• Child Health Nursing Research
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• v.25 no.4
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• pp.377-387
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• 2019

Purpose: The purpose of this study was to examine the correlation between a flexible parental visiting environment and parental stress in neonatal intensive care units (NICUs). Methods: The study participants included 60 parents of premature infants in NICUs. Structured questionnaires and interviews, as well as observations by researchers using a caregiving behavior checklist, were used to measure the flexibility of the parental visiting environment and parents' stress levels. Quantitative and qualitative data were collected concurrently and were initially analyzed as separate data sets. Data collection extended from March 11, 2018 to June 30. 2018 and the data were analyzed using descriptive statistics, the independent t-test, one-way analysis of variance, and Pearson correlation coefficients. Results: There was a negative correlation (r=-.30, p=.021) between parental stress and the total number of visits in 7 days. We also found that the average duration of each visit and the number of caregiving behaviors performed by parents were positively correlated (r=.73, p<.001). Conclusion: When designing a flexible visiting environment for parents, parents should be encouraged to visit their babies. By doing so, stress can be reduced both for babies and for parents. Therefore, it is suggested that the related polices and regulations in South Korea should be changed to provide more a flexible visiting environment to promote better parent-child attachment and family adjustment.

• Structural Engineering and Mechanics
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• v.34 no.2
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• pp.143-157
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• 2010

This paper presents theoretical solutions for the three-dimensional (3D) stress field in an infinite isotropic elastic plate containing a through-the-thickness circular hole subjected to far-field in-plane loads by using Kane and Mindlin's assumption. The dangerous position, where the premature fracture or failure of the plate will take place, the expressions of the tangential stress at the surface of the hole and the out-of-plane stress constraint factor are found in a concise, explicit form. Based on the present theoretical solutions, a comprehensive analysis is performed on the deviated degree of the in-plane stresses from the related plane stress solutions, stress concentration and out-of-plane constraint, and the emphasis has been placed on the effects of the plate thickness, Poisson's ratio and the far-field in-plane loads on the stress field. The analytical solution shows that the effects of the plate thickness and Poisson's ratio on the deviation of the 3D in-plane stress components is obvious and could not be ignored, although their effects on distributions of the in-plane stress components are slight, and that the effect of the far-field in-plane loads is just on the contrary of that of the above two. When only the shear stress is loaded at far field, the stress concentration factor reach its peak value about 8.9% higher than that of the plane stress solutions, and the out-of-plane stress constraint factor can reach 1 at the surface of the hole and is the biggest among all cases considered.

• Steel and Composite Structures
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• v.17 no.5
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• pp.601-621
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• 2014

Repairing and strengthening structural members by bonding composite materials have received a considerable attention in recent years. The major problem when using bonded FRP or steel plates to strengthen existing structures is the high interfacial stresses that may be built up near the plate ends which lead to premature failure of the structure. As a result, many researchers have developed several analytical methods to predict the interface performance of bonded repairs under various types of loading. In this paper, a numerical solution using finite - difference method (FDM) is used to calculate the interfacial stress distribution in beams strengthened with FRP plate having a tapered ends under thermal loading. Different thinning profiles are investigated since the later can significantly reduce the stress concentration. In the present theoretical analysis, the adherend shear deformations are taken into account by assuming a parabolic shear stress through the thickness of both beam and bonded plate. The shear correction factor for I-section beams is also included in the solution. Numerical results from the present analysis are presented to demonstrate the advantages of use the tapers in design of strengthened beams.

• Animal cells and systems
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• v.5 no.2
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• pp.157-161
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• 2001

Mice homozygous for the lethal autosomal recessive anorexia mutation (anx) present with premature death around postnatal day 22. The anorexia mutant mice also present phenotypes such as reduced body weight, decreased food intake, and abnormal behavior characteristics such as body tremors, hyperactivity, uncoordinated gait, and head weaving. In order to investigate the expression of c-Fos in the hippocampus of anorexia mutant mice, the immunohistochemistry was performed in this study. The anorexia mutant mice exhibited lower expression of c-Fos in the hippocampus regions thBn the control group. In the CA3 and dentate gyrus, the number of c-Fos-positive cells in anorexia mutant mice was noticeably lower than that in control mice. However, no significant difference was found in the number of c-Fos-positive cells in CA1 of the two groups. The result suggests that the phenotypic characteristics of anorexia mutant mice may be associated with the hippocampal deficits of c-Fos expression.

• Clinical and Experimental Pediatrics
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• v.64 no.1
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• pp.37-43
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• 2021

Background: Animal studies have shown that a leukocyte influx precedes the development of bronchopulmonary dysplasia (BPD) in premature sheep. The CXC chemokine receptor 2 (CXCR2) pathway has been implicated in the pathogenesis of BPD because of the predominance of CXCR2 ligands in tracheal aspirates of preterm infants who later developed BPD. Purpose: To test the effect of CXCR2 antagonist on postnatal systemic and pulmonary inflammation and alveolarization in a newborn Sprague-Dawley rat model of BPD. Methods: Lipopolysaccharide (LPS) was injected intraperitoneally (i.p.) into the newborn rats on postnatal day 1 (P1), P3, and P5 to induce systemic inflammation and inhibit alveolarization. In the same time with LPS administration, CXCR2 antagonist (SB-265610) or vehicle was injected i.p. to investigate whether CXCR2 antagonist can alleviate the detrimental effect of LPS on alveolarization by attenuating inflammation. On P7 and P14, bronchoalveolar lavage fluid (BALF) and peripheral blood (PB) were collected from the pups. To assess alveolarization, mean cord length and alveolar surface area were measured on 4 random nonoverlapping fields per animal in 2 distal lung sections at ×100 magnification. Results: Early postnatal LPS administration significantly increased neutrophil counts in BALF and PB and inhibited alveolarization, which was indicated by a greater mean cord length and lesser alveolar surface area. CXCR2 antagonist significantly attenuated the increase of neutrophil counts in BALF and PB and restored alveolarization as indicated by a decreased mean cord length and increased alveolar surface area in rat pups exposed to early postnatal systemic LPS. Conclusion: CXCR2 antagonist preserved alveolarization by alleviating pulmonary and systemic inflammation induced by early postnatal systemic LPS administration. These results suggest that CXCR2 antagonist can be considered a potential therapeutic agent for BPD that results from disrupted alveolarization induced by inflammation.

• Neonatal Medicine
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• v.28 no.3
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• pp.124-132
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• 2021

Purpose: Neonatal near miss (NNM) allows for the detection of risk factors associated with serious newborn complications and death, the prevention of which could reduce neonatal mortality. This study was conducted with the objective of identifying predictors for NNM in a tertiary hospital in Bangalore city. Methods: This was an unmatched case-control study involving 120 NNM cases and 120 controls. NNM was determined using Pileggi-Castro's pragmatic and management criteria. Data was collected from in-patient hospital records and interviews of postpartum mothers. Multiple logistic regression of exposure variables was performed to calculate adjusted odds ratio (AOR) with 95% confidence interval (CI). Results: Significant predictors were maternal age ≥30 years (AOR, 5.32; 95% CI, 1.12 to 9.29; P=0.041), inadequate antenatal care (ANC) (AOR, 8.35; 95% CI, 1.98 to 51.12; P=0.032), <3 ultrasound scans during pregnancy (AOR, 12.5; 95% CI, 1.60 to 97.27; P=0.016), maternal anaemia (AOR, 18.96; 95% CI, 3.10 to 116.02; P=0.001), and any one obstetric complication (hypertensive disorder in pregnancy, diabetes in pregnancy, preterm premature rupture of membranes, prolonged labour, obstructed labour, malpresentation) (AOR, 4.34; 95% CI, 1.26 to 14.95; P=0.02). Conclusion: The predictors of NNM identified has important implications for public health policy and practice whose modifications can improve NNM. These include expanding essential ANC package to include ultrasound scans, ensuring World Health Organization recommendations of eight ANC visits, capacity building at all levels of health care to strengthen routine ANC and obstetric care for effective screening, referral and management of obstetric complications.

• Neonatal Medicine
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• v.28 no.1
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• pp.29-35
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• 2021

Purpose: Intussusception is the most common cause of bowel obstruction in children; however, it is rarely diagnosed in newborn infants. This study aimed to describe the clinical features of intussusception in newborn infants. Methods: Medical records of eight patients diagnosed with intussusception during the newborn period at Ulsan University Hospital between March 2007 and March 2020 were retrospectively reviewed. Results: Among the eight cases, two occurred in the intrauterine period and six occurred in the postnatal period. Intrauterine intussusception presented with symptoms of bowel obstruction within 1 to 2 days after birth, and ileal atresia was diagnosed simultaneously through exploratory laparotomy. All the postnatal patients were extremely low birth weight infants (median gestational age and birth weight: 25⁺⁶ weeks and 745 g, respectively). Four cases were diagnosed preoperatively using abdominal ultrasonography. One patient was diagnosed by exploratory laparotomy because the clinical symptoms were nonspecific and difficult to differentiate from those of necrotizing enterocolitis, a more prevalent complication in preterm infants. The site of intussusception in all six patients was the small bowel. Meckel's diverticulum (one case) and meconium obstruction (two cases) were found to be the lead point. Conclusion: Neonatal intussusception tends to show different clinical features according to its period of occurrence. Intussusception, especially in preterm infants, has nonspecific clinical features; therefore, clinicians should always be cautious of this disease for its early diagnosis.

• Journal of Preventive Medicine and Public Health
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• v.54 no.3
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• pp.182-189
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• 2021

Objectives: This study investigated the relationship between sleep quality during pregnancy and preterm birth. Methods: This longitudinal study was conducted between August 2018 and May 2019. The participants were 150 pregnant women who had been referred to 7 healthcare centers in the city of Qazvin, Iran and met the inclusion criteria. The Petersburg Sleep Quality Index, the Epworth Sleepiness Scale, and 2 questions about daytime sleep status and a demographic questionnaire were administered at 14-18 weeks and 28-32 weeks of gestation. Data were analyzed using the Mann-Whitney test, the Fisher exact test, and univariate and multivariable logistic regression. Results: In the present study, poor sleep quality affected 84.7% of the participants at 14-18 weeks and 93.3% at 28-32 weeks of gestation. The final model for preterm birth prediction incorporated age and the Petersburg Sleep Quality Index score in the second and third trimesters. Preterm birth increased by 14% with each unit increase in age. With each unit increase in the Petersburg Sleep Quality Index score in the second and third trimesters, preterm birth increased by 42% and 28%, respectively, but the p-values of these factors were not significant. Conclusions: Although a significant percentage of pregnant women had poor sleep quality, no significant relationship was found between sleep quality during pregnancy and preterm birth.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.12
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• pp.113-122
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• 2021

Complicated residual stress distributions occur in the vicinity of a deposited region via directed energy deposition (DED) process owing to the rapid heating and cooling cycle of the deposited region and the substrate. The residual stress can cause defects and premature failure in the vicinity of the deposited region. Several heat treatment technologies have been extensively researched and applied on the part deposited by the DED process to relieve the residual stress. The aim of this study was to investigate the residual stress characteristics of a specimen fabricated by DED and a quenching process using thermomechanical analyses. A coupled thermomechanical analysis technique was adopted to predict the residual stress distribution in the vicinity of the deposited region subsequent to the quenching step. The results of the finite element (FE) analyses for the deposition and the cooling measures show that the residual stress in the vicinity of the deposited region significantly increases after the completion of the elastic recovery. The results of the FE analyses for the heating and quenching stages further indicate that the residual stress in the vicinity of the deposited region remarkably increases at the initial stage of quenching. In addition, it is observed that the residual stress for quenching is lesser than that after the elastic recovery, irrespective of the deposited material.

• The Journal of Health Technology Assessment
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• v.6 no.2
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• pp.123-132
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• 2018

Objectives: Maternal morbidity and mortality are important healthcare issues. However there have been few studies on cost of illness (COI) from maternal disorders. This study aimed to estimate the COI due to maternal disorders in Korea. Methods: By reviewing previous studies and consulting expert we determined the scope of maternal disorders. We operationally defined maternal disorders as maternal hemorrhage, maternal sepsis, hypertensive disorders of pregnancy, obstructed labor, and abortion for maternal disorders. The reference period of this study is the year 2015. Main source of data were the National Health Insurance Service claims data, cause of death statistics from the Korea National Statistical Office, and the Korea Health Panel study. We classified the total costs into direct and indirect costs. The direct costs cover healthcare costs and non-healthcare costs. The indirect costs consist of productivity losses due to morbidity and premature death. Results: The cost of maternal disorders in 2015 was 229.7 billion won. The direct and indirect costs of maternal disorders were 165.2 billion won and 64.5 billion won respectively. The largest cost item for maternal disorders was healthcare cost (138.3 billion won, 60.2%). By age groups, the COI in 30-39 years old women were the highest (165.1 billion won, 71.9%). Abortion was the disorder with the highest COI among maternal disorders (71.9 billion won, 31.3%). Conclusion: The COI due to maternal disorders in Korea is quite substantial. Economic burden of maternal disorder increased when being compared with the year 2012 data despite the continued low birth rate in Korea. Therefore, it is necessary to continuously monitor the social costs of the maternal disorders in Korea.