Parallel Gene Loss and Acquisition Among Strains of Different Brucella Species and Biovars

Zhijun Zhong,Yufei Wang,Jie Xu,Yanfen Chen,Yuehua Ke,Xiaoyan Zhou,Xitong Yuan,Dongsheng Zhou,Yi Yang,Ruifu Yang,Guangneng Peng,Hai Jiang,Jing Yuan,Hongbin Song,Buyun Cui,Liuyu Huang,Zeliang Chen 한국미생물학회 2012 The journal of microbiology Vol.50 No.4

The genus Brucella is divided into six species; of these, B. melitensis and B. abortus are pathogenic to humans, and B. ovis and B. neotomae are nonpathogenic to humans. The definition of gene loss and acquisition is essential for understanding Brucella’s ecology, evolutionary history, and host relationships. A DNA microarray containing unique genes of B. melitensis Type strain 16MT and B. abortus 9-941 was constructed and used to determine the gene contents of the representative strains of Brucella. Phylogenetic relationships were inferred from sequences of housekeeping genes. Gene loss and acquisition of different Brucella species were inferred. A total of 214 genes were found to be differentially distributed,and 173 of them were clustered into 15 genomic islands (GIs). Evidence of horizontal gene transfer was observed for 10GIs. Phylogenetic analysis indicated that the 19 strains formed five clades, and some of the GIs had been lost or acquired independently among the different lineages. The derivation of Brucella lineages is concomitant with the parallel loss or acquisition of GIs, indicating a complex interaction between various Brucella species and hosts.

Next-generation sequencing data used to determine the mitochondrial genomes and a preliminary phylogeny of Verophasmatodea insects

Zhijun Zhou,Bei Guan,Jinyan Chai,Xuting Che 한국응용곤충학회 2017 Journal of Asia-Pacific Entomology Vol.20 No.2

We used Illumina next-generation sequencing data to generate the nearly complete mitochondrial genomes (mitogenomes) of three phasmatodeans (Megalophasma granulata, Calvisia medogensis, and Phyllium tibetense) without the aid of additional techniques such as long-range PCR or cloning. The most surprising finding was the presence of a novel gene arrangement “trnR-trnA-trnN-trnSAGN-trnE-trnF” (genes underlined are encoded by the minority strand) that was detected in M. granulata. The ancestral order of this tRNA gene cluster is typically “trnA-trnR-trnN-trnSAGN-trnE-trnF”. However, trnA was inserted between trnR and trnN in M. granulata, and this represents a rare case of gene rearrangement in Phasmatodea. Phylogenetic analyses were conducted on the concatenated nucleotide sequences of all protein-coding genes and two ribosomal RNA genes. Both maximum likelihood and Bayesian analyses failed to support the monophyly of Areolatae, Anareolatae, Diapheromeridae, Phasmatidae, Heteropterygidae, Necrosciinae, and Necrosciini. However, the monophyly of several lower taxonomic groups were confirmed in our analysis. For instance, two Ramulus species and Entoria okinawaensis were recovered in the monophyletic Clitumnini, and Phraortes, Phyllium, and Bacillus species formed individual monophyletic clades. Our results support the hypothesis that wing-loss independently occurred several times in Verophasmatodea.

LCL resonant current depression control strategy against pulse width modulated harmonic voltage under low switching frequency

Ma, Zhijun,Zhou, Linyuan,Liu, Jinjun,Zhou, Sizhan The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.2

The LCL filter is widely used in grid connected converters for good harmonic mitigation performance. With pulse width modulation strategy, converter terminal voltage contains various sideband harmonic components together with expected components corresponding to the modulation wave, especially under a low switching frequency. Considerable resonant current can be generated if the undesired sideband harmonic voltage is located around the LCL resonant frequency. With the background of a medium voltage three-level wind power converter, where the switching frequency is as low as 1.5 kHz, a resonant current depression strategy is proposed against undesired sideband harmonic voltage under low switching frequency. Additional compensators are adopted in the converter current loop. Depending on the system mathematical model, two solutions, a Butterworth low pass filter and a notch filter, based on phase compensation and amplitude compensation, are proposed in this paper. It is shown that the Butterworth low pass filter exhibits better resonant current depression performance, while the notch filter performance is better in terms of system stability. Simulation and experimental results validated the proposed control method.

Carbon nanofibers supported Ru catalyst for sorbitol hydrogenolysis to glycols: Effect of calcination

Jinghong Zhou,Long Zhao,Hong Chen,Mingguang Zhang,Zhijun Sui,Xinggui Zhou 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.5

Carbon nanofiber (CNFs) supported Ru catalysts for sorbitol hydrogenolysis to ethylene glycol and propylene glycol were prepared by incipient wetness impregnation, calcination and reduction. The effect of calcination on catalyst properties was investigated using thermal gravimetry analysis, temperature-programmed reduction, X-ray diffraction,X-ray photoelectron spectroscopy, transmission electron microscopy and N2 physisorption. The results indicated that calcination introduced a great amount of surface oxygen-containing groups (SOCGs) onto CNF surface and induced the phase transformation of Ru species, but slightly changed the texture of Ru/CNFs. The catalytic performance in sorbitol hydrogenolysis showed that Ru/CNFs catalyst calcined at 240 oC presented the highest glycol selectivities and reasonable glycol yields. It was believed that the inhibition and confinement effect of SOCGs around Ru particles as well as the high dispersion of Ru particles was the key factor for the catalytic activity.

Quantitative trait locus mapping and genomic selection of tobacco (Nicotiana tabacum L.) based on high-density genetic map

Tong Zhijun,Xiu Zhihui,Ming Yao,Fang Dunhuang,Chen Xuejun,Hu Yafei,Zhou Juhong,He Weiming,Jiao Fangchan,Zhang Chi,Zhao Shancen,Jin Han,Jian Jianbo,Xiao Bingguang 한국식물생명공학회 2021 Plant biotechnology reports Vol.15 No.6

Tobacco ( Nicotiana tabacum L.) is an economic crop and a model organism for studies of plant biology and genetics. As an allotetraploid plant generated from interspecific hybridization, tobacco has a massive genome (4.5 Gb). Recently, a genetic map with 45,081 single nucleotide polymorphism (SNP) markers was constructed using whole-genome sequencing data for a tobacco population including 274 individuals. This provides a basis for quantitative trait locus (QTL) mapping and genomic selection, which have been widely applied to other crops but have not been feasible in tobacco. Based on this high-density genetic map, we identified QTLs associated with important agronomic traits, chemical compounds in dry leaves, and hazardous substances in processed cigarettes. The LOD values for major QTLs were highest for agronomic traits, followed by chemical compounds and hazardous substances. In addition to the identification of molecular markers, we evaluated genomic selection models and found that BayesB had the highest prediction accuracy for the recombinant inbred line population. Our results offer new insights into the genetic mechanism underlying important traits, such as agronomic traits and quality-related chemical compounds in tobacco, and will be able to support the application of molecular breeding to tobacco.

Memory characteristics and tunneling mechanism of Pt nano-crystals embedded in HfAlOx films for nonvolatile flash memory devices

Guangdong Zhou,BoWu,Zhiling Li,Zhijun Xiao,Shuhui Li,Ping Li 한국물리학회 2015 Current Applied Physics Vol.15 No.3

A non-volatile flash memory device based on metal oxide semiconductor (MOS) capacitor structure hasbeen fabricated using platinum nano-crystals(PteNCs) as storage units embedded in HfAlOx high-ktunneling layers. Its memory characteristics and tunneling mechanism are characterized by capacitanceevoltage(CeV) and flat-band voltage-time(ΔVFB-T) measurements. A 6.5 V flat-band voltage(memory window) corresponding to the stored charge density of 2.29 × 1013 cm-2 and about 88% storedelectron reserved after apply ±8 V program or erase voltage for 105 s at high frequency of 1 MHz wasdemonstrated. Investigation of leakage currentevoltage(JeV) indicated that defects-enhanced Pool-Frenkel tunneling plays an important role in the tunneling mechanism for the storage charges. Hence,the PteNCs and HfAlOx based MOS structure has a promising application in non-volatile flash memorydevices.

The One-persistent Multichannel CSMA Protocol with Monitoring Functions Based on Conflict Resolution Algorithm in WSN

Shengjie Zhou,Hongwei Ding,Yifan Zhao,Zhijun Yang,Qianlin Liu 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.1

In the Wireless Sensor Network, a new MAC protocol: one-persistent CSMA protocol with monitoring functions and multichannel mechanism for Wireless Sensor Network based on conflict resolution algorithm is proposed. Protocol from the system throughput, collision rate, better service quality for higher priority and other aspects improve the traditional CSMA system to perfect the controllability of the system, making the system more stable for the big data, better adapted to different business. The average cycle method is used to derive rigorous mathematical expressions of specific relevant parameters. Using MATLAB simulation tool for the accuracy of the agreement is demonstrated.

Temporal expression profiling of long noncoding RNA and mRNA in the peripheral blood during porcine development

Gu, Yiren,Zhou, Rui,Jin, Long,Tao, Xuan,Zhong, Zhijun,Yang, Xuemei,Liang, Yan,Yang, Yuekui,Wang, Yan,Chen, Xiaohui,Gong, Jianjun,He, Zhiping,Li, Mingzhou,Lv, Xuebin Asian Australasian Association of Animal Productio 2020 Animal Bioscience Vol.33 No.5

Objective: We investigated the temporal expression profiles of long noncoding RNA (lncRNA) and mRNA in the peripheral blood of pigs during development and identified the lncRNAs that are related to the blood-based immune system. Methods: Peripheral blood samples were obtained from the pigs at 0, 7, 28, and 180 days and 2 years of age. RNA sequencing was performed to survey the lncRNA and mRNA transcriptomes in the samples. Short time-series expression miner (STEM) was used to show temporal expression patterns in the mRNAs and lncRNAs. Gene ontology and Kyoto encyclopedia of genes and genomes analyses were performed to assess the genes' biological relevance. To predict the functions of the identified lncRNAs, we extracted mRNAs that were nearby loci and highly correlated with the lncRNAs. Results: In total of 5,946 lncRNA and 12,354 mRNA transcripts were identified among the samples. STEM showed that most lncRNAs and mRNAs had similar temporal expression patterns during development, indicating the expressional correlation and functional relatedness between them. The five stages were divided into two classes: the suckling period and the late developmental stage. Most genes were expressed at low level during the suckling period, but at higher level during the late stages. Expression of several T-cell-related genes increased continuously during the suckling period, indicating that these genes are crucial for establishing the adaptive immune system in piglets at this stage. Notably, lncRNA TCONS-00086451 may promote blood-based immune system development by upregulating nuclear factor of activated T-cells cytoplasmic 2 expression. Conclusion: This study provides a catalog of porcine peripheral blood-related lncRNAs and mRNAs and reveals the characteristics and temporal expression profiles of these lncRNAs and mRNAs during peripheral blood development from the newborn to adult stages in pigs.

Preliminary Study of the Effect of Secondary Airflow on Fiber Attenuation During Melt Blowing

Huawei Xu,Zhijun Zhou,Jie Liu,Lie Zhao,Sheng Xie,Junfeng Zhang 한국섬유공학회 2022 Fibers and polymers Vol.23 No.11

In order to enhance the fiber attenuation during the melt-blown process, a pair of air nozzle, which could eruptairflow as secondary airflow, below the spinning die was arranged and used. Firstly, the effect of applying secondary airflowon the whole airflow was explored by Computational Fluid Dynamics (CFD) simulation. The simulation results demonstratethe interactive relationship between the primary airflow from the spinning die and the secondary airflow. Then, the airvelocity of the whole airflow at conditions of with and without secondary airflow was experimental verified. Finally, theeffect of secondary airflow on the fiber diameter and the fiber evenness was investigated by a spinning experiment. Thespinning results reveals that the application of secondary airflow does not certainly enhance the fiber attenuation. The fiberdiameter decreases only when the inlet velocity of secondary airflow is higher than a critical value. In addition, the spinningexperiment indicates that the application of secondary airflow improves the evenness of fiber.

Form- finding analysis of suspension bridges using an explicit Iterative approach

Hongyou Cao,Yun-Lai Zhou,Zhijun Chen,Magd Abdel Wahab 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.62 No.1

This paper presents an explicit analytical iteration method for form-finding analysis of suspension bridges. By extending the conventional analytical form-finding method predicated on the elastic catenary theory, two nonlinear governing equations are derived for calculating the accurate unstrained lengths of the entire cable systems both the main cable and the hangers. And for the gradient-based iteration method, the derivation of explicit calculation for the Jacobian matrix while solving the nonlinear governing equation enhances the computational efficiency. The results from sensitivity analysis show well performance of the explicit Jacobian matrix compared with the traditional finite difference method. According to two numerical examples of long span suspension bridges studied, the proposed method is also compared with those reported approaches or the fundamental criterions in suspension bridge structural analysis, which eventually confirms the accuracy and efficiency of the proposed approach.