Chaotic Path Planner of Autonomous Mobile Robots Based on the Standard Map for Surveillance Missions

This paper proposes a fusion iterations strategy based on the Standard map to generate a chaotic path planner of the mobile robot for surveillance missions. The distances of the chaotic trajectories between the adjacent iteration points which are produced by the Standard map are too large for the robot to track. So a fusion iterations strategy combined with the large region iterations and the small grids region iterations is designed to resolve the problem. The small region iterations perform the iterations of the Standard map in the divided small grids, respectively. It can reduce the adjacent distances by dividing the whole surveillance workspace into small grids. The large region iterations combine all the small grids region iterations into a whole, switch automatically among the small grids, and maintain the chaotic characteristics of the robot to guarantee the surveillance missions. Compared to simply using the Standard map in the whole workspace, the proposed strategy can decrease the adjacent distances according to the divided size of the small grids and is convenient for the robot to track

Machine learning-based signature of necrosis-associated lncRNAs for prognostic and immunotherapy response prediction in cutaneous melanoma and tumor immune landscape characterization

BackgroundCutaneous melanoma (CM) is one of the malignant tumors with a relative high lethality. Necroptosis is a novel programmed cell death that participates in anti-tumor immunity and tumor prognosis. Necroptosis has been found to play an important role in tumors like CM. However, the necroptosis-associated lncRNAs’ potential prognostic value in CM has not been identified.MethodsThe RNA sequencing data collected from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression Project (GTEx) was utilized to identify differentially expressed genes in CM. By using the univariate Cox regression analysis and machine learning LASSO algorithm, a prognostic risk model had been built depending on 5 necroptosis-associated lncRNAs and was verified by internal validation. The performance of this prognostic model was assessed by the receiver operating characteristic curves. A nomogram was constructed and verified by calibration. Furthermore, we also performed sub-group K-M analysis to explore the 5 lncRNAs’ expression in different clinical stages. Function enrichment had been analyzed by GSEA and ssGSEA. In addition, qRT-PCR was performed to verify the five lncRNAs’ expression level in CM cell line (A2058 and A375) and normal keratinocyte cell line (HaCaT).ResultsWe constructed a prognostic model based on five necroptosis-associated lncRNAs (AC245041.1, LINC00665, AC018553.1, LINC01871, and AC107464.3) and divided patients into high-risk group and low-risk group depending on risk scores. A predictive nomogram had been built to be a prognostic indicator to clinical factors. Functional enrichment analysis showed that immune functions had more relationship and immune checkpoints were more activated in low-risk group than that in high-risk group. Thus, the low-risk group would have a more sensitive response to immunotherapy.ConclusionThis risk score signature could be used to divide CM patients into low- and high-risk groups, and facilitate treatment strategy decision making that immunotherapy is more suitable for those in low-risk group, providing a new sight for CM prognostic evaluation

Purely Organic Phosphor Sensitization Based Highly Efficient Electrofluorescence Material

Pure organic room temperature phosphorescence (RTP) materials are considered as potential candidates for replacing precious metal-based complexes to fabricate highly efficient organic light emitting devices (OLEDs). However, for reported RTP materials, low photoluminescence quantum yields (PLQYs) in thin film state seriously impede their applications in OLEDs. On the other hand, how using normal organic fluorescence materials to fabricate OLEDs with an internal quantum efficiency (IQE) over 25% remains a great unaddressed issue beyond the thermally activated delayed fluorescence (TADF) sensitization approach. Here, we establish a strategy to construct highly efficient OLEDs based on pure organic RTP material sensitized fluorescence emitter. The key point for our strategy is that benzimidazole-triazine molecules (PIM-TRZ), 2,6-di(phenothiazinyl)naphthalene (β-DPTZN) and 5,6,11,12-tetraphenylnaphthacene (rubrene) were screened as host, phosphor sensitizer and fluorescent emitter, respectively. Detail photophysical characterizations demonstrate that the host material PIMTRZ with unique RTP nature is critical for achieving phosphor sensitizing process. As an organic RTP compound, the singlet and triplet state energy levels of β-DPTZN perfectly match with those of PIMTRZ, resulting in the formation and lasting existence of phosphor’s excitons in emitting layer. The large overlap between the absorption spectrum of rubrene and PL spectrum of PIM-TRZ:10% β-DPTZN film can facilitate the Förster energy transfer from the triplet β-DPTZN to the singlet rubrene and the finally displayed fluorescence is derived from singlet excited states of rubrene. The perfect collocation of host, phosphorescent sensitizer and fluorescent emitter in the emitting layer promise the predominant performance of the devices with external quantum efficiency (EQE) of 15.7%. The PLQY of emitting layer is 60.3%, and therefore about 90% carrier injection induced excitons are harvested for light emission. We present a new strategy to fabricate efficient fluorescent devices by employing ingenious combination of host, phosphorescent sensitizer and fluorescent emitter, which is significant to the development of OLEDs.<br /

<i>ZmASR3</i> from the Maize <i>ASR</i> Gene Family Positively Regulates Drought Tolerance in Transgenic Arabidopsis

Abscisic acid (ABA)-, stress-, and ripening-induced (ASR) proteins are reported to be involved in drought stress responses. However, the function of maize ASR genes in enhancing drought tolerance is not known. Here, nine maize ASR members were cloned, and the molecular features of these genes were analyzed. Phenotype results of overexpression of maize ZmASR3 gene in Arabidopsis showed lower malondialdehyde (MDA) levels and higher relative water content (RWC) and proline content than the wild type under drought conditions, demonstrating that ZmASR3 can improve drought tolerance. Further experiments showed that ZmASR3-overexpressing transgenic lines displayed increased stomatal closure and reduced reactive oxygen species (ROS) accumulation by increasing the enzyme activities of superoxide dismutase (SOD) and catalase (CAT) under drought conditions. Moreover, overexpression of ZmASR3 in Arabidopsis increased ABA content and reduced sensitivity to exogenous ABA in both the germination and post-germination stages. In addition, the ROS-related, stress-responsive, and ABA-dependent pathway genes were activated in transgenic lines under drought stress. Taken together, these results suggest that ZmASR3 acts as a positive regulator of drought tolerance in plants

Confining donor conformation distributions for efficient thermally activated delayed fluorescence with fast spin-flipping

Abstract Fast spin-flipping is the key to exploit the triplet excitons in thermally activated delayed fluorescence based organic light-emitting diodes toward high efficiency, low efficiency roll-off and long operating lifetime. In common donor-acceptor type thermally activated delayed fluorescence molecules, the distribution of dihedral angles in the film state would have significant influence on the photo-physical properties, which are usually neglected by researches. Herein, we find that the excited state lifetimes of thermally activated delayed fluorescence emitters are subjected to conformation distributions in the host-guest system. Acridine-type flexible donors have a broad conformation distribution or bimodal distribution, in which some conformers feature large singlet-triplet energy gap, leading to long excited state lifetime. Utilization of rigid donors with steric hindrance can restrict the conformation distributions in the film to achieve degenerate singlet and triplet states, which is beneficial to efficient reverse intersystem crossing. Based on this principle, three prototype thermally activated delayed fluorescence emitters with confined conformation distributions are developed, achieving high reverse intersystem crossing rate constants greater than 106 s−1, which enable highly efficient solution-processed organic light-emitting diodes with suppressed efficiency roll-off