ABSTRACT
BACKGROUND: Despite the availability of a wide range of therapies for the systemic treatment of moderate to severe psoriasis, many psoriasis patients do not receive adequate treatment, suggesting that guidelines may not be correctly applied by physicians. OBJECTIVES: The aim of this study was to analyze data on physicians' implementation of, and reasons for noncompliance with, guidelines for the systemic treatment of moderate to severe psoriasis. METHODS: We conducted a systematic literature review according to the Preferred Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched the PubMed and Embase databases for studies on guideline adherence in the systemic treatment of moderate to severe psoriasis. All eligible articles were retrieved in full text and the relevant references of retrieved articles were included. RESULTS: A total of 20 studies were selected. Four studies investigated knowledge of the guidelines, six studies examined their application, and five studies focused on the various barriers to implementation. Finally, five studies discussed ways to improve implementation. Several studies on the quality of psoriasis care have revealed discrepancies between the reality and the optimal care described in national and international guidelines. CONCLUSION: Various barriers to implementation of recommendations exist, such as economic barriers, lack of dermatologic orientation towards, lack of knowledge of recommendations by other specialists, lack of applicability, and country- and practice-specific features (e.g., different benefit/risk ratios, different reimbursement rates and conditions). This review can help the everyday practitioner to better understand these barriers, which will have a direct impact on improving the quality of life of psoriasis patients.
Subject(s)
Guideline Adherence , Practice Guidelines as Topic , Psoriasis , Psoriasis/therapy , Psoriasis/drug therapy , Humans , Severity of Illness IndexABSTRACT
The rotation of a spherical magnetically soft ferromagnetic particle with uniaxial magnetic anisotropy and located in an elastomer through a certain angle under the action of a magnetic field has been studied theoretically. It was found that if the particle loses its mechanical stability, its rotation angle becomes critically dependent on the magnetic field magnitude. The magnetically induced critical rotation of the particle in the elastomer has a magneto-elastic origin and is accompanied by a critical change in the magnetization of the particle multidomain state, as occurs in the case of second-order magnetic phase transitions. The transition of a particle in a soft-elastic elastomer from the multidomain state into a uniformly magnetized one was shown to be independent of the magnitude of the particle magnetic anisotropy field. The particle rotation was found to result in the appearance of a maximum in the field dependence of the magnetic susceptibility.
ABSTRACT
Different processes governing magnetic properties of an ensemble of magnetic nanoparticles in the temperature region close to a transition from superparamagnetic to paramagnetic state are analyzed and the ways to separate them are suggested. Enhanced role of paraprocess in magnetization behavior near Curie temperature is stressed. A procedure to isolate paraprocess contribution and adequately determine spontaneous magnetization of the ensemble of superparamagnetic nanoparticles is proposed. Critical behavior of the spontaneous magnetization is experimentally determined for the ensemble of nanoparticles of lanthanum-strontium manganites, which are considered as promising materials for self-controlled magnetic nanohyperthermia. Effect of dispersion of magnetic parameters on effective magnetic characteristics of nanoparticles and their critical behavior is discussed. Theoretical background for the use of the 'effective Curie temperature for the ensemble of nanoparticles' concept is proposed for ensembles of particles with dispersion of their Curie temperature. Based on the results obtained, various strategies to develop novel biomedical applications, in particular those suitable for noninvasive temperature monitoring, are discussed.
ABSTRACT
Magnetic nanoparticles constitute promising tools for addressing medical and health-related issues based on the possibility to obtain various kinds of responses triggered by safe remote stimuli. However, such richness can be detrimental if different performances are not adequately differentiated and controlled. The aim of this work is to understand and systemize different kinds of magnetic-field-induced response for an ensemble of lanthanum-strontium manganite nanoparticles, which are considered as promising materials for self-controlled magnetic hyperthermia. A complex set of static and dynamic magnetic measurements accompanied by a numerical simulation of DC and AC magnetic behavior has been carried out. It is shown that to achieve adequate results, the dispersion of particle sizes and/or magnetic parameters should necessarily be taken into account. A quantitative description of the magnetic behavior of the ensemble should comprise two groups of nanoparticles differentiated according to the regime of their magnetization reversal: one group, which demonstrates non-hysteretic behavior similar to a superparamagnet and another one, which shows magnetic hysteresis characteristic of blocked particles. The fraction of nanoparticles in each group depends not only on the nanoparticles' parameters (in particular, their size), but also on the parameters of the external AC magnetic field (amplitude and frequency) used for remagnetization. The main outcome of this work is the development of a procedure which allows one to separately analyze contributions from different groups of nanoparticles and find the regularities of the redistribution of nanoparticles between these groups on changing the parameters of the external AC magnetic field. The results show the directions to enhance the heating efficiency of ensembles of magnetic nanoparticles and pave the way for further optimization of their characteristics and the parameters of the external field.
ABSTRACT
Here we report a study of chain formation and the magnetic anisotropy induced by them in suspensions of slightly anisotropic Fe3O4 nanoparticles in water and in aqueous V2O5 suspensions. An investigation into the magnetization of the fluid and frozen suspensions, the application of dynamic light scattering techniques and the observation of the magnetic anisotropy in the frozen magnetically aligned samples allowed us to confirm the existence of chains of Fe3O4 in both suspensions. Our study shows that the magneto-induced anisotropy appearing in magnetic fields in colloids with Fe3O4 particles is mainly due to many particle (chain) magneto-induced anisotropy, but not due to single particle magneto-induced anisotropy connected with particle shape anisotropy. In other words, the single particle magneto-induced anisotropy is much smaller than the many particle (chain) anisotropy. The anisometry of the chains provides effective coupling with the nonmagnetic V2O5 component of the suspension and results in its strong sensitivity to the magnetic field.
ABSTRACT
In the present study, the Pulsed Laser Deposition (PLD) technique was applied to coat titanium for orthopaedic and dental implant applications. Calcium carbonate (CC) was used as starting coating material. The deposited CC films were transformed into octacalcium phosphate (OCP) by chemical treatments. The results of X-ray diffraction (XRD), Raman, Fourier Transform Infrared Spectroscopy (FTIR) and scanning electron microscopy (SEM) studies revealed that the final OCP thin films are formed on the titanium surface. Human myofibroblasts from peripheral vessels and the primary bone marrow mesenchymal stromal cells (BMMSs) were cultured on the investigated materials. It was shown that all the investigated samples had no short-term toxic effects on cells. The rate of division of myofibroblast cells growing on the surface and saturated BMMSs concentration for the OCP coating were about two times faster than of cells growing on the CC films.
ABSTRACT
A plasma spraying process for the deposition of three-dimensional capillary-porous titanium coatings using a wire has been developed. In this process, two additional dc arcs are discharged between plasmatron and both the wire and the substrate, resulting in additional activation of the substrate and the particles, particularly by increasing their temperature. The shear strength of the titanium coating with 46% porosity is 120.6 MPa. A new procedure for estimating the shear strength of porous coatings has been developed.
Subject(s)
Coated Materials, Biocompatible/chemistry , Prostheses and Implants , Titanium/chemistry , Materials Testing , Porosity , Shear StrengthABSTRACT
The ability to controllably tune the heating efficiency of magnetic nanoparticles in an AC magnetic field is highly desirable for their application as mediators of magnetic hyperthermia. Traditional approaches to understand and govern the behavior of hyperthermia mediators include a combination of quasistatic and high-frequency (â¼100 kHz) magnetic measurements with subsequent simulation of underlying processes. In this paper, we draw attention to the frequently overlooked fact that for an ensemble of magnetic nanoparticles, there is no straightforward complementarity between the dynamic characteristics obtained under different experimental conditions, as well as between corresponding underlying processes. This paper analyzes mechanisms of AC losses in a fluid based on magnetic nanoparticles, with special emphasis on the domains of their validity, and shows that the mechanisms may become qualitatively different as experimental conditions change from magnetostatic to high-frequency ones. Further, the work highlights new important features which can result from the employment of the refined approaches to interpret experimental results obtained on magnetic fluids based on La1-xSrxMnO3 (x = 0.22) nanoparticles. The gained knowledge provides necessary guidelines for tailoring the properties of magnetic nanoparticles to the needs of self-controlled magnetic hyperthermia.
Subject(s)
Manganese Compounds/chemistry , Magnetic Fields , Models, Theoretical , Nanoparticles/chemistry , Nanoparticles/ultrastructure , X-Ray DiffractionABSTRACT
Polycrystalline (Co2Fe)(x)Ge(1-x) Heusler alloy films are fabricated by sputtering on amorphous substrates and shown to possess three types of magnetic anisotropy. The nearly stoichiometric composition of x = 50 m.f.% shows a rectangular hysteresis loop and isotropic coercive and ferromagnetic resonance fields when the film is field-magnetized along any in-plane direction, thus predominantly possessing rotatable in-plane magnetic anisotropy. Higher-x compositions show evidence of two- and fourfold in-plane anisotropy superposed on the rotatable one. A qualitative model of the observed anisotropic magnetic properties is proposed. The model explains the rotatable anisotropy by taking into account dry friction for the in-plane rotation of the magnetization direction in a fine-grained polycrystalline film with the magnetic grain size smaller than the correlation length of the inter-grain exchange interaction. The observed two- and fourfold magnetic anisotropy contributions are attributed to partial texturing of the fine-grained films, even though the films are grown on amorphous SiO2 substrates. These results should be valuable for understanding and controlling the magnetic behaviour of highly spin-polarized Heusler alloy films used in various magnetic nanodevices.
Subject(s)
Alloys/chemistry , Magnetic Fields , Membranes, Artificial , Metals/chemistry , Models, Chemical , Models, Molecular , Anisotropy , Computer SimulationABSTRACT
The mechanisms and properties of the equilibrium magnetization process for nanogranular films with perpendicular anisotropy placed in a tilted magnetic field are considered. The contributions of the effects of canting and flipping of the granules' magnetic moments to the process of film magnetization are studied. A critical behavior of the film magnetization at the transition, induced by a tilted magnetic field, from a state with non-uniform orientation of the granules' magnetic moments to one with a similar orientation is revealed. The results obtained within the two-level model of the orientation of the particles' magnetic moments are in good agreement with the experimental data for Co-Al(2)O(3) (61 at.% Co) granular film. The perpendicular anisotropy of the granules in this film originates mainly from their elongated shape. It is shown that in the non-uniform state the magnetostatic energy of a granular film with similarly oriented elongated granules can be described by the sum of contributions of two types: quasi-single-granular and quasi-film. The effective constant of the single-particle anisotropy of the granules in this case turns out to be dependent on the factor of volume filling of the film by granules, but not on its magnetization.
Subject(s)
Aluminum Oxide/chemistry , Cobalt/chemistry , Magnetic Phenomena , Metal Nanoparticles/chemistry , Nanostructures/chemistry , Anisotropy , Models, ChemicalABSTRACT
The present investigation was aimed at developing a protocol for long-term preservation of germplasm of Pinus kesiya Royle ex. Gord. through vitrification. Some of the critical components affecting explant tolerance to cryopreservation, such as effects of preculture, vitrification solutions, exposure time to vitrification solutions, volume of vitrification solution and its toxicity, washing of vitrified tissues after thawing, were analysed. The results showed that shoot regrowth of P. kesiya shoot-tips was considerably affected when exposed to cryoprotectants for longer periods of time (longer than 10 min). Among different vitrification solutions studied, maximum survival (76 percent) of shoot-tips was achieved with mVSL (using 0.6 ml of the solution) in MS basal medium containing 4.0 mg l-1 N6-benzyladenine (BA).
Subject(s)
Cryopreservation/methods , Cryoprotective Agents , Germ Cells, Plant/cytology , Pinus/cytology , Vitrification , Benzyl Compounds , Cold Temperature , Culture Media , Dimethyl Sulfoxide , Ethylene Glycol , Germ Cells, Plant/physiology , Glycerol , Kinetin , Osmolar Concentration , Pinus/physiology , Plant Shoots/growth & development , Plant Somatic Embryogenesis Techniques , Purines , Regeneration , SucroseABSTRACT
Antibodies to Bacillus anthracis protective antigen (PA) and to the lethal factor (LF) of B. anthracis exotoxin in the blood sera of anthrax patients and of subjects with a history of the disease, as well as of persons immunized with STI live vaccine, were studied by the heterogeneous enzyme immunoassay. In 1-6 years after convalescence the levels of anti-PA and anti-LF antibodies (at 75% and 96% detection rates respectively) were higher than on weeks 1-4 from the onset of the disease. In persons having had anthrax antibodies belonged mainly to IgG, and the anti-LF antibody level was higher than the anti-PA antibody level. In persons immunized with STI vaccine the detection rate of antibodies somewhat increased in 2-7 months after immunization, reaching, on the average, 72%, the antibody levels after primary immunization and regular annual booster immunization being similar. In 1-2 years after primary (booster) immunization the isolation rate of antibodies decreases to 21%. Specific features of postinfectious and postvaccinal immunity to anthrax and problems of retrospective diagnosis of this disease are discussed.