Independent Transport Research Articles

Variations in plume activity reveal the dynamics of water-filled faults on Enceladus

After discovering a jet activity near the south pole of Saturn’s moon Enceladus, the Cassini mission demonstrated the existence of a subsurface water ocean with a unique sampling opportunity through flybys. Diurnal variations in the observed brightness of the plume suggest a tidal control, although the existence and timing of two activity maxima seem to contradict stress analysis predictions. Here, we re-interpret the observed plume variability by combining a 3D global model of tidal deformation of the fractured ice shell with a 1D local model of transport processes within south-polar faults. Our model successfully predicts the observed plume’s temporal variability by combining two independent vapour transport mechanisms: slip-controlled jet flow and normal-stress-controlled ambient flow. Moreover, it provides a possible explanation for the differences between the vapour and solid emission rates during the diurnal cycle and the observed fractionation of the various icy particle families. Our model prediction could be tested by future JWST observations targeted when Enceladus is at different positions on its orbit and could be used to determine the optimal strategy for plume material sampling by future space missions.

The whole journey chain with public transport for people with autism spectrum disorder and attention deficit hyperactivity disorder – a scoping review

ABSTRACT Independent transport mobility is an important contributor to health, well-being, and participation. Several skills and competences are required for a person to use the transport system. The characteristics of cognitive disorders, such as Autism Spectrum Disorder (ASD) and Attention deficit/hyperactivity disorder (ADHD), may pose barriers to independent travel. Methods The study’s aim was to synthesise knowledge on the use of public transport among individuals with ASD or ADHD using the whole journey chain perspective. A scoping review using the PRISMA ScR framework was conducted, and included articles published between January 2012 and June 2022. A total of 11 studies from four countries were included in the analysis. Results This study complements the whole journey chain perspective with a phase that takes place long before the journey begins, and which concerns planning and preparation. Confident travellers could easily learn new routes, while those lacking confidence faced challenges, especially with unexpected route changes or cancellations. Conclusions There is a great need for emphasis on the design of public transport facilities and public spaces to increase the sense of safety for travellers with ASD, and to assist them with information-seeking, comprehension, and recovery between journeys.

Intra-strand phosphate-mediated pathways in microsolvated double-stranded DNA

We argue that dry DNA charge transport in molecular junctions, over distances of tens of nanometers, can take place via independent intra-strand pathways involving the phosphate groups. Such pathways explain recent single-molecule experiments that compare currents in intact and nicked 100 base-pair double-stranded DNA. We explore the conditions that favor independent intra-strand transport channels with the participation of the phosphate groups, as opposed to purely base-mediated transport involving the pi-stacked bases and inter-strand transitions. Our computations demonstrate how long-distance transport pathways in DNA are tuned by the degree of solvation, which affects the level of dynamic disorder in the pi-stacking, and the energies of phosphate-group molecular orbitals.

Directional Charge Carrier Management Enabled by Orderly Arranged Perovskite Heterodomain with Defined Size for Self‐Powered Photodetectors

AbstractPerovskite planar heterojunction is reported to promote charge‐carrier separation at the interface due to the introduced built‐in potential, leading to improved charge‐carrier harvesting. However, the possible diffusion of charge carriers along the film lateral will increase their travel distance to respective electrodes, resulting in increased recombination probabilities. Constructing independent transport channels for positive and negative charge carriers individually is an efficient way to optimize the transport in the perovskite layer and thereby to achieve enhanced device performance. Here, a solution‐based strategy is proposed to fabricate lateral bulk heterojunction (BHJ) by arranging methylammonium‐based and formamidinium‐based perovskites alternately in an ordered array with controllable domains. The structure of perovskite heterodomain directs charge carrier transport along the film normal and limits in‐plane charge carrier diffusion. Moreover, the ordered perovskite array is found to greatly increase light harvesting. Consequently, the self‐powered photodetector based on the perovskite heterodomain with a thickness of only 250 nm achieves a specific detectivity exceeding 1 × 1014 Jones for weak light over the whole visible light spectrum. This work provides guidance toward the fabrication of perovskite lateral BHJ using solution processing, meeting the requirements not only for charge‐carrier manipulation but also for light management.

Weak interlayer interactions and nearly temperature independent electrical transport in p-type 1T′-MoTe2/Sb2Te3 superlattice-like films

Thermoelectric superlattices (SLs) are one of the important focuses in the thermoelectric field due to their ordered stacking structure and the potential to obtain extremely high thermoelectric performance. To understand the critical effects of interlayer interactions, this work fabricates p-type (1T′-MoTe2)x(Sb2Te3)y SLs and investigates their electrical properties as functions of SL period and temperature. The results discovered that the weak interlayer interactions could be driven by both the small work function difference and temperature. This brings forth hole donation and energy filtering and leads to increased hole density and the carrier effective mass of (1T′-MoTe2)x(Sb2Te3)y SLs. Strikingly, the SL structure is beneficial for achieving temperature independent electrical properties, owing to the temperature driven interlayer interaction. Several SLs acquire the largest average power factor among all SLs, which is about 1.10 mWm−1K−2 within 300∼473 K, favorable for thermoelectric applications near room temperature. This work points out the beneficial effect of the SL structure on obtaining high thermoelectric properties in a wide temperature range.

Estimation of mixed-gas selectivity of membranes using the linear friction-based model

The development of analytical models for predicting the transport properties of membranes in the separation of multicomponent mixtures is highly relevant because (1) measurements of permeability and sorption of gas mixtures in membrane materials are laborious and time-consuming, and (2) estimation of transport properties based on pure gas measurements is desirable, however, rather unreliable and can lead to serious errors. In this paper, within the framework of the well-known frictional-coefficient formalism, we present nonlinear equations for the fluxes of gas mixture components through the membrane, which take into account the diffusional coupling of the fluxes compared to independent gas transport. As a result, an analytical equation for the mixed-gas selectivity was obtained. This equation has an implicit form, which is not quite convenient for practical application, since it has to be solved numerically. A simple explicit expression for mixed gas selectivity was derived using the so-called linear transport model, which is a linearized version of the original nonlinear flux equations. It is important to emphasize that a comparison of the linear model with the formally more rigorous nonlinear model showed only minor quantitative differences. The input parameters for the model are the single gas transport parameters. Testing the linear model using experimental data for the separation of hydrocarbons (n-butane/methane, n-butane/i-butane, propylene/propane) revealed an acceptable fit. A comparison of the model with recent experimental data on the separation of CO2-containing mixtures using microporous polymers is also presented. It is found that the calculated CO2/N2 mixed gas selectivity is in good agreement with the experimental data, while only a semi-quantitative agreement is observed for the CO2/CH4 separation. Besides, it is shown that the model developed for binary gas separation can be extended to ternary gas mixtures.

Saturated fatty acids inhibit unsaturated fatty acid induced glucose uptake involving GLUT10 and aerobic glycolysis in bovine granulosa cells

Fatty acids have been shown to modulate glucose metabolism in vitro and in vivo. However, there is still a need for substantial evidence and mechanistic understanding in many cell types whether both saturated and unsaturated fatty acids (SFAs and UFAs) pose a similar effect and, if not, what determines the net effect of fatty acid mixes on glucose metabolism. In the present study, we asked these questions by treating granulosa cells (GCs) with the most abundant non-esterified fatty acid species in bovine follicular fluid. Results revealed that oleic and alpha-linolenic acids (UFAs) significantly increased glucose consumption compared to palmitic and stearic acids (SFAs). A significant increase in lactate production, extracellular acidification rate, and decreased mitochondrial activity indicate glucose channeling through aerobic glycolysis in UFA treated GCs. We show that insulin independent glucose transporter GLUT10 is essential for UFA driven glucose consumption, and the induction of AKT and ERK signaling pathways necessary for GLUT10 expression. To mimic the physiological conditions, we co-treated GCs with mixes of SFAs and UFAs. Interestingly, co-treatments abolished the UFA induced glucose uptake and metabolism by inhibiting AKT and ERK phosphorylation and GLUT10 expression. These data suggest that the net effect of fatty acid induced glucose uptake in GCs is determined by SFAs under physiological conditions.

Investigating SARS-CoV-2 virion material trafficking in syrian hamster neocortecal neurons

Introduction. Taking into account the experience on the new coronavirus infection COVID-19 pandemic, the relevance of studies assessing the cellular processes of SARS-CoV-2 virus assembly and transport to justify the choice of pharmacological action points has now markedly increased. The study was aimed at analyzing morphologically assessed events of SARS-CoV-2 life cycle in neocortical neurons using electron microscopy based on its traced wide prevalence in vivo and ability to penetrate the blood-brain barrier accounts. Materials and methods. Patient-derived SARS-CoV-2 virus was obtained and accumulated in Vero(B) cell culture. An electron microscopy study (EMR) of the viral particle transport was carried out in male Syrian hamsters. Animals were inoculated intranasally with 26 μl of virus culture in an amount of 4 × 104 TCID50/ml. Animals were euthanized on day 3, 7, and 28 post-infection. The extracted brain was prepared for EMR according to methods previously described in the literature. The results were recorded using an FEI Tecnai G2 Spitit BioTWIN electron microscope. Results. Using EMR, the morphological equivalents of virus transport variants in neocortical neurons were traced dynamically during infectious process in Syrian hamsters. After synthesis, viral membrane proteins are included in transport vesicles in the endoplasmic reticulum (ER) terminal tubules and enter the intermediate compartment (IC), a collection of smooth-walled membrane vesicles between the endoplasmic reticulum (ER) and the Golgi apparatus (AG). In the first 3 days post-infection, viral copies are included in the Ag in PC membrane-formed transport vesicles. Due to the large size, viral particles are restricted to the expanded ends of the mobile AG tanks. Morphologically, destruction of AG membranes was revealed on day 7 post-infection, which indicates an interaction between PC vesicles and preserved AG membrane elements or the implementation of their independent transport function to deliver SARS-CoV-2 virus to the cell periphery and further into the intercellular space. In the neuronal processes, the transport of mature SARS-CoV-2 viral particles associated with cytoskeletal elements was observed, which was not detected in other loci of virus persistence. Conclusion. Based on data obtained, it is possible to hypothesize about a cumulative importance for progression and persistence of SARS-CoV-2 infection in cortical neurons. Early signs of neuron infection are represented by characteristic changes in the nuclei, ER hypertrophy and formation of “viral factories” based on the ER, PC and AG. The formation of viral biomass occurs inside neurons; virion exit from target cells is more accompanied by cell death rather than if a virus becomes incorporated in the lysosomal-endosomal system.

Blood-to-Testis Transport of Ribavirin Involves Carrier-Mediated Processes at the Blood–Testis Barrier

Ribavirin, an antiretroviral agent targeting the hepatitis C virus, causes male reproductive toxicity. This study investigated the mechanism of ribavirin transport at the blood–testis barrier (BTB). In vivo mouse integration plot analysis after intravenous administration revealed that the net influx clearance of [3H]ribavirin in the testis was 3.6-fold greater than that of [14C]D-mannitol, a paracellular transport marker, implying transcellular transport of ribavirin across the BTB. Moreover, [3H]ribavirin uptake by TM4 cells, mouse-derived Sertoli cells, was time- and concentration-dependent, with a Km value of 2.49 mM. S-[(4-nitrophenyl)methyl]-6-thioinosine, an inhibitor of Na+-independent equilibrative nucleoside transporters (ENTs), strongly inhibited the [3H]ribavirin uptake by TM4 cells at 100 µM. Compared to the uptake of [3H]adenosine, a typical endogenous nucleoside, [3H]ribavirin uptake was relatively similar to ENT2 transport. [3H]Ribavirin uptake was also observed in mouse ENT2-expressing Xenopus laevis oocytes, and gene silencing via the transfection of ENT2 small interfering RNA significantly reduced the [3H]ribavirin transport into TM4 cells by 13%. Taken together, these results suggest that ENT2 partially contributes to ribavirin transport at the BTB.

Secured intelligent transportation with privacy retention through blockchain framework

The Secured Independent Intelligent Transport System (SIITS) is poised to revolutionize traditional transport management systems, leveraging autonomous vehicles (AVs) connected through an open-channel Internet to link Traffic Command Centers (TCCs), Road Side Units (RSUs), and AVs within the SIITS framework. However, this reliance on the Internet exposes users to various security risks, safety vulnerabilities, and other challenges that impede the progress of SIITS applications. In this method, ensuring robust security management and trustworthiness is paramount for the long-term adoption of this innovative trend. While previous efforts have focused on integrating security methods from multiple disciplines into a unified reference design, this article presents a reference architecture primarily centered around ITS safety. Additionally, the article introduces a proposed framework for enhancing ITS safety, addressing the confidence issues. To further address these challenges, the article offers categorization of goods, Big Data methods and services, and validates the utility of ITS business analytics for corporate applications through a groundbreaking multi-tier ITS security architecture.

CFD study on flow characteristics of sieve tray columns with circular downcomers

AbstractTo investigate the flow characteristics of sieve tray columns with circular downcomers, the Euler–Euler gas–liquid two‐phase flow model is used to simulate a three‐dimensional sieve tray column. Each phase is regarded as an interpenetrating continuum with independent transport equations. The velocity distribution, clear liquid height, and foam layer height are predicted by the model. The correlation is established for predicting the clear liquid height on the sieve tray. The results show the following: (1) The sensitivity of the clear liquid height to the gas phase load is greater than that of the liquid phase load. (2) When the gas–liquid distribution is stable, the flow on the round sieve tray column presents a piston flow pattern. (3) The average liquid holdup of the circular downcomer of the three heights all showed a slow decrease at first, and then an inflection point appeared near the height of 0.02 m, after which the liquid holdup dropped sharply. (4) The established correlation has good predictive performance for calculating the clear liquid height in the column, and the relative error between the calculated value and the actual value is less than 10%.

Simulation study on transport characteristics of leakage gas from the condenser of power plant

Exploring the transport characteristics of leakage gas in the condenser can facilitate quicker identification of leak points when using Helium tracer gas method for detection. We construct a 3-D physical model of the condenser to simulate the Helium gas leakage process within the tube bundle. On the steam side, we adopt RNG k-?, porous media, steam condensation, and convective diffusion models to describe steam and leakage gas-flow. On the waterside, we use the tube bundle thermal resistance model to describe the steam-water heat transfer. The research concludes with three key points. When the centripetal pressure gradient is insufficient, there will be leakage gas enrichment, resulting in flowing out in the form of diffusion. When there is no centripetal pressure gradient in the tube bundle region, it will extract only a small amount of upstream leakage gas along with steam through the flow. When reaching a stable level for leakage gas, the leakage intensity is proportional to the outlets? flow rate but is independent of the transport form. The deviation of the mass-flow rate decreases with the mesh quantity increasing, which is less than 2% when the mesh quantity is over 638228. The deviation between simulated and actual values of the two parameters is less than 5%, which reveals the good agreement between numerical calculation and actual work conditions. These conclusions can assist employees and researchers in evaluating data on leak points and enhancing detection techniques.

Transporters involved in adult rat cortical astrocyte dopamine uptake: Kinetics, expression and pharmacological modulation.

Astrocytes, glial cells in the central nervous system, perform a multitude of homeostatic functions and are in constant bidirectional communication with neuronal cells, a concept named the tripartite synapse; however, their role in the dopamine homeostasis remains unexplored. The aim of this study was to clarify the pharmacological and molecular characteristics of dopamine transport in cultured cortical astrocytes of adult rats. In addition, we were interested in the expression of mRNA of dopamine transporters as well as dopamine receptors D1 and D2 and in the effect of dopaminergic drugs on the expression of these transporters and receptors. We have found that astrocytes possess both Na+-dependent and Na+-independent transporters. Uptake of radiolabelled dopamine was time-, temperature- and concentration-dependent and was inhibited by decynium-22, a plasma membrane monoamine transporter inhibitor, tricyclic antidepressants desipramine and nortriptyline, both inhibitors of the norepinephrine transporter. Results of transporter mRNA expression indicate that the main transporters involved in cortical astrocyte dopamine uptake are the norepinephrine transporter and plasma membrane monoamine transporter. Both dopamine receptor subtypes were identified in cortical astrocyte cultures. Twenty-four-hour treatment of astrocyte cultures with apomorphine, a D1/D2 agonist, induced upregulation of D1 receptor, norepinephrine transporter and plasma membrane monoamine transporter, whereas the latter was downregulated by haloperidol and L-DOPA. Astrocytes take up dopamine by multiple transporters and express dopamine receptors, which are sensitive to dopaminergic drugs. The findings of this study could open a promising area of research for the fine-tuning of existing therapeutic strategies.

Truthful online double auctions for on-demand integrated ride-sourcing platforms

Integrated platforms are an emerging model of business that integrates ride-sourcing services provided by multiple companies on a single platform. It reduces market fragmentation and brings benefits to both travelers and participating independent transport service providers. To ensure the sustainability of such platforms, the main challenge lies in efficient matching between travelers and ride-sourcing companies, so that both sides obtain non-negative utility. In this study, we propose a double auction based framework to solve the matching and pricing problems for on-demand integrated ride-sourcing platforms. To solve the real-time matching problem, we develop two online mechanisms with a critical price dynamic updating algorithm and a greedy algorithm. The proposed mechanisms are guaranteed to achieve the desired economic properties, and their efficiency is evaluated through numerical studies.

A biomimetic chip to assess subcutaneous bioavailability of monoclonal antibodies in humans.

Subcutaneous (subQ) injection is a common route for delivering biotherapeutics, wherein pharmacokinetics is largely influenced by drug transport in a complex subQ tissue microenvironment. The selection of good drug candidates with beneficial pharmacokinetics for subQ injections is currently limited by a lack of reliable testing models. To address this limitation, we report here a Subcutaneous Co-Culture Tissue-on-a-chip for Injection Simulation (SubCuTIS). SubCuTIS possesses a 3D coculture tissue architecture, and it allows facile quantitative determination of relevant scale independent drug transport rate constants. SubCuTIS captures key in vivo physiological characteristics of the subQ tissues, and it differentiates the transport behavior of various chemically distinct molecules. We supplemented the transport measurements with theoretical modeling, which identified subtle differences in the local absorption rate constants of seven clinically available mAbs. Accounting for first-order proteolytic catabolism, we established a mathematical framework to assess clinical bioavailability using the local absorption rate constants obtained from SubCuTIS. Taken together, the technology described here broadens the applicability of organs-on-chips as a standardized and easy-to-use device for quantitative analysis of subQ drug transport.

Transport use limitations and its association with social participation among patients with stroke living in rural India

Purpose This study aimed to investigate the limitations in transport use among stroke survivors in rural India and examine its impact on their social participation. Materials and methods A cross-sectional survey assessed transport patterns, post-stroke changes, and limitations among patients with stroke (N = 77). Social participation was measured with the Stroke Impact Scale (SIS 3.0). Results Following stroke, there was a significant decrease (28–41%) in the proportion of participants who could use various modes of transport unassisted, particularly in driving a motorbike or scooter and using a bus or train. Post-stroke changes in transport use showed that many participants ceased or decreased their use of different modes of transport. Independent users consistently had higher social participation scores than dependent users across all transport modes, indicating better social participation. The mean differences in various transport modes ranged from 6 to 11 points (p < 0.01). Conclusions Independent use of different modes of transport, particularly public transportation, reduced among rural Indian stroke survivors. These transport limitations are significantly associated with reduced social participation, highlighting the need for interventions to improve accessibility and fostering greater community engagement for stroke survivors in this population. IMPLICATIONS FOR REHABILITATION Limited transportation access limits social participation for stroke survivors in rural India. Study results show a significant decrease in independent transport use among stroke survivors, affecting their social participation. Rehabilitation interventions should focus on improving transportation accessibility to enhance social engagement for rural stroke survivors.

Inhibition of cancer-type amino acid transporter LAT1 suppresses B16-F10 melanoma metastasis in mouse models

Metastasis is the leading cause of mortality in cancer patients. L-type amino acid transporter 1 (LAT1, SLC7A5) is a Na+-independent neutral amino acid transporter highly expressed in various cancers to support their growth. Although high LAT1 expression is closely associated with cancer metastasis, its role in this process remains unclear. This study aimed to investigate the effect of LAT1 inhibition on cancer metastasis using B16-F10 melanoma mouse models. Our results demonstrated that nanvuranlat (JPH203), a high-affinity LAT1-selective inhibitor, suppressed B16-F10 cell proliferation, migration, and invasion. Similarly, LAT1 knockdown reduced cell proliferation, migration, and invasion. LAT1 inhibitors and LAT1 knockdown diminished B16-F10 lung metastasis in a lung metastasis model. Furthermore, nanvuranlat and LAT1 knockdown suppressed lung, spleen, and lymph node metastasis in an orthotopic metastasis model. We discovered that the LAT1 inhibitor reduced the cell surface expression of integrin αvβ3. Our findings revealed that the downregulation of the mTOR signaling pathway, induced by LAT1 inhibitors, decreased the expression of integrin αvβ3, contributing to the suppression of metastasis. These results highlight the critical role of LAT1 in cancer metastasis and suggest that LAT1 inhibition may serve as a potential target for anti-metastasis cancer therapy.

Feasibility and optimization of freight-on-transit schemes for the sustainable operation of passengers and logistics

The integration of passengers and cargo flows is a promising strategy to reduce negative externalities and improve the operational and environmental performances of first-last mile transport and logistics. This is supported by the recent increase in just-in-time and fragmented deliveries, as well as technological advancements in transport and logistics. In this study, we investigate the financial and operational conditions under which an integrated system can be used instead of performing conventional independent passenger transport and freight deliveries to achieve the goal of reducing freight vehicle-km and -consequently-the associated environmental impact. We propose the generalization of a multi-commodity network design problem model to address customer and policymaker preferences simultaneously for the implementation of a freight-on-transit (FOT) system. We test the model in a cross-border area between Italy and Slovenia and propose a sensitivity analysis based on several scenarios that can simulate the preferences of stakeholders under different conditions. The results show that FOT can yield considerable benefits in terms of meeting freight transport demand if it is supported by adequate policies and technologies. Furthermore, political and stakeholder engagement plays a relevant role in the success of FOT initiatives, which are aimed at utilizing transportation services and include the reduction of transport-related externalities and, more generally, the environmental and social impacts of mobility.

Research of the logistics sphere for combined cargoes delivery by the analytical methods

In the article, on the example of planning and organizing container transportation of combined cargoes along the internal transport routes of Russia, a mathematical model and methodology for studying the logistics sphere of the processes under consideration are reviewed. The logistics of combined cargoes transportation can be represented as a continuous supply chain that does not have a material expression by itself, but forms some independent transport system that ensures the physical promotion of material flows and goods. Thus, the need for logistics is dictated by the necessity for a rational solution to a number of logistics tasks related to transportation. At the same time, the transport packaging of small consignments, which meets the principles of integrity and consistency of the process under consideration, not only dictates the forms and methods of attracting modes of transport to transportation, but also largely affects the theology of transportation and transshipment applied to such cargoes, and therefore the choice of the cargo delivery route. The specifics of such goods delivery to the consumer is that small shipments at one stage of transportation often lose the advantages inherent in container theologies due to the need for timely return of linear containers to the sea terminal. At the same time, there is a need for additional transshipment operations that ensure the transfer of batches of goods from one mode of transport to another, as well as the transportation of goods in enlarged cargo spaces formed on pallets together with other people’s cargo and a number of other independent factors. The described model considers the functioning of an unmanaged logistics environment, which is characterized by a significant set of random parameters. In such an environment, using an unpredictable number of transshipment and transportation technologies, the whole set of quantitative and qualitative indicators describing its activities is proposed to be expressed in points form.

Reduced kinetic model of polyatomic gases

Kinetic models of polyatomic gas typically account for the internal degrees of freedom at the level of the two-particle distribution function. However, close to the hydrodynamic limit, the internal (rotational) degrees of freedom tend to be well represented just by rotational kinetic energy density. We account for the rotational energy by augmenting the ellipsoidal statistical Bhatnagar–Gross–Krook (ES–BGK) model, an extension of the BGK model, at the level of the single-particle distribution function with an advection–diffusion–relaxation equation for the rotational energy. This reduced model respects the$H$theorem and recovers the compressible hydrodynamics for polyatomic gases as its macroscopic limit. As required for a polyatomic gas model, this extension of the ES–BGK model not only has the correct specific heat ratio but also allows for three independent tunable transport coefficients: thermal conductivity, shear viscosity and bulk viscosity. We illustrate the effectiveness of the model via a lattice Boltzmann method implementation.