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This article proposes a line scanning chromatic confocal sensor to solve the problem of limited chromatic confocal measurement due to the small measurement range and low measurement efficiency in the industrial inspection process. To obtain an extensive dispersion range, the advantages of a simple single-axis structure are combined with the advantages of a large luminous flux of a biaxial structure. Considering large-scale measurement, our sensor uses off-axis rays to limit the illumination path and imaging path to the same optical path structure. At the same time, the field of view is expanded, and a symmetrical structure is adopted to provide a compact optical path and improve space utilization. The simulation and physical system test results shows that the sensor scanning line length is 12.5 mm, and the axial measurement range in the 450 nm to 750 nm band is better than 20 mm. The axial resolution of the detector is ±1 µm combined with the subpixel centroid extraction data processing method, and the maximum allowable tilt angle for specular reflection samples is ±7°. The thicknesses of transparent standard flat glass and the wet collagen membrane are measured. The maximum average error is 1.3 µm, and the relative error is within 0.7%. The constructed sensor is of great significance for rapidly measuring the three-dimensional profile, flatness, and thickness in the fields of transparent biological samples, optics, micromechanics, and semiconductors.

A new test based on distance covariance is proposed for testing the parametric form of the conditional variance in parametric and nonparametric regression models. Inherit from the nice properties of distance covariance, the new test is very easy to implement in practice and less effected by the dimensionality of covariates. The asymptotic properties of the test statistic are investigated under the null and alternative hypotheses. The proposed test is consistent against any alternative hypothesis and can detect some classes of local alternative hypotheses converging to the null hypothesis at the parametric rate in both the parametric and nonparametric settings. As the limiting null distribution of the test statistic is intractable, a smooth residual bootstrap is proposed to approximate the limiting null distribution. Simulation studies are conducted to assess the finite sample performance of the proposed test. A real data set is also analyzed for illustration. [ABSTRACT FROM AUTHOR]

AbstractThis study investigated the effects of hyperoside pre-treatment on the oxidative stress, inflammatory response and apoptosis in rats with cerebral ischemia-reperfusion (I/R) injury. SD rats were randomly divided into sham, I/R, hyperoside (I/R + Hyp) and nimodipine (I/R + Nim) groups. The rats in the hyperoside group and the nimodipine group were intra-gastrically given hyperoside (50 mg/kg/day) and nimodipine (15 mg/kg/day), respectively, 15 days before operation. A rat cerebral ischemia model was established by suture-occlusion 1 h after the last administration. The thread embolus was removed 2 h after the ischemia for the 24 h reperfusion. The results showed that compared with that in the I/R model group, the neurologic function of the hyperoside group rats was significantly improved and the cerebral infarction volume ratio decreased significantly. The total antioxidant capacity, the activity of superoxide dismutase and glutathione peroxidase in the brain tissue of the hyperoside group rats were significantly higher than those in the I/R model group. The content of malondialdehyde, interleukin-1β and tumour necrosis factor-α in the brain tissue of the hyperoside group rats was significantly lower than that in the I/R model group. Compared with that in the I/R model group, the expression of Bcl-2 mRNA, and p-PI3K and p-AKT proteins in the hyperoside group increased significantly, whereas that of Bax and caspase-3 mRNA decreased significantly. These results suggest that hyperoside had a significant protective effect against cerebral I/R injury in rats, which is related to its inhibiting the oxidative stress, alleviating the inflammatory response and having anti-apoptotic effects.

Multiple-supply are required to minimize the power consumptions in bio-implant systems. A single-inductor multiple-output (SIMO) switching converter is one of the solutions. But it has inherent problems which block the applications in the embedded biomedical systems. In this paper, a circuit arrangement for providing multiple outputs based on low-dropout (LDO) regulator is proposed. The regulating transistor of LDO is time-shared by N output legs. Two error amplifiers (EAs) are utilized in the topology, irrespective of number of the output legs. The corresponding switching strategy alleviates the difficulties associated with controlling multiple switching functions for conventional time-sharing methods, and thus, permits multiple outputs to be generated easily. A prototype multiple-output LDO (MOLDO) regulator with four output legs was fabricated with a standard 0.35 \mu\ m CMOS process. The measurement results verify the good performance of this design such as no cross regulation (CR), small ripples, and less power consumption. Moreover, it does not require inductor and presents low total harmonic distortion, which is very suitable for bio-implant fields. [ABSTRACT FROM PUBLISHER]