• 제목/요약/키워드: damage localization

검색결과 171건 처리시간 0.031초

Reconstruction of a long defect of the median nerve with a free nerve conduit flap

  • Campodonico, Andrea;Pangrazi, Pier Paolo;De Francesco, Francesco;Riccio, Michele
    • Archives of Plastic Surgery
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    • 제47권2호
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    • pp.187-193
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    • 2020
  • Upper limb nerve damage is a common condition, and evidence suggests that functional recovery may be limited following peripheral nerve repair in cases of delayed reconstruction or reconstruction of long nerve defects. A 26-year-old man presented with traumatic injury from a wide, blunt wound of the right forearm caused by broken glass, with soft tissue loss, complete transection of the radial and ulnar arteries, and a large median nerve gap. The patient underwent debridement and subsequent surgery with a microsurgical free radial fasciocutaneous flap to provide a direct blood supply to the hand; the cephalic vein within the flap was employed as a venous vascularized chamber to wrap the sural nerve graft and to repair the wide gap (14 cm) in the median nerve. During the postoperative period, the patient followed an intensive rehabilitation program and was monitored for functional performance over 5 years of follow-up. Our assessment demonstrated skin tropism and sufficient muscle power to act against strong resistance (M5) in the muscles previously affected by paralysis, as well as a good localization of stimuli in the median nerve region and an imperfect recovery of two-point discrimination (S3+). We propose a novel and efficient procedure to repair >10-cm peripheral nerve gap injuries related to upper limb trauma.

Annexin A2 gene interacting with viral matrix protein to promote bovine ephemeral fever virus release

  • Chen, Lihui;Li, Xingyu;Wang, Hongmei;Hou, Peili;He, Hongbin
    • Journal of Veterinary Science
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    • 제21권2호
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    • pp.33.1-33.15
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    • 2020
  • Bovine ephemeral fever virus (BEFV) causes bovine ephemeral fever, which can produce considerable economic damage to the cattle industry. However, there is limited experimental evidence regarding the underlying mechanisms of BEFV. Annexin A2 (AnxA2) is a calcium and lipid-conjugated protein that binds phospholipids and the cytoskeleton in a Ca2+-dependent manner, and it participates in various cellular functions, including vesicular trafficking, organization of membrane domains, and virus proliferation. The role of the AnxA2 gene during virus infection has not yet been reported. In this study, we observed that AnxA2 gene expression was up-regulated in BHK-21 cells infected with the virus. Additionally, overexpression of the AnxA2 gene promoted the release of mature virus particles, whereas BEFV replication was remarkably inhibited after reducing AnxA2 gene expression by using the small interfering RNA (siRNA). For viral proteins, overexpression of the Matrix (M) gene promotes the release of mature virus particles. Moreover, the AnxA2 protein interaction with the M protein of BEFV was confirmed by GST pull-down and co-immunoprecipitation assays. Experimental results indicate that the C-terminal domain (268-334 aa) of AxnA2 contributes to this interaction. An additional mechanistic study showed that AnxA2 protein interacts with M protein and mediates the localization of the M protein at the plasma membrane. Furthermore, the absence of the AnxA2-V domain could attenuate the effect of AnxA2 on BEFV replication. These findings can contribute to elucidating the regulation of BEFV replication and may have implications for antiviral strategy development.

Fine Mapping of Zenith Derived Rice Stripe Virus Resistance Gene, Stv-b

  • Sais-Beul Lee;Jun-Hyun Cho;Nkulu Rolly Kabange;Sumin Jo;Ji-Yoon Lee;Yeongho Kwon;Ju-Won Kang;Dongjin Shin;Jong-Hee Lee;You-Cheon Song;Jong-Min Ko;Dong-Soo Park
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2020년도 추계국제학술대회
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    • pp.63-63
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    • 2020
  • Rice stripe virus (RSV) disease is one of the major constraints in rice production, transmitted by the small brown planthopper (SBPH; Laodelphax striatellus). Upon RSV infection, plants develop typical symptoms, which include chlorosis and weakness of newly emerged leaves, white and yellow spots, stripe on leaves, and necrotic and wilting leaves, resulting in plant growth inhibition, oxidative damage that may culminate in programmed cell death (PCD) and plant death in severe epidemics. Although RSV-resistant quantitative trait loci (QTLs), Stv-a, Stv-b, and Stv-bi, were mapped using various resistant varieties, one RSV-resistant gene, OsSOT1, has been identified so far. In this study, we used the rice cultivar Zenith, known to carry Stv-b, to investigate novel RSV-genes through fine mapping. Therefore, we crossed Zenith (Donor parent, RSV resistant) with Ilpum (Recurrent parent, RSV susceptible) to fine-map using a BC2F2 population of 2100 plants. Chromosome segment introgression lines that were heterozygous at a different region were selected, two types of heterozygous lines showed an heterozygous genotype between Sid2 and Sid75 to Indel9 and RM6680. Interestingly, we identified qSTV11Z region harboring Stv-b, covering about 171-kb region between the InDel markers Sid75 and Indel8. The localization of qSTV11Z provides useful information that could be used for marker-assisted selection and determination of genetic resources in rice breeding.

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Sodium Hydrosulfide Enhances Drought Tolerance by Alleviating Oxidative Stress and Promoting Proline Accumulation in Brassica napus L.

  • Septi Anita Sari;Muchamad Muchlas;Bok-Rye Lee;Md Al Mamun;Tae-Hwan Kim
    • 한국초지조사료학회지
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    • 제44권3호
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    • pp.204-209
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    • 2024
  • Drought is one of the environmental factors inhibiting plant productivity and growth, leading to oxidative damage. This study aims to identify the role of sodium hydrosulfide (NaHS) as a hydrogen sulfide (H2S) donor in drought stress tolerance in Brassica napus. Drought-induced stress symptoms appeared eight days after treatment, showing wilted leaves and a significant reduction of leaf water potential. Drought-induced increase of lipid peroxidation was significantly reduced by NaHS application. NaHS-treated plants mitigated stress symptoms under drought conditions by reducing hydrogen peroxide (H2O2) content, confirmed with H2O2 localization in situ. Furthermore, NaHS promotes photosynthetic activity by maintaining chlorophyll and carotenoid content, thereby supporting plant growth under drought conditions. Pyrroline-5-carboxylate and proline contents were significantly increased by drought but further enhanced by NaHS treatment, indicating the important roles of proline accumulation in drought stress tolerance. In conclusion, this study provides valuable insight into the roles of NaHS in alleviating drought stress by reducing oxidative stress and promoting proline accumulation. Therefore, NaHS may serve as an effective strategy to enhance crop production under drought-stress conditions.

비국부 이론을 이용한 입자 강화 복합재 이중후방응력 소성 구성방정식 모델 및 전단밴드 분석 (Non-Local Plasticity Constitutive Relation for Particulate Composite Material Using Combined Back-Stress Model and Shear Band Formation)

  • 윤수진;김신회;박재범;정규동
    • 대한기계학회논문집A
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    • 제38권10호
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    • pp.1057-1068
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    • 2014
  • 2개의 상으로 구성된 입자 강화 복합재에 대한 균질화와 내부 상태 변수에 대해 2차 미분항이 포함된 비구역적 이론을 적용하여 탄소성 구성 방정식을 제안하였다. 열역학과 소성 포텐셜을 통해 내부 상태 변수에 대한 전개식 또한 본 논문에 포함되었다. 연속체 결함 모델을 이용, 결함 인자에 따른 물성 저하 현상도 감안되었으며 이중 후방응력이 조합된 전개식 또한 제시하였다. 일부 예에 대한 수치해석 결과, 비구역적 변수의 영향이 증가할수록 전단밴드는 감소하나 반면 특정 후방응력 전개가 지배적일수록 소성변형 집중이 증가함이 관찰되었다. 더욱이 두 개의 강소성 상으로 이루어진 복합재의 경우 강성이 높은 게재물의 비중이 증가함에 따라 전단밴드 형성이 용이한 것으로 나타났다. 그 밖에 제어변수들의 변화에 따른 전단밴드 형성에 대한 분석 결과는 Rice 소성 불안정성 분석결과와 잘 일치함 또한 밝혀졌다.

동래단층 지역 단층비지의 생성과정과 K-Ar 연령 (Formation Processes of Fault Gouges and their K-Ar Ages along the Dongnae Fault)

  • 장태우;추창오
    • 지질공학
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    • 제8권2호
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    • pp.175-188
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    • 1998
  • 선형계곡을 따라 발달하는 동래 단층대의 단층비지를 조사 연구하였다. 이 단층대는 내적으로 대상구조를 가지며 다중 단층핵의 형태로 산출된다. 단층핵은 비지대와 파쇄대로 구분되며 단층대의 최외곽부인 손상대에 의해 둘러싸인다. 변형작용과 변질작용의 강도는 모암으로부터 손상대 $\rightarrow}$ 파쇄대$\rightarrow}$ 비지대를 향해 증가한다. 비지대를 형성한 변형작용은 초기엔 취성변형작용의 파쇄작용(catalasis)이 주도적이었고, 단층슬립의 최대의 국지화 지역인 파쇄물질의 고변형지역(비지대)에서는 연속적인 취성단열작용의 파쇄유동으로 나아갔을 것으로 생각된다. 단층비지대의 분쇄물질의 높은 공극 및 투수성은 지하로부터 열수유체의 유입을 가능케하여 활발한 열수 변질작용이 일어남에 따라 변형작용 기구는 취성파괴로부터 유체도움 유동으로 일대변화를 겪게 되었다. 열수 유체에 의한 일라이트, 스멕타이트 등의 점토광물 생성과 철광물 및 기타원소의 침전은 단층비지대에 높은 유압을 발생시켜 단열작용과 변질작용을 반복적으로 발생시킬수 있다. 일라이트의 다형은 대부분 1Md형으로 구성된다. 암석이 분쇄되고 나서 변질작용으로 점토광물이 생성될 때까지의 시간은 매우 짧은 것으로 알려져 있다. K-Ar 연령 측정자료에 의할때 열수변질을 수반한 동래단층의 주요 단층활동 시기는 51.4~57.5Ma와 40.3~43.6Ma의 두 시기로 구분될 수 있으나 시.공간적 단층활동 형태를 구명하기 위해서는 더 많은 자료가 필요하다. 그리고 비지대 점토광물의 생성온도환경으로 판단할 때 고기운동의 열수변질이 신기운동에 비해 보다 고온에서 일어난 것으로 추정된다.

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지각 장애의 신경 심리학적 기전 (Neuropsychological Mechanism of Perceptual Disorder)

  • 이성훈;박윤조;김동화;박혜정;김지웅
    • 수면정신생리
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    • 제6권2호
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    • pp.143-148
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    • 1999
  • 목 적: 지각 장애가 어떤 뇌의 부위와 기능에 장애가 있을 때 발생되는지를 알아보기 위해 정신과와 뇌손상 환자에서 신경심리 검사와 지각 장애와 관계성을 조사하였다. 방 법: 정신과 환자 69명, 뇌손상 환자 50명, 총 119명에서 Halstead Reitan 신경 심리 검사와 K-WAIS, MMPI를 시행하였다. MMPI 항목 중 지각 장애와 관계되는 9개 항목에서 산출된 점수와 신경심리 검사의 결과와의 상관 관계를 조사하였다. 또 정신과 환자에서 지각 장애 점수가 높은 지각 장애군 21명과 지각 장애가 없는 지각 장애 17명을 t-test로 비교하였다. 결 과: 뇌손상 환자군에서 지각 장애가 전두엽 기능을 보는 범주화 검사, 선로 잇기 검사, 촉각 수행 검사, 손끝 숫자 쓰기 검사와 우측 반구 기능을 보는 촉각 수행 검사의 위치, 동작성 점수, 빠진곳 찾기, 차례 맞추기, 토막 짜기 등과 유의한 상관 관계를 보였다. 또 피질하 기능을 보는 숫자 상징, 산수, 숫자 외우기와 유의한 상관 관계를 보였다. 정신과 환자의 높은 지각 장애군은 우측 반구 편측화 지수와 빠진 곳 찾기, 토막 짜기와 같은 우측 반구 기능에서 유의한 차이가 있었고, 또 이해, 어휘, 공통성과 같은 좌측 반구 기능에서도 유의한 차이가 있었다. 결 론: 지각 장애는 전두엽, 우측 반구, 피질하 구조의 기능과 깊은 연관성을 가지고 발생이 되며, 정신과 환자군에서는 좌측 반구의 기능도 영향을 주는 것으로 생각된다.

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Mechanisms of Resorcinol Antagonism of Benzo[a]pyrene-Induced Damage to Human Keratinocytes

  • Lee, Seung Eun;Kwon, Kitae;Oh, Sae Woong;Park, Se Jung;Yu, Eunbi;Kim, Hyeyoun;Yang, Seyoung;Park, Jung Yoen;Chung, Woo-Jae;Cho, Jae Youl;Lee, Jongsung
    • Biomolecules & Therapeutics
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    • 제29권2호
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    • pp.227-233
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    • 2021
  • Benzo[a]pyrene (B[a]P) is a polycyclic aromatic hydrocarbon and ubiquitous environmental toxin with known harmful effects to human health. Abnormal phenotypes of keratinocytes are closely associated with their exposure to B[a]P. Resorcinol is a component of argan oil with reported anticancer activities, but its mechanism of action and potential effect on B[a]P damage to the skin is unknown. In this study, we investigated the effects of resorcinol on B[a]P-induced abnormal keratinocyte biology and its mechanisms of action in human epidermal keratinocyte cell line HaCaT. Resorcinol suppressed aryl hydrocarbon receptor (AhR) activity as evidenced by the inhibition of B[a]P-induced xenobiotic response element (XRE)-reporter activation and cytochrome P450 1A1 (CYP1A1) expression. In addition, resorcinol attenuated B[a]P-induced nuclear translocation of AhR, and production of ROS and pro-inflammatory cytokines. We also found that resorcinol increased nuclear factor (erythroid-derived 2)-like 2 (Nrf2) activity. Antioxidant response element (ARE)-reporter activity and expression of ARE-dependent genes NAD(P)H dehydrogenase [quinone] 1 (NQO1), heme oxygenase-1 (HO-1) were increased by resorcinol. Consistently, resorcinol treatment induced nuclear localization of Nrf2 as seen by Western analysis. Knockdown of Nrf2 attenuated the resorcinol effects on ARE signaling, but knockdown of AhR did not affect resorcinol activation of Nrf2. This suggests that activation of antioxidant activity by resorcinol is not mediated by AhR. These results indicate that resorcinol is protective against effects of B[a]P exposure. The mechanism of action of resorcinol is inhibition of AhR and activation of Nrf2-mediated antioxidant signaling. Our findings suggest that resorcinol may have potential as a protective agent against B[a]P-containing pollutants.

초음파 영상을 이용한 고강도 집중 초음파 빔 시각화 (High-intensity focused ultrasound beam path visualization using ultrasound imaging)

  • 송재희;장진호;유양모
    • 한국음향학회지
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    • 제39권1호
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    • pp.16-23
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    • 2020
  • 고강도 집중 초음파(High-Intensity Focused Ultrasound, HIFU) 치료에서 HIFU 초점의 효과적인 위치 파악은 안전한 치료 계획을 개발하는 데 중요하다. 자기 공명 영상 유도 HIFU(Magnetic Resonance Imaging guided HIFU, MRIgHIFU)는 HIFU 초점을 영상화하여 치료 중에 초음파 경로를 시각화 할 수 있지만 초음파 이미징 유도 HIFU(Ultrasound imaging guided HIFU, USIgHIFU)에서는 어려움이 있다. 본 연구에서는 USIgHIFU에 대해 HIFU 초점을 영상화할 수 있는 실시간 초음파 빔 시각화 기법을 제시 하였다. 제안 된 방법에서, 음향 강도(Ispta < 720 mW/㎠) 아래의 이미징 초음파 변환자의 동일한 중심 주파수를 갖는 짧은 펄스가 HIFU 변환기를 통해 전송되고, HIFU 빔 경로를 시각화하기 위해 수신 신호는 동적 수신 포커싱 및 후속 에코 처리를 거쳤다. 소 혈청 알부민 젤 팬텀을 이용한 생체외 실험으로부터, HIFU 빔 경로는 낮은 음향 강도 (Ispta = 94.8 mW/㎠)에서도 명확히 영상화 할 수 있었고 HIFU 초점은 손상이 생성되기 전에 성공적으로 시각화하였다. 이 결과는 제안 된 초음파 빔 경로 시각화 방법이 USIgHIFU 치료에서 원치 않는 조직 손상을 최소화하면서 실시간으로 HIFU 초점을 영상화하는 데 사용될 수 있음을 나타낸다.

Experimental and numerical disbond localization analyses of a notched plate repaired with a CFRP patch

  • Abderahmane, Sahli;Mokhtar, Bouziane M.;Smail, Benbarek;Wayne, Steven F.;Zhang, Liang;Belabbes, Bachir Bouiadjra;Boualem, Serier
    • Structural Engineering and Mechanics
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    • 제63권3호
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    • pp.361-370
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    • 2017
  • Through the use of finite element analysis and acoustic emission techniques we have evaluated the interfacial failure of a carbon fiber reinforced polymer (CFRP) repair patch on a notched aluminum substrate. The repair of cracks is a very common and widely used practice in the aeronautics field to extend the life of cracked sheet metal panels. The process consists of adhesively bonding a patch that encompasses the notched site to provide additional strength, thereby increasing life and avoiding costly replacements. The mechanical strength of the bonded joint relies mainly on the bonding of the adhesive to the plate and patch stiffness. Stress concentrations at crack tips promote disbonding of the composite patch from the substrate, consequently reducing the bonded area, which makes this a critical aspect of repair effectiveness. In this paper we examine patch disbonding by calculating the influence of notch tip stress on disbond area and verify computational results with acoustic emission (AE) measurements obtained from specimens subjected to uniaxial tension. The FE results showed that disbonding first occurs between the patch and the substrate close to free edge of the patch followed by failure around the tip of the notch, both highest stress regions. Experimental results revealed that cement adhesion at the aluminum interface was the limiting factor in patch performance. The patch did not appear to strengthen the aluminum substrate when measured by stress-strain due to early stage disbonding. Analysis of the AE signals provided insight to the disbond locations and progression at the metal-adhesive interface. Crack growth from the notch in the aluminum was not observed until the stress reached a critical level, an instant before final fracture, which was unaffected by the patch due to early stage disbonding. The FE model was further utilized to study the effects of patch fiber orientation and increased adhesive strength. The model revealed that the effectiveness of patch repairs is strongly dependent upon the combined interactions of adhesive bond strength and fiber orientation.