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ObjectiveTo investigate the effect of high-frequency repetitive transcranial magnetic stimulation （rTMS） on postoperative cognitive dysfunction （POCD） in aged mice，and analyze its mechanism.MethodsA total of 24 18 month old C57BL/6J male aged mice were randomly divided into control group，operation group and rTMS group，with 8 mice in each group. The rTMS group received 5 Hz rTMS true stimulation for 10 consecutive days before operation，and underwent experimental laparotomy. The rTMS true stimulation continued for 4 days after operation，once a day，the magnetic stimulation intensity was 0. 84 T，the frequency was 5 Hz，100 pulses per sequence，the interval time was 30 s，and 10 sequences were repeated，a total of 1000 pulses. The control group and the operation group received sham stimulation for 10 days before operation，the control group did not operate，the operation group underwent experimental laparotomy，and the control group and the operation group received sham stimulation for 4 days after operation. On the third day after operation，the locomotor activity of mice was evaluated by open field test （percentage of stay time in the central area，total distance and average speed of movement）; On the fourth day after operation，the cognitive function of mice was evaluated by Y-maze test （the percentage of times to enter the new arm，the percentage of time to stay in the new arm，and the total distance to move the new arm）; After the Y-maze test，the protein expression levels of brain-derived neurotrophic factor （BDNF），tropomyosin related kinase B （TrkB） and nerve growth factor （NGF） in mice hippocampus were detected by immunoblotting.Results（1） Exercise capacity：there was no significant difference in the percentage of time spent in the central area of the open field，total distance and average speed among the three groups （P>0. 05）. （2） Cognitive function：there was no significant difference among the three groups in the percentage of times of exploring new forearm （P>0. 05）; Compared with the control group，the percentage of stay time in the new arm and the total distance of new arm movement in the operation group were significantly reduced，and the differences were statistically significant （PPPP

Polymer dielectrics are preferred materials for high-energy-density capacitive energy storage. In particular, high-temperature dielectrics that can withstand harsh conditions, e.g., ≥150 °C, is of crucial importance for advanced electronics and electrical power systems. Herein, high-temperature dielectric polymer composites composed of polyetherimide (PEI) matrix and hafnium oxide (HfO2) nanoparticles are presented. It is found that the incorporation of HfO2 with a moderate dielectric constant and a wide bandgap improves the dielectric constant and simultaneously reduces the high-field leakage current density of the PEI nanocomposites. As a result, the PEI/HfO2 composites exhibit superior energy storage performance to the current high-temperature engineering polymers at elevated temperatures. Specifically, the nanocomposite with 3 vol% HfO2 displays a discharged energy density of 2.82 J/cm3 at 150 °C, which is 77% higher than neat PEI. This work demonstrates the effectiveness of incorporation of the nanofiller with a medium dielectric constant into the polymer on the improvement of high-temperature capacitive properties of the polymer composites.

The development of advanced dielectric materials with high breakdown strength, high dischargeable energy densities, and great efficiencies is imperative to meet the ever-increasing demand of modern power systems and electronic devices. Herein, we present the layer-by-layer solution prepared bilayer-structured nanocomposite films with much enhanced capacitive performance via resolving the typical paradox between dielectric constant and breakdown strength in dielectric materials. The bilayered nanocomposite films are composed of Al2O3 dispersed in polystyrene as the interfacial barrier layer to inhibit electrical conduction and the polystyrene layer with TiO2 to enhance dielectric constant. The resulting layered film exhibits a discharged energy density of 4.43 J/cm3 along with ultrahigh charge−discharge efficiencies of >90%, which is among the highest energy densities ever achieved in the polystyrene-based dielectric polymer nanocomposites. In addition, the composite films show outstanding cyclic stability under high electric fields, which would enable the long-term efficient operation of film capacitors. This contribution represents an efficient route to high-energy-density dielectric composite materials by using interfacial barrier architectures.

The electrification of transport requires dielectric materials capable of operating efficiently at high temperatures to meet the increasing demand of electrical energy storage at extreme conditions. Current high-temperature dielectric polymers rely on the incorporation of wide bandgap inorganic fillers to restrain electrical conduction and achieve high efficiencies at elevated temperatures. Here, we report a new class of all-polymer based high-temperature dielectric materials prepared from crosslinking of melt-processable fluoropolymers. The crosslinked polymers exhibit larger discharged energy densities and greater charge-discharge efficiencies along with excellent breakdown strength and cyclic stability at elevated temperatures when compared to the current dielectric polymers. The origins of the marked improvement in the high-temperature capacitive performance are traced to efficient charge-trapping by a range of the molecular trapping centers resulting from the crosslinked structures. In addition, the implementation of melt-extrudable polymers would enable scalable processing that is compatible with the current fabrication techniques used for polymer dielectrics, which is in sharp contrast to the dielectric polymer composites with inorganic fillers.

The exploration of high-energy-density electrostatic capacitors capable of operating both efficiently and reliably at elevated temperatures is of great significance in order to meet advanced power electronic applications. The energy density of a capacitor is strongly dependent on dielectric constant and breakdown strength of a dielectric material. Here, we demonstrate a class of solution-processable polymer nanocomposites exhibiting a concurrent improvement in dielectric constant and breakdown strength, which typically show a negative correlation in conventional dielectric materials, along with a reduction in dielectric loss. The excellent performance is enabled by the elegant combination of nanostructured barium titanate and boron nitride fillers with complementary functionalities. The ternary polymer nanocomposite with the optimized filler compositions delivers a discharged energy density of 2.92 J cm−3 and a Weibull breakdown strength of 547 MV m−1 at 150°C, which are 83% and 25%, respectively, greater than those of the pristine polymer. The conduction behaviors including interfacial barrier and carrier transport process have been investigated to rationalize the energy storage performance of ternary polymer nanocomposite. This contribution provides a new design paradigm for scalable high-temperature polymer film capacitors. (Figure presented.).

Next-generation microelectronics and electrical power systems call for high-energy-density dielectric polymeric materials that can operate efficiently under elevated temperatures. However, the currently available polymer dielectrics are limited to relatively low working temperatures. Here, the solution-processable polymer nanocomposites consisting of readily prepared Al2 O3 fillers with systematically varied morphologies including nanoparticles, nanowires, and nanoplates are reported. The field-dependent electrical conduction of the polymer nanocomposites at elevated temperatures is investigated. A strong dependence of the conduction behavior and breakdown strength of the polymer composites on the filler morphology is revealed experimentally and is further rationalized via computations. The polymer composites containing Al2 O3 nanoplates display a record capacitive performance, e.g., a discharged energy density of 3.31 J cm-3 and a charge-discharge efficiency of >90% measured at 450 MV m-1 and 150 °C, significantly outperforming the state-of-the-art dielectric polymers and nanocomposites that are typically prepared via tedious, low-yield approaches.

Spherical polyamide 12 (PA12) powder for selective laser sintering (SLS) was prepared by thermally induced phase separation (TIPS) method. It was authenticated that the mixed solvent can regulate the liquid–liquid phase separation (LLPS) process by changing the ratio of diluent to non-diluent. The polymer droplets mainly coalesced in the solution, and then the crystal nucleus of PA12 was formed in the droplets. Finally, high crystallinity PA12 powder was precipitated. The morphology, particle size distribution, thermal properties, the change of crystal structure, and powder spreading performances of the obtained powder were characterized. The powder had a narrow particle size distribution, an average particle size of 55.2 μm, and a broad sintering window of 29°C. The results exhibited that the powders prepared by TIPS had excellent sintering properties, and TIPS method provided more choices for SLS technology.

In this paper, the averaging principle for Caputo type fractional stochastic differential equations with Lévy noise is investigated with consideration of a new method for dealing with singular integrals. Firstly, the estimate on higher moments for the solution is given. Secondly, under some suitable assumptions, we prove the averaging principle for Caputo type fractional stochastic differential equations with Lévy noise by using the Hölder inequality. Finally, a simulation example is given to verify the theoretical results. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the protective effects of xylooligosaccharide (XOS) on the growth performance and intestinal health of broilers challenged by avian pathogenic Escherichia coli (APEC). A total of 144 newly hatched male Lingnan yellow-feathered broilers were randomly divided into three groups (six replicates/group): a control (CON) group, an APEC group and an XOS group (APEC-challenged broilers supplemented with 1600 mg/kg XOS). Birds in the APEC and XOS groups were orally challenged with APEC from 7 to 12 d of age. Growth performance and intestinal health-related parameters were determined on d 13 and 17. The reductions (p < 0.05) in final body weight, average daily gain and elevation (p < 0.05) in intestinal APEC colonization in challenged broilers were counteracted by the XOS addition, which also alleviated the APEC-induced reductions (p < 0.05) in jejunal goblet cell count and density in broilers on d 17. Supplementing with XOS increased (p < 0.05) jejunal villus height and crypt depth, coupled with occludin and zonula occluden-1 expression, on d 17, and diminished the change (p < 0.05) in the jejunal inflammatory cytokine expression profile in a time-dependent manner. Moreover, cecal counts of total bacteria and Lactobacillus in challenged broilers were augmented (p < 0.05) by the XOS addition, which also mitigated APEC-induced reductions (p < 0.05) in cecal acetate, butyrate and valerate concentrations in broilers on d 13 or 17. Supplementing with XOS blocked the increases (p < 0.05) in the expression of cecal E. coli virulence genes relA and ompR on d 13 along with the expression of fimH and csgA on d 17. XOS alleviated APEC-induced growth retardation and intestinal disruption in broilers partially by restraining the intestinal colonization of APEC. Furthermore, the improvements in cecal microbiota and fermentation pattern, along with attenuation of cecal E. coli virulence resulting from XOS supplementation, could also support the maintenance of intestinal health in APEC-challenged broilers. [ABSTRACT FROM AUTHOR]

Objectives: In order to enhance clinical improvement of periodontal defects, the addition of enamel matrix derivatives (EMD) to open flap debridement (OFD) has been investigated. The aim of this systematic review is to figure out whether such a combination, in comparison to the treatment with OFD alone has some effects on the following outcomes: clinical attachment level gain, probing depth reduction, and gingival recessions increase. Methods: Electronic databases (PubMed, Embase, Web of Science, and Cochrane) were searched for randomized controlled trials in humans addressing the use of a combination of OFD and EMD versus a control group with OFD alone for the treatment of periodontal defects, with a minimum of 6 months of follow‐up; meta‐analysis and trial sequential analysis were then performed. Results: From a total of 204 records screened by title and abstract, 13 studies were read full‐text and eight out of them included in the meta‐analysis. Some significant differences have been demonstrated both for clinical attachment level gain and probing depth reduction between test and control groups. Conclusions: In the treatment of periodontal defects, the addition of EMD to OFD seems to be beneficial in terms of clinical attachment level gain, probing depth reduction, promoting periodontal regeneration. However, such results should be considered with caution because of the small number of studies included in the meta‐analysis and their heterogeneity. [ABSTRACT FROM AUTHOR]

Objective To explore the role of metagenomic next-generation sequencing (mNGS) in pathogen detection of patients with skin infections of unknown origin. Methods A 68-year-old female patient presented with red, swollen nodules and pain in the left knee for 4 months, and ulceration for 20 days. mNGS was performed on the patient's skin lesion samples, and the microbial nucleic acid sequences in the samples were analyzed and compared with the pathogen database to identify pathogenic microorganisms. Results mNGS detected Mycobacterium chelonae (28 specific sequences), which was verified by PCR detection and Sanger sequencing, indicating that the pathogenic microorganism causing the skin tissue infection was Mycobacterium chelonae. Based on the patient's clinical symptoms, the final diagnosis was Mycobacterium chelonae skin infection. Conclusion mNGS can assist in the diagnosis of rare pathogenic microorganism infections and provide directions for clinical treatment. [ABSTRACT FROM AUTHOR]