1,859 research outputs found

    Random cover times using the Poisson cylinder process

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    In this paper we deal with the classical problem of random cover times. We investigate the distribution of the time it takes for a Poisson process of cylinders to cover a set A⊂Rd.A \subset \mathbb{R}^d. This Poisson process of cylinders is invariant under rotations, reflections and translations, and in addition we add a time component so that cylinders are "raining from the sky" at unit rate. Our main results concerns the asymptotic of this cover time as the set AA grows. If the set AA is discrete and well separated, we show convergence of the cover time to a Gumbel distribution. If instead AA has positive box dimension (and satisfies a weak additional assumption), we find the correct rate of convergence

    Age of HIV Acquisition Affects the Risk of Multi-Morbidity after 25 Years of Infection Exposure

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    Introduction: Understanding the intersection of HIV, aging and health is crucial due to the increasing number of people aging with HIV. Objective: The objective of the study was to assess the prevalence of, and risk factors for individual comorbidities and multi-morbidity in people living with HIV with similar duration of HIV infection, notwithstanding a 25-year difference at the time of HIV acquisition. Methods: In a cross-sectional multicentre retrospective study, we compared three match-control age groups. The "Young" were selected from Romania and included HIV-positive patients prenatally infected and assessed at the age of 25-30 years. The "Old" and the "Geriatric" were selected from Italy. These respectively included subjects infected with HIV at the age of 25 years and assessed at the age of 50-55 years, and those infected at the age of 50 years and assessed at the age of 75-80 years. Each group was sex and age matched in a 1: 5 ratio with controls selected from the CINECA ARNO database from Italy. We described non-infectious comorbidities (NICM), including cardiovascular disease, hypertension, dyslipidaemia, diabetes, chronic kidney disease, and multi-morbidity (MM >= 3 NICM). Results: MM prevalence in the "Young" group compared to controls was 6.2% vs 0%, while in the "Geriatric" was "68.2% vs 3.6%. Using "Young" as a reference, in multivariate analyses, predictors for MM were as follows: HIV serostatus (OR=47.75, IQR 14.78-154.25, p<0.01) and "Geriatric" vs "Young" (OR=30.32, IQR 5.89-155.98, p<0.01). Conclusion: These data suggest that age at acquisition of HIV should be considered as a risk factor for NICM and MM

    Inspiratory effort and lung mechanics in spontaneously breathing patients with acute respiratory failure due to COVID-19. A matched control study.

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    Several physical and biological mechanisms can drive progression between the different phases of lung injury due to SARS-CoV-2 infection, thus modifying the mechanical properties and behavior of COVID-19 over time. In this research letter we have presented the findings of a registered clinical trial aimed at describing and comparing the inspiratory effort (primary outcome) and the breathing pattern of spontaneously breathing patients with ARF in COVID-19 and historically matched non-COVID-19 patients, either candidate to NIV. Moreover, we reported the response to a 2 hours NIV trial in the two groups. Spontaneously breathing COVID-19 at their early onset of acute respiratory failure with indication for NIV showed different mechanical characteristics and breathing pattern when compared with non-COVID-19

    Compression of frailty in adults living with HIV

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    Background: Contemporary HIV care may reduce frailty in older adults living with HIV (OALWH). Objective of the study was to estimate prevalence of frailty at the age of 50 and 75 years, and build a model to quantify the burden of frailty in the year 2030. Methods: This study included OALWH attending Modena HIV Metabolic Clinic between 2009 and 2015. Patients are referred from more than 120 HIV clinics well distributed across Italy, therefore being country representative. Our model forecasts the new entries on yearly basis up to 2030. Changes in frailty over a one-year period using a 37-variable frailty index (FI) and death rates were modelled using a validated mathematical algorithm with parameters adjusted to best represent the changes observed at the clinic. In this study, we assessed the number of frailest individuals (defined with a FI &gt; 0.4) at the age of 50 and at the age 75 by calendar year. Results: In the period 2015-2030 we model that frailest OALWH at age 50 will decrease from 26 to 7%, and at the age of 75 years will increase from 43 to 52%. This implies a shift of the frailty prevalence at an older age. Conclusion: We have presented projections of how the burden of frailty in older adults, living with HIV will change. We project fewer people aged 50+ with severe frailty, most of whom will be older than now. These results suggest a compression of age-related frailty

    Compression of frailty in adults living with HIV

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    BACKGROUND: Contemporary HIV care may reduce frailty in older adults living with HIV (OALWH). Objective of the study was to estimate prevalence of frailty at the age of 50 and 75 years, and build a model to quantify the burden of frailty in the year 2030. // METHODS: This study included OALWH attending Modena HIV Metabolic Clinic between 2009 and 2015. Patients are referred from more than 120 HIV clinics well distributed across Italy, therefore being country representative. Our model forecasts the new entries on yearly basis up to 2030. Changes in frailty over a one-year period using a 37-variable frailty index (FI) and death rates were modelled using a validated mathematical algorithm with parameters adjusted to best represent the changes observed at the clinic. In this study, we assessed the number of frailest individuals (defined with a FI > 0.4) at the age of 50 and at the age 75 by calendar year. // RESULTS: In the period 2015–2030 we model that frailest OALWH at age 50 will decrease from 26 to 7%, and at the age of 75 years will increase from 43 to 52%. This implies a shift of the frailty prevalence at an older age. // CONCLUSION: We have presented projections of how the burden of frailty in older adults, living with HIV will change. We project fewer people aged 50+ with severe frailty, most of whom will be older than now. These results suggest a compression of age-related frailty

    Impact of social determinants on antiretroviral therapy access and outcomes entering the era of universal treatment for people living with HIV in Italy

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    Background: Social determinants are known to be a driving force of health inequalities, even in high income countries. Aim of our study was to determine if these factors can limit antiretroviral therapy (ART) access, outcome and retention in care of people living with HIV (PLHIV) in Italy. Methods: All ART naïve HIV+ patients (pts) of Italian nationality enrolled in the ICONA Cohort from 2002 to 2016 were included. The association of socio-demographic characteristics (age, sex, risk factor for HIV infection, educational level, occupational status and residency area) with time to: ART initiation (from the first positive anti-HIV test), ART regimen discontinuation, and first HIV-RNA &lt; 50 cp/mL, were evaluated by Cox regression analysis, Kaplan Meier method and log-rank test. Results: A total of 8023 HIV+ pts (82% males, median age at first pos anti-HIV test 36 years, IQR: 29-44) were included: 6214 (77.5%) started ART during the study period. Women, people who inject drugs (PWID) and residents in Southern Italy presented the lowest levels of education and the highest rate of unemployment compared to other groups. Females, pts aged &gt; 50 yrs., unemployed vs employed, and people with lower educational levels presented the lowest CD4 count at ART initiation compared to other groups. The overall median time to ART initiation was 0.6 years (yrs) (IQR 0.1-3.7), with a significant decrease over time [2002-2006 = 3.3 yrs. (0.2-9.4); 2007-2011 = 1.0 yrs. (0.1-3.9); 2012-2016 = 0.2 yrs. (0.1-2.1), p &lt; 0.001]. By multivariate analysis, females (p &lt; 0.01) and PWID (p &lt; 0.001), presented a longer time to ART initiation, while older people (p &lt; 0.001), people with higher educational levels (p &lt; 0.001), unemployed (p = 0.02) and students (p &lt; 0.001) were more likely to initiate ART. Moreover, PWID, unemployed vs stable employed, and pts. with lower educational levels showed a lower 1-year probability of achieving HIV-RNA suppression, while females, older patients, men who have sex with men (MSM), unemployed had higher 1-year risk of first-line ART discontinuation. Conclusions: Despite median time to ART start decreased from 2002 to 2016, socio-demographic factors still contribute to disparities in ART initiation, outcome and durability

    CD4 cell count and the risk of AIDS or death in HIV-Infected adults on combination antiretroviral therapy with a suppressed viral load: a longitudinal cohort study from COHERE.

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    BACKGROUND: Most adults infected with HIV achieve viral suppression within a year of starting combination antiretroviral therapy (cART). It is important to understand the risk of AIDS events or death for patients with a suppressed viral load. METHODS AND FINDINGS: Using data from the Collaboration of Observational HIV Epidemiological Research Europe (2010 merger), we assessed the risk of a new AIDS-defining event or death in successfully treated patients. We accumulated episodes of viral suppression for each patient while on cART, each episode beginning with the second of two consecutive plasma viral load measurements 500 copies/µl, the first of two consecutive measurements between 50-500 copies/µl, cART interruption or administrative censoring. We used stratified multivariate Cox models to estimate the association between time updated CD4 cell count and a new AIDS event or death or death alone. 75,336 patients contributed 104,265 suppression episodes and were suppressed while on cART for a median 2.7 years. The mortality rate was 4.8 per 1,000 years of viral suppression. A higher CD4 cell count was always associated with a reduced risk of a new AIDS event or death; with a hazard ratio per 100 cells/µl (95% CI) of: 0.35 (0.30-0.40) for counts <200 cells/µl, 0.81 (0.71-0.92) for counts 200 to <350 cells/µl, 0.74 (0.66-0.83) for counts 350 to <500 cells/µl, and 0.96 (0.92-0.99) for counts ≥500 cells/µl. A higher CD4 cell count became even more beneficial over time for patients with CD4 cell counts <200 cells/µl. CONCLUSIONS: Despite the low mortality rate, the risk of a new AIDS event or death follows a CD4 cell count gradient in patients with viral suppression. A higher CD4 cell count was associated with the greatest benefit for patients with a CD4 cell count <200 cells/µl but still some slight benefit for those with a CD4 cell count ≥500 cells/µl

    Electrochemistry of inherently chiral molecular materials with bisindole atropisomeric cores: interacting equivalent redox sites, configurational stability, and enantioselection ability for different chiral probes

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    In "inherently chiral" molecules chirality and key functional properties originate from the same structural element, and are thus strictly linked together. In the case of poly(hetero)aromatic electroactive molecules, this can be achieved by inserting in the main conjugated backbone a tailored torsion with an energy barrier too high to be overcome at room temperature, while not entirely hampering conjugation. This strategy results in outstanding chirality manifestations. including e.g. circularly polarized luminescence as well as outstanding enantiorecognition ability in CV experiments. For instance, large peak potential differences were observed for the enantiomers of different chiral probes on electroactive surfaces obtained by electrooligomerization of inherently chiral monomers having atropisomeric (= with hindered rotation between two moieties) bibenzothiophene (Fig 1A) or bithiophene cores. [1-4]. An interesting option is also to change the thiophene-based atropisomeric cores with 2,2'-bisindole and 3,3'-bisindole ones (Fig 1B and 1C), on account of the easy functionalization of the core e.g. with long alkyl chains, modulating solubility and processability. A B C Figure 1 R = H or C1-C6 alkyl chains; Spacer = phenyl or nothing (oligothiophene wing attached to core) The change also leads to quite interesting modifications in the electrochemical activity. Since indole is electron richer than thiophene, the first two oxidations take place at significantly less positive potentials than in the former cases, and are localized on the two interacting moieties of the bisindole core rather than on the terminal wings; thus, they are chemically reversible (oligomerization can be achieved cycling around the third oxidation peak). A peculiar attractive feature concerns the interaction between the two equivalent redox centers in the biindole core, which can be evaluated from the potential difference between the corresponding oxidation peak: it can be shown that it can account for the atropisomeric energy barrier (depending on the 2,2' or 3,3' connectivity and on the N-alkyl substituents), and is also modulated by temperature and the solvent polarity. Thus electrochemistry can provide information on the torsional energy barrier and on the enantiomer stability, as confirmed by other approaches. Besides the intrinsic interest of these inherently chiral families, they are also quite attractive from the applicative point of view, since enantioselectivity test on films obtained by electrooligomerization of the more stable 2,2' monomers yield large potential differences for the antipodes of very different chiral probes, also of pharmaceutical interest. The current support of Fondazione Cariplo/Regione Lombardia "Avviso congiunto per l\u2019incremento dell\u2019attrattivit\ue0 del sistema di ricerca lombardo e della competitivit\ue0 dei ricercatori candidati su strumenti ERC - edizione 2016\u201d (Project 2016-0923) to our inherently chiral research is gratefully acknowledged. References: 1. Angew. Chem. Int. Ed. 2014, 53, 2623. 2. Chem. Eur. J. 2014, 20, 15298. 3. Chem. Sci. 2015, 6,1706. 4. Chem. Eur.2016 , 22,10839. 5. Anal. Bioanal. Chem. 2016, 408, 7243
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