The COVID-19 pandemic forced numerous touch-based fields, including manual therapy, body psychotherapy, arts therapy, creative arts practices, and the fitness industry, to swiftly transition to ...web-based service delivery. These disciplines faced substantial challenges in adapting their traditionally in-person practices, which rely heavily on physical touch and close proximity, to a web format.
This review intends to provide a systematically sourced overview of the literature concerning innovative approaches for adapting touch-based practices to the web format in response to the COVID-19 pandemic.
A systematic search across 7 databases and gray literature sources identified studies presenting innovative web delivery methods, particularly those addressing the challenges arising from the absence of physical proximity and touch. The inclusion criteria were designed to encompass studies exploring the creative adaptation of touch-based practices to web formats in response to the COVID-19 pandemic irrespective of study methodology. The exclusion criteria applied to studies focusing solely on technical aspects of web delivery or nontouch or noninteractive practices. There were no geographical restrictions, but the selection was limited to publications from 2020 onward. As only qualitative studies were found, data synthesis was conducted thematically.
The review encompassed 17 studies revealing that touch-based fields successfully devised innovative and creative methods for web service delivery. These methods were categorized into five main themes: (1) adapted working methods (cross-field methods), (2) adapted working methods for sensorial experiences and nonphysical connections, (3) creative methods using materials or additional tools, (4) creative use of web-based platform tools or additional technologies, and (5) creative methods requiring previous preparation of practitioners or participants. These creative approaches allowed practitioners to address the challenges of web touch-based practices, fostering connections and offering unique sensory experiences, albeit with some concerns related to technology and preparation.
These innovative methods demonstrate promise in circumventing the limitations imposed by the lack of physical touch and proximity in web settings during the COVID-19 pandemic. Furthermore, these insights hold potential for application in other fields in the future. This systematic search and thematic synthesis provide valuable guidance for practitioners and educators seeking to navigate the evolving landscape of web service delivery in touch-based disciplines, ensuring continuity of care even in challenging circumstances.
PROSPERO CRD42022379731; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=379731.
Methamphetamine (METH) is abused by about 5% of the United States population with approximately 10–15% of human immunodeficiency virus-1 (HIV-1) patients reporting its use. METH abuse accelerates the ...onset and severity of HIV-associated neurocognitive disorders (HAND) and astrocyte-induced neurotoxicity. METH activates G-protein coupled receptors such as trace amine associated receptor 1 (TAAR1) increasing intracellular cyclic adenosine monophosphate (cAMP) levels in presynaptic cells of monoaminergic systems. In the present study, we investigated the effects of METH and HIV-1 on primary human astrocyte TAAR1 expression, function and glutamate clearance. Our results demonstrate combined conditions increased TAAR1 mRNA levels 7-fold and increased intracellular cAMP levels. METH and beta-phenylethylamine (β-PEA), known TAAR1 agonists, increased intracellular cAMP levels in astrocytes. Further, TAAR1 knockdown significantly reduced intracellular cAMP levels in response to METH/β-PEA, indicating signaling through astrocyte TAAR1. METH ± HIV-1 decreased excitatory amino acid transporter-2 (EAAT-2) mRNA and significantly decreased glutamate clearance. RNA interference for TAAR1 prevented METH-mediated decreases in EAAT-2. TAAR1 knockdown significantly increased glutamate clearance, which was further heightened significantly by METH. Moreover, TAAR1 overexpression significantly decreased EAAT-2 levels and glutamate clearance that were further reduced by METH. Taken together, our data show that METH treatment activated TAAR1 leading to intracellular cAMP in human astrocytes and modulated glutamate clearance abilities. Furthermore, molecular alterations in astrocyte TAAR1 levels correspond to changes in astrocyte EAAT-2 levels and function. To our knowledge this is the first report implicating astrocyte TAAR1 as a novel receptor for METH during combined injury in the context of HAND.
•Primary human astrocytes express functional TAAR1.•TAAR1 agonists, METH and β-PEA, lead to increased intracellular cAMP levels in primary human astrocytes.•TAAR1 is a potential receptor for METH-associated effects in human astrocytes.•METH and HIV-1 modulate astrocyte glutamate clearance abilities.
Molecular dynamics simulations were carried out to investigate cylindrical droplets consisting of binary mixtures of Lennard-Jones (LJ) fluids in contact with a solid substrate. The droplets are ...composed of mixtures of the monomeric LJ fluid plus linear-tangent chains of 2, 10, 20, and 30 segments per chain that interact through a harmonic potential and the spherically truncated and shifted potential Lennard-Jones. The solid surface was modeled as a semi-infinite platinum substrate with an FCC structure that interacts with the fluid by means of a LJ 9-3 potential. We place emphasis on the effect of mixing a monomeric LJ fluid with heavy components on the contact angle and on the droplet structure, especially in the liquid–solid region. The density profiles of the droplets reveal a strong discrete layering of the fluid in the vicinity of the solid–liquid interface. The layering is more pronounced at low temperatures and for mixtures of short chains (symmetric mixtures). The ordering of the fluid was much less intense for fluids of long chains (asymmetric mixtures), and some cases even show gas enrichment at the solid–liquid interface. Enrichment at the vapor–liquid interfaces and density inversion can also be observed. However, these effects are not as marked as in planar interfaces. The contact angle between the droplet and the substrate is calculated by fitting an ellipse to the vapor–liquid interface defined by the Gibbs dividing surface. In general, an increment in the concentration of the heavy component and a reduction of the temperature resulted in an increase of the contact angle, which in turn disfavored the wetting of the droplet.
Glutamate, the most abundant excitatory transmitter in the brain can lead to neurotoxicity when not properly regulated. Excitotoxicity is a direct result of abnormal regulation of glutamate ...concentrations in the synapse, and is a common neurotoxic mediator associated with neurodegenerative disorders. It is well accepted that methamphetamine (METH), a potent central nervous stimulant with high abuse potential, and human immunodeficiency virus (HIV)-1 are implicated in the progression of neurocognitive malfunction. Both have been shown to induce common neurodegenerative effects such as astrogliosis, compromised blood brain barrier integrity, and excitotoxicity in the brain. Reduced glutamate uptake from neuronal synapses likely leads to the accumulation of glutamate in the extracellular spaces. Astrocytes express the glutamate transporters responsible for majority of the glutamate uptake from the synapse, as well as for vesicular glutamate release. However, the cellular and molecular mechanisms of astrocyte-mediated excitotoxicity in the context of METH and HIV-1 are undefined. Topics reviewed include dysregulation of the glutamate transporters, specifically excitatory amino acid transporter-2, metabotropic glutamate receptor(s) expression and the release of glutamate by vesicular exocytosis. We also discuss glutamate concentration dysregulation through astrocytic expression of enzymes for glutamate synthesis and metabolism. Lastly, we discuss recent evidence of various astrocyte and neuron crosstalk mechanisms implicated in glutamate regulation. Astrocytes play an essential role in the neuropathologies associated with METH/HIV-1-induced excitotoxicity. We hope to shed light on common cellular and molecular pathways astrocytes share in glutamate regulation during drug abuse and HIV-1 infection.
Friction Theory Model for Thermal Conductivity Quiñones-Cisneros, Sergio E; Pollak, Stefan; Schmidt, Kurt A. G
Journal of chemical and engineering data,
11/2021, Letnik:
66, Številka:
11
Journal Article
Recenzirano
Thermal conductivity is an important transport property in nonequilibrium processes, for example, heat transfer between bodies. Compared to viscosity, there are relatively few experimental studies, ...and a model of engineering accuracy is needed to calculate the thermal conductivity in the absence of these experiments. This model also needs to apply to mixtures at conditions relevant to industrial processes. Numerous thermal conductivity correlations are available in the literature. However, most of them are for specific single fluids and cannot be extended to the prediction of mixture thermal conductivity. A new approach of a general nature, based on nonequilibrium properties and a common cubic equation of state, is presented in this investigation. This new approach delivers accurate and straightforward wide-range correlations for pure compounds and good predictions of mixture thermal conductivity (based on the studied test cases).
The processing, production, and transport of heavy crude oils are big challenges for the petroleum industry. Central to this challenge is the fluid viscosity: the key variable responsible for the oil ...fluidity throughout the entire production process. From the reservoir to delivery conditions, oils undergo large variations in temperature and pressure, which may cause important phase behavior and physicochemical changes, directly affecting the fluid’s thermophysical properties. In the case of heavy oils, such a broad change of conditions categorically results in several orders of magnitude viscosity span, including the possible Newtonian to non-Newtonian rheological behavior transitions. It is, therefore, of primary importance that heavy oils be rheologically well-characterized to ensure their production process is successful and viable. The viscosities of heavy and extra-heavy crude oils in extreme conditions (high pressure, high to low temperature, high to low shear rate) are, however, difficult for most service laboratories to fully measure directly. Several lapses may occur when measuring the full range of required conditions using traditional rheometers; for example, for such viscous fluids, the development of laminar-flow structural anomalies (eddies) and magnetic decoupling in the high-pressure cell are common practical problems. In an attempt to pragmatically address these problems, in this work, a methodology that may allow for the rheological characterization of heavy and extra-heavy oils within the full field operational range, but based on limited laboratory measurements, is proposed. The proposed approach does not follow from a simple extrapolation but is rather derived from the concept of control-variable shifting. For achieving this, the superposition principle is applied to shear-temperature and shear-pressure reliable measurements to construct master curves to rheologically characterize the fluid within conditions that may be too severe for direct laboratory measurements. This methodology has been successfully applied to a database of 20 Mexican fluids, going from extra-heavy to light fluids. The rheologies of the samples were originally studied using three different types of equipment: (1) a strain-controlled rheometer (for the measurement of the fluid rheology at ambient pressure and different temperatures), (2) a sliding piston viscometer for high-pressure and low-shear-rate viscosity measurements, and (3) a hybrid rheometer coupled with a pressure cell for the estimation of the fluids rheological behavior under pressure and high shear rate. The rheological behavior of crude oils could then be obtained at conditions as severe as the equipment allowed (up to 1000 bar and, in some cases, shear rate up to 1000 s–1). The master curves allowed, however, to extend the rheological characterization of the fluids within conditions that were beyond the laboratory capabilities.
PDF
