The Ageing of µPlasma-Modified Polymers: The Role of Hydrophilicity.

Thermoplastic polymers exhibit relatively limited surface energies and this results in poor adhesion when bonded to other materials. Plasma surface modification offers the potential to overcome this challenge through the functionalisation of the polymer surfaces. In this study, three polymers of differing hydrophobicity (HDPE, PA12, and PA6) were subjected to a novel, atmospheric, µPlasma surface treatment technique, and its effectiveness at increasing the surface energies was evaluated via measurement of the contact angle. To characterise the physical and chemical changes following µPlasma surface modification, the surface morphology was observed using atomic force microscopy (AFM), and the functionalisation of the surface was evaluated using infrared spectroscopy. Immediately after treatment, the contact angle decreased by 47.3° (HDPE), 42.6° (PA12), and 50.1° (PA6), but the effect was not permanent in that there was a pronounced relaxation or ageing phenomenon in operation. The ageing process over five hours was modelled using a modified stretched exponential function Kohlrausch-Williams-Watts (KWW) model, and it was found that the ageing rate was dependent on the hydrophilicity of polymers, with polyamides ageing more rapidly than polyethylene.

Porous Cellulose Thin Films as Sustainable and Effective Antimicrobial Surface Coatings.

In the present work, we developed an effective antimicrobial surface film based on sustainable microfibrillated cellulose. The resulting porous cellulose thin film is barely noticeable to human eyes due to its submicrometer thickness, of which the surface coverage, porosity, and microstructure can be modulated by the formulations and the coating process. Using goniometers and a quartz crystal microbalance, we observed a threefold reduction in water contact angles and accelerated water evaporation kinetics on the cellulose film (more than 50% faster than that on a flat glass surface). The porous cellulose film exhibits a rapid inactivation effect against SARS-CoV-2 in 5 min, following deposition of virus-loaded droplets, and an exceptional ability to reduce contact transfer of liquid, e.g., respiratory droplets, to surfaces such as an artificial skin by 90% less than that from a planar glass substrate. It also shows excellent antimicrobial performance in inhibiting the growth of both Gram-negative and Gram-positive bacteria (Escherichia coli and Staphylococcus epidermidis) due to the intrinsic porosity and hydrophilicity. Additionally, the cellulose film shows nearly 100% resistance to scraping in dry conditions due to its strong affinity to the supporting substrate but with good removability once wetted with water, suggesting its practical suitability for daily use. Importantly, the coating can be formed on solid substrates readily by spraying, which requires solely a simple formulation of a plant-based cellulose material with no chemical additives, rendering it a scalable, affordable, and green solution as antimicrobial surface coating. Implementing such cellulose films could thus play a significant role in controlling future pan- and epidemics, particularly during the initial phase when suitable medical intervention needs to be developed and deployed.

5-Methyltetrahydrofolate Alleviates Memory Impairment in a Rat Model of Alzheimer's Disease Induced by D-Galactose and Aluminum Chloride.

The effects of 5-methyltetrahydrofolate (5-MTHF) on a rat model of Alzheimer's disease (AD) induced by D-galactose (D-gal) and aluminum chloride (AlCl3) were investigated. Wistar rats were given an i.p. injection of 60 mg/kg D-gal and 10 mg/kg AlCl3 to induce AD and three doses of 1 mg/kg, 5 mg/kg or 10 mg/kg 5-MTHF by oral gavage. A positive control group was treated with 1 mg/kg donepezil by gavage. Morris water maze performance showed that 5 and 10 mg/kg 5-MTHF significantly decreased escape latency and increased the number of platform crossings and time spent in the target quadrant for AD rats. The administration of 10 mg/kg 5-MTHF decreased the brain content of amyloid ß-protein 1-42 (Aß1-42) and phosphorylated Tau protein (p-Tau) and decreased acetylcholinesterase and nitric oxide synthase activities. Superoxide dismutase activity, vascular endothelial growth factor level and glutamate concentration were increased, and malondialdehyde, endothelin-1, interleukin-6, tumor necrosis factor-alpha and nitric oxide decreased. The administration of 10 mg/kg 5-MTHF also increased the expression of disintegrin and metallopeptidase domain 10 mRNA and decreased the expression of ß-site amyloid precursor protein cleavage enzyme 1 mRNA. In summary, 5-MTHF alleviates memory impairment in a D-gal- and AlCl3-exposed rat model of AD. The inhibition of Aß1-42 and p-Tau release, reduced oxidative stress, the regulation of amyloid precursor protein processing and the release of excitatory amino acids and cytokines may be responsible.

A new approach to simultaneously reducing, nitrogen doping and noble metal coating of graphene oxide via active-screen plasma.

Graphene is widely used for various applications, especially after nitrogen doping and incorporation with metal nanoparticles. Herein, a simultaneous approach to reducing, nitrogen doping and noble metals coating of graphene oxide (GO) is reported using an advanced active-screen plasma (ASP) technique. With a noble metal plate added as an extra lid of active screen cage, the corresponding noble metal, mainly or fully in pure metal state, depending on the noble metal type, as well as a minority of Fe and Cr, is deposited on GO with simultaneous reduction and nitrogen doping. The ASP treated GO exhibits varying levels of improvement in electrical property depending on the type of noble metal nanoparticles hybridized with. Specifically, ASP treated GO incorporated with Pt or Au revealed 2-4 orders of magnitude of improvement in electrical property.

Investigation into the Properties of L-5-Methyltetrahydrofolate and Seal Oil as a Potential Atherosclerosis Intervention in Rats.

Atherosclerosis is a chronic inflammatory disease that leads to tissue ischemia. As the biologically active form of folic acid, L-5-methyltetrahydrofolate (L-5-MTHF) can improve endothelial function. And Seal oil plays a beneficial role in the progression of atherosclerosis. The study aims to evaluate beneficial effects of L-5-MTHF alone or in combination with Seal oil on atherosclerosis. Seventy-two male Wistar rats were randomly divided into 6 groups: control (normal diet), atherosclerosis (high-fat diet), folic acid (high-fat+3 mg/kg folic acid), low-dose L-5-MTHF (high-fat+3 mg/kg L-5-MTHF), low-dose L-5-MTHF+Seal oil (high-fat+3 mg/kg L-5-MTHF+0.5 g/kg Seal oil), high-dose L-5-MTHF (high-fat+10 mg/kg L-5-MTHF). After 13 wk, rats were sacrificed. Rats exhibiting atherosclerosis had dyslipidemia and serious aortic lesions. Supplementation with low-dose L-5-MTHF+Seal oil or use of high-dose L-5-MTHF increased serum folate concentrations, decreased homocysteine levels, improved the serum lipid profile, up-regulated expression of NO and NOS, enhancement of the antioxidant properties of GSH-Px activity and reduction in the concentration of MDA, levels of Olr1 and RelA mRNA decreased in aortic tissues, and expression of inflammatory factors, TNF-α, IL-6, IL-1ß and endothelial cell injury factors ET-1 and sICAM-1, were also down-regulated. In addition, HD-L-5-MTHF increased the antioxidant activity of serum SOD. We conclude that L-5-MTHF has obvious anti-inflammatory and antioxidant effects on diseased blood vessels. The intervention of L-5-MTHF alone or in combination with Seal oil can improve atherosclerosis in rats and reduce the occurrence of aortic lesions. The anti-atherosclerotic mechanism may be related to down-regulation of Olr1 and RelA expression.

Characteristics of respiratory microdroplet nuclei on common substrates.

To evaluate the role of common substrates in the transmission of respiratory viruses, in particular SARS-CoV-2, uniformly distributed microdroplets (approx. 10 µm diameter) of artificial saliva were generated using an advanced inkjet printing technology to replicate the aerosol droplets and subsequently deposited on five substrates, including glass, polytetrafluoroethylene, stainless steel, acrylonitrile butadiene styrene and melamine. The droplets were found to evaporate within a short timeframe (less than 3 s), which is consistent with previous reports concerning the drying kinetics of picolitre droplets. Using fluorescence microscopy and atomic force microscopy, we found that the surface deposited microdroplet nuclei present two distinctive morphological features as the result of their drying mode, which is controlled by both interfacial energy and surface roughness. Nanomechanical measurements confirm that the nuclei deposited on all substrates possess similar surface adhesion (approx. 20 nN) and Young's modulus (approx. 4 MPa), supporting the proposed core-shell structure of the nuclei. We suggest that appropriate antiviral surface strategies, e.g. functionalization, chemical deposition, could be developed to modulate the evaporation process of microdroplet nuclei and subsequently mitigate the possible surface viability and transmissibility of respiratory virus.

Cross-sectional study: Relationship between serum trace elements and hypertension.

BACKGROUND: A balanced intake of trace elements is beneficial for chronic diseases such as hypertension. However, the available information regarding trace elements that may be independently associated with hypertension is limited, and the relationship between this disorder and element ratios also remains unclear. METHODS: A total of 6,754 subjects from rural China were selected, after exclusion of patients who were under 18, had incomplete data or had additional related disorders, by multi-stage simple random and cluster sampling (participation rate: 95.22 %). Subjects were divided into a hypertensive (H) and a control (C) group. Data were collected on blood pressure and 12 serum trace elements were measured by flame atomic absorption spectrometry and inductively coupled plasma-mass spectrometry. Other basic information was collated from questionnaires and biochemical indicators were measured via kits. RESULTS: Differences in serum levels of magnesium (Mg(mg/l): H: 27.43 ± 12.72; C: 26.33 ± 12.16), iron (Fe(mg/l): H: 1.99 ± 1.24; C: 1.84 ± 1.16), copper (Cu(mg/l): H: 1.19 ± 0.37; C: 1.10 ± 0.36), boron (B(µg/l): H: 50.00 ± 25.21; C: 47.57 ± 26.25), selenium (Se(µg/l): H: 125.12 ± 32.81; C: 118.80 ± 29.72) and chromium (Cr(µg/l): H: 8.77 ± 10.12; C: 10.12 ± 10.72) between the hypertensive and control groups were found. There were no differences in serum contents of calcium (Ca(mg/l): H: 112.43 ± 58.25; C: 111.00 ± 59.49), zinc (Zn(mg/l): H: 1.50 ± 1.97; C: 1.44 ± 1.88), arsenic (As(µg/l): H: 4.17 ± 3.94; C: 4.10 ± 4.00), manganese (Mn(µg/l): H: 4.15 ± 4.03; C: 4.07 ± 4.05), cadmium (Cd(µg/l): H: 1.14 ± 1.11; C: 1.18 ± 1.12) or lead (Pb(µg/l): H: 4.22 ± 8.90; C: 4.26 ± 10.25). The serum Cr and Cd concentrations of hypertensive men were lower than that of male controls while Mg, Cu, Ca and Se concentrations in male controls were lower. Further differences were apparent and Fe, B, Se, Mg and Cu all showed higher levels in hypertensive females whereas Cr concentrations were higher in female controls. Serum Zn and B levels showed age-related variations among hypertensive patients and concentrations of serum Cu, Zn, Se and B showed age-related variations among control subjects. For hypertensive patients, the odds ratio (OR) and 95 % confidence interval (CI) for the association of serum Cu, Se and Cr levels with hypertension were Cu: 1.36 (1.12-1.66); Se: 1.03 (1.01-1.05); Cr: 0.89 (0.83-0.96). Moreover, when the participants in the grouping with the highest copper/zinc (Cu/Zn) and magnesium/manganese (Mg/Mn) ratios were compared with the reference group, the OR and 95 % CI for hypertension were 1.22 (1.04-1.44) and 1.20 (1.01-1.42), respectively. CONCLUSIONS: Levels of serum trace elements showed age- and sex-related differences in a group of rural Chinese adults with hypertension and healthy participants. Serum concentrations of Cu, Se and Cr may be independently associated with hypertension. Higher serum ratios of Cu:Zn and Mg:Mn may also be associated with hypertension. Further randomized trials are necessary to elucidate the true relationship between levels of Cu, Se, Cr, Cu:Zn, Mg:Mn and hypertension.

Integrative genomic analysis of early neurogenesis reveals a temporal genetic program for differentiation and specification of preplate and Cajal-Retzius neurons.

Neurogenesis in the developing neocortex begins with the generation of the preplate, which consists of early-born neurons including Cajal-Retzius (CR) cells and subplate neurons. Here, utilizing the Ebf2-EGFP transgenic mouse in which EGFP initially labels the preplate neurons then persists in CR cells, we reveal the dynamic transcriptome profiles of early neurogenesis and CR cell differentiation. Genome-wide RNA-seq and ChIP-seq analyses at multiple early neurogenic stages have revealed the temporal gene expression dynamics of early neurogenesis and distinct histone modification patterns in early differentiating neurons. We have identified a new set of coding genes and lncRNAs involved in early neuronal differentiation and validated with functional assays in vitro and in vivo. In addition, at E15.5 when Ebf2-EGFP+ cells are mostly CR neurons, single-cell sequencing analysis of purified Ebf2-EGFP+ cells uncovers molecular heterogeneities in CR neurons, but without apparent clustering of cells with distinct regional origins. Along a pseudotemporal trajectory these cells are classified into three different developing states, revealing genetic cascades from early generic neuronal differentiation to late fate specification during the establishment of CR neuron identity and function. Our findings shed light on the molecular mechanisms governing the early differentiation steps during cortical development, especially CR neuron differentiation.

Plasma Surface Functionalization of Carbon Nanofibres with Silver, Palladium and Platinum Nanoparticles for Cost-Effective and High-Performance Supercapacitors.

Due to their relatively low cost, large surface area and good chemical and physical properties, carbon nanofibers (CNFs) are attractive for the fabrication of electrodes for supercapacitors (SCs). However, their relatively low electrical conductivity has impeded their practical application. To this end, a novel active-screen plasma activation and deposition technology has been developed to deposit silver, platinum and palladium nanoparticles on activated CNFs surfaces to increase their specific surface area and electrical conductivity, thus improving the specific capacitance. The functionalised CNFs were fully characterised using scanning electron microscope (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD) and their electrochemical properties were evaluated using cyclic voltammetry and electrochemical impedance spectroscopy. The results showed a significant improvement in specific capacitance, as well as electrochemical impedance over the untreated CNFs. The functionalisation of CNFs via environmental-friendly active-screen plasma technology provides a promising future for cost-effective supercapacitors with high power and energy density.