• Journal of Radiation Protection and Research
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• v.40 no.1
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• pp.55-64
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• 2015

Dose calculations which are a crucial requirement for radiotherapy treatment planning systems require accuracy and rapid calculations. The conventional radiotherapy treatment planning dose algorithms are rapid but lack precision. Monte Carlo methods are time consuming but the most accurate. The new combined system that Monte Carlo methods calculate part of interesting domain and the rest is calculated by neural can calculate the dose distribution rapidly and accurately. The preliminary study showed that neural networks can map functions which contain discontinuous points and inflection points which the dose distributions in inhomogeneous media also have. Performance results between scaled conjugated gradient algorithm and Levenberg-Marquardt algorithm which are used for training the neural network with a different number of neurons were compared. Finally, the dose distributions of homogeneous phantom calculated by a commercialized treatment planning system were used as training data of the neural network. In the case of homogeneous phantom;the mean squared error of percent depth dose was 0.00214. Further works are programmed to develop the neural network model for 3-dimensinal dose calculations in homogeneous phantoms and inhomogeneous phantoms.

• Investigative Magnetic Resonance Imaging
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• v.2 no.1
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• pp.58-66
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• 1998

Purpose : This paper introduces a new three dimensional magnetic Resonance Image classification which is based on Mar kov Random Field-Gibbs Random Field with a line model. Material and Methods : The performance of the Gibbs Classifier over a statistically heterogeneous image can be improved if the local stationary regions in the image are disassociated from each other through the mechanism of the interaction parameters defined at the local neighborhood level. This usually involves the construction of a line model for the image. In this paper we construct a line model for multisignature images based on the differential of the image which can provide an a priori estimate of the unobservable line field, which may lie in regions with significantly different statistics. the line model estimated from the original image data can in turn be used to alter the values of the interaction parameters of the Gibbs Classifier. Results : MRF-Gibbs classifier for volumetric MR images is developed under the condition that the domain of the image classification is $E^{3}$ space rather thatn the conventional $E^{2}$ space. Compared to context free classification, MRF-Gibbs classifier performed better in homogeneous and along boundaries since contextual information is used during the classification. Conclusion : We construct a line model for multisignature, multidimensional image and derive the interaction parameter for determining the energy function of MRF-Gibbs classifier.

• Investigative Magnetic Resonance Imaging
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• v.23 no.4
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• pp.328-340
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• 2019

Purpose: To generate phase images with free of motion-induced artifact and susceptibility-induced distortion using 3D radial ultrashort TE (UTE) MRI. Materials and Methods: The field map was theoretically derived by solving Laplace's equation with appropriate boundary conditions, and used to simulate the image distortion in conventional spin-warp MRI. Manufacturer's 3D radial imaging sequence was modified to acquire maximum number of radial spokes in a given time, by removing the spoiler gradient and sampling during both rampup and rampdown gradient. Spoke direction randomly jumps so that a readout gradient acts as a spoiling gradient for the previous spoke. The custom raw data was reconstructed using a homemade image reconstruction software, which is programmed using Python language. The method was applied to a phantom and in-vivo human brain and abdomen. The performance of UTE was compared with 3D GRE for phase mapping. Local phase mapping was compared with T₂* mapping using UTE. Results: The phase map using UTE mimics true field-map, which was theoretically calculated, while that using 3D GRE revealed both motion-induced artifact and geometric distortion. Motion-free imaging is particularly crucial for application of phase mapping for abdomen MRI, which typically requires multiple breathold acquisitions. The air pockets, which are caught within the digestive pathway, induce spatially varying and large background field. T₂* map, that was calculated using UTE data, suffers from non-uniform T₂* value due to this background field, while does not appear in the local phase map of UTE data. Conclusion: Phase map generated using UTE mimicked the true field map even when non-zero susceptibility objects were present. Phase map generated by 3D GRE did not accurately mimic the true field map when non-zero susceptibility objects were present due to the significant field distortion as theoretically calculated. Nonetheless, UTE allows for phase maps to be free of susceptibility-induced distortion without the use of any post-processing protocols.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.4
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• pp.314-321
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• 2016

Conventional removable partial dentures (RPDs) with distal extensions are associated with some problems, including lack of stability that calls for frequent relining, and cantilever actions of claps that can produce excessive loading to abutment teeth, and the need for unesthetic retentive arm clasps. Therefore, IARPDs (Implant-assisted RPD) that use implants to support or retain RPDs has been reported to improve stability, esthetics and masticatory performance of RPDs. Also, an IARPD that has zirconia occlusal table can prevent the incongruity of occlusal plane and the extrusion of antagonistic tooth. In this case of partially edentulous patient with crossed occlusion, each edentulous area was restored with implant fixed prosthesis and implant retained partial denture to suit each situation. Through the procedure, satisfactory outcomes were achieved both in functional and esthetic aspects.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.360-367
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• 2014

Candida albicans is an opportunistic and the most prevalent fungal pathogen that can cause superficial and systemic infections in immunocompromised patients. C. albicans can promote the transition from budding yeast to filamentous form, generating biofilms. Infections associated with C. albicans biofilms are frequently resistant to conventional antifungal therapy. Therefore, the development of more effective antifungal drugs related with biofilm formation is required urgently. The roots of Rheum undulatum have been used for medicinal purposes in Korea and China traditionally. The aim of present study was to evaluate the effect of R. undulatum extract upon preformed biofilms of 12 clinical C. albicans isolates and the antifungal activities. Its effect on preformed biofilms was evaluated using XTT reduction assay, and metabolic activity of all tested strains was reduced significantly ($49.4{\pm}6.0%$) at 0.098 mg/ml R. undulatum. The R. undulatum extract blocked the adhesion of C. albicans biofilms to polystyrene surfaces, and damaged the cell membrane integrity of C. albicans which was analyzed by CFDA, AM, and propidium iodide double staining. It caused cell lysis which was observed by Confocal laser scanning and phase contrast microscope after propidium iodide and neutral red staining, respectively. Membrane permeability was changed as evidenced by crystal violet uptake. The data suggest that R. undulatum inhibits biofilm formation by C. albicans, which can be associated with the damage of the cell membrane integrity, the changes in the membrane permeability and the cell lysis of C. albicans.

• Applied Microscopy
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• v.28 no.2
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• pp.171-180
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• 1998

In the present study, the vacuolar apparatus were investigated in the hepatocytes of rats treated with DA by transmission electron microscopy of conventional and cytochemical thin sections. In the rats after 20 min of dehydrocholic acid treatment, the cis Golgj cisterns were sacculated in line. The saccule occasionally occured by elongation and attenuated neck. The lysosomes also showed protrudent saccule. The vesicles were observed near the cis Golgi cisterns, lysosome and bile canaliculi. Some of the vesicles appeared to be fused to bile canaliculi. The cis Golgi cisterns usually faced toward the bile canaliculi both in normal and experimental groups. The cis Golgi cisterns, protrudent saccule and vesicles were almost devoid of visible contents. The osmium deposits were heavy on the protrudent saccule as well as on the cis Golgi cisterns or on the vesicles isolated near by, but they were light or not observed on the vesicles in the immediate vicinity of bile canaliculi. The acid phosphatase activities appeared on the lysosome and vesicles located near by, but did not appear on the vesicles as approaching closer to the bile canaliculi. The evidence suggests that the vesicles are derived from the cis Gogi cistern and lysosomes and fuse to bile canaliculi for exocytosis, and that the activity in the vesicles is diminished as approaching closer to the bile canaliculi.

• Journal of Genetic Medicine
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• v.7 no.2
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• pp.156-159
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• 2010

Inversion, one of the balanced rearrangements, usually does not lead to phenotypic abnormalities; all genetic information exists in the proper amount, merely in a different order or in an abnormal location. However, offspring of an inversion carrier is at risk of chromosomal imbalance because an inversion loop can be formed during crossing-over of the paternal and the maternal chromosomes in meiosis. We report a 38-year-old woman with inversion and balanced translocation and her fetus with unusual rearrangement causing chromosomal imbalance. We performed conventional cytogenetic analysis, MLPA, and subtelomeric FISH in the cells of the embryo. The results showed that the distal portion of chromosome 13q was added to the terminal portion of chromosome 9p during crossing-over. Therefore, the final karyotype of the fetus was 46,XY,rec(9)t(9;13)(p22;q32)inv(9)(p12q13)mat, confirmed using molecular-cytogenetic analyzing tools.

• Clinics in Orthopedic Surgery
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• v.10 no.4
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• pp.439-447
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• 2018

Background: Since open Wiltse approach allows limited visualization for foraminal stenosis leading to an incomplete decompression, we report the short-term clinical and radiological results of unilateral biportal endoscopic foraminal decompression using $0^{\circ}$ or $30^{\circ}$ endoscopy with better visualization. Methods: We examined 31 patients that underwent surgery for neurological symptoms due to lumbar foraminal stenosis which was refractory to 6 weeks of conservative treatment. All 31 patients underwent unilateral biportal endoscopic far-lateral decompression (UBEFLD). One portal was used for viewing purpose, and the other was for surgical instruments. Unilateral foraminotomy was performed under guidance of $0^{\circ}$ or $30^{\circ}$ endoscopy. Clinical outcomes were analyzed using the modified Macnab criteria, Oswestry disability index, and visual analogue scale. Plain radiographs obtained preoperatively and 1 year postoperatively were compared to analyze the intervertebral angle (IVA), dynamic IVA, percentage of slip, dynamic percentage of slip (gap between the percentage of slip on flexion and extension views), slip angle, disc height index (DHI), and foraminal height index (FHI). Results: The IVA significantly increased from $6.24^{\circ}{\pm}4.27^{\circ}$ to $6.96^{\circ}{\pm}3.58^{\circ}$ at 1 year postoperatively (p = 0.306). The dynamic IVA slightly decreased from $6.27^{\circ}{\pm}3.12^{\circ}$ to $6.04^{\circ}{\pm}2.41^{\circ}$, but the difference was not statistically significant (p = 0.375). The percentage of slip was $3.41%{\pm}5.24%$ preoperatively and $6.01%{\pm}1.43%$ at 1-year follow-up (p = 0.227), showing no significant difference. The preoperative dynamic percentage of slip was $2.90%{\pm}3.37%$; at 1 year postoperatively, it was $3.13%{\pm}4.11%$ (p = 0.720), showing no significant difference. The DHI changed from $34.78%{\pm}9.54%$ preoperatively to $35.05%{\pm}8.83%$ postoperatively, which was not statistically significant (p = 0.837). In addition, the FHI slightly decreased from $55.15%{\pm}9.45%$ preoperatively to $54.56%{\pm}9.86%$ postoperatively, but the results were not statistically significant (p = 0.705). Conclusions: UBEFLD using endoscopy showed a satisfactory clinical outcome after 1-year follow-up and did not induce postoperative segmental spinal instability. It could be a feasible alternative to conventional open decompression or fusion surgery for lumbar foraminal stenosis.

• Journal of Sericultural and Entomological Science
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• v.50 no.2
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• pp.116-121
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• 2012

Cordyceps and its allies fungi has been described as a secret medicine that gives eternal youth and a long life. Some species of Cordyceps are sources of biochemicals, such ascordycepin, with interesting biological and pharmacological properties. Hence, it has been studied to uncover its pharmacological effect. We attempted to study the formation of fruiting bodies and to develop means of mass production Korean isolate of Paecilomyces tenuipes has been inoculated into silkworms, where it reproduced using culture container, mini-kit successfully. Culture container, mini-kit is composed of a cylinder-shaped body and lid. The container is made of translucent polyethylene terephthalate. The size of the container is $82{\times}75mm$, reduced by 10 times as compared with the conventional culture kit. The mini kit has many advantages - high culture amount, ability of maintaining optimal humidity, parasite-free cultivation and high-end appearance. With the kit, the optimal cultivation condition is under $22^{\circ}C$, culture period of 53 days. And synnemata of P. tenuipes could be kept fresh for 14 days at the temperature of under $10^{\circ}C$. Therefore, the Min-kit can be used in both ways as a culture container and a packing kit for end-user customers.

• Journal of Dental Anesthesia and Pain Medicine
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• v.20 no.6
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• pp.367-375
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• 2020

Background: Intraosseous anesthesia (IO) allows the anesthetic solution to be injected directly into the cancellous bone. The anesthetic solution immediately reaches the periapical region, and thus the axonal area of the nerve, where it can temporarily disable the sodium pump. The effect is felt almost without any time delay, and only a small amount of anesthetic solution is required. Methods: This study aims to investigate the efficacy of IO using the AnestoⓇ device after infiltration anesthesia (IA) and/or inferior alveolar nerve block anesthesia (IANB) failed to work in symptomatic irreversible pulpitis (hot tooth). The 33 patients included in the study were treated additionally with 1.7 ml articaine hydrochloride with 1:100,000 epinephrine hydrochloride (UltracainⓇ D-S, Sanofi-Aventis, Frankfurt, Germany) IO. Results: The electrical pulp test showed that 95.76% of the volunteers reacted positively to the combination of IANB or IA with the IO. In women, the additive IO was effective at 97.22%. In men, the IO led to pain elimination in 94.00% of cases. The duration of the IO was less than a quarter of an hour (13.03 min). The IO worked longer in women than in men (13.61 min vs. 12.33 min). Overall, more than every third tooth that needed trepanation was located in the posterior area of the mandible (36.4%). Treatment of hot teeth in this area was associated with an increased pulse rate and increased residual pain. There was a moderate correlation (Spearman-Rho [IRI] = 0.280) between the Visual Analog Scale (VAS) score and bone density, and a significant correlation (IRI = 0.612) between subjective residual pain and bone width. The IO resulted in a moderate, transient increase in the pulse rate by approximately 20 bpm. This is similar to the temporary increase in heart rate after conventional anesthesia techniques in non-preloaded patients and can be considered clinically irrelevant. Conclusion: IO with the AnestoⓇ device as an extension and deepening of local pain elimination is recommended for the treatment of hot teeth.