This paper proposes a colorimetric aptasensor for the detection of testosterone (TES) in environmental water, using TES-specific aptamer (apT5) as a sensing probe, gold nanoparticles (AuNPs) as indicator, and hexadecyltrimethylammonium bromide (CTAB) as inducer, respectively. Based on competition between TES and CTAB for apT5, the aptamer can form an aptamer–TES complex, leaving CTAB free to aggregate AuNPs in the presence of TES. Dispersed and aggregated AuNPs have different absorption wavelengths and the signal of absorption intensity is associated with the concentration of TES, so TES can be detected quantitatively based on the signal absorption intensity. This sensitive aptasensor for TES detection has a wide linear range (R=0.998) from 1.91–800nM and a limit of detection (LOD) of 1.91nM. In addition, this aptasensor has high selectivity over some interferents. The method detects TES in tap water samples with recoveries in the range of 98.9–102.6% (RSD ≤ 7.35%). This biosensor presents a good and potential application to rapidly detect TES in actual environmental water samples.

Feather shuttlecocks are chiral bodies whose rotation properties, such as trajectory and velocity, affect their motion states. This study proposes an experimental method to simulate the rotation properties of shuttlecocks. The effect of wind velocity on the angular velocity of refitting shuttlecocks is tested in a wind tunnel. The refitting parts lie on the cork of the shuttlecocks to avoid affecting the shape of the feather and the friction between air and the feather. Two types of moments are assumed to act on the shuttlecocks: driving and resistance. The driving moment is dependent on relative airflow velocity, whereas the resistance moment is related to rotation speed. Basing on wind tunnel experimental data, we illustrate the curves of the resistance and driving moments. Results provide theoretical guidance in the design of synthetic shuttlecocks and analysis of badminton techniques.

This paper presents a disc-type ultrasonic piezoelectric motor, which is designed for micro flying vehicles. It provides a high output rotation speed under low operating voltage, compared with common piezoelectric devices, by employing a “contact teeth” wave transmission structure. The ultrasonic motor (USM) consists of a trimorph disc stator, with triple internal contact teeth, a shaft and two hemispheric hard-wearing rotors. The operating principle of the USM is based on the superposition of the in-plane B03 vibration mode of the trimorph disc, and the first longitudinal vibration of the contact teeth. An optimization method of the stator structure parameters was proposed and validated by numerical modeling. The diameter and thickness of the stator are 20 mm and 1 mm, respectively. A prototype with the weight of 2 g was made for this experimental test. The optimal frequency of the excitation signal and the preload force are 98.5 kHz and 0.5 N, respectively. The minimum operating voltage was tested under 7.5 V and reached the speed of 225 rpm, and the maximum unloaded rotational speed of the USM reached 5172 rpm when 30 V driving voltage was applied. The maximum lifting force generated by this USM was measured as 46.1 mN, which is 2.35 times bigger than its weight.

No abstract

In this work, a low-voltage driven non-resonant three degree-of-freedom (DOF) eyeball-like piezoelectric actuator is proposed. Elliptical motions on the driving feet are formed from the pushing and pulling actions of the flexible displacement amplification (FDA) mechanism in the piezoelectric actuator. There are three types of elliptical movements to drive the spherical rotor around three coordinate axes while driving the different groups of piezoelectric stacks. The principles of the three-DOF rotations are analysed by theoretical and simulation methods. Fabrication of a miniature piezoelectric prototype of 34mm × 34mm × 34mm is conducted. Under a driving voltage of 40 V 0 − p , the maximum rotary velocities of the rotor around X, Y and Z axes reach to 62.5 r min−1, 65 r min−1 and 46 r min−1 at 1.5 kHz. High resolutions around X and Y axes up to 2.5 μ rad and 5 μ rad are obtained. The remarkable comprehensive performances enable much potential applications of this three-DOF eyeball-like piezoelectric actuator in precision pointing, attitude adjustment and bionic eye positioning systems.

No abstract

No abstract

The immune system plays a central role in many processes of age‐related disorders and it remains unclear if the innate immune system may play roles in shaping extreme longevity. By an integrated analysis with multiple bulk and single cell transcriptomic, so as DNA methylomic datasets of white blood cells, a previously unappreciated yet commonly activated status of the innate monocyte phagocytic activities is identified. Detailed analyses revealed that the life cycle of these monocytes is enhanced and primed to a M2‐like macrophage phenotype. Functional characterization unexpectedly revealed an insulin‐driven immunometabolic network which supports multiple aspects of phagocytosis. Such reprogramming is associated to a skewed trend of DNA demethylation at the promoter regions of multiple phagocytic genes, so as a direct transcriptional effect induced by nuclear‐localized insulin receptor. Together, these highlighted that preservation of insulin sensitivity is a key to healthy lifespan and extended longevity, via boosting the function of innate immune system in advanced ages.