High-efficiency mixing of fine powders via sound assisted fluidized bed for metal foam production by an innovative cold gas dynamic spray deposition method

Metal foams are an interesting class of materials with very low specific weight and unusual physical, mechanical and acoustic properties due to the porous structure (1). These materials are currently manufactured by means of several conventional processes (2), limited by the impossibility to produce foams with complex geometry. This paper deals with the study of an innovative method to produce complex shaped precursors for aluminum foams through cold gas dynamic spray deposition process (CGDS), aluminum alloy (AlSi12) and titanium-hydride (TiH2) being the metal and the blowing agent, respectively. However, the success of this approach strongly depends on the achievement of a homogenous and deep mixing between AlSi12 and TiH2 fine powders, belonging to group C of Geldart’s classification. Classical mixing methods (such as tumbling mixers, convective mixers, high-shear mixers, etc.) are suitable for large non-cohesive particles (\u3e 30µm) but not for micronic particles (3), agglomerated due to strong interparticle forces. Alternatively, new wet and dry mixing techniques have been proposed for fine particles (4), suffering from different disadvantages: additional steps of filtration/drying are needed for wet methods, whereas, dry methods generally involves the reduction of the granulometry and the damaging or contamination of the original powders. The sound assisted fluidization technology (140dB-80Hz) has been adopted in this work to overcome the technical issues of mixing cohesive powders (5), thus obtaining a mixing to the scale of the primary particles in a simple, economic, not intrusive and not destructive way (the properties and morphology of the original particles were preserved). Therefore, the mixed powders were then sprayed by means of the proposed CGDS process on a stainless steel sheet to obtain the precursor. This was then heated up in a furnace at 600°C for 10 minutes to obtain the foam. In particular, two different types of mixtures with 1 wt% and 2.5 wt% of TiH2 were investigated; moreover, air compressed as well as helium were used as CGDS carrier gas in order to ensure a higher impact velocity and a better compacting of the powders. A very efficient mixing of powders has been achieved as confirmed by SEM/EDS analysis performed on samples taken from the sound assisted fluidized bed (Fig.1a) and by the time-dependence of the mixing degree (Fig.1b). Macrographs of created porous structures (Fig.2) showed that the coupling of sound assisted fluidization and CGDS process under optimal conditions is a promising and effective technique in manufacturing aluminum precursors for metal foams. Please click Additional Files below to see the full abstract

No evidence of XMRV in prostate cancer cohorts in the Midwestern United States

Background: Xenotropic murine leukemia virus (MLV)-related virus (XMRV) was initially identified in prostate cancer (PCa) tissue, particularly in the prostatic stromal fibroblasts, of patients homozygous for the RNASEL R462Q mutation. A subsequent study reported XMRV antigens in malignant prostatic epithelium and association of XMRV infection with PCa, especially higher-grade tumors, independently of the RNASEL polymorphism. Further studies showed high prevalence of XMRV or related MLV sequences in chronic fatigue syndrome patients (CFS), while others found no, or low, prevalence of XMRV in a variety of diseases including PCa or CFS. Thus, the etiological link between XMRV and human disease remains elusive. To address the association between XMRV infection and PCa, we have tested prostate tissues and human sera for the presence of viral DNA, viral antigens and anti-XMRV antibodies.Results: Real-time PCR analysis of 110 PCa (Gleason scores > 4) and 40 benign and normal prostate tissues identified six positive samples (5 PCa and 1 non-PCa). No statistical link was observed between the presence of proviral DNA and PCa, PCa grades, and the RNASEL R462Q mutation. The amplified viral sequences were distantly related to XMRV, but nearly identical to endogenous MLV sequences in mice. The PCR positive samples were also positive for mouse mitochondrial DNA by nested PCR, suggesting contamination of the samples with mouse DNA. Immuno-histochemistry (IHC) with an anti-XMRV antibody, but not an anti-MLV antibody that recognizes XMRV, sporadically identified antigen-positive cells in prostatic epithelium, irrespectively of the status of viral DNA detection. No serum (159 PCa and 201 age-matched controls) showed strong neutralization of XMRV infection at 1: 10 dilution.Conclusion: The lack of XMRV sequences or strong anti-XMRV neutralizing antibodies indicates no or very low prevalence of XMRV in our cohorts. We conclude that real-time PCR- and IHC-positive samples were due to laboratory contamination and non-specific immune reactions, respectively

Lipid profile improvement in virologically suppressed hiv-1-infected patients switched to dolutegravir/ abacavir/lamivudine: Data from the SCOLTA project

open13noIntroduction: Metabolic disorders are common amongst HIV-infected patients. Data from real-life setting on the impact of DTG/ABC/3TC in virologically suppressed HIV-infected patients are scarce. Methods: We investigated the modification of metabolic profile including fasting glucose, lipid profile and markers of insulin resistance (IR) in experienced patients switching from a boosted protease inhibitors (bPI) or a non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimen to DTG/ABC/3TC in a prospective, observational, multicenter study. Results: We enrolled 131 HIV-infected patients, of whom 91 (69.5%) males, mean age was 50.5±10.6 years. CDC stage was A in 66 (50.4%) patients, of whom 91 (69.5%) had acquired HIV through sexual contacts. The previous regimen was bPI-based in 79 patients (60.3%) and NNRTI-based in 52 (39.7%). Patients switching from NNRTI showed a significant reduction at week 24 in total cholesterol (TC) and low-density lipoprotein cholesterol (LDL). Triglycerides/high-density lipoprotein cholesterol (TG/HDL) ratio, HDL, median TG and TG/HDL ratio did not show significant modification during follow-up times. Among patients switching from a bPI, we observed a significant reduction in TC and LDL at both follow-up times and a slight increase in HDL. Triglycerides/HDL ratio, median TG and TG/HDL ratio showed a decrease over time that became significant at weeks 24 and 48. Blood glucose levels did not significantly vary during the observation period in patients switching from both bPI and NNRTI-based regimens. Conclusion: Our data suggest an improvement in lipid profile and TG/HDL ratio in pretreated HIV-1-infected patients who switched to DTG/ABC/3TC over 48 weeks, especially in those previously receiving a bPI-based regimen.openBagella P.; Squillace N.; Ricci E.; Gulminetti R.; De Socio G.V.; Taramasso L.; Pellicano G.; Menzaghi B.; Celesia B.M.; Dentone C.; Orofino G.; Bonfanti P.; Madeddu G.Bagella, P.; Squillace, N.; Ricci, Elena; Gulminetti, R.; De Socio, G. V.; Taramasso, L.; Pellicano, G.; Menzaghi, B.; Celesia, B. M.; Dentone, C.; Orofino, G.; Bonfanti, P.; Madeddu, G

The discovery of potent, selective, and reversible inhibitors of the house dust mite peptidase allergen Der p 1: an innovative approach to the treatment of allergic asthma.

Blocking the bioactivity of allergens is conceptually attractive as a small-molecule therapy for allergic diseases but has not been attempted previously. Group 1 allergens of house dust mites (HDM) are meaningful targets in this quest because they are globally prevalent and clinically important triggers of allergic asthma. Group 1 HDM allergens are cysteine peptidases whose proteolytic activity triggers essential steps in the allergy cascade. Using the HDM allergen Der p 1 as an archetype for structure-based drug discovery, we have identified a series of novel, reversible inhibitors. Potency and selectivity were manipulated by optimizing drug interactions with enzyme binding pockets, while variation of terminal groups conferred the physicochemical and pharmacokinetic attributes required for inhaled delivery. Studies in animals challenged with the gamut of HDM allergens showed an attenuation of allergic responses by targeting just a single component, namely, Der p 1. Our findings suggest that these inhibitors may be used as novel therapies for allergic asthma

Clusterization of co-morbidities and multi-morbidities among persons living with HIV: a cross-sectional study

Background: Among people living with HIV (PLWH), the prevalence of non-HIV related co-morbidities is increasing. Aim of the present study is to describe co-morbidity and multi-morbidity, their clustering mode and the potential disease-disease interactions in a cohort of Italian HIV patients. Methods: Cross-sectional analysis conducted by the Coordinamento Italiano per lo Studio di Allergia e Infezioni da HIV (CISAI) on adult subjects attending HIV-outpatient facilities. Non-HIV co-morbidities included: cardiovascular disease, diabetes mellitus, hypertension, oncologic diseases, osteoporosis, probable case of chronic obstructive pulmonary disease (COPD), hepatitis C virus (HCV) infection, psychiatric illness, kidney disease. Multi-morbidity was defined as the presence of two or more co-morbidities. Results: One thousand and eighty-seven patients were enrolled in the study (mean age 47.9 \ub1 10.8). One hundred-ninety patients (17.5%) had no co-morbidity, whereas 285 (26.2%) had one condition and 612 (56.3%) were multi-morbid. The most recurrent associations were: 1) dyslipidemia + hypertension (237, 21.8%); 2) dyslipidemia + COPD (188, 17.3%); 3) COPD + HCV-Ab+ (141, 12.9%). Multi-morbidity was associated with older age, higher body mass index, current and former smoking, CDC stage C and longer ART duration. Conclusions: More than 50% of PLHW were multi-morbid and about 30% had three or more concurrent comorbidities. The identification of common patterns of comorbidities address the combined risks of multiple drug and disease-disease interactions

Deep Synoptic Array Science: First FRB and Host Galaxy Catalog

Fast Radio Bursts (FRBs) are a powerful and mysterious new class of transient that are luminous enough to be detected at cosmological distances. By associating FRBs to host galaxies, we can measure intrinsic and environmental properties that test FRB origin models, in addition to using them as precise probes of distant cosmic gas. The 110-antenna Deep Synoptic Array (DSA-110) is a radio interferometer built to maximize the rate at which it can simultaneously detect and localize FRBs. Here, we present the first sample of FRBs and host galaxies discovered by the DSA-110. This sample of 11 FRBs is the largest uniform sample of localized FRBs to date and is selected based on association to host galaxies identified in optical imaging by Pan-STARRS1 and follow-up spectroscopy at the Palomar and Keck observatories. These FRBs have not been observed to repeat and their radio properties (dispersion, temporal scattering, energy) are similar to that of the known non-repeating FRB population. Most host galaxies have ongoing star formation, as has been identified before for FRB hosts. In contrast to prior work, a large fraction (four of eleven) of the new sample are more massive than 10$^{11}$\ M$_{\odot}$ and most had elevated star formation rates more than 100 Myr in their past. The distribution of star-formation history across this host-galaxy sample shows that the delay-time distribution is wide, spanning from $\sim100$\,Myr to $\sim10$\,Gyr. This requires the existence of one or more progenitor formation channels associated with old stellar populations, such as the binary evolution of compact objects.Comment: 21 pages. Submitted to AAS Journal

Effect of Parameters on Oxychlorination of Tert-Butyl Ethers

The effect of concentration, molar ratios of reagents, pH, and temperature on formation of chloro-organic products in reaction of tert-butyl ethers with chloride ions and hydrogen peroxide has been determined. A significant effect of Cl− ions and H2O2 molar ratios on the rate of chloro-organic product formation has been observed. Studies on oxychlorination of tert-butylethyl ether (ETBE) at pH 7, 3.5, and 2.5 have been carried out. It was found that introduction of hydronium ions into the reaction system considerably hastened the process of chloro-organic product formation. Hydronium ions contribute to the formation of the reactive tert-butyl carbocation, which undergoes secondary reactions in the presence of reactive forms of chlorine and oxygen. Moreover, the effect of temperature on ETBE (tert-butylethyl ether) and MTBE (tert-butylmethyl ether) conversions was verified. The reactions of MTBE and ETBE oxychlorination were carried out at temperatures of 5°C, 20°C, and 35°C

Growing old with antiretroviral therapy or elderly people in antiretroviral therapy: two different profiles of comorbidity?

Background: In persons living with HIV (PLWH), the burden of non-communicable chronic diseases increased over time, because of aging associated with chronic inflammation, systemic immune activation, and long-term exposure to the combination antiretroviral therapy (ART). Methods: To explore the association of chronological age, age at first ART, and exposure to ART with non-communicable chronic diseases, we performed a cross-sectional analysis to evaluate the prevalence of comorbidities in patients enrolled in the SCOLTA Project, stratified by groups of chronological age (50–59 and 60–69 years) and by years of antiretroviral treatment (ART, ≤ 3 or > 3 years). Results: In 1394 subjects (23.8% women), mean age at enrollment was 57.4 (SD 6.5) years, and at first ART 45.3 (SD 10.7). Men were older than women both at enrollment (57.6 vs 56.8, p = 0.06) and at first ART (45.8 vs 43.6, p = 0.0009). ART duration was longer in women (13.1 vs 11.7 years, p = 0.01). The age- and sex-adjusted rate ratios (aRRs, and 95% confidence interval, CI) showed that longer ART exposure was associated with dyslipidemia (aRR 1.35, 95% CI 1.20– 1.52), hypertension (aRR 1.52, 95% CI 1.22–1.89), liver disease (aRR 1.78, 95% CI 1.32–2.41), osteopenia/osteoporosis (aRR 2.88, 95% CI 1.65–5.03) and multimorbidity (aRR 1.36, 95% CI 1.21–1.54). These findings were confirmed in strata of age, adjusting for sex. Conclusions: Our data suggest that longer ART exposure was associated with increased risk of dyslipidemia, hypertension, and osteopenia/osteoporosis, hence the presence of multimorbidity, possibly due to the exposition to more toxic antiretrovirals. We observed different comorbidities, according to ART exposure and age

Positioning of darunavir/cobicistat-containing antiretroviral regimens in real life: Results from a large multicentre observational prospective cohort (SCOLTA)

Background: Study aim was to evaluate the safety and durability of darunavir/cobicistat (DRV/c) in a real life setting. Methods: Multicentre prospective cohort study performed in the context of SCOLTA (Surveillance Cohort Long-Term Toxicity Antiretrovirals). Patients were evaluated at baseline, week 24 and 48. Changes were evaluated using the paired t test or signed rank test. The multivariable analysis was performed using a general linear model, after ranking of not normally distributed variables. Results: A total of 249 patients were included, 72 (29%) were in DRV/c-based dual therapies (DT). Hypercholesterolemia, HC, (total cholesterol (TC) ≥ 200 mg/dL or low density-C (LDL-C) ≥ 130 or statin use) was present in 121 (48.6%) and hypertriglyceridemia, (triglycerides (TG) ≥ 200 mg/dl or fibrate use) in 41 (16.5%) patients. Blood lipid profile did not change significantly in either the global population or patients with HC. After a median observation of 17 months (IQR 13-20), 59 (25.3%) patients discontinued DRV/c, of which 13 were in DT. The durability DT resulted higher than that of triple therapy (log-rank test p = 0.01). Main reasons for stopping DRV/c were simplification (15 patients), adverse events (13 patients), planned discontinuation for treatment initiation with DAA (4 patients), treatment failure (2 patients); death (2 patients), other causes (10 patients). Twenty-six were lost to follow-up. Conclusions: DRV/c was safe and well tolerated. Dual therapies showed a better profile of tolerability and a longer durability compared to triple therapies