• Korean Membrane Journal
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• 제5권1호
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• pp.43-53
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• 2003

The selectivity of a gas in the carbon molecular sieve membrane (CMSM) can be expressed as the ratio of the product of the diffusivity and the solubility of two different gases. The diffusivity is also expressed as the product of the entropy and the total energy (kinetic and potential energy) in the nano-sized pore of the membrane. The present study calculates the entropic-energy and selectivity of penetrant gases such as H$_2$, O$_2$, N$_2$, and CO$_2$ from the gas-in-a box theory to physically analyze the diffusivity of penetrant gas in slit-shaped pore of CMSM focusing on the restriction of gas motion based on the size difference between penetrant gas pairs. The contribution of each energy term is converted to entropic term separately. By the conjugated calculation for each entropic-energy, the entropic effects on diffusivity-selectivity for gas pairs such as H$_2$/N$_2$, CO$_2$/N$_2$, and O$_2$/N$_2$ were analyzed within active pore of CMSM. In the activated diffusion domain, the calculated value of entropic-selectivity lies between 9.25 and 111.6 for H$_2$/N$_2$, between 3.36 and 6.0 for CO$_2$/N$_2$, and between 1.25 and 16.94 for O$_2$/N$_2$, respectively. The size decrement of active pore in CMSM had the direct effect on the reduction of translational entropic-energy and the contribution of vibrational entropic-energy for N$_2$, O$_2$, and H$_2$ was almost negligible. However, the vibrational entropic term of CO$_2$ might extravagantly affect on the entropic-selectivity.

• 대한의용생체공학회:의공학회지
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• 제13권3호
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• pp.225-234
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• 1992

In order to use a low cost polymer valve in our total artificial heart and ventricular assist device, we have developed a slit-type bileaflet polymer valve[BPV 1. The aim of this study is to determine the hydrodynamic effectiveness of the newly-designed BPV and its feasibility for temporary use in the blood pumps. For hydrodynamic comparison, we investigated in-vitro the pressure drop across the valve, the leakage volume, the flow rate and the flow pattern of the BPV, two mechanical valves and a trileaflet polymer valve. We employed the ventriculo-pulmonary bypassing method for in-vivo tests of the BPV's together vilh our electrohydraulic left venIn ricular assist device in mongrel dogs. The BPV showed adquate gydrodynamic performances and in the preliminary animal bests, there was no xvi dence of thrombus formation on the valve leaflets and around the struts. Detailed results obtained from the animal tests will be separately reported. This report involves the design criteria, fabrication and hydrodynamic charateristics of she BPV, and the basic merits and demerits of the valve are dis- cussed from the hydrodynamic point of view.

• The Korean Journal of Physiology
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• 제11권1호
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• pp.45-50
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• 1977

This study was undertaken to investigate the effect of cingulate cortical ablation upon gastric ulceration, and the pathway through which cingulate cortex exerts the effect. 56 female rats were divided equally into cingulate (cingulate cortical ablation), cingulate-vagal (cingulate cortical ablation and vagotomy), normal control and vagal (vagotomy) groups. Cingulate cortex was ablated through a slit-shaped opening (1 mm in width, 13 mm in length) which was made symmetrically on both sides of, and parallel to, the sagittal suture by removing a bone flap from parietal and frontal bones on each side. Vagus nerves on both sides were transected around the distal end of the esophagus. In the normal control animals, surgical intervention ended with scalp incision. All rats were kept without restraint or food deprivation for 3 weeks after surgery. The stomach of each rat was inflated with 7 ml of physiological saline and then removed under deep anesthesia. The mucosal surface was examined under dissecting microscope for the location, shape and number of ulcers, and then enlarged photograph $(4{\times})$was taken. The incidence of ulcer in each group was counted and the number of ulceration as well as the total area of glandular mucosa were measured on the photograph. Results obtained were as follows: 1. The mean number of ulcer per stomach and the total area of ulcer exprssed as permillage of the total area of glandular mucosa were significantly higher in the cingulate group than the cingulate-vagal, the normal control and the vagal groups. There was no difference among the latter three groups. 2. The incidence of ulcer in the cingulate group was significantly higher than that in the .normal control group and was also higher, though not significantly, than those in the cingulate-vagal and the vagal groups. There was no difference among the normal control, the cingulate-vagal and the vagal groups. It is inferred from the above results that the cingulate cortex exerts an inhibitory influence upon gastric ulceration and that this influence is mediated by controlling the vagal activity.

• 대한두개안면성형외과학회지
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• 제15권2호
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• pp.82-88
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• 2014

Background: The chin shape and position is important in determining the general shape of the face, and augmentation genioplasty is performed alone or in combination with other aesthetic procedures. However, augmentation genioplasty using osteotomy is an invasive and complex procedure with the potential to damage mentalis muscle and mental nerve, to affect chin growth, and prolonged recovery. Our aim was to present our experience with a modified augmentation genioplasty procedure for hypoplastic chins using a Gore-Tex implant. Methods: Two vertical slit incisions were made at the canine level to create a supra-periosteal pocket between the incisions, preserving the periosteum and mentalis muscle. Minimal sub-periosteal dissection was performed lateral to the incisions along the mandibular border. The both wings of implant were inserted under the periosteum to achieve a stable dual plane implantation. Results: In total, 47 patients underwent dual plane chin augmentation using a Gore- Tex implant between January 2008 and May 2013. The mean age at operation was 25.77 years (range, 15-55 years). There were 3 cases of infection; one patient was treated with antibiotics, the others underwent implant removal. Additionally, two patients complained of postoperative parasthesia that spontaneously improved without any additional treatment. Most patients were satisfied with the postoperative outcomes, and no chin growth problems were observed among the younger patients. Conclusion: Dual plane Gore-Tex chin augmentation is a minimally-invasive operation that is simple and safe. All implants yielded satisfactory results with no significant complications such as mental nerve injury, lower lip incompetence, or chin growth limitation.

• 한국농촌건축학회논문집
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• 제22권2호
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• pp.1-8
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• 2020

This study is intended to derive the adaptive reuse techniques through the history and aspects of new construction, extension, repair, and other works, limited to the deep and narrow lots facing Seongan-gil and Nammun-gil in Nammun-ro 2 ga of Cheongju, the historic urban area. The results are as follows. 1) In the case of newly built reinforced concrete buildings, the central part of the top floor of the residence or all floors are opened to the open space(void) to facilitate lighting and ventilation. This is developed as a convection phenomenon due to the temperature difference from the slits between buildings, which affects the entire air flow of the block. 2) The buildings of extension and repair are composed of two-story masonry or steel frame, both the front store facing the road and the house on the back, but it looks like one because it is in contact with each other. If only a small gap between the front and rear buildings is restored to an external space or a space equipped with sun light, a small breath can be provided in lighting and ventilation. 3) The existing two-story wooden stores and houses have lost their external space due to repairs. With minimal intervention to restore the small courtyard, slits, and space under the eaves, it will not only improve lighting and ventilation, but also create a unique appearance as a segment of the elongated store.

• 대한관절경학회지
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• 제13권3호
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• pp.276-279
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• 2009

건초 섬유종은 수부나 상지에서 발생하는 양성 연부조직 종양으로 관절내에서 발생하는 경우는 아주 드물다. 대부분 천천히 자라는 섬유성 결절 조직으로 조직학적으로는 산재한 섬유모세포및 치밀한 기질과 미세 혈관세포들로 구성된다. 저자들은 54세 남자환자의 관절와 상완 관절 후상방 관절막에서 기시한 건초 섬유종을 경험하였다. 자기 공명 영상에서 저 강도 신호의 결절성 종물로 관찰되었으며 관절경하에서 절제하여 조직검사로 확진하였다. 관절내 건초 섬유종은 견관절 관절경 시술시 관절 내에서 관찰될 수 있는 종양의 하나로 감별해야 할 것으로 사료된다. 있는 술식으로 전방십자인대 수술시 좋은 치료 선택의 하나로 사료된다.

• 한국광학회지
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• 제12권2호
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• pp.83-90
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• 2001

주기적인 진폭물체를 가간섭광인 레이저광으로 조명하였을 때 이 물체가 렌즈없이 회절에 의하여 결상되는 Talbot 결상을 회절이론으로 해석하고 물체의 상이 1:1로 결상되는 Talbot 거리(Zr)를 정의 하였다. 그리고 실험적으로 이 Z/sub T//2 위치에서는 위상에서는 위상이 반전되는 현상도 동시에 관찰하였다. 이러한 Talbot 결상시 주기적인 물체의 개수, 즉 격자의 수에 따라 Talbot 상의 가시도를 Talbot 상의 FFT(Fast Fourier Transform)로부터 측정하였으며 그 결과 적어도 15개 이상의 격자들로 구성되어야 가시도 0.25로 정상적인(stationary) Talbot 결상이 됨을 알 수 있었다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2003년도 심포지엄
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• pp.43-49
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• 2003

The Xylariaceae Tul. & C. Tul is a family of sphaeriaceous genera with obscure but apparently common ancestry (Rogers, 1979). A central core of genera - Xylaria, Hypoxylon, Rosellinia, Poronia, Podosordaria, Hypocopra, Daldinia, Biscogniauxia, Kretzschmaria, Camillea, Penzigia - are obviously related, regardless of the fact that the generic limits are arguable (Rogers, 1979; Barr, 1990; Eriksson & Hawksworth, 1991; Laessoe, 1994). In general, the family Xylariaceae is primarily defined as a group of stromatic pyrenomycetes with unitunicate asci characterized by a typical apical apparatus and pigmented ascospores having a germ slit (Rogers, 1979). Since Winter (1887) circumscribed the family to include Pyrenomycetes with predominately a dark stroma, dark unveiled spores containing 5 geners: Nummularia Tul, & C. Tul., Hypoxylon Bull., ustulina Tul. & C.Tul., Poronia Willd. and XylariaHill ex Schrank, many more genera has been added to the family (Dennis, 1961; Eriksson & Hawksworth, 1993; Whalley, 1996). In the absence of the clear circumscription of the family (Rogers, 1994) the agreed number of accepted genera is governed by individual views and there are therefore difference between the proposals for the ascomycetes recognized 35 genera and indicated a further 3 which might belong there. Laessore reviewed the family and included 37 genera but a few of these were listed as uncertain (Laessoe, 1994). In the most recent accounts Whalley (1996) listed 41 genera but again a number of these were considered uncertain and Ju and Rogers (1996) accepted 39 genera in their interpretation of the family. Since Laessoe (1994) merged Daldinia and Versiomyces with Hypoxylonand Ju and Rogers (1996) combined Astrocystis with Resellinia and Helicogermslita, which can be argued strongly against, it is likely that a realistic number of genera will be close to 40(Whalley, 1996; table 1).

• Korean Journal of Ophthalmology
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• 제32권6호
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• pp.438-444
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• 2018

Purpose: To compare the success rates of performing only silicone tube intubation versus carrying out both conjunctival resection and silicone tube intubation. Methods: The subjects of this study involved 62 patients (96 eyes) between October 2015 and May 2017 who were diagnosed as having punctal stricture or nasolacrimal duct stenosis. Out of 96 eyes, 47 underwent only silicone tube intubation, and 49 underwent both silicone tube intubation and conjunctival resection. Three parameters were measured at 1, 3, and 6 months after the surgery: the area of the tear meniscus using RTVue-100 anterior segment optical coherence tomography, the height of the tear meniscus using a slit lamp microscope, and the subjective satisfaction of patients as a result of improved sympotms like epiphora. The surgery was considered successful when the patients' experienced the resolution of symptoms and reduction of the area and height of the tear meniscus. Results: The area of the tear meniscus, height of the tear meniscus, and subjective satisfaction of patients was superior in the group that underwent both silicone tube intubation and conjunctival resection compared silicone tube intubation only. Based on these results, the success rate of the surgery was 68.9% in the group that underwent only silicone tube intubation and 78.7% in the group that underwent both silicone tube intubation and conjunctival resection. Conclusions: The resection of relaxed plica semilunares seems to increase the success rate of silicone tube intubation through the reduction of the area and height of the tear meniscus. Therefore, after determining the degree of conjunctivochalasis, if it was found to be severe, a combination with conjunctival resection was expected to increase the success rate of the surgery.

• Archives of Plastic Surgery
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• 제46권1호
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• pp.34-38
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• 2019

Background Acellular dermal matrices (ADMs) have recently become widely used in breast reconstruction, but the correlation between the final expander volume and the surface area of the ADM is not well understood. In this study, the expansion of the surface area of ADM and the expander volume was studied retrospectively in cases of acellular dermis-assisted tissue expander breast reconstruction. Methods Twenty cases of immediate breast reconstruction using an ADM-assisted tissue expander from January 2015 to December 2015 were evaluated. In all 20 cases, CGCryoDerm was used as the matrix, with a thickness of 1-3 mm. No slit incisions were made. Finally, the proportional increase in the area of the fully expanded ADM was compared to that of the tissue expander volume. Results The proportional increase in the ADM surface area was calculated to be from 1.1 to 2.46, with a mean value of 1.7. Additionally, under the assumption that the expander had a spherical shape, the increase in its radius (the cube root of its volume) was assessed. The range of the proportional increase in the expander radius was 1.1 to 2.24, with a mean value of 1.66. The proportional increase in the radius of the expanded ADM surface area ranged from 1.04 to 1.34, with a mean ratio of 1.28. Conclusions The results of this study confirmed that the ADM expanded when the tissue expander was inflated. However, the ADM expanded to a lesser extent than the tissue expander, indicating that the muscle and other tissues expanded more than the ADM when the tissue expander was inflated.