• Archives of Craniofacial Surgery
• /
• v.21 no.4
• /
• pp.257-260
• /
• 2020

The concurrence of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) in a single tumor is rarely encountered. We report a case of BCC and SCC in a single tumor in the anterior auricular area. A 70-year-old woman had been diagnosed with BCC by a punch biopsy performed at a dermatology clinic. We performed wide excision of the tumor with an ulcer in the anterior auricular area. Analysis of the biopsy specimen revealed the presence of both BCC and SCC in the tumor. This case illustrates that it is necessary to establish a precise diagnosis and formulate appropriate surgical and treatment plans considering the possibility that two carcinomas may coexist, although the possibility is low in patients with skin cancer.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.15 no.3
• /
• pp.23-35
• /
• 2012

The optimum location of the prehistoric sites of Ulsan Metropolitan City are investigated by both quantile and natural breaks methods through GIS, and the settlement pattern is studied based on the possibility of presence of the prehistoric sites which are also analyzed with these methods. Such factors including elevation, slope, distance from the nearest water, aspect, geological features, soil drainage classes, subsoil and land use recommended are employed in the analysis. The optimum geographical environment is the place where it includes the water-base in the area that is the southern aspect of the gentle slope land of lowland. The geology is the Quaternary alluvium. The drainage class is fine and the deep soil saturn is the fine loamy soil and the recommendation of land use is the area that is the field. As a result of the forecast of distribution, the prehistoric sites showed the higher possibility of presence in the downstream region where the Taehwa river and Dongcheon river join because the region come close to the watercourse and the drinking water use is easy. And the aspect and elevation is the low area. The alluvium accumulated from the upper stream of the Taehwa river and Dongheon river was made roomily, the area where is suitable for the farming life. Therefore, this region is judged that the possibility of presence of the prehistoric sites is high.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.281-284
• /
• 2004

Photo-induced memory effect of an organic light-emitting diode(OLED) composed of a hydrazone-derivative(DBAH) dispersed in bis-phenol-A type polycarbonate polymer(PCA) in the presence of thio-Michler's ketone, was investigated by the measuring of the current density and luminance at the various conditions. After the light exposure, the current of the OLED was decreased approximately one order, and the luminance of the OLED also decresed. This memory effct was erasable by heating the OLED to the temperature higher than the glass transition temperature(Tg). As shown in this result, we found the memory effect was erased by heating and returned to its original state in the hole injecting layer(HIL) of the OLED. A series of these phenomena was suggested the possibility of the application to the imaging plate.

• Journal of applied mathematics & informatics
• /
• v.38 no.1_2
• /
• pp.13-36
• /
• 2020

In this paper, we have presented a multispecies prey-predator harvesting system based on Lotka-Voltera model with two competing species which are affected not only by harvesting but also by the presence of a predator, the third species. We also assume that the two competing fish species releases a toxic substance to each other. We derive the condition for global stability of the system using a suitable Lyapunov function. The possibility of existence of bionomic equilibrium is considered. The optimal harvest policy is studied and the solution is derived under imprecise inflation in fuzzy environment using Pontryagin's maximal principle. Finally some numerical examples are discussed to illustrate the model.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.12
• /
• pp.2921-2926
• /
• 2009

Cu-BTC[$Cu_3(BTC)_2(H_2O)_3$, BTC = 1,3,5-benzenetricarboxylate], one of the most well-known metal-organic framework materials (MOF), has been synthesized under atmospheric pressure and room temperature by using ultrasound. The Cu-BTC can be obtained in 1 min in the presence of DMF (N,N-dimethylformamide), suggesting the possibility of continuous production of Cu-BTC. Moreover, the surface area and pore volume show that the concentration of DMF is important for the synthesis of Cu-BTC having high porosity. The morphology and phase also depend on the concentration of DMF : Cu-BTC cannot be obtained at room temperature in the absence of DMF and aggregated Cu-BTC (with low surface area) is produced in the presence of high concentration of DMF. It seems that the deprotonation of benzenetricarboxylic acid by base (such as DMF) is inevitable for the room temperature syntheses.

• Journal of Environmental Health Sciences
• /
• v.23 no.4
• /
• pp.9-15
• /
• 1997

This experiment was carried out to examine the roles of selenium in arsenic- and chromium-induced oxidative stress, which results in chromosomal damage, such as sister chromatid exchange (SCE) and chromosomal aberration (CA). For this purpose, the frequency of CA and SCE related to the level of 0xidative stress were analyzed. Selenium decreased the frequency of CA induced by As. In order to evaluate the effect of selenium on clastogenic factors, media from As- and Cr-treated cells were ultrafiltered and added again to cells in the presence or absence of selenium. Selenium decreased the frequency of SCE by As and Cr. This observation indicates the possibility of presence of clastogenic factor. In addition, the clastogenic factor would be involed in oxidative stress since selenium decreased the level of oxidative stress. Thus, it is suggested that selenium may play a role as an anti-clastogenic effector by preventing the oxidative stress, thereby decreasing the frequency of Asand Cr-induced chromosomal damage.

• Restorative Dentistry and Endodontics
• /
• v.39 no.1
• /
• pp.45-50
• /
• 2014

Ambiguity in the root morphology of the mandibular second molars is quite common. The most common root canal configuration is 2 roots and 3 canals, nonetheless other possibilities may still exist. The presence of accessory roots is an interesting example of anatomic root variation. While the presence of radix entomolaris or radix paramolaris is regarded as a typical clinical finding of a three-rooted mandibular second permanent molar, the occurrence of an additional mesial root is rather uncommon and represents a possibility of deviation from the regular norms. This case report describes successful endodontic management of a three-rooted mandibular second molar presenting with an unusual accessory mesial root, which was identified with the aid of multiangled radiographs and cone-beam computed tomography imaging. This article also discusses the prevalence, etiology, morphological variations, clinical approach to diagnosis, and significance of supernumerary roots in contemporary clinical dentistry.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2000.05a
• /
• pp.52-55
• /
• 2000

The effects of environmental conditions, initial dissolved oxygen concentrations, pH, and the presence of electron carrier vitamin B$_{12}$ , on the reduction rate of TNT by Fe$^{0}$ was Quantitatively analyzed using a batch reactor. In all experiments, TNT reduction was best described with a first order reaction and the reduction rate decreased with the increase in the initial DO concentration. However, the specific reaction rate did not decrease linearly with the increase in the initial DO concentration. In the presence of HEPES buffer 0.2 and 2.0 mM(pH 5.7$\pm$0.2), the specific reaction rate increased more than 5.8 times, which showed reduction rate is rather significantly influenced by the pH of the solution. To test the possibility of reaction rate enhancement, well-known electron carrier(or mediator), vitamin B$_{12}$ has augmented besides Fe$^{0}$ . In the presence of 8.0 $\mu\textrm{g}$/L of vitamin B$_{12}$ , the specific reaction rate increased as much as 14.6 times. The results indicate that the addition of trace amount of vitamin B$_{12}$ can be a promising rate controlling option for the removal of organics using a Fe$^{0}$ filled permeable reactive barrier.

• Journal of Korea Multimedia Society
• /
• v.10 no.12
• /
• pp.1698-1703
• /
• 2007

The paper focuses on a new 'learning ecology' that is evolving and the challenges that educators must confront. It looks at e-learning as not just another add-on, but a technology that is transforming our educational institutions. How teaching and learning is conceptualized and experienced to generate a determined community of inquiry that integrates social, cognitive, and teaching presence in a manner that will take full advantage of the distinctive assets of e-learning is discussed. Likewise, the possibility of mobile learning is put forward.

• The Korean Journal of Pain
• /
• v.11 no.2
• /
• pp.335-337
• /
• 1998

This is a case report of a 69 years old non-smoking male patient with a lung cancer who presented with postherpetic neuralgia on the left T2, 3 and 4 dermatomes. This pain was aggravated in supine position. The patient did not have any other symtoms or signs to suggest the possibility of a lung cancer. Patient's baseline laboratory findings were essentially normal. Routine chest X-ray revealed hazy densities in the left apex. Further evaluation with chest CT confirmed the presence of a lung cancer corresponding to the densities seen on the chest X-ray.