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Synthesis of Branched Polyethylene via Bulky α-Diimine Nickel(II)-Catalyzed Ethylene Chain-Walking Polymerization

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Open Journal of Organic Polymer Materials 2024年第1期13卷 1-12页

作者： Zhengquan Dong pei li Guoyong Xu Fuzhou Wang Institutes of Physical Science and Information Technology School of Computer Science and Technology Anhui University Hefei China

The catalysis of olefin polymerization through the chain-walking process is a subject of great interest. In this contribution, the successful synthesis of a Brookhart-type unsymmetrical α-diimine nickel catalyst Ni, which contains both dibenzhydryl and phenyl groups, was determined by X-ray crystallography. The compound has a pseudo-tetrahedral geometry at the Ni center, showing pseudo-C2-symmetry. Upon activation with modified methylaluminoxane (MMAO), Ni1 exhibits high catalytic activity up to 1.02 × 107 g PE (mol Ni h)−1 toward ethylene polymerization, enabling the synthesis of high molecular weight branched polyethylene. The molecular weights and branching densities could be tuned over a very wide range. The polymerization results indicated the possibility of precise microstructure control, depending on the polymerization temperature. The branching densities were decreased with increasing the polymerization temperature.

关键词： Ethylene Polymerization α-Diimine Ni(II) Complex Chain-Walking Polymerization Branched Polyethylene

Emerging mechanisms of ferroptosis and its implications in lung cancer

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中华医学杂志(英文版) 2024年第7期137卷 818-829页

作者： li Qian Song Qibin pei Huadong Chen Yali USA State Key Laboratory of Medical Proteomics National Center for Protein Sciences (Beijing) Beijing Institute of lifeomics Beijing 102206 Cancer Center Renmin Hospital of Wuhan University Wuhan Hubei 430060 China Department of Oncology Georgetown Lombardi Comprehensive Cancer Center Georgetown University Medical Center Washington D.C. 20057

Lung cancer is one of the most common malignancies and has the highest number of deaths among all cancers. Despite continuous advances in medical strategies, the overall survival of lung cancer patients is still low, probably due to disease progression or drug resistance. Ferroptosis is an iron-dependent form of regulated cell death triggered by the lethal accumulation of lipid peroxides, and its dysregulation is implicated in cancer development. Preclinical evidence has shown that targeting the ferroptosis pathway could be a potential strategy for improving lung cancer treatment outcomes. In this review, we summarize the underlying mechanisms and regulatory networks of ferroptosis in lung cancer and highlight ferroptosis-targeting preclinical attempts to provide new insights for lung cancer treatment.

关键词： Lung cancer Ferroptosis Ferroptosis regulators Ferroptosis inducers Cancer treatment

AWG-based large dynamic range fiber Bragg grating interrogation system

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Optoelectronics Letters 2024年第3期20卷 129-134页

作者： li Shufeng YUAN pei li Ke li Ting ZHU lianqing Key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument Beijing Information Science&Technology UniversityBeijing 100192China Beijing Laboratory of Optical Fiber Sensing and System Beijing Information Science&Technology UniversityBeijing 100016China

Arrayed waveguide gratings(AWGs) are extensively employed in fiber Bragg grating(FBG) interrogation systems due to their compact size, lightweight nature, and excellent interrogation performance. The resolution and total measurement range of AWG-based FBG interrogation systems are constrained by the output properties of AWG. We proposed an AWG-based large dynamic range interrogation system. The temperature dependence of AWG is exploited to achieve continuous interrogation. The test results show that the interrogation system has a dynamic range of 28.67 nm, an interrogation accuracy better than 25 pm, and a wavelength resolution of 6 pm.

关键词： fiber waveguide AWG

Single-cell RNA sequencing to understand host-virus interactions

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Virologica Sinica 2024年第1期39卷 1-8页

作者： Jia-Tong Chang li-Bo liu pei-Gang Wang Jing An Department of Microbiology School of Basic Medical SciencesCapital Medical UniversityBeijing 100069China

Single-cell RNA sequencing(scRNA-seq)has allowed for the profiling of host and virus transcripts and host-virus interactions at single-cell resolution.This review summarizes the existing scRNA-seq technologies together with their strengths and weaknesses.The applications of scRNA-seq in various virological studies are discussed in depth,which broaden the understanding of the immune atlas,host-virus interactions,and immune repertoire.scRNA-seq can be widely used for virology in the near future to better understand the pathogenic mechanisms and discover more effective therapeutic strategies.

关键词： Single-cell RNA sequencing(scRNA-seq) Host-virus interaction COVID-19 Flavivirus

Spacelike Framed Curves with lightlike Components and Singularities of Their Evolutes and Focal Surfaces in Minkowski 3-space

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1521-1532页

作者： Peng Cheng li Dong He pei Xin ZHAO School of Mathematics and Statistics Northeast Normal UniversityChangchun 130024P.R.China Department of Mathematics Harbin Institute of TechnologyWeihai 264209P.R.China School of Mathematics and Statistics Qingdao UniversityQingdao 266071P.R.China

In this paper,we define the evolute and focal surface of a spacelike framed curve with lightlike components in Minkowski 3-space.It is a generalization of the previous results of regular spacelike curves,since singularities are allowed in the original spacelike curves studied by spacelike framed curves with lightlike components.Meanwhile,we show a new geometric invariant to characterise singularities of the focal surface.Then,the classification theorem and recognition theorem for the singularities of the focal surface in generic are also given.

关键词： Evolutes focal surfaces spacelike framed curves singularities

Temporal assembly patterns of microbial communities in three parallel bioreactors treating low-concentration coking wastewater with differing carbon source concentrations

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Journal of Environmental Sciences 2024年第3期137卷 455-468页

作者： Weijia li Yu Xia Na li Jie Chang Jing liu pei Wang Xuwen He School of Chemical and Environmental Engineering China University of Mining and Technology-BeijingBeijing 100083China

Carbon source is an important factor of biological treatment systems, the effects of which on their temporal community assembly patterns are not sufficiently understood currently.In this study, the temporal dynamics and driving mechanisms of the communities in three parallel bioreactors for low-concentration coking wastewater(CWW) treatment with differing carbon source concentrations(S0 with no glucose addition, S1 with 200 mg/L glucose addition and S2 with 400 mg/L glucose addition) were comprehensively studied. Highthroughput sequencing and bioinformatics analyses including network analysis and Infer Community Assembly Mechanisms by Phylogenetic bin-based null model(iCAMP) were used. The communities of three systems showed turnover rates of 0.0029~0.0034 every 15days. Network analysis results showed that the S0 network showed higher positive correlation proportion(71.43%) and clustering coefficient(0.33), suggesting that carbon source shortage in S0 promoted interactions and cooperation of microbes. The neutral community model analysis showed that the immigration rate increased from 0.5247 in S0 to 0.6478in S2. The iCAMP analysis results showed that drift(45.89%) and homogeneous selection(31.68%) dominated in driving the assembly of all the investigated microbial communities.The contribution of homogeneous selection increased with the increase of carbon source concentrations, from 27.92% in S0 to 36.08% in S2. The OTUs participating in aerobic respiration and tricarboxylic acid(TCA) cycle were abundant among the bins mainly affected by deterministic processes, while those related to the metabolism of refractory organic pollutants in CWW such as alkanes, benzenes and phenols were abundant in the bins dominated by stochastic processes.

关键词： Coking wastewater treatment Temporal dynamics Network analysis Deterministic processes Stochastic processes

Effective Ultra-High-Speed Identification Scheme of lightning Strikes Suitable for VSC-Based DC Grids

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 548-561页

作者： Longlong Chen Xiangyu pei Xiaoguang Wei Pengzhi li Guangfu Tang North China Electric Power University(NCEPU) Beijing 102206China Changsha University of Science and Technology Changsha 410114China State Key Laboratory of Advanced Power Transmission Technology State Grid Smart Grid Research Institute Co.Ltd.Beijing 102209China

To ensure their sound and continuous operation to the greatest extent,VSC-based DC girds have extremely stringent requirements for transmission line relay protection.In terms of guaranteeing their reliability,accurate identification of lightning strikes on DC transmission lines is one of the urgent key problems to be solved.An effective ultra-high-speed identification scheme of lightning strikes suitable for the VSC-based DC grid is proposed in this paper.First,an 1-mode reverse voltage traveling wave(RVTW)is constructed applying the pole-mode transformation theory.Next,fault traveling wave propagation characteristics along the DC transmission line are analyzed in depth utilizing Peterson's law.Then,differences of time-frequency electromagnetic transient characteristics of 1-mode RVTWs between disturbances and faults caused by lightning strikes are distinguished in detail by means of the classical wavelet transformation multi-resolution analysis theory.Finally,extensive simulations are carried out to evaluate the performance of the proposed identification scheme,and by which its excellent rapidity,reliability and robustness are validated.Index Terms-lightning-strike identification,Multi-resolution analysis,Relay protection,Traveling-wave protection,VsC-based DC grid,Wavelet transformation.

关键词： lightning-strike identification Multi-resolution analysis Relay protection Traveling-wave protection VsC-based DC grid Wavelet transformation

Privacy Preserving Algorithm for Spectrum Sensing in Cognitive Vehicle Networks

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Chinese Journal of Electronics 2024年第1期33卷 30-42页

作者： Hongning li Tonghui HU Jiexiong CHEN Xiuqiang WU Qingqi pei Guangzhou Institute of Technology Xidian University Guangzhou CEPREI Shaanxi Key Laboratory of Blockchain and Secure Computing

The scarcity of spectrum resources fails to meet the increasing throughput demands of vehicular networks. There is an urgent need to maximize the utilization of spectrum bands in mobile networks. To ascertain the availability of spectrum bands, users should engage in wireless channel sensing and collaboration. However, spectrum sensing data always involves users’ privacy, such as their location. This paper first introduces sensing trajectory inference attack in cognitive vehicular networks and then proposes a data confusion-based privacy-preserving algorithm and a cryptonym array-based privacy-preserving aggregation scheme for spectrum sensing in cognitive vehicular networks. Unlike existing methods, the proposed schemes transmit confused data during the aggregation process. This deliberate obfuscation makes it almost impossible to infer users’ location from the transmitted data. The analysis demonstrates the resilience of the proposed schemes against sensing trajectory inference attack.

关键词： Location privacy preservation Cognitive radio network Cooperative spectrum sensing

The roles of macrophage migration inhibitory factor in retinal diseases

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Neural Regeneration Research 2024年第2期19卷 309-315页

作者： Hongbing Zhang Xianjiao Zhang Hongsong li Bing Wang pei Chen Jiamin Meng Shaanxi Institute of Ophthalmology Xi’anShaanxi ProvinceChina Department of Ophthalmology First Affiliated Hospital of Northwest UniversityXi’anShaanxi ProvinceChina Department of Pathology First Affiliated Hospital of Northwest UniversityXi’anShaanxi ProvinceChina

Macrophage migration inhibitory factor(MIF),a multifunctional cytokine,is secreted by various cells and participates in inflammatory reactions,including innate and adaptive immunity.There are some evidences that MIF is involved in many vitreoretinal diseases.For example,MIF can exacerbate many types of uveitis;measurements of MIF levels can be used to monitor the effectiveness of uveitis treatment.MIF also alleviates trauma-induced and glaucoma-induced optic nerve damage.Furthermore,MIF is critical for retinal/choroidal neovascularization,especially complex neovascularization.MIF exacerbates retinal degeneration;thus,anti-MIF therapy may help to mitigate retinal degeneration.MIF protects uveal melanoma from attacks by natural killer cells.The mechanism underlying the effects of MIF in these diseases has been demonstrated:it binds to cluster of differentiation 74,inhibits the c-Jun N-terminal kinase pathway,and triggers mitogen-activated protein kinases,extracellular signal-regulated kinase-1/2,and the phosphoinositide-3-kinase/Akt pathway.MIF also upregulates Toll-like receptor 4 and activates the nuclear factor kappa-B signaling pathway.This review focuses on the structure and function of MIF and its receptors,including the effects of MIF on uveal inflammation,retinal degeneration,optic neuropathy,retinal/choroidal neovascularization,and uveal melanoma.

关键词： diabetic retinopathy glaucoma macrophage migration inhibitory factor migration inhibitory factor receptor optic neuropathy retinal degeneration retinal neovascular uveal melanoma uveitis