1.The effect of heat treatment of the TI6AL4V specimen fabricated by selective laser melting method on the crystalline structure and chemical compositions
Ho-Jun SONG ; Yeong-Joon PARK ; Won-Jin MOON ; Wan-Gil JUNG ; Seon-Shin CHO ; Byeong-Mo KANG ; Taek-Rim YOON
Korean Journal of Dental Materials 2023;50(2):99-108
In this study, the Ti6Al4V specimens were fabricated using selective laser melting (SLM) method (Ti6Al4V-AS group). These specimens were performed to heat treatment at 950℃ and 550℃ using vacuum electric furnace (Ti6Al4V-HT group). The mechanical properties, metallographic shape, crystalline structure, and chemical compositions of the alloy specimens before and after heat treatment were analyzed. The Ti6Al4V-AS group showed ultimate tensile strength (UTS) and low elongation values. Acicular crystal grains were observed in metallographic image and the α'-Ti phase was dominant. After heat treatment (Ti6Al4V-HT group), the UTS was lowered and the elongation was increased. In addition, a lamellar structure in which columnar crystal grains are arranged was observed, α+β-Ti phase was formed, and crystallinity increased. As a result of analyzing the chemical composition, the Ti6Al4V-AS specimen contained a higher carbon content than the Ti6Al4V-HT specimen. This high carbon content could be related to the formation of α'-phase, high strength and low elongation of the Ti6Al4V-AS specimen. Ti6Al4V-HT specimen showed that the overall carbon content was low, but the carbon content was locally high in the α-Ti phase region. Therefore, it is necessary to control effectively the incorporation of carbon gas in the production of Ti6Al4V specimens using SLM.
2.Effects of the Combination of Evogliptin and Leucine on Insulin Resistance and Hepatic Steatosis in High-Fat Diet-Fed Mice
Chang Yell SHIN ; Hak Yeong LEE ; Gil Hyung KIM ; Sun Young PARK ; Won Seok CHOI ; Uy Dong SOHN
Biomolecules & Therapeutics 2021;29(4):419-426
In this study, we aimed to investigate the effects of 8 weeks of treatment with a combination of evogliptin and leucine, a branchedchain amino acid, in mice with high-fat diet (HFD)-induced diabetes. Treatment with evogliptin alone or in combination with leucine reduced the body weight of the mice, compared to the case for those from the HFD control group. Long-term treatment with evogliptin alone or in combination with leucine resulted in a significant reduction in glucose intolerance; however, leucine alone did not affect postprandial glucose control, compared to the case for the mice from the HFD control group. Furthermore, the combination of evogliptin and leucine prevented HFD-induced insulin resistance, which was associated with improved homeostasis model assessment for insulin resistance, accompanied by markedly reduced liver fat deposition, hepatic triglyceride content, and plasma alanine aminotransferase levels. The combination of evogliptin and leucine increased the gene expression levels of hepatic peroxisome proliferator-activated receptor alpha, whereas those of the sterol regulatory element-binding protein 1 and stearoyl-CoA desaturase 1 were not altered, compared to the case in the HFD-fed mice (p<0.05). Thus, our results suggest that the combination of evogliptin and leucine may be beneficial for treating patients with type 2 diabetes and hepatic steatosis; however, further studies are needed to delineate the molecular mechanisms underlying the action of this combination.
3.Development and Validation of a Symptom-Focused Quality of Life Questionnaire (KOQUSS-40) for Gastric Cancer Patients after Gastrectomy
Bang Wool EOM ; Joongyub LEE ; In Seob LEE ; Young-Gil SON ; Keun Won RYU ; Sung Geun KIM ; Hyoung-Il KIM ; Young-Woo KIM ; Seong-Ho KONG ; Oh Kyoung KWON ; Ji-Ho PARK ; Ji Yeong AN ; Chang Hyun KIM ; Byoung-Jo SUH ; Hong Man YOON ; Myoung Won SON ; Ji Yeon PARK ; Jong-Min PARK ; Sang-Ho JEONG ; Moon-Won YOO ; Geum Jong SONG ; Han-Kwang YANG ; Yun-Suhk SUH ; Ki Bum PARK ; Sang-Hoon AHN ; Dong Woo SHIN ; Ye Seob JEE ; Hye-Seong AHN ; Sol LEE ; Jae Seok MIN ; Haejin IN ; Ahyoung KIM ; Hoon HUR ; Hyuk-Joon LEE ;
Cancer Research and Treatment 2021;53(3):763-772
Purpose:
Patients who have undergone gastrectomy have unique symptoms that are not appropriately assessed using currently available tools. This study developed and validated a symptom-focused quality of life (QoL) questionnaire for patients who have received gastrectomy for gastric cancer. Materials and Methods Based on a literature review, patient interviews, and expert consultation by the KOrean QUality of life in Stomach cancer patients Study group (KOQUSS), the initial item pool was developed. Two large-scale developmental studies were then sequentially conducted for exploratory factor analyses for content validity and item reduction. The final item pool was validated in a separate cohort of patients and assessed for internal consistency, test-retest reliability, construct validity, and clinical validity.
Results
The initial questionnaire consisted of 46-items in 12 domains. Data from 465 patients at 11 institutions, followed by 499 patients at 13 institutions, were used to conduct item reduction and exploratory factor analyses. The final questionnaire (KOQUSS-40) comprised 40 items within 11 domains. Validation of KOQUSS-40 was conducted on 413 patients from 12 hospitals. KOQUSS-40 was found to have good model fit. The mean summary score of the KOQUSS-40 was correlated with the EORTC QLQ-C30 and STO22 (correlation coefficients, 0.821 and 0.778, respectively). The KOQUSS-40 score was also correlated with clinical factors, and had acceptable internal consistency (> 0.7). Test-retest reliability was greater than 0.8. Conclusion The KOQUSS-40 can be used to assess QoL of gastric cancer patients after gastrectomy and allows for a robust comparison of surgical techniques in clinical trials.
4.Effects of the Combination of Evogliptin and Leucine on Insulin Resistance and Hepatic Steatosis in High-Fat Diet-Fed Mice
Chang Yell SHIN ; Hak Yeong LEE ; Gil Hyung KIM ; Sun Young PARK ; Won Seok CHOI ; Uy Dong SOHN
Biomolecules & Therapeutics 2021;29(4):419-426
In this study, we aimed to investigate the effects of 8 weeks of treatment with a combination of evogliptin and leucine, a branchedchain amino acid, in mice with high-fat diet (HFD)-induced diabetes. Treatment with evogliptin alone or in combination with leucine reduced the body weight of the mice, compared to the case for those from the HFD control group. Long-term treatment with evogliptin alone or in combination with leucine resulted in a significant reduction in glucose intolerance; however, leucine alone did not affect postprandial glucose control, compared to the case for the mice from the HFD control group. Furthermore, the combination of evogliptin and leucine prevented HFD-induced insulin resistance, which was associated with improved homeostasis model assessment for insulin resistance, accompanied by markedly reduced liver fat deposition, hepatic triglyceride content, and plasma alanine aminotransferase levels. The combination of evogliptin and leucine increased the gene expression levels of hepatic peroxisome proliferator-activated receptor alpha, whereas those of the sterol regulatory element-binding protein 1 and stearoyl-CoA desaturase 1 were not altered, compared to the case in the HFD-fed mice (p<0.05). Thus, our results suggest that the combination of evogliptin and leucine may be beneficial for treating patients with type 2 diabetes and hepatic steatosis; however, further studies are needed to delineate the molecular mechanisms underlying the action of this combination.
5.Development and Validation of a Symptom-Focused Quality of Life Questionnaire (KOQUSS-40) for Gastric Cancer Patients after Gastrectomy
Bang Wool EOM ; Joongyub LEE ; In Seob LEE ; Young-Gil SON ; Keun Won RYU ; Sung Geun KIM ; Hyoung-Il KIM ; Young-Woo KIM ; Seong-Ho KONG ; Oh Kyoung KWON ; Ji-Ho PARK ; Ji Yeong AN ; Chang Hyun KIM ; Byoung-Jo SUH ; Hong Man YOON ; Myoung Won SON ; Ji Yeon PARK ; Jong-Min PARK ; Sang-Ho JEONG ; Moon-Won YOO ; Geum Jong SONG ; Han-Kwang YANG ; Yun-Suhk SUH ; Ki Bum PARK ; Sang-Hoon AHN ; Dong Woo SHIN ; Ye Seob JEE ; Hye-Seong AHN ; Sol LEE ; Jae Seok MIN ; Haejin IN ; Ahyoung KIM ; Hoon HUR ; Hyuk-Joon LEE ;
Cancer Research and Treatment 2021;53(3):763-772
Purpose:
Patients who have undergone gastrectomy have unique symptoms that are not appropriately assessed using currently available tools. This study developed and validated a symptom-focused quality of life (QoL) questionnaire for patients who have received gastrectomy for gastric cancer. Materials and Methods Based on a literature review, patient interviews, and expert consultation by the KOrean QUality of life in Stomach cancer patients Study group (KOQUSS), the initial item pool was developed. Two large-scale developmental studies were then sequentially conducted for exploratory factor analyses for content validity and item reduction. The final item pool was validated in a separate cohort of patients and assessed for internal consistency, test-retest reliability, construct validity, and clinical validity.
Results
The initial questionnaire consisted of 46-items in 12 domains. Data from 465 patients at 11 institutions, followed by 499 patients at 13 institutions, were used to conduct item reduction and exploratory factor analyses. The final questionnaire (KOQUSS-40) comprised 40 items within 11 domains. Validation of KOQUSS-40 was conducted on 413 patients from 12 hospitals. KOQUSS-40 was found to have good model fit. The mean summary score of the KOQUSS-40 was correlated with the EORTC QLQ-C30 and STO22 (correlation coefficients, 0.821 and 0.778, respectively). The KOQUSS-40 score was also correlated with clinical factors, and had acceptable internal consistency (> 0.7). Test-retest reliability was greater than 0.8. Conclusion The KOQUSS-40 can be used to assess QoL of gastric cancer patients after gastrectomy and allows for a robust comparison of surgical techniques in clinical trials.
6.Association between Changes in Cortical Thickness and Functional Connectivity in Male Patients with Alcohol-dependence
Shin-Eui PARK ; Yeong-Jae JEON ; Hyeon-Man BAEK
Experimental Neurobiology 2021;30(6):441-450
Many studies have reported structural or functional brain changes in patients with alcohol-dependence (ADPs). However, there has been an insufficient number of studies that were able to identify functional changes along with structural abnormalities in ADPs. Since neuronal cell death can lead to abnormal brain function, a multimodal approach combined with structural and functional studies is necessary to understand definitive neural mechanisms. Here, we explored regional difference in cortical thickness and their impact on functional connection along with clinical relevance. Fifteen male ADPs who have been diagnosed by the Diagnostic and Statistical Manual of Mental Disorders 5 (DSM-5) underwent highresolution T1 and resting-state functional magnetic resonance imaging (MRI) scans together with 15 male healthy controls (HCs). The acquired MRI data were post-processed using the Computational Anatomy Toolbox (CAT 12) and CONN-fMRI functional connectivity (FC) toolbox with Statistical Parametric Mapping (SPM 12). When compared with male HCs, the male ADPs showed significantly reduced cortical thickness in the left postcentral gyrus (PoCG), an area responsible for altered resting-state FC patterns in male ADPs. Statistically higher FCs in PoCG-cerebellum (Cb) and lower FCs in PoCG-supplementary motor area (SMA) were observed in male ADPs. In particular, the FCs with PoCG-Cb positively correlated with alcohol use disorders identification test (AUDIT) scores in male ADPs. Our findings suggest that the association of brain structural abnormalities and FC changes could be a characteristic difference in male ADPs. These findings can be useful in understanding the neural mechanisms associated with anatomical, functional and clinical features of individuals with alcoholism
7.Spine Surgery Using Augmented Reality
Sang Min PARK ; Ho Joong KIM ; Jin S YEOM ; Yeong Gil SHIN
Journal of Korean Society of Spine Surgery 2019;26(1):26-32
OBJECTIVES:
To present the latest knowledge on spine surgery using augmented reality (AR).SUMMARY OF LITERATURE REVIEW: AR is a new technology that simulates interactions with real-world surroundings using computer graphics, and it is a field that has recently been highlighted as part of the fourth industrial revolution.
MATERIALS AND METHODS:
Review of related literature and introduction of latest research.
RESULTS:
Spine surgery using AR is currently in its early stages. If industry, academia, and research institutes cooperate and develop, spine surgery using AR is highly likely to develop to the next level.
CONCLUSIONS
Spine surgeons should strive to develop relevant technology.
8.The Prevalence of Rapid Eye Movement Sleep Behavior Disorder in Amyloid Positron Emission Tomography Positive Alzheimer's Disease
Hyun Suk KIM ; Hyun Joon LEE ; Dong Jin SHIN ; Yeong Bae LEE ; Young NOH ; Kee Hyung PARK
Journal of Sleep Medicine 2019;16(2):102-108
OBJECTIVES:
Rapid eye movement (REM) sleep behavior disorder (RBD) is well known as a prodromal symptom of neurodegenerative disease, especially α-synucleinopathy. In the previous literature, it has been reported the incidence rate of RBD in Alzheimer's disease (AD) is about 10%. This incidence rate is relatively low, if we consider that nearly half of AD patients also have Lewy body pathology. The objective of this study is to determine the incidence rate of RBD among patients with AD, confirmed by amyloid positron emission tomography (PET) image.
METHODS:
We enrolled 57 patients with clinically probable AD patients who identified AD pathology in amyloid PET scan. RBD was evaluated with REM sleep behavior disorder questionnaire-Korean vesion (RBDQ-KR), which validated the RBD screening questionnaire as Korean version to confirm RBD. Detailed neuropsychological tests were measured using the Seoul Neuropsychological Screening Battery (SNSB).
RESULTS:
We analyzed RBDQ-KR data collected from 57 AD patients. Dementia due to AD was 36 patients (63.2%) and mild cognitive impairment (MCI) due to AD was 21 (36.8%). AD with RBD was 14 (24.6%). Among these, AD dementia with RBD was 13 (36.1%), and MCI due to AD with RBD was 1 (4.8%). There were no significant differences in cognitive function between the patients with or without RBD, evaluated by detailed neuropsychological test.
CONCLUSIONS
In this study, the incidence of RBD in AD was not rare; therefore, if the patient shows symptoms of RBD, we should not rule out AD.
9.Spine Surgery Using Augmented Reality
Sang Min PARK ; Ho Joong KIM ; Jin S YEOM ; Yeong Gil SHIN
Journal of Korean Society of Spine Surgery 2019;26(1):26-32
STUDY DESIGN: Review article. OBJECTIVES: To present the latest knowledge on spine surgery using augmented reality (AR). SUMMARY OF LITERATURE REVIEW: AR is a new technology that simulates interactions with real-world surroundings using computer graphics, and it is a field that has recently been highlighted as part of the fourth industrial revolution. MATERIALS AND METHODS: Review of related literature and introduction of latest research. RESULTS: Spine surgery using AR is currently in its early stages. If industry, academia, and research institutes cooperate and develop, spine surgery using AR is highly likely to develop to the next level. CONCLUSIONS: Spine surgeons should strive to develop relevant technology.
Academies and Institutes
;
Computer Graphics
;
Spine
;
Surgeons
10.Pontine Infarct Presenting as Peripheral Type Unilateral Facial Palsy.
Hyun Suk KIM ; Gap Su KIM ; Yeong Bae LEE ; Kee Hyung PARK ; Hyeon Mi PARK ; Dong Jin SHIN ; Young Hee SUNG ; Dong Hoon SHIN
Journal of the Korean Neurological Association 2017;35(2):89-91
Acute peripheral facial palsy usually manifests Bell's palsy of unknown cause, and rarely lacunar infarct which located in facial nucleus can mimic peripheral facial palsy. A 73 year-old man with isolated facial asymmetry diagnosed with lacunar infarction which selectively involve the facial fascicles which lie in inferolateral aspect of pons. Clinicians should take into account the possibility of central lesion and brain stem infarction, even when patients present with isolated peripheral type facial palsy.
Bell Palsy
;
Brain Stem Infarctions
;
Facial Asymmetry
;
Facial Nucleus
;
Facial Paralysis*
;
Humans
;
Pons
;
Stroke, Lacunar

Result Analysis
Print
Save
E-mail