• Journal of Periodontal and Implant Science
• /
• v.37 no.4
• /
• pp.839-848
• /
• 2007

Purpose: Various kinds of biodegradable membranes are currently used in dental clinics. And the frequency and the necessity of their usage are increasing due to their numerous advantages. Therefore it is important to understand the difference of various membranes and histological reaction against implanted membranes. Materials and Methods: Biodegradable membranes of $Biogide^{(R)}$, $Resolute^{(R)}$, and $Tutodent^{(R)}$ were cut into small pieces by $1.0{\times}0.5cm$. The membranes were implanted 1.5cm apart from each other under the epithelium on the skull of 18 Sprague Dawley rats. The animals were sacrificed at 3, 7, and 14 days after surgical procedure. The specimens were examined by histological analysis. Results: 1. Early period after implantation of the membranes showed connective tissues surrounding membranes and there were a few inflammatory cells present. 2. In $Biogide^{(R)}$ and $Tutodent^{(R)}$ specimens, inflammatory cells and surrounding tissues were shown to infiltrate from outside with slight density difference inside. In $Resolute^{(R)}$ specimens, membranes were fragmented. Inflammatory cells and connective tissues were also observed inside. 3. In $Resolute^{(R)}$ specimen, giant cells were present which implicates that foreign body reaction has occurred. 4. $Biogide^{(R)}$ had lower integrity than other membranes and is not enough to be used alone in defect area. However, $Resolute^{(R)}$ had superior firmness than others. $Tutodent^{(R)}$ had middle level of integrity. Conclusion: This experimental model enabled to observe early inflammatory reactions and morphological changes of materials and can be used to develop and evaluate the efficacy of biodegradable membranes. Duplication of standardized human oral environment will be required in future experiments.

• Journal of the Korean Vacuum Society
• /
• v.17 no.4
• /
• pp.311-316
• /
• 2008

Since the presence of the chemical impurities and defect at surfaces and interfaces greatly influence the properties of various semiconductor devices, an unambiguous chemical characterization of the metal and semiconductor surfaces become more important in the view of the miniaturization of the devices toward nano scale. Among the various conventional surface characterization tools, Electron-induced Auger Electron Spectroscopy (EAES), X-ray Photoelectron Spectroscopy (XPS) and Secondary Electron Ion Mass Spectroscopy (SIMS) are being used for the identification of the surface chemical impurities. Recently, a novel surface characterizaion technique, Positron-annihilation induced Auger Electron Spectroscopy (PAES) is introduced to provide a unique method for the analysis of the elemental composition of the top-most atomic layer. In PAES, monoenergetic positron of a few eV are implanted to the surface under study and these positrons become thermalized near the surface. A fraction of the thermalized positron trapped at the surface state annihilate with the neighboring core-level electrons, creating core-hole excitations, which initiate the Auger process with the emission of Auger electrons almost simultaneously with the emission of annihilating gamma-rays. The energy of electrons is generally determined by employing ExB energy selector, which shows a poor resolution of $6{\sim}10eV$. In this paper, time-of-flight system is employed to measure the electrons energy with an enhanced energy resolution. The experimental result is compared with simulation results in the case of both linear (with retarding tube) and reflected TOF systems.

• Korean Journal of Microbiology
• /
• v.54 no.2
• /
• pp.91-97
• /
• 2018

The evolutionally conserved TREX complex member, Yra1/ALY, belongs to the REF (RNA and export factor binding proteins) family of hnRNP-like proteins, which has been implicated in multiple processes including transcription, nuclear RNA stability, and mRNA export. Fission yeast, Schizosaccharomyces pombe, genome encodes two members of REF proteins. In addition to Mlo3 known previously as an mRNA export factor, there is the other REF protein, Tho4, which is predicted as a component of THO complex. Here we showed that deletion of tho4 (SPBC106.12c) gene does not inhibit both growth and nuclear mRNA export. However, overexpression of tho4 displays growth retardation and slight accumulation of $poly(A)^+$ RNA in the nucleus. Neither ${\Delta}tho4$ ${\Delta}mlo3$ nor ${\Delta}tho4$ ${\Delta}mex67$ double mutants exhibit additive growth defect. Moreover, yeast two-hybrid and co-immunoprecipitation analysis did not show that the Tho4 protein interacted with any members of TREX complex and mRNA export factor Rae1. Contrary to expectation, these observations support that the S. pombe Tho4 is not a component of TREX complex, and not directly involved in bulk mRNA export from the nucleus.

• Korean Journal of Construction Engineering and Management
• /
• v.16 no.6
• /
• pp.112-123
• /
• 2015

Many disputes are happened with various causes in overseas construction projects. One of major disputes is closely related with nominated subcontractors (NSC). This paper investigates 30 judical precedents for Singapore, Malaysia and Hongkong to analyze the detailed disputes related with the NSC, and then the judical precedents are classified into 6 categories: Delay and Defect Trouble (T1), Contract Relation (T2), Payment Trouble (T3), Set-off (T4), Liquidation (T5) and so forth (T6). According to the analytical results, the frequency of occurrence of disputes is considerably related with social and economical changes, and the dispute between NSC and employer for residential and commercial building projects is the most frequently happened case. As the results of analysis, therefore, it is concluded that the employer needs to response aggressively to the problems related with NSC, and it is also important to make the council for communication among related bodies. Furthermore, the institutional reform that make the role and the responsibility of employer consistent under considering contract terms and conditions is considered as the most important and fundamental issue.

• The Journal of the Korea Contents Association
• /
• v.17 no.9
• /
• pp.99-106
• /
• 2017

This study focused on the issue that when a diagnostic detector is found to have a defect, a patient would be exposed to radiation and image quality would be degraded. Though dose analysis, an experiment was conducted to evaluate detector performance as Signal to Noise Ratio (SNR) and Contrast to Noise Ratio (CNR). Absorbed dose, SNR and CNR were measured using a dosimeter and a tissue equivalent phantom. The experiment was conducted to compare whether the dose value shown after being attached to the back side of the phantom matches the dose value attached behind the detector, where in the conditions of skull, chest and abdomen were set at 75 kVp, 25 mAs, 110 kVp, 8 mAs, and 80 kVp, 20 mAs, respectively. As a result, there was a difference in that the dose values attached to the back side of the detector were 0.004 mGy, 0.006 mGy, 0.003 mGy, whereas those of the back side of the phantom were 0.006 mGy, 0.016 mGy, 0.017 mGy. In order to match both values, the condition was increased and SNR and CNR also increased from 88.32, 88.10, 4.09, 1.63, 87.94, 79.97 to 93.87, 93.75, 4.91, 4.03, 92.02, 84.92. Though this study, we found that when a detector is found to have a aging, it shortens the life of equipment and increases the dose of a patient, also the improvement effect of image quality is inadequate.

• Journal of the Society of Disaster Information
• /
• v.8 no.4
• /
• pp.362-375
• /
• 2012

Tourist hotels are equipped with facilities such as accommodation and restaurants, exercise, recreation. Unspecified guests, visitors and management of tourist hotels are very vulnerable on the casualties and property losses due to fire peril exist. In this study, we analysis that the fire statistics status of tourist hotels from 2001 to 2010. And the 15 cases of a large hotel fire are reviewed. The total number of fires on hotel are consist of a hotel rooms fire(33.2%), a restaurant kitchen fire(11.8%). And the major causes of the fire are an electrical fire (40.8%), a cigarette fire (14.5%) and a hot-work fire (9.2%). In case study, the fire wall defect and combustible materials are major fire loss causes for 10year. Each tourist hotels are needed a development of suitable fire risk management and a field operations. A hotel is required an active fire risk management on a preventive inspection, an education and training, and a preventive maintenance. It is necessary that a fire wall maintenance to prevent of the spread of a fire and a sprinkler installation of whole area to protect fire. And it is very important an emergency response for evacuation of guest, and operate emergency procedures on a fire or emergency situation.

• Journal of Veterinary Clinics
• /
• v.25 no.6
• /
• pp.482-487
• /
• 2008

This study was performed to investigate the ophthalmic findings of the Korean traditional 'Sapsaree' dogs, and to provide ophthalmic references. Five hundred forty-seven Sapsaree dogs were randomly chosen without any criteria preference. Ophthalmic examination was performed bilaterally using ocular equipments, including slit-lamp biomicroscope, tonometer, direct and indirect ophthalmoscope. The obtained data for ophthalmic findings were analysis by the multivariate linear regression model to identify effects of sex, age and hair coat type. For congenital conditions, the incidence of persistent pupillary membrane (PPM) was the most common defect and there was present 8.8 % whereas for acquired ophthalmic diseases, cataract was the most commonly observed (3.7 %) in Sapsaree dog. Other frequent ocular finding included persistent hyaloid vessel remnant (PHVR, 6.2 %) in congenital conditions, and postinflammatory retinal degeneration (PIRD, 3.1 %) and corneal dystrophy (2.4 %) in acquired ophthalmic diseases. Only one significant effect was age of the Sapsaree for PIRD (P=0.040). There are no any significant effect for sex and hair coat types. This study will provide useful guidelines to clinicians and breeders for the basic ophthalmic information on this breed.

• Microbiology and Biotechnology Letters
• /
• v.49 no.3
• /
• pp.458-465
• /
• 2021

Tubulysins are a group of bioactive secondary metabolites from myxobacteria exhibiting strong anticancer activity against various cancer cell lines. In this study, we describe the identification of putative tubulysin biosynthetic gene clusters (tubA~tubF) in the genome sequences of two tubulysin-producing myxobacterial strains, Archangium gephyra MEHO_002 and MEHO_004. The inactivation of the putative tubulysin biosynthetic genes resulted in a tubulysin-production defect. The DNA sequences of the A. gephyra MEHO_002 and MEHO_004 tubulysin biosynthetic genes were 97% identical, and the amino acid sequences of the encoded proteins shared a similarity of 97-100%. The nucleotide sequences of the tubulysin biosynthetic gene clusters in MEHO_002 and MEHO_004 were 86% identical to that in Cystobacter sp. SBCb004 known as a tubulysin-producing myxobacterium, and the organization of the clusters was identical except for the lack of a tubZ gene in the clusters in MEHO_002 and MEHO_004. The amino acid sequences of the proteins encoded by each gene were 88-97% similar to those encoded by SBCb004, and the domain compositions of the proteins were also identical.

• Childhood Kidney Diseases
• /
• v.23 no.1
• /
• pp.36-42
• /
• 2019

Purpose: We investigated whether a renal size discrepancy on a renal sonogram (US) in children with febrile urinary tract infection (UTI) was correlated with the presence of cortical defects on their dimercaptosuccinic acid (DMSA) renal scan. Methods: We examined 911 children who were admitted consecutively to our hospital with their first episode of febrile UTI from March 2001 to September 2014. All enrolled children underwent a US and DMSA scan during admission. According to the US findings, including the renal size discrepancy, data were compared between children with positive and negative DMSA scan results. A positive DMSA scan result was defined as reduced or absent tracer localization and indistinct margins that did not deform the renal contour. Results: Mean renal lengths of the right and left kidneys were larger in children with positive DMSA scan results than in children with negative DMSA scan results ($63.2{\pm}11.3mm$ vs. $58.4{\pm}7.8mm$, P<0.001; $64.9{\pm}11.2mm$ vs. $59.9{\pm}7.9mm$, P<0.001; respectively). A significant difference was observed in both renal lengths between children with positive and negative DMSA scan results ($4.6{\pm}3.8mm$ vs. $3.3{\pm}2.6mm$, P<0.001). A multiple logistic regression analysis, revealed that a small kidney, cortical thinning, and a renal length discrepancy on US findings were significant factors for predicting the presence of cortical defects on an acute DMSA scan [P=0.028, 95% confidence interval (CI) 1.054-2.547; P= 0.004, 95% CI 1.354- 4.810; P<0.001, 95% CI 1.077-1.190, respectively]. Conclusion: In conclusion, a renal size discrepancy on US findings in children with their first episode of febrile UTI was a helpful tool for predicting the presence of cortical defects on an acute DMSA scan.

• KIPS Transactions on Software and Data Engineering
• /
• v.11 no.7
• /
• pp.299-306
• /
• 2022

In recent, sensors embedded in robots, equipment, and circuits have become common, and research for diagnosing device failures by learning measured sensor data is being actively conducted. This failure diagnosis study is divided into a classification model for predicting failure situations or types and a regression model for numerically predicting failure conditions. In the case of a classification model, it simply checks the presence or absence of a failure or defect (Class), whereas a regression model has a higher learning difficulty because it has to predict one value among countless numbers. So, the reason that regression modeling is more difficult is that there are many irregular situations in which it is difficult to determine one output from a similar input when predicting by matching input and output. Therefore, in this paper, we focus on input and output data with periodicity, analyze the input/output relationship, and secure regularity between input and output data by performing sliding window-based input data patterning. In order to apply the proposed method, in this study, current and temperature data with periodicity were collected from MMC(Modular Multilevel Converter) circuit system and learning was carried out using ANN. As a result of the experiment, it was confirmed that when a window of 2% or more of one cycle was applied, performance of 97% or more of fit could be secured.