3,624 research outputs found
Study of the features of masticatory efficiency in patients with acute cerebrovascular disorder by hemitype
The attention of dental researchers is constantly focused on assessing the quality of treatment for various pathologies of the dentоalveolar system, determining disorders of occlusal correlations, treatment, and prevention of diseases of the temporomandibular joint and periodontal tissue pathology. Numerous studies on the above aspects contain information on the characteristics of masticatory efficiency as one of the most vivid markers of orthopedic treatment, as it allows dentists to determine the quality of actual masticatory performance.The issues of functional diagnostics at the stages of rehabilitation of patients with partial defects of the dentition remain relevant, and therefore, the indicators of masticatory efficiency in prosthetics with removable dentures will be one of the most important criteria for adaptation to them. The situation exacerbates when such patients suffer from somatic pathologies of a neurological nature, in particular, acute cerebrovascular disorder.The aim of the research was to study the features of masticatory function in patients with a complicated course of acute cerebrovascular disorder with the neurological deficit by hemitypeThe study involved 25 people with a complicated course of acute cerebrovascular disorder with the neurological deficit by hemitype and 20 people from the control group, aged from 40 to 65 years, for whom partial removable laminar dentures with acrylic base and retaining bent metal clasps were manufactured according to clinical indications. All patients gave their free and informed consent to participate in the study.The masticatory efficiency was determined using the author's method based on the principle of graphical analysis of fragments of the agar-agar masticatory sample with subsequent programmed calculation and computer processing of numerical data.The evaluation indicators were as follows: the total number of fragments of the chewing sample and the number of fragments with a fraction of 500-1000 pixel2.Statistical analysis of the results was conducted using the Statistica 10.0 software package for Windows, and it embraced the following:1. Assessing the distribution of values and their correspondence to the normal one in the population.2. Comparison of the results obtained before applying a removable dental prosthesis and 30 days after its application.3. Intergroup comparison of the results.Thus, we observed an increase in the chewing sample parameters in the period from the beginning of orthopedic treatment until the 30th day of observation after applying a partial removable laminar denture. Despite the general trend, in the group of patients with ACVD, the masticatory efficiency was lower than that of the control group, which is confirmed by the difference between the total number of fragments (<17.22) and the number of fragments with a caliber of 500 to 1000 pixel2 (<4.41). In our opinion, this is due to the peculiarities of adaptation processes in patients with ACVD, who present with a much longer period than patients without a somatic pathology.The study revealed that the masticatory efficiency, restored by prosthetics with removable laminar dentures in the group of patients with a complicated course of ACVD by hemitype, one month after treatment is at the level of 88.68 (total number of fragments of the chewing sample) and 17.04 (number of fragments with a caliber of 500-1000 pixel2), which is a relatively worse indicator as compared to the control group. Thus, the total period of orthopedic rehabilitation for patients with ACVD is longer
Electron-based crystalline undulator
We discuss the features of a crystalline undulator of the novel type based on
the effect of a planar channeling of ultra-relativistic electrons in a
periodically bent crystals. It is demonstrated that an electron-based undulator
is feasible in the tens of GeV range of the beam energies, which is noticeably
higher than the energy interval allowed in a positron-based undulator.
Numerical analysis of the main parameters of the undulator as well as the
characteristics of the emitted undulator radiation is carried out for 20 and 50
GeV electrons channeling in diamond and silicon crystals along the (111)
crystallographic planes.Comment: 16 pages, 8 figures, Latex, IOP styl
Three-photon detachment of electrons from the fluorine negative ion
Absolute three-photon detachment cross sections are calculated for the
fluorine negative ion within the lowest-order perturbation theory. The Dyson
equation of the atomic many-body theory is used to obtain the ground-state 2p
wavefunction with correct asymptotic behaviour, corresponding to the true
(experimental) binding energy. We show that in accordance with the adiabatic
theory (Gribakin and Kuchiev 1997 {Phys. Rev. A} {\bf 55} 3760) this is crucial
for obtaining absolute values of the multiphoton cross sections. Comparisons
with other calculations and experimental data are presented.Comment: 10 pages, two figures, Latex, IOP styl
Coherent radiation of an ultra-relativistic charged particle channeled in a periodically bent crystal
We suggest a new type of the undulator radiation which is generated by an
ultra-relativistic particle channeled along a periodically bent
crystallographic plane or axis. The electromagnetic radiation arises mainly due
to the bending of the particle's trajectory, which follows the shape of the
channel. The parameters of this undulator, which totally define the spectrum
and the angular distribution of the radiation (both spontaneous and
stimulated), depend on the type of the crystal and the crystallographic plane
(axis), on the type of a projectile and its energy, and on the shape of the
bent channel, and, thus, can be varied significantly by varying these
characteristics.
As an example, we consider the acoustically induced radiation (AIR) which is
generated by ultra-relativistic particles channeled in a crystal which is bent
by a transverse acoustic wave. The AIR mechanism allows to make the undulator
with the main parameters varying in wide ranges, which are inaccessible in the
undulators based on the motion of particles in the periodic magnetic fields and
also in the field of the laser radiation. The intensity of AIR can be easily
made larger than the intensity of the radiation in a linear crystal and can be
varied in a wide range by varying the frequency and the amplitude of the
acoustic wave in the crystal. A possibility to generate stimulated emission of
high-energy photons (in keV - MeV region) is also discussed.Comment: published in J. Phys. G: Nucl. Part. Phys. 24 (1998) L45-L53,
http://www.iop.or
Determination of fractal dimension of the functional masticatory test patterns
Valid diagnostic assessment of the state of dentoalveolar system and its masticatory function, in particular, is considered to be an important scientific task of modern prosthodontics. Plenty of the developed ways are based on the use of up-to-date information technology, especially on computer analysis of graphic data. The development of the enhanced methods for the evaluation of masticatory efficiency in patients with both full and partial adentia urged the search of its clear and informative indicators. According to the authors, digital image fractal dimension index can meet these needs. Since most of the available masticatory function assessment methods involve the obtaining large ammount of fragments different in their quantity, size and shape. The photography of the multiplicity of these 'spasmodically' located objects allows the processing of the received image with the help of graphic editor and converting it into numeric data. Thus, the aim of the research was to study the fractal dimension of the masticatory test images, taking into account the peculiarities of the patients'denture defects. Computer software for digital image processing ImageJ 1.50b was used in the research, since it provides the option of computer calculation of the fractal dimension index. The comparison of the masticatory tests of 30 persons with intact teeth (control group) and 33 persons with denture defects has revealed statistically significant deviation in their fractal dimension index. The reduction of the range of conventional statistical norm (1.49-1.66) to the values fluctuating from 1.47 to 1.51. was observed. Therefore, the decrease of the mean value of the fractal dimension from 1.56 (St.Err.- 0.02) to 1.50 indicates the reduction of chopping function in the given masticatory test patterns. As a result, the suggested method will allow the use of fractal dimension index as an integral indicator of masticatory efficiency level
Relativistic corrections to isotope shift in light ions
We calculate isotope mass shift for several light ions using Dirac wave
functions and mass shift operator with relativistic corrections of the order of
. Calculated relativistic corrections to the specific mass shift
vary from a fraction of a percent for Carbon, to 2% for Magnesium. Relativistic
corrections to the normal mass shift are typically smaller. Interestingly, the
final relativistic mass shifts for the levels of one multiplet appear to be
even closer than for non-relativistic operator. That can be important for the
astrophysical search for possible -variation, where isotope shift is a
source of important systematic error. Our calculations show that for levels of
the same multiplet this systematics is negligible and they can be used as
probes for -variation.Comment: 7 pages, 5 tables, revtex
The myogymnastics complex as an element of rehabilitation in the process of adaptation to orthopedic appliances in patients after stroke
Introduction. Stroke has become the second leading cause of long-term disability and cognitive impairment. The disease can cause debilitating neurological disorders that lead to motor, sensory and cognitive deficits and impaired psychosocial functioning. Many researchers have established an association between dental status, infections, and systemic diseases such as acute cerebrovascular disorder.The aim of the research was to determine the impact of dental health on the quality of life in patients with cerebral circulatory disorders complicated with neurological deficits by hemitype before and 30 days after orthopedic treatment by questionnaire survey.Materials and methods. The study involved 25 people with the course of ACVD complicated with neurological deficiency by hemitype, aged from 40 to 65 years, who underwent prosthetics with partial removable laminar dentures with acrylic base and retaining bent, metal clasps according to clinical indications. The first group, where the process of adaptation to the orthopedic appliance was normal, consisted of 13 people, including 7 women and 6 men. In the second group, the adaptation process took place using the proposed rehabilitation complex, and it comprised 12 patients, including 7 women and 5 men.The changes that occurred 30 days after applying a partial removable laminar denture were as follows:The value of the indicator of restricted masticatory function in subjects of the first study group was worse by 1.375 points as compared to the second group. The value of the indicator of physical pain in the process of adaptation to the orthopedic appliance was noteworthy, since it decreased significantly in the second group and amounted to 14.404 points, which was by 1.335 points higher than in patients of the first group.The level of psychological discomfort in patients of the first group was 32.412 points, which was 1.183 points different from that of patients in the second group, in favor of the latter. At the same time, a comparison of the level of psychological inferiority showed that this indicator was higher in the first group than in the second study group by 0.988 points, i.e., the dynamics of changes in this indicator was better in the second one.Comparison of the level of social inferiority showed that in the first study group it was higher by 2.106 points than in the third group. Comparison of the level of disability showed a difference of this indicator by 1.226 points in favor of patients of the second groupThe above data suggest a general trend of improving the basic health indicators of patients in the process of orthopedic rehabilitation. At the same time, there was a clear difference between the results of the questionnaire survey between patients of the first and second groups, and these indicators were better in the latter.Conclusions. The effectiveness of the proposed rehabilitation complex for patients with cerebral circulatory disorders complicated with neurological deficiency by hemitype after prosthetics with partial removable laminar appliances was confirmed by a decrease in numerical data from the questionnaire survey by 15%, indicating an improvement in quality of life in this category of patients
Vacancy decay in endohedral atoms: the role of non-central position of the atom
We demonstrate that the Auger decay rate in an endohedral atom is very
sensitive to the atom's location in the fullerene cage. Two additional decay
channels appear in an endohedral system: (a) the channel due to the change in
the electric field at the atom caused by dynamic polarization of the fullerene
electron shell by the Coulomb field of the vacancy, (b) the channel within
which the released energy is transferred to the fullerene electron via the
Coulomb interaction. % The relative magnitudes of the correction terms are
dependent not only on the position of the doped atom but also on the transition
energy \om. Additional enhancement of the decay rate appears for transitions
whose energies are in the vicinity of the fullerene surface plasmons energies
of high multipolarity. % It is demonstrated that in many cases the additional
channels can dominate over the direct Auger decay resulting in pronounced
broadening of the atomic emission lines. % The case study, carried out for
Sc@C, shows that narrow autoionizing resonances in an
isolated Sc within the range \om = 30... 45 eV are dramatically
broadened if the ion is located strongly off-the-center. % Using the developed
model we carry out quantitative analysis of the photoionization spectrum for
the endohedral complex ScN@C and demonstrate that the additional
channels are partly responsible for the strong modification of the
photoionization spectrum profile detected experimentally by
M\"{u}ller et al. (J. Phys.: Conf. Ser. 88, 012038 (2008)).Comment: 32 pages, 11 figure
Depletion of abiotic resources in the steel production in Poland
Steelmaking processes consume a lot of energy and materials, therefore researchers are constantly looking for new ways of reducing the consumption of resources in the production processes. The main purpose of the article is to present abiotic resource depletion the in steel production in the case of integrated steelmaking route in Poland and its role in life cycle assessment. There are different methods of life cycle assessment for abiotic resources, the use of which affects the quality of the obtained information. The article presents some results of life cycle assessment of abiotic depletion
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