Effects of Temperature Distribution on Microstructure and Mechanical Properties of Hot Extruded Al–Zn–Mg–Cu Alloy Pipe with Variable Cross-Section

Lei Luo,Zhiyi Liu,Song Bai,Jing Cao,Fei Liu,Linnan Ou,Juangang Zhao 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.9

The microstructures and mechanical properties of a hot extruded Al–Zn–Mg–Cu alloy pipe with variable cross-section areinvestigated by transmission electron microscopy, electron backscattering diffraction, hardness testing and finite elementmethod. The results suggest that the variable temperature distribution at different positions along the extrusion directionafter hot extrusion attribute to the changes in hot deformation degrees. The extruded profile at billet temperature of 410 °Cand a ram speed of 1.5 mm/s shows a gradual increase in temperature from 416 to 467 °C at strains from 3.7 to 8.6 alongthe extrusion direction. The dynamic recovery (DRV) and partial dynamic recrystallization (DRX) are observed in the hotextruded profile, and high-angle grain boundaries fraction exponentially rises along the extrusion direction. The hardnessat different positions of the hot extruded profile shows a nearly exponential decline along the extrusion direction, mainlyascribes to the decrease of the dislocation density that caused by the dynamic softening.

LncRNA TMPO-AS1 promotes esophageal squamous cell carcinoma progression by forming biomolecular condensates with FUS and p300 to regulate TMPO transcription

Luo Xiao-Jing,He Ming-Ming,Liu Jia,Zheng Jia-Bo,Wu Qi-Nian,Chen Yan-Xing,Meng Qi,Luo Kong-Jia,Chen Dong-Liang,Xu Rui-Hua,Zeng Zhao-Lei,Liu Ze-Xian,Luo Hui-Yan 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Esophageal squamous cell carcinoma (ESCC) is one of the most life- and health-threatening malignant diseases worldwide, especially in China. Long noncoding RNAs (lncRNAs) have emerged as important regulators of tumorigenesis and tumor progression. However, the roles and mechanisms of lncRNAs in ESCC require further exploration. Here, in combination with a small interfering RNA (siRNA) library targeting specific lncRNAs, we performed MTS and Transwell assays to screen functional lncRNAs that were overexpressed in ESCC. TMPO-AS1 expression was significantly upregulated in ESCC tumor samples, with higher TMPOAS1 expression positively correlated with shorter overall survival times. In vitro and in vivo functional experiments revealed that TMPO-AS1 promotes the proliferation and metastasis of ESCC cells. Mechanistically, TMPO-AS1 bound to fused in sarcoma (FUS) and recruited p300 to the TMPO promoter, forming biomolecular condensates in situ to activate TMPO transcription in cis by increasing the acetylation of histone H3 lysine 27 (H3K27ac). Targeting TMPO-AS1 led to impaired ESCC tumor growth in a patient-derived xenograft (PDX) model. We found that TMPO-AS1 is required for cell proliferation and metastasis in ESCC by promoting the expression of TMPO, and both TMPO-AS1 and TMPO might be potential biomarkers and therapeutic targets in ESCC.

Connectivity map identifies luteolin as a treatment option of ischemic stroke by inhibiting MMP9 and activation of the PI3K/ Akt signaling pathway

Shijian Luo,Huiqing Li,Zhihuai Mo,Junjie Lei,Lingjuan Zhu,Yanxia Huang,Ruying Fu,Chunyi Li,Yihuan Huang,Kejia Liu,Wenli Chen,Lei Zhang 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

This study aimed to explore potential new drugs in the treatment of ischemic stroke by Connectivity Map (CMap) and to determine the role of luteolin on ischemic stroke according to its effects on matrix metalloproteinase-9 (MMP9) and PI3K/Akt signaling pathway. Based on published gene expression data, differentially expressed genes were obtained by microarray analysis. Potential compounds for ischemic stroke therapy were obtained by CMap analysis. Cytoscape and gene set enrichment analysis (GSEA) were used to discover signaling pathways connected to ischemic stroke. Cell apoptosis and viability were, respectively, evaluated by flow cytometry and an MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5- diphenyl-2-H-tetrazolium bromide) assay. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis were used to test the expression of MMP9 and the PI3K/Akt signaling pathway-related proteins in human brain microvascular endothelial cells (HBMECs) and tissues. Additionally, the infarct volume after middle cerebral artery occlusion (MCAO) was determined by a TTC (2,3,5-triphenyltetrazolium chloride) assay. The microarray and CMap analyses identified luteolin as a promising compound for future therapies for ischemic stroke. Cytoscape and GSEA showed that the PI3K/Akt signaling pathway was crucial in ischemic stroke. Cell experiments revealed that luteolin enhanced cell viability and downregulated apoptosis via inhibiting MMP9 and activating the PI3K/Akt signaling pathway. Experiments performed in vivo also demonstrated that luteolin reduced the infarct volume. These results suggest that luteolin has potential in the treatment of ischemic stroke through inhibiting MMP9 and activating PI3K/ Akt signaling pathway.

Synthesis of Porous Carbon Supported Palladium Nanoparticle Catalysts by Atomic Layer Deposition: Application for Rechargeable Lithium–O₂ Battery

Lei, Yu,Lu, Jun,Luo, Xiangyi,Wu, Tianpin,Du, Peng,Zhang, Xiaoyi,Ren, Yang,Wen, Jianguo,Miller, Dean J.,Miller, Jeffrey T.,Sun, Yang-Kook,Elam, Jeffrey W.,Amine, Khalil American Chemical Society 2013 Nano letters Vol.13 No.9

<P>In this study, atomic layer deposition (ALD) was used to deposit nanostructured palladium on porous carbon as the cathode material for Li–O<SUB>2</SUB> cells. Scanning transmission electron microscopy showed discrete crystalline nanoparticles decorating the surface of the porous carbon support, where the size could be controlled in the range of 2–8 nm and depended on the number of Pd ALD cycles performed. X-ray absorption spectroscopy at the Pd K-edge revealed that the carbon supported Pd existed in a mixed phase of metallic palladium and palladium oxide. The conformality of ALD allowed us to uniformly disperse the Pd catalyst onto the carbon support while preserving the initial porous structure. As a result, the charging and discharging performance of the oxygen cathode in a Li–O<SUB>2</SUB> cell was improved. Our results suggest that ALD is a promising technique for tailoring the surface composition and structure of nanoporous supports in energy storage devices.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2013/nalefd.2013.13.issue-9/nl401833p/production/images/medium/nl-2013-01833p_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl401833p'>ACS Electronic Supporting Info</A></P>

Characteristics of High-cell Density Cultivation of Recombinant Escherichia coli Producing RHLC Using the Fermentor Pressure Shifting Strategy

Lei Chi,Dai-Di Fan,Xiao-Xuan Ma,Yan-E Luo,Chen-Hui Zhu 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.3

To increase the biomass and production of recombinant human-like collagen (RHLC), the effect of controlled fermentor pressure during fed-batch cultivation was investigated using recombinant Escherichia coli producing RHLC. This study focused primarily on the effects of the fermentor pressure on the oxygen transfer capacity. A twostep exponential feeding strategy was used to control the specific growth rate at 0.2 and 0.1/h in the fed-batch and induction phase, respectively. A kinetic model of cell growth was developed, and the specific growth rate, specific glucose uptake rate, concentration of extracellular DNA, and percentage of plasmid loss were calculated and detected. The results demonstrated that increasing the fermentor pressure was an effective way of avoiding the oxygen transfer capacity limitation, and an increase in the dissolved CO2 content did not affect the growth of the recombinant E. coli BL21strain. At the end of the fermentation process, the cell density (represented by the dry cell weight, DCW) reached 77.3 g/L, and the RHLC concentration reached 14.1 g/L. In addition,the oxygen transfer capacity (KLaC^*) decreased drastically at approximately 5 h after induction. This is probably because of the increased concentration of extracellular DNA due to cell lysis, indicating that the cells needed to be harvested.

Effect of Bias Magnetic Field on Magnetoelectric Characteristics in Magnetostrictive/Piezoelectric Laminate Composites

Lei Chen,Yulin Luo 한국자기학회 2015 Journal of Magnetics Vol.20 No.4

The magnetoelectric (ME) characteristics for Terfenol-D/PZT laminate composite dependence on bias magnetic field is investigated. At low frequency, ME response is determined by the piezomagnetic coefficient d33,m and the elastic compliance S<SUP>H</SUP>33 of magnetostrictive material, d33,m and S<SUP>H</SUP>33 for Terfenol-D are inherently nonlinear and dependent on Hdc, leading to the influence of Hdc on low-frequency ME voltage coefficient. At resonance, the mechanical quality factor Qm dependences on Hdc results in the differences between the low-frequency and resonant ME voltage coefficient with Hdc. In terms of ΔE effect, the resonant frequency shift is derived with respect to the bias magnetic field. Considering the nonlinear effect of magnetostrictive material and Qm dependence on Hdc, it predicts the low-frequency and resonant ME voltage coefficients as a function of the dc bias magnetic field. A good agreement between the theoretical results and experimental data is obtained and it is found that ME characteristics dependence on Hdc are mainly influenced by the nonlinear effect of magnetostrictive material.

Efficacy and Safety of Endoscopic Resection Therapies for Rectal Carcinoid Tumors: A Meta-Analysis

Lei He,Tao Deng,He-Sheng Luo 연세대학교의과대학 2015 Yonsei medical journal Vol.56 No.1

Purpose: Several endoscopic resection therapies have been applied for the treatment of rectal carcinoid tumors. However, there is currently no consensus regarding the optimal strategy. We performed a meta-analysis to compare the efficacy and safety of endoscopic mucosal resection (EMR) or modified EMR (m-EMR) versus endoscopicsubmucosal dissection (ESD) for the treatment of rectal carcinoid tumors. Materials and Methods: PubMed, Web of Science, Medline, Embase and CNKI were searched up to the end of January 2014 in order to identify all studies on the effectsof EMR (or m-EMR) and ESD on rectal carcinoid tumors. Results: A total of fourteen studies involving 782 patients were included. The pooled data suggested a significantly higher rate of pathological complete resection among patients treated with ESD or m-EMR than those treated with EMR [odds ratio (OR)=0.42, 95% confidenceinterval (CI): 0.25‒0.71; OR=0.10, 95% CI: 0.03‒0.33, respectively], while there was no significant difference between the m-EMR group and ESD group (OR=1.19, 95% CI: 0.49‒2.86); The procedure time of ESD was longer than EMR or m-EMR groups [mean differences (MD)=-11.29, 95% CI: -14.19 ‒ -8.38, MD= -10.90, 95% CI: -18.69 ‒ -3.11, respectively], but it was insignificance between the EMR and m-EMR groups. No significant differences were detected among the treatmentgroups with regard to complications or recurrence. Conclusion: The results of this meta-analysis suggest that treatment of rectal carcinoid tumors with ESD or m-EMR is superior to EMR, and the efficacy of m-EMR is equivalence to ESD treatment. However, more well-designed studies are needed to confirm these findings.

Comparative study on the Lower Silurian Longmaxi marine shale in the Jiaoshiba shale gas field and the Pengshui area in the southeast Sichuan Basin, China

Lei Chen,Yongchao Lu,Jianqing Li,Xusheng Guo,Shu Jiang,Chan Luo 한국지질과학협의회 2020 Geosciences Journal Vol.24 No.1

The Jiaoshiba shale gas field and Pengshui area are both located in the southeast Sichuan Basin with only 100 km apart. Although these two areas obtained shale gas flow from the Lower Silurian Longmaxi marine shale, there is a huge difference of production in these two areas where the Jiaoshiba shale gas field is more productive than the Pengshui area. In order to figure out the reason that caused this difference, this study analyzed the Longmaxi marine shale in these two areas by using drilling cores, and mineralogical and geochemical data. The results show that the Jiaoshiba shale gas field has a higher quality shale reservoir (higher content of quartz, higher porosity, higher permeability and higher TOC (Total Organic Carbon)) in the Lower Silurian Longmaxi Formation than that of the Pengshui area. The Lower Silurian Longmaxi marine shale in the Jiaoshiba shale gas field contains a higher total gas content (3.65 m3/ton in average) than that of the Pengshui area (1.19 m3/ton in average). Through structure analysis, this study found that the Jiaoshiba shale gas field and the Pengshui area located in the different tectonic units. The Jiaoshiba shale gas filed is located in the East Sichuan fold belt (wide spaced anticlines area) at the west side of the Qiyue mountain fault where less fractures are developed and the pressure coefficient is more than 1.5, resulting in much more free gas preserved in the shale reservoirs in the Lower Silurian Longmaxi Formation (the ratio of free gas content and absorbed gas content is 1.6), while the Pengshui area is located in the Hunan-Hubei-Guizhou thrust belt area at the east side of the Qiyue mountain fault where much more fractures are developed and the pressure coefficient is less than 1.0, leading to less free gas preserved in the Longmaxi marine shale (the ratio of free gas content and absorbed gas content is 0.6), that is why the shale reservoir in the Pengshui area has a lower total gas content than that in the Jiaoshiba shale gas field.

Nasal Nitric Oxide Is Correlated With Nasal Patency and Nasal Symptoms

Lei Ren,Wei Zhang,Yuan Zhang,Luo Zhang 대한천식알레르기학회 2019 Allergy, Asthma & Immunology Research Vol.11 No.3

Purpose: Nitric oxide (NO) is an important endogenous mediator in both upper and lower respiratory systems. The purpose of the present study was to extract nasal NO (nNO) normal range of Chinese adults and the internal influencing factors. The differences in nNO levels between rhinitis and asymptomatic atopic subjects, and the diagnostic value of nNO in allergic rhinitis (AR) were further investigated. Methods: One thousand adults were recruited from the general public. Participants were divided into different subgroups according to the questionnaires and skin prick tests. In all of these subjects, nNO, fractional exhaled NO (FeNO) and nasal airflow resistance were measured. The normal ranges of nNO and FeNO, the differences between subgroups, and the correlations between NO (nNO and FeNO) and other internal factors were analyzed. Results: Both nNO and FeNO levels were significantly higher in AR patients than in healthy and asymptomatic atopic subjects. The nNO levels were significantly lower in asymptomatic atopic subjects than in normal adults. FeNO levels were significantly higher in non-AR patients than in the healthy and asymptomatic atopic adults. The cutoff value of nNO for the diagnosis of AR was 117.5 ppb (sensitivity, 50.9%; specificity, 63.9%). The nNO levels were correlated with FeNO levels, total nasal resistance measured at 75Pa, nasal volume within 0–7 cm from the anterior nares (V0-7cm) and nasal symptom visual analogue scale (VAS) scores, while the FeNO levels were correlated with age, height, weight, body surface area, nasal volume of V0-7cm and the nasal symptom VAS score. Conclusions: The nNO level can be significantly different between healthy and AR patients and may be significantly correlated with nasal symptoms and nasal patency of rhinitis patients. However, the clinical value of nNO is still in the exploration stage.

Estimation of Growth Curves and Suitable Slaughter Weight of the Liangshan Pig

Luo, Jia,Lei, Huaigang,Shen, Linyuan,Yang, Runlin,Pu, Qiang,Zhu, Kangping,Li, Mingzhou,Tang, Guoqing,Li, Xuewei,Zhang, Shunhua,Zhu, Li Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.9

The Liangshan pig is a traditional Chinese small-sized breed; it has a relatively long feeding period and low meat production ability but superior meat quality. This study utilized three non-linear growth models (Von Bertalanffy, Gompertz, and logistic) to fit the growth curve of Liangshan pigs from an unselected, random-bred pig population and estimate the pigs most suitable slaughter weight. The growth development data at 20 time points of 275 Liangshan pigs (from birth to 250 d) were collected. To analyze the relative gene expression related to development, seven slaughter weight phases (50, 58, 66, 74, 82, 90, and 98 kg) (20 pigs per phase) were examined. We found that the Liangshan pig growth curve fit the typical S-curve well and that their growth turning point was 193.4 days at a weight of 62.5 kg, according to the best fit Von Bertalanffy model based on the goodness of fit criteria. Furthermore, we estimated that the most suitable slaughter weight was 62.5 to 74.9 kg based on the growth curve and the relative expression levels of growth-related genes.