Abstract:Detaching cells from the surface of the flask is a necessary operation for the adherent cell passage. Trypsinization is currently the primary method for cell detachment. However, this method is complicated to automated cell culture. Trypsin can cause irreversible damage to cellular proteins, decreasing of cell yield and long self-repair time. Ultrasonic detachment technology uses physical means to complete cell detachment operations, which can avoid damage to cellular proteins and make the realization of automated detachment easier. In this paper, we have developed a device for ultrasonic detachment. Human umbilical cord mesenchymal stem cells were used to study ultrasonic detachment technology control parameters. The experiment results showed that, the optimum cell detachment was achieved (95% detachment rate and 70% survival rate) in 12 mL 5%-saline with 255 V and 159～161 kHz sweeping input signal, 2 min stimulation period, and 3 mm space between flask s urface and transducer.

Abstract:Mesothelin is a potential CAR-T target for treating triple-negative breast cancer (TNBC). The majority of Mesothelin CAR-T cells currently developed in clinical trials used scFv derived from murine monoclonal antibody SS1 as antigen binding domain. The murine scFv is prone to induce the production of anti-CAR antibody in the body, which leads to unsatisfactory effect. Therefore, it is urgent to develop new antigen binding domains for constructing CAR-T. A Mesothelin-targeting nanobody VHH with a similar affinity to SS1 scFv was selected. Two CAR-T cells with different antigen recognition domains (scFv and VHH) targeting Mesothelin were constructed, and their killing ability against MDA-MB-231 cells over-expressing Mesothelin was compared. The results showed that VHH CAR-T demonstrated better killing ability against triple negative breast cancer cells than scFv CAR-T cells, which was widely used in clinical trials.In addition, VHH CAR-T expressed more CD107a and CD69 than scFv CAR-T. This is the first Mesothelin CAR-T derived from VHH sequence worldwide. The study provides basis for the further development of Mesothelin CAR-T.

Abstract:Drug addiction is an intractable chronic neuropsychiatric disorder that raises serious social problems. The study of individual susceptibility in drug addiction may contribute to our understanding of neurobiological mechanism underlying addiction and making risk assessment of individual vulnerability. Use the gray-scale analysis evaluate the hair regrowth ability, and assess the addiction susceptibility with conditioned place preference and intravenous self-administration paradigm in rats. The results revealed a significant negative correlation between addiction susceptibility and hair regrowth ability. The rats with fast hair regrowth ability exhibited less CPP score and reduced drug-seeking behavior in the methamphetamine self-administration model. The open field test showed no differences in the locomotor activity and anxiety level between the two groups. The findings may be helpful for predicting drug addiction risk and further exploring the neurobiological mechanisms of addiction susceptibility based on this phenotypic difference.

Abstract:Ultrasound transducer is one of the most critical components in the intravascular ultrasound imaging systems and plays a decisive role in imaging performance. Since it is vital to obtain detailed information on atherosclerotic plaques in clinical, it is important to enhance the imaging resolution. Additionally, it is indispensable to achieve sufficient penetration depth for the complete assessment of plaque and blood vessels. The center frequency of the transducer determines the ultrasound imaging resolution and penetration depth, which are restricted by each other. In this paper, a 60 MHz miniature highfrequency transducer is carefully designed and fabricated to meet the coronary artery imaging requirements for imaging resolution and depth. The phantom experiments show that the transducer proposed in this paper can provide high-resolution imaging with the imaging depth meeting the needs of coronary imaging. In vivo experiment of large animals shows that, compared with commercial 40 MHz transducers, the transducer designed in this paper can image the vascular media intima and stent structure more clearly, which can provide more precise guidance for clinical practice.

Abstract:Behavioral analysis of animals is an essential part of neuroscience research. However, most previous methods are based on manual recognition or use image recognition technology to analyze animal trajectories. The former is time-consuming and subjective, while the latter ignores the large amount of body posture information of animals in three-dimensional space. Based on the existing three-dimensional behavioral analysis framework inspired by the natural structure of animal behaviors, this study designs and builds a three-dimensional spatial posture acquisition device applicable to multiple scenarios, such as visual innate fear behavior, and optimizes some parts of the data processing and analysis process. The results show that the system is able to accurately identify the five major types of mouse movements, and can restore the dynamic process of defensive behaviors of mice under the visually life threaten with high accuracy. This study provides an efficient, objective, and quantifiable solution for the comprehensive analysis of visuallyevoked innate fear behavior. Furthermore, combined with other cutting-edge methods, this system may provide to more finely and deeply data for the neural circuit me chanism of behaviors.

Abstract:CNN-based methods have achieved notable performance in the research of single image super resolution domain. To further improve the representation ability and performance of networks, most research works have adopted the attention mechanism. In this survey, we introduce a taxonomy for the attention based super-resolution networks and classify existing methods into two categories: first-order and secondorder attention. We also provide comparisons between the models in terms of network scale, memory footprint, type of network losses and important architectural differences for attention implementation. An analysis tool from recent network interpretation works is applied to verify the improvements of the evolving attention mechanism. Finally, we analyze and discuss challenges in processing real degraded images, and point out the problems and potential topics in future research work.

Abstract:In order to meet the requirements for the accuracy and efficiency of the insulator skirt damage detection in the field of UAV power inspection, a lightweight insulator skirt damage detection algorithm based on a double-layer pyramid structure is proposed in this paper. To avoid the filtering of useful information, the proposed method utilized both high-level and low-level semantic features from images. Simultaneously, multi-channel feature extraction is used to increase the feature expression ability of the model. In addition, deep separable convolution is employed to optimize the performance of the convolution kernel for real-time operation on a low-power embedded front-end. Experimental results show that the proposed algorithm has good accuracy, real-time performance and robustness for the insulator skirt damage detection under different working conditions.

Abstract:The reliability of Ni-Cr alloy thin film resistors were tested by an aging test under an environment of 85 ℃ and 85% relative humidity for 3 000 h. The results show that the thin-film resistors exhibit two failure modes, resistance drift, and open circuit, after aging tests at 85 ℃ and 85% relative humidity. The failure mechanism of both failure modes was further analyzed, and the causes of failure were clarified. The failed resistors were examined by a 3D laser scanning microscope, scanning electron microscope, energy dispersive spectroscopy, and focused ion beam to analyze the cause of resistor failure. The results show that there is a crack in the terminal electrode of the film resistor. In addition to the obvious problems such as cracking, the electrode layer also showed sulfide corrosion of the Ag electrode.