• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.34-38
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• 2011

Purpose: The SUV is a widely used semi-quantitative index in PET for the estimation of radio-tracer accumulation in VOI. In this study, SUVs from three different PET/CT scanners were assessed, and differences between SUVs were evaluated. Materials and Methods: The PET/CT scanners which were assessed in this study were GEMINI, GEMINI TF 64 (Philips) and Biograph True Point True V 40 (Siemens). The NEMA PET phantom (Data Spectrum Corp., USA) was used to evaluate SUVs. The NEMA PET phantom has6.8 kg weight and three hot inserts. Two different activity distributions for the background and inserts were tested. The activity ratio were 3.7:3.7:7.4:11.1 MBq (1:1:2:3) and 1.85:7.4:9.25:11.1MBq (1:4:5:6) for each of background, insert 1, insert 2 and insert 3. Acquisition time was 2 minutes per bed position and NEMA PET phantom could be covered by two bed positions for all PET/CT scanners. The SUVs from each PET/CT scanner were compared with calculated true value. Results: For both activity ratios, all scanners showed similar results. The differences between each scanner were insignificant. Each scanner showed 91.2%, 85.9% and 87.2% of true SUV for GEMINI, GEMINI TF 64, Biograph True Point TrueV, respectively. Conclusion: For all scanners, SUVs were slightly lower than true value. However, the difference between scanners was insignificant. The SUVs from these scanners would be clinically meaningful if their consistent underestimation is kept in mind.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2002.05a
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• pp.203-207
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• 2002

본 연구에서는 한국사람이 모국어인 한국어 단어를 산출할 때와 외국어인 영어 단어를 산출할 때 관여하는 대뇌 영역을 fMRI 를 통해 조사하였다. 또한, 단일 언어를 산출할 때와 두 언어를 수시로 바꾸어서 인출할 때 관련되는 뇌 영역이 어디인지를 조사하였다. 실험에 참가한 피험자는 외국어를 공식적인 교육을 통해 12 세 근처에서 배우기 시작한 대학생이었다. 흔히 분류하는 방식으로 late learner로 구분되는 학생들이었다. 한 피험자가 세 종류의 실험 모두에 참여하였다. 피험자의 실험과제는 그림을 보고 그림에 해당되는 이름을 인출하여 말하는 과제였다. 실험 1, 2, 3 모두에서 사건관련 fMRI(event-related fMRI) 기법을 사용하였다. 실험 1에서는 그림을 보고 그림 이름에 해당되는 한국어 어휘와 외래어 어휘를 산출하게 하였다. 언어관련 뇌영역인 Wernicke 영역, Broca 영역, SMA 영역, SMG 영역 등에서 유의미한 활성화가 있었다. 실험 2 에서는 실험 1 에서 사용하지 않았던 그림을 사용하여 그림의 영어 이름과 외래어 이름을 인출하게 하였다. 외국어인 영어 단어를 산출할 때에도 모국어 단어를 산출할 때와 유사한 영역이 활성화되었다. 특히 외래어 산출 시에는 뇌 활성화 영역이 모국어와 영어 단어 산출할 때와 모국어 산출할 때 활성화되는 공통 영역이 활성화되었다. 모국어 산출과 영어 단어 산출의 차이점은 외국어 산출 시에 활성화 영역이 전반적으로 더 컸다는 것과 외국어 단어 산출 시에 Broca 영역보다 조금 밑쪽에서 그리고 모국어 단어 산출시에는 전전두엽 영역에서 더 많은 활성화가 있었다. 실험 3 에서도 실험 1 과 실험 2 에 사용하지 않았던 그림을 사용하였다. 실험 3 의 특이한 결과는 언어 switching 이 있는 경우에 전통적인 언어 영역 활성화 외에 전전두엽의 활성화가 컸다는 것이다. 아마도 언어를 바꾸어 가면서 단어를 산출하는 것이 전전두엽의 정보선택과정에 많은 영향을 주었던 것으로 해석된다. 전체적으로 어휘 산출시에 모국어 어휘, 외국어 어휘, 외래어 등을 산출할 때 공통되는 언어 영역과 언어 특성적 영역이 활성화된다고 결론지을 수 있을 것 같다.

• Archives of Reconstructive Microsurgery
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• v.25 no.2
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• pp.37-42
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• 2016

Purpose: Soft tissue coverage of the distal leg and ankle region represents a surgical challenge. Beside various local and free flaps, the perforator flap has recently been replaced as a reconstructive choice because of its functional and aesthetic superiority. Although posterior tibial artery perforator flap (PTAPF) has been reported less often than peroneal artery perforator flap, it also provides a reliable surgical option in small to moderate sized defects especially around the medial malleolar region. Materials and Methods: Seven consecutive patients with soft tissue defect in the ankle and foot region were enrolled. After Doppler tracing along the posterior tibial artery, the PTAPF was elevated from the adjacent tissue. The average size of the flap was $28.08{\pm}9.31cm^2$ (range, 14.25 to $37.84cm^2$). The elevated flap was acutely rotated or advanced. Results: Six flaps survived completely but one flap showed partial necrosis because of overprediction of the perforasome. No donor site complications were observed during the follow-up period and all seven patients were satisfied with the final results. Conclusion: For a small to medium-sized defect in the lower leg, we conducted the close-by islanded PTAPF using a single proper adjacent perforator. Considering the weak point of the conventional propeller flap, this technique yields much better aesthetic results as a simple and reliable technique especially for defects of the medial malleolar region.

• The Korean Journal of Emergency Medical Services
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• v.27 no.2
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• pp.7-17
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• 2023

Purpose: This study aimed to identify the factors that contribute to head injuries among drivers of personal mobility devices and provide insights into safety perceptions. Methods: This retrospective study analyzed data of 221 trauma patients obtained from electronic medical records and the National Emergency Department Information System (NEDIS) over one year, from August 1, 2021, to July 31, 2022. The patients, all in their 20s and 30s, presented to a single emergency medical center following personal mobility device accidents (motorcycles, electric scooters, and bicycles). Results: Among motorcycle riders, 18.2% were not wearing helmets, while the percentage of e-scooter riders not wearing helmets was 87.5%. Wearing a helmet was associated with a 71.2% lower likelihood of head injuries (OR=0.288, CI=0.163 to 0.509, p=0.000). Of the personal mobility devices, motorcycles had a 0.431 times lower odds ratio for head injury compared to e-scooters (p=0.009), and there was no significant difference between e-scooters and bicycles (p=0.776). Conclusion: It is imperative to strengthen safety regulations by mandating helmet use for riders of personal mobility devices. A system to enhance driving enforcement for electric scooters, which are increasingly popular among young adults, should also be established.

• The Korean Journal of Blood Transfusion
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• v.23 no.2
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• pp.115-126
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• 2012

Background: Umbilical cord (UC) is a promising source of mesenchymal stromal cells (MSCs). We compared the characteristics of MSCs from cryopreserved UC with those from fresh tissues, and demonstrated the possibility of UC cryopreservation for acquisition of MSCs from cryopreserved UC. Methods: Each UC was sliced into two types ($1{\sim}2mm^3$ vs. 0.5 cm), and cryopreserved in liquid nitrogen using different media (autologous cord blood plasma, aCBP vs. RPMI 1640). A fresh aliquot of $1{\sim}2mm^3$-sized UC was used as control tissue. After one week, the cryopreserved tissues were thawed and cultured. For the 0.5 cm UC, a slicing step into $1{\sim}2mm^3$ was needed. Cell count, viability, proliferative activity, and surface antigens were determined from harvested MSCs. Several growth factors (EGF, IGF-1, PDGF, TGF-${\beta}$, bFGF, and VEGF), were measured from the culture supernatant. Results: Eleven UC were enrolled in the study. Efficiencies of obtaining MSCs were higher in cryopreserved UC using RPMI 1640, compared with use of aCBP; the same result was observed for 0.5 cm sized UC, compared with $1{\sim}2mm^3$ sized UC. No difference in proliferative activity was observed between MSCs from fresh and cryopreserved UC. The amount of growth factors in culture supernatant using RPMI 1640 was larger than that of fresh tissues. Conclusion: We obtained growth factors from the supernatant as well as MSCs from cryopreserved UC. As with a cord blood bank, in the future, cryopreservation of UC for acquisition of both MSCs and growth factors would be possible in a time of need.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.2
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• pp.230-238
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• 2017

We have proposed an InGaAs-based gate-all-around (GAA) tunneling field-effect transistor (TFET) with a stacked dual-metal gate (DMG). The electrical performances of the proposed TFET are evaluated through technology computer-aided design (TCAD) simulations. The simulation results show that the proposed TFET demonstrates improved DC performances including high on-state current ($I_{on}$) and steep subthreshold swing (S), in comparison with a single-metal gate (SMG) TFET with higher gate metal workfunction, as it has a thinner source-channel tunneling barrier width by low workfunction of source-side channel gate. The effects of the gate workfunction on $I_{on}$, the off-state current ($I_{off}$), and S in the DMG-TFETs are examined. The DMG-TFETs with PNPN structure demonstrate outstanding DC performances and RF characteristics with a higher n-type doping concentration in the $In_{0.8}Ga_{0.2}As$ source-side channel region.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.6
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• pp.525-530
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• 2014

Transient receptor potential vanilloid subtype 1 (TRPV1) was originally found in sensory neurons. Recently, it has been reported that TRPV1 is expressed in salivary gland epithelial cells (SGEC). However, the physiological role of TRPV1 in salivary secretion remains to be elucidated. We found that TRPV1 is expressed in mouse and human submandibular glands (SMG) and HSG cells, originated from human submandibular gland ducts at both mRNA and protein levels. However, capsaicin (CAP), TRPV1 agonist, had little effect on intracellular free calcium concentration ($[Ca^{2+}]_i$) in these cells, although carbachol consistently increased $[Ca^{2+}]_i$. Exposure of cells to high temperature (> $43^{\circ}C$) or acidic bath solution (pH5.4) did not increase $[Ca^{2+}]_i$, either. We further examined the role of TRPV1 in salivary secretion using TRPV1 knock-out mice. There was no significant difference in the pilocarpine (PILO)-induced salivary flow rate between wild-type and TRPV1 knock-out mice. Saliva flow rate also showed insignificant change in the mice treated with PILO plus CAP compared with that in mice treated with PILO alone. Taken together, our results suggest that although TRPV1 is expressed in SGEC, it appears not to play any direct roles in saliva secretion via transcellular pathway.

• Food Science of Animal Resources
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• v.29 no.2
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• pp.278-282
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• 2009

Previous studies indicate that BF-7 enhances learning and memory in normal and elderly individuals. Here, we evaluated whether milk containing BF-7 (BF-7 milk) could improve the brain function, with thirty normal university students $(21{\pm}1.2 years)$. Two versions of the Paced Auditory Serial Addition Test were used under double-blinded conditions to measure the efficacy of BF-7 milk on learning and memory, especially working memory and attention, and on mathematical ability. As a result, BF-7 milk improved the accuracy of the task more than 3-fold. Furthermore, BF-7 milk protected cultured neuronal cells from 3-hydroxykynurenine, a normal endogenous brain stress agent. These results indicate that BF-7 milk enhances memory, attention and mathematical ability in normal persons.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.4
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• pp.993-999
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• 2005

This research was peformed to investigate protective effect of Sophora Subprostrata fractions against focal ischemic brain damage after middle cerebral artery(MCA) occlusion using intraluminal suture. Rats were divided into six groups: MCA-occluded group(Control): each administered groups with Sophora Subprostrata total phase(Total), Sophora Subprostrata Aqueous phase (Aqueous), Sophora Subprostrata BuOH phase(BuOH), and Sophora Subprostrata Alkaloid phase(Alkaloid) after MCA-occlusion; sham-operated group(Sham). The right MCA was occluded by A poly-L-lysine coated 4-0 nylon suture thread through the internal carotid artery permanently. Sophora Subprostrata and fractions were administered orally(Smg/ml) for 7 days after MCA-occlusion. The Drain tissue was stained with $2\%$ triphenyl tetrazolium chloride on ischemic brain tissue(2mm section). The results showed that 1) Sophora Subprostrata total phase reduced infarct size and total infarct volume compared to the control group at 24 hours after MCA-occlusion, 2) Sophora Subprostrata Aqueous phase reduced infarct size and total infarct volume compared to the control group at 24 hours after MCA-occlusion, 3) Sophora Subprostrata Alkaloid phase reduced infarct size compared to the control group at 24 hours after MCA-occlusion, but 4) at 7 days after MCA-occlusion, Sophora Subprostrata did not show effective recovery compared with control group. Sophora Subprostrata has protective effects against brain damage at the early stage of focal cerebral ischemia. Sophora Subprostrata total and Aqueous phase produced more pronounced protective effect against focal ischemic brain damage.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.19 no.1
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• pp.44-53
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• 2016

Purpose: Parenteral nutrition (PN) not only provides nutritional support but also plays a crucial role in the treatment of children with intestinal failure. The aim of this study was to evaluate the clinical significance and clinical outcomes of long-term PN. Methods: Retrospective cohort study was conducted using the medical records of patients treated at Seoul National University Children's Hospital. This study included 19 patients who received PN for over six months. Most patients received home PN. Results: The indications for PN included short bowel syndrome, chronic intestinal pseudo-obstruction, and intractable diarrhea of infancy. The median age of PN initiation was 1.3 years, and the median treatment duration was 2.9 years. Two patients were weaned from PN; 14 continued to receive PN with enteral feedings; and 3 patients died. The overall survival rates at 2 and 5 years were 93.3% and 84.0%, respectively. The incidence of catheter-related bloodstream infections was 2.7/1,000 catheter-days and was associated with younger age at PN initiation and lower initial height Z-score. Six patients developed catheter-related central vein thrombosis, with an incidence of 0.25/1,000 catheter-days. Eleven patients experienced PN-associated liver disease (PNALD), and one patient underwent multi-visceral transplant. The patients with PNALD exhibited lower final heights and body weight Z-scores. All patients experienced micronutrient deficiencies transiently while receiving PN. Conclusion: PN is an important and safe treatment for pediatric intestinal failure. PNALD was linked to final anthropometric poor outcomes. Micronutrient deficiencies were common. Anthropometric measurements and micronutrient levels must be monitored for successful PN completion.