• Title/Summary/Keyword: acid stress

Search Result 1,659, Processing Time 0.042 seconds

Fed-batch Cultivation of Escherichia coli YK537 (pAET-8) for Production of phoA Promoter-controlled Human Epidermal Growth Factor

  • Wang Yonggang;Du Peng;Gan Renbao;Li Zhimin;Ye Qin
    • Biotechnology and Bioprocess Engineering:BBE
    • /
    • v.10 no.2
    • /
    • pp.149-154
    • /
    • 2005
  • Secretion of the expressed heterologous proteins can reduce the stress to the host cells and is beneficial to their recovery and purification. In this study, fed-batch cultures of Escherichia coli YK537 (pAET-8) were conducted in a 5-L fermentor for the secretory production of human epidermal growth factor (hEGF) whose expression was under the control of alkaline phosphatase promoter. The effects of feeding of glucose and complex nitrogen sources on hEGF production were investigated. When the fed-batch culture was conducted in a chemically de-fined medium, the cell density was 9.68 g/L and the secreted hEGF was 44.7 mg/L in a period of 60 h. When a complex medium was used and glucose was added in pH-stat mode, the secreted hEGF was improved to 345 mg/L. When the culture was fed with glucose at a constant specific rate of $0.25\;gg^{-1}h^{-1}$, hEGF reached 514 mg/L. The effects of adding a solution containing yeast extract and tryptone were further studied. Different rate of the nitrogen source feeding resulted in different levels of phosphate and acetic acid formation, thus affected hEGF expression. At the optimal feeding rate, hEGF production achieved 686 mg/L.

Investigation of Plated Contact for Crystalline Silicon Solar Cells (결정질 실리콘 태양전지에 적용될 도금전극 특성 연구)

  • Kim, Bum-Ho;Choi, Jun-Young;Lee, Eun-Joo;Lee, Soo-Hong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2007.06a
    • /
    • pp.192-193
    • /
    • 2007
  • An evaporated Ti/Pd/Ag contact system is most widely used to make high-efficiency silicon solar cells, however, the system is not cost effective due to expensive materials and vacuum techniques. Commercial solar cells with screen-printed contacts formed by using Ag paste suffer from a low fill factor and a high shading loss because of high contact resistance and low aspect ratio. Low-cost Ni and Cu metal contacts have been formed by using electro less plating and electroplating techniques to replace the Ti/Pd/Ag and screen-printed Ag contacts. Ni/Cu alloy is plated on a silicon substrate by electro-deposition of the alloy from an acetate electrolyte solution, and nickel-silicide formation at the interface between the silicon and the nickel enhances stability and reduces the contact resistance. It was, therefore, found that nickel-silicide was suitable for high-efficiency solar cell applications. Cu was electroplated on the Ni layer by using a light induced plating method. The Cu electroplating solution was made up of a commercially available acid sulfate bath and additives to reduce the stress of the copper layer. In this paper, we investigated low-cost Ni/Cu contact formation by electro less and electroplating for crystalline silicon solar cells.

  • PDF

Antioxidative and Anti-inflammatory Effect of Ethanol Extract from Duchesnea chrysantha (사매 에탄올 추출물의 항산화 및 항염증 효과)

  • Lee, Deok-Jae;Jeon, In-Hwa;Kim, Hyeon-Soo;Cho, Il-Young;Jang, Seon-Il
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.26 no.1
    • /
    • pp.59-66
    • /
    • 2012
  • Oxidative stress has been implicated in cutaneous damage in various inflammatory skin diseases, including atopic dermatitis. The present study was undertaken to investigate the antioxidative and anti-inflammatory activities of the extract of Duchesnea chrysantha (DCE). DEC was prepared by extracting with 80% ethanol. Total flavonoids and polyphenols were measured by a colorimetric assay. The free radical scavenging activity of the extract was analyzed by the DPPH (1,1-diphenyl-2-picryl hydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) and Griess reagent assay. An oxidative product of nitric oxide (NO), was measured in the culture medium by the Griess reaction. The level of prostaglandin $E_2$ ($PGE_2$) was measured by enzyme-linked immunosorbent assay. The expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were measured by Western blot analysis. Total flavonoid and polyphenol contents of DCE were included $24.73{\pm}0.45$ and $178.77{\pm}2.65$, respectively. DCE significantly increased electron donating ability (DPPH), nitrite scavenging (NO) and ABTS reducing activity in dose dependant. We investigated the anti-inflammatory effects of DCE on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. DCE significantly suppressed NO and prdstaglandin $E_2$ ($PGE_2$) in dose dependant. Furthermore, the levels of iNOS and COX-2 protein expressions were markedly suppressed by the treatment with DCE in a dose dependent manner. These results suggest that DEC may has value as natural product with its high quality functional components, antioxidative and anti-inflammatory activities.

Effect of Chungyeoldodam-tang on Hypertension (청열도담탕이 고혈압에 미치는 영향)

  • Park, Kyung-Ho;Choi, Hak-Joo;Roh, Seong-Soo;Koo, Young-Sun;Kim, Dong-Hee
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.21 no.3
    • /
    • pp.626-633
    • /
    • 2007
  • To access the safety and efficacy of Chungyeoldodam-tang(CDT), a traditional herbal medicine prescription, on hypertension we examined various parameters involved in the pathogenesis of hypertension. CDT seems to be safe because CDT at the concentrations lower that 250 ug/ml showed no toxic effects in cultured human fibroblast and no toxic effects on liver function. The production of reactive oxygen species (ROS) were greatly decreased in CDT treated group compared with control, and angiotensin converting enzyme activities were reduced by CDT in a dose dependent manner. There was no differences in weight of hearts between control and CDT treated group. The blood pressure and pulse rate were significantly decreased. CDT greatly reduced the levels of plasma hormones including aldosterone, dopamine, and norepinephrine, but not epinephrine, and serum electrocytes including Na$^+$ and Cl$^-$, but not K$^+$. were also decreased. The levels of uric acid, BUN and creatinine were significantly decreased compared with control. These results suggested that CDT has suppressive effects on various pathologic factors in hypertension, and CDT has potential as a safe and effective therapeutics for hypertension.

Effect of Bulohwan-Decoction on Antioxidant Enzyme in Rat Brain (불로환(不老丸)을 투여한 흰쥐 뇌의 항산화효과에 관한 연구)

  • Park Jin-Sung;Goh Seong-Kyu;Lee Sun-Dong
    • Journal of Society of Preventive Korean Medicine
    • /
    • v.5 no.1
    • /
    • pp.90-102
    • /
    • 2001
  • Objectives: Resently Oxidative stress of brain was proved the cause of Alzheimer and stroke sequel. It has important significance in prevention and treatment of cerebropathia that Bulnohwan used as formula of senescence delay have antioxidative effect. The purposes of this study is to investigate the effect of Bulnohwan on antioxidant defense systems such as thiobarbituric acid reactive substances(TBARS), Superoxide dismutase (SOD), Catalase (CAT), Glutathione peroxidase (GSH-PX), Glutathione S-transperase (GST), Glutathione (GSH) in rat brain. Method: Sprague - Dawley rats were divided into 3 groups; saline solution administered control group, Bulnohwan extract administered Experimental group I and Bulnohwan adminisrtrated, 40% dietary restricted Experimental group II. Animals were sacrificed at 12 weeks after treatment TBARS, SOD, CAT, GSH-PX, GST and GSH were measured in mts brain. Results: weight of brain was no stastical significance.(p>0.05) TBARS contents were significant decrease in Experimental group I, II. (p<0.001) SOD activity was stastical significance in Experimental group II, whereas it was no stastical significance Experimental group II.(p<0.0001) Catalase activites were significant increase in . (p<0.00l) Glutathione Peroxidase activites were significant increase in Experimental group I,II. (p<0.000l) Glutathione S-transferase activites were significant increase in Experimental group I, II. (p<0.000) However there were no statistical significance each other. Glutathione contents were significant increase in Experimental group I, II. (p<0.00l) Conclusions: According to the above results, it is considered that Bulohwan has antioxidants effect in rat brain. When Bulohwan goes with diet restriction, there has more Antioxidants effect in rat brain. but this study was perfored retrospectively. So more prospective studies about mutual relation of drugs are needed

  • PDF

Continuous Renal Replacement Therapy in a 4-year-old Child with Rhabdomyolysis Following Parainfluenza Virus Infection and Hyperammonemia due to Isovaleric Acidemia (Parainfluenza virus 감염 후 발생한 횡문근융해증과 isovaleric acidemia로 인한 고암모니아혈증을 가진 소아에서의 지속적 신대체요법)

  • Park, Se Jin;Cho, Soo Yeon;Pai, Ki Soo;Shin, Jae Il
    • Childhood Kidney Diseases
    • /
    • v.17 no.2
    • /
    • pp.132-136
    • /
    • 2013
  • Parainfluenza virus infection is one of the causes of fatal rhabdomyolysis. Rhabdomyolysis can be aggravated by mitochondrial fatty acid ${\beta}$-oxidation disorders during prolonged periods of fasting. Moreover, in patients with late-onset isovaleric acidemia, hyperammonemia may occur following catabolic stress. In the present report, we describe a case of a 4-year-old boy with parainfluenza virus infection and late-onset isovaleric acidemia that rapidly progressed to coma, seizures, and cardiorespiratory collapse. His serum ammonia and creatinine kinase (CK) levels were $385{\mu}Mol/L$ and 23,707 IU/L, respectively. Continuous renal replacement therapy (CRRT) was initiated using continuous venovenous hemodiafiltration, after which the ammonia and CK levels returned to normal. Thus, we recommend the immediate initiation of CRRT in the management of patients with life-threatening rhabdomyolysis and hyperammonemia.

CrABCA2 Facilitates Triacylglycerol Accumulation in Chlamydomonas reinhardtii under Nitrogen Starvation

  • Jang, Sunghoon;Kong, Fantao;Lee, Jihyeon;Choi, Bae Young;Wang, Pengfei;Gao, Peng;Yamano, Takashi;Fukuzawa, Hideya;Kang, Byung-Ho;Lee, Youngsook
    • Molecules and Cells
    • /
    • v.43 no.1
    • /
    • pp.48-57
    • /
    • 2020
  • The microalga Chlamydomonas reinhardtii accumulates triacylglycerols (TAGs) in lipid droplets under stress conditions, such as nitrogen starvation. TAG biosynthesis occurs mainly at the endoplasmic reticulum (ER) and requires fatty acid (FA) substrates supplied from chloroplasts. How FAs are transferred from chloroplast to ER in microalgae was unknown. We previously reported that an Arabidopsis thaliana ATP-binding cassette (ABC) transporter, AtABCA9, facilitates FA transport at the ER during seed development. Here we identified a gene homologous to AtABCA9 in the C. reinhardtii genome, which we named CrABCA2. Under nitrogen deprivation conditions, CrABCA2 expression was upregulated, and the CrABCA2 protein level also increased. CrABCA2 knockdown lines accumulated less TAGs and CrABCA2 overexpression lines accumulated more TAGs than their untransformed parental lines. Transmission electron microscopy showed that CrABCA2 was localized in swollen ER. These results suggest that CrABCA2 transports substrates for TAG biosynthesis to the ER during nitrogen starvation. Our study provides a potential tool for increasing lipid production in microalgae.

Altered Protein Expression in Peach (Prunus persica) Following Fruit Bagging

  • Zhang, Wei;Zhao, Xiaomeng;Shi, Mengya;Yang, Aizhen;Hua, Baoguang;Liu, Yueping
    • Horticultural Science & Technology
    • /
    • v.34 no.1
    • /
    • pp.32-45
    • /
    • 2016
  • Fruit bagging has been widely practiced in peach cultivation to produce high quality and unblemished fruit. Moreover, fruit bagging has been utilized to study the effect of shading on the quality of fruit. We conducted a proteomic analysis on peach fruit to elucidate the biochemical and physiological events that characterize the effect of bagging treatment. Comparative analysis of 2D electrophoresis (2-DE) gels showed that relative protein levels differed significantly at 125 DAFB (days after full bloom), as well as at 133 DAFB in fruit that had been bagged until 125 DAFB, followed by exposure to sunlight. Most of the proteins with altered expression were identified by MALDI TOF/TOF. Twenty-one proteins with differential expression among the groups were identified at 125 DAFB, while thirty proteins with differential expression among the groups were identified at 133 DAFB. The analysis revealed that expression of proteins involved in photosynthesis, stress responses, and biochemical processes influencing metabolism were altered during bagging treatment, suggesting that regulation of the synthesis of carbohydrates, amino acids, and proteins influenced fruit size, solid/acid ratio, and peel color. This work provides the first characterization of proteomic changes in peach in response to fruit bagging treatment. Identifying and tracking protein changes may allow us to better understand the mechanisms underlying the effects of bagging treatment.

Characterization of Electro-deposited Ni-P Layer by Using Dynamic Nano-Indentation Method (동적 나노압침법을 이용한 Ni-P 도막의 특성 연구)

  • Jung, Moo Young;Baik, Youl;Kang, Bo Kyeong;Choi, Yong;Kwon, Hyuk Joo
    • Journal of Surface Science and Engineering
    • /
    • v.51 no.4
    • /
    • pp.197-201
    • /
    • 2018
  • Dynamic nano-indentation method was applied to characterize thin electroformed Ni-P layers. The Ni-P layers were produced in a sulphamic acid bath at $50^{\circ}C$ in $0.02A/cm^2$ for 10-60 minutes. The chemical analyses by XRD and EDX showed that the Ni-P layers were very fine grains with mainly $Ni_3P$ with Ni. The surface roughness determined by atomic force microscopy increased with thickness, which was relative to the surface morphology. The nano-hardness and the stiffness of the thin Ni-P layers with thickness of 1.9, 6.2 and $7.5{\mu}m$ were 5.52, 6.52 and 6.77 [GPa] and 56.7, 76.2 and 108.0 [${\mu}N/nm$], respectively. The elastic modulus of the Ni-P layer increased with thickness such as 37.29, 54.50 and 78.76 [GPa], respectively. The surface roughness of the electroplated Ni-P layers with diverse thickness was 8.66, 18.56 and 35.22 [nm], respectively. The enhanced nano-mechanical properties were related to mainly residual stress of the Ni-P layers.

Antioxidant Activity of Mulberry Leaves Extract Fermented by Hericium erinaceum (버섯균사체 발효 뽕잎 추출물의 항산화 활성)

  • Kang, Jung Hoon
    • Journal of the Korean Applied Science and Technology
    • /
    • v.34 no.4
    • /
    • pp.1025-1035
    • /
    • 2017
  • In this study, the hot water extract from Mulberry (Morus alba) Leaves fermented with Hericium erinaceum mycelium (MA-HE) was assessed for antioxidant activity. Radical scavenging activity of MA-HE evaluated using 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical and 2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid)(ABTS) radical. MA-HE showed 63% DPPH radical scavenging activity at $500{\mu}g/mL$ and 98.27% ABTS radical scavenging activity at $250{\mu}g/mL$. MA-HE was shown to significantly inhibited DNA strand breakage induced by free radical. MA-HE also inhibited free radical-mediated human serum albumin modification. MA-HE effectively inhibited $H_2O_2$ induced cell death and significantly increased of the 8% cell survival at $100{\mu}g/mL$. MA-HE decreased intracellular reactive oxygen species (ROS) levels in $H_2O_2$-treated cells. The results suggested that MA-HE can contribute to antioxidant and protected cells from oxidative stress-induced cell injury.