High-fat diet (HFD)-induced glucose intolerance and insulin resistance increases the chances of developing type-2 diabetes and cardiovascular disease. To study the mechanism(s) by which a HFD impairs glucose tolerance, we used a quantitative proteomic platform that integrated pI-based OFFGEL fractionation and iTRAQ labeling to profile the temporal changes in adipose membrane protein expression in mice fed a HFD for up to 8 months. Within 2 months of starting the diet, the mice adipose and liver tissues accumulated fat droplets, which contributed to subsequent insulin resistance and glucose intolerance within 6 months. The membrane proteomic delineation of such phenotypic expression resulted in quantification of 1713 proteins with 266, 343, and 125 differentially expressed proteins in 2-, 6-, and 8-month HFD-fed versus control mice, respectively. Pathway analysis of these differentially expressed proteins revealed the interplay between upregulation of fatty acid metabolism and downregulation of glucose metabolism. Substantial upregulation of adipose and liver carnitine palmitoyltransferase (Cpt) 1, the rate-limiting enzyme in the transport of long-chain fatty acids into mitochondria, occurred by 2 months. The increase in hepatic Cpt 1a expression was associated with a progressive decrease in glucose uptake as evidenced by downregulation of the liver glucose transporter protein (Glut) 2. Loss of glycogen storage was found in those hepatocytes full of fat droplets. Intriguingly, skeletal muscle Cpt 1b expression was unaltered by the HFD, whereas skeletal muscle Glut 4 and tyrosine phosphoryated insulin receptor substrate 1 (p-IRS1) were substantially upregulated at the same time as abnormal glucose metabolism developed in adipose and liver tissues. This study defines some of the molecular mechanisms as well as the relationship among adipose tissue, liver and skeletal muscle during development of HFD-induced glucose intolerance in vivo and identifies Cpt 1 as a potential drug target for the control or prevention of diabetes.

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Due to the common path structure being insensitive to the environmental disturbances, relevant Fabry–Pérot interferometers have been presented for displacement measurement. However, the discontinuous signal distribution exists in the conventional Fabry–Pérot interferometer. Although a polarized Fabry–Pérot interferometer with low finesse was subsequently proposed, the signal processing is complicated, and the nonlinearity error of sub-micrometer order occurs in this signal. Therefore, a differential quadrature Fabry–Pérot interferometer has been proposed for the first time. In this measurement system, the nonlinearity error can be improved effectively, and the DC offset during the measurement procedure can be eliminated. Furthermore, the proposed system also features rapid and convenient replacing the measurement mirrors to meet the inspection requirement in various measuring ranges. In the comparison result between the commercial and self-developed Fabry–Pérot interferometer, it reveals that the maximum standard deviation is less than 0.120 μm in the whole measuring range of 600 mm. According to these results, the developed differential Fabry–Pérot interferometer is feasible for precise displacement measurement.

The quality of processed workpieces is affected directly by the precision of the linear stage. Therefore, the linear displacement calibration of machine tools must be implemented before delivery and after employment for a period of time. How to perform a precise calibration with high inspection efficiency is a critical issue in the precision mechanical engineering industry. In this study, the self-developed system integrated by the measurement module based on the common path Fabry–Pérot interferometer for linear displacement and the auto-alignment module for optical axes was proposed to realize the automatic linear displacement calibration of the linear stages. The measurement performance of the developed structure was verified experimentally. With the auto-alignment module, the cosine error was reduced to 0.36 nm and the entire procedure accomplished within 75 s without the limitation of the perceived resolution of the human eye, operational experience, and the risk of misalignment and broken cable. According to the comparison of experimental results for the linear displacement, the repeatability of the proposed measurement module was less than 0.171 μm. After the compensation procedure according to the linear displacement calibration, the systematic positional deviation, repeatability, and accuracy of the linear axis could be improved to 4 μm, 1 μm, and 5 μm respectively. Hence, the calibration efficiency can be improved by 80% with the proposed compact system, which is beneficial for the linear displacement calibration of machine tools in the precision mechanical engineering industry.