Evaluation of Mechanical Properties and Filler Interaction in the Field of SLA Polymeric Additive Manufacturing.

The paper deals with research focused on the use of fillers in the field of polymeric materials produced by additive technology SLA (stereolithography). The aim of the research is to evaluate 3D printing parameters, the mechanical properties (tensile strength, hardness), and the interaction of individual phases (polymer matrix and filler) in composite materials using SEM analysis. The tested fillers were cotton flakes and ground carbon fibres in different proportions.

[Development of chronic venous disease].

Introduction: Chronic venous disease is known to gradually worsen in the course of years. However, little clinical data is available. The patient group and methods: We used the set of our patients with completed clinical examination, duplex sonography and photoplethysmography and selected 160 patients examined at our office after 10 and more years.

Research on Low-Cycle Fatigue Engineered Hybrid Sandwich Ski Construction.

This research is aimed at evaluating the effect of low-cycle fatigue on a newly designed hybrid sandwich ski structure to determine the changes that may occur due to cyclic loading and thus affect its use. This is primarily concerned with the fatigue behavior of the tested ski over different time intervals simulating its seasonal use and its effect on the mechanical properties of the ski, i.e.

Chemical and Structural Analysis of Newly Prepared Co-W-Al Alloy by Aluminothermic Reaction.

This article is devoted to the characterization of a new Co-W-Al alloy prepared by an aluminothermic reaction. This alloy is used for the subsequent preparation of a special composite nanopowder and for the surface coating of aluminum, magnesium, or iron alloys. Due to the very high temperature (2000 °C-3000 °C) required for the reaction, thermite was added to the mixture.

Ultrasonic Pulsating Water Jet Peening: Influence of Pressure and Pattern Strategy.

Peening techniques are nowadays attracting more research attention due to their association with the extending of the service life and improving surface texture of engineering components. Ultrasonic pulsating water jet peening represents a new way of mechanical surface treatment. Accelerated water droplets via hammer effect cause small elastic-plastic deformations on the surface.

[Does the time from symptoms onset to treatment impact further development of vein thrombosis in the leg?].

Introduction: It is unknown how many days pass from the symptom onset to anticoagulation therapy of vein thrombosis (VT) in the leg in our country and whether this time has an impact on further development of the disease.

Methods: Among patients treated at our department in recent years for deep vein thrombosis in the leg, we selected 50 patients with the required data available. In each case the diagnosis was confirmed by duplex sonography.

Bacillus subtilis alters the proportion of major membrane phospholipids in response to surfactin exposure.

Surfactin, an anionic lipopeptide produced by Bacillus subtilis, is an antimicrobial that targets the cytoplasmic membrane. Nowadays it appears increasingly apparent that the mechanism of resistance against these types of antibiotics consists of target site modification. This prompted us to investigate whether the surfactin non-producing strain B.

Mimicking of Arginine by Functionalized N(ω)-Carbamoylated Arginine As a New Broadly Applicable Approach to Labeled Bioactive Peptides: High Affinity Angiotensin, Neuropeptide Y, Neuropeptide FF, and Neurotensin Receptor Ligands As Examples.

Derivatization of biologically active peptides by conjugation with fluorophores or radionuclide-bearing moieties is an effective and commonly used approach to prepare molecular tools and diagnostic agents. Whereas lysine, cysteine, and N-terminal amino acids have been mostly used for peptide conjugation, we describe a new, widely applicable approach to peptide conjugation based on the nonclassical bioisosteric replacement of the guanidine group in arginine by a functionalized carbamoylguanidine moiety. Four arginine-containing peptide receptor ligands (angiotensin II, neurotensin(8-13), an analogue of the C-terminal pentapeptide of neuropeptide Y, and a neuropeptide FF analogue) were subject of this proof-of-concept study.

Surfactin production enhances the level of cardiolipin in the cytoplasmic membrane of Bacillus subtilis.

Surfactin is a cyclic lipopeptide antibiotic that disturbs the integrity of the cytoplasmic membrane. In this study, the role of membrane lipids in the adaptation and possible surfactin tolerance of the surfactin producer Bacillus subtilis ATCC 21332 was investigated. During a 1-day cultivation, the phospholipids of the cell membrane were analyzed at the selected time points, which covered both the early and late stationary phases of growth, when surfactin concentration in the medium gradually rose from 2 to 84μmol·l(-1).

Microchip-ESI-MS determination of dissociation constant of the lysozyme-NAG(3) complex.

An on-line microfluidic system for determination of dissociation constants of enzyme/substrate weak interactions by nanoESI-MS is introduced. The microchip was designed to permit the enzyme and the substrate to mix by molecular diffusion in a pressure-driven laminar flow. Introduction of reagent solutions into the chip was an optimized combination of a micropump and an autosampler to enable automation of the measurements.

Long-term adaptation of Bacillus subtilis 168 to extreme pH affects chemical and physical properties of the cellular membrane.

We characterized physical and chemical properties of cell-membrane fragments from Bacillus subtilis 168 (trpC2) grown at pH 5.0, 7.0 and 8.

Diabetes and distal access location are associated with higher wall shear rate in feeding artery of PTFE grafts.

Background: Surgical creation of permanent vascular access for haemodialysis leads to considerable haemodynamic changes. They could be implicated in the pathogenesis of access complications, which limit access survival, especially in diabetics. Physiologically, the relation between arterial diameter and blood velocity is maintained by wall shear stress (WSS), which is directly related to both blood viscosity and wall shear rate (WSR = blood velocity/internal diameter).

Regular ultrasonographic screening significantly prolongs patency of PTFE grafts.

Background: Polytetrafluoroethylene (PTFE) dialysis grafts have considerably shorter patency than native arteriovenous fistulas, despite the use of a complex of screening monitoring methods (venous pressure, access flow). PTFE grafts are used often in subjects with depleted subcutaneous veins after previous abandoned accesses, so keeping the access patent is crucial. We hypothesized that regular duplex Doppler ultrasound screening for access stenoses, together with their sooner treatment, would prolong PTFE graft patency.

Pulse wave analysis during supine rest may identify subjects with recurrent vasovagal syncope.

In the present study, we studied whether analysis of the FAP (finger arterial pressure) waveform during supine rest discriminates subjects with recurrent VVS (vasovagal syncope) from healthy controls. Signal-averaged FAP waveforms (Finapres) were obtained in 32 head-up tilt-test-positive subjects with recurrent VVS (35 +/- 13 years) and in 32 sex- and age-matched healthy controls. The DT (time delay) between the systolic and diastolic peaks of the FAP waveform was measured and large artery SI (stiffness index) was calculated as a ratio of body height and DT.

Different structural requirements for adenylate cyclase toxin interactions with erythrocyte and liposome membranes.

The bifunctional Bordetella adenylate cyclase toxin-hemolysin (ACT) penetrates target cell membranes, forms cation-selective channels and subverts cellular signaling by catalyzing uncontrolled conversion of ATP to cAMP. While primarily targeting phagocytes expressing the alphaMbeta2 integrin (CD11b/CD18), the toxin can also penetrate mammalian erythrocytes lacking the receptor and membrane endocytosis. We sought here to analyze the membrane interactions of ACT in a liposome model.