Covalent organic frameworks (COFs) with 2D π‐conjugation were designed and synthesized as molecular photosensitizers for efficient photodynamic therapy. Two molecules, ...5′,5′′′′‐(1,4‐phenylene)bis((1,1′:3′,1′′‐terphenyl‐4,4′′‐dicarbaldehyde)) (L‐3C) and 4,4′,4′′‐(1,4‐phenylene)bis((2,2′:6′,2′′‐terpyridine‐5,5′′‐dicarbaldehyde)) (L‐3N), inactive to generating reactive oxygen species (ROS), were linked to form two COFs, COF‐808 and COF‐909, respectively, exhibiting excellent ROS production efficiency. The high permanent porosity of these COFs (surface areas 2270 and 2610 m2 g−1) promoted diffusion of both oxygen and release of ROS in cells. This, combined with the excellent photostability and biocompatibility, led to excellent PDT performance. In vitro, over 80 % of tumor cells were killed after PDT treatment using COF‐909 at the concentration of 50 μg mL−1 for 150 s. In vivo, drastic reduction of tumor size was observed (from 9 mm to less than 1 mm) after 10 day treatment.
Covalent organic frameworks (COFs) with 2D π‐conjugation were designed and synthesized as molecular photosensitizers for efficient photodynamic therapy. Two molecules inactive to generating reactive oxygen species (ROS) were linked to form two COFs exhibiting excellent ROS production efficiency. The high permanent porosity of these COFs promoted both the diffusion of oxygen and the release of ROS in cells.
Understanding the nonlinear dynamic characteristics of engineering structures is challenging, especially for the systems that exhibit asymmetric nonlinear behavior. This paper compared four parameter ...identification methods for asymmetric nonlinear systems incorporating quadratic and cubic stiffness nonlinearities. Hilbert transform, zero-crossing, direct quadrature, and wavelet transform were used to obtain the backbone, envelope, and restoring force curves from the free vibration time history. A nonlinear curve-fitting method was then applied to estimate the stiffness parameters of the asymmetric systems, and a linear least square fitting approach was utilized to estimate the damping parameters of the asymmetric systems. We used the Helmholtz–Duffing oscillator as a numerical example and a nonlinear vibration absorber with geometric imperfections to verify the feasibility and accuracy of these methods. The advantages and disadvantages of these methods and the deviations in estimated results are discussed.
•Failure mode of large brittle rocks transfers from ductile to brittle mode.•Rocks with small brittleness are damaged thoroughly under high confining pressure.•Vertical propagation of macro crack on ...large brittle rocks is restrained under confined condition.•Mean and mean peak of cutting force tend to be constants with increase of rock brittleness.•The cutting force fluctuates severely for rocks with large brittleness.
Rock brittleness is one of the most important factors to be considered in the design and selection of excavation and mining machineries. In this paper, the influence mechanism of rock brittleness on rock fragmentation and cutting performance is investigated. Rock models with different brittleness are calibrated by changing the bond shear strength to tensile strength ratio (BSTR) in PFC2D. A linear relationship between the BSTR and brittleness index of B10 with a high correlation coefficient is obtained. A series of rock cutting simulations, using PFC2D, are conducted using different cutting depths and confining pressures on rocks with different brittleness. The analysis results demonstrate that rocks with small brittleness are damaged in the ductile failure mode. In contrast, with the increase in cutting depth, the fracture mode of brittle rocks translated from ductile to brittle mode accompanying the macro crack propagation and large chip formation. Under confined conditions, rocks with small brittleness are damaged thoroughly by the synergistic effect of confining pressure and cutting disturbance when the confining pressure/ uniaxial compressive strength (UCS) ratio is 0.6. For rocks with large brittleness, the vertical propagation of macro cracks are restrained under confined conditions. Moreover, the mean cutting force (MCF) and mean peak cutting force (MPCF) increase and tend to be constants with the increase of rock brittleness and cutting depth. In addition, the instability of the cutting force is evaluated by the fluctuation index (FI) and pulse number (PN) in unit displacement. The FI increases with the increase in rock brittleness while the PN decreases, which suggests that the cutting force fluctuates more violently but less frequently during cutting rocks with large brittleness. Lastly, the analysis of specific energy (SE) on the cutting force signal is carried out, and the results show that it is more efficient to cut rocks with large brittleness than that with small brittleness.
Horizon control, maintaining the alignment of the shearer’s exploitation gradient with the coal seam gradient, is a key technique in longwall mining automation. To identify the coal seam gradient, a ...geological model of the coal seam was constructed using in-seam seismic surveying technology. By synthesizing the control resolution of the range arm and the geometric characteristics of the coal seam, a gradient identification method based on piecewise linear representation (PLR) is proposed. To achieve the maximum exploitation rate within the shearer’s capacity, the control resolution of the range arm is selected as the threshold parameter of PLR. The control resolution significantly influenced the number of line segments and the fitting error. With the decrease of the control resolution from 0.01 to 0.02 m, the number of line segments decreased from 65 to 15, which was beneficial to horizon control. However, the average fitting error increased from 0.055 to 0.14 m, which would induce a decrease in the exploitation rate. To avoid significant deviation between the cutting range and the coal seam, the control resolution of the range arm must be lower than 0.02 m. In a field test, the automated horizon control of the longwall face was realized by coal seam gradient identification.
Detecting quantitative trait loci (QTL) and estimating QTL variances (represented by the squared QTL effects) are two main goals of QTL mapping and genome-wide association studies (GWAS). However, ...there are issues associated with estimated QTL variances and such issues have not attracted much attention from the QTL mapping community. Estimated QTL variances are usually biased upwards due to estimation being associated with significance tests. The phenomenon is called the Beavis effect. However, estimated variances of QTL without significance tests can also be biased upwards, which cannot be explained by the Beavis effect; rather, this bias is due to the fact that QTL variances are often estimated as the squares of the estimated QTL effects. The parameters are the QTL effects and the estimated QTL variances are obtained by squaring the estimated QTL effects. This square transformation failed to incorporate the errors of estimated QTL effects into the transformation. The consequence is biases in estimated QTL variances. To correct the biases, we can either reformulate the QTL model by treating the QTL effect as random and directly estimate the QTL variance (as a variance component) or adjust the bias by taking into account the error of the estimated QTL effect. A moment method of estimation has been proposed to correct the bias. The method has been validated via Monte Carlo simulation studies. The method has been applied to QTL mapping for the 10-week-body-weight trait from an F2 mouse population.
Abstract
Motivation
The large-scale multidimensional omics data in the Genomic Data Commons (GDC) provides opportunities to investigate the crosstalk among different RNA species and their regulatory ...mechanisms in cancers. Easy-to-use bioinformatics pipelines are needed to facilitate such studies.
Results
We have developed a user-friendly R/Bioconductor package, named GDCRNATools, for downloading, organizing and analyzing RNA data in GDC with an emphasis on deciphering the lncRNA-mRNA related competing endogenous RNAs regulatory network in cancers. Many widely used bioinformatics tools and databases are utilized in our package. Users can easily pack preferred downstream analysis pipelines or integrate their own pipelines into the workflow. Interactive shiny web apps built in GDCRNATools greatly improve visualization of results from the analysis.
Availability and implementation
GDCRNATools is an R/Bioconductor package that is freely available at Bioconductor (http://bioconductor.org/packages/devel/bioc/html/GDCRNATools.html). Detailed instructions, manual and example code are also available in Github (https://github.com/Jialab-UCR/GDCRNATools).
The lesser grain borer (Rhyzopertha dominica), a worldwide primary pest of stored grain, causes serious economic losses and threatens stored food safety. R. dominica can respond to changes in ...temperature, especially the adaptability to heat. In this study, transcriptome analysis of R. dominica exposed to different temperatures was performed to elucidate differences in gene expression and the underling molecular mechanism.
Isoform-sequencing generated 17,721,200 raw reads and yielded 20,416 full-length transcripts. A total of 18,880 (92.48%) transcripts were annotated. We extracted RNA from R. dominica reared at 5 °C (cold stress), 15 °C (cold stress), 27 °C (ambient temperature) and 40 °C (heat stress) for RNA-seq. Compared to those of control insects reared at 27 °C, 119, 342, and 875 differentially expressed genes (DEGs) were identified at 5 °C, 15 °C, and 40 °C, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that pathways associated with "fatty acid metabolism", "fatty acid biosynthesis", "AMPK signaling pathway", "neuroactive ligand receptor interaction", and "longevity regulating pathway-multiple species" were significantly enriched. The functional annotation revealed that the genes encoding heat shock proteins (HSPs), fatty acid synthase (FAS), phospholipases (PLA), trehalose transporter (TPST), trehalose 6-phosphate synthase (TPS), and vitellogenin (Vg) were most likely involved in temperature regulation, which was also validated by RT-qPCR. Seven candidate genes (rdhsp1, rdfas1, rdpla1, rdtpst1, rdtps1, rdvg1, and rdP450) were silenced in the RNA interference (RNAi) assay. RNAi of each candidate gene suggested that inhibiting rdtps1 expression significantly decreased the trehalose level and survival rate of R. dominica at 40 °C.
These results indicated that trehalose contributes to the high temperature resistance of R. dominica. Our study elucidates the molecular mechanisms underlying heat tolerance and provides a potential target for the pest management in R. dominica.
•3-(formamidinothio)-1-propanesulfonic acid (FTPS) is used as additives of SnO2.•FTPS improves crystal quality and conductivity, reduces defects and recombination.•FTPS doped device achieves a power ...conversion efficiency of 22.52%.•While the controlled device obtains an efficiency of 20.49% at the same condition.
The electron transport layer (ETL) is one of the most important factors to determine the photovoltage (PV) performance of perovskite solar cells (PSCs), and defects and non-radiative recombination are the negative factors limiting the efficiency improvement of PSCs. Herein, using tin oxide (SnO2) as the electron transport layer and multiple functional groups organic molecule of 3-(formamidinothio)-1-propanesulfonic acid (FTPS) as additive of SnO2, we fabricated a high-effective SnO2-based planar PSC. The introduction of FTPS reduces the oxygen vacancy defects of SnO2 ETLs and accommodates perovskite crystal growth on it. The modification of FTPS improves the conductivity and the electron extraction ability of SnO2, mitigates the trap-state density and carrier non-radiative recombination at the interfaces of SnO2/perovskite. As a result, the PSC based on pristine SnO2 ETL obtains a power conversion efficiency (PCE) of 20.49%, while the champion device based on SnO2 + FTPS (0.3 mg/mL) ETL achieves an efficiency of 22.52% with insignificant hysteresis effect and excellent stability. This effective defect passivation strategy work provides a promising low-cost technology for the preparation of planar PSCs with high efficiency and stability.
Longwall shearer positioning with an inertial navigation system (INS) aided by an odometer is the key technology for automation of the longwall coal mining process. In order to improve the shearer ...positioning accuracy without using external sensors, the closing path motion characteristics of a shearer working in a longwall mining face was summarized by analyzing the longwall mining method. A closing path optimal estimation model was proposed based on the motion characteristics of the shearer and a Kalman filter (KF). Through simulation tests, it was verified that the model reduced the influence of heading angle drift of an INS on the shearer positioning accuracy without using external sensors. The shearer positioning accuracy based on the circular error probable was improved by approximately an order of one under the effect of the optimal estimation model. This was beneficial for reducing the large positioning error of the shearer in a longwall mining face during each cutting cycle for approximately 1 h. Note to Practitioners -This paper was motivated by the problem of longwall coal mining automation, especially positioning of longwall shearer, but it also applies to other mobile mining equipment. Longwall shearer positioning with an INS aided by an odometer has been regarded as an effective technological approach to longwall mining automation by coal mining workers and researchers. However, the positioning accuracy is largely subjected to the performance of the INS. This paper proposed a closing path optimal estimation model based on the motion characteristics of the shearer and a KF. Through simulation tests, it was verified that the model improved the positioning accuracy of the shearer by approximately an order of 1. This was beneficial for astricting the large positioning error of the shearer in a longwall mining face during each cutting cycle for approximately 1 h. In the future research, we will address the field tests of the closing path optimal estimation model and extending other mining applications.
Pedestrian Dead Reckoning (PDR)-based pedestrian navigation technology is an important part of indoor and outdoor seamless positioning services. To improve the performance of PDR, we have conducted ...research on a step length estimator. Firstly, based on the basic theory of inertial navigation, we analyze in detail the errors in traditional Strapdown Inertial Navigation Systems (SINSs) caused by the unique motion state of pedestrians. Then, according to the fact that the inertial data from the foot can directly reflect the gait characteristics, we conduct a step length estimator that does not rely on SINS. The experimental results show that accuracy of the proposed method is between 0.6% and 1.4% with a standard deviation of 0.25%.
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