• Title/Summary/Keyword: 무작위 실험 연구

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End Point Temperature of Rewarming and Afterdrop After Hypothermic Cardiopulmonary Bypass in Pediatric Patients (소아에서의 저체온 심폐바이패스후 재가온 종료온도와 후하강)

  • Kim, Won-Gon;Lee, Hae-Won;Lim, Cheong
    • Journal of Chest Surgery
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    • v.30 no.2
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    • pp.125-130
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    • 1997
  • Separating the patient from hypothermic cardiopulmonary bypass(CPB) before achieving adequate rewarming often results in afterdrop, which can predispose to electrolyte disturbances, arrhythmia, hemodynamic alterations, and shivering-induced increase of oxygen consumption. In an attempt to find an adequate end point temperature of rewarming after hypothermic CPB, 50 pediatric cardiac surgical patients were r ndomly assigned for end point temperature of rewarming of 35.5$^{\circ}C$ (Group 1) or 37t (Group 2), rectal temperature. Thereafter the rectal temperature was measured half, one, four, eight, and 16 hour after arrival to the intensive care unit(ICU), with heart rate and blood pressure. Additionally the rectal temperature was compared with esophageal temperature during CPB, and axillary temperature luring stay in the ICU. Nonpulsatile perfusion with a roller pump was used in all patients and a membrane or bubble oxygenator was used for oxygenation. Both groups were comparable with respect to age, sex, body surface area, total bypass time, and rewarming time. There was no afterdrop in both groups, and there were no statistical differences in the rectal temperatures between two groups. There were also no statistical dilyerences with respect to the heart rate and blood pressure between two groups. At the end of rewarming the esophageal temperature was higher than the rectal temperature. The axil ary temperature measured in ICU was always lower than the rectal temperature. No shivering was noted in all patients. In conclusion, with restoration of rectal temperature above 35.5$^{\circ}C$ at the end of CPB in pediatric patients, we did not observe an afterdrop.

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Anti-Obese Effects of Mixture Contained Pine needle, Black Tea and Green Tea Extracts (솔잎, 홍차 및 녹차 추출물 함유 조성물의 항비만 효과)

  • Jeon, Jeong-Ryae;Kim, Jong-Yeon;Lee, Kyung-Mi;Cho, Duck-Hyung
    • Applied Biological Chemistry
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    • v.48 no.4
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    • pp.375-381
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    • 2005
  • The aims of this study were to evaluate the anti-obese effects of pine needle, black tea and green tea in rats and overweight people. Supplementation of 1, 2, 4 and 8% amount to the control diet of pine needle extract and mixture groups significantly decreased body weight gain and visceral fat mass compared with that of control diet group. Supplementation of 1, 2 and 4% amount to the control diet of black and green tea extracts groups significantly decreased body weight gain and visceral fat mass compared with that of control diet group. Anti-obese effect in body weight gain and visceral fat mass of mixture group was higher than in other groups. In human study, extracts mixture supplementation to overweight subjects significantly decreased both body weight and body fat compared with placebo control group. In vitro study, black and green tea extracts significantly inhibited both the pancreatic lipase and ${\alpha}-amylase$ activities dose dependently. In conclusion, the anti-obese effects of pine needle, black, and green teas in rats were found. In overweight human subjects, extracts mixture decreased body weight and body fat compared with placebo control group. Anti-obese effect in black and green tea groups might be from an decrease in carbohydrate and fat digestions via inhibition of pancreatic ${\alpha}-amylase$ and lipase activities in part.

Therapeutic Effect of Different Doses of Recombinant Human Granulocyte Colony-Stimulating Factor(rhG-CSF) on Neonatal Sepsis Complicated by Neutropenia (호중구 감소증이 합병된 신생아 패혈증에서 Recombinant Human Granulocyte Colony-Stimulating Factor(rhG-CSF)의 투여 용량에 따른 치료 효과)

  • Choi, Moon Young;Jung, Yeon Sook;Son, Dong Woo;Ahn, Hyo Seop
    • Clinical and Experimental Pediatrics
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    • v.45 no.4
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    • pp.439-448
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    • 2002
  • Purpose : The aim of this study is to determine and compare the effects of adjunctive therapy with different doses of recombinant human granulocyte-colony stimulating factor(rhG-CSF) on reversing sepsis-associated neonatal neutropenia, and their survival rate in a group I/II-type trial. Methods : RhG-CSF was injected subcutaneously to 10 septic-neutropenic neonates with doses of $10{\mu}g/kg$ from Oct. 1995 to Sep. 1996, and was administered to another 12 septic-neutropenic neonates with doses of $5{\mu}g/kg$ from Oct. 1996 to Sep. 1997. Neutrophilic responses and the outcomes of both groups were compared. Results : In the rhG-CSF $10{\mu}g/kg$ treated group and in the $5{\mu}g/kg$ treated group, the absolute neutrophil count(ANC) was $1,065{\pm}89$($mean{\pm}SEM$) and $1,053{\pm}131$, respectively. The only difference between the two groups was the peak ANC at 48 hours. Eight patients from the remaining nine of rhG-CSF $10{\mu}g/kg$ treated group(88.9%) and ten in $5{\mu}g/kg$ treated group(83.3%) survived the sepsis and were discharged without any problems. Conclusions : RhG-CSF can increase the neutrophil count in critically ill septic neutropenic neonats. The survival rate of both groups were up to 90%. This finding suggests that both doses of rhG-CSF may be effective in a therapeutically useful time frame to treat septic neonates with neonatal neutropenia attributable to bone marrow supression or neutrophil consumption.

Comparison of Bonding Strength by Cleaning Method of Pediatric Zirconia Crown Contaminated with Saliva or Blood (타액 및 혈액오염 시 유치 지르코니아 기성관 내면의 세척 방법에 따른 결합강도의 비교)

  • Kim, Jaeyong;Park, Howon;Lee, Juhyun;Seo, Hyunwoo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.45 no.2
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    • pp.185-194
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    • 2018
  • The objective of this study was to compare the shear bonding strength of zirconia after cleaning the crown contaminated by saliva or blood and determine the effect of thermocycling. 180 specimens were embedded in acrylic resin. 20 Specimens in the positive control group were bonded with resin cement without contamination. 20 Specimens in the negative control group were washed with water for 20 seconds and then dried for 10 seconds. 120 Specimens contaminated by saliva or blood were cleaned by using three cleaning methods: 37% phosphoric acid gel, commercial cleanse, and 2.5% NaOCl. All samples were bonded with resin cement and divided into two subgroups: One was not aged, and the other was tested with 30,000 thermocycling. In both groups contamination by saliva and blood, no statistically significant difference was not found in control, groups cleansed by commercial cleanser and 2.5% NaOCl. When the groups cleansed with water and 37% phosphate gel were compared with the control, significantly low shear bond strength was shown. Thermocycling group showed statistically significantly low shear bond stress compared to the groups without thermocycling. When zirconia was contaminated by saliva or blood, its original shear bond strength could be obtained if it was cleaned with commercial cleanser or 2.5% NaOCl.

Adaptive Data Hiding Techniques for Secure Communication of Images (영상 보안통신을 위한 적응적인 데이터 은닉 기술)

  • 서영호;김수민;김동욱
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.5C
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    • pp.664-672
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    • 2004
  • Widespread popularity of wireless data communication devices, coupled with the availability of higher bandwidths, has led to an increased user demand for content-rich media such as images and videos. Since such content often tends to be private, sensitive, or paid for, there exists a requirement for securing such communication. However, solutions that rely only on traditional compute-intensive security mechanisms are unsuitable for resource-constrained wireless and embedded devices. In this paper, we propose a selective partial image encryption scheme for image data hiding , which enables highly efficient secure communication of image data to and from resource constrained wireless devices. The encryption scheme is invoked during the image compression process, with the encryption being performed between the quantizer and the entropy coder stages. Three data selection schemes are proposed: subband selection, data bit selection and random selection. We show that these schemes make secure communication of images feasible for constrained embed-ded devices. In addition we demonstrate how these schemes can be dynamically configured to trade-off the amount of ded devices. In addition we demonstrate how these schemes can be dynamically configured to trade-off the amount of data hiding achieved with the computation requirements imposed on the wireless devices. Experiments conducted on over 500 test images reveal that, by using our techniques, the fraction of data to be encrypted with our scheme varies between 0.0244% and 0.39% of the original image size. The peak signal to noise ratios (PSNR) of the encrypted image were observed to vary between about 9.5㏈ to 7.5㏈. In addition, visual test indicate that our schemes are capable of providing a high degree of data hiding with much lower computational costs.

Antiangiogenic Effect of $As_4O_6$ on the Angiogenesis Induced by Vascular Endothelial Growth Factor (VEGF) in the Rat Cornea (랫드 각막에서 Vascular Endothelial Growth Factor(VEGF)로 유발시킨 신생혈관에 대한 $As_4O_6$의 혈관신생 억제효과)

  • Kwon Do-hyoung;Jang Jae young;Yi Na-young;Jeong Man-bok;Park Shin-ae;Kim Min-su;Nam Tchi-chou;Park Myung-jin;Bae Ill-ju;Rhee Chang-hun;Seo Kang-moon
    • Journal of Veterinary Clinics
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    • v.22 no.1
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    • pp.16-20
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    • 2005
  • The purpose of this study was to compare the antiangiogenic effects of As₄O/sub 6/ to those of As₂O₃ on the rat corneal micropocket model induced by VEGF. 20 ng VEGF impregnated pellets were used for angiogenic inducer on the rat cornea micropocket assay in this study. After ophthalmoscopic examination, Sprague-Dawley rats with normal cornea were implanted VEGF pellet. Total 60 eyes were used in this study. Control group only received VEGF pellet, As₂O₃ group followed oral administration of As₂O₃ at a dose of 50 mg/kg per day after VEGF pellet implantation and As₄O/sub 6/ group followed oral administration of As₄O/sub 6/ at a dose of 50 mg/kg per day after VEGF pellet implantation were classified. The eyes were examined under a surgical microscope daily on postoperative from day 3 to day 9 after pellet implantation. The number, length, clock hour of vascularization, and area of vessels in As₄O/sub 6/ group were significantly less evident than those of control group and As₂O₃ group (P < 0.05). In conclusion, As₄O/sub 6/ had better antiangiogenic effects on the new vessel induced by VEGF in the rat cornea.

THE INFLUENCE OF THE VITAL BLEACHING AGENTS ON TRANSLUCENCY OF THE BOVINE ENAMEL (생활치 미백제가 우치 법랑질의 투명도에 미치는 영향)

  • Kim, Dong-Jun;Kim, Young-Ju;Kim, Hak-Geun;Park, Eun-Jong;Seo, Eun-Ju;Hwang, Yun-Chan;Oh, Won-Mann;Hwang, In-Nam
    • Restorative Dentistry and Endodontics
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    • v.30 no.3
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    • pp.178-183
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    • 2005
  • This study was done to evaluate whether vital bleaching agents could influence on the translucency of the bovine enamel. The anterior bovine teeth that were extracted one day before and without any gross discoloration were obtained and then were preserved in physiologic saline. 6 mm cylindrical tooth specimens were fabricated with diamond puncher perpendicularly on labial surface of bovine tooth. After embedded in transparent acrylic resin with labial surface being exposed, they were cut to a thickness of 1.2 mm with low speed diamond saw (Isomat, Buehler Co., Lake Bluff, IL, USA). They were smoothly ground to 1 mm thickness of enamel with sandpaper. 24 specimens were randomly divided into 3 groups and control group respectively. Opalescence (10% carbamide peroxide, Ultradent, South Jordan, USA), Rembrandt (10% carbamide peroxide, DenMat, USA) and Opalescence F (15% carbamide peroxide with fluoride, Ultradent, USA) were applied on labial sides of the bovine enamel for 7 days (bleaching agents were reapplied every 24 hours) and the opposite surface was contacted to cotton that soaked in distilled water. The control group was soaked in distilled water. Three stimulus value X, Y and Z were evaluated with colorimeter (Color ' Color Differencerneter, Model TC-6FX, Tokyo Denshoku Co., Japan) on the labial surface of all specimen three times on white and black background plate before the bleaching agents were applied and on 3rd, 5th and 7th day after applied. The degree of translucency was normally assessed by measuring the inverse property, opacity (contrast ratio). 10% Opalescence, 15% Opalescence-F, and control group showed no significant variation in the translucency of bovine enamel, However Rembrandt decreased the translucency of it (p < 0.01).

Establishment of a Single Dose Radiation Model of Oral Mucositis in Mice (일회 방사선조사를 이용한 마우스 구강점막염 모델의 확립)

  • Ryu, Seung-Hee;Moon, Soo-Young;Choi, Eun-Kyung;Kim, Jong-Hoon;Ahn, Seung-Do;Song, Si-Yeol;Park, Jin-Hong;Noh, Young-Ju;Lee, Sang-Wook
    • Radiation Oncology Journal
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    • v.26 no.4
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    • pp.257-262
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    • 2008
  • Purpose: Oral mucositis induced by radiotherapy to the head and neck area, is a common acute complication and is considered as the most severe symptom for cancer patients in the early stages of treatment. This study was proposed to establish the oral mucositis mouse model induced by a single dose of radiation for the facility of testing therapeutic candidates which can be used for the oral mucositis treatments. Materials and Methods: Fifty-five BALB/c mice were divided into four groups: control, 16 Gy, 18 Gy, and 20 Gy. Oral mucositis was induced by a single dose of radiation to the head and neck using 6 MV x-Ray from linear accelerator. After irradiation, body weight and physical abnormalities were checked daily. Tongue tissues from all groups were taken on days 1, 2, 3, 5, 7, 9, and 14, respectively and H&E staining was conducted to examine morphological changes. Results: Body weight dramatically decreased after day 5 in all irradiated mice. In the 16 Gy treatment group, body weight was recovered on day 14. The histology data showed that the thickness of the epithelial cell layer was decreased by the accumulated time after radiation treatment, up to day 9. Severe ulceration was revealed on day 9. Conclusion: A single dose of 16 Gy is sufficient dose to induce oral mucositis in Balb/C mice. Significant changes were observed in the Balb/C mice on days 7 and 9 after radiation. It is suggested that this mouse model might be a useful standard tool for studying oral mucositis induced by radiation.

THE EFFECT OF THERMOCYCLING ON THE DURABILITY OF DENTIN ADHESIVE SYSTEMS (열순환이 상아질 접착제의 결합 내구성에 미치는 영향)

  • Moon, Young-Hoon;Kim, Jong-Ryul;Choi, Kyung-Kyu;Park, Sang-Jin
    • Restorative Dentistry and Endodontics
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    • v.32 no.3
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    • pp.222-235
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    • 2007
  • The objectives of this study was to evaluate the effect of thermocycling on the ${\mu}TBS$ (microtensile bond strength) to dentin with four different adhesive systems to examine the bonding durability. Freshly extracted $3^{rd}$ molar teeth were exposed occlusal dentin surfaces, and randomly distributed into 8 adhesive groups 3-steps total-etching (Scotchbond Multi-Purpose Plus; SM, All Bond-2; AB), 2-steps total-etching (Single Bond; SB, One Step plus; OS), 2-steps self-etching (Clearfil SE Bond; SE, AdheSE AD) and single-step self-etching systems (Promp L-Pop; PL, Xeno III; XE) Each adhesive system in 8 adhesives groups was applied on prepared dentin surface as an instruction and resin composite (Z250) was placed incrementally and light-cured. The bonded specimens were sectioned with low-speed diamond saw to obtain $1\times1mm$ sticks after 24 hours of storage at $37^{\circ}C$ distilled water and proceeded thermocycling at the pre-determined cycles of 0, 1,000 and 2,000. The ${\mu}TBS$ test was carried out with EZ-tester at 1mm/min. The results of bond strength test were statistically analyzed using one-way ANOVA/ Duncan's test at the a < 0.05 confidence level. Also, the fracture mode of debonded surface and the interface were examined under SEM. The results of this study were as follows ; 1. 3-step total etching adhesives showed stable, but bond strength of 2-step adhesives were decreased as thermocycling stress. 2. SE showed the highest bond strength, but single step adhesives (PL, XE) had the lowest value both before and after thermocycling. 3 Most of adhesives showed adhesive failure. The total-etching systems were prone to adhesive failure and the single-step systems were mixed failure after thermocycling. Within limited results of this study, the bond strength of adhesive system was material specific and the bonding durability was affected by the bonding step/ procedure of adhesive Simplified bonding procedures do not necessarily imply improved bonding performance.

Effect of cavity shape, bond quality and volume on dentin bond strength (와동의 형태, 접착층의 성숙도, 및 와동의 부피가 상아질 접착력에 미치는 영향)

  • Lee, Hyo-Jin;Kim, Jong-Soon;Lee, Shin-Jae;Lim, Bum-Soon;Baek, Seung-Ho;Cho, Byeong-Hoon
    • Restorative Dentistry and Endodontics
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    • v.30 no.6
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    • pp.450-460
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    • 2005
  • The aim of this study was to evaluate the effect of cavity shape, bond quality of bonding agent and volume of resin composite on shrinkage stress developed at the cavity floor. This was done by measuring the shear bond strength with respect to iris materials (cavity shape , adhesive-coated dentin as a high C-factor and Teflon-coated metal as a low C-factor), bonding agents (bond quality: $Scotchbond^{TM}$ Multi-purpose and Xeno III) and iris hole diameters (volume; 1mm or 3mm in $diameter{\times}1.5mm$ in thickness). Ninety-six molars were randomly divided into 8 groups ($2{\times}2{\times}2$ experimental setup). In order to simulate a Class I cavity, shear bond strength was measured on the flat occlusal dentin surface with irises. The iris hole was filled with Z250 restorative resin composite in a bulk-filling manner. The data was analyzed using three-way ANOVA and the Tukey test. Fracture mode analysis was also done When the cavity had high C-factor, good bond quality and large volume, the bond strength decreased significantly The volume of resin composite restricted within the well-bonded cavity walls is also be suggested to be included in the concept of C-factor, as well as the cavity shape and bond quality. Since the bond quality and volume can exaggerate the effect of cavity shape on the shrinkage stress developed at the resin-dentin bond, resin composites must be filled in a method, which minimizes the volume that can increase the C-factor.