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Graphical abstract, Highlights • Tactile perception is investigated from finger friction to brain activation. • Stress concentrations around mechanoreceptors are affected by the grating textures. • Friction coefficient of finger increases with increasing grating width and spacing. • P300 peak latency is related to the difference between target and non-target stimulus. • P300 evoked by gratings is related with tribological and mechanical properties of skin., The formation of tactile perception is related to skin receptors and the cerebral cortex. In order to systematically study the tactile perception from finger friction to the brain response, a 32-channel Brain Products system and two tri-axial force sensors were used to obtain electroencephalograph (EEG) and friction signals during fingers exploring grating surfaces. A finite element finger model was established to analyze the stress changes of the skin receptors during tactile perception. Samples with different grating widths and spaces were chosen. The results indicated that different gratings induced different stress concentrations within skin that stimulated Meissner and Merkel receptors. Skin friction was affected by gratings during the tactile perception. It was also found that P300 evoked by gratings was related with the skin deformation, contact area, friction force, and stress around cutaneous mechanoreceptors. The wider grating width generated larger skin deformation, friction force, and stress, which induced stronger tactile stimulation. The smaller grating spacing generated higher vibration frequency, inducing stronger tactile stimulation. The latency of the P300 peak was related to the difference between the textured target stimulus and the smooth non-target stimulus. This study proofed that there was a relationship between the activation in brain regions, surface friction, and contact conditions of skin during the tactile perception. It contributes to understanding the formation process and cognitive mechanism of tactile perception of different surface textures.

Conventional immunoprobes have absorption capabilities across the visible to near infrared (NIR-I, 650-900 nm) region. Recently, second near infrared (NIR-II, 1000-1700 nm) window have gained much attention due to their deeper penetration depth and improved visualization. Here, we describe the design and synthesis of a fully human nanobody-based fluorescent immunoprobe (ICGM-n501) for NIR-II bioimaging with strengthened fluorescent emission by antigen for the first time. By site-directed conjugation of an FDA-approved dye analogue, indocyanine green decorated with maleimide (ICGM), into a tumor-specific n501, ICGM-n501 provides real-time monitoring of abdominal transportation pathway of antibody-based bioagents with high resolution (0.21 mm), presents better accuracy and lower dosage (0.21 μmol kg

In the detecting of joint casings in oil wells based on remote field eddy current (RFEC) testing, the two penetrations of RFEC on casings (near the transmitter and near the sensing coils) enhance the complicacy of detecting joint casings. The proposed method in this paper is an efficient way to overcome this problem by removing the signal caused by wall’s proximity to the transmitter from the testing signal. In the method, the secondary peaks caused by the transmitter passing over defects need to be removed from the testing signal by employing dual sensing coils firstly. Then the iterations of the testing signals from the dual sensing coils are deduced for the further application of the Wiener deconvolution filter to identify the signal that is used to indicate anomalies. Thirdly, the acquisition of the signal caused by normal wall’s proximity to the transmitter is obtained according to the indicator signal. Lastly, after the both removal of secondary peaks and the signal caused by normal wall’s proximity to the transmitter from the testing signal, the remaining signal can be used to monitor the present joint casings in a well adaptively. The method proposed in this paper is validated via a logging tool, the Kesuo #1 well and ANSYS simulation.

This paper represents a new scheme using the drill strings as the medium to deliver logging information via a compressional acoustic wave. Considering the comb-type frequency characteristics of an acoustic channel, non-contiguous orthogonal frequency division multiplexing (NC-OFDM) has been selected as a promising technique for achieving high-rate transmission with high spectral efficiency and immunity to multipath channels. However, the irregular pilot design and high peak-to-average power ratio (PAPR) halted the widespread application of NC-OFDM. To overcome these two disadvantages, we propose an adaptive pilot design scheme in which the dynamic range of available frequency is pre-simulated and an improved discrete Fourier transformation based least square (PDFT-LS) channel estimation scheme to obtain the channel characteristics and an improved selected mapping (PSLM) scheme with low-complexity to reduce the PAPR of the transmitter are applied. Computer simulation and circuit test results are presented to demonstrate that the data transmission rate can be in excess of 500 bps along a 53.76 m experimental channel under the conditions of the simulated impulse noise and surface noise with a low bit error rate (BER), and the PAPR reduction performance can reach almost the same as that of a conventional SLM (CSLM) scheme.