• Title/Summary/Keyword: Membrane properties

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Evaluation on the suspended solids and heavy metals removal mechanisms in bioretention systems

  • Geronimo, Franz Kevin F.;Maniquiz-Redillas, Marla C.;Hong, Jungsun;Kim, Lee-Hyung
    • Membrane and Water Treatment
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    • v.10 no.1
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    • pp.91-97
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    • 2019
  • Application of bioretention systems in Korea is highly considered due to its minimal space requirements, appropriateness as small landscape areas and good pollutant removal and peak hydraulic flow reduction efficiency. In this study, the efficiency of two lab-scale bioretention types having different physical properties, media configuration and planted with different shrubs and perennials was investigated in reducing heavy metal pollutants in stormwater runoff. Type A bioretention systems were planted with shrubs whereas type B were planted with perennials. Chrysanthemum zawadskii var. latilobum (A-CL) and Aquilegia flabellata var. pumila (A-AP) respectively were planted in each type A bioretention reactors while Rhododendron indicum linnaeus (B-RL) and Spiraea japonica (B-SJ), respectively were planted in each type B bioretention reactors. Results revealed that the four lab-scale bioretention reactors significantly reduced the influent total suspended load by about 89 to 94% (p<0.01). Type B-RL and B-SJ reactors reduced soluble Cr, Cu, Zn, and Pb by 28 to 45% that were 15 to 35% greater than the soluble metal reduction of type A-CL and A-AP reactors, respectively. Among the pollutants, total Cr attained the greatest discharged fraction of 0.52-0.81. Excluding the effect of soil media, total Pb attained the greatest retention fraction in the bioretention systems amounting to 0.15-0.34. Considering the least discharge fraction of heavy metal in the bioretention system, it was observed that the bioretention systems achieved effectual reduction in terms of total Cu, Zn and Pb. These findings were associated with the poor adsorption capacity of the soil used in each bioretention system. The results of this study may be used for estimating the maintenance requirements of bioretention systems.

Aging Property Studies on Rubber Gasket for Polymer Electrolyte Membrane Fuel Cell Stack (고분자 전해질 연료전지 스택용 고무 개스킷의 노화특성 연구)

  • Kang, Dong-gug;Hur, Byung-ki;Lee, Dong-won;Seo, Kwan-ho
    • Applied Chemistry for Engineering
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    • v.22 no.2
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    • pp.149-154
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    • 2011
  • In order to explore properties of various rubber compounds after thermal aging under the condition similar to the operating environment of a fuel cell-stack, heat resistance and compression set of those compounds were investigated for a long term operation in $H_2SO_4$, $H_2O$, and LLC (ethylene glycol : $H_2O=50:50$) solution. It was assumed that aging Acrylonitrile butadiene rubber (NBR) and Elthylene Propylene diene rubber (EDPM) compound in the solution resulted in discoloration as time passed. It was also found that hydrolysis was developed on the Silicone rubber (VMQ) compound intentionally aged under acidic condition by means of TGA, SEM, and EDS analysis.

Gallic acid-mitochondria targeting sequence-H3R9 induces mitochondria-targeted cytoprotection

  • Bae, Yoonhee;Kim, Goo-Young;Jessa, Flores;Ko, Kyung Soo;Han, Jin
    • The Korean Journal of Physiology and Pharmacology
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    • v.26 no.1
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    • pp.15-24
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    • 2022
  • The development of selective targeting of drug molecules towards the mitochondria is an important issue related to therapy efficacy. In this study, we report that gallic acid (GA)-mitochondria targeting sequence (MTS)-H3R9 exhibits a dual role as a mitochondria-targeting vehicle with antioxidant activity for disease therapy. In viability assays, GA-MTS-H3R9 showed a better rescue action compared to that of MTS-H3R9. GA-MTS-H3R9 dramatically exhibited cell penetration and intercellular uptake compared to MTS and fit escape from lysosome release to the cytosol. We demonstrated the useful targeting of GA-MTS-H3R9 towards mitochondria in AC16 cells. Also, we observed that the antioxidant properties of mitochondrial-accrued GA-MTS-H3R9 alleviated cell damage by reactive oxygen species production and disrupted mitochondrial membrane potential. GA-MTS-H3R9 showed a very increased cytoprotective effect against anticancer activity compared to that of MTS-H3R9. We showed that GA-MTS-H3R9 can act as a vehicle for mitochondria-targeting and as a reagent for therapeutic applications intended for cardiovascular disease treatment.

Effect of Porous Flow Field on PEMFC Performance with Dead Ended Anode System (Dead ended anode 시스템에서 다공성 유로가 연료전지 성능에 미치는 영향)

  • Kim, Junseob;Kim, Junbom
    • Applied Chemistry for Engineering
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    • v.33 no.6
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    • pp.646-652
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    • 2022
  • The dead-end anode (DEA) system is a method that closes the anode outlet and supplies fuel by pressure. The DEA method could improve fuel usage and power efficiency through system simplification. However, flooding occurs due to water and nitrogen back diffusion from the cathode to the anode during the DEA operation. Flooding is a cause of decreased fuel cell performance and electrode degradation. Therefore, tthe structure and components of polymer electrolyte membrane fuel cell (PEMFC) should be optimized to prevent anode flooding during DEA operation. In this study, the effect of a porous flow field with metal foam on fuel cell performance and fuel efficiency improvement was investigated in the DEA system. As a result, fuel cell performance and purge interval were improved by effective water management with a porous flow field at the cathode, and it was confirmed that cathode flow field structure affects water back-diffusion. On the other hand, the effect of the porous flow field at the anode on fuel cell performance was insignificant. Purge interval was affected by metal foam properties and shown stable performance with large cell size metal foam in the DEA system.

PSMA Inhibitors for Nuclear Imaging and Radiotherapy of Prostate Cancer

  • Sajid Mushtaq;Tugsuu Uyanga;Park Ji Ae;Jung Young Kim
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.9 no.1
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    • pp.23-33
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    • 2023
  • Prostate cancer ranks as the world's second most frequently diagnosed cancer among men, and is responsible for the fifth highest number of cancer-related deaths in this population. The development of effective diagnostic and therapeutic approaches for prostate cancer remains a major challenge in the field of oncology. Over the past few years, the prostate-specific membrane antigen (PSMA) has raised as a hopeful tracer for the diagnosis and treatment of prostate cancer.Various radioisotopes, such as 131I, 99mTc, 68Ga, and 177Lu, have been used to label PSMA analogues, with varying degrees of success. Among these, 68Ga-PSMA-11 and 177Lu-PSMA-617 have emerged as the most promising radioligands for clinical use. Recently, researchers have been exploring the use of other radioisotopes, such as 211At, 89Zr, 64/67Cu, and 203/212Pb, for the labeling of PSMA-targeted radioligands. These radioisotopes have unique properties that may offer advantages over existing radioligands, such as longer half-lives, higher specific activities, and different emission profiles. Efforts are currently underway to develop these radiopharmaceuticals and make them more widely available for clinical use. These exciting developments highlight the potential of PSMA-targeted radioligands for the diagnosis and treatment of prostate cancer, and provided significant implications for the management of this disease in the future. The current study aims to provide a comprehensive summary of the latest research and clinical applications of radiolabeled PSMA inhibitors for diagnoses and therapy of prostate cancer, emphasizing the exciting developments in the field and their potential impact on clinical practice.

Twelve-oxoeicosatetraenoic acid-induced fetal membrane release improves postpartum ovarian function, milk production, and blood plasma biochemical parameters in cows

  • Hachiro Kamada;Yoshitaka Matsui
    • Animal Bioscience
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    • v.36 no.9
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    • pp.1376-1383
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    • 2023
  • Objective: We aimed to determine the effects of 12-oxoeicosatetraenoic acid (12-KETE)-induced placenta release on the performance of mother cows (milk yield, ovarian function, and blood plasma biochemical properties). Methods: Experimental treatments were as follows: i) natural delivery including natural placental release (control cows); ii) induced calf delivery with placental retention (RP cows); and iii) induced calf delivery and 12-KETE-induced placental release (KE cows). Delivery in pregnant KE cows was induced with dexamethasone and prostaglandin. These cows were injected with 12-KETE after calf discharge, resulting in the release of the fetal placenta. RP cows were not treated with 12-KETE after inducing delivery, resulting in placental retention. Results: The milk yield in RP cows during the first 50 days after delivery was significantly lower than that in control cows (p<0.05), whereas KE cows exhibited a similar milk yield to that of control cows. The postpartum plasma progesterone levels of control cows increased 14 days after delivery on average; however, its increase was delayed by 10 days in RP cows. Meanwhile, the 12-KETE treatment (KE cows) brought the timing of progesterone increase forward to the normal level (control cows). Among the 20 biochemical parameters examined, the total cholesterol levels in blood plasma 14 days after delivery were lower in RP cows than that in the other two treatment groups (control cows and KE cows) (p<0.05). In addition, the plasma level of haptoglobin tended to be low in cows that discharged their placentas shortly after delivery. Conclusion: These findings indicate that 12-KETE treatment can alleviate the disorder caused by placental retention.

Quality comparison of non-thermal sterilized raw apple vinegar and commercial apple vinegar products

  • Sun Hwa Kim;Ji-Hyung Seo;Yong-Jin Jeong
    • Food Science and Preservation
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    • v.31 no.2
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    • pp.235-244
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    • 2024
  • A nonthermally sterilized raw apple vinegar was manufactured using an ultra-fine filtration process (0.2 ㎛ membrane filter) and its quality was comparable to commercially available vinegar products. First, using apple concentrate as a raw material, it was possible to produce non-thermal sterilized Using a two-stage fermentation process of alcohol and acetic acid fermentations, a non-thermally sterilized raw apple vinegar with pH 2.94 and an acidity of 6.20% was produced from an apple concentrate. The fermentation process increased the browning index significantly. However, the fundamental quality parameters of the non-thermal sterilized raw apple vinegar (A) with sterilized apple vinegar (B) did not differ significantly. The pH (2.92-2.95) of apple vinegar (A and B) was higher than that (pH 2.65-2.70) of commercial vinegar (C and D), and the total acidity, which is in the range of 6.20-6.21% and 6.53-6.90%, respectively, was higher in samples C and D than in samples A and B. However, four kinds of organic acids were detected in non-thermal sterilized raw apple vinegar (A), and its total organic acid content (6,245.00 mg%) was significantly higher than that of other samples (B, C, D) (p<0.05). In particular, malic acid content, as a main organic acid in apples, was very high in sample (A) (244.83 mg%) and sample (B) (210.21 mg%), compared to commercial products C (125.78 mg%) and D (86.90 mg%). The total polyphenol content and antioxidant activity of fermented apple vinegar (A, B) were more than twice as high as those of commercial products (C, D). Vinegar A had higher total polyphenol content than vinegar B. The above results suggest it is possible to manufacture and commercialize non-thermal sterilized raw apple vinegar with higher organic acid content and antioxidant properties using ultra-fine filtration.

Fabrication and characterization of hybrid AlTiSrO/rGO thin films for liquid crystal orientation (액정 배향용 하이브리드 AlTiSrO/rGO 박막 제조 및 특성 평가)

  • Byeong-Yun Oh
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.17 no.3
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    • pp.155-165
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    • 2024
  • A hybrid thin film was prepared by doping reduced graphene oxide (rGO) into a sol-gel solution mixed with aluminum, titanium, and strontium using a brush coating method. The annealing temperature was carried out at 160, 260, and 360℃, and the difference in oxidation reaction was observed. The sol-gel solution created during the membrane manufacturing process generates a contractile force due to the shear stress of the brush bristles, forming a microgroove structure. This structure was confirmed through scanning electron microscopy analysis, and the presence of rGO was clearly revealed. As the annealing temperature increases, the oxidation and reduction reactions on the thin film surface become more active, so the intensity of the surface mixture increases. Moreover, the electro-optical properties were stabilized and improved by increasing the intensity of the mixtures. Likewise, the voltage-capacitance values are also significantly improved. Lastly, the transmittance measurement showed that it was suitable for liquid crystal display application.

A Replication-Competent Retroviral Vector Expressing the HERV-W Envelope Glycoprotein is a Potential Tool for Cancer Gene Therapy

  • Byoung Kwon Kang;Yong-Tae Jung
    • Journal of Microbiology and Biotechnology
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    • v.34 no.2
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    • pp.280-288
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    • 2024
  • The fusogenic membrane glycoprotein (FMG) derived from the human endogenous retrovirus-W (HERV-W) exhibits fusogenic properties, making it a promising candidate for cancer gene therapy. When cells are transfected with HERV-W FMG, they can fuse with neighboring cells expressing the receptor, resulting in the formation of syncytia. These syncytia eventually undergo cell death within a few days. In addition, it has been observed that an HERV-W env mutant, which is truncated after amino acid 483, displays increased fusogenicity compared to the wild-type HERV-W env. In this study, we observed syncytium formation upon transfection of HeLa and TE671 human cancer cells with plasmids containing the HERV-W 483 gene. To explore the potential of a semi-replication-competent retroviral (s-RCR) vector encoding HERV-W 483 for FMG-mediated cancer gene therapy, we developed two replication-defective retroviral vectors: a gag-pol vector encoding HERV-W 483 (MoMLV-HERV-W 483) and an env vector encoding VSV-G (pCLXSN-VSV-G-EGFP). When MoMLV-HERV-W 483 and pCLXSN-VSV-G-EGFP were co-transfected into HEK293T cells to produce the s-RCR vector, gradual syncytium formation was observed. However, the titers of the s-RCR virus remained consistently low. To enhance gene transfer efficiency, we constructed an RCR vector encoding HERV-W 483 (MoMLV-10A1-HERV-W 483), which demonstrated replication ability in HEK293T cells. Infection of A549 and HT1080 human cancer cell lines with this RCR vector induced syncytium formation and subsequent cell death. Consequently, both the s-RCR vector and RCR encoding HERV-W 483 hold promise as valuable tools for cancer gene therapy.

Development of Chemical Separation Process for Thallium-201 Radioisotope with Lead Standard Material (납 표준물질을 이용한 방사성동위원소 Thallium-201의 화학적 분리공정 개발)

  • JunYoung Lee;TaeHyun Kim;JeongHoon Park
    • Journal of Radiation Industry
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    • v.17 no.4
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    • pp.543-549
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    • 2023
  • Thallium-201 (201Tl) is a medical radioisotope which emits gamma rays when it decays and used in myocardial perfusion scans in single-photon emission tomography due to its similar properties to potassium. Currently, the Korea Institute of Radiological & Medical Sciences is the only institution producing 201Tl in Korea, and optimization of 201Tl production research is necessary to meet supply compared to domestic demand. To this end, technical analysis of plating target production and chemical separation methods essential for 201Tl production research is conducted. It deals with the process of generating and separating 201Tl radioisotope and target production, It can be generated through a nuclear reaction such as natHg(p,xn)201Tl, 201Hg(p,n)201Tl, natPb(p,xn)201Bi → 201Pb → 201Tl, 205Tl(p,5n)201Pb → 201Tl, and considering impure nuclide generated simultaneously with the use of proton beam energy of 35 MeV or less, it is intended to be produced using the 203Tl(p,3n)201Pb→201Tl nuclear reaction. In particular, the chemical separation of Tl is a very important element, and the chemical separation methods that can separate it is broadly divided into four types, including solid phase extraction, liquid-liquid, electrochemical, and ion exchange membrane separation. Some chemical separations require additional separation steps, such as methods using selective adsorption. Therefore, this technical report describes four chemical separation methods and seeks to separate high-purity 201Tl using a method without additional separation steps