miR-31a-5p promotes postnatal cardiomyocyte proliferation by targeting RhoBTB1

Junjie Xiao,Hui Liu,Dragos Cretoiu,Daniela Oana Toader,Nicolae Suciu,Jing Shi,Shutong Shen,Yihua Bei,Joost PG Sluijter,Saumya Das,Xiangqing Kong,Xinli Li 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

A limited number of microRNAs (miRNAs, miRs) have been reported to control postnatal cardiomyocyte proliferation, but their strong regulatory effects suggest a possible therapeutic approach to stimulate regenerative capacity in the diseased myocardium. This study aimed to investigate the miRNAs responsible for postnatal cardiomyocyte proliferation and their downstream targets. Here, we compared miRNA profiles in cardiomyocytes between postnatal day 0 (P0) and day 10 (P10) using miRNA arrays, and found that 21 miRNAs were upregulated at P10, whereas 11 were downregulated. Among them, miR-31a-5p was identified as being able to promote cardiomyocyte proliferation as determined by proliferating cell nuclear antigen (PCNA) expression, double immunofluorescent labeling for α-actinin and 5-ethynyl-2-deoxyuridine (EdU) or Ki-67, and cell number counting, whereas miR-31a-5p inhibition could reduce their levels. RhoBTB1 was identified as a target gene of miR-31a-5p, mediating the regulatory effect of miR-31a-5p in cardiomyocyte proliferation. Importantly, neonatal rats injected with a miR-31a-5p antagomir at day 0 for three consecutive days exhibited reduced expression of markers of cardiomyocyte proliferation including PCNA expression and double immunofluorescent labeling for α-actinin and EdU, Ki-67 or phospho-histone-H3. In conclusion, miR-31a-5p controls postnatal cardiomyocyte proliferation by targeting RhoBTB1, and increasing miR-31a-5p level might be a novel therapeutic strategy for enhancing cardiac reparative processes.

Flow field characteristics of an agitator system of a large diameter slurry-water shield machine

Junjie Liao,Kun Bai,Yi-Min Xia,Haizhen Li,Xianqiong Zhao,Xuemeng Xiao,Yang Wang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.4

A numerical model was established for calculation in this study on the basis of the standard k-epsilon turbulence model and the discrete phase model of the Euler-Lagrange equation. Results of the particle image velocimetry experiment were used to verify the reliability of the numerical model. The effects of the rotation speeds, slurry densities, and impeller structures on the flow field characteristics, including velocity distribution, ballast fluidity, and power loss, were also investigated. The results indicate that the increase of rotation speed has little influence on the flow field near the wall and bottom of the agitator, and the agitator performs well when the speed is set between 30 rpm and 40 rpm. The increase of the slurry density will increase the pressure loss between the inlet and the outlet, and it will also increase the load of the agitator. Hence, the slurry density must be less than 1400 kg/m 3 . The baffle can improve the velocity distribution of the flow field and the slag discharge capacity of the agitator.

The corrosion behaviour of alloy 690 tube in simulated PWR secondary water with the effect of solid diffusing hydrogen

Chen, Junjie,Lu, Zhanpeng,Meng, Fanjiang,Xu, Xuelian,Xiao, Qian,Kim, Ho-Sub,Jang, Changheui Elsevier 2019 JOURNAL OF NUCLEAR MATERIALS Vol.517 No.-

<P><B>Abstract</B></P> <P>High-temperature water corrosion tests were performed to investigate the corrosion behaviors of Alloy 690 TT in simulated PWR secondary water with gaseous hydrogen permeation condition. Double-layer oxide films formed on hydrogen-free and hydrogen-permeating specimens. The thickness of a Cr-rich inner oxide film on the hydrogen-free specimens has no obvious difference from the hydrogen-permeating ones. For hydrogen-free specimens, the outer oxide films were Fe and Ni enriched spinel-type oxide particles. For hydrogen-permeating specimens, outer oxide films were sheet-like or needle-like Cr-rich chromia-type oxides. In summary, the solid diffusing hydrogen affected the morphology and composition of outer oxides.</P> <P><B>Highlights</B></P> <P> <UL> <LI> High temperature water corrosion test was performed in hydrogen permeation condition. </LI> <LI> The thickness of Cr-rich inner films has no obvious change by hydrogen permeation. </LI> <LI> Sheet-like outer oxides on hydrogen-permeating samples unlike hydrogen-free ones. </LI> <LI> Fe and Ni-rich spinel-type outer oxide films formed on hydrogen-free specimens. </LI> <LI> Cr-rich chromia-type outer oxide films formed on hydrogen-permeating specimens. </LI> </UL> </P>

Glutamate attenuates lipopolysaccharide induced intestinal barrier injury by regulating corticotropin-releasing factor pathway in weaned pigs

Guo Junjie,Liang Tianzeng,Chen Huifu,Li Xiangen,Ren Xiaorui,Wang Xiuying,Xiao Kan,Zhao Jiangchao,Zhu Huiling,Liu Yulan 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.8

Objective: The purpose of this study was to evaluate the protection of glutamate (GLU) against the impairment in intestinal barrier function induced by lipopolysaccharide (LPS) stress in weaned pigs. Methods: Twenty-four weaned pigs were divided into four treatments containing: i) nonchallenged control, ii) LPS-challenged control, iii) LPS+1.0% GLU, and iv) LPS+2.0% GLU. On day 28, pigs were treated with LPS or saline. Blood samples were collected at 0, 2, and 4 h post-injection. After blood samples collection at 4 h, all pigs were slaughtered, and spleen, mesenteric lymph nodes, liver and intestinal samples were obtained. Results: Dietary GLU supplementation inhibited the LPS-induced oxidative stress in pigs, as demonstrated by reduced malondialdehyde level and increased glutathione level in jejunum. Diets supplemented with GLU enhanced villus height, villus height/crypt depth and claudin-1 expression, attenuated intestinal histology and ultrastructure impairment induced by LPS. Moreover, GLU supplementation reversed intestinal intraepithelial lymphocyte number decrease and mast cell number increase induced by LPS stress. GLU reduced serum cortisol concentration at 4 h after LPS stress and downregulated the mRNA expression of intestinal corticotropin-releasing factor signal (corticotrophin-releasing factor [CRF], CRF receptor 1 [CRFR1], glucocorticoid receptor, tryptase, nerve growth factor, tyrosine kinase receptor A), and prevented mast cell activation. GLU upregulated the mRNA expression of intestinal transforming growth factor β. Conclusion: These findings indicate that GLU attenuates LPS-induced intestinal mucosal barrier injury, which is associated with modulating CRF signaling pathway. Objective: The purpose of this study was to evaluate the protection of glutamate (GLU) against the impairment in intestinal barrier function induced by lipopolysaccharide (LPS) stress in weaned pigs.Methods: Twenty-four weaned pigs were divided into four treatments containing: i) non-challenged control, ii) LPS-challenged control, iii) LPS+1.0% GLU, and iv) LPS+2.0% GLU. On day 28, pigs were treated with LPS or saline. Blood samples were collected at 0, 2, and 4 h post-injection. After blood samples collection at 4 h, all pigs were slaughtered, and spleen, mesenteric lymph nodes, liver and intestinal samples were obtained.Results: Dietary GLU supplementation inhibited the LPS-induced oxidative stress in pigs, as demonstrated by reduced malondialdehyde level and increased glutathione level in jejunum. Diets supplemented with GLU enhanced villus height, villus height/crypt depth and claudin-1 expression, attenuated intestinal histology and ultrastructure impairment induced by LPS. Moreover, GLU supplementation reversed intestinal intraepithelial lymphocyte number decrease and mast cell number increase induced by LPS stress. GLU reduced serum cortisol concentration at 4 h after LPS stress and downregulated the mRNA expression of intestinal corticotropin-releasing factor signal (corticotrophin-releasing factor [<i>CRF</i>], CRF receptor 1 [<i>CRFR1</i>], glucocorticoid receptor, tryptase, nerve growth factor, tyrosine kinase receptor A), and prevented mast cell activation. GLU upregulated the mRNA expression of intestinal transforming growth factor β.Conclusion: These findings indicate that GLU attenuates LPS-induced intestinal mucosal barrier injury, which is associated with modulating CRF signaling pathway.

Fluorogenic probes for disease-relevant enzymes

Zhang, Junji,Chai, Xianzhi,He, Xiao-Peng,Kim, Hae-Jo,Yoon, Juyoung,Tian, He The Royal Society of Chemistry 2019 Chemical Society reviews Vol.48 No.2

<P>Traditional biochemical methods for enzyme detection are mainly based on antibody-based immunoassays, which lack the ability to monitor the spatiotemporal distribution and, in particular, the <I>in situ</I> activity of enzymes in live cells and <I>in vivo</I>. In this review, we comprehensively summarize recent progress that has been made in the development of small-molecule as well as material-based fluorogenic probes for sensitive detection of the activities of enzymes that are related to a number of human diseases. The principles utilized to design these probes as well as their applications are reviewed. Specific attention is given to fluorogenic probes that have been developed for analysis of the activities of enzymes including oxidases and reductases, those that act on biomacromolecules including DNAs, proteins/peptides/amino acids, carbohydrates and lipids, and those that are responsible for translational modifications. We envision that this review will serve as an ideal reference for practitioners as well as beginners in relevant research fields.</P>

Development of a duplex stainless steel for dry storage canister with improved chloride-induced stress corrosion cracking resistance

정채원,신지호,공병서,Chen Junjie,Xiao Qian,장창희,김윤재 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.6

The chloride-induced stress corrosion cracking (CISCC) is one of the major integrity concerns in dry storage canisters made of austenitic stainless steels (ASSs). In this study, an advanced duplex stainless steel (DSS) with a composition of Fe–19Cr–4Ni-2.5Mo-4.5Mn (ADCS) was developed and its performance was compared with that of commercial ASS and DSS alloys. The chemical composition of ADCS was determined to obtain greater pitting and CISCC resistance as well as a proper combination of strength and ductility. Then, the thermomechanical processing (TMP) condition was applied, which resulted in higher strength than ASSs (304L SS and 316L SS) and better ductility than DSSs (2101 LDSS and 2205 DSS). The potentiodynamic polarization and electrochemical impedance spectra (EIS) results represented the better pitting corrosion resistance of ADCS compared to 304L SS and 316L SS by forming a better passive layer. The CISCC tests using four-point loaded specimens showed that cracks were initiated at 24 h for 304L SS and 144 h for 316L SS, while crack was not found until 1008 h for ADCS. Overall, the developed alloy, ADCS, showed better combination of CISCC resistance and mechanical properties as dry storage canister materials than commercial alloys.

Modified Wettability of Micro-structured Steel Surfaces Fabricated by Elliptical Vibration Diamond Cutting

Jianguo Zhang,Andreas Rosenkranz,Junjie Zhang,Jiang Guo,Xiaoqing Li,Xiao Chen,Junfeng Xiao,Jianfeng Xu 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.5

Hardened steel is an important material related to the development of modern industry branches. In order to satisfy the adhesion strength as well as the corrosion and wear resistance under extreme conditions, the modification of the wettability of hardened steel has become an important scientific topic. As micro/nano-structured surfaces play an essential role to induce advanced functional surfaces with wettability control, this contribution aims at presenting the feasibility of micro/nano sculpturing of hardened steels by elliptical vibration diamond cutting. The influence of the fabricated micro/nano structures on the resulting wettability is discussed and related to the contact line density as well as asperity heights. In this regard, it has been verified that a pitch value of 12 μm and structural height of 500 nm are the preferred structural parameters to increase the hydrophobicity of the textured steel specimens.

Determination of the number of ²³⁵U target nuclei in the irregular target using a fission time projection chamber

Jiajun Zhang,Jun Xiao,Junjie Sun,Mingzhi Zhang,Taiping Peng,Pu Zheng Korean Nuclear Society 2024 Nuclear Engineering and Technology Vol.56 No.2

Based on multiple measurements of ionization loss, the Time Projection Chamber (TPC) combines strong tracking ability with particle identification ability in a large momentum range, which is an important advantage of TPC detection technology over traditional ionization measurement technology. According to these two characteristics of TPC, applying it to the measurement of fission cross-section can greatly improve the measurement accuracy. During the measurement of the fission cross-section, the number of target nuclei is required to be accurately measured. So this paper introduces a method for measuring the number of ²³⁵U target nuclei using a fission TPC system. The measurement result agrees with the reference value, and relative error is around 1 %.

Polydiacetone Acrylamide as Precursors to Polymer Side-Chain Conjugates

Hongzhen Tan,Zhipeng Yu,Junjie Xiao,Xi Wang,Chunwang Yi,Shengpei Su 한국고분자학회 2018 폴리머 Vol.42 No.4

Polydiacetone acrylamide (PDAAM), a reactive polymer containing pendant ketone groups was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Kinetic studies indicated a well-controlled behavior of this RAFT polymerization. The characteristics of this RAFT polymerization was also confirmed by a wellcontrolled chain-extending RAFT polymerization using the above-synthesized PDAAM as a macromolecular chain transfer agent. Acid-catalyzed ketalization of PDAAM with trimethylol propane (TMP) was carried out to obtain the polymer containing pendant cyclic ketal groups and hydroxyl groups, PDAAM-TMP. PCL was grafted from PDAAM-TMP by ring-opening polymerization (ROP) in the presence of tin 2-ethylhexanoate as a catalyst to obtain graft copolymer. Basecatalyzed aldol condensation of PDAAM with benzaldehyde was also used to obtain poly[N-(1,1-dimethyl-3-oxo-5-phenyl-pent-4-enyl)-acrylamide] (PDMOPPEAM) having cinnamoyl groups, and the photoreactivity of polymer with cinnamoyl group was studied by UV-visible and IR absorption spectroscopy. Both of these two polymers prepared from PDAAM were characterized by FTIR and 1H NMR spectroscopy. PDAAM can be a multifunctional platform that can undergo further polymerization by ketalization and aldol condensation.

Structure and Electrical Performance of Na₂C₆O₆ under High Pressure

Wang, Xuan,Zhang, Peijie,Tang, Xingyu,Guan, Junjie,Lin, Xiaohuan,Wang, Yajie,Dong, Xiao,Yue, Binbin,Yan, Jinyuan,Li, Kuo,Zheng, Haiyan,Mao, Ho-kwang American Chemical Society 2019 The Journal of Physical Chemistry Part C Vol. No.

<P>Sodium rhodizonate (Na<SUB>2</SUB>C<SUB>6</SUB>O<SUB>6</SUB>) has very high theoretical capacity as a positive electrode material of sodium-ion batteries, but it still has problems such as low actual capacity and poor electronic/ionic conductivity. In order to improve its conductivity, we investigated its structure and electrical properties under high pressure. By performing in situ X-ray diffraction, Raman, infrared absorption, and alternating current impedance spectroscopy in the range of 0-30 GPa at room temperature, we observed a phase transition at ∼11 GPa, with the conductivity increasing by an order of magnitude. Above ∼20 GPa, Na<SUB>2</SUB>C<SUB>6</SUB>O<SUB>6</SUB> gradually amorphized. During the decompression process, the pressure regulation of the structure and properties of the material are reversible. Our study shows that applying external pressure is an effective tool to improve the conductivity of molecular battery materials. The investigation will help to obtain next-generation electrode materials.</P> [FIG OMISSION]</BR>