Composite scaffolds with increased hydrophilicity were prepared for cancellous bone regeneration by the freeze-extraction method. As a construction material, a poly–L–lactide (PLLA) was applied. As a hydrophilic, modifying agent a methacrylic acid copolymer, trade name Eudragit®, was used. Apreliminary investigation and optimization of the processwere performed. For the obtained scaffolds, regression equations determining the effect of: Eudragit®E100/PLLA weight ratio; volume ratio of methanol (porophore)/PLLA solution in dioxane on interconnected porosity and mass absorbability of obtained implants were calculated.
Peri-implantitis is a pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant connective tissue and progressive loss of supporting bone. In the treatment of peri-implantitis, a laser surgical technique is used. Lasers are a safe and gentle alternative to traditional dental tools. They allow oral surgeons and dentists to accomplish more complex tasks, reduce blood loss, decrease post-operative discomfort, reduce the chance of wound infection, achieve better wound healing and perform some procedures in close methods without access flap. The aim of the work was to determine the impact of laser surface treatment of titanium dental implants on its electrochemical behavior in artificial saliva at 37°C. The study used an Er,Cr:YSGG laser and diode lasers 810 nm and 980 nm for debridement of titanium implant surface. In the research, the thread on the surface of implant was scanned with the diode laser beam of energy 1, 1.25, 1.5 and 2 W, cw and Er, Cr YSGG: 1,5 and 2W, pulse 30Hz.
Effect of annealing on the structural properties of arsenic-implanted mercury cadmium telluride film grown by molecular beam epitaxy was studied with the use of transmission electron microscopy and optical reflection. Strong influence of the graded-gap surface layer grown on top of the film on the behaviour of implantation-induced defects under arsenic activation annealing was revealed and interpreted.
Mg-1.6Gd binary alloy was subjected to uniaxial warm rolling at a unidirectional and cross-sectional with a reduction ratio of 95% in order to observe the relationship between its microstructural changes to the degradation behavior. The warm rolling was performed at a temperature range of its recrystallization temperature, which were 400°C and 560°C, and a feed rate of 10 mm/min. Degradation behaviors of Mg-1.6Gd binary alloy was evaluated by means of potentiodynamic polarization and hydrogen evolution test in modified Kokubo’s SBF solution at temperature of 37 ± 1ºC. The lowest corrosion rate of 0.126 mm/year derived from potentiodynamic polarization test was showed by unidirectional-rolled specimen at temperature of 560 °C. Hydrogen evolution test results showed the lowest hydrogen gas formed during 24 hours of immersion was found on unidirectional-rolled specimen at temperature of 560°C with a rate of 0.268 cc/cm2/hours. While cross rolled specimens showed a high corrosion and hydrogen evolution rate of 20 mm/year and 0.28 cc/cm2/hours.
Aortic stenosis is the most common acquired valvular heart disease. Aortic stenosis has growing prevalence in people older than 75 years and natural course of disease is characterized by high mortality rate. According to epidemiological data all patients with aortic stenosis will die after 2–5 years from the first signs of disease if not undergo aortic valve replacement. However, even 40% of patients do not have surgery because of comorbidities related to advanced age. This was the main reason why in 80- and 90-ties of XX century there were intensive attempt to developed an alternative, less invasive treatment methodology for people with aortic stenosis and comorbidities and at high surgical risk. Transcatheter aortic valve implantation (TAVI) was introduced by Dr Alain Cribier in February 2nd, 2002 in Rouen, France. Since that day different aortic transcatheter bioprostheses were used in many randomized clinical trials comparing their safety and effectiveness versus surgical aortic valve replacement. Gradually, it became clear that in all older patients in all risk groups TAVI was equally or even more safe and effective than surgery. Complications after TAVI are relatively rare, but some of them are life-threatening. Heart Team plays a key role in patients selection to TAVI.
The Ca50Mg20Zn12Cu18 was assessed with different methods in order to characterize its basic characteristics, and to determine whether the amorphous alloy of such composition would be applicable as an implant material. The XRD analysis was conducted to conclude the structure of the initial material. The Ca50Mg20Zn12Cu18 ingot sample demonstrates crystalline structure containing two main intermetallic phases, however as-cast plates show features of an amorphous material, revealing the characteristic amorphous halo on the x-ray patterns. It was confirmed by the scanning electron microscopy method and fracture images revealing chevron pattern morphology with shell type fracture. Corrosion resistance, was studied using the potentiostatic analysis. The amorphous samples show higher resistance than the crystalline one. Post corrosion surface of the Ca50Mg20Zn12Cu18 alloy exhibits high concentration of magnesium and calcium hydroxides, forming the globular structures in large aggregates of spherical units.
Thiswork presents results of comparative studies of the optical absorption coefficient spectra of ion implanted layers in silicon. Three nondestructive and noncontact techniques were used for this purpose: spectroscopic ellipsometry (SE), modulated free carriers absorption (MFCA) and the photo thermal radiometry (PTR). Results obtained with the ellipsometric method are the proof of correctness of the results obtained with the MFCAandPTRtechniques. These techniques are usually used for investigations of recombination parameters of semiconductors. They are not used for investigations of the optical parameters of semiconductors. Optical absorption coefficient spectra of Fe+ and Ge+ high energy and dose implanted layers in silicon, obtained with the three techniques, are presented and compared.
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