[A model for assessing and correcting the risk of developing pressure ulcers in the system of long-term care for geriatric patients with limited mobility.]

The article is devoted to the results of the third stage of the scientific and practical project on the introduction of advanced social practices based on innovative gerontotechnologies into the system of long-term care for geriatric patients. It has been established that senile xerosis or skin «frailty¼ occurs in 75% of the population over 65 years old, when increased dryness of the skin leads to peeling, the formation of microcracks, the appearance of senile itching, sleep disturbances, the development of pressure ulcers and, as a result, a decrease in motor activity. During the project, a tactic was developed for the care of «frail¼ skin in patients with senile xerosis and the risk of pressure ulcers. The article presents information about the current problems of diagnosis, correction and prevention of pressure ulcers in patients with limited mobility of elderly and senile age. The results of a comparative analysis of the severity of pressure ulcers and their impact on the quality of life in the system of long-term care for geriatric patients with limited mobility before and after the use of Cicalfate+ Eau Thermale Avène («Pierre Fabre¼, France) emollient were presented. A model was built and practical recommendations were given on the use of the most informative and adequate scales for predicting and assessing the risk of developing pressure ulcers in patients of older age groups.

[Bacteriophages in complex treatment of septic diseases of the hand]. / Ispol'zovanie lekarstvennykh preparatov bakteriofagov v kompleksnom lechenii gnoinykh zabolevanii kisti.

OBJECTIVE: To evaluate the effectiveness of bacteriophages in complex surgical treatment of septic diseases of the hand. MATERIAL AND METHODS: We analyzed treatment outcomes in 111 patients with septic diseases of the hand (septic arthritis, tendovaginitis, phlegmon). Surgical treatment was finished by primary sutures and drainage. They were divided into two groups. Bacteriophages were used in the main group. Other components of treatment were identical. «Pyobacteriophage complex¼ was injected into drainage tubes during dressings. Effectiveness of treatment was evaluated considering elimination of septic process, bacterial flora and healing of surgical wound. In addition, we performed in vitro testing of microorganisms for sensitivity to Pyobacteriophage. RESULTS: Staphylococcus and Streptococcus genus prevailed in hand infections. Pasteurella multocida has been isolated after pet bites. Growth of microflora in drainage tubes was observed in 16.7% and 21.1% of cases, respectively (p=0.02). Wound healing via primary intention was found in 83.6% and 71.4%, respectively (p=0.03). When testing in vitro, we observed lysis of cultures of Staphylococcus aureus in 83.6% of cases, Streptococcus pyogenes - in 33.3% of cases. CONCLUSION: «Pyobacteriophage complex¼ was effective for septic diseases of the hand. However, its partial lytic activity against the most common pathogens makes it advisable to combine phages and antibiotic therapy. Systematic renewal of phages is important due to widespread resistance of bacteria.

[Current problems of polypharmacy in geriatric patients when taking drugs with a risk of photosensitivity.]

The article presents an overview of the current problems of polypharmacy in geriatric patients when taking drugs with a risk of photosensitivity. The article contains information about emerging adverse drug reactions, as well as methods for diagnosing, correcting and preventing phototoxic and photoallergic reactions in patients of older age groups. The main aspects of dermatological support in the system of long-term care for geriatric patients when taking drugs with a risk of photosensitivity are outlined. Clinical signs of senile xerosis and skin manifestations of adverse drug reactions were studied when taking drugs with the risk of photosensitization before and after the use of a photoprotector in elderly patients.

[Acute haematogenous osteomyelitis of the pelvis with multifocal pyogenic abscesses in an adult]. / Ostryi gematogennyi osteomielit taza u vzroslogo s mnozhestvennymi gnoinymi metastazami.

Acute hematogenous osteomyelitis (AHO) in adults is a rare disease complicating timely diagnosis. Even greater difficulties are observed in case of pelvic bone lesion. The authors report AHO of the pelvis an adult. Osteomyelitis was complicated by generalized infection and multiple pyogenic abscesses in subcutaneous adipose tissue of the upper and lower extremities. Detection of primary infectious focus was complicated by extreme severity of the patient's condition and low informative value of X-ray and ultrasound at the early stage of disease. Staphylococcus aureus was obtained from blood culture and infectious foci. Surgical debridement along with complex intensive care ensured a positive outcome.

[Endovascular surgery for critical ischemia of lower extremities with suppurative-necrotic lesion of the feet]. / Rentgenoéndovaskuliarnaia khirurgiia pri kriticheskoi ishemii nizhnikh konechnostei s gnoino-nekroticheskim porazheniem stop.

AIM: To improve treatment of patients with grade IV chronic ischemia of lower extremities via endovascular angioplasty combined with surgical methods for suppurative-necrotic lesions of the feet. MATERIAL AND METHODS: 51 patients with grade IV chronic ischemia of lower extremities underwent endovascular interventions (balloon angioplasty, stenting). A total of 23 stents were deployed in 16 patients including 12 stents in superficial and common femoral arteries, 5 in popliteal artery, 6 in iliac artery. There were no stents in crural arteries. The most perspective artery for wound healing was preferred in case of revascularization below popliteal segment. Necrectomy was performed along with angioplasty in patients with suppurative-necrotic lesion of the feet followed by delayed reconstructive operations if it was necessary. RESULTS: Endovascular surgery for grade IV chronic ischemia of lower extremities was associated with good immediate results in most cases due to revascularization and organ-sparing interventions for suppurative lesions of the feet. Current endovascular methods allow to perform successful re-operations to restore blood flow in previously repaired arteries and implanted stents with restenosis or thrombosis.

NPD1-mediated stereoselective regulation of BIRC3 expression through cREL is decisive for neural cell survival.

Neuroprotectin D1 (NPD1), a docosahexaenoic acid (DHA)-derived mediator, induces cell survival in uncompensated oxidative stress (OS), neurodegenerations or ischemic stroke. The molecular principles underlying this protection remain unresolved. We report here that, in retinal pigment epithelial cells, NPD1 induces nuclear translocation and cREL synthesis that, in turn, mediates BIRC3 transcription. NPD1 activates NF-κB by an alternate route to canonical signaling, so the opposing effects of TNFR1 and NPD1 on BIRC3 expression are not due to interaction/s between NF-κB pathways. RelB expression follows a similar pattern as BIRC3, indicating that NPD1 also is required to activate cREL-mediated RelB expression. These results suggest that cREL, which follows a periodic pattern augmented by the lipid mediator, regulates a cluster of NPD1-dependent genes after cREL nuclear translocation. BIRC3 silencing prevents NPD1 induction of survival against OS. Moreover, brain NPD1 biosynthesis and selective neuronal BIRC3 abundance are increased by DHA after experimental ischemic stroke followed by remarkable neurological recovery. Thus, NPD1 bioactivity governs key counter-regulatory gene transcription decisive for retinal and brain neural cell integrity when confronted with potential disruptions of homeostasis.

Evidence of a mobility edge for photons in two dimensions.

A scaling analysis of conductance for photons in two dimensions is carried out and, contrary to widely held belief, we find strong evidence of a mobility edge. Such behavior is compatible with the existence of an Anderson transition for electronic systems under symplectic symmetry, and indeed we show that the transfer matrix in the photonic system we have modelled has such a symmetry. We verify single parameter scaling of the conductance and demonstrate the transition from the metallic phase to localization. Key parameters, including the critical disorder, the conductance, and the critical exponent of the localization length are calculated, and it is shown that the value of the critical exponent is similar to that for electronic systems with symplectic symmetry.

Gap-edge Asymptotics of defect modes in 2D Photonic Crystals.

We consider defect modes created in complete gaps of 2D photonic crystals by perturbing the dielectric constant in some region. We study their evolution from a band edge with increasing perturbation using an asymptotic method that approximates the Green function by its dominant component which is associated with the bulk mode at the band edge. From this, we derive a simple exponential law which links the frequency difference between the defect mode and the band edge to the relative change in the electric energy. We present numerical results which demonstrate the accuracy of the exponential law, for TE and TM polarizations, hexagonal and square arrays, and in each of the first and second band gaps.

Conductance of photons in disordered photonic crystals.

The conductance of photons in two-dimensional disordered photonic crystals is calculated using an exact multipole-plane wave method that includes all multiple scattering processes. Conductance fluctuations, the universal nature of which has been established for electrons in the diffusive regime, are studied for photons, in both principal polarizations and for varying disorder. Our simulations show that universal conductance fluctuations can be observed in H(||) (TE) polarization for weak and intermediate disorder while, for E(||) (TM) polarization, we show that the conductance variance is essentially independent of sample size but strongly dependent on disorder. The probability distribution of the conductance is also calculated in the diffusive and localized regimes, and also at their transition, for which the distributions for both polarizations are seen to be very similar.

Bloch mode scattering matrix methods for modeling extended photonic crystal structures. I. Theory.

We present a rigorous Bloch mode scattering matrix method for modeling two-dimensional photonic crystal structures and discuss the formal properties of the formulation. Reciprocity and energy conservation considerations lead to modal orthogonality relations and normalization, both of which are required for mode calculations in inhomogeneous media. Relations are derived for studying the propagation of Bloch modes through photonic crystal structures, and for the reflection and transmission of these modes at interfaces with other photonic crystal structures.

Bloch mode scattering matrix methods for modeling extended photonic crystal structures. II. Applications.

The Bloch mode scattering matrix method is applied to several photonic crystal waveguide structures and devices, including waveguide dislocations, a Fabry-Pérot resonator, a folded directional coupler, and a Y-junction design. The method is an efficient tool for calculating the properties of extended photonic crystal (PC) devices, in particular when the device consists of a small number of distinct photonic crystal structures, or for long propagation lengths through uniform PC waveguides. The physical insight provided by the method is used to derive simple, semianalytic models that allow fast and efficient calculations of complex photonic crystal structures. We discuss the situations in which such simplifications can be made and provide examples.

Modes of coupled photonic crystal waveguides.

We consider the modes of coupled photonic crystal waveguides. We find that the fundamental modes of these structures can be either even or odd, in contrast with the behavior in coupled conventional waveguides, in which the fundamental mode is always even. We explain this finding using an asymptotic model that is valid for long wavelengths.

Density of states functions for photonic crystals.

We discuss density of states functions for photonic crystals, in the context of the two-dimensional problem for arrays of cylinders of arbitrary cross section. We introduce the mutual density of states (MDOS), and show that this function can be used to calculate both the local density of states (LDOS), which gives position information for emission of radiation from photonic crystals, and the spectral density of states (SDOS), which gives angular information. We establish the connection between MDOS, LDOS, SDOS and the conventional density of states, which depends only on frequency. We relate all four functions to the band structure and propagating states within the crystal, and give numerical examples of the relation between band structure and density of states functions.

Photonic crystal devices modelled as grating stacks: matrix generalizations of thin film optics.

A rigorous semi-analytic approach to the modelling of coupling, guiding and propagation in complex microstructures embedded in two-dimensional photonic crystals is presented. The method, which is based on Bloch mode expansions and generalized Fresnel coefficients, is shown to be able to treat photonic crystal devices in ways which are analogous to those used in thin film optics with uniform media. Asymptotic methods are developed and exemplified through the study of a serpentine waveguide, a potential slow wave device.

Effects of disorder in two-dimensional photonic crystal waveguides.

The effects of randomness on the guiding properties of waveguides embedded in disordered two-dimensional photonic crystals composed of a finite cluster of circular cylinders of infinite length are investigated for TM-polarized radiation. Different degrees of disorder in the radius, filling fraction, refractive index, and position are considered for both straight and 90 degrees bent guides. The crystals exhibit similar sensitivity to refractive index and radius disorder, with a degree of disorder from 15%-20% yielding little substantial change in the guiding properties. A smaller range of position disorder is also considered. For strong disorder in radius and refractive index, the guide effectively closes. These results were obtained by a Monte Carlo simulation method, and the performance of this method is analyzed. The method requires at least ten realizations in some cases for convergence to commence; substantially more realizations are required for moderate and strong disorder to achieve accurate results.

Three-dimensional local density of states in a finite two-dimensional photonic crystal composed of cylinders.

The three-dimensional local density of states (LDOS), which determines the radiation dynamics of a point source, is presented here for a finite two-dimensional photonic crystal as a function of space and frequency. The LDOS is obtained from the dyadic Green's function, which is calculated exactly using the multipole method. Maximum suppression in the LDOS occurs at the high frequency edge of the complete two-dimensional band gap and varies smoothly about this frequency. Macroporous silicon is shown to suppress the LDOS by one order of magnitude at the center of its air pores.

Semianalytic treatment for propagation in finite photonic crystal waveguides.

We present a semianalytic theory for the properties of two-dimensional photonic crystal waveguides of finite length. For single-mode guides, the transmission spectrum and field intensity can be accurately described by a simple two-parameter model. Analogies are drawn with Fabry-Perot interferometers, and generalized Fresnel coefficients for the interfaces are calculated.

Diffusion and anomalous diffusion of light in two-dimensional photonic crystals.

The transport properties of electromagnetic waves in disordered, finite, two-dimensional photonic crystals composed of circular cylinders are considered. Transport parameters such as the transport and scattering mean free paths and the transport velocity are calculated, for the case where the electromagnetic radiation has its electric field along the cylinder axes. The range of the parameters in which the diffusion process can take place is specified. It is shown that the transport velocity upsilon(E) can be as much as 10(8) times less than its free space value, while just outside the cluster upsilon(E) can be 0.3c. The effects of weak and strong disorders on the transport velocity are investigated. Different regimes of the wave transport-ordered propagation, diffusion, and anomalous diffusion-are demonstrated, and it is inferred that Anderson localization is incipient in the latter regime. Exact numerical calculations from the Helmholtz equation are shown to be in good agreement with the diffusion approximation.

Photonic band structure calculations using scattering matrices.

We consider band structure calculations of two-dimensional photonic crystals treated as stacks of one-dimensional gratings. The gratings are characterized by their plane wave scattering matrices, the calculation of which is well established. These matrices are then used in combination with Bloch's theorem to determine the band structure of a photonic crystal from the solution of an eigenvalue problem. Computationally beneficial simplifications of the eigenproblem for symmetric lattices are derived, the structure of eigenvalue spectrum is classified, and, at long wavelengths, simple expressions for the positions of the band gaps are deduced. Closed form expressions for the reflection and transmission scattering matrices of finite stacks of gratings are established. A new, fundamental quantity, the reflection scattering matrix, in the limit in which the stack fills a half space, is derived and is used to deduce the effective dielectric constant of the crystal in the long wavelength limit.

Two-dimensional Green's function and local density of states in photonic crystals consisting of a finite number of cylinders of infinite length.

Using the exact theory of multipole expansions, we construct the two-dimensional Green's function for photonic crystals, consisting of a finite number of circular cylinders of infinite length. From this Green's function, we compute the local density of states (LDOS), showing how the photonic crystal affects the radiation properties of an infinite fluorescent line source embedded in it. For frequencies within the photonic band gap of the infinite crystal, the LDOS decreases exponentially inside the crystal; within the bands, we find "hot" and "cold" spots. Our method can be extended to three dimensions as well as to treating disorder and represents an important and efficient tool for the design of photonic crystal devices.