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Effect of Annealing of Nafion Recast Membranes Containing Ionic Liquids

  • Park, Jin-Soo;Shin, Mun-Sik;Sekhon, S.S.;Choi, Young-Woo;Yang, Tae-Hyun
    • Journal of the Korean Electrochemical Society
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    • v.14 no.1
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    • pp.9-15
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    • 2011
  • The composite membranes comprising of sulfonated polymers as matrix and ionic liquids as ion-conducting medium in replacement of water are studied to investigate the effect of annealing of the sulfonated polymers. The polymeric membranes are prepared on recast Nafion containing the ionic liquid, 1-ethyl-3-methylimidazolium tetrafluoroborate ($EMIBF_4$). The composite membranes are characterized by thermogravitational analyses, ion conductivity and small-angle X-ray scattering. The composite membranes annealed at $190^{\circ}C$ for 2 h after the fixed drying step showed better ionic conductivity, but no significant increase in thermal stability. The mean Bragg distance between the ionic clusters, which is reflected in the position of the ionomer peak (small-angle scattering maximum), is larger in the annealed composite membranes containing $EMIBF_4$ than the non-annealed ones. It might have been explained to be due to the different level of ion-clustering ability of the hydrophilic parts (i.e., sulfonic acid groups) in the non- and annealed polymer matrix. In addition, the ionic conductivity of the membranes shows higher for the annealed composite membranes containing $EMIBF_4$. It can be concluded that the annealing of the composite membranes containing ionic liquids due to an increase in ion-clustering ability is able to bring about the enhancement of ionic conductivity suitable for potential use in proton exchange membrane fuel cells (PEMFCs) at medium temperatures ($150-200^{\circ}C$) in the absence of external humidification.

Microwave Cavity with Controllable Temperature for In Vitro Hyperthermia Investigations

  • Kiourti, Asimina;Sun, Mingrui;He, Xiaoming;Volakis, John L.
    • Journal of electromagnetic engineering and science
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    • v.14 no.3
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    • pp.267-272
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    • 2014
  • Hyperthermia is a form of cancer treatment in which affected human tissue is exposed to $>40^{\circ}C$ temperature. In this paper, our goal is to assess the efficacy of fullerene agents to reduce heating time for cancer treatment. Such agents can accelerate heating of cancer cells and improve hyperthermia treatment efficacy. Typically, in vitro testing involves cancer cell culturing, heating cell cultures in accordance to specifications, and recording cancer cell viability after hyperthermia. To heat cell cultures, we design and evaluate a 2.4-GHz microwave cavity with controllable temperature. The cavity is comprised of a polystyrene cell culture dish (diameter = 54 mm, height = 13.5 mm) and a printed monopole antenna placed within the cavity for microwave heating. The culture temperature can be controlled through the intensity and duration of the antenna's microwave radiation. Heating experiments were carried out to validate the cavity's performance for F-12K culture medium (Kaighn's F-12K medium, ATCC). Importantly, fullerene agents were shown to reduce heating time and improve hyperthermia treatment efficacy. The culture medium temperature increased, on average, from $24.0^{\circ}C$ to $50.9^{\circ}C$ (without fullerene) and from $24.0^{\circ}C$ to $56.8^{\circ}C$ (with 3 mg/mL fullerene) within 15 minutes.

Analysis of the Segmental Reinforced Retaining Wall Behavior by Field Monitoring (현장계측을 통한 블럭식 보강토 옹벽의 거동분석)

  • Shin, Eun Chul;Lee, Chang-Seup
    • Journal of the Korean Geosynthetics Society
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    • v.3 no.1
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    • pp.3-15
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    • 2004
  • Geogrid reinforced soil structures with segmental block facing have been increased since 1990's, because of the convenience of installation and the flexible appearance. In this paper, the behavior of the segmental reinforced retaining wall was analysed with the results of field monitoring. The height and length of reinforced wall are 12m and 25m, respectively. The field measurement equipments are horizontal and vertical earth pressure cells, settlement plate, strain gauge, inclinometer, and displacement pin. Based on the field monitoring, the horizontal earth pressure was approximately 0.3times higher than that of the theoretical method and the maximum tensile strength of reinforcement was 26.2kN/m. The displacement of facing wall was 23mm at the point of 7.1m height of the wall and toward the wall facing. The results of the study indicate that the segmental reinforced retaining wall is in a stable condition because of good compaction & reinforcement effects, and long period of construction time. Finally, the computer program of SRWall is very useful tool to design the segmental reinforced retaining wall.

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Studies on the Changes of Steroid Hormone Levels during the Reproductive Stage in Korean Native Goats I. Progesterone and $20\alpha$-Dihydroprogesterone Levels in Serum During the Estrous Cycle (재래산양의 번식기에 있어서 혈중 Steroid Hormone 수준 변화에 관한 연구 I. 발정주기중의 혈중 Progesterone 및 $20\alpha$-Dihydroprogesterone)

  • 민관식;장규태;오석두;성환후;이병오;윤창현
    • Korean Journal of Animal Reproduction
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    • v.16 no.2
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    • pp.133-139
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    • 1992
  • The study was conducted to find out the changes of progesterone and 20$\alpha$-dihydroprogesterone (20$\alpha$-OHP) levels during the oestrous cycle in Korean native goats. 4 cyclic goats were offered for this experiment. Blood samples were taken from jugular vein on day 0, 1, 3, 5, 7, 9, 11, 13, 15, 17 and 19 during the oestrous cycle, then the next oestrous day. The serum levels of progesterone and 20$\alpha$-OHP were measured by radioimmunoassay. The progesterone concentration in seurm of the cyclic goats was 0.29$\pm$0.06ng/ml on the first day of oestrous (day 0), increased to 5.29$\pm$0.73ng/ml on day 9, reached to a peak level of 5.73$\pm$0.61ng/ml on day 13, and thereafter decreased to 0.35$\pm$0.30ng/ml on day 1. The serum level of 20$\alpha$-OHP during the oestrous cycle was 0.42$\pm$0.33ng/ml on day 0 and then decreased to 0.28$\pm$0.01ng/ml on day 5. This basal level was maintained until day 13, increased gradually, and reached a peak level of 0.62$\pm$0.05ng/ml on day 19. From the above results, it was suggested that the enzyme 20$\alpha$-hydroxysteroid dehydrogenase(20$\alpha$-HSD) catalyzing the conversion of progesterone to a biologically inactive steroid, 20$\alpha$-OHP, should be active in the luteal cells during the oestrous cycle in Korean native goats.

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Open Channel Block of Kv3.1 Currents by Genistein, a Tyrosine Kinase Inhibitor

  • Choi, Bok-Hee;Park, Ji-Hyun;Hahn, Sang-June
    • The Korean Journal of Physiology and Pharmacology
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    • v.10 no.2
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    • pp.71-77
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    • 2006
  • The goal of this study was to analyze the effects of genistein, a widely used tyrosine kinase inhibitor, on cloned Shaw-type $K^+$ currents, Kv3.1 which were stably expressed in Chinese hamster ovary (CHO) cells, using the whole-cell configuration of patch-clamp techniques. In whole-cell recordings, genistein at external concentrations from 10 to $100{\mu}M$ accelerated the rate of inactivation of Kv3.1 currents, thereby concentration-dependently reducing the current at the end of depolarizing pulse with an $IC_{50}$ value of $15.71{\pm}0.67{\mu}M$ and a Hill coefficient of $3.28{\pm}0.35$ (n=5). The time constant of activation at a 300 ms depolarizing test pulses from -80 mV to +40 mV was $1.01{\pm}0.04$ ms and $0.90{\pm}0.05$ ms (n=9) under control conditions and in the presence of $20{\mu}M$ genistein, respectively, indicating that the activation kinetics was not significantly modified by genistein. Genistein $(20{\mu}M)$ slowed the deactivation of the tail current elicited upon repolarization to -40 mV, thus inducing a crossover phenomenon. These results suggest that drug unbinding is required before Kv3.1 channels can close. Genistein-induced block was voltage-dependent, increasing in the voltage range $(-20\'mV{\sim}0\'mV)$ for channel opening, suggesting an open channel interaction. Genistein $(20{\mu}M)$ produced use-dependent block of Kv3.1 at a stimulation frequency of 1 Hz. The voltage dependence of steady-state inactivation of Kv3.1 was not changed by $20{\mu}M$ genistein. Our results indicate that genistein blocks directly Kv3.1 currents in concentration-, voltage-, time-dependent manners and the action of genistein on Kv3.1 is independent of tyrosine kinase inhibition.

Studies on Situation and Utilization of Domestic Colostrum (국내산 초유의 현황과 이용에 관한 연구)

  • Bae, Hyung-Churl;Renchinthand, Gereltuya;Na, Seuk-Han;Choi, Seong-Hyun;Nam, Myoung-Soo
    • Food Science of Animal Resources
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    • v.27 no.4
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    • pp.517-521
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    • 2007
  • Questionnaire on utilization of colostrum was carried out in 33 farms. Highest milking cow numbers were 20-40 heads in 45.5% of the farms. Calf numbers were 20-40 heads in 39.4% of the dairy farms and 40-60 heads in 42.4% of the farms. The amount of colostrum production per day was 20-30 kg in 30.3% of the farms and 30-40 kg in 30.3% of the farms. Colostrum intake per calf per day was 4 kg in 45.5% farms. Surplus colostrum after intake by calf was farms (85%) was wasted in 67% of the farms. More than 90% of dairy farms recognize an necessity to use surplus colostrum. Selling price of surplus colostrum was below 1,000 won per kg at 15 dairy farms and 1,000-2,000 won per kg at 4 dairy farms. Colostrum collection and use should be done by the dairy farms of antibiotics free. Quality control of colostrum should be done by testing antibiotics, microbacterium, chemical composition, somatic cells and etc. The colostrum is subjected to cool down below $4^{\circ}C$ just after milking and process for the colostrum products.

Validation of a Multiplexed Opsonophagocytic Assay for 11 Additional Pneumococcal Serotypes and Its Application to Functional Antibody Evaluation Induced by Pneumococcal Polysaccharide Vaccine

  • Cha, Jihei;Kim, Han Wool;Lee, Ji Hyen;Lee, Soyoung;Kim, Kyung-Hyo
    • Journal of Korean Medical Science
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    • v.33 no.51
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    • pp.340.1-340.14
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    • 2018
  • Background: Various pneumococcal vaccines have been evaluated for immunogenicity by opsonophagocytic assay (OPA). A multiplexed OPA (MOPA) for 13 pneumococcal serotypes was developed by Nahm and Burton, and expanded to 26 serotypes in 2012. The development of new conjugate vaccines with increased valence has necessitated expanded MOPAs to include these additional serotypes. In this study, we validated this expanded MOPA platform and applied to measure antibodies against 11 additional serotypes (2, 8, 9N, 10A, 11A, 12F, 15B, 17F, 20B, 22F, and 33F) in human sera. Methods: All materials, including serum, complement, bacterial master stocks, and HL-60 cells, were evaluated for assay optimization. Following optimization, the assay was validated for accuracy, specificity, and intra- and inter-assay precision with sera from adult donors following standard protocols. The assay was applied to evaluate functional antibodies of 42 sera immunized with 23-valent pneumococcal polysaccharide vaccine (PPV23). Results: The expanded MOPA platform was specific for all serotypes, with the exception of serotype 20. The assay results were highly correlated with those obtained from single-serotype OPA, indicating acceptable accuracy. The coefficients of variation were 7%-24% and 13%-39% in tests of intra- and inter-assay precision, respectively, using three quality-control samples. A MOPA that included 11 additional serotypes in the PPV23 was established and validated with respect to accuracy, specificity, and precision. The opsonic indices of immune sera were obtained using this validated assay. Conclusion: The expanded MOPA will be useful for evaluation of the immunogenicity of PPV23 and future conjugate vaccine formulations.

A Review of the Domestic Study Trends on Obstetrics & Gynecological Diseases with Pharmacopuncture Therapy (한방 여성의학 영역에서 활용된 약침요법에 대한 국내 연구 동향 분석)

  • Hwang, Su-In;Park, Kyung-Dug;Park, Jang-Kyung;Yoon, Young-Jin
    • The Journal of Korean Obstetrics and Gynecology
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    • v.32 no.3
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    • pp.192-213
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    • 2019
  • Objectives: The purpose of this study is to analyze the domestic study trends of pharmacopuncture therapy on obstetrics and gynecological diseases in Korean literature, through reviewing the clinical and experimental studies. Methods: We searched for clinical and experimental studies using pharmacopuncture therapy on obstetrics and gynecological diseases, published from January 2000 to May 2019, through 5 Korean databases. The study design, target disease, type of pharmacopuncture, method of intervention, and study results were analyzed. Results: 36 experimental studies and 15 clinical studies were finally included according to inclusion and exclusion criteria. In experimental studies, there were 12 studies about postmenopausal osteoporosis, 9 studies about obesity, 4 studies about endometriosis, 3 studies about hemostatic effects and analgesic anticoagulative effects, 2 studies about ovarian function, and analgesic antiphlogistic anticoagulative effects, and 1 study about menopausal symptoms. In clinical studies, there were 3 studies about obesity, postpartum disorders, dysmenorrhea, and women's urologic disease, and 1 study about menopausal symptoms, atypical squamous cells of undetermined significance (ASCUS) and breast cancer. Various types of pharmacopuncture have been proved to have a therapeutic effect in each of those obstetrics and gynecological diseases. Conclusions: This study indicates that pharmacopuncture therapy could be a good treatment for obstetrics and gynecological diseases. However, more well-designed and high-quality clinical researches are needed in further studies, to prove the effectiveness and safety of pharmacopuncture therapy.

Local Silencing of Connective Tissue Growth Factor by siRNA/Peptide Improves Dermal Collagen Arrangements

  • Cho Lee, Ae-Ri;Woo, Inhae
    • Tissue Engineering and Regenerative Medicine
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    • v.15 no.6
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    • pp.711-719
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    • 2018
  • BACKGROUND: Collagen organization within tissues has a critical role in wound regeneration. Collagen fibril diameter, arrangements and maturity between connective tissue growth factor (CTGF) small interfering RNA (siRNA) and mismatch scrambled siRNA-treated wound were compared to evaluate the efficacy of CTGF siRNA as a future implement for scar preventive medicine. METHODS: Nanocomplexes of CTGF small interfering RNA (CTGF siRNA) with cell penetrating peptides (KALA and $MPG^{{\Delta}NLS}$) were formulated and their effects on CTGF downregulation, collagen fibril diameter and arrangement were investigated. Various ratios of CTGF siRNA and peptide complexes were prepared and down-regulation were evaluated by immunoblot analysis. Control and CTGF siRNA modified cells-populated collagen lattices were prepared and rates of contraction measured. Collagen organization in rabbit ear 8 mm biopsy punch wound at 1 day to 8 wks post injury time were investigated by transmission electron microscopy and histology was investigated with Olympus System and TS-Auto software. CONCLUSION: CTGF expression was down-regulated to 40% of control by CTGF siRNA/KALA (1:24) complexes (p<0.01) and collagen lattice contraction was inhibited. However, down-regulated of CTGF by CTGF $siRNA/MPG^{{\Delta}NLS}$ complexes was not statistically significant. CTGF KALA-treated wound appeared with well formed-basket weave pattern of collagen fibrils with mean diameter of $128{\pm}22nm$ (n = 821). Mismatch siRNA/KALA-treated wound showed a high frequency of parallel small diameter fibrils (mean $90{\pm}20nm$, n = 563). CONCLUSION: Controlling over-expression of CTGF by peptide-mediated siRNA delivery could improve the collagen orientation and tissue remodeling in full thickness rabbit ear wound.

Precise control of mitophagy through ubiquitin proteasome system and deubiquitin proteases and their dysfunction in Parkinson's disease

  • Park, Ga Hyun;Park, Joon Hyung;Chung, Kwang Chul
    • BMB Reports
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    • v.54 no.12
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    • pp.592-600
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    • 2021
  • Parkinson's disease (PD) is one of the most common neurodegenerative diseases in the elderly population and is caused by the loss of dopaminergic neurons. PD has been predominantly attributed to mitochondrial dysfunction. The structural alteration of α-synuclein triggers toxic oligomer formation in the neurons, which greatly contributes to PD. In this article, we discuss the role of several familial PD-related proteins, such as α-synuclein, DJ-1, LRRK2, PINK1, and parkin in mitophagy, which entails a selective degradation of mitochondria via autophagy. Defective changes in mitochondrial dynamics and their biochemical and functional interaction induce the formation of toxic α-synuclein-containing protein aggregates in PD. In addition, these gene products play an essential role in ubiquitin proteasome system (UPS)-mediated proteolysis as well as mitophagy. Interestingly, a few deubiquitinating enzymes (DUBs) additionally modulate these two pathways negatively or positively. Based on these findings, we summarize the close relationship between several DUBs and the precise modulation of mitophagy. For example, the USP8, USP10, and USP15, among many DUBs are reported to specifically regulate the K48- or K63-linked de-ubiquitination reactions of several target proteins associated with the mitophagic process, in turn upregulating the mitophagy and protecting neuronal cells from α-synuclein-derived toxicity. In contrast, USP30 inhibits mitophagy by opposing parkin-mediated ubiquitination of target proteins. Furthermore, the association between these changes and PD pathogenesis will be discussed. Taken together, although the functional roles of several PD-related genes have yet to be fully understood, they are substantially associated with mitochondrial quality control as well as UPS. Therefore, a better understanding of their relationship provides valuable therapeutic clues for appropriate management strategies.