• Title/Summary/Keyword: FD

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Aneurysmal bone cyst arising from the surgically removed craniofacial fibrous dysplasia in the long-term follow-up: a case report

  • Seungchul Baek;Byung Jun Kim
    • Archives of Craniofacial Surgery
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    • v.24 no.5
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    • pp.244-249
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    • 2023
  • Fibrous dysplasia (FD) is a rare skeletal disorder characterized by abnormal fibro-osseous connective tissue replacing normal bone. Despite its benign behavior, craniofacial FD can cause morphological disfigurement, headache, and even blindness as a result of the produced mass effect. Surgical resection is recommended when the patient shows apparent clinical symptoms or aggravating facial asymmetry. Postoperative complications have been reported, such as hematoma, surgical site infection, abscess formation, resorption of the bone graft used for reconstruction, and recurrence. An aneurysmal bone cyst (ABC) is a rare benign bony lesion that can occur secondary to preexisting bone tumor. Secondary ABCs in craniofacial FD are extremely rare in the literature, accounting for less than 30, all of which are either case reports or series. We report an extremely rare case of symptomatic secondary ABC arising from craniofacial FD that had been misdiagnosed with abscess formation or recurrence and was surgically removed. Notably, 17 years elapsed between the primary surgery and the complication of secondary ABC. The patient underwent total removal of secondary ABC. After surgery, symptoms were relieved, with no recurrence observed during a 6-month follow-up.

Low-noise fast-response readout circuit to improve coincidence time resolution

  • Jiwoong Jung;Yong Choi;Seunghun Back;Jin Ho Jung;Sangwon Lee;Yeonkyeong Kim
    • Nuclear Engineering and Technology
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    • v.56 no.4
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    • pp.1532-1537
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    • 2024
  • Time-of-flight (TOF) PET detectors with fast-rise-time scintillators and fast-single photon time resolution silicon photomultiplier (SiPM) have been developed to improve the coincidence timing resolution (CTR) to sub-100 ps. The CTR can be further improved with an optimal bandwidth and minimized electronic noise in the readout circuit and this helps reduce the distortion of the fast signals generated from the TOF-PET detector. The purpose of this study was to develop an ultra-high frequency and fully-differential (UF-FD) readout circuit that minimizes distortion in the fast signals produced using TOF-PET detectors, and suppresses the impact of the electronic noise generated from the detector and front-end readout circuits. The proposed UF-FD readout circuit is composed of two differential amplifiers (time) and a current feedback operational amplifier (energy). The ultra-high frequency differential (7 GHz) amplifiers can reduce the common ground noise in the fully-differential mode and minimize the distortion in the fast signal. The CTR and energy resolution were measured to evaluate the performance of the UF-FD readout circuit. These results were compared with those obtained from a high-frequency and single ended readout circuit. The experiment results indicated that the UF-FD readout circuit proposed in this study could substantially improve the best achievable CTR of TOF-PET detectors.

Magnetic Cloud and its Interplanetary Shock Sheath as a Modulator of the Cosmic Ray Intensity (우주선 Intensity 조정자로서 자기구름과 그 주위의 행성간 충격파 sheath 영역의 역할)

  • Oh, Su-Yeon
    • Journal of Astronomy and Space Sciences
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    • v.25 no.2
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    • pp.149-156
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    • 2008
  • Forbush Decreases (FDs) are representative events of abrupt decrease in galactic cosmic ray intensity. They are known to be strongly associated with solar wind events such as interplanetary shock (IP shock) and magnetic cloud (MC). In order to examine effectiveness of the MC on FDs, I studied the 44 MCs that occurred during the 2 years from 1998 to 1999 and investigated the properties of interplanetary magnetic field (IMF) and solar wind. As a result, I found that 11 out of 44 MCs are associated with the FDs. In particularly, it is noted that the FDs are driven by the IP shock sheaths which are associated with over 13 nT of IMF magnitude, 3 nT of IMF turbulence, and 550km/s of solar wind speed. This result indicates that magnetic cloud and its interplanetary shock sheath work as a modulator of the cosmic ray intensity.

Fungiform Papillae and its Correlation with Rome III Classification and Spleen Qi Deficiency in Functional Dyspepsia (기능성 소화불량증 환자에서 로마기준 III 아형분류 및 脾氣虛證과 심상유두 수의 상관성 분석)

  • Choi, Jane;Kim, Jin-sung
    • The Journal of Internal Korean Medicine
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    • v.36 no.3
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    • pp.308-322
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    • 2015
  • Objectives: Whether there exists a distinct pathogenesis in subgroups of functional dyspepsia (FD), the classification of epigastric pain syndrome (EPS), and postprandial distress syndrome (PDS) remains controversial. We aimed to investigate the number of fungiform papillae (FP) in the subgroups of FD and its correlation with the severity of dyspepsia symptoms and spleen qi deficiency. Methods: Patients with FD were enrolled from August to November 2014. All patients were evaluated using a questionnaire and divided into 2 groups according to the Rome III criteria for FD. The severity of dyspepsia symptoms and spleen qi deficiency were separately assessed by Nepean Dyspepsia Index-Korean (NDI-K) version and Spleen qi deficiency questionnaire (SQDQ). The number of FP was measured on the anterior part of tongue, within an area of 9 mm 2, using a digital cam Results: The NDI-K score, SQDQ score, and number of FP in the EPS group were significantly greater than those in the PDS group. Also, the EPS group had more patients diagnosed with spleen qi deficiency. The number of FP showed a significant positive correlation with epigastric pain and burning. Furthermore, the number of FP was significantly associated with the score of some items in NDI-K and SQDQ, even though not with the total score. Conclusions: Thus, measurement of the number of FP could be a new evaluation indicator for allocation into FD subtypes and to investigate the severity of dyspepsia symptoms and spleen Qi deficiency reflecting visceral hypersensitivity.

Studies on Permeation Enhancers for Ocular Peptide Delivery Systems: Pz-peptide as a Novel Enhancer of Ocular Epithelial Paracellular Permeability in the Pigmented Rabbit

  • Chung, Youn-Bok;Lee, Vincnet H.L.
    • Journal of Pharmaceutical Investigation
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    • v.24 no.3
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    • pp.49-57
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    • 1994
  • The objective of this study was to determine whether Pz-peptide, an enhancer of hydrophilic solute permeability in the intestine, could elevate the paracellular permeability of the cornea and conjunctiva in the pigmented rabbit. The in vitro penetration of four hydrophilic solutes, mannitol (MW 182), fluorescein (MW 376), FD-4 (FITC-dextran, 4 KDa), and FD-10 (FITC-dextran, 10 KDa) across the pigmented rabbit cornea and conjunctiva was studied either in the presence or absence of 3 mM enhancers. Drug penetration was evaluated using the modified Ussing chamber. The conjunctiva was more permeable than the cornea to all four markers. EDTA and cytochalasin B showed higher effects on marker transport than Pz-peptide, but Pz-peptide elevated the corneal transport of mannitol, fluoresein, and FD-4 by 50%, 26%, and 50%, respectively, without affecting FD-10 transport. Possibly due to the leakier nature of the conjunctiva, 3 mM Pz-peptide elevated the transport of only FD-4 by about 45%, without affecting the transport of other markers. Furthermore, the transport of Pz-peptide itself across the cornea and conjunctiva increased with increasing concentration in the 1-5 mM range, suggesting that Pz-peptide enhanced its own permeability, possibly by elevating paracellular permeability. Effects of ion transport inhibitors on Pz-peptide transport were then investigated. PZ-peptide penetration was not changed by mucosal addition of $10\;{\mu}M$ amiloride or $10\;{\mu}M$ hexamethylene amiloride, inhibiting serosal $Na^{+}$ exit by $100\;{\mu}M$ ouabain, or replacing $Na^{+}$ with choline chloride in the mucosal side buffer. These results seggested that Pz-peptide enhanced the paracellular permeability of rabbit cornea and conjunctiva and further indicate that ion transporters were not involved in the Pz-peptide induced elevation of paracellular marker permeability.

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Performance Evaluation of Shape Descriptors for Gait Analysis Based on Silhouette Sequence (실루엣 영상기반 보행 분석을 위한 형태 기술자의 성능 평가)

  • Kim, Seon-Jong
    • Journal of Intelligence and Information Systems
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    • v.15 no.4
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    • pp.53-64
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    • 2009
  • This paper presents a performance evaluation of shape descriptors for gait analysis in case of silhouette sequence images. We used moment descriptors(MD), Fourier descriptors(FD) and Zernike descriptors(ZD) as a shape descriptor. To evaluate their performance, we firstly defined the performance index, that is, AI(asymmetry index) and PI(periodic index) based on the periodic property of the gait images. This is why they are represented by periodic parameters due to periodic gait images. This index means that how the shape is represented periodically. According to these indexes, we evaluated the data sets with periodic images, downloaded from internet. The results showed that Zernike descriptors had better performance of AI = 1.09 and PI = 2.21 than others. And in case of FD and ZD, it's efficient to implement the gait analysis with 5~10 parameters.

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Three-dimensional Electromagnetic Modeling in Frequency Domain (주파수영역 전자법의 3차원 모델링)

  • Jang, Hannuree;Kim, Hee Joon
    • Geophysics and Geophysical Exploration
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    • v.17 no.3
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    • pp.163-170
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    • 2014
  • Development of a modeling technique for accurately interpreting electromagnetic (EM) data is increasingly required. We introduce finite difference (FD) and finite-element (FE) methods for three-dimensional (3D) frequency-domain EM modeling. In the controlled-source EM methods, formulating the governing equations into a secondary electric field enables us to avoid a singularity problem at the source point. The secondary electric field is discretized using the FD or FE methods for the model region. We represent iterative and direct methods to solve the system of equations resulting from the FD or FE schemes. By applying the static divergence correction in the iterative method, the rate of convergence is dramatically improved, and it is particularly useful to compute a model including surface topography in the FD method. Finally, as an example of an airborne EM survey, we present 3D modeling using the FD method.

Characteristics and Applications of Bioactive Peptides in Skin Care (생리활성 펩타이드의 피부미용학적 특성 및 활용)

  • Moh, Sang-Hyun;Jung, Dai-Hyun;Kim, Hyoung-Shik;Cho, Moon-Jin;Seo, Hyo-Hyun;Kim, Sung-Jun
    • KSBB Journal
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    • v.26 no.6
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    • pp.483-490
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    • 2011
  • Bioactive peptides (BAP) showed excellent cosmetic activity than bio-materials such as caffeic acid (CA), gallic acid (GA), and nicotinic acid (NA). Caffeoyl tripeptide-1 (CT-1) is a BAP that is stabilized with Gly-His-Lys (GHK) tripeptide and CA by using Fmoc solid phase peptide synthesis. Digalloyl tetrapeptide-19 (DT-19) is stabilized by combining Lys-Glu-Cys-Gly with GA and nicotinoyl tripeptide-1 (NT-1) is synthesized by GHK and NA. According to experiments, CT-1 has an excellent anti-oxidant function even with a very small amount of 10 ppm CT-1. DT-19's tyrosinase inhibition activity has the better effect of about 28.57% in 0.01% and 33.33% in 0.005% of concentration and about 7.89% in 0.001% concentration than vitamin-C. In addition, NT-1 is safer than the NA. Almost BAPs like pal-KTTKS, acetyl hexapeptide, and copper tripeptide-1 have the anti-wrinkle effect while DT-19 and NT-1 are applicable for potential BAPs focused on the whitening effect. The three kinds of BAPs like CT-1, DT-19, and NT-1 consisting of amino acids are safe to the skin, and have more excellent stability than bio-materials which are found to be unstable and cause skin irritation. Due to the high biological activity of BAP in the field of skin care, its utilization will increase constantly.

Validation of FDS for the Pool Fires within Two Rooms (이중격실 Pool 화재에 대한 FDS 검증분석)

  • Bae, Young-Bum;Ryu, Su-Hyun;Kim, Yun-Il;Lee, Sang-Kyu;Keum, O-Hyun;Park, Jong-Seok
    • Fire Science and Engineering
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    • v.24 no.5
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    • pp.60-67
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    • 2010
  • Fire model shall be verified and validated to reliably predict the consequences of fires within its limitations. Generally the verification and validation procedures are conducted by comparison with experimental test data. This study aims to evaluate predictive capabilities of FDS in the pool fire with two rooms and the sensitivity between input parameters such as heat release rate and ventilation rate and the output values like temperature, concentration, and heat flux. The predictive capabilities of FDS will be evaluated by comparing FDS simulation results with PRISME experimental data which result from the international fire test project. The sensitivity analysis will be conducted to decide which one of input parameters affects outcomes by comparison of FDS results with ${\pm}$ 10% changes of input parameter. From this study, the FDS predictive capabilities are within 20% error range. Heat release rate as input parameter affects most of outcomes and flow rate only has relation with concentration of oxygen and combustion products.

3.125Gbps Reference-less Clock and Data Recovery using 4X Oversampling (4X 오버샘플링을 이용한 3.125Gbps급 기준 클록이 없는 클록 데이터 복원 회로)

  • Jang, Hyung-Wook;Kang, Jin-Ku
    • Journal of IKEEE
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    • v.10 no.1 s.18
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    • pp.10-15
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    • 2006
  • In this paper, a clock and data recovery (CDR) circuit for a serial link with a half rate 4x oversampling phase and frequency detector structure without a reference clock is described. The phase detector (PD) and frequency detector (FD)are designed by 4X oversampling method. The PD, which uses bang-bang method, finds the phase error by generating four up/down signal and the FD, which uses the rotational method, finds the frequency error by generating up/down signal made by the PD output. And the six signals of the PD and the FD control an amount of current that flows through the charge pump. The VCO composed of four differential buffer stages generates eight differential clocks. Proposed circuit is designed using the 0.18um CMOS technology and operating voltage is 1.8V. With a 4X oversampling PD and FD technique, tracking range of 24% at 3.125Gbps is achieved.

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