Plasma and surface diagnostics of silicon nitride thin film coatings generated by SiH4+NH3 RF discharges.

Although plasma processing in low pressure electric discharge reactors has become an extensive and critical step in the fabrication of microelectronic devices, its development has been carried out mostly empirically so far, by changing external reactor parameters in order to develop the best achievable film properties, whereas the intrinsic state of the plasma has been largely unknown [1, 2]. In this work, silicon nitride (SiN) thin films have been grown on silicon samples and on AlGaN/GaN High Electron Mobility Transistors (HEMT) by Plasma Enhanced Chemical Vapor Deposition (PE-CVD). The SiN coatings have been produced in a RF discharge reactor, employing SiH4 and NH3 as precursors, at different electric powers and gas flow ratios. During depositions, the plasmas have been characterized by mass and time resolved quadrupole mass spectrometry, and the depletion ratios of parent gases have been observed. Afterwards, the refractive indexes and growth rates of the films have been analysed by ellipsometry, and their composition, by Fourier Transform Infrared Spectroscopy. The electrical characteristics and frequency responses of these films when deposited on HEMT (where they are just usually employed to passivate these devices against current collapses) have been studied too by means of DC, pulsed currents, and small signal RF measurements. The plasma characteristics for the different deposition conditions have been correlated with the subsequent changes in the properties of the films. A comparison with the results previously reported in the literature is addressed

Hierarchical self-assembly of di-, tri- and tetraphenylalanine peptides capped with two fluorenyl functionalities: from polymorphs to dendrites

Homopeptides with 2, 3 and 4 phenylalanine (Phe) residues and capped with fluorenylmethoxycarbonyl and fluorenylmethyl esters at the N-terminus and C-terminus, respectively, have been synthesized to examine their self-assembly capabilities. Depending on the conditions, the di-and triphenylalanine derivatives self-organize into a wide variety of stable polymorphic structures, which have been characterized: stacked braids, doughnut-like shapes, bundled arrays of nanotubes, corkscrew-like shapes and spherulitic microstructures. These highly aromatic Phe-based peptides also form incipient branched dendritic microstructures, even though they are highly unstable, making their manipulation very difficult. Conversely, the tetraphenylalanine derivative spontaneously self-assembles into stable dendritic microarchitectures made of branches growing from nucleated primary frameworks. The fractal dimension of these microstructures is similar to 1.70, which provides evidence for self-similarity and two-dimensional diffusion controlled growth. DFT calculations at the M06L/6-31G(d) level have been carried out on model beta-sheets since this is the most elementary building block of Phe-based peptide polymorphs. The results indicate that the antiparallel beta-sheet is more stable than the parallel one, with the difference between them growing with the number of Phe residues. Thus, the cooperative effects associated with the antiparallel disposition become more favorable when the number of Phe residues increases from 2 to 4, while those of the parallel disposition remained practically constant.Peer ReviewedPostprint (author's final draft

Prevalence of hepatitis E infection in HIV/HCV-coinfected patients in Spain (2012-2014)

Hepatitis E virus (HEV) has emerged as a relevant pathogen for HIV-infected patients. However, there is scarce data on HEV infection in HIV/HCV-coinfected individuals with advanced fibrosis, which seems to increase the risk of HEV infection and worsen the prognosis of liver disease. We aimed to determine the prevalence of anti-HEV antibodies, acute hepatitis E, resolved hepatitis E, and exposure to HEV in HIV/HCV-coinfected patients and to evaluate associations with clinical and epidemiological characteristics. We performed a cross-sectional study on 198 HIV/HCV-coinfected patients, 30 healthy controls and 36 HIV-monoinfected patients. We found a low concordance between techniques used for detection of anti-HEV antibodies (ELISA versus Immunoblot), particularly in HIV/HCV-coinfected patients. HIV/HCV-coinfected patients showed the highest prevalence of IgG against HEV, resolved hepatitis E, and exposure to HEV (19.2%, 17.2%, and 22.2% respectively). However, we did not find any samples positive for HEV-RNA nor significant differences between groups. Moreover, HIV/HCV-coinfected patients with CD4 T-cells <350 cells/mm3 had higher prevalence for anti-HEV IgG antibodies, resolved hepatitis E, and exposure to HEV than healthy controls or those with CD4 T-cells ≥ 350 cells/mm3 (p = 0.034, p = 0.035, and p = 0.053; respectively). In conclusion, HIV/HCV-coinfected patients in Spain have a high prevalence for IgG anti-HEV antibodies, resolved hepatitis E, and exposure to HEV; particularly patients with CD4+T-cells <350 cells/mm3.The HIV BioBank, integrated in the Spanish AIDS Research Network, is supported by the Institute of Health Carlos III, ISCIII, Spanish Health Ministry (Grant n° RD06/0006/0035 and RD12/0017/0037) as part of the State Plan for Scientific and Technical Research and Innovation and co-financed by ISCIII- Sub-Directorate General for Research Assessment and Promotion and European Regional Development Fund (ERDF) and Foundation for Research and Prevention of AIDS in Spain (FIPSE). The RIS Cohort (CoRIS) is funded by the ISCIII through the Spanish AIDS Research Network (RIS C03/173 and RD12/0017/0018) as part of the State Plan for Scientific and Technical Research and Innovation and co-financed by ISCIII- Sub-Directorate General for Research Assessment and Promotion and European Regional Development Fund (ERDF). This study was supported by grants from Instituto de Salud Carlos III (ISCII; grant numbers grant numbers PI14/01094 and PI17/00657 to JB, PI14/01581, and PI17/00903 to JGG, PI14CIII/00011, and PI17CIII/00003 to SR), Ministerio de Sanidad, Servicios Sociales e Igualdad (grant number EC11–241). The RD16CIII/0002/0002, RD16/0025/0017, and RD16/0025/0018 projects also funded the study as part of the Plan Nacional R + D + I and co-funded by ISCIII- Subdirección General de Evaluación and the Fondo Europeo de Desarrollo Regional (FEDER). JB is an investigator from the Programa de Intensificación de la Actividad Investigadora en el Sistema Nacional de Salud (I3SNS), Refs INT15/00079 and INT16/00100.S

Self-assembly of diphenylalanine with preclick components as capping groups

Alkyne and azide, which are commonly used in the cycloaddition reaction recognized as “click chemistry”, have been used as capping groups of two engineered diphenylalanine (FF) derivatives due to their ability to form weak intermolecular interactions (i.e. dipole–π and π–π stacking). In Poc-FF-N3, alkyne and azide act as N- and C-terminal capping groups, respectively, while such positions are exchanged in N3-FF-OPrp. The self-assembly of such two synthesized peptides has been extensively studied in their “pre-click” state, considering the influence of three different factors: the peptide concentration, the polarity of the medium, and the nature of the substrate. Poc-FF-N3 assembles into microfibers that, depending on the medium and the substrate, can aggregate hierarchically in supramolecular structures with different morphologies. The most distinctive one corresponds to very stable birefringent dendritic-like microstructures, which are derived from the ordered agglomeration of microfibers. These branched supramolecular structures, which are observed under a variety of conditions, are relatively uncommon in short FF sequences. At the molecular level, Poc-FF-N3 organizes in antiparallel β-sheets stabilized by N–H⋯O intermolecular hydrogen bonds and re-enforced by weak interactions between the azide and alkyne groups of neighbouring molecules. In contrast, N3-FF-OPrp exhibits a very poor tendency to organize into structures with a well-defined morphology. Theoretical calculations on model complexes indicate that the tendency of the latter peptide to organize into small amorphous agglomerates is due to its poor ability to form specific intermolecular interactions in comparison with Poc-FF-N3. The implications of the weak interactions induced by the alkyne and azide groups, which strengthen peptide⋯peptide hydrogen bonds and π-ladders due to the stacked aromatic phenyl side groups, are discussed.Peer ReviewedPostprint (author's final draft

Impact of the COVID pandemic on vascular access creation for haemodialysis in 16 spanish haemodialysis centres

The coronavirus disease (COVID) pandemic has resulted in a major disruption in healthcare that has affected several medical and surgical specialties. European and American Vascular Societies have proposed deferring the creation of an elective vascular access (VA) [autologous or prosthetic arteriovenous fistula (AVF) or arteriovenous graft (AVG)] in incident patients on haemodialysis (HD) in the era of the COVID pandemic. The aim of this study is to examine the impact of the COVID pandemic on VA creation and the central venous catheter (CVC)-related hospitalizations and complications in HD patients dialyzed in 16 Spanish HD units of three different regions. We compared retrospectively two periods of time: the pre-COVID (1 January 2019-11 March 2020) and the COVID era (12 March 2020-30 June 2021) in all HD patients (prevalent and incident) dialyzed in our 16 HD centres. The variables analysed were type of VA (CVC, AVF and AVG) created, percentage of CVC in incident and prevalent HD patients, CVC-related hospitalizations and complications (infection, extrusion, disfunction, catheter removal) and percentage of CVC HD sessions that did not reach the goal of Kt (>45) as a marker of HD adequacy. A total of 1791 VAs for HD were created and 905 patients started HD during the study period. Patients who underwent vascular access surgery during the COVID period compared with pre-COVID period were significantly younger, with a significant decrease in surgical activity to create AVFs and AVGs in older HD patients (>75 and >85 years of age). There was a significant increase in CVC placement (from 59.7% to 69.5%; P 45) was observed. COVID has presented a public health system crisis that has influenced VA for HD, with an increase in CVCs relative to AVFs. A decrease in HD sessions that did not reach the HD dose objective was observed in the COVID period compared with a pre-COVID period

The metabolic co-regulator PGC1α suppresses prostate cancer metastasis

Cellular transformation and cancer progression is accompanied by changes in the metabolic landscape. Master co-regulators of metabolism orchestrate the modulation of multiple metabolic pathways through transcriptional programs, and hence constitute a probabilistically parsimonious mechanism for general metabolic rewiring. Here we show that the transcriptional co-activator peroxisome proliferator-activated receptor gamma co-activator 1α (PGC1α) suppresses prostate cancer progression and metastasis. A metabolic co-regulator data mining analysis unveiled that PGC1α is downregulated in prostate cancer and associated with disease progression. Using genetically engineered mouse models and xenografts, we demonstrated that PGC1α opposes prostate cancer progression and metastasis. Mechanistically, the use of integrative metabolomics and transcriptomics revealed that PGC1α activates an oestrogen-related receptor alpha (ERRα)-dependent transcriptional program to elicit a catabolic state and metastasis suppression. Importantly, a signature based on the PGC1α–ERRα pathway exhibited prognostic potential in prostate cancer, thus uncovering the relevance of monitoring and manipulating this pathway for prostate cancer stratification and treatment

Riesgo quirúrgico tras resección pulmonar anatómica en cirugía torácica. Modelo predictivo a partir de una base de datos nacional multicéntrica

Introduction: the aim of this study was to develop a surgical risk prediction model in patients undergoing anatomic lung resections from the registry of the Spanish Video-Assisted Thoracic Surgery Group (GEVATS). Methods: data were collected from 3,533 patients undergoing anatomic lung resection for any diagnosis between December 20, 2016 and March 20, 2018. We defined a combined outcome variable: death or Clavien Dindo grade IV complication at 90 days after surgery. Univariate and multivariate analyses were performed by logistic regression. Internal validation of the model was performed using resampling techniques. Results: the incidence of the outcome variable was 4.29% (95% CI 3.6-4.9). The variables remaining in the final logistic model were: age, sex, previous lung cancer resection, dyspnea (mMRC), right pneumonectomy, and ppo DLCO. The performance parameters of the model adjusted by resampling were: C-statistic 0.712 (95% CI 0.648-0.750), Brier score 0.042 and bootstrap shrinkage 0.854. Conclusions: the risk prediction model obtained from the GEVATS database is a simple, valid, and reliable model that is a useful tool for establishing the risk of a patient undergoing anatomic lung resection

Grupo español de cirugía torácica asistida por videoimagen: método, auditoría y resultados iniciales de una cohorte nacional prospectiva de pacientes tratados con resecciones anatómicas del pulmón

Introduction: our study sought to know the current implementation of video-assisted thoracoscopic surgery (VATS) for anatomical lung resections in Spain. We present our initial results and describe the auditing systems developed by the Spanish VATS Group (GEVATS). Methods: we conducted a prospective multicentre cohort study that included patients receiving anatomical lung resections between 12/20/2016 and 03/20/2018. The main quality controls consisted of determining the recruitment rate of each centre and the accuracy of the perioperative data collected based on six key variables. The implications of a low recruitment rate were analysed for '90-day mortality' and 'Grade IIIb-V complications'. Results: the series was composed of 3533 cases (1917 VATS; 54.3%) across 33 departments. The centres' median recruitment rate was 99% (25-75th:76-100%), with an overall recruitment rate of 83% and a data accuracy of 98%. We were unable to demonstrate a significant association between the recruitment rate and the risk of morbidity/mortality, but a trend was found in the unadjusted analysis for those centres with recruitment rates lower than 80% (centres with 95-100% rates as reference): grade IIIb-V OR=0.61 (p=0.081), 90-day mortality OR=0.46 (p=0.051). Conclusions: more than half of the anatomical lung resections in Spain are performed via VATS. According to our results, the centre's recruitment rate and its potential implications due to selection bias, should deserve further attention by the main voluntary multicentre studies of our speciality. The high representativeness as well as the reliability of the GEVATS data constitute a fundamental point of departure for this nationwide cohort

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London