In this paper, a multiple light emitting diode (LED) chips parallel transmission (Multi-LED-PT) scheme for underwater visible light communication system with one photon-counting single photon ...avalanche diode (SPAD) receiver is proposed. As the lamp always consists of multi-LED chips, the data rate could be improved when we drive these multi-LED chips parallel by using the interleaver-division-multiplexing technique. For each chip, the on–off-keying modulation is used to reduce the influence of clipping. Then a serial successive interference cancellation detection algorithm based on ideal Poisson photon-counting channel by the SPAD is proposed. Finally, compared to the SPAD-based direct current-biased optical orthogonal frequency division multiplexing system, the proposed Multi-LED-PT system could improve the error-rate performance and anti-nonlinearity performance significantly under the effects of absorption, scattering and weak turbulence-induced channel fading together.
•A multi-LED chips parallel transmission scheme based on one SAPD receiver for the long distance UVLC system is proposed.•A serial successive interference cancellation algorithm based on Poisson channel by the SPAD is proposed.•The communication distances in the paper are 100 and 220 m for clear ocean and pure seawater respectively.•Our results of the proposed system correspond to the conclusions of the previous indoor photodiode-based system.
Accurately characterizing molecular interactions stands as a pivotal requirement for ensuring the reliability of molecular dynamics simulations. In line with our bond-dipole-based interaction model ...proposed by Gao et al. X.-C. Gao, Q. Hao and C.-S. Wang, J. Chem. Theory Comput. , 2017, 13 , 2730–2741., we have implemented an efficient and concise approach to compute electrostatic potential. This methodology capitalizes on the polarizable nature of chemical bond dipoles, resulting in a model of remarkable simplicity. In this study, we have revised the polarizable bond-dipole-based force field (PBFF) through the meticulous curation of quantum chemical data sets. These data sets encompass a comprehensive collection of 40 000 conformations, including those of water, methylamine, methanol, and N -methylacetamide. Additionally, we incorporate 520 hydrogen-bonded dimers into our data sets. In pursuit of enhanced accuracy in molecular dynamics simulations and a more faithful representation of potential energy landscapes, we undertook the re-optimization of the nonbonded parameters within the PBFF framework. Concurrently, we intricately fine-tuned the bonded parameters. The results of our comprehensive evaluation denote that this newly optimized force field method adeptly and efficiently computes structural characteristics, harmonic frequencies, and interaction energies. Overall, this study provides further validation for the applicability of PBFF in molecular dynamics simulations.
ABSTRACT
GRB 070707 was the first short gamma-ray burst (GRB) detected by INTEGRAL and the optical afterglow was attributed to the prolonged activity of the central engine in the literature. Here, we ...reanalyse the afterglow data and examine the physical origin of the emission. The redshift of this burst is uncertain and in this work we assume an association with a galaxy at the redshift of 0.2394 for a chance coincidence probability Pcc = 0.046. It is found that the sole forward shock radiation cannot well reproduce the data, while including a kilonova component similar to AT2017gfo is very helpful in reproducing the multiwavelength afterglow emission. The properties of the candidate host galaxy have been studied in detail; its high metallicity, low star formation rate, and old stellar population age are similar to the host galaxies of other GRBs associated with kilonovae. In view of the facts that a kilonova signal was identified in the first short GRB with detected optical emission (i.e. GRB 050709) and the first short GRB with gravitational wave detection (i.e. GRB 170817A), and now the identification of a kilonova signature in the first INTEGRAL short GRB strongly indicates that kilonovae are rather common among the neutron star merger events.
The purpose of this study was to determine the most important factor that determines young Chinese social network service (SNS) users' sustainable electronic word-of-mouth (e-WOM) behaviour in Korea. ...This study focuses on users' online flow experience to demonstrate sustainable e-WOM behaviour to develop a new customer base for Korean movie distributors and considers the acculturation effects in the flow theory model. We followed the flow theory approach for developing the measures of constructs and examined previous related studies to predict the relationships among the variables. Data were collected from 185 Chinese moviegoers attending Korean universities. Using SmartPLS 2.0 for statistical analysis, we found positive relationships between each pair of variables. Our research findings can offer insights to marketers who are interested in understanding the online behaviour of Chinese students in Korean universities and in establishing strategies to build relationships with them.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Abstract This work shows details of an evaluation of an observational system comprising a complementary metal-oxide-semiconductor detector, 60 cm telescope and filter complement. The system’s ...photometric precision and differential photometric precision, and extinction coefficients were assessed through observations of Supersky flat fields, open clusters, standard stars and exoplanets. Photometry was precision achieved at the 0.02 mag level, with differential photometry of 0.004 mag precision. Extinction was found to agree with previous studies conducted at Xinglong Observatory. Ultimately, the results demonstrate this observing system is capable of precision scientific observations with a charge-coupled device across the optical wavelengths.
Recently, visible light communication (VLC) has become a promising option for secure data transmission in industrial Internet of Things (IIoTs). In IIoT-VLC systems, small attocells are adopted to ...achieve higher spatial reuse rate, and the transmission of data, control and feedback bursts often requires high efficiency and real-time feature. Conventionally, multi-field (MF) frames are used in VLC systems which consists of sync header, channel training sequence, check field, etc. in addition to data payload. However, for short burst transmission, MF frames could result in efficiency loss and latency increase due to useless padding bits. In this paper, a novel coding scheme named integrated frame code (IFC) in physical layer to realize efficient and real-time transmission simultaneously is presented. IFC scheme reduces latency by simplifying transmission procedure and decreases overhead redundancy by integrated design. Specifically, we propose a joint soft-decision criterion for receiving without separate synchronization and channel estimation and then analyze its error performance. After that, we present IFC construction criterion and two design examples. At last, simulation results confirm that for short burst transmission, IFC achieves better efficiency and robustness than MF especially in moving process.
Advanced high-strength low alloy (HSLA) steels with outstanding corrosion resistance are extensively applied in marine engineering. However, corrosion sensitivity increases with steel strength. In ...this study, we developed a yield strength of 890 MPa ultra-high-strength offshore steel with superior corrosion resistance by regulating co-precipitation nanoparticles through co-alloying Al and Cu. Dispersed nanoparticles reduce lattice mismatch with the matrix and decrease pitting sensitivity, promoting the formation of a more homogeneous and dense passive film in the early corrosion stage. Al in EH890 steel is more prone to react with oxygen, resulting in the formation of Al
2
O
3
, which increases the protection of the passivation film. As a result, the corrosion potential of EH890 steel is higher, and its corrosion current density is five times lower than that of EH690 steel in 3.5 wt.% NaCl solution. As the corrosion progresses, Cu and Al can also encourage the formation of α-FeOOH in the rust layer, providing better protection to the substrate material. The EH890 steel has improved pitting resistance and electrochemical durability. This strategy may be informative for the development of advanced HSLA steels with superior corrosion resistance.
Abstract
Accurate identification of transcription factor binding sites is of great significance in understanding gene expression, biological development and drug design. Although a variety of methods ...based on deep-learning models and large-scale data have been developed to predict transcription factor binding sites in DNA sequences, there is room for further improvement in prediction performance. In addition, effective interpretation of deep-learning models is greatly desirable. Here we present MAResNet, a new deep-learning method, for predicting transcription factor binding sites on 690 ChIP-seq datasets. More specifically, MAResNet combines the bottom-up and top-down attention mechanisms and a state-of-the-art feed-forward network (ResNet), which is constructed by stacking attention modules that generate attention-aware features. In particular, the multi-scale attention mechanism is utilized at the first stage to extract rich and representative sequence features. We further discuss the attention-aware features learned from different attention modules in accordance with the changes as the layers go deeper. The features learned by MAResNet are also visualized through the TMAP tool to illustrate that the method can extract the unique characteristics of transcription factor binding sites. The performance of MAResNet is extensively tested on 690 test subsets with an average AUC of 0.927, which is higher than that of the current state-of-the-art methods. Overall, this study provides a new and useful framework for the prediction of transcription factor binding sites by combining the funnel attention modules with the residual network.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We synthesized a new tetraphenylethylene-modified chitosan bioconjugate,
, that shows the aggregation-induced emission effect. It can self-assemble into fluorescent polymeric nanoparticles in an ...aqueous solution at pH 5.3 either alone or with the water-soluble bowl-shaped six-fold carboxylated tribenzotriquinacene derivative
via host-guest binding. The spherical nanoparticles formed by
amphiphiles or
supra-amphiphiles disintegrated under alkaline stimulation at pH 10.4 and the dispersion of the aggregates after the collapse in the presence of
was greatly improved. In addition, the fluorescence of
was significantly enhanced by introducing
, and remained relatively stable with variations in pH for both
and
/
. Such pH-responsive supramolecular spherical nanoparticles with stable fluorescence emission based on
or
may find applications in various fields, including the development of visual oral drug delivery systems.
Hyaluronan is the main component of the cumulus-oocyte complex (COC) matrix, and it maintains the basic structure of the COC during ovulation. As a member of the transforming growth factor β (TGF-β) ...superfamily, bone morphogenetic protein 2 (BMP2) has been identified as a critical regulator of mammalian folliculogenesis and ovulation. However, whether BMP2 can regulate the production of hyaluronan in human granulosa cells has never been elucidated.
In the present study, we investigated the effect of BMP2 on the production of hyaluronan and the underlying molecular mechanism using both immortalized (SVOG) and primary human granulosa-lutein (hGL) cells. The expression of three hyaluronan synthases (including HAS1, HAS2 and HAS3) were examined following cell incubation with BMP2 at different concentrations. The concentrations of the hyaluronan cell culture medium were determined by enzyme-linked immunosorbent assay (ELISA). The TGF-β type I receptor inhibitors (dorsomorphin and DMH-1) and small interfering RNAs targeting ALK2, ALK3, ALK6 and SMAD4 were used to investigate the involvement of TGF-β type I receptor and SMAD-dependent pathway.
Our results showed that BMP2 treatment significantly increased the production of hyaluronan by upregulating the expression of hyaluronan synthase 2 (HAS2). In addition, BMP2 upregulates the expression of connective tissue growth factor (CTGF), which subsequently mediates the BMP2-induced increases in HAS2 expression and hyaluronan production because overexpression of CTGF enhances, whereas knockdown of CTGF reverses, these effects. Notably, using kinase inhibitor- and siRNA-mediated knockdown approaches, we demonstrated that the inductive effect of BMP2 on the upregulation of CTGF is mediated by the ALK2/ALK3-mediated SMAD-dependent signaling pathway.
Our findings provide new insight into the molecular mechanism by which BMP2 promotes the production of hyaluronan in human granulosa cells.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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