• The Korean Journal of Physiology and Pharmacology
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• v.28 no.2
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• pp.165-181
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• 2024

The slow and regular pacemaking activity of midbrain dopamine (DA) neurons requires proper spatial organization of the excitable elements between the soma and dendritic compartments, but the somatodendritic organization is not clear. Here, we show that the dynamic interaction between the soma and multiple proximal dendritic compartments (PDCs) generates the slow pacemaking activity in DA neurons. In multipolar DA neurons, spontaneous action potentials (sAPs) consistently originate from the axon-bearing dendrite. However, when the axon initial segment was disabled, sAPs emerge randomly from various primary PDCs, indicating that multiple PDCs drive pacemaking. Ca²⁺ measurements and local stimulation/perturbation experiments suggest that the soma serves as a stably-oscillating inertial compartment, while multiple PDCs exhibit stochastic fluctuations and high excitability. Despite the stochastic and excitable nature of PDCs, their activities are balanced by the large centrally-connected inertial soma, resulting in the slow synchronized pacemaking rhythm. Furthermore, our electrophysiological experiments indicate that the soma and PDCs, with distinct characteristics, play different roles in glutamate-induced burst-pause firing patterns. Excitable PDCs mediate excitatory burst responses to glutamate, while the large inertial soma determines inhibitory pause responses to glutamate. Therefore, we could conclude that this somatodendritic organization serves as a common foundation for both pacemaker activity and evoked firing patterns in midbrain DA neurons.

• YAKHAK HOEJI
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• v.40 no.2
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• pp.155-162
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• 1996

Hyperkeratinization is a dermatologic disorder, which is due to the increase of corneocyte cohesion force. Glycolic acid, an alpha hydroxy acid(AHA), has been used to breakdown the hyperkeratinization processes. However, it has a problem of skin irritation when applied topically, due to the strong acidity especially in high concentration. A molecular optimization of glycolic acid has been tried to reduce the skin irritation by the way of prodrug formation. Ethyl glycolate was synthesized by the esterification of glycolic acid with ethanol in acidic conditions in the presence of sulfuric acid, and examined under the spectroscopic trials, such as UV, IR, $^1H$-NMR, and GC-MS. The physicochemical and biopharmaceutical properties of the prodrug were also evaluated. Through the toxicological tests of both skin irritation and eye mucous irritation, it has been proved that ethyl glycolate was less irritant than glycolic acid, since the pH value of synthetic prodrug was higher than that of glycolic acid. In the penetration test through nude mouse skin by diffusion cell, ethyl glycolate was continuously hydrolyzed to glycolic acid, which was assayed form the receptor compartment. It was obtained that the penetrated amount of ethyl glycolate was five times higher than that of glycolic acid. These results suggest that ethyl glycolate might be a successful prodrug of glycolic acid to reduce the skin irritation and to increase the skin penetration as well.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.6
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• pp.517-527
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• 2020

Layer 2/3 pyramidal neurons (L2/3 PyNs) of the cortex extend their basal dendrites near the soma and as apical dendritic tufts in layer 1, which mainly receive feedforward and feedback inputs, respectively. It is suggested that neuromodulators such as serotonin and acetylcholine may regulate the information flow between brain structures depending on the brain state. However, little is known about the dendritic compartment-specific induction of synaptic transmission in single PyNs. Here, we studied layer-specific serotonergic and cholinergic induction of long-term synaptic plasticity in L2/3 PyNs of the agranular insular cortex, a lateral component of the orbitofrontal cortex. Using FM1-43 dye unloading, we verified that local electrical stimulation to layers 1 (L1) and 3 (L3) activated axon terminals mostly located in L1 and perisomatic area (L2/3). Independent and AMPA receptor-mediated excitatory postsynaptic potential was evoked by local electrical stimulation of either L1 or L3. Application of serotonin (5-HT, 10 μM) induced activity-dependent longterm depression (LTD) in L2/3 but not in L1 inputs. LTD induced by 5-HT was blocked by the 5-HT₂ receptor antagonist ketanserin, an NMDA receptor antagonist and by intracellular Ca²⁺ chelation. The 5-HT₂ receptor agonist α-me-5-HT mimicked the LTD induced by 5-HT. However, the application of carbachol induced muscarinic receptor-dependent LTD in both inputs. The differential layer-specific induction of LTD by neuromodulators might play an important role in information processing mechanism of the prefrontal cortex.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.5
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• pp.115-123
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• 2010

Cool-down performance after soaking is important because it affects passenger's thermal comfort. The cooling capacity of HVAC system determines initial cool down performance in most cases, the performance is also affected by location, and shape of panel vent, indoor seat arrangement. Therefore, optimal indoor designs are required in developing a new car. In this paper, initial cool down performance is predicted by CFD(computational fluid dynamics) analysis. Experimental time-averaging temperature data are used as inlet boundary condition. For more reliable analysis, real vehicle model and human FE model are used in grid generation procedure. Thermal and aerodynamic characteristics on re-circulation cool vent mode are investigated using CFX 12.0. Thermal comfort represented by PMV(predicted mean vote) is evaluated using acquired numerical data. Temperature and velocity fields show that flow in passenger's compartment after soaking is considerably unstable at the view point of thermodynamics. Volume-averaged temperature is decreased exponentially during overall cool down process. However, temperature monitored at different 16 spots in CFX-Solver shows local variation in head, chest, knee, foot. The cooling speed at the head and chest nearby panel vent are relatively faster than at the knee and foot. Horizontal temperature contour shows asymmetric distribution because of the location of exhaust vent. By evaluating the passenger's thermal comfort, slowest cooling region is found at the driver's seat.

• Journal of Chest Surgery
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• v.44 no.5
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• pp.338-342
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• 2011

Background: The axillary artery is frequently used for cardiopulmonary bypass, especially in acute aortic dissection. We have cannulated the axillary artery using a side graft or by directly using Seldinger's technique. The purpose of this study was to assess the technical problems and complications of both cannulation techniques. Materials and Methods: From January 2003 to December 2009, 53 patients underwent operations using the axillary artery for arterial cannulation. The axillary artery was cannulated with a side graft in 35 patients (side graft group) and directly using Seldinger's technique in 18 patients (direct group). Results: The results were compared between two groups, focusing on cannulation-related morbidities including neurologic morbidity. Arterial damage or dissection of the axillary artery occurred in 1 (2.9%) patient in the side graft group and in 1 (5.6%) patient in the direct group. Malperfusion and insufficient flow did not occur in either group. There were no postoperative complications related to axillary cannulation, such as brachial plexus injury, compartment syndrome, or local wound infection, in either group. Conclusion: Technical problems and complications of the axillary arterial cannulation in both techniques were rare. Direct arterial cannulation using Seldinger's technique was done safely and more simply than the previous technique. It was concluded that both axillary arterial cannulation techniques are acceptable and it remains the surgeon's preference which technique should be used.

• Korean Journal of Head & Neck Oncology
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• v.17 no.2
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• pp.205-209
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• 2001

Purpose: Most cases of primary hyperparathyroidism are due to parathyroid adenoma or parathyroid hyperplasia. Parathyroid carcinoma is a very rare cause of hyperparathyroidism. Although the diagnosis of parathyroid carcinoma is usually established by pathologic criteria especially of vascular or capsular invasion, some clinical and biochemical features differentiate it from benign forms of hyperparathyroidism. We under-took a retrospective study in 6 patients with parathyroid carcinoma, with the aim of conveying experience from management for this rare cause of hyperparathyroidism. Methods: Clinical symptoms, biochemical laboratory, radiologic, and intraoperative findings, local recurrence and distant metastasis were analyzed in 6 patients diagnosed pathologically as a parathyroid carcinoma after operation from 1992 to 2001. Results: Mean age was 50.2 years (33.0-60.0 years) and male to female ratio was 1:1. Neck mass was found in 5 patients, multiple bone pain in 3 patients and renal stone in 1 patient. One case has suffered from chronic renal failure for 19 years. Although preoperative laboratory evaluations showed the aspects of hyperparathyroidism in all cases, mean serum calcium level was 11.2mg/dl(10.5-12.1mg/dl), slightly elevated. Laboratory values after surgery were within the normal range in 5 cases. However, in one case with chronic renal failure, serum PTH levels, serially checked, were above the normal range. Any of imaging methods failed to suggest a parathyroid carcinoma preoperatively. Parathyroid adenoma was suspected in 3 cases, thyroid cancer in the other cases before surgery. The extent of resection was radical resection of parathyroid lesion with more than unilateral thyroid lobectomy and central compartment neck node dissection and in 2 cases, the resection of recurrent laryngeal nerve or strap muscles was added. During follow-up period, any local or systemic recurrence were not evident in all the cases. Conclusion: Although parathyroid carcinoma is a rare disease and its preoperative diagnosis, in our experience, could not easily be made, the understanding of characteristic clinical and biochemical feature could help diagnosis at first surgery. Radical resection without remaining residual tumor is most important for the management of the parathyroid cancer.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.4
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• pp.10-21
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• 2008

A forest functions classification map is an essential element for the management planning of national forests. This study was intended to make out the map at the stand level by utilizing the Forest Functions Evaluation Program(FFEP), developed by Korea Forest Research Institute. In this program, the potential of each function was evaluated in each grid cell, and then a forest functions estimation map was generated based on the optimum grid cell values in each sub-compartment unit. Finally, the program produced a forest functions classification map with consideration of the priority of the functions. The final forest functions classification map required for the national forest management planning made out overlapping those results which the rest of the forest classified referring priority functions classification map to national forest manager and classified according to the local administrative guidance and sustainable forest resources management guidance. The results indicated that the forest function classification using the FFEP program could be an efficient tool for providing the data required for national forest management planning. Also this study made a meaningful progress in the forest function classification by considering the local forest administrative guidance and sustainable forest resources management guidance.

• Interdisciplinary Bio Central
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• v.1 no.1
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• pp.1.1-1.5
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• 2009

Many organisms control their physiology and behavior in response to the local light environment, which is first perceived by photoreceptors that undergo light-dependent conformational changes. Phytochromes are one of the major photoreceptors in plants, controlling wide aspects of plant physiology by recognizing the light in red (R) and far-red (FR) spectra. Higher plants have two types of phytochromes; the photo-labile type I (phyA in Arabidopsis) and photo-stable type II (phyB-E in Arabidopsis). Phytochrome B (phyB), a member of the type II phytochromes in Arabidopsis, shows classical R and FR reversibility between the inter-convertible photoisomers, Pr and Pfr. Interestingly, the Pr and Pfr isomers show partitioning in the cytosol and nucleus, respectively. In the over 50 years since its discovery, it has been thought that the type II phytochromes only function to mediate R light. As described in the text, we have now discovered phyB has an active function in FR light. Even striking is that the R and FR light exert an opposite effect. Thus, FR light is not simply nullifying the R effect but has an opposing effect to R light. What is more interesting is that the phyB-mediated actions of FR and R light occur at different cellular compartment of the plant cell, cytosol and nucleus, respectively, which was proven through utilization of the cytosolic and nuclear-localized mutant versions of phyB. Our observations thus shoot down a major dogma in plant physiology and will be considered highly provocative in phytochrome function. We argue that it would make much more sense that plants utilize the two isoforms rather than only one form, to effectively monitor the changing environmental light information and to incorporate the information into their developmental programs.

• Korean Journal of Head & Neck Oncology
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• v.13 no.2
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• pp.187-199
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• 1997

Thyroid carcinoma ranks low in incidence and as a cause of death when compared to carcinomas arising in the other site. With adequate surgical treatment, the prognosis of operable thyroid carcinoma is good. However, the extent of surgical resection in treatment of thyroid cancer remains still controversy. The aim of this study was to assess the results of thyroid cancer patients treated surgically and to analyze the prognostic factors affecting survival and to improve the survival rate. We retrospectively analyzed the outcome of a total of 278 thyroid cancer patients treated surgically at Inje University Paik Hospital from 1980 to 1995 and followed for 1 to 16 years. There were man in 47 and woman in 231 patients with age range of 14 to 79 years(mean 42 years). Histopathologic findings were papillary carcinoma in 233, follicular carcinoma in 33, mixed carcinoma in 7, medullary carcinoma in 2, and undifferentiated carcinoma in 3 patients, respectively. Operative procedures were unilateral lobectomy in 111, subtotal thyroidectomy in 100, and total thyroidectomy in 67 patients. Central node dissection was performed in 92, modified neck disseciton in 62, radical neck dissection in 28, and no node dissection in 96 patients. Thyroid hormone was administered for the period of 3 to 5 years to suppress endogenous TSH production. Overall 5-year survival rate according to Kaplan-Meier method was 91.1%. Independently, significant factors affecting the prognosis were age at diagnosis, tumor size, pathologic type, tumor stage, lymph node metastasis, angioinvasion, extrathyroidal extension, and 'risk' group category. but, the prognosis were not influenced by sex and capsular invasion. Patients at low risk or with small size carcinomas had long survival over 5 years with only lobectomy. Lymph node dissection was carried out with a limited type in no jugular metastasis, radical neck dissection was performed only therapeutically in proved jugular node metastasis. Fifteen patients were dead of tumor recurrence after surviving for three months to two and half years, and the cause of death was local recurrence in nine, bone metastasis in four and lung metastasis in two patients. In conclusion, more extensive surgery including total thyroidecotmy and systematic compartment-oriented dissection of the lymph node metastases in patient at high-risk group will results in better survival and lower recurrence rate.

• Korean Journal of Heritage: History & Science
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• v.37
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• pp.91-120
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• 2004

The Yan mountain area of the northern part of Hebei province and its local neighbor area is categorized main-distribution area of the northern bronze culture of the Eastern Zhou period(770bc~221bc). Recently, it was discovered the concrete character of the culture by a large scale excavation of the Yuhuangmiao cemetery at Jundu mountain. In the chinese scholarship, the cultural character of this area has established the independent cultural type that is distinguished from the Bronze culture of existing. In this paper, I have as a target of analysis remains relate to the Yuhuangmiao culture of the mountain area of northern Hebei in the Eastern Zhou period. And I would like to judge about diverse infuluential relationships of the character of the Yuhuangmiao curture and the Bronze culture, especially burials, burial customs and the characters of the excavated article. In particular, diverse infuluential relationships of the upper Xiajiadian culture Ordos bronze culture and The Central Plains cultural from The Yan state have a important meaning to understand about the character of the Yuhuangmiao culture and the beginning development process. Ultimately, it is peculiar characters of the Yuhuangmiao culture that a shaft gave with stone compartment protecting a coffin as a symbolic form, mask-burial customs such as mainly burials of the living with the dead dogs, a drum shaped jar, a tripod jar with two handles, a short bronze sword with circle hilt, Central Plains cultural bronze containers, bronze halberd and horse-shaped accessories of cartage horse trapping are distinguished from a local neighbor, the bronze culture from northern. The territory of time-space of The Yuhuangmiao culture can be dominately recognized bewteen the upper Xiajiadian culture and Ordos bronze culture. It is the Yan culture after the middle Warring States Period considering with the peculiar chacters which reflected by burials and bural customs and diverse infuluential relationships with peripheral cultures.