A new perovskite‐like coordination polymer (CH3)2NH2Cd(N3)3 is reported which undergoes a reversible ferroelastic phase transition. This transition is due to varied modes of motion of the (CH3)2NH2+ ...guest accompanied by a synergistic deformation of the Cd(N3)3− framework. The unusual two‐staged switchable dielectric relaxation reveals the molecular dynamics of the polar cation guest, which are well controlled by the variable confined space of the host framework. As the material switches from the ferroelastic phase to the paraelastic phase, a remarkable increase of the rotational energy barrier is detected. As a result, upon heating at low temperature, this compound shows a notable change from a low to a high dielectric state in the ferroelastic phase. This thermoresponsive host–guest system may serve as a model compound for the development of sensitive thermoresponsive dielectric materials and may be key to understanding and modulating molecular/ionic dynamics of guest molecules in confined space.
Flexible frameworks: A perovskite‐like coordination polymer (CH3)2NH2Cd(N3)3 undergoes a ferroelastic‐to‐paraelastic phase transition as a result of the motion of the guest cation within the host framework (see picture), which itself undergoes a simultaneous deformation. This material acts as a thermoresponsive dielectric system owing to the well‐controlled guest molecular dynamics in the confined space.
Organophosphorus pesticides are effective, cheap, and used extensively but can harm aquatic organism and human health. Here, water quality criteria (WQCs) for dichlorvos (DDVP) and malathion (MAL) ...were derived. Nine aquatic organisms native to China were used in toxicity tests. Published toxicity data for aquatic organisms native and non-native to China were also analyzed. DDVP and MAL WQCs were derived using (log-normal model) species sensitivity distributions. Species sensitivity distribution curves indicated native and non-native species have different sensitivities to DDVP. The sensitivities of native and non-native species to MAL were not different because non-native species data for fewer than eight genera were available, so further research is required. The results indicated that native species need to be considered when deriving WQCs. The criteria maximum concentration (CMC) and criteria continuous concentration (CCC) were 1.33 and 0.132 μg/L, respectively, for DDVP, and 0.100 and 0.008 μg/L, respectively, for MAL. The CMCs for DDVP and MAL derived using ETX 2.0 software and species sensitivity ranks were different from the CMCs obtained using the SSD method because of parameter uncertainties. The DDVP and MAL WQCs were significantly lower than Chinese surface water quality standard thresholds. The results provide basic data for revising these thresholds.
Uncontrolled lithium dendrite growth and dramatic volume change during cycling have long been severely impeding the practical applications of Li metal as the ultimate anode. In this work, ultrathin ...MgF2 nanosheets encapsulated inside nitrogen‐doped graphene‐like hollow nanospheres (MgF2 NSs@NGHSs) are ingeniously fabricated to address these problems by a perfect combination of atomic layer deposition and chemical vapor deposition. The uniform and continuous Li–Mg solid‐solution inner layer formed by the MgF2 nanosheets can reduce the nucleation overpotential and induce selective deposition of Li into the cavities of the NGHSs. Furthermore, the Li deposition behavior and mechanism of the hybrid host are comprehensively explored by in situ optical microscopy at the macroscopic level, in situ transmission electron microscopy at the microscopic level, and theoretical calculations at the atomic level, respectively. Benefiting from a synergistic modulation strategy of nanosheet seed‐induced nucleation and Li‐confined growth, the designed composite demonstrates an endurance of 590 cycles for asymmetric cells and a lifespan over 1330 h for corresponding symmetric cells. When applied in LiFePO4 full cells, it provides a reversible capacity of 90.6 mAh g−1 after 1000 cycles at 1 C.
Ultrathin MgF2 nanosheets encapsulated inside N‐doped graphene‐like hollow nanospheres are prepared by the perfect combination of atomic layer deposition and chemical vapor deposition. In situ optical microscopy, in situ transmission electron microscopy, and theoretical calculations are used to investigate the deposition behavior and mechanism in detail. The Li‐metal batteries based on the designed composite anode demonstrate superior electrochemical performance.
Recently, inorganic halide perovskite (CsPbX3, X = Cl, Br, I) quantum dots (QDs) have attracted tremendous research interests because of their great potential for application in the fields of ...low-cost light sources and displays. However, the unsatisfactory structural and chemical stabilities of such materials are the main obstacles hindering reliable device operation significantly. In this study, we successfully prepared CsPbBr3/silica QD composites through a simple sol-gel reaction by using tetramethoxysilane as a single molecule precursor. The as-prepared CsPbBr3/silica QD composites demonstrated substantially improved stability against heat, light, and environmental oxygen/moisture. Besides, a relatively narrower photoluminescence linewidth and higher quantum yield were achieved compared with that of fresh CsPbBr3 QDs. Furthermore, the CsPbBr3 QDs/silica composites were applied as color-converting layer curing on blue light-emitting diodes (LEDs) for white LED applications. Finally, a high power efficiency of 63.5 lm W-1 was obtained and the light emission could be efficiently sustained over 13 h without any decay in the continuous current mode, demonstrating remarkable operation stability than that reported previously. It can be anticipated that the excellent properties and facile processing technique used here will make perovskite QDs/silica composites attractive for applications in optoelectronics and industrial fields.
Alzheimer's disease (AD) is the most prevalent type of dementia, characterized by the presence of amyloid‐β (Aβ) plaques. We previously reported that Klotho lowered Aβ levels in the brain and ...protected against cognitive deficits in amyloid precursor protein/presenilin 1(APP/PS1) mice. However, the underlying mechanism remains unclear. In this study, we induced intracerebral Klotho overexpression in 13‐month‐old APP/PS1 mice by injecting lentivirus that carried full‐length mouse Klotho cDNA in the lateral ventricle of the brain. We examined the effects of Klotho overexpression on cognition, Aβ burden, Aβ‐related neuropathology, microglia transformation, and Aβ transport systems in vivo. Additionally, we investigated the effects of Klotho on Aβ transport at the blood–cerebrospinal fluid barrier by knocking down Klotho in primary human choroid plexus epithelial cells (HCPEpiCs). The upregulation of Klotho levels in the brain and serum significantly ameliorated Aβ burden, neuronal and synaptic loss and cognitive deficits in aged APP/PS1 mice. Klotho treatment significantly inhibited NACHT, LRR, and PYD domain‐containing protein 3 (NLRP3) and the subsequent transformation of microglia to the M2 type that may enhance microglia‐mediated Aβ clearance. Meanwhile, Klotho overexpression also regulated Aβ transporter expression, which may promote Aβ transporter‐mediated Aβ clearance. Moreover, the ability of HCPEpiCs to transport Aβ in vitro was also significantly impaired by Klotho knockdown. Given the neuroprotective effect of Klotho overexpression, the present findings suggest that Klotho should be further investigated as a potential therapeutic target for AD.
Klotho, as an anti‐aging gene, has been studied in the field of AD in recent years. Our data showed that Klotho overexpression inhibited NLRP3 inflammasome activation and promoted Aβ clearance through an increase in M2 type microglia and the regulation of Aβ transporters in APP/PS1 mice, which effectively relieved neuroinflammation and Aβ burden and ameliorated AD‐like phenotypes.
Autoimmune factor was regarded as one of the risk factors in the pathogenesis of chronic pancreatitis (CP), especially for autoimmune pancreatitis (AIP). However, whether autoimmune factor plays a ...role in non-AIP CP or not was unknown.
Hospitalized patients with non-AIP CP from January 2010 to October 2016 were detected for 22 autoantibodies at the time of hospital admission. Autoantibodies with frequency > 0.5% were enrolled to calculate the frequency in historial healthy controls through literature search in PubMed. Differentially expressed autoantibodies were determined between patients and historial healthy controls, and related factors were identified by multivariate logistic regression analysis.
In a total of 557 patients, 113 cases were detected with 19 kinds of positive autoantibodies, among them anti-β2-glycoprotein I (β2-GPI) antibody was most frequent (9.16%). Compared with historial healthy controls, the frequencies of serum β2-GPI and anti SS-B antibody in patients were significantly higher, while frequencies of anti-smooth muscle antibody and anticardiolipin antibody were significantly lower (all P < 0.05). Multivariate logistic regression analysis result showed that diabetes mellitus (OR = 2.515) and common bile duct stricture (OR = 2.844) were the risk factors of positive β2-GPI antibody in patients while diabetes mellitus in first-/second-/third-degree relatives (OR = 0.266) was the protective factor. There were no related factors for other three differentially expressed autoantibodies.
Four autoantibodies were expressed differentially between patients with non-AIP CP and historial healthy controls. Due to limited significance for diagnosis and treatment of chronic pancreatitis, autoantibodies detection is not recommended conventionally unless suspected of AIP.
Neonatal hypoxic–ischaemic (HI) injury is a serious complication of neonatal asphyxia and the leading cause of neonatal acute death and chronic neurological injury, and the effective therapeutic ...method is lacking to improve patients' outcomes. We reported in this study that panax notoginseng saponin (PNS) may provide a treatment option for HI. HI model was established using neonatal Sprague–Dawley rats and then intraperitoneally injected with different dosage of PNS, once a day for 7 days. Histological staining and behavioural evaluations were performed to elucidate the pathological changes and neurobehavioural variation after PNS treatment. We found PNS administration significantly reduced the infarct volume of brain tissues and improved the autonomous activities of neonatal rats, especially with higher dosage. PNS treatment at 40 mg/kg reduced neuronal damage, suppressed neuronal apoptosis and depressed astroglial reactive response. Moreover, the long‐term cognitive and motor functions were also improved after PNS treatment at 40 mg/kg. Importantly, PNS treatment elevated the levels of BDNF and TrkB but decreased the expression of p75NTR both in the cortex and hippocampus of HI rats. The therapeutic efficacy of PNS might be correlated with PNS‐activated BDNF/TrkB signalling and inactivation of p75NTR expression, providing a novel potential therapy for alleviating HI injury.
PNS ameliorated the acute cerebral injury induced by HI in neonatal rats. PNS treatment suppressed the neuronal apoptosis in neonatal HI rats and alleviated GFAP‐mediated inflammatory response. The long‐term neurological dysfunctions in neonatal HI rats were relieved after PNS treatment.
Environmentally friendly and efficient transition metal phosphide (TMP) electrocatalysts for oxygen evolution reaction (OER) are developed to meet the growing demand for clean energy. Here we report ...a novel and environmentally friendly strategy for the preparation of MOF-derived bimetallic phosphide embedded in the carbonaceous matrix (FeNiP/C). With 3-dimensional hollow barrel shape and high specific surface, FeNiP/C-900 performs excellent OER catalytic performance, reaching a current density of 10 mA cm−2 at an overpotential of 229 mV with a low Tafel slope of 74.5 mV dec−1. Meantime, we explore the thermal conversion mechanism of P-containing MOF and the compositional changes during heat treatment.
Schematic illustration represents the synthesis of FeNiP/C composite, which is prepared by the self-assembly of Ni2+, H3TPO, and dabco to form BMM-10 microcrystals, followed by the treatment of the Fe3+ etching and direct pyrolyzation. In-situ formed FeNiP nanoparticles anchored on the carbon layer with 3D hollow structure performs an enhanced electrocatalyst activity for OER. Finally, the transformation mechanism of this P-contained BMM-10 is also well explored. Display omitted
•A less toxic strategy to prepare porous MOF-derived transition metal phosphide nano-composites.•The as-obtained hollow FeNiP/C-900 nano-composite possesses the high electrocatalytic activity for OER.•The chemical bond and phase changes are discussed to form FeNiP/C nano-particles.
Objectives
Glial cell activation contributes to the inflammatory response and occurrence of epilepsy. Our preliminary study demonstrated that the long non‐coding RNA, H19, promotes hippocampal glial ...cell activation during epileptogenesis. However, the precise mechanisms underlying this effect remain unclear.
Materials and methods
H19 and let‐7b were overexpressed or silenced using an adeno‐associated viral vector in vivo. Their expression in a kainic acid‐induced epilepsy model was evaluated by real‐time quantitative PCR, fluorescence in situ hybridization, and cytoplasmic and nuclear RNA isolation. A dual‐luciferase reporter assay was used to evaluate the direct binding of let‐7b to its target genes and H19. Western blot, video camera monitoring and Morris water maze were performed to confirm the role of H19 and let7b on epileptogenesis.
Results
H19 was increased in rat hippocampus neurons after status epilepticus, which might be due to epileptic seizure‐induced hypoxia. Increased H19 aggravated the epileptic seizures, memory impairment and mossy fibre sprouting of the epileptic rats. H19 could competitively bind to let‐7b to suppress its expression. Overexpression of let‐7b inhibited hippocampal glial cell activation, inflammatory response and epileptic seizures by targeting Stat3. Moreover, overexpressed H19 reversed the inhibitory effect of let‐7b on glial cell activation.
Conclusions
LncRNA H19 could competitively bind to let‐7b to promote hippocampal glial cell activation and epileptic seizures by targeting Stat3 in a rat model of temporal lobe epilepsy.
Mutations in myosin-VIIa (MYO7A) cause Usher syndrome type 1, characterized by combined deafness and blindness. MYO7A is proposed to function as a motor that tensions the hair cell ...mechanotransduction (MET) complex, but conclusive evidence is lacking. Here we report that multiple MYO7A isoforms are expressed in the mouse cochlea. In mice with a specific deletion of the canonical isoform (Myo7a-ΔC mouse), MYO7A is severely diminished in inner hair cells (IHCs), while expression in outer hair cells is affected tonotopically. IHCs of Myo7a-ΔC mice undergo normal development, but exhibit reduced resting open probability and slowed onset of MET currents, consistent with MYO7A's proposed role in tensioning the tip link. Mature IHCs of Myo7a-ΔC mice degenerate over time, giving rise to progressive hearing loss. Taken together, our study reveals an unexpected isoform diversity of MYO7A expression in the cochlea and highlights MYO7A's essential role in tensioning the hair cell MET complex.
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