The development of highly efficient and robust photocatalysts has attracted great attention for solving the global energy crisis and environmental problems. Herein, we describe the synthesis of a p–n ...heterostructured photocatalyst, consisting of ZnO nanorod arrays (NRAs) decorated with BiOI nanoplates (NPs), by a facile solvothermal method. The product thus obtained shows high photoelectrochemical water splitting performance and enhanced photoelectrocatalytic activity for pollutant degradation under visible light irradiation. The p‐type BiOI NPs, with a narrow band gap, not only act as a sensitizer to absorb visible light and promote electron transfer to the n‐type ZnO NRAs, but also increase the contact area with organic pollutants. Meanwhile, ZnO NRAs provide a fast electron‐transfer channel, thus resulting in efficient separation of photoinduced electron–hole pairs. Such a p–n heterojunction nanocomposite could serve as a novel and promising catalyst in energy and environmental applications.
Improved electron–hole separation: ZnO nanorod arrays have been decorated with BiOI nanoplates. The p–n heterojunction thus obtained plays a significant role in photoelectrocatalytic processes, where the BiOI nanoplates provide reaction sites for the degradation of organic pollutants, and the ZnO nanorods provide a fast transfer channel for electrons, which are ultimately transported to the counter electrode along an FTO substrate (see figure; FTO=fluorine‐doped tin oxide).
This article deals with a free boundary problem of the Lotka–Volterra type prey–predator model with advection in one space dimension. The model considered here may be applied to describe the ...expanding of an invasive or new predator species adopting a combination of random movement and advection upward or downward along the resource gradient, with the free boundaries representing expanding fronts of predator species. The main purpose of this article is to understand the influence of the advection environment on the dynamics of the model. We provide sufficient conditions for spreading and vanishing of the predator species, and we find a sharp threshold between the spreading and vanishing concerning this model. Moreover, for the case of successful spreading for the predator, we give estimates of asymptotic spreading speeds and nonlocal long‐time behavior of the prey and the predator.
Colorimetric sensors for the rapid detection of numerous analytes have been widely applied in many fields such as biomedicine, food industry and environmental science due to their highly sensitive ...and selective response, easy operation and visual identification by naked eyes. In this review, the recent progress of the colorimetric sensors based on the magnetic nanomaterials with unique nanozymes-like catalytic activity (magnetic nanozyme) and their colorimetric sensing applications are presented. Emerging magnetic nanozyme-based colorimetric sensors, such as metal oxide/sulfides-based, metal-based, carbon-based, and aptamer-conjugated magnetic nanomaterials, offer many desirable features for target analytes detection. And due to the unique nanoscale physical-chemical properties, magnetic nanozymes have been used to mimic the catalytic activity of natural enzymes such as peroxidases, oxidases and catalases. This review also highlights the catalytic mechanisms of enzyme-like reactions, and promising colorimetric sensing system for the detection of chemical compounds like H2O2, pesticide, ascorbic acid, dopamine, tetracyclines, perfluorooctane sulfonate, phenolic compounds, heavy metal ion and sulfite have been deeply discussed. In addition, the remaining challenges and future directions in utilizing magnetic nanozyme for colorimetric sensors are addressed.
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•The recent progress of magnetic nanomaterials with unique nanozymes-like activity are presented.•The colorimetric sensors based on magnetic nanomaterials and their sensing applications are reviewed.•The remaining challenges in utilizing magnetic nanomaterials for colorimetric sensors are addressed.
Besides generating vision, light modulates various physiological functions, including mood. While light therapy applied in the daytime is known to have anti-depressive properties, excessive light ...exposure at night has been reportedly associated with depressive symptoms. The neural mechanisms underlying this day-night difference in the effects of light are unknown. Using a light-at-night (LAN) paradigm in mice, we showed that LAN induced depressive-like behaviors without disturbing the circadian rhythm. This effect was mediated by a neural pathway from retinal melanopsin-expressing ganglion cells to the dorsal perihabenular nucleus (dpHb) to the nucleus accumbens (NAc). Importantly, the dpHb was gated by the circadian rhythm, being more excitable at night than during the day. This indicates that the ipRGC→dpHb→NAc pathway preferentially conducts light signals at night, thereby mediating LAN-induced depressive-like behaviors. These findings may be relevant when considering the mental health effects of the prevalent nighttime illumination in the industrial world.
A series of NH
-functionalized nano-sized magnetic metal-organic frameworks (MOFs) were prepared in this study for Cr(VI) removal from wastewater. It was observed that not only the morphological, ...i.e., orientation growth of N-doped and iron-based metal-organic frameworks, but also the adsorption of magnetic MOFs is largely related to the used amount of ammonium hydroxide in preparation. For example, with increasing amounts of ammonium hydroxide used in preparation, the morphology of magnetic MOFs changed from spherical to cube and triangular cone. Moreover, the maximum adsorption capacity of spherical-magnetic MOFs, cubic-magnetic MOFs and triangular cone-magnetic MOFs could be up to 204.08 mg/g, 232.56 mg/g and 270.27 mg/g, respectively. Under optimal conditions, the adsorption process of magnetic MOFs for Cr(VI) was consistent with the pseudo-second-order rate equation (R
= 1) and Langmuir isotherm model (R
> 0.99). Therefore, magnetic MOFs developed in this work offered a viable option for the removal of Cr(VI) from wastewater.
A series of ethylenediamine (EDA)-functionalized magnetic polymers (EDA-MPs) have been prepared via suspension polymerization with the usage amount of the functional monomer glycidylmethacrylate ...(GMA) varied during the suspension polymerization procedure. The EDA-MPs were characterized by transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), X-ray diffractometer (XRD), thermogravimetry and differential thermogravimetry analysis (TG-DTA), Fourier-transformed infrared spectroscopy (FTIR) and elementary analyzer (EA). The adsorption properties of the EDA-MPs for the removal of Cr(VI) in wastewater were deeply studied. The results showed the adsorption efficiency was highly pH dependent and decreased with the increasing of initial concentration of Cr(VI). The adsorption data taken at the optimized condition, i.e., 35 degrees C and pH of 2.5 were well fitted with the Langmuir isotherm. The maximum adsorption capacities (q(m)) of EDA-MPs to Cr(VI) were highly related to the contents of EDA-MPs, i.e., the q(m) of EDA-MPs to Cr(VI) calculated from the Langmuir isotherm increased from 32.15 to 61.35 mg g(-1) with the increasing of the usage amount of GMA. The adsorption kinetic data were modeled by the pseudo-second-order rate equation, and the adsorption of Cr(VI) by all the present EDA-MPs reached equilibrium in 60 min.
The determination of isotope ratios in individual uranium particles is very important for nuclear safeguards. In this work, accelerator mass spectrometry (AMS), thermal ionization mass spectrometry ...(TIMS), and secondary ion mass spectrometry (SIMS) were applied to isotope ratio analysis of individual uranium particles and compared in terms of background, measurement accuracy, and efficiency. Several individual uranium particles (1–7 μm) from certified reference materials were used as samples. The results show that the average values of blank counting rate of 235U for AMS, FT‐TIMS (FT: fission track), SEM‐TIMS (SEM: scanning electron microscope), and SIMS were 7.3, 7.8, 2.7 and 2.2 cps, respectively. The relative error of 234U/235U and 234U/236U isotope ratios of the particles from U200 for AMS were within 10% and 20%, whereas the results of FT‐TIMS and SIMS were within 5% and 10%, respectively. The relative error and external precision of 234U/238U and 235U/238U of the particles from U850 for the method of AMS, SEM‐TIMS, and SIMS were within 10% and 5%, respectively. For 236U/238U, the average values of the relative error and external precision measured by AMS were within 5%, which measured by SEM‐TIMS and SIMS were all within 10%. AMS has advantages in measuring 236U/238U. The measurement time of AMS and SEM‐TIMS was shorter than that of FT‐TIMS and longer than that of SIMS. It is considered that AMS and SEM‐TIMS have a certain development prospect, and it is necessary to research deeply.
Despite much attention, history of sheep (Ovis aries) evolution, including its dating, demographic trajectory and geographic spread, remains controversial. To address these questions, we generated 45 ...complete and 875 partial mitogenomic sequences, and performed a meta-analysis of these and published ovine mitochondrial DNA sequences (n = 3,229) across Eurasia. We inferred that O. orientalis and O. musimon share the most recent female ancestor with O. aries at approximately 0.790 Ma (95% CI: 0.637-0.934 Ma) during the Middle Pleistocene, substantially predating the domestication event (∼8-11 ka). By reconstructing historical variations in effective population size, we found evidence of a rapid population increase approximately 20-60 ka, immediately before the Last Glacial Maximum. Analyses of lineage expansions showed two sheep migratory waves at approximately 4.5-6.8 ka (lineages A and B: ∼6.4-6.8 ka; C: ∼4.5 ka) across eastern Eurasia, which could have been influenced by prehistoric West-East commercial trade and deliberate mating of domestic and wild sheep, respectively. A continent-scale examination of lineage diversity and approximate Bayesian computation analyses indicated that the Mongolian Plateau region was a secondary center of dispersal, acting as a "transportation hub" in eastern Eurasia: Sheep from the Middle Eastern domestication center were inferred to have migrated through the Caucasus and Central Asia, and arrived in North and Southwest China (lineages A, B, and C) and the Indian subcontinent (lineages B and C) through this region. Our results provide new insights into sheep domestication, particularly with respect to origins and migrations to and from eastern Eurasia.
In this work, magnetic tetraethylenepentamine (TEPA)-modified carboxyl–carbon nanotubes were synthesized, characterized, and used as adsorbents to conduct magnetic solid-phase extraction (MSPE) for ...the preconcentration of seven local anesthetic drugs (procaine, lidocaine, mepivacaine, oxybuprocaine, bupivacaine, tetracaine, and cinchocaine) from human plasma. The separation and determination of analytes were performed on high-performance liquid chromatography with UV detection. Several factors affected the extraction efficiency, such as the amount of adsorbents used, extraction time, sample pH, and optimization of elution conditions. Under optimal conditions, satisfactory linear relationships were obtained in the range of 0.02–5.00 mg/L, with the limits of detection (LOD) ranging from 0.003 mg/L to 0.008 mg/L. The recoveries of analytes for spiked human plasma were in the range of 82.0–108%. Moreover, the precision with intra-day and inter-day RSD values were obtained in the range of 1.5–7.7% and 1.5–8.3%. The results indicated that this method could determine the concentration of seven local anesthetic drugs in human plasma with high precision and repeatability and provide support for the clinical monitoring of the concentration of local anesthetic drugs in human plasma.
Metal chelators may retard the Alzheimer’s disease progression via countering neuroinflammation.
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Alzheimer’s disease (AD), characterized by the β-amyloid protein (Aβ) deposition and ...tau hyperphosphorylation, is the most common dementia with uncertain etiology. The clinical trials of Aβ monoclonal antibody drugs have almost failed, giving rise to great attention on the other etiologic hypothesis regarding AD such as metal ions dysmetabolism and chronic neuroinflammation. Mounting evidence revealed that the metal ions (iron, copper, and zinc) were dysregulated in the susceptible brain regions of AD patients, which was highly associated with Aβ deposition, tau hyperphosphorylation, neuronal loss, as well as neuroinflammation. Further studies uncovered that iron, copper and zinc could not only enhance the production of Aβ but also directly bind to Aβ and tau to promote their aggregations. In addition, the accumulation of iron and copper could respectively promote ferroptosis and cuproptosis. Therefore, the metal ion chelators were recognized as promising agents for treating AD. This review comprehensively summarized the effects of metal ions on the Aβ dynamics and tau phosphorylation in the progression of AD. Furthermore, taking chronic neuroinflammation contributes to the progression of AD, we also provided a summary of the mechanisms concerning metal ions on neuroinflammation and highlighted the metal ion chelators may be potential agents to alleviate neuroinflammation under the condition of AD. Nevertheless, more investigations regarding metal ions on neuroinflammation should be taken into practice, and the effects of metal ion chelators on neuroinflammation should gain more attention.
Running title: Metal chelators against neuroinflammation.
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