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Abstract Objective Iron accumulation is associated with osteoporosis. This study aims to explore the effect of chronic iron accumulation induced by hepcidin1 deficiency on aging osteoporosis. Methods Iron accumulation in hepcidin1 knockout aging mice was assessed by atomic absorption spectroscopy and Perl’s staining. Bone microarchitecture was observed using Micro-CT. Hepcidin, ferritin, oxidative stress, and markers of bone turnover in serum were detected by enzyme-linked immunosorbent assay. Bone formation and resorption markers were measured by real-time quantitative PCR. Cell aging was induced by D-galactose treatment. CCK-8, flow cytometry, EdU assays, and Alizarin red staining were performed to reveal the role of hepcidin1 knockout in cell model. Iron Colorimetric Assay Kit and western blot were applied to detect iron and ferritin levels in cells, respectively. Results In hepcidin1-knockout mice, the ferritin and iron contents in liver and tibia were significantly increased. Iron accumulation induced by hepcidin1 knockout caused a phenotype of low bone mass and deteriorated bone microarchitecture. Osteogenic marker was decreased and osteoclast marker was increased in mice, accompanied by increased oxidative stress level. The mRNA expression levels of osteoclast differentiation markers (RANKL, Mmp9, OPG, Trap, and CTSK) were up-regulated, while bone formation markers (OCN, ALP, Runx2, SP7, and Col-1) were down-regulated in model group, compared to wild type mice. In vitro, hepcidin1 knockdown inhibited proliferation and osteogenic differentiation, while promoted apoptosis, with increased levels of iron and ferritin. Conclusion Iron accumulation induced by hepcidin1 deficiency aggravates the progression of aging osteoporosis via inhibiting osteogenesis and promoting osteoclast genesis.

A systematic method is employed for the design and analysis of a small size eddy current (EC) displacement sensor. Simulations are first performed to determine the optimal winding structure and dimensions of the sensor. A linear-fitting approach is then developed for converting the AC displacement signal of the sensor to a DC signal. Finally, a compensation method is proposed for mitigating the temperature drift of the EC sensor under different working temperatures. The experimental results show that the proposed sensor has a sensitivity of approximately 3 μm, a working temperature range of 25–55 °C, and a linearity of ±1.025%.

Permanent magnet synchronous motors (PMSMs) are the main source of power in modern machine tools and are required to generate a high torque over a wide speed range in order to improve manufacturing efficiency. This study sets out to optimize the rotor design of a PMSM with a rated power, rated speed, rated torque and maximum speed of 34 kW, 2250 rpm, 144.3 N·m and 11,250 rpm, respectively. A multi-objective optimization algorithm is employed to determine the rotor design parameters which maximize the output torque of the PMSM over three different load conditions (no load, rated load and maximum speed load). ANSYS multi-physics simulations are conducted to examine the electromagnetic, the structural field, temperature/flow field, demagnetization parament analysis and map analysis of global characteristics of the optimized PMSM. In general, the results show that the optimized PMSM provides a high torque and high-speed expansion performance, and thus facilitates a wide range of applications from low-speed heavy cutting to high-speed cutting without the need to replace the motor or machine tool.

Design, measurement, and characterization of a low-loss Lange coupler on Si-substrate up to 170 GHz are presented in this paper. How to determine the value of the even number of the strip lines according to the process design rules is illustrated carefully based on odd- and even-mode impedance theory and calculation. The deembedding procedures of GSG pads and 50 Ω termination resistors are illustrated in details. Simulation and measurement results indicate that the fabricated on-chip 50 Ω resistors can be used for characterization of four-port Lange coupler by two-port network analyzer within expected measurement errors. Measurement results show that the minimum insertion loss of 0.7 dB at central frequency of 140 GHz is achieved, which is in excellent agreement with simulated data. [ABSTRACT FROM AUTHOR]