Leptogenesis beyond the limit of hierarchical heavy neutrino masses

We calculate the baryon asymmetry of the Universe in thermal leptogenesis beyond the usual lightest right-handed (RH) neutrino dominated scenario (N_1DS) and in particular beyond the hierarchical limit (HL), M_1 << M_2 << M_3, for the RH neutrino mass spectrum. After providing some orientation among the large variety of models, we first revisit the central role of the N_1DS, with new insights on the dynamics of the asymmetry generation and then discuss the main routes departing from it, focusing on models beyond the HL. We study in detail two examples of `strong-strong' wash-out scenarios: one with `maximal phase' and the limit of very large M_3, studying the effects arising when delta_2=(M_2-M_1)/M_1 is small. We extend analytical methods already applied to the N_1DS showing, for example, that, in the degenerate limit (DL), the efficiency factors of the RH neutrinos become equal with the single decay parameter replaced by the sum. Both cases disprove the misconception that close RH neutrino masses necessarily lead to a final asymmetry enhancement and to a relaxation of the lower bounds on M_1 and on the initial temperature of the radiation-dominated expansion. We also explain why leptogenesis tends to favor normal hierarchy compared to inverted hierarchy for the left-handed neutrino masses.Comment: 30 pages, 8 figures; corrected typo in Eq. (67); shortened Introduction, Section 3 and Conclusions; one figure removed; added 2 references; to appear in JCA

Activation of WNT and BMP signaling in adult human articular cartilage following mechanical injury

Peer reviewedPublisher PD

Lanthanide-Based Complexes Containing a Chiral trans-1,2-Diaminocyclohexane (DACH) Backbone: Spectroscopic Properties and Potential Applications

In this minireview, we give an overview on the use of the chiral molecule trans-1,2-diaminocyclohexane (DACH) in several fields of application. This chiral backbone is present in a variety of metal complexes which are employed in (enantioselective) catalysis, chiral discrimination, molecular recognition and supramolecular chemistry. Metal extraction and biochemical and pharmaceutical applications also use the DACH molecule. This contribution is particularly focused on the interesting chemical-physical properties discussed so far in the literature concerning lanthanide-based complexes containing chiral ligands characterized by the presence of DACH in the structure. In particular, the interconnection between luminescence (total and circularly polarized), structure and thermodynamics of Eu(III), Tb(III) and Sm(III) complexes will be discussed also in light of their use as optical or chiroptical probes for the sensing of important analytes dissolved in aprotic and protic polar solvents. Several complexes show potential interest in the solid state as phosphors for light emitting devices or for the detection of volatile organic compounds

Unenhanced helical CT of ureterolithiasis: incidence of secondary urinary tract findings

Objective: To determine the incidence of secondary signs of obstruction in patients with ureteral stones on unenhanced helical CT scans.MATERIAL AND Methods: Three hundred consecutive patients with suspected renal colic referred by the emergency department for an unenhanced helical CT scan were evaluated. One hundred and thirty two patients with ureteric calculi were viewed prospectively for the secondary signs of obstruction, which include hydronephrosis, hydroureter, perinephric stranding, nephromegaly, periureteral edema and difference in attenuation between acutely obstructed kidney and unobstructed kidney.Results: In the evaluated 132 patients, calculi were present in the proximal, mid and distal ureter in 12, 18 and 112 patients respectively. Four patients had a contralateral ureteric calculus while none had more than one ureteric calculus on the same site. Concurrent renal parenchymal calculi were seen in 40 patients with ureteric stones, hydronephrosis in 69, hydroureter in 93 and perinephric strandings in 66 patients. Nephromegaly was seen in 15 and periureteral edema in 42 patients. In 87% patients with acute renal obstruction, the affected kidney was less dense than the unobstructed kidney. Only 5 of 132 patients had no associated findings.CONCLUSION: Unenhanced helical CT has rapidly become the imaging technique of choice in evaluating patients with acute ureteric colic. The secondary signs of obstruction provide supportive evidence of acute obstructive process

Conversion of cytochrome c into a peroxidase: inhibitory mechanisms and implication for neurodegenerative diseases.

A further function of cytochrome c (cyt c), beyond respiration, is realized outside mitochondria in the apoptotic program. In the early events of apoptosis, the interaction of cyt c with a mitochondrion-specific phospholipid, cardiolipin (CL), brings about a conformational transition of the protein and acquirement of peroxidase activity. The hallmark of cyt c with peroxidase activity is its partial unfolding accompanied by loosening of the Fe sixth axial bond and an enhanced access of the heme catalytic site to small molecules like H2O2. To investigate the peroxidase activity of non-native cyt c, different forms of the protein were analyzed with the aim to correlate their structural features with the acquired enzymatic activity and apoptogenic properties (wt cyt c/CL complex and two single cyt c variants, H26Y and Y67H, free and bound to CL). The results suggest that cyt c may respond to different environments by changing its fold thus favouring the exertion of different biological functions in different pathophysiological cell conditions. Transitions among different conformations are regulated by endogenous molecules such as ATP and may be affected by synthetic molecules such as minocycline, thus suggesting a mechanism explaining its use as therapeutic agent impacting on disease-associated oxidative and apoptotic mechanisms

Three-Dimensional Bioprinted Controlled Release Scaffold Containing Mesenchymal Stem/Stromal Lyosecretome for Bone Regeneration: Sterile Manufacturing and In Vitro Biological Efficacy

Recently, 3D-printed scaffolds for the controlled release of mesenchymal stem cell (MSC) freeze-dried secretome (Lyosecretome) have been proposed to enhance scaffold osteoinduction and osteoconduction; coprinting of poly(ε-caprolactone) (PCL) with alginate hydrogels allows adequate mechanical strength to be combined with the modulable kinetics of the active principle release. This study represents the feasibility study for the sterile production of coprinted scaffolds and the proof of concept for their in vitro biological efficacy. Sterile scaffolds were obtained, and Lyosecretome enhanced their colonization by MSCs, sustaining differentiation towards the bone line in an osteogenic medium. Indeed, after 14 days, the amount of mineralized matrix detected by alizarin red was significantly higher for the Lyosecretome scaffolds. The amount of osteocalcin, a specific bone matrix protein, was significantly higher at all the times considered (14 and 28 days) for the Lyosecretome scaffolds. Confocal microscopy further confirmed such results, demonstrating improved osteogenesis with the Lyosecretome scaffolds after 14 and 28 days. Overall, these results prove the role of MSC secretome, coprinted in PCL/alginate scaffolds, in inducing bone regeneration; sterile scaffolds containing MSC secretome are now available for in vivo pre-clinical tests of bone regeneration

Transfer of Axial Chirality to the Nanoscale Endows Carbon Nanodots with Circularly Polarized Luminescence

We report the synthesis, purification and characterization of chiral carbon nanodots starting from atropoisomeric precursors. The obtained atropoisomeric carbon nanodots are soluble in organic solvents and have good thermal stability, which are desirable features for technological applications. The synthetic protocol is robust, as it supports a number of variations in terms of molecular doping agents. Remarkably, the combination of axially chiral precursors and 1,4-benzoquinone as doping agent results in green-emissive carbon dots displaying circularly polarized luminescence. Dissymmetry factors of |3.5|×10−4 are obtained in solution, without the need of any additional element of chirality. Introducing axial chirality expands the strategies available to tailor the properties of carbon nanodots, paving the way for carbon nanoparticles that combine good processability in organic solvents with engineered advanced chiroptical properties

Biorthogonal quantum mechanics

The Hermiticity condition in quantum mechanics required for the characterization of (a) physical observables and (b) generators of unitary motions can be relaxed into a wider class of operators whose eigenvalues are real and whose eigenstates are complete. In this case, the orthogonality of eigenstates is replaced by the notion of biorthogonality that defines the relation between the Hilbert space of states and its dual space. The resulting quantum theory, which might appropriately be called 'biorthogonal quantum mechanics', is developed here in some detail in the case for which the Hilbert-space dimensionality is finite. Specifically, characterizations of probability assignment rules, observable properties, pure and mixed states, spin particles, measurements, combined systems and entanglements, perturbations, and dynamical aspects of the theory are developed. The paper concludes with a brief discussion on infinite-dimensional systems. © 2014 IOP Publishing Ltd