753 research outputs found
Numerical analysis of dielectric micro-particle motion in a fluid and electric field
We present numerical analysis of a coupled problem composed of fluidics,
electromagnetic and particle dynamics. The forces acting on the dielectric micro-particle
consist of a dielectrophoretic(DEP) force, drag force and gravitational force in the proposed
analysis model. DEP force and drag force are calculated using the distribution of the electric
field and fluid velocity field to analyze the characteristic of the micro-particle motion. The
forces exerted by each field are driving terms in the Newton’s equation for particle motion.
The designed particle separating device, which has the one inlet and the two outlets, is
simulated to validate proposed numerical scheme. The analysis results show the trace of the
micro-particles can be analyzed using the proposed numerical approach
Experimental Study on the Fire Spreading between Vehicles Using a Real Scale Fire Test
Extended Abstract With increasing vehicle, the vehicle fire is considered one of the dangerous disaster. Because vehicles have the many inflammable materials as like gasoline engine oil, plastic and leather etc. Especially, when the vehicle fire is occurred in underground parking lot, the fire can easily spread around the vehicles due to the narrow parking space. [1] Thus, the vehicle fire can be developed to the large fire. In order to prevent the fire spreading, the fire extinguishing systems are installed in underground parking lot. However, these extinguishing systems are designed initial fire suppression, thus it is difficult to extinguish the large fire due to the fire spreading. [2] Therefore, fire spread between vehicles should be considered to improve extinguishing performance. In this study, experimental studies are performed to analyse the fire spread characteristics between vehicles using a real scale fire tests. The fire spread characteristics is analysed by using the temperature measured in various part of the vehicle. The fire is occurred at passenger seat by using the gasoline. Also, the vehicles used in the experiments are the fourwheel sedan. The vehicle is divided into four regions according to the characteristics of the inflammable materials (seat, engine room, fuel tank and bumper
Emergency department utilization in elderly patients: a report from the National Emergency Department Information System (NEDIS) of Korea, 2018-2022
Objective With general aging of the population, emergency department (ED) utilization by elderly patients is increasing. In this study, we analyzed data on ED visits of patients aged 65 years and older in Korea. Methods The study is a retrospective analysis of National Emergency Department Information System (NEDIS) data from 2018–2022, focusing on patients aged 65 years and older who visited EDs across Korea. ED utilization data were analyzed using Korean Triage and Acuity Scale (KTAS) scores. The patients were divided into three age groups, and common chief complaints and diagnoses were identified. Age- and sex-standardized ED visits per 100,000 population and outcomes were also analyzed. Results During the study period, there was a total of 9,803,065 elderly patient ED visits. The mean patient age was 76.4±7.6 years, and 47.6% were men. The ED mortality rate and in-hospital mortality rate were 1.8% and 4.6%, respectively. The KTAS scores 1–2 group accounted for 11.0% of patients, KTAS score 3 group for 42.5%, KTAS scores 4–5 group for 37.2%, and KTAS score unknown group for 9.4%. When patients were categorized into three age groups, the oldest group exhibited the highest rates of KTAS score 1, severe illness diagnoses, and mortality. The most frequently reported chief complaint was abdominal pain, and the most common diagnosis was light headedness. When analyzing the data by year, the COVID-19 outbreak had a discernible impact on ED visits and clinical outcomes. Conclusion Over the past 5 years, ED visits for elderly patients have averaged 26,050 per 100,000 population per year, with a temporary decline during the COVID-19 pandemic and a subsequent upward trend
COVID-19 in a Patient Previously Exposed to Toxic Disinfectant from a Humidifier
In August, 2011, the Korean Public Health Surveillance declared an outbreak of pulmonary disease due to the inhalation of humidifier disinfectants (HDs), which led to approximately 20,000 deaths. In March, 2020, the World Health Organization declared coronavirus disease-2019 (COVID-19) a pandemic. In this Case Report, we present a rare case of a patient who inhaled toxic HDs and developed COVID-19. He was young and had a low risk of severe COVID-19, however, he had a critical course to recovery. He was admitted to the intensive care unit and administered high-flow oxygen via a nasal cannula. He received dexamethasone injections each day for 10 days and his condition began to improve on hospital Day 6, although radiographical findings revealed no improvement. He was discharged on hospital Day 26. Despite the patient’s chronic lung disease becoming asymptomatic, HDs could be an important risk factor affecting the clinical course of COVID-19
Patterns of inflammatory immune responses in patients with septic shock receiving vitamin C, hydrocortisone, and thiamine: clustering analysis in Korea
Background Sepsis is characterized by heterogeneous immune responses that may evolve during the course of illness. This study identified inflammatory immune responses in septic patients receiving vitamin C, hydrocortisone, and thiamine. Methods This was a single-center, post-hoc analysis of 95 patients with septic shock who received the vitamin C protocol. Blood samples were drawn on days 1–2, 3–4, and 6–8 after shock onset. Group-based multi-trajectory modeling was used to identify immune trajectory groups. Results The median age was 78 years (interquartile range, 70–84 years), and 56% were male. Clustering analysis identified group 1 (n=41), which was characterized by lower interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-10 levels, and these levels remained stationary or mildly increased until day 7. Conversely, group 2 (n=54) expressed initially higher IL-6, TNF-α, and IL-10 levels that decreased rapidly by day 4. There was a nonsignificant increase in lymphocyte count and a decrease in C-reactive protein level until day 7 in group 2. The intensive care unit mortality rate was significantly lower in group 2 (39.0% vs. 18.5%, P=0.03). Group 2 also had a significantly higher decrease in the mean (standard deviation) vasopressor dose (norepinephrine equivalent: –0.09±0.16 μg/kg/min vs. –0.23±0.31 μg/kg/min, P<0.001) and Sequential Organ Failure Assessment score (0±5 vs. –4±3, P=0.002) between days 1 and 4. Conclusions There may be different subphenotypes in septic patients receiving the vitamin C protocol
A Case Series of Trauma Resuscitation in the Intensive Care Unit Bypassing the Emergency Room During the Conversion to a COVID-19 Only Hospital
When a patient with severe trauma is admitted to the emergency room (ER), they are evaluated before transfer to either the intensive care unit (ICU) or operating room. To minimize the time until a definitive treatment can be provided, direct operating room resuscitation can be performed. In this hospital the ER was closed during the hospital’s transition to a coronavirus disease 2019-dedicated hospital, and direct ICU resuscitation for patients with trauma was performed for a short period. To perform effective trauma resuscitation, all ICU beds were reorganized to achieve a modified, experienced nurse: patient ratio (1:2–3) and 2 beds were assigned for trauma ICU resuscitation alone. The equipment for initial resuscitation was installed and ICU nurses received training. Consultations with the hospital administration, nursing, and pharmaceutical departments were completed in advance to avoid formal problems. Conversion of the ICU for direct resuscitation procedures was performed in 4 patients
A Case of Graves' Disease Combined with Hantaan Virus Infection
Graves' disease (GD) is generally presented by thyrotoxicosis with hyperthyroidism, and it is an organ-specific autoimmune disease induced by thyroid-stimulating hormone receptor autoantibodies. However, among diverse etiologies, viral infections have been suggested to trigger or to be involved in the pathogenesis of GD. Hantaan virus infection causing hemorrhagic fever with renal syndrome (HFRS) is common in South Korea and its pathogenesis is suggested to be an immunologic mechanism. We have experienced a patient who was diagnosed as HFRS with thyrotoxicosis. So we herein report the case as GD combined with the hantaan virus infection
Identification of replicative senescence-associated genes in human umbilical vein endothelial cells by an annealing control primer system
Cellular senescence is regulated by specific genes in many organisms. The identification and functional analysis of senescence-associated genes could provide valuable insights into the senescence process. Here, we employed a new and improved differential display reverse transcription-polymerase chain reaction (DDRT-PCR) method that involves annealing control primers (ACPs) to identify genes that are differentially expressed in human umbilical endothelial cells during replicative senescence. Using 120 ACPs, we identified 31 differentially expressed genes (DEGs). Basic local alignment search tool (BLAST) search revealed 29 known genes and two unknown genes. Expression levels of the 29 known genes were confirmed by real-time quantitative RT-RCR and by Western blotting for eight of these genes. CD9 antigen, MHC class I chain-related sequence A (MICA) and cell division cycle 37 homolog (CDC37) were up-regulated, and bone morphogenetic protein 4 (BMP4), dickkopf-1 (DKK1), and transcription factor 7-like 1 (TCF7L1) were down-regulated in old cells. Treatment with recombinant human MICA caused a decrease in cell proliferation and an increase in senescence-associated beta-galactosidase staining. Further analysis of differentially expressed genes may provide insights into the molecular basis of replicative senescence and vascular diseases associated with cellular senescence
Dual Effect of Chrysanthemum indicum
The risk of bone-related diseases increases due to the imbalance between bone resorption and bone formation by osteoclasts and osteoblasts, respectively. The goal in the development of antiosteoporotic treatments is an agent that will improve bone through simultaneous osteoblast stimulation and osteoclast inhibition without undesirable side effects. To achieve this goal, numerous studies have been performed to identify novel approaches using natural oriental herbs to treat bone metabolic diseases. In the present study, we investigated the effect of Chrysanthemum indicum extract (CIE) on the differentiation of osteoclastic and osteoblastic cells. CIE inhibited the formation of TRAP-positive mature osteoclasts and of filamentous-actin rings and disrupted the bone-resorbing activity of mature osteoclasts in a dose-dependent manner. CIE strongly inhibited Akt, GSK3β, and IκB phosphorylation in RANKL-stimulated bone marrow macrophages and did not show any effects on MAP kinases, including p38, ERK, and JNK. Interestingly, CIE also enhanced primary osteoblast differentiation via upregulation of the expression of alkaline phosphatase and the level of extracellular calcium concentrations during the early and terminal stages of differentiation, respectively. Our results revealed that CIE could have a potential therapeutic role in bone-related disorders through its dual effects on osteoclast and osteoblast differentiation
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