Biophotons: New Experimental Data and Analysis.

Biophotons are an ultra-weak emission of photons in the visible energy range from living matter. In this work, we study the emission from germinating seeds using an experimental technique designed to detect light of extremely small intensity. The emission from lentil seeds and single bean was analyzed during the whole germination process in terms of the different spectral components through low pass filters and the different count distributions in the various stages of the germination process. Although the shape of the emission spectrum appears to be very similar in the two samples used in our experiment, our analysis can highlight the differences present in the two cases. In this way, it was possible to correlate the various types of emissions to the degree of development of the seed during germination.

Intrinsically Conductive Polymers for Striated Cardiac Muscle Repair.

One of the most important features of striated cardiac muscle is the excitability that turns on the excitation-contraction coupling cycle, resulting in the heart blood pumping function. The function of the heart pump may be impaired by events such as myocardial infarction, the consequence of coronary artery thrombosis due to blood clots or plaques. This results in the death of billions of cardiomyocytes, the formation of scar tissue, and consequently impaired contractility. A whole heart transplant remains the gold standard so far and the current pharmacological approaches tend to stop further myocardium deterioration, but this is not a long-term solution. Electrically conductive, scaffold-based cardiac tissue engineering provides a promising solution to repair the injured myocardium. The non-conductive component of the scaffold provides a biocompatible microenvironment to the cultured cells while the conductive component improves intercellular coupling as well as electrical signal propagation through the scar tissue when implanted at the infarcted site. The in vivo electrical coupling of the cells leads to a better regeneration of the infarcted myocardium, reducing arrhythmias, QRS/QT intervals, and scar size and promoting cardiac cell maturation. This review presents the emerging applications of intrinsically conductive polymers in cardiac tissue engineering to repair post-ischemic myocardial insult.

Biophotons and Emergence of Quantum Coherence-A Diffusion Entropy Analysis.

We study the emission of photons from germinating seeds using an experimental technique designed to detect light of extremely small intensity. We analyze the dark count signal without germinating seeds as well as the photon emission during the germination process. The technique of analysis adopted here, called diffusion entropy analysis (DEA) and originally designed to measure the temporal complexity of astrophysical, sociological and physiological processes, rests on Kolmogorov complexity. The updated version of DEA used in this paper is designed to determine if the signal complexity is generated either by non-ergodic crucial events with a non-stationary correlation function or by the infinite memory of a stationary but non-integrable correlation function or by a mixture of both processes. We find that dark count yields the ordinary scaling, thereby showing that no complexity of either kinds may occur without any seeds in the chamber. In the presence of seeds in the chamber anomalous scaling emerges, reminiscent of that found in neuro-physiological processes. However, this is a mixture of both processes and with the progress of germination the non-ergodic component tends to vanish and complexity becomes dominated by the stationary infinite memory. We illustrate some conjectures ranging from stress induced annihilation of crucial events to the emergence of quantum coherence.

Poly(ethylene glycol) Diacrylate Hydrogel with Silver Nanoclusters for Water Pb(II) Ions Filtering.

Poly(ethylene glycol) diacrylate (PEGDA) hydrogels modified with luminescent silver nanoclusters (AgNCs) are synthesized by a photo-crosslinking process. The hybrid material thus obtained is employed to filter Pb(II) polluted water. Under the best conditions, the nanocomposite is able to remove up to 80-90% of lead contaminant, depending on the filter composition. The experimental results indicate that the adsorption process of Pb(II) onto the modified filter can be well modeled using the Freundlich isotherm, thus revealing that the chemisorption is the driving process of Pb(II) adsorption. In addition, the parameter n in the Freundlich model suggests that the adsorption process of Pb(II) ions in the modified hydrogel is favored. Based on the obtained remarkable contaminant uptake capacity and the overall low cost, this hybrid system appears to be a promising sorbent material for the removal of Pb(II) ions from aqueous media.

Extrinsically Conductive Nanomaterials for Cardiac Tissue Engineering Applications.

Myocardial infarction (MI) is the consequence of coronary artery thrombosis resulting in ischemia and necrosis of the myocardium. As a result, billions of contractile cardiomyocytes are lost with poor innate regeneration capability. This degenerated tissue is replaced by collagen-rich fibrotic scar tissue as the usual body response to quickly repair the injury. The non-conductive nature of this tissue results in arrhythmias and asynchronous beating leading to total heart failure in the long run due to ventricular remodelling. Traditional pharmacological and assistive device approaches have failed to meet the utmost need for tissue regeneration to repair MI injuries. Engineered heart tissues (EHTs) seem promising alternatives, but their non-conductive nature could not resolve problems such as arrhythmias and asynchronous beating for long term in-vivo applications. The ability of nanotechnology to mimic the nano-bioarchitecture of the extracellular matrix and the potential of cardiac tissue engineering to engineer heart-like tissues makes it a unique combination to develop conductive constructs. Biomaterials blended with conductive nanomaterials could yield conductive constructs (referred to as extrinsically conductive). These cell-laden conductive constructs can alleviate cardiac functions when implanted in-vivo. A succinct review of the most promising applications of nanomaterials in cardiac tissue engineering to repair MI injuries is presented with a focus on extrinsically conductive nanomaterials.

Effects of progressive halogen substitution on the photoluminescence properties of an erbium-porphyrin complex.

We have investigated the photoluminescence properties of porphyrin-based erbium and gadolinium complexes at different levels of halogen substitution. Both the intensity and the decay time of the erbium near-infrared emission correlate with the degree of the halogenation. Conversely, no clear correlation is found with the triplet-state energy levels nor with the intensity of the residual visible emission. Such findings confirm that the key role in the low efficiency of the near-infrared emission is played by the nonradiative quenching of the erbium emitting level due to the vibrational modes of the surrounding C-H bonds.

Anodization-based process for the fabrication of all niobium nitride Josephson junction structures.

We studied the growth and oxidation of niobium nitride (NbN) films that we used to fabricate superconductive tunnel junctions. The thin films were deposited by dc reactive magnetron sputtering using a mixture of argon and nitrogen. The process parameters were optimized by monitoring the plasma with an optical spectroscopy technique. This technique allowed us to obtain NbN as well as good quality AlN films and both were used to obtain NbN/AlN/NbN trilayers. Lift-off lithography and selective anodization of the NbN films were used, respectively, to define the main trilayer geometry and/or to separate electrically, different areas of the trilayers. The anodized films were characterized by using Auger spectroscopy to analyze compounds formed on the surface and by means of a nano-indenter in order to investigate its mechanical and adhesion properties. The transport properties of NbN/AlN/NbN Josephson junctions obtained as a result of the above described fabrication process were measured in liquid helium at 4.2 K.

Scaffold-in-Scaffold Potential to Induce Growth and Differentiation of Cardiac Progenitor Cells.

The design of reliable biocompatible and biodegradable scaffolds remains one of the most important challenges for tissue engineering. In fact, properly designed scaffolds must display an adequate and interconnected porosity to facilitate cell spreading and colonization of the inner layers, and must release physical signals concurring to modulate cell function to ultimately drive cell fate. In this study, a combination of optimal mechanical and biochemical properties has been considered to design a one-component three-dimensional (3D) multitextured hydrogel scaffold to favor cell-scaffold interactions. A polyethylene glycol diacrylate woodpile (PEGDa-Wp) structure of the order of 100 µm has been manufactured using a microstereolithography process. Subsequently, the PEGDa-Wp has been embedded in a PEGDa hydrogel to obtain a 3D scaffold-in-scaffold (3D-SS) system. Finally, the 3D-SS capability to address cell fate has been assessed using human Lin- Sca-1+ cardiac progenitor cells (hCPCs). Results have shown that a multitextured 3D scaffold represents a favorable microenvironment to promote hCPC differentiation and orientation. In fact, while cultured on 3D-SS, hCPCs adopt an ordered 3D spatial orientation and activate the expression of structural proteins, such as the α-sarcomeric actinin, a specific marker of the cardiomyocyte phenotype, and connexin 43, the principal gap junction protein of the heart. Although preliminary, this study demonstrates that complex multitextured scaffolds closely mimicking the extracellular matrix structure and function are efficient in driving progenitor cell fate. A leap forward will be determined by the use of advanced 3D printing technologies that will improve multitextured scaffold manufacturing and their biological efficiency.

Synthesis, X-ray diffraction characterization, and radiative properties of Er(2)O(3)-ZrO(2) nanocrystals embedded in LAS glass ceramic.

Low thermal expansion Li(2)O-Al(2)O(3)-SiO(2) (LAS) glass ceramic was examined as a host matrix for erbium ions. ZrO(2) was added to the glass since it serves as a nucleating agent and as a good environment for the luminescent ions. The study was carried out on amorphous powders of the Li(2)O-Al(2)O(3)-SiO(2)/ZrO(2)/Er(2)O(3) system prepared by the sol-gel method and successively crystallized at different temperatures. X-ray diffraction (XRD), transmission electron microscopy (TEM), and infrared (IR) spectroscopy were employed to study the evolution of the crystalline phases and the distribution of the erbium ions. The TEM micrographs confirmed that, after thermal treatment at 1000 degrees C, the crystallization of nanoparticles constituted by an Er(2)O(3)-ZrO(2) solid solution with narrow size distribution could be achieved. On the contrary, erbium silicate was detected in the samples without ZrO(2). The repartition constant of Er(2)O(3) between ZrO(2) and LAS matrix has been also evaluated.