Image restoration is a critical procedure for underwater images, which suffer from serious color deviation and edge blurring. Restoration can be divided into two stages: de-scattering and edge ...enhancement. First, we introduce a multi-scale iterative framework for underwater image de-scattering, where a convolutional neural network is used to estimate the transmission map and is followed by an adaptive bilateral filter to refine the estimated results. Since there is no available dataset to train the network, a dataset which includes 2000 underwater images is collected to obtain the synthetic data. Second, a strategy based on white balance is proposed to remove color casts of underwater images. Finally, images are converted to a special transform domain for denoising and enhancing the edge using the non-subsampled contourlet transform. Experimental results show that the proposed method significantly outperforms state-of-the-art methods both qualitatively and quantitatively.
Lead-free (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 (BCTZ) piezoelectric ceramics were prepared by a conventional oxide-mixed method at various calcination and sintering temperatures. Both calcination and ...sintering temperatures had an effect on the density and grain size, which are closely related to piezoelectric and other properties of ceramics. The calcination temperature had a great influence on the grain boundary, which also played an important role in the piezoelectric properties. With increased calcination and sintering temperature, the ferroelectric and piezoelectric properties were enhanced. The BCTZ ceramics calcined at 1300 C and sintered at 1540 C exhibited optimal electrical properties: d33 = 650 pC/N, d31 = 74 pC/N, kp = 0.53, kt = 0.38, k31 = 0.309, S(E/11) = 14.0 x 10 exp(-12) m2/N, epsilonr = 4500, Pr = 11.69 microC/cm2, making it a promising lead-free piezoelectric.
The COVID-19 pandemic resulted in hundreds of thousands of deaths in the first six months of 2020. It also exposed and led to increases in the inequalities that exist worldwide. This paper draws ...attention to the prejudices and biases toward three vulnerable social groups-women, the elderly and Asian ethnic minorities during the crisis. It shows that while women 'held up more than half of the sky' both inside and outside the house, they struggled against rising domestic violence and various forms of sexism. The elderly, the most at risk of infection, are being 'abandoned,' 'abused' or 'obliged' to sacrifice themselves to the capitalist market economy. Ethnic minorities, especially Asian/Chinese immigrants in western countries have been subjected to racial stereotypes in their everyday life. Although the coronavirus will disappear, the 'shadow' of the pandemic will undoubtedly remain unless we rebuild solidarity and work together to reflect, reconcile and redress the inequalities entrenched in our societies.
In this paper, we investigate a generalized inhomogeneous fifth-order nonlinear Schrödinger equation, generated by deforming the inhomogeneous Heisenberg ferromagnetic spin system through the space ...curve formalism. Based on the Ablowitz-Kaup-Newell-Segur system, infinitely many conservation laws will be obtained. Via the introduction of the auxiliary functions, bilinear form and
N
-soliton solutions have been derived with symbolic computation. Propagation and interaction of solitons have been studied through the analytical results. Effects of the inhomogeneous functions
f
=
μ
1
x
+
ν
1
and
h
=
μ
2
x
+
ν
2
on the soliton velocity and interactions have been discussed graphically and analytically.
Pyruvate kinase M2 isoform （PKM2） catalyzes the last step of glycolysis and plays an important role in tumor cell proliferation. Recent studies have reported that PKM2 also regulates apoptosis. ...However, the mechanisms under- lying such a role of PKM2 remain elusive. Here we show that PKM2 translocates to mitochondria under oxidative stress. In the mitochondria, PKM2 interacts with and phosphorylates Bcl2 at threonine （T） 69. This phosphoryla- tion prevents the binding of Cul3-based E3 ligase to Bcl2 and subsequent degradation of Bcl2. A chaperone protein, HSP90al, is required for this function of PKM2. HSP90al＇s ATPase activity launches a conformational change of PKM2 and facilitates interaction between PKM2 and Bci2. Replacement of wild-type Bcl2 with phosphorylation-de- ficient Bcl2 T69A mutant sensitizes glioma cells to oxidative stress-induced apoptosis and impairs brain tumor for- mation in an orthotopic xenograft model. Notably, a peptide that is composed of the amino acid residues from 389 to 405 of PKM2, through which PKM2 binds to Bcl2, disrupts PKM2-BcI2 interaction, promotes Bcl2 degradation and impairs brain tumor growth. In addition, levels of Bcl2 T69 phosphorylation, conformation-altered PKM2 and Bcl2 protein correlate with one another in specimens of human glioblastoma patients. Moreover, levels of Bcl2 T69 phos- phorylation and conformation-altered PKM2 correlate with both grades and prognosis of glioma malignancy. Our findings uncover a novel mechanism through which mitochondrial PKM2 phosphorylates Bcl2 and inhibits apoptosis directly, highlight the essential role of PKM2 in ROS adaptation of cancer cells, and implicate HSP90-PKM2-Bcl2 axis as a potential target for therapeutic intervention in glioblastoma.
Grain refinement can strengthen the mechanical properties of materials according to the classical Hall-Petch relationship but does not always result in better corrosion resistance. During the past ...few decades, various techniques have been dedicated to refining grain, along with relevant studies on corrosion behavior, including general corrosion, pitting corrosion, and stress corrosion cracking. However, the fundamental consensus on how grain size influences corrosion behavior has not been reached. This paper reviews existing literature on the beneficial and detrimental effects of grain refinement on corrosion behavior. Moreover, the effects of microstructural changes (i.e., grain boundary, dislocation, texture, residual stress, impurities, and second phase) resulting from grain refinement on corrosion behavior are discussed. The grain refinement not only has an impact on the corrosion performance, but also results in microstructural changes that have a non-negligible effect on corrosion behavior or even outweigh that of grain refinement. Grain size is not the only factor affecting the corrosion behavior of metallic materials; thus, the overall influence of microstructures on corrosion behavior should be understood.
Calcium-ion batteries are promising candidate as alternative to lithium-ion batteries with appealing features of abundant resource and high theoretical specific capacity up to 1337 mAh g−1. However, ...the development of calcium-ion batteries is primarily hindered by the lack of satisfactory electrode materials due to the large radius and charge density of calcium ion. Herein, we report the reversible calcium ion intercalation in layered potassium vanadate K2V6O16·2.7H2O as stable cathode with impressive electrochemical performance for Ca ion battery. The potassium vanadate nanowires obtained by facile hydrothermal process (typical lengths of 0.5–1.5 μm, widths of 70–100 nm) deliver a high initial capacity of 113.9 mAh g−1 at current density of 20 mA g−1 and high capacity retention of 78.30% at 50 mA g−1 after 100 cycles. In addition, the reversible intercalation of calcium ion in this layered potassium vanadate material with stable crystal structure is verified by ex-situ XPS and XRD techniques, demonstrating that layered K2V6O16·2.7H2O could be a potential cathode material for calcium-ion batteries.
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•Layered potassium vanadate K2V6O16 is investigated as Ca-ions battery cathode.•High discharge capacity of 113.9 mAh g−1 with retention of 78.3% were achieved.•Reversible Ca2+ insertion/extraction and high structure stability were verified.
Recently, all-inorganic perovskite quantum dots (QDs) (CsPbX
3
, X = Cl, Br, I) as the emerging semiconductor materials have been intensively studied owing to superior optical properties. Currently, ...the strategy for preparation of inorganic perovskite QDs mainly focuses on the hot-injection method, but requires inert gas protection and is difficult to mass-produce. In this work, we developed a simple and low-cost strategy for preparing highly luminescent and air-stable all-inorganic perovskite QDs by directly heating perovskite precursors in octane in air. The emission wavelength of CsPbX
3
perovskite QDs can be tunable from ultraviolet (UV) to infrared region by simply controlling their halide composition and display high PLQYs. Moreover, CsPbX
3
perovskite QDs in octane can exist more than half a year in air and the film of CsPbX
3
perovskite QDs also shows good thermal stability and air stability, especially high iodide-substituted CsPbBr
3−
x
I
x
perovskite QDs. The CsPbX
3
perovskite QDs can be easily blended with PDMS and used as color conversion layer on the blue LEDs chip for high-quality white LEDs. Our work opens a window for the potential application of such highly luminescent material in the fields of multicolor LEDs, backlight display and other related optoelectronic devices.
Mesenchymal stem cell (MSC)-based therapies may aid in the repair of articular cartilage defects. The purpose of this study was to investigate the effects of intraarticular injection of allogeneic ...MSCs in an in vivo anterior cruciate ligament transection (ACLT) model of osteoarthritis in rabbits. Allogeneic bone marrow-derived MSCs were isolated and cultured under hypoxia (1% O2). After 8 weeks following ACLT, MSCs suspended in hyaluronic acid (HA) were injected into the knees, and the contralateral knees were injected with HA alone. Additional controls consisted of a sham operation group as well as an untreated osteoarthritis group. The tissues were analyzed by macroscopic examination as well as histologic and immunohistochemical methods at 6 and 12 weeks post-transplantation. At 6 and 12 weeks, the joint surface showed less cartilage loss and surface abrasion after MSC injection as compared to the tissues receiving HA injection alone. Significantly better histological scores and cartilage content were observed with the MSC transplantation. Furthermore, engraftment of allogenic MSCs were evident in surface cartilage. Thus, injection of the allogeneic MSCs reduced the progression of osteoarthritis in vivo.
Aqueous V2O5–Zn batteries, an alternative chemistry format that is inherently safer to operate than lithium‐based batteries, illuminates the low‐cost deployment of the stationary energy storage ...devices. However, the cathode structure collapse caused by H2O co‐insertion in aqueous solution dramatically deteriorates the electrochemical performance and hampers the operation reliability of V2O5–Zn batteries. The real‐time phase tracking and the density functional theory (DFT) calculation prove the high energy barrier that inhibits the Zn2+ diffusion into the bulk V2O5, instead the ZnCl2 “water‐in‐salt electrolyte” (WiSE) can enable the dominant proton insertion with negligible lattice strain or particle fragment. Thus, ZnCl2 WiSE enables the enhanced reversibility and extended shelf life of the V2O5–Zn battery upon the high temperature storage. The improved electrochemical performance also benefits by the inhibition of vanadium cation dissolution, enlarged voltage window, as well as the suppression of the Zn dendrite protrusion. This study comprehensively elucidates the pivotal role of a concentrated ZnCl2 electrolyte to stabilize the aqueous batteries at both the static storage and dynamic operation scenarios.
The application of ZnCl2 “water‐in‐salt” electrolyte in V2O5—Zn battery can effectively enhance the electrochemical performance no matter in dynamic or static conditions. This improvement is ascribed to the inhibition of cathode dissolution, extended voltage window, and the suppression of the Zn dendrite protrusion. Moreover, it is proved that proton inertion contributes most of the capacity, benefiting the particle integrity.
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