187 research outputs found

    In-Plane Strengthening of Unreinforced Masonry Walls by Glass Fiber-Reinforced Polyurea

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    Strengthening techniques have been employed in Korea to unreinforced masonry walls (UMWs) for several years to protect them from damage caused by the intermittent occurrence of earthquakes. Polyurea, which has a high tensile strength and elongation rate, can be utilized as a strengthening material to enhance the in-plane strength and ductility of UMWs. Glass fiber-reinforced polyurea (GFRPU) is a composite elastomer manufactured by progressively adding milled glass fiber to polyurea. The purpose of this study is to investigate the enhancement of the in-plane strength and ductility of UMWs using GFRPU, depending on the shape of the GFRPU coating on the wall. Four masonry wall specimens are tested with test variables of the number of strengthening sides and coating shapes. It is illustrated that the GFRPU reinforcement of masonry wall leads to enhanced load-carrying capacity, ductility, and energy absorption. An empirical formula to represent the degree of strengthening effected by GFRPU is proposed in this study. Doi: 10.28991/cej-2021-03091782 Full Text: PD

    Out-of-Plane Strengthening of Unreinforced Masonry Walls by Glass Fiber-Reinforced Polyurea

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    Fiber-reinforced polymer reinforcement or polyurea reinforcement techniques are applied to strengthen unreinforced masonry walls (UMWs). The purpose of this experimental study is to verify the out-of-plane reinforcing effect of sprayed glass fiber-reinforced polyurea (GFRPU), which is a composite elastomer made of polyurea and milled glass fibers on UMW. The out-of-plane strengths and ductile behaviors based on various coating shapes are compared in this study. An empirical formula to describe the degree of reinforcement on the out-of-plane strength of the UMW is derived based on the experimental results. It is observed that the peak load-carrying capacity, ductility, and energy absorption capacity gradually improve with an increase in the strengthening degree or area. Compared with the existing masonry wall reinforcement method, the GFRPU technique is a construction method that can help improve the safety performance along with ease of construction and economic efficiency. Doi: 10.28991/CEJ-2022-08-01-011 Full Text: PD

    Acquired Omental Cystic Lymphangioma after Subtotal Gastrectomy: A Case Report

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    We herein describe a case of cystic lymphangioma in the greater omentum of the remnant stomach, which is thought it to be related with subtotal gastrectomy 10 yr ago for early gastric cancer. A 76-yr-old man was admitted to our department with postprandial abdominal discomfort and bowel habit change. Intraabdominal multilocular cystic mass was detected by ultrasonography and computed tomography. We performed a complete En-bloc tumor resection including spleen and distal pancreas, and histological examination confirmed cystic lymphangioma originated from the greater omentum of the remnant stomach. Although the etiology of omental lymphangioma remains largely unclear, these findings suggested strongly that obstruction of the lymphatic vessels after gastric resection for gastric carcinoma might be the most plausible cause. The surgical extirpation with resection of organs involved appears to be a treatment of choice for such unusual case

    Characteristics of primary and immortalized fibroblast cells derived from the miniature and domestic pigs

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    <p>Abstract</p> <p>Background</p> <p>The pig, <it>Sus scrofa domestica </it>includes both the miniature and commercial domestic breed. These animals have influenced the human life and economies and have been studied throughout history. Although the miniature breeds are more recent and have increasingly been used in a variety of biomedical studies, their cell lines have rarely been established. Therefore, we sought to establish primary and immortal cell lines derived from both the miniature and domestic pig to better enable insight into possible <it>in vivo </it>growth differences.</p> <p>Results</p> <p>The <it>in vitro </it>lifespan of primary domestic pig fibroblast (PF) and miniature pig fibroblast (MPF) cells using a standard 3T3 protocol was determined. Both of the primary PF and MPF cells were shown to have a two-step replicative senescence barrier. Primary MPF cells exhibited a relatively shorter lifespan and slower proliferation rate compared to those of primary PF cells. Beyond senescence barriers, lifespan-extended PF and MPF cells were eventually established and indicated spontaneous cellular immortalization. In contrast to the immortalized PF cells, immortal MPF cells showed a transformed phenotype and possessed more frequent chromosomal abnormalities and loss of p53 regulatory function. The lifespan of primary MPF and PF cells was extended by inactivation of the p53 function using transduction by SV40LT without any detectable senescent phenotype.</p> <p>Conclusion</p> <p>These results suggest that p53 signaling might be a major determinant for the replicative senescence in the MPF cells that have the shorter lifespan and slower growth rate compared to PF cells <it>in vitro</it>.</p

    Clinical Outcome of Squamous Cell Carcinoma of the Tongue in Young Patients: A Stage-Matched Comparative Analysis

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    ObjectivesThe reported incidence of tongue cancer in young patients has recently increased. The aim of this study was to analyze the clinical characteristics of tongue cancer in a young group of patients, and to compare them with those of an older group of tongue cancer patients.MethodsWe retrospectively reviewed the records of 85 patients who were diagnosed with squamous cell carcinoma of the tongue. They were divided into two age groups: over 45 years of age and under 45 years. To compare the prognosis of similarly staged patients in the group, each age group was divided into the early (stage I, II) and advanced stage groups (stage III, IV), and then they were compared. The young group consisted of 23 patients and the older group had 62 patients.ResultsAt the early stage, the clinical prognosis of the patients in both age groups was good, and no significant difference was observed. However, at the advanced stage, the overall and regional recurrence rates were significantly higher in the younger age group as compared to that in the old age group (P=0.007, P=0.001, respectively). The disease-specific survival rate of the patients in the young group was significantly lower than that in the old age group (P=0.025).ConclusionTongue cancer in young subjects has significantly different clinical outcomes according to the stage. The clinical outcome of the advanced-stage tongue cancer in young subjects was poorer than that in the older subjects. Regional recurrence seemed to be the main cause of the poor prognosis

    Magnetic Resonance Imaging Compatibility of the Polymer-based Cochlear Implant

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    ObjectivesIn this study, we compared the magnetic resonance (MR) image artifacts caused by a conventional metal-based cochlear implant and a newly developed liquid crystal polymer (LCP)-based device.MethodsThe metal-based cochlear implant system (Nurobiosys Co.) was attached to side of the head of a subject and the LCP-based device was attached to opposite side. In both devices, alignment magnets were removed for safety. Magnetic resonance imaging (MRI) was performed on a widely used 3.0 T and an ultra-high 7.0 T MRI machine. 3.0 and 7.0 T MR images were acquired using T1- and T2*-weighted gradient echo sequences, respectively.ResultsIn the 3.0 T images, the metal-based device on the left side generated the significant amount of artifacts. The MR images in the proximity of the metal package were obscured by the artifacts in both axial and sagittal views. On the other hand, the MR images near the LCP-based device were relatively free from the artifacts and clearly showed the brain structures. 7.0 T MR images showed the more severe distortion in the both sides but the metal-based cochlear implant system caused a much larger obscure area than the LCP-based system.ConclusionThe novel LCP-based cochlear implant provides a good MRI compatibility beyond present-day cochlear implants. Thus, MR images can be obtained from the subjects even with the implanted LCP-based neural prosthetic systems providing useful diagnostic information. Furthermore, it will be also useful for functional MRI studies of the auditory perception mechanism after cochlear implantations as well as for positron emission tomography-MRI hybrid imaging

    Intramuscular fat formation in fetuses and the effect of increased protein intake during pregnancy in Hanwoo cattle

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    Understanding adipocyte development in fetus during bovine pregnancy is important for strengthening fattening technology. Additionally, nutritional level of dams during pregnancy has the potential to improve offspring growth and fat development. The purpose of this study is to evaluate the intramuscular adipocyte development and expression level of related genes in bovine fetus, and the effect of increased crude protein (CP) intake during pregnancy on the growth performance and carcass characteristics of male offspring. Eighty six pregnant Hanwoo cows (average body weight, 551.5 ± 51.3 kg, age 5.29 ± 0.61 y) were used. Fetuses were collected at 90, 180 and 270 d of gestation from 18 pregnant Hanwoo cows. The remaining 68 pregnant cows were randomly assigned to 2 feeding groups. The control (CON) group was provided the standard protein diet (n = 34), and treatment (TRT) group was provided a diet with a 5% increase in CP intake (n = 34). Male offspring were divided into two groups according to protein treatment of the pregnant cows: CON male offspring (CON-O) and TRT male offspring (TRT-O). Intramuscular adipocytes were found in the fetal skeletal muscle after 180 days of gestation. Male calf’s birth weight increased in the TRT group compared to that in the CON group (p &lt; 0.002). The final body weight (p &lt; 0.003) and average daily gain (p &lt; 0.019) of male offspring were significantly higher in TRT-O than in CON-O. The feed conversion ratio was also improved by 10.5% in TRT-O compared to that in CON-O (p &lt; 0.026). Carcass weight was significantly higher in the TRT-O group than that in the CON-O group (p &lt; 0.003), and back fat was thicker in the TRT-O group (p = 0.07). The gross receipts and net income were higher in TRT-O than in CON-O (p &lt; 0.04). Thus, fetal intramuscular fat can be formed from the mid-gestation period, and increased CP intake during pregnancy can increase net income by improving the growth and carcass weight of male offspring rather than intramuscular fat

    Clinical Practice Guidelines for the Endoscopic Management of Peripancreatic Fluid Collections

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    Endoscopic ultrasonography-guided intervention has gradually become a standard treatment for peripancreatic fluid collections (PFCs). However, it is difficult to popularize the procedure in Korea because of restrictions on insurance claims regarding the use of endoscopic accessories, as well as the lack of standardized Korean clinical practice guidelines. The Korean Society of Gastrointestinal Endoscopy (KSGE) appointed a Task Force to develope medical guidelines by referring to the manual for clinical practice guidelines development prepared by the National Evidence-Based Healthcare Collaborating Agency. Previous studies on PFCs were searched, and certain studies were selected with the help of experts. Then, a set of key questions was selected, and treatment guidelines were systematically reviewed. Answers to these questions and recommendations were selected via peer review. This guideline discusses endoscopic management of PFCs and makes recommendations on Indications for the procedure, pre-procedural preparations, optimal approach for drainage, procedural considerations (e.g., types of stent, advantages and disadvantages of plastic and metal stents, and accessories), adverse events of endoscopic intervention, and procedural quality issues. This guideline was reviewed by external experts and suggests best practices recommended based on the evidence available at the time of preparation. This will be revised as necessary to address advances and changes in technology and evidence obtained in clinical practice and future studies

    Prevalence of BRCA1 and BRCA2 Mutations in Korean Breast Cancer Patients

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    The incidence of breast cancer in Korea has been increasing in recent years, such that it is now the most common female cancer. Breast cancer in Korea is characterized by an earlier age of onset than in Western countries, suggesting that it would be related with genetic background. We assayed germline mutations in the BRCA genes to evaluate their genetic pathology in Korean breast cancer patients. The study subjects consisted of 173 patients at clinically higher risk and 109 unselected patients. Germline mutations in the entire coding sequences of the BRCA1 and BRCA2 genes were analyzed by Conformation-Sensitive Gel Electrophoresis (CSGE), and any aberrantly-sized band was sequenced. BRCA mutations were present in 12.7% of the high risk patients, compared with 2.8% of the unselected patients. Among high risk patients, mutations were most prevalent in patients with a family history of breast or first-degree ovarian cancer (22.1%), followed by those with male breast cancer (20%), bilateral breast cancer (20%), multiple organ cancer including breast (13%) and younger breast cancer patients (aged <35 yr) (8.1%). Moreover, BRCA mutations were detected in 34.8% of patients having two high-risk factors. These findings suggest that BRCA gene mutation analysis should be performed on Korean patients with high-risk factors for breast cancer
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