Excellent microwave absorption of FeCo/ZnO composites with defects in ZnO for regulating the impedance matching

Bao, Xiukun,Wang, Xiaolei,Zhou, Xinao,Shi, Guimei,Xu, Ge,Yu, Jin,Guan, Yinyan,Zhang, Yajing,Li, Da,Choi, Chuijin Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.769 No.-

<P><B>Abstract</B></P> <P>FeCo/ZnO composites have been successfully prepared through liquid-phase reduction process for the formation of FeCo polyhedrons and sequentially thermal decomposition of colloidal mixture of FeCo and Zn(Ac)<SUB>2</SUB>·2H<SUB>2</SUB>O under nitrogen atmospheres. ZnO nanoparticles are homogeneously deposited on the surface of FeCo polyhedrons and the level of oxygen-vacancy defects in ZnO can be elevated with the increase of ZnO content. By comparison with FeCo polyhedrons, FeCo/ZnO composites exhibit excellent microwave absorption. The optimal RL value can reach −34.8 dB at 14.8 GHz and effective bandwidth (RL < −10 dB) is 5.1 GHz in the frequency range of 12.4–17.5 GHz with a matching thickness of 1.5 mm. The integrated bandwidth with RL < −10 dB can reach 14.1 GHz covering 3.4–17.5 GHz. Theory analysis demonstrates the interfacial polarization, dipole polarization and high conductivity due to oxygen-vacancy defects in FeCo/ZnO composites contribute to enhancement of dielectric loss capacity, which is more favorable for impedance matching.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The preferable impedance matching of FeCo/ZnO composites can be achieved by regulating the ZnO content. </LI> <LI> The optimal reflection loss (RL) can reach −34.8 dB with a matching thickness of 1.5 mm. </LI> <LI> The effective bandwidth with RL < −10 dB achieve 14.1 GHz covering 3.4–17.5 GHz with integrated thickness of 1.5–5 mm. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

形式動詞“進行”構成句式的多角度考察

李桂梅(Li Guimei) 한국중국어교육학회 2016 중국어교육과연구 Vol.0 No.24

This paper, analyses the sentence with dummy verb “进行” in depth from the new perspectives of event frame, cognitive factor of nominalization, social power. This paper argues that the semantic meaning of sentence with “jinxing” is “the agent acts of his/her own free will”, the events that presented by the sentence holds the semantic features of integrity, some relevant out-event perspective characteristics and multi-informational structure feature. Its usage is constrained by the social power and the importance of the event.

漢語中介語語料庫建設的甁頸及解決方案

李桂梅 ( Li Guimei ) 한국외국어대학교 중국연구소 2018 中國硏究 Vol.75 No.-

This paper points out that the biggest bottleneck in the construction of Chinese interlanguage corpora is corpus collection, and building corpus with Chinese test corpora is the best way to solve this problem. The cooperation between Chinese interlanguage corpus construction and Chinese testis very important not only to improve the efficiency and quality of the construction of Chinese interlanguage, but also to the field of Chinese international education, such as Chinese test, teaching and acquisition research, and the compilation of teaching materials.

LINC01232 Promotes Gastric Cancer Proliferation through Interacting with EZH2 to Inhibit the Transcription of KLF2

( Jing Liu ),( Zhen Li ),( Guohua Yu ),( Ting Wang ),( Guimei Qu ),( Yunhui Wang ) 한국미생물 · 생명공학회 2021 Journal of microbiology and biotechnology Vol.31 No.10

To clarify the role of long intergenic nonprotein-coding RNA 1232 (LINC01232) in the progression of gastric cancer and the potential mechanism, we analyzed the expression of LINC01232 in TCGA database using the GEPIA online tool, and the LINC01232 level in gastric cancer cell lines was detected by quantitative real time-polymerase chain reaction (qRT-PCR) as well. Cell proliferation assay, colony formation assay, transwell assay and tumor formation experiment in nude mice were conducted to observe the biological behavior changes of gastric cancer cells through the influence of LINC01232 knockdown. LncATLAS database and subcellular isolation assay were used for subcellular distribution of LINC01232 in gastric cancer cells. The interaction among LINC01232, zeste homolog 2 (EZH2) and kruppel-like factor 2 (KLF2) was clarified by RNA-protein interaction prediction (RPISeq), RNA immunoprecipitation (RIP), qRT-PCR and chromatin immunoprecipitation (ChIP) assay. Rescue experiments were further conducted to elucidate the biological function of LINC01232/KLF2 axis in the progression of gastric cancer. LINC01232 was upregulated in stomach adenocarcinoma (STAD) tissues and gastric cancer lines. LINC01232 knockdown inhibited the proliferative capacities of gastric cancer cells in vitro, and impaired in vivo tumorigenicity. LINC01232 was mainly distributed in the cell nucleus where it epigenetically repressed KLF2 expression via binding to the enhancer of EZH2, which was capable of binding to promoter regions of KLF2 to induce histone H3 lysine 27 trimethylation (H3K27me3). LINC01232 exerts oncogenic activities in gastric cancer via inhibition of KLF2, and therefore, the knockdown of KLF2 could reverse the regulatory effect of LINC01232 in the proliferative ability of gastric cancer cells.

Influence of Mode of Delivery on Children’s Attention Deficit Hyperactivity Disorder and Childhood Intelligence

Min Xu,Xuemei Yu,Benjie Fan,Guimei Li,Xinxin Ji 대한신경정신의학회 2023 PSYCHIATRY INVESTIGATION Vol.20 No.8

Objective To investigate whether differences exist in attention deficit hyperactivity disorder (ADHD) and intelligence between children born by cesarean delivery and those born by vaginal delivery.Methods This retrospective study included singleton children that were born between January 2013 and December 2014. The Chinese version of the Conners’ Parent Rating Scale–Revised (CPRS-48) was required on the probability of psychological and behavioral problems. The China–Wechsler Intelligence Scale for Children (C-WIRS) was used for evaluation of crystallized intelligence and Raven’s Standard Progressive Matrices for evaluation of fluid intelligence.Results A total of 10,568 valid questionnaires were obtained. CPRS-48 ADHD index and detection rate were higher in cesarean delivery group than those in vaginal delivery group. Cesarean delivery groups had a lower performance intelligence quotient score according to C-WISC.Conclusion Children born by cesarean delivery were more likely to have a risk of ADHD and a lower performance intelligence quotient compared with those born by vaginal delivery.

Gallic Acid Ameliorates Cognitive Impairment Caused by Sleep Deprivation through Antioxidant Effect

Pang Xiaogang,Xu Yifan,Xie Shuoxin,Zhang Tianshu,Cong Lin,Qi Yuchen,Liu Lubing,Li Qingjun,Mo Mei,Wang Guimei,Du Xiuwei,Shen Hui,Li Yuanyuan 한국뇌신경과학회 2023 Experimental Neurobiology Vol.32 No.4

Sleep deprivation (SD) has a profound impact on the central nervous system, resulting in an array of mood disorders, including depression and anxiety. Despite this, the dynamic alterations in neuronal activity during sleep deprivation have not been extensively investigated. While some researchers propose that sleep deprivation diminishes neuronal activity, thereby leading to depression. Others argue that short-term sleep deprivation enhances neuronal activity and dendritic spine density, potentially yielding antidepressant effects. In this study, a two-photon microscope was utilized to examine the calcium transients of anterior cingulate cortex (ACC) neurons in awake SD mice in vivo at 24-hour intervals. It was observed that SD reduced the frequency and amplitude of Ca2+ transients while increasing the proportions of inactive neurons. Following the cessation of sleep deprivation, neuronal calcium transients demonstrated a gradual recovery. Moreover, whole-cell patch-clamp recordings revealed a significant decrease in the frequency of spontaneous excitatory post-synaptic current (sEPSC) after SD. The investigation also assessed several oxidative stress parameters, finding that sleep deprivation substantially elevated the level of malondialdehyde (MDA), while simultaneously decreasing the expression of Nuclear Factor erythroid 2-Related Factor 2 (Nrf2) and activities of Superoxide dismutase (SOD) in the ACC. Importantly, the administration of gallic acid (GA) notably mitigated the decline of calcium transients in ACC neurons. GA was also shown to alleviate oxidative stress in the brain and improve cognitive impairment caused by sleep deprivation. These findings indicate that the calcium transients of ACC neurons experience a continuous decline during sleep deprivation, a process that is reversible. GA may serve as a potential candidate agent for the prevention and treatment of cognitive impairment induced by sleep deprivation.