu Lihua Hu Zheng-Guo He State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources Guangxi Research Center for Microbial and Enzyme Engineering TechnologyCollege of Life Scienceand TechnologyGuangxi UniversityNanningChina

Insertion sequences(ISs)exist widely in bacterial genomes,but their roles in the evolution of bacterial antiphage defense remain to be ***,we report that,under the pressure of phage infection,the IS1o96 transposition of Mycobacterium smegmatis into the Isr2 gene can occur at high frequencies,which endows the mutant mycobacterium with a broad-spectrum antiphage ***2 functions as a negative regulator and directly silences expression of a gene island composed of 11 lipid metabolism-related *** complete or partial loss of the gene island leads to a significant decrease of bacteriophage adsorption to the mycobacterium,thus defending against phage ***,a phage that has evolved mutations in two tail-filament genes can re-escape from the Isr2 inactivation-triggered host *** study uncovered a new signaling pathway for activating antimycobacteriophage immunity by Is transposition and provided insight into the natural evolution of bacterial antiphage defense.

关键词： antiphage defense bacteriophage gene island insertion sequence mycobacteria

Tracking structure suitable for L6 signal

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The Journal of China Universities of Posts and Telecommunications 2021年第4期28卷 64-74页

作者： Wang Yiting ba.xiaohui Liu Xueyong Yang Ying Li Jian Chen Jie System on Chip Lab Institute of Microelectronics of the Chinese Academy of SciencesBeijing 100029China College of Electronic and Electrical Communication Engineering University of Chinese Academy of SciencesBeijing 100049China

A tracking structure suitable for L6 signal of quasi-zenith satellite system(QZSS) was proposed in order to track the L6 signal without other frequency assistance. Moreover, the tracking structure does not change the receiver’s hardware structure. The main difference between the proposed and the traditional tracking structure lies in the generation of local codes of E,P and L branches. The method of local code generation is designed in a two-stage manner. The first stage is the generation of the P branch local code with fast fouriertransform(FFT). In the second stage, the local codes of the E and L branches are obtained with the code-chip interval. The tracking structure can track and decode L6 signal separately, and track code shift keying(CSK)modulated signal as well. The structure was verified using both simulation data, generated in different conditions, and actual data obtained from QZSS satellites respectively. The results show that the improved tracking loop is able to track L6 signal without other frequency assitance. Furthermore, the biterror ratio(BER) of L6 tracking algorithm is lower than that of L1C/A assist L6 algorithm, when the Doppler remains a constant and reed solomn(RS)encode are applied. To be more specific, with the proposed structure the BER decreased by 11.40%, 17.07%, 15.00%, 11.15%, 5.19% when carrier to noise ratio(CNR) is 36-40 dB·Hz.

关键词： quasi-zenith satellite system L6 signal code shift keying modulation tracking algorithm

Assisting Ni catalysis by CeO_(2) with oxygen vacancy to optimize the hydrogen storage properties of MgH_(2)

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Journal of Materials Science & Technology 2023年第28期159卷 62-71页

作者： Jiangchuan Liu Qinke Tang Yunfeng Zhu Yana Liu Jiguang Zhang Zhixin ba.xiaohui Hu Liquan Li College of Materials Science and Engineering Jiangsu Collaborative Innovation Centre for Advanced Inorganic Function CompositesNanjing Tech UniversityNanjing 211816China School of Materials Science and Engineering Nanjing Institute of TechnologyNanjing 211167China

Although MgH_(2) has been widely regarded as a promising material for solid-state hydrogen storage,its high operating temperature and slow kinetics pose a major bottleneck to its practical ***,a nanocomposite catalyst with interfacial coupling and oxygen defects,Ni/CeO_(2),is fabricated to promote H_(2) desorption and absorption properties of MgH_(2).The interface of Ni/CeO_(2) contributes to both strong mechanical coupling towards stabilizing partial Ni and electronic coupling towards inducing a high con-centration of oxygen vacancies in CeO_(2).Theoretical calculations evidence that CeO_(2) with oxygen vacancy assist Ni in weakening the energy of Mg-H bond as well as enhancing the adsorption energy of Ni upon hydrogen atoms,and the extent of this assistance surprisingly increases with increasing oxygen vacancies *** a result,an impressive performance is achieved by MgH_(2)-5 wt.%Ni/CeO_(2) with onset desorption temperature of only 165°C,and it absorbs approximately 80%hydrogen in just 800 s at 125°*** generation mechanism of intermediate active species concerning Ni/CeO_(2) in different states has been analyzed for the first time,and the relationship between interfacial coupling and phase evolution has been ***,a mechanism of the catalysis-assisting effect regarding oxygen defects is *** is believed that this work provides a unique perspective on the mechanism of interfacial coupling and the generation of defects in composite catalysts.

关键词： Hydrogen storage Interfacial coupling Oxygen defects Catalysis-assisting

Genomic surveillance of emerging SARS-CoV-2 Omicron variations in Tianjin Municipality, China 2022

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Biosafety and Health 2024年第2期6卷 61-69页

作者： Xin Gao Ming Zou Yue Lei Zhaolin Tan Zhichao Zhuang baolu Zheng Aiping Yu Yanzhen Han xiaohui Lu Xiaochang Liu Ying Wang Yuan Wang Liru Guo Guangwen Liu Wen Li Yang Liu Likun Lv Peiyong Ning Xiaoyan Li Tianjin Centers for Disease Control and Prevention Tianjin 300011China Tianjin Key Laboratory of Pathogenic Microbiologyof Infectious Disease Tianjin Centers for Disease Controland PreventionTianjin 300011China

The coronavirus disease 2019(COvID-19)pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has severely impacted public *** 2022,the Omicron variant of SARS-CoV-2 rapidly became the dominant circulating variant in the local COVID-19 outbreaks in Tianjin Municipality,*** gain a deeper understanding of the genetic variations of the Omicron variant in Tianjin,specimens from indi-viduals who tested positive for SARS-CoV-2 between December 2021 and November 2022 were used for virus whole genome sequencing and phylogenetic analysis.A total of 1,674 high-quality Omicron sequences were obtained,consisting of 1,339 sequences from local cases belonging to 20 Phylogenetic Assignment of Named Global Outbreak(PANGO)lineages and 335 sequences from imported cases belonging to 70 *** experienced five waves of local outbreaks,accompanied by multiple substitutions among subvariants,ranging from the initial ba.1.1 lineage to the subsequent ba.2,BF.7,and ba.5.2 *** evolutionary rate of local strains,estimated to be 28.999 substitutions per year,and the evolutionary rate of imported strains,estimated to be 24.946 substitutions per year,were lower than that of the strains circulating *** addi-tional substitutions and deletions of local strains have been used to identify and disrupt the virus transmission *** subvariants such as ba.5.2.48,ba.5.2.49,BF.7.14,and XBB.1 circulating in the fifth epidemic wave presented criterial immune escape mutations including S:R346T,S:L452R and S:*** is essential to implement genomic surveillance strategies to investigate further the development of genomic mutation char-acteristics in the SARS-CoV-2 *** ongoing monitoring will contribute to a better understanding of the virus's genetic changes and aid in effective control measures.

关键词： Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) Coronavirus disease 2019(COVID-19) Omicron variant Whole genome sequencing(WGS)

Chemical characteristics and Pb isotopic compositions of PM2.5 in Nanchang, China

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Particuology 2017年第3期15卷 95-102页

作者： Yang Zhao Ruilian Yu Gongren Hu xiaohui Lin Xianrong Liu College of Chemical Engineering Huoqiao University Xiamen 361021 China Environmental Protection Agency of Nanchang City Nanchang 330038 China

In mid-September 2013, PM2.5 samples were collected at six sites in Nanchang, Jiangxi Province, China, to quantify nine water-soluble ions （Ca2＋, Mg2＋, K＋, Na＋, NH4＋, SO42-, Cl-, F , NO3 ）, 29 trace elements （ba, Zn, Pb, Ni, Mo, Cr, Cu, Sr, Sb, Rb, Cd, Bi, Zr, V, Ga, Li, Y, Nb, W, Cs, Tl, Sc, Co, U, Hf, In, Re, Be, and Ta）, and to characterize Pb isotopic ratios （^207pb/^206pb, ^208pb/^206pb, and ^207pb/^204pb） for identifying the main source（s） of Pb. The results showed that the average daily PM2.5 concentration （53.16 ± 24.17） Dg/m3 was within the secondary level of the Chinese ambient air quality standard. The combined concentrations of SO42-, NH4＋, and NO3- to total measured water-soluble ion concentrations in PM2.5 ranged from 79.40% to 95.18%, indicating that anthropogenic sources were significant. Coal combustion and vehicle emissions were both contributors to PM2.5 based on the NO3-/SO4^2- ratios. Wushu School experienced the lowest concentrations of PM2.s and most trace elements among the six sampling sites. Enrichment factor results showed that TI, Cr, In, Cu, Zn, Pb, Bi, Ni, Sb, and Cd in PM2.5 were affected by anthropogenic activities. Cluster analysis suggested that Cd, Sb, Pb, Re, Zn, Bi, Cs, Tl, Ga, and In were possibly related to coal combustion and vehicle exhaust, while Ni, Nb, Cr, and Mo may have originated from metal smelting. Pb isotopic tracing showed that coal dust, cement dust, road dust and construction dust were the major Pb sources in PM2.5 in Nanchang. Combined, these sources contributed an average of 72.51% of the Pb measured, while vehicle exhaust accounted for 27.49% of Pb based on results from a binary Pb isotope mixed model,

关键词： PMzs Water-soluble ions Trace elements Pb isotopic composition Nanchang

海洋来源低温果胶酶产生菌筛选、鉴定与酶学性质研究

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食品工业科技 2024年第10期45卷 133-140页

作者：赵子琪刘烨瑀于爽迟雪梅金书寒陈立功张庆芳王晓辉大连大学医学院辽宁大连116000 辽宁省海洋微生物工程技术研究中心辽宁大连116622 大连大学生命科学与技术学院辽宁大连116622 深圳市新产业生物医学工程股份有限公司广东深圳518000

目的:从海洋底泥样品中筛选能低温降解果胶的新颖菌株,发掘具有潜在产业化价值的果胶酶。方法:以果胶为唯一碳源,利用透明圈法和3,5-二硝基水杨酸法(DNS法)从大连渤海湾海泥中筛出一株高产果胶酶菌株。对其进行形态学、生理生化特征分... 详细信息

目的:从海洋底泥样品中筛选能低温降解果胶的新颖菌株,发掘具有潜在产业化价值的果胶酶。方法:以果胶为唯一碳源,利用透明圈法和3,5-二硝基水杨酸法(DNS法)从大连渤海湾海泥中筛出一株高产果胶酶菌株。对其进行形态学、生理生化特征分析以及16S rDNA序列测定,BLAST同源基因比对后构建系统发育树,并进一步研究其酶学特性。结果:筛选高产果胶酶菌株命名为LY-1,通过16S rDNA序列分析并结合生理生化鉴定确定该菌株为橄榄灰链霉菌(Streptomyces olivogriseus)。菌株LY-1在25℃、180 r/min的条件下培养至24 h时,果胶酶的酶活力为30.56 U/mL。最适酶pH为8.0,最适酶温度为20℃。此外,该酶在60℃孵育2 h仍保持70%以上的酶活性,在pH7.0~9.0范围内稳定性良好,酶活性稳定维持在90%以上。金属离子Cu^(2+)、ba^(2+)、Mg^(2+)、Ca^(2+)、K+、Co^(2+)促进该酶活性,Mn^(2+)、Zn^(2+)、Hg^(2+)、Na^(+)则抑制该酶活性。结论:菌株LY-1所产的果胶酶具有应用于产业化商用果胶酶的潜力。

关键词：果胶酶筛选鉴定酶学性质

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A Novel GPS Cross-Correlation Mitigation Algorithm based on Code Phase Comparison

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A Novel GPS Cross-Correlation Mitigation Algorithm Based on ...

基于“高精一号”接收机对QZSS系统特性的分析

第四届中国卫星导航学术年会

作者： xiaohui ba Huahua Duan Yun Wang Jie Chen the Institute of Microelectronics of Chinese Academy of Sciences （IMECAS）

The cross-correlation problems occur in any instance in which weak GPS signals need to be acquired and tracked in the presence of other strong GPS signals. The influence of cross-correlation must be considered in the design of high-sensitivity acquisition method. In this paper, a new detection method is presented based on multiple times acquisition and code phase comparison （CPC）. One group of code phases is obtained after one acquisition and the code phases of the maximum several peaks are selected and stored in an array. After multiple times acquisition, multiple groups of code phase are obtained. We can find whether the code phase of autocorrelation appears according to the comparison method presented in this paper. The CPC algorithm need not reconfigure the strong PRN signal and has relative higher acquisition sensitivity in the presence of cross-correlation interference. The experimental results show that the CPC method can effectively find autocorrelation peak of weak signal with -147dBm power level, in presence of one strong signal with -124dBm power level.

关键词： GPS Cross-correlation High-sensitivity Code Phase Comparison

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中国惯性技术学报 2018年第4期26卷 452-457页

作者：王依婷巴晓辉中国科学院微电子研究所北京100029 中国科学院大学北京100049

日本的QZSS刚完成第一阶段四颗卫星的部署。利用自主研发的"高精一号"多模多频接收机对QZSS卫星的L1C/A、L1-SAIF、L2C和L5信号特性、系统可见性以及定位服务性能进行研究。通过对监测结果的分析与对比,在中国区域观测到QZSS四颗卫星,... 详细信息

日本的QZSS刚完成第一阶段四颗卫星的部署。利用自主研发的"高精一号"多模多频接收机对QZSS卫星的L1C/A、L1-SAIF、L2C和L5信号特性、系统可见性以及定位服务性能进行研究。通过对监测结果的分析与对比,在中国区域观测到QZSS四颗卫星,其中三颗QZO轨道卫星的星下点轨迹重合呈不对称"8"字形;使用QZSS卫星协同配合GPS系统可以有效减少定位误差,提高GNSS接收机定位成功率和定位精度,相较于GPS L5信号单独定位,在北京地区,截止仰角为10°和20°时,成功率分别提升52%、68%。

关键词： GNSS接收机 “准天顶”卫星系统 L1C/A L1-SAIF L2C L5

适用于BOC(m,n)信号的无模糊捕获技术

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航空学报 2017年第4期38卷 217-226页

作者：张洪伦巴晓辉陈杰周航中国科学院微电子研究所北京100029 中国科学院大学北京100049

针对二进制偏移载波(BOC)调制信号自相关多峰特性引起的信号捕获模糊性问题,提出了一种子相关相乘边峰消除技术(CMSCT)。根据BOC子相关函数的特性,通过将不同子相关函数相乘获得边峰消除能力,并且为了充分利用接收信号,进一步提高捕获性... 详细信息

针对二进制偏移载波(BOC)调制信号自相关多峰特性引起的信号捕获模糊性问题,提出了一种子相关相乘边峰消除技术(CMSCT)。根据BOC子相关函数的特性,通过将不同子相关函数相乘获得边峰消除能力,并且为了充分利用接收信号,进一步提高捕获性能,提出了相应的优化算法。分析对比了提出算法的实现复杂度和基于恒虚警率准则的峰值发现概率,对Galileo E1C中频采样信号的处理结果表明:提出的边峰消除方法有效解决了捕获模糊性问题。

关键词：全球导航卫星系统二进制偏移载波调制无模糊捕获相关函数边峰消除