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To ensure detection accuracy, the focus of the terahertz lens is required to be located on the surface of the workpiece in the process of terahertz imaging detection, and the outgoing optical axis of the lens is also required to be perpendicular to the surface of the workpiece. Therefore, when imaging curved samples, a 6-degree freedom manipulator is generally used to drive the terahertz lens, and the lens realizes non-destructive testing along the workpiece surface. The mechanical arm is required to drive the terahertz lens to move along the rotation curve in a two-dimensional plane when the mechanical arm is used to detect the power insulator of the rotating structure. This paper focuses on the path planning of the manipulator, that is, the curve is divided into several connected straight lines and arcs, and the manipulator moves continuously in each characteristic line segment. The D-H dynamic model of the manipulator was established to analyze the joint velocity and acceleration to ensure the stability of the moving process.

The development of non-precious metal catalysts with high efficiency and superior reaction durability for oxygen reduction reaction (ORR) is of great importance for construction of next-generation fuel cells. Herein, we report the preparation of in-situ nitrogen-doped carbon nanotube electrocatalysts (PPy-NCNTs) which were prepared by the pyrolysis of one-dimensional nanotube-like polypyrrole conjugated polymers precursor (PPy-Tubes) synthesized by oxidative polymerization and self-assembly method. The as-prepared PPy-NCNTs show good ORR performance, e.g., its half-wave potential reaches 0.826 V. In order to further improve the ORR performance of PPy-NCNTs, we prepared the Co-N co-doped carbon nanotube materials (Co-N-PPy-NCNTs) with different Co contents by adding cobalt nitrate into the polymerization solution during synthesis of PPy nanotube followed by a pyrolysis treatment. Comparatively, the Co-N-PPy-NCNTs have better ORR performance than that of PPy-NCNTs with a half-wave potential of 0.830 V, a biased 4e− reaction pathway, and better stability and methanol tolerance (high than Pt/C catalysts in the methanol tolerance test and the durability test). Taking advantages of its simple and cost-efficient preparation, high ORR performance and superior stability and methanol tolerance, the Co-N-PPy-NCNTs should be a kind of ideal candidate as an alternative to the precious metal platinum-based catalysts for fuel cells.

The RNA-guided CRISPR/Cas9 system could cleave double-stranded DNA at the on-target sites but also induce off-target mutations in unexpected genomic regions. The base-pairing interaction of sgRNA with off-target DNA was still not well understood and also lacked a direct cell-based assay. Herein we developed a fast target DNA mutagenesis-based fluorescence assay to directly detect the Cas9 activity at different off-target sites in living cells. The results showed that Cas9 nuclease had low tolerance to the nucleotide mismatches in the binding region adjacent to PAM sites, and a tradeoff between Cas9 activity and specificity was also observed compared with the high-fidelity Cas9 variant. The combination of computer-based predictions and this target DNA mutagenesis-based fluorescence assay could further provide accurate off-target prediction guidance to minimize off-target effects to enable safer genome engineering.

Solar vapor generation based on light-to-heat conversion via photothermal materials has been considered as one of the emerging technologies for utilizing solar energy. Here, we report the fabrication of a novel monolithic aerogel (PNGA) composed of hydrophilic treated MnO2 nanowires and reduced graphene oxide (rGO) followed by in situ coating of polypyrrole on the surface of the PNGA to construct a light-to-heat conversion layer for efficient solar steam generation. Analysis of the morphology and porosity of the PNGA shows that the aerogel is full of interconnected pores and open channels with a low apparent density (0.127 g cm−3) and large specific surface area (1142.7 m2 g−1), which endow it with excellent thermal insulation (a low thermal conductivity of 0.21882 W m−1 K−1 in the wet state), self-floating and rapid water transmission properties. Benefiting from the polypyrrole coating, the PNGA shows a superintense optical absorption of ca. 100%. Interestingly, a superhydrophilic wettability could be achieved after surface modification of the PNGA with phytic acid, which could dramatically enhance its water transportation ability. Furthermore, the PNGA maintains a certain mechanical strength (0.08 MPa under 30% strain), thus making it mechanically robust to withstand the harsh environment. Taking the advantages mentioned above, our PNGA possesses an outstanding energy conversion efficiency of 93.8% under 1 kW m–2 irradiation, which is 4.9 times that of pure water (19.1%). In addition to the excellent ionic isolation and dye liquid treatment ability, the PNGA shows excellent stability and its energy conversion efficiency remains nearly unchanged after ten consecutive tests. Based on its excellent mechanical stability and high recyclability and a simple and scalable manufacture process, our PNGA sample may have great potential as an efficient photothermal material for a wide range of large-scale applications such as solar steam generation, wastewater treatment, seawater desalination and so on.

Qiuling Wang,1,* Jingxin Han,1,* Pu Xu,1 Xinchun Jian,1,2 Xieshan Huang,1 Deyu Liu1 1Stomatology Center, Affiliated Haikou Hospital of Xiangya Medical College, Central South University, Haikou, Hainan, 570208, People’s Republic of China; 2Department of Oral and Maxillofacial Surgery, Xiangya Hospital, Central South University, Central South University, Changsha, Hunan, 410008, People’s Republic of China*These authors contributed equally to this workCorrespondence: Deyu LiuStomatology Center, Affiliated Haikou Hospital, Xiangya Medical College, Central South University, Renmin Road No. 43, Haikou, Hainan, 570208, People’s Republic of ChinaEmail mant3345@163.comBackground: Targeting the long non-coding RNAs (LncRNAs)-microRNAs (miRNAs)-mRNA competing endogenous RNA (ceRNA) networks has been proved as an effective strategy to treat multiple cancers, including oral squamous cell carcinoma (OSCC). Based on this, the present study identified a novel LncRNA SNHG16/miR-17-5p/CCND1 signaling pathway that played an important role in regulating the pathogenesis of OSCC.Methods: The expression levels of cancer-associated genes were examined by Real-Time qPCR and Western Blot at transcriptional and translated levels, respectively. CCK-8 assay was performed to determine cell proliferation, and cell apoptosis ratio was measured by the Annexin V-FITC/PI double staining assay. Transwell assay was performed to examine cell migration, and dual-luciferase reporter gene system assay was used to validate the ceRNA networks.Results: LncRNA SNHG16 and CCND1 were upregulated, while miR-17-5p was downregulated in OSCC tissues and cell lines, compared to their normal counterparts. Also, miR-17-5p negatively correlated with both LncRNA SNHG16 and CCND1 mRNA, but LncRNA SNHG16 was positively relevant to CCND1 mRNA in OSCC tissues. By performing the gain- and loss-of-function experiments, we noticed that LncRNA SNHG16 overexpression aggravated the malignant phenotypes, such as cell proliferation, viability, migration and epithelial-mesenchymal transition (EMT) in OSCC cells, while LncRNA SNHG16 knock-down had opposite effects. Furthermore, our dual-luciferase reporter gene system evidenced that LncRNA SNHG16 sponged miR-17-5p to upregulate CCND1 in OSCC cells, and the inhibiting effects of LncRNA SNHG16 ablation on OSCC progression were abrogated by both downregulating miR-17-5p and overexpressing CCND1. Finally, the xenograft tumor-bearing mice models were established, and our data validated that LncRNA SNHG16 served as an oncogene to promote tumorigenicity of OSCC cells in vivo.Conclusion: Taken together, targeting the LncRNA SNHG16/miR-17-5p/CCND1 axis hindered the development of OSCC, and this study provided potential diagnostic and therapeutic biomarkers for OSCC in clinic.Keywords: oral squamous cell carcinoma, competing endogenous RNA, LncRNA SNHG16, MiR-17-5p, cyclin D1

As one of the foundations of existential positive psychology, self-transcendence can bring positive intrapersonal and interpersonal outcomes, especially in the COVID-19 era in which people are suffering huge mental stress. Based on Schwartz's theory of human basic values, the current study combines variable-centered and person-centered approaches to examine the relationships between adolescents' values and mental health across two regions in China. The results generally showed that (1) both self-enhancement and conservation values were positively correlated with depression and loneliness, while both self-transcendence and openness to change values negatively correlated with depression and loneliness. The results also showed that (2) there were four value clusters (i.e., self-focus, other-focus, anxiety-free, undifferentiated), and, compared to adolescents in the self-focus and undifferentiated values cluster, all adolescents in the anxiety-free values cluster reported lower depression and loneliness, while all adolescents in the other-focus values cluster reported higher depression and loneliness. The differences between the two regional groups only emerged in depression. Specifically, adolescents in Shanghai have higher levels of depression than adolescents in Qingdao. This study provides some evidence for the new science of self-transcendence among adolescents and also sheds light on how we may improve the level of mental health during the COVID-19 era.

The development of high-performance non-precious metal electrocatalysts is of great importance for construction of next generation fuel cells. Herein, we report for the first time the creation of new metal-free porous carbon framework catalysts derived from N-rich hypercrosslinked polymers (HCPs) using pyrrole as building blocks for oxygen reduction reaction (ORR) (denoted as PCF-HCPs). The PCF-HCPs obtained at the pyrolysis temperature of 900 °C (PCF-HCP-900), displayed outstanding catalytic activity towards the ORR compared with other PCF-HCPs pyrolysis temperature. Due to PCF-HCP-900 with large specific surface, excellent porosity and, importantly, exposed active sites caused by N doping with high density, the catalysts exhibited outstanding ORR activity in alkaline medium, i.e., the PCF-HCP-900 yielded a half-wave potential of 0.84 V, which was 10 mV higher than that of the state of-the-art Pt/C catalyst (0.83 V), and onset potential of 0.95 V (vs. RHE), a high diffusion limiting current density of 4.8 mA cm−2, better methanol tolerance and long-term stability (2 mV negative shift after 3000 potential cycles) than commercial Pt/C. Furthermore, PCF-HCP-900 shows a favorable 4-electron transfer process (n ≈ 3.96) and lower H2O2 yield. Based on these merits, the PCF-HCP-900 may open a new possibility for design of ORR metal-free catalyst of fuel-cell technologies.

To achieve multisite-targeting-based DNA cleavage simultaneously, we designed two kinds of CRISPR RNA arrays by fusing four single guide RNAs (sgRNAs for Cas9 or crRNAs for Cpf1) with uncleavable RNA linkers (CRISPRay). The CRISPRay could operate on four adjacent target sites to cleave target DNA in a collaborative manner. Two CRISPR RNA arrays demonstrated robust inactivation of the firefly luciferase gene in living cells. In vitro DNA cleavage and DNA sequencing also verified that sgRNA arrays directed SpCas9 nuclease to cut target DNA at four cleavage sites simultaneously whereas crRNA-array-guided FnCpf1 nuclease showed target-activated, nonspecific DNase activity on both target DNA and nontarget DNA at random sites. Through optimization of the ratio of nuclease and CRIPSR RNAs, CRISPRay should further enhance gene interference in cells. This work presents a simple approach through which to improve multisite-directed gene disruption by fusing four guide RNAs (sgRNAs or crRNAs) into a CRISPR RNA string.

There has been considerable interest in crowd simulation and creating crowds of virtual humans that will move in a virtual environment in a believable way. This paper presents an experimental design for assessing human behavior in emergency evacuation of an aircraft among a team of players in a game set in a virtual environment. We present the sense of presence in a virtual environment as a possible way of validating human behavior and crowd simulation models. We are conducting a pilot experiment to explore crowd simulation in aircraft evacuation using Virtual Reality to achieve high levels of presence and thus could be used as a framework for validating crowd behavior simulations. We present two approaches for controlling crowd behavior. First by defining rules for computer simulated agents, second by providing controls to the users to navigate in the environment as autonomous agents and guiding other agents. Our contribution lies in our approach to combining these two approaches of behavior in order to simulate the crowd behavior in emergencies.