High Capacity Silicon Electrodes with Nafion as Binders for Lithium-Ion Batteries

Silicon is capable of delivering a high theoretical specific capacity of 3579 mAh g−1 which is about 10 times higher than that of the state-of-the-art graphite based negative electrodes for lithium-ion batteries. However, the poor cycle life of silicon electrodes, caused by the large volumetric strain during cycling, limits the commercialization of silicon electrodes. As one of the essential components, the polymeric binder is critical to the performance and durability of lithium-ion batteries as it keeps the integrity of electrodes, maintains conductive path and must be stable in the electrolyte. In this work, we demonstrate that electrodes consisting of silicon nanoparticles mixed with commercially available Nafion and ion-exchanged Nafion can maintain a high specific capacity over 2000 mAh g−1 cycled between 1.0 V and 0.01 V. For comparison, the capacity of electrodes made of the same silicon nanoparticles mixed with a traditional binder, polyvinylidene fluoride (PVDF), fades rapidly. In addition, stable cycling at 1C rate for more than 500 cycles is achieved by limiting the lithiation capacity to 1200 mAh g−1

Neural activity dissociation between thought-based and perception-based response conflict

Based on the idea that intentions have different penetrability to perception and thought (Fodor, 1983), four Stroop-like tasks, AA, AW, WA, and WW are used, where the A represents an arrow and the CPPR (closest processing prior to response) is perception, and the W represents a word and the CPPR is thought. Event-related brain potentials were recorded as participants completed these tasks, and sLORETA (standardized low resolution brain electromagnetic tomography) was used to localize the sources at specific time points. These results showed that there is an interference effect in the AA and WA tasks, but not in the AW or WW tasks. The activated brain areas related to the interference effect in the AA task were the PFC and ACC, and PFC activation took place prior to ACC activation; but only PFC in WA task. Combined with previous results, a new neural mechanism of cognitive control is proposed

Endothelial nitric oxide synthase expression is progressively increased in primary cerebral microvascular endothelial cells during hyperbaric oxygen exposure

Exposure to hyperbaric oxygen (HBO) can lead to seizures. Many studies have demonstrated that there exist a very close relationship between the alteration of cerebral blood flow (CBF) and the onset of seizures. Nitric oxide (NO) may play a key role in the change of CBF during exposure, and modulation of endothelial nitric oxide synthase (eNOS)-derived NO by HBO is responsible for early vasoconstriction, whereas late HBO-induced vasodilation depends upon a large amount of NO from both eNOS and neuronal nitric oxide synthase (nNOS). To investigate the effect of HBO on the activity and expression of eNOS in cerebral microvascular endothelial cells (CMEC) in vitro, primarily cultured CMEC from neonatal rats were exposed to oxygen at 500 kPa [5 atmosphere absolute (ATA)] for 10, 20, 30, 60 and 120 minutes (min), then eNOS activity, protein and mRNA contents in cells were detected. Our results showed that immediately after exposure, 30, 60 and 120 min HBO exposures did not alter NOS activity. When detected no matter immediately or six hours (h) after exposure, these exposures also did not alter eNOS protein and mRNA levels. However, when detected 24 h after exposure, 30, 60 and 120 min exposures upregulated eNOS protein content by 39%, 60% and 40% respectively. 10 and 20 min exposures upregulated eNOS mRNA content by about 15%, while 30, 60 and 120 min exposures upregulated it by about 20–30%. The increased eNOS protein and mRNA contents at 24 h after exposure may reflect new protein synthesis for eNOS. Our studies showed that with the exposing protocols we used, HBO did induce eNOS expression increase in CMEC. However, compared with the decrease of CBF in vivo, which occurred in a relative short time after rat was exposed to HBO above 4 ATA, the responses of eNOS in CMEC in vitro were a little slow. Thus we considered that for the vasodilation in the late period of HBO exposure before seizure, the effect of NO produced by eNOS was limited

Thermal expansion behavior of co-extruded wood-plastic composites with glass-fiber reinforced shells

Coextruded wood-plastic composites (WPCs) with glass-fiber (GF) filled shells were manufactured, and their thermal expansion behavior was studied. A three-dimensional finite element model (FEM) considering differential properties of both shell and core layers was developed to predict the linear coefficient of thermal expansion (LCTE) of the material. It was shown that the LCTE values varied with composite structure and composition (i.e., core-shell thicknesses and materials). The use of GF-filled shells helped lower overall composite LCTE values. The imbalance of shell and core LCTE, and their moduli led to complex stress fields within a given composite system. The FEM predicted a trend of LCTE change with varying composite structures, which was in good agreement with the experimental data. This study provides for the first time a finite element modeling technique to optimize raw material composition and composite structure for optimizing thermal expansion behavior of co-extruded WPCs

Tetraspanin CD151 plays a key role in skin squamous cell carcinoma

Here we provide the first evidence that tetraspanin CD151 can support de novo carcinogenesis. During two-stage mouse skin chemical carcinogenesis, CD151 reduces tumor lag time and increases incidence, multiplicity, size, and progression to malignant squamous cell carcinoma (SCC), while supporting both cell survival during tumor initiation and cell proliferation during the promotion phase. In human skin SCC, CD151 expression is selectively elevated compared to other skin cancer types. CD151 support of keratinocyte survival and proliferation may depend on activation of transcription factor STAT3, a regulator of cell proliferation and apoptosis. CD151 also supports PKCα-α6β4 integrin association and PKC-dependent β4 S1424 phosphorylation, while regulating α6β4 distribution. CD151-PKCα effects on integrin β4 phosphorylation and subcellular localization are consistent with epithelial disruption to a less polarized, more invasive state. CD151 ablation, while minimally affecting normal cell and normal mouse functions, markedly sensitized mouse skin and epidermoid cells to chemicals/drugs including DMBA (mutagen) and camptothecin (topoisomerase inhibitor), as well as to agents targeting EGFR, PKC, Jak2/Tyk2, and STAT3. Hence, CD151 ‘co-targeting’ may be therapeutically beneficial. These findings not only support CD151 as a potential tumor target, but also should apply to other cancers utilizing CD151-laminin-binding integrin complexes

Intralayer Negative Poisson's Ratio in Two-Dimensional Black Arsenic by Strain Engineering

Negative Poisson's ratio as the anomalous characteristic generally exists in artificial architectures, such as re-entrant and honeycomb structures. The structures with negative Poisson's ratio have attracted intensive attention due to their unique auxetic effect and many promising applications in shear resistant and energy absorption fields. However, experimental observation of negative Poisson's ratio in natural materials barely happened, although various two-dimensional layered materials are predicted in theory. Herein, we report the anisotropic Raman response and the intrinsic intralayer negative Poisson's ratio of two-dimensional natural black arsenic (b-As) via strain engineering strategy. The results were evident by the detailed Raman spectrum of b-As under uniaxial strain together with density functional theory calculations. It is found that b-As was softer along the armchair than zigzag direction. The anisotropic mechanical features and van der Waals interactions play essential roles in strain-dependent Raman shifts and negative Poisson's ratio in the natural b-As along zigzag direction. This work may shed a light on the mechanical properties and potential applications of two-dimensional puckered materials.Comment: 23 pages, 4 figure

Influence on emergency digit replantation and outcome assessment after COVID-19 virus nucleic acid testing normalization

ObjectiveThe study aims to compare the implementation and prognosis of emergency digit replantation surgery before and after normalized corona virus disease 2019 (COVID-19) nucleic acid testing for patients taking emergency operation and to explore the influence of normalized COVID-19 nucleic acid testing on replantation surgery.MethodNormalized COVID-19 nucleic acid testing for patients taking emergency operation has been carried out since 1 August 2021 at our hospital, which means each patient who needs emergency surgical treatment has to obtain either positive or negative results of COVID-19 nucleic acid before entering the operating room. This research reviewed and compared the prognosis of the injured extremity that had emergency severed digit replantation between June and September 2021, at the Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, and analyzed the impact of normalized COVID-19 nucleic acid testing on the outcome of the replanted fingers of different severity using disability of arm-shoulder-hand (DASH) and hand injury severity scoring (HISS) scoring systems.ResultsA total of 54 cases with 74 severed replanted phalanges were included replanted by the research group between 1 August and 30 September 2021, without any COVID-19 suspected/confirmed case detected. Compared with previous period (1 June to 31 July, 2021), although the interval between emergency visits and emergency replantation did increase significantly after normalized COVID-19 nucleic acid testing [(3.83 ± 0.94) to (1.77 ± 0.67) h, P < 0.05], we observed no significant difference in the improvement rate of the DASH scoring of the disabled upper extremity 3-month postoperatively (P = 0.538) nor in the complication rate (P = 0.344). Moreover, there was no significant difference in the improvement rate of the DASH scoring of the disabled upper extremity 3-month postoperatively in patients with different traumatic severities before and after normalized COVID-19 nucleic acid testing (moderate P = 0.269, severe P = 0.055, major P = 0.149).ConclusionDespite the preoperative delay, the policy of COVID-19 nucleic acid testing normalization does not have explicit influence on the short-term outcomes of emergency digit replantation surgery. With this evidence, microsurgeons could pay attention to the patients' anxiety and spend more effort in comforting them during the prolonged preoperative wait. These insights may have implications for other emergency department resource management whenever a social crisis occurs

Retinal microvasculature features in patients with migraine: a systematic review and meta-analysis

BackgroundMigraine is a central nervous system disorder involving neuronal and vascular factors. The brain has a close anatomical relationship with retinal vessels and similar regulatory processes, and the retinal vascular system is the only in vivo vessel that can be directly visualized, while optical coherence tomography angiography (OCTA) is an advanced retinal vascular imaging technique. In this study, OCTA was used to study the retinal vascular density (VD) and foveal avascular zone (FAZ) in migraine patients, which provided a theoretical basis for its use as a candidate for rapid and non-invasive diagnosis of migraine.MethodsPublished studies comparing retinal microvascular profiles between migraine patients and healthy controls were obtained by a comprehensive search of electronic databases. Nine studies were finally included, including 775 eyes (migraine group: 444 eyes, control group: 331 eyes). Pooled effect sizes were presented as standardized mean differences (SMDs) and 95% confidence intervals (CIs). Statistical analysis was performed using Review Manager software (version 5.30).ResultsThe combined results revealed that the superficial and deep macular whole enface VD (MWEVD) (superficial VD: SMD = −0.30, P = 0.0001; deep VD: SMD = −0.61, P = 0.02), superficial foveal VD (FVD) (SMD = −0.42, P = 0.03), deep parafoveal VD (PFVD) (SMD = −0.31, P = 0.002), and peripapillary VD (PVD) (SMD = −0.49, P = 0.002) were significantly reduced in migraine patients compared with healthy people. However, there was a significant increase in the area of the FAZ in migraine patients (SMD = 0.56, P < 0.0001).ConclusionMigraine patients are prone to retinal microcirculation disorders, such as decreased blood vessel density and increased avascular area in the fovea. This provides a theoretical basis for OCTA as a candidate for rapid, non-invasive diagnosis of migraine

Probing high-momentum component in nucleon momentum distribution by neutron-proton bremsstrahlung {\gamma}-rays in heavy ion reactions

The high momentum tail (HMT) of nucleons, as a signature of the short-range correlations in nuclei, has been investigated by the high-energy bremsstrahlung $\gamma$ rays produced in $^{86}$Kr + $^{124}$Sn at 25 MeV/u. The energetic photons are measured by a CsI(Tl) hodoscope mounted on the spectrometer CSHINE. The energy spectrum above 30 MeV can be reproduced by the IBUU model calculations incorporating the photon production channel from $np$ process in which the HMTs of nucleons is considered. A non-zero HMT ratio of about $15\%$ is favored by the data. The effect of the capture channel $np \to d\gamma$ is demonstrated