• 제목/요약/키워드: Anti-resonance

검색결과 235건 처리시간 0.024초

Amyloid-Related Imaging Abnormalities in the Era of Anti-Amyloid Beta Monoclonal Antibodies for Alzheimer's Disease: Recent Updates on Clinical and Imaging Features and MRI Monitoring

  • So Yeong Jeong;Chong Hyun Suh;Sang Joon Kim;Cynthia Ann Lemere;Jae-Sung Lim;Jae-Hong Lee
    • Korean Journal of Radiology
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    • 제25권8호
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    • pp.726-741
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    • 2024
  • Recent advancements in Alzheimer's disease treatment have focused on the elimination of amyloid-beta (Aβ) plaque, a hallmark of the disease. Monoclonal antibodies such as lecanemab and donanemab can alter disease progression by binding to different forms of Aβ aggregates. However, these treatments raise concerns about adverse effects, particularly amyloid-related imaging abnormalities (ARIA). Careful assessment of safety, especially regarding ARIA, is crucial. ARIA results from treatment-related disruption of vascular integrity and increased vascular permeability, leading to the leakage of proteinaceous fluid (ARIA-E) and heme products (ARIA-H). ARIA-E indicates treatment-induced edema or sulcal effusion, while ARIA-H indicates treatment-induced microhemorrhage or superficial siderosis. The minimum recommended magnetic resonance imaging sequences for ARIA assessment are T2-FLAIR, T2* gradient echo (GRE), and diffusion-weighted imaging (DWI). T2-FLAIR and T2* GRE are necessary to detect ARIA-E and ARIA-H, respectively. DWI plays a role in differentiating ARIA-E from acute to subacute infarcts. Physicians, including radiologists, must be familiar with the imaging features of ARIA, the appropriate imaging protocol for the ARIA workup, and the reporting of findings in clinical practice. This review aims to describe the clinical and imaging features of ARIA and suggest points for the timely detection and monitoring of ARIA in clinical practice.

Anti-carcinogenic effects of non-polar components containing licochalcone A in roasted licorice root

  • Park, So Young;Kim, Eun Ji;Choi, Hyun Ju;Seon, Mi Ra;Lim, Soon Sung;Kang, Young-Hee;Choi, Myung-Sook;Lee, Ki Won;Yoon Park, Jung Han
    • Nutrition Research and Practice
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    • 제8권3호
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    • pp.257-266
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    • 2014
  • BACKGROUND/OBJECTIVE: Licorice has been shown to possess cancer chemopreventive effects. However, glycyrrhizin, a major component in licorice, was found to interfere with steroid metabolism and cause edema and hypertension. The roasting process of licorice modifies the chemical composition and converts glycyrrhizin to glycyrrhetinic acid. The purpose of this study was to examine the anti-carcinogenic effects of the ethanol extract of roasted licorice (EERL) and to identify the active compound in EERL. MATERIALS/METHODS: Ethanol and aqueous extracts of roasted and un-roasted licorice were prepared. The active fraction was separated from the methylene chloride (MC)-soluble fraction of EERL and the structure of the purified compound was determined by nuclear magnetic resonance spectroscopy. The anti-carcinogenic effects of licorice extracts and licochalcone A was evaluated using a MTT assay, Western blot, flow cytometry, and two-stage skin carcinogenesis model. RESULTS: EERL was determined to be more potent and efficacious than the ethanol extract of un-roasted licorice in inhibiting the growth of DU145 and MLL prostate cancer cells, as well as HT-29 colon cancer cells. The aqueous extracts of un-roasted and roasted licorice showed minimal effects on cell growth. EERL potently inhibited growth of MCF-7 and MDA-MB-231 breast, B16-F10 melanoma, and A375 and A2058 skin cancer cells, whereas EERL slightly stimulated the growth of normal IEC-6 intestinal epithelial cells and CCD118SK fibroblasts. The MC-soluble fraction was more efficacious than EERL in inhibiting DU145 cell growth. Licochalcone A was isolated from the MC fraction and identified as the active compound of EERL. Both EERL and licochalcone A induced apoptosis of DU145 cells. EERL potently inhibited chemically-induced skin papilloma formation in mice. CONCLUSIONS: Non-polar compounds in EERL exert potent anti-carcinogenic effects, and that roasted rather than un-roasted licorice should be favored as a cancer preventive agent, whether being used as an additive to food or medicine preparations.

헬리콥터용 반토오크 시스템 1차 시제 성능시험

  • 송근웅;강희정;심정욱;이제동;김승범
    • 항공우주기술
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    • 제4권2호
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    • pp.50-59
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    • 2005
  • 본 연구에서는 개발된 테일팬 1차 시제품의 성능시험에 대한 것이다. 한국항공우주연구원에서는 헬리콥터용 반 토오크 시스템으로 테일팬 시스템을 개발하였으며, 제작된 1차 시제품의 성능시험을 위해 테일팬 성능시험장치를 제작하였다. 테일팬 성능시험을 위해 먼저 시험장치에 대한 제작 검증용 시험을 수행하였고, 다음으로 팬블레이드와 시험장치의 고유진동수를 확인하였다. 성능 시험용 시험장치 운용회전수를 결정하기 위한 운용시험을 수행하였다. 테일기어박스(TGB)에 가속도계를 부착하여 단계적으로 회전수와 부착물들을 변화시켜가며 고유진동수와 진동 레벨을 확인하였다. 운용시험 결과로부터 테일팬 성능시험용 시험장치 운용회전수를 결정하였고, 무풍조건과 비행 조건에 따른 성능시험을 수행하였다. 측정된 데이터는 무차원화하여 분석하였고, 이 결과로 개발 시제품이 성능 요구조건을 만족시킴을 확인할 수 있었다.

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Anti-proliferative and Antioxidant Activities of 1-methoxy-3-methyl-8-hydroxy-anthraquinone, a Hydroxyanthraquinoid Extrolite Produced by Amycolatopsis thermoflava strain SFMA-103

  • Kumar, C. Ganesh;Mongolla, Poornima;Chandrasekhar, Cheemalamarri;Poornachandra, Yedla;Siva, Bandi;Babu, K. Suresh;Ramakrishna, Kallaganti Venkata Siva
    • 한국미생물·생명공학회지
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    • 제45권3호
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    • pp.200-208
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    • 2017
  • Actinobacteria are prolific producers of a large number of natural products with diverse biological activities. In the present study, an actinobacterium isolated from sunflower rhizosphere soil sample collected from Medak, Andhra Pradesh, South India was identified as Amycolatopsis thermoflava strain SFMA-103. A pigmented secondary metabolite in culture broth was extracted by using methanol and it was further purified by silica gel column chromatography with methanol-chloroform solvent system. Structural elucidation studies based on UV-visible, 1D and 2D-NMR, FT-IR, and mass spectroscopic analyses confirmed the structure as 1-methoxy-3-methyl-8-hydroxy-anthraquinone. It showed significant in vitro anticancer activity against lung cancer and lymphoblastic leukemia cells with $IC_{50}$ values of 10.3 and $16.98{\mu}M$, respectively. In addition, 1-methoxy-3-methyl-8-hydroxy-anthraquinone showed good free radical scavenging activity by DPPH method with an $EC_{50}$ of $18.2{\mu}g/ml$. It also showed other promising superoxide radical scavenging, nitric oxide radical scavenging and inhibition of lipid peroxidation activities. This is a first report of anti-proliferative and antioxidant activities of 1-methoxy-3-methyl-8-hydroxy-anthraquinone isolated from A. thermoflava strain SFMA-103 which may find potential application in biotechnological and pharmaceutical fields.

Cobrotoxin이 전립선 암세포 $NF-{\kappa}B$ 활성에 미치는 영향 (The Effects of Cobrotoxin on $NF-{\kappa}B$ Activation in Human Prostatic Cancer Cell Line(PC-3))

  • 채상진;송호섭
    • Journal of Acupuncture Research
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    • 제22권5호
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    • pp.37-48
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    • 2005
  • Objectives : The purpose of this study was to investigate the anti-caner effect of cobrotoxin on the prostatic cancer cell line(PC-3). Methods : After the treatment of PC-3 cells with cobrotoxin, we performed fluorescence microscope, MTT assay, Western blotting, Flow cytometry, PAGE electrophoresis and Surface plasmon resonance analysis to identify $NF-{\kappa}B$ the change of calcium and NO. Results : 1. The expression of $NF-{\kappa}B$ was decreased at 1nM and It·as decreased significantly at 2, 4, 8nM. 2. $I{\kappa}B,\;NF-{\kappa}B$ inhibitor, was decreased significantly at 8nM and $p-l{\kappa}Ba$, phosphrylation of $I{\kappa}B$, was decreased significantly at all concentrations of cobrotoxin. 3. The expressions of p50 and p65 were decreased significantly and dose-dependently at 1, 2, 4, 8nM. 4. The expression of p53 was increased significantly at 1, 2, 4, 8nM. 5. The calcium concentration in cell wasn't changed at 1, 2, 4, 8nM, but was increased dose-dependently at 30, 70, 130, 250nM comparing with lower dose of cobrotoxin. 6. The NO concentration in cell was increased significantly at 1, 2, 4, 8nM. 7. In immunochemical staining, we found that cobrotoxin-immunochemical complex move into intracellular space dose-dependently. Conclusion : These results indicate that cobrotoxin has anti-cancer effects by inducing apoptosis.

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Vertical equipment isolation using piezoelectric inertial-type isolation system

  • Lu, Lyan-Ywan;Lin, Ging-Long;Chen, Yi-Siang;Hsiao, Kun-An
    • Smart Structures and Systems
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    • 제26권2호
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    • pp.195-211
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    • 2020
  • Among anti-seismic technologies, base isolation is a very effective means of mitigating damage to structural and nonstructural components, such as equipment. However, most seismic isolation systems are designed for mitigating only horizontal seismic responses because the realization of a vertical isolation system (VIS) is difficult. The difficulty is primarily due to conflicting isolation stiffness demands in the static and dynamic states for a VIS, which requires sufficient rigidity to support the self-weight of the isolated object in the static state, but sufficient flexibility to lengthen the isolation period and uncouple the ground motion in the dynamic state. To overcome this problem, a semi-active VIS, called the piezoelectric inertia-type vertical isolation system (PIVIS), is proposed in this study. PIVIS is composed of a piezoelectric friction damper (PFD) and a leverage mechanism with a counterweight. The counterweight provides an uplifting force in the static state and an extra inertial force in the dynamic state; therefore, the effective vertical stiffness of PIVIS is higher in the static state and lower in the dynamic state. The PFD provides a controllable friction force for PIVIS to further prevent its excessive displacement. For experimental verification, a shaking table test was conducted on a prototype PIVIS controlled by a simple controller. The experimental results well agree with the theoretical results. To further investigate the isolation performance of PIVIS, the seismic responses of PIVIS were simulated numerically by considering 14 vertical ground motions with different characteristics. The responses of PIVIS were compared with those of a traditional VIS and a passive system (PIVIS without control). The numerical results demonstrate that compared with the traditional and passive systems, PIVIS can effectively suppress isolation displacement in all kinds of earthquake with various peak ground accelerations and frequency content while maintaining its isolation efficiency. The proposed system is particularly effective for near-fault earthquakes with long-period components, for which it prevents resonant-like motion.

Muscular invasion by oral squamous cell carcinoma of the posterior mandibular alveolar ridge is associated with cervical lymph node metastasis

  • Min, Seung-Ki;Myoung, Hoon;Lee, Jong-Ho;Kim, Myung-Jin
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제42권3호
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    • pp.133-138
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    • 2016
  • Objectives: To assess the association between muscle invasion by oral squamous cell carcinoma of the posterior mandibular alveolar ridge and cervical lymph node metastasis on the basis of preoperative magnetic resonance imaging (MRI). Materials and Methods: Twenty-six patients with oral squamous cell carcinoma of the posterior mandibular alveolar ridge were evaluated by MRI. The associations between cervical lymph node metastasis and independent factors evaluated by MRI were analyzed. Overall survival was also analyzed in this manner. Representative biopsy specimens were stained with anti-podoplanin and anti-CD34 antibodies. Results: Mylohyoid muscle invasion was associated with cervical lymph node metastasis. A combinational factor of mylohyoid and/or buccinator muscle invasion was also associated with cervical lymph node metastasis. Cervical lymph node metastasis and masticator space invasion had a negative effect on overall survival. No lymphatic vessels were identified near the tumor invasion front within the mandible. In contrast, lymphatic vessels were identified near the front of tumor invasion in the muscles. Conclusion: This study demonstrates an association between muscular invasion by oral squamous cell carcinoma of the posterior mandibular alveolar ridge and cervical lymph node metastasis.

중추신경 장애를 가진 시추 종의 개에서 지속적인 가속성 심실고유 율동 (Persistent Accelerated Idioventricular Rhythm in a Shih Tzu with Central Neuropathy)

  • 한숙희;현창백
    • 한국임상수의학회지
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    • 제27권4호
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    • pp.440-444
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    • 2010
  • 5.2 kg의 7살령 중성화 된 수컷 시추가 심각한 신경증상(paddling, 무의식, 실명, 발작)으로 내원하였다. 내원 당시 ECG 상에 심실 유래의 심박동 약 140회의 가속성 심실 고유박동(AVIR)이 지속적으로 나타났다. 이 환축은 자기공명영상법(MRI)과 뇌척수액검사(CSF)를 통해 파종성 육아종성 뇌수막염(GME)로 잠정 진단 내려졌다. 신경증상은 스테로이드제와 항경련제, 이뇨제, 항생제, 20% 만니톨 정맥 주사 등으로 호전 되었으며 부정맥은(AIVR) mexiletin으로 통제되었다. 신경학적인 문제에 대한 응급 처치 후 증상의 호전에도 불구하고 항부정맥제 처치 없이는 심장의 리듬이 불안정 했기 때문에 항부정맥 처치는 신경증상이 완전히 소실 될 때까지 유지되었다.

FRET에 기반한 Open Sandwich Fluoroimmunoassay (Development of an Open Sandwich Fluoroimmunoassay Based on FRET)

  • ;이문권;성기훈;주재범;이은규
    • KSBB Journal
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    • 제22권6호
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    • pp.426-432
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    • 2007
  • QDs을 기반으로 하는 OsFIA는 매우 빠르고 간단히 수행될 수 있다. 또한 이 분석법은 고체상의 담체나 결합/잔류시약의 분리 등과 같은 여러 과정을 필요로 하지 않으며, 적은 양의 시약으로도 분석이 가능하다. 본 분석법은 높은 감도로 항원을 측정할 수 있으며, 일상적인 분석에도 쉽게 도입될 수 있을 것이다. 선형 범위 내에서 측정 가능한 receptor의 최소농도는 0.05 nM (2.65 ng/mL) 정도이다. 또한, 일반적으로 상용화된 항체를 가치고 수행이 가능하다. 이 OsFIA 분석법은 기존의 실험적 sandwich immunoassay의 효과적인 대안으로 제시된다.

회전자계 역수신 코일을 이용한 관벽의 자기공명 영상 (Magnetic Resonance Imaging of Lumen Wall using Quadrature-typed Inside-out Receiver Coil)

  • 문치웅;조종운
    • 대한의용생체공학회:의공학회지
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    • 제22권5호
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    • pp.385-392
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    • 2001
  • 본 연구에서는 회전자계역수신코일(quadrature typed inside-out receiver coil)을 제작하고 이를 이용하여 코일 바깥 영역인 팬텀 관벽에 대한 자기공명영상(Magnetic Resonance Imaging, 이하 MRI라 함)을 얻었다. 자기공명영상법에 있어서 역 솔레노이드코일이나 8극 코일과 같은 기존의 역수신코일(inside-out receiver coil)은 영상영역(Imaging region)이 좁을 뿐만 아니라 영상영역 내의 영상신호가 불균일 (inhomogeneous)하다는 단점들이 있었다. 본 연구에서는 이들을 보완하면서 신호대잡음비(S/N ratio)도 이론적으로 약 1.4배 높일 수 있는 회전자계역수신코일(quadratic inside-out receiver coil)을 제안하여 관벽의 영상을 얻을 수 있는 코일을 개발하였다. 코일은 두 개의 안장코일 (saddle coil)을 서로 수직 방향으로 배치하여 서로 간섭을 일으키지 않으면서 최대의 신호를 수신할 수 있게 하였다. 코일에 대한 컴퓨터 모의실험(simulation)을 8극코일. 단일안장코일과 회전자계코일에 대해서 수행하였고 이들 각각 코일을 제작하여 팬텀 관벽의 영상 실험을 1.5T와 0.3T MRI 장치에서 수행하였다. 회전자계역수신코일의 성능은 단일안장코일과 8극코일보다 감도의 균일도가 우수하였고 신호대 잡음비도 단일안장코일에 비하여 약 36% 높게 측정되어 이론적인 41%와 근사한 결과를 얻었다

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