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An antibacterial peptide (AMP), i.e., nisin, was covalently bound to gelatin through a protein–protein coupling. Various reaction conditions were tested to study and optimize parameters of grafting e.g., orientation and density of AMP, which could impact the final antibacterial activity of the modified biopolymer. Modification was investigated by Fourier transform infrared (FT‐IR) spectroscopy and zeta potential. The antibacterial activity of the nisin‐enriched gelatin was evaluated against two staphylococci bacterial strains, i.e., Staphylococus epidermidis and Staphylococcus aureus. A higher activity was found for gelatin modified at pH = 7.4 revealing an influence of the nisin orientation on the protein antibacterial property. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41825. 相似文献
3.
ABSTRACTThis paper proposes the multiple-hypotheses image segmentation and feed-forward neural network classifier for food recognition to improve the performance. Initially, the food or meal image is given as input. Then, the segmentation is applied to identify the regions, where a particular food item is located using salient region detection, multi-scale segmentation, and fast rejection. Then, the features of every food item are extracted by the global feature and local feature extraction. After the features are obtained, the classification is performed for each segmented region using a feed-forward neural network model. Finally, the calorie value is computed with the aid of (i) food volume and (ii) calorie and nutrition measure based on mass value. The experimental results and performance evaluation are validated. The outcome of the proposed method attains 0.947 for Macro Average Accuracy (MAA) and 0.959 for Standard Accuracy (SA), which provides better classification performance. 相似文献
4.
A Nu?ez C De la Roza ML Rodrigo-Angulo W Bu?o F Reinoso-Suárez 《Canadian Metallurgical Quarterly》1997,754(1-2):1-11
This study analyses the relationship between the use of rotating instruments, the production of a smear layer and the presence of alterations to enamel microstructures. The rotating instruments used were carbide (8-12 blade) and diamond tipped (30-15 m) cutters. Cavities were made in extracted teeth. Subsequently, half the sample was analysed using the rugosimeter before and after the application of ortophosphoric acid at 35% for 15 and the other half suing a Scansion Electronic microscope (SEM). The results obtained showed on the one hand that carbide cutters leave a smoother surfacer than diamond tipped cutters, and on the other that the smear layer is eliminated better by carbide cutters compared to diamond tipped cutters. Moreover, there are no major traumatic-type alterations at the level of the enamel affecting the microstructure after the use of carbide cutters. 相似文献
5.
A Sketch-Based Interface for Clothing Virtual Characters 总被引:5,自引:0,他引:5
Emmanuel Turquin Jamie Wither Laurence Boissieux Marie-Paule Cani John F. Hughes 《Computer Graphics and Applications, IEEE》2007,27(1):72-81
This interactive system for garment creation determines a garment's shape and how the character wears it based on a user-drawn sketch. The system then uses distances between the 2D garment silhouette and the character model to infer remaining distance variations in 3D 相似文献
6.
The catalytic activity of fresh Pd and Pt catalysts supported on γ-alumina in the complete oxidation of CH4 traces under lean-burn conditions was studied in the presence or the absence of water or H2S. Steam-aged catalysts were also studied in order to simulate long-term ageing in real lean-burn natural gas fuelled vehicles (NGVs) exhaust conditions. Without water or H2S added to the feed, Pd catalysts exhibit a superior catalytic activity in methane oxidation compared to Pt ones, whatever the catalysts were fresh or aged. The addition of 10 vol.% water vapour to the feed strongly affects the activity of the fresh Pd catalyst, thus being only slightly more efficient than the fresh Pt one. H2S has a strong poisoning effect on the catalytic activity of Pd catalysts, while Pt catalysts are more resistant. The fresh H2S-poisoned Pd/Al2O3 catalyst was studied by TPD in O2/He. Poisoning species decompose above 873 K as SO2 and O2 in relative concentrations consistent with the decomposition of surface sulphate species. However, a treatment in O2/He at temperatures as high as 923 K does not allow the complete regeneration of the catalytic activity of H2S-poisoned Pd/Al2O3. A mechanism involving the poisoning of PdO by sulphate species is proposed. Different diffusion processes by which these sulphate species can migrate back and forth between PdO and the support, depending on the experimental conditions, are suggested. 相似文献
7.
Polymer nanocomposites with layered silicates as the inorganic phase (reinforcement) are discussed. The materials design and synthesis rely on the ability of layered silicates to intercalate in the galleries between their layers a wide range of monomers and polymers. Special emphasis is placed on a new, versatile and environmentally benign synthesis approach by polymer melt intercalation. In contrast to in-situ polymerization and solution intercalation, melt intercalation involves mixing the layered silicate with the polymer and heating the mixture above the softening point of the polymer. Compatibility with various polymers is accomplished by derivatizing the silicates with alkyl ammonium cations via an ion exchange reaction. By fine-tuning the surface characteristics nanodispersion (i. e. intercalation or delamination) can be accomplished. The resulting polymer layered silicate (PLS) nanocomposites exhibit properties dramatically different from their more conventional counterparts. For example, PLS nanocomposites can attain a particular degree of stiffness, strength and barrier properties with far less inorganic content than comparable glass- or mineral reinforced polymers and, therefore, they are far lighter in weight. In addition, PLS nanocomposites exhibit significant increase in thermal stability as well as self-extinguishing characteristics. The combination of improved properties, convenient processing and low cost has already led to a few commercial applications with more currently under development. 相似文献
8.
Emmanuel. Delamarche Bruno. Michel Hans A. Biebuyck Christoph Gerber 《Advanced materials (Deerfield Beach, Fla.)》1996,8(9):719-729
Self-assembled monolayers (SAMs) of alkanethiols and disulfides on gold form organic interfaces with properties largely controlled by the end groups of the molecules composing the film. SAMs provide a unique link between the science of organic surfaces and technologies that seek to exploit their adaptable character. Many techniques are useful for probing the structure of SAMs although only scanning tunneling microscopy (STM) at picoamperes reveals the details of the packing of their end groups at the sub-angstrom level. This review demonstrates that STM effectively tests new types of control over the microscopic structure–property relationships characteristic of SAMs on gold that should prove useful to their application. 相似文献
9.
The newly described slow cortical rhythm (approximately 0.3 Hz), whose depolarizing-hyperpolarizing components are analyzed in the preceding article, is now investigated from the standpoint of its relations with delta (1-4 Hz) and spindle (7-14 Hz) rhythmicity. Regular-spiking and intrinsically bursting cortical neurons were mostly recorded from association suprasylvian areas 5 and 7; fewer neurons were also recorded from pericruciate motor and posterolateral visual areas. Although most cells were investigated under various anesthetics, a similar slow cortical rhythm was found in animals with brainstem transection at the low- or high-collicular levels. These cerveau isolé (isolated forebrain) preparations display the major sleep rhythms of the EEG in the absence of general anesthetics. In 38% of recorded cortical neurons (n = 105), the slow rhythm was combined with delta oscillation. Both cellular rhythms were phase locked to the slow and delta oscillations in the surface- and depth-recorded EEG. In a group of this cell sample (n = 47), delta activity occurred as stereotyped, clock-like action potentials during the interdepolarization lulls of the slow rhythm. In another neuronal subsample (n = 58), delta events were grouped in sequences superimposed upon the depolarizing envelope of the slow rhythm, with such sequences recurring rhythmically at approximately 0.3-0.4 Hz. The associations between the two cellular and EEG rhythms (1-4 Hz and 0.3-0.4 Hz) were quantified by means of autocorrelograms, cross-correlograms, and spike-triggered averages. In 26% of recorded neurons (n = 72), the slow rhythm was combined with spindle oscillations. Regular-spiking cortical neurons fully reflected the whole frequency range of thalamically generated spindles (7-14 Hz). However, during similar patterns of EEG spindling, intrinsically bursting cells fired grouped action potentials (with intraburst frequencies of 100-200 Hz) at only 2-4 Hz. The dependence of the slow cortical oscillation upon the thalamus was studied by lesions and stimulation. The slow rhythm survived extensive ipsilateral thalamic destruction by means of electrolytic lesions or kainate-induced loss of perikarya in thalamic nuclei that were input sources to the recorded cortical neurons. To further prevent the possibility of a thalamic role in the genesis of the slow rhythm, through the contralateral thalamocortical systems and callosal projections, we also transected the corpus callosum in thalamically lesioned animals, and still recorded the slow rhythm in cortical neurons. These data indicate that the thalamus is not essentially implicated in the genesis of the slow rhythm.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
10.
This second article deals with using the Comsis software for a particular application. Simulation is used to determine the maximum channel density in presence of crosstalk. In a first part, the modelling of the system is described. The simulation parameters of different optical elements are given. The results show that in the case of channels modulated at 500 Mbitls using fsk modulation format, and a direct detection operation at 1,5 μm, a minimum spacing of 6 GHz can be obtained with a 2 dB penalty. Thus if only the bandwidth of the erbium doped fibre amplifier is taken into account, the maximum number of channels which can be used is 250. However if the fsr (free spectral range) of optical filter is taken into account, the maximun number of channels is limited to 30. 相似文献