• Title/Summary/Keyword: Stress concentration analysis

Search Result 976, Processing Time 0.03 seconds

Characterization of Mulberry Root Bark Extracts (Morus alba L.) Based on the Extraction Temperature and Solvent

  • Lee, Sora;Kim, Soo Hyun;Jo, You-Young;Kim, Seong-Wan;Kim, Hyun-Bok;Kweon, HaeYong;Ju, Wan-Taek
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • v.41 no.2
    • /
    • pp.36-44
    • /
    • 2020
  • Mulberry root bark is one of potential plant sources for antioxidant materials which can be used for the relief of oxidative stress. To explore the effects of solvent type and temperature on the structural characteristics and antioxidant activity of the root bark extracts, we prepared various extracts of mulberry root bark (Morus alba L.) using 0 - 100 % ethanol (EtOH) at RT - 100℃. EtOH concentration and temperature critically affected the extraction yields, the content of bioactive components, and antioxidant activity of the extracts. Use of high content of EtOH solvent and low temperature resulted in the low extraction yield. Meanwhile, it was revealed that the extract prepared using absolute EtOH at room temperature contained polyphenols and flavonoids with the highest contents among other extracts. Interestingly, the temperature differently affected the polyphenol and flavonoid contents according to the solvent types. In the case of 30% EtOH solvent, polyphenol and flavonoid contents increased with an increase in temperature, whereas in the case of 70 and 100 % EtOH, these contents decreased. Using the radical scavenging assay, it was confirmed that the 100% EtOH extracts had higher antioxidant activity compared to distilled water (DW) extracts regardless of temperature. Also, heating might extract more antioxidant components from the root bark. Especially, the extract prepared using 30% EtOH solvent at 100℃ showed the highest antioxidant activity. Taken together, these experimental results imply that the extraction parameters should be designed carefully considering the productivity, the extracted bioactive components, and antioxidant activity.

Hygro-thermo-mechanical bending response of FG plates resting on elastic foundations

  • Merazka, Bouzid;Bouhadra, Abdelhakim;Menasria, Abderrahmane;Selim, Mahmoud M.;Bousahla, Abdelmoumen Anis;Bourada, Fouad;Tounsi, Abdeldjebbar;Benrahou, Kouider Halim;Tounsi, Abdelouahed;Al-Zahrani, Mesfer Mohammad
    • Steel and Composite Structures
    • /
    • v.39 no.5
    • /
    • pp.631-643
    • /
    • 2021
  • The aim of this work is to study the hygro-thermo-mechanical bending responses of simply supported FG plate resting on a Winkler-Pasternak elastic foundation. The effect transverse shear strains is taken into account in which the zero transverse shear stress condition on the top and bottom surfaces of the plate is ensured without using any shear correction factors. The developed model contains only four unknowns variable which is reduced compared to other HSDTs models. The material properties of FG-plate are supposed to vary across the thickness of the plate according to power-law mixture. The differential governing equations are derived based on the virtual working principle. Numerical outcomes of bending analysis of FG plates under hygro-thermo-mechanical loads are performed and compared with those available in the literature. The effects of the temperature, moisture concentration, elastic foundation parameters, shear deformation, geometrical parameters, and power-law-index on the dimensionless deflections, axial and transverse shear stresses of the FG-plate are presented and discussed.

Analysis of Schizandrin Content and Biological Activities of Schisandra chinensis Extract (오미자 추출물의 Schizandrin 함량 분석 및 생리활성 평가)

  • Jeong Ho, Lee;Kyoung Ok, Jeong;So Yeon, Im;Da Mon, Jin;Se-Won, Lee;Jeong Muk, Lim
    • Korean Journal of Pharmacognosy
    • /
    • v.53 no.4
    • /
    • pp.213-225
    • /
    • 2022
  • Schisandra chinensis is widely known to regulate fatigue recovery, lowering blood pressure, and contains several bioactive compounds such as schizadran. In this study, we obtained basic data for the development of health food by measuring the schizandrin content, antioxidant activity, anti-inflammatory, antibacterial activity, and enzyme activity of the hot water extract (SCW) and 40% ethanol extract (SCE) of S. chinensis grown in Sunchang-gun, Korea. Schizandrin content was measured as 7.87 ± 0.01 mg/g for SCW and 10.38 ± 0.05 mg/g for SCE. SCE had higher DPPH and ABTS radical scavenging activity than SCW, and the total polyphenol and flavonoid contents were also higher. Both SCW and SCE (500 ㎍/mL) exhibited more than 55% protective effects against oxidative stress in HepG2 cell lines. Anti-inflammatory efficacy was assessed using RAW 264.7 and Caco-2 cells and both SCW and SCE do not have cytotoxic effects. Anti-inflammatory results showed concentration-dependent NO activity and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) inhibition. The antibacterial activity increased with increasing dose concentrations of SCW and SCE, and the MIC was 25 mg/mL for L. monocytogenes, S. typhimurium, and 75 mg/mL for H. pylori. In addition, amylase and protease enzyme activity was observed in both SCW and SCE.

Investigation of the effect of Lithospermi Radix on tight-junction related genes in HaCaT cells (자초(紫草) 열수추출물이 각질형성세포 HaCaT의 세포 연접 관련 유전자의 발현에 미치는 영향 연구)

  • Cho, Namjoon;Lee, Byeongkwon;Lee, Woonghee;Kim, Keekwang;Kim, Kyoon Eon;Han, Hyosang
    • The Korea Journal of Herbology
    • /
    • v.32 no.3
    • /
    • pp.55-61
    • /
    • 2017
  • Objectives : The aim of this research was to determine the diverse effects of Lithospermi Radix Water Extract (LR) on human keratinocyte HaCaT cells, and to examine whether those effects could be applied to the human skin. Methods : We examined effect of LR on the cell viability of using the MTS assay in human keratinocyte HaCaT cells. The antioxidation effect of LR was analyzed relative to the well-known antioxidant resveratrol, using an ABTS assay. Quantitative RT-PCR analysis revealed that, in HaCaT cells, LR influenced the mRNA expression of tight-junction genes associated with skin moisturization. Furthermore, a wound-healing assay demonstrated altered cell migration in LR-treated HaCaT cells. Result : The cytotoxicity was confirmed to be higher in LR at a concentration of $800{\mu}g/m{\ell}$ using the MTS assay in HaCaT cells. In comparison to $100{\mu}M$ resveratrol, $1,600{\mu}g/m{\ell}$ LR showed either a similar or superior antioxidation effect. LR treatment in HaCaT cells reduced the mRNA expression levels of claudin 3, claudin 4, claudin 6, claudin 8, and ZO-2 to less than 0.80-fold, whereas JAM-A and Tricellulin mRNA expression level increased more than 1.33-fold. In addition, HaCaT cells migration was decreased to 83.9% by LR treatment. Conclusions : LR of antioxidation activity will have an anti-aging effect on the skin by reducing oxidative stress. Further studies are required to address the implications for human skin, given LR's effects of altering mRNA expression of tight junction-related gene and decreasing cell migration of HaCaT cells.

Investigation of the effect of water extract from Cudrania tricuspidata fruit on tight junction in human keratinocyte (꾸지뽕 열매 추출물이 인간 유래 각질 형성 세포의 밀착연접에 미치는 영향)

  • Lee, Sang Soo;Choi, Sun Kyung;Kim, Jae Whan;Han, Hyo Sang;Kim, Kee Kwang
    • The Korea Journal of Herbology
    • /
    • v.34 no.1
    • /
    • pp.99-107
    • /
    • 2019
  • Objectives : Cudrania tricuspidata (C. tricuspidata) is well-known traditional herbal remedy and its root, leaf and fruit were used for treatment of inflammation, tumor and painkilling. However, effect of C. tricuspidata fruit on tight junction is still unknown. The aim of this research was to determine the effect of C. tricuspidata fruit extract on human keratinocyte HaCaT cells. Methods : The antioxidant effects of water extract of C. tricuspidata (WECT) and ethanol extract of C. tricuspidata (EECT) were analyzed by using an ABTS assay. To confirm the cytotoxicity of WECT and EECT, MTS assay was performed. The mRNA expression levels of tight junction related genes were analyzed using quantitative RT-PCR analysis. Furthermore, dispase assay was used to investigate the alteration of cell-cell adhesion strength of EECT treated HaCaT cells. Results : WECT and EECT showed strong antioxidant activity. No obvious cytotoxicity was observed in both WECT and EECT until $2.0mg/m{\ell}$ concentration. The mRNA expression level of Claudin 6 were significantly increased by EECT treatment, whereas the WECT did not affect the expression of Claudin 6. Furthermore, EECT treatment enhances cell-cell adhesion strength. Conclusions : In this study, we investigated the physiological activities of the extracts of Cudrania tricuspidata fruit extracts on human keratinocytes by two different extraction methods. EECT might have an anti-aging activity on the skin by reducing oxidative stress. Moreover, it may be a useful ingredient in atopic dermatitis and skin-moisturizing, given its effects of altering Claudin 6 gene expression and enhancing cell-cell adhesion strength.

Qualitative and quantitative assessment of process related impurities in Brigatinib raw material and formulations using HPLC

  • Attada Tharun;Potnuru Jagadeesh;B Srinivasa Kumar;Kota Thirumala Prasad;Venkateswara Rao Anna
    • Analytical Science and Technology
    • /
    • v.36 no.4
    • /
    • pp.180-190
    • /
    • 2023
  • The presence of process related impurities in any drug or the drug product was associated with its safety, stability and efficacy. The overall literature survey proved that there is no method published on the assessment of process related impurities in brigatinib. In this study, a simple, reliable and stable HPLC qualitative method was reported for quantification of process related impurities with easy and quick extraction procedure. The impurities along with standard brigatinib was resolved on Lichrospher® C18 (250 mm × 4.6 mm; 5 ㎛ particle size) column in room temperature using methanol, acetonitrile, pH 4.5 phosphate buffer in 55:25:20 (v/v) at 1.0 mL/min as mobile phase and UV detection at 261 nm. The method produces well resolved peaks at retention time of 4.60 min, 12.28 min, 3.37 min, 7.34 min and 8.39 min respectively for brigatinib, impurity A, B, C and D. The method produces a very sensitive detection limit of 0.0065 ㎍/mL, 0.0068 ㎍/mL, 0.0053 ㎍/mL and 0.0058 ㎍/mL for impurity A, B, C and D respectively with calibration curve linear in the concentration range of 22.5-135 ㎍/mL for brigatinib and 0.0225-0.135 ㎍/mL for impurities. The method produces all the validation parameters under the acceptable level and doesn't produces any considerable changes in peak area response while minor changes in the developed method conditions. The method can effectively resolve the unknown stress degradation products along with known impurities with less % degradation. The method can efficiently resolve and quantify the impurities in formulation and hence can suitable for the routine quality analysis of brigatinib in raw material and formulation.

Retinoic acid loaded with chitosan nanoparticles improves spermatogenesis in scrotal hyperthermia in mice

  • Fatemeh Mazini;Mohammad-Amin Abdollahifar;Hassan Niknejad;Asma Manzari-Tavakoli;Mohsen Zhaleh;Reza Asadi-Golshan;Ali Ghanbari
    • Clinical and Experimental Reproductive Medicine
    • /
    • v.50 no.4
    • /
    • pp.230-243
    • /
    • 2023
  • Objective: High temperatures can trigger cellular oxidative stress and disrupt spermatogenesis, potentially leading to male infertility. We investigated the effects of retinoic acid (RA), chitosan nanoparticles (CHNPs), and retinoic acid loaded with chitosan nanoparticles (RACHNPs) on spermatogenesis in mice induced by scrotal hyperthermia (Hyp). Methods: Thirty mice (weighing 25 to 30 g) were divided into five experimental groups of six mice each. The groups were as follows: control, Hyp induced by a water bath (43 ℃C for 30 minutes/day for 5 weeks), Hyp+RA (2 mg/kg/day), Hyp+CHNPs (2 mg/kg/72 hours), and Hyp+RACHNPs (4 mg/kg/72 hours). The mice were treated for 35 days. After the experimental treatments, the animals were euthanized. Sperm samples were collected for analysis of sperm parameters, and blood serum was isolated for testosterone measurement. Testis samples were also collected for histopathology assessment, reactive oxygen species (ROS) evaluation, and RNA extraction, which was done to compare the expression levels of the bax, bcl2, p53, Fas, and FasL genes among groups. Additionally, immunohistochemical staining was performed. Results: Treatment with RACHNPs significantly increased stereological parameters such as testicular volume, seminiferous tubule length, and testicular cell count. Additionally, it increased testosterone concentration and improved sperm parameters. We observed significant decreases in ROS production and caspase-3 immunostaining in the RACHNP group. Moreover, the expression levels of bax, p53, Fas, and FasL significantly decreased in the groups treated with RACHNPs and RA. Conclusion: RACHNPs can be considered a potent antioxidative and antiapoptotic agent for therapeutic strategies in reproductive and regenerative medicine.

Effect of Hypoxia on the Signal Transduction of Apoptosis in Osteoblasts (저산소 상태에서 조골세포 고사의 신호전달 기전)

  • Park, Young-Joo;Oh, Soh-Taek;Kang, Kyung-Hwa;Kim, Sang-Cheol
    • The korean journal of orthodontics
    • /
    • v.33 no.6 s.101
    • /
    • pp.453-463
    • /
    • 2003
  • Mammalian cell is critically dependent on a continuous supply of oxygen. Even brief periods of oxygen deprivation can result in profound cellular damage. The aim of this study was to examine the possible mechanism of apoptosis in response to hypoxia in MC3T3E1 osteoblasts. MC3T3El osteoblasts under hypoxic conditions ($2\%$ oxygen) resulted in apoptosis in a time-dependent manner, determined by DNA fragmentation assay and nuclear morphology, stained with fluorescent dye (Hoechst 33258) Pretreatment with Z-VAD-FMK, a pancaspase inhibitor, or Z-DEVD-CHO, a specific caspase-3 inhibitor, suppressed the DNA ladder in response to hypoxia in a concentration dependent manner. An increase in caspase-3-like protease (DEVDase) activity was observed during apoptosis, but no caspase-l activity (YVADase) was detected. To confirm what caspases were involved in apoptosis, western blot analysis was performed using an anticaspase-3 or 6 antibody. The 17-kDa protein, that corresponds to the active products of caspase-3 and the 20-kDa protein of the active protein of caspase-6 were generated in hypoxia-challenged lysates, in which the full length forms of caspase-3 and 6 were evident. With a time course similar to caspase-3 and 6 activation, hypoxic stress also caused the cleavage of Lamin A, typical of caspase-6 activity. In addition, the hypoxic stress elicited the release of cytochrome c into the cytosol during apoptosis. These findings suggested that the activation of caspases accompanied by a cytochrome c release in response to hypoxia was involved in apoptotic cell death in MC3T3E1 osteoblasts.

Design on the large section of station tunnel under shallow overburden (저토피고 대단면 정거장터널의 설계)

  • Jeong, Yun-Young;Choi, Hae-Joon;Kim, Byung-Ju;Yu, Bong-Won;Kim, Yong-Il;Oh, Sung-Jin
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.9 no.2
    • /
    • pp.171-182
    • /
    • 2007
  • For minimizing the effect on the focus of civil traffic and environment conditions related to the excavation at the traffic jamming points, an underground station tunnel was planned with 35.5 m in length and bigger area than $200\;m^2$ in sedimentary rock mass. It faced the case that the overburden was just under 13 m. Not based on a pattern design but on the case histories of similar projects and arching effect, the design of large section tunnel under shallow overburden was investigated on three design subjects which are shape effect on the section area, application method of support pressure, and supporting and tunnel safety. According to the mechanical effect from section shape, a basic design and a preliminary design was obtained, and then supporting method of large section was planned by the supporting of NATM and a pipe roof method for subsidence prevention and mechanical stability. From the comparative study between both designs, it was found that the basic design was suitable and acceptable for the steel alignment of tunnel lining, safety and the design parameter restricted by the limit considered as partition of the excavation facilities. Through the analysis result of preliminary design showing the mechanical stability without stress concentration in tunnel arch level, it also was induced that shape effect of the large section area and yielding load obtained from deformation zone in the surrounding rock mass of tunnel have to be considered as major topics for the further development of design technique on the large section tunnel.

  • PDF

Improvement of Milk Fatty Acid Composition for Production of Functional Milk by Dietary Phytoncide Oil Extracted from Discarded Pine Nut Cones (Pinus koraiensis) in Holstein Dairy Cows

  • Kim, Min Jeong;Jung, U Suk;Jeon, Seung Woo;Lee, Jae Sung;Kim, Won Seob;Lee, Sang Bum;Kim, Youn Chil;Kim, Bae Young;Wang, Tao;Lee, Hong Gu
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.29 no.12
    • /
    • pp.1734-1741
    • /
    • 2016
  • This study was conducted to examine the effects of adding phytoncide oil extracted from Korean pine nut cone by-product to the diet of dairy cows on milk yield and compositions, fatty acid characteristics, complete blood count and stress response. A total of 74 Holstein cows were used for 30 days and divided into two groups. Each group was given a basal diet (C) or an experimental diet containing phytoncide additives at 0.016% (T) in feed. The results showed that phytoncide feeding had no effect on milk yield. In addition, there were no observed effects on milk composition, but the ratio of fatty acid in milk was significantly affected by the phytoncide diet, and it showed a positive effect. Not only were the major functional fatty acids, conjugated linoleic acid and eicosapentaenoic acid increased, but also ${\omega}6:{\omega}3$ fatty acid ratio was reduced in milk of T group (p<0.05). In blood analysis, the complete blood count showed no significant difference between C and T group on all parameters. However, the cortisol concentration was significantly decreased in T group compared to control (p<0.05). Taken together, we suggest that phytoncide oil does not have a great influence on the physiological changes, but can be a potential feed additive that improves the milk fatty acid and stress resilience in dairy cows. In addition, it will contribute to the development of feed resource, a reduction in feed cost and a lessening of environmental pollution.