Maakivi ehitusmaterjalina: töötlemine ja kasutus

Fieldstone has been used as a building material for many centuries. In Estonia, two large groups of stone suitable for building can be distinguished in terms of architectural outcome and construction technique: calcareous stones (mostly carbonate flagstone and dolomite) and granite boulders, or field stones. The latter cover a broad spectrum of natural igneous and metamorphic rocks (rapakivi granite, diabases, gneiss etc.). In this article, we focus on natural stone belonging to the second group: in particular how it can be processed – split with wedges or a sledgehammer – and historical means of transporting stones. We also take a look at the ethical, aesthetic and cultural aspects of fieldstone use.Field stones were carried to Estonia by the continental glacier. In general, it can be said that fieldstone is a hard and strong stone suitable for use as a building material, which due to its density and low porosity can be used in underground and other supporting structures. These properties mean that fieldstone’s thermal conductivity is high, which is why it is not suitable for building dwellings. It has most commonly been used to build stables, cellars, barns and, to a lesser extent, taverns and other public buildings.Fieldstone is a material with a small ecological footprint which does not participate directly in the carbon cycle, as does timber. Fieldstone processing and transport is relatively energy-intensive, but this is compensated for by the longevity of the structures made. Visually, fieldstone is a very strong and eye-catching material. The surface of each stone is different, making each structure unique. The strong visual message and the long tradition of using fieldstone as a building material are the main factors that guarantee that there are people in Estonia who still commission fieldstone buildings and smaller items

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PURPOSE. To determine whether in vivo confocal microscopy (IVCM) of the cornea can be used for the label-free detection and monitoring of lymph vessels in live corneas. METHODS. Parallel corneal hemangiogenesis and lymphangiogenesis was induced by the placement of a single suture in one cornea of male Wistar rats. Fourteen days after suture placement and under general anesthesia, laser-scanning IVCM was performed in the vascularized region. Corneas were subsequently excised for flat-mount double immunofluorescence with a pan-endothelial marker (PECAM-1/CD31) and a lymphatic endothelial specific marker (LYVE-1). Using the suture area and prominent blood vessels as points of reference, the identical microscopic region was located in both fluorescent and archived in vivo images. Additionally, vessel diameter, lumen contrast, and cell diameter and velocity within vessels were quantified from in vivo images. RESULTS. Comparison of identical corneal regions in fluorescence and in vivo revealed prominent CD31(+)/LYVE-1(3+) lymph vessels that were visible in vivo. In vivo, corneal lymph vessels were located in the vascularized area in the same focal plane as blood vessels but had a darker lumen (P andlt; 0.001) sparsely populated by highly reflective cells with diameters similar to those of leukocytes in blood vessels (P = 0.61). Cell velocity in lymph vessels was significantly reduced compared with blood particle velocity (P andlt; 0.001). Morphologic characteristics enabled subsequent identification of corneal lymphatics in live, vascularized rat corneas before immunofluorescence labeling. CONCLUSIONS. IVCM enabled the nondestructive, label-free, in vivo detection of corneal lymphatics. IVCM provides the possibility of observing lymphatic activity in the same live corneas longitudinally and, as a clinical instrument, of monitoring corneal lymphatics in live human subjects

Application of Continuous Culture Methods to Recombinant Protein Production in Microorganisms

Depending on the environmental conditions, cells adapt their metabolism and specific growth rate. Rearrangements occur on many different levels such as macromolecular composition, gene and protein expression, morphology and metabolic flux patterns. As the interplay of these processes also determines the output of a recombinant protein producing system, having control over specific growth rate of the culture is advantageous. Continuous culture methods were developed to grow cells in a constant environment and have been used for decades to study basic microbial physiology in a controlled and reproducible manner. Our review summarizes the uses of continuous cultures in cell physiology studies and process development, with a focus on recombinant protein-producing microorganisms

Maakiviehitus: ajalooline ülevaade ja tööprotsessid Joona talu kõrvalhoone näitel

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Comparative in-vitro activity of new quinolones against clinical isolates and resistant mutants

The in-vitro activity of five new fluoroquinolones, WIN 57273, sparfloxacin, flerox-acin, temafloxacin and tiprofloxacin was determined against 543 recent clinical isolates and eight quinolone resistant strains derived by mutation and their five parent strains. WIN 57273 was the most active compound against Gram-positive bacteria, sparfloxacin had a broad spectrum which was similar to that of cipro-floxacin. Ciprofloxacin showed the greatest activity against Gram-negative bacteria. Temafloxacin showing some activity against Gram-positive organisms and Acinetobacter spp. Fleroxacin was the least active compound studied. Compared to wild type parent strains, the mutated strains produced the following results. In Enterobacter cloacae OmpF deficiency increased the MICs of all quinolones by 8-32-fold. In Pseudomonas aeruginosa OmpF deficiency had a limited effect, Omp D2 deficiency combined with an increased lipopolysaccharide content produced greater resistance, i.e. 4-16-fold; mutations in gyrase were associated with variously increased MICs, depending on the strain and compound teste

Improving protein delivery of fibroblast growth factor-2 from bacterial inclusion bodies used as cell culture substrates

Altres ajuts: We are indebted CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN, Spain) for funding our research on inclusion bodies.Bacterial inclusion bodies (IBs) have recently been used to generate biocompatible cell culture interfaces, with diverse effects on cultured cells such as cell adhesion enhancement, stimulation of cell growth or induction of mesenchymal stem cell differentiation. Additionally, novel applications of IBs as sustained protein delivery systems with potential applications in regenerative medicine have been successfully explored. In this scenario, with IBs gaining significance in the biomedical field, the fine tuning of this functional biomaterial is crucial. In this work, the effect of temperature on fibroblast growth factor-2 (FGF-2) IB production and performance has been evaluated. FGF-2 was overexpressed in Escherichia coli at 25 and 37 °C, producing IBs with differences in size, particle structure and biological activity. Cell culture topographies made with FGF-2 IBs biofabricated at 25 °C showed higher levels of biological activity as well as a looser supramolecular structure, enabling a higher protein release from the particles. In addition, the controlled use of FGF-2 protein particles enabled the generation of functional topographies with multiple biological activities being effective on diverse cell types