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Aiming at the complex running state and instability state of rail car body under high-speed impact, a mathematical model of the collision force and overturning force of the car body is established by using the state space trajectory method of modern control theory. The program is written by Matlab language to solve the motion state of the rail car under high-speed impact, and then the change law of the motion state of the car body under different working conditions is obtained. The results show that the maximum nodding angle is related to the impact speed and the length-height ratio of the car body. The nodding angle increases with the increase of impact speed while decreases with the increase of length-height ratio. The turning radius of the rail is related to the turning angle. The limit instability state of the car body is affected by side-impact angle and varies with speed. The larger the speed, the smaller the allowable value. The stability of the car body motion state and the limit instability speed decrease with the decrease of the impact slope. With the increase of the impact slope, the stability of the car body motion state increases, and the limit instability speed increases. [ABSTRACT FROM AUTHOR]

Purpose: To study the response under impact load of carbon fiber reinforced composite materials that have excellent mechanical properties. Design/methodology/approach: Finite element analysis of unidirectional plates was conducted under unsymmetrical impact load based on drop weight impact test. At the macroscopic scale, a finite element model was built on ANSYS/LS-DYNA, which took the impact response of carbon fiber unidirectional plates as unknown quantity. The model considered the macroscopic response of carbon fiber unidirectional plates under different initial conditions, from the aspects of stress, strain, energy change and deformation degree of unidirectional plates. Finally, a mathematical model of energy recovery of carbon fiber composite materials under partial impact load was established, and the energy recovery amount under different fiber orientations was calculated on MATLAB. Findings: The impact energy absorbed by the unidirectional plate is the largest when the fiber orientation is 30°. To improve the impact resistance of unidirectional plates under unsymmetrical impact load, laying schemes should be avoided at fiber orientations of 0°, 15° and 60°, and be recommended at 30°, 45°, and 75°. For impact velocity, 4.71 and 7.54 m/s should be avoided, while 2 m/s is recommended. For the impact weight, 50 and 250 kg weights should be avoided, and 150 and 200 kg weights are recommended. Originality/value: This model not only provides reference for similar impact resistance research, but also predicts the impact response of unidirectional plates under different initial loads in the future. It can also provide reference for the structure using carbon fiber composite materials to achieve lightweight. [ABSTRACT FROM AUTHOR]

Summary: This work proposes a novel liquid‐cooling system that employs the phase change material (PCM) emulsion as the coolant for the battery pack. To compare the proposed scheme with the traditional water cooling system, a thermal model is developed for the battery pack with cooling systems, where the system start‐stop control and time hysteresis phenomenon are considered in simulations. The results show that either increasing the inlet velocity or temperature improves the battery temperature uniformity for the two schemes, but it enlarges the pumping energy consumption during the whole discharging process. Compared with the water cooling system, the proposed PCM emulsion cooling scheme can not only significantly decrease the battery temperature difference but also effectively shorten the system operating time. According to the calculation, the pumping energy consumption with using the PCM emulsions as the coolant decreases 18.9% in minimum and 66.6% in maximum than that with using the water as the coolant. Consequently, the proposed PCM emulsion cooling system is superior to the water cooling system in terms of the heat dissipation capacity, the temperature uniformity, the pump power requirement, and the pumping energy consumption, which is well‐suited for the cooling system of the battery pack in electric vehicles. In addition, the proposed thermal model can be used well to simulate the thermal characteristics of the vehicle‐mounted battery liquid‐cooling system under actual operating conditions. [ABSTRACT FROM AUTHOR]

Background: Radiation-induced skin injury is a major side-effect observed in cancer patients who received radiotherapy. Thus identifying new radioprotective drugs for prevention or treatment of post-irradiation skin injury should be prompted. A large number of clinical studies have confirmed that Compound Kushen injection (CKI) can enhance efficacy and reduce toxicity of radiotherapy. The aim of this study is to confirm the effect of CKI in alleviating radiotherapy injury in the skin and explore the exact mechanism. Methods: 60 patients who met the inclusion/exclusion criteria were allocated to treatment group (CKI before radiotherapy) or control group (normal saline before radiotherapy) randomly. MTT assay, flow cytometry, Western Blot, and transient transfection were performed to detect the cell viability, cell apoptosis and Bim expression after treatment with CKI or/and radiotherapy. Results: CKI had the effect of alleviating skin injury in cancer patients who received radiotherapy in clinic. CKI induced cancer cell apoptosis when combined with irradiation (IR), while it reversed the induction of cell apoptosis by IR in human skin fibroblast (HSF) cells. And Bim, as a tumor suppressor, was induced in cancer cells but had no change in HSF cells when treated with CKI. Moreover, the above effect could be attenuated when Bim was silenced by siRNA. Conclusion: We conclude that CKI represents a promising radio-protective agent with a potential differential beneficial effect on both cancer cells (inducing apoptosis) and HSF cells (providing radio-protection via inhibiting IR-induced apoptosis), via regulating Bim. Our study uncovers a novel mechanism by which CKI inhibits human cancer cell while protects skin from radiotherapy, indicating CKI might be a promising radio-protective drug. Clinical Trial Registration: Chinese Clinical Trial Registry (www.chictr.org.cn), identifier ChiCTR2100049164. [ABSTRACT FROM AUTHOR]

Coupling electromechanical cell-based smoothed finite element method (CSFEM) with the asymptotic homogenization method (AHM) is presented to overcome the overstiffness of FEM. This method could accurately simulate the dynamic responses and electromechanical coupling effects of piezoelectric composite material (PCM) structures. Firstly, the efficient performances for active compounds of round cross-section fibers are calculated based on AHM. Secondly, in the CSFEM, electromechanical multi-physic-field FEM is coupled with gradient smoothing technique. CSFEM returns the nearly exact stiffness of continuum structures, which auto discretes the elements in complex areas more readily and thus remarkably reduces the numerical errors. Static and dynamic characteristics of four PCM structures are investigated using CSFEM with AHM. Results are compared with analytical solution and those of FEM, which proves that CSFEM with AHM is more accurate and reliable than the standard FEM when solving problems of complex structures. Additionally, CSFEM could provide results of higher accuracy even using distorted meshes. Therefore, such method is a robust tool for analyzing mechanical properties of PCM structures. [ABSTRACT FROM AUTHOR]

Numerous studies have shown that the dysregulation of microRNA (miRNA/miR) is an important factor in the pathogenesis of lung cancer. However, the role of miR-891a-5p in non-small cell lung cancer (NSCLC) remains unclear. Therefore, the present study aimed to examine the clinical value and biological function of miR-891a-5p in NSCLC. The mRNA expression level of miR-891a-5p in NSCLC was determined using reverse transcription-quantitative PCR and was used to determine the diagnostic value of miR-891a-5p, by creating a receiver operating characteristic curve. Kaplan-Meier and Cox regression analyses were used to evaluate its prognostic value in patients with NSCLC. Furthermore, cell experiments were performed to investigate the underlying mechanisms and functional role of miR-891a-5p in NSCLC progression. The results indicated that miR-891a-5p expression level was significantly higher in serum and tissues from patients with NSCLC and NSCLC cell lines. In addition, serum miR-891a-5p was found to have a diagnostic value in patients with NSCLC, and the increase in the expression level of miR-891a-5p in tumor tissues was associated with differentiation, and the tumor, node and metastases stages of cancer, which could be used for NSCLC prognosis. In addition, the experiments revealed that NSCLC cell proliferation, invasion and migration were significantly increased by the overexpression of miR-891a-5p and were significantly reduced by its downregulation. Furthermore, a luciferase reporter assay and the protein expression levels of HOXA5 showed that HOXA5 might be a miR-891a-5p target gene. In summary, the results indicated that high miR-891a-5p expression level could be a novel biomarker in patients with NSCLC and that it promoted tumor cell proliferation, invasion and migration. HOXA5 may be a target of miR-891a-5p, which may mediate miR-891a-5p function in NSCLC. [ABSTRACT FROM AUTHOR]