The evolution of surfaces and mechanisms of contact electrification between metals and polymers

Contact electrification (CE) is a pretty common phenomenon, but still is poorly understood. The long-standing controversy over the mechanisms of CE related to polymers is particularly intense due to their complexity. In this paper, the CE between metals and polymers is systematically studied, which shows the evolution of surfaces accompanied by variations of CE outputs. The variations of CE charge are closely related to the creep and deformation of the polymer and metal surfaces. Then the relationship between CE and polymer structures is put forward, which is essentially determined by the electronegativity of elements and the functional groups in the polymers. The effects of load and contact frequency on the CE process and outputs are also investigated, indicating the increase of CE charge with load and frequency. Material transfer from polymer to metal is observed during CE while electrons transfer from metal to polymer, both of which are believed to have an influence on each other. The findings advance our understanding on the mechanism of CE between metal and polymers, and provides insights into the performance of CE-based application in various conditions, which sheds light on the design and optimization of CE-based energy harvest and self-powered sensing devices.

The transfer and persistence of metals in latent fingermarks

In forensic science, knowledge and understanding of material transfer and persistence is inherent to the interpretation of trace evidence and can provide vital information on the activity level surrounding a...

Lithium, Oxygen and Magnesium Isotope Systematics of Volcanic Rocks in the Okinawa Trough: Implications for Plate Subduction Studies

Determining the influence of subduction input on back-arc basin magmatism is important for understanding material transfer and circulation in subduction zones. Although the mantle source of Okinawa Trough (OT) magmas is widely accepted to be modified by subducted components, the role of slab-derived fluids is poorly defined. Here, major element, trace element, and Li, O and Mg isotopic compositions of volcanic lavas from the middle OT (MOT) and southern OT (SOT) were analyzed. Compared with the MOT volcanic lavas, the T9-1 basaltic andesite from the SOT exhibited positive Pb anomalies, significantly lower Nd/Pb and Ce/Pb ratios, and higher Ba/La ratios, indicating that subducted sedimentary components affected SOT magma compositions. The δ7Li, δ18O, and δ26Mg values of the SOT basaltic andesite (−5.05‰ to 4.98‰, 4.83‰ to 5.80‰ and −0.16‰ to −0.09‰, respectively) differed from those of MOT volcanic lavas. Hence, the effect of the Philippine Sea Plate subduction component, (low δ7Li and δ18O and high δ26Mg) on magmas in the SOT was clearer than that in the MOT. This contrast likely appears because the amounts of fluids and/or melts derived from altered oceanic crust (AOC, lower δ18O) and/or subducted sediment (lower δ7Li, higher δ18O and δ26Mg) injected into magmas in the SOT are larger than those in the MOT and because the injection ratio between subducted AOC and sediment is always >1 in the OT. The distance between the subducting slab and overlying magma may play a significant role in controlling the differences in subduction components injected into magmas between the MOT and SOT.

The Role of the Microbiota in Graves’ Disease and Graves’ Orbitopathy

Graves‘ disease (GD) is a clinical syndrome with an enlarged and overactive thyroid gland, an accelerated heart rate, Graves’ orbitopathy (GO), and pretibial myxedema (PTM). GO is the most common extrathyroidal complication of GD. GD/GO has a significant negative impact on the quality of life. GD is the most common systemic autoimmune disorder, mediated by autoantibodies to the thyroid-stimulating hormone receptor (TSHR). It is generally accepted that GD/GO results from complex interactions between genetic and environmental factors that lead to the loss of immune tolerance to thyroid antigens. However, the exact mechanism is still elusive. Systematic investigations into GD/GO animal models and clinical patients have provided important new insight into these disorders during the past 4 years. These studies suggested that gut microbiota may play an essential role in the pathogenesis of GD/GO. Antibiotic vancomycin can reduce disease severity, but fecal material transfer (FMT) from GD/GO patients exaggerates the disease in GD/GO mouse models. There are significant differences in microbiota composition between GD/GO patients and healthy controls. Lactobacillus, Prevotella, and Veillonella often increase in GD patients. The commonly used therapeutic agents for GD/GO can also affect the gut microbiota. Antigenic mimicry and the imbalance of T helper 17 cells (Th17)/regulatory T cells (Tregs) are the primary mechanisms proposed for dysbiosis in GD/GO. Interventions including antibiotics, probiotics, and diet modification that modulate the gut microbiota have been actively investigated in preclinical models and, to some extent, in clinical settings, such as probiotics (Bifidobacterium longum) and selenium supplements. Future studies will reveal molecular pathways linking gut and thyroid functions and how they impact orbital autoimmunity. Microbiota-targeting therapeutics will likely be an essential strategy in managing GD/GO in the coming years.

Writing And Reading With The Longitudinal Component of Light Using Carbazole-Containing Azopolymer Thin Films

It is well known that azobenzene-containing polymers (azopolymers) are sensitive to the polarization orientation of the illuminating radiation, with the resulting photoisomerization inducing material transfer at both the meso-and macroscale. As a result, azopolymers are efficient and versatile photonic materials, for example, they used for the fabrication of linear diffraction gratings, including subwavelength gratings, microlens arrays, and spectral filters. Here we propose to use carbazole-containing azopolymer thin films to directly visualize the longitudinal component of the incident laser beam, a crucial task for the realization of 3D structured light yet remaining experimentally challenging. We demonstrate the approach on both scalar and vectorial states of structured light, including higher-order and hybrid cylindrical vector beams. In addition to detection, our results confirm that carbazole-containing azopolymers are a powerful tool material engineering with the longitudinal component of the electric field, particularly to fabricate microstructures with unusual morphologies that differentiate from the total intensity distribution of the writing laser beam.

Impact of the Age of Cecal Material Transfer Donors on Alzheimer’s Disease Pathology in 5xFAD Mice

Alzheimer’s disease is a progressive neurodegenerative disorder affecting around 30 million patients worldwide. The predominant sporadic variant remains enigmatic as the underlying cause has still not been identified. Since efficient therapeutic treatments are still lacking, the microbiome and its manipulation have been considered as a new, innovative approach. 5xFAD Alzheimer’s disease model mice were subjected to one-time fecal material transfer after antibiotics-treatment using two types of inoculation: material derived from the caecum of age-matched (young) wild type mice or from middle aged, 1 year old (old) wild type mice. Mice were profiled after transfer for physiological parameters, microbiome, behavioral tasks, and amyloid deposition. A single time transfer of cecal material from the older donor group established an aged phenotype in the recipient animals as indicated by elevated cultivatable fecal Enterobacteriaceae and Lactobacillaceae representative bacteria, a decreased Firmicutes amount as assessed by qPCR, and by increased levels of serum LPS binding protein. While behavioral deficits were not accelerated, single brain regions (prefrontal cortex and dentate gyrus) showed higher plaque load after transfer of material from older animals. We could demonstrate that the age of the donor of cecal material might affect early pathological hallmarks of Alzheimer’s disease. This could be relevant when considering new microbiome-based therapies for this devastating disorder.

Strategies for the Control of Visible Particles in Sterile Devices

Currently, limited guidance is available for the contamination control of visible particles for the manufacture of sterile devices; thus, a comprehensive guidance is warranted. Sterile devices require stringent control of visible particulates to ensure proper functionality, performance assurance of sterility, reliability, patient safety, efficacy, and product quality. This paper outlines practical and science-based strategies to prevent/minimize visible particle contamination from non-process related extrinsic and process related intrinsic sources. Witness plates are proposed as a comprehensive strategy for the real time detection of visible particles, sources of extrinsic and intrinsic visible particles, and methods to identify particle types. Implementing the control measures described herein, which include air ionization units for the control and neutralization of static charges, would maximize device yield and quality, thus reducing rework and leading to increased profitability. Installing validated air ionization systems at appropriate manufacturing and processing locations, storage, product transfer areas, and gown-up rooms can significantly reduce visible particle contamination accumulation, dispersion, and yield losses. Implementing effective material transfer practices can further minimize the risk of introduction of unwanted particles and particle dispersion within classified areas. Also described are additional control measures, such as material systems and supply chain controls, good facility design, gowning practices, manufacturing equipment and tool controls, and manual visual inspections which would further contribute to the overall reduction of particle burden. Crucial elements of an effective particle removal process are the dry and wet cleaning processes and the facility surveillance program. Process-product-particle traceability matrices can serve as effective tools to promptly identify trends and reduce device conformity defects. For this paper, the meaning of the term particle only includes particulates and particulate matter. Microbial contamination control approaches, including facility decontamination, are outside the scope of this paper.

Oligodendrocytes are a lifelong source of nuclear and ribosomal material for neurons in the mouse brain

Nuclear and ribosomal components define cell identity and function by regulating chromatin dynamics, gene expression, and protein turnover. Here we report that in the mouse central nervous system (CNS) under normal conditions, neurons accumulate nuclear and ribosomal material of oligodendrocyte (OL) origin. We show that neuronal accumulation of OL-derived nuclear and ribosomal material is brain area-specific, and in the cortex and hippocampal dentate gyrus gradually propagates during postnatal brain maturation. We further demonstrate that OL-to-neuron material transfer persists throughout adulthood and responds to neuroinflammation. We found that satellite OL of the gray matter form internuclear contacts with receiving neurons in the mouse brain. Similar close internuclear associations between satellite OL and neurons are present in the adult human cortex. Our findings provide the first evidence of wide-spread dynamic and selective OL-to-neuron nuclear and ribosomal material transfer in the mouse CNS and indicate that satellite OL serve as powerful mediators of neuronal function. Equivalent processes may occur in the human CNS and cause neurological disorders when dysregulated.