Transporter Density Research Articles

Diverging functional connectivity timescales: Capturing distinct aspects of cognitive performance in early psychosis

BackgroundPsychosis spectrum disorders (PSDs) are marked by cognitive impairments, the neurobiological correlates of which remain poorly understood. Here, we investigate the entropy of time-varying functional connectivity (TVFC) patterns from resting-state functional magnetic resonance imaging (rs-fMRI) as potential biomarker for cognitive performance in PSDs. By combining our results with multimodal reference data, we hope to generate new insights into the mechanisms underlying cognitive dysfunction in PSDs. We hypothesized that low-entropy TVFC patterns (LEN) would be more behaviorally informative than high-entropy TVFC patterns (HEN), especially for tasks that require extensive integration across diverse cognitive subdomains. Methodsrs-fMRI and behavioral data from 97 patients in the early phases of psychosis and 53 controls were analyzed. Positron emission tomography (PET) and magnetoencephalography (MEG) data were taken from a public repository (Hansen et al., 2022). Multivariate analyses were conducted to examine relationships between TVFC patterns at multiple spatial scales and cognitive performance in patients. ResultsCompared to HEN, LEN explained significantly more cognitive variance on average in PSD patients, driven by superior encoding of information on psychometrically more integrated tasks. HEN better captured information in specific subdomains of executive functioning. Nodal HEN-LEN transitions were spatially aligned with neurobiological gradients reflecting monoaminergic transporter densities and MEG beta-power. Exploratory analyses revealed a close statistical relationship between LEN and positive symptom severity in patients. ConclusionOur entropy-based analysis of TVFC patterns dissociates distinct aspects of cognition in PSDs. By linking topographies of neurotransmission and oscillatory dynamics with cognitive performance, it enhances our understanding of the mechanisms underlying cognitive deficits in PSDs.

Modelling of Ni Nitridation in NH3-Fueled Solid Oxide Fuel Cells

In the past decade NH3 fueled solid oxide fuel cells (SOFCs) are getting increasing attention. As compared to hydrogen, ammonia has the advantages of higher energy density and ease of storage and transportation. Due to the high operating temperature of SOFCs, typically in the range of 550-750C, NH3 can be easily decomposed into nitrogen and hydrogen over Ni-based cermet fuel electrodes. Previous studies have demonstrated NH3-fueled SOFCs with high power density, high efficiency and low emissions. One of the remaining challenges is the nitridation of Ni electrode. Under realistic operating conditions, Ni in the support and active layers of the fuel electrode has a tendency of being nitride when exposed to NH3, forming Ni3N and resulting in performance degradation. In this work, the thermodynamics of the Ni-N system is explored using the CALculation of PHAse Diagrams (CALPHAD) method. The kinetics of Ni3N formation in NH3-fuelled SOFCs is then predicted, taking into account the kinetics of both ammonia decomposition and Ni3N formation. The locations inside NH3-fuled SOFCs with potential risks of Ni nitridation are then predicted and strategies to avoid or reduce nitridation are further proposed.

Using Live-Cell Imaging to Measure the Effects of Pathological Proteins on Axonal Transport in Primary Hippocampal Neurons.

Bidirectional transport of cargos along the axon is critical for maintaining functional synapses, neural connectivity, and healthy neurons. Axonal transport is disrupted in multiple neurodegenerative diseases, and projection neurons are particularly vulnerable because of the need to transport cellular materials over long distances and sustain substantial axonal mass. Pathological modifications of several disease-related proteins negatively affect transport, including tau, amyloid-β, α-synuclein, superoxide dismutase, and huntingtin, providing a potential common mechanism by which pathological proteins exert toxicity in disease. Methods to study these toxic mechanisms are necessary to understand neurodegenerative disorders and identify potential therapeutic interventions. Here, cultured primary rodent hippocampal neurons are co-transfected with multiple plasmids to study the effects of pathological proteins on fast axonal transport using live-cell confocal imaging of fluorescently-tagged cargo proteins. We begin with the harvest, dissociation, and culturing of primary hippocampal neurons from rodents. Then, we co-transfect the neurons with plasmid DNA constructs to express fluorescent-tagged cargo protein and wild-type or mutant tau (used as an exemplar of pathological proteins). Axons are identified in live cells using an antibody that binds an extracellulardomain of neurofascin, an axon initial segment protein, and an axonal region of interest is imaged to measure fluorescent cargo transport. Using KymoAnalyzer, a freely available ImageJ macro, we extensively characterize the velocity, pause frequency, and directional cargo density of axonal transport, all of which may be affected by the presence of pathological proteins. Through this method, we identify a phenotype of increased cargo pause frequency associated with the expression of pathological tau protein. Additionally, gene-silencing shRNA constructs can be added to the transfection mix to test the role of other proteins in mediating transport disruption. This protocol is easily adaptable for use with other neurodegenerative disease-related proteins and is a reproducible method to study the mechanisms of how those proteins disrupt axonal transport.

Enhanced Performances for Solid-State Lithium-Ion Batteries with Llzo Thin Electrolyte and Silicon-Nanowires Electrode

In the past decades, due to an always more electrification and the research of a greener environment, Li-ion Batteries (LIB) have taken an important place in worldwide research. Solid-state batteries (SSBs) have the potential to revolutionize the energy storage industry, offering superior safety and energy density in comparison to traditional LIBs[1, 2]. Our research aims to enhance the performance and safety of solid-state batteries at ambient temperature by incorporating electrodes with high specific capacity with a lithium lanthanum zirconate (LLZO) solid electrolyte.The integration of SiNW electrodes into the solid-state battery architecture offers several advantages. SiNWs are known for their large surface area and superior electrical conductivity and offer a strong platform for efficient lithium-ion transport and cell energy density optimization, theoretically almost 10 times the capacity of graphite[3, 4]. Furthermore, LLZO solid electrolytes are a stable and non-flammable alternative to conventional liquid electrolytes[2, 5], significantly improving battery safety.The main objectives of this study are to investigate the combined effects of silicon nanowires (SiNWs) electrodes and LLZO solid electrolyte and to determine the optimal amount of liquid electrolytes to improve cell safety.In this work, an LLZO thin solid electrolyte tape has been manufactured by casting technique. Precise volumes of liquid electrolyte have been added to the LLZO tape to improve surface contact and ion conductivity. Furthermore, the study will provide a view of the relationship between the quantity of liquid electrolytes introduced and their impact on cell stability and safety.Preliminary results show the preparation of a mechanically stable LLZO tape with high ionic conductivity (>10-4 S cm-1) through an easy and up-scalable procedure. Improvements have been reported in the electrochemical performance of SiNW-LLZO solid-state batteries compared to the relative Li-ion liquid cell.In conclusion, here we developed a new thin solid electrolyte tape with high ionic conductivity, used in solid-state LIBs with silicon nanowires as anode material. Moreover, we standardized a procedure to optimize the use of organic liquid electrolytes as an additive, without omitting the volume or using any excess that could lead to safety issues. This optimization process can contribute to the development of solid-state batteries that are not only high-performance but also safe and reliable for various applications, including electric vehicles and portable electronics. References Wu, F., J. Maier, and Y. Yu, Guidelines and trends for next-generation rechargeable lithium and lithium-ion batteries. Chem Soc Rev, 2020. 49(5): p. 1569-1614.Wang, C., et al., Garnet-Type Solid-State Electrolytes: Materials, Interfaces, and Batteries. Chem Rev, 2020. 120(10): p. 4257-4300.Chan, C.K., et al., High-performance lithium battery anodes using silicon nanowires. Nat Nanotechnol, 2008. 3(1): p. 31-5.Kennedy, T., M. Brandon, and K.M. Ryan, Advances in the Application of Silicon and Germanium Nanowires for High-Performance Lithium-Ion Batteries. Adv Mater, 2016. 28(27): p. 5696-704.Xu, L., et al., Garnet Solid Electrolyte for Advanced All ‐Solid ‐State Li Batteries. Advanced Energy Materials, 2020. 11(2).

Abnormal interhemispheric functional cooperation in schizophrenia follows the neurotransmitter profiles.

Interhemispheric cooperation is one of the most prominent functional architectures of the human brain. In patients with schizophrenia, interhemispheric cooperation deficits have been reported using increasingly powerful neurobehavioural and neuroimaging measures. However, these methods rely in part on the assumption of anatomic symmetry between hemispheres. In the present study, we explored interhemispheric cooperation deficits in schizophrenia using a newly developed index, connectivity between functionally homotopic voxels (CFH), which is unbiased by hemispheric asymmetry. Patients with schizophrenia and age- and sexmatched healthy controls underwent multimodal MRI, and whole-brain CFH maps were constructed for comparison between groups. We examined the correlations of differing CFH values between the schizophrenia and control groups using various neurotransmitter receptor and transporter densities. We included 86 patients with schizophrenia and 86 matched controls in our analysis. Patients with schizophrenia showed significantly lower CFH values in the frontal lobes, left postcentral gyrus and right inferior temporal gyrus, and significantly greater CFH values in the right caudate nucleus than healthy controls. Moreover, the differing CFH values in patients with schizophrenia were significantly correlated with positive symptom score and illness duration. Functional connectivity within frontal lobes was significantly reduced at the voxel cluster level compared with healthy controls. Finally, the abnormal CFH map of patients with schizophrenia was spatially associated with the densities of the dopamine D1 and D2 receptors, fluorodopa, dopamine transporter, serotonin transporter and acetylcholine transporter. Regional abnormalities in interhemispheric cooperation may contribute to the clinical symptoms of schizophrenia. These CFH abnormalities may be associated with dysfunction in neurotransmitter systems strongly implicated in schizophrenia.

Analyzing Temperature Distribution, Mass Transport, and Cell Performance in PEM Fuel Cells with Emphasis on GDL Face Permeability and Thermal Contact Resistance Parameters.

Temperature distribution, mass transport, and current density are crucial parameters to characterize the durability and output performance of proton exchange membrane fuel cell (PEMFC), which are affected by thermal contact resistance (TCR) and gas diffusion layer (GDL) face permeability within both cathode and anode GDL porous jumps. This study examined the effects of TCR and GDL face permeability on a single PEM fuel cell's temperature profiles, mass transport, and cell performance using a three-dimensional, nonisothermal computational model with an isotropic gas diffusion layer (GDL). This model calculates the ideal thermal contact resistance by comparing the expected plate-cathode electrode temperature difference to the numerical and experimental literature. The combined artificial neural network-genetic algorithm (ANN-GA) method is also applied to identify the optimum powers and their operating conditions in six cases. Theoretical findings demonstrate that TCR and suitable GDL face permeability must be considered to optimize the temperature distribution and cell efficiency. TCR and GDL face permeability lead to a 1.5 °C rise in maximum cell temperature at 0.4 V, with a "Λ" shape in temperature profiles. The TCR and GDL face permeability also significantly impacts electrode heat and mass transfer. Case 6 had 1.91, 6.58, and 8.72% higher velocity magnitudes, oxygen mass fractions, and cell performances than case 1, respectively. Besides, the combined ANN-GA method is suitable for predicting fuel cell performance and identifying operation parameters for optimum powers. Therefore, the findings can improve PEM fuel cell performance and give a reference for LT-PEMFC design.

Neighborhood-Level Socioeconomic Status and Prescription Fill Patterns Among Patients With Heart Failure

Medication nonadherence is common among patients with heart failure with reduced ejection fraction (HFrEF) and can lead to increased hospitalization and mortality. Patients living in socioeconomically disadvantaged areas may be at greater risk for medication nonadherence due to barriers such as lower access to transportation or pharmacies. To examine the association between neighborhood-level socioeconomic status (nSES) and medication nonadherence among patients with HFrEF and to assess the mediating roles of access to transportation, walkability, and pharmacy density. This retrospective cohort study was conducted between June 30, 2020, and December 31, 2021, at a large health system based primarily in New York City and surrounding areas. Adult patients with a diagnosis of HF, reduced EF on echocardiogram, and a prescription of at least 1 guideline-directed medical therapy (GDMT) for HFrEF were included. Patient addresses were geocoded, and nSES was calculated using the Agency for Healthcare Research and Quality SES index, which combines census-tract level measures of poverty, rent burden, unemployment, crowding, home value, and education, with higher values indicating higher nSES. Medication nonadherence was obtained through linkage of health record prescription data with pharmacy fill data and was defined as proportion of days covered (PDC) of less than 80% over 6 months, averaged across GDMT medications. Among 6247 patients, the mean (SD) age was 73 (14) years, and majority were male (4340 [69.5%]). There were 1011 (16.2%) Black participants, 735 (11.8%) Hispanic/Latinx participants, and 3929 (62.9%) White participants. Patients in lower nSES areas had higher rates of nonadherence, ranging from 51.7% in the lowest quartile (731 of 1086 participants) to 40.0% in the highest quartile (563 of 1086 participants) (P < .001). In adjusted analysis, patients living in the lower 2 nSES quartiles had significantly higher odds of nonadherence when compared with patients living in the highest nSES quartile (quartile 1: odds ratio [OR], 1.57 [95% CI, 1.35-1.83]; quartile 2: OR, 1.35 [95% CI, 1.16-1.56]). No mediation by access to transportation and pharmacy density was found, but a small amount of mediation by neighborhood walkability was observed. In this retrospective cohort study of patients with HFrEF, living in a lower nSES area was associated with higher rates of GDMT nonadherence. These findings highlight the importance of considering neighborhood-level disparities when developing approaches to improve medication adherence.

Nonlocal Lagrange multipliers and transport densities

We prove the existence of generalized solutions of the Monge–Kantorovich equations with fractional [Formula: see text]-gradient constraint, [Formula: see text], associated to a general, possibly degenerate, linear fractional operator of the type, [Formula: see text] with integrable data, in the space [Formula: see text], which is the completion of the set of smooth functions with compact support in a bounded domain [Formula: see text] for the [Formula: see text]-norm of the distributional Riesz fractional gradient [Formula: see text] in [Formula: see text] (when [Formula: see text], [Formula: see text] is the classical gradient). The transport densities arise as generalized Lagrange multipliers in the dual space of [Formula: see text] and are associated to the variational inequalities of the corresponding transport potentials under the constraint [Formula: see text]. Their existence is shown by approximating the variational inequality through a penalization of the constraint and nonlinear regularization of the linear operator [Formula: see text]. For this purpose, we also develop some relevant properties of the spaces [Formula: see text], including the limit case [Formula: see text] and the continuous embeddings [Formula: see text], for [Formula: see text]. We also show the localization of the nonlocal problems ([Formula: see text]), to the local limit problem with classical gradient constraint when [Formula: see text], for which most results are also new for a general, possibly degenerate, partial differential operator [Formula: see text] with coefficients only integrable and bounded gradient constraint.

Multiscale modelling of species transport in hydrophilic Nafion®-coated Cu catalysts for CO2 electro-reduction

Ionomers such as Nafion are being used for engineering the microenvironment of the CO2RR towards selectivity to higher hydrocarbons. Their cationic exchange qualities mitigate homogeneous bicarbonate reactions, providing favourable conditions for production of C2-C3 products. The proximity of Nafion® layers to the negatively charged electrode surface results in complex effects that have yet to be explored computationally. We combine mass transport equations and density functional theory (DFT) calculations to model the hydrophilic moieties in Nafion® layer on a 1D planar copper electrode. We vary the Nafion® layer thickness in the thick film regime (200–1100 nm), the ionic strength of supporting aqueous electrolyte and the applied voltage to investigate the concentration profile of participating species within the Nafion® layer. We find that the bicarbonate ion concentration and local pH decrease with decreasing thickness which makes thinner films better at mitigating bicarbonates at the cost of a relatively lower pH. We observe the breakdown of Donnan exclusion effects with higher ionic strength electrolytes which allows diffusion of both co-ions and counter-ions, promoting the bicarbonate reactions. Further, we find that the pKa of Nafion® generally increases as the local dielectric constant of the reaction medium decreases. This is primarily due to the accumulation of K+ and production of low dielectric constant products such as ethanol, albeit their concentrations are low on planar Cu electrodes. The lower permittivity of the reaction medium weakens the exclusion forces and changes the morphology of Nafion® which ultimately impacts its ability to mitigate homogeneous bicarbonate reactions.

Optimal region for the transport problem to the boundary

We consider a region Ω⊂R2 where a mass f is transported to the boundary and the aim is to find an optimal free transport region E that minimizes the total cost outside E of this transport problem plus a penalization term on E. First, we study the regularity of the transport density σ in this transport problem to the boundary. Then, we show existence of an optimal set E for this shape optimization problem and, we prove regularity on this optimal set E in the case where the penalization term on E is given by the perimeter (or the fractional perimeter) of E.

Cardiac sympathetic "morbidity" might reflect the neurobiology of early Parkinson's disease.

An appropriate extracranial biomarker that delineates endophenotypes of Parkinson's disease (PD) at an early stage and reflects the neurodegenerative process is lacking. An evaluation of myocardial sympathetic nerve terminals could be a good candidate. This study aimed to explore subtypes of PD patients that showed cardiac catecholaminergic vesicular defect and their characteristics. This study included 122 early drug-naïve PD patients who were followed for approximately 4-5years. All patients were examined with 18F-N-(3-fluoropropyl)-2beta-carbon ethoxy-3beta-(4-iodophenyl) nortropane positron-emission tomography and 123I-meta-iodobenzylguanidine myocardial scintigraphy. Cardiac scans were reexamined two or three times. Patients were subgrouped into the sympathetic denervated group at the initial scan, those without evidence of denervated myocardium in the first and subsequent scans, and the converters whose myocardium was initially normal but became impaired in the subsequent scans. Cognition in 99 patients was initially assessed with neuropsychological tests. Any associations between cardiac denervation subtypes and presynaptic dopamine transporter densities were investigated. Cognitive status relevant to cardiac sympathetic denervation status was evaluated. This study found that cross-sectional comparisons of presynaptic monoamine transporter availability with a predefined order of cardiac denervation groups revealed parallel degeneration. A quadratic correlation between cardiac catecholamine capacity and cognition was observed. This association was interpreted to reflect the early neurobiology of PD. An observed cardiac catecholaminergic gradient was to mirror the central neurobiology of early PD.

Hemispheric asymmetry in cortical thinning reflects intrinsic organization of the neurotransmitter systems and homotopic functional connectivity

Hemispheric lateralization and its origins have been of great interest in neuroscience for over a century. The left-right asymmetry in cortical thickness may stem from differential maturation of the cerebral cortex in the two hemispheres. Here, we investigated the spatial pattern of hemispheric differences in cortical thinning during adolescence, and its relationship with the density of neurotransmitter receptors and homotopic functional connectivity. Using longitudinal data from IMAGEN study (N = 532), we found that many cortical regions in the frontal and temporal lobes thinned more in the right hemisphere than in the left. Conversely, several regions in the occipital and parietal lobes thinned less in the right (vs. left) hemisphere. We then revealed that regions thinning more in the right (vs. left) hemispheres had higher density of neurotransmitter receptors and transporters in the right (vs. left) side. Moreover, the hemispheric differences in cortical thinning were predicted by homotopic functional connectivity. Specifically, regions with stronger homotopic functional connectivity showed a more symmetrical rate of cortical thinning between the left and right hemispheres, compared with regions with weaker homotopic functional connectivity. Based on these findings, we suggest that the typical patterns of hemispheric differences in cortical thinning may reflect the intrinsic organization of the neurotransmitter systems and related patterns of homotopic functional connectivity.

Increasing dopamine synthesis in nigrostriatal circuits increases phasic dopamine release and alters dorsal striatal connectivity: implications for schizophrenia

One of the most robust neurochemical abnormalities reported in patients with schizophrenia is an increase in dopamine (DA) synthesis and release, restricted to the dorsal striatum (DS). This hyper functionality is strongly associated with psychotic symptoms and progresses in those who later transition to schizophrenia. To understand the implications of this progressive neurobiology on brain function, we have developed a model in rats which we refer to as EDiPs (Enhanced Dopamine in Prodromal schizophrenia). The EDiPs model features a virally mediated increase in dorsal striatal (DS) DA synthesis capacity across puberty and into adulthood. This protocol leads to progressive changes in behaviour and neurochemistry. Our aim in this study was to explore if increased DA synthesis capacity alters the physiology of DA release and DS connectivity. Using fast scan cyclic voltammetry to assess DA release we show that evoked/phasic DA release is increased in the DS of EDiPs rats, whereas tonic/background levels of DA remain unaffected. Using quantitative immunohistochemistry methods to quantify DS synaptic architecture we show a presynaptic marker for DA release sites (Bassoon) was elevated within TH axons specifically within the DS, consistent with the increased phasic DA release in this region. Alongside changes in DA systems, we also show increased density of vesicular glutamate transporter 1 (VGluT1) synapses in the EDiPs DS suggesting changes in cortical connectivity. Our data may prove relevant in understanding the long-term implications for DS function in response to the robust and prolonged increases in DA synthesis uptake and release reported in schizophrenia.

Efficiency benchmarking and its determinants in high-speed railways: Reference for China

The high-speed railway (HSR) performance has drawn considerable attention from international scholars and policymakers. One heatedly-discussed topic is measuring HSR efficiency and its important determinants, particularly HSR organizational structures. The main contribution of our research is the adoption of the multi-stage Network Data Envelopment Analysis (DEA) and Tobit Model, which provides a rational and coherent method to address this issue.We select the dataset from main HSR countries during the period of 2009–2018, and rank the efficiency of HSRs of different countries. Subsequently we examine the relationship between HSR efficiency and characteristic determinants, along with geographical and economic indicators that may influence the model.The results have revealed the HSR productivity difference do exist among countries. Overall, Asia's HSR systems demonstrate higher efficiency compared to those in Europe; while China's HSR efficiency ranks medium in the HSR multi-stages chain but higher in the service stage. Furthermore, the determinants of organizational structure can significantly effect on the effectiveness of HSR systems under a certain transport density threshold. In conclusion, regulators and operators should endeavor to increase traffic by meeting the demand to improve system efficiency. For China, focusing on vertical integration should be the key aspect of future HSR reform.

An investigation of combined effects of road capacity and accessibility on urban density, land use mix, and vitality

This study examines the combined impact of road accessibility and road capacity on urban form characteristics such as land use mix, building density, and vitality. The investigation was conducted in three cities in Sri Lanka: Colombo, Kurunegala, and Mawanalla. The study recognises the fundamental role of accessibility in shaping land use mix and urban densities and acknowledges the reciprocal relationship between transport infrastructure and land use decisions. It also recognises that the capacity of road infrastructure can influence land use choices and development patterns. Accessibility, in this context, can be thought of as the degree to which different parts of the city are well-connected and easily reachable. It includes not only the presence of roads but also their connectivity. By investigating how variations in accessibility and road capacity affect land use mix, densities, and vitality within the study areas, the study aims to discern the intricate relationships between transportation networks, land use, and density decisions. This study finds that accessibility has a stronger influence on density, land use mix, and vitality than road capacity. Further, the study finds that the influence of vehicle movement on land use mix, density, and vitality indicated a strong relationship, while the influence of pedestrian movement indicated a weak relationship. Accordingly, the findings of this study have practical implications for both transport and urban planning professionals and academics. Transport engineers can help promote desirable urban form characteristics by improving the accessibility of the road network. Urban planners can consider key findings when making zoning plans and urban development plans.

Assessing multi-spatial driving factors of urban land use transformation in megacities: a case study of Guangdong–Hong Kong–Macao Greater Bay Area from 2000 to 2018

ABSTRACT Rapid morphological and socioeconomic changes have accelerated the urbanization process and urban land use transformation in China. Megacities comprise clusters of urban cities and exhibit both newly formed and well-developed urban land use development beyond administrative boundaries. It is necessary to distinguish the changing effects of spatial-varying driving factors on newly formed urban land uses from well-developed built-up areas in megacities. This study proposed a multi-spatial urbanization framework to quantify region-level socioeconomics, cluster-level ecological morphologies, and grid-level urban functional morphologies. A three-level Bayesian hierarchical model was developed to investigate the impacts of multi-spatial driving factors on urban land use transformation in megacities. The study period focused on the urbanization process between 2000 and 2018 in Guangdong–Hong Kong–Macao Greater Bay Area (GBA). Results revealed that compared with well-developed urban built-up land, changing impacts of three-level driving factors in urban land use transformation could be captured based on the proposed Bayesian hierarchical model. The region-level total population was associated with increasing possibilities in forming new residential land than the well-developed ones in 35 districts/counties/cities in GBA. Cluster-level ecological attributes with higher proportion, lower edge density of urban built areas, and lower-degree ecological complexity showed increasing probability on newly formed industrial and public land. Grid-level urban functional factors including public transportation density and shopping/dining distribution exhibited significantly decreasing probability (coefficients: −2.12 to −0.51) on contributing newly formed land uses compared with the well-developed areas, whereas business/industry distribution represented higher (coefficients: 0.99 and 0.15) and lower probabilities (coefficient: −0.22) of forming industrial/public land and residential land separately. This research shows a new attempt to distinguish multi-spatial morphological and socioeconomic effects in urban land use transformation in megacities.

Noradrenaline transporter PET reflects neurotoxin-induced noradrenaline level decrease in the rat hippocampus

BackgroundThe neuropathological changes of early Alzheimer’s disease (AD) include neurodegenerative loss of noradrenaline neurons in the locus coeruleus with decreasing noradrenaline availability in their projection areas such as the hippocampus. This diminishing noradrenaline availability is thought to play an important role pathophysiologically in the development of cognitive impairment in AD, because noradrenaline is not only essential for maintaining cognitive functions such as memory, learning and attention, but also its anti-inflammatory action, where its lack is known to accelerate the progression of AD in the mouse model. Therefore, the availability of in vivo biomarkers of the integrity of noradrenaline neurons may be beneficial for furthering our understanding of the role played by the noradrenaline system in the progressive cognitive dysfunction seen in AD patients. In this study, we investigated if PET imaging of noradrenaline transporters can predict the level of noradrenaline in the brain. Our hypothesis was PET measured noradrenaline transporter densities could predict the level of noradrenaline concentrations in the rat hippocampus after lesioning of noradrenaline neurons in this region.ResultsWe chemically lesioned the hippocampus of rats (n = 15) by administering a neurotoxin, DSP-4, in order to selectively damage axonal terminals of noradrenergic neurons. These rats then underwent PET imaging of noradrenaline transporters using [11C]MRB ((S,S)-[11C]Methylreboxetine). To validate our hypothesis, postmortem studies of brain homogenates of these rats were performed to measure both noradrenaline transporter and noradrenaline concentrations. [11C]MRB PET showed decreased noradrenaline transporter densities in a DSP-4 dose-dependent manner in the hippocampus of these rats. In turn, these PET measured noradrenaline transporter densities correlated very well with in vitro measured noradrenaline concentrations as well as in vitro transporter densities.Conclusions[11C]MRB PET may be used as an in vivo biomarker of noradrenaline concentrations in the hippocampus of the neurodegenerating brain. Further studies appear warranted to extend its applicability to AD studies.

Is high-speed rail a sustainable mobility option? A life-cycle assessment of the Basque Y project in Spain

The Basque Y High Speed Rail connection between Madrid and the Basque Autonomous Community is, quite exceptionally, a mixed freight and passengers HSR line, that has been presented as a fundamental step towards a more sustainable mobility. In this paper, a life-cycle assessment (LCA) is conducted to assess the environmental performance of the line throughout its lifetime, based on the latest data available, including both construction and maintenance burdens. Results show that this new corridor is not justified in terms of reducing emissions and energy consumption, mainly due to its low transport density. It also has a negligible impact on Spanish current low rail freight traffic. We conclude, therefore, that Spain needs to reconsider its AVE network expansion if aiming at increasing rail's modal share and meeting the emissions targets set by the EU. From a policy perspective, many information inconsistencies have been found regarding the demand projections of freight transport, which cast serious doubt about the decision-making process behind Trans-European transport projects.

Assembly of Alloyed PdM (Ag, Cu, and Sn) Nanosheets and Their Electrocatalytic Oxidation of Ethanol and Methanol.

Direct alcohol fuel cells are popular due to their high energy density, abundant sources, and ease of transportation and storage. Palladium-based nanosheet self-assembled materials have emerged as an effective catalyst for alcohol oxidation reactions. In this work, nanosheets were synthesized with the same feeding ratio assembly of alloyed PdM (M = Ag, Cu, and Sn). The introduction of the second element was able to enhance the catalytic response of the catalysts to alcohol electrooxidation. Among them, the PdCu alloy exhibited the best performance in terms of catalytic activity, toxicity resistance, and stability to ethanol oxidation reaction (EOR) and methanol oxidation reaction (MOR). The catalytic current densities for EOR can reach 2226, 2518, and 1598 mA mg-1 for PdAg, PdCu, and PdSn nanosheet assemblies, respectively. These are mainly attributed to better electronic effects, altered atomic distances within the cell for the d-band centers of Pd, and a larger electrochemical active surface area (ECSA). The optimized d-band center is beneficial to promote the catalytic performance of EOR and MOR. Experimental data also demonstrated that higher electrocatalytic temperature, higher pH, and higher alcohol concentration can accelerate the rate of alcohol electrooxidation. These results have the potential to be extended to Pd-M (M = other metals) nanosheets and help for a wider range of catalytic applications.

High capacity rechargeable coin cells using all active material electrodes and percolated networks of LiCoO2 blended with LiNi0.8Co0.15Al0.05O2

Lithium-ion batteries have become a popular rechargeable energy storage technology due to high volumetric and gravimetric energy density. One route to increase energy density at the cell level is to increase electrode thickness. All active material (AAM) electrodes, fabricated via hydraulic compression and mild sintering of only electroactive material (no polymer binder or conductive additives) provide a robust route to thick lithium-ion electrodes. However, depending on the materials chosen, AAM electrodes can have high matrix electronic conductivity resistance due to low intrinsic electronic conductivity of the electroactive materials. Herein, a multicomponent AAM was constructed using a blend of electroactive material with high electronic conductivity to facilitate matrix electronic transport and high energy density to increase overall cell capacity. The electrode thicknesses were matched within the geometry of a 2032-type coin cell, resulting in high overall reversible capacity for these AAM electrode cells.