119 research outputs found
Myasthenia Gravis Diagnosis with Surface-enhanced Raman Spectroscopy
Modern medicine aims to diagnose diseases at early stages which constitutes a
relevant task of biomedical research. The present investigation focuses on
myasthenia, a disease that takes the third place in terms of frequency
worldwide, has complex symptoms and is difficult to treat. It is early
diagnostics that allows for providing competent medical assistance and,
sometimes, curing the patient. To detect the cause of the disease, the Raman
spectroscopy was used to study blood serum samples covered with quartz glass
with gold clusters embedded. The Raman cross-section has been amplified with
the gold nanoparticles which made it possible to detect Botulotoxin-A in blood
serum of patients suffering from myastheni
Regularization of inverse signal recovery problems
The main problem studied in the literature review of this paper is the instability of the calculated estimations of input actions regarding the effects of feedback registration errors. Therefore, various techniques have been developed for regularizing the original equations on the basis of converting them into another equation, whose solution is calculated stabl
The Restoration of the Function of the Thumb using Sequential Arthroplasty of the Trapeziometacarpal and Metacarpophalangeal Joints
Background. The opposition function of the thumb is extremely important and is provided mainly due to the biomechanical features of the trapeziometacarpal and metacarpophalangeal joints. Surgical treatment of complex deformities of these joints is often described in isolated studies, and there are practically no descriptions of the results of their combined treatment. The authors of the article did not find a single report on total arthroplasty of the adjacent joints of the thumb.Aim of the study. To analyze the clinical observation of two patients in the early period after performing sequential non-simultaneous total arthroplasty of the trapeziometacarpal and metacarpophalangeal joints of the thumb using ceramic endoprostheses. Both endoprostheses were presented in pairs with two unconnected components, installed using the press-fit method. When the head and cup interact, there are no shear forces in them that impede multiaxial movements.Materials and methods. The study included two patients: a 67-year-old man and a 77-year-old woman. Patients had stage 3 osteoarthritis of the trapeziometacarpal and metacarpophalangeal joints of the thumb and underwent staged surgical treatment (about 2–3 years between the stages). In 1 month and 1 year after the treatment we assessed the results using clinical and instrumental research methods.Conclusion. No complications were observed during the follow-up. There were no indications for revision surgery. The design features of ceramic endoprostheses, due to their short stems, make it possible to combine components in the adjacent joints of the thumb. In our opinion, joint arthroplasty is an effective and promising method of functional restoration. It remains the patient’s last hope for maintaining painless, stable mobility of the thumb
Clinical case of the surgical treatment of complete rupture of distal biceps tendon using two cortical buttons
Distal biceps tendon injuries mainly occur in men from the active groups of population. Among the athletes and military personnel, the incidence rate is 2–10 % of the upper limb tendon injuries. Comparative studies have shown the achievement of better functional results in surgical treatment, while maintaining overall complication rate of 4.6–25 %. The aim. To demonstrate a new reinsertion technique with two cortical buttons in case of complete rupture of distal biceps tendon as part of a clinical case. Materials and methods. The article presents a clinical case of surgical treatment of a patient with complete rupture of dominant limb distal biceps tendon which was more than 2 weeks old and was accompanied by lacertus fibrosus provocation and persistent muscle retraction. Results. We obtained the following clinical results by the week 24 after the surgery: VAS (Visual Analogue Scale) score – 1 cm, ASES (American Shoulder and Elbow Surgeons) score – 99 points, DASH (Disabilities of the Arm, Shoulder and Hand) score – 15 points. Dynamometry results: Dex. 85; sin. 90 (2daN); range of motion corresponds to the same of a healthy joint. MRI at 1.5 T shows no signs of synostosis or heterotopic ossification; MSCT shows no signs of migration of cortical buttons in comparison with intraoperative X-ray control. Discussion. Extracortical methods of distal biceps tendon positioning in anatomical reinsertion have lower strength indicators, comparable with the use of transosseous sutures and anchor fixators. A larger area of contact of the studied zone in case of minimal tendon compression in the area of proximal radioulnar space or inside the formed radial bone canal provides high strength indicators and reduces the risk of repeated injury. Conclusion. The scores of the scales (VAS, DASH, ASES) turned out to be better than when using other common methods. The technique of dipping distal biceps tendon stump into the formed oval canal of the “anatomical impression” using the proposed method meets the objectives of careful attitude to the tendon and provides the largest area of its contact with the bone
Endoprosthesis replacement at the treatment of elbow joint defects
Results of 25 total endoprosthesis operations in patients with defects of the elbow joint of various ethiology are analysed. The endoprostheses produced by Endoservis (Russia] and Coоnrad/Mоrrey Zimmer (USA] were used. The technique of operation and postoperative rehabilitation is described in the article. The estimation of results of treatment was performed by «the Estimation of surgery of an elbow» (American Shoulder and Elbow Surgeons (ASES] Assessments; Richards R.R. et al. 1994]. Radiographically the results of treatment were estimated by the method of X-ray stability of the implants by O.A. Kudinov, V.l. Nujdin. The majority of patients undergoing arthroplasty of the elbow joint for its defects were of young age (40-45 years], and that has left its mark on the technology of operation and maintenance of the patients in different periods after surgery. The analysis of results of treatmentfor 1 year until 1-15 years after the operation was carried out. Good and excellent results, were received in 68 %, satisfactory - in 30 %. The unsatisfactory result of endoprosthesis surgery took place in 8 % of operated (2 patients]. It has been established that the endoprosthesis replacement for elbow joint defects in high-tech surgery is definitely an alternative to traditional methods of treatment, and in most cases should be seen as a method of choice for treatment of this disease
Control landscapes for two-level open quantum systems
A quantum control landscape is defined as the physical objective as a
function of the control variables. In this paper the control landscapes for
two-level open quantum systems, whose evolution is described by general
completely positive trace preserving maps (i.e., Kraus maps), are investigated
in details. The objective function, which is the expectation value of a target
system operator, is defined on the Stiefel manifold representing the space of
Kraus maps. Three practically important properties of the objective function
are found: (a) the absence of local maxima or minima (i.e., false traps); (b)
the existence of multi-dimensional sub-manifolds of optimal solutions
corresponding to the global maximum and minimum; and (c) the connectivity of
each level set. All of the critical values and their associated critical
sub-manifolds are explicitly found for any initial system state. Away from the
absolute extrema there are no local maxima or minima, and only saddles may
exist, whose number and the explicit structure of the corresponding critical
sub-manifolds are determined by the initial system state. There are no saddles
for pure initial states, one saddle for a completely mixed initial state, and
two saddles for other initial states. In general, the landscape analysis of
critical points and optimal manifolds is relevant to the problem of explaining
the relative ease of obtaining good optimal control outcomes in the laboratory,
even in the presence of the environment.Comment: Minor editing and some references adde
Large Nongaussianity from Nonlocal Inflation
We study the possibility of obtaining large nongaussian signatures in the
Cosmic Microwave Background in a general class of single-field nonlocal
hill-top inflation models. We estimate the nonlinearity parameter f_{NL} which
characterizes nongaussianity in such models and show that large nongaussianity
is possible. For the recently proposed p-adic inflation model we find that
f_{NL} ~ 120 when the string coupling is order unity. We show that large
nongaussianity is also possible in a toy model with an action similar to those
which arise in string field theory.Comment: 27 pages, no figures. Added references and some clarifying remark
Dynamics with Infinitely Many Derivatives: The Initial Value Problem
Differential equations of infinite order are an increasingly important class
of equations in theoretical physics. Such equations are ubiquitous in string
field theory and have recently attracted considerable interest also from
cosmologists. Though these equations have been studied in the classical
mathematical literature, it appears that the physics community is largely
unaware of the relevant formalism. Of particular importance is the fate of the
initial value problem. Under what circumstances do infinite order differential
equations possess a well-defined initial value problem and how many initial
data are required? In this paper we study the initial value problem for
infinite order differential equations in the mathematical framework of the
formal operator calculus, with analytic initial data. This formalism allows us
to handle simultaneously a wide array of different nonlocal equations within a
single framework and also admits a transparent physical interpretation. We show
that differential equations of infinite order do not generically admit
infinitely many initial data. Rather, each pole of the propagator contributes
two initial data to the final solution. Though it is possible to find
differential equations of infinite order which admit well-defined initial value
problem with only two initial data, neither the dynamical equations of p-adic
string theory nor string field theory seem to belong to this class. However,
both theories can be rendered ghost-free by suitable definition of the action
of the formal pseudo-differential operator. This prescription restricts the
theory to frequencies within some contour in the complex plane and hence may be
thought of as a sort of ultra-violet cut-off.Comment: 40 pages, no figures. Added comments concerning fractional operators
and the implications of restricting the contour of integration. Typos
correcte
Определение оптимальных условий экстракции фурокумаринов из плодов амми большой
Extracting time and the multiplicity of extraction of furocoumarins from the fruits of Ammi majus were determined on the basis of experimental data, with the use of method of natural scales. The found conditions enable reducing the technological process time and labor, also reducing the consumption of the extraction agent.На основании экспериментальных данных, с использованием метода натуральных масштабов, определены экстрагент, время и кратность экстракции фурокумаринов из плодов амми большой. Подобранные условия позволяют сократить время технологического процесса, снизить расход экстрагента и трудозатраты
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