Investigating the angular distortion impact on vehicular optical camera communication (OCC) systems.

Optical camera communication (OCC) shows promise for optical wireless communication (OWC) in vehicular networks. However, vehicle mobility-induced angular distortions hinder system throughput by degrading non-isotropic vehicular OCC channel gain. Few of the prior works have ever made a comprehensive analysis of their impact, especially based on the pixel value which reflects the camera imaging features. To address this knowledge gap, a pixel value-described vehicular OCC system model accounting for transmitter imaging location and intensity from the geometry and radiometry aspects is presented in this paper with common types of the offset and rotation angles included. We integrate a MATLAB-based simulated vehicular OCC system with an experimentally designed testbed for validation and performance analysis. For a single-time snapshot, we investigate the impacts of common angular distortion types in vehicular OCC systems on maximum pixel value, imaging location, and communication-related metrics. Furthermore, we statistically analyze their influences by considering two driving scenarios with respective angular distributions. The angular distortion characterization from this work is expected to lay a stepping stone to addressing mobility in vehicular OCC systems.

Reactive Oxygen Species-Responsive Composite Fibers Regulate Oxidative Metabolism through Internal and External Factors to Promote the Recovery of Nerve Function.

It is challenging to sufficiently regulate endogenous neuronal reactive oxygen species (ROS) production, reduce neuronal apoptosis, and reconstruct neural networks under spinal cord injury conditions. Here, hydrogel surface grafting and microsol electrospinning are used to construct a composite biomimetic scaffold with "external-endogenous" dual regulation of ROS. The outer hydrogel enhances local autophagy through responsive degradation and rapid release of rapamycin (≈80% within a week), neutralizing extracellular ROS and inhibiting endogenous ROS production, further reducing neuronal apoptosis. The inner directional fibers continuously supply brain-derived neurotrophic factors to guide axonal growth. The results of in vitro co-culturing show that the dual regulation of oxidative metabolism by the composite scaffold approximately doubles the neuronal autophagy level, reduces 60% of the apoptosis induced by oxidative stress, and increases the differentiation of neural stem cells into neuron-like cells by ≈2.5 times. The in vivo results show that the composite fibers reduce the ROS levels by ≈80% and decrease the formation of scar tissue. RNA sequencing results show that composite scaffolds upregulate autophagy-associated proteins, antioxidase genes, and axonal growth proteins. The developed composite biomimetic scaffold represents a therapeutic strategy to achieve neurofunctional recovery through programmed and accurate bidirectional regulation of the ROS cascade response.

2D Air-Stable Nonlayered Ferrimagnetic FeCr2S4 Crystals Synthesized via Chemical Vapor Deposition.

The discovery of intrinsic 2D magnetic materials has opened up new opportunities for exploring magnetic properties at atomic layer thicknesses, presenting potential applications in spintronic devices. Here a new 2D ferrimagnetic crystal of nonlayered FeCr2S4 is synthesized with high phase purity using chemical vapor deposition. The obtained 2D FeCr2S4 exhibits perpendicular magnetic anisotropy, as evidenced by the out-of-plane/in-plane Hall effect and anisotropic magnetoresistance. Theoretical calculations further elucidate that the observed magnetic anisotropy can be attributed to its surface termination structure. By combining temperature-dependent magneto-transport and polarized Raman spectroscopy characterizations, it is discovered that both the measured Curie temperature and the critical temperature at which a low energy magnon peak disappeared remains constant, regardless of its thickness. Magnetic force microscopy measurements show the flipping process of magnetic domains. The exceptional air-stability of the 2D FeCr2S4 is also confirmed via Raman spectroscopy and Hall hysteresis loops. The robust anisotropic ferrimagnetism, the thickness-independent of Curie temperature, coupled with excellent air-stability, make 2D FeCr2S4 crystals highly attractive for future spintronic devices.

Charge-Transfer-Induced Interfacial Ferromagnetism in Ferromagnet-Free Oxide Heterostructures.

Due to the strong interlayer coupling between multiple degrees of freedom, oxide heterostructures have demonstrated exotic properties that are not shown by their bulk counterparts. One of the most interesting properties is ferromagnetism at the interface formed between "nonferromagnetic" compounds. Here we report on the interfacial ferromagnetic phase induced in the superlattices consisting of the two paramagnetic oxides CaRuO3 (CRO) and LaNiO3 (LNO). By varying the sublayer thickness in the superlattice period, we demonstrate that the ferromagnetic order has been established in both CaRuO3 and LaNiO3 sublayers, exhibiting an identical Curie temperature of ∼75 K. The X-ray absorption spectra suggest a strong charge transfer from Ru to Ni at the interface, triggering superexchange interactions between Ru/Ni ions and giving rise to the emergent ferromagnetic phase. Moreover, the X-ray linear dichroism spectra reveal the preferential occupancy of the d3z2-r2 orbital for the Ru ions and the dx2-y2 orbital for the Ni ions in the heterostructure. This leads to different magnetic anisotropy of the superlattices when they are dominated by CRO or LNO sublayers. This work clearly demonstrates a charge-transfer-induced interfacial ferromagnetic phase in the whole ferromagnet-free oxide heterostructures, offering a feasible way to tailor oxide materials for desired functionalities.

A Genetically Engineered "Reinforced Concrete" Scaffold Regulates the N2 Neutrophil Innate Immune Cascade to Repair Bone Defects.

The innate immune response is crucial to inflammation, but how neutrophils and macrophages act in bone repair and tissue engineering treatment strategies await clarification. In this study, it is found that N2 neutrophils release stronger "eat me" signals to induce macrophage phagocytosis and polarize into the M2 anti-inflammatory phenotype. Guided by this biological mechanism, a mesoporous bioactive glass scaffold (MBG) is filled with hyaluronic acid methacryloyl (HAMA) hydrogel loaded with Transforming growth factor-ß1 (TGFß1) adenovirus (Ad@H), constructing a genetically engineered composite scaffold (Ad@H/M). The scaffold not only has good hydrophilicity and biocompatibility, but also provides mechanical stress support for bone repair. Adenovirus infection quickly induces N2 neutrophils, upregulating NF-κB and MAPK signaling pathways through Toll-like receptor 4 (TLR4) to promote the inflammatory response and macrophage phagocytosis. Macrophages perform phagocytosis and polarize towards the M2 phenotype, mediating the inflammatory response by inhibiting the PI3K-AKT-NF-κB pathway, maintaining homeostasis of the osteogenic microenvironment. The role of the Ad@H/M scaffold in regulating early inflammation and promoting long-term bone regeneration is further validated in vivo. In brief, this study focuses on the cascade of reactions between neutrophils and macrophage subtypes, and reports a composite scaffold that coordinates the innate immune response to promote bone repair.

Layered Ferromagnetic Structure Caused by the Proximity Effect and Interlayer Charge Transfer for LaNiO3/LaMnO3 Superlattices.

Magnetic proximity-induced magnetism in paramagnetic LaNiO3 (LNO) has spurred intensive investigations in the past decade. However, no consensus has been reached so far regarding the magnetic order in LNO layers in relevant heterostructures. This paper reports a layered ferromagnetic structure for the (111)-oriented LNO/LaMnO3 (LMO) superlattices. It is found that each period of the superlattice consisted of an insulating LNO-interfacial phase (five unit cells in thickness, ∼1.1 nm), a metallic LNO-inner phase, a poorly conductive LMO-interfacial phase (three unit cells in thickness, ∼0.7 nm), and an insulating LMO-inner phase. All four of these phases are ferromagnetic, showing different magnetizations. The Mn-to-Ni interlayer charge transfer is responsible for the emergence of a layered magnetic structure, which may cause magnetic interaction across the LNO/LMO interface and double exchange within the LMO-interfacial layer. This work indicates that the proximity effect is an effective means of manipulating the magnetic state and associated properties of complex oxides.

Enhancing Interfacial Ferromagnetism and Magnetic Anisotropy of CaRuO3 /SrTiO3 Superlattices via Substrate Orientation.

Artificial oxide heterostructures have provided promising platforms for the exploration of emergent quantum phases with extraordinary properties. One of the most interesting phenomena is the interfacial magnetism formed between two non-magnetic compounds. Here, a robust ferromagnetic phase emerged at the (111)-oriented heterointerface between paramagnetic CaRuO3 and diamagnetic SrTiO3 is reported. The Curie temperature is as high as ≈155 K and the saturation magnetization is as large as ≈1.3 µB per formula unit for the (111)-CaRuO3 /SrTiO3 superlattices, which are obviously superior to those of the (001)-oriented counterparts and are comparable to the typical itinerant ferromagnet SrRuO3 . A strong in-plane magnetic anisotropy with six-fold symmetry is further revealed by the anisotropic magnetoresistance measurements, presenting a large in-plane anisotropic field of 3.0-3.6 T. More importantly, the magnetic easy axis of the (111)-oriented superlattices can be effectively tuned from 〈 11 2 ¯ $11\overline{2}$ 1〉 to 〈 1 1 ¯ 0 $1 \bar{1}0$ 〉 directions by increasing the layer thickness of SrTiO3 . The findings demonstrate a feasible approach to enhance the interface coupling effect by varying the stacking orientation of oxide heterostructures. The tunable magnetic anisotropy also shows potential applications in low-power-consumption or exchange spring devices.

Direct Observation of Magnetic Skyrmions and Their Current-Induced Dynamics in Epitaxial Single-Crystal Oxide Films.

Magnetic skyrmions are scarcely investigated for single-crystal quality films, for which skyrmions may have a remarkable performance. Even in the limited studies in this aspect, the skyrmions are usually probed by the topological Hall effect, missing important information on dynamic properties. Here, we present a comprehensive investigation on the generation/manipulation of magnetic skyrmions in La0.67Ba0.33MnO3 single-crystal films. Using the technique of magnetic force microscopy, the current-driven skyrmion dynamics are directly observed. Unlike isolated skyrmions produced by magnetic field alone, closely packed skyrmions can be generated by electric pulses in a magnetic background, with a high density (∼60/µm2) and a small size (dozens of nanometers). The threshold current moving skyrmions is ∼2.3 × 104 A/cm2, 2-3 orders of magnitude lower than that required by metallic multilayers or van der Waals ferromagnetic heterostructures. Our work demonstrates the great potential of single-crystal oxide films in developing skyrmion-based devices.

Infinite-layer/perovskite oxide heterostructure-induced high-spin states in SrCuO2/SrRuO3 bilayer films.

Heterostructures composed of dissimilar oxides with different properties offer opportunities to develop emergent devices with desired functionalities. A key feature of oxide heterostructures is interface electronics and orbital reconstructions. Here, we combined infinite-layered SrCuO2 and perovskite SrRuO3 into heterostructures. A rare high spin state as large as 3.0 µB f.u-1 and an increase in Curie temperature by 12 K are achieved in an ultrathin SrRuO3 film capped by a SrCuO2 layer. Atomic-scale lattice imaging shows the uniform CuO2-plane-to-RuO5-pyramid connection at the interface, where the regularly arranged RuO5 pyramids were elongated along the out-of-plane direction. As revealed by theoretical calculations and spectral analysis, these features finally result in an abnormally high spin state of the interfacial Ru ions with highly polarized eg orbitals. The present work demonstrates that oxygen coordination engineering at the infinite-layer/perovskite oxide interface is a promising approach towards advanced oxide electronics.

Gas-Particle Partitioning of Carbonyl Compounds in the Ambient Atmosphere.

Despite their crucial roles in health and climate concerns, the gas-particle partitioning of carbonyl compounds is poorly characterized in the ambient atmosphere. In this study, we investigate their partitioning by simultaneously measuring six carbonyl compounds (formaldehyde, acetaldehyde, acetone, propionaldehyde, glyoxal, and methylglyoxal) in the gas and particle phase at an urban site in Beijing. The field-derived partitioning coefficients ( Kpf) are in the range of 10-5-10-3 m3 µg-1, and the corresponding effective Henry's law coefficients ( KHf) should be 107-109 M atm-1. The Pankow's absorptive partitioning theory and Henry's law both significantly underestimate concentrations of particle-phase carbonyl compounds (105-106 times and >103 times, respectively). The observed "salting-in" effects only partially explain the enhanced partitioning to particles, which is approximately 1 order of magnitude. The measured Kpf values are higher at low relative humidity, and the overall effective vapor pressure of these carbonyl species are lower than their hydrates, indicating that carbonyl oligomers potentially formed in highly concentrated particle phase. The reaction kinetics of oligomer formation should be included if applying Henry's law to low-to-moderate relative humidity, and the high partitioning coefficients observed need to be proved by further field and laboratory studies. These findings provide deeper insights into the formation of carbonyl secondary organic aerosols in the ambient atmosphere.

Screening of freshwater fungi for decolorizing multiple synthetic dyes

Abstract The biodegradation of synthetic dyes by fungi is emerging as an effective and promising approach. In the present study, freshwater fungal strains isolated from submerged woods were screened for the decolorization of 7 synthetic dyes. Subsequently, 13 isolates with high decolorization capability were assessed in a liquid system; they belonged to 9 different fungal species. Several strains exhibited a highly effective decolorization of multiple types of dyes. New absorbance peaks appeared after the treatment with 3 fungal strains, which suggests that a biotransformation process occurred through fungal biodegradation. These results showed the unexploited and valuable capability of freshwater fungi for the treatment of dye-containing effluents. The ability of certain fungi to decolorize dyes is reported here for the first time.

Screening of freshwater fungi for decolorizing multiple synthetic dyes.

The biodegradation of synthetic dyes by fungi is emerging as an effective and promising approach. In the present study, freshwater fungal strains isolated from submerged woods were screened for the decolorization of 7 synthetic dyes. Subsequently, 13 isolates with high decolorization capability were assessed in a liquid system; they belonged to 9 different fungal species. Several strains exhibited a highly effective decolorization of multiple types of dyes. New absorbance peaks appeared after the treatment with 3 fungal strains, which suggests that a biotransformation process occurred through fungal biodegradation. These results showed the unexploited and valuable capability of freshwater fungi for the treatment of dye-containing effluents. The ability of certain fungi to decolorize dyes is reported here for the first time.

Life cycle assessment of electronic waste treatment.

Life cycle assessment was conducted to estimate the environmental impact of electronic waste (e-waste) treatment. E-waste recycling with an end-life disposal scenario is environmentally beneficial because of the low environmental burden generated from human toxicity, terrestrial ecotoxicity, freshwater ecotoxicity, and marine ecotoxicity categories. Landfill and incineration technologies have a lower and higher environmental burden than the e-waste recycling with an end-life disposal scenario, respectively. The key factors in reducing the overall environmental impact of e-waste recycling are optimizing energy consumption efficiency, reducing wastewater and solid waste effluent, increasing proper e-waste treatment amount, avoiding e-waste disposal to landfill and incineration sites, and clearly defining the duties of all stakeholders (e.g., manufacturers, retailers, recycling companies, and consumers).

Degradation and dechlorination of pentachlorophenol by microwave-activated persulfate.

The degradation performance of pentachlorophenol (PCP) by the microwave-activated persulfate (MW/PS) process was investigated in this study. The results indicated that degradation efficiency of PCP in the MW/PS process followed pseudo-first-order kinetics, and compared with conventional heating, microwave heating has a special effect of increasing the reaction rate and reducing the process time. A higher persulfate concentration and reaction temperature accelerated the PCP degradation rate. Meanwhile, increasing the pH value and ionic strength of the phosphate buffer slowed down the degradation rate. The addition of ethanol and tert-butyl alcohol as hydroxyl radical and sulfate radical scavengers proved that the sulfate radicals were the dominant active species in the MW/PS process. Gas chromatography-mass spectrometry (GC-MS) was employed to identify the intermediate products, and then a plausible degradation pathway involving dechlorination, hydrolysis, and mineralization was proposed. The acute toxicity of PCP, as tested with Photobacterium phosphoreum, Vibrio fischeri, and Vibrio qinghaiensis, was negated quickly during the MW/PS process, which was in agreement with the nearly complete mineralization of PCP. These results showed that the MW/PS process could achieve a high mineralization level in a short time, which provided an efficient way for PCP elimination from wastewater.