In vitro evaluation of freeze-dried bone allografts combined with platelet rich plasma and human bone marrow stromal cells for tissue engineering

Freeze-dried bone allograft (FDBA) might be more effective in combination with platelet rich plasma (PRP) and bone marrow stromal cells (BMSC) in accelerating bone healing. The isolation of BMSC through density gradient (pBMSC) is not extensively applicable in clinical practice, because it increases the risk of infection. Alternatively, BMSC can be concentrated by simple centrifugation (wBMSC) directly in the operating room. However, we do not know if wBMSC act in the same way as pBMSC. BMSC from 10 donors were tested whether, in the presence of a combination of FDBA and autologous PRP, the osteogenic differentiation of the cells concentrated by simple centrifugation (wBMSC + FDBA + PRP) was similar to that of pBMSC. Cell-associated alkaline phosphatase, osterix and fibroblast growth factor-2 were higher in wBMSC + FDBA + PRP. In conclusion, the combination of FDBA and PRP had a favouring effect on the differentiation towards osteoblasts and allowed BMSC concentrated by simple centrifugation to differentiate as fast as BMSC purified by density gradient.     

Independent component analysis: fetal signal reconstruction from magnetocardiographic recordings

Independent component analysis (ICA) was used for the processing of cardiological signals obtained by means of fetal magnetocardiography (fMCG), a technique allowing the non-invasive recording of the weak magnetic field variations associated to the electrical activity of the fetal heart. Purpose of the present work was to verify whether a computational-light ICA algorithm (FastICA), tailored to the characteristics of fMCG, could reconstruct reliable signals of the fetal cardiac activity during the last gestational trimester, when good electrophysiological traces are difficult to obtain although being extremely important for clinical diagnosis of severe fetal dysrhythmias. Several combinations of input recordings and output components were examined in order to assess the best configuration to successfully use FastICA. The reconstructed traces were compared with those obtained with deterministic techniques already used for this purpose, and they showed to be stable and reliable, unaffected by overlapped maternal and fetal beats and suitable for clinical applications.     

Effects of fining with different bentonite labels and doses on colloidal stability and colour of a Valpolicella red wine

This study addressed four different labels of activated sodium bentonite during the fining of a young Valpolicella red wine. Preliminary tests determined the bentonite dose (0.15, 0.30 or 0.50 g L^?1) that would achieve colloidal stability, and this dose was further applied during laboratory‐scale trials. The bentonites were characterised by physico‐chemical parameters, and the effects of the label and dose on the wine colloidal stability, proteins, colour indices and phenolic compounds were measured. The results demonstrated that 0.50 g L^?1 for every bentonite label provided colloidal stabilisation without harshly affecting the colour. Unlike to what happens in white wines the least charged bentonite labels were effective at stabilising the red wine colloidal state by partially reducing its protein content. Simultaneously, the most negatively charged clay samples determined the largest depletions on the total polyphenols, anthocyanins, tannins and polymeric pigments. The differentiated action of clays with different surface charge density among white and red wines may be explained by the interaction mediated by positively charged anthocyanins towards either protein or tannin depletion. Although pioneering, these results may move towards the definition of a safe, allergen‐free, and effective adjuvant for colloidal stabilisation targeted to wine type.     

Sensory evaluation of high-moisture dried prunes preserved with sodium benzoate

Both sodium benzoate and potassium sorbate were significantly detected (P < 0.05) in prune juice at levels of 500 to 600 parts/million. Detection levels for both preservatives in high-moisture dried prunes were higher (about 800 parts/million). No significant flavour differences were found between prunes treated with similar amounts of sodium benzoate and potassium sorbate. Since it was necessary to use more sodium benzoate than potassium sorbate to preserve prunes, comparisons were made between prunes containing equally effective levels of the two preservatives. No significant flavour differences were found between prunes effectively preserved with sodium benzoate and potassium sorbate. This suggests that sodium benzoate could be used as a preservative for high-moisture dried prunes with essentially no flavour problem.     

Relationship between wear of friction materials and dissipated power density

Specific tribometric tests showed both the effect and relevance of the power dissipated by friction upon the transition from mild wear to severe wear for friction materials. The dissipated power density could be viewed as an important variable either to identify the critical wear characteristics of friction materials or to make comparisons among different types of friction materials. The scanning electron microscopy analysis showed some correspondence between the sliding surface morphology after the friction tests and the wear rate obtained. Moreover, the phenomena observed are related to known mechanochemical wear mechanisms.     

AFM characterization of biomolecules in physiological environment by an advanced nanofabricated probe

Many relevant questions in biology and medicine require both topography and chemical information with high spatial resolution. Several biological events that occur at the nanometer scale level need to be investigated in physiological conditions. In this regard Atomic Force Microscopy (AFM) is one of the most powerful tools for label‐free nanoscale characterization of biological samples in liquid environment. Recently, the coupling of Raman spectroscopy to scanning probe microscopies has opened new perspectives on this subject; however, the coupling of quality AFM spectroscopy with Raman spectroscopy in the same probe is not trivial. In this work we report about the AFM capabilities of an advanced high‐resolution probe that has been previously nanofabricated by our group for coupling with Raman spectroscopy applications. We investigate its use for liquid AFM measurements on biological model samples like lipid bilayers, amyloid fibrils, and titin proteins. We demonstrate topography resolution down to nanometer level, force measurement and stable imaging capability. We also discuss about its potential as nanoscale chemical probe in liquid phase. Microsc. Res. Tech., 2012. © 2012 Wiley Periodicals, Inc.