Controlled oxygen plasma treatment of single-walled carbon nanotube films improves osteoblastic cells attachment and enhances their proliferation

The effects of oxidative treatment of single-walled carbon nanotubes (SWCNTs) on the adhesion and proliferation of human osteoblasts (SAOS-2) were investigated. The surface properties of SWCNTs after oxygen plasma treatment were characterized by contact angle measurement, scanning electron microscopy and Raman spectroscopy. The immunofluorescent staining of vinculin, actin filaments and nuclei was used to probe cell adhesion and growth on SWCNT films. Our results show that adhesion and proliferation of human osteoblasts cultivated on SWCNT films indeed depends on the degree of an oxidative treatment. As an optimal procedure was found the treatment with oxygen plasma for 5 min. In the latter case the osteoblasts form a confluent layer with pronounced focal adhesions throughout the entire cell body. The optimal conditions compromise the effect of hydrophilic character of SWCNT films and the level of damage of SWCNT surface.     

Textural and physicochemical predictors of sensory texture and sweetness of boiled plantain

Boiled pulp is a major form of consumption for plantain. We assessed instrumental (puncture test and texture profile analysis) and sensory texture attributes of 13 plantain cultivars, two cooking hybrids and one dessert banana at different stages of ripeness after cooking in boiling water. Firmness, chewiness, stickiness, mealiness, sweetness and moistness described sensory variability, which was greater between stages of ripeness than between types of cultivars. Firmness and chewiness were well-predicted by instrumental force and hardness (r² > 0.72), and by soluble solid and dry matter content (r² > 0.85). Complementary sensitivity analysis revealed that a pulp puncture force or a hardness of at least 2.1 N or of 0.3 N/mm² was needed before a difference in firmness or chewiness could be perceived; a Brix of 3.7 was required to ensure a detectable difference in sweetness. Rheological and biochemical predictors can be useful for breeders for high-throughput phenotyping.     

Revisiting the Sources of Borel's Interest in Probability: Continued Fractions,Social Involvement,Volterra's Prolusione

In this paper, we revisit the origins of Emile Borel's developing interest in probability around 1905. This resulted from new findings in his research on continued fraction, but it also cannot be separated from the discovery of new applications for the mathematics of randomness (such as biology or economics) and of their importance as a life‐changing tool for the citizen. In particular, we underline the role of a paper published by Vito Volterra in Borel's Revue du Mois.     

Structure activity relationships of monocyte chemoattractant proteins in complex with a blocking antibody

Monocyte chemoattractant proteins (MCPs) are cytokines that direct immune cells bearing appropriate receptors to sites of inflammation or injury and are therefore attractive therapeutic targets for inhibitory molecules. 11K2 is a blocking mouse monoclonal antibody active against several human and murine MCPs. A 2.5 A structure of the Fab fragment of this antibody in complex with human MCP-1 has been solved. The Fab blocks CCR2 receptor binding to MCP-1 through an adjacent but distinct binding site. The orientation of the Fab indicates that a single MCP-1 dimer will bind two 11K2 antibodies. Several key residues on the antibody and on human MCPs were predicted to be involved in antibody selectivity. Mutational analysis of these residues confirms their involvement in the antibody-chemokine interaction. In addition to mutations that decreased or disrupted binding, one antibody mutation resulted in a 70-fold increase in affinity for human MCP-2. A key residue missing in human MCP-3, a chemokine not recognized by the antibody, was identified and engineering the preferred residue into the chemokine conferred binding to the antibody.     

Causal cross-spectral analysis of heart rate and blood pressure variability for describing the impairment of the cardiovascular control in neurally mediated syncope

A causal approach to the calculation of coherence and transfer function between systolic pressure (SP) and RR interval variability was applied in eight patients and eight control subjects during prolonged tilt test for investigating the impairment of cardiovascular control related to neurally mediated syncope. The causal analysis showed a depressed baroreflex regulation in resting patients, with reduced gain and increased latency from SP to RR, and a drop of the baroreflex coupling immediately before syncope. These findings, which were not elicited by traditional cross-spectral analysis, strongly suggest the use of the causal approach for the study of syncope mechanisms.     

On the flow dependency of the electrical conductivity of blood

Experiments presented in the literature show that the electrical conductivity of flowing blood depends on flow velocity. The aim of this study is to extend the Maxwell-Fricke theory, developed for a dilute suspension of ellipsoidal particles in an electrolyte, to explain this flow dependency of the conductivity of blood for stationary laminar flow in a rigid cylindrical tube. Furthermore, these theoretical results are compared to earlier published measurement results. To develop the theory, we assumed that blood is a Newtonian fluid and that red blood cells can be represented by oblate ellipsoids. If blood flows through a cylindrical tube, shear stresses will deform and align the red blood cells with one of their long axes aligned parallel to the stream lines. The pathway of a low-frequency (< 1 MHz) alternating electrical current will be altered by this orientation and deformation of the red blood cells. Consequently, the electrical conductivity in the flow direction of blood increases. The theoretically predicted flow dependency of the conductivity of blood corresponds well with experimental results. This theoretical study shows that red blood cell orientation and deformation can explain quantitatively the flow dependency of blood conductivity.