Simulación mediante dinámica molecular de la irradiación de sílice con iones rápidos pesados

Simulación mediante dinámica molecular de la irradiación de sílice con iones rápidos pesado

A molecular dynamics study of swift heavy ion irradiation of amorphous silica: the role of thermal effects

Irradiation with swift heavy ions (SHI), roughly defined as those having atomic masses larger than 15 and energies exceeding 1 MeV/amu, may lead to significant modification of the irradiated material in a nanometric region around the (straight) ion trajectory (latent tracks). In the case of amorphous silica, SHI irradiation originates nano-tracks of higher density than the virgin material (densification). As a result, the refractive index is increased with respect to that of the surroundings. Moreover, track overlapping leads to continuous amorphous layers that present a significant contrast with respect to the pristine substrate. We have recently demonstrated that SHI irradiation produces a large number of point defects, easily detectable by a number of experimental techniques (work presented in the parallel conference ICDIM). The mechanisms of energy transfer from SHI to the target material have their origin in the high electronic excitation induced in the solid. A number of phenomenological approaches have been employed to describe these mechanisms: coulomb explosion, thermal spike, non-radiative exciton decay, bond weakening. However, a detailed microscopic description is missing due to the difficulty of modeling the time evolution of the electronic excitation. In this work we have employed molecular dynamics (MD) calculations to determine whether the irradiation effects are related to the thermal phenomena described by MD (in the ps domain) or to electronic phenomena (sub-ps domain), e.g., exciton localization. We have carried out simulations of up to 100 ps with large boxes (30x30x8 nm3) using a home-modified version of MDCASK that allows us to define a central hot cylinder (ion track) from which heat flows to the surrounding cold bath (unirradiated sample). We observed that once the cylinder has cooled down, the Si and O coordination numbers are 4 and 2, respectively, as in virgin silica. On the other hand, the density of the (cold) cylinder increases with respect to that of silica and, furthermore, the silica network ring size decreases. Both effects are in agreement with the observed densification. In conclusion, purely thermal effects do not explain the generation of point defects upon irradiation, but they do account for the silica densification

p38γ and p38δ as biomarkers in the interplay of colon cancer and inflammatory bowel diseases

descripción no proporcionada por scopusThis research was funded by the MCIN/AEI/10.13039/501100011033 (PID2019-108349RB100 and SAF2016-79792R) to AC and JJSE; Villum Foundation, grant no. 13152 to KA; by Agencia Estatal de Investigación (PID2019-104867RBI00/AEI/10.13039/501100011033) and the Instituto de Salud Carlos III- Fondo Europeo de Desarrollo Regional (CIBERONC/CB16/12/00273 and ICI20/00057) to AM and AB. PF received MCIN FPI fellowship (BES-2017-080139)

Alternative p38MAPKs as biomarkers in the interplay of colon cancer and inflammatory bowel diseases

Trabajo presentado en el 44º Congreso Nacional de la Sociedad Española de Bioquímica y Biología Molecular (SEBBM), celebrado en Málaga (España) del 06 al 09 de septiembre de 2022.Chronic inflammation in inflammatory bowel disease (IBD) is a risk factor for Colorectal cancer (CRC) development, but our understanding of this interplay at a molecular level is still limited. p38γ and p38δ, are central in the development of mouse colitis-associated CRC (CAC) by modulating the inflammatory immune response. However, their implication in human CRC and IBD is not well defined. In this study we perform an integrative analysis of p38γ and p38δ mRNA and protein expression and activation in human patients; using human CRC derived organoids and plasma samples, as well as data from different human CRC and IBD mRNA databases. We found that, p38δ levels were decreased, whereas p38γ expression and phosphorylation were significantly increased in CRC compared to normal colon samples. This increase correlated with the expression of genes implicated in inflammation. Examine of p38γ/p38δ in IBD patients showed that p38γ mRNA and protein levels were increased in Crohn’s disease and ulcerative colitis patients. Contrary, p38δ mRNA was significantly decreased. We also investigated the expression of miRNAs, miR-128-2, miR133a and miR-155, implicated in inflammation and cancer development. In mouse model of colitis and CAC, miR128-2 level was regulated by p38γ/p38δ. In the plasma of IBD and CRC patients, miR128-2 was increased compared to healthy donors, and this correlated with p38γ and p38δ levels. Our results show an opposite regulation of p38γ and p38δ in both CRC and IBD; and suggest that p38γ acts as a link between colitis and CRC by favouring an inflammatory environment that promotes tumour development. We provided evidence that p38γ/p38δ, together with miR-128-2, can be useful as biomarkers, and as potential treatment targets, for colitis and early-stage CRC

The ERA-EDTA Registry Annual Report 2018 : a summary

Background. The European Renal Association - European Dialysis and Transplant Association (ERA-EDTA) Registry collects data on kidney replacement therapy (KRT) via national and regional renal registries in Europe and countries bordering the Mediterranean Sea. This article summarizes the 2018 ERA-EDTA Registry Annual Report, and describes the epidemiology of KRT for kidney failure in 34 countries. Methods. Individual patient data on patients undergoing KRT in 2018 were provided by 34 national or regional renal registries and aggregated data by 17 registries. The incidence and prevalence of KRT, the kidney transplantation activity and the survival probabilities of these patients were calculated. Results. In 2018, the ERA-EDTA Registry covered a general population of 636 million people. Overall, the incidence of KRT for kidney failure was 129 per million population (p.m.p.), 62% of patients were men, 51% were >= 65years of age and 20% had diabetes mellitus as cause of kidney failure. Treatment modality at the onset of KRT was haemodialysis (HD) for 84%, peritoneal dialysis (PD) for 11% and pre-emptive kidney transplantation for 5% of patients. On 31 December 2018, the prevalence of KRT was 897 p.m.p., with 57% of patients on HD, 5% on PD and 38% living with a kidney transplant. The transplant rate in 2018 was 35 p.m.p.: 68% received a kidney from a deceased donor, 30% from a living donor and for 2% the donor source was unknown. For patients commencing dialysis during 2009-13, the unadjusted 5-year survival probability was 42.6%. For patients receiving a kidney transplant within this period, the unadjusted 5-year survival probability was 86.6% for recipients of deceased donor grafts and 93.9% for recipients of living donor grafts.Peer reviewe

Roflumilast in moderate-to-severe chronic obstructive pulmonary disease treated with longacting bronchodilators: two randomised clinical trials

Background Patients with chronic obstructive pulmonary disease (COPD) have few options for treatment. The efficacy and safety of the phosphodiesterase-4 inhibitor roflumilast have been investigated in studies of patients with moderate-to-severe COPD, but not in those concomitantly treated with longacting inhaled bronchodilators. The effect of roflumilast on lung function in patients with COPD that is moderate to severe who are already being treated with salmeterol or tiotropium was investigated. Methods In two double-blind, multicentre studies done in an outpatient setting, after a 4-week run-in, patients older than 40 years with moderate-to-severe COPD were randomly assigned to oral roflumilast 500 mu g or placebo once a day for 24 weeks, in addition to salmeterol (M2-127 study) or tiotropium (M2-128 study). The primary endpoint was change in prebronchodilator forced expiratory volume in 1s (FEV(1)). Analysis was by intention to treat. The studies are registered with ClinicalTrials.gov, number NCT00313209 for M2-127, and NCT00424268 for M2-128. Findings In the salmeterol plus roflumilast trial, 466 patients were assigned to and treated with roflumilast and 467 with placebo; in the tiotropium plus roflumilast trial, 371 patients were assigned to and treated with roflumilast and 372 with placebo. Compared with placebo, roflumilast consistently improved mean prebronchodilator FEV(1) by 49 mL (p<0.0001) in patients treated with salmeterol, and 80 mL (p<0.0001) in those treated with tiotropium. Similar improvement in postbronchodilator FEV(1) was noted in both groups. Furthermore, roflumilast had beneficial effects on other lung function measurements and on selected patient-reported outcomes in both groups. Nausea, diarrhoea, weight loss, and, to a lesser extent, headache were more frequent in patients in the roflumilast groups. These adverse events were associated with increased patient withdrawal. Interpretation Roflumilast improves lung function in patients with COPD treated with salmeterol or tiotropium, and could become an important treatment for these patients

The ERA-EDTA Registry Annual Report 2018 : A summary

Funding Information: The ERA-EDTA Registry is funded by the ERA-EDTA. This article was written by A.K. et al. on behalf of the ERA-EDTA Registry, which is an official body of the ERA-EDTA. In addition, V.S.S. reports grants from ERA-EDTA, during the conduct of the study; S.B. reports personal fees from Astra Zeneca, outside the submitted work; P.F. reports personal fees from Baxter, outside the submitted work; and K.J.J. reports grants from ERA-EDTA, during the conduct of the study. Publisher Copyright: © The Author(s) 2020. Published by Oxford University Press on behalf of ERA-EDTA.Background. The European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry collects data on kidney replacement therapy (KRT) via national and regional renal registries in Europe and countries bordering the Mediterranean Sea. This article summarizes the 2018 ERA-EDTA Registry Annual Report, and describes the epidemiology of KRT for kidney failure in 34 countries. Methods. Individual patient data on patients undergoing KRT in 2018 were provided by 34 national or regional renal registries and aggregated data by 17 registries. The incidence and prevalence of KRT, the kidney transplantation activity and the survival probabilities of these patients were calculated. Results. In 2018, the ERA-EDTA Registry covered a general population of 636 million people. Overall, the incidence of KRT for kidney failure was 129 per million population (p.m.p.), 62% of patients were men, 51% were 65 years of age and 20% had diabetes mellitus as cause of kidney failure. Treatment modality at the onset of KRT was haemodialysis (HD) for 84%, peritoneal dialysis (PD) for 11% and pre-emptive kidney transplantation for 5% of patients. On 31 December 2018, the prevalence of KRT was 897 p.m.p., with 57% of patients on HD, 5% on PD and 38% living with a kidney transplant. The transplant rate in 2018 was 35 p.m.p.: 68% received a kidney from a deceased donor, 30% from a living donor and for 2% the donor source was unknown. For patients commencing dialysis during 2009-13, the unadjusted 5-year survival probability was 42.6%. For patients receiving a kidney transplant within this period, the unadjusted 5-year survival probability was 86.6% for recipients of deceased donor grafts and 93.9% for recipients of living donor grafts.Peer reviewe

The V471A polymorphism in autophagy-related gene ATG7 modifies age at onset specifically in Italian Huntington disease patients

The cause of Huntington disease (HD) is a polyglutamine repeat expansion of more than 36 units in the huntingtin protein, which is inversely correlated with the age at onset of the disease. However, additional genetic factors are believed to modify the course and the age at onset of HD. Recently, we identified the V471A polymorphism in the autophagy-related gene ATG7, a key component of the autophagy pathway that plays an important role in HD pathogenesis, to be associated with the age at onset in a large group of European Huntington disease patients. To confirm this association in a second independent patient cohort, we analysed the ATG7 V471A polymorphism in additional 1,464 European HD patients of the “REGISTRY” cohort from the European Huntington Disease Network (EHDN). In the entire REGISTRY cohort we could not confirm a modifying effect of the ATG7 V471A polymorphism. However, analysing a modifying effect of ATG7 in these REGISTRY patients and in patients of our previous HD cohort according to their ethnic origin, we identified a significant effect of the ATG7 V471A polymorphism on the HD age at onset only in the Italian population (327 patients). In these Italian patients, the polymorphism is associated with a 6-years earlier disease onset and thus seems to have an aggravating effect. We could specify the role of ATG7 as a genetic modifier for HD particularly in the Italian population. This result affirms the modifying influence of the autophagic pathway on the course of HD, but also suggests population-specific modifying mechanisms in HD pathogenesis

Time to Switch to Second-line Antiretroviral Therapy in Children With Human Immunodeficiency Virus in Europe and Thailand.

Background: Data on durability of first-line antiretroviral therapy (ART) in children with human immunodeficiency virus (HIV) are limited. We assessed time to switch to second-line therapy in 16 European countries and Thailand. Methods: Children aged <18 years initiating combination ART (≥2 nucleoside reverse transcriptase inhibitors [NRTIs] plus nonnucleoside reverse transcriptase inhibitor [NNRTI] or boosted protease inhibitor [PI]) were included. Switch to second-line was defined as (i) change across drug class (PI to NNRTI or vice versa) or within PI class plus change of ≥1 NRTI; (ii) change from single to dual PI; or (iii) addition of a new drug class. Cumulative incidence of switch was calculated with death and loss to follow-up as competing risks. Results: Of 3668 children included, median age at ART initiation was 6.1 (interquartile range (IQR), 1.7-10.5) years. Initial regimens were 32% PI based, 34% nevirapine (NVP) based, and 33% efavirenz based. Median duration of follow-up was 5.4 (IQR, 2.9-8.3) years. Cumulative incidence of switch at 5 years was 21% (95% confidence interval, 20%-23%), with significant regional variations. Median time to switch was 30 (IQR, 16-58) months; two-thirds of switches were related to treatment failure. In multivariable analysis, older age, severe immunosuppression and higher viral load (VL) at ART start, and NVP-based initial regimens were associated with increased risk of switch. Conclusions: One in 5 children switched to a second-line regimen by 5 years of ART, with two-thirds failure related. Advanced HIV, older age, and NVP-based regimens were associated with increased risk of switch