• Title/Summary/Keyword: Cold Plasma

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The Evaluation of Surface and Adhesive Bonding Properties for Cold Rolled Steel Sheet for Automotive Treated by Ar/O2 Atmospheric Pressure Plasma (대기압 Ar/O2 플라즈마 표면처리된 자동차용 냉연강판의 표면특성 및 접착특성평가)

  • Lee, Chan-Joo;Lee, Sang-Kon;Park, Geun-Hwan;Kim, Byung-Min
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.4
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    • pp.354-361
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    • 2008
  • Cold rolled steel sheet for automotive was treated by Ar/$O_2$ atmospheric pressure plasma to improve the adhesive bonding strength. Through the contact angle test and calculation of surface free energy for cold rolled steel sheet, the changes of surface properties were investigated before and after plasma treatment. The contact angle was decreased and surface free energy was increased after plasma treatment. And the change of surface roughness and morphology were observed by AFM(Atomic Force Microscope). The surface roughness of steel sheet was slightly changed. Based on Taguchi method, single lap shear test was performed to investigate the effect of experimental parameter such as plasma power, treatment time and flow rate of $O_2$ gas. Results shows that the bonding strength of steel sheet treated in Ar/$O_2$ atmospheric pressure plasma was improved about 20% compared with untreated sheet.

Supplementary prenatal copper increases plasma triiodothyronine and brown adipose tissue uncoupling protein-1 gene expression but depresses thermogenesis in newborn lambs

  • Smith, Stephen B.;Sweatt, Craig R.;Carstens, Gordon E.
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.3
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    • pp.506-514
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    • 2020
  • Objective: We tested the hypothesis that increasing dietary copper (Cu) to gravid ewes would enhance brown adipose tissue (BAT) thermogenesis in their offspring. Methods: Twin-bearing ewes were assigned on d 70 of gestation to diets containing 3, 10, or 20 ppm dietary Cu (n = 8 per group). Twin lambs were assigned at birth to a cold (6℃) or warm (28℃) environmental chamber for 48 h. Blood was collected from ewes and from lambs and perirenal BAT was collected after 48 h in the environmental chambers. Results: Prenatal Cu exposure increased ewe plasma triiodothyronine (T3) and thyroxine concentration (T4) (p<0.01) but prenatal Cu exposure had no effect on lamb plasma concentrations of T3, T4, glucose, or nonesterified fatty acid concentration (p≥0.08). The high level of prenatal Cu exposure depressed 48-h rectal temperature (p = 0.03). Cold exposure decreased BAT norepinephrine (NE) and increased BAT dopamine (p≤0.01), but prenatal Cu exposure had no effect on BAT cytochrome C oxidase activity or BAT NE or dopamine (p≥0.07). However, BAT of lambs from high-Cu ewes maintained higher uncoupling protein-1 (UCP1) gene expression than BAT of lambs from low- and medium-Cu ewes following warm or cold exposure in environmental chambers (p = 0.02). Cold exposure caused near depletion of BAT lipid by 48 h (p<0.001), increased BAT cytochrome c oxidase activity (p<0.01), and depressed plasma fatty acid concentrations (p<0.001). Conclusion: Although prenatal Cu exposure increased BAT UCP1 expression during warm and cold exposure, prenatal cold Cu exposure depressed 48-h rectal temperature. Cold exposure decreased BAT lipid content by over 80% and decreased lamb plasma fatty acid concentration by over 40%, indicating that fuel reserves for thermogenesis were nearly depleted by 48 h of cold exposure.

Combined Effect of Cold Plasma and UV-C Against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on Fresh-cut Lettuce (양상추에 인위접종된 Escherichia coli O157:H7, Salmonella Typhimurium과 Listeria monocytogenes에 대한 저온 플라즈마와 UV-C의 살균 효과)

  • Seong, Ji-Yeong;Park, Mi-Jung;Kwon, Ki-Hyun;Oh, Se-Wook
    • Journal of Food Hygiene and Safety
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    • v.32 no.1
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    • pp.64-69
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    • 2017
  • This study was conducted to investigate the effect of cold plasma combined with UV-C irradiation against Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes on lettuce. E. coli O157:H7, S. Typhimurium, and L. monocytogenes, corresponding to approximately 5.82, 5.09, 5.65 log CFU/g, were inoculated on lettuce, respectively. Then, the lettuce was treated with cold plasma, UV-C and combination (cold plasma + UV-C), respectively. The treated lettuce was stored for 9 days at $4^{\circ}C$ for microbiological analysis and sensory evaluation. Cold plasma reduced the populations of E. coli O157:H7, S. Typhimurium, and L. monocytogenes by 0.26, 0.65, and 0.93 log CFU/g, respectively. Each microorganism were reduced by 0.87, 0.88, and 1.14 log CFU/g after UV-C treatment. And, the combined treatment that was treated by cold plasma after UV-C treatment reduced the populations of inoculated microorganisms by 1.44, 2.70, 1.62 log CFU/g, respectively. The all treatment significantly (p < 0.05) reduced the populations of all inoculated bacteria compared to untreated lettuce. UV-C combined with cold plasma was the most effective for reducing the pathogenic bacteria on lettuce, by showing log-reductions of ${\geq}2.0\;log\;CFU/g$. All treatment was not significantly different until 6 day storage compared to control group in terms of appearance, texture and overall acceptability. Therefore, the combined treatment will be an effective intervention method to control the bacteria on lettuce.

Cold Ethanol Fractionation and Heat Inactivation of Hepatitis A Virus During Manufacture of Albumin from Human Plasma

  • Kim, In-Seop;Park, Yong-Woon;Lee, Sung-Rae;Sung, Hark-Mo
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.9 no.1
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    • pp.65-68
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    • 2004
  • The purpose of the present study was to examine the efficacy and mechanism of fraction IV cold ethanol fractionation and pasteurization (60$^{\circ}C$ heat treatment for 10 h), involved in the manufacture of albumin from human plasma, in the removal and/or inactivation of the hepatitis A virus (HAV). Samples from the relevant stages of the production process were spiked with HAV and the amount of virus in each fraction then quantified using a 50% tissue culture infectious dose (TCID$\_$50/). HAV was effectively partitioned from albumin during the fraction IV cold ethanol fractionation with a log reduction factor of 3.43. Pasteurization was also found to be a robust and effective step in inactivating HAV, where the titers were reduced from an initial titer of 7.60 log TCID$\_$50/ to undetectable levels within 5 h of treatment. The log reduction factor achieved during pasteurization was $\geq$4.76. Therefore, the current results indicate that the production process for albumin has sufficient HAV reducing capacity to achieve a high margin of virus safety.

Effects of Taste and Quality of Drugs on the Plasma Corticosterone Level in Mice exposed to Heat and Cold Stress (한약(韓藥)의 기미(氣味)가 한열자극(寒熱刺戟)을 받은 생쥐의 혈중(血中) corticosterone에 미치는 효과(效果))

  • Nam Yeo-Jeong;Lee Tae-Hee
    • Herbal Formula Science
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    • v.10 no.1
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    • pp.157-167
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    • 2002
  • This study was performed to investigate what effect the taste and quality of drugs would have on the cold and heat mechanisms of human body. We administered Hwangryeunhaedok-tang composed of bitter-tasted, cold-qualified drugs and Gungangbuza-tang composed of spice-tasted. hot-qualified drugs, respectively to the mice 1 hr before exposure to heat stress or cold stress. Plasma corticosterone level of mice was measured. The results were as follows: 1. The elevated corticosterone level in the mice exposed to heat stress was significantly decreased after administration of Gungangbuza-tang but there was no decrease after administration of Hwangryeunhaedok-tang. 2. The elevated corticosterone level in the mice exposed to cold stress was significantly decreased after administration of Hwangryeunhaedok-tang but there was mild decrease after administration of Gungangbuza-tang. 3. When the doses, 3g/kg and 1g/kg were administerd to mice exposed to heat stress. both dose showed significant decrease of corticosterone level and the dose. 3g/kg was more effective. However, in the mice exposed to cold stress, the dose, 3g/kg showed mild decrease and 1g/kg showed significant decrease. These data suggested that HW decreased the plasma corticosterone level in the mice exposed to cold stress and GB also decreased the plasma corticosterone level in the mice exposed to heat stress. In conclusion, our study revealed that the taste and quality of drugs controled the cold and heat mechanism of human body.

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Changes of Thyroid Hormone Levels in Plasma of Rats during Cold Exposure (저온환경 적응에 있어서의 갑상선 Hormone의 변동)

  • Lee, H.W.;Kim, W.J.;Hong, S.S.;Kim, H.S.;Hong, S.U.
    • The Korean Journal of Pharmacology
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    • v.17 no.2
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    • pp.37-45
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    • 1981
  • The importance of thyroid hormones for the survival of rats in the cold is along-established fact. Hypothyroid animals are unable to survive in a cold environment. It was also reported that acute exposure of rats, guinea pigs and rabbits to cold produced an increased secretion of TSH and thereby thyroid hormone secretion within 10 to 30 min, but this increase of thyroid activity disappeared quite rapidly during warming. However, in human study no significant difference was found in the concentration of $T_4$, TSH and cortisol between summer and winter. But plasma $T_3$ concentration was increased significantly in winter in 56 adult men. On the other hand, it has been also known that catecholamines are important in the maintenance of body temperature of rat exposured to cold. Abundant evidences suggest that the sympathetic nervous system is involved in the activation of nonshivering thermogenesis and that thyroid hormone metabolism and secretion are influenced by catecholamines and consequently by the activity of the sympatheticadrenal system. Many of the metabolic effects of catecholamines are associated with an increase in the level of cAMP mediated through activation of adenylate cyclase which converts ATP to cAMP. Other studies have shown that thyroid hormones affect the amount of adenylate cyclase present in the adipose tissue. On the other hand. it was also reported that a particulate cAMP phosphodiesterase activity in fat cells was modulated by the action of thyroid hormones. The objective of the present study was to determine the interaction between thyroid activity and cyclic nucleotides during acute exposure to cold. Albino rats weighing around 200 g were used as the experimental animal. The room temperature group was kept at $25^{\circ}C$ and the cold-exposured group was kept at $4^{\circ}C$ for 1 week or 2 weeks. Each group was subdivided into three subgroups; control, KI, and MTU group. At the end of experiment the animals were etherized and blood was taken from abdominal aorta for $T_4,\;T_3$ and cyclic nucleotides. The determinations of $T_3,\;T_4$ and cyclic nucleotides were carried out with a radioimmunoassay(RIA) method. The results were summerized as followings. 1) A significant increase of thyroid weight was observed in rats exposured to cold for 2 weeks. Furthermore, in rats administered MTU while to exposure to cold the thyroid weight was also increased significantly. 2) After 2 weeks $T_3$ concentration in the plasma of cold-exposured rats was significantly increased in KI group and MTU group as well as in control group. On the contrary, after 2 weeks of cold exposure $T_4$ level was decreased in control group. 3) In the case of cyclic nucleotides, plasma cAMP was increased in the control group after 1 or 2 weeks of cold exposure. However, cAMP level in plasma was rather significantly decreased in KI group and MTU group as well as in control group.

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Research on the Relative Contribution of Two Electron Groups of Ar plasma with Non-thermal Equilibrium Electron Distribution (열적 비평형 전자분포를 갖는 아르곤 플라즈마의 두 전자그룹의 상대적인 기여도에 대한 연구)

  • Lee, Young Seok;Lee, Jang Jae;Kim, Si Jun;You, Shin Jae
    • Journal of the Semiconductor & Display Technology
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    • v.17 no.1
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    • pp.76-83
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    • 2018
  • The electron energy probability function (EEPF) is of significant importance since the plasma chemistry such as the rate of ionization is determined by the electron energy distribution function. It is usually assumed to be Maxwell distribution for 0-D global model. Meanwhile, it has been observed experimentally that the form of EEPF of Ar plasma changes from being two-temperature to Druyvesteyn like as the gas pressure increases. Thus, to apply the 0-D global model of Maxwellian distribution to the non-Maxwellian plasma, we investigated the relative contribution of two distinct electrons with different temperatures. The contributions of cold/hot electrons to the equilibrium state of the plasma have attracted interest and been researched. The contributions to the power and particle balance of cold/hot electrons were studied by comparing the result of the global model considering all combinations of electron temperatures with that of 1-D Particle-in-Cell and Monte Carlo collision (PIC-MCC) simulation and the results of studies were analyzed physically. Furthermore, comparisons term by term for variations of the contribution of cold/hot electrons at different driving currents are presented.

Co-amplification at Lower Denaturation-temperature PCR Combined with Unlabled-probe High-resolution Melting to Detect KRAS Codon 12 and 13 Mutations in Plasma-circulating DNA of Pancreatic Adenocarcinoma Cases

  • Wu, Jiong;Zhou, Yan;Zhang, Chun-Yan;Song, Bin-Bin;Wang, Bei-Li;Pan, Bai-Shen;Lou, Wen-Hui;Guo, Wei
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.24
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    • pp.10647-10652
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    • 2015
  • Background: The aim of our study was to establish COLD-PCR combined with an unlabeled-probe HRM approach for detecting KRAS codon 12 and 13 mutations in plasma-circulating DNA of pancreatic adenocarcinoma (PA) cases as a novel and effective diagnostic technique. Materials and Methods: We tested the sensitivity and specificity of this approach with dilutions of known mutated cell lines. We screened 36 plasma-circulating DNA samples, 24 from the disease control group and 25 of a healthy group, to be subsequently sequenced to confirm mutations. Simultaneously, we tested the specimens using conventional PCR followed by HRM and then used target-DNA cloning and sequencing for verification. The ROC and respective AUC were calculated for KRAS mutations and/or serum CA 19-9. Results: It was found that the sensitivity of Sanger reached 0.5% with COLD-PCR, whereas that obtained after conventional PCR did 20%; that of COLD-PCR based on unlabeled-probe HRM, 0.1%. KRAS mutations were identified in 26 of 36 PA cases (72.2%), while none were detected in the disease control and/or healthy group. KRAS mutations were identified both in 26 PA tissues and plasma samples. The AUC of COLD-PCR based unlabeled probe HRM turned out to be 0.861, which when combined with CA 19-9 increased to 0.934. Conclusions: It was concluded that COLD-PCR with unlabeled-probe HRM can be a sensitive and accurate screening technique to detect KRAS codon 12 and 13 mutations in plasma-circulating DNA for diagnosing and treating PA.

Current Status and Future Trends of Cold Atmospheric Plasma as an Oncotherapy

  • Xiaofeng Dai;Jiale Wu;Lianghui Lu;Yuyu Chen
    • Biomolecules & Therapeutics
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    • v.31 no.5
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    • pp.496-514
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    • 2023
  • Cold atmospheric plasma (CAP), a redox modulation tool, is capable of inhibiting a wide spectrum of cancers and has thus been proposed as an emerging onco-therapy. However, with incremental successes consecutively reported on the anticancer efficacy of CAP, no consensus has been made on the types of tumours sensitive to CAP due to the different intrinsic characteristics of the cells and the heterogeneous design of CAP devices and their parameter configurations. These factors have substantially hindered the clinical use of CAP as an oncotherapy. It is thus imperative to clarify the tumour types responsive to CAP, the experimental models available for CAP-associated investigations, CAP administration strategies and the mechanisms by which CAP exerts its anticancer effects with the aim of identifying important yet less studied areas to accelerate the process of translating CAP into clinical use and fostering the field of plasma oncology.

Protective effect of platelet-rich plasma against cold ischemia-induced apoptosis of canine adipose-derived mesenchymal stem cells

  • Suji Shin;Sung-Eon Kim;Seong-Won An;Seong-Mok Jeong;Young-Sam Kwon
    • Korean Journal of Veterinary Research
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    • v.64 no.1
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    • pp.2.1-2.8
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    • 2024
  • This study was performed to assess the antiapoptotic effect of canine platelet-rich plasma (PRP) treated on the canine adipose-derived mesenchymal stem cells (cMSCs) under cold ischemic conditions. The effect of preventing apoptosis of cMSCs was evaluated in the apoptotic condition induced by cold ischemic injury in vitro. To determine the progression of apoptosis, the changes in cell nucleus were observed using 4',6-diamidino-2-phenylindole (DAPI) fluorescence staining. In addition, we examined the mitochondrial membrane potential (MMP) and caspase-3 activity. When the cold hypoxic injury was applied to cMSCs, the apoptotic change was observed by DAPI staining, mitochondrial staining for MMP, and caspase-3 assay. PRP significantly decreased the number of apoptotic cells. Nuclear shrinkage and fragmentation of apoptotic cells in control groups were observed by DAPI staining. The MMP was recovered by the treatment of PRP. In addition, when the luminescence intensity was measured for caspase-3 activity, the value was significantly higher in the PRP treated groups than the control groups. The results of this study showed that the PRP may have a beneficial effect on apoptosis induced by cold ischemic injury.