409 research outputs found
Effects of child pick-up behavior on emergency evacuations
The child pick-up behavior of parents during an emergency can cause heavy traffic congestion and failing to evacuate an affected area successfully. In this study, we analyzed the effect of child pick-up behavior using, as an example, a nuclear power plant accident caused by an earthquake, which is a typical no-notice emergency. A quake was assumed to occur near the Shin-Kori nuclear power plant in Ulsan, Korea, resulting in a nuclear power plant accident. An agent-based dynamic simulation model using VISSIM was employed to conduct sensitivity analyses with different child pick-up rates. The results confirmed that parents are a major cause of congestion and a vulnerable class in an emergency evacuation. The child pick-up behavior caused significant traffic congestion, and parents who pick up their children showed a higher evacuation failure rate
Enhancing training motivation in the public sector in South Korea: The value of a contingency approach
Beta Thalassemia Presenting with Neonatal Cholestasis and Extensive Hemosiderosis: A Case Report
Neonatal cholestasis is caused by various forms of liver injury and has a complex etiological background. Among these, cases of severe cholestasis due to primary hemolytic disease are rare. Herein, we report a case in which thalassemia-induced severe hemolysis caused bile duct injury by hemosiderosis, with cholestasis occurring shortly after birth and lasting for >4 months. In addition, complete recovery of liver pathology was observed both biochemically and histologically. Hence, clinicians should consider hemolytic disease as a rare cause of neonatal cholestasis in the differential diagnosis of neonates as well as the advisability of conservative treatment based on case progression
Knuckling Down on Predictive Factors for Early Relapse after Posterolateral Percutaneous Endoscopic Lumbar Discectomy
Objective Percutaneous endoscopic lumbar discectomy (PELD) has several advantages, but it is not used routinely due to early relapse and steep learning curve. We have studied the factors associated with early relapse in patients who underwent posterolateral PELD at or above the L4-5 level. Methods In this retrospective study, we have enrolled 200 cases and divided them into 4 groups (A, B, C, and D) with 50 patients in each group, that had undergone PELD by 2 different techniques (inside-out and outside-in with or without anti-adhesive agent) and operated by 2 different surgeons between May 2009 and November 2010. The factors studied were - Age, gender, disc (degeneration grade, location, level), associated adjacent level herniated nucleus pulposus (HNP), episode (first or recurrent), anti-adhesive agent, annulus preservation, approach, disc height and segmental dynamic motion (discrepancy in flexion and extension). Statistical analysis was done by Pearsonās chi-square test and p value (significance). The clinical results were evaluated by visual analogue scale (VAS). Results The mean age and mean follow-up period was comparable in all four groups. The overall recurrence rate was 9.5% (19/200). Average early relapse time was 3.26 months. Factors like Age of the patient, multilevel HNP and degeneration grade showed significant correlation with relapse rate. The change in VAS pre-operatively to post-operatively was significant across all groups (p<0.001). Conclusion Based on the results of this study, high grade disc degeneration, multilevel disc herniation, and early postoperative activity are significantly associated with early relapse after PELD
Molecular Responses in Osteogenic Differentiation of Mesenchymal Stem Cells Induced by Physical Stimulation
Mesenchymal stem cells (MSCs) have been recognized as a great source of stem cells in the field of regenerative medicine and regulation of MSCs such as differentiation into specific cells. Particular interest is the use of physical stimulation for the expression of the osteoblast-specific genes from MSCs for bone tissue regeneration. The mechanical forces on MSCs, such as fluid flow, enhance the mineralized matrix and specific gene expressions. This process called mechanotransduction comprises of the steps of mechanoreception, biochemical coupling, transmission of signal and effector cell response. Physical stimuli effectively regulate extracellular and intracellular signaling pathways to enhance the expression of specific transcription factors, and the release of osteocytes, ultimately expedite the production of active osteoblasts. Thus understating, identification and functional characterization of the mechanotransduction underlying the physical stimulation of MSCs is a critical issue for devising new bone regenerative treatments for bone-related diseases. In this review, we focus on the molecular mechanism responsible for the mechanotransduction of osteogenic differentiation of MSCs induced by physical stimulation.
Spontaneous Spinal Canal Remodeling after Postural Pillow Reduction and Lordotic Posterior Column Compressive Percutaneous Transpedicular Screw Fixation in Neurologically Intact Thoracolumbar Burst Fractures
Objective The optimal treatment methods for thoracolumbar burst fracture with intact neurology are not established yet. Spinal canal integrity, sagittal balance and anterior column intactness are very important for successful outcome in this type of injury. There is no study analyzing restoration of these parameters by low pressure restoration using postural pillow reduction and lordotic posterior column compressive percutaneous transpedicular screw fixation and this study analyzes canal remodeling, spinal balance and anterior column intactness after this procedure. Methods The surgical procedure included three different elements: (1) preoperative postural pillow reduction for 1-2 days, (2) augmentation of fractured vertebra by polymethylmethacrylate (PMMA) in osteoporotic bone or by non-PMMA materials in non-osteoporotic bone, and (3) lordotic, posterior column compressive, percutaneous transpedicular screw fixation. We measured anterior vertebral height, canal size and lordotic angle preoperatively, immediate postoperatively and after 6 months in 34 patients treated with this technique and were analyzed. Results Of 34 patients 17 were male. The mean age was 52.03Ā±12.51 years. They were followed for 30.68Ā±11.67 months on average. At 6 months, preoperative canal stenosis of 44% remodeled to 12%, preoperative anterior vertebral height of 44% increased to 77% and preoperative average kyphosis of 14 degrees corrected to 3.4 degrees No neurological deterioration noted. Functionally all patients returned to their previous status. Conclusion The postural pillow reduction and lordotic posterior column compressive percutaneous screw fixation in patients with neurologically intact thoracolumbar burst fracture is effective and safe
Role of intermediate phase for stable cycling of Na_7V_4(P_2O_7)_4PO_4 in sodium ion battery
Sodium ion batteries offer promising opportunities in emerging utility grid applications because of the low cost of raw materials, yet low energy density and limited cycle life remain critical drawbacks in their electrochemical operations. Herein, we report a vanadium-based ortho-diphosphate, Na_7V_4(P_2O_7)_4PO_4, or VODP, that significantly reduces all these drawbacks. Indeed, VODP exhibits single-valued voltage plateaus at 3.88 V vs. Na/Na+ while retaining substantial capacity (>78%) over 1,000 cycles. Electronic structure calculations reveal that the remarkable single plateau and cycle life originate from an intermediate phase (a very shallow voltage step) that is similar both in the energy level and lattice parameters to those of fully intercalated and deintercalated states. We propose a theoretical scheme in which the reaction barrier that arises from lattice mismatches can be evaluated by using a simple energetic consideration, suggesting that the presence of intermediate phases is beneficial for cell kinetics by buffering the differences in lattice parameters between initial and final phases. We expect these insights into the role of intermediate phases found for VODP hold in general and thus provide a helpful guideline in the further understanding and design of battery materials
Rubus Crataegifolius Bunge Regulates Adipogenesis Through Akt and Inhibits High-Fat Diet-Induced Obesity in Rats
BACKGROUND: Obesity is one of the greatest public health problems and major risk factors for serious metabolic diseases and significantly increases the risk of premature death. The aim of this study was to determine the inhibitory effects of Rubus crataegifolius Bunge (RCB) on adipocyte differentiation in 3 T3-L1 cells and its anti-obesity properties in high fat diet (HFD)-induced obese rats.
METHODS: 3 T3-L1 adipocytes and HFD-induced obese rats were treated with RCB, and its effect on gene expression was analyzed using RT-PCR and Western blotting experiments.
RESULTS: RCB treatment significantly inhibited adipocyte differentiation by suppressing the expression of C/EBPĪ², C/EBPĪ±, and PPARĪ³ in the 3 T3-L1 adipocytes. Subsequently, the expression of the PPARĪ³ target genes aP2 and fatty acid synthase (FAS) decreased following RCB treatment during adipocyte differentiation. In uncovering the specific mechanism that mediates the effects of RCB, we demonstrated that the insulin-stimulated phosphorylation of Akt strongly decreased and that its downstream substrate phospho-GSK3Ī² was downregulated following RCB treatment in the 3 T3-L1 adipocytes. Moreover, LY294002, an inhibitor of Akt phosphorylation, exerted stronger inhibitory effects on RCB-mediated suppression of adipocyte differentiation, leading to the inhibition of adipocyte differentiation through the downregulation of Akt signaling. An HFD-induced obesity rat model was used to determine the inhibitory effects of RCB on obesity. Body weight gain and fat accumulation in adipose tissue were significantly reduced by the supplementation of RCB. Moreover, RCB treatment caused a significant decrease in adipocyte size, associated with a decrease in epididymal fat weight. The serum total cholesterol (TC) and triglyceride (TG) levels decreased in response to RCB treatment, whereas HDL cholesterol (HDL-C) increased, indicating that RCB attenuated lipid accumulation in adipose tissue in HFD-induced obese rats.
CONCLUSION: Our results demonstrate an inhibitory effect of RCB on adipogenesis through the reduction of the adipogenic factors PPARĪ³, C/EBPĪ±, and phospho-Akt. RCB had a potent anti-obesity effect, reducing body weight gain in HFD-induced obese rats
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