The Effect of Gap Size on Counter Current Flow Limitation Phenomena in Narrow Annular Gaps with Large Diameter

JiHwanJeong,SeungJinLee,RaeJoonPark,SangBaekkim 한국원자력학회 2002 Nuclear Engineering and Technology Vol.34 No.4

Growth Factor Releasing Porous Poly(ε-caprolactone)-Chitosan Matrices for Enhanced Bone Regenerative Therapy

SuYeonIm,SeonHyeCho,JeongHyoHwang,SeungJinLee 대한약학회 2003 Archives of Pharmacal Research Vol.26 No.1

Drug releasing porous poly(e-caprolactone) (PCL)-chitosan matrices were fabricated for bone regenerative therapy. Porous matrices made of biodegradable polymers have been playing a crucial role as bone substitutes and as tissue-engineered scaffolds in bone regenerative therapy. The matrices provided mechanical support for the developing tissue and enhanced tissue formation by releasing active agent in controlled manner. Chitosan was employed to enhance hydrophilicity and biocompatibility of the PCL matrices. PDGF-BB was incorporated into PCLchitosan matrices to induce enhanced bone regeneration efficacy. PCL-chitosan matrices retained a porous structure with a 100-200 mm pore diameter that was suitable for cellular migration and osteoid ingrowth. NaHCO3 as a porogen was incorporated 5% ratio to polymer weight to form highly porous scaffolds. PDGF-BB was released from PCL-chitosan matrices maintaining therapeutic concentration for 4 week. High osteoblasts attachment level and proliferation was observed from PCL-chitosan matrices. Scanning electron microscopic examination indicated that cultured osteoblasts showed round form and spread pseudopods after 1 day and showed broad cytoplasmic extension after 14 days. PCL-chitosan matrices promoted bone regeneration and PDGF-BB loaded matrices obtained enhanced bone formation in rat calvarial defect. These results suggested that the PDGF-BB releasing PCL-chitosan porous matrices may be potentially used as tissue engineering scaffolds or bone substitutes with high bone regenerative efficacy.

Color Correction in Portable-type Urine Analyzer

jae-HyungKim,ChangHeePark,SeungJinLee,GyeRokJeon,GiRyonKim 한국전기전자재료학회 2002 Transactions on Electrical and Electronic Material Vol.3 No.4

Color correction methods of chromaticity coordinates using Color Matching Function (CMF) were studied to develop a device-independent portable-type urine analyzer. The reflection spectra were measured for the degrees of 10 test items of the urine reagent strip (urine strip) to develop a portable-type urine analyzer. A computer simulation was performed to quantitatively distinguish the color reactions of the urine system, by using the spectral power distribution of Light Emitting Diode(LED), the reflection of a urine strip, and spectral sensitivity of a photodiode. To develop a device-independent system, chromaticity coordinates were modified to reduce the color deviations in the urine strip, by using the temperature compensation of LED and the color transformation by CMF. The experimental values obtained by developed urine system exhibited the accuracy above 95% for all color samples.

Direct-Current Treatment as a Safe Sterilization Method for Electrospun Biodegradable Polymer

HyeLeeKim,JeongHyunLee,MiHeeLee,HakHeeKim,JungsungKim,InhoHan,BongJooPark,JeongKooKim,DongWookHan,SooHyunKim,SeungJinLee,JongChulPark 한국조직공학·재생의학회 2011 조직공학과 재생의학 Vol.8 No.3

Sterilization is an essential process for biodegradable polymers to be used as biomaterials or tissue engi-neered-scaffolds. The characteristics of biodegradable scaffolds can change due to decomposition of constituentpolymers due to high temperature, pressure, or moisture during sterilization. This study investigated direct-current (DC) treatment as a safe method that can prevent structural change and deformation. Treatment of electrospun poly (lactic-co-glycolic acid) (PLGA) with DC showed a bactericidal effect within 40 sec at 4 V. When DC was appliedat 6 V to the electrospun PLGA, the bactericidal effect emerged within 30 sec. The morphology of fibers and molec-ular weight of PLGA polymer was maintained after DC treatment. In contrast, electrospun PLGA exposed to ethyl-ene oxide showed fiber degradation, and gamma or e-beam irradiation resulted in decreased molecular weight. Thedemonstrated improvement in chemical and physical stability of biodegradable polymers after DC sterilization mayhelp extend their application.

Type Analysis of Drug Intoxicated Patients in Daegu Emergency Medical Center and Medical Flexibility of Diagnostic Test Using Drug Addiction Selecting Kit

( Seung-jin Lee ),( Soon-ok Lim ),( Tae-jeong Kim ),( Min-jeong Park ),( Jong-ha Ryu ) 대한임상검사과학회 2013 대한임상검사과학회지(KJCLS) Vol.45 No.3

It is important to check the types of drugs when treating acute drug intoxication. This study researches the clinical characteristics and types of patients hospitalized in emergency medical center for drug addiction in 2009 and 2010. By applying a drug addiction selecting kit, it studied the flexibility and clinical efficiency during diagnosis and treatment. The study result shows, among thedrugs causing addiction, Sedative accounts for 34.4%, Herdicide 23.5%, Analgesic 17.2%, Insectide7.8% and else 17.2%. Sedative showed the highest proportion both in 2009 and 2010. Among the drug addicted patients, 39 cases did not know that the drugs are poisonous and among them, the drug addiction selecting kit was positive in 32 cases (82.0%). In 42 cases where addiction was suspicious, 25 cases (59.5%) were positive in the drug addiction selecting kit. In 57 cases of using drug addiction selecting kits, the cases in which benzodiazepine was positive, were 30 and the most frequently cases were as follows; Tricyclic Antidepressants (TCA) 13 cases, Amphetamines 3 cases, barbiturate 3 cases, and piate 3 cases. In the district using drug addiction kit meaningfully had Flumazenil injection much greater impact than the one not using the kit. This proves the efficiency of the kit (p<0.05). The uses of drug addiction selecting kits are for acute drug intoxicated patients and for providing objective and scientific information when emergency medical doctor are checking unchecked poisoning drugs. It is considered that drug addiction selecting kits would give help when treating the early stage of drug addicted patients in emergency medical treatment.

Can manipulation under anesthesia alone provide clinical outcomes similar to arthroscopic circumferential capsular release in primary frozen shoulder (FS)?: the necessity of arthroscopic capsular release in primary FS

Seung-Jin Lee,Jun-Hyuk Jang,Yoon-Suk Hyun 대한견주관절의학회 2020 대한견주관절의학회지 Vol.23 No.4

Background: We evaluated the need for arthroscopic capsular release (ACR) in refractory primary frozen shoulder (FS) by comparing clinical outcomes of patients treated with ACR and manipulation under anesthesia (MUA). Methods: We assessed patients with refractory primary FS, 57 patients (group A) who were treated with MUA and 22 patients (group B) who were treated with ACR. In group A, manipulation including a backside arm-curl maneuver was performed under interscalene brachial block. In group B, manipulation was performed only to release the inferior capsule before arthroscopic circumferential capsular release, which was carried out for the unreleased capsule after manipulation. Pain, range of shoulder motion, and American Shoulder and Elbow Surgeons score were recorded at 1 week, 3 months, 6 months, and 1 year after surgery. We compared outcome variables between treatment groups and between diabetics and non-diabetics and also evaluated the numbers of patients receiving additional intra-articular steroid injection. Results: Outcome variables at 3 months after surgery and improvements in outcome variables did not differ between groups. Group A showed significantly better results than group B in the evaluation of pain and range of motion at 1 week. Diabetics showed comparable outcomes to non-diabetics for most variables. Eleven patients required additional steroid injections between 8 to 16 weeks after surgery: 12.2% in group A, 18.2% in group B. Additional injections were given three times more often in diabetics compared to non-diabetics. Conclusions: MUA alone can yield similar clinical outcomes to ACR in refractory FS.

A 345 mW Heterogeneous Many-Core Processor With an Intelligent Inference Engine for Robust Object Recognition

Seungjin Lee,Jinwook Oh,Junyoung Park,Joonsoo Kwon,Minsu Kim,Hoi-Jun Yoo IEEE 2011 IEEE journal of solid-state circuits Vol.46 No.1

<P>A heterogeneous many-core object recognition processor is proposed to realize robust and efficient object recognition on real-time video of cluttered scenes. Unlike previous approaches that simply aimed for high GOPS/W, we aim to achieve high Effective GOPS/W, or EGOPS/W, which only counts operations carried out on meaningful regions of an input image. This is achieved by the Unified Visual Attention Model (UVAM) which confines complex Scale Invariant Feature Transform (SIFT) feature extraction to meaningful object regions while rejecting meaningless background regions. The Intelligent Inference Engine (HE), a mixed-mode neuro-fuzzy inference system, performs the top-down familiarity attention of the UVAM which guides attention toward pre-learned objects. Weight perturbation-based learning of the HE ensures high attention precision through online adaptation. The SIFT recognition is accelerated by an optimized array of 420-way SIMD Vector Processing Elements, 32 MIMD Scalar Processing Elements, and 1 Feature Matching Processor. When processing 30 fps 640 × 480 video, the 50 mm<SUP>2</SUP> object recognition processor implemented in a 0.13 μm process achieves 246 EGOPS/W, which is 46 % higher than the previous work. The average power consumption is only 345 mW.</P>

Development of a Novel DNA Reporter for Sensitive CRISPR/Cas12a-Based Biosensor

Seungjin LEE,Ki Soo PARK 한국생물공학회 2023 한국생물공학회 학술대회 Vol.2023 No.4

Quercus glauca Extract and Rutin Inhibit the UVB-induced Expression of Matrix Metalloproteinase-1 in Human Dermal Fibroblasts

( Seung Jin Lee ),( Yong Chool Boo ),( Jae Sook Koh ),( Byung Jhip Ha ) 한국응용생명화학회 2010 Applied Biological Chemistry (Appl Biol Chem) Vol.53 No.6

Matrix metalloproteinases (MMPs) are known to be up-regulated by a reactive oxygen species (ROS)-dependent mechanism in skin after exposure to ultraviolet radiation (UV) and to participate in tissue remodeling, leading to wrinkles and other phenotypes of photo-aging. Thus, it has been assumed that the progress of photo-aging may be decelerated by suppressing the UVinduced expression of MMPs. In this regard, plant extracts enriched with polyphenolic antioxidants are attractive materials, because they may suppress the expression of MMPs by lowering ROS levels. To examine this possibility, the extracts of twelve plants were tested for their ability to alter the UVB-induced MMP-1 expression in cultured human dermal fibroblasts. Among the tested extracts, an extract of Quercus glauca Thunberg (QG) inhibited MMP-1 expression most effectively without any noticeable cytotoxicity. In addition, its water fraction was more active than 1-buthanol and methylene chloride fractions, implicating the active constituents may be watersoluble. Rutin, one of the major water-soluble polyphenolic constituents of QG, showed an inhibitory effect against UVB-induced MMP-1 expression. Both QG extract and rutin lowered ROS levels in UVB-exposed cells, suggesting that their inhibitory effects on MMP-1 expression may be associated with the antioxidant effects of lowering intracellular ROS levels. The watersoluble constituents of QG may provide a protective effect against the UVB-induced photo-aging of human skin.

24-GOPS 4.5-<tex> ${\rm mm}^{2}$</tex> Digital Cellular Neural Network for Rapid Visual Attention in an Object-Recognition SoC

Seungjin Lee,Minsu Kim,Kwanho Kim,Joo-Young Kim,Hoi-Jun Yoo IEEE 2011 IEEE transactions on neural networks Vol.22 No.1

<P>This paper presents the Visual Attention Engine (VAE), which is a digital cellular neural network (CNN) that executes the VA algorithm to speed up object-recognition. The proposed time-multiplexed processing element (TMPE) CNN topology achieves high performance and small area by integrating 4800 (8060) cells and 120 PEs. Pipelined operation of the PEs and single-cycle global shift capability of the cells result in a high PE utilization ratio of 93%. The cells are implemented by 6T static random access memory-based register files and dynamic shift registers to enable a small area of 4.5 . The bus connections between PEs and cells are optimized to minimize power consumption. The VAE is integrated within an object-recognition system-on-chip (SoC) fabricated in the 0.13- complementary metal-oxide-semiconductor process. It achieves 24 GOPS peak performance and 22 GOPS sustained performance at 200 MHz enabling one CNN iteration on an 8060 pixel image to be completed in just 4.3 . With VA enabled using the VAE, the workload of the object-recognition SoC is significantly reduced, resulting in 83% higher frame rate while consuming 45% less energy per frame without degradation of recognition accuracy.</P>