Dexmedetomidine (DEX) is a highly selective α2 adrenergic receptor (α2AR) agonist currently used in clinical settings. Because DEX has dose-dependent advantages of sedation, analgesia, antianxiety, ...inhibition of sympathetic nervous system activity, cardiovascular stabilization, and significant reduction of postoperative delirium and agitation, but does not produce respiratory depression and agitation, it is widely used in clinical anesthesia and ICU departments. In recent years, much clinical study and basic research has confirmed that DEX has a protective effect on a variety of organs, including the nervous system, heart, lungs, kidneys, liver, and small intestine. It acts by reducing the inflammatory response in these organs, activating antiapoptotic signaling pathways which protect cells from damage. Therefore, based on wide clinical application and safety, DEX may become a promising clinical multiorgan protection drug in the future. In this article, we review the physiological effects related to organ protection in α2AR agonists along with the organ-protective effects and mechanisms of DEX to understand their combined application value.
As a new form of computing based on the core technology of cloud computing and built on edge infrastructure, edge computing can handle computing-intensive and delay-sensitive tasks. In mobile edge ...computing (MEC) assisted by 5G technology, offloading computing tasks of edge devices to the edge servers in edge network can effectively reduce delay. Designing a reasonable task offloading strategy in a resource-constrained multi-user and multi-MEC system to meet users’ needs is a challenge issue. In industrial internet of things (IIoT) environment, considering the rapid increase of industrial edge devices and the heterogenous edge servers, a particle swarm optimization (PSO)-based task offloading strategy is proposed to offload tasks from resource-constrained edge devices to edge servers with energy efficiency and low delay style. A multi-objective optimization problem that considers time delay, energy consumption and task execution cost is proposed. The fitness function of the particle represents the total cost of offloading all tasks to different MEC servers. The offloading strategy based on PSO is compared with the genetic algorithm (GA) and the simulated annealing algorithm (SA) through simulation experiments. The experimental results show that the task offloading strategy based on PSO can reduce the delay of the MEC server, balance the energy consumption of the MEC server, and effectively realize the reasonable resource allocation.
Photon upconversion in lanthanide-doped upconversion nanoparticles offers a wide variety of applications including deep-tissue biophotonics. However, the upconversion luminescence and efficiency, ...especially involving multiple photons, is still limited by the concentration quenching effect. Here, we demonstrate a multilayered core-shell-shell structure for lanthanide doped NaYF
, where Er
activators and Yb
sensitizers are spatially separated, which can enhance the multiphoton emission from Er
by 100-fold compared with the multiphoton emission from canonical core-shell nanocrystals. This difference is due to the excitation energy transfer at the interface between activator core and sensitizer shell being unexpectedly efficient, as revealed by the structural and temperature dependence of the multiphoton upconversion luminescence. Therefore, the concentration quenching is suppressed via alleviation of cross-relaxation between the activator and the sensitizer, resulting in a high quantum yield of up to 6.34% for this layered structure. These findings will enable versatile design of multiphoton upconverting nanoparticles overcoming the conventional limitation.
We aim to assess the level of family burden of schizophrenia patients and identify its predicting factors in a rural community sample of China. A sample of 327 primary caregivers was recruited ...through a one-stage cluster sampling in Ningxiang County of Hunan province, China. Family burden was assessed using the Family Burden Interview Schedule (FBIS) of Pai and Kapur. Our results showed that the mean score of FBIS was 23.62±9.76 (range, 0-48), with over half (52%) caregivers reported their family burden being moderate and severe. Among the six domains of family burden, financial burden (76%) was the commonest burden, while disruption of family interactions (37%) was the least mentioned. A multivariate analysis of family burden revealed that patient being admitted for over 3 times, caregiver being female, having a middle school education, and with additional dependents, as well as higher care network function were positive predictors of family burden, while higher patient function and family function, and increasing patient age were negative predictors of family burden. Intervention to decrease family burden may be best served by improving family function and exploring alternative care model instead of hospitalization.
Tuning the local reaction environment is an important and challenging issue for determining electrochemical performances. Herein, we propose a strategy of intentionally engineering the local reaction ...environment to yield highly active catalysts. Taking Pt
nanoparticles supported on oxygen vacancy enriched MgO nanosheets as a prototypical example, we have successfully created a local acid-like environment in the alkaline medium and achieve excellent hydrogen evolution reaction performances. The local acid-like environment is evidenced by operando Raman, synchrotron radiation infrared and X-ray absorption spectroscopy that observes a key H
O
intermediate emergence on the surface of MgO and accumulation around Pt
sites during electrocatalysis. Further analysis confirms that the critical factors of the forming the local acid-like environment include: the oxygen vacancy enriched MgO facilitates H
O dissociation to generate H
O
species; the F centers of MgO transfers its unpaired electrons to Pt, leading to the formation of electron-enriched Pt
species; positively charged H
O
migrates to negatively charged Pt
and accumulates around Pt
nanoparticles due to the electrostatic attraction, thus creating a local acidic environment in the alkaline medium.
The widespread presence of ferrihydrite in the environment makes many contaminants including metal-EDTA complexes being adsorbed on it. However, the fate of metal-EDTA complexes during the ...transformation of ferrihydrite was poorly understood. Understanding the migration and speciation changes of metal-EDTA adsorbed on ferrihydrite during the transformation was helpful to predict its fate in some natural and engineering environments. In this work, the interaction of the two metal-EDTA complexes (Ni(II)-EDTA and Ca(II)-EDTA) and ferrihydrite during the 9-day transformation of ferrihydrite at different pH values was studied. The results showed that part of EDTA complexing metals changed to non-complexed metals during the ferrihydrite transformation, which was due to the fact that metal in the metal-EDTA exchanged with Fe(III) on ferrihydrite. Besides, different speciation of metal ions migrated during the transformation of ferrihydrite. Meanwhile, Fe(III)-EDTA formed in this process, and the exchange of metal in Ca(II)-EDTA with Fe(III) in ferrihydrite was faster than that of Ni(II)-EDTA. Besides, the presence of metal-EDTA affected the transformation rate of ferrihydrite under neutral and alkaline condition, and metal-EDTA accelerated the dissolution of ferrihydrite to form goethite. Therefore, ferrihydrite and metal-EDTA influenced each other during the transformation of ferrihydrite. The results of this work revealed that the process of metal-EDTA dissolving ferrihydrite not only included the dissociation of metal-EDTA, but also involved the migration of metal ions and affected the transformation of ferrihydrite.
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•The fate of metal-EDTA was affected by the transformation of ferrihydrite.•The speciation of metal-EDTA changed during the ferrihydrite transformation.•The formation of Fe(III)-EDTA in Fh-(Ca-EDTA) was easier than that of Fh-(Ni-EDTA).•Ni(II)-EDTA retarded the conversion of ferrihydrite at initial pH of 7.0 and 9.0.•Ca(II)-EDTA was more conducive to the conversion of ferrihydrite into goethite.
► Advanced Fenton-chemical precipitation was proposed to treat chelated heavy metal. ► Heavy metal and COD were effectively removed by this process. ► This process is promising due to its efficiency ...and simplicity of handling.
Industrial and remedial processes produce wastewater containing chelated heavy metal. Chelated heavy metal containing wastewater needs to be treated not only for the toxic heavy metal, but also for the chelating agent. The treatment of strong stability chelated heavy metal wastewater is a hot and difficult issue in these years. To solve this problem, a novel strategy, advanced Fenton-chemical precipitation process (AF-CPP) is proposed to address chelated heavy metal containing wastewater. The process uses zero-valent iron and hydrogen peroxide for degrading the chelated compound, followed by alkali precipitation of heavy metal. NiEDTA was selected as a model of strong stability of chelated heavy metal pollutant. This process can remove not only nickel ions, but also reduces COD values. Parameters affecting nickel removal are discussed. At optimum condition, the nickel removal efficiency attained was 98.4% and the residual concentrations of nickel fell below the value stipulated in Integrated Wastewater Discharge Standard of China (GB8978-1996). AF-CPP appears promising and effective for the treatment of strong stability chelated heavy metal containing wastewaters.
Abstract
Metamaterial absorbers (MMAs) offer a novel and flexible method to realize perfect absorption in specific frequencies, especially in the THz range. Despite the exotic abilities to manipulate ...light, most previously reported MMAs still suffer from limited bandwidth and tunability. Here we present a thermally switchable terahertz (THz) metasurface that exhibits ultra-broadband absorption and high-transmission characteristics at different ambient temperatures. Our simulations demonstrate that at room temperature the structure is highly transparent. When the ambient temperature reaches 358 K, the proposed design exhibits an ultra-broadband absorption from 0.398 to 1.356 THz with the absorptivity maintaining above 90% and the relative absorption bandwidth reaches up to 109.2%. The structure is demonstrated to be insensitive to the incident angle. Moreover, the bandwidth of such a structure can easily be expanded or reduced by cascading or removing the rings, providing high scalability in practical applications. Such a thermally switchable THz metasurface may have potential applications in various fields, such as optical switching, THz imaging, modulating and filtering.
BODIPY dyes are privileged fluorophores that are now widely used in highly diverse research fields. An overview of BODIPY dyes and a summarization of the different synthetic methodologies reported ...for direct C–H functionalization of the BODIPY framework have been provided.
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Fluorescent dyes are heavily sought for their potentials applications in bioimaging, sensing, theranostic, and optoelectronic materials. Among them, BODIPY dyes are privileged fluorophores that are now widely used in highly diverse research fields. The increasing success of BODIPY dyes is closely associated with their excellent and tunable photophysical properties due to their rich functionalization chemistry. Recently, growing research efforts have been devoted to the direct functionalization of the BODIPY core, because it allows the facile installation of desired functional groups in a single atom economical step. The challenges of this direct C–H derivation come from the difficulties in finding suitable functionalization agents and proper control of the regioselectivity of the functionalization. The aim of this work is to provide an overview of BODIPY dyes and a summarization of the different synthetic methodologies reported for direct C–H functionalization of the BODIPY framework.
Ferrihydrite is a crucial scavenger for hexavalent chromium (Cr(VI)) via coprecipitation processes. Foreign impurities widely exist in soils and sediments, which influence mineral recrystallization ...and transformation processes. Under the circumstances, the speciation and migration behavior of Cr(VI) will change accordingly. In this research, we explored the impact of tartaric acid and Cu(II) on ferrihydrite transformation, as well as the sequestration of Cr(VI) on iron minerals. Our results manifested that tartaric acid affected the valence of Cr on iron oxides. The adsorbed Cr(VI) was reduced to Cr(III) by tartaric acid on the surface of iron oxides and not released into the aqueous phase, which greatly reduced its toxicity. It was conducive to the conversion of ferrihydrite into hematite when tartaric acid concentration was 1.0 mM, because tartaric acid could facilitate the hematite nucleation to induce the generation of hematite from ferrihydrite. Moreover, Cu(II) promoted the formation of hematite and played a synergistic role in Cr(VI) fixation. Therefore, tartaric acid and Cu(II) are important factors decreasing the toxicity of Cr(VI) when considering Cr(VI) retention on iron minerals in complicated environments. This work has a vital implication for understanding the impact of the co-existent metals and organic substances on Cr(VI) retention in complex environments.
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•Both tartaric acid and Cu(II) affected Cr(VI) fate during Fh-Cr transformation.•Tartaric acid could induce the generation of hematite from ferrihydrite.•Reduction of Cr(VI) to Cr(III) by tartaric acid occurred during Fh-Cr aging.•The presence of Cu(II) promoted the formation of hematite.•Cu(II) could enhance Cr(VI) immobilization during Fh-Cr transformation.
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