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1.
Carriers for targeted delivery and controlled release of poorly water-soluble active substances (PWSAS) are facing three challenges: (a) the encapsulation issues, (b) limitations of PWSAS water solubility, and (c) burst drug release which can be pharmacologically dangerous and economically inefficient. The present study brings a novel strategy for encapsulation and controlled release of PWSAS—caffeine in concentrations which are higher than its maximal water solubility without the possibility of burst effect. The modification of hydrophilic carrier based on poly(methacylic acid) was done using casein and liposomes. To further increase the maximal caffeine loading inside the carrier nicotinamide was used. The release study of the encapsulated PWSAS was elaborated with respect to morphology of the carriers and interactions that could be established between its structural components. The carriers swelling and the release of caffeine and nicotinamide were also investigated depending on caffeine concentration, the presence of different liposomal formulations and the volume ratio of liposomal formulation, in three media with different pH simulating the path of the carrier through the human gastrointestinal tract. The synthesized carriers are promising candidates for encapsulation of PWSAS in concentrations which are higher than its maximal water solubility and for the targeted delivery of those dosages.  相似文献   
2.
RE Rada 《Canadian Metallurgical Quarterly》1997,16(4):94, 96, 98-94, 96, 99
Vital bleaching can be a relatively unpredictable treatment. Photographs of previous cases and cosmetic imaging, although useful, may lead to unrealistic expectations on the part of the patient. The high-tech mystique of computer imaging and viewing one's own teeth has a significant impact on the dental patient. Whether imaged by the dentist or an auxiliary, patients must be aware of alternatives that may exist both before and during treatment. Cosmetic imaging should be used as an adjunct to, not as the prime motivator for, treatment planning in bleaching cases. Excellent communication between the practitioner and patient is the most important factor in assuring positive bleaching results and patient satisfaction.  相似文献   
3.
The presence of nitric oxide synthase (NO-synthase), the enzyme responsible for the production of nitric oxide (NO) from L-arginine, is shown immunocytochemically in the intrinsic neurons of the human and porcine respiratory tract. NO-synthase immunoreactivity is demonstrated in a subpopulation of neurons of the microganglia present in the wall of the extra- and intrapulmonary bronchi as well as in the hilar region of the lung in relation to blood vessels. The immunostaining was also found in some nerve fibers of the respiratory nervous system. Human and porcine lung gave similar results. The possible involvement of NO in the nonadrenergic noncholinergic (NANC) nervous regulation of the lung is discussed.  相似文献   
4.
Abstract In an effort to reduce the expensive resource requirements in courseware production and to allow effective management of, and communication and collaboration between authors, a model is needed to harmonize the diverse theoretical backgrounds such a process requires. To this end we look at five abstract models which where chosen for their apparent appropriateness within the general area of collaborative authoring and reuse of multimedia courseware. These models consist of a functional model of hypertext, an infrastructure model for an open collaborative authoring system, two object-oriented communication models, and a courseware production model. We attempt a consolidation of these models and ultimately make several conclusions, which are exposed during a conceptual harmonisation. The principal conclusion is that a hypermedia logical model is not by itself adequate to support collaboration and reuse. Our modeling conclusions have driven the design of a system which will be implemented and tested.  相似文献   
5.
Molecular distillation, or short‐path distillation (SPD), is particularly appropriate for processing of low‐volatility compounds, which are easily altered at high temperature. Olea europaea L. leaves constitute an olive tree by‐product very interesting for their natural antioxidants content. In this research, molecular distillation technology has been applied to obtain high‐value‐added compounds by the SPD fractionation of an olive tree leaf extract. The process consists of two stages: (a) ethanolic extraction of the olive leaves, followed by incorporation of the extract into glycerine and (b) molecular distillation of the glycerine enriched in olive leaf extract compounds (terpenic and phenolic compounds). Four molecular distillation tests under different conditions were carried out. Results showed that 80.9% 3,4‐dihydroxy‐phenylethanol (hydroxytyrosol) was recovered from the glycerine admixture under a pressure of 1.50–2.00 mbar, a temperature of 190 °C and a feed rate of 15 mL/min.  相似文献   
6.
We propose an adaptive neuro‐fuzzy inference system (ANFIS) for stock portfolio return prediction. Previous work has shown that portfolio optimization can be improved by using predicted stock earnings rather than historical earnings. We show that predicted portfolio returns can be improved by using ANFIS and taking as input a variety of technical and fundamental attributes about various indices of the stock market. To generate membership functions, we use a robust noise rejection‐clustering algorithm. The neuro‐fuzzy model is tested on portfolios constituted from the Tehran Stock Exchange. In our experiments, the proposed method performs better in predicting the portfolio return than the classical Markowitz portfolio optimization method, a multiple regression, a neural network, and the Sugeno–Yasukawa method. © 2010 Wiley Periodicals, Inc.  相似文献   
7.
To facilitate knowledge refinement, a system should be designed so that small changes in the knowledge correspond to small changes in the function or performance of the system. Two sets of experiments show the value of small, heuristically guided changes in a weighted rule base. In the first set, the ordering among numbers (reflecting certainties) makes their manipulation more straightforward than the manipulation of relationships. A simple credit assignment and weight adjustment strategy for improving numbers in a weighted, rule-based expert system is presented. In the second set, the rearrangement of predicates benefits from additional knowledge about the ``ordering' among predicates. A third set of experiments indicates the importance of the proper level of granularity when augmenting a knowledge base. Augmentation of one knowledge base by analogical reasoning from another knowledge base did not work with only binary relationships, but did succeed with ternary relationships. To obtain a small improvement in the knowledge base, a substantial amount of structure had to be treated as a unit.  相似文献   
8.
The suitability of using visible/near infrared spectroscopy (Vis/NIR), as a rapid and non‐destructive technique for monitoring the quality of argan seeds (Argania spinosa Skeels) was studied. The analyzed parameters were the fatty acid composition of argan seed oil, seed moisture content, seed oil content and oil stability index (OSI). The ratio between major unsaturated and saturated fatty acids (U/S) during the oxidation assay at constant temperature was studied. Values from infrared drying were used as a laboratory reference for the moisture. Argan seed oil content was determined by Soxhlet extraction. A fatty acid analysis was carried out by gas chromatography and the OSI was determined by the Rancimat test. Predictive models of argan seed moisture, ratio U/S and OSI showed good accuracy. Therefore, Vis/NIR measurements can be used for controlling several argan seed quality parameters. This procedure might be of interest to the argan oil industry, which is currently in the process of modernization and expansion.  相似文献   
9.
Nanostructural TiO2/modified multi-wall carbon nanotubes photocatalysts were prepared by hydrolysis of Ti(iso-OC3H7)4 providing chemical bonding of anatase TiO2 nanoparticles onto oxidized- or amino-functionalized multi-wall carbon nanotubes (MWCNT). The processes of functionalization of the MWCNT and the deposition of TiO2 influence the photocatalytic activity of the synthesized nanocomposites. The phase composition, crystallite size, and the structural and surface properties of the obtained TiO2/modified-MWCNT nanocomposite were analyzed from XRD, FEG-SEM, TEM/HRTEM and FTIR data, as well low temperature N2 adsorption. In the photocatalytic study, the TiO2/oxidized-MWCNT catalyst showed the highest and the TiO2/amino functionalized-MWCNT catalysts somewhat lower degradation rates, indicating that the enhancement of photocatalysis was supported by the more effective electron transfer properties of the oxygen- than amino-containing functional groups, which support the efficient charge transportation and separation of the photogenerated electron-hole pairs.  相似文献   
10.
This paper describes photosensitive properties and spectroscopic studies on the xPbO(100 − x)[6TeO2·4V2O5] (where x = 0-100 mol%) glass system. Our FTIR, UV-vis spectroscopic data and density measurements exhibit compositional dependent trends and the existence of characteristic vanadate (orthovanadate, pyrovanadate) structural units in these glasses. By laser exposures of the samples, variations observed in the FTIR and UV-vis spectra show that the existence a redox couple between lead ions and vanadate network.  相似文献   
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