Recent advances in the development of magnetically recoverable metal nanoparticle catalysts

The aim of this Account is to provide an overview of our current research activities on the design and modification of superparamagnetic nanomaterials for application in the field of magnetic separation and catalysis. First, an introduction of magnetism and magnetic separation is done. Then, the synthetic strategies that have been developed for generating superparamagnetic nanoparticles spherically coated by silica and other oxides, with a focus on well characterized systems prepared by methods that generate samples of high quality and easy to scale-up, are discussed. A set of magnetically recoverable catalysts prepared in our research group by the unique combination of superparamagnetic supports and metal nanoparticles is highlighted. This Account is concluded with personal remarks and perspectives on this research field

The genetics of exceptional longevity identifies new druggable targets forvascular protection and repair

Therapeutic angiogenesis is a relatively new medical strategy in the field of cardiovascular diseases. The underpinning concept is that angiogenic growth factors or proangiogenic cells could be exploited therapeutically in cardiovascular patients to enhance native revascularization responses to an ischemic insult, thereby accelerating tissue healing. The initial enthusiasm generated by preclinical studies has been tempered by the modest success of clinical trials assessing therapeutic angiogenesis. Similarly, proangiogenic cell therapy has so far not maintained the original promises. Intriguingly, the current trend is to consider regeneration as a prerogative of the youngest organism. Consequentially, the embryonic and foetal models are attracting much attention for clinical translation into corrective modalities in the adulthood. Scientists seem to undervalue the lesson from Mother Nature, e.g. all humans are born young but very few achieve the goal of an exceptional healthy longevity. Either natural experimentation is driven by a supreme intelligence or stochastic phenomena, one has to accept the evidence that healthy longevity is the fruit of an evolutionary process lasting million years. It is therefore extremely likely that results of this natural experimentation are more reliable and translatable than the intensive, but very short human investigation on mechanisms governing repair and regeneration. With this preamble in mind, here we propose to shift the focus from the very beginning to the very end of human life and thus capture the secret of prolonged health span to improve well-being in the adulthood

Latin Americans and Caribbeans in Europe. A cross-country analysis

With the beginning of the 21st century, there has been an acceleration of migratory flows from Latin America and the Caribbean (LAC) to Europe. As a result, and despite the negative impact of the economic crisis, 4.6 million Latin American and Caribbean immigrants reside in Europe, half of them in Spain. This article analyses the recent evolution of these migratory flows, their territorial distribution, and their demographic profiles according to the 2011 European census data disseminated by a new tool -the Census Hub- implemented by the European Statistical System. The analysis shows the existence of a high LAC immigrant concentration in Spain and in certain European cities, a marked young and feminized demographic profile, a great variety of educational levels and a different insertion in each European labour market, although many LAC immigrants work in low-skill occupations, being overqualified and underemployed in most of the countries

Investigation of the effects of atmospheric pressure cold plasma on human cells and tissues

Atmospheric pressure cold plasma (APCP) is a novel tool in medicine for tissue disinfection. We recently reported that 2 minutes of APCP generated by a new portable device that ionizes a flow of helium gas exerted an antimicrobial effect, mainly due to the action of reactive oxygen species (ROS) (P. Brun et al., 2012). Since ROS induced DNA lesions that could lead to point mutations, before using plasma in medical treatment it is important to ascertain the safe usage of this device. In the study presented, we analysed the presence of ROS levels, pre-mutagenic 8-oxodeoxyguanosine (8-OHdG) and the expression of OGG1, a DNA glycosylase specific for the removal of 8-OHdG lesions in cell (fibroblasts and keratocytes) cultures. ROS levels in APCP-exposed microorganisms and keratocytes were detected by 2’,7’-dichlorofluorescein diacetate (HDCF-DA) fluorescence; the potential genotoxic effects of plasma were evaluated by analyses of cell cycle distribution, externalization of phosphatidylserine, HPLC determination of 8-OHdG expression, qRT-PCR and Western blotting of OGG1 gene and protein, at set time intervals. Our results demonstrated that APCP induced ROS formation in exposed human cells, a transient 8-OHdG expression and a consequent adaptative OGG1 response at the transcriptional and translational level. In conclusion, the short application of APCP to cells and tissues has a disinfection effect and leads to time-restricted ROS generation and to oxidative-stress related responses

Polymer versus phosphine stabilized Rh nanoparticles as components of supported catalysts : implication in the hydrogenation of cyclohexene model molecule

The solution synthesis of rhodium nanoparticles (Rh NPs) was achieved from the organometallic complex [Rh(η³-C₃H₅)₃] under mild reaction conditions in the presence of a polymer (PVP), a monophosphine (PPh₃) and a diphosphine (dppb) as a stabilizer, leading to very small Rh NPs of 2.2, 1.3 and 1.7 nm mean size, with PVP, PPh3 and dppb, respectively. The surface properties of these nanoparticles were compared using a model catalysis reaction namely, hydrogenation of cyclohexene, first under colloidal conditions and then under supported conditions after their immobilization onto an amino functionalized silica-coated magnetite support. PVP-stabilized Rh NPs were the most active catalyst whatever the catalytic conditions as a result of a strong coordination of the phosphine ligands at the metal surface that blocks some surface atoms even after several recycles of the supported nanocatalysts and limit the reactivity of the metallic surface

Hematopoietic progenitor cell liabilities and alarmins S100A8/A9-related inflammaging associate with frailty and predict poor cardiovascular outcomes in older adults

Frailty affects the physical, cognitive, and social domains exposing older adults to an increased risk of cardiovascular disease and death. The mechanisms linking frailty and cardiovascular outcomes are mostly unknown. Here, we studied the association of abundance (flow cytometry) and gene expression profile (RNAseq) of stem/progenitor cells (HSPCs) and molecular markers of inflammaging (ELISA) with the cardiorespiratory phenotype and prospective adverse events of individuals classified according to levels of frailty. Two cohorts of older adults were enrolled in the study. In a cohort of pre‐frail 35 individuals (average age: 75 years), a physical frailty score above the median identified subjects with initial alterations in cardiorespiratory function. RNA sequencing revealed S100A8/A9 upregulation in HSPCs from the bone marrow (>10‐fold) and peripheral blood (>200‐fold) of individuals with greater physical frailty. Moreover higher frailty was associated with increased alarmins S100A8/A9 and inflammatory cytokines in peripheral blood. We then studied a cohort of 104 more frail individuals (average age: 81 years) with multidomain health deficits. Reduced levels of circulating HSPCs and increased S100A8/A9 concentrations were independently associated with the frailty index. Remarkably, low HSPCs and high S100A8/A9 simultaneously predicted major adverse cardiovascular events at 1‐year follow‐up after adjustment for age and frailty index. In conclusion, inflammaging characterized by alarmin and pro‐inflammatory cytokines in pre‐frail individuals is mirrored by the pauperization of HSPCs in frail older people with comorbidities. S100A8/A9 is upregulated within HSPCs, identifying a phenotype that associates with poor cardiovascular outcomes