Experimental Investigation on the Performance Levels and Drift Capacity of SRC Columns

Lei Zhang,Xiaolei Han,Jing Ji,Haoyu Lin 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.4

To promote the performance-based seismic design and assessment of steel-reinforced concrete(SRC) structures, 27 SRC columns, varying axial load ratio n, steel ratio ρss, and shear span ratio λ, were tested under quasi-static cyclic loadings. The failure modes, hysteretic response, performance levels (PLs), damage states and drift limits of the SRC columns were reported and discussed. The results showed that the failure mode shifted gradually from flexural to shear as λ decreased, but the deformability was not weakened obviously. Six PLs were defined based on the backbone curve of the SRC columns. Each PL was correlated to a damage state that represents a specific macroscopic damage extent. The relative error of drift limits between performance levels and damage states was less than 9% on average. Parametric analysis showed that n and ρss were the most influential factors for drift limits, whereas λ had an ignorable effect. Then, practical regression formulas were established in terms of n and ρss for drift limits of three key PLs (PL1, PL5, and PL6) of the SRC columns, and they were in good agreement with the experimental results. Finally, the average damage indices of PL1 to PL6, calculated using the model proposed in this paper, were 0.26, 0.45, 0.65, 0.83, 0.95, and 0.99, respectively.

Conceptual configuration and seismic performance of high-rise steel braced frame

Shengfang Qiao,Xiaolei Han,Kemin Zhou,Weichen Li 국제구조공학회 2017 Steel and Composite Structures, An International J Vol.23 No.2

Conceptual configuration and seismic performance of high-rise steel frame-brace structure are studied. First, the topology optimization problem of minimum volume based on truss-like material model under earthquake action is presented, which is solved by full-stress method. Further, conceptual configurations of 20-storey and 40-storey steel frame-brace structure are formed. Next, the 40-storeystructure model is developed in Opensees. Two common configurations are utilized for comparison. Last, seismic performance of 40-storey structure is derived using nonlinear static analysis and nonlinear dynamic analysis. Results indicate that structural lateral stiffness and maximum roof displacement can be improved using brace. Meanwhile seismic damage can also be decreased. Moreover, frame-brace structure using topology optimization is most favorable to enhance lateral stiffness and mitigate seismic damage. Thus, topology optimization is an available way to form initial conceptual configuration in high-rise steel frame-brace structure.

Choice of Capecitabine or S1 in Combination with Oxaliplatin based on Thymidine Phosphorylase and Dihydropyrimidine Dehydrogenase Expression Status in Patients with Advanced Gastric Cancer

Xu, Rong,He, Xiaolei,Wufuli, Reyina,Su, Ying,Ma, Lili,Chen, Ru,Han, Zhongcheng,Wang, Fang,Liu, Jiang The Korean Gastric Cancer Association 2019 Journal of gastric cancer Vol.19 No.4

Purpose: To study the efficacy of capecitabine or S-1 plus oxaliplatin (CAPOX or SOX) for treating thymidine phosphorylase (TP)- or dihydropyrimidine dehydrogenase (DPD)-positive advanced gastric cancer. Materials and Methods: Eighty-six patients with stage IIIC to IV gastric cancer were assessed for TP and DPD expression by immunohistochemistry. The association between CAPOX or SOX efficacy and TP/DPD expression was retrospectively analyzed. Results: There were no significant differences in the objective remission rate (ORR, 52.27% vs. 47.62%; P>0.05), disease control rate (72.73% vs. 73.81%, P>0.05), progression-free survival (hazard ratio [HR], 1.119; 95% confidence interval [CI], 0.739-1.741; P=0.586), and overall survival (OS; HR, 0.855; 95% CI, 0.481-1.511; P=0.588) between CAPOX and SOX. A higher number of stage IV patients showed TP positivity, while DPD-positive patients predominantly showed intestinal type of gastric cancer. In TP-positive patients, the ORRs associated with CAPOX and SOX treatments were 57.14% and 38.10%, respectively; OS was better with CAPOX than with SOX (HR, 0.447; 95% CI, 0.179-0.978; P=0.046). Among DPD-positive patients, the SOX treatment-associated ORR (60.87%) was significantly higher than the CAPOX treatment-associated ORR (43.48%). Furthermore, SOX treatment resulted in better OS than did CAPOX treatment (HR, 2.020; 95% CI, 1.019-4.837; P=0.049). Conclusions: No significant difference in clinical efficacy was found between CAPOX and SOX. TP-positive patients might respond better to CAPOX while DPD-positive patients may respond better to SOX. Our findings might serve as a guide for personalized chemotherapy for gastric cancer.

Choice of Capecitabine or S1 in Combination with Oxaliplatin based on Thymidine Phosphorylase and Dihydropyrimidine Dehydrogenase Expression Status in Patients with Advanced Gastric Cancer

Jiang Liu,Rong Xu,Xiaolei He,Reyina Wufuli,Ying Su,Lili Ma,Ru Chen,Zhongcheng Han,Fang Wang 대한위암학회 2019 Journal of gastric cancer Vol.19 No.4

Purpose: To study the efficacy of capecitabine or S-1 plus oxaliplatin (CAPOX or SOX) for treating thymidine phosphorylase (TP)- or dihydropyrimidine dehydrogenase (DPD)-positive advanced gastric cancer. Materials and Methods: Eighty-six patients with stage IIIC to IV gastric cancer were assessed for TP and DPD expression by immunohistochemistry. The association between CAPOX or SOX efficacy and TP/DPD expression was retrospectively analyzed. Results: There were no significant differences in the objective remission rate (ORR, 52.27% vs. 47.62%; P>0.05), disease control rate (72.73% vs. 73.81%, P>0.05), progression-free survival (hazard ratio [HR], 1.119; 95% confidence interval [CI], 0.739–1.741; P=0.586), and overall survival (OS; HR, 0.855; 95% CI, 0.481–1.511; P=0.588) between CAPOX and SOX. A higher number of stage IV patients showed TP positivity, while DPD-positive patients predominantly showed intestinal type of gastric cancer. In TP-positive patients, the ORRs associated with CAPOX and SOX treatments were 57.14% and 38.10%, respectively; OS was better with CAPOX than with SOX (HR, 0.447; 95% CI, 0.179–0.978; P=0.046). Among DPD-positive patients, the SOX treatment-associated ORR (60.87%) was significantly higher than the CAPOX treatment-associated ORR (43.48%). Furthermore, SOX treatment resulted in better OS than did CAPOX treatment (HR, 2.020; 95% CI, 1.019–4.837; P=0.049). Conclusions: No significant difference in clinical efficacy was found between CAPOX and SOX. TP-positive patients might respond better to CAPOX while DPD-positive patients may respond better to SOX. Our findings might serve as a guide for personalized chemotherapy for gastric cancer.

A Unifying Framework of Mining Trajectory Patterns of Various Temporal Tightness

Jae-Gil Lee,Jiawei Han,Xiaolei Li IEEE 2015 IEEE TRANSACTIONS ON KNOWLEDGE AND DATA ENGINEERIN Vol.27 No.6

<P>Discovering trajectory patterns is shown to be very useful in learning interactions between moving objects. Many types of trajectory patterns have been proposed in the literature, but previous methods were developed for only a specific type of trajectory patterns. This limitation could make pattern discovery tedious and inefficient since users typically do not know which types of trajectory patterns are hidden in their data sets. Our main observation is that many trajectory patterns can be arranged according to the strength of temporal constraints. In this paper, we propose a unifying framework of mining trajectory patterns of various temporal tightness, which we call unifying trajectory patterns (UT-patterns). This framework consists of two phases: initial pattern discovery and granularity adjustment. A set of initial patterns are discovered in the first phase, and their granularities (i.e., levels of detail) are adjusted by split and merge to detect other types in the second phase. As a result, the structure called a pattern forest is constructed to show various patterns. Both phases are guided by an information-theoretic formula without user intervention. Experimental results demonstrate that our framework facilitates easy discovery of various patterns from real-world trajectory data.</P>

Seismic analysis of steel structure with brace configuration using topology optimization

Shengfang Qiao,Kemin Zhou,Jing Ji,Xiaolei Han 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.21 No.3

Seismic analysis for steel frame structure with brace configuration using topology optimization based on truss-like material model is studied. The initial design domain for topology optimization is determined according to original steel frame structure and filled with truss-like members. Hence the initial truss-like continuum is established. The densities and orientation of truss-like members at any point are taken as design variables in finite element analysis. The topology optimization problem of least-weight truss-like continuum with stress constraints is solved. The orientations and densities of members in truss-like continuum are optimized and updated by fully-stressed criterion in every iteration. The optimized truss-like continuum is founded after finite element analysis is finished. The optimal bracing system is established based on optimized truss-like continuum without numerical instability. Seismic performance for steel frame structures is derived using dynamic time-history analysis. A numerical example shows the advantage for frame structures with brace configuration using topology optimization in seismic performance.

Nitro-oleic Acid Decreases Transcription of the Angiotensin II Type I Receptor Gene in Aortic Smooth Muscle Cells

Huan Wang,Hongsheng Ouyang,Yaping Tian,Zhuang Liu,Xiaolei Han,Xingxing Liu,Guangyao Ran,Gangqi Wang,Daxin Pang,Xiaochun Tang 한국생물공학회 2014 Biotechnology and Bioprocess Engineering Vol.19 No.4

Nitroalkene derivatives of nitro-oleic acid(OA-NO2) regulate pluripotent cell signaling in vivo underphysiological and pathological conditions. Angiotensin IItype 1 receptor (AT1R) plays an important role in thecardiovascular system. In this study, OA-NO2 reduced theAT1R mRNA level, specifically in primary smooth musclecells, showing a 70% reduction in rat smooth muscle cells(RASMCs) and a 50% reduction in pig smooth musclecells (PASMCs). These effects were not observed in CHOcells, which highly express AT1R. The AT1R mRNA decayrate was unchanged after OA-NO2 compared with OAtreatment. Nitric oxide (NO) and peroxisome proliferatoractivatedreceptor gamma (PPARγ) did not alter thereduced effects of OA-NO2 on the AT1R mRNA level inSMCs. However, Sp1-mediated activation of the AT1Rpromoter was reduced in response to OA-NO2 in RASMCsbut not 293T cells. In addition, the nuclear factor-kappa B(NF-κB) pathway was involved in the OA-NO2-mediateddownregulation of AT1R transcription in SMCs. Takentogether, our results demonstrate that OA-NO2 specificallyinhibits AT1R mRNA expression in primary smooth musclecells via the NF-κB pathway.

Bifunctionally active and durable hierarchically porous transition metal-based hybrid electrocatalyst for rechargeable metal-air batteries

Seo, Min Ho,Park, Moon Gyu,Lee, Dong Un,Wang, Xiaolei,Ahn, Wook,Noh, Seung Hyo,Choi, Sung Mook,Cano, Zachary P.,Han, Byungchan,Chen, Zhongwei Elsevier 2018 Applied catalysis. B, Environmental Vol.239 No.-

<P><B>Abstract</B></P> <P>In this work, we show an effective strategy combining experimental and computational methods to explore and clarify rational design approaches utilizing transition metals for enhanced electrocatalysis of oxygen reactions. We report a bifunctional electrocatalyst synthesized by a chemical deposition of palladium (Pd) nanoparticles on three-dimensionally ordered mesoporous cobalt oxide (Pd@3DOM-Co<SUB>3</SUB>O<SUB>4</SUB>) demonstrating extreme stability and activity towards electrocatalytic oxygen reduction and evolution reactions (ORR and OER). Pd@3DOM-Co<SUB>3</SUB>O<SUB>4</SUB> exhibits a significantly positive-shifted ORR half-wave potential of 0.88 V (vs. RHE) and a higher OER current density of 41.3 mA cm<SUP>−2</SUP> measured at 2.0 V (vs. RHE) relative to non-deposited 3DOM-Co<SUB>3</SUB>O<SUB>4</SUB>. Moreover, in terms of durability, Pd@3DOM-Co<SUB>3</SUB>O<SUB>4</SUB> demonstrates a negligible half-wave potential loss with 99.5% retention during ORR and a high current density retention of 96.4% during OER after 1000 cycles of accelerated degradation testing (ADT). <I>Ab-initio</I> computational simulation of the oxygen reactions reveals that the modification of the electronic structure by combining Pd and Co<SUB>3</SUB>O<SUB>4</SUB> lowers the Pd d-band center and enhances the electron abundance at the Fermi level, resulting in improved kinetics and conductivity. Furthermore, it is elucidated that the enhanced electrochemical stability is attributed to an elevated carbon corrosion potential (<I>U<SUB>corr,C</SUB> </I>) for the Pd@3DOM-Co<SUB>3</SUB>O<SUB>4</SUB> surface and an increased dissolution potential (U<SUB>diss</SUB>) of Pd nanoparticles. Meanwhile, synergistic improvements in the bifunctional activity resulting from the combination of Pd and 3DOM-Co<SUB>3</SUB>O<SUB>4</SUB> were confirmed by both electrochemical and physical characterization methods, which highlights the practical viability of Pd@3DOM-Co<SUB>3</SUB>O<SUB>4</SUB> as an efficient bifunctional catalyst for rechargeable metal-air batteries.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Strategy for rational design of transition metal-based bifunctional electrocatalyst. </LI> <LI> Synergistic combination of Pd and 3DOM Co<SUB>3</SUB>O<SUB>4</SUB> for enhanced activity and durability. </LI> <LI> Doped-Pd on 3DOM Co<SUB>3</SUB>O<SUB>4</SUB> leads to electron abundance at the Fermi level. </LI> <LI> Low carbon corrosion and bulk–like dissolution tendency of doped-Pd on 3DOM Co<SUB>3</SUB>O<SUB>4</SUB>. </LI> <LI> 500 h of Zn-air battery operation with improved charge-discharge performance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>