Search

Background Cholinergic dysfunction and oxidative stress are the crucial mechanisms of Alzheimer's disease (AD). GAPT, also called GEPT (a combination of several active components extracted from the Chinese herbs ginseng, epimedium, polygala and tuber curcumae) or Jinsiwei, is a patented Chinese herbal compound, has been clinically widely used to improve learning and memory impairment, but whether it can play a neuroprotective role by protecting cholinergic neurons and reducing oxidative stress injury remains unclear. Methods Male ICR mice were intraperitoneally injected with scopolamine (3 mg/kg) to establish a learning and memory disordered model. An LC‐MS method was established to study the chemical compounds and in vivo metabolites of GAPT. After scopolamine injection, a step‐down passive‐avoidance test (SDPA) and a Y maze test were used to estimate learning ability and cognitive function. In addition, ELISA detected the enzymatic activities of acetylcholinesterase (AChE), acetylcholine (ACh), choline acetyltransferase (ChAT), malondialdehyde (MDA), glutathione peroxidase (GPX), and total superoxide dismutase (T‐SOD). The protein expressions of AChE, ChAT, SOD1, and GPX1 were observed by western blot, and the distribution of ChAT, SOD1, and GPX1 was observed by immunohistochemical staining. Results After one‐half or 1 month of intragastric administration, GAPT can ameliorate scopolamine‐induced behavioral changes in learning and memory impaired mice. It can also decrease the activity of MDA and protein expression level of AChE, increase the activity of Ach, and increase activity and protein expression level of ChAT, SOD, and GPX in scopolamine‐treated mice. After one and a half month of intragastric administration of GAPT, echinacoside, salvianolic acid A, ginsenoside Rb1, ginsenoside Rg2, pachymic acid, and beta asarone could be absorbed into mice blood and pass through BBB. Conclusions GAPT can improve the learning and memory ability of scopolamine‐induced mice, and its mechanism may be related to protecting cholinergic neurons and reducing oxidative stress injury., GAPT can improve the learning and memory ability of scopolamine‐induced mice, and its mechanism may be related to protecting cholinergic neurons and reducing oxidative stress injury.

Purpose Library intelligence institutions, which are a kind of traditional knowledge management organization, are at the frontline of the big data revolution, in which the use of unstructured data has become a modern knowledge management resource. The paper aims to discuss this issue. Design/methodology/approach This research combined theme logic structure (TLS), artificial neural network (ANN), and ensemble empirical mode decomposition (EEMD) to transform unstructured data into a signal-wave to examine the research characteristics. Findings Research characteristics have a vital effect on knowledge management activities and management behavior through concentration and relaxation, and ultimately form a quasi-periodic evolution. Knowledge management should actively control the evolution of the research characteristics because the natural development of six to nine years was found to be difficult to plot. Originality/value Periodic evaluation using TLS-ANN-EEMD gives insights into journal evolution and allows journal managers and contributors to follow the intrinsic mode functions and predict the journal research characteristics tendencies.

Understanding how a customer perceives an undefined commodity problem is important for online retailers so that they can address problems and satisfy and gain customers. Data mining technological maturation and developments in online review systems means that it is now possible to mine for customer perceptions on commodity problems from structured and unstructured data. This research, therefore, mainly used an unsupervised machine learning, stacked denoising autoencoder-K-means, to resolve the customer perception process for undefined commodity problems. It was found that: 1) textual reviews and quantitative scores are mutually complementary when analysing online buyer perceptions; 2) customer perception systems have a typical line-of-sight to capture the undefined commodity problem attributions. Although the attributions related to undefined commodity problems are very scattered, a highly unified strategy, providing after-sales service, was found to exist within each group, which was agreed through group consensus by about 98% of the consumers.

As one of the four major industrial raw materials in the world, natural rubber is closely related to the national economy and people’s livelihood. The analysis of natural rubber price and volatility can give hedging guidance to manufacturers and provide investors with uncertainty and risk information to reduce investment losses. To effectively analyses and forecast the natural rubber’s price and volatility, this paper constructed a hybrid model that integrated the bidirectional gated recurrent unit and variational mode decomposition for short-term prediction of the natural rubber futures on the Shanghai Futures Exchange. In data preprocessing period, time series is decomposed by variational mode decomposition to capture the tendency and mutability information. The bidirectional gated recurrent unit is introduced to return the one-day-ahead prediction of the closing price and 7-day volatility for the natural rubber futures. The experimental results demonstrated that: (a) variational mode decomposition is an effective method for time series analysis, which can capture the information closely related to the market fluctuations; (b) the bidirectional neural network structure can significantly improve the model performance both in terms of fitting performance and the trend prediction; (c) a correspondence was found between the predicted target, i.e., the price and volatility, and the intrinsic modes, which manifested as the impact of the long-term and short-term characteristics on the targets at different time-scales. With a change in the time scale of forecasting targets, it was found that there was some variation in matching degree between the forecasting target and the mode sub-sequences.

Polyacrylonitrile (PAN) precursor nanofibers with average diameter of 400 nm were synthesized by electrospinning. They were stabilized at 250–280 °C for 1–3 h, followed by carbonization at 1000 °C to fabricate CNFs with a diameter of 200 nm. The morphology, thermal properties, and chemical structure of the precursor nanofibers, the stabilized fibers and the final CNFs, were characterized by SEM, TEM, DSC, TG, XRD and XPS. It was found that the optimum stabilization conditions involved thermally treating them from 30 to 280 °C at a heating rate of 2 °C/min under a constant load of 1 kN, and keeping them at 280 °C for 2 h. Under these conditions, dehydrogenation and intra-cyclization reactions were almost completed; the PAN crystal structure was almost completely destroyed, and a thermally-stable ladder-like polymeric structure was formed. Nanofibers carbonized at 1000 °C were electrically conductive, and the conductivity was highly dependent on the stabilization conditions. The best electrical conductivity of ∼20.2 ± 1.2 S cm −1 was obtained under the conditions described.

In this study, randomly organized and uniaxially aligned polyacrylonitrile (PAN) nanofibers with an average diameter of ∼550 nm were prepared by electrospinning. They were embedded into poly(methylmethacrylate) (PMMA) to fabricate reinforced composite films by solution impregnation technique. Though the PAN nanofibrous mats were white in color, and fiber contents in composites were as much as 16 wt%, and the refractive index (RI) was different between PAN (RI = 1.5187) and PMMA (RI = 1.489), the composite films showed excellent optical transparency with as high as 90% light transmittance in the visible light range, regardless of the fiber orientation. The mechanical properties of composite films steadily improved with nanofiber contents, and were dependent on the fiber orientation. The tensile strength and Young’s modulus of the composite film containing 16% aligned fibers were respective 40% and 30% more than that with the corresponding amount of randomly organized fibers. The embedding of PAN nanofibers displayed no effect on the glass transition temperature of PMMA matrix, but increased the stiffness of the composite films in the glassy and glass–rubber transition state, as demonstrated by the dynamic mechanical analysis. This optically transparent PMMA composite with improved mechanical strength may be potentially used as the windshield for the highly moving objects.

Uniaxially oriented cellulose nanofibers were fabricated by electrospinning on a rotating cylinder collector. The fiber angular standard deviation (a parameter of fiber orientation) of the mats was varied from 65.6 to 26.2o by adjusting the rotational speed of the collector. Optically transparent epoxy resin composite films reinforced with the electrospun cellulose nanofibrous mats were then prepared by the solution impregnation method. The fiber content in the composite films was in the range of 5–30 wt%. Scanning electron microscopy studies showed that epoxy resin infiltrated and completely filled the pores in the mats. Indistinct epoxy/fiber interfaces, epoxy beads adhering on the fiber surfaces, and torn fiber remnants were found on the fractured composite film surfaces, indicating that the epoxy resin and cellulose fibers formed good interfacial adherence through hydrogen-bonding interaction. In the visible light range, the light transmittance was 88–92% for composite films with fiber loadings of 16–32 wt%. Compared to the composite films reinforced with 20 wt% randomly oriented fibers, the mechanical strength and Young’s modulus of the composite films reinforced with same amount of aligned fibers increased by 71 and 61%, respectively. Dynamical mechanical analysis showed that the storage moduli of the composite films were greatly reinforced in the temperature above the glass transition temperature of the epoxy resin matrix.

Electrospun cellulose nanofibrous mats (CNM) and cellulose acetate nanofibrous mats (CANM) reinforced poly(vinyl alcohol) (PVA) composites films were fabricated through solution impregnation method. The effect of fiber size and surface structure on the fiber/PVA interfacial adhesion, and consequently on the macroscopic properties such as optical, tensile, and dynamical mechanical properties of composite films were studied. The fractured surface morphology was examined by scanning electron microscopy. It showed that interfacial debonding happened to CANM/PVA composites, whereas good interfacial adhesion was formed for CNM/PVA composites. The visible light transmittance and the mechanical properties of PVA composite films were evaluated. CNM/PVA showed higher optical transparency than CANM/PVA composite films. Additionally, the light transmittance of CNM/PVA was insensitive to temperature. Dynamical mechanical analysis demonstrated that the storage moduli of electrospun fiber/PVA composite films were obviously improved in the glass–rubber transition and rubbery zone, but more significantly in the melting zone.

This work reported the effect of surface chemistry and roughness of electrospun fibers on fiber/matrix interfacial structures and the resultant macroscopical properties of composite films. Three types of fibrous mats composed of ultrafine fibers, that is, cellulose acetate (CANM), polyurethane (PUNM), and cellulose acetate/polyurethane composite (CAPUNM) were fabricated through electrospinning. CA fiber surfaces were rough with many hydroxyl groups; PU fiber surfaces were smooth, whereas CAPU composite fibers exhibited cocontiuous structure with rough surfaces. The fiber-reinforced epoxy composite films were prepared by the solution impregnation method. The fractured surfaces of the composites were analyzed by scanning electron microscopy. Severe interfacial debonding and fiber pullouts were observed for PUNM/epoxy composites, while strong interfacial adhesion was formed for CANM/epoxy and CAPUNM/epoxy composites. The interfacial structure played important roles in the visible light transmittance of the composite films. For example, CANM/epoxy films showed the best optical property, whereas PUNM/epoxy films displayed the poorest light transmitting property and were translucent. The interfacial structure also affected the mechanical properties of the composites. The mechanical strength of fibrous mats followed an increasing order of CANM CAPUNM/epoxy > PUNM/epoxy. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers

Withholding treatment for discharged patients are largely dependent on follow-up. With more and more patients and their different conditions and drugs, the effectiveness of follow-up faces obstacles. The development and popularity of mobile internet technology, makes it possible for changing the way of follow-up from traditional telephones and letters to modern mobile devices based follow-up system. In this paper, we design a follow-up system, to handle a large quantity of follow-up data. The system could gather medical data, such as treatment information, medicine information and health condition, from medical data center, and push the information to real-name binding patient devices. Discharged patient fills in the questionnaire survey on devices and sends feedback to medical data center. The data center applies a series of professional rules to follow-up data, and reports the patients with potential risk to corresponding doctors in charge. With real-name binding and SSL encryption technique, the privacy of patient is guaranteed.

Cloud computing is a recently proposed concept, aiming at making the internet a common infrastructure just like electricity. Middleware is a general service between the platform and applications, which is standardized by some interfaces and protocols. However, there's by far no adaptation platform to bridge the terminals and the cloud. In this paper we propose a novel cloud terminal adaptation platform based on mobile web-middleware, which acts as a standard interface for the mobile middleware and the cloud. For case study, we introduce a mobile network based postoperative survey system based on our proposed platform.

The need for mobility support on existing networks led to the formulation of the mobile IP protocol, which can provide seamless connectivity between fixed and mobile nodes. However, the inherent drawbacks of the protocol led to route optimization proposals of which one was accepted by the IETF. While attempting to solve the triangle routing problem, the adopted route optimization places extra constraints on the network nodes. This work is motivated by the need to find an alternative solution that would effectively solve the triangle routing problem without sacrificing performance, transparency, and simplicity. The proposed solution is an agent-based route optimization, which moves the tasks of maintaining and updating binding caches and encapsulating messages away from individual correspondent nodes to the correspondent agents. We setup a simulation environment to evaluate the proposed methodology. Simulation results show that the proposed protocol outperforms the existing protocols in terms of system message complexity, protocol simplicity, and scalability.

Automatic repeat request (ARQ) is a well-known technique to provide error control. In reliable satellite multicasting, ARQ may reduce system throughput as the number of receivers increases since the satellite has to retransmit a packer until all receivers correctly receive it. This performance degradation might be alleviated substantially by conducting retransmissions through terrestrial paths from the sender to each receiver instead of through the multicast satellite link. However, this approach may not be possible when some receivers do not have terrestrial connections to the sender. Also, a large volume of feedback traffic from the receivers to the sender may cause a feedback implosion at the sender. In this paper, we propose a scalable framework to solve these problems. Our solution enables receivers to form groups to avoid unnecessary retransmissions as long as a correct packet call be found inside the group. Using analytical models, we demonstrate that the proposed solution can significantly improve system throughput.

In order to effectively utilize the broadcast bandwidth, it is necessary to have efficient on-line scheduling algorithms that can balance individual and overall performance and can scale in terms of database sizes and client populations. Moreover, the scheduling algorithm should be applicable to a heterogeneous environment where data items have different sizes. We address these issues in this paper. As stretch is widely adopted as a performance metric for variable-size data requests, we propose a broadcast scheduling algorithm to optimize the system performance in terms of stretch. We show by analysis that the proposed algorithm can indeed achieve the optimal performance in terms of stretch. Moreover, the proposed scheduling algorithm has very low decision overhead, which makes it a practical solution for on-demand broadcast scheduling. Simulation results demonstrate that our algorithm significantly outperforms existing scheduling algorithms under various scenarios.

Broadcasting is a very effective technique to disseminate information to a massive number of clients when the data size is small. However, if the data size is large, the broadcast cycle may be long, and hence the access delay becomes a problem. Caching frequently accessed data at the client side can reduce the access latency and improve the bandwidth utilization. However, caching techniques may not perform well when the data are frequently updated. In this paper, we propose to apply different techniques (broadcasting and caching) to deal with different components of the data based on their update frequency. Compared to previous schemes, the proposed solution not only reduces the query latency, but also improves the throughput and the bandwidth utilization.