• Title/Summary/Keyword: 과학실험

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Characterization of a cDNA Encoding Transmembrane Protein 258 from a Two-spotted Cricket Gryllus bimaculatus (쌍별귀뚜라미(Gryllus bimaculatus)의 GbTmem258 cDNA 클로닝과 발현분석)

  • Kisang Kwon;Honggeun Kim;Hyewon Park;O-Yu Kwon
    • Journal of Life Science
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    • v.33 no.10
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    • pp.828-834
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    • 2023
  • The cDNA that encodes transmembrane protein 258 (Tmem258) was cloned from Gryllus bimaculatus and named GbTmem258. This protein comprises 80 amino acids, has no N-glycosylation site, and contains five potential phosphorylation sites at two serines, two threonines, and one tyrosine. The predicted molecular mass of GbTmem258 is 9.06 kDa, and its theoretical isoelectric point is 5.5. The tertiary structure of GbTmem258 was predicted using the available secondary structure information, which suggests the presence of alpha helices (52.5%), random coils (22.5%), extended strands (16.25%), and beta turns (8.75%). Homology analysis revealed that GbTmem258 exhibits high similarity at the amino-acid level to Tmem258 found in other species. The effect of starvation and refeeding on GbTmem258 mRNA expression was also examined in this study. It was found that GbTmem258 mRNA expression in the hindgut progressively increased throughout the starvation period, peaking at almost 1.5 times the control level after six days of starvation. However, refeeding for one to two days after the six-day starvation period restored GbTmem258 mRNA expression to the control level. In fat body, GbTmem258 mRNA expression was almost 3-fold higher during starvation compared to the control level. Refeeding for one to two days after the six-day fast resulted in a decline in the expression to about a 2.5-fold increase over the control level. Throughout the starving and refeeding periods, no other tissues showed any discernible alterations in GbTmem258 mRNA expression.

Ameliorative Effects of Soybean Leaf Extract on Dexamethasone-Induced Muscle Atrophy in C2C12 Myotubes and a C57BL/6 Mouse Model (콩잎 추출물의 근위축 개선 효과)

  • Hye Young Choi;Young-Sool Hah;Yeong Ho Ji;Jun Young Ha;Hwan Hee Bae;Dong Yeol Lee;Won Min Jeong;Dong Kyu Jeong;Jun-Il Yoo;Sang Gon Kim
    • Journal of Life Science
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    • v.33 no.12
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    • pp.1036-1045
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    • 2023
  • Sarcopenia, a condition characterized by the insidious loss of skeletal muscle mass and strength, represents a significant and growing healthcare challenge, impacting the mobility and quality of life of aging populations worldwide. This study investigated the therapeutic potential of soybean leaf extract (SL) for dexamethasone (Dexa)-induced muscle atrophy in vitro and in an in vivo model. In vitro experiments showed that SL significantly alleviated Dexa-induced atrophy in C2C12 myotube cells, as evidenced by preserved myotube morphology, density, and size. Moreover, SL treatment significantly reduced the mRNA and protein levels of muscle RING-finger protein-1 (MuRF1) and muscle atrophy F-box (MAFbx), key factors regulating muscle atrophy. In a Dexa-induced atrophy mouse model, SL administration significantly inhibited Dexa-induced weight loss and muscle wasting, preserving the mass of the gastrocnemius and tibialis anterior muscles. Furthermore, mice treated with SL exhibited significant improvements in muscle function compared to their counterparts suffering from Dexa-induced muscle atrophy, as evidenced by a notable increase in grip strength and extended endurance on treadmill tests. Moreover, SL suppressed the expression of muscle atrophy-related proteins in skeletal muscle, highlighting its protective role against Dexa-induced muscle atrophy. These results suggest that SL has potential as a natural treatment for muscle-wasting conditions, such as sarcopenia.

The influence of fitness and type of luting agents on bonding strength of fiber-reinforced composite resin posts (섬유강화 복합레진 포스트의 결합강도에 대한 포스트 공간 적합도 및 접착 시멘트의 영향)

  • Kkot-Byeol Bae;Hye-Yoon Jung;Yun-Chan Hwang;Won-Mann Oh;In-Nam Hwang
    • Journal of Dental Rehabilitation and Applied Science
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    • v.39 no.4
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    • pp.187-194
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    • 2023
  • Purpose: A mismatched size in the post and post space is a common problem during post-fixation. Since this discordance affects the bonding strength of the fiber-reinforced composite resin post (FRC Post), a corresponding luting agent is required. The aim of this study was to evaluate the bonding strength of the FRC post according to the fitness of the fiber post and the type of luting agent. Materials and Methods: Thirty mandibular premolar were endodontic-treated and assigned to two groups according to their prepared post space: Fitting (F) and Mismatching (M). These groups were further classified into three subgroups according to their luting agent: RelyX Unicem (ReX), Luxacore dual (Lux), and Duolink (Duo). A push-out test was performed to measure the push-out bond strengths. The fractured surfaces of each cross-section were then examined, and the fracture modes were classified. Results: In the ReX and Duo subgroups, the F group had a higher mean bond strength; however, the Lux subgroup had no significant difference between the F and M groups. In the analysis of the failure modes, the ReX subgroup had only adhesive failures between the cement and dentin. Conclusion: The result of this study showed that the bond strength of an FRC post was influenced by the type of luting agent and the mismatch between the diameter of the prepared post space and that of the post.

8년여의 세월호 사고원인 규명활동 결과의 정리와 분석 (1/2)

  • 조상래
    • Bulletin of the Society of Naval Architects of Korea
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    • v.61 no.1
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    • pp.16-29
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    • 2024
  • 2014년 4월 18일 오전 8시 48분경 전라남도 병풍도 인근 해역에서 세월호는 전복된 후 침몰하였다. 사고 당시 이 배에는 승객 443명과 선원 및 승무원 33명 모두 476명이 타고 있었고, 이 중 미수습자 5명을 포함하여304명이 생명을 잃었다. 그 동안 공식적인 사고원인 규명활동이 꾸준히 진행되어 이 사고의 원인을 규명하기 위한 조사가 네 차례 있었다. 하지만 아직까지 사고 원인이 무엇인지 명쾌하게 밝혀지지 않고 있다. 이 글에서는 먼저 그동안 있었던 네 차례의 공식적인 세월호 사고원인 규명활동을 정리하였다. 가장 먼저 사고원인 규명활동을 전개한 해양안전심판원 특별조사부는 2014년 사고 직후부터 그해 12월까지 활동하였다. 특별조사부 최종보고서에는 화물의 과적과 평형수 적재 부족으로 인한 선박복원성 기준 미달, 타각의 대각도 조타와 장시간 유지로 인한 부적절한 조타, 화물의 부실한 고박으로 인한 화물의 이동, 수밀문의 관리 부실로 인한 조기 침수와 비상대피장소(muster station)로의 승객대피 조치 미이행을 사고의 원인으로 들고 있다. 2015년 3월부터 2016년 6월까지 활동한 4·16세월호참사 특별조사위원회(특조위)는 '4·16 세월호 참사 특별 조사위원회 청산 백서'만을 간행하고 최종보고서를 제출하지 못한 채 활동을 종료하였다. 세월호 선체조사위원회(선조위)는 2017년 4월부터 2018년 8월까지 활동하였다. 선조위는 세월호 사고원인 규명을 위한 다른 기구에 비해 위원의 구성도 균형이 있었고, 직권사건 위주의 조사방법도 적절하였다. 또한 조타기와 조타 과실 여부, 급선회 항적 및 횡경사와 핀안정기의 물리적 손상에 관한 용역을 국내 여러 기관에 발주하였다. 뿐만 아니라 다양한 해양사고 원인규명 용역에 참여한 실적이 있는 영국의 기술용역회사인 Brookes Bell에 급선회와 빠른 침몰의 원인 조사를 요청하였다. 아울러 세계에서 가장 활발히 수조실험을 수행하고 있는 상업 연구소인 네덜란드의 MARIN에 수조시험과 시뮬레이션도 의뢰하였다. 하지만 아쉽게도 선조위는 서로 다른 사고 원인을 주장하는 두 권의 종합보고서를 간행하였다. 종합보고서로 '내인설' 종합보고서[6]는 타기 솔레노이드 밸브의 고착으로 시작된 급선회를 사고의 직접 원인으로 지목하고 있다. 하지만 '열린안' 종합보고서[7]에서는 수중체와의 충돌을 직접적인 사고 원인으로 밝히고 있다. 마지막으로 가습기살균제 사건과 4·16세월호 참사 특별조사위원회(사참위)가 2019년 3월부터 2022년 9월까지 활동하였다. 사참위는 위원으로 조선해양공학과 항해학 전문가가 포함되어 있지 않아 세월호의 사고원인 규명활동을 효과적으로 수행하기에는 적절하지 못하였다. 사참위는 주로 조타장치 고장에 따른 세월호 전타 선회현상 검증, 세월호 변형 손상부의 확인 및 원인 조사와 세월호 횡경사 원인과 침수과정 분석을 직권 과제로 추진하였다. 또한 네덜란드 MARIN에 자유항주시험을 추가로 의뢰하였으며, 핀란드의 NAPA group에도 복원성 계산과 침수해석을 의뢰하였다. 사참위는 선조위의 두 가지 사고원인에 대해 '내인설'의 솔레노이드 밸브 고착은 사고원인일 가능성이 매우 낮고, '열린안'의 수중체와의 충돌 시나리오는 근거가 부족함을 확인하였다. 이상에서 정리한 바와 같이 규명활동이 진행됨에 따라 사고원인이 수렴되어야 함에도 불구하고 아직까지 원인을 시원하게 밝히지 못하고 있다. 이 글에서는 사고원인 규명활동을 수행한 네 개 기구의 구성과 활동 내용을 비교하고, 사고조사 위원회의 바람직한 구성과 위원회의 운영 방법을 제시하고 있다. 또한 Brookes Bell 보고서에 수록된 출항 당시의 흘수에 근거한 배수량과 선미 램프의 폐쇄 전후의 횡경사각으로부터 도출한 GoM도 소개하고 있다. 아울러 출항 당시의 GoM값으로 추정한 사고 당시의 GoM값도 소개하고 있고, 수중체와의 충돌 시나리오를 후보 사고 시나리오에서 제외시켜야 할 이유도 열거하고 있다. 끝으로 해양사고 원인규명 활동이 보다 과학적으로 그리고 보다 합리적으로 이루어질 수 있기 위해 그리고 우리 사회의 안전문화 제고를 위한 몇 가지의 방안을 제시하고 있다. 또한 세월호 사고로 치른, 아직도 치르고 있는 희생을 딛고 해양안전문화가 한 걸음 더 나아가기 위해서는 세월호 사고의 원인을 반드시 규명해야 한다는 말씀으로 글을 마무리하고 있다.

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Research on Immune Responses Induced by Salmonella Typhimurium Infectionin CRIP1-Deficient Condition (CRIP1결손조건 하에서 Salmonella Typhimurium 감염에 의해 유도되는 면역반응에 관한 연구)

  • Dongju Seo;Se-Hui Lee;Sun Park;Hyeyun Kim;Jin-Young Yang
    • Journal of Life Science
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    • v.34 no.1
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    • pp.48-58
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    • 2024
  • Salmonella is a common food-borne intracellular bacterial pathogen that has triggered significant public health concerns. Salmonella hosts' genetic factors play a pivotal role in determining their susceptibility to the pathogen. Cysteine-rich intestinal protein 1 (CRIP1), a member of LIM/double zinc finger protein family, is widely expressed in humans, such as in the lungs, spleen, and especially the gut. Recently, CRIP1 has been reported as a key marker of several immune disorders; however, the effect of CRIP1 on bacterial infection remains unknown. We aimed to elucidate the relationship between Salmonella infection and CRIP1 gene deficiency, as Salmonella spp. is known to invade the Peyer's patches of the small intestine, where CRIP1 is highly expressed. We found that CRIP1-deficient conditions could not alter the characteristics of bone marrow-derived myeloid cells in terms of phagocytosis on macrophages and the activation of costimulatory molecules on dendritic cells using ex vivo differentiation. Moreover, flow cytometry data showed comparable levels of MHCII+CD11b+CD11c+ dendritic cells and MHCII+F4/80+CD11b+ macrophages between WT and CRIP1 knockout (KO) mice. Interestingly, the basal population of monocytes in the spleen and neutrophils in MLNs is more abundant in a steady state of CRIP1 KO mice than WT mice. Here, we demonstrated that the CRIP1 genetic factor plays dispensable roles in host susceptibility to Salmonella Typhimurium infections and the activation of myeloid cells. In addition, differential immune cell populations without antigen exposure in CRIP1 KO mice suggest that the regulation of CRIP1 expression may be a novel immunotherapeutic approach to various infectious diseases.

A Study of the Anti-inflammatory Effects of Abies nephrolepis MAX. Extract in RAW 264.7 Cells (RAW 264.7 세포에서 분비나무(Abies nephrolepis MAX.) 추출물의 항염 효과에 대한 연구)

  • Min-Jeong Oh;Hyeon-Ji Yeom;Jin-Young Lee
    • Journal of Life Science
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    • v.34 no.3
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    • pp.160-169
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    • 2024
  • In this study, Abies nephrolepis MAX. was divided into A. nephrolepis MAX. stem (AS) extract and A. nephrolepis MAX. leaf (AL) extract. Their anti-inflammatory abilities and applicability as cosmetic materials were determined. Tests of the cell survival rate measured using RAW 264.7 cells and extracts of AS and AL showed 97.8% and 95.6% cell viability at a 500 ㎍/ml concentration. To determine anti-inflammatory activity, we examined the inhibitory effects on the production of LPS-induced NO in RAW 264.7 cells by Griess assay. The results showed that the AS and AL extracts presented a concentration-dependent inhibition of NO production. The protein expression inhibitory effects of AS and AL extracts were measured by western blot at 25, 50, and 100 ㎍/ml concentrations. β-actin was used as a positive control. The results of western blot of extracts from AS showed that the expression inhibition rate of the iNOS protein was decreased by 50.1% at the 100 ㎍/ml concentration. Additionally, the results of western blot of AL extracts showed that the expression inhibition rate of COX-2 and iNOS protein was decreased by 66% and 8.2% at the 100 ㎍/ml concentration. The mRNA inhibitory effect was measured by RT-PCR at 25, 50, and 100 ㎍/ml concentrations. GAPDH was used as a positive control. Consequently, the iNOS mRNA expression effect by RT-PCR of AS extract demonstrated by RT-PCR decreased by 27.9% at the 100 ㎍/ml concentration, and the iNOS and IL-6 mRNA expression effect of AL extract measured by RT-PCR decreased by 48.6% and 48.7% at the 100 ㎍/ml concentration.

Studies on the Antibiotic Residues in Milk of Cows, Goats and Dogs (유우(乳牛), 산양(山羊) 및 견(犬)의 유즙내(乳汁內) 잔류항생물질(殘留抗生物質)에 관한 연구(硏究))

  • Kim, Kyo Jun
    • Korean Journal of Agricultural Science
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    • v.2 no.1
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    • pp.199-231
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    • 1975
  • It is well known fact that antibiotic residues in milk of cows create significant problem for the fermented dairy industry and public health because of inhibition of starter activity and of creation of allergic disease. It can be assumed that antibiotic residues in milk of other aniimals also can create some problems for their infants as in the case of humen. For the above mentioned reasons, present studies were undertaken to determine concentration and duration of antibiotic residues in milk of cows, goats and dogs following intramuscular or intravenous injection and intramammary infusion of penicillin, streptomycin and oxytetracycline at usual dosage. The cylinder-plate method was used for their assay. The results obtained were summerized as follows: 1) Following the intramuscular injection of penicillin, the antibiotic was detected in milk of cows up to 72 hours, in milk of goats 48 hours and in milk of dogs 60 hours of postinjection. The mean peak concentrations were recorded at 12 hours as 0.136 I.U./ml in cows. 6 hours as 0.773 I.U./ml in goats and 3 hours as 1.192 I.U./ml in dogs. 2) Following the intramuscular injection of streptomycin, the antibiotic was detected in milk of cows and goats up to 36 hours and in milk of dogs 24 hours of post-injection. The mean peak concentration were recorded at 6 hours as $0.26{\mu}g/ml$ in cows and at 3 hours in goats and dogs $0.45{\mu}g/ml$ and $0.36{\mu}g/ml$ respectively. 3) Following the intra venous injection of oxytetracycline, the antibiotic was detectable in milk of all the test animals up to 48 hours of postinjection. The mean peak concentrations were recorded at 6 hours as $3.5{\mu}g/ml$ in cows $2.4{\mu}g/ml$ in goats and $2.0{\mu}g/ml$ in dogs respectively. 4) Following intrarnammary infusion of penicillin in amounts of 100,000 I.U. for cows, 20.000 I.U. for goats and 10,000 I.U. for dogs, the penicillin residues in milk of the infused quarter perssisted to 72 hours in cows and 84 hours in goats and dogs. 5) Following intramammary infusion of streptomycin in amount of 500mg for cows, 100mg for goats and 25mg for dogs, the streptomycin residues in milk of the infused quarter persisted to 72 hours in cows and goats and 60 hours in dogs. 6) Following intramammary infusion of oxytetracycline in amount of 500mg for cows, 100mg for goats and 25mg for dogs, the oxytetracycline residues in milk of the infused quarter persisted to 72 hours in cows and 60 hours in goats and dogs. 7) A corelation between the residual antibiotic concentration and milk yield in cows and goats was observed; That is, the lower in the milk production showed a higher the concentration of an antibiotic residues and a longer the time in persistance. 8) Intramammary transfer of the antibiotic from an infused to non infused quarters, in dogs, was observed following the intramammary infusion of penicillin. streptomycin and oxytetracyclne in amounts of 10.000 I.U. 25mg and 25mg respectively. However, no transfer by 100.000 I.U. or 20.000 I.U. of penicillin. 500mg of streptomycin and 100mg of oxytetracyline was observed in cows and goats. 9) In dogs, minimum dosage of antibiotics for transfer fro in treated to untreated quarters following intramammary infusion were 2,500 I.U. of penicillin and 5mg each of streptomycin and oxytetracycline.

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Effect of Cooling Timing in the Root Zone on Substrate Temperature and Physiological Response of Sweet Pepper in Summer Cultivation (여름 파프리카 수경재배에서 근권 냉방 시간이 근권 온도와 생리적 반응에 미치는 영향)

  • Choi, Ki Young;Ko, Ji Yeon;Yoo, Hyung Joo;Choi, Eun Young;Rhee, Han Cheol;Lee, Yong-Beom
    • Horticultural Science & Technology
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    • v.32 no.1
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    • pp.53-59
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    • 2014
  • This study aimed to determine an appropriate cooling timing in the root zone for lowering substrate temperature and its effect on physiological response of sweet pepper (Capsicum annum L. 'Orange glory') grown on coir substrate in summer, from the July 16 to October 15, 2012. Daily temperature of substrate, root activity, leaf water potential, first flowering date, and the number of fruits were measured by circulating cool water through a XL pipe in the root zone during either all day (all-day) or only night time (5 p.m. to 3 a.m.; night) from the July 23 to September 23, 2012. For comparison, no cooling (control) was also applied. Between the $23^{rd}$ of July and $31^{st}$ of August (hot temperature period), daily average temperatures in substrates were $25.6^{\circ}C$, $26.1^{\circ}C$, and $29.1^{\circ}C$ for the all-day and night treatment, and control respectively. About 1.8 to $5^{\circ}C$ lower substrate temperature was observed in both treatments compared to that of control. In sunny day ($600-700 W{\cdot}m^{-2}{\cdot}s^{-1}$), the highest temperature of substrate was measured between 4 p.m. and 5 p.m. under both the all-day and night treatments, whereas it was measured between 7 p.m. and 8 p.m. under the control. Substrate temperatures during the day (6 a.m. to 8 p.m.) and night (8 p.m. to 6 a.m.) differed depending on the treatments. During the day and night, averaged substrate temperature was lower about $3.3^{\circ}C$ and $4.0^{\circ}C$ for the all-day, and $2.1^{\circ}C$ and $3.4^{\circ}C$ for the night treatment, compared to that of control. In the all-day and night treatment, the TD [TD = temperature of (control)] was greater in bottom than that of other regions of the substrate. Between the day and night, no different TD values were observed under the all-day treatment, whereas under the night treatment there was difference with the greatest degree in the bottom of the substrate. During the hot temperature period, total numbers of days when substrate temperature was over $25^{\circ}C$ were 40, 23 and 27 days for the control, all-day, and night treatment, respectively, and the effect of lowering substrate temperature was therefore 42.5% and 32.5% for the all-day and night treatment, respectively, compared to that for the control. Root activity and leaf water potential of plants grown under the all-day treatment were significantly higher than those under the night treatment. The first flowering date in the all-day treatment was similar to that in the night treatment, but 4-5 day faster than in the control. Also, the number of fruits in both treatments was significantly higher than that in the control. However, there was no effect of root zone cooling on eliminating delay in fruiting caused by excessively higher air temperature (> $30^{\circ}C$), although the substrate temperature was reduced $18^{\circ}C$ to $5^{\circ}C$. These results suggest that the method of cooling root zone temperature need to be incorporated into the lowering growing temperature for growth and fruit set of health paprika.

Studies on the Shade Tolerance, Light Requirement, and Water Relations of Economic Tree Species(III) - Analysis of Pressure-Volume Curves on the Changes of Tissue Water Relations of Five Deciduous Hardwood Species Subjected to Artificial Shading Treatments - (주요경제수종(主要經濟樹種)의 내음성(耐陰性) 및 광선요구도(光線要求度)와 수분특성(水分特性)에 관한 연구(III) - 인공피음처리하(人工被陰處理下)에서 자라는 활엽수(闊葉樹) 5수종(樹種)의 수분특성(水分特性) 변화(變化)에 대한 P-V곡선(曲線) 분석(分析) -)

  • Choi, Jeong Ho;Kwon, Ki Won
    • Journal of Korean Society of Forest Science
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    • v.90 no.4
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    • pp.524-534
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    • 2001
  • The pressure-volume curve parameters were investigated to elucidate the effects of shading treatment on the water relations of the one year old seedlings of Betula platyphylla var. japonica, Betula schmidtii, Zelkova serrata, Acer mono and Prunes sargentii subjected to five levels of artificial shading treatments. The osmotic potentials at full turgor(${\phi}_{{\pi}o}$) measured under full sunlight changed with species and growing season in the ranges of -1.04~-1.27MPa, -1.03~-1.48MPa, -0.94~-1.44MPa in first year treatment, and -0.90~-1.37MPa, -1.05~-1.79MPa, -0.99~-1.30MPa in second year treatment in June, July, and September, respectively. The osmotic potentials at full turgor increased with increment of shading level in the ranges of -0.90~-1.79MPa in full sunlight and -0.58~-1.23MPa in nearly full shading level(E) through the growing seasons in all the species studied. The osmotic potentials at turgor loss point(${\phi}_{{\pi}p}$) measured in full sunlight changed in the ranges of -1.64~-2.11MPa, -1.67~-2.15MPa, -1.47~-2.11MPa, and -1.45~-2.04MPa, -1.30~-2.00MPa, -1.28~-2.33MPa in June, July, and September of first and second years, respectively. Most of ${\phi}_{{\pi}p}$ measurements were lower within about 0.5MPa in comparison with those of ${\phi}_{{\pi}o}$. The measurements of ${\phi}_{{\pi}p}$ also increased with increment of shading level, and the differences in ${\phi}_{{\pi}p}$ among shading levels were generally greater than those in ${\phi}_{{\pi}o}$ by species and by growing season. Most of the osmotic potentials at turgor loss point as like as at full turgor were lowered in July than in June and September. The measurements of relative water content at turgor lass point(RWCp) in full sunlight were in the similar ranges of 81~88%, 71~86%, 75~84%, and 82~87, 72~84%, 76~86% in June, July, and September of first and second years, respectively. The RWCp were a little higher in A. mono and P. sargentii than in B. platyphylla var. japonica, B. schmidtii, and Z. serrata. The RWCp also decreased from 71~88% in full sunlight to 48~77% in nearly full shading treatment with increment of shading level. Even if there were some exceptions by species or by growing season, the shading effects on the changes in some P-V parameters were distinctly observed in the present study. The change in P-V parameters following shading treatment may be presumably inferred on the changes in solute accumulation, membrane elasticity, symplasmic water volume, and so on. But much more experiments should be necessarily continued for getting detailed informations on the physiological mechanism of shading effects relating to the changes in P-V parameters.

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In vitro Antioxidant, Anti-allergic and Anti-inflammatory Effects of Ethanol Extracts from Korean Sweet Potato Leaves and Stalks (한국산 고구마잎과 고구마줄기 에탄올 추출물의 in vitro 항산화, 항알레르기 및 항염증효과)

  • Kwak, Chung Shil;Lee, Kun Jong;Chang, Jin Hee;Park, June Hee;Cho, Ji Hyun;Park, Ji Ho;Kim, Kyung Me;Lee, Mee Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.3
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    • pp.369-377
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    • 2013
  • In order to increase the utilization of sweet potato leaves and stalks as much as roots, it is necessary to study their beneficial potential. In this study, the antioxidant, antiallergic and anti-inflammatory effects of sweet potato leaves and stalks were evaluated by measuring total polyphenol and flavonoid contents, DPPH radical scavenging effects, the reducing power and inhibition effects on xanthine oxidase (XO), 5-lipoxygenase (LOX), and cyclo-oxygenase (COX)-2 activities. Blanched sweet potato leaves (SL), raw whole purple stalks (ST) and peeled stalks (PST) were freeze-dried and extracted with 95% ethanol. Total polyphenol content was highest in SL (11.03 mg/g), followed by ST (0.87 mg/g), and PST (0.37 mg/g). Total flavonoid content was highest for SL (9.01 mg/g), followed by ST (0.50 mg/g) and PST (0.25 mg/g). The $IC_{50}$ for DPPH radical scavenging effects was highest for SL ($43.6{\mu}g/mL$), followed by ST ($308.4{\mu}g/mL$) and PST ($1,631.3{\mu}g/mL$). The reducing power was highest for SL ($59.72{\mu}g$ ascorbic acid eq./mL), followed by ST ($12.56{\mu}g$ ascorbic acid eq./mL) and PST ($2.18{\mu}g$ ascorbic acid eq./mL) with $1,000{\mu}g/mL$ of ethanol extract. The inhibition rate on XO activity was highest for SL (13.06%), followed by ST (5.05%) and PST (0.0%) at $250{\mu}g/mL$ extract treatment. The inhibition rate on COX-2 activity was highest for SL (55.34%), followed by ST (2.18%) and PST (0.0%) at $250{\mu}g/mL$ extract treatment. The inhibition rate on 5-LOX activity was highest for SL (91.16%), followed by ST (33.38%) and PST (14.93%) at $50{\mu}g/mL$ treatment. Taken together, sweet potato leaves showed high antioxidative, anti-allergic and anti-inflammatory activities, especially with very strong inhibition effects on 5-LOX activity. These beneficial effects of sweet potato leaves might be mainly caused by the high content of polyphenols and flavonoids.