Silver Nanoclusters Encapsulated into Metal-Organic Frameworks for Rapid Removal of Heavy Metal Ions from Water.

Metal nanomaterials have been reported as effective absorbents for the removal of pollutants in the water system, but the release of ions from these nanomaterials brings another concern. Herein, silver nanoclusters (AgNCs) were encapsulated in porous metal-organic frameworks of ZIF-8 (MOF-AgNCs). Compared to AgNCs, the release of Ag+ significantly decreases from MOF-AgNCs, indicating that the product presents a lower threat to the environment. The MOF-AgNCs were employed for the rapid removal of heavy metals, such as Pb2+ and Mn2+, from water. The mechanism and removal efficiencies were investigated.

Thermalization of gluons with Bose-Einstein condensation.

We study the thermalization of gluons far from thermal equilibrium in relativistic kinetic theory. The initial distribution of gluons is assumed to resemble that in the early stage of ultrarelativistic heavy ion collisions. Only elastic scatterings in static, nonexpanding gluonic matter are considered. At first we show that the occurrence of condensation in the limit of vanishing particle mass requires a general constraint for the scattering matrix element. Then the thermalization of gluons with Bose-Einstein condensation is demonstrated in a transport calculation. We see a continuously increasing overpopulation of low energy gluons, followed by a decrease to the equilibrium distribution, when the condensation occurs. The times of the completion of the gluon condensation and of the entropy production are calculated. These times scale inversely with the energy density.

[Design of an embedded stroke rehabilitation apparatus system based on Linux computer engineering].

A realizaton project of electrical stimulator aimed at motor dysfunction of stroke is proposed in this paper. Based on neurophysiological biofeedback, this system, using an ARM9 S3C2440 as the core processor, integrates collection and display of surface electromyography (sEMG) signal, as well as neuromuscular electrical stimulation (NMES) into one system. By embedding Linux system, the project is able to use Qt/Embedded as a graphical interface design tool to accomplish the design of stroke rehabilitation apparatus. Experiments showed that this system worked well.

Development of nanozymes for promising alleviation of COVID-19-associated arthritis.

The COVID-19 pandemic caused by SARS-CoV-2 has been identified as a culprit in the development of a variety of disorders, including arthritis. Although the emergence of arthritis following SARS-CoV-2 infection may not be immediately discernible, its underlying pathogenesis is likely to involve a complex interplay of infections, oxidative stress, immune responses, abnormal production of inflammatory factors, cellular destruction, etc. Fortunately, recent advancements in nanozymes with enzyme-like activities have shown potent antiviral effects and the ability to inhibit oxidative stress and cytokines and provide immunotherapeutic effects while also safeguarding diverse cell populations. These adaptable nanozymes have already exhibited efficacy in treating common types of arthritis, and their distinctive synergistic therapeutic effects offer great potential in the fight against arthritis associated with COVID-19. In this comprehensive review, we explore the potential of nanozymes in alleviating arthritis following SARS-CoV-2 infection by neutralizing the underlying factors associated with the disease. We also provide a detailed analysis of the common therapeutic pathways employed by these nanozymes and offer insights into how they can be further optimized to effectively address COVID-19-associated arthritis.

Investigation of bacteria and detergent residues on undergraduate students' dinner plates in dormitories during university lockdown.

The COVID-19 outbreak has disrupted undergraduate students' experiments since their access to the laboratory is limited. To address this problem, the bacteria and detergent residues on undergraduate students' dinner plates were investigated by the students in the dormitories. Five different types of dinner plates from 50 students were collected, which were cleaned with detergent and water in the same way and naturally dried. Then, Escherichia coli (E. coli) test papers and sodium dodecyl sulfonate test kits were used to understand the bacteria and detergent residuals. Commonly available equipment such as a yogurt maker was used for bacterial culture; detergent analyses were performed using centrifugation tubes. Effective sterilization methods and safety protection were achieved by dormitory available methods. According to the investigated results, the students found the differences in bacteria and detergent residuals between different dinner plates and made suitable choices for the future.

Nonlinear thermal responses in geometrically anisotropic metamaterials.

Nonlinear metamaterials have great potential in heat management, which has aroused intensive research interest in both theory and application, especially for their response to surroundings. However, most existing works focus on geometrically isotropic (circular) structures, limiting the potential versatile functionalities. On the other hand, anisotropy in architecture promisingly offers an additional degree of freedom in modulating directional heat transfer. Here, we investigate nonlinear composition effects in geometrically anisotropic (confocal elliptical) thermal medium under the framework of effective medium approximation, and deduce a series of general formulas for quantitatively predicting nonlinearity enhancement. Enhancement coefficients are analytically derived by the Taylor expansion method in different nonlinearity cases. In particular, we find that some coupling conditions can greatly promote the nonlinear modulation coefficients, introducing stronger enhancement beyond isotropic construction. Our theoretical predictions are verified by finite-element simulation, and feasible experimental suggestions are also given. For extending these results to practical scenes, two intelligent thermal metadevices are designed in proof of concept and demonstrated by numerical simulation. Our works provide a unified theory for anisotropic nonlinear thermal metamaterial design and may benefit flexible applications in self-adaptive thermal management, such as switchable cloaks, concentrators, or macroscopic thermal diodes.

Retraction: Efficient in vivo wound healing using noble metal nanoclusters.

Retraction of 'Efficient in vivo wound healing using noble metal nanoclusters' by Kuo Li et al. Nanoscale, 2021, 13, 6531-6537. DOI: 10.1039/D0NR07176E.

Assembly of Carbon Dots into Frameworks with Enhanced Stability and Antibacterial Activity.

Carbon dots (CDs) have been widely used as antimicrobials due to their active surface, but some CDs suffer instability. Therefore, the relative applications such as the antibacterial activity may not be reliable for long-term use. Herein, we synthesize CDs with blue fluorescence by a hydrothermal process. Thereafter, polyethylenimine was applied for the assembly of CDs into CDs-based frameworks (CDFs). The CDFs exhibited quenched fluorescence but showed more stable properties based on the scanning electron microscope and zeta potential investigations. Both CDs and CDFs show antibacterial activity toward Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), but CDFs exhibited better antibacterial performance, and S. aureus could be completely inhibited with the minimum inhibitory concentration of 30 µg/mL. This reveals CDFs magnify both the stability and antibacterial activity, which would be more promising for practical applications.

Efficient in vivo wound healing using noble metal nanoclusters.

The wound healing process involves multiple steps including hemostasis, inflammation, proliferation, and tissue remodeling. Nanomaterials have been employed externally for healing wounds. However, their use as systemic therapeutics has not been extensively explored. We report the use of ultra-small noble metal nanoclusters (NCs) for the treatment of skin wounds. Both in vitro and in vivo studies indicate NCs have comprehensive therapeutic effects for wound healing, promoting cell proliferation and migration while decreasing inflammation.

Fabrication of antibacterial sponge cleaner using gold nanoclusters.

From the dinner table to the office, many surfaces contain bacteria and the threat to human health. In this work, cost-effective antimicrobial foams were developed by the adsorption of lysozyme protected gold nanoclusters (AuNCs) in sponges. Antibacterial activities of the prepared antibacterial AuNCs were evaluated using typical Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus). The antibacterial foams were further fabricated by the absorption of the positively charged AuNCs in the negatively charged sponges. The inhibitions of bacteria on random surfaces, such as mobile phones, tables, doorknobs, and cabinet handles, were exhibited by cleaning them with the antibacterial foams.

Ultra-Small Lysozyme-Protected Gold Nanoclusters as Nanomedicines Inducing Osteogenic Differentiation.

PURPOSE: Ultra-small gold nanoclusters (AuNCs), as emerging fluorescent nanomaterials with excellent biocompatibility, have been widely investigated for in vivo biomedical applications. However, their effects in guiding osteogenic differentiation have not been investigated, which are important for osteoporosis therapy and bone regeneration. Herein, for the first time, lysozyme-protected AuNCs (Lys-AuNCs) are used to stimulate osteogenic differentiation, which have the potential for the treatment of bone disease. METHODS: Proliferation of MC3T3E-1 is important for osteogenic differentiation. First, the proliferation rate of MC3T3E-1 was studied by Cell Counting Kit-8 (CCK8) assays. Signaling pathways of PI3K/Akt play central roles in controlling proliferation throughout the body. The expression of PI3K/Akt was investigated in the presence of lysozyme, and lysozyme-protected AuNCs (Lys-AuNCs) by Western blot (WB) and intracellular cell imaging to evacuate the osteogenic differentiation mechanisms. Moreover, the formation of osteoclasts (OC) plays a negative role in the differentiation of osteoblasts. Nuclear factor κB ligand (RANKL) and macrophage colony-stimulating factor (M-CSF) signaling pathways are used to understand the negative influence of the osteogenic differentiation by the investigation of Raw 264.7 cell line. Raw 264.7 (murine macrophage-like) cells and NIH/3T3 (mouse fibroblast) cells were treated with tyloxapol, and the cell viability was assessed. Raw 264.7 cells have also been used for in vitro studies, on understanding the osteoclast formation and function. The induced osteoclasts were identified by TRAP confocal fluorescence imaging. These key factors in osteoclast formation, such as (NFATc-1, c-Fos, V-ATPase-2 and CTSK), were investigated by Western blot. RESULTS: Based on the above investigation, Lys-AuNCs were found to promote osteogenic differentiation and decrease osteoclast activity. It is noteworthy that the lysozyme (protected template), AuNPs, or the mixture of Lysozyme and AuNPs have negligible effects on osteoblastic differentiation compared to Lys-AuNCs. CONCLUSION: This study opens up a novel avenue to develop a new gold nanomaterial for promoting osteogenic differentiation. The possibility of using AuNCs as nanomedicines for the treatment of osteoporosis can be expected.

A cyano-bridged tubular coordination polymer with dominant ferromagnetic interactions.

It is a challenge to synthesize a porous tubular coordination polymer with magnetic properties. Utilizing [Fe(II)(bipy)(CN)4](2-) (bipy = 2,2'-bipyridine) as the building block to react with Mn(2+), we successfully synthesized a cyano-bridged tubular coordination polymer with dominant ferromagnetic interactions. The inner surface of the heterometallic tube is hydrophilic, whereas the outer surface is hydrophobic. The framework is stable up to 320 °C and can adsorb N2 and CO2. The ferromagnetic interactions were transmitted via the diamagnetic N-C-Fe(II)-C-N species between Mn(2+) ions in the tube.

Single-molecule magnet behavior in three cyano-bridged heterometallic Fe(III)-Ni(II) clusters.

One trinuclear and two tetranuclear cyanide-bridged Fe(III)-Ni(II) complexes were synthesized via treatment of a tricyanometallate with divalent Ni salts in the presence of 1-butylimidazole, 2,2-bipyrimidyl and 1,10-phenanthroline, respectively. Magnetic property studies demonstrated that the three complexes exhibit single-molecule magnet behavior as a result of strong intracluster ferromagnetic coupling and weak intercluster magnetic interactions.

12-Metal 36-membered ring based W(V)-Co(II) layers showing spin-glass behavior.

The present study describes the designed synthesis, X-ray structures, and magnetic properties of two 2D cyano bridged heterobimetallic W(V)-Co(II) networks, {[W(CN)8]2[Co(phpy)4]3}·2CH3OH·2H2O (1) and {[W(CN)8]2[Co(4-spy)4]3}·6H2O (2) (phpy = 4-phenylpyridine, 4-spy = 4-styrylpyridine). Both compounds consist of cyano-bridged 12-metal 36-membered ring units, Co6W6(CN)12, joined by organic linkers into a 2D plane. The layer presents a corrugated configuration in compound 1 and a plane configuration in compound 2 due to different π-π stacking interactions. Magnetic measurements reveal that both 1 and 2 have a transition to the spin glass-like phase due to competitive magnetic interactions.

Slow magnetic relaxation in a cyano-bridged ferromagnetic {Fe(III)Ni(II)} alternating chain.

A cyano-bridged ferromagnetic {Fe(III)Ni(II)} alternating chain {[Fe(pzTp)(CN)3][Ni(chxn)2]}·ClO4·H2O (1) (pzTp = tetrakis(pyrazolyl)borate, chxn = (1R,2R)-1,2-diaminocyclohexane) was synthesized via rational design. Crystal structure analysis and magnetic studies demonstrated that compound had a one-dimensional zigzagging chain-like structure and slow magnetic relaxation.

J/psi production in quark-gluon plasma.

We study J/psi production at RHIC and LHC energies with both initial production at energies reached and the BNL Relativistic Heavy Ion Collider (RHIC) and CERN Large Hadron Collider (LHC) with regeneration. We solve the coupled set of transport equations for the J/psi distribution in phase space and the hydrodynamic equation for evolution of quark-gluon plasma. At RHIC, continuous regeneration is crucial for the J/psi momentum distribution while the elliptic flow is still dominated by initial production. At energies reached at the LHC energy, almost all the initially created J/psis are dissociated in the medium and regeneration dominates the J/psi properties.