• Applied Chemistry for Engineering
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• v.35 no.2
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• pp.140-147
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• 2024

In order to increase the utilization of biomass, an electrochemical performance was considered after manufacturing a carbon anode material (SV-C) for a Setaria viridis-based lithium ion secondary battery through a heat treatment process. When the heat treatment temperature of the Setaria viridis is as low as 750 ℃, the capacitance (1003.3 mAh/g, at 0.1 C) is high due to the negative (-) charge of oxygen present on the surface attracting lithium, along with the low crystallinity and high specific surface area (126 m²/g), but the capacity retention rate is believed to be as low as 61.0% (at 500 cycles and 1 C). In addition, it was confirmed that when the heat treatment temperature increased to 1150 ℃, the carbon layer was condensed to be excellent in arrangement, and the structural defects were reduced, resulting in a significant reduction in the specific surface area (32 m²/g) of the pores. Furthermore, when the surface defects of the anode material are reduced and the crystallinity is increased, the capacity retention rate is as high as 89.7% (at 500 cycles and 1 C), but the degree of defects is small, the active point is reduced, and the specific capacity is considered to be very low at 471.7 mAh/g. In the scope of this study, it was found that in the case of the Setaria viridis-based carbon anode material manufactured according to the heat treatment temperature, the surface oxygen content and crystallinity have higher reliability on the electrochemical properties of the anode material than the specific surface area.

• Archives of Plastic Surgery
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• v.38 no.6
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• pp.829-835
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• 2011

Purpose: The two major concerns in skin grafting are poor color match in the recipient site and the donor site morbidity. And, glabrous skin on the palmar aspect of the hands and plantar aspect of the feet attributes define the skin on the palm and fingers sole as functionally and aesthetically different from skin on other parts of the body. When there is a glabrous skin defect, it should be replaced with similar skin to restore function and aesthetics. The palmar crease areas were used to minimize these problems. The purpose of this study is to present the precise surgical technique of the full thickness skin graft using distal palmar and midpalmar creases for aesthetic better outcome for hand injuries. Methods: From May 2006 to April 2010, 10 patients with 11 defects underwent glabrous full thickness skin grafting of finger defects. Causes included seven machinery injuries, two secondary burn reconstructions, and one knife injury. Donor sites included ten glabrous full thickness skin graft from the distal palmar crease and one from the midpalmar crease. Results: Follow-up ranged from 3 months to 24 months. All glabrous skin grafts demonstrated complete taking the recipient sites and no incidence of the complete or partial loss. The donor site healed without complications, and there were no incidences of significant hypopigmantation, hyperpigmentation, or hypertrophic scarring. Conclusion: The important aspects of this method involve immediate return of glabrous skin to the defect site and restoration of the recipient site's crease by simple primary closure from adjacent skin. The glabrous skin of the palm provides the best tissue match for the reconstruction of the hands, but only a limited amount of tissue is available for this purpose. Full thickness skin grafting using palmar crease of the defects is the ideal way of reconstructing glabrous skin to restore both function and aesthetics and minimize donor site morbidity.

• Archives of Plastic Surgery
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• v.42 no.3
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• pp.288-294
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• 2015

Background Surgical ablation for locally advanced breast cancer results in large chest wall defects, which can then be managed with local flaps or skin grafts. The purpose of this article is to evaluate the outcomes of three types of local skin flaps. Methods Among 25 local flaps in 24 patients, 6 were bilateral advancement (BA) flaps, 9 were thoracoabdominal (TA) flaps, and 10 were thoracoepigastric (TE) flaps. Clinical outcomes were compared including complications, the need for a secondary surgical intervention, and the timing of adjuvant therapy. Results The mean defect size was $436.2cm^2$. Two patients with TA flaps and 6 patients with TE flaps developed distal flap necrosis, and skin grafts were needed to treat 2 patients with TE flaps. Radiation was administered to the BA, TA, and TE patients after average postoperative durations of 28, 30, or 41 days, respectively. The incidence of flap necrosis tended to be higher in TE patients, which lead to significant delays in adjuvant radiation therapy (P=0.02). Conclusions Three types of local skin flaps can be used to treat large chest wall defects after the excision of locally advanced breast cancer. Each flap has its own merits and demerits, and selecting flaps should be based on strict indications based on the dimensions and locations of the defects.

• Archives of Plastic Surgery
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• v.36 no.6
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• pp.788-791
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• 2009

Purpose: Reconstruction of full - thickness defects of the nasal ala has always been a challenge. Local flaps can be used easily, and good result can be achieved when it is indicated. But local flaps often result in facial scars and bulky ala that require secondary revisions. Composite auricular chondrocutaneous graft may matches nasal alae well in terms of contour, color and texture, however, the size of composite graft is limited. We performed free vascularized helical root flaps for reconstruction of nasal ala. Methods: Bilateral ala were excised and the defects were reconstructed with a chondrocutaneous free helical root flap. Each side of ala was reconstructed in 3 months interval. Superficial temporal vessels of vascularized helical root flap were anastomosed to facial vessels. Great saphenous vein was used for interpositional vascular graft. Results: Flaps were survived successfully. The contour, texture and color match were satisfactory. Functional problem of nasal obstruction caused by scar stenosis of nostrils was also resolved. Conclusion: The free vascularized helical root flap is a reliable method in reconstruction of nasal alar defects. The donor deformity was minimal.

• Archives of Plastic Surgery
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• v.46 no.4
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• pp.365-370
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• 2019

The syndrome of the trephined is a neurologic phenomenon that manifests as sudden decline in cognition, behavior, and sensorimotor function due to loss of intracranial domain. This scenario typically occurs in the setting of large craniectomy defects, resulting from trauma, infection, and/or oncologic extirpation. Cranioplasty has been shown to reverse these symptoms by normalizing cerebral hemodynamics and metabolism. However, successful reconstruction may be difficult in patients with complex and/or hostile calvarial defects. We present the case of a 48-year-old male with a large cranial bone defect, who failed autologous cranioplasty secondary to infection, and developed rapid neurologic deterioration leading to a near-vegetative state. Following debridement and antibiotic therapy, delayed cranioplasty was accomplished using a polyetheretherketone (PEEK) implant with free chimeric latissimus dorsi/serratus anterior myocutaneous flap transfer for vascularized resurfacing. Significant improvements in cognition and motor skill were noted in the early postoperative period. At 6-month follow-up, the patient had regained the ability to speak, ambulate and self-feed-correlating with evidence of cerebral/ventricular re-expansion on computed tomography. Based on our findings, we advocate delayed alloplastic implantation with total vascularized soft tissue coverage as a viable alternative for reconstructing extensive, hostile calvarial defects in patients with the syndrome of the trephined.

• Tuberculosis and Respiratory Diseases
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• v.71 no.6
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• pp.454-458
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• 2011

Chronic lymphocytic leukemia (CLL) is the most common type of leukemia occurring in Western nations. In CLL it is well known that the risk of a secondary malignancy is higher than in the normal population. But in Korea, CLL is a rare type of leukemia, so there have been only a few reported cases with a secondary malignancy. CLL is characterized by progressive defects in both cell-mediated and humoral immunity. It is known that defects in the immune system of patients with CLL contribute to the development of a secondary malignancy. We experienced a case of a 71-year-old man who suffered from a chronic cough and was diagnosed with small cell lung cancer coexisting with CLL. Until this case, there was no reported case in Korea of small cell lung cancer coexisting with CLL. We now report a case of small cell lung cancer coexisting with CLL and present a literature review.

• The Mathematical Education
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• v.37 no.1
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• pp.35-54
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• 1998

Half century has passed since Korean peninsula was divided into South and North Korea. Now a days, there are many differences of politics, economy, culture and education between South and North Korea. Especially mathematics education in which I am interested has a lot of changes and differences. This is proved true by defects' proof. For those reasons, I compared South Korea's education ideology, goal and system, and goals of mathematics education with North Korea's. I compared geometric(1-4 years, published by Pyong-yang Educational Book Publication Co. 1991) of mathematics texts(1-6 years) which are used in the secondary school with mathematics text of South Korea in contents and organization of them. As a result of this comparison, education ideology and goal are distinctly different from those of South Korea because of the difference of pursuing humanity. In North Korea, the curriculum is very strict without autonomy. There are 1283 mathematics classes which are occupied 19% for six years during the secondary school. The contents are very similar, but there is a little difference in the definition of a term. The problems which praise Kim Il-sung and his son and reveal loyalty to them were found, and there were a lot of problems in order to promote hostile feeling against U.S.A and South Korea, too. In conclusion, mathematics education of Korean peninsula should be reunified in the fields of the terms and contents at first.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.2 no.2
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• pp.77-82
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• 1992

When a crystal is grown by FZ process, the melt zone is located at between the solid of upper and lower side and is kept by the solid-liquid interface tension. On the surface of the melt zone, a surface tension gradient is occured by the difference of temperature and solute concentration, it is the driving force of marangoni flow. The crystal even in the steady state growth can become imperfect for the dislocation distribution and the solute concentration in the peripheral region of the crystal are higher than those in the inner part and the probability of the formation of the defects such as voids, bubble penetration, secondary phase creation and crack is high near the solid-liquid interface. This is because the solid -liquid interface becomes irregular because of the local variation of temperature in that region due to marangoni convection.

• Korean Journal of Materials Research
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• v.12 no.7
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• pp.580-586
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• 2002

The effect of processing and designing variables such as pouring temperature(1400 or $1500^{\circ}C$), inoculation and risering design(T and H type) on the formation of defects such as external depression, primary and secondary shrinkage cavities in GC150 gray cast iron was investigated. In T type risering design, external depression or primary shrinkage cavity due to liquid contraction was formed in all of the eight cases. Regardless of its modulus value, the riser could not function properly in T type risering design because directional solidification was not promoted toward the riser. On the other hand, the four cases of H type risering design in which thermal sleeves were set onto the risers produced defect-free castings. In both types of the risering designs, secondary shrinkage cavity caused by solidification contraction was not observed in the casting because of the expansion pressure due to graphite precipitation and the application of rigid pep-set mold. The degree of external depression or primary shrinkage cavity was reduced with lowered pouring temperature. The effect of inoculation was diminished because of the high carbon equivalent of GC 150 gray cast iron.

• Advances in pediatric surgery
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• v.8 no.2
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• pp.119-125
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• 2002

The aim of this study was to evaluate the posterior sagittal anorectoplasty (PSARP) as a re-do operation in patients who failed initial repair of anorectal malformation. Nine patients (4 boys and 5 girls) who had previous failed surgery for anorectal malformation underwent secondary operations through posterior sagittal approach. The main reasons of surgery were constipation (n=3) and persistent anatomical derangement in spite of previous correction surgery (n=6). In addition to constipation, the former group (n=3) had various anatomical defects, and the latter group (n=6), of course, had constipation in some degrees. Patients ranged in age from 2 to 19 years (median 3 years) with only one over the age of 6 years. The primary procedures included PSARP (n=8) and anoplasty (n=1). The rectum was mobilized from surrounding structures through posterior sagittal approach and anatomical defects were corrected. The rectum underwent reconstruction, which involved relocation of the rectum and anus within the limits of the intact muscle complex. Patients underwent follow-up for periods ranging from 6 to 77 months (mean 37 months) after surgery. Anatomical corrections of all the defects were successfully fulfilled in 9 patients. All the patients were satisfied with the functional results after redo-PSARP compared with the preoperative defecatory function. This study suggests that (1) some of the patients with troublesome constipation may have anatomical defects, prominent or hidden, (2) surgeons should suspect the possibility of anatomical defect as the cause of incontinence and (3) preoperative thorough investigation to reveal the anatomical defects should be included in estimating patients with severe incontinence after previous surgery and planning the correction for failed previous surgery as well.