Microstructure and Mechanical Properties of Mg–2.0Gd–1.2Y–1.0Zn–0.2Zr Alloy

Jianan Liu,Xiaoru Zhang,Wenxue Lv,Yumei Zhou,Daqing Fang,Xiangdong Ding,Jun Sun 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

The microstructural evolution of Mg–2.0Gd–1.2Y–1.0Zn–0.2Zr (GWZK) alloy during homogenization and subsequentaging heat-treatment and the tensile properties of the peak-aged sample at various temperatures have been investigated. Thephase transformation during homogenization, static precipitation during aging, and deformation mechanisms at 250 °C aresystematically analyzed through XRD, TEM and EBSD measurements. The peak-aged GWZK alloy has good combinationof strength and ductility at elevated temperatures owing to its high thermal stability by the LPSO phases distributed alongthe grain boundaries. The change (19 MPa) in the yield strength of peak-aged samples between RT and 250 °C is mainlyrelated to easy gliding of dislocations on the non-basal planes due to the decrease in critical resolved shear stress of slip. Two strengthening models are applied to quantitatively describe the efect of {11 −2 0}훼precipitate plates on Orowanstrengthening corresponding to RT and 250 °C. Ignoring changes in solid solution strengthening and grain boundary strengthening of the peak-aged sample caused by increasing temperature, the calculated reduction value (16.5 MPa) in macroscopicyield strength from RT (based on the basal<a>slip mode) to 250 °C (based on the pyramidal<c+a>slip mode) is in goodagreement with the measured reduction value (19 MPa).

Recent Advances in Functional Hydrogel for Repair of Abdominal Wall Defects: A Review

Ye Liu,Jinjian Huang,Sicheng Li,Ze Li,Canwen Chen,Guiwen Qu,Kang Chen,Yitian Teng,Rui Ma,Jianan Ren,Xiuwen Wu 한국생체재료학회 2024 생체재료학회지 Vol.28 No.00

The abdominal wall plays a crucial role in safeguarding the internal organs of the body, serving as an essential protective barrier. Defects in the abdominal wall are common due to surgery, infection, or trauma. Complex defects have limited self-healing capacity and require external intervention. Traditional treatments have drawbacks, and biomaterials have not fully achieved the desired outcomes. Hydrogel has emerged as a promising strategy that is extensively studied and applied in promoting tissue regeneration by filling or repairing damaged tissue due to its unique properties. This review summarizes the five prominent properties and advances in using hydrogels to enhance the healing and repair of abdominal wall defects: (a) good biocompatibility with host tissues that reduces adverse reactions and immune responses while supporting cell adhesion migration proliferation; (b) tunable mechanical properties matching those of the abdominal wall that adapt to normal movement deformations while reducing tissue stress, thereby influencing regulating cell behavior tissue regeneration; (c) drug carriers continuously delivering drugs and bioactive molecules to sites optimizing healing processes enhancing tissue regeneration; (d) promotion of cell interactions by simulating hydrated extracellular matrix environments, providing physical support, space, and cues for cell migration, adhesion, and proliferation; (e) easy manipulation and application in surgical procedures, allowing precise placement and close adhesion to the defective abdominal wall, providing mechanical support. Additionally, the advances of hydrogels for repairing defects in the abdominal wall are also mentioned. Finally, an overview is provided on the current obstacles and constraints faced by hydrogels, along with potential prospects in the repair of abdominal wall defects.

Novel designs of polycarboxylate superplasticizers for improving resistance in clay-contaminated concrete

Xiao Liu,Jianan Guan,Guanghong Lai,Yunsheng Zheng,Ziming Wang,Suping Cui,Mingzhang Lan,Huiqun Li 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.55 No.-

Certain clays attached around the aggregates contaminate the concrete and also greatly affect the concrete workability, the mechanism of which was investigated through calculating the volume change of solid and liquid phases of concrete mixture containing clay. To minimize this detrimental effect, two novel designs based on the transfer of theory and techniques from polymer science, i.e., molecular design of polycarboxylate superplasticizer (PCE), were proposed. The one was “intercalator” synthesized via Hofmann rearrangement and cationization, and the other was “star-shaped polycarboxylate super- plasticizer (SPCE)” synthesized via a route of “core first and arm second”. The results of Infrared Spectroscopy (IR) and 1H Nuclear Magnetic Resonance (1H NMR) confirm the designed structures. The applications of these polymers in clay-contaminated cement paste and concrete were tested. The results showed that, the dispersing capacities of “Intercalator + Comb-shaped polycarboxylate superplasticizer (CPCE)” and SPCE were less affected by adding clay in both cement paste and concrete. Adsorption and Xray diffraction (XRD) experiments revealed less harmful intercalation for SPCE and preferential occupation in the interlayer space of clay for intercalator to protect other workable PCEs. It is interesting that optimizing charge characteristic and “disassembling-assembling” molecular arrangement can contribute to excellent resistance towards clay. The aim of this study is to offer two promising alternatives, which attractively provide the theoretical basis and technological application in researching advanced materials in clay-contaminated concrete.

Damage detection of bridge structures under unknown seismic excitations using support vector machine based on transmissibility function and wavelet packet energy

Lijun Liu,Jianan Mi,Yixiao Zhang,Ying Lei 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.27 No.2

Since it may be hard to obtain the exact external load in practice, damage identification of bridge structures using only structural responses under unknown seismic excitations is an important but challenging task. Since structural responses are determined by both structural properties and seismic excitation, it is necessary to remove the effects of external excitation and only retain the structural information for structural damage identification. In this paper, a data-driven approach using structural responses only is proposed for structural damage alarming and localization of bridge structures. The transmissibility functions (TF) of structural responses are used to eliminate the influence of unknown seismic excitations. Moreover, the inverse Fourier transform of TFs and wavelet packet transform are used to reduce the influence of frequency bands and to extract the damagesensitive feature, respectively. Based on Support vector machines (SVM), structural responses under ambient excitations are used for training SVM. Then, structural responses under unknown seismic excitations are also processed accordingly and used for damage alarming and localization by the trained SMV. The numerical simulation examples of beam-type bridge and a cablestayed bridge under unknown seismic excitations are studied to illustrate the performance of the proposed approach.

Identification of a mimotope of an infectious bronchitis virus S1 protein

Jingming Zhou,Jianan Li,Yanghui Li,Hongliang Liu,Yanhua Qi,Aiping Wang 대한수의학회 2021 Journal of Veterinary Science Vol.22 No.4

The S1 protein of the infectious bronchitis virus (IBV) is a major structural protein that induces the production of the virus-neutralization antibodies. The monoclonal antibody against the IBV M41 S1 protein was used as a target for biopanning. After three rounds of biopanning, randomly selected phages bound to the monoclonal antibody. Sequence analysis showed that the dominant sequence was SFYDFEMQGFFI. Indirect competitive enzyme-linked immunosorbent assay showed that SFYDFEMQGFFI is a mimotope of the S1 protein that was predicted by PepSurf. The mimotope may provide information for further structural and functional analyses of the S1 protein.

Raspberry-Like Nanocomposite Microsphere via Double In situ Miniemulsion Polymerization Using Interfacial Redox Initiator System

Beibei Yang,Jianan Zhang,Jizhi Lin,Bo Wu,Qing Liu,Wenlong Yang,Mingyuan Wu,Qingyun Wu,Jianjun Yang 한국고분자학회 2013 Macromolecular Research Vol.21 No.2

Prediction Model for unfavorable Outcome in Spontaneous Intracerebral Hemorrhage Based on Machine Learning

Shengli Li,Jianan Zhang,Xiaoqun Hou,Yongyi Wang,Tong Li,Zhiming Xu,Feng Chen,Yong Zhou,Weimin Wang,Mingxing Liu 대한신경외과학회 2024 Journal of Korean neurosurgical society Vol.67 No.1

Objective : The spontaneous intracerebral hemorrhage (ICH) remains a significant cause of mortality and morbidity throughout the world. The purpose of this retrospective study is to develop multiple models for predicting ICH outcomes using machine learning (ML). Methods : Between January 2014 and October 2021, we included ICH patients identified by computed tomography or magnetic resonance imaging and treated with surgery. At the 6-month check-up, outcomes were assessed using the modified Rankin Scale. In this study, four ML models, including Support Vector Machine (SVM), Decision Tree C5.0, Artificial Neural Network, Logistic Regression were used to build ICH prediction models. In order to evaluate the reliability and the ML models, we calculated the area under the receiver operating characteristic curve (AUC), specificity, sensitivity, accuracy, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR). Results : We identified 71 patients who had favorable outcomes and 156 who had unfavorable outcomes. The results showed that the SVM model achieved the best comprehensive prediction efficiency. For the SVM model, the AUC, accuracy, specificity, sensitivity, PLR, NLR, and DOR were 0.91, 0.92, 0.92, 0.93, 11.63, 0.076, and 153.03, respectively. For the SVM model, we found the importance value of time to operating room (TOR) was higher significantly than other variables. Conclusion : The analysis of clinical reliability showed that the SVM model achieved the best comprehensive prediction efficiency and the importance value of TOR was higher significantly than other variables.

Metabolic engineering for the microbial production of marine bioactive compounds

Mao, Xiangzhao,Liu, Zhen,Sun, Jianan,Lee, Sang Yup Elsevier 2017 BIOTECHNOLOGY ADVANCES Vol.35 No.8

<P>Many marine bioactive compounds have medicinal and nutritional values. These bioactive compounds have been prepared using solvent-based extraction from marine bio-resources or chemical synthesis, which are costly, inefficient with low yields, and environmentally unfriendly. Recent advances in metabolic engineering allowed to some extent more efficient production of these compounds, showing promises to meet the increasing demand of marine natural bioactive compounds. In this paper, we review the strategies and statuses of metabolic engineering applied to microbial production of marine natural bioactive compounds including terpenoids and their derivatives, omega-3 polyunsaturated fatty acids, and marine natural drugs, and provide perspectives. (C) 2017 Elsevier Inc. All rights reserved.</P>

Improving Mechanical Properties and Thermal Conductivity of Styrene-Butadiene Rubber via Enhancing Interfacial Interaction Between Rubber and Graphene Oxide/Carbon Nanotubes Hybrid

Zhenghua Qian,Jianan Song,Zijin Liu,Zonglin Peng 한국고분자학회 2019 Macromolecular Research Vol.27 No.11

To fully utilize the fascinating comprehensive properties of graphene oxide (GO) and carbon nanotubes (CNTs), GO was used to promote the dispersion of carboxylated multi-walled carbon nanotubes (CC) in rubber matrix. Additionally, carboxylated acrylonitrile butadiene rubber (xNBR) was used to enhance the interfacial interaction between the styrene-butadiene rubber (SBR) and the GO/CC hybrid fillers for the formation of hydrogen bonds between the oxygenated functional groups of GO/CC hybrid fillers and the carboxyl groups of xNBR. Moreover, the interfacial interaction was investigated by Fourier transform infrared spectroscopy and further proved by differential scanning calorimetry. As a result, the mechanical property and thermal conductivity of SBR composites were improved significantly compared with the neat SBR vulcanizate, which were much higher than those of the SBR composites without xNBR. In contrast to adding GO/CNTs directly to the rubber matrix, enhancing the interfacial interaction between GO/CC hybrid fillers and rubber matrix as demonstrated herein is a valuable strategy to prepare rubber composites with remarkable comprehensive properties.

Electrochemical enhanced heterogeneous activation of peroxymonosulfate by CoFe2O4 nanoparticles to degrade moxifloxacin

Meng Zhang,Lili Liu,Jianan Li,Rui Zhan,Zhiping Wang,Haosheng Mi,Yunxiao Zhang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.127 No.-

The catalytic mechanism of CoFe2O4 nanoparticles (NPs) was investigated in the system of electrochemicalenhanced heterogeneous activation of peroxymonosulfate (EC/CoFe2O4/PMS) with moxifloxacin(MOX) as target contaminant. The removal efficiencies of MOX in PMS, CoFe2O4, EC, CoFe2O4/PMS, andEC/CoFe2O4/PMS system were 18.3%, 36.1%, 43.7%, 96.9%, and 98.3%, respectively. Although there wasno synergy effect between EC and heterogeneous catalytic oxidation reaction (HCOR) on MOX removal,the value of apparent rate constant (karc) was much higher in EC/CoFe2O4/PMS system (0.24 min1) comparedwith CoFe2O4/PMS system (0.13 min1). Therefore, EC not only kept the structure of CoFe2O4 NPsstable, but also significantly accelerated the reaction rate of HCOR. Meanwhile, according to electrochemicalimpedance spectra of catalysts synthesized based on ion-substitution strategy and the EC-HCORexperimental results, the decisive role of „Co in PMS activation and the electron transfer between„Co and „Fe were confirmed. The TOC removal efficiency was reached 74.4% as the ratio of PMS toCoFe2O4 NPs being 0.8 mM to 50 mg/L (30 min), and further improved to 87.6% with batch addition(0.25 mM per 30 min) of PMS (120 min, CoFe2O4 = 100 mg/L). The research results could improve theunderstanding of catalytic mechanism of spinel oxide in electrochemical system.