331 research outputs found

    Performance Comparison of Design Optimization and Deep Learning-based Inverse Design

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    Surrogate model-based optimization has been increasingly used in the field of engineering design. It involves creating a surrogate model with objective functions or constraints based on the data obtained from simulations or real-world experiments, and then finding the optimal solution from the model using numerical optimization methods. Recent advancements in deep learning-based inverse design methods have made it possible to generate real-time optimal solutions for engineering design problems, eliminating the requirement for iterative optimization processes. Nevertheless, no comprehensive study has yet closely examined the specific advantages and disadvantages of this novel approach compared to the traditional design optimization method. The objective of this paper is to compare the performance of traditional design optimization methods with deep learning-based inverse design methods by employing benchmark problems across various scenarios. Based on the findings of this study, we provide guidelines that can be taken into account for the future utilization of deep learning-based inverse design. It is anticipated that these guidelines will enhance the practical applicability of this approach to real engineering design problems

    Fabrication of core/shell ZnWO4/carbon nanorods and their Li electroactivity

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    Carbon-coated ZnWO4 [C-ZW] nanorods with a one-dimensional core/shell structure were synthesised using hydrothermally prepared ZnWO4 and malic acid as precursors. The effects of the carbon coating on the ZnWO4 nanorods are investigated by thermogravimetry, high-resolution transmission electron microscopy, and Raman spectroscopy. The coating layer was found to be in uniform thickness of approximately 3 nm. Moreover, the D and G bands of carbon were clearly observed at around 1,350 and 1,600 cm-1, respectively, in the Raman spectra of the C-ZW nanorods. Furthermore, lithium electroactivities of the C-ZW nanorods were evaluated using cyclic voltammetry and galvanostatic cycling. In particular, the formed C-ZW nanorods exhibited excellent electrochemical performances, with rate capabilities better than those of bare ZnWO4 nanorods at different current rates, as well as a coulombic efficiency exceeding 98%. The specific capacity of the C-ZW nanorods maintained itself at approximately 170 mAh g-1, even at a high current rate of 3 C, which is much higher than pure ZnWO4 nanorods

    Wheel Impact Test by Deep Learning: Prediction of Location and Magnitude of Maximum Stress

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    The impact performance of the wheel during wheel development must be ensured through a wheel impact test for vehicle safety. However, manufacturing and testing a real wheel take a significant amount of time and money because developing an optimal wheel design requires numerous iterative processes of modifying the wheel design and verifying the safety performance. Accordingly, the actual wheel impact test has been replaced by computer simulations, such as Finite Element Analysis (FEA), but it still requires high computational costs for modeling and analysis. Moreover, FEA experts are needed. This study presents an aluminum road wheel impact performance prediction model based on deep learning that replaces the computationally expensive and time-consuming 3D FEA. For this purpose, 2D disk-view wheel image data, 3D wheel voxel data, and barrier mass value used for wheel impact test are utilized as the inputs to predict the magnitude of maximum von Mises stress, corresponding location, and the stress distribution of 2D disk-view. The wheel impact performance prediction model can replace the impact test in the early wheel development stage by predicting the impact performance in real time and can be used without domain knowledge. The time required for the wheel development process can be shortened through this mechanism

    The Effects of Gymnema sylvestre in High-Fat Diet-Induced Metabolic Disorders

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    This study used an integrated approach to investigate the effects of Gymnema sylvestre (GS) extract as a functional dietary supplement with a high-fat diet. This approach examined insulin resistance, the dysfunction of adipose tissue, and liver steatosis. Male C57BL/6J mice were fed a normal chow or high-fat diet (HFD) for the acute and chronic study, in addition to GS in different doses (100, 250 and 500 mg/kg body weight). Their body composition changes, serum lipid and glucose parameters, adipose and liver tissue histology, and gene expression were measured. It was found that GS significantly suppressed the increase of body weight, serum levels of lipid, insulin and leptin, and adipose tissue, and liver inflammation. GS also demonstrated hypoglycemic effects due to the amylase inhibition activity. Our results support the existence of a relationship between the HFD induced insulin resistance, adipose dysfunction and liver steatosis. In conclusion, GS works as a functional dietary supplement with preventative effects against metabolic disorder.

    Enhanced cytotoxic effect of radiation and temozolomide in malignant glioma cells: targeting PI3K-AKT-mTOR signaling, HSP90 and histone deacetylases

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    BACKGROUND: Despite aggressive treatment with radiation therapy and concurrent adjuvant temozolomide (TMZ), glioblastoma multiform (GBM) still has a dismal prognosis. We aimed to identify strategies to improve the therapeutic outcome of combined radiotherapy and TMZ in GBM by targeting pro-survival signaling from the epidermal growth factor receptor (EGFR). METHODS: Glioma cell lines U251, T98G were used. Colony formation, DNA damage repair, mode of cell death, invasion, migration and vasculogenic mimicry as well as protein expression were determined. RESULTS: U251 cells showing a low level of methyl guanine transferase (MGMT) were highly responsive to the radiosensitizing effect of TMZ compared to T98G cells having a high level of MGMT. Treatment with a dual inhibitor of Class I PI3K/mTOR, PI103; a HSP90 inhibitor, 17-DMAG; or a HDAC inhibitor, LBH589, further increased the cytotoxic effect of radiation therapy plus TMZ in U251 cells than in T98G cells. However, treatment with a mTOR inhibitor, rapamycin, did not discernibly potentiate the radiosensitizing effect of TMZ in either cell line. The mechanism of enhanced radiosensitizing effects of TMZ was multifactorial, involving impaired DNA damage repair, induction of autophagy or apoptosis, and reversion of EMT (epithelial-mesenchymal transition). CONCLUSIONS: Our results suggest possible strategies for counteracting the pro-survival signaling from EGFR to improve the therapeutic outcome of combined radiotherapy and TMZ for high-grade gliomas

    Is restrictive transfusion sufficient in colorectal cancer surgery? A retrospective study before and during the COVID-19 pandemic in Korea

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    Purpose Blood transfusion is one of the most common procedures used to treat anemia in colorectal surgery. Despite controversy regarding the adverse effects of blood products, surgeons have maintained standards for administering blood transfusions. However, this trend was restrictive during the COVID-19 pandemic because of a shortage of blood products. In this study, we conducted an analysis to investigate whether the restriction of blood transfusions affected postoperative surgical outcomes. Methods Medical records of 318 patients who underwent surgery for colon and rectal cancer at Ewha Womans University Mokdong Hospital between June 2018 and March 2022 were reviewed retrospectively. The surgical outcomes between the liberal and restrictive transfusion strategies in pre– and post–COVID-19 groups were analyzed. Results In univariate analysis, postoperative transfusion was associated with infectious complications (odds ratio [OR], 1.705; 95% confidence interval [CI], 1.015–2.865; P=0.044). However, postoperative transfusion was not an independent risk factor for the development of infectious complications in multivariate analysis (OR, 1.305; 95% CI, 0.749–2.274; P=0.348). In subgroup analysis, there was no significant association between infectious complications and the hemoglobin threshold level for the administration of a transfusion (OR, 1.249; 95% CI, 0.928–1.682; P=0.142). Conclusion During colorectal surgery, the decision to perform a blood transfusion is an important step in ensuring favorable surgical outcomes. According to the results of this study, restrictive transfusion is sufficient for favorable surgical outcomes compared with liberal transfusion. Therefore, modification of guidelines is suggested to minimize unnecessary transfusion-related side effects and prevent the overuse of blood products

    Effect of rotational-state-dependent molecular alignment on the optical dipole force

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    The properties of molecule-optical elements such as lenses or prisms based on the interaction of molecules with optical fields depend in a crucial way on the molecular quantum state and its alignment created by the optical field. Herein, we consider the effects of state-dependent alignment in estimating the optical dipole force acting on the molecules and, to this end, introduce an effective polarizability which takes proper account of molecular alignment and is directly related to the alignment-dependent optical dipole force. We illustrate the significance of including molecular alignment in the optical dipole force by a trajectory study that compares previously used approximations with the present approach. The trajectory simulations were carried out for an ensemble of linear molecules subject to either propagating or standing-wave optical fields for a range of temperatures and laser intensities. The results demonstrate that the alignment-dependent effective polarizability can serve to provide correct estimates of the optical dipole force, on which a state-selection method applicable to nonpolar molecules could be based. We note that an analogous analysis of the forces acting on polar molecules subject to an inhomogeneous static electric field reveals a similarly strong dependence on molecular orientation.clos

    Candida tropicalis arthritis of the elbow in a patient with Ewing's sarcoma that successfully responded to itraconazole

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    Fungal infections are rarely responsible for arthritis. Few cases of fungal arthritis have been reported, even in immunocompromised hosts susceptible to low-virulence organisms. Herein, the authors report the first case of Candida tropicalis arthritis in a child with a solid tumor. A 13-year-old boy with Ewing's sarcoma developed arthritis in his elbow during the neutropenic period after chemotherapy. Despite treatment with broad-spectrum antibiotics, his condition did not improve and serial blood cultures failed to reveal any causative organisms. After surgical drainage, culture of the joint fluid revealed the presence of C. tropicalis. Itraconazole treatment was started and after 3 months of therapy, the patient completely recovered full elbow function
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