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Images taken on rainy days have rain streaks of varying degrees of intensity, which seriously affect the visibility of the background scene. Aiming at the above problems, we propose a rain mark removal algorithm based on the combination of dual-attention mechanism U-Net and multi-convolution. First, we add a double attention mechanism to the encoder of U-Net. It can give different weights to the rain mark features that need to be extracted in different channels and spaces so that sufficient rain mark features can be obtained. With different dilation factors, we can obtain rain mark characteristics of different depths. Secondly, the multi-convolutional channel integrates the characteristics of rain streaks and prepares sufficient rain mark information for the task of clearing rain streaks. By introducing a cyclic rain streaks detection and removal mechanism into the network architecture, it can achieve gradual removal of rain streaks. Even in the case of heavy rain, our algorithm can get good results. Finally, we tested on both synthetic and real datasets to obtain subjective results and objective evaluations. Experimental results show that for the rainy day image de-rain task with different intensities of rain streaks, our algorithm is more robust. Moreover, the ability of our algorithm to remove rain streaks is better than that of the other five different classical algorithms. The de-raining images produced by our algorithm are visually sharper, and its visibility enhancements are effective for computer vision applications (Google Vision API). [ABSTRACT FROM AUTHOR]

Valanimycin is an azoxy‐containing natural product isolated from the fermentation broth of Streptomyces viridifaciens MG456‐hF10. While the biosynthesis of valanimycin has been partially characterized, how the azoxy group is constructed remains obscure. Herein, the membrane protein VlmO and the putative hydrazine synthetase ForJ from the formycin biosynthetic pathway are demonstrated to catalyze N−N bond formation converting O‐(l‐seryl)‐isobutyl hydroxylamine into N‐(isobutylamino)‐l‐serine. Subsequent installation of the azoxy group is shown to be catalyzed by the non‐heme diiron enzyme VlmB in a reaction in which the N−N single bond in the VlmO/ForJ product is oxidized by four electrons to yield the azoxy group. The catalytic cycle of VlmB appears to begin with a resting μ‐oxo diferric complex in VlmB, as supported by Mössbauer spectroscopy. This study also identifies N‐(isobutylamino)‐d‐serine as an alternative substrate for VlmB leading to two azoxy regioisomers. The reactions catalyzed by the kinase VlmJ and the lyase VlmK during the final steps of valanimycin biosynthesis are established as well. The biosynthesis of valanimycin was thus fully reconstituted in vitro using the enzymes VlmO/ForJ, VlmB, VlmJ and VlmK. Importantly, the VlmB‐catalyzed reaction represents the first example of enzyme‐catalyzed azoxy formation and is expected to proceed by an atypical mechanism. [ABSTRACT FROM AUTHOR]

Valanimycin is an azoxy‐containing natural product isolated from the fermentation broth of Streptomyces viridifaciens MG456‐hF10. While the biosynthesis of valanimycin has been partially characterized, how the azoxy group is constructed remains obscure. Herein, the membrane protein VlmO and the putative hydrazine synthetase ForJ from the formycin biosynthetic pathway are demonstrated to catalyze N−N bond formation converting O‐(l‐seryl)‐isobutyl hydroxylamine into N‐(isobutylamino)‐l‐serine. Subsequent installation of the azoxy group is shown to be catalyzed by the non‐heme diiron enzyme VlmB in a reaction in which the N−N single bond in the VlmO/ForJ product is oxidized by four electrons to yield the azoxy group. The catalytic cycle of VlmB appears to begin with a resting μ‐oxo diferric complex in VlmB, as supported by Mössbauer spectroscopy. This study also identifies N‐(isobutylamino)‐d‐serine as an alternative substrate for VlmB leading to two azoxy regioisomers. The reactions catalyzed by the kinase VlmJ and the lyase VlmK during the final steps of valanimycin biosynthesis are established as well. The biosynthesis of valanimycin was thus fully reconstituted in vitro using the enzymes VlmO/ForJ, VlmB, VlmJ and VlmK. Importantly, the VlmB‐catalyzed reaction represents the first example of enzyme‐catalyzed azoxy formation and is expected to proceed by an atypical mechanism. [ABSTRACT FROM AUTHOR]

We show how one can test the cosmological Poisson equation by requiring only the validity of three main assumptions: the energy-momentum conservation equations of matter, the equivalence principle, and the cosmological principle. We first point out that one can only measure the combination M ≡ Ω m (0) μ , where μ quantifies the deviation of the Poisson equation from the standard one and Ω m (0) is the fraction of matter density at present. Then we employ a recent model-independent forecast for the growth rate f (z) and the expansion rate E (z) to obtain constraints on M for a survey that approximates a combination of the Dark Energy Spectroscopic Instrument (DESI) and Euclid. We conclude that a constant M can be measured with a relative error σ M = 4.5 % , while if M is arbitrarily varying in redshift, it can be measured only to within 13.4% (1 σ c.l.) at redshift z = 0.9 , and 15-22% up to z = 1.5. We also project our constraints on some parametrizations of M proposed in literature, while still maintaining model-independence for the background expansion, the power spectrum shape, and the non-linear corrections. Generally speaking, as expected, we find much weaker model-independent constraints than found so far for such models. This means that the cosmological Poisson equation remains quite open to various alternative gravity and dark energy models. [ABSTRACT FROM AUTHOR]

[Display omitted] • A flexible MOF film with a vertical structure. • A unique substrate of cellulose fiber–hydroxyapatite nanowire. • Separation of the mixed dyes and heavy metal ions from complex wastewater. • Enhanced removal rate of vertical MOF film compared to horizontal one. Flexible metal–organic framework (MOF) films are greatly desired for the separation of hazardous molecules and ions from wastewater. The current MOF films are usually horizontally deposited on the substrates, and thus restricted by brittleness, low exposure of surface area, as well as poor separation functions. Here, an organic–inorganic mixed substrate is firstly fabricated by growing hydroxyapatite (HA) nanowire arrays on the cellulose fiber (CF). Subsequently, MIL-100(Fe) nanocrystals are assembled on the surfaces of HA nanowire arrays through a layer-by-layer manner, leading to a unique vertical MOF film. The resulting vertical MOF films show competitive advantages over the horizontal counterparts: (i) they show excellent flexibility and they are tolerant to serious physical damage; (ii) they have multiple separation functions including ion exchange of HA, excellent adsorption of MOFs, and strong electrostatic interaction of CF; and (iii) the agglomeration of MIL-100(Fe) nanocrystals is effectively suppressed. Therefore, the average roughness, specific surface area, and average pore size of films are optimized. As a result, the vertical MOF films show universal separation of positively/negatively-charged dyes and Pb2+ ion, with high removal rates of > 94 %. More appealing, the mixed pollutants in the complex wastewater can be one-step separated through the vertical MOF films, with high removal rates of > 96 %. [ABSTRACT FROM AUTHOR]

A novel organic-inorganic zwitterionic polymer was developed via free radical copolymerization using quaternary ammonium salt as hydrophilic monomer. The unique structure realizes the perfect compromise between the hydrophobicity and hydrophilicity. The chemical composition, the physical properties, the anti-fog characteristic and mechanism of the zwitterionic acrylate coating were investigated by FT-IR, UV-VIS spectrometry, XPS, AFM and water contact angle. After anti-fogging test under ultralow temperature at −40 °C, the resultant zwitterionic acrylate polymer displays high transparency of 91 %, significantly better than that of the bare PC board 21 %. AFM images and water contact angle test demonstrate that the hydrophilic (the soft) region is continuously distributed on the surface of SMA-H coating with smaller water contact angle of 10°, indicates better hydrophilicity and wettability. The organic-inorganic zwitterionic polymer endows the coating on polycarbonate (PC) substrate with excellent anti-fog/frost performance, good adhesion and stability (repeated use for 100 times) under wider temperature range (−40 ∼ 80 °C) of applications. [ABSTRACT FROM AUTHOR]

Femtosecond-laser modified silicon materials have excellent optoelectronic properties and device application prospects, thus capturing pervasive interest from academia and industry. Nevertheless, efficiently achieving large-area uniform modification on silicon surfaces with Gaussian laser beams, especially fabricating evenly and extensively distributed microcone structures, remains a formidable obstacle. Our theoretical and experimental investigations demonstrate that the pulse-shaping technique effectively regulates the light–matter interaction, leading to improved surface uniformity through nonlinear and linear modulation. A large-area uniformly distributed microcones are prepared on the silicon surface through pure temporal modulation of the pulse. In addition, the method is easy to implement and has good compatibility. These findings carry significant implications for advancing the femtosecond-laser processing technology and promoting the industrial utilization of modified silicon materials, including photoelectric detection and solar cell fields. [ABSTRACT FROM AUTHOR]

A facile and effective transformation of α to β phase in electrospinning of PVDF was demonstrated by adding emeraldine base polyaniline (PANI). Results from FTIR and X-ray studies revealed that a very large amount of the electraoctive β-phase can be obtained by controlling the amount of PANI loading and the electrospinning parameters, whereas the γ-phase normally showed a very tiny amount, much lower than the β-phase, for all samples with PANI loading. The above results indicate that the addition of PANI into the PVDF solution during electrospinning is a powerful way to enhance the electroactive β-phase of the fibers, which is significant for developing high-performance fiber-based piezoelectric devices. [ABSTRACT FROM PUBLISHER]

In this study, multiple rare earth elements were introduced to modify the multiferroic properties of BiFeO 3. The effects of co-substitution on the structural evolution and properties were thoroughly investigated. With increasing substitution content, the ceramics underwent a symmetry transition from R 3 c to Pna 2 1 and finally to Pbnm. Co-substitution significantly enhanced the ferroelectric properties, with the highest remanent polarization of 33.14 μC/cm² observed at x = 0.10. Due to the symmetry evolution, ferromagnetism was released from the cycloidal spin structure, and the hysteresis loop gradually saturated, with the highest remanent magnetization (M r) of 0.25 emu/g observed at x = 0.16. The concurrent improvement in ferroelectricity and ferromagnetism resulted in substantial magnetoelectric coupling performance, with α ME = 3.50 mV/(cm·Oe). Moreover, direct current poling significantly induced the reverse transition from R 3 c to Pna 2 1 , indicating the potential for electrically controlled magnetism. This study provides a new perspective for modifying the magnetoelectric properties of BiFeO 3. [ABSTRACT FROM AUTHOR]

Subtalar osteoarthritis (STOA) is often secondary to chronic ankle sprains, which seriously affects the quality of life of patients. Due to its etiology and pathogenesis was not studied equivocally yet, there is currently a lack of effective conservative treatments. Although they have been used for tissue repair, platelet-rich plasma-derived exosomes (PRP-Exo) have the disadvantage of low retention and short-lived therapeutic effects. This study aimed to determine whether incorporation of PRP-Exo in thermosensitive hydrogel (Gel) increased their retention in the joint and thereby playing a therapeutic role on STOA due to chronic mechanical instability established by transecting lateral ligaments (anterior talofibular ligament (ATFL)/calcaneal fibular ligament (CFL)). PRP-Exo incorporated Gel (Exo-Gel) system, composed of Poloxamer-407 and 188 mixture-based thermoresponsive hydrogel matrix in an optimal ratio, was determined by its release ability of Exo and rheology of Gel response to different temperature. The biological activity of Exo-Gel was evaluated in vitro, and the therapeutic effect of Exo-Gel on STOA was evaluated in vivo. Exo released from Exo-Gel continuously for 28 days could promote the proliferation and migration of mouse bone mesenchymal stem cells (mBMSCs) and chondrocytes, at the same time enhance the chondrogenic differentiation of mBMSCs, and inhibit inflammation-induced chondrocyte degeneration. In vivo experiments confirmed that Exo-Gel increased the local retention of Exo, inhibited the apoptosis and hypertrophy of chondrocytes, enhanced their proliferation, and potentially played the role in stem cell recruitment to delay the development of STOA. Thus, Delivery of PRP-Exo incorporated in thermosensitive Gel provides a novel approach of cell-free therapy and has therapeutic effect on STOA. [ABSTRACT FROM AUTHOR]

As a persistent and widespread toxic organic pollutant in the environment, perfluorooctane sulfonate (PFOS) has the potential to cause great harm to wildlife. In our study, the effects of PFOS on neurodevelopment gene expression, neurotransmitter content, neuronal morphology, acetylcholinesterase (AChE) activity were examined, and the potential neurotoxicity mechanisms of PFOS were also investigated in planarians, Dugesia japonica . Using quantitative real-time PCR analysis, five neurodevelopmental related genes were measured, among which, DjotxA , DjotxB , DjFoxD , and DjFoxG were found to be down-regulated, while Djnlg was found to be up-regulated, following exposure to PFOS for 10 days compared with control groups. In addition, the neurotransmitters including dopamine, serotonin, and γ-aminobutyricacid as well as the acitivity of AChE were altered by PFOS exposure. Furthermore, PFOS exposure altered brain morphology as well as smaller cephalic ganglia which displayed reduced nerve fiber density decreased brain branches compared to controls. Our results demonstrate that neurotransmission was disturbed after exposure to PFOS and that exposure to this pollutant can cause neurotoxic defects. Results from this study provide valuable information regarding the neuro- and ecological toxicity of PFOS in aquatic animals and aquatic environments. [ABSTRACT FROM AUTHOR]

Abstract: Aim: The aim of this study was to explore the mechanism underlying the protective effects of 2,3,5,4‐tetrahydroxystilbene‐2‐o‐β‐D‐glucoside (TSG) against osteoporosis. Method: MC3T3‐E1 mouse osteoblast precursor cells were used to analyze the protective effects of TSG on osteoblast apoptosis and differential inhibition induced by oxidative stress to determine the gene expression of forkhead transcription factor FKHRL1 (FoxO3a), T cell factors (TCFs), and downstream genes. A mouse model was used to assess the protective effects of TSG on ovariectomy‐induced osteoporosis as well as on Cell Counting Kit‐8 (CCK) gene expression, including that of FoxO3a. The mechanism underlying the protective effects of TSG against osteoporosis was further explored using high‐throughput sequencing data. Results: A CCK‐8 assay in MC3T3‐E1 cells and hematoxylin and eosin staining in mouse tissue indicated that cell viability and bone tissue development were inhibited by oxidative stress and ovariectomy and that TSG neutralized or attenuated this effect. The expression levels of FoxO3a, TCF, and downstream genes and the indices of oxidative stress were the same in MC3T3‐E1 cells and the bone tissues of the mouse model. Bioinformatics analysis indicated that the cardiac muscle contraction and chemokine signaling pathway were disturbed in MC3T3‐E1 cells treated with hydrogen peroxide. Gene ontology‐biological process analysis revealed the influence of TSG treatment. Conclusion: Osteoporosis and cardiac diseases appear to share a common mechanism. In addition to Wnt/FoxO3a signaling, the immune system and the chemokine signaling pathway may contribute to the protective mechanism of TSG. [ABSTRACT FROM AUTHOR]

A novel algorithm for enhancing the details of the blurred infrared images based on frequency extrapolation has been raised in this paper. Unlike other researchers’ work, this algorithm mainly focuses on how to predict the higher frequency information based on the Laplacian pyramid separation of the blurred image. This algorithm uses the first level of the high frequency component of the pyramid of the blurred image to reverse-generate a higher, non-existing frequency component, and adds back to the histogram equalized input blurred image. A simple nonlinear operator is used to analyze the extracted first level high frequency component of the pyramid. Two critical parameters are participated in the calculation known as the clipping parameter C and the scaling parameter S . The detailed analysis of how these two parameters work during the procedure is figure demonstrated in this paper. The blurred image will become clear, and the detail will be enhanced due to the added higher frequency information. This algorithm has the advantages of computational simplicity and great performance, and it can definitely be deployed in the real-time industrial applications. We have done lots of experiments and gave illustrations of the algorithm’s performance in this paper to convince its effectiveness. [ABSTRACT FROM AUTHOR]

• The paper confirm that the reaction process of methanol on Pt surface is related to the scan rate. • The sustained increase in rotation rate decreases the oxidation current regardless of the scan rate. • The transfer transition zone at different scan rates is determined by means of the mathematical fitting. The oxidation mechanism of methanol on a smooth polycrystalline Pt electrode surface is discussed in detail by using a rotating disk electrode (RDE) technique. The results indicate that the reaction process of methanol is closely related to the scan rate and mass transport effect. The results demonstrate that the methanol oxidation mechanism on Pt electrode surface is different due to the changes in the scan rate. The transfer transition zone at different sweep speeds is finally determined by means of the mathematical fitting. [ABSTRACT FROM AUTHOR]