Volume Expansion Research Articles

A 3D flexible conductive network skeleton by SWCNT-COOH and PVA-PAA enabling high performance for Si anode

Silicon anode undergoes dramatic volume expansion during charge and discharge, causing structural and interfacial instability that severely degrades battery cycling performance. Herein, we propose a three-dimensional (3D) flexible self-standing SiMP/SWCNT-COOH@PVA/PAA anode, in which carboxylation-modified single-walled carbon nanotubes (SWCNT-COOH) construct a highly conductive and flexible skeleton to provide rapid electron transport channels for micron silicon (SiMP), while polyacrylic acid-polyvinyl alcohol (PVA-PAA) cross-linking layer forms a high-strength polymer interface to strengthen the conductive skeleton and helps to maintain the structural integrity of SiMP. The resulting electrode exhibits ultra-high electrical conductance (12406 S m−1) and exceptional mechanical characteristic (tensile strength of 46.95 MPa). More importantly, it demonstrates extremely stable electrochemical properties, with an impressive maximum capacity of approximately 2868.5 mAh g−1 at 0.2C, while retaining an exceptional 96.49 % of capacity even after 100 cycles. A consistent capacity of 1000 mAh g−1 at 1C throughout 1000 cycles is also realized. Furthermore, a flexible full battery based on SiMP/SWCNT-COOH@PVA/PAA anode achieves a discharge capacity of 49.5 mAh g−1 following 100 cycles, and illuminates a LED strip normally under various bending conditions. These results are expected to open a new way towards enhanced performance silicon-based electrodes within flexible LIBs.

Moulding Test and Process Parameter Optimization of Biomass Seedling Pots for Cow Dung and Corn Stover

In order to determine the optimal moulding process parameters of biomass seedling pots prepared from fermented cow dung mixed with corn stover, the moulding pressure, baking time, and baking temperature of biomass seedling pots were taken as the influencing factors, and the expansion rate, durability rate, wet swelling rate (48 h), and resistance to damage were taken as the evaluation indexes, and the Box–Behnken design of the response surface method was used to analyze the significance of interactions among the different influencing factors in the moulding process of biomass seedling pots and to optimize the moulding process. The experiment was conducted in the Biomass Laboratory of Heilongjiang Bayi Agricultural University. The response surface method Box–Behnken design was used to analyze the significance of the interaction between different influencing factors in the biomass seedling pots moulding process and optimize the moulding process. The results showed that the optimum moulding process conditions obtained using the Box–Behnken design were the following: a moulding pressure of 520.393 kN, baking temperature of 202.870 °C, and baking time of 8.573 min. The model was validated by testing and a response value of 10.522% was obtained for expansion, 99.598% for durability rate, 11.145% for wet swelling (48 h), and 4503.545 N for resistance to damage. The experimental verification showed that the deviation of the actual value obtained under this condition from the predicted value is less than 5%, indicating that the model reproduces well and meets the experimental requirements. Based on the optimal moulding process conditions determined in this experiment, the total porosity, EC, and pH of the Biomass seedling pots were determined to be 67.32%, 1.63 mS/cm, and 6.7, respectively, which met the seedling requirements.

Spatial and Temporal Change Analysis of Urban Built-Up Area via Nighttime Lighting Data—A Case Study with Yunnan and Guizhou Provinces

As urbanization accelerates, characteristics of urban spatial expansion play a significant role in the future utilization of land resources, the protection of the ecological environment, and the coordinated development of population and land. In this study, Yunnan and Guizhou provinces were selected as the study area, and the 2013–2021 National Polar-Orbiting Partnership’s Visible Infrared Imaging Radiometer Suite (NPP-VIIRS) nighttime light (NTL) data were utilized for spatial and temporal change analysis of urban built-up areas. Firstly, the built-up areas in Yunnan and Guizhou provinces were extracted through ENUI (Enhanced Nighttime Lighting Urban Index) indices, and then the urban expansion speed and urban center of gravity migration were constructed and used to explore and analyze the spatial and temporal change and expansion characteristics of built-up areas in Yunnan and Guizhou provinces. The results showed the following. (1) Due to the complementarity between data types, such as NTL, EVI, NDBI, and NDWI, ENUI has better performance in expressing urban characteristics. (2) Influenced by national and local policies, such as “One Belt, One Road”, transportation infrastructure construction, geographic location, the historical background, and other factors, the urban expansion rate of Yunnan and Guizhou provinces in general showed a continuous advancement from 2013 to 2021, and there were three years in which the expansion rate was positive. (3) The center of gravity migration distance of most cities in Guizhou Province shows a trend of increasing and then decreasing, while the center of gravity migration distance in Yunnan Province shows a trend of continuous decrease in general. From the perspective of migration direction, Guizhou Province has the largest number of migrations to the northeast, while Yunnan Province has the largest number of migrations to the southeast. (4) Influenced by policy, economy, population, geography, and other factors, urban compactness in Yunnan and Guizhou provinces continued to grow from 2013 to 2021. The results of this study can help us better understand urbanization in western China, reveal the urban expansion patterns and spatial characteristics of Yunnan and Guizhou provinces, and provide valuable references for development planning and policymaking in Yunnan and Guizhou provinces.

Construction of Heterointerfaced Nanoreactor Electrocatalyst via In Situ Evolution Toward Practical Room‐Temperature Sodium–Sulfur Batteries

AbstractSodium‐sulfur (Na─S) batteries have drawn considerable research interest owing to their high theoretical energy density and nature abundance. However, the intrinsic sluggish kinetics that has so far been scarcely explored in the conversion reaction of sodium polysulfides (NaPS) hinders its practical application. Herein, the design strategy of heterointerfaced nanoreactor is presented as sulfur reduction reaction (SRR) electrocatalyst for room temperature Na─S batteries. The synergistic incorporation of heterointerface and confined structure design can modulate the electronic structure of transitional metal active site and upshift its d‐band center, leading to enhanced NaPS adsorption and catalytic conversion toward streamlined SRR. Moreover, the spatial confinement of nanoreactor can not only stockpile nanoparticles to avoid their agglomeration and detachment, but also effectively immobilize sulfur species to inhibit shuttle effect and accommodate volume expansion over sodiation. The as‐developed electrocatalyst can achieve high discharge capacity of 1310 mAh g−1, remarkable cycling stability over 2500 cycles, and excellent performance under high sulfur loading and lean electrolyte/sulfur ratio. Ah level pouch cell can also exhibit promising performance for practical application. This strategy affords a synergistic combination of nanoreactor and heterointerface structure engineering toward fast and reliable electrochemistry, paving ways for the practical application of room temperature Na─S batteries.

Vertically Fluorinated Graphene Encapsulated SiOx Anode for Enhanced Li+ Transport and Interfacial Stability in High-Energy-Density Lithium Batteries.

Achieving high energy density has always been the goal of lithium-ion batteries (LIBs). SiOx has emerged as a compelling candidate for use as a negative electrode material due to its remarkable capacity. However, the huge volume expansion and the unstable electrode interface during (de)lithiation, hinder its further development. Herein, we report a facile strategy for the synthesis of surface fluorinated SiOx (SiOx@vG-F), and investigate their influences on battery performance. Systematic experiments investigations indicate that the reaction between Li+ and fluorine groups promotes the in situ formation of stable LiF-rich solid electrolyte interface (SEI) on the surface of SiOx@vG-F anode, which effectively suppresses the pulverization of microsized SiOx particles during the charge and discharge cycle. As a result, the SiOx@vG-F enabled a higher capacity retention of 86.4 % over 200 cycles at 1.0 C in the SiOx@vG-F||LiNi0.8Co0.1Mn0.1O2 full cell. This approach will provide insights for the advancement of alternative electrode materials in diverse energy conversion and storage systems.

Brain volume loss after cranial irradiation: a controlled comparison study between photon vs proton radiotherapy for WHO grade 2-3 gliomas.

Radiation therapy (RT) is an integral treatment component in patients with glioma but associated with neurotoxicity. Proton RT (PRT), as compared with photon RT (XRT), reduces excess radiation to nontarget tissue. We used a retrospective method to evaluate brain imaging metrics of neurotoxicity after treatment with PRT and XRT for glioma. We analyzed brain volume change in thirty-four patients with WHO grade 2-3 gliomas treated with either PRT (n = 17) or XRT (n = 17). Both groups were carefully matched by demographic/clinical criteria and assessed longitudinally for two years post-radiotherapy. Brain volume change was measured as ventricular volume expansion in the tumor free hemisphere (contralateral to RT target) as a proxy indicator of brain volume loss. We further assessed the impact of volumetric changes on cognition in PRT patients, who completed neuropsychological testing as part of an outcome study. We found significant ventricular volume increases in the contralesional hemisphere in both groups at two years post-RT (F(1, 31) = 18.45, p < 0.000, partial η2 = 0.373), with greater volume change observed in XRT (26.55%) vs. PRT (12.03%) (M = 12.03%, SD = 16.26; F(1,31) = 4.26, p = 0.048, partial η2 = 0.121). Although, there was no group-level change on any cognitive test in PRT treated patients, individual changes on cognitive screening, working memory, processing speed and visual memory tasks correlated with contralesional brain volume loss. This study suggests progressive brain volume loss following cranial irradiation, with greater severity after XRT vs. PRT. Radiation-induced brain volume loss appears to be associated with measurable cognitive changes on an individual level. Prospective studies are warranted to validate these findings and their impacts on long-term cognitive function and quality of life. An improved understanding of the structural and functional consequences of cranial radiation is essential to develop neuroprotective strategies.

A method of pretreating incineration ashes containing metallic aluminium using NaOH to mitigate volume expansion under highly alkaline conditions

Globally, millions of tonnes of incineration ashes are produced with a substantial portion remaining underutilized in low-value applications or disposed in landfills. Many types of fly ashes and bottom ashes contain metallic aluminium (Al0), which causes volume expansion when the ashes are used in alkali-activated materials and as a supplementary cementitious material due to the generation of hydrogen gas at high-pH conditions. This phenomenon significantly restricts the potential applications of these ashes. To address this issue, ashes can be pretreated with NaOH to oxidize the metallic aluminium (Al0) before their utilization. This study focuses on investigating the effect of the NaOH pre-treatment duration on fly ashes from the co-combustion of recovered solid fuel, peat, and wood. A pre-treatment process was conducted using 8 mol/L aqueous NaOH solution to treat the fly ash for up to 60 minutes. The formed slurry was subsequently used to prepare alkali-activated material by mixing it with bottom ash and employing either sodium silicate or sodium carbonate as an alkali activator. The NaOH pre-treatment demonstrated a 100 % metallic aluminium conversion into oxidized form resulting enhancement in mechanical performance, microstructure, and water absorption properties. The proposed method offers a highly efficient and rapid solution for eliminating the drawbacks caused by the presence of metallic aluminium and it can be conveniently implemented on construction sites. Concurrently, this study also explores the leaching behaviour of heavy metals during alkali-activation. Significant reductions in the leaching of Ba, Cr, Cu, Mo, and Pb were observed, highlighting the environmental remediation potential of alkali-activation methods.

Tuning Crystalline Preferred Orientation of SnSe2 Anode by Co-doping to Enhance Pseudocapacitive Behaviors for High-Performance Sodium Storage.

SnSe2 has attracted great attention due to its unique 2D-layered structure, which makes it capable of sodium ion storage and higher theoretical capacities compared to traditional anode materials like hard carbon for sodium ion batteries (SIBs). However, SnSe2-based materials will cause structural damage due to volume expansion during ion storage, leading to poor cycle stability and rate capacity. In this work, Co-doped SnSe2 (Co-SnSe2) with preferred crystal orientation was fabricated by a one-step solvothermal method. It has been found that after doping Co, the lower (001) crystal plane located at 14.4° replaced the higher (101) plane at 30.7° as the dominant crystal plane in Co-SnSe2, which significantly promoted ion diffusion and enhanced the pseudocapacitance behavior. Therefore, this Co-SnSe2 anode achieves a high capacity of 504 mAh g-1 at 1 A g-1, and a high-rate cycle stability, delivering a reversible capacity of 302 mAh g-1 at 5 A g-1 after 1800 cycles with a retained capacity rate of 94%. Moreover, the Na3V2(PO4)3||Co-SnSe2 full cell exhibits a stable cycle performance of over 300 cycles at 1 A g-1, demonstrating great promise for practical applications. This work provides an effective reference for the exploration of high-performance sodium storage anode materials.

Carbonaceous C@FeS Flow Electrode for Electrochemcal Capacitive Deionization Application

Abstract FeS has attracted much attention in the field of capacitive deionisation of flow electrodes due to its high theoretical specific capacity and wide range of sources. However, it usually exhibits frustrating performance due to its inherent low conductivity and volume expansion during charging and discharging. Herein, we successfully prepared calcium alginate-coated FeS carbon spheres (C@FeS) with a hollow nanosphere structure by a combination of sol-gel and solid-phase sintering using sodium alginate as a carbon source. This unique hollow structure provides enough space for the expansion of FeS and enhances the stability of the sulfide; meanwhile, the internal “surface-line-surface” structure not only facilitates the migration and charge transfer of ions inside, but also provides more active electrosorption sites. When assembled as the flow electrode of the flow electrode capacitive deionisation (FCDI) system, the desalination capacity of the electrode was improved from 25.32 mg g−1 to 53.12 mg g−1. Therefore, the C@FeS composite is expected to provide a new candidate electrode material for the FCDI system, which will make the future desalination process more cost-effective and efficient.

Assessing the Imbalances in Growth between Urban Land and Urban Population and the Influencing Factors: An Allometric Growth Perspective

Maintaining a balance between urban land (UL) expansion and urban population (UP) growth is one of the goals of sustainable development, and maintaining this balance requires more theoretical exploration and regional experience. This paper re-evaluated the imbalances in growth between urban land and urban population (IGULUP) from the perspective of allometric growth and explored its influencing mechanism, taking urban agglomerations (UAs) in China as a case. This paper reveals that the growth rate of UL in China is slightly higher than that of the UP. However, the IGULUP vary according to development stages. UAs in the primary stage and the early growth stage face the dilemma where UL grows faster than the UP. Conversely, for UAs in the later growth stage and the mature stage, the growth rate of the UP is higher than that of UL. Finally, an increase in economic development level, population agglomeration, fiscal expenditure, and urban compactness can help mitigate the gap between UL and UP. In contrast, industrial structure, urbanization level, and foreign direct investment may hinder the improvement of IGULUP by accelerating the rate of land expansion. These findings may make theoretical contributions to the formulation of more targeted land use control policies and urban population growth strategies.

Combined effect of self-stressing and confinement on GFRP-LC3 interface bond

The load capacity, failure mode and durability of reinforced concrete members are strongly affected by the bond strength between the concrete and the reinforcement. This work presents a physics-based approach to improve the bond strength based on self-stressing effect. Combination of limestone calcined clay cement (LC3) and calcium sulphoaluminate cement (CSA) with different ratios was employed to develop self-stressing function. The addition of CSA induces a remarkable volume expansion of matrix due to the formation of ettringite, it however leads to a decreased compressive strength because of the reduced Portlandite content and increased porosity. A push-out test was conducted to evaluate the interface properties between glass fiber reinforced polymer (GFRP) and LC3-based matrix. The results show that the interface bond strength is highly dependent on the matrix strength under unconfined condition. On the contrary, under confined condition, the interface bond strength increases linearly with the expansion value regardless of matrix strength, attributed to that the self-stressing effect can effectively refine the matrix pores and densify the interface transition zone. The findings from this work demonstrate that the self-stressing effect holds promise to be a plausible method to strengthen the overall properties of reinforced concrete without creating additional carbon emission.

CVD-Synthesized Titanium Carbide Nanoflowers as High-Performance Anodes for Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) have emerged as promising candidates for energy storage applications due to the abundance and low cost of sodium. However, the larger radius of sodium ions limits their diffusion kinetics within electrode materials and contributes to electrode volume expansion. Here, we successfully synthesized porous titanium carbide (TiC) nanoflowers through chemical vapor deposition (CVD). The TiC nanoflowers exhibit exceptional electrochemical performance as SIB anodes, with their porous structure enhancing the conductivity, mechanical stability, and Na-ion diffusion. The TiC nanoflowers demonstrate a high reversible specific capacity of 73.5 mAh g-1 at 1 A g-1 after 2500 cycles, corresponding to an impressive capacity retention of 80.81%. Additionally, we developed a full sodium-ion cell utilizing TiC nanoflowers as the anode and Na3V2(PO4)3 as the cathode, which demonstrates a substantial reversible capacity and outstanding cycling stability. Our work presents a promising strategy for synthesizing nanostructured TiC materials as anode electrodes for SIBs.

Comparison of single Shockley-type stacking fault expansion rates in 4H-SiC under ultraviolet illumination after hydrogen or fluorine ion implantation

Abstract The expansion of single Shockley-type stacking faults (1SSFs) was observed in 4H-SiC below the ion-implanted region of hydrogen or fluorine under ultraviolet illumination, and it was found that 1SSF expansion slowed, the expansion angle decreased, and the termination of 1SSF expansion became deeper as the dose of implanted ions was increased. A comparison of implanted ion species revealed that fluorine ion implantation more strongly suppresses 1SSF expansion under ultraviolet illumination than hydrogen ion implantation. The thermal stability of hydrogen and fluorine was also compared by using depth profiles of the implanted species concentrations before and after annealing. Fluorine was found to have superior thermal stability to that of hydrogen.

A versatile opened hollow carbon sphere with highly loaded antimony alloy for ultra-stable potassium-ion storage

Carbon materials meet the stringent practical requirements for anodes for potassium-ion batteries (PIBs) due to their abundance and chemical stability. The major issue of carbon-based anodes is the low specific capacity and poor cyclic stability. Equally importantly, scalable synthesis approaches for electrodes are highly desired for the future application in large-scale energy storage systems. Herein, we developed a novel composite of Sb encapsulated in N/P co-doped opened hollow carbon spheres (N/POHCs) with high Sb loading through a simple carbonization and subsequent impregnation process. Beneficial from the virtue of abundant pyridinic-N−P bonding and opened hollow spherical structure advantages, N/POHCs exhibit much lower diffusion barrier than that of pure carbon, prominent Sb carrier capability, as well as the extraordinary resistance to volume expansion. The resulting Sb@N/POHCs composite delivers a high specific capacity of 533.3 mAh g−1 at 0.1 A g−1 with an initial Coulombic efficiency of 83 %, and can maintain a specific capacity of 345 mAh g−1 at 1 A g−1 after 4000 cycles. This work provides rational structure design with universal carrier capability of active materials to achieve high-capacity and long cycle life anode for advanced PIBs accompanied by the potential for large-scale production.

Sulfur Distribution Analysis in Lithium−Sulfur Cathode via Confined Inverse Vulcanization in Carbon Frameworks

AbstractLithium–Sulfur (Li–S) batteries are promising energy storage devices due to their high theoretical energy density. However, challenges such as the shuttling effect and volume expansion have significantly hindered their cycle life and capacity retention. Furthermore, the complex kinetic pathways in Li–S batteries call for advanced characterization techniques to unravel underlying mechanisms. In this study, a hollow porous carbon (HPC) is used as a microreactor, where inverse vulcanization occurs between 1,3‐diisopropylbenzene (DIB) and sulfur (S8), resulting in the creation of three‐dimensionally interconnected and well‐distributed S‐DIB in carbon frameworks. As a result, the dual confinement strategy imparts Li–S coin cells with remarkable cycling stability and capacity retention, exhibiting an impressive capacity of 866 mAh g−1 when returning to 0.1 C after 100 cycles of rate capability tests. Particularly, the Energy‐selective Backscattered (EsB) assisted Scanning Electron Microscope (SEM) technique as a novel approach is introduced to distinguish different lengths of polysulfides. Their distribution is visualized in the cross‐section view of the electrode in a micrometer range. These EsB images provide concrete indications of the sulfur evolution process and explain the capacity degradation during cycling.

Investigating the expansion behavior of silicon nitride nanopores

Nanopores are a single-molecule detection platform that has attracted more and more researchers’ attention, but so far there is still a lack of systematic research on their stability. In this study, we investigated the mechanism behind the expansion behavior of solid-state nanopores and its effect on the electrical properties of nanopores. Through the analysis of electron energy loss spectroscopy, it was found that the expansion process of nanopores is accompanied by the loss of silicon elements. Three nanopore expansion models can well explain the differential impact of silicon element loss in different regions on the electrical properties of nanopores. Molecular dynamics simulations analyzed the differences in nanopore conductivity and expansion rate corresponding to different expansion models from the perspective of single-atom loss. Finally, we demonstrated that chemical modification can isolate direct contact between the nanopore wall and the solution, thereby greatly delaying the expansion behavior of solid-state nanopores.

Study of the patterns of ice lake variation and the factors influencing these changes in the western Nyingchi area

Abstract The current ice lake dataset in the western region of Nyingchi requires further improvement. Due to the intricate distribution of ice lakes and imprecise boundary delineation, research tends to overlook small-scale ice lakes in this area. Moreover, most related studies have focused solely on variations in ice lake areas within key regions, such as the Himalayas, with little attention given to changes occurring in southeastern Tibet. The frequency of ice and snow disasters in the study area has been steadily increasing over the years. Therefore, this study utilizes Landsat satellite images and employs visual interpretation methods to generate more precise and comprehensive maps depicting the distribution of ice lakes in the western region of Nyingchi Province for the years 1994, 2010, 2018, and 2022. Additionally, changes in scale and spatial patterns of different types of ice lakes were investigated. Between 1994 and 2022, the ice lake area in the study area significantly increased by 22.5%, reaching a total of 35.8 ± 3.0 km2. This expansion was primarily driven by glacier-fed lakes, which experienced a remarkable growth rate of 30.8%. In contrast, the non-glacier-fed lakes experienced an increase by only 15.6%. Notably, ice lakes at higher elevations exhibited a peak in expansion, with those above 5143.0 m experiencing the most substantial growth rate of 44.8%. The long-term expansion rate of ice lakes is investigated through the measurement of changes in their boundaries, with the aim to understand the factors contributing to their growth. These findings indicate the rapid expansion of the ice lake near the glacier, with an annual growth rate of 1.3% per annum. Specifically, the glacial-fed section exhibited an expansion rate of 1.1% per annum, while the nonglacial-fed section experienced a growth rate of 0.6% per annum. The seasonal variability in marine glaciers is the primary factor influencing the expansion of ice lakes in this region, with temperature and precipitation serving as the principal driving forces impacting the transformation of these lakes. The data provided by the research results will facilitate a comprehensive understanding of the dynamics and mechanisms governing the ice lake in western Nyingchi, thereby contributing to an enhanced scientific comprehension of potential disaster risks associated with this ice lake.

Study on the anchoring properties of new water glass-modified alkali-activated portland cement materials

This study developed a novel water glass-modified alkali-activated portland cement (WGSC) anchoring agent, characterized by low cost, rapid setting, early strength, and slight expansion. It is suitable for fully bonded anchor rod anchoring in soft rock tunnels. Using orthogonal experiments and range analysis, the optimal composition of WGSC was determined: silicate cement as the matrix, water-cement ratio of 0.3, 20 % sodium silicate with a modulus of 3.3, 2.5 % early strength agent, and 9 % UEA. The initial/final setting times were 6.72/8.63 minutes, linear expansion rates at 3 days/7 days were 0.32 %/0.54 %, and compressive strengths at 1 hour/24 hours were 16.4/28.2 MPa. Pull-out model tests demonstrated a 47.95–92.85 % increase in 24 h tensile bond strength compared to conventional silicate cement anchoring agents. Corrosion resistance tests indicated WGSC maintained a stable appearance compared to traditional agents. SEM analysis revealed a dense structure and clear network in WGSC, while XRD analysis identified microcomponents mainly as CSH, active silica (SiO2), and CASH, contributing to its dense structure and ideal expansion properties, facilitating superior anchoring and durability. This research elucidates the mechanism of WGSC, confirming its rapid setting, compressive strength, and corrosion resistance advantages, making it economically feasible and advantageous for application and promotion, thereby providing insights for the development of anchoring materials in highly deformed soft rock tunnels.

Age-dependent somatic expansion of the ATXN3 CAG repeat in the blood and buccal swab DNA of individuals with spinocerebellar ataxia type 3/Machado-Joseph disease.

Spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD) is caused by the expansion of a genetically unstable polyglutamine-encoding CAG repeat in ATXN3. Longer alleles are generally associated with earlier onset and frequent intergenerational expansions mediate the anticipation observed in this disorder. Somatic expansion of the repeat has also been implicated in disease onset and slowing the rate of somatic expansion has been proposed as a therapeutic strategy. Here, we utilised high-throughput ultra-deep MiSeq amplicon sequencing to precisely define the number and sequence of the ATXN3 repeat, the genotype of an adjacent single nucleotide variant and quantify somatic expansion in blood and buccal swab DNA of a cohort of individuals with SCA3 from the Azores islands (Portugal). We revealed systematic mis-sizing of the ATXN3 repeat and high levels of inaccuracy of the traditional fragment length analysis that have important implications for attempts to identify modifiers of clinical and molecular phenotypes. Quantification of somatic expansion in blood DNA and multivariate regression revealed the expected effects of age at sampling and CAG repeat length, although the effect of repeat length was surprisingly modest with much stronger associations with age. We also observed an association of the downstream rs12895357 single nucleotide variant with the rate of somatic expansion, and a higher level of somatic expansion in buccal swab DNA compared to blood. These data suggest that the ATXN3 locus in SCA3 patients in blood or buccal swab DNA might serve as a good biomarker for clinical trials testing suppressors of somatic expansion with peripheral exposure.

Enhancing Electrochemical Performance of Si@CNT Anode by Integrating SrTiO3 Material for High-Capacity Lithium-Ion Batteries

Silicon (Si) has attracted worldwide attention for its ultrahigh theoretical storage capacity (4200 mA h g−1), low mass density (2.33 g cm−3), low operating potential (0.4 V vs. Li/Li+), abundant reserves, environmentally benign nature, and low cost. It is a promising high-energy-density anode material for next-generation lithium-ion batteries (LIBs), offering a replacement for graphite anodes owing to the escalating energy demands in booming automobile and energy storage applications. Unfortunately, the commercialization of silicon anodes is stringently hindered by large volume expansion during lithiation–delithiation, the unstable and detrimental growth of electrode/electrolyte interface layers, sluggish Li-ion diffusion, poor rate performance, and inherently low ion/electron conductivity. These present major safety challenges lead to quick capacity degradation in LIBs. Herein, we present the synergistic effects of nanostructured silicon and SrTiO3 (STO) for use as anodes in Li-ion batteries. Si and STO nanoparticles were incorporated into a multiwalled carbon nanotube (CNT) matrix using a planetary ball-milling process. The mechanical stress resulting from the expansion of Si was transferred via the CNT matrix to the STO. We discovered that the introduction of STO can improve the electrochemical performance of Si/CNT nanocomposite anodes. Experimental measurements and electrochemical impedance spectroscopy provide evidence for the enhanced mobility of Li-ions facilitated by STO. Hence, incorporating STO into the Si@CNT anode yields promising results, exhibiting a high initial Coulombic efficiency of approximately 85%, a reversible specific capacity of ~800 mA h g−1 after 100 cycles at 100 mA g−1, and a high-rate capability of 1400 mA g−1 with a capacity of 800 mA h g−1. Interestingly, it exhibits a capacity of 350 mAh g−1 after 1000 lithiation and delithiation cycles at a high rate of 600 mA hg−1. This result unveils and sheds light on the design of a scalable method for manufacturing Si anodes for next-generation LIBs.