410 research outputs found
Simulation Model for Salmonella Typhimurium on a Farrow-to-Finish Herd
A stochastic model which simulates they dynamics of Salmonella Typhimurium in moderate to highly infeted farrow-to-finish farms in Portugal was developed. The model comprises six different stages: three at the reproductive phase (sows) and another three for pig growth
The role of mutual in-feeding in maintaining problematic self-narratives: exploring one path to therapeutic failure
According to the author’s narrative model of change, clients may maintain a problematic self-stability across therapy, leading
to therapeutic failure, by a mutual in-feeding process, which involves a cyclical movement between two opposing parts of the
self. During innovative moments (IMs) in the therapy dialogue, clients’ dominant self-narrative is interrupted by exceptions to
that self-narrative, but subsequently the dominant self-narrative returns. The authors identified return-to-the-problem markers
(RPMs), which are empirical indicators of the mutual in-feeding process, in passages containing IMs in 10 cases of narrative
therapy (five good-outcome cases and five poor-outcome cases) with females who were victims of intimate violence. The
poor-outcome group had a significantly higher percentage of IMs with RPMs than the good-outcome group. The results
suggest that therapeutic failures may reflect a systematic return to a dominant self-narrative after the emergence of novelties (IMs
Second-derivative spectrophotometry for the analysis of simvastatin in polymeric nanocapsules
Conventional spectrophotometry methods are very susceptible to the presence of interferences in complex mixtures such as nanoparticules, requiring prior treatment or extraction of the analyte, and not always providing an adequate response. Derivative spectrophotometry method is capable to eliminate its interference; it is an alternative method for drugs determination in complex matrices. This work investigated the utility of derivate spectrophotometry in assay of simvastatin in polymeric nanocapsules (SIVNC). Shimadzu® UV-1650 double-beam spectrophotometer with 1.0 cm quartz cells was used in this study. The second-order derivative spectrum was obtained employing Δλ=20,000 nm and scaling factor=9.0. The determinations were made at 239 nm (2D239) by zero-crossing method. 2D239 method was validated employing the parameters: specificity, linearity, robustness, precision and accuracy. Results: The specificity test showed there was no interference of constituents commonly found in SIVNC formulation in 2D239. The standard curve showed a correlation coefficient of 0.994. The robustness was evaluated by small changes in the conditions of sample analysis and however, no significant changes were observed regarding drug quantitation. The precision was demonstrated by relative standard deviation (RSD) of intra-day (RSD=1.61-3.76) and inter-day studies (RSD=2.32). The recovery test resulted in an average of 100.66%, which confirmed the accuracy of the method. The procedure was simple and rapid; therefore this technique offers an alternative for determination of SIVNC without interferences
Diagnostic Ability Of Barrett’s Index to Detect Dysthyroid Optic Neuropathy Using Multidetector Computed Tomography
OBJECTIVES: The objective of this study was to evaluate the ability of a muscular index (Barrett's Index), calculated with multidetector computed tomography, to detect dysthyroid optic neuropathy in patients with Graves' orbitopathy. METHODS: Thirty-six patients with Graves' orbitopathy were prospectively studied and submitted to neuro-ophthalmic evaluation and multidetector computed tomography scans of the orbits. Orbits were divided into two groups: those with and without dysthyroid optic neuropathy. Barrett's index was calculated as the percentage of the orbit occupied by muscles. Sensitivity and specificity were determined for several index values. RESULTS: Sixty-four orbits (19 with and 45 without dysthyroid optic neuropathy) met the inclusion criteria for the study. The mean Barrett's index values (± SD) were 64.47% ± 6.06% and 49.44% ± 10.94%in the groups with and without dysthyroid optic neuropathy, respectively (p<0.001). Barrett's index sensitivity ranged from 32% to 100%, and Barrett's index specificity ranged from 24% to 100%. The best combination of sensitivity and specificity was 79%/72% for BI=60% (odds ratio: 9.2). CONCLUSIONS: Barrett's Index is a useful indicator of dysthyroid optic neuropathy and may contribute to early diagnosis and treatment. Patients with a Barrett's index >60% should be carefully examined and followed for the development of dysthyroid optic neuropathy
High in vitro activity of synthetic 5-aminoimidazole-4-carboxamidrazones against Candida biofilms formation on nanohydroxyapatite
Comunicação apresentada no: "4th I3S Annual Meeting"Fundação para a Ciência e Tecnologia [PEst-C/QUI/UI0686/2013 (FCOMP-01-0124-FEDER-037302)], PTNMR and a PhD grant awarded to Nádia Senhorães (SFRH/BD/73721/2010)
Influence of different surface modification treatments on silk biotextiles for tissue engineering applications
Biotextile structures from silk fibroin have demonstrated to be particularly interesting for tissue engineering
(TE) applications due to their high mechanical strength, interconnectivity, porosity, and ability to degrade under physiological conditions. In this work, we described several surface treatments of knitted silk fibroin (SF) scaffolds, namely sodium hydroxide (NaOH) solution, ultraviolet radiation exposure in an ozone atmosphere (UV/O3) and oxygen (O2) plasma treatment followed by acrylic acid (AAc), vinyl phosphonic
acid (VPA), and vinyl sulfonic acid (VSA) immersion. The effect of these treatments on the mechanical properties of the textile constructs was evaluated by tensile tests in dry and hydrated states. Surface properties such as morphology, topography, wettability and elemental composition were also affected by the applied treatments. The in vitro biological behavior of L929 fibroblasts revealed that cells were able to
adhere and spread both on the untreated and surface-modified textile constructs. The applied treatments had different effects on the scaffoldsâ surface properties, confirming that these modifications can be considered as useful techniques to modulate the surface of biomaterials according to the targeted application.Contract grant sponsor: Portuguese Foundation for Science and Technology under POCTI and/or FEDER programs under the scope of the project TISSUE2TISSUE; contract grant number: PTDC/CTM/105703/2008Contract grant sponsor: Investigator FCT program (to A.N.L.); contract grant number: IF/00411/201
Antimicrobial enzyme immobilization in bacterial cellulose
This work studied the physical immobilization of laccase on bacterial nanocellulose (BNC) aiming to identify the enzyme antibacterial properties suitable for wound dressings. The pH optimum and activation energy of free laccase depends on the substrate employed. The Michaelis-Menten constant for the immobilized laccase was found to be almost double of that of the free enzyme. However, the specific activities of immobilized and free laccase are similar suggesting that entrapped laccase on BNC maintain some flexibility and favour substrate accessibility. The results clearly show the antimicrobial effect of laccase and cytotoxicity acceptable for wound dressing applications.A. Zille acknowledges funding from FCT within the scope of the project POCI-01-0145-
FEDER-007136 and UID/CTM/00264.info:eu-repo/semantics/publishedVersio
Finely tuned fiber-based porous structures for bone tissue engineering applications
info:eu-repo/semantics/publishedVersio
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