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•Introduction of HA nanoparticles results in higher SME activation energy.•Shape programming at 64°C led to the maximum recovery stress.•Accumulation of defects led to decrease in ...shape recovery rate and recovery stresses.•3D-printed PLA/HA scaffolds support MSCs survival and stimulate active proliferation.
3D-printed porous scaffolds based on polylactide (PLA)/15% wt. nano-hydroxyapatite (HA) with shape memory effect (SME) for self-fitting implants were studied. Introduction of HA nanoparticles into the PLA matrix had an effect on the ordering of polymer molecular chains. The presence of HA nanoparticles caused a change in friction between molecular chains during the glass transition. Apparent activation energies of SME for PLA and PLA/HA 3D-printed samples were 490 and 555kJ/mol, respectively. HA nanoparticles acted as centers for the formation of additional rigid fixed phase that governed shape memory properties. The maximum recovery stress was observed in case of shape programming in the glass transition interval at 64°C. However, cyclic SME tests showed that the increase in number of cycles “programming – SME activation” led to decrease in shape recovery rate and recovery stresses due to accumulation of defects. It was demonstrated that 3D-printed porous PLA/HA scaffolds support mesenchymal stromal cells (MSCs) survival, and stimulate active proliferation of the cells as well. Such scaffolds with SME colonized by MSCs have the potential to be used as self-fitting implants for bone replacement and could also be beneficial in the engineering of complex tissues. MSCs colonization of scaffold favors vascularization of the implant, which is essential for the successful bone prosthesis.
Visual art is an integral part of human life, which, like a mirror, reflects the lifestyle and capabilities of a generation. Moreover, each epoch contributes to the development of artistic expression ...techniques. In this article, we discuss three novel approaches to visual art and design from the point of view of modern photonics and laser technology. Laser methods of metal coloring are considered regarding their physical nature, and their ample opportunities for the creation of different artworks are demonstrated.
The effect of quenching modes on the structure, phase composition and hardness of austenitic-ferritic stainless steel 20Kh25N8AD3M2 is studied by optical microscopy, x-ray diffraction phase analysis ...and hardness measurement. Corrosion tests are conducted in a 3% aqueous solution of NaCl with the use of potentiometry and potentiodynamic analysis. Heat treatment modes improving the resistance of steel 20Kh25N8AD3M2 to general and pitting corrosion are suggested. It is shown that aluminum and titanium used to deoxidize the steel can cause pitting corrosion even after quenching.
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Within the framework of this work, using a three-dimensional numerical model of the general circulation of the Martian atmosphere MAOAM (Martian Atmosphere: Observation and Modeling), also known as ...MPI-MGCM (Max Planck Institute Martian General Circulation Model), we simulated the planet’s hydrological cycle during the 28 and 34 Martian years (MY28 and MY34) dust storm seasons. A quantitative assessment of the photodissociation of water vapor under the influence of solar radiation at the Lyman-alpha wavelength has been carried out. The simulation results are compared with individual profiles obtained with the Atmospheric Chemistry Suite (ACS) spectrometer installed on the
ExoMars Trace Gas Orbiter
(TGO) spacecraft. The MAOAM model has a spectral dynamical core and successfully predicts the temperature regime of Mars through the use of physical parameterizations that are characteristic of both Earth and Martian models. The hydrodynamic block of the model includes the transfer scheme, microphysics of water vapor and ice, heterogeneous nucleation, sedimentation, photodissociation, and exchange of water with the surface. Studies show the effect of dust storms on both the total water vapor content in the atmosphere and its vertical distribution. More intense pumping of water vapor into the upper atmosphere during dust storms provides more intense photodissociation of water vapor (in some seasons up to 6.5 tons per second in total in the entire atmosphere). The strongest photodissociation is observed at heights of 50 to 80 km for MY34 and 70 to 80 km for MY28. The dissociated water vapor can then potentially become a source of hydrogen dissipation into space, followed by a decrease in the mass of water on the planet.
We offer to use optical features of surface plasmon resonance in Ag nanoparticles for jewelry application as a method for the well-controlled decoration of silver items. The novel approach of silver ...nanoparticles formation with sizes from 5 to 50 nm via nanosecond direct laser writing allows for controlling the reflectance spectra, thus creating a color image on precious metals with a high resolution of about 450 dpi without dyes or hazardous chemicals. Moreover, the large-scale color image can be applied in single-step processing with significant productivity of 2 cm
per minute. This work opens a strong direction for the practical application in the jewelry industry, art, and coining.
The paper presents the results of experimental measurements of the emission properties of water plasma in an inductive discharge. The power of the inductive discharge was 600 W at a frequency of 27 ...MHz and a pressure from 0.25 to 4 mbar. Plasma temperature was estimated from the Balmer hydrogen series using relative intensities method. It is shown that in this pressure range, the plasma is not in equilibrium and the energy difference between individual excited states increased with distance from the tube axis. The plasma heating time was estimated from the dynamics of the spectral line intensities to be 200 ms.
Gadolinium oxide nanoparticles were synthesized by the electrophysical method of spark discharge. Their structural features and magnetic and magnetocaloric properties have been comparatively ...analyzed. According to X-ray diffraction analysis data, the synthesized Gd
2
O
3
nanoparticles contain two crystallographic phases, cubic and monoclinic. The magnetic entropy change Δ
S
M
is determined from the data of magnetic isotherm measurements by the Maxwell relationship. The maximal Δ
S
M
at a magnetic field change amplitude of 2 T is approximately 17 J/(kg K) and observed at a temperature of 2.5 K.
Introduction
. Benign prostatic hyperplasia (BPH) is a common condition in aging men that is often associated with lower urinary tract symptoms (LUTS).
Objective.
To determine the clinical portrait ...of an "ordinary" patient with benign prostatic hyperplasia and develop an algorithm for improving the efficacy of treating lower urinary tract symptoms in benign prostatic hyperplasia.
Materials & methods
. The study included 112 BPH-patients who received tamsulosin therapy or a combination of tamsulosin + solifenacin for three months. After three months of therapy, the patients were divided into two groups depending on the effectiveness of therapy: group 1 — a positive result (n = 77); group 2 — no positive effect (n = 35). Due to the lack of efficacy in patients of group 2, a multichannel urodynamics was performed, according to the results of which the patients were prescribed treatment with a subsequent assessment of the result after 3 months.
Results
. After 3 months of therapy in patients of group 1, a decrease in pollakiuria was noted. Regression of obstructive and irritative symptoms was also observed, and the urination-associated quality of life (QoL) improved. The maximum urine flow rate (Q max) remained unchanged mainly. By the sixth month, the frequency of urination continued to decrease (11.05 vs 9.32 episodes; p = 0.022), as well as the improvement of other parameters (IPSS, QoL, Q max and post-void residual urine volume (PVR) (80.87 vs 56.17 ml; p = 0.012). The indicators of patients of group 2 following three months of therapy remained without significant changes. Sixteen patients underwent transurethral prostate resection, 19 patients underwent therapy correction, which allowed reducing the number of episodes of daily pollakiuria. The total IPSS score decreased by 4.37 compared to baseline (IPSS (obstructive) — 13.79 vs 7.26 pts; p = 0.032). The QoL value was 2.84 pts, Q max — 14.90 mL/s, PVR — 10.58 mL.
Conclusion
. 19.8% of BPH-patients are resistant to drug therapy. The ineffectiveness of therapy may be due to the severe BOO. In the absence of the effect of the therapy within 3 months, it is recommended to perform multichannel urodynamics. Correction of therapy according to the multichannel urodynamics data improves its effectiveness by the sixth month of treatment. Indicators of IPSS, Q max and PVR after 3 months of therapy allow predicting the effectiveness of therapy, or suspect the need for surgical treatment.
This paper presents the results of comparative experiments on the excitation of inductively coupled plasma in water vapor in cylindrical and toroidal discharge chambers having the same outer ...diameter. The plasma temperature in the cylindrical and toroidal chambers was determined using the Boltzmann plot method. With equal discharge power and pressure, the temperature in the toroidal chamber was found to be higher than that in the cylindrical chamber. This is attributed to the lower heat transfer and the absence of a near-axial layer in the toroidal chamber as compared with cylindrical geometry.
Assessment of cognitive and motor function in older age groups is carried out to identify neurological deficits, clinical and functional prognosis, determination of rehabilitation potential, ...organization of accessible environment, prevention of progression of geriatric syndromes. The development of an applied methodology aimed at assessing both cognitive and motor functions, as well as cognitive-motor interaction in aging in normal and pathological conditions, is at the initial stage of formation. This article presents an overview of the methods used to assess cognitive and motor functions in clinical practice, analyzes the possibilities of their use for older age groups, and considers promising areas.
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