Fast-response thermo-sensitive actuator based on asymmetric structured PNIPAM hydrogel with inorganic particles embedding

Fan Zhuanzhuan,Weizhong Xu,Ruofei Wang,Huaping Wu,Aiping Liu 한국고분자학회 2023 Macromolecular Research Vol.31 No.6

Hydrogel actuators have potential applications in many fields because of their multiple responsiveness to environmental stimuli. However, it is still very challenging to design a hydrogel actuator with simple preparation, fast response, and good mechanical properties. In this work, a facile and convenient method to obtain a fast responsive hydrogel actuator has been successfully developed by embedding uniform inorganic particles into Poly(N-isopropylacrylamide) hydrogel network to form an asymmetric structure. By controlling the types and contents of inorganic particles, a wide range of adjustable actuation property can be achieved. At the same time, the introduction of inorganic particles greatly increases the mechanical properties of hydrogels, which is also very important for actuation performance improvement of hydrogel actuators. The optimized hydrogel exhibits relatively fast bending deformation under thermal stimulation (60 ℃), with a bending velocity of about 13.0° s−1 within first 10 s and a bending amplitude of about 328.1° within 1 min. The hydrogel can be designed to be temperature-controlled claw actuators with programmable shapes, indicating its application prospects in encapsulating, grasping, and transporting objects in water environment.

Robust People Counting in Complicated Situations

Zhi Zhong,Ning Ding,Weizhong Ye,Xinyu Wu,Yangsheng Xu 동국대학교 정보융합기술원 2008 International Journal of Assistive Robotics and Sy Vol.9 No.2

People counting is a basic yet important aspect in intelligent video surveillance. In some places full of moving pedestrians or objects, it is a real challenge for traditional image processing approaches. This paper addresses the issue of how to enhance the robustness of people counting in two complicated situations, one is to count individuals mixed with objects and the other is to count people in a crowded scene. Based on modeling method and machine learning, we employ a new way to tackle the problem, which reduces the error rate and the miss rate dramatically. Experimental results have demonstrated the robust function of the system.

Robust People Counting in Complicated Situations

Zhi Zhong,Ning Ding,Weizhong Ye,Xinyu Wu,Yangsheng Xu 한국과학기술원 인간친화 복지 로봇 시스템 연구센터 2008 International Journal of Assistive Robotics and Me Vol.9 No.2

  People counting is a basic yet important aspect in intelligent video surveillance. In some places full of moving pedestrians or objects, it is a real challenge for traditional image processing approaches. This paper addresses the issue of how to enhance the robustness of people counting in two complicated situations, one is to count individuals mixed with objects and the other is to count people in a crowded scene. Based on modeling method and machine learning, we employ a new way to tackle the problem, which reduces the error rate and the miss rate dramatically. Experimental results have demonstrated the robust function of the system.

Bioinformatic and integrated analysis identifies an lncRNA–miRNA–mRNA interaction mechanism in gastric adenocarcinoma

Yong Liao,Wen Cao,Kunpeng Zhang,Yang Zhou,Xin Xu,Xiaoling Zhao,Xu Yang,Jitao Wang,Shouwen Zhao,Shiyu Zhang,Longfei Yang,Dengxiang Liu,Yanpeng Tian,Weizhong Wu 한국유전학회 2021 Genes & Genomics Vol.43 No.6

Background lncRNAs–miRNAs–mRNAs networks play an important role in Gastric adenocarcinoma (GA). Identifcation of these networks provide new insight into the role of these RNAs in gastric cancer. Objectives Biological information databases were screened to characterize and examine the regulatory networks and to further investigate the potential prognostic relationship this regulation has in GA. Methods By mining The Cancer Genome Atlas (TCGA) database, we gathered information on GA-related lncRNAs, miRNAs, and mRNAs. We identifed diferentially expressed (DE) lncRNAs, miRNAs, and mRNAs using R software. The lncRNA–miRNA–mRNA interaction network was constructed and subsequent survival examination was performed. Representative genes were selected out using The Biological Networks Gene Ontology plug-in tool on Cytoscape. Additional analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) terms were used to screen representative genes for functional enrichment. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) were used to identify the expression of fve candidate diferential expressed RNAs. Results Information of samples from 375 cases of gastric cancer and 32 healthy cases (normal tissues) were downloaded from the TCGA database. A total of 1632 DE-mRNAs, 1008 DE-lncRNAs and 104 DE-miRNAs were identifed and screened. Among them, 65 DE-lncRNAs, 10 DE-miRNAs, and 10 DE-mRNAs form lncRNAs–miRNAs–mRNAs regulatory network. Additionally, 10 lncRNAs and 2 mRNAs were associated with the prognosis of GA. Multivariable COX analysis revealed that AC018781.1 and VCAN-AS1 were independent risk factors for GA. GO functional enrichment analysis found DE-mRNA was signifcantly enriched TERM (P<0.05). The KEGG signal regulatory network analysis found 11 signifcantly enrichment networks, the most prevailing was for the AGE-RAGE signaling pathway associated with Diabetic complications. Results of RT-qPCR was consistent with the in silico results. Conclusions The results of the present study represent a view of GA from a analysis of lncRNA, miRNA and mRNA. The network of lncRNA–miRNA–mRNA interactions revealed here may potentially further experimental studies and may help biomarker development for GA.

Ultrahigh Energy Storage Capacitance and High Breakdown Strength in Biaxially Oriented Poly(vinylidene fluoride) Using a High-Electric-Induced Technique

Hongwei Lu,Jianxin Du,Cuiping Yu,Xingping Wang,Yanlin Gao,Weizhong Xu,Aiping Liu,Xiaoxiao Lu,Yingxin Chen 한국고분자학회 2020 Macromolecular Research Vol.28 No.6

The development of high dielectric materials with high energy densities is a crucial research domain in the modern microelectronics and power systems. The objective of this work was to develop the highly ordered crystal orientations and large ferroelectric crystalline β/γ-phases in the biaxially oriented poly(vinylidene fluoride) (BOPVDF). Importantly, a high discharged energy density and high dielectric constant was achieved by using a high-electric-induced technique. A suitable poling electric field was applied to the BOPVDF films in order to enhance the breakdown strength. Remarkably, the BOPVDF film poled at the electric field of 113 MV m-1 achieved an unprecedented discharged energy density of 25.4 J cm-3 at an ultra-high electric field of 550 MV m-1, which is by far the highest value ever achieved in flexible polymer-based capacitor films. Comparatively, the unpoled BOPVDF and commercial biaxially oriented polypropylene (BOPP) exhibited only a discharged energy density of 7.9 J cm-3 and 1.2 J cm-3, respectively. This systematic study provides a new design paradigm to exploit PVDF-based dielectric polymers for capacitor applications.

Modeling and Verification of a Contactless Air Film Conveyor Using a Viscous Traction Principle

Wei Zhong,Xiaoyu Gu,Ke Xu,Fanghua Liu,Xin Li,Toshiharu Kagawa 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.12

Many industries require contactless transport of delicate or clean products such as silicon wafers, flat foodstuffs and freshly painted objects. In this study, a contactless air film conveyor for flat objects is introduced. The object is supported by a thin film formed between the object and the conveyor surface and transported by viscous traction which is generated by controlled airflow underneath the object. Experiments are conducted to investigate the film pressure distribution and viscous force. The results show that the film pressure is symmetrically distributed along the direction perpendicular to the airflow in the actuating cells and non-symmetrically distributed along the airflow direction. The viscous force decreases as the increase of gap thickness. A simplified model is established to help understand and characterize the viscous force. The calculated results show a good agreement with the experimental data. It is revealed that the viscous force is the resultant of an actuating force in the pocket and side areas and a drag force from airflow across the dam area. Simulation and experiments are conducted using a PID controller for one dimension position control and position tracking. The results verify the effectiveness of the theoretical modeling and control method.