• International Journal of Computer Science & Network Security
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• 제21권8호
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• pp.17-27
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• 2021

Non-abelian group based cryptosystems are a latest research inspiration, since they offer better security due to their non-abelian properties. In this paper, we propose a novel approach to non-abelian group based public-key cryptographic protocols using semidirect products of finite groups. An intractable problem of determining automorphisms and generating elements of a group is introduced as the underlying mathematical problem for the suggested protocols. Then, we show that the difficult problem of determining paths and cycles of Cayley graphs including Hamiltonian paths and cycles could be reduced to this intractable problem. The applicability of Hamiltonian paths, and in fact any random path in Cayley graphs in the above cryptographic schemes and an application of the same concept to two previous cryptographic protocols based on a Generalized Discrete Logarithm Problem is discussed. Moreover, an alternative method of improving the security is also presented.

• Journal of Korean Neurosurgical Society
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• 제62권3호
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• pp.321-327
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• 2019

Focal cortical dysplasia (FCD) is the major cause of intractable focal epilepsy in childhood leading to epilepsy surgery. The overall seizure freedom after surgery ranges between 50-75% at 2 years after surgery and the long-term seizure freedom remain relatively stable. Seizure outcome after surgery depends on a various factors such as pathologic etiologies, extent of lesion, and types of surgery. Therefore, seizure outcome after surgery for FCD should be analyzed carefully considering cohorts' characteristics. Studies of pediatric epilepsy surgery emphasize the early surgical intervention for a better cognition. Early surgical intervention and cessation of seizure activity are important for children with intractable epilepsy. However, there are limited data on the cognitive outcome after surgery in pediatric FCD, requiring further investigation. This paper reviews the seizure and cognitive outcomes of epilepsy surgery for FCD in children. Several prognostic factors influencing seizure outcome after surgery will be discussed in detail.

• 대한후두음성언어의학회지
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• 제31권2호
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• pp.87-91
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• 2020

The tracheostomy directs external air into the airway tract. This process causes mucosal dryness, irritation and inflammation in the tracheo-bronchial tree. In order to prevent such problems, several methods are applied; ointment application, humidification and careful suction etc. The heat-moisture exchanger (HME) is commercially sold device that assists heating and humidification of the inhaled air. The authors experienced successful treatment outcome of intractable tracheitis caused by repetitive and vigorous intra-tracheal suction by applying HME in a total laryngectomized patient. We report an interesting and didactic case with a brief literature review.

• 대한족부족관절학회지
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• 제25권4호
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• pp.190-194
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• 2021

A bursa is an obstructive sac filled with synovial fluid and usually occurs in any area of the body exposed to friction. The bursa of the ankle is not a normal anatomical structure and is caused by repetitive trauma, constant friction, or inflammatory disease of the ankle. Bursitis can occur in any bursa in the human body; however it rarely progresses to septic arthritis. We report a rare case of septic ankle arthritis following intractable lateral malleolar bursitis successfully treated with negative-pressure wound therapy.

• 대한임상약리학회:학술대회논문집
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• 대한임상약리학회 1996년도 정기총회 및 추계학술대회
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• pp.27-27
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• 1996

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권1호
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• pp.1-2
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• 2014

• The Korean Journal of Pain
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• 제32권1호
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• pp.55-56
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• 2019

• Molecules and Cells
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• 제24권3호
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• pp.431-436
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• 2007

Stem cell-based therapy is being considered as an alternative treatment for cardiomyopathy. Hence understanding the basic molecular mechanisms of cardiomyocyte differentiation is important. Besides BMP or Wnt family proteins, $TGF-{\beta}$ family members are thought to play a role in cardiac development and differentiation. Although $TGF-{\beta}$ has been reported to induce cardiac differentiation in embryonic stem cells, the differential role of $TGF-{\beta}$ isoforms has not been elucidated. In this study, employing the DMSO-induced cardiomyocyte differentiation system using P19CL6 mouse embryonic teratocarcinoma stem cells, we investigated the $TGF-{\beta}$-induced signaling pathway in cardiomyocyte differentiation. $TGF-{\beta}1$, but not the other two isoforms of $TGF-{\beta}$, was induced at the mRNA and protein level at an early stage of differentiation, and Smad2 phosphorylation increased in parallel with $TGF-{\beta}1$ induction. Inhibition of $TGF-{\beta}1$ activity with $TGF-{\beta}1$-specific neutralizing antibody reduced cell cycle arrest as well as expression of the CDK inhibitor $p21^{WAF1}$. The antibody also inhibited induction of the cardiac transcription factor Nkx2.5. Taken together, these results suggest that $TGF-{\beta}1$ is involved in cardiomyocyte differentiation by regulating cell cycle progression and cardiac gene expression in an autocrine or paracrine manner.

• Journal of Korean Neurosurgical Society
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• 제39권1호
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• pp.16-19
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• 2006

Objective : The purpose of this study is to evaluate the effect of the corpus callosotomy and to elucidate possible prognostic factors. Methods : The cases of 39 patients who underwent corpus callosotomy were reviewed retrospectively. Clinical outcomes were analyzed using Engel's classification, with consideration of various presurgical conditions and the extent of the callosal resection during follow-up more than one year. Results : Satisfactory outcome [Engel's class I, II] was obtained in 20 patients [51%] of 39 patients. In 36 cases with drop attack seizures, the class I, II outcomes were 22 patients [61%]. When the patients were grouped according to the extent of callosal resection, the class I, II outcomes were 50% of the patients with anterior 1/2 or 2/3, 50% of those with anterior 4/5 callosotomy, and 57% of those with total callosotomy, respectively. The mean follow-up period was 34 months [24 to 58 months]. Conclusion : Although it is not statistically significant, the patients who had underwent total callosotomy show better outcomes than those with partial callosotomy. Corpus callosotomy is efficacious in controlling medically intractable epilepsy in appropriately selected patients.

• Clinical and Experimental Pediatrics
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• 제56권7호
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• pp.275-281
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• 2013

Temporal lobe epilepsy (TLE) is the most common type of medically intractable epilepsy in adults and children, and mesial temporal sclerosis is the most common underlying cause of TLE. Unlike in the case of adults, TLE in infants and young children often has etiologies other than mesial temporal sclerosis, such as tumors, cortical dysplasia, trauma, and vascular malformations. Differences in seizure semiology have also been reported. Motor manifestations are prominent in infants and young children, but they become less obvious with increasing age. Further, automatisms tend to become increasingly complex with age. However, in childhood and especially in adolescence, the clinical manifestations are similar to those of the adult population. Selective amygdalohippocampectomy can lead to excellent postoperative seizure outcome in adults, but favorable results have been seen in children as well. Anterior temporal lobectomy may prove to be a more successful surgery than amygdalohippocampectomy in children with intractable TLE. The presence of a focal brain lesion on magnetic resonance imaging is one of the most reliable independent predictors of a good postoperative seizure outcome. Seizure-free status is the most important predictor of improved psychosocial outcome with advanced quality of life and a lower proportion of disability among adults and children. Since the brain is more plastic during infancy and early childhood, recovery is promoted. In contrast, long epilepsy duration is an important risk factor for surgically refractory seizures. Therefore, patients with medically intractable TLE should undergo surgery as early as possible.