Liposomes-entrapped chondroitin sulphate: ultrastructural characterization and in vitro biocompatibility

The purpose of this study was ultrastructural characterization of liposomes-entrapped chondroitin sulphate and to prove their in vitro biocompatibility in a human dermal fibroblast culture system, in order to use liposome-entrapped chondroitin sulphate in the treatment of inflammatory disorders. Chondroitin sulphate entrapped in liposomes appears as electron-dense particles in ultra-thin section. Comparative studies using chondroitin sulphate, empty liposomes and liposome-chondroitin sulphate systems were performed in order to evaluate their effect on growth and morphology of fibroblasts after 48 h of culture. Light microscopy indicated that chondroitin sulphate, empty liposomes and liposome-chondroitin sulphate systems do not induce appreciable cytotoxic effects, and cells maintain normal morphology when compared to control fibroblasts.     

Radiative energy loss in a finite dynamical QCD medium

The radiative energy loss of a quark jet traversing a finite size QCD medium with dynamical constituents is calculated to first order in opacity. Although finite size corrections reduce the energy loss relative to an infinite dynamical QCD medium, under realistic conditions it remains significantly larger than in a static medium. Quantitative predictions of jet suppression in relativistic heavy ion collisions must therefore account for the dynamics of the medium's constituents. Finite size effects are shown to induce a nonlinear path length dependence of the energy loss. Our results suggest a simple general mapping between energy loss expressions for static and dynamical QCD media.     

Computation of Saturation Dependence of Effective Diffusion Coefficient in Unsaturated Argillite Micro-fracture by Lattice Boltzmann Method

Getting access to the effective diffusion coefficient is a key point to provide realistic predictions of migration of radionuclides from radioactive waste repository in deep argillaceous geological formations. In the present work, the effective diffusion coefficient was computed inside an argillite micro-fracture as a function of its saturation level. The micrometric fracture geometry was extracted from the X-ray \(\mu \)-tomography image (\(0.7\,\upmu \mathrm{m}\) voxel resolution) of an Opalinus clay sample. It was collected in the host rock excavated damaged zone surrounding a borehole in the Mont Terri laboratory. The computations were performed using two two-relaxation-time lattice Boltzmann models. The first one, a phase separation model, was used to extract the connected liquid phase inside the fracture for given saturations. The second, a diffusion model, was used to compute non-reactive tracer diffusion in the connected liquid phase of the fracture and to calculate the effective diffusion coefficient for the associated saturations. The dependence of the effective diffusion coefficient on saturation was found to be quasi-linear and to qualitatively match the Maxwell expression for saturations lower than 0.8.     

Simulation and optimization of 2.6–2.8 μm GaSb-based VCSELs

We present the simulation results of threshold operation of mid-infrared GaSb-based vertical-cavity surface-emitting lasers (VCSELs) obtained with the use of comprehensive fully self-consistent optical-electrical-thermal-recombination numerical model. The results show that by a proper design of VCSEL structure and composition of the active region it is theoretically possible to achieve room-temperature (RT) threshold operation for wavelength of 2.8 μm which is about 0.2 μm longer than those reported so far in the literature for III-V VCSELs with type-I quantum wells. Calculated values of the RT threshold current were equal to 2.5 and 4.0 mA for tunnel-junction diameters of 2 and 4 μm, respectively.     

Distigmasterol-Modified Acylglycerols as New Structured Lipids—Synthesis,Identification and Cytotoxicity

Plant sterols, also referred as phytosterols, have been known as bioactive compounds which have cholesterol-lowering properties in human blood. It has been established that a diet rich in plant sterols or their esters alleviates cardiovascular diseases (CVD), and also may inhibit breast, colon and lung carcinogenesis. Phytosterols, in their free and esterified forms, are prone to thermo-oxidative degradation, where time and temperature affect the level of degradation. Looking for new derivatives of phytosterols with high thermo-oxidative stability for application in foods, our idea was to obtain novel structured acylglycerols in which two fatty acid parts are replaced by stigmasterol residues. In this work, asymmetric (1,2- and 2,3-) distigmasterol-modified acylglycerols (dStigMAs) were synthesized by the covalent attachment of stigmasterol residues to sn-1 and sn-2 or sn-2 and sn-3 positions of 3-palmitoyl-sn-glycerol or 1-oleoyl-sn-glycerol, respectively, using a succinate or carbonate linker. The chemical structures of the synthesized compounds were identified by NMR, HR-MS, and IR data. Moreover, the cytotoxicity of the obtained compounds was determined. The dStigMAs possessing a carbonate linker showed potent cytotoxicity to cells isolated from the small intestine and colon epithelium and liver, whereas the opposite results were obtained for compounds containing a succinate linker.     

Structural Effects of Disease-Related Mutations in Actin-Binding Period 3 of Tropomyosin

Tropomyosin (Tpm) is an actin-binding coiled-coil protein. In muscle, it regulates contractions in a troponin/Ca²⁺-dependent manner and controls the thin filament lengths at the pointed end. Due to its size and periodic structure, it is difficult to observe small local structural changes in the coiled coil caused by disease-related mutations. In this study, we designed 97-residue peptides, Tpm1.1_64–154 and Tpm3.12_65–155, focusing on the actin-binding period 3 of two muscle isoforms. Using these peptides, we evaluated the effects of cardiomyopathy mutations: I92T and V95A in Tpm1.1, and congenital myopathy mutations R91P and R91C in Tpm3.12. We introduced a cysteine at the N-terminus of each fragment to promote the formation of the coiled-coil structure by disulfide bonds. Dimerization of the designed peptides was confirmed by gel electrophoresis in the presence and absence of dithiothreitol. Using circular dichroism, we showed that all mutations decreased coiled coil stability, with Tpm3.12_65–155R91P and Tpm1.1_64–154I92T having the most drastic effects. Our experiments also indicated that adding the N-terminal cysteine increased coiled coil stability demonstrating that our design can serve as an effective tool in studying the coiled-coil fragments of various proteins.     

Arene-Ruthenium(II) Complexes with Carbothiamidopyrazoles as a Potential Alternative for Antibiotic Resistance in Human

To meet the demand for alternatives to commonly used antibiotics, this paper evaluates the antimicrobial potential of arene-ruthenium(II) complexes and their salts, which may be of value in antibacterial treatment. Their antimicrobial activity (MIC, MBC/MFC) was examined in vitro against Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Pseudomonas aeruginosa, Proteus vulgaris and Candida albicans and compared with classic antibiotics used as therapeutics. Selected arene-ruthenium(II) complexes were found to have synergistic effects with oxacillin and vancomycin against staphylococci. Their bactericidal effect was found to be associated with cell lysis and the ability to cut microbial DNA. To confirm the safety of the tested arene-ruthenium(II) complexes in vivo, their cytotoxicity was also investigated against normal human foreskin fibroblasts (HFF-1). In addition, the antioxidant and thus pro-health potential of the compounds, i.e., their nonenzymatic antioxidant capacity (NEAC), was determined by two different methods: ferric-TPTZ complex and DPPH assay.     

Influence of Rootstock on Yield Quantity and Quality,Contents of Biologically Active Compounds and Antioxidant Activity in Regent Grapevine Fruit

The cultivation of vines in temperate climates poses many difficulties to be overcome. The soil and climatic conditions in Poland limit the choice of vine varieties that can be used in the field; therefore, growers are often limited to varieties that are tolerant to extreme winter temperatures and spring frosts and to cultivars that are able to achieve optimum berry maturity at the end of the season. The study evaluated the effect of six rootstock types and own-root bushes on yield quantity and quality and on the content of biologically active compounds and antioxidant activity in Regent grapevine fruit. The research was conducted in 2015 at NOBILIS Vineyard (50°39′ N; 21°34′ E) in the Sandomierz Upland. Among the evaluated rootstocks, 125AA turned out to exert the significantly best effect on the yield, grape and berry weight, and number of grapes per bush. The fruit from bushes grafted on the 5BB rootstock were characterised by the highest content of L-ascorbic acid and tannins.     

A Uniform Benchmark for Testing SsrA-Derived Degrons in the Escherichia coli ClpXP Degradation Pathway

The ssrA degron is commonly used in fusion proteins to control protein stability in bacteria or as an interaction module. These applications often rely on the modular activities of the ssrA tag in binding to the SspB adaptor and in engaging the ClpXP protease. However, a comparison of these activities for a substantial standard set of degron variants has not been conducted previously, which may hinder the development of new variants optimized exclusively for one application. Here, we strive to establish a benchmark that will facilitate the comparison of ssrA variants under uniform conditions. In our workflow, we included methods for expression and purification of ClpX, ClpP, SspB and eGFP-degrons, assays of ClpX ATPase activity, of eGFP-degron binding to SspB and for measuring eGFP-degron degradation in vitro and in vivo. Using uniform, precise and sensitive methods under the same conditions on a range of eGFP-degrons allowed us to determine subtle differences in their properties that can affect their potential applications. Our findings can serve as a reference and a resource for developing targeted protein degradation approaches.     

Thermal analysis applied to studying the influence of ionic liquids on the vulcanization,thermal stability and damping properties of ethylene-propylene-diene rubber

The main aspect of the research was developing new systems for activating sulfur vulcanization of ethylene-propylene-diene elastomer (EPDM) with greater activity than the micrometer zinc oxide that is traditionally used. Differential scanning calorimetry (DSC) was applied to study the temperature and enthalpy of EPDM vulcanization. The range of vulcanization temperatures and the enthalpy of this process were determined. Thermogravimetric analysis was performed to characterize the effect of ILs on the thermal stability of vulcanizates. Dynamic mechanical analysis with tension deformation was used to study the influence of ILs on the loss factor (tan δ) of EPDM determined as a function of temperature, which is a measure of the ability of the material to dampen vibration. DSC results indicated that ILs significantly reduced the onset temperature and enthalpy of EPDM vulcanization. The most active were alkylimidazolium chlorides, which eliminated the post-curing process. Owing to lower decomposition temperature compared to EPDM, ILs decreased the thermal stability of vulcanizates. On the other hand, ILs had no significant influence on damping properties of EPDM in the rubbery elastic region. Vulcanizates containing ILs exhibited stable dynamic properties at the temperatures of use.