LncRNA SNHG6 promotes glycolysis reprogramming in hepatocellular carcinoma by stabilizing the BOP1 protein

Kai Chen,Xi Wang,Bowen Wei,Rongcun Sun,Chunlin Wu,Hong-ji Yang 한국통합생물학회 2022 Animal cells and systems Vol.26 No.6

Metabolic reprogramming is an important feature in tumor progression. Long noncoding RNA’s (lncRNA) small nucleolar RNA host gene 6 (SNHG6) acts as a proto-oncogene in hepatocellular carcinoma (HCC) but its role in glycolysis is mostly unknown. The role of SNHG6 and Block of proliferation 1 (BOP1) on glycolysis is assessed by glucose uptake, lactate production, oxygen consumptive rate (OCR) and extracellular acidification rate (ECAR) and glycolytic enzyme levels. The regulatory effect of SNHG6 on BOP1 protein was confirmed by Western blotting, MS2 pulldown, RNA pull-down, and RIP assay. SNHG6 and BOP1 levels were increased in HCC tissues and cells. SNHG6 and BOP1 were prognostic factors in HCC patients and significantly correlated to TP53 mutant and tumor grade. SNHG6 promoted proliferation, inhibited apoptosis, enhanced glucose uptake and lactate production, decreased OCR, and increased ECAR in HCC cell lines. SNHG6 could bind the BOP1 protein and enhance its stability. BOP1 overexpression rescued the change of proliferation, apoptosis, and glycolysis in HCCLM3 and SMMC-7721 cells. Our data indicate that SNHG6 accelerates proliferation and glycolysis and inhibits the apoptosis of HCC cell lines by binding the BOP1 protein and enhancing its stability. Both SNHG6 and BOP1 are promising prognostic and therapeutic markers in HCC.

Creep Failure and Damage Mechanism of Inconel 718 Alloy at 800–900 °C

Kai Chen,Jianxin Dong,Zhihao Yao 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

The creep behavior and damage mechanisms of 718 alloys were investigated at 800–900 °C in air. The fracturemorphology and microstructure evolution were observed by optical, scanning and transmission electron microscope. Besides,the creep damage tolerance (λ) and creep strain evolution curve were also calculated. The results showed that the creep curvesof 718 alloys at 800 or 850 °C consisted of primary and tertiary stages, while the steady-state region became apparent at900 °C. The apparent creep activation energy of 718 alloy was in the range from 446.3 to 491.8 kJ/mol. The alloy presentedductile fracture at 800 °C due to the nucleation, growth and linkage of creep voids. However, the failure of alloys at 850 or900 °C presented necking to a point due to the microstructure degradation. Further investigations showed the softening ofmaterials and the loss of mechanical performance could be mainly attributed to the coarsening or decrease of strengtheningprecipitates. Above 850 °C, it was found that γ′ phases would dissolve into matrix and stress promoted the re-dissolution ofγ′ phases or led to the break of δ phases. Moreover, the creep strain evolution curves indicated that 718 alloys kept a relativestable state at 800–900 °C when the strain fraction was below 1.

High‑speed growth of high‑quality polycrystalline diamond films by MPCVD

Kai Chen,Tao Tao,Wenxiao Hu,Yucong Ye,Kaiwen Zheng,Jiandong Ye,Ting Zhi,Xiwei Wang,Bin Liu,Rong Zhang 한국탄소학회 2023 Carbon Letters Vol.33 No.7

High-quality diamond films have attracted extensive attentions due to their excellent optical and electrical properties. However, several issues, such as random orientation, stress accumulation, and slow growth rate, severely limit its applications. In this paper, high-quality polycrystalline diamond films with highly ordered (100) orientation were prepared by microwave plasma chemical vapor deposition. The effects of growth parameters on the microstructure, quality and residual stress of diamond films were investigated. Experimental results indicate that relatively high temperature at low methane concentration will promote the formation of (100) oriented grains with a low compressive stress. Optimized growth parameters, a methane concentration of 2% along with a pressure of 250 Torr and temperature at 1050 ℃, were used to acquire high growth rate of 7.9 μm/h and narrow full width at half maximum of Raman peak of 5.5 cm? 1 revealing a high crystal quality. It demonstrates a promising method for rapid growth of high-quality polycrystalline diamond films with (100) orientation, which is vital for improving the diamond related applications at low cost.

Detecting LDoS Attacks based on Abnormal Network Traffic

( Kai Chen ),( Huiyu Liu ),( Xiaosu Chen ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.7

By sending periodically short bursts of traffic to reduce legit transmission control protocol (TCP) traffic, the low-rate denial of service (LDoS) attacks are hard to be detected and may endanger covertly a network for a long period. Traditionally, LDoS detecting methods mainly concentrate on the attack stream with feature matching, and only a limited number of attack patterns can be detected off-line with high cost. Recent researches divert focus from the attack stream to the traffic anomalies induced by LDoS attacks, which can detect more kinds of attacks with higher efficiency. However, the limited number of abnormal characteristics and the inadequacy of judgment rules may cause wrong decision in some particular situations. In this paper, we address the problem of detecting LDoS attacks and present a scheme based on the fluctuant features of legit TCP and acknowledgment (ACK) traffic. In the scheme, we define judgment criteria which used to identify LDoS attacks in real time at an optimal detection cost. We evaluate the performance of our strategy in real-world network topologies. Simulations results clearly demonstrate the superiority of the method proposed in detecting LDoS attacks.

Corporate control through Management Buyouts

Kai Chen,Yong-Cheol Kim,Richard D. Marcus 한국재무학회 2011 한국재무학회 학술대회 Vol.2011 No.05

This paper investigates the effects of managerial ownership on shareholder wealth gains in management buyouts to study whether target managers expropriate public shareholder interests when they buy out a firm. We find that the transaction premiums are negatively associated with the buyout managers’ stock holdings, but not with their option holdings. This evidence indicates that acquiring managers, using their corporate power associated with their stock holdings, pursue their own interests at the expense of public shareholders, and that their interest in the post-buyout firm dominates their interest associated with their options. We also find that the transaction premiums are not associated with the nonbuyout managers’ stock and option holdings.

Development of Penicillium italicum-Specific Primers for Rapid Detection among Fungal Isolates in Citrus

( Kai Chen ),( Zhonghuan Tian ),( Fatang Jiang ),( Chao-an Long ) 한국미생물생명공학회(구 한국산업미생물학회) 2019 Journal of microbiology and biotechnology Vol.29 No.6

Blue mold in citrus is caused by Penicillium italicum. In this study, the P. italicum-specific primers were developed for rapid detection based on the conserved genes RPB1 and RPB2 among Penicillium genomes. The two primer pairs RPB1-a and RPB1-b proved to be specific to detect P. italicum. The PCR assay among 39 fungal isolates and the colonial, pathogenic morphologies and molecular methods validated the specificity and reliability of these two primer pairs. This report provided a method and P. italicum-specific primers, which might greatly contribute to citrus postharvest industry.

Safety evaluation of early drain removal following pancreatic resections: Meta-analysis and single-center retrospective cohort study

Kai CHEN,Xiaodong TIAN,Yinmo YANG 한국간담췌외과학회 2022 Annals of hepato-biliary-pancreatic surgery Vol.26 No.-

Selective adsorption of L-TA/D-TA by β-cyclodextrin derivative modified with l-tryptophan: Isotherm, kinetic and thermodynamics studies

Kaichen He,Fengxian Qiu,Jiao Qin,Jie Yan,Dongya Yang 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

b-Cyclodextrin derivative modified with L-tryptophan (L-Trp-CD) was prepared for recognitive chiral separation of tartaric acid enantiomers from ethanol solution. Kinetic properties were successfully investigated by pseudo-first-order model and pseudo-second-order model. Equilibrium data were described by the Langmuir and Freundlich isotherm models. The thermodynamics parameters (positive values of DH8 and DS8, negative values of DG8) indicated that binding system for L-Trp-CD was endothermic, entropy gained and spontaneous. Selective adsorption result of L-tartaric acid (L-TA)/Dtartaric acid (D-TA) by L-Trp-CD indicated that L-Trp-CD has significantly higher adsorption capacity for L-TA compared with D-TA, and the selectivity coefficient is 3.36.

Preparation and characterization of L-phenylalanine-derivatized β-cyclodextrin-bonded silica and its application on chiral separation of alanine acid racemates

Fengxian Qiu,Kaichen He,Jiao Qin,Jie Yan,Dongya Yang 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.11

A chiral adsorption material, L-phenylalanine-derivatized β-cyclodextrin-bonded silica (L-Phe-CD/SiO2),was prepared and characterized by Fourier transform infrared (FT-IR), elemental analysis, field emission scanning electron microscope (FESEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) measurements. Langmuir and Freundlich isotherm models were employed to simulate the equilibrium data. The results showed that the equilibrium data were well represented by Langmuir isotherm model. Experimental data were analyzed using pseudofirst order and pseudo-second order kinetic models and the obtained results indicated that kinetics followed a pseudosecond order equation. The static adsorption experiments indicated that L-Phe-CD/SiO2 had significantly higher adsorption capacity for L-alanine (L-Ala) compared with D-alanine (D-Ala); and the selectivity coefficient is 2.53. The result shows that the prepared L-Phe-CD/SiO2 could be applied to chiral separation of the racemic alanine acid solution.

Nanophotonic-Engineered Photothermal Harnessing for Waste Heat Management and Pyroelectric Generation

Wang, Xiao-Qiao,Tan, Chuan Fu,Chan, Kwok Hoe,Xu, Kaichen,Hong, Minghui,Kim, Sang-Woo,Ho, Ghim Wei American Chemical Society 2017 ACS NANO Vol.11 No.10

<P>At present, there are various limitations to harvesting ambient waste heat which include the lack of economically viable material and innovative design features that can efficiently recover low grade heat for useful energy conversion. In this work, a thermal nanophotonic-pyroelectric (TNPh-pyro) scheme consisting of a metamaterial multilayer and pyroelectric material, which performs synergistic waste heat rejection and photothermal heat-to-electricity conversion, is presented. Unlike any other pyroelectric configuration, this conceptual design deviates from the conventional by deliberately employing back-reflecting NIR to enable waste heat reutilization/recuperation to enhance pyroelectric generation, avoiding excessive solar heat uptake and also retaining high visual transparency of the device. Passive solar reflective cooling up to 4.1 degrees C is demonstrated. Meanwhile, the photothermal pyroelectric performance capitalizing on the back-reflecting effect shows an open circuit voltage (V-oc) and short circuit current (I-sc) enhancement of 152 and 146%, respectively. In addition, the designed photoactive component (TiO2/Cu) within the metamaterial multilayer provides the TNPh-pyro system with an effective air pollutant photodegradation functionality. Finally, proof-of-concept for concurrent photothermal management and enhanced solar pyroelectric generation under a real outdoor environment is demonstrated.</P>