The main aim of this study was to prepare and characterize polymeric nanoparticles containing two cardiovascular active pharmaceutical ingredients: valsartan (VAL) and amlodipine besylate (AML). Six formulations were evaluated with different ratios of AML:VAL:PLGA (1:16:17, 1:16:34, and 1:16:51) and different stirring speed (1200 and 2400 rpm). Encapsulation efficiency (EE, %) and particle size analyses were performed to characterize and optimize the formulation. All loaded nanoparticles showed a high EE (%), nano-size, negative x-potential and a high homogeneity.
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Utilization of computer-aided design/computer-aided manufacturing (CAD/CAM) rapidly increases in dental medicine. Making of computer-engineered complete denture is based on scanning of patient data, designing of prosthesis and milling or rapid prototyping. This is digital denture, term that includes innovative devices, software programmes and corresponding materials. Industrially polymerized cross-linked polymethyl methacrylate (PMMA) is the material used for fabrication of digital denture. The aim of this study is to analyze the different cross-linked PMMA used for fabrication of CAD/CAM complete denture.
The study aimed to assess the changes of the surface roughness induced by some acidic beverages on indirect restorative materials by using profilometry. Twenty samples of three composite resins (Ceramage, SR Adoro, Luna-Wing) and three ceramics (IPS In Line, Hera Ceram, Reflex Dimension) immersed in three acidic beverages (Red Bul, wine, Coca Cola), for 5 minutes, three times daily, 14 days. The control samples were immersed in artificial saliva during the study periode. After the end of the erosive cycles and before to determine the surface roughness of the samples in the study groups, all the samples were immersed in artificial saliva for 18 hours. The surface roughness was determined in relation to the baseline surface using profilometer Perthometer_M1 (Mahr Gottingen GmbH, Germany). The immersion of the indirect restorative materials tested in the three acidic beverages lead has resulted to changes in their surface roughness. The most aggressive was wine, followed by Coca Cola, and Red Bull.
This paper presents the results of the experimental researches obtained in the three-point test of the glass-fiber-reinforced polymeric composites. Mathematical modeling of experimental results was performed using a virtual instrument (VI) developed in the graphical programming language called LabVIEW. In order to process the experimental data and display the results, the virtual instrument (VI) allows both the reading of experimental data from a saved text file from the same folder as the current VI file and the direct entry of experimental values into a control element disposed on its front panel. The virtual instrument described in this article is part of a more complex project used for the mathematical modeling of the experimental data obtained in determining the physic-mechanical characteristics of glass fiber randomly reinforced polymeric composites.
The aim of the study was to measure the goniometric differences of the knee and hip joints and the changes regarding the features of fitness balls by taking into consideration its circumference and the vertical and horizontal diameters under the action of the body weight. The outcomes of the study have resulted in the creation of a table with reference values regarding the size of fitness balls in relation to the height and body mass index of the subjects.
The present paper deals with a comparative study on the influence of two different bioplasticizers: acetyl tributylcitrate (ATBC) and LAPOL108 on the mechanical and antimicrobial properties of poly(lactic acid) PLA containing 1 wt.% chitosan. PLA based biocomposites were investigated by means of processing behavior, FT-IR spectroscopy, DSC analysis, tensile and barrier properties, migration in food simulants and antifungal activity. Based on the obtained results it can appreciated that the properties of the PLA based biocomposites could be appropriate for designing flexible or rigid food packaging depending of the bioplasticizer used.
Possible causes of microleakage and microfractures of dental fillings are often in the center of many academic research and investigations. Some authors found that one important cause of microleakage is the contraction/ shrinkage of the filling materials during polymerization. The purpose of this study is to demonstrate that microcracks and consequent microleakage is influenced by mechanical stresses occurring inside of dental filling materials and at the interface of the dental cavities and dental filling materials. We also tried to evaluate the deformation of some dental filling material types during mechanical loading. Cylindrical specimens were made of different types of dental filling materials, namely microhybrid composites and glass ionomer cement. Some extracted teeth were prepared with class II cavities, and filled. The lateral swelling of the tested specimens and the deformation of the filled teeth during vertical axial loading was measured with an optical method, ESPI/ Shearography.Of the tested specimen, the least deformable dental filling materials were the composite materials. During occlusal vertical loading of the filled teeth, there were found that mechanical stresses were different inside of the filling material than inside of the walls of the dental tissues, mechanical stressed being concentrated at the restoration interface. The ESPI/Shearography meth ode proved to be very useful for investigation in this field. Due to mechanical stresses accumulating at the interface of the dental filling material and the walls of the dental cavity, it is possible that later microcracks to appear due to masticatory forces.
The aims of our study were to assess the cytotoxic effect of five orthodontic bonding materials, in vitro, on HUVECs to study the induction of apoptosis and inflammatory response generated to assess the shear-bond strength of the 5 tested materials in order to quantify their performance. Standardized samples from each material were obtained and incubated with HUVEC cells for 24 and 72 h immersed in complete medium. Cell viability was determined by means of MTS method. Active caspase 3 and TNFa protein levels were measured through ELISA techniques. The shear-bond strength was tested on 60 extracted premolars which were bonded with the same type of bracket, using the 5 different materials. Statistical analysis Student T-tests, Chi-square and Anova tests were used for results interpretation. Cell viability was decreased with material exposure in a time dependent manner. All materials exerted cytotoxic effects, the experimental materials showed a significantly higher decrease in cell viability at the 72 h reading. Shear Bond strength was superior for the resin commercial bracket-bonding materials. The study shows that orthodontic adhesives’ cytotoxicity and physical performance is related to their chemical properties and proves that all orthodontic practitioners should use freely their material of choice on condition they are aware of all its’ properties.
The thoracic wall resections for tumoral affections are laborious surgical interventions characterized by a high mortality and mobility. In order to create this paper we created a observational retrospective study in which we included 21 patients that have underwent parietal thoracic resections for tumoral affections. In all the patients we practiced the reconstruction of the thoracic wall using polypropylene mesh. The main postoperative complications were: seromas (14.28% of the cases), hematomas (9.52% of the cases), wound infection (4.76% of the cases), pneumonia (23.8% of the cases), respiratory failure (23.8% of the cases), paradoxical movement of the thoracic wall (52.38% of the cases). No deceases were recorded. In conclusion, the use of polypropylene mesh in the reconstructive techniques of the thoracic wall after thoracic wall resection represents a viable method, with good respiratory functional results.
Polyelectrolyte multilayer capsules are synthesized comprising of 12 total layers each containing a single layer of iron oxide nanoparticles in shells 4, 6, 8 or 10. A protein-labelled dye is embedded in the calcium carbonate template core as a model for the encapsulation of a drug. The core is dissolved after 6 layers are formed. Two types of magnetic nanoparticles are incorporated into various capsule shells: ferric oxide (Fe2O3, 50 nm) and iron oxide (Fe3O4, 15 nm), a 1:1 (vol.) mixture of the two types of nanoparticles suspensions is also used. Nanoparticle inclusion reduces the capsule sizes in all cases with the order of effect Fe3O4 [ Fe2O3 [ Fe2O3/Fe3O4 mixture. When Fe3O4 or a Fe2O3/Fe3O4 mixture is incorporated in layer 6 the reduction in size of the final capsules is less than expected. The number of surviving capsules containing nanoparticles are lower than control regardless of which of the nanoparticles is used but here the effect of Fe3O4 or a mixture of the two types of nanoparticles incorporated in layer 6 was slightly out of step. The amount of iron incorporated is almost the same regardless of which shell the nanoparticles were incorporated but the iron content using 50 nm nanoparticles is generally slightly higher than that obtained with 15 nm nanoparticles.