Structural Distortion-Modulated Magnetic and Dielectric Properties in Nonstoichiometric Yb2-xTi2O7-δ Pyrochlore.

Rare-earth titanate pyrochlores have attracted considerable attention for their unique magnetic frustration. Among those compounds, Yb2Ti2O7, a candidate for quantum spin ice, has been extensively studied in its magnetic ground state. However, works on its dielectric property and structure-property relationship lag far more behind. Here, by preparing and investigating nonstoichiometric Yb2-xTi2O7-δ (x = 0-0.15) ceramics, we demonstrate that the samples with x ≤ 0.05 maintain a single-pyrochlore phase, but the nonstoichiometry arouses significant structural distortion and increased oxygen vacancy. As a result, the ferromagnetism, indicated by a positive Curie-Weiss temperature, decreases almost linearly with increasing x value. Remarkably composition-dependent low-temperature dielectric relaxations have been observed. In addition, through introducing nonstoichiometry, the relaxor degree of dielectric behavior is enhanced, and the dielectric curve shows an altered shape. The origin of this dielectric relaxation is attributed to the increased structural distortion reflected by the changed bond length/angle, since there is no phase transition in 90-300 K. Our work gives a comprehensive view on the structural, magnetic, and dielectric properties of Yb2Ti2O7, which is instructive for further work on pyrochlores.

Design of Two-Dimensional Multiferroics with Direct Polarization-Magnetization Coupling.

The recent discovery of two-dimensional (2D) ferromagnetism in van der Waals materials has opened the door to the control of 2D magnetism by means of electric field. Here we demonstrate the magnetization reversal through switching polarization in a designed 2D multiferroic oxide by combining group theory analysis and first-principles calculation. We show that ferroelectricity can be induced by a specific octahedral rotation in a perovskite bilayer. Ferromagnetism can be introduced simultaneously by extending the guideline to the B-site ordered double-perovskite bilayer. We have found two coupling mechanisms between polarization and magnetization that enable the reversal of the in-plane magnetization by ferroelectric switching. Our work provides guidelines for the design of 2D multiferroics with intrinsic magnetoelectric coupling and helps to control the 2D magnetism by electric field.

Upregulation of the lncRNA MEG3 improves cognitive impairment, alleviates neuronal damage, and inhibits activation of astrocytes in hippocampus tissues in Alzheimer's disease through inactivating the PI3K/Akt signaling pathway.

OBJECTIVE: The purpose of this study was to elucidate the expression of the long noncoding RNA (lncRNA) maternally expressed gene 3 (MEG3) in rats with Alzheimer's disease (AD) and to explore its potential mechanisms. METHODS: An AD rat model was induced by microinjection of Aß25-35 . On the first day after successful modeling, pcDNA3.1 plasmid and pcDNA3.1-MEG3 plasmid were continuously infused into the third ventricle through a micro-osmotic pump to interfere with the expression level of MEG3. The spatial learning ability and memory ability, the histopathological changes of hippocampus tissues, the ultrastructure of hippocampal neurons, astrocyte activation as well as the survival and apoptosis of hippocampal neurons in each group was observed. The expression of apoptosis, PI3/Akt signaling pathway-related proteins, glial fibrillary acidic protein, inflammatory factors, malondialdehyde, glutathione-peroxidase, and superoxide dismutase levels were determined. The deposition of amyloid beta (Aß) in the hippocampus of rats by was observed by Aß immunohistochemical staining. RESULTS: Downregulated MEG3 was detected in the tissues of AD rats. In addition, upregulation of MEG3 contributed to an improvement of spatial learning ability and memory ability, inhibited the pathological injury and its apoptosis of hippocampal neurons, decreased Aß positive expression, inhibited oxidative stress injury and inflammatory injury as well as the activated astrocytes in AD rats via inactivation of the PI3/Akt pathway. CONCLUSION: Our study highlights that upregulation of the lncRNA MEG3 improves cognitive impairment, alleviates neuronal damage, and inhibits activation of astrocytes in hippocampus tissues in AD through inhibiting the PI3K/Akt signaling pathway.

LncRNA SNHG12 as a potent autophagy inducer exerts neuroprotective effects against cerebral ischemia/reperfusion injury.

Long-non-coding RNA small nucleolar RNA host gene 12(SNHG12) was reported to be highly up-regulated in brain microvascular endothelium after cerebral ischemia. Autophagy has been shown to have protective effects against cerebral ischemic insults. However, molecular mechanisms of SNHG12 in regulating autophagy during cerebral ischemia/reperfusion (I/R) injury remain unclear. Here, we established middle cerebral artery occlusion/reperfusion (MCAO/R) model in mice and adopted oxygen-glucose deprivation and reperfusion (OGD/R) SH-SY5Y cell model to mimic cerebral I/R injury in vitro. Triphenyltetrazolium chloride (TTC) staining was used to measure infarct size. Bederson and Longa score systems were used to evaluate neurological behavioral and defects, respectively. CCK-8, EdU staining, flow cytometry and Hoechst 33258 staining were performed to determine the biological function of SNHG12 on SH-SY5Y cell under OGD/R condition. The autophagy levels were determined by Western blotting and LC3B immunofluorescence. We found the expression of SNHG12 was up-regulated by cerebral I/R in mice andSH-SY5Y cell model after OGD/R. Up-regulated SNHG12 alleviated OGD/R-induced SH-SY5Y cell injury and induced autophagy activation, as indicated by an increased ratio of LC3 II/I and Beclin-1, decreased p62. On the contrary, down-regulation of SNHG12 exacerbated SH-SY5Y cell injury after OGD/R and inhibited autophagy. Furthermore, autophagy activator rapamycin or inhibitor 3-MA partially reversed the down-regulation or up-regulation of SNHG12 effect in OGD/R-inducedSH-SY5Y cell injury, respectively. Taken together, these findings suggest that SNHG12 as an autophagy inducer alleviates cerebral I/R injury, which might be a new therapeutic target of ischemic stroke.

Improved magnetic and magnetoelectric properties in BaFe12O19 nanostructures.

The structural, magnetic and magnetoelectric properties were investigated for sol-gel prepared BaFe12O19 nanorods and plate-like nanoparticles. Based on comparative experiments with bulk ceramics, it is found that larger structural distortion is present in nanostructures, which could cause the enhancement of magnetocrystalline anisotropy and the off-center displacement of Fe3+ ions, and thus result in improved magnetic and magnetoelectric properties in BaFe12O19 plate-like nanoparticles. Meanwhile, the local (Fe2+-Fe3+) dipoles, which usually appear during a high temperature sintering process, can also contribute to the negative magnetoelectric effect of BaFe12O19 nanorods and a large room temperature magnetodielectric coefficient of about -13% is observed at 104 Hz and 9 kOe.

Induced core-shell structure and the electric properties of (K0.48Na0.52)0.95Li0.05Nb0.95Sb0.05O3 ceramics.

The relationship among dielectric anomaly, ferroelectric response, defects, and microstructures was established for (K0.48(1+x)Na0.52)0.95Li0.05Nb0.95Sb0.05O3 (x = 0.04, 0.00, -0.02, -0.04 and -0.08) ceramics. For x = -0.02 and -0.04, larger coercive fields and lower remnant polarizations were obtained; besides, an additional dielectric relaxation behavior was observed with the activation energy Ea being about 2.19 eV and 1.92 eV, respectively. Furthermore, the grain and grain boundary contributions to the capacitance were separated using impedance spectroscopy, which, combined with back-scattering characterization, firmly indicates the core-shell structure of K-deficient samples (x = -0.02 and -0.04). Unlike the cores, the shells possess a large amount of K+ vacancies (). This work paves a way for regulating the fine structure and more on the electrical properties of KNN-based materials.

Combination of early constraint-induced movement therapy and fasudil enhances motor recovery after ischemic stroke in rats.

PURPOSE: Constraint-induced movement therapy (CIMT) is a promising technique for the recovery of upper extremity movement in chronic stroke patients. However, the effectiveness of its use in acute ischemia has not been confirmed. Myelin-associated inhibitors, which have upregulated functions in tissues affected by acute focal infarction, limit axonal regeneration via activation of the Rho-Rho-associated protein kinase (ROCK) pathway. The present study examined whether early CIMT combined with the ROCK inhibitor fasudil promotes motor recovery after acute ischemic stroke. MATERIALS AND METHODS: Rats were trained to perform the skilled-reach test and then subjected to middle cerebral artery occlusion (MCAO), producing a stroke affecting the preferred forelimb. Rats were assigned to one of four groups (N = 6/group): (nontreated) Control, CIMT, Fasudil, or CIMT+fasudil. CIMT and/or intraperitoneal infusion of fasudil were initiated 1 day postMCAO. Skilled reach and foot fault test data were collected once before and repeatedly over 4 weeks after the operation. Infarct volumes were calculated. RESULTS: All four groups showed similar forelimb impairment before treatment. The performance of CIMT alone group was similar to that of controls on both tests. Fasudil alone facilitated recovery in the foot-fault test, but not in the skilled-reach test. Rats in the CIMT+fasudil group demonstrated enhanced recovery in both tests, including better performance over time than the Fasudil group on the foot-fault test. Infarct size did not differ significantly between the groups. CONCLUSIONS: Early CIMT promotes motor recovery after acute ischemic stroke when it is administered with fasudil pharmacotherapy, but not without it.

High Serum GFAP Levels in SCA3/MJD May Not Correlate with Disease Progression.

Spinocerebellar ataxia type 3(SCA3), also known as Machado-Joseph disease (MJD), is the most frequent subtype of autosomal dominant inherited spinocerebellar ataxias, which caused by the expansion of CAG repeats in the ATXN3 gene. The number of CAG repeats of the abnormal allele determines the rate of disease progression in patients with SCA3/MJD. Markers to assess the clinical severity, to predict the course of illness and to monitor the efficacy of therapeutic measures, can be clinical, biological, and radiological. Here, we aimed to explore whether the serum glial fibrillary acidic protein (GFAP) may act as a biomarker in SCA3/MJD patients and to evaluate the correlation between some markers with the number of CAG repeats in SCA3/MJD patients. We showed that the serum levels of GFAP were significantly higher in SCA3/MJD patients than in controls. There was a strong positive correlation between the age-adjusted GFAP levels with the number of CAG repeats. Age-adjusted International Cooperative Ataxia Rating Scale (ICARS) scores and Scale for the Assessment and Rating of Ataxia (SARA) scores correlated with the number of CAG repeats. Raw scores and disease duration-adjusted GFAP levels, ICARS scores, and SARA scores were not correlated with the number of CAG repeats. Our results reveal novel evidence for the role of the triplet expansion in SCA3/MJD-associated neuronal damage.

Spectrum reconstruction using relative-deviation-based kernel regression in temporally and spatially modulated Fourier transform imaging spectrometer.

During the temporally and spatially modulated Fourier transform imaging spectrometer push-broom scanning process, the motion state of the spectrometer platform can vary. Thus, the target interferogram obtained from the image sequence deviates from the ideal interferogram obtained using high platform stability. The recovered target spectrum will not reflect the true target characteristics. We adopted target tracking to acquire the target position in the image sequence via a proposed kernel regression, with a relative deviation method for determining the target intensities, and the recovery of the spectrogram using the nonuniform fast Fourier transform algorithm. We tested our algorithm on simulated and experimentally obtained aerial images and, from comparison with accurate spectrograms, demonstrate the effectiveness of the proposed method.

Hepatic encephalopathy coexists with acquired chronic hepatocerebral degeneration.

Hyperkinetic extrapyramidal syndrome is the typical clinical characteristic of acquired hepatocerebral degeneration (AHD), but is usually not observed with hepatic encephalopathy (HE). We present a case of AHD coexisting with HE. Both conditions were secondary to liver cirrhosis and hepatitis C virus infection. The brain MRI showed bilateral and symmetric high T1 signal-intensity in the globus pallidus, and diffuse high signal-intensity of the hemispheric white matter on T2-FLAIR images. As we usually neglect the existence of AHD, the diagnosis is often ignored, especially when it coexists with HE. This case highlights the need to distinguish irreversible AHD from HE.

MicroRNA profiling in the serums of SCA3/MJD patients.

Spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD) is the most common type of spinocerebellar ataxia in China. However, the pathogenesis of SCA3/MJD is still unknown. MicroRNAs (miRNAs) have been repeatedly demonstrated to exist in human peripheral serum in a bio-stable form and have been shown to be useful biomarkers for other neurodegenerative disorders. However, no study of SCA3/MJD patients has assessed specific changes in regulatory miRNAs. Therefore, we systematically used the miRCURYTM LNA Array, followed by quantitative real-time polymerase chain reaction validation, to access miRNA expression levels in the serums from SCA3/MJD patients. Our results show that miR-25, miR-125b, miR-29a, and miR-34b could be potential biomarkers for SCA3/MJD and could be used to further investigate the pathogenesis of SCA3/MJD and drug development.

Lithium chloride alleviates neurodegeneration partly by inhibiting activity of GSK3ß in a SCA3 Drosophila model.

Spinocerebellar ataxia type 3 (SCA3) is an autosomal dominant neurodegenerative disorder caused by the expansion of a CAG trinucelotide repeat that encodes an abnormal polyglutamine (PolyQ) tract in the disease protein, ataxin-3. The formation of neuronal intranuclear inclusions in the specific brain regions is one of the pathological hallmarks of SCA3. Acceleration of the degradation of the mutant protein aggregates is proven to produce beneficial effects in SCA3 and other PolyQ diseases. Lithium is known to be neuroprotective in various models of neurodegenerative disease and can reduce the mutant protein aggregates by inducing autophagy. In this study, we explored the therapeutic potential of lithium in a SCA3 Drosophila model. We showed that chronic treatment with lithium chloride at specific doses notably prevented eye depigmentation, alleviated locomotor disability, and extended the median life spans of SCA3 transgenic Drosophila. By means of genetic approaches, we showed that co-expressing the mutant S9E, which mimicked the phosphorylated S9 state of Shaggy as done by lithium, also partly decreased toxicity of gmr-SCA3tr-Q78. Taken together, our findings suggest that lithium is a promising therapeutic agent for the treatment of SCA3 and other PolyQ diseases.

Optogenetic investigation of neuropsychiatric diseases.

Optogenetic technology, also known as optogenetics, is a novel multidisciplinary field in biotechnology that integrates genetic engineering, electrophysiology, and optical and electronic engineering. This recently developed technology has evolved rapidly and generated considerable excitement in neuroscience research. This technology successfully solves the severe problem of achieving both high temporal and spatial precision within intact neural tissues of animals that electrical stimulation and pharmacological methods cannot achieve. It allows neurons to express light-sensitive genes that enable the identification, dissection, and manipulation of specific neural populations and their connections in the tissues and organs of awake animals with unprecedented spatial and temporal precision. Light-sensitive genes chiefly including the genetically targeted light-gated channels channelrhodopsin-2 (ChR2) and halorhodopsin (NpHR) cause intracellular ion flow during optical illumination. Subsequently, the neurons undergo a series of changes resulting from membrane depolarization or hyperpolarization. To date, there are many published research articles and reviews that describe this new technology; however, few of the reports concern its application to neuropsychiatric diseases. In this review, we summarize the most recent optogenetic research in these diseases, including Parkinson's disease (PD), epilepsy, schizophrenia, anxiety, fear, reward behaviors, and sleep disorders. We propose that novel optogenetics technology creates excellent opportunities for innovative treatment strategies of neuropsychiatric diseases.

[Cloning and localization of A3IP -a novel protein that interacts with ataxin-3].

OBJECTIVE: To clone an A3IP gene and investigate its cellular and histological localization based on previous research which has identified part of A3IP sequence interacting with carboxyl-terminal of ataxin-3. METHODS: Bioinformatic and Northern blotting were applied to clone the A3IP gene and detect the expression of its transcripts in various human tissues and brain regions. Western blotting and immunofluorescence staining were applied to detect expression of A3IP protein in cultured cells. Immunohistochemistry staining was applied to study the expression of A3IP protein in various human tissues and brain regions. RESULTS: cDNA cloning of A3IP gene's reading frame and its sequence assembly were completed. Three transcripts (1 kb, 1.35 kb and 6 kb, respectively) of A3IP were found to express in various human tissues and brain regions. A3IP pEGFP expresses in cytoplasm of cultured COS-7 cells and various human tissues and brain regions including cerebral cortex, cerebellum, muscle, peripheral nerve, liver and kidney. CONCLUSION: The cloned A3IP gene encodes A3IP, a novel ataxin-3 interacting protein. Three transcripts of A3IP are expressed in various human tissues and brain regions. A3IP is a cytosolic protein.

Direct Measurement of Negative Capacitance in Ferroelectric/Semiconductor Heterostructures.

Negative capacitance (NC) is now an attractive research topic owing to its potential applications. For better integration, investigation about the phenomenon and mechanism of NC in ferroelectric materials on semiconductor substrates is important. In this work, ferroelectric BaTiO3 (BTO) films are deposited on the low-resistance Si(100) substrates to constitute Pt/BTO/p-Si/Pt samples with the metal/ferroelectric/semiconductor/metal (MFSM) structure, on which NC are directly measured at low frequencies with a large DC bias. Because of the unique asymmetric interface, the NC value is tunable by the polarity and magnitude of the DC bias. Analysis based on the impedance and ferroelectric characteristics reveals that, in addition to the displacement current related to the electric polarization, there is also relaxation current caused by interface charge injection and oxygen vacancy migration. This work provides another idea for studying miniaturized and low-energy devices utilizing NC, which is of great significance for the development of silicon-based ferroelectric devices.

Effects of schedule exercise therapy on chronic insomnia.

Schedule exercise therapy (SET) is a novel nonpharmacological intervention for the treatment of chronic insomnia disorder (CID). The aim of this study was to explore the effects of SET on CID. Methods: One hundred and eighteen CID were recruited and randomized into medication (MED) or medication combined with SET (MSET) groups. Over 12 observational weeks, sleep and mood status were evaluated using the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS), Self-rating Depression Scale (SDS), and Self-rating Anxiety Scale (SAS). At the end of the observational period, the rates of clinically effective hypnotic use were calculated. At 12 weeks, the PSQI progressively decreased for all subjects combined (P < .001) as well as ISI (P < .001), ESS (P < .001), SDS (P < .001), and SAS (P < .001). The decreases in PSQI (P < .05), ISI (P < .05), SDS (P < .01), and SAS (P < .05) in the MSET group were significantly larger than those in the MED group, but not the same as those in the ESS group (P > .05). At the trial endpoint, the clinically effective rate was significantly higher (P < .05) and the hypnotic usage rate was lower (P < .05) in the MSET group than in the MED group. SET may be an effective treatment for insomnia in patients with CID.

[Simulated annealing based phase correction of interferogram in Fourier transform imaging spectrometer].

Phase correction is one of the key technologies in the spectrum recovery of the Fourier transform imaging spectrometer. The present paper proposes a correction method based on simulated annealing algorithm to calculate phase error, which overcomes the disadvantage of the existing methods that can not correct the interferogram with noise. The method determines the phase optimum solution by controlling the phase decrease function, attaining objective function value by correcting interferogram data with random phase value generated in the phase range, and determining the objective function increment in accordance with the Metropolis criterion. The simulation result of the algorithm indicates that the optimized phase error is less than 0.5%, and both the error accuracy and stability of the spectrum-recovered relative spectrum is less than 1%, which is a great improvement compared with the existing algorithm.

Controllable Distribution and Reversible Migration of Charges in BiFeO3-Based Films on Si Substrates.

In ferroelectric-based integrated devices, there are usually buffer layers between ferroelectric films and semiconductor substrates. Here, Bix%FeO3-δ (x = 95, 100, and 105) (BFOx) films are prepared directly on n-Si substrates by the sol-gel method, and the variation of the hysteresis loops with Bi content and heat treatment is investigated. With the help of the dielectric measurement and the composition analysis, a PN heterojunction is believed to exist at the BFOx/Si interface. The Bi/Fe ratio determines not only the type and concentration of charged defects in the films but also the height of the interface barrier and its binding effect on mobile charges. Furthermore, the distribution and the migration of charges can be regulated reversibly by heat treatment. This work reveals the interaction between ferroelectric films and semiconductor substrates, providing an important reference for the design and application of ferroelectric/semiconductor heterostructures.

Case report: narcolepsy type 2 due to temporal lobe glioma.

RATIONALE: The orexin projection system includes the lateral hypothalamus, reticular activating structure, and ventrolateral preoptic nucleus, and this system is related to the pathogenesis of narcolepsy. Here, we report a case of narcolepsy type 2 caused by hippocampal glioma of the right temporal lobe. PATIENT CONCERNS: A 44-year-old male farmer complained of excessive daytime sleepiness (EDS) over the past 3 months and more. INTERVENTIONS: The lesion of the right anteromedial temporal lobe was removed and its pathological examination was carried out. OUTCOMES: General examination showed no abnormalities of his heart, lungs, or abdomen. Neurological examination showed no positive sign. The blood routine and biochemical examination were normal. He scored 7 on the Pittsburg sleep quality index, 16 on the Epworth sleepiness scale, 52 on the self-rating anxiety scale, and 48 on the self-rating depression scale. The multiple sleep latency test data showed 2 periods of sleep-onset rapid eyes movement period across 4 successive tests; the average sleep latency was under 8 minutes, and the rapid eyes movement latency was under 7 minutes. Lesion of glioma in hippocampus area of the right anteromedial temporal lobe was confirmed through magnetic resonance imaging, magnetic resonance spectroscopy, and histological examination. After surgical removal of the glioma from the hippocampus area of the right anteromedial temporal lobe, the patient's EDS symptoms disappeared immediately. He scored 3 on the Epworth sleepiness scale. During our follow-up three months later, he remained well with no complications. DIAGNOSIS: We diagnosed the patient with narcolepsy type 2 according to the 3rd Edition of International Classification of Sleep Disorders (ICSD-3). CONCLUSION: The patient suffered from EDS and was diagnosed with narcolepsy type 2. The narcolepsy type 2 was linked to glioma of the hippocampus area. The hippocampus might be another part of regulating the sleep-arousal pathway, and the glioma secretion might interact with the orexin projection system.

Ectopic expression of a R2R3 MYB transcription factor of dove tree (Davidia involucrata) aggravates seed abortion in Arabidopsis thaliana.

Serious seed abortion of dove tree (Davidia involucrate Baill.) is one of the critical factors leading to the low fecundity of this species. Seed abortion is a complicated process and various factors have been verified to synergistically determine the fate of seeds. To reveal the mechanism of seed abortion in D. involucrata, we performed transcriptome analysis in normal and abortive seeds of D. involucrata. According to the transcriptome data, we noticed that most of the genes encoding a MYB transcription factor were predominantly expressed in abortive seeds. Among these, a gene named DiMYB1 was selected and its function was validated in this study. Overexpression of DiMYB1 resulted in obviously reduced viability of transgenic seeds and seedlings, and caused a significantly higher seed abortion rate. The vegetative growth of transgenic plants was hindered, resulting in an earlier flowering time. In addition, colour changes occurred in transgenic plants. Some transgenic sprouts, stems and pods appeared purple instead of green in colour. Our finding demonstrated that DiMYB1 participates in multiple plant developmental processes, especially in seed development in Arabidopsis thaliana (L.) Heynh., which indicated the similar role of this gene in D. involucrata.