• Korean Journal of Metals and Materials
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• v.50 no.2
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• pp.171-175
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• 2012

By measuring the absorbed hydrogen quantity as a function of the number of cycles, the cycling properties of the Mg-15 wt%Ni-5 wt%$Fe_2O_3$ alloy were investigated. The absorbed hydrogen quantity decreased as the number of cycles increased. The $H_a$ value varied almost linearly with the number of cycles. The maintainability of absorbed hydrogen quantity at n=100 was 89.0% for the hydriding reaction time of 10 min. After the $150^{th}$ hydriding-dehydriding cycle, Mg, $Mg_2Ni$, $Mg(OH)_2$, MgO, and Fe were observed. The phases were analyzed by Rietveld analysis from the XRD patterns of the Mg-15 wt%Ni-5 wt%$Fe_2O_3$ alloy after 150 hydriding-dehydriding cycles. The crystallite size and strain of Mg were then estimated with the Williamson-Hall technique.

• Korean Journal of Metals and Materials
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• v.50 no.5
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• pp.383-387
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• 2012

The activation of Mg-10 wt%$Fe_2O_3$ was completed after one hydriding-dehydriding cycle. Activated Mg-10 wt%$Fe_2O_3$ absorbed 5.54 wt% H for 60 min at 593 K under 12 bar $H_2$, and desorbed 1.04 wt% H for 60 min at 593 K under 1.0 bar $H_2$. The effect of the reactive grinding on the hydriding and dehydriding rates of Mg was weak. The reactive grinding of Mg with $Fe_2O_3$ is believed to increase the $H_2$-sorption rates by facilitating nucleation (by creating defects on the surface of the Mg particles and by the additive), by making cracks on the surface of Mg particles and reducing the particle size of Mg and thus by shortening the diffusion distances of hydrogen atoms. The added $Fe_2O_3$ and the $Fe_2O_3$ pulverized during mechanical grinding are considered to help the particles of magnesium become finer. Hydriding-dehydriding cycling is also considered to increase the $H_2$-sorption rates of Mg by creating defects and cracks and by reducing the particle size of Mg.

• Journal of Hydrogen and New Energy
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• v.32 no.6
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• pp.592-611
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• 2021

In this study a rarely available high-throughput cycling data set of 124 commercial lithium iron phosphate/graphite cells cycled under fast-charging conditions, with widely varying cycle lives ranging from 150 to 2,300 cycles including in-cycle temperature and per-cycle IR measurements. We worked out own Python codes which reproduced the various data plots and machine learning approaches for cycle life prediction using early cycles and more details not presented in the article and the supplementary information. Particularly, we applied regularized ridge, lasso and elastic net linear regression models using features extracted from capacity fade curves, discharge voltage curves, and other data such as internal resistance and cell can temperature. We found that due to the limitation in the quantity and quality of the data from costly and lengthy battery testing a careful hyperparameter tuning may be required and that model features need to be extracted based on the domain knowledge.

• Journal of Industrial Technology
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• v.42 no.1
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• pp.7-12
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• 2022

High nickel layered oxide cathodes are gaining increasing attention for lithium-ion batteries due to their higher energy density and lower cost compared to LiCoO₂. However, they suffer from the formation of residual lithium on the surface in the form of LiOH and Li₂CO₃ on exposure to ambient air. The residual lithium causes notorious issues, such as slurry gelation during electrode preparation and gas evolution during cell cycling. In this review, we investigate the residual lithium issues through its impact on cathode slurry instability based on deformed polyvinylidene fluoride (PVdF) as well as its formation and reduction mechanism in terms of inherently off-stoichiometric synthesis of high nickel cathodes. Additionally, new analysis method with anhydrous methanol was introduced to exclude Li⁺/H⁺ exchange effect during sample preparation with distilled water. We hope that this review would contribute to encouraging the academic efforts to consider practical aspects and mitigation in global high-energy-density lithium-ion battery manufacturers.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.5
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• pp.2499-2506
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• 2016

Background: Gastric cancer (GC) is the second leading cause of cancer-related death worldwide. Several environmental, genetic and epigenetic factors have been suggested to have a role in GC development. Epigenetic mechanisms like histone changes and promoter hyper-methylation are now being increasingly studied. Associations between methylation of many gene promoters with the risk of gastric cancer have been investigated worldwide. Such aberrant methylation may result in silencing of specific genes related to cell cycling, cell adhesion, apoptosis and DNA repair. Thus this molecular mechanism might have a key role in proliferation and migration of cancerous cells. Materials and Methods: In this review article we included studies conducted on DNA methylation and gastric cancer in Iranian populations. Using Science direct, Pubmed/PMC, Springer, Wiley online library and SciELO databases, all published data until 31 January 2016 were gathered. We also searched Science direct data base for similar investigations around the world to make a comparison between Iran and other countries. Results: By searching these databases, we found that the association between methylation of seven gene promoters and gastric cancer had been studied in Iran until 31 January 2016. These genes were p16, hLMH1, E-cadherin, CTLA4, $THR{\beta}$, mir9 and APC. Searching in science direct database also showed that 92 articles had been published around the world till January 2016. Our investigation revealed that despite the importance of GC and its high prevalence in Iran, the methylation status of only a few gene promoters has been studied so far. More studies with higher sample numbers are needed to reveal the relation of methylation status of gene promoters to gastric cancer in Iran. Conclusions: Further studies will be helpful in identifying associations of DNA methylation in candidate genes with gastric cancer risk in Iranian populations.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.359-362
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• 2003

The recent development of methods for culturing hair follicles in vitro has proved an important tool to investigate many aspects of drug screening. Human hair follicle is composed of multiple types of cells, whose interactions regulate morphology and cycling-anagen, catagen, and telogen. Many investigators have tried to develop models to prolong of the period of hair elongation in vitro. However these are limited in submerged culture, which don't work due to the lack of cell-cell interactions which are abundant in vivo environment. So we applied dermal equivalent (DE) to culturing flair follicles to prolong hair growth period.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.11a
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• pp.136-140
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• 1992

The purpose of this research is to develop the lithium secondary battery. This paper describes the preparation, electrochemical properties of nontstoichiometric(NS)-$V_6O_{13}$ and characteristics of Li/$V_6O_{13}$ secondary battery. NS-$V_6O_{13}$ was prepared by thermal decomposition of $NH_4VO_3$ under Ar stream of 140ml/min~180ml/min flow rate. And then, this NS-$V_6O_{13}$ was used for cathode active material. Cathode sheet was prepared by compressing the composite of NS-$V_6O_{13}$, acetylene black(A.B) and teflon emulsion (T.E). Characteristics of the test cell are summarised as follows. Oxidation capacity of NS-$V_6O_{13}$ was about 20% less than its reduction capacity. A part of NS-$V_6O_{13}$ cathode active material showed irreversible reaction in early charge-discharge cycle. This phenomena seems to be caused by irreversible incoporation/discoporation of lithium cation to/from NS-$V_6O_{13}$ host. Discharge characteristics curve of Li/$V_6O_{13}$ cell showed 4 potential plateaus. Charge-discharge capacity was declined in the beginning of cycling and slowly increased in company with increasing of coulombic efficiency. Energy density per weight of $V_6O_{13}$ cathode material was as high as 522Wh/kg~765Wh/kg.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.837-845
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• 2014

Background: Overweight and obesity are recognized as major drivers of cancers including breast cancer. Several cytokines, including interleukin-6 (IL-6), IL-10 and lipocalin 2 (LCN2), as well as dysregulated cell cycle proteins are implicated in breast carcinogenesis. The nuclear, casein kinase and cyclin-dependent kinase substrate-1 (NUCKS-1), is a nuclear DNA-binding protein that has been implicated in several human cancers, including breast cancer. Objectives: The present study was conducted to evaluate NUCKS-1 mRNA expression in breast tissue from obese patients with and without breast cancer and lean controls. NUCKS-1 expression was correlated to cytokine profiles as prognostic and monitoring tools for breast cancer, providing a molecular basis for a causal link between obesity and risk. Materials and Methods: This study included 39 females with breast cancer (G III) that was furtherly subdivided into two subgroups according to cancer grading (G IIIa and G IIIb) and 10 control obese females (G II) in addition to 10 age-matched healthy lean controls (G I). NUCKS-1 expression was studied in breast tissue biopsies by means of real-time PCR (RT-PCR). Serum cytokine profiles were determined by immunoassay. Lipid profiles and glycemic status as well as anthropometric measures were also recorded for all participants. Results: IL-6, IL-12 and LCN2 were significantly higher in control obese and breast cancer group than their relevant lean controls (p<0.05), while NUCKS-1 mRNA expression was significantly higher in the breast cancer group compared to the other groups (p<0.05). Significant higher levels of IL-6, IL-12, and LCN2 as well as NUCKS-1 mRNA levels were reported in G IIIb than G IIIa, and positively correlated with obesity markers in all obese patients. Conclusions: Evaluation of cytokine levels as well as related gene expression may provide a new tool for understanding interactions for three axes of carcinogenesis, innate immunity, inflammation and cell cycling, and hope for new strategies of management.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.24
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• pp.10819-10824
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• 2015

Aims: To explore the effect and probable mechanism of a synthetic retinoid 4-amino-2-tri-fluoromethylphenyl ester (ATPR) on apoptosis of MDA-MB-231 breast cancer cells. Materials and Methods: MTT assays were performed to measure the proliferation of MDA-MB-231 cells treated with different concentrations of all-trans retinoic acid (ATRA) and ATPR. Morphologic changes were observed by microscopy. The apoptosis rates and cell cycling of MDA-MB-231 cells treated with ATRA or ATPR were assessed using flow cytometry analysis. Expression of retinoic acid receptor and phosphorylation of ERK, JNK, p38 proteins were detected by Western blotting. Results: Treatment of the cells with the addition of $15{\mu}mol/L$ ATPR for 48 h clearly demonstrated reduced cell numbers and deformed cells, whereas no changes in the number and morphology were observed after treatment with ATRA. The apoptosis rate was 33.2% after breast cancer MDA-MB-231 cells were treated by ATPR ($15{\mu}mol/L$) whereas ATRA ($15{\mu}mol/L$) had no apoptotic effect. ATPR inhibited the phosphorylation of ERK, JNK, and p38 while ATRA had no significant effect. ATPR inhibited the expression of BiP and increased the expression of Chop at the protein level compared with control groups, ATRA and ATPR both decreased the protein expression of $RXR{\alpha}$, ATPR reduced the protein expression of $RAR{\beta}$ and $RXR{\beta}$ while ATRA did not decrease $RAR{\beta}$ or $RXR{\beta}$. Conclusions: ATPR could induce apoptosis of breast cancer MDA-MB-231 cells, possible mechanisms being binding to $RAR{\beta}/RXR{\beta}$ heterodimers, then activation of ER stress involving the MAPK pathway.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.24
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• pp.10847-10853
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• 2015

Background: Lapatinib, a dual tyrosine kinase inhibitor that interrupts the epidermal growth factor receptor (EGFR) and HER2/neu pathways, has been indicated to have significant efficacy in treating HER2-positive breast cancer. However, acquired drug resistance has become a very serious clinical problem that hampers the use of this agent. In this study, we aimed to screen small molecule drugs that might reverse lapatinib-resistance of breast cancer by exploring differentially expressed genes (DEGs) via a bioinformatics method. Materials and Methods: We downloaded the gene expression profile of BT474-J4 (acquired lapatinib-resistant) and BT474 (lapatinib-sensitive) cell lines from the Gene Expression Omnibus (GEO) database and selected differentially expressed genes (DEGs) using dChip software. Then, gene ontology and pathway enrichment analyses were performed with the DAVID database. Finally, a connectivity map was utilized for predicting potential chemicals that reverse lapatinib-resistance. Results: A total of 1, 657 DEGs were obtained. These DEGs were enriched in 10 pathways, including cell cycling, regulation of actin cytoskeleton and focal adhesion associate examples. In addition, several small molecules were screened as the potential therapeutic agents capable of overcoming lapatinib-resistance. Conclusions: The results of our analysis provided a novel strategy for investigating the mechanism of lapatinib-resistance and identifying potential small molecule drugs for breast cancer treatment.