Lithium–sulfur (Li–S) batteries receive great attention due to their high theoretical energy density and low cost. However, the sulfur–carbon cathode suffers from the polysulfide dissolution during ...cycling, and the severe shuttle effect limits the practical application of Li–S batteries. In this work, a carbon material (XU76 carbon) derived from industry-residual petroleum was synthesized with a simple and low-cost method. Nitrogen adsorption, small-angle neutron scattering (SANS), adsorption kinetics, and UV–vis spectroscopy results show that the interconnected micromesopores in XU76 could act as a reservoir and trap polysulfide intermediates efficiently. The XU76 carbon with high surface area (∼1005 m2 g–1), good electric conductivity, good ion transport, and optimized distribution of interconnected micromesopores is used as the sulfur host for trapping polysulfide intermediates and advancing sulfur redox kinetics. The Li–S battery with the sulfur–XU76 carbon cathode gives an initial discharge capacity of ∼1200 mAh g–1 in the initial cycle and reversible capacity of ∼700 mAh g–1 after 100 cycles at a C rate of 0.1 C while the Li–S battery with the sulfur–KB carbon cathode only delivers a discharge capacity of 400 mAh g–1 after 100 cycles. Also, a discharge capacity of 462 mAh g–1 is obtained after 200 cycles at a high C rate (1 C). The detailed reaction mechanism of sulfur–carbon cathodes is systematically studied at high C rates using operando Raman and S K-edge X-ray absorption spectroscopy.
Mesoporous Cu-Ni/Al2O4 catalyst of high surface area (176 m2g−1) is synthesized through a simple hydrothermal reconstruction process by using low-cost activated alumina as the aluminate source ...without organic templates. The desired mesoporous structure of the catalyst is formed by the addition of Cu2+ and Ni2+ metal ions in the gel solution of the activated alumina followed by hydrothermal treatment at 70 °C and calcination at temperatures in the range of 600 to 800 °C. To consider the environmental concern, we found the concentration of the Cu2+ and Ni2+ ion in the residual filtrate is less than 0.1 ppm which satisfies the effluent standard in Taiwan (<1.0 ppm). The effects of the pH value, hydrothermal treatment time, and calcination temperature on the structure, morphology and surface area of the synthesized Cu-Ni/Al2O4 composites are investigated as well. In addition, the Cu-Ni/Al2O4 catalyst synthesized at pH 9.0 with a hydrothermal treatment time of 24 h and a calcination temperature of 600 °C is used for hydrogen production via the partial oxidation of methanol. The conversion efficiency is found to be >99% at a reaction temperature of around 315 °C, while the H2 yield is 1.99 mol H2/mol MeOH. The catalyst retains its original structure and surface area following the reaction process, and is thus inferred to have a good stability. Overall, the hydrothermal reconstruction route described herein is facile and easily extendable to the preparation of other mesoporous metal-alumina materials for catalyst applications.
•NbC/polyimide-derived graphene (PDG) composite has been prepared via laser scribing route.•The NbC decorated PDG show enhanced electric and thermal conductivities.•The NbC/PDG can be used as ...efficient heat sinks for industrial computers, LEDs and LIBs.•The photothermal properties of the NbC/PDG are also evaluated.
Thermal management and heat dissipation are universal challenges related to high-power systems. Graphene and its related composite materials exhibit the potential for widespread application as thermal management materials owing to their high thermal conductivity and emissivity. In this study, we synthesize polyimide (PI)-derived graphene (PDG) incorporated with NbC nanoparticles via CO2 laser scribing on Nb precursor-containing PI sheets. The resultant NbC-decorated PDG (NbC-PDG) shows improved thermal conductivity (0.70 W/m·K) compared with bare PDG (0.24 W/m·K). We use NbC-PDG as an efficient heat sink for industrial computers (ICs), light-emitting diode (LED) modules, and lithium-ion batteries (LIBs). The equilibrium temperature of the applications can be reduced significantly by the NbC-PDG layer owing to its excellent radiation heat transfer. After integration of the NbC-PDG heat sink, the equilibrium temperatures of the IC, LED module, and LIB decreased by 8.1, 9.9, and 7.3 °C, respectively. Accordingly, the performance, efficiency, and lifetime of optoelectronic and electrochemical systems can be enhanced considerably. The NbC-PDG composite with broadband absorption and excellent photothermal properties can be applied for efficient solar–thermal energy conversion. Additionally, we fabricate an NbC-PDG-deposited melamine sponge via spray coating and evaluate its performance in solar-driven desalination and water purification.
Elucidating how appropriate neurite patterns are generated in neurons of the olfactory system is crucial for comprehending the construction of the olfactory map. In the Drosophila olfactory system, ...projection neurons (PNs), primarily derived from four neural stem cells (called neuroblasts), populate their cell bodies surrounding to and distribute their dendrites in distinct but overlapping patterns within the primary olfactory center of the brain, the antennal lobe (AL). However, it remains unclear whether the same molecular mechanisms are employed to generate the appropriate dendritic patterns in discrete AL glomeruli among PNs produced from different neuroblasts. Here, by examining a previously explored transmembrane protein Semaphorin-1a (Sema-1a) which was proposed to globally control initial PN dendritic targeting along the dorsolateral-to-ventromedial axis of the AL, we discover a new role for Sema-1a in preventing dendrites of both uni-glomerular and poly-glomerular PNs from aberrant invasion into select AL regions and, intriguingly, this Sema-1a-deficient dendritic mis-targeting phenotype seems to associate with the origins of PNs from which they are derived. Further, ectopic expression of Sema-1a resulted in PN dendritic mis-projection from a select AL region into adjacent glomeruli, strengthening the idea that Sema-1a plays an essential role in preventing abnormal dendritic accumulation in select AL regions. Taken together, these results demonstrate that Sema-1a repulsion keeps dendrites of different types of PNs away from each other, enabling the same types of PN dendrites to be sorted into destined AL glomeruli and permitting for functional assembly of olfactory circuitry.
Guillain-Barré syndrome (GBS) often develops after a respiratory or gastrointestinal infection. A few cases have been reported on GBS following elective spinal surgery not preceded by an infectious ...disease. In patients with underlying upper motor neuron disease such as a spinal cord injury, concurrent development of lower motor neuron diseases, such as GBS, could be overlooked. Here, we present an uncommon case of an 87-year-old man with GBS that had developed after an operation for a traumatic cervical spinal cord injury. After surgery, he showed weakness over all four limbs with paresthesia, but he was able to hold a standing position with minimal assistance. Unfortunately, his muscle strength over his four limbs gradually weakened from two to four weeks later, and he became almost completely paralyzed. Cerebrospinal fluid (CSF) studies revealed albuminocytologic dissociation. A nerve conduction study (NCS) indicated an acute axonal polyneuropathy superimposed on chronic sensorimotor polyneuropathy. Thus, the patient was diagnosed with GBS. However, the patient’s family declined immune-modulatory therapy due to personal reasons. The patient progressed into respiratory failure and remained ventilator-dependent before his death three years later. This case highlights the importance of taking GBS into account when postoperative weakness occurs in patients with spinal cord injury, and a worse prognosis if GBS is left untreated.
Magnetic proximity effect of YIG/PtSe2 Wang, Meng-Chien; Xu, Hongjun; Hsu, Jen-Hwa ...
Journal of magnetism and magnetic materials,
12/2022, Letnik:
563
Journal Article
Recenzirano
Odprti dostop
•The magneto-transport properties in YIG/PtSe2 suggests the acute MPE at the interface.•AMR and SMR are both existed in YIG/PtSe2.•Defect induced magnetism in PtSe2 also plays a role.
The magnetic ...proximity effect has pronounced influence on the transport properties of bilayer system with a heavy metal and a magnetic insulator. Here we first review the magneto-transport properties of non-magnetic heavy metal/magnetic insulator bilayer structure and emphasize the role played by magnetic proximity effect. Since there are no current shunting and Joule heating effects within the insulating layer, it is relatively easier to understand the physical origin and impact of the magnetic proximity response for these bilayers. In the second part of this article, we study magneto-transport properties of YIG/PtSe2. YIG is known to have large band gap and low magnetization damping coefficient and is a frequently used magnetic insulator, while PtSe2 belongs to the family of two dimensional (2D) transition metal dichalcogenides in which spin–orbit coupling is strong. We found that the spontaneous magnetization in PtSe2 has been induced by the proximity of YIG, which results in a negative MR. Moreover, the AMR and spin Hall MR are both existed in YIG/PtSe2 system. The value of Anomalous Hall resistance can reach 1 Ω, which is much greater than that of the planar Hall effect due to the spontaneous magnetization in PtSe2.
Direct comparisons of the effectiveness of allopurinol with that of other urate-lowering agents in chronic kidney disease (CKD) populations, as well as guideline recommendations for clinical ...practice, are lacking.
We constructed a pharmacoepidemiology cohort study by including patients from Taiwan's long-term integrated CKD care program to compare the effectiveness among allopurinol, febuxostat and benzbromarone in reducing the risk of progression to dialysis. A total of 874 patients with hyperuricemia who were newly treated with allopurinol, febuxostat or benzbromarone were included. The primary and secondary outcomes were incident end-stage renal disease (ESRD) and the serum uric acid (SUA) changes from baseline, respectively. The results were analyzed using multiple Cox proportional models adjusted for multinomial propensity scores. For subgroup analyses, we further stratified patients according to whether their latest SUA level reached the therapeutic target.
Compared with allopurinol, benzbromarone therapy was associated with a reduced risk of progression to dialysis, the adjusted hazard ratio was 0.50 (95% confidence interval, 0.25-0.99). Patients who received allopurinol or febuxostat exhibited a comparable risk of ESRD adjusted hazard ratio, 0.99 (0.40-2.44). Febuxostat was significantly more potent than allopurinol or benzbromarone in lowering SUA levels in the fully adjusted model. Among patients who reached the therapeutic target, those with febuxostat and benzbromarone initiation had a significantly lower risk of ESRD.
In conclusion, compared with conventional allopurinol, febuxostat and benzbromarone may be more effective in reducing the risk of progression to dialysis and in lowering SUA levels in CKD populations.
Summary
A simple synthetic method without organic template is proposed for the synthesis of Ni‐silicate. The resulting Ni‐phyllosilicates are reconstructed by hydrothermal treatment to a porous ...structure with a high surface area (552 m2 g−1). Notably, the residual filtrate has a Ni2+ ion content of less than 0.1 ppm, and therefore satisfies the effluent standard in Taiwan (<1.0 ppm). As a result, it can be disposed of directly without the need for additional treatment. The effects of the pH value and hydrothermal treatment time on the structure, morphology, and surface area of the Ni‐silicate composites have been investigated. When applied to hydrogen production, the mesoporous Ni‐silicate shows a high catalytic capability (>99%) toward ammonia decomposition at a temperature of 400°C. Overall, the proposed synthetic method is facile and easily extendable to the production of other metal‐silicate materials for hydrogen generation.
A simple organic template‐free method is proposed for the synthesis of sheet‐like mesoporous Ni‐silicate. The Ni2+ ion content in the filtrated solution is less than 0.1 ppm. The Ni‐silicate demonstrated a high catalytic capability (>99%) toward the ammonia decomposition at 400°C.
Density‐functional theory (DFT) is pivotal in the advancement of photocatalysis and photoelectrocatalysis. Its capability to explore electronic structures of materials contributes significantly to ...clarifying the mechanisms of photocatalytic (PC) and photoelectrocatalytic (PEC) processes. DFT calculations enable a deeper understanding of how these processes work at a molecular level, which is essential for designing versatile photocatalysts and photoelectrodes and optimizing reaction pathways. In this perspective, key PC and PEC applications, such as H2 production, CO2 reduction, dye degradation, and N2 reduction, where DFT is instrumental in optimizing materials designs and reaction pathways, are highlighted. Exploration on the synergy between experimental research and DFT calculations is highlighted, which is crucial for the development of efficient and environmentally friendly energy solutions. The discussion further extends to challenges and future directions, emphasizing the need for incorporating factors, including discrepancy in scale, light illumination, electrolyte presence, and applied bias, into DFT calculations, to achieve a more comprehensive understanding of PC and PEC systems. In this perspective, it is aimed to provide a holistic view of the current state and potential advancements in photocatalyst and photoelectrode modeling, thereby guiding future research toward more effective and sustainable energy and chemical production processes in PC and PEC systems.
In this perspective, key photocatalytic and photoelectrocatalytic applications, where density‐functional theory (DFT) is instrumental in optimizing materials designs and reaction pathways, are highlighted. Herein, the challenges and prospects associated with the adaption of DFT calculations are delved into, with the aim of providing researchers with a comprehensive overview for expanding the scope and accuracy of DFT in photocatalyst and photoelectrode modeling.
A polyacrylonitrile (PAN)-interpenetrating cross-linked polyoxyethylene (PEO) network (named XANE) was synthesized acting as separator and as gel polymer electrolytes simultaneously. SEM images show ...that the surface of the XANE membrane is nonporous, comparing to the surface of the commercial separator to be porous. This property results in excellent electrolyte uptake amount (425 wt %), and electrolyte retention for XANE membrane, significantly higher than that of commercial separator (200 wt %). The DSC result indicates that the PEO crystallinity is deteriorated by the cross-linked process and was further degraded by the interpenetration of the PAN. The XANE membrane shows significantly higher ionic conductivity (1.06–8.21 mS cm–1) than that of the commercial Celgard M824 separator (0.45–0.90 mS cm–1) ascribed to the high electrolyte retention ability of XANE (from TGA), the deteriorated PEO crystallinity (from DSC) and the good compatibility between XANE and electrode (from measuring the interfacial-resistance). For battery application, under all charge/discharge rates (from 0.1 to 3 C), the specific half-cell capacities of the cell composed of the XANE membrane are all higher than those of the aforementioned commercial separator. More specifically, the cell composed of the XANE membrane has excellent cycling stability, that is, the half-cell composed of the XANE membrane still exhibited more than 97% columbic efficiency after 100 cycles at 1 C. The above-mentioned advantageous properties and performances of the XANE membrane allow it to act as both an ionic conductor as well as a separator, so as to work as separator-free gel polymer electrolytes.
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