• 동력기계공학회지
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• 제5권1호
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• pp.21-26
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• 2001

This paper represents the turbulent intensity, the turbulent kinetic energy and Reynolds shear stress in the X-Y plane of cone type swirl gas burner measured by using X-probe from the hot-wire anemometer system. The experiment is carried out at flowrate 350 and $450{\ell}/min$ respectively in the test section of subsonic wind tunnel. The turbulent intensity and the turbulent kinetic energy show that the maximum value is formed in the narrow slits distributed radially on the edge of a cone type swirl burner, hence, the combustion reaction is anticipated to occur actively near this region. And the turbulent intensities ${\upsilon}\;and\;{\omega}$ are disappeared faster than the turbulent intensity u due to the inclined flow velocity ejecting from the swirl vanes of a cone type baffle plate of burner. Moreover, the Reynolds shear stress $u{\upsilon}$ is distributed about three times as large as the Reynolds shear stress $u{\omega}$ in the outer region of the cone type gas burner.

• 대한치과보철학회지
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• 제33권1호
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• pp.98-129
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• 1995

The purpose of this study was to evaluate how mandibular implant-supported fixed complete prosthesis, implant and mandible responded mechanically, according to curvature of arch, number and location of fixture, and amounts of load. The shape of mandibular arch was tapered or square form and, 4 or 6 fixtures were implanted in each arch model. A vertical load of 10kg was applied at the center of prosthesis and a vertical load of 20kg was applied at the location of the 10mm or 20mm cantilever posterior to the most distal implant. Three-dimensional finite element analysis was performed for stress distribution and deflection using commercial software(ABAQUS program) for Sun-SPARC Workstation. The results were as follows : 1. The case square arch form was more stable to compare with that of tapered arch form in respect of stress distribution and displacement under vertical load on the center of prosthesis. 2. 6-implants cases were more stable than 4-implants cases for decreasing bending torque under vertical load on the center of prosthesis. 3. Under vertical load on cantilever extension, the case of 10mm long cantilever was more stable than that of 20mm long cantilever in respect of stress distribution and displacement. 4. Under vertical load on cantilever extension, 6-implants cases had a tendency to reduce displacement and to increase the reaction force of supporting point due to increasing of the bending stiffness of the prosthesis than 4-implant case. 5. When the ends of 10mm or 20mm long cantilever were loaded, the most distal implant was under compressive stress but the second most distal implant was under the highest tensile stress and the remaining implants were under varying tensile stress. 6. Because 6-implants cases had smaller displacement than 4-implants cases, 6-implants cases were more favorable in respect of prevention of screw loosening under repeated loadings.

• 문화기술의 융합
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• 제8권3호
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• pp.149-158
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• 2022

본 연구는 청소년의 월경에 대한 태도 중 폐쇄성, 정적 수용, 신체 증상, 대처 행동, 정서적 민감성의 5항목과 학업 스트레스가 월경 증상인 월경 전 증후군과 월경곤란증에 미치는 영향을 파악하기 위해 시행되었다. 연구 참여에 동의한 고등학생 여학생 126명의 설문지가 분석되었다. 그 결과 대상자의 월경 전 증후군 점수는 22.48점, 월경곤란증은 4.66점이었으며, 월경양이 많을수록 월경 전 증후군과 월경곤란증 점수는 증가함을 알 수 있었다. 월경 전 증후군에 영향을 미치는 요인은 폐쇄성과 신체 증상, 대처 행동, 정서적 민감성이었고, 이들 변수의 설명력은 49.9%이었다. 또한 정적 수용과 신체 증상은 청소년의 월경곤란증에 유의한 영향을 주었으며, 설명력은 66.3%이었다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1997년도 제25회 춘계학술대회
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• pp.33-40
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• 1997

This study was undertaken to investigate tribology characteristics of the alumina ceramics($Al_2O_3$) for the vauiation of ambient condition such as air and distilled water. The results obtained were as follows. As the sliding speed increases, the friction coefficient in the air decreased due to the reduction of sheafing stress caused by the heat accumulation of contact interface. And the friction coefficient in the distilled water decreased due to an activation of the tribochemical reaction. As the contact load increases, the friction coefficient is small in the air due to temperature rise of the contact interface. However, at the low speed side in the distilled water, the friction coefficient holds a large value due to decrease of the tribochemical reaction. The friction surface of ceramics can be protected in the air by the influence of the oxides tansfered from STB2 and also in the distilled water by the influence of the corrosive productive hydroxides.

• 부모자녀건강학회지
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• 제8권2호
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• pp.123-136
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• 2005

This research is to compare the infant's temperament and parenting stress perceived by premature infants' mother and full-term infants' mother. It aims at establishing the healthy relationship between mothers and infants. It investigates the basic data of nursing intervention program to help the mother of premature infant. The period of data collection was from May 1, 2005 to May 30, 2005, and the subjects were total 123 mothers: 44 mothers of premature infants and 79 mothers of full-term infants under 6 months who visited general hospitals, individual pediatrics, and health center located in G city. "What My Baby Is Like(WBL)" developed by Pridham, Chang, and Chiu(1994) and translated by Bang Kyeong Sook(1999) was used as a measuring instrument of infants' temperament, and Parenting Stress Index (PSI) developed by Abidin(1990) and revised and complemented by Kim Dong Hee(1997) was used as a measuring instrument of parenting stress. Collected Data were analyzed through $X^2$-test, t-test, Pearson's correlation with SPSS 12.0 window program. The results are as follows: 1. There was a significant difference in the infant's temperament perceived by premature infants' mothers and full-term infants' mothers (t=-4.08, p=.00). In subcategory, there were significant difference between premature infants' mother and full-term infants' mother in geniality(t=-3.62, p=.00), adaptation(t=-3.43, p=.00) and reaction(t=-2.01, p=.05). 2. There was a significant difference in parenting stress between premature infants' mother and full-term infants' mother(t=6.57, p=.00). The parenting stress of premature infants mothers appeared to be higher than full-term infants' mothers. They showed the higher stress in the mother-child relationship area(t=6.27, p=.00) and child area(t=7.38, p=.00) among 3 areas of parenting stress. 3. There were negative correlation between infants' temperament and parenting stress. As mothers perceived the infant's temperament negatively, the parenting stress. Especially, the negative correlation of infants' temperament and parenting stress of premature infants' mothers(r=-.44) was stronger than that of full-term infants' mothers(r=-37). From the research, as mothers of premature infants receive more stress, their stress can cause the serious problem to the relationship of the mother and the infant. Therefore, the nursing intervention should be carried out in order to change the negative perception of mothers towards their infants into the positive perception reduce the parenting stress.

• Journal of Ginseng Research
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• 제43권1호
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• pp.135-142
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• 2019

Background: Panax ginseng Meyer, known as Korean Red Ginseng (KRG), is one of the important age-old traditional herbs used in boosting libido and improving male fertility. In this study, the effects of Rg3-enriched KRG extract (KGC04P) on heat stress-induced testicular damage in experimental rats was evaluated. Methods: Male rats (Sprague-Dawley) were divided into four groups (n = 10): normal control (NC), heat-stressed control (HC), heat-stressed plus KGC04P-100 mg/kg (HK100), and heat-stressed plus KGC04P-200 mg/kg (HK200) groups. Starting 1 week prior to heat stress, animals were administered orally with KGC04P (100 and 200 mg/kg) mixed with a regular pellet diet and continued for 25 weeks. Heat stress was induced to HC, HK100, and HK200 groups by intermittently exposing the animals to high temperatures ($32{\pm}1^{\circ}C$, 2 h/day). After 6 months, animals were euthanized under general anesthesia with carbon dioxide and evaluated for various parameters in serum and testicular tissue by using Western blotting, biochemical kits, and reverse transcription-polymerase chain reaction. Results: Significant (p < 0.05) alterations in several parameters, such as body/organ weight, sperm kinematics, and lipid metabolism marker levels, in the serum and testis of rats were observed. Further, the expression of testicular antioxidant enzymes, inflammatory cytokines, sex hormonal receptors, and spermatogenesis-related genes were also affected significantly (p < 0.05) in the heat-stressed group. However, KGC04P prevented the heat stress-induced changes in rats significantly (p < 0.05) at both concentrations. Conclusion: KGC04P attenuated heat stress-induced testicular damage by a multifunctional approach and can be developed as an excellent therapeutic agent for hyperthermia-mediated male infertility.

• Journal of Veterinary Science
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• 제25권2호
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• pp.21.1-21.15
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• 2024

Background: Peste des petits ruminants (PPR) is a contagious and fatal disease of sheep and goats. PPR virus (PPRV) infection induces endoplasmic reticulum (ER) stress-mediated unfolded protein response (UPR). The activation of UPR signaling pathways and their impact on apoptosis and virus replication remains controversial. Objectives: To investigate the role of PPRV-induced ER stress and the IRE1-XBP1 and IRE1-JNK pathways and their impact on apoptosis and virus replication. Methods: The cell viability and virus replication were assessed by 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay, immunofluorescence assay, and Western blot. The expression of ER stress biomarker GRP78, IRE1, and its downstream molecules, PPRV-N protein, and apoptosis-related proteins was detected by Western blot and quantitative reverse transcription-polymerase chain reaction, respectively. 4-Phenylbutyric acid (4-PBA) and STF-083010 were respectively used to inhibit ER stress and IRE1 signaling pathway. Results: The expression of GRP78, IRE1α, p-IRE1α, XBP1s, JNK, p-JNK, caspase-3, caspase-9, Bax and PPRV-N were significantly up-regulated in PPRV-infected cells, the expression of Bcl-2 was significantly down-regulated. Due to 4-PBA treatment, the expression of GRP78, p-IRE1α, XBP1s, p-JNK, caspase-3, caspase-9, Bax, and PPRV-N were significantly downregulated, the expression of Bcl-2 was significantly up-regulated. Moreover, in PPRV-infected cells, the expression of p-IRE1α, p-JNK, Bax, and PPRV-N was significantly decreased, and the expression of Bcl-2 was increased in the presence of STF-083010. Conclusions: PPRV infection induces ER stress and IRE1 activation, resulting in apoptosis and enhancement of virus replication through IRE1-XBP1s and IRE1-JNK pathways.

• 한국도로학회논문집
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• 제17권2호
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• pp.13-20
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• 2015

PURPOSES: This paper describes the expansion caused by the alkali-aggregate reaction (AAR) in concrete pavement currently in service. It also discusses the effects of joints installed to release the stress induced by the AAR expansion. METHODS: The expansion effect on concrete pavement was verified by a visual inspection and long-term measurement of the joint width of a cut-section. The behaviors of 16 newly installed joints were monitored as part of the investigation and long-term monitoring was carried out for three years after cutting. RESULTS: The behavior of a bridge was affected when AAR occurred in the connected pavement. The newly installed joints shrank in the longitudinal direction of the bridge after cutting. The width of the joints decreased over the six months after cutting. A large portion of the joint width (8.5cm) was found to have closed nine months after cutting. It had ultimately shrunk by about 92 percent when the final measurement was taken. CONCLUSIONS : The expansion of the pavement due to AAR was quantitatively described by visual inspection and the long-term monitoring of the newly cut joints. However, the width of the new joints decreased over the six to nine months after cutting. Additional research should be conducted to determine a means of controlling the expansion due to AAR in the pavement.

• Journal of Microbiology and Biotechnology
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• 제28권10호
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• pp.1604-1613
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• 2018

Lactobacillus rhamnosus GG (LGG) is a probiotic commonly used in fermented dairy products. In this study, RNA-sequencing was performed to unravel the effects of acid stress on LGG. The transcriptomic data revealed that the exposure of LGG to acid at pH 4.5 (resembling the final pH of fermented dairy products) for 1 h or 24 h provoked a stringent-type transcriptomic response wherein stress response- and glycolysis-related genes were upregulated, whereas genes involved in gluconeogenesis, amino acid metabolism, and nucleotide metabolism were suppressed. Notably, the pilus-specific adhesion genes, spaC, and spaF were significantly upregulated upon exposure to acid-stress. The transcriptomic results were further confirmed via quantitative polymerase chain reaction analysis. Moreover, acid-stressed LGG demonstrated an enhanced mucin-binding ability in vitro, with 1 log more LGG cells (p < 0.05) bound to a mucin layer in a 96-well culture plate as compared to the control. The enhanced intestinal binding ability of acid-stressed LGG was confirmed in an animal study, wherein significantly more viable LGG cells (${\geq}2log\;CFU/g$) were observed in the ileum, caecum, and colon of acid-stressed LGG-treated mice as compared with a non-acid-stressed LGG-treated control group. To our knowledge, this is the first report showing that acid stress enhanced the intestine-binding ability of LGG through the induction of pili-related genes.

• Journal of Hospice and Palliative Care
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• 제10권3호
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• pp.120-127
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• 2007

Bereavement is the state of loss resulting from death. Grief is the emotional response associated with loss, intense and acute sorrow resulting from loss. Complicated grief represent a pathological outcome involving social, physical, emotional, cognitive, spiritual morbidity. The common psychiatric disorders associated complicated grief or abnormal grief responses include clinical depression, anxiety disorders, alcohol abuse or other substance abuse, and dependence, psychotic disorders, and post-traumatic stress disorder (PTSD). Grief tasks involve a series of stage or phases following an important loss that gradually permit adjustment and recovery. Three phases of grief involve phase 1 (walking the edges), phase 2 (entering the depths), and phase 3 (reconnecting the world). For intervention to be effective they need to be individually tailored to abnormal grief reaction or unresolved grief reaction. Clear understandings of complicated grief, abnormal responses, factors increasing risk after bereavement will often enable us to prevent psychiatric disorders in bereaved patients.