Search

Bioactive calcium phosphate ceramics (CaPs) are one of the building components of the inorganic part of bones. Synthetic CaPs are frequently used as materials for filling bone defects in the form of pastes or composites; however, their porous structure allows modification with active substances and, thus, subsequent use as a drug carrier for the controlled release of active substances. In this study, four different ceramic powders were compared: commercial hydroxyapatite (HA), TCP, brushite, as well as HA obtained by wet precipitation methods. The ceramic powders were subjected to physicochemical analysis, including FTIR, XRD, and determination of Ca/P molar ratio or porosity. These techniques confirmed that the materials were phase-pure, and the molar ratios of calcium and phosphorus elements were in accordance with the literature. This confirmed the validity of the selected synthesis methods. CaPs were then modified with the antibiotic clindamycin. Drug release was determined on HPLC, and antimicrobial properties were tested against Staphylococcus aureus. The specific surface area of the ceramic has been demonstrated to be a factor in drug release efficiency.

Synthetic implants are used to treat large bone defects that are often unable to regenerate, for example those caused by osteoporosis. It is necessary that the materials used to manufacture them are biocompatible and resorbable. Polymer-ceramic composites, such as those based on poly(L-lactide) (PLLA) and calcium phosphate ceramics (Ca-P), are often used for these purposes. In this study, we attempted to investigate an innovative strategy for two-step (dual) modification of composites and their components to improve the compatibility of composite components and the adhesion between PLA and Ca-P whiskers, and to increase the mechanical strength of the composite, as well as improve osteological bioactivity and prevent bone resorption in composites intended for bone regeneration. In the first step, Ca-P whiskers were modified with a saturated fatty acid namely, lauric acid (LA), or a silane coupling agent γ-aminopropyltriethoxysilane (APTES). Then, the composite, characterized by the best mechanical properties, was modified in the second stage of the work with an active chemical compound used in medicine as a first-line drug in osteoporosis—sodium alendronate, belonging to the group of bisphosphonates (BP). As a result of the research covered in this work, the composite modified with APTES and alendronate was found to be a promising candidate for future biomedical engineering applications.

NA61/SHINE is a multi-purpose fixed-target experiment located at the Super Proton Synchrotron at CERN. The main goals of the experiment include studies for physics of strong interactions, neutrino physics, and cosmic-rays physics. After the upgrade of the detector system, the experiment will collect data up to 1 kHz event rate. The development of new detectors, used to measure the positions of incoming beam particles in the transverse plane, is a crucial part of the upgrade. Two new kinds of beam position detectors are prepared and tested. One of them is the scintillating fiber detector with a multi-anode photomultiplier readout. It is built of two perpendicularly arranged ribbons, each consisting of two shifted layers of green-emitting scintillating fibers with a diameter of 250 μm. The second type of detector is based on single-sided silicon strip detector (Hamamatsu S13804). The paper gives an overview of both detectors’ design and readout concepts.

The “Multifunctional biologically active composites for applications in bone regenerative medicine” project is carried out within the TEAM-NET program of the Foundation for Polish Science financed by the European Union under the European Regional Development Fund. The authors gratefully acknowledge the financial support. T.E.L.D. thanks N8 Agrifood for its financial support in the framework of the pump priming grant “Food2Bone”. Hydroxyapatite (HAp) is a bioactive ceramic with great potential for the regeneration of the skeletal system. However, its mechanical properties, especially its brittleness, limit its application. Therefore, in order to increase its ability to transmit stresses, it can be combined with a polymer phase, which increases its strength without eliminating the important aspect of bioactivity. The presented work focuses on obtaining organic–inorganic hydrogel materials based on whey protein isolate (WPI) reinforced with nano-HAp powder. The proportion of the ceramic phase was in the range of 0–15%. Firstly, a physicochemical analysis of the materials was performed using XRD, FT-IR and SEM. The hydrogel composites were subjected to swelling capacity measurements, potentiometric and conductivity analysis, and in vitro tests in four liquids: distilled water, Ringer’s fluid, artificial saliva, and simulated body fluid (SBF). The incubation results demonstrated the successful formation of new layers of apatite as a result of the interaction with the fluids. Additionally, the influence of the materials on the metabolic activity according to ISO 10993-5:2009 was evaluated by identifying direct contact cytotoxicity towards L-929 mouse fibroblasts, which served as a reference. Moreover, the stimulation of monocytes by hydrogels via the induction of nuclear factor (NF)-κB was investigated. The WPI/HAp composite hydrogels presented in this study therefore show great potential for use as novel bone substitutes.

The description of clinical manifestation of hearing problems in cleidocranial dysplasia (CCD) remains limited and incomplete, since CCD constitutes a rare congenital disorder. The study aims to provide a complex panel analysis of the auditory system in patients suffering from the disease.The study group consisted of 4 children with CCD (aged: 12-15), who underwent orthodontic treatment. A full panel analysis of their auditory systems was performed, including high-frequency audiometry and a new method of middle ear assessment - WBT (Wideband Tympanometry).A slight conductive hearing loss was diagnosed in 3 out of 4 patients. While high frequency audiometry has shown a deterioration of hearing in 3 patients, in one case, the obtained thresholds were within the normal range. A decrease of absorbance in low frequencies has been observed in one or both ears. Only one patient has had a shift of maximum absorbance towards high frequencies in the left ear.The presented manuscript is the first with a complete evaluation of the auditory system comprising 4 cases of children in a similar age group. All of the examined patients presented an air-bone gap indicating conductive disorders.

Praca wykonana w ramach projektu 501/01-34-1-7217 „Procesy separacji, mielenia i granulacji materialow ziarnistych oraz mieszanie ukladow cieklych".

In the paper the range of requirements concerning grinded surface layers for deposition of protective PVD coatings on magnesium alloys has been presented. Also difficulties concerning the preparation of surface layer and literature review have been depicted. For solving of the problems concerning proper preparation of magnesium alloy surface layer the conventional grinding process using ceramic grinding wheels and the process of cleaning of CSGW during machining has been applied. The machining parameters has been determined and the surface geometrical structure has been assessed using optical profiling in 3D configuration.

This work describes measurement methodology on acrylic acid-based hydrogels with nanogold and starch, including evaluation of pro-inflammatory activity and cytotoxicity by MTT reduction assay, swelling capacity, tensile strength using Brookfield texture analyzer, surface morphology by scanning electron microscopy, structure by FT-IR spectroscopy, crystallinity by X-ray diffraction and hydrogel behaviour in simulated body fluids. The modified polymers exhibited approx. 75% lower deformation than unmodified polymer. Hydrogels showed buffering properties in simulated body fluids. Hydrogels containing 5–10% starch solution did not exhibit cytotoxicity. Cells exposed to unmodified hydrogel and to hydrogels containing 5% and 10% starch solutions were characterized by the desired morphology. Importantly, hydrogel nanocomposites have not showed pro-inflammatory activity. It was proved that highly developed specific surface area of modified hydrogels affected their sorption properties. Nanogold present in nanocomposites did not affect directly their physicochemical properties but, due to its features, antibacterial activity of so modified materials could be enhanced.

This note describes a newly developed technique for evaluation of cutaneous microcirculation. The technique called Flow Mediated Skin Fluorescence (FMSF) is based on monitoring of NADH fluorescence intensity emitted from the skin tissue cells of a forearm. The changes in fluorescence intensity as a function of time in response to blocking and releasing of blood flow in a forearm are used as a measure of oxygen transport with blood to the tissue, which directly correlates with the skin microcirculation status. Preliminary results collected for healthy volunteers and patients experiencing serious cardiovascular problems indicated a usefulness of FMSF technique for evaluation of health related perturbations in cutaneous microcirculation.

The TLRs play a key role in host defense against infection and injury, and mounting evidence suggests that these receptors may also play a role in diseases such autoimmunity, atherosclerosis, and cancer. Activation of TLRs on macrophages results in the production of multiple soluble mediators including the key inflammatory cytokines, TNF and IL-6. Thus, the intracellular signaling mechanism by which TLRs signal is a subject of great interest. As well as activating the NF-κB and MAPK pathways, TLR engagement leads to tyrosine kinase activation within minutes. Src family kinases (SFKs) are the largest nonreceptor tyrosine kinase family with nine members: Src, Hck, Lyn, Fyn, Fgr, Blk, Lck, Yes, and Ylk. The role of the SFKs in TLR signaling has been an area of much controversy, with conflicting findings between studies using chemical inhibitors and knockout mice. Using primary human macrophages in combination with adenoviral overexpression and small interfering RNA knockdown studies, we show that the SFK, Hck, has a pre-eminent role in LPS/TLR4-induced TNF and IL-6 production. Hck kinase mediates TLR4-induced transcription of both TNF and IL-6 by a mechanism that involves neither the NF-κB nor the MAPK pathways, but rather leads to AP-1 binding with a complex of c-fos and JunD. These data highlight the importance of Hck as an active component in LPS-induced TLR signaling and suggest the possibility of targeting this kinase for the alleviation of excessive inflammation.

The activity of tyrosine kinases is central to many cellular processes, and accumulating evidence suggests that their role in inflammation is no less profound. Three main tyrosine kinase families, the Src, Tec and Syk kinase families are intimately involved in TLR signalling, the critical first step in cellular recognition of invading pathogens and tissue damage. Their activity results in changes in gene expression in affected cells. Key amongst these genes are the cytokines, which orchestrate both the duration and extent of inflammation. Tyrosine kinases also play important roles in cytokine function, and are implicated in signalling through both pro- and anti-inflammatory cytokines such as TNF, IL-6 and IL-10. Thus, strategies to modulate tyrosine kinase activity have significant therapeutic potential in combating the chronic inflammatory state that is typical of many major health issues that face us today, including Rheumatoid Arthritis, Cardiovascular disease and cancer. Here we review current knowledge of the role of tyrosine kinases in inflammation with particular emphasis on their role in TLR signalling.

Medical grade UHMWPE-s: GUR 1020 and 1050, were subjected to ion bombardment with H 2 + , He+, Ar+ or Ag+ of different energy and various doses. The work presents changes to micromechanical profiles and surface morphology (AFM, SEM) of polyethylenes due to the treatment. Mechanisms behind the modification have been proposed owing to structural and chemical analyses by s-SIMS, FTIR-IRS, confocal Raman microscopy and “nuclear depth profiling”. Studies revealed that hardness of the surface layer increases due to radiolysis, probably leading to cross-polymerization of polyethylene. The depth of modification is limited to the penetration of ion beam, being dependent on a dose and a kind of ions applied. The treatment results additionally in oxidation, which together with a development of the surface geometry is responsible for its hydrofilization and, in some cases bacteriostatic character. Friction and wear of polyethylenes under a high load, adequate to extreme conditions of exploitation of hip joints, can be reduced even by three times, due to a proper ion beam treatment.

The paper deals with the comparison of grinding results achieved with vitrified and resin-bonded superhard wheels during the grinding of high-speed steel. Several dressing conditions were applied. Grinding results were determined on the basis of the measurements of grinding efficiency, grinding forces and surface roughness achieved during the process.

In the first of two experiments four rumen-cannulated sheep were used to determine the degree of rumen protein degradation in blood meal (BM), fish meal (FM), soybean meal (SBM) or casein (C) using the in sacco method. In the second experiment, four cannulated rams were fed isonitrogenous and isoenergetic diets to ascertain the influence of the same protein feeds on metabolic changes in the rumen and flow of amino acids through the duodenum. Rumen non-degradable N in BM, FM, SBM or C total-N was 74%, 62%, 38% and 11%, respectively. Rumen ammonia-N (NH3-N) was highest (P < 0.05) in lambs fed C, lowest with FM. Source of dietary protein did not affect dry matter or organic matter digestibility in the rumen. Total-N, nonammonia N and amino acid flow through the duodenum was highest (P < 0.05) in lambs fed FM and lowest with C. Combinations of protein sources may best supply amino acids to ruminants in optimal proportions.

Thirty-two rams of Polish Merino breed, average initial body weight 25 kg (SE ± 0.8 kg) were fed isonitrogenous and isoenergetic diets in which the main sources of protein were blood meal (BM), fish meal (FM), soybean meal (SBM) or casein (C). The highest gains (P < 0.05) were obtained in lambs fed FM diets (197 g day−1), followed by BM, SBM and C (181 g, 175 g and 114 g day−1, respectively). Lambs supplemented with C were characterised by the highest protein and energy consumption per kilogram body weight (BW) gain. Source of protein did not affect chemical composition of empty BW. The highest values of the kf coefficient were found in lambs fed FM (0.38) and the lowest in those fed C (0.20). Protein deposition was highest (P < 0.05) in animals fed FM (35.5 g day−1), followed by BM, SBM and C (31.7 g, 30.0 g and 23.7 g day−1, respectively). FM was the optimal source of supplemental protein.

Two experiments were carried out. In the first experiment, four sheep (45 kg) with a cannula in the rumen were used to determine the extent of rumen protein degradation of dehydrated alfalfa (DA), applying the nylon bag technique. In the second experiment, five lambs (25 kg) with cannulas in the rumen and duodenum were fed all-concentrate, pelleted isonitrogenous (about 16% crude protein kg−1 dry matter) and isoenergetic (about 12.8 MJ metabolizable energy kg−1 dry matter) diets containing 0, 5, 10, 15 and 20% of DA in a 5 × 5 Latin square arrangement of treatments. After 24 h incubation period in the rumen, 61.2% DA protein was not degraded in this forestomach. The pH of rumen fluid increased only slightly with the increase of the DA concentration in the diets, while the level of NH3N in the rumen fluid decreased from 9.42 to 4.44 mM l−1 fluid. Total ruminal volatile fatty acid concentration dropped together with the increase of the DA content in diets (from 72.1 to 65.2 mM l−1), whereas acetate to propionate ratio increased significantly (P < 0.05) from 1.61 to 2.08. The highest and statistically significant (P < 0.05) flow of total N (23.17 g day−1), non-ammonia N (22.37 g day−1) and essential (53.74 g day−1), non-essential (77.07 g day−1) and total amino acids (130.81 g day−1) was observed in lambs fed 10% DA.

Defined perpendicular anisotropy gradients in the Co sublayers of a [Co(0.6 nm)/Au(2 nm)](3) sputter-deposited multilayer have been introduced by light ion bombardment through a wedged Au stopper layer. Within such a layer system, domain walls between up- and down-magnetized areas are controllably movable by an external perpendicular homogeneous magnetic field. This method and layer system is very promising for a controlled magnetic particle transport within the stray fields of the moving domain walls.