• Title/Summary/Keyword: 무작위 실험연구

Search Result 616, Processing Time 0.032 seconds

Bond strength of orthodontic brackets bonded to enamel with a self-etching primer after bleaching and desensitizer application (미백과 탈감작제 도포 후 셀프 에칭 프라이머를 이용한 브라켓 접착 시 법랑질과 브라켓 간의 결합 강도)

  • Attar, Nuray;Korkmaz, Yonca;Kilical, Yasemin;Saglam-Aydinatay, Banu;Bicer, Ceren Ozge
    • The korean journal of orthodontics
    • /
    • v.40 no.5
    • /
    • pp.342-348
    • /
    • 2010
  • Objective: The aim of this study was to compare the shear bond strengths (SBS) of orthodontic brackets bonded to enamel with a self-etching primer after bleaching, desensitizer application and combined treatment. Methods: Forty-eight premolars were randomly divided into four groups, each with n = 12 premolar samples. The four groups were; Group1: 15% hydrogen-peroxide office bleaching agent (Illumin$\acute{e}$ Office-IO), Group 2: IO + BisBlock Oxalate Dentin-Desensitizer, Group 3: Bis Block Oxalate Dentin-Desensitizer, Group 4: No treatment (control). Twenty-four hours after bonding, the specimens were tested in SBS at a crosshead speed of 5 mm/min until the brackets debonded. The failure mode of the brackets was determined by a modified adhesive remnant index. Results: Bleaching, bleaching and desensitizer treatment, and desensitizer treatment alone all significantly reduced SBS of the orthodontic brackets ($p$ = 0.001). No statistically significant difference was found between Group 1, Group 2 and Group 3 (Group 1-Group 2, $p$ = 0.564; Group 1-Group 3, $p$ = 0.371; Group 2-Group 3, $p$ = 0.133). The predominant mode of failure for the treatment groups (Group1, Group 2 and Group 3) was at the enamel-adhesive interface leaving 100% of the adhesive on the bracket base. Conclusions: Bleaching and desensitizer treatment should be delayed until the completion of orthodontic treatment.

Effects of Electrical Stimulation on the Mast Cell of Skin in Rats (전기자극이 흰쥐의 피부 비만세포에 미치는 영향)

  • Lee Jae-Hyoung;Jekal Seung-Joo;Park Seung-Teack
    • The Journal of Korean Physical Therapy
    • /
    • v.11 no.3
    • /
    • pp.81-87
    • /
    • 1999
  • The purpose of this study was to determine the effect of electrical stimulation on the number of MCs and percent of degranulated MCs in rat skin. Twelve male Sprague-Dawley rats were divided into two group; electrical stimulation group (n=6) and control group (n=6). Each animals hair on the back was removed. The electrical stimulation group received an positive rectangular pulsed electrical stimulation, while the control group was given the same treatment without electricity. The biopsy specimens were fixed in formalin, embedded in paraffin and stained with toluidine blue-nuclear fast red and alcian blue-safranin O. respectively. The MCs were counted using a light microscope and computerized image analysis system and calculated as the density and the percent. A t-test showed a significantly higher density of MCs in the electrical stimulated rats than control rats(p<0.05), and the percent of degranulated MCs in the electrical stimulated rats was higher than in the control rats (p<0.05) in toluidine blue stained sections. The density of MCs was significantly higher in the electrical stimulated rats than the control rats in alcian blue-safranin O Stained sections (P<0.01). An analysis of variance showed that the densities of CTMCs was significantly lower than the densities of MMCs and mixed MCs in electrical stimulated rat in alcian blue-safranin O Stained sections (p<0.05). These results suggest that the electrical stimulation may have potential for increasing the number of MCs and lead to degranulate the MCs in rat skin.

  • PDF

EFFECT OF THE CHLORHEXIDINE AND FLUORIDE-CONTAINING VARNISH ON THE LEVEL OF SALIVARY MUTANS STREPTOCOCCI (Chlorhexidine과 fluoride 성분의 varnish가 타액 내 mutans streptococci 수에 미치는 효과)

  • Seo, Jeong-Ah;Baik, Byeong-Ju;Yang, Yeon-Mi;Lee, Yong-Hee;Kim, Sang-Hoon;Kim, Jae-Gon
    • Journal of the korean academy of Pediatric Dentistry
    • /
    • v.31 no.4
    • /
    • pp.579-586
    • /
    • 2004
  • The objective of the present prospective trial was to compare the efficacy of chlorhexidine(Cervitec), Fluoride (Fluorprotector) and combination of chlorhexdine and fluoride varnishes in decreasing the level of salivary mutans streptococci. Forty healthy students of school of dentistry, Chonbuk national university were investigated to evaluate mutans streptococci(MS) counts and randomized into four groups to treat with the experimental varnishes; A) untreated group(n=10), B) chlorhexidine group(n=10), C) fluoride group(n=10), D) chlorhexidine and fluoride group(n=10). Dentocult $SM^{(R)}$ (Orion Diagnostica) strip method was used for measurement of the level of mutans streptococci in saliva. Stimulated saliva were collected at baseline for mutans streptococci counts evaluation (ms1), 12 weeks later the completion of each varnish treatment, mutans streptococci counts were re-evaluated. In varnish group with chlorhexidine, fluoride and combination of chlorhexidine and fluoride, the level of mutans streptococci was lower after 12 weeks than at baseline, but there were no significant differences in saliva(p>0.05), when compared with baseline. After 12 weeks, a remarkable reduction was still found in the subjects with high level of mutans streptococci at baseline, but not different in the low and moderate level of mutans streptococci(p>0.05).

  • PDF

The effect of MTAD as a final root canal irrigants on the coronal bacterial leakage of obturated root canals (최종 근관세척제로서의 MTAD 근관세척제가 치관부 세균미세누출에 미치는 영향)

  • Kim, Tae-Woo;Chang, Seok-Woo;Park, Dong-Sung
    • Restorative Dentistry and Endodontics
    • /
    • v.33 no.4
    • /
    • pp.397-404
    • /
    • 2008
  • The purpose of this study was to evaluate the effects of MTAD, EDTA and sodium hypochlorite(NaOCl) as final irrigants on coronal leakage resistance to Enterococcus faecalis. Forty extracted human maxillary molars were used in this experiment. The teeth were randomly divided into positive control group (Group 1; n = 5), negative control group (Group 2; n = 5) and three experimental groups (n = 30). In Group 3 (n = 10), the root canals were irrigated with sodium hypochlorite. In Group 4 (n = 10) and 5 (n = 10), the root canals were irrigated with sodium hypochlorite and rinsed with EDTA and MTAD, respectively. The teeth in each group were cleaned and shaped to #40 profile with .04 taper, and obturated with gutta-percha and AH-26 root canal sealer. The coronal portion of each tooth was placed in contact with inoculum of Enterococcus faecalis in Brain Heart Infusion (BHI) culture media. Each root tip was placed in a vial containing sterile culture media. The vials were placed in anaerobic chamber and observed everyday for turbidity for 180 days. Statistical analysis was performed using Fisher's Exact Test. After 180 days, Group 3, 4, and 5 showed 7, 4 and 5 leaking samples respectively. The differences in leakage resistance were not statistically significant among Group 3, 4 and 5.

The Protective Effects of Vitamin C on Hepatotoxicity Induced by Radiation (비타민 C의 방사선에 의한 간독성 완화 효과)

  • Ahn Kijung;Park Sungkwang;Cho Heunglae;Kang Kimun;Chung Duckwha;Kang Jinsoon;Chai Gyuyoung
    • Radiation Oncology Journal
    • /
    • v.22 no.4
    • /
    • pp.280-287
    • /
    • 2004
  • Purpose: This study was carried out to determine the protective effects of vitamin C on the hepatotoxicily induced by radiation. Materials and Methods : The Spraque Dawley rats were randomly divided into 3 groups; the control group, the radiation exposed group, aud the radiation and vitamin C-treated group. SOD activity, ca-talase, malondialdehyde and liver enzymes were analyzed to assess the antioxidant effects of vitamin C. Results: The increased level of malondialdehyde and the decreased catalase activity that were induced by radiation were improved after vitamin C but there was no statistical significance among three groups. The superoxide dismutase activity of the liver was increased by vitamin C, but there were no statistically significant differences between the vitamin C-treated group and the non vitamin C-treated group. The level of liver enzymes in sera such as glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, lactate dehyrogenase and alkaline phosphatase were remarkably elevated by radiation. The levels of those enzymes were decreased in the vitamin C-treated group and statistical significance was noted for the GPT level ($p<0.01$). On the electromicrographic findings, the hepatic cell destruction was considerably decreased in the vitamin C-treated group. Conclusion: Vitamin C is thought to be an effective antioxidant against the hepatotoxicity induced by radiation.

The Effect of Abdominal Draw-in Maneuver with Leg Movements on Transversus Abdominis Thickness and Trunk Control in Stroke Patients (다리 움직임을 동반한 복부 드로우-인 기법이 뇌졸중 환자의 배가로근 두께와 몸통 조절에 미치는 영향)

  • Kang, Jeong-Il;Moon, Young-Jun;Jeong, Dae‐Keun
    • Journal of Korea Entertainment Industry Association
    • /
    • v.14 no.8
    • /
    • pp.287-294
    • /
    • 2020
  • The purpose of this study was, base on the observation that the leg movement has effect on muscles around trunk, to provide clinical fundamental data to develop effective abdominal draw-in technique by investigating the effect of abdominal draw-in exercise accompanying leg movement on the thickness of transversus abdominis muscle and trunk control ability in patients with stroke. The subjects were assigned randomly to experimental group I (n=9) on which the abdominal draw-in technique is applied and experimental group II (n=9) on which the abdominal draw-in technique accompanying leg movement is applied. The thickness of transversus abdominis muscle in the affected side and the trunk control ability were measured before and after treatment using ultrasonography and trunk impairment scale. A session of 30 minutes per day were performed four days a week for four weeks and the measured outcomes were analyzed. The in-group comparison showed significant difference both thickness of transversus abdominis muscle during abdominal draw-in technique application (p<0.01) and trunk control ability (p<0.001) between before and after treatment. The significant difference between two groups were observed only in trunk control ability (p<0.05). It was concluded that the abdominal draw-in technique accompanying leg movement is an intervention that has positive effect not only on transversus abdominis muscle but also on tunk control ability by inducing more efficient contraction reaction in muscles around trunk through autonomic pelvic movement caused by leg movement.

Effects of Dietary Vitamins C and E on Egg Shell Quality of Broiler Breeder Hens under Heat Stress

  • Chung, M.K.
    • Proceedings of the Korea Society of Poultry Science Conference
    • /
    • 2004.11a
    • /
    • pp.69-79
    • /
    • 2004
  • A feeding trial was conducted to determine whether dietary vitamin C (200 mg/kg) and vitamin E (250 mg/kg) prevent any drops in egg shell quality under heat stress in broiler breeder hens. One hundred and sixty molted Ross broiler breeders were housed randomly in an individual cage at 83 weeks of age. Four dietary treatments with forty hens and four replications per treatment were control (no additional vitamins). vitamin C-. or vitamin E-supplemented. and combined supplementation of the two vitamins. After a ten-day-adaptation period at 25 $^{\circ}C$. the ambient temperature was kept at 32 $^{\circ}C$ for a three-week-testing period. Egg production dropped dramatically over week but it did not show a significant change among treatments (P<0.05). However. egg weight. SG. shell thickness. SWUSA. puncture force and shell breaking strength of the birds fed the diet with the combined vitamins C and E were significantly improved than those fed the basal diet during the heat stress period (P<0.05). The hens fed the vitamin C supplemented diet showed a tibia breaking strength of 37.16 kg statistically higher than those of the basal and the vitamin E supplemented groups (P<0.05). The hens fed the basal diet showed higher serum corticosterone levels. a mean of 5.97 ng/ml. than those of the rest of treatments (P<0.05). The heat stress elevated heterophils but decreased lymphocytes in serum. and it changed H/L ratios of all the treatments. The increases in H/L ratios were alleviated in the bird by feeding vitamin C and/or vitamin E supplemented diets. but they did not differ significantly (P<0.05). In conclusion. vitamins C (200 mg/kg) and/or E (250 mg/kg) supplementation to diets could prevent drops in egg shell quality and tibia bone strength by alleviating stressful effects from high temperature in broiler breeder hens.

  • PDF

Detection Fastener Defect using Semi Supervised Learning and Transfer Learning (준지도 학습과 전이 학습을 이용한 선로 체결 장치 결함 검출)

  • Sangmin Lee;Seokmin Han
    • Journal of Internet Computing and Services
    • /
    • v.24 no.6
    • /
    • pp.91-98
    • /
    • 2023
  • Recently, according to development of artificial intelligence, a wide range of industry being automatic and optimized. Also we can find out some research of using supervised learning for deteceting defect of railway in domestic rail industry. However, there are structures other than rails on the track, and the fastener is a device that binds the rail to other structures, and periodic inspections are required to prevent safety accidents. In this paper, we present a method of reducing cost for labeling using semi-supervised and transfer model trained on rail fastener data. We use Resnet50 as the backbone network pretrained on ImageNet. At first we randomly take training data from unlabeled data and then labeled that data to train model. After predict unlabeled data by trained model, we adopted a method of adding the data with the highest probability for each class to the training data by a predetermined size. Futhermore, we also conducted some experiments to investigate the influence of the number of initially labeled data. As a result of the experiment, model reaches 92% accuracy which has a performance difference of around 5% compared to supervised learning. This is expected to improve the performance of the classifier by using relatively few labels without additional labeling processes through the proposed method.

Effects of Visiting Prehabilitation Program against Functional Decline in the Frail Elderly: A Prospective Randomized Community Trial (허약노인을 위한 방문재활 프로그램의 장애발생예방 효과에 대한 연구)

  • Kim, Chang-O;Lee, Heeyeon;Ho, Seung Hee;Park, Hyunsuk;Park, Chulwoo
    • 한국노년학
    • /
    • v.30 no.4
    • /
    • pp.1293-1309
    • /
    • 2010
  • This study is aimed to evaluate the effects of community-based prehabilitation program developed to prevent functional decline in the frail elderly and to provide a basis to practically operate this program in the public health care service. From March to August 2009, 110 frail elderly people were recruited among the registered participants of the home visit program in Korea to perform a prospective randomized community trial. We randomly assigned these people into two groups. One group (n=50) participated in the visiting prehabilitation program for 3 months focusing on improving their muscle strength of upper and lower limbs, walking ability, and balancing. The other group (n=60) underwent our visiting fall prevention program for control. To assess the effectiveness of prehabilitation program, physical functioning (PF) and short physical performance battery (SPPB) were measured for the primary outcomes and also some other indicators: exercise performance, nutritional status, emotional functioning, experience of admission, and events of fall. As a result, significant improvements of geriatric functional status were noticed among the participants. After 3 months, PF increased by 1.3 ± 3.8 points in prehabilitation group and decreased by 1.1 ± 5.4 points in controls (p=.020). SPPB improved by 2.4 ± 2.0 points in prehabilitation group and increased only 0.3 ± 1.5 points in controls (p<.001). Significant effects were also shown in their exercise performance tests and emotional status, the number of multiple falls, and the experience of functional decline after the fall (p .002-.038). Visiting prehabilitation program is safe and effective program for frail older adults. Thus, it is strongly recommended to universally adopt this program to prevent functional decline in the frail elderly.

Effects of Occupational Therapeutic Craft Activity on improvement cognitive function and hand function in acute patients with stroke (수공예 작업치료 프로그램 활동이 급성기 뇌졸중 환자의 손 기능에 미치는 효과)

  • Jang, Tae-Yong;Park, Bo-Ra;Yang, Yeong-Ae
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.18 no.5
    • /
    • pp.355-365
    • /
    • 2017
  • This study investigatedwhether occupational therapeutic craft activity improves cognitive function and hand function in patients with acute stroke, with the hope of providing clinically useful results for further studies. From March 2016 to November 2016, thirty acute patients with stroke at A general hospital and B rehabilitation hospital in Seoul and Gyeonggi-do, Korea were enrolled and randomly divided into two groups. One group was treated with occupational therapeutic craft activity,and the other general exercise. The subjects performed each activity for 30 minutestwice weekly, for four weeks. To test the effect of intervention, hand function was tested with the Box & Block Test and the Jebsen-Taylor Hand Function Test.Cognitive function measures were the NCSE and Trail-Making Test. Over the four weeks of treatment activities, in the occupational therapeutic craft activity group, hand function measures(p<.05) increased significantly,as did cognitive function measures(p<.05). This study shows that occupational therapeutic craft activity improves hand function and cognitive function effectively in patients with acute stroke. Occupational therapeutic craft activity programscan be based on this study to prepare intervention programs for further studies with acute stroke patients.