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Silica aerogel membranes are renowned for their high porosity and superior thermal insulation capabilities. However, they are known to have limited mechanical strength and tend to shed surface particles easily. To address these drawbacks, a novel PVDF/SiO2/PVDF(PSP) composite membrane with a three-layered structure has been successfully fabricated by coating the surface of silica aerogel membranes with polyvinylidene fluoride (PVDF) using a straightforward and effective coating technique. This innovative approach not only effectively addresses the issue of particle shedding but also endows the silica aerogel membrane with organic functionality. The resulting PSP membranes offer significant improvements over traditional polyolefin separators, including higher porosity, enhanced electrolyte affinity, and superior thermal dimensional stability. These membranes boast an impressive ionic conductivity of 1.405 mS/cm and a lithium-ion transference number of 0.550. Moreover, when incorporated into a LiFePO4-based coin battery, the PSP membranes deliver a remarkable discharge-specific capacity of 143.5 mAh/g and an impressive capacity retention rate of 93.7% after undergoing 200 charge/discharge cycles at a rate of 0.5C. [ABSTRACT FROM AUTHOR]

Li4Ti5O12 (LTO) is considered as a new anode material with great potential because of its “zero strain” performance. To further improve the electrochemical behavior, Sr-doped LTO was synthesized via a facile hydrothermal method. The Sr2+ with bigger radius integrated into LTO did not change the origin crystal morphology of pure Li4Ti5O12 but attenuate the layered structure. XRD results testified that the lattice parameter of doped materials increases with the doping amount. EDS mapping further demonstrated the homogeneous distribution of strontium. Electrochemical tests show that Li3.975Sr0.025Ti5O12 presents optimal electrochemical properties. It possesses the highest initial discharge capacity of 215 mAh/g, while the pristine LTO just owns 163 mAh/g at 0.2 C. Li3.975Sr0.025Ti5O12 also delivers superior rate performance and cycling stability. It has a specific capacity retention of 80.02% at 10 C for 500 cycles, much higher than the 66.06% of pristine LTO. The thin and layered structure and increased electrical conductivity synergically improve the electrochemical performance of the doped material. [ABSTRACT FROM AUTHOR]

LiNi0.5Mn1.5O4 (LNMO), as a promising cathode material for high energy density lithium-ion batteries, has been limited by its intrinsic side effects with electrolytes at high voltage resulting in serious Mn dissolution and capacity attenuation. To address this issue, a sol–gel method was used to prepare LiNi0.49Mn1.49−xSrxY0.02O4 (x = 0.02, 0.04, 0.06). In addition, the LNMO material co-doped with Sr and Y was also studied for its crystal structure, microscopic morphology, and electrochemical properties. Structural characterization has revealed that the doping of Sr2+ and Y3+ into the LNMO material results in a reduction in particle size, a decrease in the content of Mn3+, and an increased proportion of the (100) crystal plane of the LNMO material. These modifications contribute to an improvement in the electrochemical performance of the LNMO material. The LiNi0.49Mn1.45Sr0.04Y0.02O4 LNMO sample showed the optimal electrochemical performance, with a discharge capacity of 131.84 mAh g−1 after 100 cycles at 1 C, retaining 95.55% of its initial capacity, and achieving a specific capacity of 104.79 mAh g−1 at 5 C. New Sr and Y co-doping strategy was designed and LiNi0.49Mn1.49−xSrxY0.02O4 (x = 0.02, 0.04, 0.06) sample was obtained via citric acid aided route to enhance the electrochemical property of LiNi0.5Mn1.5O4 cathode material for the first time. [ABSTRACT FROM AUTHOR]

Biodegradable poly(butylene adipate-co-terephthalate)/poly(lactic acid) (PBAT/PLA) composites were prepared by melt blending, and chain extender was used to improve the compatibility of PBAT/PLA blends through the chemical reaction. The influence of PLA and chain extender contents on mechanical properties, morphology, and rheological properties of PBAT/PLA composites was systematically investigated. The results revealed that the Young's modulus and stress values gradually increased under the same strain, whereas the elongation at break decreased with the increase of chain extender content for PBAT/PLA (80/20) composites. Noteworthy, the presence of chain extender improves the interfacial compatibility between PLA and PBAT phases. At the chain extender content of 0.4, 0.6, and 0.8 wt.%, the extensional viscosity of the composites exhibited an increasing trend, whereas an obvious strain-hardening phenomenon emerged in the uniaxial extensional curves. [ABSTRACT FROM AUTHOR]

Gelatin was applied as a dispersant into the preparation of Li1.2Mn0.54Ni0.13Co0.13O2 cathode material via sol–gel method. The effect of gelatin on the microstructure and electrochemical performance of this material was systematically explored. The addition of gelatin can effectively reduce the particle size and also make the samples have better particle size distribution. X-ray diffraction characterization reveals that gelatin can change the cation mixing of materials, which has close connection to lithium ions transfer in the active material. At 1 C rate (1 C = 250 mA g−1), sample with 15 wt% gelatin can maintain 189.4 mAh g−1 after 100 cycles, corresponding to the capacity retention of 97.5%, while the pristine sample only has 132.6 mAh g−1 and 87.5%. At the same time, sample with 15 wt% gelatin possesses a capacity of 75 mAh g−1 at the current density of 20 C, while pristine Li1.2Mn0.54Ni0.13Co0.13O2 just has 14 mAh g−1. The lithium diffusion coefficient (DLi+) of that with 15 wt% gelatin is 3.13 × 10−15 cm2 s−1, 72.9% bigger than the pristine sample. [ABSTRACT FROM AUTHOR]

In this work, three organic acids were, respectively, used as complexing agent to synthesize LiNi0.5Mn1.5O4 (LNMO) materials. Lactic and malic acid were applied for the first time to prepare LNMO successfully. The materials are well crystallized and show a disordered Fd3m structure. Citric acid is conducive to grain refinement and has the smallest grain size and biggest surface area among these samples. Material with citric acid presents a better stability of the coulombic efficiency exceeding 95% at 1 C rate after 500 cycles and retains more than 70% capacity retention, while lactic acid shows a fast capacity decay during the charging and discharging circulation. EIS spectra indicate that small grain size is good for the charge transfer, and LNMO with citric acid possesses the greatest DLi+ of 5.39 × 10−12 cm2 s−1, while it is two times bigger than that with malic acid and almost ten times as fast as LNMO by lactic acid. Citric acid has the optimal electrochemical performance than lactic and malic acid. Our work could provide a pretty reference for the researchers to select a special acid. [ABSTRACT FROM AUTHOR]

Spinel LiNi0.5Mn1.5O4 (LNMO) has been considered as an appropriate cathode material for lithium-ion batteries because of its non-toxicity, high voltage platform and high energy density. Whereas, an occurrence of Jahn–Teller distortion in disordered structure of spinel is inevitable due to the presence of Mn3+ ion and the cycling behavior is inadequate. Hence, a citric acid-aided method is used to address above question by adding yttrium dopant. A series of characterization methods are measured. Characterization results display that Y3+ doping decreases lattice parameter and Mn3+ content, and results in a decrease in grain size for Y-doped LNMO samples. These changes by Y3+ doping can reduce the degree of electrochemical polarization and enhance insertion and extraction reaction of Li+. On the other hand, the changes can also improve structural stability and retard the Jahn–Teller distortion. Therefore, the effect of Y3+ doping on crystalline structure, grain morphology and Mn3+ concentration is revealed and displayed a positive effect on enhancing rate performance and cycling stability of LNMO. Compared to other three LNMO samples, LiNi0.49Mn1.49Y0.02O4 LNMO sample exhibits best rate capacity and delivers highest discharge retention rate of 98.8% after 100 cycles at 1 C. Our research demonstrates that yttrium doping to enhance the electrochemical properties of LiNi0.5Mn1.5O4 cathode materials is an efficacious route. [ABSTRACT FROM AUTHOR]

The ubiquitin-proteasome pathway is the central mediator of regulated proteolysis in cells, and defects in this pathway are associated with cancer and neurodegenerative diseases. To assess 26S proteasome function in living animals, we developed a ubiquitin-luciferase reporter for bioluminescence imaging. The reporter was degraded rapidly under steady-state conditions and stabilized in a dose- and time-dependent manner in response to proteasome inhibitors. Using bioluminescence imaging after one dose of the chemo-therapeutic proteasome inhibitor bortezomib (PS-341), proteasome function in tumor xenografts was blocked within 30 min and returned to nearly baseline by 46 h. After a 2-week regimen of bortezomib, however, imaging of target tumors showed significantly enhanced proteasome inhibition that no longer returned to baseline. The ubiquitin-luciferase reporter enables repetitive tissue-specific analysis of 26S proteasome activity in vivo and should facilitate development and validation of proteasome inhibitors in mouse models, as well as investigations of the ubiquitin-proteasome pathway in disease pathogenesis., Author(s): Gary D Luker [1]; Christina M Pica [1]; Jiling Song [1]; Kathryn E Luker [1]; David Piwnica-Worms (corresponding author) [1, 2] The 26S proteasome degrades proteins that control essential [...]

The LiNi0.5Mn1.5O4 (LNMO) is an ideal cathode material of lithium-ion battery due to its high operating voltage. However, the corrosion of the electrolyte at high voltage is also a key issue for the LNMO cathode. In current work, the CeF4 were used to coat LNMO pristine via a simple calcining synthesis process. The microstructure and morphology of the pristine and CeF4-coated samples were studied by XRD, FTIR, XPS SEM, and TEM. The microstructure and morphology analysis show that CeF4 successfully coats on the surface of LNMO and forms a uniform coating layer. The CeF4 layers have little effect on the crystal structure of the LNMO and surface characters keep stable. The electrochemical performance study revealed that the CeF4-coated samples owned higher rate capacity and galvanostatic change–discharge capacity at 5C because the CeF4 layer was benefit to Li+ diffusion that decrease the polarization resistance. Moreover, the CeF4-3 has best cycling performance and rate capacity among all samples. After 100 charge–discharge cycles, the specific discharge capacity of CeF4-3 is still maintained 120 mAh/g with 97.6% capacity retention, while the pristine LNMO is only 97 mAh/g with 94.0% capacity retention. Therefore, CeF4 can be regarded as a promising anode modification material to improve the electrochemical performance. [ABSTRACT FROM AUTHOR]

Background and objectives: The domestication of cultivated rice (Oryza sativa L.) has long been studied, and many agronomically relevant genes have undergone artificial selection. Among them, the selection history of the starch synthase IIa (SSIIa) has not been fully discovered. The SSIIa is a genetic factor that controls the gelatinization temperature (GT) of rice starch, an important parameter for rice cooking quality. Findings: The A/GC haplotype in SSIIa only presented in the japonica subspecies. GT was found to be strongly associated with SNPs in SSIIa, that is, G/GC haplotype rice had high or intermediate GT, while G/TT or A/GC haplotype rice had low GT. The nucleotide diversity (π) in japonica was much lower than that of indica and wild rice, indicating that a population bottleneck was experienced during japonica rice domestication. A possible positive selection on the A SNP of SSIIa in temperate japonica rice favoring low GT starch synthesis was proposed. Conclusions: The evolution of SSIIa in the japonica rice was possibly under positive selection favoring low GT rice, which requires low energy input for cooking. The A SNP of SSIIa is only present in the japonica rice, which might be derived from a recent mutation. There are two ways, A/GC and G/TT, to make japonica rice with low GT, explaining why all the temperate japonica rice cultivars have low GT. Significance and novelty: Findings of this study provide an understanding of why all the temperate japonica rice have low GT starch, because there are two ways to make it GT low. [ABSTRACT FROM AUTHOR]