Computer simulations of catanionic surfactants adsorbed at air/water interfaces: II. Full coverage

We extend our previous molecular dynamics experiments Rodriguez et al., J. Phys. Chem. B 109, 24427 (2005) to the analysis of the adsorption of catanionic surfactants at water/air interfaces, at a surfactant coverage close to that of the saturated monolayer: 30.3 Å2 per headgroup. The mixture of surfactants investigated corresponds to equal amounts of dodecytrimethylammonium DTA and dodecylsulfate DS. The structure of the interface is analyzed in terms of the local densities and orientational correlations of all relevant interfacial species. In accordance with experimental evidence, the DTA headgroups penetrate deeper into the aqueous substrate than the DS ones, although the average positions of all headgroups, with respect to the interface, lie in positions somewhat more external than the ones observed at lower coverages. Average tail tilts are close to 45°. The characteristics of the headgroup-water substrate correlations are also analyzed using a tessellation procedure of the interface. The density and polarization responses of the interfacial domains closest to the DS headgroups are enhanced, compared to those adjacent to the DTA detergents. Dynamical aspects related to the diffusion and to the orientational correlations of different water layers in close contact with the surfactant are also investigated.Fil: Clavero, Esteban Dario. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Rodriguez, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Laria, Daniel Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentin

Wear Behavior of a Ni/Co Bilayer Coating by Physical Vapor Deposition on AISI 1045 Steel

Coatings by physical vapor deposition (PVD) have become highly relevant due to their wide range of applications and the rapid rate of coating formation. In this work, AISI steel 1045 was coated with two layers, Ni and Co using the PVD technique. Each coating was deposited with a thickness of 1 μm. After applying the coatings, a post-treatment was applied in an AC plasma reactor using a boron nitride blank in an Ar atmosphere at a pressure of 3 Torr, 0.3 A, and 460 V at 4, 8, and 12h. The post-treatment was characterized by optical emission spectroscopy (OES) in a range of 200-1100 nm. The main species observed by OES were Ar+, N2, N2+, and B+. The coatings on 1045 steel and posttreatment were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Also, were subjected to tribological tests to analyze wear resistance, using the Pin-on-Disk technique. The coatings on steel 1045 present remarkably better wear properties than the uncoated 1045 steel, being the sample post-treated at 4h that showed a lower wear rate

Health care experiences of Black cancer survivors: A qualitative study exploring drivers of low and high Consumer Assessment of Healthcare Providers and Systems global ratings of care

Background: The purpose of this study was to understand the experiences of Black patients with cancer in health care by comparing drivers of high and low ratings. / Methods: Semistructured in-depth interviews were conducted with 18 Black patients with cancer recruited from cancer survivorship support groups and Facebook between May 2019 and March 2020. Interviews were coded across all transcripts by using a thematic analysis approach before comparing low- and high-rating groups. / Results: There were three major themes that influenced whether patients rated their care as low or high, which included the patient–provider relationship, health care staff interactions, and cancer care coordination. For example, the high-rating group described good communication with the health care team as physicians listening to their needs, being responsive to their concerns, and providing recommendations on how to address side effects. In contrast, the low-rating group described poor communication with their health care team as their needs being dismissed and being excluded from decision-making processes. Additionally, there were two distinct themes that influenced patients’ low ratings: insurance and financial toxicity issues and experiences of health care discrimination. / Conclusions: In an effort to promote equitable cancer care experiences for Black patients, it is important that health systems work to prioritize patient interactions with health care providers and staff, comprehensive care management for patients with cancer, and reductions in the financial burden of caring for cancer

The CARMA Study: Early Infant Antiretroviral Therapy - Timing Impacts on Total HIV-1 DNA Quantitation 12 Years Later

Background. Strategies aimed at antiretroviral therapy (ART)-free remission will target individuals with a limited viral reservoir. We investigated factors associated with low reservoir measured as total human immunodeficiency virus type 1 (HIV-1) DNA in peripheral blood mononuclear cells (PBMCs) in perinatal infection (PaHIV).Methods. Children from 7 European centers in the Early Treated Perinatally HIV Infected Individuals: Improving Children's Actual Life (EPIICAL) consortium who commenced ART aged <2 years, and remained suppressed (viral load [VL] <50 copies/mL) for >5 years were included. Total HIV-1 DNA was measured by quantitative polymerase chain reaction per million PBMCs. Factors associated with total HIV-1 DNA were analyzed using generalized additive models. Age, VL at ART initiation, and baseline CD4% effects were tested including smoothing splines to test nonlinear association.Results. Forty PaHIV, 27 (67.5%) female 21 (52.5%) Black/Black African, had total HIV-1 DNA measured; median 12 (IQR, 7.3-15.4) years after ART initiation. Eleven had total HIV-1 DNA <10 copies/10(6) PBMCs. HIV-1 DNA levels were positively associated with age and VL at ART initiation, baseline CD4%, and Western blot antibody score. Age at ART initiation presented a linear association (coefficient = 0.10 +/- 0.001, P <= .001), the effect of VL (coefficient = 0.35 +/- 0.1, P <= .001) noticeable >6 logs. The effect of CD4% (coefficient = 0.03 +/- 0.01, P <= .049) was not maintained >40%.Conclusions. In this PaHIV cohort, reduced total HIV-1 DNA levels were associated with younger age and lower VL at ART initiation. The impact of early-infant treatment on reservoir size persists after a decade of suppressive therapy

Size of HIV-1 reservoir is associated with telomere shortening and immunosenescence in early-treated European children with perinatally acquired HIV-1

INTRODUCTION: Persistence of HIV-1, causing chronic immune activation, is a key determinant of premature senescence. Early antiretroviral therapy (ART) has been associated with a reduced HIV-1 reservoir in children with perinatally acquired HIV-1 (PHIV), but its impact on the senescence process is an open question. We investigated the association between HIV-1 reservoir and biological and immune ageing profile in PHIV enrolled in the multicentre cross-sectional study CARMA (Child and Adolescent Reservoir Measurements on early suppressive ART) conducted within the EPIICAL (Early treated Perinatally HIV Infected individuals: Improving Children's Actual Life) consortium. METHODS: Between September 2017 and June 2018, CARMA enrolled 40 PHIV who started ART before 2 years of age and had undetectable viremia for at least 5 years before sampling date. Samples from 37 children with a median age of 13.8 years were available for this study. HIV-1 DNA copies on CD4 cells, relative telomere length (marker of cellular senescence) and levels of T-cell receptor rearrangement excision circle (TREC, marker of thymic output) on CD4 and CD8 cells were quantified by qPCR. Immunological profile was assessed by flow cytometry. Associations between molecular and phenotypic markers, HIV-1 reservoir and age at ART initiation were explored using a multivariable Poisson regression. RESULTS: Higher HIV-1 reservoir was associated (p<0.001) with telomere shortening (incidence rate ratio [IRR] = 0.15 [0.13-0.17]), immunosenescence (CD28- CD57+ , IRR = 1.23 [1.21-1.26]) and immunoactivation (CD38+ HLADR+ , IRR = 7.29 [6.58-8.09]) of CD4 cells. Late ART initiation (after 6 months of age) correlated with higher HIV-1 reservoir levels (552 [303-1001] vs. 89 [56-365] copies/106 CD4 cells, p = 0.003) and percentage of CD4 senescent cells (2.89 [1.95-6.31] vs. 1.02 [0.45-2.69, p = 0.047). TREC levels in CD8 cells were inversely associated with HIV-1 reservoir (IRR = 0.77 [0.76-0.79]) and were significantly lower in late treated PHIV (1128 [486-1671] vs. 2278 [1425-3314], p = 0.042). CONCLUSIONS: Later ART initiation is associated with higher HIV-1 reservoir size, which correlates with increased telomere shortening and senescence of CD4 cells. Timing of ART initiation in infancy has long-term consequences on the immune and biological ageing profile of children with perinatally acquired HIV-1

Gout, allopurinol intake and clinical outcomes in the hospitalized multimorbid elderly

Background: Increased serum uric acid has been considered a cardiovascular risk factor but no study has assessed its relation with hospital mortality or length of stay. On the basis of data obtained from a prospective registry, the prevalence of gout/hyperuricemia and its association with these and other clinical parameters was evaluated in an Italian cohort of elderly patients acutely admitted to internal medicine or geriatric wards. Methods: While the prevalence of gout was calculated by counting patients with this diagnosis hyperuricemia was inferred in patients taking allopurinol at hospital admission or discharge, on the assumption that this drug was only prescribed owing to the \ufb01nding of high serum levels of uric acid. A series of clinical and demographic variables were evaluated for their association with gout/hyperuricemia. Results: Of 1380 patients, 139 (10%) had a diagnosis of gout or were prescribed allopurinol. They had more co-morbidities (7.0 vs 5.6; P b 0.0001) and consumed more drugs (6.8 vs 5.0; P b 0.0001). The CIRS (co-morbidity index) was worse in these patients (OR 1.28 95% CI 1.15\u20131.41). Multivariable regression analysis showed that only renal and heart failures were independently associated with gout/allopurinol intake. Moreover, this combined event was associated with an increased risk of adverse events during hospitalization (OR 1.66, 95% CI 1.16\u20132.36), but not with the risk of re-hospitalization, length of hospital stay or death. Conclusions: Gout/allopurinol intake has a high prevalence in elderly patients acutely admitted to hospital and are associated with renal and cardiovascular diseases, an increased rate of adverse events and a high degree of drug consumption. In contrast, this \ufb01nding did not affect the length of hospitalization nor hospital mortality