Input variable selection plays a key role in data-driven streamflow forecasting models. In this study, we propose a two-stage wrapper model to drive one-month-ahead streamflow forecasting in the ...context of high-dimensional candidate input variables. Initially, the Boruta algorithm, a feature selection method, was applied to select all the relevant input variables for the streamflow series. Then, a novel binary grey wolf optimizer (BGWO)-regularized extreme learning machine (RELM) wrapper was derived. We carried out experiments on two US catchments with 132 candidate input variables, including local meteorological information, global climatic indices, and lags of the streamflow series. Furthermore, the sensitivities of the proposed model in terms of the optimal objective function were compared. The results indicate two important findings. First, the proposed model outperformed commonly used models in terms of four error evaluation criteria. Second, for the proposed model, the root mean square error is a more suitable criterion than the Akaike information criterion (AIC) and the Bayesian information criterion (BIC) for the optimal objective function. These findings are of great reference value for developing ELM models for streamflow forecasting.
Monodispersed microspheres play a major role in optical science and engineering, providing ideal building blocks for structural color materials. However, the method toward high solid content (HSC) ...monodispersed microspheres has remained a key hurdle. Herein, a facile access to harvest monodispersed microspheres based on the emulsion polymerization mechanism is demonstrated, where anionic and nonionic surfactants are employed to achieve the electrostatic and steric dual‐stabilization balance in a synergistic manner. Monodispersed poly(styrene‐butyl acrylate‐methacrylic acid) colloidal latex with 55 wt% HSC is achieved, which shows an enhanced self‐assembly efficiency of 280% compared with the low solid content (10 wt%) latex. In addition, Ag‐coated colloidal photonic crystal (Ag@CPC) coating with near‐zero refractive index is achieved, presenting the characteristics of metamaterials. And an 11‐fold photoluminescence emission enhancement of CdSe@ZnS quantum dots is realized by the Ag@CPC metamaterial coating. Taking advantage of high assembly efficiency, easily large‐scale film‐forming of the 55 wt% HSC microspheres latex, robust Ag@CPC metamaterial coatings could be easily produced for passive cooling. The coating demonstrates excellent thermal insulation performance with theoretical cooling power of 30.4 W m−2, providing practical significance for scalable CPC architecture coatings in passive cooling.
A dual‐surfactants‐mediated emulsion polymerization mechanism is proposed, where anionic and nonionic surfactants are employed due to their synergistic effect to guarantee the electrostatic and steric dual‐stabilization balance. Thus, 55 wt% high solid content poly(styrene‐butyl acrylate‐methacrylic acid) monodispersed colloidal latex is achieved, which can be used to construct metamaterials toward photoluminescence enhancement and passive cooling coatings.
Inducing cancer differentiation is a promising approach to treat cancer. Here, we identified chlorogenic acid (CA), a potential differentiation inducer, for cancer therapy, and elucidated the ...molecular mechanisms underlying its differentiation-inducing effects on cancer cells.
Cancer cell differentiation was investigated by measuring malignant behavior, including growth rate, invasion/migration, morphological change, maturation, and ATP production. Gene expression was analyzed by microarray analysis, qRT-PCR, and protein measurement, and molecular biology techniques were employed for mechanistic studies. LC/MS analysis was the method of choice for chemical detection. Finally, the anticancer effect of CA was evaluated both
and
Results: Cancer cells treated with CA showed reduced proliferation rate, migration/invasion ability, and mitochondrial ATP production. Treating cancer cells with CA resulted in elevated SUMO1 expression through acting on its 3'UTR and stabilizing the mRNA. The increased SUMO1 caused c-Myc sumoylation, miR-17 family downregulation, and p21 upregulation leading to G
/G
arrest and maturation phenotype. CA altered the expression of differentiation-related genes in cancer cells but not in normal cells. It inhibited hepatoma and lung cancer growth in tumor-bearing mice and prevented new tumor development in naïve mice. In glioma cells, CA increased expression of specific differentiation biomarkers Tuj1 and GFAP inducing differentiation and reducing sphere formation. The therapeutic efficacy of CA in glioma cells was comparable to that of temozolomide. CA was detectable both in the blood and brain when administered intraperitoneally in animals. Most importantly, CA was safe even at very high doses.
CA might be a safe and effective differentiation-inducer for cancer therapy. "Educating" cancer cells to differentiate, rather than killing them, could be a novel therapeutic strategy for cancer.
BiCuSeO oxyselenides are promising thermoelectric materials, yet further thermoelectric figure of merit ZT improvement is largely limited by the inferior electrical transport properties. The ...established literature on these materials shows only one power factor maximum upon carrier concentration optimization, which is typical for most thermoelectric semiconductors. Surprisingly, we found three power factor maxima when doping Bi with Pb. Based on our first-principles calculations, numerical modeling, and experimental investigation, we attribute the three maxima to the Fermi energy optimization, band convergence, and compositing effect due to in situ formed PbSe precipitates. Consequently, three ZT peaks of 0.9, 1.1, and 1.3 at 873 K are achieved for 4, 10, and 14 at.% Pb-doped samples, respectively, revealing the significance of complex electronic structure and multiple roles of Pb in BiCuSeO. The results establish an accurate band structure characterization for BiCuSeO and identify the role of band convergence and nanoprecipitation as the driving mechanism for high ZT.
Kcnq1 overlapping transcript 1 (kcnq1ot1), an imprinted antisense lncRNA in the kcnq1 locus, acts as a potential contributor to cardiovascular disease, but its role in atherosclerosis remains ...unknown. The aim of this study was to explore the effects of kcnq1ot1 on atherogenesis and the underlying mechanism. Our results showed that kcnq1ot1 expression was significantly increased in mouse aorta with atherosclerosis and lipid-loaded macrophages. Lentivirus-mediated kcnq1ot1 overexpression markedly increased atherosclerotic plaque area and decreased plasma HDL-C levels and RCT efficiency in apoE
mice fed a Western diet. Upregulation of kcnq1ot1 also reduced the expression of miR-452-3p and ABCA1 but increased HDAC3 levels in mouse aorta and THP-1 macrophages. Accordingly, kcnq1ot1 overexpression inhibited cholesterol efflux and promoted lipid accumulation in THP-1 macrophages. In contrast, kcnq1ot1 knockdown protected against atherosclerosis in apoE
mice and suppressed lipid accumulation in THP-1 macrophages. Mechanistically, kcnq1ot1 enhanced HDAC3 expression by competitively binding to miR-452-3p, thereby inhibiting ABCA1 expression and subsequent cholesterol efflux. Taken together, these findings suggest that kcnq1ot1 promotes macrophage lipid accumulation and accelerates the development of atherosclerosis through the miR-452-3p/HDAC3/ABCA1 pathway.
Modulating the transport route of photogenerated carriers on hollow cadmium sulfide without changing its intrinsic structure remains fascinating and challenging. In this work, a series of ...well-defined heterogeneous hollow structural materials consisting of CdS hollow nanocubes (CdS NCs) and graphitic C3N4 nanoparticles (CN NPs) were strategically designed and fabricated according to an electrostatic interaction approach. It was found that such CN NPs/CdS NCs still retained the hollow structure after CN NP adorning and demonstrated versatile and remarkably boosted photoreduction performance. Specifically, under visible light irradiation (λ ≥ 420 nm), the hydrogenation ratio over 2CN NPs/CdS NCs (the mass ratio of CN NPs to CdS NCs is controlled to be 2%) toward nitrobenzene, p-nitroaniline, p-nitrotoluene, p-nitrophenol, and p-nitrochlorobenzene can be increased to 100%, 99.9%, 83.2%, 93.6%, and 98.2%, respectively. In addition, based on the results of photoelectrochemical performances, the 2CN NPs/CdS NCs reach a 0.46% applied bias photo-to-current efficiency, indicating that the combination with CN NPs can indeed improve the migration and motion behavior of photogenerated carriers, besides ameliorating the photocorrosion and prolonging the lifetime of CdS NCs.
Abstract
We report the generation of frequency-uncorrelated photon pairs from counter-propagating spontaneous parametric down-conversion in a periodically-poled KTP waveguide. The joint spectral ...intensity of photon pairs is characterized by measuring the corresponding stimulated process, namely, the difference frequency generation process. The experimental result shows a clear uncorrelated joint spectrum, where the backward-propagating photon has a narrow bandwidth of 7.46 GHz and the forward-propagating one has a bandwidth of 0.23 THz like the pump light. The heralded single-photon purity estimated through Schmidt decomposition is as high as 0.996, showing a perspective for ultra-purity and narrow-band single-photon generation. Such unique feature results from the backward-wave quasi-phase-matching condition and does not has a strict limitation on the material and working wavelength, thus fascinating its application in photonic quantum technologies.
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