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Four ruthenium(II) N-heterocyclic dicarbene complexes of general formula [Ru{MeIm(CH2)nImMe}2(RCN)2][PF6]2 (1: n = 1, R = Me; 2: n = 1, R = Ph; 3: n = 2, R = Me; 4: n = 2, R = Ph; MeIm = 3-methylimidazol-2-yliden-1-yl) have been synthesised by transmetalation of the dicarbene ligand from a dicarbene silver complex with [RuCl2(COD)]x (COD = 1,5-cyclooctadiene) or [RuCl2(p-cymene)]2 as ruthenium precursors. The relative position of the coordinated nitrile molecules (cis or trans) depends on the group that links the two carbene moieties: the dicarbene with the methylene bridge affords the trans isomer, whereas the cis complex is obtained with the ethylene bridge. The lability of coordinated nitriles towards entering nucleophiles, in particular, cyclohexyl and tert-butyl isocyanide, has been carefully checked, and the corresponding substitution complexes [Ru{MeIm(CH2)nImMe}2(RNC)2][PF6]2 (6: n = 1, R = Cy; 7: n = 2, R = Cy; 8: n = 2, R = tBu) have been synthesised. The trans complexes are more inert than the cis ones, and benzonitrile is a better leaving group than acetonitrile; these characteristics allow a proper tuning of the coordination set and the stereoelectronic properties of these dicarbene ruthenium complexes. The X-ray crystal structures of 1 and 7 have also been determined.

Signals downstream of Akt can either favor or oppose stem cell (SC) maintenance, but how this dual role can be achieved is still undefined. Using human limbal keratinocyte stem cells (LKSCs), a SC type used in transplantation therapies for corneal regeneration, we show that Akt signaling is prominent in SC populations both in vivo and in vitro, and that Akt1 promotes while Akt2 opposes SC self-renewal. Noteworthy, loss of Akt2 signaling enhances LKSC maintenance ex vivo, whereas Akt1 depletion anticipates SC exhaustion. Mechanistically, the antagonistic functions of Akt1 and Akt2 in SC control are mainly dictated by their differential subcellular distribution, being nuclear Akt2 selectively implicated in FOXO inhibition. Akt2 downregulation favors LKSC maintenance as a result of a gain of FOXO functions, which attenuates the mechanistic target of rapamycin complex one signaling via tuberous sclerosis one gene induction, and promotes growth factor signaling through Akt1. Consistently, Akt2 deficiency also enhances limbal SCs in vivo. Thus, our findings reveal distinct roles for nuclear versus cytosolic Akt signaling in normal epithelial SC control and suggest that the selective Akt2 inhibition may provide novel pharmacological strategies for human LKSC expansion in therapeutic settings and mechanistic research. Stem Cells 2014;32:754–769

CVD (ChemicalVapour Deposition)technique is a useful method to obtain coatings with the aim to protect the metallic surface from wear, erosion, corrosion and oxidationat high temperatures.This technique is versatile: it is possible to choose omong several precursors and optimise the deposition parometers. One kind of CVD technique is called MOCVD (Metallorganic Chemical Vapour Deposition) in which the precursor is a metallorganic specie. In this study fhe MOCVD process has been used to deposit noble metals (as Ag or Pt),oxides (as ZrO2, Al203 an Cr2O3), nonostructured coatings, multilayered hetero-sfructures and nanocomposite structures. CVD techniques allow to obtain coatings with new and better tribologlcal properties, as a lower friction coefficient and a higher hardness. For thls reason, CVD can be applied, for example in the field of tools and moulds.

Studies examining the role of the cell-surface heparan sulfate proteoglycan syndecan-4 have yielded a plethora of information regarding its role in both cell-matrix and growth-factor mediated signaling events. Many of the initial conclusions drawn from such research placed syndecan-4 in a keystone position within various signaling pathways though the generation of syndecan-4 null mice have surprised many in the field by indicating otherwise. These contradictory results place researchers in the frustrating and yet exhilarating position of still asking the question, "What role does syndecan-4 play in life?"

To evaluate the prevalence of carotid lesions and silent coronary artery disease in asymptomatic patients, we studied 31 subjects with one or more risk factors for atherosclerosis. All patients have been studied by means of non invasive cardiologic evaluations and carotid echo color Doppler. The prevalence of carotid and or coronary artery disease was 80%. The prevalence of silent coronary artery disease was 19% and carotid artery disease 61%. Patients with more than one risk factor showed a higher prevalence of carotid lesions (84%) than those with only one risk factor (16%). In conclusion, the prevalence of carotid disease in asymptomatic patients, at risk for atherosclerosis, is high. The echo color Doppler system represents the best approach to study carotid atherosclerosis in vivo. When carotid lesions are present, a non invasive cardiological evaluation may be useful to reveal a silent coronary artery disease.