Search

Sub-10 nm metal-based nanoparticles have garnered immense interest due to their unique properties and versatile applications. In this study, we created sub-10 nm Ag-based particles with a spark discharge generator and explored the parameters impacting their size distribution and charging properties, including carrier gas flow rates, spark discharge voltage, electrode gap distances, and capacitance. Our findings illuminate that there is a comparable influence of different factors on both self-charged and neutral particles. Among the different factors, carrier gas flow rates emerging as a paramount determinant in particle size. While increasing spark discharge voltage and capacitance within the spark circuit increases particle concentrations, the associated changes in particle size prove to be less straightforward. Significant differences between the concentration of positive and negative self-charged particles manifest when the carrier gas flow rate surpasses 5.0 L min−1, with positive particles ranging from 0.8 to 1.2 nm and negative particles spanning 0.8 to 3.0 nm. Self-charged particles close to 1 nm tend to exhibit positive charges, whereas those larger than 2 nm tend to acquire negative charges, which suggests the growth of negative particles is faster than positive ones in the spark chamber. Nevertheless, these disparities between bipolar particles diminish with the increase of residence time, leading to the observation of similar particle size distributions. Positive particles consistently bear a single charge, while some negative particles exceeding 3 nm exhibit multiple charges, primarily under carrier gas flow rates exceeding 7.5 L min−1. This study provides insights into the control of properties of nano-sized metal particles, which are crucial for their practical utilization. Copyright © 2024 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

Methadone maintenance treatment is effective for managing opioid use disorder, but it can have many adverse effects that result in dose reduction. Patients often report persistent withdrawal symptoms after the dose reduction, which can decrease their adherence to treatment and increase the risk for relapse. Acupuncture has been recognized as an appropriate nonpharmacologic treatment for substance dependence. This multicenter, randomized, sham-controlled trial assessed the efficacy of acupuncture versus sham acupuncture on methadone dose reduction. Visual Abstract. Effect of Acupuncture for Methadone Reduction: Methadone maintenance treatment is effective for managing opioid use disorder, but it can have many adverse effects that result in dose reduction. Patients often report persistent withdrawal symptoms after the dose reduction, which can decrease their adherence to treatment and increase the risk for relapse. Acupuncture has been recognized as an appropriate nonpharmacologic treatment for substance dependence. This multicenter, randomized, sham-controlled trial assessed the efficacy of acupuncture versus sham acupuncture on methadone dose reduction. Background: Methadone maintenance treatment (MMT) is effective for managing opioid use disorder, but adverse effects mean that optimal therapy occurs with the lowest dose that controls opioid craving. Objective: To assess the efficacy of acupuncture versus sham acupuncture on methadone dose reduction. Design: Multicenter, 2-group, randomized, sham-controlled trial. (Chinese Clinical Trial Registry: ChiCTR2200058123) Setting: 6 MMT clinics in China. Participants: Adults aged 65 years or younger with opioid use disorder who attended clinic daily and had been using MMT for at least 6 weeks. Intervention: Acupuncture or sham acupuncture 3 times a week for 8 weeks. Measurements: The 2 primary outcomes were the proportion of participants who achieved a reduction in methadone dose of 20% or more compared with baseline and opioid craving, which was measured by the change from baseline on a 100-mm visual analogue scale (VAS). Results: Of 118 eligible participants, 60 were randomly assigned to acupuncture and 58 were randomly assigned to sham acupuncture (2 did not receive acupuncture). At week 8, more patients reduced their methadone dose 20% or more with acupuncture than with sham acupuncture (37 [62%] vs. 16 [29%]; risk difference, 32% [97.5% CI, 13% to 52%]; P  < 0.001). In addition, acupuncture was more effective in decreasing opioid craving than sham acupuncture with a mean difference of −11.7 mm VAS (CI, −18.7 to −4.8 mm; P  < 0.001). No serious adverse events occurred. There were no notable differences between study groups when participants were asked which type of acupuncture they received. Limitation: Fixed acupuncture protocol limited personalization and only 12 weeks of follow-up after stopping acupuncture. Conclusion: Eight weeks of acupuncture were superior to sham acupuncture in reducing methadone dose and decreasing opioid craving. Primary Funding Source: National Natural Science Foundation of China. [ABSTRACT FROM AUTHOR]

INTRODUCTION: The cognitive impairment patterns and the association with Alzheimer's disease (AD) in mental disorders remain poorly understood. METHODS: We analyzed data from 486,297 UK Biobank participants, categorizing them by mental disorder history to identify the risk of AD and the cognitive impairment characteristics. Causation was further assessed using Mendelian randomization (MR). RESULTS: AD risk was higher in individuals with bipolar disorder (BD; hazard ratio [HR] = 2.37, P < 0.01) and major depressive disorder (MDD; HR = 1.63, P < 0.001). MR confirmed a causal link between BD and AD (ORIVW = 1.098), as well as obsessive‐compulsive disorder (OCD) and AD (ORIVW = 1.050). Cognitive impairments varied, with BD and schizophrenia showing widespread deficits, and OCD affecting complex task performance. DISCUSSION: Observational study and MR provide consistent evidence that mental disorders are independent risk factors for AD. Mental disorders exhibit distinct cognitive impairment prior to dementia, indicating the potential different mechanisms in AD pathogenesis. Early detection of these impairments in mental disorders is crucial for AD prevention. Highlights: This is the most comprehensive study that investigates the risk and causal relationships between a history of mental disorders and the development of Alzheimer's disease (AD), alongside exploring the cognitive impairment characteristics associated with different mental disorders.Individuals with bipolar disorder (BD) exhibited the highest risk of developing AD (hazard ratio [HR] = 2.37, P < 0.01), followed by those with major depressive disorder (MDD; HR = 1.63, P < 0.001). Individuals with schizophrenia (SCZ) showed a borderline higher risk of AD (HR = 2.36, P = 0.056).Two‐sample Mendelian randomization (MR) confirmed a causal association between BD and AD (ORIVW = 1.098, P < 0.05), as well as AD family history (proxy‐AD, ORIVW = 1.098, P < 0.001), and kept significant after false discovery rate correction. MR also identified a nominal significant causal relationship between the obsessive‐compulsive disorder (OCD) spectrum and AD (ORIVW = 1.050, P < 0.05).Individuals with SCZ, BD, and MDD exhibited impairments in multiple cognitive domains with distinct patterns, whereas those with OCD showed only slight declines in complex tasks. [ABSTRACT FROM AUTHOR]

In radioactive waste repositories and tunnel engineering, the near-field groundwater environment is extremely complex, and changes in multiple chemical components are bound to disrupt the long-term stability of soft rock and soil, thus inducing a series of environmental and engineering geological problems. In this study argillaceous slate was selected as the research object and different types of aqueous chemical solutions were prepared. Lateral constraint expansion tests, X-ray diffraction tests, nuclear magnetic resonance tests and scanning electron microscopy tests were then carried out. The expansion characteristics and evolution mechanism of argillaceous slate in a hydrochemical environment are then revealed at the multiscale level, and the internal relationship between the macroscopic expansion of argillaceous slate and the microscopic and mesoscopic structures explored. Finally, based on experimental data and the grey theory, a non-equal step GM(1, N) grey prediction model was constructed. The results indicated that: (1) the water‒rock physicochemical reactions mainly affect the microstructure evolution of the argillaceous slate expansion process through pore changes, mineral dissolution and ion exchange; (2) there is a certain correlation between the microstructure parameters and the expansion rate, and it was found that pore volume and clay mineral content are the main factors affecting the expansion of soft rocks; and (3) the model verification results show that the non-equal step GM(1, N) grey prediction model established in this study can effectively predict the expansion trend of soft rocks in different hydrochemical environments. The research findings can provide a reference for the study of the expansion mechanism of soft rocks in complex hydrochemical environments and the disposal of expansion problems. Supplementary material: the Supplementary Figures and Tables are available at https://doi.org/10.6084/m9.figshare.c.7095856 [ABSTRACT FROM AUTHOR]

This study investigated the inhibition effect of nanoscale silver–copper particle (20 nm) against Coriolus versicolor and Gloeophyllumtrabeum. Poplar wood samples (Populus L.) were vacuum-impregnated using aqueous nano-AgCu solutions at concentrations of 0.01 %, 0.02 %, 0.03 %, 0.05 %, 0.075 %, and 0.1 %. Alkaline copper quaternary (ACQ, 0.1 %), boric acid (0.2 %) and untreated control group (CK) were employed for comparisons. Decay resistance and leachability were studied. The anti-fungi effects were compared between nano-AgCu, nano-Ag, Ag+ (silver nitrate), Cu2+ (copper nitrate), and a composite of Ag+–Cu2+. Nano-AgCu particle exhibited effective resistance to fungi after 12 weeks of exposure. The threshold retention of the nano-AgCu against C. versicolor and G. trabeum on poplar wood was 0.19 kg m−3 and 0.62 kg m−3, respectively. The silver–copper nanoparticles demonstrated excellent leach resistance, and the inhibition effect was retained after leaching. The nano-AgCu particle provided better antifungal effects than single ions or metal nanoparticles. This study illustrates the potential of using nano-AgCu particle as an efficient wood preservative compared to commercial water-soluble preservatives. [ABSTRACT FROM AUTHOR]

Nano inorganic antibacterial materials (such as nano silver and nano copper) are popular in preventing the spread of bacteria on wood and protecting human health. However, their antibacterial activity and cost are always difficult to balance, and their leachability during the applied procedure impedes service life. Herein, a low-cost nano AgCu alloy with high antibacterial activity is synthesized by a liquid reduction method and further physically mixed with waterborne paint to fabricate the composite paint. The obtained nano AgCu alloy is demonstrated to possess superior antibacterial performance against Escherichia coli and Staphylococcus aureus with a low concentration (10 ppm), a short time (1 min), and a 100% antibacterial rate, due to the synergistic effect between Ag and Cu, and the promoted release of Ag ion. Meanwhile, the composite coating containing nano AgCu alloy could endow the effective migration of Ag ions and further facilitate the high durability and maintain the lasting antibacterial effect on the wood surface by reducing the leaching rate of nano alloy particles from 1.58% to 0.62%. This work provides a reference for future research and development on antibacterial coatings of wood surfaces. [ABSTRACT FROM AUTHOR]

Nucleophilic high molecular-weight organic compounds (HMWOCs) are sensitive to protons (H+) in Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analysis. A comprehensive evaluation of the diurnal evolution of nucleophilic HMWOCs was performed. HMWOCs aged significantly in daily cycles, accompanied by functionality shifts, particularly oxygenated and reduced nitrogen (CHON and CHN) as well as oxygenated organics. The intensities of high molecular-weight (HMW) oxygenated compounds increased during both daytime and nighttime. The daytime evolution produced more nitrogen-containing compounds with carboxylic group (–COOH) homologues with molecular weights greater than 300, while the nighttime evolution produced mostly small CHON compounds (molecular weights < 300). During evolution, nighttime CHON removals were observed; meanwhile, carboxylation was also identified in CHON groups. The daytime evolution produced significantly more reduced-nitrogen-containing compounds; a day- and nighttime increase in CHN compounds with five members was also observed. This study can provide insights into the aging of less polar organic aerosols. [ABSTRACT FROM AUTHOR]

Under a global carbon-neutralizing environment, renewable wood is a viable alternative to non-renewable resources due to its abundance and high specific strength. However, fast-growing wood is hard to be applied extensively due to low mechanical strength and poor dimensional stability and durability. In this study, epoxy-acrylic resin-modified wood was prepared by forming a functional monomer system with three monomers [glycidyl methacrylate (GMA), maleic anhydride (MAN), and polyethylene glycol-200-dimethylacrylic acid (PEGDMA)] and filling into the wood cell cavity. The results showed that in the case of an optimal monomer system of nGMA:nPEGDMA = 20:1 and an optimal MAN dosage of 6%, the conversion rate of monomers reached 98.01%, the cell cavity was evenly filled by the polymer, with the cell wall chemically bonded. Thus, a bonding strength of as high as 1.13 MPa, a bending strength of 112.6 MPa and an impact toughness of 74.85 KJ/m2 were applied to the modified wood, which presented excellent dimensional stability (720 h water absorption: 26%, and volume expansion ratio: 5.04%) and rot resistance (loss rates from white rot and brown rot: 3.05% and 0.67%). Additionally, polymer-modified wood also exhibited excellent wear resistance and heat stability. This study reports a novel approach for building new environmentally friendly wood with high strength and toughness and good structural stability and durability. [ABSTRACT FROM AUTHOR]

The interrelation between grassland vegetation greenness and hydrothermal conditions on the Tibetan Plateau demonstrates a significant correlation. However, understanding the spatial patterns and the degree of this correlation, especially in relation to minimum and maximum air temperatures across various vertical gradient zones of the Plateau, necessitates further examination. Utilizing the normalized difference phenology index (NDPI) and considering four distinct hydrothermal conditions (minimum, maximum, mean temperature, and precipitation) during the growing season, an analysis was conducted on the correlation of NDPI with hydrothermal conditions across plateau elevations from 2000 to 2021. Results indicate that the correlation between vegetation greenness and hydrothermal conditions on the Tibetan Plateau grasslands is spatially varied. There is a pronounced negative correlation of greenness to maximum temperature and precipitation in the northeastern plateau, while areas exhibit stronger positive correlations to mean temperature. Additionally, as elevation increases, the positive correlation and sensitivity of alpine grassland vegetation greenness to minimum temperature significantly intensify, contrary to the effects observed with maximum temperature. The correlations between greenness and mean temperature in relation to elevational changes primarily exhibit a unimodal pattern across the Tibetan Plateau. These findings emphasize that the correlation and sensitivity of grassland vegetation greenness to hydrothermal conditions are both elevation-dependent and spatially distinct. [ABSTRACT FROM AUTHOR]

The activation of large ancient rock landslides caused by reservoir operation is a primary threat to the TGR. Understanding the deformation characteristics and failure mechanisms of these landslides can be helpful for stability assessment and long-term landslide prediction. The primary aim of this study is to research the motion characteristics of ancient rock landslides and their relationships with engineering activities and natural factors. The Tanjiahe landslide, a large reactivated landslide in the TGR region, is used as an example. Long-term professional monitoring data collected since 2006 show that the landslide is experiencing creep deformation. By combining 15 years of meteorological, hydrological and manual GNSS monitoring information, 5 years of displacement measurements from open fractures and deep boreholes, automatic GNSS measurements, and macroscopic inspection results, the deformation mechanisms of landslides are studied in detail. The study shows that landslide deformation is affected by the reservoir water level and that rainfall promotes landslide deformation. Specifically, from November to May, during the high reservoir water level stage and subsequent declining water level stage, the landslide exhibits a very distinct movement pattern with high deformation, lasting nearly 7 months. As the water level rises, the deformation subsides until almost no deformation exists. Landslide displacement continues to increase each year, indicating likely slope instability. However, the deformation rate of the Tanjiahe landslide is gradually decreasing, and the probability of large-scale sliding is low; still, the monitoring system must be strengthened, and additional research must be performed on the corresponding deformation mechanism. [ABSTRACT FROM AUTHOR]