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81.
Sodium alendronate (ALD) is a bisphosphonate used to treat osteoporosis. However, its oral administration has been associated with side effects as gastroesophageal reflux. Moreover, there are some particularities for the intake of the medicine, which also hinder the patient's compliance, for example, the instruction that it has to be taken with an empty stomach, 30 to 60 min before breakfast and avoid the decubitus position after using the drug. Therefore, biomaterials for applications in osteoporotic bones are a good alternative. Thus, this work aimed to produce a Polycaprolactone (PCL) and ALD-based powder as a supply to build biomaterials by selective laser sintering, compression molding (CM), solvent casting (SC), among others. The powder was produced by coating the ALD particles with PCL and films were produced by SC and CM techniques. The samples were characterized by Scanning Electron Microscopy, Energy-dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectrometry and thermal analysis. Furthermore, the drug release was evaluated by UV–Vis spectroscopy. Results showed that ALD particles were successfully coated by PCL and applied to the production of biomaterials, highlighting its potential in the treatment of osteoporosis.  相似文献   
82.
The effect of melatonin (MEL) on the nephropathy and the oxidative stress induced by a single and high dose of Adriamycin (AD) has been studied in Wistar male rats. MEL (50 microg/kg/day) was injected intraperitoneally 3 and 7 days, respectively, before and after AD injection (20 mg/kg i.p.). Trunk blood was drawn and triglycerides, total cholesterol, phospholipids, high-density lipoprotein cholesterol, urea, creatinine, total protein, lipoperoxides, and reduced glutathione (GSH) levels and catalase activity (CAT) were determined in serum. In kidney homogenates, lipoperoxides, GSH, and CAT were measured as well as total protein in urine. AD administration resulted in hyperlipidemia and high-grade proteinuria and a marked increase in serum lipoperoxides, urea, and creatinine. In the kidney, the increase in lipoperoxides was accompanied by a significant decrease of GSH and CAT. The efficiency of MEL was specially remarkable in restoring GSH, CAT, and proteinuria to the levels of controls. These results confirm the involvement of free radicals in the pathogenesis of nephrotoxicity induced by AD. Likewise, they show the high antioxidative power of MEL and its marked effect on the prevention and suppression of this nephropathy.  相似文献   
83.
84.
Error-correcting properties of a binary adaptive nonlinear multiplexing system which trades channel activity for redundancy are studied. The main results are a family of data channel carriers, a way to establish the multiplex error-correction power, and the specification of desirable properties for a set of data channel carriers. Channel activity is extracted at the receiver, directly from the multiplexed signal.<>  相似文献   
85.
The comparative importance of phospholipid hydroperoxide glutathione peroxidase (PHGPx) and of "classic" glutathione peroxidase (GPx) in the reduction of phospholipid hydroperoxides is unclear. Although GPx activity is 500-fold higher than that of PHGPx in rat liver, the reduction of phospholipid hydroperoxides by glutathione (GSH) through GPx may be strongly limited by a low PLA2 activity. We address this issue using a moderately detailed kinetic model of mitochondrial lipid peroxidation in rat liver. The model was based on published data and was subjected to validation as reported in the references. It is analysed by computer simulation and sensitivity analysis. Results suggest that in rat liver mitochondria PHGPx is responsible for almost all phospholipid hydroperoxide reduction. Under physiological conditions, the estimated flux of phospholipid hydroperoxides reduction through PHGPx is about four orders of magnitude higher than the estimated hydrolysis flux through PLA2. On the other hand, virtually all hydrogen peroxide is reduced through GPx. Therefore, a functional complementarity between PHGPx and GPx is suggested. Because the results are qualitatively robust to changes of several orders of magnitude in PLA2 and PHGPx levels, the conclusions may not be limited to mitochondria.  相似文献   
86.
In 1987, Wisnivesky et al. developed "Maria" sensor box (MSB) which was assayed by sanitary agents, during a surveillance phase. In 1987, this design, with the same strategy, was assayed in an area of Santa Fe Province where very good results were obtained. Due to the deterioration of the Primary Health Care system, Santa Fe's Control Programme has carried out a study with MSB used by the owners of the houses. Some difficulties related with the internal structure of MSB were detected. A new model named "Detector SANTA FE" (DSF) was designed in order to overcome these difficulties. The sensitivity and cost of both models were compared in this study. Evaluation of 63 households was carried out with 172 elements distributed in bedrooms, in Villa Minetti (9 de Julio Department). One MSB and one DSF were placed on the walls above the bed-heads, separated by 30 cm, 1.5 m from the floor. Results show that 22 houses were positive after the evaluations. Of those 22 positives, 7 were detected by both models simultaneously, 1 only by MSB and 14 by DSF alone. Sensitivity for MSB was 36% and for DSF was 95%. Regarding efficiency, MSB costs $3.00 per unit, while DSF costs $1.00 per unit. The conclusion of the study is that DSF is remarkably more sensitive and cheaper than MSB.  相似文献   
87.
Enterprise models assist the governance and transformation of organizations through the specification, communication and analysis of strategy, goals, processes, information, along with the underlying application and technological infrastructure. Such models cross-cut different concerns and are often conceptualized using domain-specific modelling languages. This paper explores the application of graph-based semantic techniques to specify, integrate and analyse multiple, heterogeneous enterprise models. In particular, the proposal described in this paper (1) specifies enterprise models as ontological schemas, (2) uses transformation mapping functions to integrate the ontological schemas and (3) analyses the integrated schemas with graph querying and logical inference. The proposal is evaluated through a scenario that integrates three distinct enterprise modelling languages: the business model canvas, e3value, and the business layer of the ArchiMate language. The results show, on the one hand, that the graph-based approach is able to handle the specification, integration and analysis of enterprise models represented with different modelling languages and, on the other, that the integration challenge resides in defining appropriate mapping functions between the schemas.  相似文献   
88.
There are many different ways to reduce the construction industry’s impact on environment. The incorporation of waste in the fabrication of construction materials may be beneficial for both the waste management sector and the construction industry. The aim of this research was to investigate the use of three different waste materials (construction and demolition waste, brick powder and fly ash) as filler in asphalt mixtures. Limestone filler was used as reference material. The materials were characterized in terms of their geometrical, physical and chemical properties, and the interaction with bitumen was assessed with two mastic test methods using four different bitumens. The specific surface of waste materials shows a wide-ranging variation due to material specific shape and texture of particles. However, the Rigden voids and bitumen number tests adequately measure the stiffening effect of these materials. The delta ring and ball test results showed there is a good relation with the filler content when the results are affected by the bitumen type. The f/b ratio for a specific bitumen–filler combination can be determined from the maximum filler-to-bitumen ratio and the recommended stiffening increase. The mastics with these waste materials showed strong resistance to water damage.  相似文献   
89.
In 2005, a new phase for primary health care (PHC) in Portugal began, leading to the voluntary and independent creation of Family Health Units. The impact of this reform is now being witnessed, which justifies the need to evaluate its results as far as best practices in PHC are concerned. This work uses a value-based data envelopment analysis (DEA) method, which combines an additive DEA model with multi-criteria decision analysis concepts, to allow incorporating managerial preferences in the performance assessment of 12 health centres in a Portuguese region. Two models are presented for evaluating access to PHC, which resulted from discussions with a group of decision makers. This analysis helped the decision makers in the identification of best practices, sources of inefficiency and gaps relatively to the best practices, thus leading to shape opportunities for improvement.  相似文献   
90.
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