The drug carriers represent a very important and modern pathway used to increase the therapeutic efficacy of the natural active substances. Nano-sized assemblies of noble metals and herbal extracts represent very simple, cheap, biologically and ecologically friendly synthesis. The main aims of this study were to obtain polyurethane nanovesicles containing silver nanoparticles and to evaluate their release rate. The vesicles’ sizes, homogeneity and surface charge were studied using a Cordouan Technol. Zetasizer, while the thermal behaviour was assessed by DSC. UV-Vis measurements were done to evaluate the release rate. Toxicological effects were studied by non-invasive techniques on human skin. The results suggest the obtaining of homogenous polyurethane nanovesicles between 80 and 95 nm, with positive surface charge, very good thermal stability and a prolonged release. The non-irritation potential recommends these vesicles as a safe carrier for different herbal extracts.
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Sewage sludge resulted from urban wastewater treatment plants is generally accepted as a valuable source of nutrient and soil conditioner for agricultural usage. Analysis of amount of heavy metals in sewage sludge is essential previous to utilization of the sludge to agriculture considering the inevitable risk of heavy metal toxicity to soil, vegetation and humans. The present paper aims to analyse the characteristics of the sewage sludge resulted in an urban area for 5 years. Sewage sludge generated from five wastewater treatment plants in the South and South Est part of Romania were analysed.
In total edentulous treatment can be used a variety of means capable to reconstruct through artificial prosthetic devices the edentulous dental arches, in an individualized manner depending on the clinical situation, objectives and criteria for treatment. The present study was intended to evaluate the effectiveness of general treatment with vitamin B12 and the effectiveness of local treatment, achieved through complete dentures and to emphasize the much easier and cheaper way to do the same treatment over the same time period.
The purpose of this experimental study is to present the design and biomechanical characteristics of cemented total knee prostheses type rotating-hinge RT-PLUS® (Smith&Nephew), as well as to evaluate their use in severe haemophilic knee arthropathy with major bone damage, ligamentous lesions, axial deviations and muscle retractions. We retrospectively evaluated 5 patients with severe haemophilic arthropathy with an average age of 48.5years. The functional results are good, with a significant improvement of range of motion (ROM) and pain relief resulting in a much better life quality. We did not have any stem loosening or any other complications except 2 wound healing problems which were treated successfully. The authors recommend this type of arthroplasty in severe haemophilic knee arthropathy or in any primary knee osteoarthritis with severe bone loss or any kind of ligamentous lesions.
Importance and use of composite materials are no longer a subject that should be emphasized. They offer a successful replacement for classical materials in most areas of engineering, conferring similar elastic-mechanical properties to metal or non-metal alloys with several advantages such as reduced mass, chemical resistance etc. Considering this, knowledge of the elastic-mechanical characteristics is of utmost importance. The present article aims to create a finite element model that can predict the longitudinal elastic modulus of a double-layered composite material based on the elastic characteristics of its constituents. For this, the elastic characteristics of the constituents were determined, then used in the finite element analysis thus obtaining the Young’s modulus for the numerical composite material. Also, the longitudinal elastic modulus of the resultant composite was determined experimentally. The results of the finite element model were compared with experimental values.
In this research are establish the technology of 3D printable parts by the principle of FDM 3D printed for threaded made by PLA, ABS, Nylon or PETG. In the paper are present first the dimensional generation and specific aspects that need to be considered to produce threaded with internal teeth of the metric, round or trapezoidal type. Generating the threaded appeared as a necessity for the reconditioning or made of the components of the processing machines made both in the process of elaboration of the bachelor’s and the laboratory works, with reduced energy resource consumption and low pollution as low as possible. After the construction, it is identify the dimension that have implications for both mechanical and kinematic resistance to make a product with good cinematic and functional characteristics. After that are made an analysis of the layers generated, both from the computer simulation and from the point of view of the analysis of layers physically generated for a threaded with internal teeth. At the end are presented which are necessary for operations to obtain a product with good features starting from two types of thread generated 8x2 and 10x2 moments.
Turmeric, with its active component curcumin has been regarded lately as an important potential therapeutic agent due to its properties and many uses. Further research needs to be done both on animals and humans in order for it to be used at a large scale. As curcumin gets absorbed better through topical and not oral administration, curcumin-based pharmaceuticals with skin passage must be devised. In order for this to be done, the need for a standardized, verified and simple extraction method and one for ointment preparation with stability in time rises. We propose in this study a method for curcumin extraction, one that ensures an adequate stability in time and a method for pharmaceutical control.
The crystal structure of tetrakis(2,2’-bithiophene-5-yl)silane, C16H10S4Si0.5, has been determined at 293K in the Monoclinic (I2) symmetry. The Si atom has quasi-perfect tetrahedral geometry and bithiophene unit are quasi-planar. Comparison of Si-C bond lengths with literature data indicates an electron donating effect of the terminal thienyl ring on the first C linked to the Si central atom. The study of C-C bond lengths reveals a much more aromatic character for the four thienyl rings directly linked to the Si atom. The molecular packing arrangement shows that each molecule presents eight intermolecular contacts.
The paper presents the obtaining of zinc and zinc composite coatings using electrochemical TiO2 nanoparticles as well as the determination of the influence of gelatin used as an additive on electrically co-deposited layers. The obtained coatings were studied at the electronic scanning microscope (SEM) for microstructure observation. A distinction was made between the pure zinc electro-deposed layer and the influence of nano-TiO2 on the morphology of zinc nanocomposite layers Zn/nano-TiO2, as well as the determination of the degree of inclusion of nano particles of TiO2 into the zinc matrix. It was confirmed that with the introduction of nano-TiO2, both the roughness of the electro-deposed layer and the micro hardness of the electro-deposed layer significantly increased compared to the micro hardness of the pure zinc electro-deposed layers confirming the existence and beneficial effects of nano-TiO2 in electro-co-deposed nano-composite layers.
The paper focuses on the obtaining of novel nanocomposite hydrogels based on polyacrylamide and layered double hydroxides (LDHs) modified with double bonds. The modification of LDH clay was investigated by FTIR, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analyses. Mechanical properties of the nanocomposite hydrogels were employed by compression and rheological measurements. The formation of exfoliated and intercalated structures was evidenced in transmission electron microscopy (TEM). Chemical cross-linking of hydrogels using both classical cross-linker and modified clay was an efficient method to improve the mechanical properties of novel nanocomposite hydrogels. These hydrogels with improved mechanical properties could be further tested for biomedical applications such as tissue engineering.