Effect of Recombinant Spidroins Self-Assembly on Rheological Behavior of Their Dispersions and Structure of Electrospun Nanofibrous Materials.

The effect of primary amino acid sequence in recombinant spidroins on their spatial organization is crucial for the fabrication of artificial fibers and fibrous materials. This study focuses on the rheological properties of aqueous and alcoholic solutions of recombinant analogs of natural spidroins (rS1/9 and rS2/12), as well as the structure of their films and nanofibrous materials. Non-Newtonian flow behavior of aqueous solutions of these proteins was observed at certain concentrations in contrast to their solutions in hexafluoroisopropanol.

[Clinical case of angiosarcoma of ethmoidal labyrinth and frontal sinus, issues of morphological verification of diagnosis].

A clinical case of incorrect verification of the angiosarcoma of the ethmoidal labyrinth and frontal sinus in a 36-year-old man is presented. A feature of this case is the disregard of additional research methods without taking into account the unilateralism of the pathological process, which led to the wrong tactics of surgical treatment and the development of a relapse of the disease complicated by nasal liquorrhea. A thorough examination of the patient and an analysis of a series of computer tomograms of the paranasal sinuses suggested a diagnosis of malignancy.

The sialyl-O-acetylesterase NanS of Tannerella forsythia encompasses two catalytic modules with different regiospecificity for O7 and O9 of sialic acid.

The periodontal pathogen Tannerella forsythia utilizes host sialic acids as a nutrient source. To also make O-acetylated sialyl residues susceptible to the action of its sialidase and sialic acid uptake system, Tannerella produces NanS, an O-acetylesterase with two putative catalytic domains. Here, we analyzed NanS by homology modeling, predicted a catalytic serine-histidine-aspartate triad for each catalytic domain and performed individual domain inactivation by single alanine exchanges of the triad nucleophiles S32 and S311.

Analysis of structural organization and interaction mechanisms of detonation nanodiamond particles in hydrosols.

Structural organization of hydrogen and oxygen functionalized nanodiamond (ND) particles in hydrosols was investigated using a cryo-TEM method. The formation of chain-like structures was observed for hydrogen functionalized NDs while oxygen functionalized NDs tend to form more compact structures. In order to understand possible interaction mechanisms between NDs in hydrosols and to explain these experimental results, first-principles calculations were performed.

Magnetic levitational bioassembly of 3D tissue construct in space.

Magnetic levitational bioassembly of three-dimensional (3D) tissue constructs represents a rapidly emerging scaffold- and label-free approach and alternative conceptual advance in tissue engineering. The magnetic bioassembler has been designed, developed, and certified for life space research. To the best of our knowledge, 3D tissue constructs have been biofabricated for the first time in space under microgravity from tissue spheroids consisting of human chondrocytes.

Effect of exfoliating agent on rheological behavior of β-chitin fibrils in aqueous suspensions and on mechanical properties of poly(acrylic acid)/β-chitin composites.

Chitin whiskers are promising reinforcing filler for composites due to their mechanical properties, renewable nature and low cost. A new method for preparation of β-chitin fibrils from squid pens in ascorbic acid aqueous solutions (AscA) was developed. Stirring of the solution with 2 g/l AscA for 2 h disperses the swollen chitin to individualized fibrils with an aspect ratio > 250.

The use of fecal calprotectin in monitoring activity of inflammatory bowel diseases.

Aim: To compare fecal calprotectin (FC) concentration with laboratory and diagnostic methods in patients with inflammatory bowel diseases (IBD).

Materials And Methods: The level of FC was measured in 110 patients with established IBD. Crohn diseases (CD) was diagnosed in 50 patients, ileocolitis - in 38 and terminal ileitis in 12 individuals.

Colloids of detonation nanodiamond particles for advanced applications.

Nanodiamond (ND) is one of the most attractive allotropic modification of carbon due to their unique physical and chemical properties. In the present review the current state of science and technology in the field of NDs is analyzed. ND can be used in various application and in different form e.

Viscoll collagen solution as a novel bioink for direct 3D bioprinting.

Collagen is one of the most promising materials for 3D bioprinting because of its distinguished biocompatibility. Cell-laden constructs made of pure collagen with or without incorporated growth supplements support engineered constructs persistence in culture and are perfectly suitable for grafting. The limiting factor for direct 3D collagen printing was poor printability of collagen solutions, especially admixed with cells or tissue spheroids.

Control on rheological behavior of collagen 1 dispersions for efficient electrospinning.

For efficient manufacturing of fibrous collagen-based materials by electrospinning, the search on optimal rheological parameters is of the great importance. Rheological characteristics and denaturation of collagen in aqueous dispersions were studied as a function of shear rate and acetic acid concentration in the range of 3-9% w/w at temperature from 20 to 40°C. It was shown that an increase in temperature, acetic acid concentration of the collagen dispersion leads to a significant decrease in its viscosity.

Levocarnitine normalizes elevated blood level of soluble Fas mRNA in patients with acute myocardial infarction.

Fas-induced apoptosis plays an important role in the mechanisms of tissue injury in myocardial infarction. The level of membrane Fas mRNA was elevated during the postinfarction period in the blood of patients and did not change in response to levocarnitine. The mRNA level of soluble Fas, inhibiting Fas-dependent apoptosis, remained normal during the first 7 days, but increased 14 days after myocardial infarction, which corresponded to previously detected increase of serum level of soluble Fas molecules.

Investigation on F/M material aspects of IRT-Sofia NCT channel.

The filter/moderator area of IRT-Sofia BNCT channel was investigated in this study in order to find a higher radiation resistant material as a suitable substitution for the Teflon(®). Two options - Al2O3 and graphite - were investigated. The results show, that both graphite and the Al2O3 can be successfully used as a filter/moderator material at IRT-Sofia.

Transfer-matrix approach for finite-difference time-domain simulation of periodic structures.

Optical properties of periodic structures can be calculated using the transfer-matrix approach, which establishes a relation between amplitudes of the wave incident on a structure with transmitted or reflected waves. The transfer matrix can be used to obtain transmittance and reflectance spectra of finite periodic structures as well as eigenmodes of infinite structures. Traditionally, calculation of the transfer matrix is performed in the frequency domain and involves linear algebra.

IRT-Sofia BNCT beam tube optimization study.

An optimization study of IRT-Sofia BNCT beam tube is presented. In the study we used the MIT/FCB experience. The enlarging of filter/moderator cross section dimensions and the decreasing of collimator length within the limits of the IRT-Sofia reactor design were analyzed.

[Prevalence and structure of anemia in patients with chronic heart failure in a therapeutic hospital].

We carried out retrospective analysis of 219 case histories of patients with chronic heart failure admitted to a general medical hospital. Anemia (hemoglobin level below 130 g/l in men and below 120g/l in women) was found in 23.3% of cases.

Preliminary modeling of BNCT beam tube on IRT in Sofia.

The technical design of the research reactor IRT in Sofia is in progress. It includes an arrangement for a BNCT facility for tumor treatment. Modeling of geometry and material composition of filter/collimator for the BNCT beam tube on IRT has been carried out following the beam tube configuration of the Massachusetts Institute of Technology Reactor [Harling et al.

Hybrid transfer-matrix FDTD method for layered periodic structures.

A hybrid transfer-matrix finite-difference time-domain (FDTD) method is proposed for modeling the optical properties of finite-width planar periodic structures. This method can also be applied for calculation of the photonic bands in infinite photonic crystals. We describe the procedure of evaluating the transfer-matrix elements by a special numerical FDTD simulation.

[Plasma levels of cytokines in patients with active infiltrative pulmonary tuberculosis].

The levels of interferon-y (IFN-gamma), tumor necrosis factor-gamma (TNF-alpha), and interleukin-8 (IL-8) and their changes during chemotherapy and laser chemotherapy were studied in 97 patients with active infiltrative pulmonary tuberculosis, by taking into account Mycobacterium tuberculosis (MBT) sensitivity to chemical agents. The studies have indicated that the levels of IFN-gamma, TNF-alpha, and IL-8 are increased and may be markers of an active process. Chemotherapy causes a reduction in increased cytokinemia.

Iterative technique for analysis of periodic structures at oblique incidence in the finite-difference time-domain method.

Normal incidence of a plane electromagnetic wave on a periodical structure can be simulated by the finite-difference time-domain method using a single unit cell with periodical boundary conditions imposed on its borders. For the oblique wave incidence, the boundary conditions would contain time delays and thus are difficult to implement in the time-domain method. We propose a method of oblique incidence simulation, based on an iterative algorithm.

[Immunologic reactions with group-specific antigens of group A Streptococcus in rheumatic fever].

The levels of Group A streptococcal antigens, characterized by group specificity, incorporated in the immune complexes, were measured by enzyme immunoassay, and antibodies to group-specific polysaccharide were titered in patients with rheumatic fever of the minimal activity, running a protracted course. A statistically significant rise of these parameters was revealed in rheumatic patients as against normal subjects or patients with chronic tonsillitis with tonsillogenic cardiopathy. The diagnostic informativeness of these methods was found higher than that of antistreptolysin-O determination.

[Group-specific antigens of streptococci in the make-up of circulating immune complexes in rheumatism and rheumatoid arthritis].

The level of "A" and "B" streptococcal antigens in the circulating immune complexes, structure and the level of antibodies to the group specific streptococcal polysaccharides in the patients with minimal activity and latent course rheumatism and in the patients with rheumatoid arthritis of different duration is studied. It is shown that the concentration of the "A" group streptococcal antigens in the circulating immune complexes is higher in rheumatic patients, than in healthy subjects and tonsillitis patients. The high "B" group streptococcal antigen content is found in the patients with rheumatoid arthritis.