• Archives of Plastic Surgery
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• v.33 no.2
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• pp.205-212
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• 2006

Using adipose derived stem cells(ASCs), neurogenic differentiation was induced in a mono layered culture medium containing neuronal induction agents. Cells differentiated to the neuronal cells were observed with a inverted microscope and immunofluorecent study. We made a 15 mm long defect in the sciatic nerve of 14 rats and connected a silicone tube to the defect. Then, we mixed neuronal progenitor cells differentiated from ASCs with collagen gel and grafted them to a group of rats(experimental group) and grafted only collagen gel into another group(control group). In 4 and 8 weeks after the graft, histological observation was made. According to the result, the number and diameter of myelinated axons were significantly increased in the experimental group. In addition, the nerve conduction velocity was improved more in the experimental group and neovascularity also increased. Moreover, reaction with S100 and p75 was observed in regenerated nerves in the experimental group, suggesting that the grafted cells were differentiated into supportive cells such as Schwann's cells. In conclusion, this research proved that ASCs can multiply and differentiate into neuronal cells. If they are grafted into nerve defects, the grafted cells are differ entiated into supportive cells such as Schwann's cells and thus contribute to nerve regeneration. Accordingly, the use of adipose tissue obtained easily without the limitation of donor site can be greatly helpful in treating peripheral nerve defects.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.4
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• pp.426-437
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• 2005

Statement of problem : Although zirconium oxide ceramics are more and more commonly used in restorative dentistry, for many clinical applications only limited data can be found in the literature. However it is quite clear that hydrofluoric acid etching is impossible with zirconia ceramics. Therefore, other bonding techniques are required in order to lute these materials adhesively. Purpose : The purpose or this study was to evaluate the effects of surface treatments on shear bond strengths between two resin cements and a zirconia ceramic. Materials and methods : Experimental industrially manufactured yttrium-oxide-partially-stabilized zirconia ceramic discs (Adens, Korea) were used for this study. The ceramic specimens divided into five experimental groups and a control group (as received). Five surface treatments were studied 1) sandblasting with 110$\mu$m $Al_2O_3$ at 3 bars pressure 13 seconds at a distance of 10 mm, 2) flame-treated with the Silano-Pen for 5 $s/cm^3$, 3) grinding with a diamond bur. 4) sandblasting + Silano-Pen treatment, 5) diamond bur preparation + Silano-Pen treatment. Acrylic plastic tube (5 mm in height and 3 mm in diameter) were filled with composite to fabricate composite cylinders The composite cylinders were bonded to the ceramic specimens with either Superbond C&B or Panavia F resin luting agents. All cemented specimens were tested under shear loading until fracture on universal testing machine at a crosshead speed 1mm/min; the maximum load at fracture was recorded. Sheat bond strength data were analyzed with oneway analysis of variance and Tukey HSD tests (P<.05). Treated ceramic surfaces and fracture surfaces after shear testing were examined morphologically using scanning electron microscope. Results: Ceramic surface treatment with Silano-Pen after sandblasting improved the bond strength of Superbond C&B resin cement. Supevbond C& B resin cement at Silano-Pen aiker sandblasting($27.4{\pm}3.8MPa$) showed statistically higher shear bond strength than the others. Conclusion: Within the limitation of this study, Superbond C& &B resin cement are suitable for cementation of zirconia ceramics and flame-treated with the Silano-Pen after sandblasting is required to enhance the bond strength.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.793-798
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• 2017

In modern naval ships, an infrared signature suppression (IRSS) system is used to reduce the metal surface temperature of the heated exhaust pipe and high-temperature exhaust gases generated from the propulsion system. Generally, the IRSS systems used in Korean naval ships consist of an eductor, mixing tube, and diffuser. The diffuser reduces the temperature of the metal surface by creating an air film due to a pressure difference between the internal gas and the external air. In this study, design variables were selected by analyzing the shapes of a diffuser designed by an advanced overseas engineering company. The characteristics of the design variables that affect the performance of the IRSS were investigated through the Taguchi experimental method. A heat flow analysis technique for IRSS systems established in previous studies was used analyze the performance of the diffuser. The performance evaluation was based on the area-averaged value of the metal surface temperature and exhaust gas temperature at the outlet of the diffuser, which are directly related to the intensity of the infrared signature. The results show that the temperature of the exhaust gas was significantly affected by changes in the diameter of the diffuser outlet, and the temperature of the diffuser's metal surface was significantly affected by changes in the number of diffuser rings.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.5
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• pp.491-498
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• 2010

Humidification of PEM fuel cells is necessary for enhancing their performance and lifetime. In this study, a humidification system was designed and tested; the system includes an air-supply tube (inner diameter: 75 mm) through which a nozzle can be directly inserted and a cyclonic separator for the removal of water droplets. Three types of nozzles were employed to study the influence of injection pressure, air flow rate, and spray direction on the humidification performance. To evaluate the humidification performance, the concept of humidification efficiency was defined. In the absence of an external heat source, latent heat for evaporation will be supplied by the own enthalpies of water and air. Thus, the amount of water sprayed from the nozzle is the most critical factor affecting the humidification efficiency. Water droplets were efficiently removed by a cyclonic separator, but re-entrainment occurred at high air flow rates. The absolute humidity and humidification efficiency were $21.29\;kJ/kg_{da}$ and 86.57%, respectively, under the following conditions: nozzle type PJ24; spray direction angle $90^{\circ}$; injection pressure 1200 kPa; air flow rate 6000 Nlpm.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.606-611
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• 1999

To identify irradiated foods, studies have been carried out with electron spin resonance (ESR) spectroscopy on bone containing foods, such as chicken, pork, and beef. Bones cleaned, pieced and dried were irradiated with doses of 0, 1, 3, 5 kGys using a $Co^{60}$ irradiator. The bones were placed in a resonant quartz tube with an internal diameter of about 4.0 mm within the Bruker Win-ESR spectrometer, and the intensity of the ESR signal could be quantified by double integration of the first derivative spectrum. The irradiated bone presented an asymmetric absorption in shape, different from that of an unirradiated one. It could be possible to detect at doses lower than 1 kGy below the dose employed commercially (3 kGy) in the case of irradiated chicken bone. The signal intensity was greatest in the beef bone, intermediate in the pork bone and lowest in the chicken bone; it was normally lower for smaller animals than for larger species, and small variations were observed between samples of the same species. The intensity of the signal induced in bones increased linearly with irradiation doses in the range of 1.0 kGy to 5.0 kGy, and it was possible to distinguish between samples given low and high doses of irradiation. The signal stability for 6 weeks made them ideal for the quick and easy identification of irradiated meats.

• Korean Journal of Environmental Biology
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• v.19 no.1
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• pp.79-86
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• 2001

The apicomplexan parasite, Perkinsus sp., has been reported as a causative pathogen responsible for the mass mortality of the Manila clams, Ruditapes philippinarum in European countries as well as in Korea. Prevalence, infection intensity, histopathologic features and zoosporulation of Perkinsus found in the Manila clams distributed along the coast of Cheju Island were investigated in this study. Clams were collected from nine different beaches along the Cheju Island from May to July in 2000. Ray's Fluid Thioglycollate Medium (RFTM) and Choi's NaOH lysis methods were applied in the diagnosis and quantification of the Perkinsus infection. Prevalence, percentage infection of the parasite examined was 100% in Pyosun, 70% in Sungsan, 63% in Kumneong, 33% in Jongdalri, 21% in Iho, 17% in Moslpo, and 14% in Seogwipo. No Perkinsus was found in the clams collected from Kimnyong and Yongmeo-ri. Infection intensity as a number of Perkinsus cells per gram tissue wet weight (twwt), was 98,430 cells/g twwt in Pyosun, 78,553 cells/g twwt in Sungsan, 18,980 cells/g twwt in Kumneong, 4,290 cells/g twwt in Jongdalri, 1,527 cells/g twwt in Iho, 1,069 cells/g twwt in Moslpo, and 853 cells/g twwt in Seogwipo. Histological preparation of the infected tissues revealed trophozoites of Perkinsus sp., ranged from 5 to 10 ${\mu}{\textrm}{m}$, in diameter mostly distributed in the digestive gland and the gill filaments. Zoospores were discharged from the hypnospore via discharging tube about 2 days after incubated in filtered and aerated seawater. In general, the prevalence and infection intensity of Perkinsus in Cheju Island were much lower than that reported from the western and southern coast of Korea.

• Progress in Medical Physics
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• v.14 no.2
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• pp.99-107
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• 2003

This study was performed to prepare the verification film for localizing beam-target position with the Photon Knife radiosurgery system (PKRS) using linear accelerator(Mitsubishi, Model ML-15MDX). We developed a laser calibration system using a reticle of transparent lucite to detect Inlet and outlet beams. We verified fixation of the second collimator with film mounted on a holder in the shape of an octagon block 5cm apart from the isocenter. The film was exposed to photon beams of linear accelerator at an interval of 45 degrees during the gantry movement. There were no shifts in the beam of the second collimator during gantry movement. We used a position marker which is designed a head-shaped small lead block and a 10 mm in diameter of steel bead in the plastic tube. The position marker helped to verify the beam directions with patient position in multi-arc and trans-multi-arc of PKRS The verification of beam alignments showed an average 0.8$\pm$0.26 mm discrepancy in LINAC-gram images of PKRS. In our study, the couch movement was $\pm$5 mm laterally, while it shook $\pm$ 2 mm toward the couch axis. The couch, however, was immediately returned to the initial site after shaking. Thus, we postulate that the beam-target position(s) should be verified with LINAC-gram in a stereotactic radiosurgery system to achieve the accuracy of beam-target alignment.

• Journal of Aquaculture
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• v.12 no.1
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• pp.15-24
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• 1999

From January 1997 to May, the red marbled rockfish, Sebastiscus tertius (Barsukov et Chen) was reared in the laboratory, and observed the morphological characteristies of egg and development of larvae and juveniles. The egg is spherical in shape colorless and transparent, measuring 0.72~0.80mm in diameter (mean 0.75mm, n=50). The naturally bearing larvae were 3.79~3.97mm in total length with 7~8＋15~16=22~24 myomeres, and mouth and anus were open. Melanophores were present on the yolk of the larva and ventral margins of the tail. The 1~2 days after bearing larvae measured 3.90~4.13mm in total length, and transformed to postlarval stage, and yolk sac were completely resorbed. On the lower jaw melanophores were present. Total length of the larvae was 4.23~4.60mm in total length (11 days after bearing), number of elongated pectoral fin rays was 9~10, and melanophores distributed on the top of head, around the intestine tube, ventral margins of the tail and on the pectoral fin. In 21 days after bearing, the larva were 5.83~7.10mm in total length, and the caudal notochord flex $45^{\circ}$. Individuals of 9.80~12.36mm in total length (33 days after bearing) are regarded to have reached to the juvenile stage with all the fins were developed.

• Journal of Sasang Constitutional Medicine
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• v.25 no.2
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• pp.108-114
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• 2013

Objectives This study was aimed to review a standardized method of retention enema by extracting elements associated with methods of retention enema from papers involved. Methods 1) Data sources : Retrieval was made, using 'Enema' or 'Retention Enema' as search words in MEDLINE, The Cochrane Library, KISS, RISS, and NDSL DB. 2) Study selection : Two authors excluded irrelevant papers and chose qualified abstracts in the rest of the papers. The chosen studies were reviewed fully by the authors so that they could screen the significant papers based on the exclusion criteria. 3) Data extraction : Data on the total number of subjects, the target disease, the type, quality, length, diameter of catheter, the insertion length of catheter, the sample, the sample volume, the process of retention enema and the number of performing retention enema were extracted from the selected studies. Results & Conclusions The retention enema can be applied to gastrointestinal diseases, genitourinary diseases, metabolic diseases such as hypertension and diabetes, headaches and neurological disorders. The standardized treatment method is as following: 1) inserting a rental tube of 18-28 Fr that measures 20 to 30 cm into the patient's anus, 2) injecting herbal medicines which have purgative action or benefit on stomach and intestinal tract at the rate of 4 ml/min, and 3) holding them for 10 to 15 minutes.

• Korean Journal of Agricultural Science
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• v.27 no.1
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• pp.13-19
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• 2000

The external morphology of male and female of Liriomyza trifolii (Burgess) was studied using the scanning electron microscopy (SEM). Three types of sensilla were identified on the funicle of antennae. The trichoid sensilla were most conspicious and distributed with a characteristic sharp structure at the apical end. Basiconic sensilla were showed distal curvature about $13{\mu}m$ long and $1.2{\mu}m$ to $1.4{\mu}m$ in diameter. Grooved sensilla were showed a finger-like projections at the peg apex. The function of these sensilla likely to be olfactory. The mouthparts were adapted for sucking food, and formed a elongate rostrum which was incorporated with labrum. The labrum was a small and flap-like shape. The slender and paired maxillary palp seemed to combine with each other lengthwise to long tube. The tarsus typically consisted of 5 segments, which might be variously modified, principally by thickening or flattening. The segment beared a pair of claws. Beneath the claws, there was a pair of pad-like pulvillia and a bristle-like median empodium. L. trifolii might secreted on the pulvillus and empodium an adhesive substance that enable them to cling to smooth surfaces. Male terminalia was complicated. The name 'aedeagus' seemed the best available general term for the copulatory organ, otherwise, female terminalia was usually relatively simple. This structure was reduced and formed a telescopic, eversible, and tubular ovipositor.