In SR-GIXRD Study of Oxide Film Evaluation on AISI 304 Stainless Steel in High Temperature Water

Yan Zhao,Jianjun Guan,Feng Liu,Ping Liang,Congqian Cheng,Jie Zhao 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.5

Oxide films on AISI 304 stainless steel in high temperature and high pressure water were detected by a new method thatsynchrotron radiation grazing incidence X-ray diffraction. The morphology, phase structure, thickness and electrochemicalcorrosion resistance of the oxide films were illustrated. A empirical equation for oxide growth is applied to evaluate thechanges in film thickness. Observations suggest that small irregular granular (Fe, Cr)2O3 oxides and polyhedral block (Fe,Cr)3O4 oxides are grown on stainless steel surface. The fine inner (Fe, Cr)2O3 particles preferentially form, and the part isprecipitated by the (Fe, Cr)3O4 structure for the diffusion outward, leading to the formation of external coarse grain oxides. The average size of (Fe, Cr)2O3 is slightly oscillated with the oxidation time, and that of (Fe, Cr)3O4 oxides increases withthe increasing exposure time. The oxide film thickness is less than 500 nm for 24 h oxidation in high temperature water, andfor 240 h oxidation the thickness is less than 800 nm. Polarization and EIS test results indicate that the oxide films of (Fe,Cr)2O3 and (Fe, Cr)3O4 provides corrosion resistance for stainless steel.

Micellization behavior of binary mixtures of amino sulfonate amphoteric surfactant with different octylphenol polyoxyethylene ethers in aqueous salt solution: Both cationic and hydrophilic effects

Zhao Hua Ren,Jing Huang,Yue Luo,Yan Cheng Zheng,Ping Mei,Lu Lai,Yan Ling Chang 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.36 No.-

The effect of different valent inorganic cations and the hydrophilic group of surfactant on themicellization behavior of binary surfactant mixtures constituted by an amphoteric surfactant, sodium3-(N-dodecyl ethylenediamino)-2-hydropropyl sulfonate (C12AS), and three nonionic surfactantsoctylphenol polyoxyethylene ether (OP-n) with different numbers of oxyethylene glycol ethers (n),namely, OP-10, OP-7, and OP-4 was investigated in aqueous solution. These inorganic cations includeNa+, K+, Mg2+, Ca2+, Ba2+, Al3+ and Fe3+. Both the tensiometry and the UV–vis spectrophotometry usingpyrene as a probe were adopted to determine the critical micelle concentrations (cmc) of individual ormixed surfactants. Interaction parameters between two surfactants and other parameters were obtainedbased on the regular solution theory, the pseudophase separation model, Rubingh’s model, etc. Thermodynamic parameters including Gibbs energy of micellization and thermodynamic stability werealso calculated by both the equation proposed by Molyneux et al. and Maeda’s treatment, respectively. The effect of different valent cations on both the mixed cmc of surfactant mixtures and the molar fractionof C12AS in mixed micelle (X1) can be explained theoretically by the salting-out effect, electrostaticinteraction and steric effect. For three binary surfactant mixtures, the chain length of hydrophilic groupof surfactant results in different micellization behaviors. On adding salts, the interaction parametersshow that there exists a synergistic effect between two surfactants, and the effect increases withincreasing the ratio of valence (Z) and atom radius (R) of cation, especially, for the C12AS/OP-4 mixture. With increasing the Z/R value of cation, a deviation of X1 from the ideal value shows a divergence forthree binary surfactant mixtures because of different hydrophilicities of surfactant. Thermodynamicparameters indicate that the addition of cations with a large Z/R value can be contributive moreeffectively to the formation of stable mixed micelle than the case in the presence of cations with a smallZ/R value.

Factors Potentially Associated with Chemotherapy-induced Anemia in Patients with Solid Cancers

Cheng, Ke,Zhao, Feng,Gao, Feng,Dong, Hang,Men, Hai-Tao,Chen, Ye,Li, Long-Hao,Ge, Jun,Tang, Jie,Ding, Jing,Chen, Xin,Du, Yang,Luo, Wu-Xia,Liu, Ji-Yan Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.10

Purpose: Chemotherapy-induced anemia (CIA) is one of the most important causes of anemia in cancer patients. This study was conducted to describe the prevalence and characteristics of CIA in solid cancer patients in the Chinese population, and to explore the relationship of white blood cell (WBC) or platelet decrease with CIA. Methods: Data on age, gender, tumor diagnosis, anti-cancer treatment and blood cell analyses were available from 220 untreated non-anemic cancer patients who received at least 2 cycles of chemotherapy, and the data were analyzed to assess their relationship with CIA or its severity. Results: 139 patients (63.2%) presented anemia, most being Grade 1 or 2. Esophageal and lung cancers were associated with a high prevalence. G3/4 leucopenia and decrease of platelets were identified as independent risk factors for the occurrence of CIA. Moreover, G3/4 leucopenia, decrease of platelet and G3/4 thrombocytopenia were found to be also associated with the severity of CIA. Cisplatin-containing regimens were a main potential factor in causing CIA, although significant association was only found on univariate analysis. Conclusion: Anemia or decrease in hematoglobin are common in Chinese cancer patients receiving chemotherapy. Cisplatin-containing regimens might be an important factor influencing the occurrence of CIA. Our analysis firstly described some risk factors, such as decrease of platelets or WBCs, severity of leucopenia or thrombocytopenia, associated with the occurrence and severity of CIA.

Generation of Selenoprotein with Glutathione Peroxidase Activity by Chemical Modification of the Single-chain Variable Fragment Expressed in a Single-protein Production System and Its Antioxidant Ability

Cheng Wang,Gang-Lin Yan,Shao-Wu Lü,Chun-Hong Sui,Yang Zhao,Ya-Wei Xu,Gang Zhao,Jun-jie Xu,Ping-Sheng Gong,Gui-Min Luo,Ying Mu 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.1

Glutathione peroxidase (GPX) is one of the important members of the antioxidant enzyme family. It can catalyze the reduction of hydroperoxides with glutathione to protect cells against oxidative damage. Single-chain variable fragment (scFv) can be converted into seleniumcontaining single-chain variable fragment (Se-scFv) by chemical modification of the hydroxyl groups in scFv, thus Se-scFv possesses GPX activity and becomes a prodrug. To improve the expression of scFv and simplify its purification steps, Single-protein production (SPP) system was used to express scFv and chemical modification was used to synthesize Se-scFv. Therefore, we must construct a new scFv-WCD1-lessACA gene, which can express its mRNA not containing any ACA sequences and express its amino acid sequence of target protein (scFv) being same to scFv-WCD1. In this way, the scFv-WCD1-lessACA can be only expressed in SPP system and no other background proteins in the cells could be expressed. The expression results showed that high level of scFv-WCD1-lessACA synthesis was at least sustained for 96 h in the virtual absence of background protein synthesis. Then, selenocysteine (Sec) was incorporated into the scFv-WCD1-lessACA by chemical modification and resulted in Se-scFv-WCD1-lessACA. The enzymatic characteristics of Se-scFv-WCD1-lessACA were determined. GPX activity was 2,563 U/μmol,its binding constant for GSH was 0.687 ×105/mol. Moreover,Se-scFv-WCD1-lessACA was confirmed to have a strong antioxidant ability to protect mitochondria against oxidative damage induced by Vc/Fe2+ (mitochondrial damage model),suggesting that Se-scFv-WCD1-lessACA has potential application for protection of mitochondrial damage induced by reactive oxygen species (ROS).

A sharp interface immersed boundary method for flow-induced noise with moving boundary

Cheng Zhao,Yan Yang,Tao Zhang 한국전산유체공학회 2022 한국전산유체공학회 학술대회논문집 Vol.2022 No.10

Reliability-based assessment of American and European specifications for square CFT stub columns

Zhao-Hui Lu,Yan-gang Zhao,Zhi-wu Yu,Cheng Chen 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.19 No.4

This paper presents a probabilistic investigation of American and European specifications (i.e., AISC and Eurocode 4) for square concrete-filled steel tubular (CFT) stub columns. The study is based on experimental results of 100 axially loaded square CFT stub columns from the literature. By comparing experimental results for ultimate loads with code-predicted column resistances, the uncertainty of resistance models is analyzed and it is found that the modeling uncertainty parameter can be described using random variables of lognormal distribution. Reliability analyses were then performed with/without considering the modeling uncertainty parameter and the safety level of the specifications is evaluated in terms of sufficient and uniform reliability criteria. Results show that: (1) The AISC design code provided slightly conservative results of square CFT stub columns with reliability indices larger than 3.25 and the uniformness of reliability indices is no better because of the quality of the resistance model; (2) The uniformness of reliability indices for the Eurocode 4 was better than that of AISC, but the reliability indices of columns designed following the Eurocode 4 were found to be quite below the target reliability level of Eurocode 4.

Distinctive Roles of Wnt Signaling in Chondrogenic Differentiation of BMSCs under Coupling of Pressure and Platelet-Rich Fibrin

Cheng Baixiang,Feng Fan,Shi Fan,Huang Jinmei,Zhang Songbai,Quan Yue,Tu Teng,Liu Yanli,Wang Junjun,Zhao Ying,Zhang Min 한국조직공학과 재생의학회 2022 조직공학과 재생의학 Vol.19 No.4

BACKGROUND: Although newly formed constructs of feasible pressure-preadjusted bone marrow mesenchymal stem cells (BMSCs) and platelet-rich fibrin (PRF) showed biomechanical flexibility and superior capacity for cartilage regeneration, it is still not very clear how BMSCs and seed cells feel mechanical stimuli and convert them into biological signals, and the difference in signal transduction underlying mechanical and chemical cues is also unclear. METHODS: To determine whether mechanical stimulation (hydrostatic pressure) and chemical cues (platelet-rich fibrin, PRF) activate canonical or noncanonical Wnt signaling in BMSCs, BMSCs cocultured with PRF were subjected to hydrostatic pressure loading, and the activation of the Wnt signaling molecules and expression of cartilage-associated proteins and genes were determined by western blotting and polymerase chain reaction (PCR). Inhibitors of canonical or noncanonical Wnt signaling, XVX-939 or L690,330, were adopted to investigate the role of Wnt signaling molecules in mechanically promoted chondrogenic differentiation of BMSCs. RESULTS: Hydrostatic pressure of 120 kPa activated both Wnt/b-catenin signaling and Wnt/Ca2? signaling, with the the maximum promotion effect at 60 min. PRF exerted no synergistic effect on Wnt/b-catenin signaling activation. However, the growth factors released by PRF might reverse the promotion effects of pressure on Wnt/Ca2? signaling. Real-time PCR and Western blotting results showed that pressure could activate the expression of Col-II, Sox9, and aggrecan in BMSCs cocultured with PRF. Blocking experiment found a positive role of Wnt/b-catenin signaling, and a negative role of Wnt/ Ca2? signaling in chondrogenic differentiation of the BMSCs. Mutual inhibition exists between canonical and noncanonical Wnt signaling in BMSCs under pressure. CONCLUSION: Wnt signaling participates in the pressure-promoted chondrogenesis of the BMSCs co-cultured with PRF, with canonical and noncanonical pathways playing distinct roles during the process.

The Efficacy of Aspirin in Preventing the Recurrence of Colorectal Adenoma: a Renewed Meta-Analysis of Randomized Trials

Zhao, Tai-Yun,Tu, Jing,Wang, Yin,Cheng, Da-Wei,Gao, Xian-Kui,Luo, Hao,Yan, Bi-Chun,Xu, Xiao-Li,Zhang, Hong-Ling,Lu, Xing-Jun,Wang, Yao-Jun Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.5

Background: Through search the possible randomized control trials, we make a renewed meta-analysis in order to assess the impact of aspirin in preventing the recurrence of colorectal adenoma. Materials and Methods: The Medicine/PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Chinese biomedical literature service system (SinoMed) databases were searched for the related randomized controlled trials until to the April 2016. Three different authors respectively evaluated the quality of studies and extracted data, and we used the STATA software to analyze, investigate heterogeneity between the data, using the fixed-effects model to calculate and merge data. Results: 7 papers were included the renewed meta-analysis, among these studies, two pairs were identified as representing the same study population, with the only difference being the duration of follow-up. Thus there were only five papers included our meta-analysis, and one Chinese paper were also included the work. Results were categorized by the length of follow-up, different kinds of people, varied dose of oral aspirin. The relative of adenoma in patients taking aspirin vs placebo were 0.73 (95% CI 0.55-0.98, P=0.039) with 1 year follow up; 0.84 (95% CI 0.72-0.98, P=0.484) with greater than 1 year follow up; for the advanced adenoma, the RR 0.68 (95% CI 0.49-0.94, P=0.582),for one year; RR=0.75 (95% CI 0.52-1.07, P=0.552) for greater one year. Furthermore the white population could divided into two subgroups according to the different length of follow-up time. When the length of follow-up time less than 3-year, The RR of two subgroups respective were RR=0.86 (95% CI 0.76-0.98, P=0.332), $I^2=0%$, RR=0.68 (95% CI 0.47-0.98, P=0.552), $I^2=64.6%$, But with the extension of follow-up time greater than 2-year, with the white, oral aspirin without considering dose had no efficacy on preventing the recurrence of any adenoma, the RR was 0.86 (95% CI 0.71-1.05, P=0.302), $I^2=16.4%$. Conclusions: This meta-analysis indicated that oral aspirin is associated with a remarkable decrease in the recurrence of any adenoma and advanced adenomas in patients follow-up for 1 year without concerning the dose of aspirin, but with the extension of follow-up time for greater than 1 year, oral aspirin can be effective on preventing the recurrence of any adenoma, but for the advanced adenoma, the result indicated that oral aspirin had no efficacy, According to the inclusion of ethnic groups, we also divided relevant papers into two subgroups as the yellow and white group. Then the follow-up time was less than 3 years, oral aspirin without considering the dose, had an significant efficacy on preventing the recurrence of any adenoma. But with the follow-up greater than 2 years, oral aspirin had no effect in the white.

Preparation and In Vitro Characterization of Gelatin Methacrylate for Corneal Tissue Engineering

Yan Yayun,Cao Yanyan,Cheng Rong,Shen Zhizhong,Zhao Yajing,Zhang Yixia,Zhou Guohong,Sang Shengbo 한국조직공학과 재생의학회 2022 조직공학과 재생의학 Vol.19 No.1

BACKGROUND: Corneal disease is second only to cataract considered as the leading cause of blindness in the world, with high morbidity. Construction of corneal substitutes in vitro by tissue engineering technology to achieve corneal regeneration has become a research hotspot in recent years. We conducted in-depth research on the biocompatibility, physicochemical and mechanical properties of rat bone marrow mesenchymal stem cells (rBM-MSCs)-seeded gelatin methacrylate (GelMA) as a bioengineered cornea. METHODS: Four kinds of GelMA with different concentrations (7, 10, 15 and 30%) were prepared, and their physicchemical, optical properties, and biocompatibility with rBM-MSCs were characterized. MTT, live/dead staining, cell morphology, immunofluorescence staining and gene expression of keratocyte markers were performed. RESULTS: 7%GelMA hydrogel had higher equilibrium water content and porosity, better optical properties and hydrophilicity. In addition, it is more beneficial to the growth and proliferation of rBM-MSCs. However, the 30%GelMA hydrogel had the best mechanical properties, and could be more conducive to promote the differentiation of rBM-MSCs into keratocyte-like cells. CONCLUSION: As a natural biological scaffold, GelMA hydrogel has good biocompatibility. And it has the ability to promote the differentiation of rBM-MSCs into keratocyte-like cells, which laid a theoretical and experimental foundation for further tissue-engineered corneal stromal transplantation, and provided a new idea for the source of seeded cells in corneal tissue engineering.

Stock Performance and Insider Trading in Completed and Canceled Private Placements

Yan Zhao,Kung-Chi Chen,Lee-Young Cheng,Ting-Wen Wu 한국증권학회 2019 Asia-Pacific Journal of Financial Studies Vol.48 No.1

This paper examines the impact of insider trading on completed and canceled private equity offerings. We find that insider trading has no impact on firms’ decisions to complete or cancel offerings, but it has a positive impact on the long-run stock performance of the issuing firms. Firms complete the undervalued offerings and cancel the offerings when they no longer perceive their shares are undervalued. Firms with weaker operating performance are more likely to complete private placements because they regard private offering as the last resort for raising equity capital. Firms that complete private placements have significantly better long-term stock performance than firms that cancel private placements.