• Communications of Mathematical Education
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• v.3
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• pp.229-249
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• 1997

폴리아가 그의 저서 ‘How to Solve It.'에서 주창한 문제 해결의 모형은 이렇게 해석될 수 있다. 곧, 절대 다수의 수학 문제는 조건문 (p${\rightarrow}$q)의 명제 형식으로 분해된다는 것이다. 그리하여 순조롭게 발생되는 문제 해법의 전과정은 아래와 같이 마치 징검다리를 놓듯 추이율(transitivity)을 연거퍼 적용하는(이른바 연추적이라 함) 절차이다. (p: 주어진 정보) ${\rightarrow}$ ${\cdots}$ ${\rightarrow}$ ${\cdots}$ ${\rightarrow}$ (구하는 정보: q) 이것은, 일반적으로, 추이율이 성립하는 모든 관계(relation)의 연추적 확인 과정으로 확장될 수 있다. 요컨대 항진식 (p${\rightarrow}$r) ${\wedge}$ (r${\rightarrow}$q) ${\rightarrow}$ (p${\rightarrow}$q)의 보장 아래 관계의 추이율 xRz ${\wedge}$ zRy ${\rightarrow}$ xRy 로 연결되는 온갖 경로를 포괄한다. 이상과 같이 정식화되는 이 도식의 한계와 효용은 (1) 모든 문제가 조건문의 형태를 갖추고 있는 것은 아니며, (2) 조건문 형식의 문제라도 해법이 반드시 연추적으로 발생되는 법도 아니고, (3) 더구나 이것이 해법 발생의 만능 열쇠는 아닐뿐더러, (4) 발상을 촉진하는 데는 교육공학적으로 더 정교한 배려가 필요하므로, (5) 초보 단계에서 행동 수정을 위한 치유 목적으로 사용됨이 바람직하다.

• The Korean Journal of Pharmacology
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• v.31 no.2
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• pp.207-217
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• 1995

To investigate the functional and immunological properties of the Ca-release channel in the sarcoplasmic reticulum(SR) of the eel skeletal muscle, $[^3H]ryanodine$ binding, SDS gel electrophoresis, $^{45}Ca\;release$ studies, and immunoblot assay were carried out in the SR of the eel skeletal muscle. Maximal binding sites(Bmax) and $K_D$ values of $[^3H]ryanodine$ for Ca-release channel of the SR of the eel skeletal muscle were $19.44{\pm}1.40\;pmole/mg$ protein and $15.55{\pm}1.69\;nM$, respectively. $[^3H]Ryanodine$ binding to RyR was increased by calcium and AMP. The SR of the eel skeletal muscle has two high molecular weight bands on the SDS PAGE. The mobility of upper band was more slower than the single band of the rabbit skeletal muscle, and that of the lower band was similar with the single band of canine cardiac muscle. Vesicular $^{45}Ca-release$ was activated by calcium. Ca-induced $^{45}Ca-release$ was significantly inhibited by $MgCl_2(2\;mM)$, ruthenium red$(10\;{/mu}M)$ or tetracaine(1 mM), but not by high concentration of calcium itself. AMP-induced $^{45}Ca-release$ was slightly occurred only in the absence of calcium, it was not inhibited by $MgCl_2$ or ruthenium red. Caffeine also increased $^{45}Ca-release$ from the SR vesicles, but it was not affected by $MgCl_2$ or ruthenium red. Polyclonal Ab against rat skeletal muscle RyR is reacted with that of rabbit, but not reacted with that of the eel skeletal muscle. These results suggested that ryanodine receptor of the SR of the eel skeletal muscle is showing some similar properties with that of mammalian skeletal muscle, but might be an another isotype channel having two bands which is less sensitive to AMP, not cross-reacted with antisera against rat RyR, and not inhibited by high concentration of calcium.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.05a
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• pp.361-362
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• 2006

HUE05-1는 Bjerkandera adusta와 87.7% 정도만이 유사도를 갖고 있는 다른 새로운 종의 색도제거능력이 있는 균주로 판별되었으며, RO 16, RB 19, RB 49, RY 145, AO 10, AV 43, AB 350, DB 106등의 8가지 염료에 대하여 우수한 색도제거효과를 보였다.

• Proceedings of the Korean Society of Veterinary Clinics Conference
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• 2009.04a
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• pp.279-279
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• 2009

• Proceedings of the Korean Biophysical Society Conference
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• 2001.06a
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• pp.46-46
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• 2001

Evidence has suggested that an anion channel blocker, 4, 4'-diisothiocyanatostilbene-2, 2' disulfonic acid (DIDS) could trigger Ca release from skeletal sarcoplasmic reticulum (SR) by binding to a 30 kDa SR protein. Since the high molecular weight $Ca^{2＋}$ release channel (CRC)/ryanodine receptor (RyR) is the main SR protein that conducts $Ca^{2＋}$ efflux in skeletal muscles, the relationship between CRC and the 30kDa protein remains to be elucidated.(omitted)

• The Pure and Applied Mathematics
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• v.2 no.2
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• pp.149-156
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• 1995

In stability theory of polysystems two concepts that playa very important role are the limit set and the prolongational limit set. For the above two concepts, A.Bacciotti and N.Kalouptsidis studied their properties in a locally compact metric space [2]. In this paper we investigate their results in c-first countable space which is more a general space than a metric space.(omitted)

• Journal of Chest Surgery
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• v.18 no.4
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• pp.615-622
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• 1985

Supravalvular aortic stenosis was relatively uncommon form of congenital heart disease. This patient had typical "elfin faces" with mental retardation, and supravalvular aortic stenosis. The diagnosis was confirmed by pressure tracing obtained at retrograde left heart catheterization and aortography. The type of supravalvular aortic stenosis was localized hourglass narrowing, which was treated by insertion of prosthetic gusset placed across the area of narrowing under the cardiopulmonary bypass.ry bypass.

• Molecules and Cells
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• v.20 no.1
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• pp.51-56
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• 2005

Excitation-contraction coupling (ECC) proteins in the human heart were characterized using human atrial tissues from different age groups. The samples were classified into one infant group (Group A: 0.2-7 years old) and three adult groups (Group B: 21-30; Group C: 41-49; Group D: 60-66). Whole homogenates (WH) of atrial tissues were assayed for ligand binding, $^{45}Ca^{2+}$ uptake and content of ECC proteins by Western blotting. Equilibrium [$^3H$]ryanodine binding to characterize the ryanodine receptor (RyR) of the sarcoplasmic reticulum (SR) showed that the maximal [$^3H$]ryanodine binding ($B_{max}$) to RyR was similar in all the age groups, but the dissociation constant ($k_d$) of ryanodine was higher in the infant group than the adult groups. Oxalate-supported $^{45}Ca^{2+}$ uptake into the SR, a function of the SR SERCA2a activity, was lower in the infant group than in the adult groups. Similarly, [$^3H$]PN200-110 binding, an index of dihydropyridine receptor (DHPR) density, was lower in the infant group. Expression of calsequestrin and triadin assessed by Western blotting was similar in the infant and adult groups, but junctin expression was considerably higher in the adult groups. These differences in key ECC proteins could underlie the different $Ca^{2+}$ handling properties and contractility of infant hearts.

• YAKHAK HOEJI
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• v.59 no.4
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• pp.158-163
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• 2015

Cardiac myocytes are subjected to fluid shear stress during each contraction and relaxation. Under pathological conditions, such as valve disease, heart failure or hypertension, shear stress in cardiac chamber increases due to high blood volume and pressure. The shear stress induces proarrhythmic longitudinal global $Ca^{2+}$ waves in atrial myocytes. In the present study, we further explored underlying cellular mechanism for the shear stress-induced longitudinal global $Ca^{2+}$ wave in isolated rat atrial myocytes. A shear stress of ${\sim}16dyn/cm^2$ was applied onto entire single myocyte using pressurized fluid puffing. Confocal $Ca^{2+}$ imaging was performed to measure local and global $Ca^{2+}$ signals. Shear stress elicited longitudinally propagating global $Ca^{2+}$ wave (${\sim}80{\mu}m/s$). The occurrence of shear stress-induced atrial $Ca^{2+}$ wave was eliminated by the inhibition of ryanodine receptors (RyRs) or inositol 1,4,5-trisphosphate receptors ($IP_3Rs$). In addition, pretreatment of phospholipase C (PLC) inhibitor U73122, but not its inactive analogue U73343, abolished the generation of longitudinal $Ca^{2+}$ wave under shear stress. Our data suggest that shear-induced longitudinal $Ca^{2+}$ wave may be induced by $Ca^{2+}$-induced $Ca^{2+}$ release through the RyRs which is triggered by $PLC-IP_3R$ signaling in atrial myocytes.

• Journal of Gastric Cancer
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• v.22 no.3
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• pp.220-234
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• 2022

Purpose: The incidence of adenocarcinoma of the esophagogastric junction (AEG) has increased in recent years, and the optimal surgical strategy for AEG remains highly controversial. We aimed to evaluate the safety and efficacy of proximal gastrectomy with double-tract reconstruction (PG-DT) for the treatment of patients with AEG. Materials and Methods: We retrospectively analyzed patients with Siewert type II/III AEG between January 2013 and July 2018. Clinicopathological characteristics, survival, surgical outcomes, quality of life (QOL), and nutritional status were compared between the PG-DT and total gastrectomy with Roux-en-Y anastomosis (TG-RY) groups. Results: After propensity score matching, 33 patients in each group were analyzed. There were no statistical differences between the 2 groups in terms of disease-free survival and overall survival. The surgical option was not an independent prognostic factor based on the multivariate analysis. In addition, no differences were found in terms of surgical complications. There were no significant differences in QOL assessed by the Visick grade, Gastrointestinal Symptom Rating Scale, or endoscopic findings. Furthermore, the long-term nutritional advantage of the PG-DT group was significantly greater than that of the TG-RY group. Conclusions: PG-DT is a safe and effective procedure for patients with local Siewert type II/III AEG, regardless of the TNM stage.