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All-solid-state batteries (ASSBs) that employ anode-less electrodes have drawn attention from across the battery community because they offer competitive energy densities and a markedly improved cycle life. Nevertheless, the composite matrices of anode-less electrodes impose a substantial barrier for lithium-ion diffusion and inhibit operation at room temperature. To overcome this drawback, here, the conversion reaction of metal fluorides is exploited because metallic nanodomains formed during this reaction induce an alloying reaction with lithium ions for uniform and sustainable lithium (de)plating. Lithium fluoride (LiF), another product of the conversion reaction, prevents the agglomeration of the metallic nanodomains and also protects the electrode from fatal lithium dendrite growth. A systematic analysis identifies silver (I) fluoride (AgF) as the most suitable metal fluoride because the silver nanodomains can accommodate the solid-solution mechanism with a low nucleation overpotential. AgF-based full cells attain reliable cycling at 25 °C even with an exceptionally high areal capacity of 9.7 mAh cm

Since the emergence of SARS-CoV-2, several studies have been published describing neuromuscular manifestations of the disease, as well as management of pre-existing pediatric neuromuscular disorders during the COVID-19 pandemic. These disorders include muscular dystrophies, myasthenic syndromes, peripheral nerve disorders, and spinal muscular atrophy. Such patients are a vulnerable population due to frequent complications such as scoliosis, cardiomyopathy, and restrictive lung disease that put them at risk of severe complications of COVID-19. In this review, neuromuscular manifestations of COVID-19 in children and the management of pre-existing pediatric neuromuscular disorders during the COVID-19 pandemic are discussed. We also review strategies to alleviate pandemic-associated disruptions in clinical care and research, including the emerging role of telemedicine and telerehabilitation to address the continued special needs of these patients.

This study investigates the morphology, microstructure, compressive behavior, biocorrosion properties, and cytocompatibility of magnesium (Mg)-aluminum (Al) alloy (AE42) scaffolds for their potential use in biodegradable biomedical applications. Mg alloy scaffolds were successfully synthesized via a camphene-based freeze-casting process with precisely controlled heat treatment. The average porosity was approximately 52% and the median pore diameter was ∼13 μm. Salient deformation mechanisms were identified using acoustic emission (AE) signals and adaptive sequential k-means (ASK) analysis. Twinning, dislocation slip, strut bending, and collapse were dominant during compressive deformation. Nonetheless, the overall compressive behavior and deformation mechanisms were similar to those of bulk Mg based on ASK analysis. The corrosion potential of the Mg alloy scaffold (-1.44 V) was slightly higher than that of bulk AE42 (-1.60 V), but the corrosion rate of the Mg alloy scaffold was faster than that of bulk AE42 due to the enhanced surface area of the Mg alloy scaffold. As a result of cytocompatibility evaluation following ISO10993-5, the concentration of the Mg alloy scaffold extract reducing cell growth rate to 50% (IC50) was 10.7%, which is higher (less toxic) than 5%, suggesting no severe inflammation by implantation into muscle.

In this study, we prepared and characterized Nb-doped Li7La3Zr2−xO12 (LLZNO) powder and pellets with a cubic garnet structure by using a modified sol-gel synthesis and hot pressing. LLZNO powder with a very small grain size and cubic structure without secondary phases could be obtained by using a synthesis method in which Li and La sources in a propanol solvent were mixed together with Zr and Nb sources in 2-methoxy ethanol. A pure cubic phase LLZNO pellet could be fabricated from the prepared LLZNO and an additional 6-wt% of Li2CO3 powder by hot pressing at 1050 °C and 15.8 MPa. The hot-pressed LLZNO pellet with a relative density of 99% exhibited a very dense surface morphology. The total Li ionic conductivity of the hot-pressed LLZNO was 7.4×10 −4 S/cm at room temperature, which is very high level compared to other reported values. The activation energy for ionic conduction was estimated to be 0.40 eV.

Since the first reports of SARS-CoV-2 infection from China, multiple studies have been published regarding the epidemiologic aspects of COVID-19 including clinical manifestations and outcomes. The majority of these studies have focused on respiratory complications. However, recent findings have highlighted the systemic effects of the virus, including its potential impact on the nervous system. Similar to SARS-CoV-1, cellular entry of SARS-CoV-2 depends on the expression of ACE2, a receptor that is abundantly expressed in the nervous system. Neurologic manifestations in adults include cerebrovascular insults, encephalitis or encephalopathy, and neuromuscular disorders. However, the presence of these neurologic findings in the pediatric population is unclear. In this review, the potential neurotropism of SARS-CoV-2, known neurologic manifestations of COVID-19 in children, and management of preexisting pediatric neurologic conditions during the COVID-19 pandemic are discussed.

Pathological features of Parkinson's disease include the formation of Lewy bodies containing α-synuclein and the accumulation of iron in the substantia nigra. Previous studies have suggested that iron accumulation contributes to the Parkinson's disease pathology through reactive oxygen species production and accelerated α-synuclein aggregation. This study examines the effects of commonly occurring H63D variant of the homeostatic iron regulatory (HFE) gene on α-synuclein pathology in cell culture and animal models. H63D HFE expression in SH-SY5Y cells lowered endogenous α-synuclein levels and significantly decreased pre-formed fibril-induced α-synuclein aggregation. H63D HFE cells were also protected from pre-formed fibril-induced apoptosis. Autophagic flux, a major pathway for α-synuclein clearance, was increased in H63D HFE cells. Expression of REDD1 was elevated and rapamycin treatment was unable to further induce autophagy, indicating mTORC1 inhibition as the main mechanism of autophagy induction. Moreover, siRNA knockdown of REDD1 in H63D HFE cells decreased autophagic flux and increased the sensitivity to PFF-mediated toxicity. While iron chelator (deferiprone) treatment rescued WT HFE cells from pre-formed fibril toxicity, it exacerbated or was unable to rescue H63D HFE cells. In the in vivo pre-formed fibril intracranial injection model, H67D Hfe (mouse homolog of the human H63D HFE variant) C57BL/6J × 129 mice showed less α-synuclein aggregation and less decline in motor function compared to WT Hfe. Collectively, this study suggests that H63D HFE variant modifies α-synuclein pathology through the induction of autophagy and has the potential to impact the pathogenesis and treatment response in Parkinson's disease.

In Li-ion technology, increasing electrode loading (thickness) is one approach to improve performance; however, this approach typically compromises power density and safety. To achieve the goal of decoupling energy and power density, a novel electrode architecture is proposed. The electrode design enhances uniform ionic current, especially in thick electrodes. A highly ordered and hierarchical (HOH) graphite anode concept was designed, fabricated, and tested for efficacy. The HOH electrodes consisted of ordered arrays of macro-scale line-of-sight linear channels made through laser ablation. SEM and Raman spectroscopy demonstrated that laser ablation is a feasible approach to fabricate HOH electrodes without affecting the graphite anode chemistry, respectively. A 65–120% improvement in charge rate acceptance (5.5 mAh/cm2) was achieved in the HOH electrodes compared to conventional electrodes. A restricted diffusion direct current polarization test determined that the HOH design improved ionic flow throughout porous electrodes. Altogether, the results of this study suggest that improved charge rate acceptance can be achieved by engineering electrode porosity to mitigate the effects of concentration polarization in high energy density graphite anodes. These findings can facilitate the development of higher energy and power density Li-ion batteries, while improving resilience against Li plating under severe charge conditions.

In this paper, we review the challenges and opportunities for foam materials and their composites as novel energy conversion materials. Specifically, foams with an exceptionally high specific surface area could be a perfect solution for advanced energy applications because the electrodes with limited reaction area between an electrolyte and an active material have been identified as one of the key factors affecting the low-level performance of Li-ion batteries, which is a major challenge hindering their commercial application. In the past decade, several electrode materials, structures, and fabrication processes have been developed and investigated with the intention of improving electrode performance. Among these processes, foam architecture is attractive as an electrode structure in Li-ion batteries as it has an intrinsic structural integrity with the ability to buffer stress caused by the large volume changes in high capacity anode materials during cycling. In this review, the electrochemical properties, reversible capacity, long cycle capability, high discharge capacity, battery lifetime, power density, energy efficiency, tensile strength, and mechanical properties of various foam electrode materials are discussed. The foremost objective of this review is to provide an overview on the latest research on improved electrode performance and current perspectives on porous electrode materials for future Li-ion batteries.

The effect of relative density on the hardness and fracture toughness of Al-substituted cubic garnet Li6.19Al0.27La3Zr2O12 (LLZO) was investigated. Polycrystalline LLZO was made using solid-state synthesis and hot-pressing. The relative density was controlled by varying the densification time at fixed temperature (1050°C) and pressure (62 MPa). After hot-pressing, the average grain size varied from approximately 2.7–3.7 μm for the 85% and 98% relative density samples, respectively. Examination of fracture surfaces revealed a transition from inter- to intragranular fracture as the relative density increased. The Vickers hardness increased with relative density up to 96%, above which the hardness was constant. At 98% relative density, the Vickers hardness was equal to the hardness measured by nanoindentation 9.1 GPa, which is estimated as the single-crystal hardness value. An inverse correlation between relative density and fracture toughness was observed. The fracture toughness increased linearly from 0.97 to 2.37 MPa√m for the 98% and 85% relative density samples, respectively. It is suggested that crack deflection along grain boundaries can explain the increase in fracture toughness with decreasing relative density. It was also observed that the total ionic conductivity increased from 0.0094 to 0.34 mS/cm for the 85%–98% relative density samples, respectively. The results of this study suggest that the microstructure of LLZO must be optimized to maximize mechanical integrity and ionic conductivity.

Iron accumulation is a recurring pathological phenomenon in many neurological diseases including Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis, and others. Iron is essential for normal development and functions of the brain; however, excess redox-active iron can also lead to oxidative damage and cell death. Especially for terminally differentiated cells like neurons, regulation of reactive oxygen species is critical for cell viability. As a result, cellular iron level is tightly regulated. Although iron accumulation related to neurological diseases has been well documented, the pathoetiological contributions of the homeostatic iron regulator (HFE), which controls cellular iron uptake, is less understood. Furthermore, a common HFE variant, H63D HFE, has been identified as a modifier of multiple neurological diseases. This review will discuss the roles of iron and HFE in the brain as well as their impact on various disease processes.

Background: Superior vena cava (SVC) syndrome may result from extravascular compression or intravascular obstruction such as thrombosis. Recurrent venous thrombosis is typically associated with a hypercoagulable state such as malignancy, and inheritable or acquired coagulopathy. Sarcoidosis is a derangement of the immune system, and it has been associated with malignant diseases and hypercoagulation. The association of pancreatic cancer and sarcoidosis with SVC syndrome has not been reported previously. Here, we present a case of recurrent venous thrombosis causing SVC syndrome in a patient with pancreatic ductal adenocarcinoma and underlying thoracic sarcoidosis. Methods: The patient’s electronic health record was retrospectively analyzed. Results: A 66-year-old woman with pancreatic adenocarcinoma was treated with neoadjuvant chemotherapy followed by Whipple procedure, before developing tumor recurrence in the liver. Her treatment course was complicated with repeated incidents of venous thrombosis in the presence of a central venous catheter leading to recurrent SVC syndrome, which resolved with anti-coagulation. Conclusions: This case raises a plausible inter-relationship between sarcoidosis, pancreatic cancer, and hypercoagulable state. We suggest that patients with multiple risk factors for developing venous thrombosis should be carefully monitored for any thrombotic event, and they may benefit from prophylactic anti-coagulation.

Transitioning skutterudite (SKD) thermoelectric technology from space to terrestrial power generation requires oxidation suppression technology. One approach involves the development of protective coatings consisting of the following properties: (i) low thermal conductivity to prevent parasitic heat loss, (ii) low electrical conductivity to prevent short-circuiting, (iii) coefficient(s) of thermal expansion matching that of the thermoelectric material, and (iv) adequate thermal stability and mechanical strength for durability. In this work, n-type Ba0.05Yb0.025CoSb3 and p-type Ce0.9Co0.5Fe3.5Sb12 were coated with a silica-based enamel to prevent their oxidation. This work demonstrates the efficacy of enamel coatings for suppressing oxidation of n-type SKD, and for the first time, p-type SKD in static and thermal cyclic heating tests up to 600 °C in air. The coating process, physical characterization of the enamel, and materials characterization data are presented and discussed.

This paper proposes a coordinated multi-point (CoMP) based dynamic transmission scheme in a downlink multi-ship network, where a central ship selects a ship in order to maximize the utility function. The proposed scheduling scheme dynamically decides to the usage of the coordinated multi transmissions and selects a user to be served for every frame, in order to the utility function on the basis of the throughput and fairness. In particular, the proposed utilify function based scheduling scheme aims to increase the quality of service of ships at the edge of cells. Under the proportional fair scheduling, the simulation results show that the proposed utility function-based scheduling improves the throughput of the ships at the cell edge with the little sacrifice of the

The thin-plate specimen of 316L austenite stainless steel was charged with hydrogen using a cathodic charging technique. Despite the short diffusion distance of hydrogen predicted by the diffusion-controlled model for a semi-infinite sheet, the Vickers hardness measurements revealed the full effect of hydrogen in the center of the cross-sections of thin-plate specimens as well as in the vicinity of the outer surfaces, which appears to be due to the short-circuit diffusion mechanism along the grain boundaries. The room-temperature tensile properties of both undeformed and deformed (20, 40%) samples were examined and compared. Hydrogen softening was apparent in both types of samples. For example, the 40% deformed sample showed an approximately 17 and 7% lower yield and tensile strength, respectively, after H charging at a strain rate of 2 × 10−4 s−1 with a concomitant decrease in ductility compared to that without H.

The electrochemical stability of Li6.5La3Zr1.5Nb0.5O12 (LLZNO) and Li6.5La3Zr1.5Ta0.5O12 (LLZTO) against metallic Li was studied using direct current (DC) and electrochemical impedance spectroscopy (EIS). Dense polycrystalline LLZNO (ρ = 97%) and LLZTO (ρ = 92%) were made using sol–gel synthesis and rapid induction hot-pressing at 1100°C and 15.8 MPa. During DC cycling tests at room temperature (± 0.01 mA/cm2 for 36 cycles), LLZNO exhibited an increase in Li–LLZNO interface resistance and eventually short-circuiting while the LLZTO was stable. After DC cycling, LLZNO appeared severely discolored while the LLZTO did not change in appearance. We believe the increase in Li–LLZNO interfacial resistance and discoloration are due to reduction of Nb5+ to Nb4+. The negligible change in interfacial resistance and no color change in LLZTO suggest that Ta5+ may be more stable against reduction than Nb5+ in cubic garnet versus Li during cycling.

Linking accounts of the same user across datasets -- even when personally identifying information is removed or unavailable -- is an important open problem studied in many contexts. Beyond many practical applications, (such as cross domain analysis, recommendation, and link prediction), understanding this problem more generally informs us on the privacy implications of data disclosure. Previous work has typically addressed this question using either different portions of the same dataset or observing the same behavior across thematically similar domains. In contrast, the general cross-domain case where users have different profiles independently generated from a common but unknown pattern raises new challenges, including difficulties in validation, and remains under-explored. In this paper, we address the reconciliation problem for location-based datasets and introduce a robust method for this general setting. Location datasets are a particularly fruitful domain to study: such records are frequently produced by users in an increasing number of applications and are highly sensitive, especially when linked to other datasets. Our main contribution is a generic and self-tunable algorithm that leverages any pair of sporadic location-based datasets to determine the most likely matching between the users it contains. While making very general assumptions on the patterns of mobile users, we show that the maximum weight matching we compute is provably correct. Although true cross-domain datasets are a rarity, our experimental evaluation uses two entirely new data collections, including one we crawled, on an unprecedented scale. The method we design outperforms naive rules and prior heuristics. As it combines both sparse and dense properties of location-based data and accounts for probabilistic dynamics of observation, it can be shown to be robust even when data gets sparse.

This study simulated the performance of Cu-cored solder joints in microelectronic components subjected to the extreme thermal cycling conditions often encountered in the automobile industry by comparing the thermal cycling behavior of Cu-cored solder joints containing two different coating layers of Sn–3.0Ag and Sn–1.0In with that of a baseline Sn–3.0Ag–0.5Cu solder joint under a severe temperature cycling range of −55 to +150 °C. Both Cu-cored solder joints can be considered a potential solution to interconnects in microelectronic semiconductor packages used under harsh thermal conditions on account of their greater resistance to thermal stress caused by the severe temperature cycling than the baseline Sn–3.0Ag–0.5Cu solder joint.

The mechanical properties of new lead-free Sn–Ag–Cu solder alloys containing 0.05–0.1 wt.% boron were investigated under a range of isothermal aging and reflow conditions. The boron-doped solder joints showed higher ball pull strength than the baseline Sn-1.0Ag-0.5Cu solder joint under all isothermal aging and reflow conditions examined. In particular, the high-speed ball pull strength of the 0.05 wt.% B-doped solder joint was approximately 2.5 times greater than that of the baseline Sn-1.0Ag-0.5Cu solder joint aged at 150 °C for 200 h, which is attributed mainly to the reduced rate of grain growth in the intermetallic compound (IMC) layers of B-doped solder joints under aging conditions.

Copper-cored solder can be regarded as the next-generation solder for microelectronic semiconductors exposed to harsh operating conditions owing to its excellent sustainability under extreme thermal conditions, e.g., in microelectronic semiconductors used in transportation systems. Cu-cored solder joints with two different coating layers, Sn–3.0Ag and Sn–1.0In, were compared with the baseline Sn–3.0Ag–0.5Cu solder. The fracture strength and failure mode were examined using the high-speed ball-pull and normal-speed shear tests. The Cu-cored solder joint with the Sn–1.0In plating layer exhibited the highest ball-pull and shear strengths. In addition, it showed a much lower percentage of interface fracture between the Cu-core and plating layer than the interface fracture percentage in the Sn–3.0Ag plating layer due to the improved wettability between the Cu-core and Sn–1.0In plating layer.

This study examined how the strain rate affects the room-temperature tensile behavior of hydrogen-charged 316L stainless steels. A hightemperature homogenization treatment was applied to the specimens after hydrogen charging and copper electroplating to remove the hydrogen concentration gradient. A softening phenomenon was observed in the hardening behavior of the H-charged and homogenized specimen at a strain rate of 2 � 10 � 3 /s. The observation was further confirmed by an inspection of the fracture surface of the tensile test specimen. [doi:10.2320/matertrans.M2010273]

This study assesses the reliability of eutectic Sn–Pb, Sn–1.0Ag–0.5Cu, Sn–3.0Ag–0.5Cu and Sn–4.0Ag–0.5Cu solder bumps on three different pad surface finishes (ENIG, electrolytic Ni/Au and Cu-OSP) with and without an aging treatment at 150 °C for 100 h. This study focused primarily on how the pad surface finish and solder alloy composition affects the reliability of solder joints using a high-speed ball pull test method. The fracture forces and failure mechanisms were also examined. The results showed that the electrolytic Ni/Au surface finish had the highest fracture forces for all four different solder alloys with and without the aging process.

Despite being expensive and time consuming, board-level drop testing has been widely used to assess the drop or impact resistance of the solder joints in handheld microelectronic devices, such as cellphones and personal digital assistants (PDAs). In this study, a new test method, which is much simpler and quicker, is proposed. The method involves evaluating the elastic strain energy and relating it to the impact resistance of the solder joint by considering the Young’s modulus of the bulk solder and the fracture stress of the solder joint during a ball pull test at high strain rates. The results show that solder joints can be ranked in order of descending elastic strain energy as follows: Sn-37Pb, Sn-1Ag-0.5Cu, Sn-3Ag-0.5Cu, and Sn-4Ag-0.5Cu. This order is consistent with the actual drop performances of the samples.

An increasing fraction of users access content on the web from social media. Endorsements by microbloggers and public figures you connect with gradually replaces the curation originally in the hand of traditional media sources. One expects a social media provider to possess a unique ability to analyze audience and trends since they collect not only information about what you actively share, but also about what you silently watch. Your behavior in the latter seems safe from observations outside your online service provider, for privacy but also commercial reasons.In this paper, we show that supposing that your passive web visits are anonymous to your host is a fragile assumption, or alternatively that third parties -- content publishers or providers serving ads onto them -- can efficiently reconciliate visitors with their social media identities. What is remarkable in this technique is that it need no support from the social media provider, it seamlessly applies to visitors who \emph{never} post or endorse content, and a visitor's public identity become known after a few clicks. This method combines properties of the public follower graph with posting behaviors and recent time-based inference, making it difficult to evade without drastic or time-wasting measures. It potentially offers researchers working on traffic datasets a new view into who access content or through which channels.

A high peak-to-average power ratio (PAPR) is one of the serious disadvantages of an orthogonal frequency-division multiplexing (OFDM) system. Therefore, many PAPR reduction methods have been introduced. Especially, the signal scrambling methods such as selective mapping (SLM), partial transmit sequences (PTS), and polyphase interleaving and inversion (PII) are the attractive methods for obtaining a better PAPR property because the methods do not cause signal distortion. The multiple-input multiple-output (MIMO)-OFDM systems also have the high PAPR like the OFDM systems. In this paper, the partial shift sequence (PSS) method is proposed because it has a good PAPR reduction performance and low computational complexity. The PSS method is compared with the PII method in terms of the complementary cumulative distribution function (CCDF).

A solution-based process was investigated for synthesizing cubic Li7La3Zr2O12 (LLZO), which is known to exhibit the unprecedented combination of fast ionic conductivity, and stability in air and against Li. Sol-gel chemistry was developed to prepare solid metal-oxide networks consisting of 10 nm cross-links that formed the cubic LLZO phase at 600 ° C. Sol-gel LLZO powders were sintered into 96% dense pellets using an induction hot press that applied pressure while heating. After sintering, the average LLZO grain size was 260 nm, which is 13 times smaller compared to LLZO prepared using a solid-state technique. The total ionic conductivity was 0.4 mS cm(-1) at 298 K, which is the same as solid-state synthesized LLZO. Interestingly, despite the same room temperature conductivity, the sol-gel LLZO total activation energy is 0.41 eV, which 1.6 times higher than that observed in solid-state LLZO (0.26 eV). We believe the nano-scale grain boundaries give rise to unique transport phenomena that are more sensitive to temperature when compared to the conventional solid-state LLZO.