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71.
Novel biological vascular conduits, such as decellularized tissue engineered vascular grafts (TEVGs) are hindered by high thrombogenicity. To mimic the antithrombogenic surface of native vessels with a continuous glycosaminoglycan layer that is present on endothelial cells (ECs), a hyaluronic acid (HA) modified surface is established, to effectively shield blood platelets from collagen‐triggered activation. Using the amine groups present on 4 mm diameter decellularized TEVGs, a continuous HA hydrogel coating is built via a bifunctional thiol‐reactive cross‐linker, thereby avoiding nonspecific collagen matrix cross‐linking. The HA hydrogel layer recreates a luminal wall, “hiding” exposed collagen from the bloodstream. In vitro blood tests show that adhered platelets, fibrinogen absorption, and fibrin formation on HA‐coated decellularized TEVGs are significantly lower than on uncoated decellularized TEVGs. The HA surface also inhibits macrophage adhesion in vitro. HA‐coated decellularized syngeneic rat aortae (≈1.5 mm diameter), and TEVGs in rat and canine models, respectively, are protected from aggressive thrombus formation, and preserve normal blood flow. Re‐endothelialization is also observed. HA‐coated TEVGs may be an off‐the‐shelf small‐diameter vascular graft with dual benefits: antithrombogenic protection and promotion of endothelium.  相似文献   
72.
In the present work the composition of apple liqueurs has been analysed, since the consumption of these beverages in Spain has increased during the last years. Twenty-five samples, belonging to the most representative five brands of the Spanish market have been analysed. The following determinations were carried out: alcoholic grade, total acidity, methanol, furfurol, dry extract, reducing sugars, sucrose, ash contact, macroelements (Na, K, Ca, Mg) and microelements (Cu, Fe, Mn, Zn). These parameters enable the quality evaluation of these beverages and contribute to their characterization with respect to the fruit used in their elaboration. To complete the experimental study, a BMDP 7M discriminant statistical analysis has been applied to the results obtained. The variables that best discriminate the groups have been determined and all the samples have been classified and differentiated.
Analytisches Studium der Apfelsaftliköre
Zusammenfassung Es wurde die Zusammensetzung von Apfelsaftlikören analysiert, weil diese Getränke öfter in Spanien getrunken werden. Fünfundzwanzig Proben von fünf bestimmten, spanischen Markengetränken wurden analysiert. Es wurden folgende Bestimmungen ausgeführt: Alkoholkonzentration, Gehalt an Säure, Methanol, Extrakt, Zucker, Sucrose, Asche, Macroelemente (Na, K, Ca, Mg) und Mikroelemente (Cu, Fe, Mn, Zn). Diese Parameter erlauben die Qualität dieser Getränke zu schätzen und ihre Charakterisierung auf Grund des Fruchtgehaltes. Weiterhin wurde eine BMDP 7M diskriminant-statistische Analyse der Resultate angewandt. Die diskriminant-Variablen der Gruppe wurden bestimmt und alle Proben konnten klassifiziert und unterschieden werden.
  相似文献   
73.
In response to energy market liberalisation and privatisation initiatives promoted by the EU and other European states in the 1990s, a large number of US energy utilities expanded their activities in Europe, mainly through acquisitions. The size of their investment was, a decade later, matched by the ensuing scale of their retreat, wealth destruction and often forced exit. Combining interviews, industry studies, published financial data and company reports, this article examines critically their strategy and, in light of widespread failures, seeks to answer the question of what went wrong. It is argued that mistakes might have been avoided through greater appreciation of how market liberalisation evolves given changing government priorities and general sovereign risk.  相似文献   
74.
The use of visual search for knowledge gathering in image decision support   总被引:1,自引:0,他引:1  
This paper presents a new method of knowledge gathering for decision support in image understanding based on information extracted from the dynamics of saccadic eye movements. The framework involves the construction of a generic image feature extraction library, from which the feature extractors that are most relevant to the visual assessment by domain experts are determined automatically through factor analysis. The dynamics of the visual search are analyzed by using the Markov model for providing training information to novices on how and where to look for image features. The validity of the framework has been evaluated in a clinical scenario whereby the pulmonary vascular distribution on Computed Tomography images was assessed by experienced radiologists as a potential indicator of heart failure. The performance of the system has been demonstrated by training four novices to follow the visual assessment behavior of two experienced observers. In all cases, the accuracy of the students improved from near random decision making (33%) to accuracies ranging from 50% to 68%.  相似文献   
75.
The main weakness of elastic optical networks (EON), under dynamic traffic conditions, stems from spectrum fragmentation. A lot of research efforts have been dedicated during recent years to spectrum defragmentation. In this work, a thorough study about proactive defragmentation is carried out. Effects of the different defragmentation parameters on the EON performance are analyzed, and appropriate values of the defragmentation period, which guarantee suitable network performance while keeping the network control complexity at reasonable values, are obtained by means of extensive simulations. Benefit obtained by applying different defragmentation strategies, in terms of increase in the supported load at a given bandwidth blocking probability, is also reported. Different traffic conditions and network topologies are simulated to assess the validity of the obtained results.  相似文献   
76.
Metal halide perovskite (MHP) semiconductors have driven a revolution in optoelectronic technologies over the last decade, in particular for high-efficiency photovoltaic applications. Low-dimensional MHPs presenting electronic confinement have promising additional prospects in light emission and quantum technologies. However, the optimisation of such applications requires a comprehensive understanding of the nature of charge carriers and their transport mechanisms. This study employs a combination of ultrafast optical and terahertz spectroscopy to investigate phonon energies, charge-carrier mobilities, and exciton formation in 2D (PEA)2PbI4 and (BA)2PbI4 (where PEA is phenylethylammonium and BA is butylammonium). Temperature-dependent measurements of free charge-carrier mobilities reveal band transport in these strongly confined semiconductors, with surprisingly high in-plane mobilities. Enhanced charge-phonon coupling is shown to reduce charge-carrier mobilities in (BA)2PbI4 with respect to (PEA)2PbI4. Exciton and free charge-carrier dynamics are disentangled by simultaneous monitoring of transient absorption and THz photoconductivity. A sustained free charge-carrier population is observed, surpassing the Saha equation predictions even at low temperature. These findings provide new insights into the temperature-dependent interplay of exciton and free-carrier populations in 2D MHPs. Furthermore, such sustained free charge-carrier population and high mobilities demonstrate the potential of these semiconductors for applications such as solar cells, transistors, and electrically driven light sources.  相似文献   
77.
Wireless transmission of a patient's electrocardiogram (ECG) signals can be used to reduce cardiac healthcare cost. However, wireless transmissions have high error rates due to radio interference. The ECG signal, where every second of data could mean abnormal patterns, cannot tolerate such losses. Due to this healthcare crisis, the ability for a device to remotely monitor a patient's medication intake and transmit accurate ECG readings, while being cost efficient, is a major innovation. In this research, we integrate a multi‐hop wireless sensor network (WSN) with radio frequency identification (RFID) readers. Our system has two distinct features: (1) remotely supervise patient medication intake via RFID technology, and (2) accurately and remotely transmitting a patient's ECG by adopting extended Kalman filter (EKF) for wireless error recovery. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
78.
Microcavity arrays represent millions of different reaction compartments to screen, for example, molecular interactions, exogenous factors for cells or enzymatic activity. A novel method is presented to selectively synthesize different compounds in arrays of microcavities with up to 1 000 000 cavities per cm2. In this approach, polymer microparticles with embedded pre‐activated monomers are selectively transferred into microcavities with laser radiation. After particle patterning, heating of the particle matrix simultaneously leads to diffusion and coupling of the monomers inside each microcavity separately. This method exhibits flexibility, not only in the choice of compounds, but also in the choice of particle matrix material, which determines the chemical reaction environment. The laser‐assisted selective functionalization of microcavities can be easily combined with the intensively growing number of laser applications for patterning of molecules and cells, which is useful for the development of novel biological assays.  相似文献   
79.
The authors report findings of a large-scale, multitask investigation of sex differences in both structural asymmetries and lateralization of word reading. Two hundred participants were tested in eight divided visual field lexical tasks, and each received a structural magnetic resonance imaging scan. The authors examined whether there was evidence for sex differences in overall measures of neuroanatomical and behavioral lateralization, in specific language tasks and brain regions, and in variation in asymmetry within and across tasks and brain regions. There was very little evidence for sex differences on any behavioral measure. The few indications of sex differences in the current report accounted for 2% or less of the individual variation in asymmetry and could not be replicated in independent subsamples. No sex differences were observed in the asymmetry of structures in Broca's and Wernicke's areas such as pars triangularis, pars opercularis, the planum temporale, planum parietale, or Heschl's gyrus. There were also no sex differences in the variability of neuroanatomical asymmetries within or between brain regions. However, a significant relationship between planum temporale and behavioral asymmetry was restricted to men. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
80.
To improve cognitive and behavioral therapies (CBT) for depression, several approaches recommend an increased focus on the occurrence of problems as they occur in the therapeutic relationship or in relation to the live therapy process, referred to as present-focused. A lingering question has been the degree to which CBT therapists already engage in present-focused work. This study utilized sessions from recent trials of CBT for depression and, in Phase I, raters identified present-focused interventions on a turn-by-turn basis. Phase II raters used a qualitative analysis to determine categories of present-focused interventions. Results indicated that therapists rarely focused on the therapeutic relationship; when they did, it was often transient and lacking in the elaborations suggested by newer approaches. Therapists more often performed therapy process and emotion focused interventions, but these also tended to lack elaboration. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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