치과 재료용 NiTi 합금의 특성에 대한 Ag 첨가의 영향

오근택,박기호,심형민,황충주,김경남 大韓齒科器材學會 2001 대한치과재료학회지 Vol.28 No.4

Equiatomic and near-equiatomic nickel-titanium alloys have shape memory effect and superelasticity. However nickel-titanium alloys are extremely sensitive to the precise nickel-titanium ratio and alloying additions. There are many reports on the alloying additions such as Fe, Al, Cr, Co, V, Pt, Pd, Zr, Hf, Nb and Cu. The purpose of this study was to investigate the effect of silver addition to nickel-titanium alloy for dental and medical application.Arc melting process was used to fabricate nickel-titanium alloys. The casts were heat-treated in a vacuum furnace at 950℃ for 72 hours to homogenize their composition. Subsequently, they were hot-rolled at 950℃ to obtain the plate samples and annealed in a vacuum furnace at 950℃. To investigate the properties of nickel-titanium alloys, phases, transformation temperature, compositions, corrosion resistance and hardness were evaluated using X-ray diffractometer, differential scanning calorimeter, energy dispersive spectroscopy or atomic absorption spectroscopy, potentiostat and micro-vickers hardness tester, respectively. NiTiAg alloys showed the low silver recovery rate for the cast due to its low evaporation temperature, and showed low silver solubility to NiTi alloy. Silver addition to NiTi alloy increased transition temperature range (TTR) above 100℃ and stabilized martensitic phase(monoclinic structure) at room temperature because Ms temperature was above room temperature. Martensitic and austenitic phase existed in x-ray diffraction pattern of solution annealed NiTiAg alloys. The Silver addition is considered to improve corrosion resistance and change largely the mechanical properties depending upon the amount of alloying addition and types of addition elements.

Wolff-Parkinson-White증후군의 임상상 및 전기생리학적 소견

안신기,이문형,장양수,오동진,최인석,하종원,임세중,김병옥,정남식,심원흠,조승연,김성순 대한순환기학회 1997 Korean Circulation Journal Vol.27 No.9

Rehabilitation Program for Improved Musculoskeletal Pain in Gastrointestinal Endoscopists: Multicenter Prospective Cohort Study

Nam Su Youn,Nam Kwangwoo,Shim Ki-Nam,Yang Seoyon,Tae Chung Hyun,Jo Junwoo,Kim Nayoung,Park Seon Mi,Park Young Sook,Park Seun Ja,Jung Sung-Ae 거트앤리버 소화기연관학회협의회 2023 Gut and Liver Vol.17 No.6

Background/Aims: This study aimed to develop a rehabilitation program for musculoskeletal pain experienced by gastrointestinal endoscopists and to investigate its usefulness. Methods: This was a multicenter cohort study. During the first 2 weeks, a questionnaire regarding daily workload and musculoskeletal symptoms was administered. Then, a rehabilitation program including equipment/posture correction and stretching was conducted during the remaining 6 weeks. Follow-up daily workload and musculoskeletal symptom surveys were distributed during the last 2 weeks. The program satisfaction survey was performed at the 6th and 8th weeks. Results: Among 118 participants (69 men), 94% (n=111) complained of musculoskeletal pain at baseline. Various hospital activities at baseline were associated with multisite musculoskeletal pain, whereas only a few workloads were correlated with musculoskeletal pain after the rehabilitation program. Follow-up musculoskeletal pain was negatively correlated with equipment/posture program performance; arm/elbow pain was negatively correlated with elbow (R=–0.307) and wrist (R=–0.205) posture; leg/foot pain was negatively correlated with monitor position, shoulder, elbow, wrist, leg, and foot posture. Higher performance in the scope position (86.8% in the improvement vs 71.3% in the aggravation group, p=0.054) and table height (94.1% vs 79.1%, p=0.054) were associated with pain improvement. An increased number of colonoscopy procedures (6.27 in the aggravation vs 0.02 in the improvement group, p=0.017) was associated with pain aggravation. Most participants reported being average (32%) or satisfied (67%) with the program at the end of the study. Conclusions: Our rehabilitation program is easily applicable, satisfactory, and helpful for improving the musculoskeletal pain experienced by gastrointestinal endoscopists.

Socioeconomic burden of sugar-sweetened beverages consumption in Korea

Jee-Seon Shim,Nam Hoon Kang,Jung Sug Lee,Ki Nam Kim,Hae Kyung Chung,Hae Rang Chung,Hung-Ju Kim,Yoon-Sook Ahn,Moon-Jeong Chang 한국영양학회 2019 Nutrition Research and Practice Vol.13 No.2

BACKGROUND/OBJECTIVES: Excessive sugar consumption may increase the risk for development of several diseases. Although average dietary sugar intake of Koreans is within the recommended level, an increasing trend has been found in all age groups. This study aimed to evaluate the population attributable fractions (PAF) to dietary sugar for disease and death in Korea, and to estimate the socioeconomic effects of a reduction in dietary sugar. MATERIALS/METHODS: The prevalence of sugar-sweetened beverages (SSB) overconsumption (≥ 20 g of sugar from beverages) was analyzed using the Korean National Health and Nutrition Examination Survey 2015. Disease-specific relative risks of excessive SSB consumption were obtained through reviewing previous studies. Using the prevalence of SSB overconsumption and each relative risk, PAFs for morbidity and mortality were calculated. Socioeconomic costs of diseases and death attributable to SSB overconsumption were estimated by using representative data on national medical expenditures, health insurance statistics, employment information, and previous reports. RESULTS: Disease-specific PAF to SSB consumption ranged from 3.11% for stroke to 9.05% for obesity and dental caries, respectively. Costs from disease caused by SSB overconsumption was estimated at 594 billion won in 2015. About 39 billion won was estimated to be from SSB consumption-related deaths, and a total of 633 billion won was predicted to have been saved through preventing SSB overconsumption. CONCLUSIONS: Sugars overconsumption causes considerable public burdens, although the cost estimates do not include any informal expenditure. Information on these socioeconomic effects helps both health professionals and policy makers to create and to implement programs for reducing sugar consumption.

Diagnostic Performance of a Novel Method for Fractional Flow Reserve Computed from Noninvasive Computed Tomography Angiography (NOVEL-FLOW Study)

Chung, J.H.,Lee, K.E.,Nam, C.W.,Doh, J.H.,Kim, H.I.,Kwon, S.S.,Shim, E.B.,Shin, E.S. Cahners Pub. Co., etc.] ; Elsevier Science Ltd 2017 The American Journal of Cardiology Vol.120 No.3

Coronary computed tomography angiography (CCTA)-derived fractional flow reserve from computed tomography (CT-FFR) may provide better diagnostic performance over CCTA alone, but the complexity of its method limits the use in clinical environment. The aim of the present study is to validate a newly developed vessel-length based computational fluid dynamics scheme for the computation of FFR based on CCTA data, compare them with invasively measured FFR, and evaluate its diagnostic performance with that of CCTA. One hundred seventeen patients from 4 medical institutions who had clinically indicated invasive coronary angiography for suspected coronary artery disease (CAD) were enrolled. Invasive FFR measurement was performed in 218 vessels and these measurements were regarded as the reference standard. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CT-FFR on a per-vessel basis were 85.8%, 86.2%, 85.5%, 79.8%, and 90.3%, respectively, for CT-FFR @?0.80, and 66.1%, 75.9%, 59.5%, 55.5%, and 78.8%, respectively, for CCTA ≥50%. A higher area under the receiver operating characteristic curve for CT-FFR was observed compared with CCTA (0.93 vs 0.74, p <0.0001). The CT-FFR and FFR correlated well (r = 0.76, p <0.001) with slight underestimation by CT-FFR (0.014 +/- 0.077, p = 0.007). With a novel method of vessel-length based computational fluid dynamics scheme, CT-FFR can be performed at a personal computer enhancing its applicability in clinical situation. The diagnostic accuracy of CT-FFR for the detection of functionally significant CAD was good and was superior to that of CCTA within a population of suspected CAD.

BRCA1 and XRCC1 polymorphisms associated with survival in advanced gastric cancer treated with taxane and cisplatin

Shim, Hyun Jeong,Yun, Joo Young,Hwang, Jun Eul,Bae, Woo Kyun,Cho, Sang Hee,Lee, Ji Hee,Kim, Hee Nam,Shin, Min Ho,Kweon, Sun Seog,Lee, Jae Hyuk,Kim, Hyeoung Joon,Chung, Ik Joo Wiley (Blackwell Publishing) 2010 CANCER SCIENCE Vol.101 No.5

콩의 倒伏에 影響하는 生育形質 및 遺傳分析 Ⅰ. 倒伏에 미치는 生育形質의 影響

Nam Jin Chung(丁南眞),Jae Wook Shim(沈載昱) 한국육종학회 1990 한국육종학회지 Vol.22 No.1

The growth characters influencing the lodging degrees were examined in 10 cultivars of soybean under dense spacing and heavy dressing. Among major growth characters of soybean which related to lodging, plant height, number of branch and LAI were correlated positively to lodging and stem diameter and root dry weight were correlated negatively to lodging. The dominant factors related to lodging analyzed by path coefficient were number of branch and LAI, which were closely related to the decrease of light penetration into the canopy. Also the light penetration rate showed significant negative correlation with lodging degree, suggesting that the main factor of lodging under dense spacing and heavy dressing whould be the decrease of light penetration into soybean canopy.

Corrosion resistance of titanium–silver alloys in an artificial saliva containing fluoride ions

Shim, Hyung-Min,Oh, Keun-Taek,Woo, Jae-Young,Hwang, Chung-Ju,Kim, Kyoung-Nam Wiley Subscription Services, Inc., A Wiley Company 2005 Journal of biomedical materials research. Part B, Vol.b73 No.2

<P>Dental gels and rinses for caries prophylactic contain fluoride at concentrations ranging from 0.1 to 1%. In addition, many types of fluoride-releasing materials have been used in dental applications. The purpose of the study was to investigate the addition effect of fluoride into artificial saliva on the corrosion resistance of pure titanium and titanium–silver alloys. Titanium and titanium–silver alloys were arc melted, homogenized at 950°C for 72 h, hot rolled, and solution heat treated and quenched. In order to investigate the effect of the fluoride ions on the corrosion resistance, potentiodynamic polarization testing, potentiostatic testing, and open-circuit potential measurements were performed in plain artificial saliva and 0.1 and 1% NaF-added artificial saliva. The passive current densities of titanium and titanium–silver alloys increased with increasing fluoride-ion concentration. Ti2.0Ag and Ti3.0Ag exhibited a low current density relatively and showed a stable behavior compared to titanium. The open-circuit potential of titanium decreased and current density at 250 mV (SCE) potentiostatic testing reacted sensitively with increasing fluoride concentration. On the other hand, the open-circuit potential of titanium–silver alloys with a high silver content (3.0–4.0 at %) reacted less sensitively to the fluoride-ion concentration. Among titanium–silver alloys, Ti3.0Ag alloy had a higher resistance against the attack of fluoride ions and showed a more stable open-circuit potential and current density than titanium in the fluoride-containing solution. It is concluded that they are electrochemically stable and maintained good corrosion resistance in fluoride-containing artificial saliva. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater</P>

Clinical Spectrum of Reflux Esophagitis Among 25,536 Koreans Who Underwent a Health Check-up: A Nationwide Multicenter Prospective, Endoscopy-based Study

Shim, Ki-Nam,Hong, Su Jin,Sung, Jae Kyu,Park, Kyung Sik,Kim, Seong-Eun,Park, Hyun-Shin,Kim, Young Sun,Lim, Seon Hee,Kim, Chung Hyeon,Park, Min Jung,Yim, Jeong Yoon,Cho, Kyung Ran,Kim, Donghee,Park, Se Lippincott WilliamsWilkins, Inc. 2009 JOURNAL OF CLINICAL GASTROENTEROLOGY Vol.43 No.7

BACKGROUND: Gastroesophageal reflux is a commonly encountered condition, but detailed data on reflux symptoms in Asian countries are lacking. GOALS: To evaluate the prevalence and to document the clinical spectrum of endoscopic reflux esophagitis (RE). STUDY: A total 25,536 subjects underwent an upper gastrointestinal endoscopic examination as part of a health check, and completed a gastroesophageal reflux questionnaire. Endoscopic findings classified according to the Los Angeles (LA) classification and the data from gastroesophageal reflux questionnaire were analyzed. RESULTS: On the basis of endoscopic findings, 2019 subjects (7.91%) were found to have RE: 5.87% in LA-A; 1.84% in LA-B; 0.18% in LA-C; and 0.02% in LA-D. Heartburn, acid regurgitation, chest pain, hoarseness, globus sensation, cough, and epigastric soreness were found to be associated with RE (P<0.05). Heartburn, acid regurgitation, and epigastric soreness were more frequent in LA-B than in LA-A (P<0.05). Epigastric soreness was most bothersome in LA-A and LA-B, and acid regurgitation was most bothersome in LA-C and LA-D (P<0.01). Heartburn, hoarseness, and globus sensation were more frequent in men with RE, and acid regurgitation was most common in women. CONCLUSIONS: The prevalence of RE was found to be 7.91% in Korea, and the profiles of reflux symptoms were found to depend on grade of RE and sex.

Clinical practice guidelines for percutaneous endoscopic gastrostomy

Chung Hyun Tae,Ju Yup Lee,Moon Kyung Joo,Chan Hyuk Park,Eun Jeong Gong,Cheol Min Shin,Hyun Lim,Hyuk Soon Choi,Miyoung Choi,Sang Hoon Kim,Chul-Hyun Lim,Jeong-Sik Byeon,Ki-Nam Shim,Geun Am Song,Moon Sun 대한소화기내시경학회 2023 Clinical Endoscopy Vol.56 No.4

With an aging population, the number of patients with difficulty in swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. However, the long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach that is aided endoscopically and may be an alternative to a nasogastric tube when enteral nutritional is required for four weeks or more. This paper is the first Korean clinical guideline for PEG developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tube removal for PEG based on the currently available clinical evidence.