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Introduction: The intensity of daily training increases with the development of aerobics, presenting a series of requirements for students’ body posture and sports performance. Objective: Study the effect of postural training on the performance of university students practicing aerobics. Methods: The experiment lasted nine weeks, performed three times a week. The control group was trained according to traditional aerobics teaching, while the experimental group was introduced to practice dance movements based on aerobics training to strengthen postural teaching. Results: The total performance score of the experimental group before the experiment was 70.32 points, which rose to 80.19 points, representing an increase of 12.30%; the initial performance score of the control group was 68.13 points, rising to 75.32 points, an increase of 9.54%. Conclusion: Body posture training can optimize students’ physical fitness and flexibility, improving their artistic expression skills and aerobic expression scores, and should be promoted. Level of evidence II; Therapeutic studies - investigation of treatment outcomes. RESUMO Introdução: A intensidade do treinamento diário aumenta com o desenvolvimento da aeróbica, apresentando uma série de exigências para a postura corporal e o desempenho esportivo dos alunos. Objetivo: Estudar o efeito do treinamento postural sobre o desempenho dos estudantes universitários praticantes de aeróbica. Métodos: O experimento durou 9 semanas, realizado três vezes por semana. O grupo controle foi treinado de acordo com o ensino tradicional da aeróbica, enquanto que ao grupo experimental foi introduzida a prática de movimentos de dança baseados no treinamento da aeróbica para fortalecer o ensino postural. Resultados: A pontuação total de desempenho do grupo experimental antes do experimento foi de 70,32 pontos, que se elevou para 80,19 pontos, representando um aumento de 12,30%; a pontuação no desempenho inicial do grupo controle foi de 68,13 pontos, elevando-se para 75,32 pontos, um aumento de 9,54%. Conclusão: O treinamento da postura corporal pode otimizar a aptidão física e a flexibilidade dos estudantes, melhorando as suas capacidades de expressão artística e a pontuação da expressão aeróbica, devendo ser promovido. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento. RESUMEN Introducción: La intensidad del entrenamiento diario aumenta con el desarrollo del aeróbic, presentando una serie de exigencias para la postura corporal y el rendimiento deportivo de los alumnos. Objetivo: Estudiar el efecto del entrenamiento postural en el rendimiento de estudiantes universitarios que practican aeróbic. Métodos: El experimento duró 9 semanas y se realizó tres veces por semana. Al grupo de control se le entrenó según la enseñanza tradicional de aeróbic, mientras que al grupo experimental se le introdujo la práctica de movimientos de danza basados en el entrenamiento de aeróbic para reforzar la enseñanza postural. Resultados: La puntuación total de rendimiento del grupo experimental antes del experimento fue de 70,32 puntos, que ascendió a 80,19 puntos, lo que representa un aumento del 12,30%; la puntuación inicial de rendimiento del grupo de control fue de 68,13 puntos, que ascendió a 75,32 puntos, lo que representa un aumento del 9,54%. Conclusión: El entrenamiento de la postura corporal puede optimizar la aptitud física y la flexibilidad de los alumnos, mejorando sus habilidades de expresión artística y sus puntuaciones de expresión aeróbica, debiendo ser promovido. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

To predict suitable growing regions for Leonurus japonicus and to provide scientific sopport for the habitat conservation and the exploitation and utilization of germplasm resources under climate change conditions, this study combined niche and priority conservation models to assess the future potential distribution of L. japonicus in China. To this end, distribution points and samples of L. japonicus were gathered through online and field surveys. The Maxent model with optimized parameters was used for predicting the suitable habitats of L. japonicus at different stages, and the Marxan model was used to determine the priority of protected areas. The results showed that the highest temperature in the hottest month, the lowest temperature in the coldest month, the precipitation in the wettest month, the precipitation in the driest month, and altitude were the main environmental factors influencing the distribution of L. japonicus. Under the three climate change scenarios, the centroid of the suitable area of L. japonicus migrated northward, and the migration position tended to expand further northwest. In the future, there would be no significant niche differentiation of L. japonicus; the Marxan results showed that priority protected areas for L. japonicus were in southwestern central China, Lingnan, southern east China, and Guizhou. Overall, the results of this research can provide a strategy for the determination of priority protection areas for Leonurus japonicus in China.

Purpose To prevent the steps of the deep brain stimulation (DBS) operation from affecting the accuracy of target due to cerebral hemorrhage, cerebrospinal fluid loss and brain tissue displacement caused by microelectrode. Methods In the course of DBS, the preoperative operation plan was determined by double-dose enhanced intracranial vascular imaging, and involved the use of a microelectrode without dura mater incision and other methods. Through systematic retrospective analysis, the data of 34 patients who underwent DBS surgery in the Second Affiliated Neurosurgery Department of Nanchang University from May 2016 to August 2018 were compared before and after using these methods. Results 1. Among the 34 patients, there were 19 males (55.9%) and 15 females (44.1%). In terms of age, 26 patients were older than 60 years old, accounting for 76.5% of the patients, and 8 patients were under 60 years old, accounting for 23.5% of the patients. According to the postoperative intracranial gas accumulation, before use of the improved method, the intracranial gas accumulation was 10.719 ± 14.001 ml, and after use of the improved method, the intracranial gas accumulation was 9.241 ± 9.818 ml. Chi-square analysis comparing the data before and after the improved method revealed a significant difference between the two patient groups. Before use of the improved method, two patients (13.3%) had cerebral hemorrhage, and the bleeding rate after use of the improved method was 0. Conclusion After improving the operation procedure, the displacement of brain tissue and bleeding during the operation were significantly reduced, the risks from the operation were reduced, the curative effect of the operation was improved, and good quality of life was obtained.

A vortex beam interferometer based on Doppler frequency shift is proposed to retrieve the dynamic non-uniform phase shift from the petal-like fringes produced by the coaxial superposition of high-order conjugated Laguerre–Gaussian modes. Unlike the uniform phase shift measurement in which the petal-like fringes rotate as a whole, the fringes due to the dynamic non-uniform phase shift rotate at different angles at different radii, resulting in highly twisted and stretched petals; this hinders rotation angle identification and phase retrieval via image morphological operation. To address the problem, a rotating chopper combined with a collecting lens and a point photodetector are placed at the exit of the vortex interferometer to introduce a carrier frequency in the absence of the phase shift. Once the phase starts to shift non-uniformly, the petals at different radii generate different Doppler frequency shifts, owing to their different rotation velocities. Thus, identification of spectral peaks near the carrier frequency immediately indicates the rotation velocities of the petals and the phase shifts at those radii. The results verified a relative error of phase shift measurement to be within 2.2% at the surface deformation velocities of 1, 0.5, and 0.2 µm/s. The method manifests itself to have potential in exploiting mechanical and thermophysical dynamics from the nanometer to micrometer scale.

The present work investigated the degradation of norfloxacin (NOR) antibiotics as a model pollutant in the bioelectro-Fenton (BEF) system. The BEF was catalyzed by three types of composite electrod...

This research was conducted to investigate the removal effect and mechanisms of emulsified oil by ferrite-coated ceramic membranes. Three kinds of ferrite-coated ceramic membranes (CuFe2O4, CoFe2O4 and Co0.5Cu0.5Fe2O4) were prepared by the sol–gel method. The structure and valence state confirmed the presence of spinel ferrite on the surface of the ceramic membrane. The coated form of ferrite retained the porous structure of the ceramic membrane surface. The coated ceramic membrane has been shown to effectively improve the removal rate of emulsified oil and improve the antifouling ability of the ceramic membrane. When the influent concentration of emulsified oil was 45 ± 5 mg L−1, the removal rate of emulsified oil reached 87–93% after 2 hours, and the normalized flux after 2 hours was increased from 0.08 of the blank ceramic membrane to 0.17 of the copper ferrite-coated ceramic membrane. The generation of free radicals proved that the ferrite-coated ceramic membrane can catalyze the degradation of emulsified oil by H2O2. The low metal ion leaching concentration also met the sewage discharge requirements. Therefore, the ferrite-coated ceramic membrane is an option in improving the removal rate of emulsified oil, strengthening the antifouling ability of the ceramic membrane, avoiding the generation of iron sludge, reacting at room temperature without additional UV light and solving the recovery of spinel ferrite.

Construction and demolition (C&D) waste generated in the process of urban development has rapidly increased in recent years around the world in large quantities without proper reuse, resulting in n...

Amine-impregnated sorbents can be applied in CO₂ sequestration, but they suffer from low amine utility due to slow diffusion of CO₂, leading to reduced accessibility of buried amines. We examined silica-supported polyethylenimine (PEI) sorbents and blended them with polyethylene glycol (PEG) as an additive to study the role of PEG in modifying sorption performance. We report an increase in amine efficiency, a decrease in the heat of sorption and regeneration temperature, and a change CO₂ amine speciation with the addition of PEG. The increase in viscosity due to CO₂ sorption leads to greater diffusion resistance; increases in viscosity were lower during CO₂ sorption in blends with higher PEG composition. ¹³C NMR results on CO₂-saturated PEI–PEG blends revealed the formation of carbamic acid and carbamate and showed a larger fraction of carbamic acid in PEG-rich samples. We propose PEG increases the amine efficiency by enabling the diffusion of CO₂ due to viscosity reduction and changes in the CO₂-amine speciation (carbamate versus carbamic acid), which modifies the theoretical CO₂/amine stoichiometry.

Due to the uncontrollable anticoagulant activity and limited source, Heparin, which is commonly used in clinical anticoagulation therapies, faces the risk of spontaneous bleeding and thrombocytopenia. Herein, a series of anionic poly(amino acid) s poly ( l -Serine-ran-L-Glutamic acid-ran-L-Cysteine-SO3) (PSEC-SO3) were prepared by the controlled Ring Opening Polymerization (ROP) of N-Carboxyanhydrides (NCAs). The anticoagulant activities of PSEC-SO3 can be regulated by simply adjusting the feeding ratio of monomers. In vitro tests show that these polypeptides can effectively prolong the Activated Partical Thromboplastin Time (APTT) and inhibit Factor IIa and Factor Xa, but has no significant effect on Prothrombin Time (PT) and Thrombin Time (TT), which indicates that PSEC-SO3 mainly act on the intrinsic pathway. In summary, the activity-tunable heparin-like polypeptides are expected to have good application prospects in the anticoagulant field.

Morchella sextelata, one of the true morels, has recently been artificially cultivated with stable production in China. Analysis of the variations in primary metabolites during the vegetative stages of M. sextelata is critical for understanding the metabolic process. In this study, three developmental stages were categorized based on morphological and developmental changes, including the young mushroom period, marketable mature period, and physiological maturity period. Untargeted metabolomics-based mass spectrometry was used to analyze the change of metabolites during the growth stages of M. sextelata. The result showed that the metabolites’ content at the different growth stages were significantly different. The relative contents of linoleic acid, mannitol, oleamide, and betaine were higher at each growth stage. Flavor substances were significantly metabolizable during commodity maturity, while amino acids, organic acids, and lipids were significantly metabolizing at physiological maturity. Pathway analysis of the most significant changes involved Pyrimidine metabolism, Vitamin B6 metabolism, Arginine biosynthesis, Lysine biosynthesis, and Lysine degradation. The results can provide a theoretical basis for further clarifying the metabolic regulation mechanism and lay the foundation for optimizing the cultivation process of M. sextelata.

Objective We studied the role of the P2X7 receptor on cognitive dysfunction in a mouse model of schizophrenia. Methods An adult mouse model was established by treatment with phencyclidine (PCP), an N-methyl-D-aspartate (NMDA) receptor antagonist. Young mice were divided into three groups: 1) the control (saline-injected) group; 2) experimental 5 mg/kg PCP-injected group; and 3) experimental 10 mg/kg PCP-injected group. The mice were subjected to the open-field and Morris water maze tests at 7 weeks. After intraperitoneal injection of the P2X7 receptor antagonist JNJ-47965567, the behaviour tests were performed again. Samples were taken after testing. The P2X7 receptor protein and mRNA expression levels were detected by immunohistochemistry, Western blotting and PCR. Results This study revealed that the infant sub-chronic PCP mice model showed severe spatial learning and memory impairment in the Morris water maze and schizophrenia-like symptoms (hypermotor behaviour) in the open-field test. The P2X7 receptor protein was highly expressed in the sub-chronic PCP mouse model and more highly expressed in the hippocampus than the prefrontal lobe. After the P2X7 receptor was blocked with JNJ-47965567, P2X7 receptor protein and mRNA expression in the frontal lobe were significantly increased, and the spatial memory impairment and hypermotor behaviour induced by PCP were reversed. Conclusion PCP-induced cognitive impairment can be significantly improved by antagonizing the P2X7 receptor. Therefore, we believe that the P2X7 receptor plays an important role in the cognition of schizophrenic-like mice.

Metal-organic frameworks (MOFs), which are also referred to as coordination polymers, have been widely used in adsorption separation and catalysis, especially in the field of physical chemistry in the past few years, because of their unique physical structure and potential chemical properties. In recent years, particularly with the continuous expansion of the research field, deepening of research levels, and sustained advancements in science and technology, powerful and diverse MOFs that have demonstrated great biomedical application potential have been successively developed. Consequently, this study summarizes the origin, development, and common synthesis methods of MOFs, with major emphasis on their antibacterial application and safety evaluation in biomedicine.

Swine manure is considered as an extensive reservoir of antibiotic resistance genes (ARGs) spreading in the natural environment after application in soils. To understand whether ARGs abundance in swine manure is underestimated and the hosts are ignored, this study successively extracted DNA from swine manure six times and determined the abundance of several ARGs, class I integron (intI1), and 16S rRNA as well as the microbial communities. It is found that successive six DNA extraction of swine manures elevated the yield of DNA and strongly increased the abundance of ARGs, intI1, and 16S rRNA. Compared with single DNA extraction, the most dominant bacterial phylum in swine manures shifted from Proteobacteria to Firmicutes, and the dominant bacterial genera changed from Acinetobacter Clostridium after six DNA extraction. The ignored abundance of bacterial phylum and genus emphasized the possible hosts carrying these genes should be paid more attention. It is suggested that the successive DNA extraction of manures is required in the future study to improve the knowledge of estimating the risk and hosts of ARGs in manures entering the environment.

Morels (Morchella spp.) are valuable medicinal and edible mushrooms. In this study, chemical profiles of aromas and lipophilic extracts of black morel (Morchella importuna) grown in China were analyzed by gas chromatography/mass spectroscopy, along with the evaluation of antioxidant and antimicrobial activities for the lipophilic extracts. Sixty-five compounds in total were identified from the aromas, and 1-octen-3-ol was the main component for aromas of fresh (34.40%) and freeze-dried (68.61%) black morels, while the most abundant compound for the aroma of the oven-dried sample was 2(5H)-furanone (13.95%). From the lipophilic extracts, 29 compounds were identified with linoleic acid as the main compound for fresh (77.37%) and freeze-dried (56.46%) black morels and steroids (92.41%) as the main constituent for an oven-dried sample. All three lipophilic extracts showed moderate antioxidant activities against 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) with the IC50 values ranging 7.56 ∼ 17.52 mg/mL and 5.75 ∼ 9.73 mg/mL, respectively, and no obvious antimicrobial activity was observed for lipophilic extracts. The drying methods affect the chemical profile of black morel, and freeze-drying was favorable for retaining nutrients and morel smell. This is the first report on the aroma and lipophilic extracts of M. importuna grown in China.

Acute alcohol exposure induces unconscious condition such as coma whose main physical manifestation is the loss of righting reflex (LORR). Xingnaojing Injection (XNJI), which came from Chinese classic formulaAn Gong Niu HuangPill, is widely used for consciousness disorders in China, such as coma. Although XNJI efficiently shortened the duration of LORR induced by acute ethanol, it remains unknown how XNJI acts on ethanol-induced coma (EIC). We performed experiments to examine the effects of XNJI on orexin and adenosine (AD) signaling in the lateral hypothalamic area (LHA) in EIC rats. Results showed that XNJI reduced the duration of LORR, which implied that XNJI promotes recovery form coma. Microdialysis data indicated that acute ethanol significantly increased AD release in the LHA but had no effect on orexin A levels. The qPCR results displayed a significant reduction in the Orexin-1 receptors (OX1R) expression with a concomitant increase in the A1receptor (A1R) and equilibrative nucleoside transporter type 1 (ENT1) expression in EIC rats. In contrast, XNJI reduced the extracellular AD levels but orexin A levels remained unaffected. XNJI also counteracted the downregulation of the OX1R expression and upregulation of A1R and ENT1 expression caused by EIC. As for ADK expression, XNJI but not ethanol, displayed an upregulation in the LHA in EIC rats. Based on these results, we suggest that XNJI promotes arousal by inhibiting adenosine neurotransmission via reducing AD level and the expression of A1R and ENT1.

Natural ecosystems provide essential regulatory services for local residents and provide benefits to human populations living outside a particular region through various transmission pathways. Accordingly, a spatially explicit conservation network is needed to protect key features from human disturbance. However, existing ecosystem protection surrogates have traditionally focused on biodiversity components or local ecosystem services (ESs). Additionally, conservation plans that protect the delivery value of an ES for regional, social and ecological security are lacking. Herein, we use a multi-objective optimisation method to design a conservation network that maximises the benefits of two regulatory ecosystem services (RESs) in a key eco-region, the Qinling Mountains of China. We identify a set of alternative conservation networks under different land restriction scenarios for both delivery and non-delivery RESs. Our planning results reveal clear spatial distinction between ES delivery and non-delivery values. Moreover, planning focusing on ES non-delivery values tends to ignore several areas that transmit important regulatory functions to downstream conurbations. Based on comparison of ES distribution, biodiversity richness, and existing nature reserves, we suggest that ES delivery values, especially those flowing along a terrain gradient, should be selected as a key protection proxy to complement nature conservation decisions associated solely with biodiversity indicators.

The performance of API 5L X56 submarine pipes subjected to transverse impact is investigated through both drop weight impact tests and finite element simulations. To study the improvement of resistance to transverse impact for pipe-in-pipe specimens, corresponding single-layer pipe specimens under impacting load were also tested for comparison. From the experimental tests, the failure mode, the impact force-time history curve, the displacement-time history curve, the strain-time history curve and the impact force - displacement curve of all specimens were obtained. The pipe-in-pipe specimens are found to have superior performance to resist impacting loading compared to single-layer specimens because smaller global bending deformation and local indentation were observed in them. In addition, the cross-section deformation rate, R, was proposed, and the local indentation length of the specimen was divided into three zones based on experimental observation and numerical simulation. A comprehensive comparison of the length and the depth of local indentation in the pipe-in-pipe specimens shows that the local indentation decreases and the impact resistance increases due to the presence of the inner tube. Finally, the post-peak mean force (Pm) and the energy absorption capacity (EAC) were used to evaluate the energy dissipation mechanism of different specimens. The results also indicate that the pipe-in-pipe specimens have better energy absorption performance.

Ethnopharmacological relevance The traditional Chinese medicine formula Danggui-Shaoyao-San (DSS) has been reported to show therapeutic effect on alleviating the symptoms of Alzheimer's disease (AD). Aim of the study The present study aims to investigate the relation between DSS treatment of AD and DHA metabolism and evaluates its neuroprotective effect on cognitive in APP/PS1 mice. Material and methods DSS (1.6, 3.2, 6.4 g/kg/day) or Aricept (3 mg/kg/day) was orally administered (i.g.) to APP/PS1 mice, and saline was orally administered to Wild-type (WT) male mice as control group. Then, the Morris water maze (MWM) test, Y-maze spontaneous alternation test, open filed test and fear conditioning test were conducted for evaluation of learning and memory abilities. The DHA content was assessed by HPLC-MS/MS. Physiological indices were determined, including triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), ROS level, activity of superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA), PEG2, TXB2 and LTB4. The expressions of COX-1, COX-2, cPLA2, iPLA2, 15-LOX, and were assessed by Western blot. Results APP/PS1 mice showed serious cognitive impairment in behavioral tests. However, treatment of DSS extract significantly ameliorated the cognitive deficits of APP/PS1 mice. Biochemical measurements showed the increases in TG, TC, LDL-c and the decrease in HDL-c in APP/PS1 mice compared with WT mice, and DSS extract significantly retarded these changes. Low content of DHA, low expression of iPLA2 and 15-LOX were observed both in hippocampus and cortex of APP/PS1 mice, while DSS extract significantly restored these changes. Additionally, the abnormal activity of SOD and ROS level, the decreased levels of MDA and GSH were observed in APP/PS1 mice, while DSS extract prominently lessened these changes. Moreover, DSS extract decreased the level of PEG2, TXB2 and LTB4 and also attenuated the expression of cPLA2, COX-1 and COX-2 in hippocampus as well as cortex of APP/PS1 mice. Conclusions Based on these results, we suggest that DSS play a positive effective role in increasing DHA content by up-regulating iPLA2 and 15-LOX, resulting in ameliorating oxidative stress and inflammation and finally ameliorating cognition deficits in APP/PS1 mice.

High dielectric constant (high-k) polymer composites have many applications in electrical insulation and energy storage systems because of their ease of processing. An important route to high-k polymer composites is to introduce high-aspect-ratio conductive nanoparticles (e.g., carbon nanotubes, CNTs) into a dielectric polymer. However, it is difficult to tune the dielectric properties of the composites via only adjusting the nanoparticle loading, particularly when the conductive nanoparticle concentration is near the percolation threshold. In this work, by using surface-initiated atom transfer radical polymerization, poly(methyl methacrylate) encapsulated CNTs (PMMA@CNTs) were prepared and used to tune the dielectric properties of PMMA composites. It was found that the PMMA@CNTs can be well dispersed into the PMMA matrix, regardless of the thickness of the PMMA shell grafted onto the CNT surface. The electrical parameters of the composites, such as percolation threshold, electrical conductivity, dielectric constant and dielectric loss tangent, can be tuned by controlling the thickness of the PMMA shell on the CNT surface. High dielectric constant and low dielectric loss can be achieved by adjusting the loading of PMMA@CNTs and the thickness of the PMMA shell on the CNT surface.

Highly filled dielectric polymer nanocomposites with high dielectric constant nanoparticles (e.g., BaTiO3) have promising application in many fields such as energy storage. The effectiveness of these nanoparticles to increase the dielectric constant and energy density of the resulting nanocomposites has already been demonstrated. However, the role of interface between the nanoparticles and polymer matrix on thermal expansion, energy storage and breakdown strength-the three parameters that are important for practical application of the dielectric polymer nanocomposites, has not been systematically documented. In this contribution, we investigated the effect of six kinds of nanoparticle surface chemistry on the processing, coefficient of thermal expansion, energy storage and breakdown strength of highly filled epoxy/BaTiO3 nanocomposites. It was found that all these aspects, in particular the processability of the nanocomposites, are associated with the nanoparticle surface chemistry. Combining the processability, coefficient of thermal expansion, energy storage and breakdown strength of the nanocomposites, we conclude that the nanoparticles functionalized by silane coupling agents with terminal groups capable of reacting with the epoxy matrix are more suitable for preparing highly filled dielectric polymer nanocomposites.

The interface is critical for the design of polymer nanocomposites with desirable properties. The effect of interface behavior on the properties of polymer nanocomposites with low nanoparticle loading has been well documented. However, our understanding of the role of the interface in highly filled polymer nanocomposites is still limited because of the lack of comprehensive research work. In this contribution, by using BaTiO3 nanoparticles with six kinds of surface chemistry, we have prepared highly filled epoxy nanocomposites (50 vol% nanoparticle loading). The role of nanoparticle surface chemistry on the dielectric properties of epoxy nanocomposites is investigated at a wide frequency and temperature range by using broadband dielectric spectroscopy. Combining the microstructure analysis of the highly filled nanocomposites with a comprehensive X-ray photoelectron spectroscopy characterization of the surface chemistry of the BaTiO3 nanoparticles, an understanding is formed of the correlation between the nanoparticle surface chemistry and the dielectric properties of the nanocomposites. The functional group density, functional group type, and electrical properties of the modifier-the three parameters that are inherent from the nanoparticle surface modification-have a strong impact on the temperature and frequency dependence of the dielectric constant and dielectric loss tangent. This work demonstrates the great importance of surface chemistry in tuning the electrical properties of dielectric polymer nanocomposites.

Polymer-based composites with high thermal conductivity and breakdown strength have become increasingly desirable in both the electronic and electric industries. Herein, we have designed a nano–micro structure of 2-D micro-scale hexagonal boron nitride (h-BN) and 0-D nano-scale α-alumina (α-Al2O3) hybrid fillers for epoxy composites with high thermal conductivity and breakdown strength. So as to improve interface interaction, both fillers are functionalized with hyperbranched aromatic polyamide (HBP). It is found that both structure design and surface modification play important roles. Surface modification can enhance many physical properties of composites, such as thermal conductivity, thermal stability and breakdown strength. Importantly, the nano–micro structure presents noticeable synergistic effects on both thermal conductivity and ac breakdown strength. The obtained composite with 26.5 vol% fillers presents a high thermal conductivity of 0.808 W m−1 K−1 (4.3 times that of epoxy). In addition, the breakdown strength of the composite at 4.4 vol% content is up to 40.55 kV mm−1, 21.5% higher than that of neat epoxy (33.38 kV mm−1).

Corrosive fatigue failure of submarine pipelines is very common because the pipeline is immersed in a sea environment. In Bohai sea, many old pipelines are made of API 5L X56 steel materials, and it is necessary to provide an accurate method for predicting the residual life of these pipelines. As Paris law has been proven to be reliable in predicting the fatigue crack growth in metal materials, the two constants in Paris law for API 5L X56 steel materials are obtained by using a new proposed shape factor based on the analysis of experimental data measured from fatigue tests on compact tension specimens immersed in the water of Bohai sea. The results of the newly proposed shape factor show that, for a given stress intensity factor range (&Delta, K), the fatigue crack growth rate (da/dN) in seawater is 1.6 times of that that in air. With the increase of fatigue crack growth rate, the influence of seawater on corrosive fatigue decreases gradually. Thereafter, a finite element model for analyzing the stress intensity factor of fatigue crack in pipelines is built, and the corrosive fatigue life of a submarine pipeline is then predicted according to the Paris law. To verify the presented method, the fatigue crack growth (FCG) behavior of an API 5L X56 pipeline with an initial crack under cyclic load is tested. Comparison between the prediction and the tested result indicates that the presented method is effective in evaluating the corrosive fatigue life of API 5L X56 pipelines.

Objectives: To study the therapeutic effect and complications of deep brain stimulation (DBS) to Parkinson’s disease (PD). Patients and Methods: A retrospective analysis of DBS performed on 44 patients with Parkinson’s disease who had complications in the post-operation. Results: 1). A stimulation effect was observed in all PD patients during the operation, with the most obvious effect being relief of muscular tension, followed by improvement in tremor and bradykinesia. 2). The implantable pulse generator was activated from 3 days to 1 month after the implantation of the stimulation electrode, and then had an obvious effect. 3). Clinical follow-up was performed from 3 months to 2.5 years post-implantation. The symptoms assessed using the UPDRS score were significantly improved. 4). Two cases of cerebral hemorrhage and vesicular effusion were related to surgical methods. There were several cases of pneumonia in the postoperative fever and two cases of urinary system infection. One case of traverse fracture also occurred. Postoperative electrode exposure and local infection occurred in 1 case. There were 3 cases of lethargy, 2 cases of hallucinations. In the postoperative period, intelligence decreased further in 1 case. One patient had no obvious improvement in rigidity. 5). One case had difficulties in eye opening within 1 month. One case of PD had poor rigidity control. There was also decrease memory after stimulation in 2 cases. Conclusion: Proper selection of patients, appropriate DBS surgical methods and reasonable adjustment of stimulation parameters can effectively prevent and treat related complications.

Polymer nanocomposites with high dielectric constant have extensive applications in the electronic and electrical industry because of ease of processing and low cost. Blending and in situ polymerization are two conventional methods for the preparation of polymer nanocomposites. However, the resulting nanocomposites, particularly highly filled nanocomposites, generally have some disadvantages such as high dielectric loss and low dielectric constant and thus show low energy density and low energy efficiency. Here we developed a core@double-shell strategy to prepare barium titanate (BT)-based high performance polymer nanocomposites, in which the first shell is hyperbranched aromatic polyamide (HBP) and the second shell is poly(methyl methacrylate) (PMMA). This method utilized the advantages of both polymer shells, resulting in superior dielectric property which cannot be achieved in nanocomposites prepared by the conventional blending methods. It is found that, compared with the conventional solution blended...

Polymer nanocomposites with high energy density and low dielectric loss are highly desirable in electronic and electric industry. Achieving the ability to tailor the interface between polymer and nanoparticle is the key issue to realize desirable dielectric properties and high energy density in the nanocomposites. However, the understanding of the role of interface on the dielectric properties and energy density of polymer nanocomposites is still very poor. In this work, we report a novel strategy to improve the interface between the high dielectric constant nanoparticles (i.e., BaTiO3) and ferroelectric polymer [i.e., poly(vinylidene fluoride-co-hexafluoro propylene)]. Core–shell structured BaTiO3 nanoparticles either with different shell thickness or with different molecular structure of the shell were prepared by grafting two types of fluoroalkyl acrylate monomers via surface-initiated reversible addition–fragmentation chain transfer (RAFT) polymerization. The dielectric properties and energy storage c...

Aluminum nitride (AlN) nanoparticles were firstly treated with a silane coupling agent, γ-aminopropyl-triethoxysilane (γ-APS), to introduce amine groups (AlN-APS), then grafting of the hyperbranched aromatic polyamide started from the modified surface (AlN-HBP). The surface modified AlN nanoparticles were characterized by Fourier transform infrared, nuclear magnetic resonance, and thermogravimetric analyzer. Then the nanoparticles with these three different interface structures were selected as reinforcing fillers for epoxy composites. The study reports the influence of interfacial structure of nanoparticles on the morphology and thermal properties of epoxy composites. It was found that the AlN-HBP nanoparticles result in a strong interface and thus the incorporation of the AlN-HBP nanoparticles not only improved the dispersion of the nanoparticles in the epoxy matrix but also enhanced the thermal conductivity, thermal stability, glass transition temperatures, and dynamical thermomechanical properties. Copyright © 2013 John Wiley & Sons, Ltd.

Epoxy microcomposites with high loading micro alumina (Al2O3, 100–400 phr) were prepared by casting method and their thermal and electrical properties were studied at temperatures from 25 to 150 °C. The electric resistance device and the dielectric electrode device were designed to measure the electrical properties of the composites. Thermogravimetric analysis (TGA) and scanning electron microscopic proves the homodispersion of Al2O3 microparticles in epoxy. TGA indicates that the temperature of 5 % weight loss of epoxy/Al2O3 (100 phr) composite is 366 °C, 34 °C higher than that of pure epoxy. Differential scanning calorimetry shows that the glass transition temperature of epoxy/Al2O3 composite (400 phr) increases to 114.7 °C, 9.2 °C higher than that of pure epoxy. Thermal conductivity test demonstrated that with increasing Al2O3 content at 25 °C, thermal conductivity of epoxy/Al2O3 composites increased to 1.382 W/(m K) which is 5.62 times that of pure epoxy. Electrical tests demonstrate that by increasing of Al2O3 content and temperature, the electric resistance and dielectric properties of the composites show great dependencies on them. Resistivities of all the specimens decreased with the increasing of temperature owing to the increasing molecular mobility in the higher temperature. Resistivity of pure epoxy at 25 °C is about 9.56 × 1016 Ω cm, about one order of magnitude higher than that of pure epoxy at 125 °C and two orders of magnitude higher than that of pure epoxy at 150 °C. These results can give some advice to design formulations for practical applications in power apparatus.

A novel route to prepare core-shell structured nanocomposites with excellent dielectric performance is reported. This approach involves the grafting of polystyrene (PS) from the surface of BaTiO(3) by an in situ RAFT polymerization. The core-shell structured PS/BaTiO(3) nanocomposites not only show significantly increased dielectric constant and very low dielectric loss, but also have a weak frequency dependence of dielectric properties over a wide range of frequencies. In addition, the dielectric constant of the nanocomposites can also be easily tuned by varying the thickness of the PS shell. Our method is very promising for preparing high-performance nanocomposites used in energy-storage devices.

Polymer composites with high permittivity and low dielectric loss are highly desirable in electronic and electrical industry. Adding conductive fillers could significantly increase the permittivity of a polymer. However, polymer composites containing conductive fillers often exhibit very high dielectric loss due to their large electrical conduction or leakage currents. In this work, by engineering TiO 2 -nanorod-decorated multi-walled carbon nanotubes (TD-CNTs), polystyrene (PS) composite with high permittivity and low dielectric loss have been successfully prepared. The composite containing of 17.2 vol.% TD-CNTs has a permittivity of 37 at 1 kHz, which is 13.7 times higher than that of the pure PS (2.7), while the dielectric loss still remains at a low value below 0.11. The dielectric properties of the composites are closely related to the length of CNTs and the loading level of TiO 2 -nanorods on the CNT surfaces.