Ductile Fracture Simulation of Full-scale Circumferential Cracked Pipes: (II) Stainless Steel

AbstractThis paper reports ductile fracture simulation of full-scale circumferentially cracked pipes using finite element (FE) damage analysis. In the structural integrity, without experimental investigations or with few ones, it is not an easy task to properly evaluate the crack initiation and crack propagation of large-scale components with a crack-like defect. Unfortunately, from an economic perspective, performing experiments of large-scale components would be consequently unfavorable. For these reasons, ductile fracture simulation using FE damage analysis to predict crack behavior is one efficient way to replace the test procedures. In order to simulate ductile tearing of large-scale cracked pipes, element-size-dependent critical damage model based on the stress-modified fracture strain model is proposed. To evaluate fracture behavior of full-scale cracked pipes, tensile and C(T) specimens are calibrated by FE analysis technique. Tensile properties and fracture toughness of stainless steel at 288oC are taken from Battelle Pipe Fracture Encyclopedia. After calibrations, simulated results of the full-scale pipes with a circumferential crack are compared with test data to validate the proposed method

Low-temperature synthesis of CuO-interlaced nanodiscs for lithium ion battery electrodes

In this study, we report the high-yield synthesis of 2-dimensional cupric oxide (CuO) nanodiscs through dehydrogenation of 1-dimensional Cu(OH)2 nanowires at 60°C. Most of the nanodiscs had a diameter of approximately 500 nm and a thickness of approximately 50 nm. After further prolonged reaction times, secondary irregular nanodiscs gradually grew vertically into regular nanodiscs. These CuO nanostructures were characterized using X-ray diffraction, transmission electron microscopy, and Brunauer-Emmett-Teller measurements. The possible growth mechanism of the interlaced disc CuO nanostructures is systematically discussed. The electrochemical performances of the CuO nanodisc electrodes were evaluated in detail using cyclic voltammetry and galvanostatic cycling. Furthermore, we demonstrate that the incorporation of multiwalled carbon nanotubes enables the enhanced reversible capacities and capacity retention of CuO nanodisc electrodes on cycling by offering more efficient electron transport paths

Cloning and expression of oil palm (Elaeis guineensis Jacq.) type 2 ribosome inactivating protein in Escherichia coli

EgT2RIP is a type 2 ribosome-inactivating protein isolated from oil palm (Elaeis guineensis Jacq.). Its transcript abundance was reported to be up-regulated in oil palm roots upon inoculation of pathogenic fungus Ganoderma boninense in a recent study. This study aims to produce an active recombinant EgT2RIP protein for biological studies. The DNA fragments encoding Chain A (CA) and Chain B (CB) of EgT2RIP were cloned individually in an expression vector. Soluble CA and partially soluble CB were expressed in Escherichia coli Rosetta-gami 2 (DE3). Purified recombinant CA and CB were associated in a cysteine/cystine reduced/oxidized system, yielding a heterodimer protein (AB). The AB protein showed growth inhibitory activity against breast cancer cell lines (MCF-7) as well as non-tumorigenic breast epithelial cell line (MCF-10A) at IC50 = 1.4 and 10.9 μg mL−1, respectively. The active protein produced from this study may have the potential to be used for treatment in medical and agricultural fields

IL-17 induces production of IL-6 and IL-8 in rheumatoid arthritis synovial fibroblasts via NF-κB- and PI3-kinase/Akt-dependent pathways

Recent studies of the pathogenesis of rheumatoid arthritis (RA) have revealed that both synovial fibroblasts and T cells participate in the perpetuation of joint inflammation as dynamic partners in a mutual activation feedback, via secretion of cytokines and chemokines that stimulate each other. In this study, we investigated the role of IL-17, a major Th1 cytokine produced by activated T cells, in the activation of RA synovial fibroblasts. Transcripts of IL-17R (IL-17 receptor) and IL-17RB (IL-17 receptor B) were present in fibroblast-like synoviocytes (FLS) of RA patients. IL-17R responded with increased expression upon in vitro stimulation with IL-17, while the level of IL-17RB did not change. IL-17 enhanced the production of IL-6 and IL-8 in FLS, as previously shown, but did not affect the synthesis of IL-15. IL-17 appears to be a stronger inducer of IL-6 and IL-8 than IL-15, and even exerted activation comparable to that of IL-1β in RA FLS. IL-17-mediated induction of IL-6 and IL-8 was transduced via activation of phosphatidylinositol 3-kinase/Akt and NF-κB, while CD40 ligation and p38 MAPK (mitogen-activated protein kinase) are not likely to partake in the process. Together these results suggest that IL-17 is capable of more than accessory roles in the activation of RA FLS and provide grounds for targeting IL-17-associated pathways in therapeutic modulation of arthritis inflammation

Facile synthesis of nano-Li4 Ti5O12 for high-rate Li-ion battery anodes

One of the most promising anode materials for Li-ion batteries, Li4Ti5O12, has attracted attention because it is a zero-strain Li insertion host having a stable insertion potential. In this study, we suggest two different synthetic processes to prepare Li4Ti5O12 using anatase TiO2 nanoprecursors. TiO2 powders, which have extraordinarily large surface areas of more than 250 m2 g-1, were initially prepared through the urea-forced hydrolysis/precipitation route below 100°C. For the synthesis of Li4Ti5O12, LiOH and Li2CO3 were added to TiO2 solutions prepared in water and ethanol media, respectively. The powders were subsequently dried and calcined at various temperatures. The phase and morphological transitions from TiO2 to Li4Ti5O12 were characterized using X-ray powder diffraction and transmission electron microscopy. The electrochemical performance of nanosized Li4Ti5O12 was evaluated in detail by cyclic voltammetry and galvanostatic cycling. Furthermore, the high-rate performance and long-term cycle stability of Li4Ti5O12 anodes for use in Li-ion batteries were discussed

Psychiatric understanding and treatment of patients with amputations

Amputation changes the lives of patients and their families. Consequently, the patient must adapt to altered body function and image. During this adaptation process, psychological problems, such as depression, anxiety, and posttraumatic stress disorder, can occur. The psychological difficulties of patients with amputation are often accepted as normal responses that are often poorly recognized by patients, family members, and their primary physicians. Psychological problems can interfere with rehabilitation and cause additional psychosocial problems. Therefore, their early detection and treatment are important. A multidisciplinary team approach, including mental health professionals, is ideal for comprehensive and biopsychosocial management. Mental health professionals could help patients set realistic goals and use adaptive coping styles. Psychiatric approaches should consider the physical, cognitive, psychological, social, and spiritual functions and social support systems before and after amputation. The abilities and limitations of physical, cognitive, psychological, and social functions should also be considered. To improve the patient’s adaptation, psychological interventions such as short-term psychotherapy, cognitive behavioral therapy, mindfulness meditation, biofeedback, and group psychotherapy can be helpful

Development of a clinical scoring system for appendicitis in children with presumed appendicitis

Purpose To develop a clinical scoring system for children with presumed appendicitis who visit the emergency department. Methods A registry based-retrospective study was conducted in the pediatric emergency department between September 2015 and December 2016. Patients aged 4 to 17 years who had a > 1 of 5 Likert scale for possibility of appendicitis were included. Multiple logistic regressions based on Akaike information criterion were performed using variables regarding clinical features and inflammatory markers to develop the clinical scoring system. Results A total of 233 patients were included, and 93 (39.9%) had the final diagnosis of appendicitis. The final model with the lowest Akaike information criterion (171.7) consisted of 5 variables, including vomiting (1 point), absence of watery diarrhea (1 point), duration of symptoms ≤ 3 days (1 point), rebound tenderness (1 point), and white blood cell count > 10.0 × 109/L (2 points). If the clinical score was ≥ 4 of 6 points, the area under the receiver operating characteristic curve was 0.78 (95% confidence interval, 0.71-0.86) with a 78.9% sensitivity, 66.7% specificity, positive and negative predictive values of 70.0% and 76.2%, respectively, and positive and negative likelihood ratios of 2.4 and 0.3, respectively. Conclusion The 5-item clinical scoring system shows a fair performance for prediction of pediatric appendicitis. This simple tool could be applied to predict the pediatric appendicitis, and to avoid the use of potentially unnecessary computed tomography