• Title/Summary/Keyword: zinc resistance

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Zn3(PO4)2 Protective Layer on Zn Anode for Improved Electro-chemical Properties in Aqueous Zn-ion Batteries

  • Chae-won Kim;Junghee Choi;Jin-Hyeok Choi;Ji-Youn Seo;Gumjae Park
    • Journal of Electrochemical Science and Technology
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    • v.14 no.2
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    • pp.162-173
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    • 2023
  • Aqueous zinc-ion batteries are considered as promising alternatives to lithium-ion batteries for energy storage owing to their safety and cost efficiency. However, their lifespan is limited by the irreversibility of Zn anodes because of Zn dendrite growth and side reactions such as the hydrogen evolution reaction and corrosion during cycling. Herein, we present a strategy to restrict direct contact between the Zn anode and aqueous electrolyte by fabricating a protective layer on the surface of Zn foil via phosphidation method. The Zn3(PO4)2 protective layer effectively suppresses Zn dendrite growth and side reactions in aqueous electrolytes. The electrochemical properties of the Zn3(PO4)2@Zn anode, such as the overpotential, linear polarization resistance, and hydrogen generation reaction, indicate that the protective layer can suppress interfacial corrosion and improve the electrochemical stability compared to that of bare Zn by preventing direct contact between the electrolyte and the active sites of Zn. Remarkably, MnO2 Zn3(PO4)2@Zn exhibited enhanced reversibility owing to the formation a stable porous layer, which effectively inhibited vertical dendrite growth by inducing the uniform plating of Zn2+ ions underneath the formed layer.

Increasing the attractiveness of physical education training with the involvement of nanotechnology

  • Jinyan Ge;Yuxin Hong;Rongtian Zeng;Yunbin Li;Mostafa Habibi
    • Advances in concrete construction
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    • v.16 no.6
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    • pp.291-302
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    • 2023
  • As the first part of the body that strikes the ground during running, sports shoes are especially important for improving performance and reducing injuries. The use of new nanotechnology materials in the shoe's sole that can affect the movement angle of the foot and the ground reaction forces during running has not been reported yet. It is important to consider the material of the sole of the shoe since it determines the long-term performance of sports shoes, including their comfort while walking, running, and jumping. Running performance can be improved by polymer foam that provides good support with low energy dissipation (low energy dissipation). Running shoes have a midsole made of ethylene propylene copolymer (EPP) foam. The mechanical properties of EPP foam are, however, low. To improve the mechanical performance of EPP, conventional mineral fillers are commonly used, but these fillers sacrifice energy return. In this study, to improve the magnificence of physical education training with nanotechnology, carbon nanotubes (CNTs) derived from recycled plastics were prepared by catalytic chemical vapor deposition and used as nucleating and reinforcing agents. As a result of the results, the physical, mechanical, and dynamic response properties of EPP foam combined with CNT and zinc oxide nanoparticles were significantly improved. When CNT was added to the nanocomposites with a weight percentage of less than 0.5 wt%, the wear resistance, physical properties, dynamic stiffness, compressive strength, and rebound properties of EPP foams were significantly improved.

Nutrition Support in Critically Ill Cancer Patient Receiving Extracorporeal Membrane Oxygenation: A Case Report

  • Ji-Yeon Kim;Gyung-Ah Wie;Kyoung-A Ryu;So-Young Kim
    • Clinical Nutrition Research
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    • v.12 no.2
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    • pp.91-98
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    • 2023
  • Adequate nutritional support is crucial in preventing complications and improving outcomes in critically ill patients. Extracorporeal membrane oxygenation (ECMO) is a mode of supportive care for patients with respiratory and/or cardiac failure. ECMO patients frequently exhibit a hypermetabolic state characterized by protein catabolism and insulin resistance, which can lead to malnutrition. Nutritional therapy is a vital component of intensive care, but its optimal administration for ECMO patients is unknown. This case report aims to provide insights into effective nutritional management for critically ill patients undergoing ECMO therapy. The patient was a 72-year-old male with a history of gastric and lung cancer who underwent a lobectomy complicated by bronchopleural fistula, postoperative bleeding, pneumonia, and acute respiratory distress syndrome (ARDS). The patient's nutritional status was assessed indicating a high risk of malnutrition, using the modified Nutrition Risk in the Critically Ill (mNUTRIC) Score. Nutritional support was administered based on the recommendations of European Society for Clinical Nutrition and Metabolism (ESPEN) and the American Society for Parenteral and Enteral Nutrition (ASPEN), with energy requirements set at 25-30 kcal/kg/d and protein requirements set at 1.2-2.0 g/kg/day. The patient received parenteral nutrition until the enteral nutrition target amount was reached, with zinc supplements for wound healing. The study highlights the need for further research on proactive and effective nutritional support for ECMO patients to improve compliance and prognosis.

ACY-241, a histone deacetylase 6 inhibitor, suppresses the epithelial-mesenchymal transition in lung cancer cells by downregulating hypoxia-inducible factor-1 alpha

  • Seong-Jun Park;Naeun Lee;Chul-Ho Jeong
    • The Korean Journal of Physiology and Pharmacology
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    • v.28 no.1
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    • pp.83-91
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    • 2024
  • Hypoxia-inducible factor-1 alpha (HIF-1α) is a transcription factor activated under hypoxic conditions, and it plays a crucial role in cellular stress regulation. While HIF-1α activity is essential in normal tissues, its presence in the tumor microenvironment represents a significant risk factor as it can induce angiogenesis and confer resistance to anti-cancer drugs, thereby contributing to poor prognoses. Typically, HIF-1α undergoes rapid degradation in normoxic conditions via oxygen-dependent degradation mechanisms. However, certain cancer cells can express HIF-1α even under normoxia. In this study, we observed an inclination toward increased normoxic HIF-1α expression in cancer cell lines exhibiting increased HDAC6 expression, which prompted the hypothesis that HDAC6 may modulate HIF-1α stability in normoxic conditions. To prove this hypothesis, several cancer cells with relatively higher HIF-1α levels under normoxic conditions were treated with ACY-241, a selective HDAC6 inhibitor, and small interfering RNAs for HDAC6 knockdown. Our data revealed a significant reduction in HIF-1α expression upon HDAC6 inhibition. Moreover, the downregulation of HIF-1α under normoxic conditions decreased zinc finger E-box-binding homeobox 1 expression and increased E-cadherin levels in lung cancer H1975 cells, consequently suppressing cell invasion and migration. ACY-241 treatment also demonstrated an inhibitory effect on cell invasion and migration by reducing HIF-1α level. This study confirms that HDAC6 knockdown and ACY-241 treatment effectively decrease HIF-1α expression under normoxia, thereby suppressing the epithelial-mesenchymal transition. These findings highlight the potential of selective HDAC6 inhibition as an innovative therapeutic strategy for lung cancer.

An In Silico Drug Repositioning Strategy to Identify Specific STAT-3 Inhibitors for Breast Cancer

  • Sruthy Sathish
    • Journal of Integrative Natural Science
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    • v.16 no.4
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    • pp.123-131
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    • 2023
  • Breast cancer continues to pose a substantial worldwide health challenge, thereby requiring the development of innovative strategies to discover new therapeutic interventions. Signal Transducer and Activator of Transcription 3 (STAT-3) has been identified as a significant factor in the development of several types of cancer, including breast cancer. This is primarily attributed to its diverse functions in promoting tumour formation and conferring resistance to therapeutic interventions. This study presents an in silico drug repositioning approach that focuses on identifying specific inhibitors of STAT-3 for the purpose of treating breast cancer. We initially examined the structural and functional attributes of STAT-3, thereby elucidating its crucial involvement in cellular signalling cascades. A comprehensive virtual screening was performed on a diverse collection of drugs that have been approved by the FDA from zinc15 database. Various computational techniques, including molecular docking, cross docking, and cDFT analysis, were utilised in order to prioritise potential candidates. This prioritisation was based on their predicted binding energies and outer molecular orbital reactivity. The findings of our study have unveiled a Dihydroergotamine and Paritaprevir that have been approved by the FDA and exhibit considerable promise as selective inhibitors of STAT-3. In conclusion, the utilisation of our in silico drug repositioning approach presents a prompt and economically efficient method for the identification of potential compounds that warrant subsequent experimental validation as selective STAT-3 inhibitors in the context of breast cancer. The present study highlights the considerable potential of employing computational strategies to expedite the drug discovery process. Moreover, it provides valuable insights into novel avenues for targeted therapeutic interventions in the context of breast cancer treatment.

A Study on Dimethacryloyloxy Alkane Derivatives Having an Anti-wear Performance as Lubricating Oil Additives (윤활유첨가제로써 마모억제 성능을 갖는 Dimethacryloyloxy Alkane 유도체에 관한 연구)

  • Han, Hye-Rim;Cho, Jung-Eun;Sim, Dae-Seon;Kang, Chung-Ho;Kim, Young-Wun;Jeong, Noh-Hee;Kang, Ho-Cheol
    • Applied Chemistry for Engineering
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    • v.27 no.6
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    • pp.583-589
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    • 2016
  • Lubricant additives including zinc dialkyldithiophosphate (ZDDP) containing metal have been widely used due to the advantage of very low cost, but they can generate impurities such as ash. In this work, ZDDP containing metals was partially replaced with bis[3-(dialkyloxyphosphorothionyl) thio-2-methylpropanyloxy] butane (BAP4s) which was synthesized conveniently and effectively from alkanediol without any metal components. Also, the wear resistance property of synthesized BAP4s were studied. Wear scar diameter (WSD) values of BAP4s with butyl, octyl, decyl, dodecyl or tetradecyl groups were also measured by four-ball test. As the length of the alkyl group increased from 4 to 8, the WSD value of BAP4s decreased rapidly from 0.59 to 0.45 mm, but from 8 to 14, the value increased very slowly from 0.45 to 0.50 mm. Thus, among all BAP4s, B8P4 having BAP4 with the octyl group, showed the lowest WSD value. Furthermore, the WSD values were measured in a lubricant base oil mixed with a 0.50 percent concentration (w/w) of either BAP4 or ZDDP. The former was 0.55 mm, and the latter was 0.45 mm. The thermal stability and tribofilm formation peroperty were also measured by thermogravimetric analyzer (TGA) and energy-dispersive X-rays spectroscopy (EDS), respectively.

'Hyangcheola', A New Fragrant Rice Variety with High Iron and Zinc Content (철과 아연 함량이 높고 향기가 있는 벼 '향철아')

  • Jeong, Eung-Gi;Ahn, Eok-Keun;Won, Yong-Jae;Lee, Jeong-Heui;Lee, Sang-Bok;Jeong, Jong-Min;Oh, Sea-Kwan;Choi, Yong-Hwan;Lee, Jeom-Ho;Suh, Jung-Pil;Hyun, Ung-Jo;Jung, O-Young;Kim, Bo-Kyeong;Son, Ji-Young
    • Korean Journal of Breeding Science
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    • v.50 no.4
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    • pp.472-477
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    • 2018
  • "Hyangcheola" is a new japonica rice variety developed as a cross between "Joryeong" and "Seolhyangchal" by the rice breeding team at NICS in 2014. The heading date of "Hyangcheola" is July 28 in the middle plain area, which is 8 days earlier than that of "Hwaseong." "Hyangcheola" has a 76 cm long culm, which is 8 cm shorter than "Hwaseong" and has 86 spikelets per panicle. The viviparous germination rate of "Hyangcheola" was 27.9%. It showed resistance to stripe virus but susceptibility to bacterial blight (K1, K2, and K3 races), dwarf and black streak dwarf viruses and planthoppers. The milled rice of this variety exhibits translucent and medium short grain shape. The protein content of "Hyangcheola" was 8.2%, which was 1.5% higher than that of "Hwaseong." "Hyangcheola" is a rice with a fragrant aroma. The content of iron in 100 g of brown "Hyangcheola" rice was 15.12 mg, which is 3.69 mg higher than that of "Hwaseong," and the zinc content was 32.24 mg, which is 8.75 mg more than that of the comparative variety "Hwaseong." The average milled rice yield of "Hyangcheola" was 4.8 MT/ha at our sites under ordinary cultivation (Registration No. 6807).

THE EFFECT OF SURFACE TREATMENT ON FRACTURE STRENGTH OF DENTAL CERAMICS (도재와 상아질의 표면 처리가 도재의 파절 강도에 미치는 영향)

  • Lee, Shin-Won;Lee, Sun-Hyung;Yang, Jae-Ho;Chung, Hun-Young
    • The Journal of Korean Academy of Prosthodontics
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    • v.37 no.5
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    • pp.658-671
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    • 1999
  • The major influencing factors on the strength of all-ceramic crowns are types of dental ceramics, fabrication techniques, methods of abutment preparation and cementation modes of all-ceramic restorations. Zinc phosphate cement and glass-ionomer cement were used as an early lot-ing media for all-ceramic crowns. Recently many studies have reported that resin cements have more advantages in increasing the fracture strength of restorations comparing with zincphosphate cement and glass-ionomer cement. The purpose of this study is to investigate the effect of etching, silane treatment, sandblasting and dentin bonding agents on fracture strengths of dental ceramics. 40 flat dentin specimens and 40 ceramic discs of 1.5mm thickness and 8mm diameter were fabricated, and divided into 4 groups according to surface treatments. Surface treatments before cementation were as follows Group I : (ceramic) : HF etching - silane treatment - application of bonding resin (dentin) : application of dentin bonding agent Group II : (ceramic) : sandblasting - application of bonding resin (dentin) : application of dentin bonding agent Group III : (ceramic) : application of bonding resin (dentin) : application of dentin bonding agent Group IV : (ceramic) : HF etching - silane treatment - application of bonding resin (dentin) : no dentin bonding procedure Dentin specimens and ceramic discs were cemented with dual cure resin cement, and went through thermocycling. Compressive stress es were loaded on the centers of ceramic discs with Instron test-ing machine, and fracture strengths resistance for catastrophic fracture were measured The results were as follows. 1. The group I showed the highest fracture resistance. The next was group II And group III, IV followed. 2. There was a significant difference in the mean value of fracture strengths between group I and group III (p<0.05), but no significant differences between group I and group II, and group II and group III (p>0.05). 3. There was a significant difference in the mean value of fracture strengths between group I and group IV (p<0.05).

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The Effect of Additives on the Properties of Zn Electrode in Zn/AgO Secondary Battery (Zn/AgO Secondary Battery용 아연 양극의 성능에 미치는 첨가제의 영향)

  • Park, Kyung-Wha;Kim, Chang-Hwan;Moon, Kyung-Man
    • Journal of the Korean Electrochemical Society
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    • v.6 no.3
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    • pp.196-202
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    • 2003
  • We investigated the effect of both 4 types additives and $0.5wt\%\;Pb_3O_4$ which have been reported to show an improvement on the performance of Zinc anode. And Experimental methods such as corrosion potential measurement, potentiodynamic polorization test and charging-discharging cycle life test were carried out in $40 wt\%$ KOH with $Pb_3O_4(0.5, \;10\;&\;2.0wt\%)$ and 4 types additives $(0.4wt\%\;of\;Ca(OH)_2$, 0.025M of Citrate, Tartrate and Gluconate). Corrosion potential was shifted to high direction and also changed to high and low direction repeatedly with increasing of $Pb_3O_4$ quantity. However by adding $0.5wt\%\;Pb_3O_4$, corrosion potential shifted to low direction and showed stable condition. Furthermore it was well known that corrosion resistance was predominantly increased compared to no addition and improved charging-discharging property with adding additives. By SEM analysis, it was concluded that the morphology of surface in case of only $0.5wt\%\;Pb_3O_4$ addition was nearly the same as that of Tartrate additive and in the other additives such as $Ca(OH)_2$, Citrate, Tartrate and Gluconate, their morphologies showed dendrite growth. Eventually it was thought that the additive of Tartrate indicated comparatively good corrosion resistance effect as well as charging-discharging property improvement among those four types additives.

Studies on the tolerance of Halophyte Arabis stelleri under heavy metals and Salt stress condition (염생식물 섬갯장대(Arabis stelleri var. japonica)의 중금속 및 고염 농도 스트레스 상태에서 내성 연구)

  • Kim, Donggiun
    • The Journal of the Convergence on Culture Technology
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    • v.5 no.4
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    • pp.373-378
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    • 2019
  • In the marine area, the salt concentration in the soil increases, and the inland heavy metal pollution increases the damage of plants. In the inland industrial development area, researches on the genetic resources of plants together with the heavy metal accumulation of Co, Ni, Zn, and so on are required. Both of these problems have caused scientists to work hard to find plants that are likely to cause stress in plant roots. In this study, seeds of Arabis stelleri var. japonica collected near the shore were used for germination. The growth and development and tolerance of both Arabis and Arabidopsis seeds were investigated under laboratory culture conditions. As a result, Arabis showed resistance about 3 times in 250 mM nickle and cobalt, and more than 4 times in 1 mM zinc when compared to Arabidopsis. The tolerance of Arabis to Na salts increased by 20% or more at 50 mM concentration and Arabis was resistant to heavy metals and salt concentration. The accumulation of Na ions in the body was measured as a preparation for studying the intracellular mechanism. As a result, it showed a further decrease in resistance to ground water roots. It is considered that the activity of the exporting gene is important rather than the mechanism of accumulation.