• Applied Microscopy
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• 제42권4호
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• pp.200-206
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• 2012

Induction of neurogenesis can occur in the hippocampus in response to various pathological conditions, such as Alzheimer's disease. The aim of this study was to investigate the changes that occur in endogenous neural stem cells in response to amyloid beta $(A{\beta})_{25-35}$-induced neuronal cell damage in organotypic hippocampal slice cultures. Cresyl violet staining and Fluoro-Jade B staining were used to detect neuronal cell damage and changes of mossy fiber terminals were observed by Timm's staining. The immunofl uorescence staining was used to detect the newly generated cells in the subgranular zone (SGZ) of the dentate gyrus with specific marker, 5-bromo-2'-deoxyuridine (BrdU), Ki-67, Nestin, and doublecortin (DCX). In compared to control slices, neuronal cell damage was observed and the mossy fibers were expanded to CA3 area by treatment with $A{\beta}_{25-35}$. Ki-67/Nestin- and BrdU/DCX-positive cells were detected in the SGZ. In conclusion, these results demonstrate that $A{\beta}$-induced neuronal damage results in an increase in endogenous neural stem cells in rat hippocampal slice cultures not only for gliosis but also for neurogenesis.

• 한국식품영양학회지
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• 제12권5호
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• pp.478-483
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• 1999

This study was conducted to investigate functional properties of 70% acetone extract in different parts of two potato varieties. 'Superior' and 'Atlantic' potato were processed by following method. Potatoes are washed, peeled, sliced and steamed before hot air drying for flesh and peel powder. Hunter's L and b values of flesh powder from blanched 'Superior' potato were higher than flesh powder from fresh 'Superior' potato. Discoloration of 'Superior' potato was inhibited by steam blanching. Contents of total polyphenol and chlorogenic acid in the 70% acetone extract of 'Superior' potato were higher than those of 'Atlantic' potato paticularly in the blanched flesh and peel. But flavonoid was not detected in flesh extract. The phenolic concentration was not decreased by the heat treatment. The nitritescavenging and electron donating ability was greatest at the tuber peel including the skin and cortex tissue 1mm beneath the skin. From the above results browning reaction and polyphenol contents in different parts of potato slices were dependent on cutivars. Peels contained more polyphenols than those from the flesh. The results indicate that potato peel extract of steam blanched plus hot air dried potato tuber showed the effectiveness as a natural nitrite scavenger and antioxidant.

• 동아시아식생활학회지
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• 제27권3호
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• pp.295-303
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• 2017

Physicochemical and antioxidant activity characteristics of radish pickles added with different amounts of stevia leaf (0, 1.0, 2.0, and 3.0 g) were investigated. Radish slices ($4{\times}4{\times}4cm$) were salted with NaCl, soaked into pickling solution added with different amounts of stevia leaf, and then stored at $4^{\circ}C$ for 6 months. Throughout the whole storage periods, L and b values of radish pickles increased significantly with increasing amount of stevia leaf, whereas a value decreased. Hardness and strength increased significantly with increasing amount of stevia leaf during the storage period. Antioxidant compound contents and antioxidant activity increased significantly with increasing amount of stevia leaf. These results are expected to be useful in producing stevia leaf radish pickles with antioxidant activity and we propose the manufacture and commercialization of radish pickles added with 2.0 g of stevia leaf.

• Computers and Concrete
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• 제11권5호
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• pp.383-397
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• 2013

Two-dimensional tensile stresses are occurring at the back of the anchorage of the tendons of prestressed concrete bridges. A new method named "tensile stress region" for the design of the reinforcement is presented in this paper. The basic idea of this approach is the division of an anchor block into several slices, which are described by the tensile stress region. The orthogonal reinforcing wire mesh can be designed in each slice to resist the tensile stresses. Additionally the sum of the depth of every slice defined by the tensile stress region is used to control the required length of the longitudinal reinforcement bars. An example for the reinforcement design of an anchorage block of an external prestressed concrete bridge is analyzed by means of the new presented method and a finite element model is established to compare the results. Furthermore the influence of the transverse and vertical prestressing on the ordinary reinforcement design is taken into account. The results show that the amount of reinforcement bars at the anchorage block is influenced by the layout of the transverse and the vertical prestressing tendons. Using the "tensile stress region" method, the ordinary reinforcement bars can be designed more precisely compared to the design codes, and arranged according to the stress state in every slice.

• 한국축산식품학회지
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• 제39권1호
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• pp.121-138
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• 2019

In the present study, comparative efficacy of natural as well as synthetic tenderizers on the quality characteristics of restructured spent hen meat slices (RSHS) was studied. Four different batches of RSHS viz. Control (without any tenderizer), T1 (1.25% calcium chloride replacing salt in formulation), T2 and T3 (1.5% each of pineapple rind and fig powder, replacing binder in the formulation) were developed in pre-standardized formulation. Vacuum tumbling was performed for 2.5 h and cooked product (RSHS) was assayed for quality attributes. Samples were packaged in aerobic conditions, stored for 21 days under refrigeration ($4{\pm}1^{\circ}C$) and were evaluated for pH, oxidative and microbial quality parameters at regular interval of 7 days. Water holding capacity of T2 was recorded the highest and significantly higher (p<0.05) than all other samples. The textural attributes of T2 were comparable to T1 but significantly higher (p<0.05) than C and T3. The colour attributes ($L^*$, $a^*$, and $b^*$ value) of T2 and T3 were improved due to use of natural tenderizers. During sensory evaluation, tenderness scores for T2 samples were recorded the highest. Throughout storage period, thiobarbituric acid reactive substances (TBARS), free fatty acids (FFA) and peroxide value (PV) followed an increasing trend for control as well as treated products; however, T2 showed a significantly (p<0.05) lower value than control and other treated samples. It can be concluded that good quality RSHS with better storage stability could be prepared by utilizing 1.5% pineapple rind powder as natural tenderizer.

• The Korean Journal of Physiology and Pharmacology
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• 제8권2호
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• pp.69-76
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• 2004

A variety of G protein coupled receptors (GPCRs) are expressed in the presynaptic terminals of central and peripheral synapses and play regulatory roles in transmitter release. The patch-clamp whole-cell recording technique, applied to the calyx of Held presynaptic terminal in brainstem slices of rodents, has made it possible to directly examine intracellular mechanisms underlying the GPCR-mediated presynaptic inhibition. At the calyx of Held, bath-application of agonists for GPCRs such as $GABA_B$ receptors, group III metabotropic glutamate receptors (mGluRs), adenosine $A_1$ receptors, or adrenaline ${\alpha}2$ receptors, attenuate evoked transmitter release via inhibiting voltage-activated $Ca^{2+}$ currents without affecting voltage-activated $K^+$ currents or inwardly rectifying $K^+$ currents. Furthermore, inhibition of voltage-activated $Ca^{2+}$ currents fully explains the magnitude of GPCR-mediated presynaptic inhibition, indicating no essential involvement of exocytotic mechanisms in the downstream of $Ca^{2+}$ influx. Direct loadings of G protein ${\beta}{\gamma}$ subunit $(G{\beta}{\gamma})$ into the calyceal terminal mimic and occlude the inhibitory effect of a GPCR agonist on presynaptic $Ca^{2+}$ currents $(Ip_{Ca})$, suggesting that $G{\beta}{\gamma}$ mediates presynaptic inhibition by GPCRs. Among presynaptic GPCRs glutamate and adenosine autoreceptors play regulatory roles in transmitter release during early postnatal period when the release probability (p) is high, but these functions are lost concomitantly with a decrease in p during postnatal development.

• The Journal of Advanced Prosthodontics
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• 제8권2호
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• pp.101-109
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• 2016

PURPOSE. To investigate the void parameters within the resin cements used for fiber post cementation by micro-CT (${\mu}CT$) and regional push-out bonding strength. MATERIALS AND METHODS. Twenty-one, single and round shaped roots were enlarged with a low-speed drill following by endodontic treatment. The roots were divided into three groups (n=7) and fiber posts were cemented with Maxcem Elite, Multilink N and Superbond C&B resin cements. Specimens were scanned using ${\mu}CT$ scanner at resolution of $13.7{\mu}m$. The number, area, and volume of voids between dentin and post were evaluated. A method of analysis based on the post segmentation was used, and coronal, middle and apical thirds considered separately. After the ${\mu}CT$ analysis, roots were embedded in epoxy resin and sectioned into 2 mm thick slices (63 sections in total). Push-out testing was performed with universal testing device at 0.5 mm/min cross-head speed. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests (${\alpha}=.05$). RESULTS. Overall, significant differences between the resin cements and the post level were observed in the void number, area, and volume (P<.05). Super-Bond C&B showed the most void formation ($44.86{\pm}22.71$). Multilink N showed the least void surface ($3.51{\pm}2.24mm^2$) and volume ($0.01{\pm}0.01mm^3$). Regional push-out bond strength of the cements was not different (P>.05). CONCLUSION. ${\mu}CT$ proved to be a powerful non-destructive 3D analysis tool for visualizing the void parameters. Multilink N had the lowest void parameters. When efficiency of all cements was evaluated, direct relationship between the post region and push-out bonding strength was not observed.

• 한국식품저장유통학회지
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• 제17권2호
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• pp.202-207
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• 2010

신선절단 '홍옥' 사과의 저장 중 품질에 대한 초음파 및 ascorbic acid의 병용처리의 효과를 조사하였다. 준비한 사과 절편을 초음파 처리(US), ascorbic acid 용액 침지처리(AA), 초음파 및 ascorbic acid 병용 처리(UA) 하였으며 $10^{\circ}C$에서 12일간 저장하였다. UA 처리구에서는 높은 $L^{*}$ 및 hue 값과 낮은 $a^{*}$, $b^{*}$, chroma 및 ${\Delta}E$값이 관찰되었으나 반면 무처리구와 US 처리구에서는 상당한 수준의 갈변이 관찰되었다. UA 처리에 의하여 유의적으로 높은 수준의 polyphenol oxidase 활성 억제가 확인되었으며 처리 당일 UA 처리구에서 다른 처리구에 비해 높은 수준의 총 페놀성 화합물 함량이 측정되었고 모든 처리구에서 총 가용성 고형분 함량, pH, 적정산도 및 포장 내 가스 농도는 큰 차이를 보이지 않았다. 따라서 초음파와 ascorbic acid의 병용처리가 신선절단 '홍옥' 사과의 효소적 갈변억제와 총 페놀성 화합물 함량의 유지에 효과가 있음을 확인하였다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.489-492
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• 1997

The general pattern of adaptation in the appendicular skeleton with aging is that the subperiosteal apposition of bone occur along with endosteal absorption. This remodeling of diaphysis to a cylinder of larger diameter is hypothesized to serve a mechanical compensatory unction by increasing the moment of inertia as the cortex thins with aging. These findings is only true of the diaphysis of long bone. Measuring the area and inertia at each section of femur, the age-related change of proximal emur and diaphysis is observed. After screening by physical and radiological examination, 200 normal Korean adults divided 5 groups in both male and female based on age. Twenty persons were in each group. One femur in each person was analyzed using CT images. femur scanned with 60 to 80 slices and this images were digitized. Then 2-D images were reconstructed into 3-D images. Using the nonlinear method, normalization and interpolation technique, 7 locations of interest (trochanteric area: 1, 2 subtrochanteric area: 3, 4, isthmic area: 5, 6, 7) were determined. On the each cross section at each location, the area (total, cortical and medullary) and 5 inertia of moment were measured. The results were analyzed statistically. With aging, significant area change occurred mainly in diaphysis and female. In trochanteric area, no significant change was noted. With aging, total and medullary area were increased, but cortical area was not changed. In diaphysis, lateral bendingresistanceincreasedsignificantly. No inertia change was noted in trochanteric area. Anteroposterior bending resistance was constant with aging. In more than age 60, total area and medullary area were larger than that of others. Lateral bending resistance was higher especially in diaphysis. In diaphysis, with aging, the decreased properties is compensated with the increased lateral bending resistance by geometric remodeling. In trochanteric area, no compensation occur. With aging, especially in more than age 60, the higher rate of trochanteric fracture is expected.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.590-592
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• 1997

Making physical models of human body is not only time-consuming but also very expensive since they are usually hand-made. This problem is doubled with implant fabrication because an implant is almost always custom-made. Recently, RP is emerging as an alternative, and many RP applications are proposed in the medical field. The major advantage of this approach is due to a significant reduction of both time and cost required or the production. However, the technology is not much in practical use yet, especially in Korea. In this paper, we provide a method of generating STL files that are the standard format to RP machines. The original data are obtained from two-dimensional slices of MRI/CT machine. Example bone models have been produced using a commercially available RP machine, and the results are presented.