Summary
Multi‐walled carbon nanotube (MWCNT) protection layers have previously been used to trap polysulfides and suppress the shuttle effect in lithium sulfur (Li‐S) batteries, leading to ...significant performance improvement. While the MWCNT is inherently highly conductive and mechanically strong, the cost can be significant and in turn hampered wider application of MWCNT protection layers. Here, we employed lignin, a byproduct during high‐quality bleached paper manufacturing, to replace a portion of MWCNT in the protection layer to reduce cost and enhance surface properties of pristine MWCNT protection layers. We found that the protection layer with 25 wt% lignin leads to the best overall electrochemical performance of Li‐S batteries during charging/discharging at 0.5°C and 1C rate (1C = 1,675 mA g−1) among various weight‐ratios of lignin/MWCNT, and a low decay rate (0.20% per cycle) and high initial capacity (1342 mA g−1 and 1437 mA g−1 for 1C and 0.5C, respectively) are demonstrated. Besides, Li‐S cells with 25 wt% lignin/MWCNT composite protection layer also exhibited great rate capability, of which the specific capacities at 0.1C, 0.5C, 1C, and 2C were 1150, 913, 824, and 637 mAh g−1, respectively. The enhanced electrochemical stability and performance of Li‐S batteries can be attributed to strengthened polysulfide trapping and improved lithium ion transport with lignin reinforced MWCNT protection layers. We showcased an economic approach to extend cycle life and improve rate capability of Li‐S batteries.
The MWCNT protection layer has been shown to effectively suppress shuttle effects. In this work, we further improve the pore distribution and surface area of the protection layer by lignin addition to facilitate lithium ion transport and electrolyte uptake while maintaining its ability to intercept polysulfides. Li‐S batteries equipped with this lignin/MWCNT composite protection layer are demonstrated to exhibit high electrochemical performance and strong rate capability.
Scalable nanoelectronics with energy‐efficient logic technology is crucial for next‐generation edge devices. Low‐dimensional semiconductors, such as transition metal dichalcogenides and single‐walled ...carbon nanotubes (SWCNTs), have tunable properties with reduced short‐channel effects. The unique properties of each material can be utilized owing to the heterogeneous integration of multiple semiconducting channels to form complementary metal‐oxide‐semiconductor (CMOS) logic. However, the integration remains challenging. This study reveals the realization of low static power hetero‐CMOS inverters by the integration of n‐type monolayer MoS2 and p‐type SWCNT networks. The balanced inverter exhibits a large peak gain of ≈67 at a supply voltage of 2 V with the customized design of the wafer‐scale synthetic process and channel integration. An ultralow standby power consumption of ≈5 pW and a practical peak gain of ≈7 at a reduced supply voltage of 0.25 V are achieved. A high noise margin (>70%) validates the circuit's tolerance to external noises and the dynamic analysis of the inverting amplifier in push–pull configuration exhibits a large AC gain. This work paves the way toward the wafer‐scale integration of low‐dimensional materials for low‐power nanoelectronics.
Wafer‐scale low‐power hetero‐CMOS inverters are realized by integrating monolayer MoS2 and SWCNT networks. An ultralow standby power consumption of ≈5 pW at a reduced supply voltage of 0.25 V, high NMs (>70%), and dynamic analysis in a push‐pull configuration are achieved. It paves the way toward the wafer‐scale integration of low‐dimensional materials for low‐power nanoelectronics.
To examine the impact of nutritional and physical activity (PA) policies and practices at early care and education centres on behavioural changes among children ages 2-5.
The study population ...included 586 children from 25 education centres throughout the state of Georgia. Policies and practices were measured using the Georgia Nutrition and PA Assessment at the start of school year in Fall 2017. Survey data were collected at the beginning of school year September/October 2017 and at the end of school year April/May 2018 to measure changes in children's nutritional and PA behaviour over the school year. We used generalised estimating equations to estimate odds ratios and 95% confidence intervals.
Children at centres with a high nutrition assessment score had higher odds of increasing vegetable consumption (OR = 2.1; 95% CI: 1.1, 4.0) while the odds of increasing fruit (OR = 1.4; 95% CI: 0.8, 2.4) and water (OR = 1.2; 95% CI: 0.5, 2.7) consumption increased non-significantly. The odds of improving PA were similar between children at centres with a high versus a low PA assessment score.
The results, though insignificant, indicate that policies and practices could influence children's health behaviours. Further research is warranted to examine whether improvements in policies and practices could explain changes in children's health behaviours, the impact of educator's knowledge on children's health behaviours and the implementation of and adherence to policy and practice improvement plans.
Colorectal cancer (CRC) exhibits highly metastatic potential even in the early stages of tumor progression. Gallic acid (GA), a common phenolic compound in plants, is known to possess potent ...antioxidant and anticancer activities, thereby inducing cell death or cell cycle arrest. However, whether GA reduces the invasiveness of CRC cells without inducing cell death remains unclear. Herein, we aimed to investigate the antimetastatic activity of low‐dose GA on CRC cells and determine its underlying mechanism. Cell viability and tumorigenicity were analyzed by MTS, cell adhesion, and colony formation assay. Invasiveness was demonstrated using migration and invasion assays. Changes in protein phosphorylation and expression were assessed by Western blot. The involvement of microRNAs was validated by microarray analysis and anti‐miR antagonist. Our findings showed that lower dose of GA (≤100 μM) did not affect cell viability but reduced the capabilities of colony formation, cell adhesion, and invasiveness in CRC cells. Cellularly, GA downregulated the cellular level of integrin αV/β3, talin‐1, and tensin and diminished the phosphorylated FAK, paxillin, Src, and AKT in DLD‐1 cells. Microarray results revealed that GA increased miR‐1247‐3p expression, and pretreatment of anti‐miR antagonist against miR‐1247‐3p restored the GA‐reduced integrin αV/β3 and the GA‐inhibited paxillin activation in DLD‐1 cells. Consistently, the in vivo xenograft model showed that GA administration inhibited tumor growth and liver metastasis derived from DLD‐1 cells. Collectively, our findings indicated that GA inhibited the metastatic capabilities of CRC cells, which may result from the suppression of integrin/FAK axis mediated by miR1247‐3p.
To determine the association of prior traumatic brain injury (TBI) with subsequent diagnosis of neurodegeneration disease.
All studies from 1980 to 2016 reporting TBI as a risk factor for diagnoses ...of interest were identified by searching PubMed, Embase, study references, and review articles. The data and study design were assessed by 2 investigators independently. A meta-analysis was performed by RevMan 5.3.
There were 18 studies comprising 3,263,207 patients. Meta-analysis revealed a significant association of prior TBI with subsequent dementia. The pooled odds ratio (OR) for TBI on development of dementia, FTD and TDP-43 associated disease were 1.93 (95% CI 1.47-2.55, p < 0.001), 4.44 (95% CI 3.86-5.10, p < 0.001), and 2.97 (95% CI 1.35-6.53, p < 0.001). However, analyses of individual diagnoses found no evidence that the risk of Alzheimer's disease, and Parkinson's disease in individuals with previous TBI compared to those without TBI.
History of TBI is not associated with the development of subsequent neurodegeneration disease. Care must be taken in extrapolating from these results because no suitable criteria define post TBI neurodegenerative processes. Therefore, further research in this area is needed to confirm these questions and uncover the link between TBI and neurodegeneration disease.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Hydrogen is considered as sustainable and environmentally friendly energy for global energy demands in the future. Here a Co‐FeS2 catalyst with surface phosphide doping (P/Co‐FeS2) for hydrogen ...evolution reaction (HER) in acidic solutions is developed. The P/Co‐FeS2 exhibits superior HER electrochemical performance with overpotential of ‐90 mV at 100 mA cm−2 and Tafel slope of 41 mV/decade and excellent durability.
A series of dimetallic palladium(II)‐NHC complexes comprised of 1,4‐naphthalenyl or 9,10‐anthracenyl spacer sandwiched between two imidazole rings was successfully synthesized. These complexes were ...characterized by 1H and 13C{1H} NMR spectroscopy and elemental analysis. The structures of two dimetallic palladium complexes and a related mononuclear palladium complex to be used for comparative studies were further characterized by X‐ray diffraction. The dimetallic palladium complex with the 9,10‐anthracenyl linker was very efficient in catalyzing direct C−H arylation reactions of heteroaromatic compounds (imidazoles, imidazo1,2‐apyridine, and thioazole) with a broad range of aryl chlorides, employing a mild monopalladium loading of 1.5 mol%. It allows for the effective use of aryl chlorides to prepare arylated heterocycles, previously only accessible with the more reactive bromide counterparts. Importantly, the catalytic activity of the dimetallic precatalyst was found to be higher than that of an analogous mononuclear complex.
A 16-channel closed-loop neuromodulation system-on-chip (SoC) for human epileptic seizure control is proposed and designed. In the proposed SoC, a 16-channel neural-signal acquisition unit (NSAU), a ...biosignal processor (BSP), a 16-channel high-voltage-tolerant stimulator (HVTS), and wireless power and bidirectional data telemetry are designed. In the NSAU, the input protection circuit is used to prevent MOSFET from overstressing by the high-voltage stimulations. Hence, NSAUs can share electrodes with stimulators. The auto-reset chopper-stabilized capacitive-coupled instrumentation amplifiers (AR-CSCCIAs) are designed with the chopper-stabilized technique with a new offset reduction loop. The measured input-referred noise is 2.09 <inline-formula> <tex-math notation="LaTeX">\mu \textrm {V}_{\mathrm {rms}} </tex-math></inline-formula> and the noise-efficiency factor (NEF) is 3.78. The entropy-and-spectrum seizure detection algorithm is implemented in the BSP with 0.76-s seizure detection latency and 97.8% detection accuracy. When the seizure onset is detected by the BSP, the HVTS with adaptive supply control delivers 0.5-3-mA biphasic current stimulation to suppress the seizure onset. The proposed SoC is powered wirelessly, and the bidirectional data telemetry is realized through the same pair of coils in 13.56 MHz. The downlink data rate is 211 Kb/s with the binary phase-shift keying (BPSK) modulation and a new BPSK demodulator. The uplink data rate is 106 Kb/s with the load-shift keying (LSK) modulation. The proposed SoC is fabricated in a 0.18-<inline-formula> <tex-math notation="LaTeX">\mu \text{m} </tex-math></inline-formula> CMOS technology and occupies 25 mm 2 . Electrical tests have been performed to characterize the SoC performance. In vivo animal experiments using mini-pigs have been performed to successfully verify the closed-loop neuromodulation functions on epileptic seizure suppression.
Indoor utilization of emerging photovoltaics is promising; however, efficiency characterization under room lighting is challenging. We report the first round-robin interlaboratory study of ...performance measurement for dye-sensitized photovoltaics (cells and mini-modules) and one silicon solar cell under a fluorescent dim light. Among 15 research groups, the relative deviation in power conversion efficiency (PCE) of the samples reaches an unprecedented 152%. On the basis of the comprehensive results, the gap between photometry and radiometry measurements and the response of devices to the dim illumination are identified as critical obstacles to the correct PCE. Therefore, we use an illuminometer as a prime standard with a spectroradiometer to quantify the intensity of indoor lighting and adopt the reverse-biased current–voltage (I–V) characteristics as an indicator to qualify the I–V sampling time for dye-sensitized photovoltaics. The recommendations can brighten the prospects of emerging photovoltaics for indoor applications.
PDF
