Experimental and Numerical Investigation of Stress Concentration at Rib-to-Crossbeam Joint

Heng Fang,Nouman Iqbal,Gilles Van Staen,Hans De Backer 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.1

In orthotropic steel decks (OSDs), the rib-to-crossbeam joint is the most vulnerable detail that has not been drawn enough attention. The failure mode of cracks initiate from the lower weld end on rib wall is governing its fatigue performance. However, relevant detail categories are still missing in prevailing codes. This paper mainly focuses on the stress concentrations at the rib-to-crossbeam joint induced by rib distortions. A series of static load tests were fi rst performed on a full-scale OSD specimen with diff erent weld length between the ribs and the crossbeam. Then, corresponding numerical simulations were fi nished. Several possibilities that may cause the diff erences between the measurements and the calculations are investigated. At last, fatigue assessments based on infl uence lines of structural hot spot stress (SHSS) are completed. Research results reveal that the measurement results of reference points for SHSS method would be very sensitive to the exact location of strain gauges. Due to the manual welding, the deviation of strain gauge positions induced by the irregular weld shape is thought to be the main reason that causes the diff erences between measurements and calculations. Raising the location of cope hole terminations would decrease distortional stresses. However, the infl uence of this parameter on fatigue lives is rather small. The fatigue lives of points along the lower weld toe are very close. Hence, the point at the middle plane of crossbeam could be used as the reference point for fatigue assessments. Meanwhile, the center between ribs could be used as the reference transverse load position for fatigue assessments of this joint.

Synthesis and Antibacterial Activity of 1,3-Diallyltrisulfane Derivatives

Fang-Kui Ren,Xiao-Yan He,Li Deng,Bo-Heng Li,Dong-Soo Shin,Zhu-Bo Li 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.3

A series of novel 1,3-diallyltrisulfane analogues were synthesized and assayed in vitro for antimicrobial activity against Gram positive, Gram negative bacteria and fungi. The antimicrobial activity of the 1,3-diallyltrisulfane derivatives showed, on the whole, very potent towards all the tested Gram positive, Gram negative and fungi (MIC ranging from 4 to 256 μg/mL). 1,3-Di(pent-4-enyl)trisulfane 3b and 1,3-bis(3-methylbut-2-enyl)trisulfane 3e exhibited the strongest antibacterial activity among all the compounds, and both of them were more active than 1,3-diallyltrisulfane (DATS). Results indicated the relationship of either carbon number or lipophilicity with antimicrobial activity presented “V” shape. These observations provided some predictions in order to further design 1,3-diallyltrisulfane derivatives with antimicrobial activity.

Synthesis and Antibacterial Activity of 1,3-Diallyltrisulfane Derivatives

Ren, Fang-Kui,He, Xiao-Yan,Deng, Li,Li, Bo-Heng,Shin, Dong-Soo,Li, Zhu-Bo Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.3

A series of novel 1,3-diallyltrisulfane analogues were synthesized and assayed in vitro for antimicrobial activity against Gram positive, Gram negative bacteria and fungi. The antimicrobial activity of the 1,3-diallyltrisulfane derivatives showed, on the whole, very potent towards all the tested Gram positive, Gram negative and fungi (MIC ranging from 4 to 256 μg/mL). 1,3-Di(pent-4-enyl)trisulfane 3b and 1,3-bis(3-methylbut-2-enyl)trisulfane 3e exhibited the strongest antibacterial activity among all the compounds, and both of them were more active than 1,3-diallyltrisulfane (DATS). Results indicated the relationship of either carbon number or lipophilicity with antimicrobial activity presented “V” shape. These observations provided some predictions in order to further design 1,3-diallyltrisulfane derivatives with antimicrobial activity.

Treatment Retention Rates of 3-monthly Paliperidone Palmitate and Risk Factors Associated with Discontinuation: A Population-based Cohort Study

Chien-Heng Lin,Huang-Li Lin,Chih-Lin Chiang,Yi-Wen Chen,Yan-Fang Liu,Yen Kuang Yang,Chao-Hsiun Tang 대한정신약물학회 2023 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.21 No.3

Objective: Limited evidence exists regarding real-world 3-monthly paliperidone palmitate (PP3M) treatment retention and associated factors. Methods: We conducted a retrospective, nationwide cohort study using the Taiwan National Health Insurance Research Database between October 2017 and December 2019. Adult patients with schizophrenia initiated on PP3M were enrolled. The primary outcomes were time to PP3M discontinuation, time to psychiatric hospitalization, and the proportions of patients receiving the next PP3M dose within 120 days among first-, second-, and third-dose completers. Key covariates included prior PP1M duration and adequate PP3M initiation. Results: The PP3M treatment retention rates were 79.7%, 66.3%, and 52.5% after 6, 12, and 24 months, respectively, with 86.4%, 90.6%, and 90.0% of respective first-, second-, and third-dose completers receiving the next PP3M dose. Adequate PP3M initiation and prior PP1M treatment duration > 180 days were associated with favorable PP3M treatment retention. In multivariate analyses, PP1M durations of 180−360 days (adjusted relative risk [aRR], 1.76) or < 180 days (aRR, 2.79) were associated with PP3M discontinuation at the second dose. Inadequate PP3M initiation was associated with discontinuation at the third dose (aRR, 2.18). Patients fully adherent to PP3M treatment in the first year had a higher probability of being free from psychiatric hospitalization (86.7% at 2 years), compared with those partially adherent or non-adherent to PP3M in the first year. Conclusion: Prior PP1M duration and adequate PP3M initiation are major factors affecting PP3M treatment retention. Higher PP3M treatment retention is associated with a lower risk of psychiatric hospitalization.

Increased Serotonin Signaling Contributes to the Warburg Effect in Pancreatic Tumor Cells Under Metabolic Stress and Promotes Growth of Pancreatic Tumors in Mice

Jiang, Shu-Heng,Li, Jun,Dong, Fang-Yuan,Yang, Jian-Yu,Liu, De-Jun,Yang, Xiao-Mei,Wang, Ya-Hui,Yang, Min-Wei,Fu, Xue-Liang,Zhang, Xiao-Xin,Li, Qing,Pang, Xiu-Feng,Huo, Yan-Miao,Li, Jiao,Zhang, Jun-Feng Elsevier 2017 Gastroenterology Vol.153 No.1

<P><B>Background & Aims</B></P> <P>Desmoplasia and poor vascularity cause severe metabolic stress in pancreatic ductal adenocarcinomas (PDACs). Serotonin (5-HT) is a neuromodulator with neurotransmitter and neuroendocrine functions that contributes to tumorigenesis. We investigated the role of 5-HT signaling in the growth of pancreatic tumors.</P> <P><B>Methods</B></P> <P>We measured the levels of proteins that regulate 5-HT synthesis, packaging, and degradation in pancreata from Kras<SUP>G12D/+</SUP>/Trp53<SUP>R172H/+</SUP>/Pdx1-Cre (KPC) mice, which develop pancreatic tumors, as well as in PDAC cell lines and a tissue microarray containing 81 human PDAC samples. We also analyzed expression levels of proteins involved in 5-HT synthesis and degradation by immunohistochemical analysis of a tissue microarray containing 311 PDAC specimens, and associated expression levels with patient survival times. 5-HT level in 14 matched PDAC tumor and non-tumor tissues were analyzed by ELISA. PDAC cell lines were incubated with 5-HT and cell survival and apoptosis were measured. We analyzed expression of the 5-HT receptor HTR2B in PDAC cells and effects of receptor agonists and antagonists, as well as HTR2B knockdown with small hairpin RNAs. We determined the effects of 5-HT stimulation on gene expression profiles of BxPC-3 cells. Regulation of glycolysis by 5-HT signaling via HTR2B was assessed by immunofluorescence and immunoprecipitation analyses, as well as by determination of the extracellular acid ratio, glucose consumption, and lactate production. Primary PDACs, with or without exposure to SB204741 (a selective antagonist of HTR2B), were grown as xenograft tumors in mice, and SB204741 was administered to tumor-bearing KPC mice; tumor growth and metabolism were measured by imaging analyses.</P> <P><B>Results</B></P> <P>In immunohistochemical analysis of a tissue microarray of PDAC specimens, increased levels of TPH1 and decreased level of MAOA, which regulate 5-HT synthesis and degradation, correlated with stage and size of PDACs and shorter patient survival time. We found levels of 5-HT to be increased in human PDAC tissues compared with non-tumor pancreatic tissues, and PDAC cell lines compared with non-transformed pancreatic cells. Incubation of PDAC cell lines with 5-HT increased proliferation and prevented apoptosis. Agonists of HTR2B, but not other 5-HT receptors, promoted proliferation and prevented apoptosis of PDAC cells. Knockdown of HTR2B in PDAC cells, or incubation of cells with HTR2B inhibitors, reduced their growth as xenograft tumors in mice. We observed a correlation between 5-HT and glycolytic flux in PDAC cells; levels of metabolic enzymes involved in glycolysis, the phosphate pentose pathway, and hexosamine biosynthesis pathway increased significantly in PDAC cells following 5-HT stimulation. 5-HT stimulation led to formation of the HTR2B–LYN–p85 complex, which increased PI3K–Akt–mTOR signaling and the Warburg effect by increasing protein levels of MYC and HIF1A. Administration of SB204741 to KPC mice slowed growth and metabolism of established pancreatic tumors and prolonged survival of the mice.</P> <P><B>Conclusions</B></P> <P>Human PDACs have increased levels of 5-HT, and PDAC cells increase expression of its receptor, HTR2B. These increases allow for tumor glycolysis under metabolic stress and promote growth of pancreatic tumors and PDAC xenograft tumors in mice.</P>

Targeted Efficacy of Dihydroartemisinin for Translationally Controlled Protein Expression in a Lung Cancer Model

Liu, Lian-Ke,Wu, Heng-Fang,Guo, Zhi-Rui,Chen, Xiang-Jian,Yang, Di,Shu, Yong-Qian,Zhang, Ji-Nan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Objective: Lung cancer is one of the malignant tumors with greatest morbidity and mortality around the world. The keys to targeted therapy are discovery of lung cancer biomarkers to facilitate improvement of survival and quality of life for the patients with lung cancer. Translationally controlled tumor protein (TCTP) is one of the most overexpressed proteins in human lung cancer cells by comparison to the normal cells, suggesting that it might be a good biomarker for lung cancer. Materials and Methods: In the present study, the targeted efficacy of dihydroartemisinin (DHA) on TCTP expression in the A549 lung cancer cell model was explored. Results and Conclusions: DHA could inhibit A549 lung cancer cell proliferation, and simultaneously up-regulate the expression of TCTP mRNA, but down-regulate its protein expression in A549 cells. In addition, it promoted TCTP protein secretion. Therefore, TCTP might be used as a potential biomarker and therapeutic target for non-small cell lung cancers.

Expression and Clinical Significance of REPS2 in Human Esophageal Squamous Cell Carcinoma

Zhang, Hang,Duan, Chao-Jun,Zhang, Heng,Cheng, Yuan-Da,Zhang, Chun-Fang Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.5

Objective: REPS2 plays important roles in inhibiting cell proliferation, migration and in inducing apoptosis of cancer cells, now being identified as a useful biomarker for favorable prognosis in prostate and breast cancers. The purpose of this study was to assess REPS2 expression and to explore its role in esophageal squamous cell carcinoma (ESCC). Methods: Protein expression of REPS2 in ESCCs and adjacent non-cancerous tissues from 120 patients was analyzed by immunohistochemistry and correlated with clinicopathological parameters and patient outcome. Additionally, thirty paired ESCC tissues and four ESCC cell lines and one normal human esophageal epithelial cell line were evaluated for REPS2 mRNA and protein expression levels by quantitative RT-PCR and Western blotting. Results: REPS2 mRNA and protein expression levels were down-regulated in ESCC tissues and cell lines. Low protein levels were significantly associated with primary tumour, TNM stage, lymph node metastasis and recurrence (all, P < 0.05). Survival analysis demonstrated that decreased REPS2 expression was significantly associated with shorter overall survival and disease-free survival (both, P < 0.001), especially in early stage ESCC patients. When REPS2 expression and lymph node metastasis status were combined, patients with low REPS2 expression/lymph node (+) had both poorer overall and disease-free survival than others (both, P < 0.001). Cox multivariate regression analysis further revealed REPS2 to be an independent prognostic factor for ESCC patients. Conclusions: Our findings demonstrate that downregulation of REPS2 may contribute to malignant progression of ESCC and represent a novel prognostic marker and a potential therapeutic target for ESCC patients.

Alkaloids from the bulbs of Lycoris longituba and their neuroprotective and acetylcholinesterase inhibitory activities

Yun-Yun Zhu,Xue Li,Heng-Yi Yu,Yu-Fang Xiong,Peng Zhang,Hui-Fang Pi,Han-Li Ruan 대한약학회 2015 Archives of Pharmacal Research Vol.38 No.5

Three novel alkaloids (1–3), together withnineteen known ones (4–22), were isolated from the bulbsof Lycoris longituba. Their structures were elucidated onthe basis of extensive spectroscopic analyses, which belongto several Amaryllidaceae alkaloid skeletons. Amongthem, the harmane-type alkaloids (the new compound 1and the known compounds 5, 6 and 7) were found for thefirst time from Lycoris genus. The isolates were tested fortheir neuroprotective activities against CoCl2, H2O2 andAb25–35-induced SH-SY5Y cell injuries, and the majorityof them exhibited neuroprotective activities of differentdegrees. The acetylcholinesterase (AChE) inhibitoryactivities of the isolated alkaloids were also evaluated,while compounds 12, 14–20 and 22 exhibited extremelysignificant AChE inhibitory activities.

Four new compounds from the bulbs of Lycoris aurea with neuroprotective effects against CoCl2 and H2O2-induced SH-SY5Y cell injuries

An Jin,Xuelian Xiang,Yun-Yun Zhu,Heng-Yi Yu,Hui-Fang Pi,Peng Zhang,Han-Li Ruan 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.3

Three new alkaloids, 2a-hydroxy-6-O-n-butyloduline,O-n-butyllycorenine, (-)-N-(chloromethyl)lycoramine(1–3), and a new phenolic compound, ((7S)-7-(4-hydroxyphenyl)-7-hydroxypropyl)-20-methylbenzene-30,60-diol (14), along with ten known alkaloids (4–13), wereisolated from the bulbs of Lycoris aurea collected fromHuaihua County of Hunan Province, China. Their structureswere elucidated by spectroscopic methods includingHRESIMS, UV, IR, and NMR. All the isolated compoundswere tested for their neuroprotective effects against CoCl2and H2O2-induced SH-SY5Y cell death. Compounds 1–7and 10 exhibited significant neuroprotective effects againstCoCl2-induced SH-SY5Y cell injury, while compounds1–5, 7, 10 and 12 showed obvious neuroprotective effectsagainst H2O2-induced SH-SY5Y cell death.

New Safrole Oxide Derivatives: Synthesis and in vitro Antiproliferative Activities on A549 Human Lung Cancer Cells

Li-Ying Wang,Xiu-Hua Wang,Jia-Lian Tan,Shuai Xia,Heng-Zhi Sun,Jin-Wen Shi,Ming-Dong Jiang,Liang Fang,Hua Zuo,Gautam Dupati,장기완,신동수 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.11

A number of novel small molecules, safrole oxide derivatives 4a-c, 6a-c, 9a-h, were synthesized by the reaction of safrole oxide with anilines 3 and 5, or its alkyl allyl ether derivative 7 with alkyl bromide 8 in moderate yields. The antiproliferative effects of all the target molecules on A549 cell growth were investigated and it was found that the 14 novel compounds could suppress A549 lung cancer cell growth. Among them, compound 6b was the most effective compound in inhibiting the proliferation of A549 cells.