The streaming instability is a fundamental process that can drive dust–gas dynamics and ultimately planetesimal formation inprotoplanetary discs. As a linear instability, it has been shown that its ...growth with a distribution of dust sizes can be classifiedinto two distinct regimes, fast- and slow-growth, depending on the dust-size distribution and the total dust-to-gas density ratio . Using numerical simulations of an unstratified disc, we bring three cases in different regimes into non-linear saturation. Wefind that the saturation states of the two fast-growth cases are similar to its single-species counterparts. The one with maximumdimensionless stopping timeτs,max=0.1 and =2 drives turbulent vertical dust–gas vortices, while the other withτs,max=2and =0.2 leads to radial traffic jams and filamentary structures of dust particles. The dust density distribution for the former isflat in low densities, while the one for the latter has a low-end cut-off. By contrast, the one slow-growth case results in a virtuallyquiescent state. Moreover, we find that in the fast-growth regime, significant dust segregation by size occurs, with large particlesmoving towards dense regions while small particles remain in the diffuse regions, and the mean radial drift of each dust speciesis appreciably altered from the (initial) drag-force equilibrium. The former effect may skew the spectral index derived frommultiwavelength observations and change the initial size distribution of a pebble cloud for planetesimal formation. The latteralong with turbulent diffusion may influence the radial transport and mixing of solid materials in young protoplanetary discs.
Direct detection of circularly polarized light (CPL) is a challenging task due to limited materials and ambiguous structure–property relationships that lead to low distinguishability of the light ...helicities. Perovskite ferroelectric semiconductors incorporating chirality provide new opportunities in dealing with this issue. Herein, a pair of 2D chiral perovskite ferroelectrics is reported, which have enhanced CPL detection performance due to interplays among lattice, photon, charge, spin, and orbit. The chirality‐transfer‐induced chiral&polar ferroelectric phase enhances the asymmetric nature of the photoactive sublattice and achieves a switchable self‐powered detection via the bulk photovoltaic effect. The single‐crystal‐based device exhibits a CPL‐sensitive detection performance under 430 nm with an asymmetric factor of 0.20 for left‐ and right‐CPL differentiation, about two times that of the pure chiral counterparts. The enhanced CPL detection performance is ascribed to the Rashba–Dresselhaus effect that originates from the bulk inversion asymmetry and strong spin–orbit coupling, shown with a large Rashba coefficient, which is demonstrated by density functional theory calculation and circularly polarized light excited photoluminescence measurement. These results provide new perspectives on chiral Rashba ferroelectric semiconductors for direct CPL detection and ferroelectrics‐based chiroptics and spintronics.
A pair of 2D chiral perovskite Rashba ferroelectric semiconductors is reported. The fabricated single‐crystal device responds to circularly polarized light (CPL) under 430 nm with an anisotropy factor of 0.20 for the left‐ and right‐CPL differentiation, about two times of reported pure chiral counterparts. The enhanced performance is ascribed to the Rashba–Dresselhaus effect with a large Rashba coefficient of 0.93 eV Å.
The engineering of a series of multienzyme‐mimicking covalent organic frameworks (COFs), COF‐909‐Cu, COF‐909‐Fe, and COF‐909‐Ni, as pyroptosis inducers, remodeling the tumor microenvironment to boost ...cancer immunotherapy, is reported. Mechanistic studies reveal that these COFs can serve as hydrogen peroxide (H2O2) homeostasis disruptors to elevate intracellular H2O2 levels, and they not only exhibit excellent superoxide dismutase (SOD)‐mimicking activity and convert superoxide radicals (O2•−) to H2O2 to facilitate H2O2 generation, but also possess outstanding glutathione peroxidase (GPx)‐mimicking activity and deplete glutathione (GSH) to alleviate the scavenging of H2O2. Meanwhile, the outstanding photothermal therapy properties of these COFs can accelerate the Fenton‐like ionization process to facilitate their chemodynamic therapy efficiency. One member, COF‐909‐Cu, can robustly induce gasdermin E (GSDME)‐dependent pyroptosis and remodel the tumor microenvironment to trigger durable antitumor immunity, thus promoting the response rate of αPD‐1 checkpoint blockade and successfully restraining tumor metastasis and recurrence.
A series of multienzyme‐mimicking covalent organic frameworks (COFs) is constructed by dispersing active sites into the COF backbone. In contrast to their corresponding bulk species, these enzyme‐mimicking COFs can serve as H2O2 homeostasis disruptors to elevate intracellular H2O2 levels, thus exhibiting excellent chemodynamic therapy and pyroptosis efficacy, favorable for boosting cancer immunotherapy.
Two-dimensional phosphorene with desirable optoelectronic properties (ideal band gap, high carrier mobility, and strong visible light absorption) is a promising metal-free photocatalyst for water ...splitting. However, the band edge positions of the valence band maximum (VBM) and conduction band maximum (CBM) of phosphorene are higher than the redox potentials in photocatalytic water splitting reactions. Thus, phosphorene can only be used as the photocathode for hydrogen evolution reaction as a low-efficiency visible-light-driven photocatalyst for hydrogen production in solar water splitting cells. Here, we propose a new mechanism to improve the photocatalytic efficiency of phosphorene nanoribbons (PNRs) by modifying their edges for full reactions in photocatalytic water splitting. By employing first-principles density functional theory calculations, we find that pseudohalogen (CN and OCN) passivated PNRs not only show desired VBM and CBM band edge positions induced by edge electric dipole layer, but also possess intrinsic optoelectronic properties of phosphorene, for both water oxidation and hydrogen reduction in photocatalytic water splitting without using extra energy. Furthermore, our calculations also predict that the maximum energy conversion efficiency of heterojunction solar cells consisting of different edge-modified PNRs can be as high as 20% for photocatalytic water splitting.
Long non‐coding RNA (lncRNA) lnc‐ISG20 has been found aberrantly up‐regulated in the glomerular in the patients with diabetic nephropathy (DN). We aimed to elucidate the function and regulatory ...mechanism of lncRNA lnc‐ISG20 on DN‐induced renal fibrosis. Expression patterns of lnc‐ISG20 in kidney tissues of DN patients were determined by RT‐qPCR. Mouse models of DN were constructed, while MCs were cultured under normal glucose (NG)/high glucose (HG) conditions. The expression patterns of fibrosis marker proteins collagen IV, fibronectin and TGF‐β1 were measured with Western blot assay. In addition, the relationship among lnc‐ISG20, miR‐486‐5p, NFAT5 and AKT were analysed using dual‐luciferase reporter assay and RNA immunoprecipitation. The effect of lnc‐ISG20 and miR‐486/NFAT5/p‐AKT axis on DN‐associated renal fibrosis was also verified by means of rescue experiments. The expression levels of lnc‐ISG20 were increased in DN patients, DN mouse kidney tissues and HG‐treated MCs. Lnc‐ISG20 silencing alleviated HG‐induced fibrosis in MCs and delayed renal fibrosis in DN mice. Mechanistically, miR‐486‐5p was found to be a downstream miRNA of lnc‐ISG20, while miR‐486‐5p inhibited the expression of NFAT5 by binding to its 3'UTR. NFAT5 overexpression aggravated HG‐induced fibrosis by stimulating AKT phosphorylation. However, NFAT5 silencing reversed the promotion of in vitro and in vivo fibrosis caused by lnc‐ISG20 overexpression. Our collective findings indicate that lnc‐ISG20 promotes the renal fibrosis process in DN by activating AKT through the miR‐486‐5p/NFAT5 axis. High‐expression levels of lnc‐ISG20 may be a useful indicator for DN.
We report herein the discovery of highly potent PROTAC degraders of androgen receptor (AR), as exemplified by compound 34 (ARD-69). ARD-69 induces degradation of AR protein in AR-positive prostate ...cancer cell lines in a dose- and time-dependent manner. ARD-69 achieves DC50 values of 0.86, 0.76, and 10.4 nM in LNCaP, VCaP, and 22Rv1 AR+ prostate cancer cell lines, respectively. ARD-69 is capable of reducing the AR protein level by >95% in these prostate cancer cell lines and effectively suppressing AR-regulated gene expression. ARD-69 potently inhibits cell growth in these AR-positive prostate cancer cell lines and is >100 times more potent than AR antagonists. A single dose of ARD-69 effectively reduces the level of AR protein in xenograft tumor tissue in mice. Further optimization of ARD-69 may ultimately lead to a new therapy for AR+, castration-resistant prostate cancer.
In recent years, carbon quantum dots (CQDs) has received a lot of attentions owing to their great physical and optical properties. There are different kinds of carbon sources applied in various ...fields, however, CQDs used in the food industry have higher requirements for their safety. Therefore, it is the best way to use natural materials for preparing CQDs without the participation of chemicals. Up to now, there are many natural food products for preparing CQDs. However, food waste is often overlooked. Actually, food waste is rich in carbon sources. And the efficient utilization of food waste plays a positive role in economic benefit and environmental pollution.
Proper use of food waste as carbon source not only facilitates food safety detection but also increases byproduct value. This paper was intended to review the research progress of food waste utilization as carbon precursor and applications in food safety detection. The approaches of preparing CQDs from different sorts of food wastes, the characteristics and applications of CQDs were described in detail. Particularly the applications in food quality and safety detection including food additives, heavy metal ions were also elaborated.
Currently, food waste as carbon source could be divided into plant byproducts, animal food byproducts and food processing byproducts. Moreover, there are many applications of food waste as carbon precursor in CQDs technology to detect food additives and heavy metal ions. However, detection of pathogens and other harmful substances in food industry is rare. Last but not least, it was concluded that food waste had potential to prepare CQDs and be applied to food safety detection.
•The knowledges of carbon quantum dot technology are described.•Food waste as source in carbon quantum dot technology are reviewed.•The applications of carbon quantum dot in food industry are reviewed.•The green synthesis methods of carbon quantum dot are outlined.
Currently most of food printers apply one printhead to extrude a single or a mixture of multiple materials. Such a printhead cannot control the materials distribution in a drop-on-demand way, while a ...multi-extruder printer enables the fabrication of highly attractive multi-material constructs with higher geometric complexity. In this study, the effects of extruder offset and retraction on the printing behavior were firstly optimized, followed by the preliminary tests of two methods of dual extrusion 3D printing. Method A is to create a multi-part model and assign each of them to one extruder. Method B is to create a single part model and assign different roles to each extruder. Some constructs with different inside shape were created using Method A. Product hardness and gumminess increased linearly with mashed potatoes (MP) percentage but showed no correlation with inside shape. Porous samples with special texture were printed using Method B by varying infill levels. Total printing time, firmness, hardness and gumminess increased with infill levels, and a clear discrimination was observed by principle component analysis (PCA). This suggested that dual extrusion 3D printing enables the fabrication of attractive multi-material constructs and has a potential to tailor textural properties of samples through varying infill percentage.
•A multi-extruder printer was used to print mashed potatoes/strawberry juice gel.•Extruder offset and retraction value of dual extrusion printing were optimized.•Texture modified edible parts were created by varying internal infill level.
The streaming instability is a mechanism to concentrate solid particles into overdense filaments that undergo gravitational collapse and form planetesimals. However, it remains unclear how the ...initial mass function of these planetesimals depends on the box dimensions of numerical simulations. To resolve this, we perform simulations of planetesimal formation with the largest box dimensions to date, allowing planetesimals to form simultaneously in multiple filaments that can only emerge within such large simulation boxes. In our simulations, planetesimals with sizes between 80 km and several hundred kilometers form. We find that a power law with a rather shallow exponential cutoff at the high-mass end represents the cumulative birth mass function better than an integrated power law. The steepness of the exponential cutoff is largely independent of box dimensions and resolution, while the exponent of the power law is not constrained at the resolutions we employ. Moreover, we find that the characteristic mass scale of the exponential cutoff correlates with the mass budget in each filament. Together with previous studies of high-resolution simulations with small box domains, our results therefore imply that the cumulative birth mass function of planetesimals is consistent with an exponentially tapered power law with a power-law exponent of approximately −1.6 and a steepness of the exponential cutoff in the range of 0.3–0.4.
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