Influence of solids concentration on the microstructure of suspension plasma sprayed Y-TZP/Al2O3/SiC composite coatings

The present research focuses on the effect of feedstock suspension solid concentration on the microstructure of suspension plasma sprayed Y-TZP/Al2O3/SiC composite coatings. For this purpose, concentrated aqueous suspensions were prepared at 10, 20 and 30 vol.% of particles. Suspensions were characterised in terms of colloidal stability, rheological behaviour and sedimentation trend. The optimised suspensions were plasma sprayed, and the thickness, porosity, amount of resolidified particles and SiC content in the coatings were evaluated by optical microscopy, scanning electron microscopy and X-ray diffraction. The results revealed that stand-off distance and suspension solid content have a strong and similar influence on the coating microstructure due to the great impact that these two parameters exerts on the energy that particles and substrate receive during plasma operation. Thus, cauliflower-like microstructure is well-developed in most of the coatings, particularly for longer distances and lower solid contents. Porosity and amount of resolidified particles in the coatings are favoured by increasing the stand-off distance and decreasing the solids content, while thickness is strongly affected by solids content variation. On the other hand, Rietveld method from X-ray diffraction showed that large amount of the initial SiC was preserved in the final coatings whereas this amount remains almost constant for the three suspension feedstock tested

Microstructure assessment of suspension plasma spraying coatings from multicomponent submicronic Y-TZP/Al2O3/SiC particles

In this research, Suspension Plasma Spraying (SPS) technique was used for the thermal deposition of a multicomponent mixture made up of an Y-TZP/Al2O3 matrix with SiC particles. Two suspensions of Y-TZP and Al2O3 with different SiC particles content (6 wt% and 12 wt%) were tested as feedstocks in the SPS process. Three stand-off distances were varied in order to assess coating microstructure and evaluate the presence of SiC in the final coatings. Coatings were characterised in terms of porosity, microstructure and phase distribution. The estimate of the amount of SiC in the coating was carried out by XRD technique. Findings showed typical cauliflower-like SPS microstructure which intensifies with stand-off distance. Coatings porosity varied significantly between 8% and 25% whereas minimum porosity was found for the intermedium stand-off distance of 40 mm. Microstructure analysis also revealed the presence of SiC particles in the coatings which was confirmed by EDX analysis, overall XRD tests as well as TG analysis. Finally, evaluation of SiC content in the final coatings by means of XRD analysis showed that most of SiC particles (c.a 80%) of the feedstocks were preserved in the final coatings

Microfluidic rheology: A new approach to measure viscosity of ceramic suspensions at extremely high shear rates

This paper describes the operation principles of a micro-scale rheometry equipment based on the technology of microchannels on a chip and compares it with a conventional macro-scale rotational rheometer. Both techniques are used for the study of different solutions and suspensions of ceramic particles with different saccharides, which are subjected to a wide variety of shear rates from their preparation to their processing and injection in plasma spraying processes. The results have shown a clear difference between the rheological values obtained between both equipment, clearly influenced by the different measurement method. However, the microfluidic technique has higher accuracy to characterise fluids at high shear rates and low viscosities, and the apparent shear thickening observed in rotational rheometry for low viscosity samples due to wall slippage is not observed. In contrast, the fine microchannels of are easily clogged in concentrated suspensions

Effect of fructose-containing feedstocks on the microstructure of multicomponent coatings deposited by suspension plasma spraying

This work addressed to investigate the use of fructose as an additive in the water-based suspension feedstock of a Y-TZP/Al2O3/SiC multicomponent coating manufactured by suspension plasma spraying. The effect of fructose on suspension rheology and surface tension and on the microstructure and thermal conductivity of the resulting coatings was assessed. It was observed that addition of fructose slightly affected the rheological behaviour of the suspensions while a strong decrease in the surface tension of water occurred. The fructose addition led to the development of columnar-like structures, probably associated with its effect on surface tension. X-ray diffraction patterns in the final coating displayed that crystallinity of tetragonal zirconia formed when fructose was added whereas silicon carbide crystalline phase was practically preserved. The determination of thermal conductivity showed that the formation of a controlled columnar structure along with inter-columnar porosity can be beneficial for thermal insulation

Energy Metabolism in H460 Lung Cancer Cells: Effects of Histone Deacetylase Inhibitors

BACKGROUND: Tumor cells are characterized by accelerated growth usually accompanied by up-regulated pathways that ultimately increase the rate of ATP production. These cells can suffer metabolic reprogramming, resulting in distinct bioenergetic phenotypes, generally enhancing glycolysis channeled to lactate production. In the present work we showed metabolic reprogramming by means of inhibitors of histone deacetylase (HDACis), sodium butyrate and trichostatin. This treatment was able to shift energy metabolism by activating mitochondrial systems such as the respiratory chain and oxidative phosphorylation that were largely repressed in the untreated controls. METHODOLOGY/PRINCIPAL FINDINGS: Various cellular and biochemical parameters were evaluated in lung cancer H460 cells treated with the histone deacetylase inhibitors (HDACis), sodium butyrate (NaB) and trichostatin A (TSA). NaB and TSA reduced glycolytic flux, assayed by lactate release by H460 cells in a concentration dependent manner. NaB inhibited the expression of glucose transporter type 1 (GLUT 1), but substantially increased mitochondria bound hexokinase (HK) activity. NaB induced increase in HK activity was associated to isoform HK I and was accompanied by 1.5 fold increase in HK I mRNA expression and cognate protein biosynthesis. Lactate dehydrogenase (LDH) and pyruvate kinase (PYK) activities were unchanged by HDACis suggesting that the increase in the HK activity was not coupled to glycolytic flux. High resolution respirometry of H460 cells revealed NaB-dependent increased rates of oxygen consumption coupled to ATP synthesis. Metabolomic analysis showed that NaB altered the glycolytic metabolite profile of intact H460 cells. Concomitantly we detected an activation of the pentose phosphate pathway (PPP). The high O(2) consumption in NaB-treated cells was shown to be unrelated to mitochondrial biogenesis since citrate synthase (CS) activity and the amount of mitochondrial DNA remained unchanged. CONCLUSION: NaB and TSA induced an increase in mitochondrial function and oxidative metabolism in H460 lung tumor cells concomitant with a less proliferative cellular phenotype

The management of acute venous thromboembolism in clinical practice. Results from the European PREFER in VTE Registry

Venous thromboembolism (VTE) is a significant cause of morbidity and mortality in Europe. Data from real-world registries are necessary, as clinical trials do not represent the full spectrum of VTE patients seen in clinical practice. We aimed to document the epidemiology, management and outcomes of VTE using data from a large, observational database. PREFER in VTE was an international, non-interventional disease registry conducted between January 2013 and July 2015 in primary and secondary care across seven European countries. Consecutive patients with acute VTE were documented and followed up over 12 months. PREFER in VTE included 3,455 patients with a mean age of 60.8 ± 17.0 years. Overall, 53.0 % were male. The majority of patients were assessed in the hospital setting as inpatients or outpatients (78.5 %). The diagnosis was deep-vein thrombosis (DVT) in 59.5 % and pulmonary embolism (PE) in 40.5 %. The most common comorbidities were the various types of cardiovascular disease (excluding hypertension; 45.5 %), hypertension (42.3 %) and dyslipidaemia (21.1 %). Following the index VTE, a large proportion of patients received initial therapy with heparin (73.2 %), almost half received a vitamin K antagonist (48.7 %) and nearly a quarter received a DOAC (24.5 %). Almost a quarter of all presentations were for recurrent VTE, with >80 % of previous episodes having occurred more than 12 months prior to baseline. In conclusion, PREFER in VTE has provided contemporary insights into VTE patients and their real-world management, including their baseline characteristics, risk factors, disease history, symptoms and signs, initial therapy and outcomes

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic